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ABSTRACT: BACKGROUND: Knowledge of patient activities after total elbow arthroplasty may help delineate the true functional gains obtained after replacement. Experience suggests that some patients may perform activities excessively demanding on elbow implants, but compliance with activity restrictions recommended after elbow arthroplasty is largely unknown. MATERIALS AND METHODS: All patients who underwent a primary or revision total elbow arthroplasty at a single institution from 2005 to 2007 were surveyed regarding their activity level. The University of California, Los Angeles (UCLA) activity score and Mayo Elbow Performance Score were assessed. Patients were also questioned about whether they recalled which activities were not recommended by their surgeon. RESULTS: One hundred thirteen completed surveys were analyzed. There were 29 men and 84 women with a mean age of 65 years. Of the patients, 64 had primary and 49 had revision operations. The mean Mayo Elbow Performance Score was 77 points (range, 15-100 points). The mean University of California, Los Angeles activity score was 5 points (range, 1-10 points). Moderate-demand activities were performed by 94% of patients, and high-demand activities were performed by 40% of patients. Male gender and a diagnosis of fracture/nonunion was associated with increased performance of high-demand activities (P < .05). Eighty percent of patients remembered receiving postoperative restrictions, and of these patients, 83% interpreted that they were compliant with their restrictions. CONCLUSION: Ninety-four percent of patients engaged in moderate-demand activities after total elbow arthroplasty. Forty percent engaged in high-demand activities. Factors correlated with more demanding activities included male gender and diagnosis of fracture/nonunion. The vast majority of patients remembered receiving postoperative restrictions.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 03/2013; · 1.93 Impact Factor
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ABSTRACT: Stress shielding is known to occur around rigidly fixed implants. We hypothesized that stress shielding around radial head prostheses is common but nonprogressive. In this study, we present a classification scheme to support our radiographic observations.
We reviewed charts and radiographs of 86 cases from 79 patients with radial head implants from both primary and revision surgeries between 1999 and 2009. Exclusion criteria included infection, loosening, or follow-up of less than 12 months. We classified stress shielding as: I, cortical thinning; II, partially (IIa) or circumferentially (IIb) exposed stem; and III, impending mechanical failure.
Of 26 well-fixed stems, 17 (63%) demonstrated stress shielding: I = 2, II = 15 (IIa = 12, IIb = 3), and III = 0. We saw stress shielding with all stem types: cemented or noncemented; long or short; and straight, curved, or tapered. The only significant difference was that stems implanted into the radial shaft had less stress shielding than stems implanted into the neck or tuberosity (P = .03). The average follow-up was 33 months (range, 13-70 mo). Stress shielding was detectable by an average of 11 months (range, 1-15 mo). The pattern of bone loss was similar in 16 of 17 cases (94%), starting on the outer periosteal cortex. The 3 cases with circumferential exposure of the stem (stage IIb) averaged 2.6 mm (range, 1-4 mm) of exposed stem. Stress shielding never extended to the bicipital tuberosity, and there were no cases of impending mechanical failure.
Stress shielding around radial head prostheses is common, regardless of stem design. However, it is typically minor, nonprogressive, and of questionable clinical consequence.
Therapeutic IV.
The Journal of hand surgery 10/2012; 37(10):2118-25. · 1.33 Impact Factor
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ABSTRACT: Management for Mason type II radial head fractures is controversial. We hypothesized that angulation or depression of a marginal radial head fragment would affect radiocapitellar stability similarly to fragment excision.
A Mason type II radial head fracture was created in 6 cadaveric elbows by excising a segment from the anterolateral quadrant that was 30% of the diameter of the articular surface. Radiocapitellar stability was recorded under 5 sets of conditions: (1) intact radial head (intact), (2) 30% surface area fragment resected (partially excised), (3) anatomic fragment fixation with screws (fixed), (4) fragment fixation with 2 mm of depression relative to the articular surface (depressed), and (5) fragment fixation after a 30° wedge resection (angulated).
The forces required to subluxate the joint were greatly reduced after fragment excision (5 ± 1 N; P = .0001) and restored to normal (21 ± 1 N; P = .9) after anatomic fixation of the excised fragment. The peak forces were significantly reduced with fragment depression (4 ± 1 N) and angulation (4 ± 2 N; P = .0001).
A radial head fracture that is depressed 2 mm or angulated 30° may cause up to an 80% loss of concavity-compression stability of the radiocapitellar joint.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 04/2012; 21(6):789-94. · 1.93 Impact Factor
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ABSTRACT: Osteointegration of press-fit radial head implants is achieved by limiting micromotion between the stem and bone. Aspects of stem design that contribute to the enhancement of initial stability (ie, stem diameter and surface coating) have been investigated. The importance of total prosthesis length and level of the neck cut has not been examined.
Cadaveric radii were implanted with cementless, porous-coated radial head stems. We resected 10, 12, 15, 20, and 25 mm of radial neck in each specimen. Stem-bone micromotion was measured after each cut. Values were expressed in terms of quotients (cantilever quotient).
A threshold effect was observed at 15 mm of neck resection (cantilever quotient, 0.4), with a significant increase in micromotion observed between 12 mm (40 ± 10 μm) and 15 mm (80 ± 25 μm). A cantilever quotient of 0.35 or less predicted implant stability, whereas implants with a cantilever quotient of 0.6 or more were unstable. In between, the stems were "at risk" of instability.
Initial stem stability of a porous-coated, cementless radial head implant is dependent on length of the implant stem within bone and the level of the cut (amount of bone resected). Stability may be compromised by an implant with a combined head and neck length that is too long compared with the stem length within the canal. We found a critical ratio of exposed prosthesis to total implant length (cantilever quotient of 0.4), which puts the prosthesis at risk of inadequate initial stability. These data carry important implications for implant design and use.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 03/2012; 21(11):1559-64. · 1.93 Impact Factor
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ABSTRACT: There have been reports of total radial head allografts showing variable outcomes. This case series reports the novel use of an allograft for partial radial head replacement in the treatment of elbow fracture-dislocation.
Eight patients underwent partial radial head allograft reconstruction to restore stability for complex fracture-dislocations involving fractures of the coronoid and radial head, with collateral ligament disruption. Two patients were treated acutely. Six were referred from other centers 2 to 48 weeks after injury following failure of primary treatment. In each case, it was not possible to perform stable open reduction-internal reduction of the radial head fracture, or the fracture fragment had already been excised. A fresh-frozen partial radial head allograft was used to replace the defect and restore the joint surface. The coronoid fracture and injury to collateral ligaments were also managed surgically. Patient charts, surgical records, and radiographs were reviewed. Patients were contacted at a mean of 79 months after treatment to answer questions to determine the Mayo Elbow Performance Score and the score on the shortened version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaire.
Clinical and radiologic reviews confirmed union of graft in all cases. None resorbed or collapsed. Three patients had resorption of the coronoid fragment resulting in poor outcomes, with one patient ultimately undergoing total elbow arthroplasty.
Partial radial head allograft may be a useful alternative to radial head prosthesis in unstable fracture-dislocations in which the radial head cannot be restored fully.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 03/2012; 21(3):396-404. · 1.93 Impact Factor
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ABSTRACT: A critical component of evaluating the outcomes after surgery to restore lost elbow motion is the range of motion (ROM) of the elbow. This study examined if digital photography-based goniometry is as accurate and reliable as clinical goniometry for measuring elbow ROM.
Instrument validity and reliability for photography-based goniometry were evaluated for a consecutive series of 50 elbow contractures by 4 observers with different levels of elbow experience. Goniometric ROM measurements were taken with the elbows in full extension and full flexion directly in the clinic (once) and from digital photographs (twice in a blinded random manner).
Instrument validity for photography-based goniometry was extremely high (intraclass correlation coefficient: extension = 0.98, flexion = 0.96). For extension and flexion measurements by the expert surgeon, systematic error was negligible (0° and 1°, respectively). Limits of agreement were 7° (95% confidence interval [CI], 5° to 9°) and -7° (95% CI, -5° to -9°) for extension and 8° (95% CI, 6° to 10°) and -7° (95% CI, -5° to -9°) for flexion. Interobserver reliability for photography-based goniometry was better than that for clinical goniometry. The least experienced observer's photographic goniometry measurements were closer to the reference measurements than the clinical goniometry measurements.
Photography-based goniometry is accurate and reliable for measuring elbow ROM. The photography-based method relied less on observer expertise than clinical goniometry. This validates an objective measure of patient outcome without requiring doctor-patient contact at a tertiary care center, where most contracture surgeries are done.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 01/2012; 21(1):29-35. · 1.93 Impact Factor
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ABSTRACT: To test the hypothesis that visual estimation by a trained observer is as accurate and reliable as clinical goniometry for measuring elbow range of motion.
Instrument validity and inter-observer reliability of visual estimation was evaluated on a consecutive series of 50 elbow contractures. Four observers with different levels of elbow experience first estimated extension and flexion of the contracted elbows and then measured them with a blinded goniometer.
Instrument validity for visually-based goniometry was extremely high. ICC scores were 0.97 for both extension and flexion estimations. Systematic error was negligible (1°) with upper limits of agreement being 9° (95% CI: 7°-11°) and 8° (95% CI: 6°-10°), respectively, for extension and flexion. For the expert surgeon, 92% of the visual estimates were within 5° of the value obtained by clinical goniometry. Between experienced observers (elbow surgeon and physician assistant), the ICC's were very high-0.96 for extension and 0.93 for flexion. The systematic errors were low, from -1° to 1° with upper limit of agreement being 11° (95% CI: 8°-14°). However, agreement was poor between an inexperienced study coordinator and the others (ICC's: 0.51-0.38, systematic errors: 8°-18°, upper limit of agreement: 32°-40°). The accuracy of the visual estimations made by the experienced elbow surgeon was as good as the measurements taken with a goniometer by the physician assistant or the clinical fellow and better than those taken by an inexperienced study coordinator.
The trained human eye is highly capable of accurately estimating the range of motion of the elbow, compared to conventional clinical goniometry, depending on the experience of the observer.
Diagnostic study, Level II.
Knee Surgery Sports Traumatology Arthroscopy 11/2011; 20(7):1378-85. · 2.21 Impact Factor
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ABSTRACT: Options for repair of distal biceps tendon ruptures are well-described. However, scant data exist in the literature regarding failure strength of the native tendon. We hypothesize that a) the distal biceps tendon failure strength is sensitive to loading angle, and b) the failure strength is greater than what has been previously reported in the literature.
15 radii were potted in a simulated supine position, and the native tendon was pulled from the tuberosity at angles of 90, 60, and 30° of flexion (5 per group) relative to the long axis of the radius. The failure load and stiffness were recorded and compared.
The native tendon's mean failure load tended to increase as flexion angle decreased. Due to the large variability in strength, mean failure loads of the 90° (mean 358 (SE 117N)), 60° (mean 617 (SE 141N)), and 30° (mean 762 (SE 130N)) groups were not statistically different from each other (P=0.12). The mean stiffness results for each group (mean 501 (SE 176N/mm), mean 763 (SE 226N/mm), and mean 756N (SE 179N/mm), respectively) were not significantly different from each other (P>0.6).
The load to failure of the distal biceps tendon may be higher than what has previously been reported, and may be dependent on the elbow flexion angle. Though this difference may be attributed to the difference in methodology it should be taken into account during consideration of repair and rehabilitation.
Clinical biomechanics (Bristol, Avon) 10/2011; 27(3):263-7. · 1.76 Impact Factor
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ABSTRACT: After post-traumatic radial head replacement, pain caused by a loose prosthesis might incorrectly be assumed to be post-traumatic. Reliable guidelines for diagnosing a symptomatic loose radial head prosthesis are lacking. We noted that pain from a loose stem within the proximal radius may present as proximal radial forearm pain.
The medical records and radiographs of 14 consecutive cases (13 patients) with proximal radial forearm pain associated with a loose radial head prosthesis were reviewed retrospectively. The indication for revision surgery was painful loosening of the prosthesis within the canal of the proximal radius in 7 patients (8 cases) and pain without preoperative confirmation of the loosening in 2 patients (2 cases). Various prosthetic designs had been used in the primary operations.
In 12 of 14 cases, the loosening was evident radiographically, but in 2 the only indication of a loose prosthesis (confirmed surgically) was proximal radial forearm pain. One patient was lost to follow-up. Revision or prosthetic removal eliminated the pain in 7 of 9 cases and decreased it in 1. One patient with moderate pain had an arthritic elbow and had no significant lasting relief from surgery. Follow-up averaged 27 months.
The presence of proximal radial forearm pain in a patient with a radial head prosthesis is an indicator of symptomatic mechanical loosening. If the prosthesis has a textured surface for bone ingrowth, and was inserted without cement, we now consider this a strong indicator of loosening, even in the absence of radiographic signs.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 08/2011; 21(1):92-7. · 1.93 Impact Factor
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ABSTRACT: Radial head prosthetic stems designed for bone ingrowth are available with both plasma spray and grit blasted surfaces. A recent study comparing micromotion between the 2 demonstrated greater micromotion in the plasma spray than grit blasted stems, even though the latter had lower surface roughness. This raised the question that perhaps the size mismatch for grit-blasted radial head stems (0.5 mm) might be inadequate for plasma spray stems.
A tighter initial press-fit with plasma spray radial head stems may be gained by preparation with an undersized rasp.
Paired cadaveric radii were implanted with plasma spray stems. The surgical control was prepared with a rasp designated for its corresponding stem size ("size-matched"), while the experimental group was prepared with a rasp 0.5 mm smaller than designated ("undersized").
The micromotion for the undersized rasp group (46 ± 12 μm) was not significantly different than for the size-matched rasp group (21 ± 12 μm) (P = .1).
Contrary to our hypothesis, no reduction in micromotion was observed when using an undersized rasp with a plasma spray stem. The micromotion results were not different from those observed when using a size-matched rasp, and actually approached significance in the opposite direction. This may be due to the rough stem surface chipping away bone fragments, rather than the bone being cut away precisely as is done with a rasp.
The use of an undersized rasp prior to implantation of a plasma spray radial head prosthesis does not confer any added benefit in terms of initial stability.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 08/2011; 21(7):955-60. · 1.93 Impact Factor
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ABSTRACT: Successful bone ingrowth around cementless implants requires adequate initial stability. Hoop stress fractures during stem insertion can potentially hinder prosthesis stability.
We hypothesized that an oversized radial head prosthetic stem (1 mm "too large" and causing a hoop stress fracture during insertion) would result in an unacceptable amount of micromotion.
Grit-blasted radial head prosthetic stems were implanted into cadaveric radii. Rasp and stem insertion energies were measured, along with micromotion at the stem tip. The sizes were increased until a fracture developed in the radial neck.
Prosthetic radial head stems that were oversized by 1 mm caused small cracks in the radial neck. Micromotion of oversized stems (42 ± 7 μm) was within the threshold conducive for bone ingrowth (<100 μm) and not significantly different from that for the maximum sized stems (50 ± 12 μm) (P ≥ .4).
Contrary to our hypothesis, hoop stress fractures caused by implantation of a stem oversized by 1 mm did not result in loss of stability. Stem micromotion remained within the range for bone ingrowth and was not significantly diminished after the fracture. This suggests that if a crack occurs during the final stages of stem insertion, it may be acceptable to leave the stem in place without adding a cerclage wire.
A small radial neck fracture occurring during insertion of a radial head prosthetic stem oversized by 1 mm does not necessarily compromise initial stability.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 08/2011; 21(7):949-54. · 1.93 Impact Factor
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ABSTRACT: Radial head prostheses are available with multiple geometric properties. The effect of design features on radiocapitellar stability has not been investigated.
The shape (depth and radius of curvature) of the articulating dish of a radial head prosthesis affects radiocapitellar stability.
Radiocapitellar stability due to concavity-compression was evaluated in 8 fresh frozen elbows before and after radial head replacement with 2 different designs of radial head implants (RH 1 and RH 2). Both functioned as monopolar implants. Peak forces resisting subluxation and force-displacement characteristics were compared between the 2 and to the native radial head.
Radial head design significantly affected radiocapitellar stability. RH 1, which had a deeper dish than RH 2, required significantly higher peak forces to subluxate the radiocapitellar joint. The peak subluxation forces and the slopes of the force-displacement curves were not significantly different from the native radial head for RH 1, but they were for RH 2.
The shape of the articular dish (depth, radius of curvature) of a monopolar radial head implant affects its contribution to radiocapitellar stability. An implant that mimics normal anatomy is more effective than a shallow radial head implant with a radius of curvature that is longer than normal.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 06/2011; 20(6):885-90. · 1.93 Impact Factor
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ABSTRACT: Radiocapitellar stability depends, in part, on concavity-compression mechanics. This study was conducted to examine the effects of the soft tissues on radiocapitellar stability with radial head prostheses.
Monopolar radial head implants are more effective in stabilizing the radiocapitellar joint than bipolar radial head prostheses, with the soft tissues intact or repaired.
Twelve fresh frozen elbow specimens were used to evaluate radiocapitellar stability with monopolar and bipolar radial heads. The study variables focused on varying soft tissue conditions and examined the mean peak subluxation forces put forth by each prosthesis design.
With the soft tissues intact, the mean peak force resisting posterior subluxation depended significantly on the radial head used (P = .03). Peak force was greatest for the native radial head (32 ± 7 N) and least with the bipolar prosthesis (12 ± 3 N), with the monopolar prosthesis falling in between (21 ± 4 N). The presence of soft tissues significantly affected the bipolar implant's ability to resist subluxation, though it did not significantly impact the native or monopolar radial heads.
This study reveals the dependence of radiocapitellar stability on soft tissue integrity, particularly for bipolar prostheses. Overall, monopolar prostheses have a better capacity to resist radiocapitellar subluxation.
From a biomechanical perspective, the enhancement of elbow stability with a monopolar radial head prosthesis is superior to that with a bipolar design. This is especially true when the integrity of the soft tissues has been compromised, such as in trauma.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 03/2011; 20(2):219-25. · 1.93 Impact Factor
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ABSTRACT: Initial stability of a textured surface prosthetic stem is necessary for bone in-growth. Surfaces currently used for radial head prostheses include titanium plasma spray and grit-blasted titanium.
Plasma spray radial head prosthetic stems are less dependent than grit-blasted stems on a tight press fit. Good initial press-fit stability, with acceptable micro-motion, can be achieved with a greater range of stem sizes using a plasma spray than grit-blasted surface.
Paired cadaveric radii were implanted with plasma spray or grit-blasted radial head prosthetic stems. Micromotion at the stem tip was measured under circumstances simulating eccentric loads.
Micromotion in the plasma spray (PS) stems (49 ± 37) μm was not better than that in the grit-blasted (GB) stems (28 ± 10) μm (P = .13). Micromotion of less than 100 μm was measured in all 12 GB stems that were maximum or 1 mm less than maximum size, versus 5/6, and 4/6 PS stems, respectively.
Micromotion in plasma spray prosthetic radial head stems was not better than that seen in grit-blasted stems, contrary to our initial hypothesis.
Grit-blasted prosthetic radial head stems confer initial press-fit stability that is as good as, or slightly better than, corresponding plasma spray stems. Acceptable amounts of micromotion can be achieved with 2 grit-blasted stem sizes and probably with 2 plasma spray stem sizes.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 02/2011; 20(5):717-22. · 1.93 Impact Factor
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ABSTRACT: Although most people can lead near-normal lives with a limited but functional arc of elbow motion, athletes may find loss of terminal extension severely impairing.
Arthroscopic contracture release is effective in restoring full elbow extension in athletes whose loss of terminal extension impairs their intensities and/or levels of performance in sport.
Case series; Level of evidence, 4.
Between 1997 and 2007, 24 athletes (26 elbows; mean age, 38 years [range, 12-58]) whose chief complaint was limited elbow extension (≤35°) underwent arthroscopic release of contractures (average follow-up, 33 months [range, 12-88]). All the patients were classified according to a sport-specific scoring system using the subjective patient outcome for return to sports score and the summary outcome determination score.
All 26 elbows improved subjectively and objectively with surgery. Of the 26 elbows, 25 were rated by the patients as normal (n = 15) or near-normal (n = 10) at final follow-up. Pain during intense sporting activities was absent in 17, mild and occasional without affecting performance in 6, and severe enough to affect performance in 1. Of the 24 patients (26 elbows), 22 patients (23 elbows) returned to the same sport at the same level of intensity and performance as before injury. Two patients (3 elbows) returned to the same sport but failed to reach their preinjury levels of performance. Extension improved in all patients, with the average flexion contracture decreasing from 27° ± 7° (range, 10°-35°) to 6° ± 9° (range, 10° of hyperextension to 25°; P < .001). Lack of extension was not a residual impairment factor in any patients. Three patients developed delayed-onset ulnar neuropathy after surgery, 2 of which were treated by subcutaneous transposition. All 3 resolved completely, 2 within the first 6 weeks; the other took longer than a year.
The arthroscopic release of contractures is a predictable technique to achieve a highly functional elbow in athletes.
The American journal of sports medicine 12/2010; 38(12):2509-15. · 3.61 Impact Factor
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ABSTRACT: Compared to fully textured prosthetic stems, partial texturing lessens bone loss due to stress shielding and makes removal easier. However, initial press-fit stability is necessary for bone ingrowth.
There is no significant difference in the initial stability of radial head prostheses that are partially grit-blasted compared to those that are fully grit-blasted.
Cadaveric radii were implanted with partial or fully grit-blasted radial head prostheses. Micromotion of the stem at the isthmus of the canal and stem tip were measured under circumstances simulating eccentric loads.
Micromotion was not significantly different in the fully grit-blasted stems (isthmus, 11 ± 1 μm; tip, 21 ± 2 μm) and partially grit-blasted stems (isthmus, 13 ± 2 μm; tip, 25 ± 2 μm) (P = 0.4). The direction of loading had no effect on micromotion characteristics in either the fully or partially grit-blasted stems (P = .07).
Micromotion is comparable in partially and fully grit-blasted radial head prosthetic stems. For both stem surfaces, micromotion was well within the range that is conducive for bone ingrowth. A partially textured stem might have less bone loss due to stress shielding, making it easier to remove without destroying bone.
The initial stability of a radial head stem that is partially grit-blasted only at the proximal end is comparable to that of a radial head stem that is grit-blasted along its entire length.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 10/2010; 20(1):27-32. · 1.93 Impact Factor
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ABSTRACT: The purpose of this study was to investigate the effect of directional fluid flow on periosteal chondrogenesis. Periosteal explants were harvested from 2-month-old rabbits and sutured onto poly-epsilon-caprolactone (PCL) scaffolds with the cambium layer facing away from the scaffolds. The periosteum/PCL composites were cultured in suspension in spinner flask bioreactors and exposed to various fluid flow velocities: 0, 20, 60, and 150 rpm for 4 h each day for 6 weeks. The application of fluid flow significantly increased percent cartilage yield in periosteal explants from 17% in the static controls to 65-75% under fluid flow (there was no significant difference between 20, 60, or 150 rpm). The size of the neocartilage was also significantly greater in explants exposed to fluid flow compared with static culture. The development of zonal organization within the engineered cartilage was observed predominantly in the tissue exposed to flow conditions. The Young's modulus of the engineered cartilage exposed to 60 rpm was significantly greater than the samples exposed to 150 and 20 rpm. These results demonstrate that application of directional fluid flow to periosteal explants secured onto PCL scaffolds enhances cell proliferation, chondrogenic differentiation, and cell organization and alters the biomechanical properties of the engineered cartilage.
Journal of Biomedical Materials Research Part A 10/2010; 95(1):156-63. · 2.63 Impact Factor
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ABSTRACT: Chronic longitudinal radioulnar dissociation has been associated with unpredictable and generally unfavorable outcomes. Metallic radial head replacement may address this treatment deficiency.
Eight patients were treated with a metallic radial head replacement for chronic longitudinal radioulnar dissociation. The average treatment delay was 3.3 years. All eight patients were seen for a clinical and radiographic assessment.
Five of the 8 failed after a mean of 3 years (range, 1-5.7). Revision to bipolar metallic radial head replacement was successful in the short term in 2 of 3 that failed from aseptic loosening. One of 2 failures due to painful radiocapitellar arthritis was salvaged with a capitellar replacement.
Reconstruction for symptoms following an Essex-Lopresti injury remains problematic. A metallic radial head implant appears to be an effective adjunct, but not a perfect solution in all patients. Recognition of the negative impact of residual lateral ulnar collateral ligament laxity is an important observation and should be specifically addressed with the reconstructive procedure.
Metallic monoblock radial head replacement did not reliably address the functional deficiency from chronic radioulnar dissociation primarily due to malalignment and implant loosening. A cemented bipolar radial head implant may provide a better alternative as a long-term solution. Regardless, ligamentous integrity at the elbow should also be addressed at the time of the reconstruction.
Journal of shoulder and elbow surgery / American Shoulder and Elbow Surgeons ... [et al.] 09/2010; 19(6):929-36. · 1.93 Impact Factor
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ABSTRACT: The purpose of this study was to document management strategies and complications relating to the use of anteromedial portals for elbow arthroscopy in a series of patients with subluxating or previously transposed ulnar nerves.
A review of 913 elbow arthroscopies showed that 59 elbows with a subluxating or previously transposed ulnar nerve required anterior compartment arthroscopic surgery. The patients with subluxating nerves had proximal anteromedial portals established by reducing and holding the nerve behind the epicondyle with a thumb while establishing or entering the portal. In cases of prior nerve transposition, the following techniques were used if, by palpation, localization of the ulnar nerve was considered to be (1) unequivocal, (2) equivocal, or (3) impossible: In group 1 (unequivocal) the proximal anteromedial portal was established in the normal antegrade fashion. In group 2 (equivocal) a 1-cm incision was made at the planned proximal anteromedial portal site and blunt dissection down to the capsule was performed without identification of the nerve. In group 3 (impossible) a 2- to 4-cm skin incision was made and the nerve was identified before placement of the portal.
We found that 59 elbows in 56 patients had a subluxating ulnar nerve (31 elbows) or previous ulnar nerve transposition (28 elbows). The transposition had been subcutaneous in 21 and submuscular in 7. The proximal anteromedial portal was used in all but 3 cases (2 patients) of submuscular transposition that were early in the series. In those cases only 2 lateral portals were used for anterior compartment surgery. There were no operative ulnar nerve injuries related to the use of the proximal anteromedial portal.
Neither elbow arthroscopy nor specifically the use of the proximal anteromedial portal is contraindicated in patients with prior transposition or subluxation of the ulnar nerve. The management of the nerve can be based on the degree of certainty with which the nerve can be localized by palpation in the region of the planned portal.
Level IV, therapeutic case series.
Arthroscopy The Journal of Arthroscopic and Related Surgery 08/2010; 26(8):1045-52. · 3.02 Impact Factor
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ABSTRACT: The purpose of this report is to describe and demonstrate the potential advantages of a technique to image the distal biceps tendon using a medial approach: the pronator window.
Distal biceps tendon imaging via the medial approach was shown using real-time sonography on an asymptomatic volunteer as well as cadaveric anatomic dissection.
The medial approach images the biceps tendon with minimal anisotropy while providing several potential advantages, including (1) complete visualization of the ulnarly facing radial tuberosity and the tapered distal biceps insertion, (2) increased contrast and reduced beam attenuation at the interface between the biceps tendon and overlying brachial artery, and (3) avoidance of the beam-attenuating effects of the supinator encountered when imaging the tendon from a lateral approach.
The medial approach to image the distal biceps tendon complements previously described techniques and should be considered in the evaluation of patients presenting with distal biceps tendon disorders. Future clinical studies may elucidate the relative advantages and disadvantages of sonographic distal biceps imaging techniques in specific patient populations.
Journal of ultrasound in medicine: official journal of the American Institute of Ultrasound in Medicine 05/2010; 29(5):861-5. · 1.25 Impact Factor
