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Reliability and validity of carpal alignment measurements in evaluating deformities of scaphoid fractures
Abstract
Several radiographic carpal alignment indices are used to evaluate the deformities of scaphoid fractures. The purpose of this study was to determine the reliabilities and validities of radiographic carpal alignment indices commonly used to evaluate deformities of scaphoid fractures.
Thirty-six patients with a scaphoid fracture were evaluated. Five carpal alignment indices were assessed on lateral plain radiographs, namely, scapholunate angle, radioscaphoid angle, radiolunate angle, radiocapitate angle, and capitolunate angle. Three examiners measured these radiographic indices at two sessions, and intraobserver and interobserver reliabilities were determined and expressed as intraclass correlation coefficients. Discriminant validities of radiographic carpal alignment indicies between injured and uninjured wrists were evaluated. For convergent validity testing, the correlation between the radiographic carpal alignment indices and intrascaphoid angles (ISAs) or height-to-length (HL) ratios on CT longitudinal scans was assessed. Further, carpal alignment indices after surgical reconstruction were compared to the Mayo wrist score.
Scapholunate and radiolunate angles had the highest reliabilities, and radiocapitate angle had the lowest. Radiolunate angle had the highest discriminant validity followed by scapholunate, and capitolunate angles. In convergent validity testing, scapholunate angles and radiolunate angles correlated with ISA angles, and radiolunate and capitolunate angles correlated with HL ratios. Only the radiolunate angles correlated with the Mayo wrist scores.
Among radiographic carpal alignment measures, radiolunate angle is the most reliable and valid carpal alignment index for evaluating deformities of scaphoid fractures. Scapholunate and capitolunate angles could be used as an alternative, but have less validity.
... In the malunited scaphoid, loss of height, increased flexion and potential dorsal intercalated segment instability will result in alteration of wrist biomechanics with an acceleration of radiocarpal arthritis and impairment of function (Dias and Singh, 2011;Gillette et al., 2017;Lindstrom and Nystrom, 1990;Nakamura et al., 1991). To investigate the clinical importance of scaphoid malunion, accurate and reproducible assessment of scaphoid deformity and carpal malalignment is essential (Roh et al., 2014). However, owing to the complex geometry and orientation of the scaphoid, assessment of the fracture line, comminution, displacement and degree of union is difficult (Dias, 2001). ...
... In addition, scaphoid shortening with decreased axial length because of fracture malunion may also result in carpal malalignment (Nakamura et al., 1991;Watanabe, 2011). However, previous studies have shown that the radiographic parameters used in conventional radiography may not always reflect the actual amount of scaphoid deformity (Nakamura et al., 1991;Oka et al., 2005;Roh et al., 2014). ...
... Many carpal alignment indices for assessing deformities after healing of scaphoid waist fractures have been studied (Jiranek et al., 1992;Megerle et al., 2012;Roh et al., 2014;Watanabe, 2011). Larsen et al. (1991) first measured carpal angles on standardized lateral radiographs of 75 uninjured wrists to establish their normal values. ...
Correct interpretation of scaphoid axial length and carpal malalignment is difficult owing to the complex geometry of the scaphoid. Traditional measurements, such as the scapholunate angle and radiolunate angle, have shown limited reproducibility. To improve the assessment of these measurements, we used multiplanar reformation computed tomography with added average intensity projection. Four measurements for scaphoid morphology and carpal alignment were independently measured by four observers on computed tomography scans of 39 consecutive patients who were treated conservatively for scaphoid fracture. Fleiss’s kappa for categorical results showed substantial agreement for the measurements of the scapholunate and radiolunate angles. Intraclass correlation coefficients were significant for measurements of the axial length, scapholunate angle and radiolunate angle. Our results suggest that multiplanar reformation computed tomography with added average intensity projection is a reliable technique for assessment of scaphoid morphology and carpal alignment.
Level of evidence: II
... Only a few studies in the past have tried to find out reliable carpal alignment indices but could comment only on the validity of the radiolunate angle. [4] The scaphoid bone not only plays an important role in wrist mechanics by acting as a link between two rows of carpals, but it is also the most frequently fractured carpal bone, with an incidence of about 82%-89% among all carpal fractures. [5,6] These fractures are usually through the waist and, although not displaced often, can be complicated by a "humpback deformity" with or without union because of extension, supination, and anterior translation of the proximal fragment relative to the distal fragment. ...
... A 3D reconstruction template study done to quantify potential left-right differences found that regions of the scaphoid contra laterally may differ up to 1.9 mm, a fact which must be taken into account if the contralateral scaphoid is to be used in surgical planning. [18] Surgeons dealing with the treatment of mal-union or nonunion of the scaphoid may use various indices such as lateral intrascaphoid angle (LISA) or dorsal cortical angle (DCA) for predicting the outcome such as restoration of movement and function, [4] but their normal ranges have not been determined for major population groups and to the best of our knowledge never in the Indian population. The purpose of this study is to investigate the precision of estimating normal scaphoid lengths based on intact adjacent bone dimensions, also compared with the contralateral scaphoid length in the normal adult population by creating a reference database of normal carpal anatomy which will provide valuable reference information to facilitate diagnosis and treatment in planning for injuries and diseases in the wrist. ...
Introduction
The accurate assessment of scaphoid bone morphometry is a prerequisite before internal fixation treatment for fractures. We intended to arrive at a method for exact quantification of the scaphoid length by measuring intact adjacent bones and the contralateral scaphoid in the normal population, which can then be translated into use for planning surgical repair in case of fracture or nonunion.
Methodology
A prospective, descriptive study was conducted where three-dimensional reconstruction of the wrist with computed tomography scan was done to document lengths of the scaphoid (bilaterally), capitate, radius width, and lateral intra scaphoid angle and dorsal cortical angle of scaphoid were measured.
Results
The mean scaphoid length, capitate length, and width of radius were significantly more in males as compared to females. The capitate length and contralateral scaphoid length were most significantly related to scaphoid length. The mean scaphoidcapitate ratio (SCR) was found to be 1.08.
Conclusion
Using the liner regression model, scaphoid length can be predicted from variables such as capitate length and SCR with 99.99% accuracy, aiding surgeons in scaphoid fixation in cases of fractured scaphoid, malunion, and nonunion.
... The incidence in the United Kingdom is estimated at 12.4 in 100.00 cases per annum in the general population. The highest incidence is found in males between 15 and 19 years of age [4]. ...
... Thereby horizontal fractures heal faster than vertical ones, which in turn heal slightly faster than transverse fractures. Equally, fractures of the proximal third demonstrate a longer time to union and are prone to present more frequently as a nonunion [4,16]. ...
Introduction:
Fractures of the scaphoid account for the most commonly injured carpal bone. Minimally displaced fractures of the waist will heal in 85-90% when using a below elbow cast. However, fractures with displacement have a higher risk for nonunion. Therefore, open reduction and fixation with headless compression screws (HCS) have become the preferred method of treatment. The aim of this study was to compare the radiological and clinical outcome of unstable scaphoid B2 type fractures, stabilized using one or two headless compression screws.
Patients and methods:
A total of 47 unstable scaphoid B2 type fractures were included in this retrospective follow-up study. Twelve patients were not accessable and three refused to attend follow-up checks. Therefore, a total of 32 patients were included in this study with a mean follow-up interval of 43 (12-81) months. Twenty-two patients were treated using one HCS and ten with two HCS. Clinical assessment included range of motion (ROM), pain according to the visual analogue scale (VAS), grip strength, Disability of the Arm, Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O'Brien Wrist Score. The follow-up study on each patient included a CT-Scan of the wrist which was analyzed for union, osteoarthritis, dorsiflexed intercalated segment instability and humpback deformity.
Results:
Radiologically, 29/32 (91%) of the scaphoid B2 type fractures showed union, 10/10 (100%) in the two HCS group and 19/22 (86%) in the one HCS group (p < 0.05). No significant differences could be found in respect to ROM, grip strength, VAS and scores between the groups. Screw removal was necessary in two patients in the two HCS group and one in the one HCS group.
Conclusion:
The unstable B2 type fractures of the scaphoid, when using two HCS without bone grafting is a safe method, shows a significantly higher union rate and equal clinical outcome compared to stabilization using only one HCS.
... Moreover, the ulnar-carpal ratio and radial-carpal ratio can show us carpal translocation and misalignment, which are symptoms of wrist arthritis. 10,11 Physicians have been able to identify small angulations and aberrant bone and joint connections using precise measurements from X-rays. However, the normal side does not give a better reference than normal values acquired from databases due to the variability between the right and left wrist, radial inclination and radial tilt of the distal radius, and ulnar variance. ...
Background
The wrist is a complex joint that plays a role in several everyday tasks. Various radiological indices have been created to assess the alignment and structure of the wrist using standard X-ray images. Nevertheless, these indicators may differ based on variables such as age, gender, ethnicity, handedness, and wrist position. This research aimed to assess the radiological indices of the wrist in a group of healthy people from Jordan and investigate the impact of age and gender on these indices.
Methods
We obtained data from a sample of 385 patients who presented at our hospital with minor non-specific wrist pain and satisfied the specified criteria for inclusion. We conducted measurements of radial inclination, radial height, volar tilt, ulnar variance, and carpal height ratio using both anteroposterior and lateral views of the wrist. We used linear regression and independent sample t-test to examine the correlation between age, gender, and radiological indicators. The reliability of the measurements was assessed using the intraclass correlation coefficient (ICC).
Results
Our study revealed a negative correlation between age and carpal height ratio (r = -0.13, p = 0.03). However, no significant gender differences were seen in any of the radiological indices (p > 0.05). Our findings indicate that ulnar variance had the greatest level of reliability across observers, with an intra-observer intraclass correlation coefficient (ICC) of 0.95 and an inter-observer ICC of 0.8. Conversely, volar tilt exhibited the lowest inter-observer reliability, with an ICC of 0.1.
Our results provide a valuable point of reference for the wrist morphology and alignment in the Jordanian population. Our suggestion is that the carpal height ratio might indicate alterations in the wrist joint due to aging, whereas ulnar variation may serve as a dependable indicator of wrist alignment. We suggest doing more research to investigate the biological and anatomical factors behind these results and to compare them with other demographic groups.
... To investigate the deformity and reduction of the scaphoid itself, the SLA should be the most effective criterion [1,36]. However, previous studies [37,38] showed that among carpal alignment indices, the RLA is the most reliable and valid carpal alignment index for evaluating the deformities of scaphoid nonunions, and it correlated with clinical outcome after reconstruction. Thus, we could not verify the superiority of the correction capability of 2 bone graft sources with only SLA. ...
Background
Corticocancellous bone grafting from the iliac crest is acceptable treatment for unstable scaphoid nonunion with a viable proximal pole. However, harvesting graft from the iliac crest is associated with donor site morbidity and the requirement of general anesthesia. Thus, bone grafting from the anterolateral metaphysis of the distal radius (DR) can be a treatment option. However, no study has compared the clinical effect between the two grafting techniques.
Methods
From 2014 to 2019, patients with unstable scaphoid nonunion with humpback deformity underwent corticocancellous bone grafting from the anterolateral metaphysis of the DR (group DR) or iliac crest (group IC). Humpback deformity was determined by evaluating the scapholunate angle (SLA) ≥ 60°, intrascaphoid angle (ISA) ≥ 45°, and radiolunate angle (RLA) ≥ 15° from preoperative radiographs and computed tomography scans. The SLA, ISA, and RLA served to gauge carpal alignment. The operative time, grip strength, active range of motion (ROM), the Modified Mayo Wrist score (MMWS), and Disabilities of Arm, Shoulder, and Hand (DASH) score were assessed postoperatively.
Results
Thirty-eight patients qualified for the study (group DR, 15; group IC, 23). Union rates did not differ by patient subset (group DR, 100%; group IC, 95.7%; P = .827), and grip strength, ROM, MWS, and DASH score were similar between groups at the last follow-up. The operative time (minutes) was significantly shorter in group DR (median, 98; quartiles, 80, 114) than in group IC (median, 125; quartiles, 105, 150, P < .001). The ISA, RLA, and SLA improved postoperatively in both groups (P < 0.001). The degree of restoring carpal alignment, as evaluated by SLA, showed superior correction capability in group DR (median, 25.3% quartiles, 21.1, 35.3, P < 0.05). Donor site complications were not significantly different between the groups.
Conclusions
Corticocancellous bone graft from the anterolateral metaphysis of the DR for unstable scaphoid nonunion is associated with a shorter operation time and comparable results with that from the iliac crest in regard to union, restoration of carpal alignment, and wrist function.
Level of Evidence
Level III.
... To investigate the deformity and reduction of the scaphoid itself, the SLA should be the most effective criterion 1,21 . However, previous studies 22,23 showed that among carpal alignment indices, the RLA is the most reliable and valid carpal alignment index for evaluating the deformities of scaphoid nonunions, and it correlated with clinical outcome after reconstruction. Thus, we could not verify the superiority of the correction capability of 2 bone graft sources with only SLA. ...
Background
Corticocancellous bone grafting from the iliac crest is acceptable treatment for unstable scaphoid nonunion with a viable proximal pole. However, harvesting graft from the iliac crest is associated with donor site morbidity and the requirement of general anesthesia. Thus, bone grafting from the anterolateral metaphysis of the distal radius (DR) can be a treatment option. However, no study has compared the clinical effect between the two grafting techniques.
Methods
From 2010 to 2016, patients with unstable scaphoid nonunion with humpback deformity underwent corticocancellous bone grafting from the anterolateral metaphysis of the DR (group DR) or iliac crest (group IC). Humpback deformity was determined by evaluating the scapholunate angle (SLA) ≥ 60°, intrascaphoid angle (ISA) ≥ 45°, and radiolunate angle (RLA) ≥ 15° from preoperative radiographs and computed tomography scans. The SLA, ISA, and RLA served to gauge carpal alignment. The operative time, grip strength, active range of motion (ROM), Mayo wrist score (MWS), and Disabilities of Arm, Shoulder, and Hand (DASH) score were assessed postoperatively.
Results
Thirty-eight patients qualified for the study (group DR, 15; group IC, 23). Union rates did not differ by patient subset (group DR, 100%; group IC, 95.7%; P = .827), and grip strength, ROM, MWS, and DASH score were similar between groups at the last follow-up. The operative time (minutes) was significantly shorter in group DR (median, 98; quartiles, 80, 114) than in group IC (median, 125; quartiles, 105, 150, P < .001). The ISA, RLA, and SLA improved postoperatively in both groups (P < 0.001). The degree of restoring carpal alignment, as evaluated by SLA, showed superior correction capability in group DR (median, 25.3% quartiles, 21.1, 35.3, P < 0.05). Donor site complications were not significantly different between the groups.
Conclusions
Corticocancellous bone graft from the anterolateral metaphysis of the DR for unstable scaphoid nonunion is associated with a shorter operation time and comparable results with that from the iliac crest in regard to union, restoration of carpal alignment, and wrist function.
Level of Evidence: Level III
... Several studies have reported on the reliability and validity of carpal angles on wrist radiographs. 1,7,8,13 Larsen et al 1 measured the RCA, RLA, and RSA of 23 wrists using both axial and tangential techniques for axis determination of each bone for a total of 11 different angles. They calculated intrarater and interrater variation for each of these angles to determine which measurement techniques were the most reliable. ...
Purpose:
Carpal angles traditionally are measured on the lateral projection of a standard wrist series; however, this often necessitates obtaining additional radiographic views resulting in additional radiation exposure and increased cost. We aimed to determine whether carpal angles could be measured accurately on a standard series of hand radiographs when compared to wrist radiographs.
Methods:
Carpal indices were measured on lateral wrist and hand radiographs of 40 patients by three orthopedic upper extremity surgeons. Inclusion criteria were no metabolic disease, no hardware, no fractures, radiographic positioning of the wrist in flexion/extension <20°, minimum 3 cm of distal radius visible, and acceptable scaphopisocapitate relationship (defined as the volar cortex of the pisiform lying between the volar cortices of the distal pole of the scaphoid and capitate). Angles measured included radioscaphoid (RSA), radiolunate (RLA), scapholunate (SLA), capitolunate (CLA), and radiocapitate (RCA). Measurements on wrist versus hand radiographs were compared for each patient. Interclass correlation coefficients (ICCs) were computed to assess interrater and intrarater agreement.
Results:
Interrater agreement for hand and wrist radiographs were (respectively): SLA 0.746 and 0.763, RLA 0.918 and 0.933, RCA 0.738 and 0.538, CLA 0.825 and 0.650, RSA 0.778 and 0.829. Interrater agreement was superior in favor of hand radiographs for the RCA (0.738 [0.605-0.840] vs 0.538 [0.358-0.700]) and CLA (0.825 [0.728-0.896] vs 0.650 [0.492-0.781]), but not the SLA, RLA, or RSA. Two of the three raters had excellent intrarater agreement for all hand radiograph measures (ICC range, 0.907-0.995). The mean difference in measured angles on hand versus wrist radiographs was <5° for all angles.
Conclusions:
Carpal angles may be measured reliably on hand radiographs with an acceptable scaphopisocapitate relationship and wrist flexion/extension of <20°.
Clinical relevance:
By mitigating the need to obtain additional radiographic views, surgeons may be able to reduce the cost and radiation exposure to their patients.
... For radiographic outcomes, the union rate will be evaluated with CT scans undertaken every second week. DCA and HLR will be measured preoperative and at follow-up on CT scans to evaluate the correction of deformity [11,31]. ...
Background:
Scaphoid non-union results in pain and decreased hand function. Untreated, almost all cases develop degenerative changes. Despite advances in surgical techniques, the treatment is challenging and often results in a long period with a supportive bandage until the union is established. Open, corticocancellous (CC) or cancellous (C) graft reconstruction and internal fixation are often preferred. Arthroscopic assisted reconstruction with C chips and internal fixation provides minimal trauma to the ligament structures, joint capsule, and extrinsic vascularization with similar union rates. Correction of deformity after operative treatment is debated with some studies favouring CC, and others found no difference. No studies have compared time to union and functional outcomes in arthroscopic vs. open C graft reconstruction. We hypothesize that arthroscopic assisted C chips graft reconstruction of scaphoid delayed/non-union provides faster time to union, by at least a mean 3 weeks difference.
Methods:
Single site, prospective, observer-blinded randomized controlled trial. Eighty-eight patients aged 18-68 years with scaphoid delayed/non-union will be randomized, 1:1, to either open iliac crest C graft reconstruction or arthroscopic assisted distal radius C chips graft reconstruction. Patients are stratified for smoking habits, proximal pole involvement and displacement of > / < 2 mm. The primary outcome is time to union, measured with repeated CT scans at 2-week intervals from 6 to 16 weeks postoperatively. Secondary outcomes are Quick Disabilities of the Arm, Shoulder and Hand (Q-DASH), visual analogue scale (VAS), donor site morbidity, union rate, restoration of scaphoid deformity, range of motion, key-pinch, grip strength, EQ5D-5L, patient satisfaction, complications and revision surgery.
Discussion:
The results of this study will contribute to the treatment algorithm of scaphoid delayed/non-union and assist hand surgeons and patients in making treatment decisions. Eventually, improving time to union will benefit patients in earlier return to normal daily activity and reduce society costs by shortening sick leave.
Trial registration:
ClinicalTrials.gov NCT05574582. Date first registered: September 30, 2022. Items from the WHO trial registry are found within the protocol.
... Radiographic outcome Union rate will be evaluated with CT scans undertaken every second week. DCA, and HLR will be measured preoperative and at follow-up on CT scans to evaluate correction of deformity [11,31]. ...
Background: Scaphoid non-union results in pain and decreased hand function. Untreated, almost all cases develop degenerative changes. Despite advances in surgical techniques, the treatment is challenging and often results in a long period with a supportive bandage until the union is established. Open, corticocancellous (CC) or cancellous (C) graft reconstruction and internal fixation are often preferred. Arthroscopic assisted reconstruction with C chips and internal fixation provides minimal trauma to the ligament structures, joint capsule, and extrinsic vascularization with similar union rates. Correction of deformity after operative treatment is debated with some studies favouring CC, and other found no difference. No studies have compared time to union and functional outcomes in arthroscopic vs. open C graft reconstruction. We hypothesize that Arthroscopic assisted C chips graft reconstruction of scaphoid delayed/non-union provide faster time to union, by at least mean 3 weeks difference.
Methods: Single site, prospective, observer-blinded randomized controlled trial. Eighty-eight patients aged 18-68 years with scaphoid delayed/non-union, will be randomized, 1:1, to either open iliac crest C graft reconstruction or arthroscopic assisted distal radius C chips graft reconstruction. Patients are stratified for smoking habits, proximal pole involvement, and displacement of >/<2mm. The primary outcome is time to union, measured with repeated CT scans at 2-week intervals from 6 to 16 weeks postoperatively. Secondary outcomes are Quick disabilities of the Arm, Shoulder and Hand (Q-DASH), Visual Analogue scale (VAS), donor site morbidity, union rate, restoration of scaphoid deformity, range of motion, key-pinch, grip strength, EQ5D-5L, patient satisfaction, complications, and revision surgery.
Discussion: The results of this study will contribute to the treatment algorithm of scaphoid delayed/non-union and assist hand surgeons and patients in making treatment decisions. Eventually, improving time to union will benefit patients in earlier return to normal daily activity and reduce society costs by shortening sick leave.
Trial registration: clinicaltrials.gov, NCT05574582
... Functional outcome was evaluated by comparing the modified Mayo wrist score and the VAS score, which were measured preoperatively and at the final follow-up. [15] For the radiologic assessment, the SL and RL angles were measured on radiographs obtained preoperatively and at the final follow-up according to the recommendation of Roh et al [16] Two hand surgeons individually measured the SL and RL angles. The data are expressed as the mean ± standard deviation. ...
To report the clinical and radiological outcomes of arthroscopic bone grafting and percutaneous K-wire fixation without radial styloidectomy in patients with scaphoid nonunion advanced collapse (SNAC).
We retrospectively analyzed the records of 15 patients with SNAC who were treated with arthroscopic bone grafting and percutaneous K-wire fixation and subsequently followed up for a minimum of 1 year between November 2009 and March 2018. The clinical outcomes were evaluated by comparing the range of motion (ROM), grip strength, the modified Mayo Wrist Score, and visual analog scale (VAS) scores for pain, all of which were measured preoperatively and at the last follow-up. The radiologic outcomes were evaluated by comparing the scapholunate (SL) and radiolunate (RL) angles preoperatively and at the last follow-up.
All 15 cases of nonunion were resolved. The average radiologic union time was 9.7 ± 1.2 weeks. The average VAS score increased from 5.7 ± 2.3 (range, 2 − 10) preoperatively to 1.3 ± 1.3 (range, 0 − 3) at the last follow-up (P < .05). The average modified Mayo wrist score increased from 58.3 ± 14.0 preoperatively to 80.0 ± 9.2 at the last follow-up (P < .05). The mean ROM of the wrist improved, but there was no statistical significance. At the last follow-up, the mean flexion and radial deviation on the affected side were significantly decreased, and the mean extension on the affected side was significantly improved compared to the normal side (P < .05). The mean preoperative SL and RL angles were 66 ± 11.9° and 7.2 ± 6.8°, respectively, and were decreased to 50.4 ± 7.5° and 6.4 ± 5.2°, respectively, at the last follow-up. The mean SL angle was significantly corrected (P = .01).
Arthroscopic bone grafting and percutaneous Kerschner (K)-wire fixation without radial styloidectomy are considered to be very effective methods for correcting scaphoid deformities to treat SNAC stage I. However, caution may be needed during the surgery to prevent reductions in flexion and the radial deviation of the wrist.
... Because of the relevant biomechanical role of the scaphoid into the carpal rows function, its non-union or "humpback" malunion develops a carpal instability and collapses into a dorsal intercalated segment instability (DISI) pattern [9,11,12]. Prompt diagnosis and structural screw support by compressing the fragments are mandatory in healing and to achieve excellent outcomes. ...
Background
Complex fractures of the carpal scaphoid with poles fragmentation, edges comminution, bone loss and non-union of fractures previously treated by screw fixation remain challenging for hand surgeons. The authors present the indications, advantages and results of scaphoid plating, underlining the importance of correct plate positioning well shaped onto the bone.Materials and methodsThe study includes 11 patients presenting acute fracture with distal pole fragmentation, acute fracture with comminution and non-union after prior failure of screw fixation. All patients were treated with volar locked plate fixation, adding a cortical bone graft in cases of non-union.ResultsBone consolidation was achieved in all cases; excellent outcomes in fracture healing and relevant improvement in symptoms and functions were obtained in non-union group that are consistent with the literature. Only one patient underwent early further surgery (first row carpectomy) with poor results.Conclusion
The treatment of the selected scaphoid lesions with volar locked plate is a surely efficient technique. The plate can be easily adjusted to the shape of the scaphoid and can achieve an adequate correction of bone deformity and high degree of stability both in non-union and fractures.
... Scaphoid nonunions are primarily treated to achieve union, correct deformity, relieve symptoms, improve range of motion and prevent the progression of osteoarthritis [13][14][15][16]. Several treatment options are available for scaphoid nonunions: non-vascularized bone grafting from the iliac crest or distal radius, vascularized bone grafting with or without additional stabilization using either K-wires, headless compression screw (HCS) or plate [17][18][19][20][21]. ...
Introduction
Scaphoid nonunion remains challenging for hand surgeons. Several treatment options are available such as: non-vascularized or vascularized bone grafting, with or without additional stabilization. In the last few decades, extracorporeal shockwave therapy (ESWT) has become an established procedure for treating delayed and nonunions. Purpose of this retrospective follow-up study was (a) to investigate union rate and clinical outcome of the different implants [either one/two headless compression screws (HCS) or a plate] and (b) union rate and clinical outcome using only surgery, or a combination of surgery and ESWT.
Materials and methods
The study included 42 patients with scaphoid nonunions of the waist with a mean follow-up of 52 months. All patients received a non-vascularized bone graft from the iliac crest and stabilization was achieved by using one, two HCS or a plate. ESWT was performed with 3000 impulses, energy flux density per pulse 0.41 mJ/mm² within 2 weeks after surgery. Clinical assessment included range of motion (ROM), pain according to the Visual Analog Scale (VAS), grip strength, Disability of the Arm Shoulder and Hand Score, Patient-Rated Wrist Evaluation Score, Michigan Hand Outcomes Questionnaire and modified Green O’Brien (Mayo) Wrist Score. In addition, each patient had a CT scan of the wrist.
Results
A total of 33/42 (79%) patients showed union at the follow-up investigation. Patients treated with additional ESWT showed bony healing in 21/26 (81%) and without ESWT in 12/16 (75%). Patients that were stabilized using one HCS showed bony healing in 6/10 (60%), with two HCS 10/12 (83%) and by plate 17/20 (85%). The ESWT group had a significantly lower pain score according to the VAS and better modified Green O’Brien (Mayo) Score. No differences could be found in respect of ROM, grip strength, functional outcome score depending of which stabilization method was used.
Conclusions
Stabilization of scaphoid waist nonunions with two HCS or plate showed higher union rates than a stabilization using only one HCS. In addition, ESWT combined with a nonvascularized bone graft from the iliac crest seems a suitable option for treating scaphoid nonunions.
... Much research has been documented regarding diagnostic steps, treatment options and salvage procedures in lost cases [2,4,6,[13][14][15][16]. Studies addressing the topic of stability in treatment of injured scaphoids have focused on comparing different types of screws, screw placement as well as axial bending loads [1,2,5,9,14,[17][18][19][20]. ...
Background
The literature describes the treatment of scaphoid fractures comparing the volar and dorsal approaches, the advantages and disadvantages of percutaneous screw fixation, as well as the treatment of scaphoid nonunions using different types of cancellous or corticocancellous bone grafts. Yet, to date no studies are available comparing the outcome of rotational stability in screw-fixed scaphoid fractures to angular stable systems. The purpose of this study is to provide reliable data about rotational stability in stabilised scaphoid fractures and to gain information about the rigidity and the stability of the different types of fixation. Methods
Three groups of different stabilisation methods on standardised scaphoid B2 fractures were tested for rotational stability. Stabilisation was achieved using one or two cannulated compression screws (CCS) or angular stable plating. We performed ten repetitive cycles up to 10°, 20° and 30° rotation, measuring the maximum torque and the average dissipated work at angle level. ResultsOur study showed that rotational stability using a two CCS fixation is significantly (p < 0.05) higher than single CCS fixation. Using the angular stable plate system was also superior to the single CCS (p < 0.05). There was, however, no significant difference between two CCS fixation and angular stable plate fixation. Conclusion
Even though indications of using screws or plate systems might be different and plate osteosynthesis may be preferable in treatment of dislocated or comminuted fractures as well as for nonunions, our study showed a better rotational stability by choosing more than just one screw for osteosynthesis. Angular stable plating of scaphoid fractures also provides more rotational stability than single CCS fixation. The authors therefore hypothesise higher union rates in scaphoid fractures using more stable fixation systems.
... However, the authors did not comment on the degree of radiolunate angle correction or residual DISI deformity. Roh et al 34 showed that radiolunate angle is the most reliable and valid carpal alignment index for evaluating deformities of scaphoid fractures. For severe collapse deformities such as those demonstrated in this cohort, placement of a cortical strut simplifies the procedure and ensures correction of the humpback deformity and DISI. ...
Purpose:
To assess the results of a hybrid Russe procedure using a corticocancellous strut, cancellous autologous nonvascularized bone graft, and cannulated headless compression screw to reduce the deformity reliably from a collapsed scaphoid nonunion, provide osteoinductive stimulus, and stabilize the fracture for predictable union.
Methods:
A hybrid Russe procedure was performed for scaphoid waist fracture nonunions with humpback deformity and no evidence of avascular necrosis. A volar distal radius autologous bone graft was harvested and a strut of cortical bone was fashioned and placed into the nonunion site to restore length and alignment. We packed cancellous bone graft in the remainder of the nonunion site and fixed the scaphoid was with a headless compression screw. Union was determined by radiographs or computed tomography, and intrascaphoid, scapholunate, and radiolunate angles were calculated on final radiographs. We recorded wrist range of motion, grip strength, pinch strength, pain, and complications.
Results:
Fourteen male and 3 female patients (average age, 32 years; range, 16-78 years), with a mean follow-up of 32 months, were examined clinically and radiographically. All 17 scaphoids united with a mean time for union of 3.6 months. The mean postoperative intrascaphoid angle was significantly reduced from 65° preoperatively to 35° postoperatively. The mean radiolunate angle was significantly improved from 20° from neutral (lunate tilted dorsally) preoperatively to 0° postoperatively. The scapholunate angle also demonstrated significant improvement from 70° preoperatively to 56° postoperatively. Grip strength improved from 70% of the contralateral hand to 89% after the procedure. All patients were satisfied with the functional outcome and no donor site morbidity or hardware issues were identified.
Conclusions:
This straightforward hybrid Russe technique predictably restored radiolunate, scapholunate, and intrascaphoid angles with a 100% union incidence. The technique provides excellent functional results in patients with a challenging clinical problem, and we recommend it for scaphoid fracture waist nonunions with dorsal intercalated segment instability deformity.
Type of study/level of evidence:
Therapeutic IV.
... However, Farnell and Dickson emphasized the practical problems of performing a CT scan for every patient with a scaphoid fracture, because of higher costs, less availability, and greater radiation exposure compared to standard radiographic examination [1,22]. Furthermore, plain radiographs may also provide useful additional information regarding scaphoid fracture deformation correlated with clinical outcome [27]. ...
Introduction:
Conventional radiographic imaging is the first imaging tool of choice in scaphoid fractures. The majority of undisplaced scaphoid waist fractures unite after 6 weeks of cast immobilization. We hypothesized that conventional radiographic imaging at 6 weeks after injury can both accurately and reliably predict union in undisplaced scaphoid waist fractures.
Materials and methods:
Fleiss' kappa statistics were used concerning the opinions of four observers reviewing 47 sets of good-quality scaphoid radiographs of undisplaced scaphoid waist fractures. As reference standard for union, radiographs were taken at a minimum of 6 months after injury to determine validity.
Results:
Overall agreement was defined as moderate. (κ = 0.583) "No consolidation" (κ = 0.816), "full consolidation" (κ = 0.517) and "partial consolidation" (κ = 0.390) were defined as good, moderate and fair agreement, respectively. The average sensitivity and specificity of diagnosing scaphoid waist fracture union on standard scaphoid radiographs were 0.65 and 0.67, respectively. The positive predictive value for diagnosing union was 0.93 and the negative predictive value was 0.22.
Conclusions:
Conventional radiographic imaging is accurate and moderately reliable in diagnosing union, and reliable but inaccurate in diagnosing nonunion of scaphoid waist fractures at 6 weeks follow-up.
The scaphotrapezial–trapezoidal (STT) ligament complex is an important stabilizer of the proximal carpal row, and its disruption may cause carpal instability. We hypothesized that trapeziectomy with ligament reconstruction and tendon interposition (T + LRTI) has a higher risk of carpal alignment changes compared to thumb carpometacarpal arthrodesis. Thus, we investigated changes in carpal alignment after T + LRTI and arthrodesis.
We retrospectively analyzed 22 wrists that underwent T + LRTI and 29 wrists that underwent arthrodesis. We measured the scapholunate angle (SLA), radiolunate angle (RLA), radioscaphoid angle (RSA), capitolunate angle (CLA), and carpal height ratio (CHR). We compared these parameters preoperatively and postoperatively in both groups and compared the parameters' changes (Δ) between the groups. Moreover, we analyzed correlations among carpal alignment parameters in each group.
In the T + LRTI group, postoperative values decreased significantly in the RLA (preoperation to postoperation: 3.2 degrees to −1.7 degrees), RSA (58.0 to 52.3 degrees), and CHR (0.51 to 0.49 degrees), whereas postoperative values remained unchanged for the SLA (54.8 to 53.9 degrees) and CLA (−12.3 to −11.3 degrees). In the arthrodesis group, the postoperative values did not change significantly in the SLA (57.8 to 57.7 degrees), RLA (2.2 to 1.4 degrees), RSA (60.0 to 59.1 degrees), CLA (−11.5 to −10.2 degrees), and CHR (0.51 to 0.50). The ΔRLA was significantly lower in the T + LRTI group (−4.8 degrees) than in the arthrodesis group (−0.9 degrees). However, ΔRLA was positively correlated with ΔRSA in both groups. Postoperative dorsal intercalated segmental instability (DISI) developed in the T + LRTI group (n = 2) and the arthrodesis group (n = 1). Wrists with STT osteoarthritis after arthrodesis had greater reductions in the RLA and CHR than did wrists without STT osteoarthritis.
T + LRTI significantly reduced the RLA, RSA, and CHR and posed a risk of DISI development, whereas arthrodesis did not significantly change carpal alignment. However, postoperative STT osteoarthritis could be associated with lunate extension, even during arthrodesis.
Even today, the treatment of scaphoid nonunions remains challenging for the treating hand surgeon. Considering the biomechanical principles of wrist kinematics, especially the three-dimensional movement of the scaphoid, it is evident that a single headless compression screw does not provide sufficient stability to counteract all these forces, particularly rotational forces. Palmar plate fixation was initially introduced as a salvage procedure after failed screw fixation. It ensures very high rotational stability but also supports correction of the humpback deformity, reconstruction of scaphoid length, and prevents bone graft extrusion. However, indications have since been extended to include primary nonunion treatment in cases with humpback deformity or comminuted fractures. Even in recalcitrant cases (substantial bone loss, prior surgery failure, avascular necrosis, or durations exceeding 2 years), high union rates and favorable functional outcomes have been reported. This article attempts to summarize the biomechanical principles, indications, surgical techniques, and results following palmar angular stable plate fixation in scaphoid nonunions.
PURPOSE: We quantified the morphology and angulation of the third metacarpal (MC3) relative to the capitate using three-dimensional computed tomography data to inform surgical procedures such as total wrist arthroplasty and wrist arthrodesis. Specifically, we report the three-dimensional location of the intersections of the long axis of MC3 axis with the capitate cortical surface, the sagittal and coronal angles between the MC3 and capitate axes, and the MC3 shaft angle in the sagittal plane. We tested the hypothesis that these metrics did not differ between women and men.
METHODS: Three-dimensional bone models of the capitate and MC3 were analyzed in 130 subjects (61M and 69F). Long axes of the MC3 and capitate were computed. The intersection of the metacarpal long axis with the cortical surface of the capitate, the angle between the metacarpal-capitate axes, and metacarpal shaft angle were calculated and compared between men and women.
RESULTS: The long axis of the MC3 intersected the capitate at two locations on the outer cortical surface of the capitate. The proximal intersection was located near the midportion of the capitate, whereas the distal intersection was typically located within the capitate-MC3 articulation. The angle between the axes of the capitate and MC3 in the sagittal plane was a mean of 15°, ranging from 5° to 23°. The mean sagittal MC3 shaft angle was 166° and ranged from 158° to 173°.There were only subtle differences in these metrics between the sexes.
CONCLUSIONS: The long axis of the MC3 penetrates the dorsal surface of the capitate about its midportion, but there is notable variation in this location as well as in the angular relationships.
CLINICAL RELEVANCE: Three-dimensional measurements of the relationships between the third metacarpal and the capitate may serve as an important reference for the placement of intramedullary wires, plates, devices, and prosthetics.
Background
Bone grafting in patients with scaphoid waist nonunion can present several technical challenges. In this study, we aimed to present a modified surgical technique for scaphoid waist nonunion, which consisted of subchondral radial and ulnar K-wires positions with cancellous bone graft, and to compare the clinical outcome of this modified technique with the conventional method.
Methods
We retrospectively reviewed 72 patients with scaphoid waist nonunion who had been surgically treated between January 2011 and December 2020. Of these, 34 patients were treated with the modified method and 38 with the conventional method. Debridement of the nonunion site was performed using a curette, rongeur, and microburr. Two or 3 K-wires were inserted along the cancellous portion of the scaphoid in the conventional method. In the modified method, 2 K-wires were inserted along the ulnar and radial subchondral portion of the scaphoid to increase the space for bone grafting in the cancellous portion of the scaphoid. The autologous cancellous bone grafted in both the methods. Demographic, radiological, and clinical outcomes were reviewed and compared between the groups.
Results
There were no significant differences in demographics and characteristics of nonunion between the 2 groups of patients. The modified method group showed significantly shorter union time than the conventional method group (conventional group: 13.0 ± 1.3 weeks, modified group: 11.4 ± 1.1 weeks; P < 0.001). The bony union rate was 97.1% for the modified method and 89.5% for the conventional method. Satisfactory clinical outcomes (excellent and good Mayo wrist scores) were achieved in 27 cases (81.8%) using the modified method and 22 cases (64.7%) using the conventional method.
Conclusion
Subchondral radial and ulnar K-wire positioning with cancellous bone graft (modified method) can improve the union time with satisfactory clinical outcomes in the treatment of scaphoid waist nonunion.
The purpose of this study was to compare computer-aided analysis and different methods of manual measurements in the evaluation of carpal alignment. The radioscaphoid, radiolunate, radiocapitate and radiometacarpal angles were measured on cone-beam computed tomography (CT) scans of 30 healthy wrists by automated software (Disior Ltd.) and by hand surgeons using lateral radiographs reconstructed from the CT data. Hand surgeons were either given ( n = 6) or not given ( n = 7) prior instructions on how to perform the measurements. Inter- and intra-observer reliability of manual measurements ranged from good to excellent (intra-class correlation coefficients [ICC] 0.77–0.99), being highest in specialists with standardized methods and in reconstructed radiographs with bone overlap digitally removed. Computer-aided software provided excellent intra-observer reliability (ICC 0.94–1.00) consistently and values that were highly comparable (mean difference range 1°–7°) with the manual measurements made in optimal settings. Computer-aided software provides an accurate and repeatable method to measure carpal alignment in CT scans, minimizing observational errors.
The aim of this retrospective study was to assess the relation between carpal malalignment correction and radiological union rates in surgery for scaphoid nonunions. A total of 59 scaphoid waist fracture nonunions treated with open reduction and palmar tricortical autograft were divided according to their pre- and postoperative scapholunate (SL) and radiolunate (RL) angles. We found that carpal malalignment failed to correct in 32 of 59 (54.2%) patients despite meticulous surgical technique and placement of an appropriately sized wedge-shaped graft. In total, 43 (72.9%) fractures united at a mean of 4.47 months (range 3–11). Of the 27 fractures with postoperative SL and RL angles within the normal range, 21 united, whereas 22 of the 32 remaining fractures that failed to achieve postoperative angles within the normal range went on to union. The postoperative SL and RL angles were not related to union. Our findings suggest that in scaphoid fracture nonunion surgery, carpal malalignment may not be corrected in a substantial proportion of patients, but such correction may not be essential for bony union. Our findings also show that there is no marked collapse of the scaphoid graft in the early postoperative period.
Level of evidence
IV
Background Scaphoid malunion is rarely reported. Previous literature has attributed loss of carpal height and degenerative changes to scaphoid malunion, but the percentage of asymptomatic malunions remains unknown.
Purpose The authors of this study aim to define predictors of malunion and outcomes associated with scaphoid malunion.
Methods Institutional board review was obtained prior to evaluating medical records of patients 18 years and older who were treated for scaphoid fractures and/or nonunion between 2000 and 2020. The following data were collected for each patient: age, gender, fracture location, surgical technique, time to union, and whether malunion resulted. Malunion was defined using a lateral intrascaphoid angle (LISA) >45 degrees and height-to-length ratio (HLR) >60. Pain scores, range of motion (ROM), and secondary surgery were also evaluated.
Results Overall, 355 scaphoid injuries, including 196 acute fractures and 159 nonunions, were evaluated in this analysis. Of these, 55 scaphoids (15%) met the definition of malunion. Of these patients, 23% were female. The mean age at the time of injury was 29 years. Nonunion cases were more likely than acute cases to be associated with malunion. Proximal pole fractures were more likely to associated with malunion than waist fractures. When controlling for nonunion and fracture location, malunited scaphoids were not associated with any significant difference in pain score, ROM, or secondary surgery, compared with nonmalunion cases. A total of 10 patients (3.3%) without malunion and 2 patients (3.6%) with malunion went on to a secondary surgery. Final extension/flexion was 67/67 degrees and 56/59 degrees in nonmalunion and malunion groups, respectively, but these differences were not significant.
Conclusion Compared with scaphoid injuries that do not result in malunion, scaphoid injuries that heal into malunion have similar outcomes. While scaphoid malunion in a single case or series may be associated with poor outcomes, this study suggests that scaphoid malunions do not have worse functional outcomes.
Level of Evidence This is a Level IV study.
Purpose
We evaluated the impact of structural versus nonstructural bone grafting on the time to union, scaphoid deformity correction, and clinical outcomes in adults with unstable scaphoid waist nonunion without avascular necrosis. We hypothesized that nonstructural grafting would provide earlier time to union, restoration of scaphoid anatomy, and equivalent clinical outcomes compared with structural grafting.
Methods
We prospectively randomized 98 patients to undergo open reduction, iliac crest bone grafting with either corticocancellous (CC group) or cancellous bone only (C-only), and internal fixation using a Herbert screw. The lateral intrascaphoid angle (LISA) and scaphoid height length ratio (HLR) were measured on wrist computed tomography scans along the scaphoid longitudinal axis before surgery and an average of 84 weeks afterward. Pain, range of motion, grip strength, and Quick–Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score were measured before surgery and an average 84 weeks afterward.
Results
The trajectory of scaphoid union showed a higher union rate of the C-only group at 12, 14, and 16 weeks after surgery. However, at 24 weeks after surgery, there was no difference between the groups, The union rate was 94% in patients treated with C-only and 90% with CC grafting. In patients with preoperative LISA less than 70° and/or HLR less than 0.80 (n = 53), there were no differences between the CC and C-only grafting techniques for radiographic and clinical outcomes, QuickDASH scores, and malunion rate. In patients who had preoperative LISA greater than 70° and/or HLR greater than 0.80 (n = 45), radiographic outcome measures, range of motion, and QuickDASH scores were significantly better in the CC than in the C-only group. Scaphoid malunion was observed in 9 of 22 of C-only patients (41%) and 4 of 23 of CC patients (18%).
Conclusions
The severity of the scaphoid deformity may be a factor in determining the best graft type, because this may affect the rate of successful deformity correction. Corticocancellous grafting in patients who had a high degree of scaphoid deformity provided consistent deformity correction and superior QuickDASH scores. Otherwise, C-only grafting provides earlier time to union and equivalent clinical and radiographic outcomes compared with CC grafting.
Type of study/level of evidence Therapeutic I.
Background: Hybrid Russe technique for the treatment of scaphoid nonunion with humpback deformity has been described with a reported 100% union rate. We sought to evaluate the reproducibility of this technique. Methods: We completed a retrospective chart review of patients with a scaphoid waist nonunion and humpback deformity treated with the hybrid Russe technique from 2015 to 2019 with a minimum of 3-month follow-up. Twenty patients with 21 nonunions were included (mean follow-up: 7.0 months). Scapholunate angle was the primary outcome measure. Secondary outcomes included: intrascaphoid angle, radiolunate angle, pain on the visual analog scale (VAS), and Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score. Other variables included: time to computed tomography (CT) union, range of motion, and complications. Descriptive statistics were presented. Pre- and postoperative angles, VAS, and QuickDASH scores were evaluated with Wilcoxon signed rank tests. Results: The mean scapholunate angle improved −17.6° ± 6.4°. The mean intrascaphoid angle improved 28.2° ± 6.3°. The mean radiolunate angle improved 12.8° ± 8.8°. Of the 21 scaphoids, 20 (95%) demonstrated union on a CT scan. One patient was diagnosed with a nonunion. In total, 90% of patients noted symmetric range of motion compared with the contralateral side. The mean VAS pain score improved 6 ± 3 points. The mean QuickDASH score improved 10 ± 8 points. Complications (aside from nonunion) included 1 patient with persistent wrist pain that resolved with removal of hardware. Conclusions: The hybrid Russe technique for the treatment of scaphoid nonunions with humpback deformity demonstrates a 95% union rate. This technique is effective, reproducible, and may serve as an alternative to techniques that include structural grafts from distant sites.
Objective
Stabilization of comminuted fractures and nonunions of the scaphoid with an angular stable low-profile scaphoid plate.
Indications
Scaphoid nonunions with a large palmar defect, second and third surgical procedure after previous stabilization by headless compression screw (HCS). Comminuted fractures of the scaphoid that cannot be sufficiently stabilized by screws.
Contraindications
Radio- and midcarpal osteoarthritis, small proximal pole fragments, fragmentation of the proximal pole.
Surgical technique
The scaphoid is accessed by a palmar approach. After correcting the DISI (dorsal intercalated segment instability) deformity of the lunate and humpback deformity of the scaphoid, the reduction is secured by temporary Kirschner wires. The nonunion is debrided and the bone defect filled with cancellous bone graft. Subsequently the scaphoid plate and the angular stable screw are positioned in the order to place three screws in the proximal and distal fragment of the scaphoid. Comminuted fractures of the scaphoid are fixated by temporary Kirschner wires, then the plate is positioned in the same way as nonunions.
Postoperative management
Comminuted fractures and nonunions of the scaphoid are immobilized by a below-elbow cast or thermoplastic splint with inclusion of the thumb for 8 weeks. No heavy work, high-risk or contact sport activities for 12 weeks. Plate removal is recommended after 6 months or after bony healing.
Results
By stabilizing scaphoid nonunions with a plate, high union rates with good clinical outcome can be achieved if the indication is correct.
Background Scaphoid fracture accounts for approximately 15% of acute wrist fractures. Clinical examination and plain X-rays are commonly used to diagnose the fracture, but this approach may miss up to 16% of fractures in the absence of clear-cut lucent lines on plain radiographs. As such, additional imaging may be required. It is not clear which imaging modality is the best. The goal of this study is to summarize the current literature on scaphoid fractures to evaluate the sensitivity, specificity, and accuracy of four different imaging modalities.
Case description A systematic-review and meta-analysis was performed. The search term “scaphoid fracture” was used and all prospective articles investigating magnetic resonance imaging (MRI), computed tomography (CT), bone scintigraphy, and ultrasound were included. In total, 2,808 abstracts were reviewed. Of these, 42 articles investigating 51 different diagnostic tools in 2,507 patients were included.
Literature review The mean age was 34.1 ± 5.7 years, and the overall incidence of scaphoid fractures missed on X-ray and diagnosed on advanced imaging was 21.8%. MRI had the highest sensitivity and specificity for diagnosing scaphoid fractures, which were 94.2 and 97.7%, respectively, followed by CT scan with a sensitivity and specificity at 81.5 and 96.0%, respectively. The sensitivity and specificity of ultrasound were 81.5 and 77.4%, respectively. Significant differences between MRI, bone scintigraphy, CT, and ultrasound were identified.
Clinical relevance MRI has higher sensitivity and specificity than CT scan, bone scintigraphy, or ultrasound.
Level of Evidence This is a Level II systematic review.
Successful bone union is only a portion of scaphoid fracture management. Malunion is possible and can alter wrist kinematics, potentially causing wrist pain and accelerated degeneration. Evaluation of scaphoid malunion begins with adequate imaging and understanding of deformity. Treatment includes nonoperative management, reconstruction, or salvage options. Correction of malunion can be obtained with an osteotomy and the use of structural graft to recreate anatomy and restore normal carpal motion. Clinical improvement of symptomatic scaphoid malunion can be reliably obtained with reconstruction, although the natural history and role for intervention in asymptomatic malunions remains unclear.
The displacement in scaphoid fractures is understudied and frequently underestimated. Displacement and it's severity can influence outcome. This is typically done by imaging. Although plain radiographs provide adequate screening for scaphoid fracture displacement, a more detailed imaging modality is required to define its magnitude. Large studies favor using magnetic resonance imaging (MRI) to assess scaphoid fractures. However, although MRIs are excellent at identifying the occult fracture, the edema from a displaced fracture makes this modality a suboptimal choice to assess displacement. The recommended diagnostic test is therefore high-resolution computed tomography (CT) scans with an ability to perform multiplanar reconstruction, with bone-specific windows, in the scaphoid plane.Following acquisition of a CT scan, displacement can be described as gapping, translation or step, angulation, and rotation. There are no evidence-based figures outlining how far or angulated the fragments are required to have moved before they can be called displaced. Most studies use a figure of 1. mm gapping or translation as identifying displacement. Angulation can be measured indirectly via assessing the height to length of the scaphoid.In conclusion, the imaging modality of choice to define displacement is a high-resolution CT scan, and if fragments gap or are translated by more than 1. mm, the scaphoid fracture should be considered displaced.
Hand and wrist radiographic indexes such as radial inclination, ulnar variance, carpal height ratio, and radial tilt play an important role in the diagnosis and management of medical disorders, so they should be modified regarding the population and race difference. This study aims to compare the normal radiologic wrist indexes in Mashhad population with other existing databases and define some of the factors that may influence the normal radiographic indexes. A total of 100 healthy participants were enrolled in this prospective cross-sectional study. After performing PA and lateral wrist radiographs, all radiological indexes including the wrist height; 1st and 3rd metacarpal length; ulnar variance; radial tilt and radial inclination; radiolunate, capitolunate, and scapholunate angle; capitate and scaphoid length; lunate and wrist width; and lunate diameter were measured. Significant differences were found between the two genders in the 1st and 3rd metacarpal length (P < 0.001 and P < 0.001 respectively), wrist height (P < 0.001), radial tilt (P=0.027), radiolunate angle (P=0.001), capitate and scaphoid length (P < 0.001 and P < 0.001 respectively), lunate and wrist width (P < 0.001 and P < 0.001 respectively),lunate length (P=0.003), and lunate diameter (P < 0.001). A significant linear correlation was found between ulnar variance (P=0.003), scapholunate angle (P=0.016), and wrist ratio (P=0.011) with age. According to our findings, using population specific wrist and hand indexes is recommended to diagnose and follow up upper extremities conditions.
Background Displaced scaphoid fractures have a relatively high rate of nonunion. Detection of displacement is vital in limiting the risk of nonunion when treating scaphoid fractures.
Questions/Purpose We evaluated the ability to diagnose displacement on radiographs and computed tomography (CT), hypothesizing that displacement is underestimated in assessing scaphoid fracture by radiograph compared with CT.
Patients/Methods Thirty-five preoperative radiographs and CT scans of acute scaphoid fractures were evaluated by two blinded observers. Displacement and angular deformity were measured, and the fracture was judged as displaced or nondisplaced. Scapholunate, radiolunate, and intrascaphoid angles were measured. Radiograph and CT measurements between nondisplaced and displaced fractures were compared. Intraobserver reliability was measured.
Results Reader 1 identified 12 fractures as nondisplaced on radiograph, but displaced on CT (34%). Reader 2 identified 9 fractures as nondisplaced on radiograph, but displaced on CT (26%). For displaced fractures, the mean intrascaphoid angle was over three times greater when measured on CT than on radiograph (56 vs. 16 degrees). Scapholunate angle >65 degrees and radiolunate angle >16 degrees were significantly associated with displacement on CT. Interobserver reliability for diagnosing displacement was perfect on CT but less reliable on radiograph.
Conclusion Scaphoid fracture displacement on CT was identified in 26 to 34% of fractures that were nondisplaced on radiograph, confirming that radiographic evaluation alone underestimates displacement. These results underscore the importance of CT scan in determining displacement and angular deformity when evaluating scaphoid fractures, as it may alter the decision on treatment and surgical approach to the fracture. We recommend considering CT scan to evaluate all scaphoid fractures.
Level of Evidence Level III.
Purpose
The effect of scaphoid nonunion deformity on wrist function is uncertain due to the lack of reliable imaging tools. Advanced three-dimensional (3-D) computed tomography (CT)-based imaging techniques may improve deformity assessment by using a mirrored image of the contralateral intact wrist as anatomic reference. The implementation of such techniques depends on the extent to which conventional CT is currently used in standard practice. The purpose of this systematic review of medical literature was to analyze the trend in CT scanning scaphoid nonunions, either unilaterally or bilaterally.
Materials and methods
Using Medline and Embase databases, two independent reviewers searched for original full-length clinical articles describing series with at least five patients focusing on reconstructive surgery of scaphoid nonunions with bone grafting and/or fixation, from the years 2000–2015. We excluded reports focusing on only nonunions suspected for avascular necrosis and/or treated with vascularized bone grafting, as their workup often includes magnetic resonance imaging. For data analysis, we evaluated the use of CT scans and distinguished between uni- and bilateral, and pre- and postoperative scans.
Results
Seventy-seven articles were included of which 16 were published between 2000 and 2005, 19 between 2006 and 2010, and 42 between 2011 and 2015. For these consecutive intervals, the rates of articles describing the use of pre- and postoperative CT scans increased from 13%, to 16%, to 31%, and from 25%, to 32%, to 52%, respectively. Hereof, only two (3%) articles described the use of bilateral CT scans.
Conclusion
There is an evident trend in performing unilateral CT scans before and after reconstructive surgery of a scaphoid nonunion. To improve assessment of scaphoid nonunion deformity using 3-D CT-based imaging techniques, we recommend scanning the contralateral wrist as well.
We analysed scaphoid deformity as a result of surgical treatment of scaphoid fracture nonunion and assessed the deformity associated with a dorsal intercalated segmental instability pattern of carpal malalignment. A total of 45 patients who were treated for scaphoid fracture nonunion were included in the study. The height-to-length ratio of the scaphoid was measured on computed tomographic images and used to assess scaphoid deformity. Carpal malalignment was quantified based on the radio-lunate angle. A correlation analysis between the height-to-length ratio and the radio-lunate angle was performed. Dorsal intercalated segmental instability was defined as a radio-lunate angle >15°, and a receiver operating curve analysis was used to calculate the cutoff height-to-length ratio that can be accompanied with dorsal intercalated segmental instability. Extension of the lunate increases in proportion to the flexion deformity of the scaphoid; dorsal intercalated segmental instability can occur if the height-to-length ratio of the scaphoid is >0.73.
Level of evidence: IV
A method is developed to calculate the approximate number of subjects required to obtain an exact confidence interval of desired width for certain types of intraclass correlations in one-way and two-way ANOVA models. The sample size approximation is shown to be very accurate.
Axial rotation of the carpal bones forms an important component of all wrist movements; however, carpal alignment in the axial plane has somehow not attracted attention. The present study comprised computed tomography (CT) imaging of the wrist joint in 53 asymptomatic volunteers lying prone with the shoulder abducted, elbow flexed and the palm facing down. Axial axes of various carpal bones and the distal radius were drawn and measured. The scaphoid axis was found to be in neutral position in 11%, and supinated in 89% of wrists, with mean of 16 degrees (SD 9 degrees ) while the lunate axis was in neutral position in 17% and supinated in 83% of the wrists with mean of 13 degrees (SD 9 degrees ). The axis for the triquetrohamate joint was found to be 9 degrees pronated (SD 13 degrees ) and 6 degrees supinated (SD 7 degrees ) for the capitohamate joint. Mean values for various carpal angles were 24 degrees, 21 degrees, 3 degrees, 22 degrees and 7 degrees for the radioscaphoid, radiolunate, scapholunate, lunotriquetral and lunocapitate angle, respectively. Examination was repeated in ten volunteers and showed statistically similar values for the various measurements, except the lunotriquetral angle. The present study provides a reference database of normal anatomy for carpal axial alignment. Its potential applications include identifying abnormal axial alignment of the carpal bones that may occur in various pathological conditions affecting the wrist joint, and also quantification of normal and abnormal axial motion of the carpal bones.
Forty-five patients with 46 scaphoid fractures were studied more than 6 months after union by clinical examination and trispiral tomography. Twenty had normal scaphoid alignment with lateral intrascaphoid angles less than 35 degrees; the rest had varying degrees of increased flexion angulation of the scaphoid, ranging from 36 degrees to 60 degrees. Increasing lateral scaphoid angulation, eventually resulting in a "humpback" deformity, was associated with progressively poor clinical and radiographic results. There were satisfactory clinical outcomes in 83% and posttraumatic arthritis in only 22% of those with normal scaphoid anatomy. Those with greater than 45 degrees of lateral intrascaphoid angulation present at the time of union had a satisfactory clinical outcome in 27% and posttraumatic arthritis in 54%. Union alone is an insufficient criterion for success in treating scaphoid fractures.
The purpose of this study was to find out whether the carpal indices measured on lateral radiographs with a slightly malpositioned wrist are the same as those measured in the true neutral position. Lateral radiographic views of 25 wrists were taken with 5° intervals from 20° of flexion to 20° of extension. Most carpal indices measured in the flexed or extended position were significantly different from the wrist in zero flexion-extension, except scapholunate angle at 5° of extension and scaphocapitate angle at 5° and 10° of flexion. Starting from the flexed position, there was an average of -4.0° change in radioscaphoid angle, -1.0° in scapholunate angle, -1.0° in scaphocapitate angle, +3.0° in radiolunate angle, and +2.0° in lunocapitate angle for each 5° of extension with linear trends. The results from this study suggest that even minimal degrees of flexion-extension can affect the measurements of carpal indices on lateral radiographs.
Background:
Fracture displacement is the most important factor associated with nonunion of a scaphoid waist fracture.We evaluated the performance characteristics of radiographs and computed tomography (CT) in the diagnosis of intraoperative displacement and instability of scaphoid waist fractures using wrist arthroscopy as the reference standard.
Methods:
During a six-year period (2004 to 2010) at two institutions, forty-four adult patients with a scaphoid waist fracture underwent arthroscopy-assisted operative fracture treatment at a mean of nine days (range, two to twenty-two days) after injury. Subjects included all of those with a displaced scaphoid fracture seen on radiographs and a selection of patients with a nondisplaced scaphoid fracture. All patients had preoperative radiographs and CT. Arthroscopy with up to 5 kg of traction was the reference standard for fracture displacement and instability.
Results:
The reference standard (arthroscopy) led to a diagnosis of twenty-two displaced fractures (all unstable) and twenty-two nondisplaced fractures (seven unstable). Displacement was diagnosed in eleven patients (25%) with the use of radiographs and in twenty (45%) with CT. The sensitivity, specificity, and accuracy for diagnosing intraoperative displacement were 45%, 95%, and 70%, respectively, with the use of radiographs and 77%, 86%, and 82%, respectively, with CT. The sensitivity, specificity, and accuracy for diagnosing intraoperative instability were 34%, 93%, and 55%, respectively,with the use of radiographs and 62%, 87%, and 70%, respectively, with CT. Assuming a 10% prevalence of fracture displacement and instability among all scaphoid waist fractures, the positive and negative predictive values for displacement were 53% and 94%, respectively, with the use of radiographs and 39% and 97% with CT whereas the positive and negative predictive values for instability were 36% and 93%, respectively, with radiographs and 34% and 95% with CT.
Conclusions:
Radiographs and CT scans cannot be relied on to accurately diagnose intraoperative scaphoid fracture displacement or instability compared with arthroscopic examination. The influence, with regard to the risk of nonunion, of intraoperative instability of a scaphoid fracture that is seen to be nondisplaced on radiographs or CT is currently unknown.
Level of evidence:
Diagnostic Level III.
To virtually assess nonunions of the scaphoid waist using 3-dimensional computed tomography (CT) reconstruction for the amount of displacement of the distal fragment and the postfracture reduction position using the intact opposite scaphoid for reference.
We generated 3-dimensional reconstructions for 11 nonunions of the scaphoid waist and the contralateral intact scaphoids based on CT. The mean age of the patients was 25 years and the time from injury to the CT scan was 2.4 years. We used the mirrored 3-dimensional model of the healthy scaphoid to guide virtual reduction of the nonunion and calculated the amount of displacement of the distal pole fragment from prereduction to postreduction. We compared the results with the intrascaphoid angles calculated using single CT slices.
The scaphoid nonunions showed a mean flexion deformity of 23°, an ulnar deviation of 5°, and a pronation deformity of 10°. Mean translation was 0.9 mm volarward, 0.2 mm radialward, and 3.3 mm distalward. After reduction, all scaphoids showed a bony overlap on the dorsoradial side; the mean volume of this region was 3% of total bone volume. There was no correlation between the degree of displacement and the intrascaphoid angle measurements.
Preoperative planning for scaphoid reconstruction is usually performed using conventional radiographs and single CT slices. However, by synthesizing the information from the CT into a 3-dimensional reconstruction, an exact analysis is possible. This method also allows quantification of prosupination displacement. The postreduction area of dorsal bone overlap may be due to appositional callus formation.
Simple volar opening of the scaphoid allows correction of angulation deformities but results in lengthening of the scaphoid. Correct reduction of the scaphoid fragments is often only possible if the dorsal appositional callus is resected.
Using quantitative analysis of three-dimensional reconstructions of computed tomography scan data, a normative database of carpal bone morphology was built. Thirfy-five wrists were imaged in a computed tomography scanner. Each slice was processed to determine the bone edges and essembled as a three-dimensional model by stacking. Quantilative measurements of volume, surface area, maximum length, and intercarpal distances were then assessed. A reliable three-dimensional carpal height ratio was calculated by dividing the carpal height (minimum distance between the fourth metacarpal and the radius) by the capitate maximum length. For volume, maximum length, and surface area, the order for the eight, carpal bones with respect to size (in descending order) were: capitate, hamate, scaphoid, trapezium, lunate, trapezoid, triquetrum, and pisiform. Male wrists were significantly larger than female wrists. There were no significant differences in the relative dimensions between left and right wrists, or between left and right wrists of matched pairs. This technology offers automated analysis of three-dimensional geometric carpal information and the opportunity to obtain a body of information about normal and abnormal morphology as well as spatial relationships between carpal bones.
A displaced fracture of the scaphoid is one in which the fragments have moved from their anatomical position or there is movement between them when stressed by physiological loads. Displacement is seen in about 20% of fractures of the waist of the scaphoid, as shown by translation, a gap, angulation or rotation. A CT scan in the true longitudinal axis of the scaphoid demonstrates the shape of the bone and displacement of the fracture more accurately than do plain radiographs. Displaced fractures can be treated in a plaster cast, accepting the risk of malunion and nonunion. Surgically the displacement can be reduced, checked radiologically, arthroscopically or visually, and stabilised with headless screws or wires. However, rates of union and deformity are unknown. Mild malunion is well tolerated, but the long-term outcome of a displaced fracture that healed in malalignment has not been established.
This paper summarises aspects of the assessment, treatment and outcome of displaced fractures of the waist of the scaphoid.
Scaphoid malunion and carpal malalignment can result after scaphoid reconstruction, if the two fragments are not properly reduced before fixation. However, currently there is no information about which degree of deformity or malalignment can be tolerated without impairing clinical function. The purpose of this study was to investigate the influence of the scaphoid morphology and carpal alignment on clinical outcomes after scaphoid reconstruction. A total of 65 patients with an average age of 29 years were followed-up after a mean period of 45 months. In all patients, osseous union after a first-time scaphoid reconstruction in the middle third had been confirmed. Scapholunate (SL) and radiolunate (RL) angles were obtained on plain radiographs as were intrascaphoid (ISA) and dorsal cortical (DCA) angles and the height/length (H/L) ratio of the reconstructed scaphoid on computed tomography (CT) scans. These parameters were correlated with clinical outcome measures. RL angles correlated significantly with wrist range of motion, grip strength and pain levels, whilst SL angles, ISA, DCA and H/L ratio failed to show significant correlations. Our data suggest that clinical outcome is correlated with correct restoration of bone morphology and carpal alignment. After reconstruction, the RL angle should not exceed 10°.
The intra- and interobserver variability of 3 techniques for measuring the humpback deformity of 37 scaphoids using longitudinal computed tomography was assessed. The 3 measuring techniques were the lateral intrascaphoid angle, the dorsal cortical angle, and the height-to-length ratio. The intraobserver reliability of the intrascaphoid angle was poor; the dorsal cortical angle was moderate to excellent, and the height-to-length ratio was excellent. The interobserver reliability of the intrascaphoid angle was poor to moderate, the dorsal cortical angle was moderate to excellent, and the height-to-length ratio was moderate to excellent. For all 3 observers, the intra- and interobserver reliability was the best for the height-to-length ratio and worst for the intrascaphoid angle. The height-to-length ratio is the most reproducible method of assessing the humpback deformity. Clinical correlation is required to establish whether the height-to-length ratio will be of value in predicting the outcome of fractures of the scaphoid.
To clarify the correlation between a scaphoid deformity and carpal malalignment in patients with scaphoid waist nonunion and to investigate how accurately a corrective bone graft improves carpal malalignment according to the preoperative plan.
A total of 38 patients were analyzed retrospectively. Surgery was performed according to the anterior wedge bone graft method described by Fernandez. The scaphoid deformity and carpal malalignment were evaluated by the changes in the intrascaphoid angle (ISA) and axial length (AL) and by the changes in the radiolunate angle (RLA) and scapholunate angle (SLA), respectively, compared with the uninjured side by using standardized x-rays. Each variable was measured at 1 year after surgery. By performing multiple regression analysis, the correlation between the scaphoid deformity and carpal malalignment and between the correction of the scaphoid deformity and the change in carpal alignment were analyzed.
Compared with the uninjured side, the mean respective changes in the ISA, AL, RLA, and SLA were 11°, -1.3 mm, 14°, and 11°, preoperatively. The changes in the RLA and SLA correlated with the change in the ISA, but not with the change in the AL. The mean postoperative corrections of the ISA and AL were 15° from full extension and 1.7 mm, and the changes in the RLA and SLA were 18° and 12° from full extension, respectively. The change in the RLA correlated with the corrections of the ISA and AL. Although the change in the SLA did not correlate with either of them, the mean postoperative SLA was not significantly different from the mean value of the uninjured side.
The degree of humpback deformity of the scaphoid correlated with the degree of carpal malalignment. The corrective bone graft resulted in the expected recovery of carpal alignment according to the preoperative plan.
Prognostic IV.
To evaluate the position of the screws and find the difference of clinical and radiologic outcome between the volar approach and the dorsal approach groups in percutaneous screw fixation for acute scaphoid fractures.
Forty-one consecutive patients with an acute scaphoid fracture, who had percutaneous fixation via either the volar approach or the dorsal approach, were evaluated at an average of 30 months after the surgery. The volar approach was used in 19 patients and the dorsal approach in 22 patients. By using a computerized digital image program, angles between the Herbert screw with respect to the long axis of the scaphoid and the fracture line were measured with plain radiographs in the posteroanterior, lateral, and the 45 degrees semipronated oblique views.
The screws showed no significant difference between the 2 groups in posteroanterior and lateral views; however, screws in the dorsal approach group were observed to be placed more parallel to the long axis of the scaphoid in the semipronated oblique view. The screws in the dorsal approach group were positioned more perpendicular to the fracture lines of the scaphoid compared with those of the volar approach group for all 3 different radiographic views. There was no statistically significant difference between the 2 treatment groups regarding fracture healing. According to the Mayo wrist score system, excellent results were recorded in 18 patients in the dorsal approach group and 15 patients in the volar approach group.
This study suggests that screws are placed more parallel to the long axis of the scaphoid and perpendicular to the fracture line via the dorsal approach; however, there was no significant difference with regard to functional outcome and bone union.
Therapeutic IV.
Twenty-five patients had Russe anterior corticocancellous bone-grafting between 1973 and 1984 for twenty-six symptomatic established non-unions of the scaphoid. The mean duration of follow-up was eleven years (range, seven to eighteen years). Twenty-one (81 per cent) of the twenty-six scaphoid bones united. We developed two rating scales to evaluate the results of the operation. One scale, based on objective findings, included the radiographic appearance of the wrist, the range of motion, and strength; the other scale, based on subjective findings, comprised function, pain, perception of a decrease in performance because of limitation of motion or strength, and satisfaction. These scales were used to compare the objective and subjective results in patients who had a malunion of the scaphoid in which the lateral intrascaphoid angle was more than 45 degrees convex dorsally between the proximal and distal poles (a so-called flexion or humpback deformity, which results in extension of the proximal fragment of the scaphoid at the radiocarpal joint) with the results in patients who had no such deformity. The lateral intrascaphoid angle was more than 45 degrees in thirteen (50 per cent) of the twenty-six wrists. Although the difference in the objective results between the wrists that had a malunion and those that did not have a malunion was highly significant (p = 0.001), there was no significant difference in the subjective results between the two groups, including satisfaction of the patient (p = 0.39). Twenty-three patients (92 per cent) returned to full-time employment and twenty-two (88 per cent), to sports activities. Twenty-three patients (92 per cent) reported that they had pronounced relief of pain and that the procedure had improved their quality of life. The presence of this deformity of the scaphoid after bone-grafting for a symptomatic non-union was not predictive of a poor long-term subjective outcome.
Scaphoid fracture displacement was studied in twenty-five patients using three-dimensional computed tomography. Fracture displacement was more readily detected and distinct in three-dimensional computed tomography images than in plain radiography. Two different types of offset of the distal fragment with respect to the proximal fragment are described on three dimensional computed tomography; volar type and dorsal type. In the volar type, the distal fragment overhung in the volar direction relative to the proximal fragment and was frequently accompanied by humpback deformity and axial rotation. In the dorsal type, the distal fragment slipped dorsal on the proximal fragment and was commonly accompanied by humpback deformity. The volar type had a transverse or vertical fracture line on both the volar and dorsal surfaces of the scaphoid, while the dorsal type had a horizontal fracture line. The volar type was frequently found when the fracture was distal, whereas the dorsal type was noted more frequently for proximally located fracture.
Determinations of carpal bone angles are used in the clinical evaluation of carpal malalignment. Eleven frequently referred radiological measures in lateral projection of the wrists in 23 wrists were assessed using different definitions of axes. Interobserver- and intraobserver variations were calculated. The standard deviation of the interobserver variation ranged from 2.60 degrees to 18.15 degrees, and the intraobserver variation from 1.89 degrees to 4.66 degrees depending on the angles measured. The use of three angles for the least observer variability in assessment of carpal alignment is recommended. These angles were defined from the following carpal bone axes: radius, the line through the center of the medullary canal at 2 cm and 5 cm proximal to the radiocarpal joint; lunate, the line perpendicular to the tangent of the two distal poles; scaphoid, the tangent of the palmar proximal and distal margins, and capitate, the tangent of the dorsal margin of the diaphysis of the third metacarpal bone (substitute axis).
The radioscaphoid, radiolunate, and radiocapitate angles of nine lateral projections of the wrist (three in flexion, three in extension, and three in neutral position) of three fresh cadaver specimens were measured. Seven orthopedic surgeons (six hand surgeons and one orthopedic surgeon) made the measurements with a standard goniometer using both the axial and tangential methods of angle determination. The overall standard deviation for all measurements was 5.2 degrees, and no significant difference in variability between axial and tangential methods was found. By comparing the same angles from different wrist positions, the amount of flexion-extension motion of the capitate, scaphoid, and lunate with respect to the radius was estimated. To assess the accuracy of such a method of carpal motion determination, a more accurate stereoradiographic method of analysis of carpal kinematics was utilized. The overall estimated error of this standard goniometric method of carpal motion determination averaged 7.4 degrees.
The kinematics of five fresh frozen wrist specimens were studied before and after a simulated scaphoid waist fracture. To determine the change in wrist motion and fracture site characteristics associated with an unstable wrist, the relative motion of each carpal bone was determined from the movement of implanted carpal markers on biplanar radiographs obtained in neutral and the four extreme wrist positions. The kinematics of the wrist in our specimens before the osteotomy were similar to previous studies. After the osteotomy, the proximal and distal segments of the scaphoid moved independently. The distal scaphoid assumed a relatively flexed stance and displayed increased motion. The proximal scaphoid fragment and lunate assumed a relatively extended stance and displayed less motion after the osteotomy. These kinematic abnormalities produced significant interfragmentary motion that would be expected to complicate normal fracture healing. The spontaneous collapse of the two scaphoid fragments produced a dorsal angulation or "humpback" deformity that simulated the clinical situation of displaced scaphoid nonunions. The scaphoid serves an important role maintaining normal alignment of the carpal bones and producing normal wrist motion.
Twenty-one cases of unstable fractures of the scaphoid were treated by open reduction, length restoration by interpositional anterior wedge grafting, and fixation with a Herbert screw to obtain union and restore carpal stability. There was primary union in 15 (71%) of 21 patients. Two failed cases were treated with a second anterior wedge graft and Herbert screw fixation; overall rate of union was 81%. Nonunions were related to improper screw placement, failure of compression at the nonunion, bone-graft resorption, or persistent avascular necrosis. In the united scaphoids, carpal instability was corrected, with improvement in the scapholunate angle (65 degrees to 54 degrees) and capitolunate angulations (35 degrees to 15 degrees). Scaphoid malalignment associated with nonunion was improved on biplanar tomographic measurement of the scaphoid angles.
This article describes the effects of various operative exposures for insertion of the Herbert screw on the internal vascularity of the scaphoid. Vessels supplying the proximal 70% to 80% of the scaphoid were intact in all specimens except one, which had a combined palmar and dorsal. approach. Vessels supplying the tubercle and the distal 20%-30% were disrupted in five of 18 specimens undergoing the palmar approach. The palmar approach did not disrupt the significant dorsal blood supply, and the dorsal approach was safe provided care was taken to preserve the visible dorsal vascular leash.
The deformity known as the humpback scaphoid is difficult to visualize on radiographs. Three patients were studied by imaging with computerized axial tomography (CT scan) in the true longitudinal axis of the scaphoid. This projection demonstrates the anatomy, allowing assessment of fractures, the humpback deformity, and the shape of the scaphoid after grafting.
We reviewed the cases of fifty-six scaphoid non-unions in fifty-five patients, none of whom had received treatment of any kind before examination. In the thirty-two patients who had been injured five years or more earlier, arthritis developed in thirty-one (97 per cent). The one patient in whom osteoarthritis developed less than four years after injury also had avascular necrosis of the scaphoid. The incidence of osteoarthritis increased with time after injury. We concluded that patients with established scaphoid non-union should be advised that osteoarthritis will most likely develop.
Fractures of the scaphoid can be classified into either undisplaced, stable fractures or displaced, unstable fractures by their roentgenographic appearance. When there is greater than 1 mm of fracture offset or an instability collapse pattern (dorsal lunate rotation) on the lateral view, an unstable, displaced fracture is present. When doubt exists after reviewing routine films, special X-rays, such as radial-ulnar deviation stress views, traction oblique views, or trispiral tomography should be obtained. In acute scaphoid fractures, where no displacement of the fracture fragments or lunate dorsal tilting can be seen, a short-arm thumb spica cast provides satisfactory support for fracture union. A wrist position of volar flexion-radial deviation is preferred to the more traditional positions of wrist extension with radial deviation or wrist extension with ulnar deviation with 100% union rate and no malunions. In displaced scaphoid fractures, a long-arm cast is recommended, with reduction of the fracture by wrist flexion and radial deviation. If accurate reduction is not obtained or is lost during the course of treatment, open reduction and internal fixation should be strongly considered. In scaphoid nonunions, undisplaced fractures can be treated satisfactorily by an inlay bone graft, using either a dorsal or a volar approach. For displaced scaphoid nonunions, either a dorsal approach with internal fixation should be done (particularly if there is evidence of radioscaphoid arthrosis), or a volar approach with internal fixation can be performed. Peg graft techniques had a higher rate of nonunion and secondary arthritis. Nonunions should be immobilized a minimum of 4 months or until roentgenographic union is present.
The extraosseous and intraosseous vascularity of the carpal scaphoid was studied in 15 fresh cadaver specimens by injection and clearing techniques. The major blood supply to the scaphoid is via the radial artery. Seventy to eight percent of the intraosseous vascularity and the entire proximal pole is from branches of the radial artery entering through the dorsal ridge. Twenty to thirty percent of the bone, in the region of the distal tuberosity, receives its blood supply from volar radial artery branches. There is an excellent collateral circulation to the scaphoid by way of the dorsal and volar branches of the anterior interosseous artery. An explanation for the cause of scaphoid necrosis on the basis of the vascular anatomy is proposed. The volar operative approach would be least traumatic to the proximal pole's blood supply.
We investigated the dependence of 20 radiographic carpal measurements (carpal indices) on rotational positioning errors in posteroanterior and lateral radiographs. The measurements were made from "true perspective" digitally reconstructed radiographs created from computed tomography data. Most posteroanterior indices were not affected by rotation. Carpal height, carpal height ratio, revised carpal height ratio, capitate-radius distance, and carpal ulnar translocation were particularly robust. Lateral-view indices involving the scaphoid were the most sensitive to simulated malpositioning: radioscaphoid, scapholunate, and scaphocapitate angles were reduced from 58 degrees, 48 degrees, and 56 degrees at true lateral to 30 degrees, 24 degrees, and 34 degrees, respectively, at 20 degrees external rotation. Observers were unable to estimate the degree of malpositioning accurately in either view. Our results support use of the "scaphopisocapitate" criterion for assessing correct positioning in lateral plain radiographs.
Scaphoid fracture is a common injury encountered in family medicine. To avoid missing this diagnosis, a high index of suspicion and a thorough history and physical examination are necessary, because early imaging often is unrevealing. Anatomic snuffbox tenderness is a highly sensitive test for scaphoid fracture, whereas scaphoid compression pain and tenderness of the scaphoid tubercle tend to be more specific. Initial radiographs in patients suspected of having a scaphoid fracture should include anteroposterior, lateral, oblique, and scaphoid wrist views. Magnetic resonance imaging or bone scintigraphy may be useful if the diagnosis remains unclear after an initial period of immobilization. Nondisplaced distal fractures generally heal well with a well-molded short arm cast. Although inclusion of the thumb is the standard of care, it may not be necessary. Nondisplaced proximal, medial, and displaced fractures warrant referral to an orthopedic subspecialist.
The influence of angular deformity of the scaphoid on wrist function and arthrosis is debated and the reliability of the described quantitative measurements of deformity has been questioned. We hypothesized that the inherent imprecision with which computed tomography scanning planes are selected introduces another source of variability in measurements of scaphoid deformity, further diminishing their reliability.
Sagittal plane images of 15 computed tomograms of normal scaphoids were evaluated in 3 different reconstruction planes. Four observers measured the lateral intrascaphoid angle, the dorsal cortical angle, and the height-to-length ratio of the 45 images in random order and then measured them again in a distinct random order 2 weeks later. The variability of each observer's measurements (intraobserver reliability) was evaluated with Pearson correlation coefficients. The agreement of the measurements made by the 4 observers (interobserver reliability) and the agreement of the measurements of the same bone in different reconstruction planes (interplane reliability) were evaluated using interclass correlation coefficients.
The intraobserver reliability was poor for 27 of 36 comparisons. The interobserver reliability of the dorsal cortical angle and the intrascaphoid angle was poor for all reconstruction planes. The interobserver reliability of the height-to-length ratio was good for 2 planes and poor for the third plane. The interplane reliability was poor for 7 of 12 comparisons, with no single measurement technique remaining consistent for all observers across reconstruction planes.
Quantitative measurements of scaphoid deformity have very limited reliability for individual observers, between different observers, and depending on the plane in which the image of the scaphoid is produced. Even the most reliable measure of deformity (height-to-length ratio) was not consistent between reconstruction planes. Unless more reliable scanning and measurement techniques are developed ideas about the effect of scaphoid deformity on wrist function will remain to a large degree speculative.
To clarify quantitatively the 3-dimensional deformity of the carpus in scaphoid nonunion on the basis of fracture location.
Three-dimensional computed tomography was used to examine 20 patients with scaphoid nonunion. Displacements of the distal and proximal fragments of the scaphoid, lunate, triquetrum, and capitate were visualized and quantified using a 3-dimensional image-matching technology. Cases were categorized as distal fracture (16 cases) or proximal fracture (4 cases) based on the location of the fracture line relative to the dorsal apex of the scaphoid ridge where the dorsal scapholunate interosseous ligament is attached.
The displayed distal scaphoid fractures showed that the proximal fragment of the scaphoid, lunate, and triquetrum rotated into extension and supination. The distal fragment of the scaphoid and capitate translated dorsally without notable rotation. The deformity in proximal fractures was less remarkable than that in distal fractures. Most distal scaphoid nonunions had dorsal intercalated segment instability deformity patterns, whereas a dorsal intercalated segment instability occurred in only 1 case of a proximal fracture.
Whether the fracture line passes distal or proximal to the dorsal apex of the scaphoid determines the subsequent carpal deformity. Dorsal translation of the distal fragment might be one of the factors in the development of degenerative change at the radial styloid.
Displacement is an important risk factor for nonunion of scaphoid wrist fractures. We compared computed tomography with radiographs with regard to their ability to detect displacement.
Six blinded observers rated thirty scaphoid fractures (ten displaced and twenty nondisplaced) with use of radiographs and computed tomography. The radiographs were evaluated separately from the computed tomography scans and then, in a third evaluation, the two imaging studies were reviewed simultaneously. The evaluations were repeated four weeks later. Observers were asked to evaluate specific measures of fracture displacement and then to judge the fracture as being displaced or nondisplaced.
Intraobserver reliability was better for computed tomography alone and the combination of radiographs and computed tomography than it was for radiographs alone (kappa values, 0.65, 0.63, and 0.54, respectively; all p<0.001). The interobserver reliability was also better for computed tomography alone and the combination of radiographs and computed tomography than it was for radiographs alone (kappa values, 0.43, 0.48, and 0.27, respectively; all p<0.001). The average sensitivity was 75% for radiographs alone, 72% for computed tomography alone, and 80% for both; the average specificity was 64%, 80%, and 73%, respectively; the average accuracy was 68%, 77%, and 75%, respectively. The positive predictive values (assuming a 5% prevalence of fracture displacement) were low (0.10, 0.13, and 0.16) and the negative predictive values were high (0.97, 0.98, and 0.99) for the radiographs, computed tomography, and combined modality.
Computed tomography improves the reliability of detecting scaphoid fracture displacement but has a more limited effect on accuracy, which remains <80%. The utility of computed tomography scans for diagnosing scaphoid fracture displacement is affected by the low prevalence of fracture displacement. This study suggests that computed tomography scans are useful for ruling out displacement but not for diagnosing it. We recommend that all scaphoid fractures be evaluated with computed tomography in order to rule out displacement.
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