Stuart, Michael J.

Background: As anterior cruciate ligament (ACL) reconstruction is performed increasingly in the United States, the rate of revision ACL reconstruction continues to rise. A paucity of literature exists with respect to repeat ACL revision surgery. Purpose: To evaluate the functional outcomes of patients who had undergone at least 2 revision ACL reconstructions. Study Design: Case series; Level of evidence, 4. Methods: The records of all patients who had undergone repeat revision ACL reconstructions between 1998 and 2009 were retrospectively reviewed. Data collected included patient demographics, operative findings, pre- and postoperative physical examination findings, radiographs, and Tegner, Lysholm, and International Knee Documentation Committee (IKDC) subjective scores. Results: Fifteen patients had undergone repeat revision ACL reconstruction during the study period. Mean age was 27 years (range, 18-57 years). Mean follow-up was 5 years (range, 2-10 years). At the time of repeat revision surgery, new tunnels were drilled in 9 of 15 (60%) cases. Of those, 8 of 9 (89%) were drilled because femoral tunnels were deemed “too anterior.” During repeat revision, 11 of 15 (73%) patients were noted to have a meniscal tear, and 9 of 15 (67%) had International Cartilage Repair Society (ICRS) grade 3 or 4 chondral lesions. Mean Lysholm score was 60 preoperatively and increased to 82 postoperatively ( P < .001). Mean preoperative IKDC score was 59, which increased to 80 postoperatively ( P < .001). Mean preoperative Tegner score was 6.0. Mean postoperative Tegner score was 4.5, with only 4 of 15 (27%) patients having returned to their prior activity level ( P < .001). Two patients (13%) sustained a traumatic rerupture. Presence of grade 3 or 4 chondral lesions and body mass index greater than 28 at the time of repeat revision were associated with a “fair” or “poor” outcome by Lysholm score ( P = .007 and P = .03, respectively) and IDKC subjective scoring ( P = .04 and P = .007, respectively). Conclusion: Repeat revision ACL reconstruction may improve the functional outcomes of patients who have failed revision ACL reconstruction. Most patients do not return to prior activity level following repeat revision. Presence of grade 3 or 4 chondral lesions and body mass index greater than 28 were associated with worse outcomes.

AbstractPurposeThe primary purpose of this study was to investigate the intra‐tester and inter‐tester reliability of the dial test using a handheld digital inclinometer. Additionally, we examined the responsiveness of the test, and side‐to‐side differences for meaningful comparison.Materials/methodsTwenty‐four healthy subjects (22.5 ± 2.8 years) participated in the study. The dial test was performed on both knees at 30° and 90° of knee flexion with the subject supine. While maintaining a neutral position of the ankle, an inclinometer was positioned parallel to the medial border of the foot to quantify external rotation of the tibia. Two examiners performed the dial test in a blinded manner. The minimal detectable change across repeated measures and side‐to‐side difference was calculated.ResultsIntra‐tester reliability for examiner 1 (E1) was 0.83 at 30° knee flexion and 0.89 at 90° knee flexion. Reliability values for examiner 2 (E2) were 0.86 at 30° and 0.87 at 90° knee flexion. Inter‐tester reliability was 0.74 at 30° and 0.83 at 90°. The minimal detectable change (MDC) for E1 at 30° was ±9.4° and ±7.4° at 90°. For E2, the MDC value was ±9.1° at 30° and ±8.3° at 90°. Ninety‐five percent limits of agreement for side‐to‐side difference was 16.1° and 11.3° ° for E1 at 30° and 90° and for E2 13.9° at 30° and 14.1° at 90°.ConclusionsThis instrumented dial test using a handheld digital inclinometer to measure external rotation can be performed with acceptable reliability in the clinical setting. A difference of 10° between two measurements on the same knee suggests that a meaningful change has occurred. For right to left comparison, differences greater than 15° suggest clinical significance.Level of evidenceIII.

AbstractPurposeThe purpose of this study is to determine whether the RetroScrew tibial fixation system offers a biomechanical advantage over the Delta screw for anterior cruciate ligament (ACL) reconstruction in cadaveric tibias with low bone mineral density (BMD).MethodsTen matched pairs of osteoporotic cadaveric tibiae underwent simulated ACL reconstruction using quadrupled hamstring grafts with one of the two tibial fixation constructs. Group 1 was fixed with the Delta screw (DS; 35‐mm antegrade biointerference screw), and group 2 was fixed with the RetroScrew system (RSS; 20‐mm retrograde and 17‐mm antegrade biointerference screws). Each construct was cyclically loaded (50–200 N, 1 Hz, 500 cycles) and subsequently loaded to failure (20 mm/s).ResultsAll specimens were osteoporotic without significant segmental (proximal, middle, and distal) BMD differences between groups by quantitative computed tomography (P = n.s.). A trend was noted for more construct failures due to graft slippage in the DS group (n = 3) over the RSS group (n = 1). There were no significant differences in cyclic displacement (P = n.s.), maximum cyclic stiffness (P = n.s.), maximum load at failure (P = n.s.), or pullout stiffness (P = n.s.) between groups.ConclusionsIn an osteoporotic cadaveric model, there was no significant biomechanical advantage of the RetroScrew system versus the Delta screw for tibial fixation in soft tissue graft ACL reconstruction. However, a trend toward lower graft fixation failure to cyclic loading was noted with the RetroScrew system.Level of evidenceBiomechanical comparative study, Level II.

AbstractPurposeThe purpose of this study is to determine the effect of bioabsorbable interference screw (BIS) tibial fixation with the Delta screw (antegrade) and RetroScrew (retrograde) on initial (time zero) intra‐articular graft tension in soft tissue anterior cruciate ligament (ACL) reconstruction in a cadaveric model.MethodsTen matched pairs of cadaveric tibias received one of two tibial fixation constructs using quadrupled hamstring grafts, Delta screw (antegrade) or the RetroScrew (retrograde). Each specimen was mounted to the materials testing device with the displacement force vector in line with the tibial tunnel. The construct was pre‐tensioned (10–30 N, 0.1 Hz, 10 cycles), a baseline tension of 25 N was introduced, and the change in intra‐articular graft tension before and after screw insertion was recorded.ResultsSegmental (proximal, middle, distal) BMD was utilized to assess BMD using quantitative computed tomography (qCT). The Delta screw had a higher maximum insertion torque (P = 0.03) and exhibited a larger increase in intra‐articular graft tension as compared to the RetroScrew (38.3 ± 17.9 N, 7.6 N ± 14.4, P = 0.004), respectively. There were no significant correlations between intra‐articular graft tension increase to maximum insertion torque (P = NS) or corresponding segmental BMD (P = NS).ConclusionsDelta screw tibial fixation (antegrade) in soft tissue ACL reconstruction significantly increases the initial intra‐articular graft tension as compared to RetroScrew screw fixation (retrograde) in this cadaveric model. Delta screw (antegrade) tibial fixation may increase initial quadrupled hamstring graft intra‐articular tension with currently accepted insertion techniques.

Background The medial patellofemoral ligament (MPFL) is the primary restraint to extreme lateral displacement and is typically disrupted with an acute lateral patellar dislocation. Patients who fail a comprehensive nonoperative program and experience recurrent lateral patellar instability episodes are candidates for surgical treatment. Current surgical procedures include a variety of proximal realignment techniques, including repair or reconstruction of the MPFL along with distal realignment of the tibial tubercle when indicated. Purpose The objective of this study was to review the clinical, functional, and radiographic outcomes of isolated MPFL repair for recurrent lateral patellar dislocation. Study Design Case series; Level of evidence, 4. Methods The records of all patients undergoing MPFL repair for recurrent patellar dislocation at the Mayo Clinic from 2001 to 2006 were retrospectively reviewed. Twenty-seven patients (29 knees) with an average age of 19 years (range, 11-32 years) were included in this study. Clinical, functional, and radiographic outcomes were assessed at an average of 4 years after surgery (range, 2-7 years), using recurrent instability as the primary end point. Results The success rate of MPFL repair for preventing recurrent dislocations was 72% (21 of 29 knees). Eight patients (28%) experienced a recurrent lateral patellar dislocation. Five of these patients required a reoperation, including two MPFL reconstructions, 1 tibial tubercle osteotomy with MPFL reconstruction, 1 tibial tubercle osteotomy with revision MPFL repair, and 1 revision MPFL repair. At final follow-up, the mean Lysholm and Kujala scores were 86 (range, 42-100) and 92 (range, 57-105), respectively. Postoperative radiographs revealed a mean patellofemoral congruence angle improvement of 27° (range, 5°-44°). The only statistically significant risk factor for failure was nonanatomical MPFL repair at the medial femoral condyle (P = .004). Conclusion Isolated repair of the MPFL for recurrent patellar instability is associated with a relatively high failure rate, but remains a viable surgical option if surgical technique principles are followed. The clinical success of this operation depends on restoration of the anatomical origin of the MPFL and careful patient selection.

AbstractPurposeNumerous surgical techniques have been described for the treatment of peroneal nerve palsy after knee dislocation with less than optimal outcomes. The purpose of this article is to present a review of the literature including modern surgical treatment options for peroneal nerve palsy after knee dislocation.MethodReview of the current body of literature relevant to the topic was undertaken and summarized accordingly. Mechanism of injury, pathology and prognosis as well as current and novel treatment options are presented.ResultsNeurolysis and nerve grafting results are dependant on nerve graft length, with documented recovery rates of only 44% for nerve grafts longer than 6 cm. Posterior tibial tendon transfer procedures have had reasonable success in allowing patients to return to ambulation without assistive devices; however, dorsiflexion strength on the affected side has been reported at only 30% that of the normal contralateral side, and return to activities more strenuous than walking has not been reported. Future concepts including partial nerve transfer of a motor branch of the tibial nerve to the peroneal nerve have been described, but no outcome data is currently available.ConclusionPeroneal nerve palsy after knee dislocation leads to significant functional impairment. Prior treatment strategies utilized for restoration of dorsiflexion and peroneal nerve function have yielded overall poor results. Newer surgical techniques are being developed and clinical trials are under way to evaluate their effectiveness.

AbstractPurposeThe purpose of this study was (1) to describe a staged protocol for management of the dislocated knee and (2) to describe clinical and functional outcomes for patients who received initial spanning external fixation as part of this protocol.MethodNine knees in 9 patients, consisting of 6 males and 3 females, mean age 30.4 (range 19–44) years with diagnosis or presumption of knee dislocation were treated with a protocol of stabilization with external fixator. Mean follow‐up was 24 (range 13–42) months. Indications for spanning external fixation included significant vascular injury, gross instability on examination with failure to maintain joint reduction, open knee dislocation, inability to tolerate mobilization in a brace. The standard protocol involved vascular examination including ankle‐brachial index, ligamentous examination (under anesthesia when applicable), stabilization with temporary joint spanning external fixator, thromboprophylaxis, reconstructive knee surgery, and standard rehabilitation.ResultsMean range of motion (ROM) was 97.4° (range 80°–150°, SD 20.75, median 127.5). Median IKDC score was 80 (range 30–95), and mean Lysholm score was 76.7 (range 46–95). Heterotopic ossification (HO) was noted in 4 knees (44%).ConclusionThe treatment algorithm utilized in this series for management of the dislocated knee demonstrated satisfactory clinical and functional outcomes. This staged protocol provides a management option for those patients who may be best served with initial spanning joint external fixation. Larger prospective studies are needed to fully understand the merit of staged protocols in this setting.

Background Osteochondritis dissecans lesions of the knee in adult patients frequently require surgical intervention. However, the ideal method of osteochondral fragment fixation remains uncertain. Purpose This study was undertaken to determine the clinical, functional, and radiographic outcomes of bioabsorbable fixation for unstable osteochondritis dissecans lesions involving the femoral condyles of the knee in skeletally mature patients. Study Design Case series; Level of evidence, 4. Methods Skeletally mature patients with an unstable osteochondritis dissecans lesion of the femoral condyle (Ewing and Voto stages II-IV) treated with bioabsorbable internal fixation and minimum 1-year follow-up were included in this retrospective study cohort. Pre- and postoperative radiographs were reviewed and postoperative Lysholm and International Knee Documentation Committee (IKDC) scores were documented. Results A total of 21 knees in 21 patients satisfied the inclusion criteria, and 3 patients were lost to follow-up. The remaining 18 patients were evaluated at a mean of 59 months after surgery (range, 12-154 months). The 14 male and 4 female patients had a mean age of 19 years at the time of surgery (range, 14-39 years). Ewing and Voto classification included 8 stage II lesions, 9 stage III lesions, and 1 stage IV lesion. Fragment fixation methods included bioabsorbable nails (11), pins (3), darts (2), screws (1), and combined screws and darts (1). Mean postoperative Lysholm and IKDC scores were 85 and 82, respectively. Fragment union occurred in 12 knees (67%); the remaining 6 knees (33%) required removal of the loose fragment. Of the 11 patients treated with bioabsorbable nails, 2 (18%) required reoperation for nail back-out. Conclusion The authors recommend caution when using bioabsorbable fixation for osteochondritis dissecans lesions in skeletally mature patients because of the low rate of clinical healing and high complication rate. Failure with unthreaded fixation devices may be caused by inadequate compression and not necessarily be related to bioabsorbability.