Initial Outcomes After Unicompartmental Tibiofemoral Bipolar Osteochondral and Meniscal Allograft Transplantation in the Knee Using MOPS-Preserved Fresh (Viable) Tissues

Multi-Surface Cartilage Defects about the Knee Treated with Cartilage Restoration Procedures Show Good Outcomes and Survivorship at Minimum 2-Year Follow-Up

OBJECTIVE

We aimed to evaluate the outcomes, survivorship, and complications following multi-surface cartilage procedures at minimum 2-year follow-up.

DESIGN

Patients with either (1) single-surface osteochondral allograft transplantation (OCAT) with third-generation matrix-induced autologous cultured chondrocyte implantation (MACI) or particulated juvenile cartilage implantation (DeNovo), or (2) multiple-surface OCAT ± associated MACI/DeNovo procedures for grade IV chondral or osteochondral defects about the knee with minimum 2-year follow-up were analyzed. Patient-reported outcome measures (PROMs), including International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales, were obtained preoperatively and at minimum 2 years postoperatively. The percentage of patients who met the minimal clinically important difference (MCID) for each PROM was reported. Failure was defined as revision OCAT, conversion to patellofemoral/total/unicompartmental joint arthroplasty, or Arthrosurface HemiCAP placement.

RESULTS

Of 257 patients identified, 35 were included. There was a significant increase in IKDC, KOOS-pain, KOOS-symptom, KOOS-sport, and KOOS-quality of life scores from preoperative to postoperative evaluation (P < 0.03 for all). More than 50% of patients met the MCID for each PROM. There were 2 failures, 1 of the patella and 1 of the medial femoral condyle, at 39.7 and 38.6 months postoperatively, respectively.

DISCUSSION

Multi-surface cartilage procedures are a safe, efficacious treatment option for multifocal cartilage defects about the knee at short-term follow-up.

Cell-Mediated Immune Responses May Play Roles in Osteochondral Allograft Transplantation Osteointegration Failures

Prolonged and incomplete osteochondral allograft (OCA) osteointegration is consistently cited as a major mechanism for OCA treatment failure. Subrejection immune responses may play roles in this mode of failure. Preimplantation OCA preparation techniques, including subchondral bone drilling, thorough irrigation, and autogenous bone marrow aspirate concentrate saturation, may dampen immune responses and improve OCA osteointegration. This study sought to further characterize potential immune system contributions to OCA transplantation treatment failures by analyzing donor-recipient ABO and Rh-factor mismatches and histological and immunohistochemical assessments of transplanted OCA tissues recovered from revision surgeries. Using a dedicated registry, OCA transplant recipients with documented treatment failures who met inclusion criteria (n = 33) as well as age-, body mass index-, and joint-matched patients with successful outcomes (n = 70) were analyzed to compare matched cohorts of patients with successful versus failed OCA transplantation outcomes. Tissues recovered from 18 failed OCA transplants and portions of 7 nonimplanted OCA controls were further analyzed to provide contributing evidence for potential immune response mechanisms. For patients analyzed, no statistically significant differences in proportions for treatment success versus failure based on mismatches for ABO type, Rh factor, or both were noted. Further, no statistically significant differences in proportions for histological immune response presence or absence based on mismatches for ABO type, Rh factor, or both were noted. Twelve (67%) of the failed OCA tissues contained lymphocyte aggregations in the subchondral bone, which were comprised of combinations of CD3 + , CD4 + , CD8 + , and CD20+ lymphocytes. The mechanisms of failure for these 12 OCA transplants involved insufficient OCA osteointegration. Results of this study suggest that T- and B-cell-mediated subrejection immune responses may play roles in OCA transplant treatment failures independent of donor-recipient blood type mismatch effects.

Influence of Concomitant Meniscal Allograft Transplantation on Midterm Outcomes After Osteochondral Allograft Transplantation: A Comparative Matched-Pair Analysis

BACKGROUND

Osteochondral allograft transplantation (OCAT) is an accepted knee joint-preserving treatment strategy for focal osteochondral lesions that is often conducted in combination with meniscal allograft transplantation (MAT). Despite its frequent and simultaneous utilization, there remains a lack in the literature reporting on outcomes and failure rates after concomitant procedures.

PURPOSE

To determine (1) the midterm clinical success rate after OCAT+MAT in comparison with a matched-pair cohort undergoing isolated OCAT, (2) whether patient-specific and procedural variables influence the risk of failure, and (3) patient-reported outcome measures over time.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A single-center matched-pair cohort study was conducted investigating outcomes in patients who underwent OCAT of the medial or lateral femoral condyle with and without MAT between 2004 and 2020. Patients were matched 1:1 by age (±5 years), sex (male or female), body mass index (±5), and grouped Kellgren and Lawrence grade (grades 0-1 or 2-4). The minimum follow-up time was 2 years. Radiographic variables (International Cartilage Regeneration & Joint Preservation Society [ICRS] grade and Kellgren and Lawrence grade) were assessed preoperatively and at follow-up. Subjective patient-reported outcome measures (Lysholm score, Knee injury and Osteoarthritis Outcome Score [KOOS] including subscores, International Knee Documentation Committee [IKDC] score, and visual analog scale score) were collected preoperatively and at follow-up. Clinical failure was defined as revision surgery for graft failure or conversion to total knee arthroplasty. Patient-reported, clinical, and radiographic outcomes were compared between groups.

RESULTS

In total, 66 patients (33 treated with isolated OCAT, 33 treated with OCAT+MAT; 57.6% male) with a mean age of 26.3 years (range, 18-62 years) were followed for a mean of 5.6 years (minimum, 2 years; range, 24-218 months). The 2 cohorts showed no difference in Kellgren and Lawrence grade postoperatively (P = .59). There was a significantly higher ICRS grade detected at follow-up in the OCAT+MAT group (2.81 ± 1.10) compared with the OCAT group (2.04 ± 0.96) (P < .05). There were no statistically significant differences between the groups regarding reoperation rate (OCAT: n = 6; OCAT+MAT: n = 13; P = .116), time to reoperation (OCAT: 46.67 ± 47.27 months vs OCAT+MAT: 28.08 ± 30.16 months; P = .061), and failure rate (OCAT: n = 4 [12.1%] vs OCAT+MAT: n = 5 [15.2%]; P = .66). In the OCAT+MAT group, an increase of tibial slope by 1° conferred a 1.65-fold increase in the hazard for failure over decreased slope (hazard ratio, 1.65; 95% CI, 1.10-2.50; P < .05). The overall survival rate was 86% at a mean follow-up of 5.6 years. Patient-reported outcome scores were significantly improved at the final follow-up compared with preoperative status. No significant differences were seen between groups with respect to subjective IKDC, Lysholm, Tegner, and KOOS results, except for the KOOS Symptoms subscale score, which was significantly higher in the OCAT+MAT group than in the OCAT group (mean difference, 14.6; P < .05) and did exceed the minimal clinically important difference threshold of 10.7.

CONCLUSION

Midterm results after isolated OCAT and OCAT+MAT show high rates of healing and sustainable subjective improvement of knee function and quality of life. However, it should be noted that the difference in reoperation rate and time to reoperation between the groups is arguably clinically important and that lack of statistical significance may be because of low power. These results imply that isolated OCAT is an efficient joint-preserving treatment that can be combined with MAT in well-selected patients with meniscal insufficiency without negative influence on global clinical outcomes.

Short-Term Outcomes After Bipolar Osteochondral Allograft Transplantation (OCAT) in the Ankle

Treatment options for symptomatic cartilage loss in the ankle are not consistently effective. This study documents initial outcomes for patients undergoing bipolar OCAT in the ankle after advances in tissue preservation, transplantation techniques, and patient management strategies were implemented. Patients were prospectively enrolled into a registry designed to follow outcomes after OCAT in the ankle. Fourteen patients were included for analyses (12 primary OCAT, 2 revision OCAT). Four patients underwent Bipolar OCAT (tibia, talus) and 10 Bipolar+ OCAT (tibia, talus, fibula). Short-term (median follow-up 43, range 13-73 months) success was documented for 13 patients. Radiographic assessments indicated OCA integration and maintenance of joint space in 12 patients. Statistically significant (p < .030) and clinically meaningful improvements in AAOS and VAS pain scores were noted at 3 months, 6 months, 1 year, and 2 years following OCA transplantation when compared to preoperative measures. For patients that were nonadherent to postoperative restriction and rehabilitation protocols, all 1-year postoperative PROs were significantly lower (p < .050) than for patients who were adherent. The successful outcomes documented in 13 of 14 patients in conjunction with significant and clinically meaningful improvements in patient-reported measures of pain and function support OCA transplantation as an appropriate treatment option in indicated patients. These improvements in outcomes were associated with advances in OCA preservation, preimplantation treatment, transplantation techniques, and patient management strategies, suggesting this shift in practice be considered for OCA transplantation in the ankle.

Treatment failures (revision or arthroplasty) after knee osteochondral allograft transplantation with minimum two-year follow-up

BACKGROUND

Knee osteochondral allograft transplantation (OCAT) has been associated with good short- to mid-term outcomes, however, treatment failures occur more frequently than desired. This study used data from a lifelong outcomes registry to analyze knee OCAT treatment failure rates, variables associated with knee OCAT treatment failures, and outcomes after revision or arthroplasty surgery for knee OCAT treatment failures.

METHODS

Patient outcomes were followed after knee OCAT performed using standard preservation (SP) or Missouri Osteochondral Preservation System (MOPS®) allografts. The study population consisted of patients undergoing primary OCAT with ≥ 2-year follow-up. For comparisons, the treatment failure population was defined by patients in the study population with documented treatment failure (revision or arthroplasty) with ≥ 2-year follow-up after failure. Functional graft survival was defined as no further need for revision surgery after primary or revision OCAT.

RESULTS

A total of 262 patients (n = 136 males; 51.9%) were analyzed. SP grafts were used for 59 cases and MOPS grafts were used for 203 cases. Treatment failure was documented in 61 cases (23.3%). MOPS grafts were 3.3 times more likely to be associated with functional graft survival. SP grafts, older patient age, higher BMI, tibiofemoral bipolar OCAT and non-adherence to the postoperative rehabilitation protocol were significantly associated with treatment failure.

CONCLUSIONS

Knee OCAT resulted in functional graft survival at short- to mid-term follow-up in the majority (70-88%) of cases. In addition, revision of primary OCAT resulted in functional graft survival for at least 2 years after revision surgery in the majority (66%) of patients.

LEVEL OF EVIDENCE

2, prospective cohort study.

Evaluating the Use of PROMs in Paediatric Orthopaedic Registries

Patient-reported outcome measures (PROMs) provide structured information on the patient's health experience and facilitate shared clinical decision-making. Registries that collect PROMs generate essential information about the clinical course and efficacy of interventions. Whilst PROMs are increasingly being used in adult orthopaedic registries, their use in paediatric orthopaedic registries is not well known. The purpose of this systematic review was to identify the frequency and scope of registries that collect PROMs in paediatric orthopaedic patient groups. In July 2023, six databases were systematically searched to identify studies that collected PROMs using a registry amongst patients aged under 18 years with orthopaedic diagnoses. Of 3190 identified articles, 128 unique registries were identified. Three were exclusively paediatric, 27 were majority paediatric, and the remainder included a minority of paediatric patients. One hundred and twenty-eight registries collected 72 different PROMs, and 58% of these PROMs were not validated for a paediatric population. The largest group of orthopaedic registries collected PROMs on knee ligament injuries (21%). There are few reported dedicated orthopaedic registries collecting PROMs in paediatric populations. The majority of PROMs collected amongst paediatric populations by orthopaedic registries are not validated for patients under the age of 18 years. The use of non-validated PROMs by registries greatly impedes their utility and impact. Dedicated orthopaedic registries collecting paediatric-validated PROMs are needed to increase health knowledge, improve decision-making between patients and healthcare providers, and optimise orthopaedic management.