[Use of frozen osteochondral allograft for the treatment of cartilage defects of the knee. Results at seven-year follow-up]. / Injerto osteocondral congelado para tratamiento de lesiones de cartílago de rodilla: resultados a 7 años de seguimiento.

INTRODUCTION: Knee osteochondral lesions represent a frequent pathology within young active patients. One possible indication for severe lesions or in case of impossibility of harvesting an autograft is the use of fresh frozen allograft. The objective of this study was to retrospectively analyze functional results and failure rate after osteochondral transplants using fresh frozen allografts. METHODS: We analyzed data from patients who underwent knee osteochondral transplant using mosaicplasty technique with fresh frozen allografts at our institution between 2014 and 2019. We included those patients with at least two-year follow-up. Demographic characteristics such as age at the moment of intervention and size of the defect were included. Functional results were assessed using pre and postoperative Lysholm and IKDC scores. Patients who underwent a knee replacement were considered failures. RESULTS: Twenty-five patients were included. The median age was 43.5 years (IQR 29-50), 45% were female and the mean follow-up was 83 months (SD 54.6). Mean osteochondral defect size was 4 cm2. Mean pre and postoperative Lysholm scores were 39 (SD 19.3) and 82 (SD 15.4) respectively (p < 0.01). Mean pre and postoperative IKDC scores were 42 (SD 13.8) and 60 (SD 13.5) respectively (p < 0.01). Five patients (20%) underwent a knee replacement afterwards and were considered failures. DISCUSSION: Our results after a mean seven-year follow-up evidenced an overall improvement in functional scores and a failure rate of 20%. Osteochondral transplant using fresh frozen allografts is a reliable and feasible treatment for patients with large osteochondral defects.

Introducción: Las lesiones osteocondrales de rodilla son una afección frecuente en jóvenes. Los trasplantes alogénicos usando injerto congelado se presentan como una opción de tratamiento en pacientes con lesiones grandes o sin zona dadora. Este trabajo buscó analizar retrospectivamente los resultados funcionales y la tasa de falla de los trasplantes osteocondrales con injerto cadavérico congelado. Métodos: Se incluyeron pacientes sometidos a trasplantes osteocondrales de rodilla con injerto cadavérico congelado en nuestra institución, entre 2014 y 2019, con dos años de seguimiento mínimo. Variables evaluadas: edad al momento de la intervención, escalas funcionales International Knee Documentation Committee (IKDC) y Lysholm pre y post operatorios, complicaciones y tasa de falla. Resultados: Incluimos 25 pacientes. La edad media fue de 43.5 años (RIQ 29-50), 45% fueron mujeres y el seguimiento promedio fue de 83 meses (DS 54.6). El tamaño promedio del defecto osteocondral fue de 4 cm2. La escala de Lysholm promedio pre y postoperatorio fue de 39 (DS 19.3) y 82 (DS 15.4) respectivamente (p < 0.01). El IKDC promedio pre y postoperatorio fue de 42 (DS 13.8) y 60 (DS 13.5) respectivamente (p < 0.01). La tasa de falla fue del 20% (n=5). Discusión: Los pacientes presentaron una mejoría postoperatoria evidenciada en los resultados funcionales, y una tasa de falla del 20%. El uso de trasplante osteocondral congelado se presenta como un recurso útil para el tratamiento de lesiones condrales graves.

Editorial Commentary: Meniscal Allograft Transplantation Results in Both Pain Relief and Chondroprotection.

Meniscal allograft transplantation (MAT) effectively alleviates symptoms of the meniscus deficiency. Thus, MAT is a widely accepted and recommended treatment for individuals with unicompartmental pain due to meniscus deficiency. Long-term follow-up studies have indicated that MAT yields favorable clinical outcomes, demonstrating high survivorship and low rates of serious complications. In addition, the ability of MAT to function akin to the native meniscus and shield the knee cartilage from osteoarthritis has been a subject of ongoing investigation, and recent direct magnetic resonance imaging evidence shows long-term chondroprotection following MAT. Cartilage lesions worsen during the meniscus deficiency period. Consequently, delaying MAT until patients become more symptomatic may lead to poor outcomes and low graft survivorship due to concomitant cartilage lesions. These findings prompt a reevaluation of the purpose and timing of MAT decisions for meniscectomy patients, suggesting a more proactive approach to recommending MAT, particularly for patients at high risk of postmeniscectomy syndrome and osteoarthritis progression.

Characterizing Osteochondral Allograft Biomechanics for Optimizing Transplant Success: A Systematic Review.

Osteochondral allograft (OCA) transplantation has been largely successful in treating symptomatic articular cartilage lesions; however, treatment failures persist. While OCA biomechanics have been consistently cited as mechanisms of treatment failure, the relationships among mechanical and biological variables that contribute to success after OCA transplantation have yet to be fully characterized. The purpose of this systematic review was to synthesize the clinically relevant peer-reviewed evidence targeting the biomechanics of OCAs and the impact on graft integration and functional survival toward developing and implementing strategies for improving patient outcomes. The Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, MEDLINE, PubMed, Cumulative Index to Nursing and Allied Health (CINAHL), Google Scholar, and EMBASE were searched to identify articles for systematic review. This review of relevant peer-reviewed literature provided evidence that the biomechanics related to OCA transplantation in the knee have direct and indirect effects on functional graft survival and patient outcomes. The evidence suggests that biomechanical variables can be optimized further to enhance benefits and mitigate detrimental effects. Each of these modifiable variables should be considered regarding indications, patient selection criteria, graft preservation methodology, graft preparation, transplantation, fixation techniques, and prescribed postoperative restriction and rehabilitation protocols. Criteria, methods, techniques, and protocols should target OCA quality (chondrocyte viability, extracellular matrix integrity, material properties), favorable patient and joint characteristics, rigid fixation with protected loading, and innovative ways to foster rapid and complete OCA cartilage and bone integration to optimize outcomes for OCA transplant patients.

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.

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

BACKGROUND: Unicompartmental tibiofemoral bipolar osteochondral allograft transplantation (OCAT) with meniscal allograft transplantation (MAT) has not historically been associated with consistently successful outcomes for treatment of knee articular cartilage defects with meniscal deficiency. HYPOTHESIS: Primary OCAT and MAT using fresh tissues will be associated with successful short-term outcomes based on statistically significant and clinically meaningful improvements in pain and function in the majority of patients. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Patients were prospectively enrolled into a registry for outcomes after OCAT and MAT. Patients included those who underwent primary OCAT and MAT using Missouri Osteochondral Preservation System (MOPS)-preserved allografts for treatment of large bipolar tibiofemoral articular cartilage defects with meniscal deficiency and had a minimum of 2-year follow-up data. RESULTS: A total of 76 patients (n = 52 male; 68%) met inclusion criteria (mean follow-up, 52 months). The mean age was 41.1 years (range, 15-69 years), and the mean body mass index was 28.9 (range, 17-46); 48 patients underwent another OCAT in addition to the unicompartmental bipolar tibiofemoral OCAT and MAT; 23 patients (30.3%) were documented to be nonadherent to the prescribed postoperative restriction and rehabilitation protocol. The initial success rate (>2 years) was 77.6%, with 8 patients (10.5%) undergoing revision and 9 (11.8%) converting to arthroplasty. Variables associated with an increased risk for treatment failure (revision or arthroplasty) included ipsilateral osteotomy (P = .046; odds ratio [OR] = 3.3), ipsilateral concurrent procedure (P = .0057; OR = 5.5), and nonadherence (P = .0009; OR = 7.2). None of the patients undergoing revision surgery required arthroplasty at the time of data analysis such that the overall success rate for primary and revision unicompartmental bipolar OCA plus MAT was 88.2%. There were statistically significant (P < .0001) and clinically important improvements for all patient-reported outcomes at each annual follow-up time point. CONCLUSION: Unicompartmental tibiofemoral bipolar OCAT and MAT can result in successful short-term outcomes (2-6 years) and satisfaction in the majority of patients (78%). Primary MOPS-preserved OCAT with MAT for treatment of femoral condyle and tibial plateau articular cartilage defects with concurrent meniscal deficiency was associated with statistically significant and clinically meaningful improvements in patient-reported measures of pain and function.

Effect of Mosaic Allograft Osteochondral Transplantation Combined with Corrective Osteotomy in Treating Osteochondral Lesions of the Talus on Ankle and Knee Joint Function and Lower Limb Alignment.

Objective: To explore the effect of mosaic allograft osteochondral transplantation combined with corrective osteotomy in treating osteochondral lesions of the talus (OLT) on ankle and knee joint function and lower limb alignment. Methods: One hundred and thirty-three OLT patients treated in our hospital between July 2015 and October 2019 were enrolled. Regarding the various surgical approaches, they were categorized into two groups, namely, A and B including 69 and 64 cases, respectively. The patients in group A were processed with mosaic allograft osteochondral transplantation combined with corrective osteotomy, and the patients in group B were processed with microfracture surgery. The Baird ankle function score and visual analog scale (VAS) were employed for evaluating the surgical efficacy and the degree of pain prior to and following surgery. The pre- and postoperative surgery-related indicators, Ankle Hindfoot Scale (AOOFAS), HSS score, lower limb alignment, and range of motion of the ankle were compared between the two groups, and changes in growth factor levels prior to and following processing were observed. Results: Overall scores were better in group A than in group B (P < 0.05). The operation length was longer in group A, the amount of intraoperative blood loss was greater, and the length of hospitalization was less than in group B. The VAS score 48 hours after surgery was also lower (P < 0.05). Postoperative AOFAS scores in group A were better, and lower limb alignment was also less than in group B (P < 0.05). The postoperative HSS score did not differ significantly between the two groups (P > 0.05). The range of plantar flexion and dorsiflexion of the ankle joint was better in group A, and the levels of endothelial growth factor (VEGF), platelet-derived growth factor (PDG), and transforming growth factor ß1 (TGF-ß1) were lower than those in group B (P < 0.05). The occurrence of postoperative problems did not differ between the groups (P > 0.05). Conclusion: Mosaic allograft osteochondral transplantation combined with corrective osteotomy has a high effective rate in the treatment of OLT, which can promote the healing of articular cartilage and the recovery of ankle joint functions, improve the range of motions of the ankle, and improve the lower limb alignment.

Effect analysis of iliac bone autografting for Hepple V osteochondral lesions of the talus.

BACKGROUND: Talar cartilage injury is a kind of disease that causes long-term and chronic pain of ankle joint. Autologous osteochondral transplantation has been viewed as an alternative choice for treating these lesions, but donor-site morbidity has limited its application. This study aimed to analyze the efficacy of iliac bone autografting for Hepple V osteochondral lesions of the talus. METHODS: This retrospective study included 32 patients surgically treated for Hepple V osteochondral lesions of the talus from January 2015 to January 2020. All patients underwent open surgery. Ipsilateral iliac bone grafts were taken and filled with talar cartilage injury area. The improvement of postoperative ankle pain was evaluated by Visual Analogue Scale (VAS), and the improvement of ankle function was evaluated by the American Orthopaedic Foot & Ankle Society (AOFAS). During the postoperative follow-up, X-ray examination of the front and side of the ankle joint and CT of the ankle joint were performed to evaluate the bone cartilage healing in the graft area. RESULTS: Thirty-two patients (32 ankles) (100%) returned for clinical and radiologic follow-up at an average of 28 (range 24-36) months postoperatively. At 3 months postoperatively and at the last follow-up, the AOFAS scores were (80.4 ± 3.6) and (89.2 ± 6.4), respectively, which were significantly improved compared with the preoperative score (49.7 ± 8.1), and the difference was statistically significant (P < 0.05). The VAS scores were (2.1 ± 0.9) and (1.5 ± 0.8), respectively, which were significantly better than the preoperative score (6.2 ± 1.7), and the difference was statistically significant (P < 0.05). Re-examination of the front and side of the ankle joint X-rays and CT showed that the bone healing at the osteotomy of medial malleolus and osteochondral transplantation area. All patients had no pain at the donor site. No complications occurred in 32 patients at the last follow-up. CONCLUSIONS: With iliac bone autografting for Hepple V osteochondral lesions of the talus can effectively relieve ankle joint pain and significantly improved ankle function. LEVEL OF EVIDENCE: Level III, Retrospective series.

The effect of synthesized cartilage tissue from human adipose-derived mesenchymal stem cells in orthopedic spine surgery in patients with osteoarthritis.

Osteoarthritis is a joint disease that causes degeneration of articular cartilage and involvement of subcutaneous bone and inflammation of surrounding tissues. It can affect any joints, but the most common joints are the joints of the hands, feet, knees, thighs, and spine. Osteoarthritis patients need surgery in acute cases. The use of methods that increase the efficiency of this surgery has always been considered by researchers and surgeons. For this purpose, in the current study, the effect of synthesized cartilage tissue from human adipose-derived mesenchymal stem cells was considered in orthopedic spine surgery in patients with osteoarthritis. Thirty patients over the age of 60 who had acute spinal osteoarthritis and required surgery were selected. The pellet culture system of human adipose-derive mesenchymal stem cells of each patient was used to construct cartilage tissue. For 15 of them, in addition to implants, cartilage grafts were transplanted during surgery. All patients were monitored by the Oswestry Disability Index questionnaire, for one year. In general, the results showed that over time, patients with transplanted cartilage tissue and implants were in a better condition than patients who underwent only implant surgery.

Outcomes of Bulk Fresh Osteochondral Allografts for Cartilage Restoration in the Knee.

BACKGROUND: Symptomatic osteochondral defects of the knee in young patients can cause substantial disability and predispose to osteoarthritis. Fresh osteochondral allografts (FOCAs) are a treatment option for such defects. With our institution having one of the longest-running FOCA programs, we investigated the long-term outcomes of bulk FOCA in the knee, focusing on graft survivorship, function, complications, and reoperation. METHODS: A total of 244 patients underwent bulk FOCA in the knee from 1972 to 2018, with a mean age of 37.8 years (range, 10 to 75 years) and a mean follow-up of 9.0 years (range, 1.0 to 29.8 years). Cartilage defects were very large and uncontained, such that they were not amenable to plug transplantation. Survivorship according to Kaplan-Meier analysis was the primary outcome, and failure was defined as conversion to total knee arthroplasty, repeat allograft, graft removal, knee arthrodesis, or amputation. Functional outcome was evaluated with use of the modified Hospital for Special Surgery (mHSS) score, and radiographic evidence of osteoarthritis was classified with use of the Kellgren-Lawrence grading scale. RESULTS: Graft survivorship was 86.6% at 5 years, 73.3% at 10 years, 58.1% at 15 years, 43.7% at 20 years, 31.9% at 25 years, and 22.6% at 30 years. The most common complications were pain (14.8%), malalignment (13.9%), and stiffness (5.8%). A total of 93 grafts (38.1%) failed at a mean of 11.0 years (range, 0.5 to 34.0 years). The mean mHSS score improved significantly, from 68.7 (range, 19 to 91) preoperatively to 80.3 (range, 52 to 100) at the time of the latest follow-up (p < 0.001). Preoperative mHSS score had a negative correlation with Kellgren-Lawrence grade at the time of the latest follow-up. Multivariate analysis revealed that graft location (i.e., medial-sided or multiple grafts) and increased age were significantly negatively associated with survival. Ten-year survival was >80% in patients below 50 years old, but <40% in patients >60 years old. CONCLUSIONS: Bulk FOCA provided promising long-term graft survival and functional improvement in patients <50 years old. It can delay or prevent the need for total knee arthroplasty in young patients. Older patients and patients with a medial-sided graft, or multiple grafts within the same knee, had a less favorable prognosis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Etiology of Cartilage Lesions Does Not Affect Clinical Outcomes of Patellofemoral Autologous Chondrocyte Implantation.

OBJECTIVE: To determine the relationship between cartilage lesion etiology and clinical outcomes after second-generation autologous chondrocyte implantation (ACI) in the patellofemoral joint (PFJ) with a minimum of 2 years' follow-up. METHODS: A retrospective review of all patients that underwent ACI in the PFJ by a single surgeon was performed. Seventy-two patients with a mean follow-up of 4.2 ± 2.0 years were enrolled in this study and were stratified into 3 groups based on the etiology of PFJ cartilage lesions: patellar dislocation (group 1; n = 23); nontraumatic lesions, including chondromalacia, osteochondritis dissecans, and degenerative defects (group 2; n = 28); and other posttraumatic lesions besides patellar dislocations (group 3; n = 21). Patient's mean age was 29.6 ± 8.7 years. Patients in group 1 were significantly younger (25.4 ± 7.9 years) than group 2 (31.7 ± 9.6 years; P = 0.025) and group 3 (31.5 ± 6.6 years; P = 0.05). Body mass index averaged 26.2 ± 4.3 kg/m2, with a significant difference between group 1 (24.4 ± 3.2 kg/m2) and group 3 (28.7 ± 4.5 kg/m2; P = 0.005). A clinical comparison was established between groups based on patient-reported outcome measures (PROMs) and failure rates. RESULTS: Neither pre- nor postoperative PROMs differed between groups (P > 0.05). No difference was seen in survivorship between groups (95.7% vs. 82.2% vs. 90.5%, P > 0.05). CONCLUSION: Cartilage lesion etiology did not influence clinical outcome in this retrospective study after second generation ACI in the PFJ. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Effect of cartilage thickness mismatch in osteochondral grafting from knee to talus on articular contact pressures: A finite element analysis.

OBJECTIVES: The aim of this study was to investigate the effect of cartilage thickness mismatch on tibiotalar articular contact pressure in osteochondral grafting from femoral condyles to medial talar dome using a finite element analysis (FEA). MATERIALS AND METHODS: Flush-implanted osteochondral grafting was performed on the talar centromedial aspect of the dome using osteochondral plugs with two different cartilage thicknesses. One of the plugs had an equal cartilage thickness with the recipient talar cartilage and the second plug had a thicker cartilage representing a plug harvested from the knee. The ankle joint was loaded during a single-leg stance phase of gait. Tibiotalar contact pressure, frictional stress, equivalent stress (von Mises values), and deformation were analyzed. RESULTS: In both osteochondral grafting simulations, tibiotalar contact pressure, frictional stress, equivalent stress (von Mises values) on both tibial and talar cartilage surfaces were restored to near-normal values. CONCLUSION: Cartilage thickness mismatch does not significantly change the tibiotalar contact biomechanics, when the graft is inserted flush with the talar cartilage surface.

Systematic Review of Osteochondral Allograft Transplant Immunology: How We Can Further Optimize Outcomes.

Despite the growing success for osteochondral allograft (OCA) transplantation in treating large articular cartilage lesions in multiple joints, associated revision and failure rates are still higher than desired. While immunorejection responses have not been documented, the effects of the host's immune responses on OCA transplantation failures have not been thoroughly characterized. The objective of this study was to systematically review clinically relevant peer-reviewed evidence pertaining to the immunology of OCAs to elucidate theragnostic strategies for improving functional graft survival and outcomes for patients undergoing OCA transplantation. This systematic review of Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, MEDLINE, PubMed, and EMBASE suggests that host immune responses play key roles in incorporation and functional survival of OCA transplants. OCA rejection has not been reported; however, graft integration through creeping substitution is reliant on host immune responses. Prolonged inflammation, diminished osteogenic potential for healing and incorporation, and relative bioburden are mechanisms that may be influenced by the immune system and contribute to undesirable outcomes after OCA transplantation. Based on the safety and efficacy of OCA transplantation and its associated benefits to a large and growing patient population, basic, preclinical, and clinical osteoimmunological studies on OCA transplantation that comprehensively assess and correlate cellular, molecular, histologic, biomechanical, biomarkers, diagnostic imaging, arthroscopic, functional, and patient-reported outcome measures are of high interest and importance.

Return-to-Sport Review for Current Cartilage Treatments.

The return to play outcome is an important measure for orthopaedic sports medicine treatments. This variable is especially important when discussing cartilage treatments because there are many different cartilage options available to athletes with articular injuries and this population is particularly interested in the ability to return to activities. Although many outcome variables are considered in any surgical procedure, the return-to-sport variable is focused on an active population and can be tailored to that patient's sport-specific goals. In this article, we will review some of the most recent and up-to-date articles describing return-to-sport outcomes for various knee cartilage treatments. This article will focus on the most common current knee cartilage treatments including microfracture, autologous chondrocyte implantation, osteochondral autograft transplant, and osteochondral allograft transplantation.

Chondral Lesions of the Knee: An Evidence-Based Approach.

➤: Management of chondral lesions of the knee is challenging and requires assessment of several factors including the size and location of the lesion, limb alignment and rotation, and the physical and mental health of the individual patient. ➤: There are a multitude of options to address chondral pathologies of the knee that allow individualized treatment for the specific needs and demands of the patient. ➤: Osteochondral autograft transfer remains a durable and predictable graft option in smaller lesions (<2 cm2) in the young and active patient population. ➤: Both mid-term and long-term results for large chondral lesions (≥3 cm2) of the knee have demonstrated favorable results with the use of osteochondral allograft or matrix-associated chondrocyte implantation. ➤: Treatment options for small lesions (<2 cm2) include osteochondral autograft transfer and marrow stimulation and/or microfracture with biologic adjunct, while larger lesions (≥2 cm2) are typically treated with osteochondral allograft transplantation, particulated juvenile articular cartilage, or matrix-associated chondrocyte implantation. ➤: Emerging technologies, such as allograft scaffolds and cryopreserved allograft, are being explored for different graft sources to address complex knee chondral pathology; however, further study is needed.

Osteochondral Allograft Transplant for Focal Cartilage Defects of the Femoral Condyles: Clinically Significant Outcomes, Failures, and Survival at a Minimum 5-Year Follow-up.

BACKGROUND: Osteochondral allograft (OCA) transplant for symptomatic focal cartilage defects in the knee has demonstrated favorable short- to midterm outcomes. However, the reoperation rate is high, and literature on mid- to long-term outcomes is limited. PURPOSE: To analyze clinically significant outcomes (CSOs), failures, and graft survival rates after OCA transplant of the femoral condyles at a minimum 5-year follow-up. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Review of a prospectively maintained database of 205 consecutive patients who had primary OCA transplant was performed to identify patients with a minimum of 5 years of follow-up. Outcomes including patient-reported outcomes (PROs), CSOs, complications, reoperation rate, and failures were evaluated. Failure was defined as revision cartilage procedure, conversion to knee arthroplasty, or macroscopic graft failure confirmed using second-look arthroscopy. Patient preoperative and surgical factors were assessed for their association with outcomes. RESULTS: A total of 160 patients (78.0% follow-up) underwent OCA transplant with a mean follow-up of 7.7 ± 2.7 years (range, 5.0-16.3 years). Mean age at the time of surgery was 31.9 ± 10.7 years, with a mean symptom duration of 5.8 ± 6.3 years. All mean PRO scores significantly improved, with 75.0% of patients achieving minimal clinically important difference (MCID), and 58.9% of patients achieving significant clinical benefit for the International Knee Documentation Committee score at final follow-up. The reoperation rate was 39.4% and was associated with a lower probability of achieving MCID. However, most patients undergoing reoperation did not proceed to failure at final follow-up (63.4% of total reoperations). A total of 34 (21.3%) patients had failures overall, and the 5- and 10-year survival rates were 86.2% and 81.8%, respectively. Failure was independently associated with greater body mass index, longer symptom duration, number of previous procedures, and previous failed cartilage debridement. Athletes were protected against failure. Survival rates over time were not affected by OCA site (P = .154), previous cartilage or meniscal procedure (P = .287 and P = .284, respectively), or concomitant procedures at the time of OCA transplant (P = .140). CONCLUSION: OCA transplant was associated with significant clinical improvement and durability at mid- to long-term follow-up, with 5- and 10-year survival rates of 86.2% and 81.8%, respectively. Maintenance of CSOs can be expected in the majority of patients at a mean of 7.7 years after OCA transplant. Although the reoperation rate was high (39.4%) and could have adversely affected chances of maintaining MCID, most patients did not have failure at long-term follow-up.

Management of bilateral osteochondritis dissecans of the trochlea in a skeletally immature patient.

Osteochondritis dissecans (OCD) lesions are injuries that occur more commonly in the skeletally immature population. In most cases, the aetiology is not well understood, but fortunately, many OCD lesions may heal on their own over time, particularly in skeletally immature patients with open physes. Conversely, if the lesion is considered unstable, surgical intervention may be required. This case demonstrates an especially rare presentation of bilateral OCD lesions within the lateral femoral trochlear facet. The lesions became symptomatic approximately 1 year apart without a specific injury. Non-operative treatment was not recommended in either case due to the size and instability of each lesion. The surgical treatment used an augmented microfracture technique. At 12 and 23 months after surgery, both knees remain asymptomatic and the patient has returned to their desired activities.

The Role of Hypertension in Cartilage Restoration: Increased Failure Rate After Autologous Chondrocyte Implantation but Not After Osteochondral Allograft Transplantation.

Objectives. The purpose of this study was to examine whether patients with diagnosed hypertension have an increased risk of graft failure following cartilage repair with either autologous chondrocyte implantation (ACI) or osteochondral allograft transplantation (OCA). We hypothesized that hypertension is related to higher ACI and OCA graft failure. Design. Patients who underwent ACI or OCA transplantation between February 2009 and December 2016 were included in this study. Inclusion criteria were (1) at least 2 years' follow-up, (2) available information related to the living habits (smoking and medication status), and (3) available information related to the presence of hypertension, diabetes mellitus, or hyperlipidemia. To identify potential independent risk factors of graft failure, univariate screening was performed and factors with significance at a level of P < 0.1 were entered in multivariate logistic regression models. Results. A total of 368 patients (209 ACI and 159 OCA) were included into our study. In the ACI group, 61 patients' (29.1%) graft failed. Univariate screening identified older age, female gender, defect size, higher prevalence of hypertension, and smoking as a predictor of graft failure. Following, multivariate logistic regression revealed female gender (odds ratio [OR] 1.02, P = 0.048), defect size (OR 1.07, P = 0.035), and hypertension (OR 3.73, P = 0.023) as significant independent risk factors predicting graft failure after ACI. In the OCA group, 29 patients' (18.2%) graft failed and none of the included factors demonstrated to be a potential risk factor for graft failure. Conclusion. Hypertension, defect size, and female gender seem to predict ACI graft failure but not OCA failure.

Comparison of meniscal allograft transplantation techniques using a preclinical canine model.

Meniscal allograft transplantation (MAT) can be a safe, effective treatment for meniscal deficiency resulting in knee dysfunction, leading to osteoarthritis (OA) without proper treatment with 5-year functional success rates (75%-90%). While different grafts and techniques have generally proven safe and effective, complications include shrinkage, extrusion, progression of joint pathology, and failure. The objective of this study was to assess the functional outcomes after MAT using three different clinically-relevant methods in a preclinical canine model. The study was designed to test the hypothesis that fresh meniscal-osteochondral allograft transplantation would be associated with significantly better function and joint health compared with fresh-viable or fresh-frozen meniscus-only allograft transplantations. Three months after meniscal release to induce meniscus-deficient medial compartment disease, research hounds (n = 12) underwent MAT using meniscus allografts harvested from matched dogs. Three MAT conditions (n = 4 each) were compared: frozen meniscus-fresh-frozen meniscal allograft with menisco-capsular suture repair; fresh meniscus-fresh viable meniscal allograft (Missouri Osteochondral Preservation System (MOPS)-preservation for 30 days) with menisco-tibial ligament repair; fresh menisco-tibial-fresh, viable meniscal-tibial-osteochondral allografts (MOPS-preservation for 30 days) with menisco-tibial ligament preservation and autogenous bone marrow aspirate concentrate on OCA bone. Assessment was performed up to 6 months after MAT. Pain, comfortable range of motion, imaging, and arthroscopic scores as well histological and cell viability findings were superior (P < .05) for the fresh menisco-tibial group compared with the two other groups. Novel meniscal preservation and implantation techniques with fresh, MOPS-preserved, viable meniscal-osteochondral allografts with menisco-tibial ligament preservation appears to be safe and effective for restoring knee function and joint health in this preclinical model. This has the potential to significantly improve outcomes after MAT.

First Clinical Application of Polyurethane Meniscal Scaffolds with Mesenchymal Stem Cells and Assessment of Cartilage Quality with T2 Mapping at 12 Months.

BACKGROUND: Complex meniscal lesions often require meniscectomy with favorable results in the short term but a high risk of early osteoarthritis subsequently. Partial meniscectomy treated with meniscal substitutes may delay articular cartilage degeneration. PURPOSE: To evaluate the status of articular cartilage by T2 mapping after meniscal substitution with polyurethane scaffolds enriched with mesenchymal stem cells (MSC) and comparison with acellular scaffolds at 12 months. METHODS: Seventeen patients (18-50 years) with past meniscectomies were enrolled in 2 groups: (1) acellular polyurethane scaffold (APS) or (2) polyurethane scaffold enriched with MSC (MPS). Patients in the MPS group received filgrastim to stimulate MSC production, and CD90+ cells were obtained and cultured in the polyurethane scaffold. The scaffolds were implanted arthroscopically into partial meniscus defects. Concomitant injuries (articular cartilage lesions or cartilage lesions) were treated during the same procedure. Changes in the quality of articular cartilage were evaluated with T2 mapping in femur and tibia at 12 months. RESULTS: In tibial T2 mapping, values for the MPS group increased slightly at 9 months but returned to initial values at 12 months (P > 0.05). In the APS group, a clear decrease from 3 months to 12 months was observed (P > 0.05). This difference tended to be significantly lower in the APS group compared with the MPS group at the final time point (P = 0.18). In the femur, a slight increase in the MPS group (47.8 ± 3.4) compared with the APS group (45.3 ± 4.9) was observed (P > 0.05). CONCLUSION: Meniscal substitution with polyurethane scaffold maintains normal T2 mapping values in adjacent cartilage at 12 months. The addition of MSC did not show any advantage in the protection of articular cartilage over acellular scaffolds (P > 0.05).

Modernizing Storage Conditions for Fresh Osteochondral Allografts by Optimizing Viability at Physiologic Temperatures and Conditions.

Objective. Osteochondral allograft (OCA) transplantation has demonstrated good long-term outcomes in treatment of cartilage defects. Viability, a key factor in clinical success, decreases with peri-implantation storage at 4°C during pathogen testing, matching logistics, and transportation. Modern, physiologic storage conditions may improve viability and enhance outcomes. Design. Osteochondral specimens from total knee arthroplasty patients (6 males, 5 females, age 56.4 ± 2.2 years) were stored in media and incubated at normoxia (21% O2) at 22°C or 37°C, and hypoxia (2% O2) at 37°C. Histology, live-dead staining, and quantitative polymerase chain reaction (qPCR) was performed 24 hours after harvest and following 7 days of incubation. Tissue architecture, cell viability, and gene expression were analyzed. Results. No significant viability or gene expression deterioration of cartilage was observed 1-week postincubation at 37°C, with or without hypoxia. Baseline viable cell density (VCD) was 94.0% ± 2.7% at day 1. At day 7, VCD was 95.1% (37°C) with normoxic storage and 92.2% (37°C) with hypoxic storage (P ≥ 0.27). Day 7 VCD (22°C) incubation was significantly lower than both the baseline and 37°C storage values (65.6%; P < 0.01). COL1A1, COL1A2, and ACAN qPCR expression was unchanged from baseline (P < 0.05) for all storage conditions at day 7, while CD163 expression, indicative of inflammatory macrophages and monocytes, was significantly lower in the 37°C groups (P < 0.01). Conclusion. Physiologic storage at 37°C demonstrates improved chondrocyte viability and metabolism, and maintained collagen expression compared with storage at 22°C. These novel findings guide development of a method to optimize short-term fresh OCA storage, which may lead to improved clinical results.