Adam B. Yanke

Prospective Evaluation of Concurrent Meniscus Transplantation and Articular Cartilage Repair Minimum 2-Year Follow-Up

Background Recognition of the symbiotic relationship between the meniscus and articular cartilage is critical to the success of meniscal allograft transplantation. Simultaneous combined meniscal allograft transplantation and cartilage restoration procedures have been proposed for patients with a symptomatic postmeniscectomy knee with a focal chondral defect that would have traditionally been considered a contraindication to meniscal allograft transplantation. Hypothesis Combined meniscal allograft transplantation and cartilage restoration procedures can be used to neutralize traditional contraindications to meniscal allograft transplantation with results comparable to either procedure performed in isolation. Study Design Case series; Level of evidence, 4. Methods Thirty patients underwent 31 combined meniscal allograft transplantation and cartilage restoration procedures between 1997 and 2004. These patients were prospectively studied, and completed standardized outcome surveys (including Lysholm, International Knee Documentation Committee, and Short Form-12 scales) preoperatively and annually thereafter for a minimum of 2-year follow-up. Patients were grouped according to concomitant procedure: 16 (52%) underwent meniscal allograft transplantation combined with autologous chondrocyte implantation; 15 (48%) had meniscal allograft transplantation combined with an osteochondral allograft. Two patients were lost to follow-up, leaving 29 procedures for review. Results As a combined group, statistically significant improvements were observed in all standardized outcomes scores and satisfaction scales, except Short Form-12 mental, at a mean 3.1-year follow-up. Excluding the 2 lost to follow-up, 76% of all study participants (80% autologous chondrocyte implantation; 71 % osteochondral allograft) reported that they were completely (31 %) or mostly (45%) satisfied with their results. Overall, 48% of patients (60% autologous chondrocyte implantation; 36% osteochondral allograft) were classified as normal or nearly normal at their most recent follow-up using the International Knee Documentation Committee examination score. Ninety percent of patients would have the surgery again. Conclusion Combined meniscal allograft transplantation and cartilage restoration offers a safe alternative for patients with persistent symptoms after meniscectomy and focal cartilage injury. Results of combined procedures were comparable to published reports of these procedures performed in isolation. Long-term follow-up is needed to define the survivorship of these procedures in a young patient population.

Long-Term Effects of Bupivacaine on Cartilage in a Rabbit Shoulder Model

Background Previous investigations have reported on the chondrotoxicity of bupivacaine in short-term in vivo and in vitro models. This study was designed to provide additional information on the long-term effects of bupivacaine infusion on articular cartilage in an established rabbit shoulder model. Hypothesis Infusion of bupivacaine into the rabbit shoulder will have long-term deleterious effects on articular cartilage. Study Design Controlled laboratory study. Methods Thirty-six rabbits were randomized into 3 groups and were infused over 48 hours with saline (S), bupivacaine alone (B), or bupivacaine with epinephrine (B+E) into the glenohumeral joint. Animals were sacrificed after 3 months, and tissue samples were analyzed with live/dead cell assay, proteoglycan (PG) synthesis and content assays, and conventional histological evaluation. Results No macroscopic or radiographic changes were detected in the infused shoulders. Sulfate uptake of infused shoulders relative to controls was elevated to 112% ± 39% (S), 166% ± 67% (B), and 210% ± 127% (B+E). Statistical analysis of PG content demonstrated significantly increased levels in bupivacaine groups compared with saline. There were no significant differences among groups in cell count, percentage of living cells, or histological grade. Conclusions No permanent impairment of cartilage function was detected 3 months after intra-articular infusion of bupivacaine. Cartilage metabolism was increased, indicating a possible reparative response. This suggests that, at least in the model used, articular cartilage has the ability to recover from the chondrotoxic effects of bupivacaine infusion. Before extrapolating these results to human cartilage, other factors including underlying cartilage injury or disease, decreased chondrocyte density, and increased bupivacaine dosing need to be taken into account. Clinical Relevance Bupivacaine toxicity has recently been implicated in the development of chondrolysis after arthroscopic shoulder procedures, but these findings suggest that additional noxious stimuli might be required before permanent damage ensues.

Outcomes of Autologous Chondrocyte Implantation in a Diverse Patient Population

Background Autologous chondrocyte implantation is indicated as a second-line treatment of large, irregularly shaped chondral defects after failure of first-line surgical intervention. This study examines the clinical results of a patient cohort undergoing autologous chondrocyte implantation and elucidates factors associated with subjective improvement after implantation. Hypothesis Autologous chondrocyte implantation will result in long-term functional and symptomatic improvement. Study Design Case series; Level of evidence, 4. Methods The cohort included 137 subjects (140 knees) who underwent autologous chondrocyte implantation of the knee. Mean defect size per patient was 5.2 ± 3.5 cm2 (range, 0.8-26.6 cm2). Patients averaged 30.3 ± 9.1 years of age (range, 13.9-49.9 years) and were followed for 4.3 ± 1.8 years (range, 2.0-9.7 years). Outcomes were assessed via clinical assessment and established outcome scales, including the Lysholm scale, International Knee Documentation Committee scale, and Short Form-12. Results A significant improvement after surgery was observed in all outcome assessments including the Lysholm (41 to 69; P < .001) and International Knee Documentation Committee (34 to 64; P < .001) scales. Subjectively, 75% of patients indicated they were completely or mostly satisfied with the outcome and 83% would have the procedure again. Preoperatively, 32% of patients had a Tegner score of 6 or greater, compared with 82% before injury and 65% at most recent follow-up. Multivariate analysis identified age (P < .021) and receiving workers’ compensation (P < .018) as independent predictors of follow-up Lysholm score. Twenty-one patients (16%) required debridement of the autologous chondrocyte implantation site secondary to persistent symptoms, whereas 9 knees (6.4%) clinically failed and underwent a revision procedure. Conclusion Autologous chondrocyte implantation is a viable treatment option for chondral defects of the knee, resulting in durable functional and symptomatic improvement. Age and workers’ compensation status are independent predictors of outcome.

Minced articular cartilage--basic science, surgical technique, and clinical application.

Minced articular cartilage procedures are attractive surgical approaches for repairing articular cartilage, as they are 1-staged, autologous, and inserted on a carrier that can potentially be placed arthroscopically. The principle of mincing the autologous donor cartilage is to create a larger surface area for cartilage expansion. Placement on a scaffold carrier allows for a chondro-inductive and chondro-conductive milieu. Early animal and preclinical models have demonstrated hyaline-like tissue repair. Further work needs to be conducted in this promising approach.

Biceps tendinitis in chronic rotator cuff tears : A histologic perspective

Patients with chronic rotator cuff tears frequently have anterior shoulder pain attributed to the long head of the biceps brachii (LHBB) tendon. In this study, tenodesis or tenotomy samples and cadaveric controls were assessed by use of immunohistochemical and histologic methods to quantify inflammation, vascularity, and neuronal plasticity. Patients had moderate pain and positive results on at least 1 clinical test of shoulder function. The number of axons in the distal LHBB was significantly less in patients with biceps tendinitis. Calcitonin gene-related peptide and substance P immunostaining was predominantly within nerve roots and blood vessels. A moderate correlation (R = 0.5) was identified between LHBB vascularity and pain scores. On the basis of these results, we conclude that, in the context of rotator cuff disease, the etiology of anterior shoulder pain with macroscopic changes in the biceps tendon is related to the complex interaction of the tendon and surrounding soft tissues, rather than a single entity.

Meniscal Allograft Size Can Be Predicted by Height, Weight, and Gender

PURPOSE Our purpose was to determine if height, weight, and gender can be used to accurately predict proper meniscal allograft dimensions. METHODS Data were obtained from the Joint Restoration Foundation (AlloSource, Centennial, CO) regarding meniscal size and patient characteristics from meniscal donors. Donor height, weight, sex, age, and anatomic meniscal dimensions were recorded for 930 donor menisci in 664 patients. Multivariate regressions were completed using gender, height, and weight as independent variables and lateral meniscus length, lateral meniscus width, medial meniscus length, and medial meniscus width as dependent variables. The regression formulas were then reapplied to the data in order to produce estimated meniscus dimensions based on donor height, weight, and gender. A 90:10 split of the data was used to validate the regression models. Predicted meniscal size was then compared to actual meniscal size and the results compared to current measurement techniques. RESULTS Regression formulas showed the ability to predict meniscal size based on gender, height, and weight with standard deviations (SDs) equal to or less than current radiographic techniques (SD, 6.4% to 8.2%). Average differences between predicted size and actual size ranged from 5.2% to 6.5% for length and 5.2% to 6.0% for width. Patient height was found to be a much more powerful predictor of meniscal size than patient weight. Data from the 90:10 split of data validated the model on an independent sample. These validated outputs were then compared to contemporary techniques and found to have lower SDs and average error rates in the majority of cases. CONCLUSIONS We have proposed a validated regression model that uses height, weight, and gender variables to accurately predict required allograft meniscal size. We compared it against previously published data for radiographic and magnetic resonance imaging sizing techniques and found it to produce results that were, overall, slightly more accurate. CLINICAL RELEVANCE This model provides a novel method for sizing meniscal allografts.

Endoscopic repair of full-thickness abductor tendon tears: surgical technique and outcome at minimum of 1-year follow-up.

PURPOSE The purpose of this study was to assess the surgical outcomes of endoscopically repaired full-thickness abductor tendon tears using validated outcome measures. METHODS After institutional review board approval was obtained, clinical outcome data were retrospectively collected from patients who underwent endoscopic gluteus medius and/or minimus repair by a single surgeon between August 2009 and September 2011. With a minimum follow-up of 1 year, patients were evaluated using the modified Harris Hip Score and the validated Hip Outcome Score (HOS). The HOS questionnaire included 2 subsections: HOS-Activities of Daily Living and HOS-Sports. Physical examination data were gathered during routine clinic visits, 1 year postoperatively. Statistical analysis was descriptive. The change in strength testing postoperatively was assessed with the Wilcoxon signed rank test, with significance set at P ≤ .05. RESULTS Twelve patients were identified, 1 of whom was excluded; 10 of 11 patients (91%) completed the study requirements. The mean patient age was 65.9 years (range, 60 to 74 years), 70% were women, and the mean follow-up period was 23 months (range, 13 to 38 months). The mean postoperative scores were 84.7 (SD, 14.5) for the modified Harris Hip Score and 89.1 (SD, 11.3) for the HOS-Activities of Daily Living, with 90% patient satisfaction. All patients had clinically and statistically improved abductor tendon strength (P = .004). Patients with good to excellent outcomes were younger (P < .001). There were no complications identified. CONCLUSIONS In our small series, endoscopic abductor tendon repair was an effective surgical intervention after failed conservative management at short-term follow-up. Patients had reliably good to excellent outcomes with improved strength during hip abduction, were at low risk of complications, and were satisfied with the outcome. In addition, younger patients achieved better outcomes. LEVEL OF EVIDENCE Level IV, therapeutic case series.

The Biomechanical Effects of 1.0 to 1.2 Mrad of Gamma Irradiation on Human Bone–Patellar Tendon–Bone Allografts

Background: Recent data suggest that anterior cruciate ligament (ACL) reconstruction with irradiated allograft tissue may lead to increased failure rates. Hypothesis: Low-dose (1.0-1.2 Mrad) gamma irradiation does not significantly alter the preimplantation biomechanical properties of bone–patellar tendon–bone (BTB) allografts. Study Design: Controlled laboratory study. Methods: Cyclic and failure mechanical properties were evaluated for 20 paired central-third human BTB allografts, with and without 1.0 to 1.2 Mrad of gamma irradiation. Testing included cyclic loading at 0.5 Hz for 100 cycles from 50 to 200 N and failure testing at a strain rate of 10% per second. Results: Cyclic elongation did not change significantly (P = .151) with irradiation, increasing from a mean ± SD of 9.4 ± 2.1 mm to 11.3 ± 3.4 mm. Cyclic creep strain approached a significant increase with irradiation (1.3% ± 0.8% to 2.6% ± 1.5%; P = .076). Failure testing was not affected with irradiation with regard to maximum load (1680 ± 417 mm to 1494 ± 435 mm), maximum stress (40.8 ± 10.6 MPa to 37.5 ± 15.7 MPa), elongation (7.85 ± 1.35 mm to 8.67 ± 2.05 mm), or strain at maximum stress (0.158 ± 0.03 to 0.175 ± 0.03). Graft stiffness significantly decreased by 20% with irradiation (278 ± 67 N/mm to 221 ± 50 N/mm; P = .035). Conclusion: Low-dose (1.0-1.2 Mrad) gamma irradiation decreases BTB graft stiffness by 20%, but it does not affect other failure or cyclic parameters. Clinical Relevance: Aside from graft stiffness during load to failure testing, low-dose (1.0-1.2 Mrad) gamma irradiation of central-third human BTB allografts is not deleterious to preimplantation biomechanical properties.

Arthroscopic Treatment of Multidirectional Shoulder Instability With Minimum 270° Labral Repair: Minimum 2-Year Follow-up

PURPOSE The purpose of this study was to analyze results of arthroscopic stabilization with labral repair in a subset of patients with multidirectional shoulder instability and frank labral tear. METHODS A review of 13 patients (10 male and 3 female; mean age, 27.2 years) with multidirectional instability involving a labral tear of 270 degrees or greater requiring arthroscopic labral repair was performed at a mean follow-up of 56 months (range, 29 to 72 months). All patients were evaluated by use of the Short Form 12, Western Ontario Shoulder Instability Index, Simple Shoulder Test, American Shoulder and Elbow Surgeons score, and visual analog pain scale. Physical examination included range of motion, strength testing, and stability testing. RESULTS Of the 13 patients, 2 (15%) had recurrent instability after repair (subluxation or dislocation). Of the patients, 9 (69%) were completely satisfied, 2 (15%) were mostly satisfied, and 2 (15%) were completely unsatisfied. At final follow-up, the median scores were as follows: Western Ontario Shoulder Instability Index, 471; American Shoulder and Elbow Surgeons score, 96.7; Simple Shoulder Test score, 12; visual analog pain scale, 0; and Short Form 12 mental component/physical component, 57/44. There were no differences in range of motion compared with the opposite extremity. Cybex strength testing (Lumex, Ronkonkoma, NY) did show a statistically different difference in forward elevation (P < .005). There were no complications, and no patient has undergone reoperation. CONCLUSIONS Arthroscopic stabilization with labral repair in patients with multidirectional instability and a minimum 270 degrees labral pathology provided good results (85%) in terms of pain relief and clinical stability at a minimum 2-year follow-up.

Medial Versus Lateral Supraspinatus Tendon Properties Implications for Double-Row Rotator Cuff Repair

Background Rotator cuff repair retear rates range from 25% to 90%, necessitating methods to improve repair strength. Although numerous laboratory studies have compared single-row with double-row fixation properties, little is known regarding regional (ie, medial vs lateral) suture retention properties in intact and torn tendons. Hypothesis A torn supraspinatus tendon will have reduced suture retention properties on the lateral aspect of the tendon compared with the more medial musculotendinous junction. Study Design Controlled laboratory study. Methods Human supraspinatus tendons (torn and intact) were randomly assigned for suture retention mechanical testing, ultrastructural collagen fibril analysis, or histologic testing after suture pullout testing. For biomechanical evaluation, sutures were placed either at the musculotendinous junction (medial) or 10 mm from the free margin (lateral), and tendons were elongated to failure. Collagen fibril assessments were performed using transmission electron microscopy. Results Intact tendons showed no regional differences with respect to suture retention properties. In contrast, among torn tendons, the medial region exhibited significantly higher stiffness and work values relative to the lateral region. For the lateral region, work to 10-mm displacement (1592 ± 261 N-mm) and maximum load (265 ± 44 N) for intact tendons were significantly higher (P < .05) than that of torn tendons (1086 ± 388 N-mm and 177 ± 71 N, respectively). For medial suture placement, maximum load, stiffness, and work of intact and torn tendons were similar (P >. 05). Regression analyses for the intact and torn groups revealed generally low correlations between donor age and the 3 biomechanical indices. For both intact and torn tendons, the mean fibril diameter and area density were greater in the medial region relative to the lateral (P ≤. 05). In the lateral tendon, but not the medial region, torn specimens showed a significantly lower fibril area fraction (48.3% ± 3.8%) than intact specimens (56.7% ± 3.6%, P < .05). Conclusion Superior pullout resistance of medially placed sutures may provide a strain shielding effect for the lateral row after double-row repair. Larger diameter collagen fibrils as well as greater fibril area fraction in the medial supraspinatus tendon may provide greater resistance to suture migration. Clinical Relevance While clinical factors such as musculotendinous integrity warrant strong consideration for surgical decision making, the present ultrastructural and biomechanical results appear to provide a scientific rationale for double-row rotator cuff repair where sutures are placed more medially at the muscle-tendon junction.