[Show abstract][Hide abstract] ABSTRACT: uni kompartimentellen Kniegelenkar throse beim aktiven Patienten stellt den Orthopäden vor schwierige Ent scheidungen. Vor den operativen Ver sorgungsmöglichkeiten mittels ar throskopischem Débridement, knor pelerhaltenden Prozeduren, der Um stellungsosteotomie sowie der uni und bikompartimentellen Kniege lenkprothese steht zunächst die kon servative Therapie. Neben dem Ein satz von physiotherapeutischer Übungsbehandlung, nonsteroidalen Antiphlogistika, Analgetika, intraar tikulären Injektionen mittels Gluko kortikoiden, Lokalanästhetika und Hy aluronsäure werden verschiedene symptomatischen Therapien wie Ultra schalltherapie, Akkupunktur, Elek trotherapie eingesetzt. Darüber hi naus stellt der Einsatz valgisieren der Knieorthesen (sog. "unloader bra ces") eine weitere Möglichkeit der Be handlung dar. Ein wichtiger Einflussfaktor sowohl für die Entstehung, als auch für die Progres-sion der medialen Gonarthrose ist das Ausmaß der Varusdeformität [5, 26]. Ein vergrößertes Adduktionsmoment (Va-rus) des Kniegelenks führt zu einer me-dialen Verschiebung der Belastungsach-se, wodurch die einwirkende Kraft und die Kompression des medialen Kompar-timents erhöht werden . Die daraus resultierende Überlastung des medialen Kompartiments kann den medialen Knie-gelenkschmerz verstärken und zu einer Progression des medialen Kniegelenkar-throse führen [2, 12, 15, 20]. Bereits ein Varus von 4–6° kann den Druck im medialen Kompartiment wäh-rend des Einbeinstands zwischen 70 und 90 % erhöhen . Behandlungsmetho-den zur Reduktion der Druckbelastung im medialen Kniegelenkkompartiment sind daher von großem Interesse.
[Show abstract][Hide abstract] ABSTRACT: Unicondylar knee replacement (UKA) is a viable alternative to high tibial osteotomy (HTO) and total knee replacement in the treatment of medial osteoarthritis of the knee. With the correct indication, the results of UKA and HTO are comparable.
[Show abstract][Hide abstract] ABSTRACT: Changes of patellar position (height, tilt, and shift) and arthritis of the patellofemoral joint might potentially influence outcome after unicompartmental knee replacement.
[Show abstract][Hide abstract] ABSTRACT: The present article summarizes the different osteotomy techniques for an extension of standard surgical approaches to the knee joint in selected patients. The aim is to achieve satisfactory exposure and reduce potential postoperative complications compared to alternative techniques, such as the V-Y plasty or the quadriceps snip procedures. Osteotomy of the tibial tubercle is a reasonable extension of the anteromedial or the anterolateral surgical approach in selected patients undergoing revision total knee replacement. This osteotomy will provide excellent surgical exposure of the knee without the risk of avulsion of the patellar tendon and will preserve the blood supply of the patella and the surrounding soft tissue. Moreover, functional clinical outcome will be improved by minimizing damage to the extensor mechanism. Osteotomy of the lateral femoral condyle gives excellent exposure of the posterolateral aspect of the knee joint which might be necessary in some patients with fractures of the posterolateral tibial plateau as well as patients undergoing open allograft transplantation of the lateral meniscus. An alternative option for an extended exposure to the posterolateral knee joint is accomplished by osteotomy or partial resection of the fibular head which is also described as having good clinical results and a low complication rate.
[Show abstract][Hide abstract] ABSTRACT: The increasing number of total hip arthroplasty procedures lead to an increasing number of revision surgeries. The trochanteric osteotomy technique is an established procedure in selected cases with the necessity of extending the usual surgical approach. Trochanteric osteotomy is also successfully performed in other areas, such as trauma surgery and joint-preserving surgery (surgical dislocation). Several techniques for trochanteric osteotomy are availably employing various fixation techniques and implants. This article presents the most common trochanteric osteotomy techniques for extension of the surgical approach (the classical according to Charnley, the trochanter slide, the extended trochanteric, and the stepped osteotomy) as well as clinical results and biomechanical experiences.
[Show abstract][Hide abstract] ABSTRACT: The decrease of femoral offset might play a role in the emergence of hip spacer dislocations, but it has not been discussed in the literature yet. The present work describes a technique for femoral offset adjustment. Either a bended blade plate or a dynamic hip screw can be used. The depth of the insertion and the angle of the particular implant are defined by the size of the offset adjustment required in each case. The described technique is feasible to produce a customized hip spacer, allowing for the preservation of an adequate muscle tension by individual adjustment of the femoral offset between stages.
Journal of surgical technique and case report. 01/2013; 5(1):18-20.
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND:The double-row suture bridge repair was recently introduced and has demonstrated superior biomechanical results and higher yield load compared with the traditional double-row technique. It therefore seemed reasonable to compare this second generation of double-row constructs to the modified single-row double mattress reconstruction. HYPOTHESIS:The repair technique, initial tear size, and tendon subregion will have a significant effect on 3-dimensional (3D) cyclic displacement under additional static external rotation of a modified single-row compared with a double-row rotator cuff repair. STUDY DESIGN:Controlled laboratory study. METHODS:Rotator cuff tears (small to medium: 25 mm; medium to large: 35 mm) were created in 24 human cadaveric shoulders. Rotator cuff repairs were performed as modified single-row or double-row repairs, and cyclic loading (10-60 N, 10-100 N) was applied under 20° of external rotation. Radiostereometric analysis was used to calculate cyclic displacement in the anteroposterior (x), craniocaudal (y), and mediolateral (z) planes with a focus on the repair constructs and the initial tear size. Moreover, differences in cyclic displacement of the anterior compared with the posterior tendon subregions were calculated. RESULTS:Significantly lower cyclic displacement was seen in small to medium tears for the single-row compared with double-row repair at 60 and 100 N in the x plane (P = .001) and y plane (P = .001). The results were similar in medium to large tears at 100 N in the x plane (P = .004). Comparison of 25-mm versus 35-mm tears did not show any statistically significant differences for the single-row repairs. In the double-row repairs, lower gap formation was found for the 35-mm tears (P ≤ .05). Comparison of the anterior versus posterior tendon subregions revealed a trend toward higher anterior gap formation, although this was statistically not significant. CONCLUSION:The tested single-row reconstruction achieved superior results in 3D cyclic displacement to the tested double-row repair. Extension of the initial rupture size did not have a negative effect on the biomechanical results of the tested constructs. CLINICAL RELEVANCE:Single-row repairs with modified suture configurations provide comparable biomechanical strength to double-row repairs. Furthermore, as increased gap formation in the early postoperative period might lead to failure of the construct, a strong anterior fixation and restricted external rotation protocol might be considered in rotator cuff repairs to avoid this problem.
The American journal of sports medicine 11/2012; · 3.61 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: Biplanar open-wedge high tibial osteotomy (HTO) is thought to promote rapid bone healing due to the increased cancellous bone surface compared to other HTO techniques. However, precise data on the bone surface area and wedge volume resulting from both open- and closed-wedge HTO techniques remain unknown. We hypothesized that biplanar rather than uniplanar HTO better reflects the ideal geometrical requirements for bone healing, representing a large cancellous bone surface combined with a small wedge volume. METHODS: Tibial saw bones were assigned to 4 different groups of valgisation high tibial osteotomies: group 1: open-wedge uniplanar HTO; group 2: open-wedge biplanar HTO with ascending frontal cut; group 3: open-wedge biplanar HTO with descending frontal cut (retrotubercule osteotomy technique), and group 4: closed-wedge uniplanar HTO. Bone surface areas of all osteotomy planes were quantified. Wedge volumes were determined using a prism-based algorithm, applying standardized wedge heights of 5, 10, and 15 mm. RESULTS: The open-wedge biplanar osteotomy with a descending frontal cut (group 3) created significantly larger bone surfaces compared to the "classic" biplanar technique with an ascending frontal cut (group 2) and compared to all uniplanar techniques. Bone surfaces after the classic open-wedge technique (group 2) were slightly larger compared to all uniplanar techniques (group 1 and 4). No significant differences of wedge volumes were found between the retrotubercle (group 3) and classic open-wedge techniques (group 2). Wedge volumes were significantly higher in the uniplanar open-wedge technique (group 1) compared to the biplanar open-wedge techniques (group 2 and 3). CONCLUSION: Bone geometry following HTO suggests that the biplanar open-wedge techniques simultaneously create smaller wedge volumes and larger bone surface areas compared to the uniplanar open-wedge techniques. The relatively neglected closed-wedge technique still offers in theory the best healing potential, characterized by an almost absent wedge volume and a large bone-to-bone contact area. Although this idealized geometric view on bony geometry excludes all biologic factors that influence bone healing, the current data suggest a general rule for the applied standard osteotomy techniques and all of their surgical modifications: reducing the amount of slow gap healing and simultaneously increasing the area of faster contact healing may be beneficial for osteotomy healing. Thus, a biplanar rather than a uniplanar osteotomy may be performed for high tibial osteotomy in clinical practice.
Knee Surgery Sports Traumatology Arthroscopy 02/2012; · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: Influence of the initial rotator cuff tear size and of different subregions of the SSP tendon on the cyclic loading behavior of a modified single-row reconstruction compared to a suture-bridging double-row repair. METHODS: Artificial tears (25 and 35 mm) were created in the rotator cuff of 24 human cadaver shoulders. The reconstructions were performed as a single-row repair (SR) using a modified suture configuration or a suture-bridge double-row repair (DR). Radiostereometric analysis was used under cyclic loading (50 cycles, 10-180 N, 10-250 N) to calculate cyclic displacement in three different planes (anteroposterior (x), craniocaudal (y) and mediolateral (z) level). Cyclic displacement was recorded, and differences in cyclic displacement of the anterior compared to the posterior subregions of the tendon were calculated. RESULTS: In small-to-medium tears (25 mm) and medium-to-large tears (35 mm), significant lower cyclic displacement was seen for the SR-reconstruction compared to the DR-repair at 180 N (p ≤ 0.0001; p = 0.001) and 250 N (p = 0.001; p = 0.007) in the x-level. These results were confirmed in the y-level at 180 N (p = 0.001; p = 0.0022) and 250 N (p = 0.005; p = 0.0018). Comparison of the initial tear sizes demonstrated significant differences in cyclic displacement for the DR technique in the x-level at 180 N (p = 0.002) and 250 N (p = 0.004). Comparison of the anterior versus the posterior subregion of the tendon revealed significant lower gap formation in the posterior compared to the anterior subregions in the x-level for both tested rotator cuff repairs (p ≤ 0.05). CONCLUSIONS: The tested single-row repair using a modified suture configuration achieved superior results in three-dimensional measurements of cyclic displacement compared to the tested double-row suture-bridge repair. The results were dependent on the initial rupture size of the rotator cuff tear. Furthermore, significant differences were found between tendon subregions of the rotator cuff with significantly higher gap formation for the anterior compared to the posterior subregions.
Knee Surgery Sports Traumatology Arthroscopy 01/2012; · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The present article summarizes current trends in arthroscopic rotator cuff repairs focusing on the used repair technique, potential influencing factors on the results, and long-term outcome after reconstruction of the rotator cuff. Moreover, different treatment options for the treatment for irreparable rotator cuff ruptures were described, and the results of additional augmentation of the repairs with platelet-rich plasma were critically analyzed. Based on the current literature, double-row repairs did not achieve superior clinical results compared to single-row repairs neither in the clinical results nor in the re-rupture rate. Multiple factors such as age, fatty infiltration, and initial rupture size might influence the results. If the rupture is not repairable, various options were described including cuff debridement, partial repair, tuberoplasty, or tendon transfers. The additional augmentation with platelet-rich plasma did not reveal any significant differences in the healing rate compared to conventional rotator cuff repairs. LEVEL OF EVIDENCE: IV.
[Show abstract][Hide abstract] ABSTRACT: The present article summarizes the development of a simple, objective, and non-invasive measurement device for tibiofemoral rotation to assess static rotational knee laxity.
The device is based on the dial test with the patient lying prone and the knee flexed to 30°. From measurements of 30 healthy participants, the device achieved high inter- and intra-observer reliability and showed a high correlation of the measured results with the contralateral knees of the participants. Measurements of the device were also performed in a human cadaver study and revealed highly correlated results when compared to the simultaneous measurements of a knee navigation system, which was used as an invasive standard method to assess tibial rotation. In human cadaver specimens, it was shown that a simulated tear of the posterolateral bundle as well as a complete ACL tear led to a significant increase in isolated tibiofemoral rotation compared to the intact ACL. A retrospective case series investigated the clinical results as well as knee laxity measurements after ACL surgery in vivo. Rotational, as well as anteroposterior (AP), knee laxity was objectively assessed in 52 patients at a mean postoperative follow-up of 27 months by comparing the measured results with the results of the contralateral unaffected knee in each patient. The clinical results were comparable to the results reported in the literature. Moreover, rotational laxity was successfully restored after ACL reconstruction, whereas AP laxity showed significant differences compared to the contralateral knees although they were defined as clinically successful according to the IKDC classification.
A non-invasive and objective knee rotational measurement device has been developed, which offers good potential for objective quality control in knee ligament injuries and their treatment.
Review article, Level IV.
[Show abstract][Hide abstract] ABSTRACT: The literature data on patellar height following unicompartmental knee arthroplasty (UKA) are scarce.
A total of 41 knee joints in 37 patients after UKA were prospectively evaluated for patellar height by using the Insall-Salvati and modified Insall-Salvati ratio. Patellar height was measured preoperatively, postoperatively, at 6, 12 weeks, and, at 1 year postoperatively. Patients were categorized according to age, gender, operated side, and rehabilitation program.
Regarding all the patients, the Insall-Salvati ratio demonstrated a significant decrease only for the time period "postoperatively-1 year postoperatively", whereas the modified Insall-Salvati ratio showed a significant decrease only for the period "preoperatively-postoperatively". The Insall-Salvati ratio showed a significant decrease in the patellar height of men and left knees, whereas the modified Insall-Salvati ratio revealed a significant decrease in patients older than 65 years and those who followed a specific rehabilitation program.
The decrease in the patellar height after UKA occurs within the first postoperative year. Women, right knees, patients younger than 65 years and those who do not follow a specific rehabilitation program are less prone to decrease in the patellar height; ratio-specific differences are evident for each subgroup.
Diagnostic study, Level III.
[Show abstract][Hide abstract] ABSTRACT: To compare the biomechanical properties and footprint coverage of a single-row (SR) repair using a modified suture configuration versus a double-row (DR) suture-bridge repair in small to medium and medium to large rotator cuff tears.
We created 25- and 35-mm artificial defects in the rotator cuff of 24 human cadaveric shoulders. The reconstructions were performed as either an SR repair with triple-loaded suture anchors (2 to 3 anchors) and a modified suture configuration or a modified suture-bridge DR repair (4 to 6 anchors). Reconstructions were cyclically loaded from 10 to 60 N. The load was increased stepwise up to 100, 180, and 250 N. Cyclic displacement and load to failure were determined. Furthermore, footprint widths were quantified.
In the 25-mm rupture, ultimate load to failure was 533 ± 107 N for the SR repair and 681 ± 250 N for the DR technique (P ≥ .21). In the 35-mm tear, ultimate load to failure was 792 ± 122 N for the SR reconstruction and 891 ± 174 N for the DR reconstruction (P ≥ .28). There were no statistically significant differences for both tested rupture sizes. Cyclic displacement showed no significant differences between the tested configurations at 60 N (P = .563), 100 N (P = .171), 180 N (P = .211), and 250 N (P = .478) for the 25-mm tear. For the 35-mm tear, cyclic displacement showed significantly lower gap formation for the SR reconstruction at 180 N (P = .037) and 250 N (P = .020). No significant differences were found at 60 N (P = .296) and 100 N (P = .077). A significantly greater footprint width (P = .028) was seen for the DR repair (16.2 mm) compared with the SR repair (13.8 mm). However, both reconstructions were able to achieve complete footprint coverage compared with the initial footprint.
The tested SR repair using a modified suture configuration was similar in load to failure and cyclic displacement to the DR suture-bridge technique independent of the tested initial sizes of the rupture. The tested DR repair consistently restored a larger footprint than the SR method. However, both constructs achieved complete footprint coverage.
SR repairs with modified suture configurations might combine the biomechanical advantages and increased footprint coverage that are described for DR repairs without increasing the overall costs of the reconstruction.
Arthroscopy The Journal of Arthroscopic and Related Surgery 11/2011; 28(2):178-87. · 3.10 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: PURPOSE: Since in vivo stability following high tibial osteotomy is unknown, surgeons customize the postoperative rehabilitation to the assumed implant stability, leaving us with numerous rehabilitation protocols. The purpose of the study is to quantify the fixation stability of different open-wedge high tibial osteotomy implants. It is hypothesized that the higher fixation stability of a plate fixator justifies early weight bearing. METHODS: In this prospective 30-subject clinical trial, fixation stability was determined over a 2-year period using radiostereometric analysis (RSA). Patients were assigned to two angle-stable osteotomy plates: a spacer plate with 6 postoperative weeks of feather-touch weight bearing versus a plate fixator with 2 postoperative weeks of feather-touch weight bearing. RESULTS: Postoperative RSA data showed a significant higher lateral translation of the distal tibia and a significantly increased subsidence, varus and internal rotation of the tibial head in the spacer plate compared to the plate fixator group. Weight bearing following spacer plate fixation induced significant micromotion 6 weeks after surgery. Three months after surgery, bone healing was achieved regardless of the used implant. CONCLUSIONS: Early weight bearing is appropriate for plate fixator fixation. The 6-week period of delayed weight bearing following spacer plate fixation is inadequate and should be prolonged presumably up to 8-10 weeks to avoid pseudarthrosis and/or recurrence of varus angulation. LEVEL OF EVIDENCE: Level II, diagnostic study-investigating a diagnostic test.
Knee Surgery Sports Traumatology Arthroscopy 10/2011; · 2.68 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The goal of the present study was to evaluate static anteroposterior and rotational knee laxity after ACL reconstructions with two noninvasive measurement devices by comparing the measured results of the operated with the contralateral healthy knees of the patients.
Fifty-two consecutive patients were reviewed after isolated single-bundle transtibial ACL reconstruction using a BPTB graft. At a mean follow-up of 27 months, sagittal AP laxity was tested using a noninvasive knee measurement system (Genourob) with an applied pressure of 67 N, 89 N and 134 N. Rotational laxity was measured using a noninvasive rotational knee laxity device (Rotameter) with an applied torque of 5, 8 and 10 Nm. The results were compared with the measurements of the patients' healthy contralateral knees. Tegner, Lysholm and IKDC score were used in order to evaluate the clinical outcome.
Pivot shift was negative (33) or glide (16) in 49 patients with 12 of 16 (75%) patients having also a pivot glide on the healthy contralateral side; Lachman tests were negative in 50 cases. Subjective assessment of the IKDC score was classified according to category A in 44 patients, B in 5 patients and C in 3 patients. Mean Lysholm score was 94.5 ± 9.5, median Tegner score was 7 (3-9) preoperative and 6 (3-9) at follow-up (n.s.). Anteroposterior knee laxity measurements revealed mean side-to-side differences of 0.6-1.3 mm (P < 0.0001). Rotational laxity measurements revealed no statistical significant differences between the operated and the contralateral knee (n.s.). The measured differences in the entire rotational range varied from 0.2° to 1° depending on the applied torque. In those 3 patients with a positive pivot shift, differences in the entire rotational range of 4.5° at 5 N, 4.6° at 8 N and 4.1° at 10 N were found.
Static knee laxity was quantified after ACL surgery using the introduced noninvasive measurement systems by comparing the measured results of the operated with the contralateral healthy knees. Significant differences were found in AP laxity although they were defined as clinically successful according to the IKDC classification. No significant differences were found in rotational knee laxity measurements. Therefore, the used noninvasive masurement devices might offer a high potential for objective quality control in knee ligament injuries and their treatment.
Retrospective case series, Level IV.
[Show abstract][Hide abstract] ABSTRACT: Achieving an adequate restoration of the muscle-tendon-bone unit and the anatomical footprint is essential for a successful outcome in open and arthroscopic rotator cuff repair. The described suture grasping technique using triple-loaded suture anchors might combine high initial fixation strength with good footprint coverage. It describes two mattress' stitches medial at the articular margin of the tendon. Additionally, a third mattress stitch is performed laterally to increase footprint contact and avoid dog-ear deformity. The triple-mattress repair is easy to perform and might be a good alternative in either arthroscopic or open rotator cuff repair.
Archives of Orthopaedic and Trauma Surgery 03/2011; 131(8):1073-6. · 1.36 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of this prospective study was to evaluate the patellar height in 90° knee flexion.
A total of 85 patients with 95 knee joints were included in the study. Patellar height was measured according to the Blackburne-Peel, Labelle-Laurin, Insall-Salvati, Linclau, and Caton-Deschamps methods in the whole group and in subgroups based on age, gender, and side.
The BP-ratio showed a patella norma in 45 cases, and in 25 cases a patella alta and infera, respectively. The Labelle-Laurin method determined a patella norma in eight knees, in 35 a patella alta and in 52 a patella infera. The IS-ratio revealed a patella norma in 52 patients, a patella alta in six and in 37 a patella infera. The Linclau method demonstrated in 52 cases a patella norma, in 17 a patella alta and in 26 a patella infera. The CD-ratio showed the highest values of a patella norma among all tested methods in 67 knees, whereas a patella alta was evident in 13 and a patella infera in 15 cases. In the subgroups, discrepancies depended on the subgroup and method used.
Our results demonstrate a method-dependent discrepancy in the measurement of patellar height. A future study should evaluate this effect in a direct comparison between 30° and 90° knee flexion.
International Orthopaedics 03/2011; 35(12):1791-7. · 2.32 Impact Factor