Safety, Feasibility, and Radiographic Outcomes of the Anterior Meniscal Takedown Technique to Approach Chondral Defects on the Tibia and Posterior Femoral Condyle: A Matched Control Study.

OBJECTIVE: Takedown of the anterior meniscus to facilitate exposure of the cartilage defects located on the tibial plateau and/or posterior femoral condyle with subsequent reattachment is being performed clinically; however, clinical evidence is lacking to support the safety of this technique. The aim of this study was therefore to investigate whether meniscal extrusion develops after patients undergo meniscus takedown and transosseous refixation during autologous chondrocyte implantation (ACI). DESIGN: We analyzed data from 124 patients with a mean follow-up of 6.8 ± 2.5 years. Sixty-two patients who underwent (ACI) with anterior meniscus takedown and refixation by the senior surgeon (TM), were compared with a matched control group of patients who underwent ACI without meniscus takedown. Meniscal extrusion was investigated by measuring the absolute value and the relative percentage of extrusion (RPE) on 1.5-T magnetic resonance images (MRI) at final follow-up. The number of menisci with radial displacement greater or lesser than 3 mm was determined. In cases where a preoperative MRI was available, both pre- and postoperative meniscal extrusion was evaluated (n = 30) in those patients undergoing meniscal takedown. RESULTS: There was no significant difference in either absolute meniscus extrusion, RPE, or extrusion rate in patients with and without meniscus takedown. Among patients with meniscal takedown and both pre- and postoperative MRI scans, absolute meniscus extrusion, RPE, and extrusion rate showed no significant differences. CONCLUSION: Meniscal takedown and subsequent transosseous refixation is a safe and effective technique for exposure of the tibial plateau and posterior femoral condyle.

Clinical Outcomes after Revision of Autologous Chondrocyte Implantation to Osteochondral Allograft Transplantation for Large Chondral Defects: A Comparative Matched-Group Analysis.

OBJECTIVE: Osteochondral allograft transplantation (OCA) is a well-established procedure for patients with symptomatic cartilage defects in the knee. Revision to OCA after prior failed cartilage repair has shown similar clinical outcomes as primary OCA; however, most of the failed procedures were arthroscopic procedures for smaller defects. There is no literature investigating the clinical outcomes after OCA for prior failed autologous chondrocyte implantation (ACI) for the treatment of large chondral defects of the knee. The purpose of this study was therefore to determine clinical outcomes of patients undergoing revision to OCA after prior failed ACI as compared with a matched cohort of patients undergoing OCA as a primary cartilage repair procedure (primary OCA). DESIGN: In this review of prospectively collected data, we analyzed data from 26 patients with at least 2 years follow-up. Thirteen patients who underwent revision to OCA after prior failed ACI by a single surgeon were compared with a matched group of patients who underwent primary OCA. The patients were matched per age, gender, body mass index, and defect size. Patient-reported outcomes, reoperations, and survival rates were compared between groups. RESULTS: There were no significant differences in patient-reported clinical outcome scores between the groups at final follow-up. Moreover, there was no significant difference in reoperation rates and survival rates between the groups. CONCLUSION: The present study demonstrates that revision to OCA is a viable treatment option with favorable functional outcomes and similar reoperation and survival rate as primary OCA even for revision of large chondral defects previously treated with ACI.

Effect of Graft-Host Interference Fit on Graft Integration after Osteochondral Allograft Transplantation: A Comparative MRI Analysis of Two Instrumentation Sets.

OBJECTIVE: Precise graft-host interference fit is a potentially import factor for the successful incorporation of osteochondral allograft (OCA) transplants for the treatment of symptomatic focal cartilage defects. It was hypothesized that selection of OCA plug instrumentation set has a significant effect on graft integration and morphology after OCA transplantation. METHODS: Thirty-one patients who underwent OCA transplantation between July 2013 and July 2016 were identified for this comparative magnetic resonance imaging (MRI) analysis. Patients were stratified into two groups based on the treatment with the Arthrex Allograft OATS Instrument Set or the JRF Ortho Osteochondral Allograft Plug Instrumentation. MRI was obtained at 12 months postoperatively. All grafts were assessed for integration using the Osteochondral Allograft MRI Scoring System (OCAMRISS), host marrow edema size, graft-host interface distance, graft cartilage integrity, cyst size, graft contour and presence of effusion. RESULTS: At a mean follow-up of 11.39 ± 1.98 months, 95.5% of all grafts showed osseous integration into the recipient bone with 68.2% presenting without cystic changes of the graft or host-graft junction. No differences were seen in any OCAMRISS subscale besides cartilage signal, which demonstrated minimal differences (P = 0.046). CONCLUSION: OCAs show excellent osseous integration at the graft-host junction at 12 months postoperatively. The comparative MRI analysis of two instrumentation sets yielded no significant differences in terms of graft integration, bone marrow edema, or cystic formation. Hence, this study cannot recommend one instrumentation set over the other. Consequently, the individual preference should guide the surgeon's selection of instrumentation for OCA transplantation.

Trochlear Dysplasia Does Not Affect the Outcomes of Patellofemoral Autologous Chondrocyte Implantation.

PURPOSE: To evaluate the influence of trochlear dysplasia on clinical outcomes after autologous chondrocyte implantation (ACI) for the treatment of large cartilage lesions in the patellofemoral joint (PFJ) with a minimum of 2 years' follow-up. METHODS: We performed a retrospective review of prospectively collected data of all patients submitted to cartilage repair with ACI for focal cartilage defects in the PFJ by a single surgeon. Patient factors, lesion morphology, and preoperative and postoperative patient-reported outcome measures including the Knee Injury and Osteoarthritis Score, Lysholm score, Tegner activity level, and International Knee Documentation Committee Subjective Knee Evaluation Form score were collected. Two independent observers assessed preoperative imaging to determine the presence and grade of trochlear dysplasia. Patients were stratified into 2 groups based on the presence or absence of trochlear dysplasia. Patients without trochlear dysplasia served as controls. Patients were matched 1:1 for sex, age, body mass index, lesion size, and location. RESULTS: Forty-six patients who underwent ACI in the PFJ with a mean follow-up period of 3.7 ± 1.9 years (range, 2-9 years) were enrolled in this study (23 in the trochlear dysplasia group vs 23 in the normal trochlea group). The patients' mean age was 30.1 ± 8.8 years. Patient-reported outcome measures at final follow-up did not differ between the 2 groups (P > .05). No difference in failure rates was seen between the 2 groups (n = 1 [4.3%] vs n = 1 [4.3%], P > .999). Additionally, no difference in clinical outcomes was seen between patients with high-grade dysplasia (19 patients; Dejour types B-D) and patients without dysplasia (19 patients) (P > .05). CONCLUSIONS: ACI in the PFJ provides favorable outcomes even in patients with trochlear dysplasia, which are comparable to those in patients with normal trochlear anatomy. Thus, trochlear dysplasia seems to not influence the clinical outcomes of ACI in the PFJ. LEVEL OF EVIDENCE: Level III, retrospective comparative trial.

Validation of the Oswestry Risk of Knee Arthroplasty Index (ORKA-1) for Patients Undergoing Autologous Chondrocyte Implantation.

OBJECTIVE: The purpose of this study was first to externally validate the Oswestry Risk of Knee Arthroplasty index (ORKA-1) by applying it to an autologous chondrocyte implantation (ACI) patient cohort in the United States with a broader definition of failure than only arthroplasty, and second, to determine predictive factors for the risk of ACI failure as defined by the senior author. DESIGN: A total of 171 patients that underwent ACI were included to validate the ORKA-1 as all factors needed for calculation and outcomes were recorded. For Cox regression analysis, 154 patients were included as they completed preoperative Knee Injury and Osteoarthritis Outcome Score (KOOS), Tegner, Lysholm, International Knee Documentation Committee (IKDC), and 12-item Shor Form (SF-12) scores. Patient- and lesion-associated parameters were recorded for each patient. RESULTS: At final follow-up (maximum of 10 years post-ACI), a total of 27 patients (15.8%) were considered a failure by senior author's definition. With ACI failure as endpoint, the mean survival was 7.96 years in risk group 1 and 5.4 years in risk group 5. Cox regression analysis identified preoperative KOOS Sport/Recreation as the only significant predictive factor for ACI failure (P = 0.007). CONCLUSION: The ORKA-1 is a helpful tool for surgeons to estimate an individual patient's likelihood of ACI survival. Further studies with larger patient cohorts as well as a consensus definition of failure are needed to further refine predictors of ACI failure.

Preoperative Mental Health Has a Stronger Association with Baseline Self-Assessed Knee Scores than Defect Morphology in Patients Undergoing Cartilage Repair.

OBJECTIVE: The purpose of this study was to assess potential correlations between the mental component summary of the Short Form-12 (SF-12 MCS), patient characteristics or lesion morphology, and preoperative self-assessed pain and function scores in patients undergoing autologous chondrocyte implantation (ACI). DESIGN: A total of 290 patients underwent ACI for symptomatic cartilage lesions in the knee. One hundred and seventy-eight patients were included in this study as they completed preoperative SF-12, Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner, Lysholm, and International Knee Documentation Committee (IKDC) scores. Age, sex, smoker status, body mass index, Worker's Compensation, previous surgeries, concomitant surgeries, number of defects, lesion location in the patella, and total defect size were recorded for each patient. Pearson's correlation and multivariate regression models were used to distinguish associations between these factors and preoperative knee scores. RESULTS: The SF-12 MCS showed the strongest bivariate correlation with all KOOS subgroups (P < 0.001) (except KOOS Symptom; P = 0.557), Tegner (P = 0.005), Lysholm (P < 0.001), and IKDC scores (P < 0.001). In the multivariate regression models, the SF-12 MCS showed the strongest association with all KOOS subgroups (P < 0.001) (except KOOS Symptom; P = 0.91), Lysholm (P = 0.001), Tegner (P = 0.017), and IKDC (P < 0.001). CONCLUSION: In patients with symptomatic cartilage defects of the knee, preoperative patient mental health has a strong association with self-assessed pain and functional knee scores. Further studies are needed to determine if preoperative mental health management can improve preoperative symptoms and postoperative outcomes.

Minimal Clinically Important Differences and Substantial Clinical Benefit in Patient-Reported Outcome Measures after Autologous Chondrocyte Implantation.

OBJECTIVE: We sought to determine the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) associated with the Knee Injury and Osteoarthritis Outcome Score (KOOS), International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Form, Lysholm, and Short Form-12 (SF-12) after autologous chondrocyte implantation (ACI). DESIGN: Ninety-two patients with satisfaction surveys at a minimum of 2 years postoperatively and at least 1 repeated patient-reported outcome measure (PROM) were analysed. The MCID was determined using 4 anchor-based methods: average change, mean change, minimally detectable change, and the optimal cutoff point for receiver operating characteristic (ROC) curves. If an anchor-based method was not applicable, standard deviation-based and effect size-based estimates were used. SCB was determined using ROC curve analysis. RESULTS: The 4 anchor-based methods provided a range of MCID values for each PROM (11-18.8 for the KOOS pain, 9.2-17.3 for the KOOS activities of daily living, 12.5-18.6 for the KOOS sport/recreation, 12.8-19.6 for the KOOS quality of life, 10.8-16.4 for the IKDC, and 6.2-8.2 for the SF-12 physical component summary). Using the 2 distribution-based methods, the following MCID value ranges were obtained: KOOS symptom, 3.6 to 8.4; the Lysholm, 4.2 to 10.5; and the SF-12 mental component summary, 1.9 to 4.6. SCB was 30 for the KOOS sport/recreation and 34.4 for the IKDC, which most accurately predict substantial improvement. No significant association was noted between SCB achievement and the baseline PROMs. CONCLUSION: The MCID and SCB determined in our study will allow interpretation of the effects of treatment in clinical practice and trials. Given the varied MCID values in this study, standardisation of the most appropriate calculation methods is warranted.