Faculty Bibliography

BACKGROUND:Autologous osteochondral transplantation (AOT) is used to treat osteochondral lesions (OCLs) of the talus, typically reserved for lesions greater than 150 mm(2). Few studies exist examining the functional and magnetic resonance imaging (MRI) outcomes following this procedure. The purpose of this study was to investigate functional and MRI outcomes, including quantitative T2 mapping following AOT. METHODS:Eighty-five consecutive patients who underwent AOT were identified. Functional outcomes were assessed pre- and postoperatively using the Foot and Ankle Outcome Score (FAOS). The Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score was used to assess cartilage incorporation. Quantitative T2 MRI relaxation time of graft tissue and adjacent normal cartilage values were recorded in a subset of 61 patients. The mean clinical follow-up was 47.2 months, with mean MRI follow-up of 24.8 months. RESULTS:Mean FAOS improved pre- to postoperatively from 50 to 81 (P < .001). The mean MOCART score was 85.8. Lesion size was negatively correlated with MOCART score (r = -0.36, P = .004). Superficial T2 values in graft tissue were higher than control tissue (42.0 vs 35.8, P < .001). Deep T2 values in graft tissue were similar to the control values (30.9 vs 30.0, P = .305). Functional outcomes were similar in patients irrespective of whether they had previous microfracture or concomitant procedures. CONCLUSION/CONCLUSIONS:AOT was an effective treatment for large OCLs of the talus in the current study. MOCART scoring indicated good structural integrity of the graft. Quantitative T2 mapping suggests that graft tissue may not always mirror native hyaline cartilage. The long-term implications of this are not yet known. LEVEL OF EVIDENCE/METHODS:Level IV, case series.

PURPOSE/OBJECTIVE:The purpose of this systematic review was to report the effects of gastrocnemius recession on ankle dorsiflexion range of motion, function, and push-off power. METHODS:The MEDLINE and EMBASE databases were reviewed with terms "gastrocnemius recession". The inclusion criteria were: (1) clinical studies, (2) published in a peer-reviewed journal within the past 10 years, and (3) published in English. Excluded were: (1) review articles, (2) cadaveric studies, (3) studies including patients under the age of 18 years, (4) studies evaluating a neurologic condition, (5) level of evidence 5, and (6) Quality of Evidence Score <3. Data were then extracted and analysed for trends. The PearlDiver Database was also used to review de-identified patient information retrospectively between 2007 and 2011. RESULTS:Full-text review yielded 23 articles that fit the inclusion criteria. Twenty-one of 23 (91%) and 2/23 (9%) studies were level of evidence 4 and 3, respectively. Twelve of 23 (52%) studies reported follow-up assessment between 12 and 36 months, and no studies reported longer-term follow-up. Twelve of 12 (100%) studies reported improved dorsiflexion range of motion 9/9 (100%) reported improved AOFAS, and 11/11 (100%) reported improved VAS. Five of 23 (22%) studies reported strength in a measured and controlled fashion with variable results, but of these, no study reported a return to normal power. The mean complication rate was 14%. CONCLUSION/CONCLUSIONS:The available evidence supports that GR improves functional outcomes and increases dorsiflexion range of motion. Furthermore, GR affects gait kinematics, which may cause compensatory effects at the knee, ankle, and subtalar joints. Evidence has shown that power does not return to normal levels. Clinicians may utilize these data clinically to determine whether patients may benefit from GR or not. LEVEL OF EVIDENCE/METHODS:IV.

BACKGROUND:While successful subtalar joint arthrodesis provides pain relief, resultant alterations in ankle biomechanics need to be considered, as this procedure may predispose the remaining hindfoot and tibiotalar joint to accelerated degenerative changes. However, the biomechanical consequences of isolated subtalar joint arthrodesis and additive fusions of the Chopart's joints on tibiotalar joint biomechanics remain poorly understood. QUESTIONS/PURPOSES/OBJECTIVE:We asked: What is the effect of isolated subtalar fusion and sequential Chopart's joint fusions of the talonavicular and calcaneocuboid joints on tibiotalar joint (1) mechanics and (2) kinematics during loading for neutral, inverted, and everted orientations of the foot? METHODS:We evaluated the total force, contact area, and the magnitude and distribution of the contact stress on the articular surface of the talar dome, while simultaneously tracking the position of the talus relative to the tibia during loading in seven fresh-frozen cadaver feet. Each foot was loaded in the unfused, intact control condition followed by three randomized simulated hindfoot arthrodesis modalities: subtalar, double (subtalar and talonavicular), and triple (subtalar, talonavicular, and calcaneocuboid) arthrodesis. The intact and arthrodesis conditions were tested in three alignments using a metallic wedge insert: neutral (flat), 10° inverted, and 10° everted. RESULTS:Tibiotalar mechanics (total force and contact area) and kinematics (external rotation) differed owing to hindfoot arthrodeses. After subtalar arthrodesis, there were decreases in total force (445 ± 142 N, 95% CI, 340-550 N, versus 588 ± 118 N, 95% CI, 500-676 N; p < 0.001) and contact area (282 mm(2), 95% CI, 222-342 mm(2), versus 336 ± 96 mm(2), 95% CI, 265-407 mm(2); p < 0.026) detected during loading in the neutral position; these changes also were seen in the everted foot position. Hindfoot arthrodesis also was associated with increased external rotation of the tibiotalar joint during loading: subtalar arthrodesis in the neutral loading position (3.3° ± 1.6°; 95% CI, 2°-4.6°; p = 0.004) and everted loading position (4.8° ± 2.6°; 95% CI, 2.7°-6.8°; p = 0.043); double arthrodesis in neutral (4.4° ± 2°; 95% CI, 2.8°-6°; p = 0.003) and inverted positions (5.8° ± 2.6°; 95% CI, 3.7°-7.9°; p = 0.002), and triple arthrodesis in all loaded orientations including neutral (4.5° ± 1.8°; 95% CI, 3.1°-5.9°; p = 0.002), inverted (6.4° ± 3.5°; 95% CI, 3.6°-9.2°; p = 0.009), and everted (3.6° ± 2°; 95% CI, 2°-5.2°; p = 0.053) positions. Finally, after subtalar arthrodesis, additive fusions at Chopart's joints did not appear to result in additional observed differences in tibiotalar contact mechanics or kinematics with the number of specimens available. CONCLUSIONS:Using a cadaveric biomechanical model, we identified some predictable trends in ankle biomechanics during loading after hindfoot fusion. In our tested specimens, fusion of the subtalar joint appeared to exert a dominant influence over ankle loading. CLINICAL RELEVANCE/CONCLUSIONS:A loss or deficit in function of the subtalar joint may be sufficient to alter ankle loading. These findings warrant consideration in the treatment of the arthritic hindfoot and also toward defining biomechanical goals for ankle arthroplasty in the setting of concomitant hindfoot degeneration or arthrodesis.

The objective of this study was to evaluate the effect of chemical tissue bonding (CTB) on adhesion strength, fluid permeability, and cell viability across a cartilaginous graft-host interface in an in vitro autologous chondral transplant (ACT) model. Chitosan-based cross-linkers; Chitosan-Rose Bengal [Chi-RB (Ch-ABC)], Chitosan-Genipin [Chi-GP (Ch-ABC)], and Chitosan-Rose Bengal-Genipin [Chi-RB-GP (Ch-ABC)] were applied to bovine immature cartilage explants after pre-treatment with surface degrading enzyme, Chondroitinase-ABC (Ch-ABC). Adhesion strength, fluid permeability and cell viability were assessed via mechanical push-out shear testing, fluid transport and live/dead cell staining, respectively. All three chitosan-based cross-linkers significantly increased the adhesion strength at the graft-host interface, however, only a statistically significant decrease in fluid permeability was noted in Chi-GP (Ch-ABC) specimen compared to untreated controls. Cell viability was maintained for 7 days of culture across all three treatment groups. These results show the potential clinical relevance of novel chitosan-based hydrogels in enhancing tissue integration and reducing synovial fluid penetration after ACT procedures in diarthoidal joints such as the knee and ankle. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1139-1146, 2016.

Football is the most popular sport worldwide and is associated with a high injury rate, most of which are the result of trauma from player contact. Ankle injuries are among the most commonly diagnosed injuries in the game. The result is reduced physical activity and endurance levels, lost game time, and considerable medical cost. Sports medicine professionals must employ the correct diagnostic tools and effective treatments and rehabilitation protocols to minimize the impact of these injuries on the player. This review examines the diagnosis, treatment, and postoperative rehabilitation for common football injuries of the ankle based on the clinical evidence provided in the current literature.

PURPOSE/OBJECTIVE:The primary purpose of this study was to evaluate clinical outcomes following peroneal tendoscopy for the treatment of peroneal pathology. Correlation between pre-operative magnetic resonance imaging (MRI) and peroneal tendoscopic diagnostic findings was also assessed. METHODS:Twenty-three patients with a mean age of 34 ± 8.8 years undergoing peroneal tendoscopy were pre- and post-operatively assessed with the foot and ankle outcome score (FAOS) and the Short Form-12 (SF-12) outcome questionnaires. Follow-up was over 24 months in all patients. The sensitivity and specificity of MRI were calculated in comparison with peroneal tendoscopy, including the positive predictive value (PPV). RESULTS:Both the FAOS and the SF-12 improved significantly (p < 0.05) at a mean follow-up of 33 ± 7.3 months significantly. MRI showed an overall sensitivity of 0.90 (95% confidence interval (CI) = 0.82-0.95) and specificity of 0.72 (95% CI 0.62-0.80). The PPV for MRI diagnosis of peroneal tendon pathology was 0.76 (95% CI 0.68-0.83). CONCLUSIONS:The current study found good clinical outcomes in patients with peroneal tendon disorders, treated with peroneal tendoscopy. Although a relatively small number of patients were included, the study suggests good correlation between tendoscopic findings and pre-operative MRI findings of peroneal tendon pathology, supporting the use of MRI as a useful diagnostic modality for suspected peroneal tendon disorders. LEVEL OF EVIDENCE/METHODS:Level IV, retrospective case series.

PURPOSE/OBJECTIVE:The purpose of this study was to assess the effect(s) of platelet-rich plasma (PRP) on osteochondral donor site healing in a rabbit model. METHODS:Osteochondral donor sites 3 mm in diameter and 5 mm in depth were created bilaterally on the femoral condyles of 12 New Zealand White rabbits. Knees were randomized such that one knee in each rabbit received an intra-articular injection of PRP and the other received saline (placebo). Rabbits were euthanized at 3, 6, and 12 weeks following surgery. Repair tissue was evaluated using the International Cartilage Repair Society (ICRS) macroscopic and histological scores. RESULTS:No complications occurred as a result of the interventions. There was no significant difference in macroscopic scores between the 2 groups (5.5 ± 3.8 vs. 3.8 ± 3.5; P = 0.13). Subjective macroscopic assessment determined greater tissue infill with fewer fissures and a more cartilage-like appearance in PRP-treated knees. Overall ICRS histological scores were better in the PRP group compared with the placebo (9.8 ± 2.0 vs. 7.8 ± 1.8; P = 0.04). Histological scores were also higher in the PRP group compared with the placebo group at each time point. Greater glycosaminoglycan and type II collagen content were noted in the repair tissue of the PRP group compared with the placebo group. CONCLUSION/CONCLUSIONS:The results of this study indicate that PRP used as an intra-articular injection may improve osteochondral healing in a rabbit model.

PURPOSE:To determine if functional outcomes and magnetic resonance imaging (MRI) outcomes were significantly different between patients receiving primary autologous osteochondral transplantation (AOT) and patients receiving secondary AOT surgery after failed microfracture. METHODS:A group of 76 patients enrolled into the Foot and Ankle Service between 2006 and 2012 was retrospectively analyzed. Patient-reported outcomes were evaluated in 76 patients using the Foot and Ankle Outcome Score (FAOS). Superficial and deep tissues at the repaired defect site, as well as the adjacent normal cartilage, were analyzed using quantitative T2 mapping MRI. Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) allowed for morphological evaluation of the repair tissue. The mean clinical follow-up time was 51 ± 23 months (range, 12 to 97 months), and the mean MRI follow-up time was 26 months (range, 24 to 36 months). RESULTS:Twenty-two patients received primary AOT and 54 received secondary AOT after failed microfracture. Patient characteristics between groups were similar with regard to age, gender, lesion size, and follow-up time. The mean postoperative FAOS was 10 points higher in the primary AOT group (83.2 ± 17.0) compared with the secondary AOT group (72.4 ± 19.4) (P = .01). Regression analysis showed that secondary AOT patients preoperative to postoperative change in FAOS was 9 points lower than in primary AOT patients after adjustment for age, preoperative FAOS, and lesion size (P = .045). The mean MOCART score, superficial T2 and deep T2 values, and the difference between normal and repair cartilage T2 values were not significantly different between groups. Lesion size was negatively correlated with MOCART scores (ρ = -0.2, P = .04), but positively correlated with difference in T2 values between repair and adjacent normal cartilage in the superficial layer (ρ = 0.3, P = .045). CONCLUSIONS:Primary AOT shows better functional outcomes compared with secondary AOT after failed microfracture in patients with similar characteristics and lesion size. No significant differences in T2 mapping relaxation times and MOCART scores were identified. LEVEL OF EVIDENCE:Level III, case control study.

Arthroscopic and open ankle arthrodesis have been compared in very few studies, and no consensus has been reached regarding the incidence of postoperative revision surgery associated with each technique. The purpose of the present study was to compare these 2 approaches for the incidence of postsurgical operations. Patients who had undergone either arthroscopic or open ankle arthrodesis were identified between January 2005 to December 2011 in the PearlDiver(™) database using a predetermined algorithm and searched for the following postsurgical operations: revision ankle arthrodesis, midfoot arthrodesis, and hindfoot arthrodesis. In the current database, 7322 cases were performed with an open technique and 1152 arthroscopically. The incidence of revision arthrodesis was not significantly different statistically between the 2 techniques. However, the incidence of subsequent adjacent joint arthrodesis was greater for the open cohort (5.6% versus 2.6%; odds ratio 2.17, 95% confidence interval 1.49 to 3.16). In the open cohort, the incidence of hindfoot arthrodesis was greater than the incidence of midfoot arthrodesis (3.9% versus 1.6%, odds ratio 2.43, 95% confidence interval 1.95 to 3.01). The results showed that although open ankle arthrodesis is more commonly performed, it is associated with a greater incidence of subsequent adjacent joint arthrodesis specifically in the hindfoot.

BACKGROUND:Autologous osteochondral transplantation (AOT) has an inherent risk of donor site morbidity (DSM). The reported rates of DSM vary from 0% to 50%, with few studies reporting clinical or imaging outcomes at the donor site as a primary outcome and even fewer report these outcomes when a biosynthetic plug backfill is employed. Although TruFit (Smith & Nephew, Andover, MA) plugs have been removed from the market for regulatory purposes, biphasic plugs (including TruFit plugs) have been used for several years and the evaluation of these is therefore pertinent. METHODS:Thirty-nine patients who underwent forty AOT procedures of the talus, with the donor graft being taken from the ipsilateral knee, were included. Postoperative magnetic resonance imaging (MRI) was used to assess the donor site graded with magnetic resonance observation of cartilage repair tissue (MOCART) scoring. Lysholm scores were collected preoperatively, at the time of magnetic resonance imaging (MRI), and again at 24 months and at final follow-up to assess clinical outcomes. Statistical analysis was performed to establish if there was any correlation between MRI assessment of the donor site and clinical outcomes. The mean patient age was 36.2 ± 15.7 years with a mean follow-up of 41.8 ± 16.7 months. RESULTS:All patient donor site defects were filled with OBI TruFit biphasic plugs. DSM was encountered in 12.5% of the patient cohort at 24 months, and in these patients, the Lysholm score was a mean 87.2 ± 5.0. At final follow-up, DSM was reduced to 5%. Lysholm scores for the entire cohort were 98.4 ± 4.6 and 99.4 ± 3.1 at 24 months and final follow-up, respectively. MRI of the donor sites were taken at an average of 18.1 ± 13.5 (range, 3-48) months postoperatively and the mean MOCART score was 60.0 ± 13.5. No correlation was found between the MOCART score and Lysholm outcomes at the donor knee (P = .43, r = 0.13). CONCLUSION/CONCLUSIONS:Low incidence of DSM and good functional outcomes were achieved with AOT. Additionally, MRI findings did not predict clinical outcomes in our study. LEVEL OF EVIDENCE/METHODS:Level IV, retrospective case series.