Osteochondral Transplantation Research Articles

Osteoperiosteal Iliac Autograft Transplantation for Unreconstructable Tibial Plafond After Malunions of Pilon Fractures in Young Patients.

Malunion of tibial pilon fracture, especially with a large cartilage loss of the tibial plafond, is a tough clinical conundrum. This study describes a joint-preserving technique that mainly involves corrective intraarticular osteotomy and osteoperiosteal iliac autograft transplantation for treating these generally considered unreconstructable tibial plafond. Sixteen patients with an average age of 33.6 years who were treated with this joint-preserving method between 2013 and 2020 were retrospectively analyzed. Ankle distraction was applied in all patients. Additional osteochondral autograft transplantation for talus was performed in 4 patients and supramalleolar osteotomy in 2 patients. The visual analog scale (VAS) score, the American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot score, the 36-Item Short Form Health Survey (SF-36) score, and the ankle range of motion (ROM) were used for outcome analysis. Radiographic assessment was conducted, and the complications were recorded. At a mean follow-up of 41.1 months, the mean VAS, AOFAS, and SF-36 scores improved from 6.3, 47.6, and 38.0 to 1.7, 84.4, and 70.8, respectively (P < .001 for each). The ankle ROM improved from 27.5 to 32.2 degrees (P = .023). The mean area of ilium blocks was 3.5 cm2, and the mean external fixation time was 94.1 days. Radiographs showed that good osteointegration was found in all patients and no significant progression of osteoarthritis in 15 patients. The major complications included poor incision healing in 2 patients and severe ankle stiffness in 2 patients, with one of them developing considerable varus-type osteoarthritis but reporting no pain. No deep infection, nonunion, or malunion occurred, and no secondary arthrodesis was performed during the final follow-up. Osteoperiosteal iliac autograft transplantation might be an alternative surgical option for reconstructing unreconstructable malunited pilon fractures with a large cartilage loss of the tibial plafond in young patients. Level IV, case series.

Outcomes of Osteochondral Allograft Transplantation: A Comparative Study of BioUni and Snowman Techniques for Ovoid Lesions.

Treatment of large articular cartilage lesions of the knee includes surgical options one of which includes cartilage replacement therapies. Among these therapies include osteochondral allograft (OCA) transplantation, which can be performed utilizing a BioUni® (Arthrex BioUni® Instrumentation System; Arthrex, Naples, FL) replacement and a 'snowman' technique of repair. To compare clinical and radiographic outcomes in patients who have undergone multiplug OCA transplantations utilizing a BioUni® replacement and a 'snowman' technique of repair. Patients who underwent OCA transplantation utilizing a snowman technique or BioUni® replacement between January 1st, 2012 and December 31st, 2018, and who had a minimum 1-year follow-up at the same institution were identified for inclusion in this study via current procedural terminology (CPT) codes. Charts of included patients were reviewed for injury and treatment details as well as demographic information. Imaging studies and operative reports were reviewed and pre and postoperative subjective and objective outcome measures were recorded. Twenty-eight patients underwent OCA transplantation with either BioUni® replacement (n=5) or with snowman technique repair (n=23). Defects in both groups had similar characteristics including size, area, location, and classifications. Patient-reported outcomes using the Knee Injury and Osteoarthritis Outcome Score-Joint Replacement (KOOS-JR), International Knee Documentation Committee (IKDC), and Physical Health Composite Score (PCS-12) were similar at baseline and increased post-operatively for both groups with no significant differences between techniques after a mean follow-up of 2.77 ± 0.83. Although it did not reach significance, the snowman group had higher rates of knee-related complications (13%) and need for revision surgery (22%) when compared to BioUni® (0% and 0%, respectively). The use of both BioUni® and snowman techniques for large, unicondylar articular cartilage lesions of the femoral condyle demonstrate improved patient-reported outcomes at short-term follow-up. The use of the snowman technique presents relatively higher rates of revision similar to previous studies with no statistical difference in patient-reported outcomes when compared to those of a single plug OCA using a BioUni® system.

Outcomes after Bipolar Osteochondral Allograft Transplantation in the Ankle

Category: Ankle Arthritis; Ankle Introduction/Purpose: Surgical treatment options for symptomatic, full-thickness articular cartilage loss in the ankle are not consistently effective in restoring ankle function. Osteochondral allograft transplantation provides a standard-of-care alternative for patients, however, outcomes reported to date have been only fair, with a high incidence of reoperation and revision. However, recent cartilage storage and preservation techniques have significantly improved the percent viable chondrocytes at the time of implantation in OCAs. These high-chondrocyte-viability allografts should lead to improved survivability of OCAs and improved outcome measures. This study aimed to document the initial outcomes for patients undergoing bipolar OCA transplantation in the ankle after advances in tissue preservation, transplantation techniques, and patient management strategies. Methods: Patients with symptomatic tibiotalar arthritis were prospectively enrolled into a registry designed to follow outcomes after OCA surgeries in the ankle. All patients underwent complete OCA replacement of their tibial plafond and talar dome, with most undergoing fibular articular resurfacing. All OCA were size and side matched and preserved in Missouri Osteochondral Allograft Preservation System (MOPS). Patients followed a standardized, procedure-specific rehabilitation protocol after surgery, including remaining non-weight bearing for 8 weeks, weekly therapy visits, limited step count during recovery, and avoidance of high impact activities until 1 year after surgery. Patients followed-up with their physician at regular post-operative timepoints. Radiographs and patient reported outcome measures (VAS, AAOS Foot and Ankle, PROMIS PF, PROMIS Mobility) were obtained at each follow-up visit. Demographic and operative data were collected from the electronic medical record. All reported complications, reoperations, revisions, and failures were recorded in the EMR. Results: 14 patients were included for analyses with 12 undergoing primary OCA transplantation, and 2 undergoing revision OCA transplantation. Mean age and follow up was 36 and 44.1 months, respectively. All patients underwent tibia and talus OCA transplantation, with 10/14 including a fibula OCA transplantation. Initial success was 92.9% with one documented failure (tibial OCA collapse). Radiographic assessments indicated OCA integration and maintenance of joint space in 12 patients (85.7%). AAOS and VAS pain scores improved significantly from preoperative measures at each timepoint (p=.002, p=.03), while postoperative improvements in PROMIS Mobility and PROMIS Physical Function scores did not reach significance (p&gt;0.15) (Table 1). Patients that were non-adherent to postoperative restriction and rehabilitation protocols, all 1-year postoperative PROs were significantly lower than for patients who were adherent. Conclusion: Ankle osteoarthritis in young patients continues to present a challenging dilemma. Previous attempts at large bipolar OCAs in the ankle have yielded fair, to poor, results. However, recent advances in bulk osteochondral allograft preservation has improved chondrocyte viability. Based on the results of our study, the use of high-chondrocyte-viability allografts for OCA transplantation is a viable option for the treatment of symptomatic bipolar osteochondral defects in the ankle joint. However, post operative rehab protocols are equally important in determining outcomes, and patient selection and education is key to ensuring successful outcomes. Longer term follow up is ongoing.

Pediatric Osteochondral Lesions of the Talus: A Systematic Review and Treatment Algorithm

Category: Hindfoot; Ankle Introduction/Purpose: Osteochondral lesions of the talus (OLT) peak in incidence during childhood, yet there exists a paucity of research on treatment among skeletally immature populations due to their high potential for spontaneous recovery without interventions. Unfortunately for patients who do require treatment, existing guidelines are based on adult studies, which likely differ in prognoses and outcomes due to varying capacity for regeneration. This paper compares outcomes across conservative and various surgical interventions for pediatric OLTs, with the synthesized evidence forming the basis of a treatment algorithm. Methods: An electronic literature search was conducted across PubMed, EMBASE, and MEDLINE databases for primary studies published prior to January 2022. Pediatric status in OLTs was defined as age &lt; 18 at diagnosis, since many studies did not assess skeletal maturity. The main outcomes were clinical and radiological success rates, defined as achievement of good or fair outcomes according to measures used by individual studies. Articles were categorized by treatment method, and outcome rates were obtained via simple pooling. Results: 35 studies involving 714 lesions were included. Studies were categorized into five overarching treatment methods – (1) conservative treatment, (2) bone marrow stimulation, (3) retrograde drilling, (4) fixation, and (5) osteochondral transplantation. These interventions had pooled clinical success rates of (1) 45%, (2) 85%, (2) 90%, (4) 82%, and (5) 74%, respectively. The pooled radiological success rates were (1) 58%, (2) 85%, (3) 55%, (4) 89%, and (5) 81%. Escalation from conservative to surgical treatment occurred at a rate of 62% among studies in which this was reported. Articles were heterogeneous in measurement tools and pre- treatment characteristics; average baseline lesion size was (1) 129.8, (2) 131.0, (3) 87.8, (4) 137.8, and (5) 237.5mm^2 across the five treatment methods, and initial Berndt-Harty staging was likewise disparate. Conclusion: Conservative treatments yielded lower clinical and radiological success rates than surgical interventions, but warrant an initial trial in stable lesions due to their cost-effective and non-invasive nature. Surgery should be indicated for unstable lesions, or failed conservative treatment. Drilling and bone marrow stimulation are effective in lower grade lesions, while fixation should be considered for loosened fragments, and transplantation for large, non-salvageable lesions. Future research utilizing more robust methodology and reporting outcomes according to baseline lesion characteristics will consolidate these guidelines.

All-Arthroscopic Treatment of Off-Track Hill–Sachs Lesions Using Fresh Osteochondral Allograft Plugs: “Rocks in a Stream”

Osteochondral allograft transplantation is a well-described technique for the treatment of large, engaging Hill–Sachs lesions. Traditionally, osteochondral allografts are size-matched to the defect, which can be expensive and time-consuming, and the majority of described techniques require an open approach. This Technical Note describes an all-arthroscopic approach to Hill–Sachs osteochondral allograft transplantation using premade osteochondral allograft plugs, eliminating the need for size-matching and graft harvest. This approach works not by anatomically filling the defect, but rather by bridging the defect to prevent it from engaging the glenoid.

Characteristics and Clinical Outcomes After Osteochondral Allograft Transplantation for Treating Articular Cartilage Defects: Systematic Review and Single-Arm Meta-analysis of Studies From 2001 to 2020.

Osteochondral allograft transplantation (OCA) treats symptomatic focal cartilage defects with satisfactory clinical results. To comprehensively analyze the characteristics and clinical outcomes of OCA for treating articular cartilage defects. Systematic review; Level of evidence, 4. We searched Embase, PubMed, Cochrane Database, and Web of Science for studies published between January 1, 2001, and December 31, 2020, on OCA for treating articular cartilage defects. Publication information, patient data, osteochondral allograft storage details, and clinical outcomes were extracted to conduct a comprehensive summative analysis. In total, 105 studies involving 5952 patients were included. The annual reported number of patients treated with OCA increased from 69 in 2001 to 1065 in 2020, peaking at 1504 cases in 2018. Most studies (90.1%) were performed in the United States. The mean age at surgery was 34.2 years, and 60.8% of patients were male and had a mean body mass index of 26.7 kg/m2. The mean lesion area was 5.05 cm2, the mean follow-up duration was 54.39 months, the mean graft size was 6.85 cm2, and the number of grafts per patient was 54.7. The failure rate after OCA was 18.8%, and 83.1% of patients reported satisfactory results. Allograft survival rates at 2, 5, 10, 15, 20, and 25 years were 94%, 87.9%, 80%, 73%, 55%, and 59.4%, respectively. OCA was mainly performed on the knee (88.9%). The most common diagnosis in the knee was osteochondritis dissecans (37.9%), and the most common defect location was the medial femoral condyle (52%). The most common concomitant procedures were high tibial osteotomy (28.4%) and meniscal allograft transplantation (24.7%). After OCA failure, 54.7% of patients underwent revision with primary total knee arthroplasty. The annual reported number of patients who underwent OCA showed a significant upward trend, especially from 2016 to 2020. Patients receiving OCA were predominantly young male adults with a high body mass index. OCA was more established for knee cartilage than an injury at other sites, and its best indication was osteochondritis dissecans. This analysis demonstrated satisfactory long-term postoperative outcomes.

Autologous Costal Osteochondral Transplantation for Cystic Osteochondral Lesions of the Talus: Feasible and Effective.

Osteochondral lesions of the talus (OLT) is a common and clinically challenging disease. The optimal management is still under debate. The purpose of this prospective study was to investigate the feasibility and clinical outcomes of autologous costal osteochondral transplantation (ACOT) for the treatment of cystic OLT. From November 2021 to April 2023, five patients underwent autologous costal osteochondral transplantation (ACOT) for cystic OLT. The demographic data was described, including age, gender, lesion size and location. We prospectively evaluated their functional and imaging outcomes of the five patients for 12 months postoperatively, including numeric rating score (NRS) for pain when walking, Tegner score, American Orthopedic Foot & Ankle Society (AOFAS) score and Foot and Ankle Ability Measure (FAAM) score, and imaging results. A paired t-test was used for preoperative and postoperative comparison of the paired-design dataset. The average age was 36.6 ± 11.1 years. The average diameter of chondral lesions was 14.95 ± 2.71 mm, the average diameter of subchondral cysts was 10.66 ± 1.84 mm, and their average depth was 10.40 ± 1.86 mm. At 12 months postoperatively, the clinical function indexes improved significantly, including NRS (from 5.2 ± 2.3 to 0), Tegner score (from 3.2 ± 0.4 to 5.8 ± 0.4), AOFAS score (from 72.8 ± 10.0 to 98.2 ± 4.0), and FAAM score (FAAM/ADL from 61.2 ± 24.7 to 99.3 ± 1.6; FAAM/Sports from 32.5 ± 13.73 to 96.3 ± 8.4). Their magnetic resonance observation of cartilage repair tissue (MOCART) scores reached 78.0 ± 7.6 points. ICRS scores of three patients were nearly normal (10 or 11 points). The biopsy of the surviving grafts showed plenty of hyaline cartilage matrix and scattered chondrocytes histologically. No major severe complications were reported during the 12 months follow-up. ACOT could significantly relieve the symptoms of patients with OLT and improve their clinical function at short-term follow-up. ACOT might be a feasible and useful method for repairing OLT with subchondral cysts.

Minimum 10-Year Clinical Outcomes and Survivorship of Meniscal Allograft Transplantation With Fresh-Frozen Allografts Using the Bridge-in-Slot Technique.

Meniscal allograft transplantation (MAT) has been shown to provide clinical benefits in patients with symptomatic meniscal deficiency in the short term and midterm. There is, however, a paucity of data regarding long-term outcomes after MAT using fresh-frozen allografts and the bridge-in-slot technique. To report clinical outcomes and revision rates after primary MAT with fresh-frozen allografts and the bridge-in-slot technique in a large case series of patients at a 10-year minimum follow-up. Case series; Level of evidence, 4. A retrospective review of prospectively collected data was performed on patients undergoing primary MAT between 2001 and 2012. Lysholm, International Knee Documentation Committee subjective form, and Knee injury and Osteoarthritis Outcome Score subscales were collected preoperatively and at 1-, 2-, 5-, and minimum 10-year follow-ups. Cox proportional hazards modeling was used to identify variables associated with reoperation and failure, defined as revision MAT or conversion to arthroplasty. Reoperation was defined as a subsequent surgical intervention on the transplanted meniscus, including partial or total meniscectomy, meniscal repair, or failure as defined in the previous sentence. A total of 174 patients undergoing MAT met the inclusion criteria and were followed for a mean of 12.7 ± 2.7 years (range, 10.0-21.0 years). The mean age at surgery was 28.3 ± 10.1 years. The patients were predominantly female (n = 92; 53%), and medial MAT was the most commonly performed procedure (n = 91; 52%). Concomitant procedures were performed in 115 patients (66%), with the most common procedure being osteochondral allograft transplantation (n = 59; 34%). Patients demonstrated statistically significant postoperative improvements at all time points for all patient-reported outcome measures (P≤ .0001). A total of 65 patients (37%) underwent a meniscal reoperation at a mean time of 6.6 ± 5.5 years (range, 0.3-16.7 years) postoperatively. A total of 40 patients (23%) met the criteria for failure at a mean time of 7.3 ± 5.0 years (range, 1.0-17.4 years) after MAT, with 22 of these patients having undergone a previous meniscal reoperation. At the final follow-up, 13 patients (7%) had undergone revision MAT and 27 (15%) had converted to arthroplasty. The MAT survival rates free of meniscal reoperation and failure were 73% and 85% at 10 years and 60% and 72% at 15 years, respectively. At the time of the final follow-up, 86% of patients reported that they were satisfied with their overall postoperative condition. Primary MAT demonstrates efficacy and durability with high rates of patient satisfaction at a minimum 10-year follow-up. Patients should be counseled that although reoperation rates may approach 40% at 15 years, rates of overall revision MAT and conversion to arthroplasty remain low at long-term follow-up.

Early Complication Rates Are Equivalent Between Isolated Cartilage Restoration and Concomitant Cartilage Restoration and Osteotomy of the Knee.

Realignment osteotomy performed concomitantly with cartilage restoration typically requires early restricted weightbearing and can add significant morbidity, potentially leading to an increased risk of early perioperative complications. The purpose of this study was to compare the 30-day complication rates after isolated cartilage restoration (ICR) versus concomitant cartilage restoration and osteotomy (CRO) using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. NSQIP registries between 2006 and 2019 were queried using Current Procedural Terminology codes to identify patients undergoing ICR (autologous chondrocyte implantation, osteochondral autograft transfer, or osteochondral allograft transplantation) and CRO (with concomitant high tibial osteotomy, distal femoral osteotomy, and/or tibial tubercle osteotomy). Complications rates between treatment groups were compared using multivariate logistic regression analyses adjusted for sex, age, steroid use, and respiratory status. A total of 773 ICR and 97 CRO surgical procedures were identified. Mean patient ages were 35.9 years for the ICR group and 31.2 years for the CRO group. Operative time was significantly longer in the CRO group (170.8 min) compared with the ICR group (97.8 min). Multivariate analysis demonstrated no significant differences in rates of PE, VTE, and all-cause readmission between the ICR and CRO groups. No events of wound disruption, SSI and reoperation were found in the CRO group, while the ICR group was characterized by low rates of wound disruption, reoperation, and SSI (<1.1%). These findings further support concomitant osteotomy with cartilage restoration when appropriate and aid surgeons in the preoperative counseling of patients undergoing cartilage restoration treatment.

Effect of storage media on chondrocyte viability during cold storage of osteochondral dowels.

Osteochondral allograft transplantation is a successfully proven method to repair articular cartilage defects and prevent the degenerative effects of osteoarthritis. The number of osteochondral transplantations that can be performed each year is limited by availability of donor cartilage tissue and storage time constraints. Osteochondral transplantation success has been linked to high chondrocyte viability of the donor cartilage tissue at the time of implantation. Determining optimal storage conditions for donor cartilage is essential for tissue banks to safely provide quality cartilage tissue. In this study, we compared three tissue/cell media (DMEM/F12, RPMI-1640 and X-VIVO 10) for their ability to maintain chondrocyte viability during hypothermic storage for 28days. Porcine osteochondral dowels were stored in each media for 28days and cell viability was assessed every 7days. Over the 28day storage period, the chondrocyte viability of dowels stored in DMEM/F12, RPMI-1640, and X-VIVO 10 media all declined in a similar fashion. Our results show that all three media were equivalent in their ability to maintain cell viability of the cartilage tissue and provides rationale for the use of lower cost cell media (DMEM/F12 and RPMI-1640) for hypothermic storage of articular cartilage tissue.

Revision and Conversion to Arthroplasty Are Low Among Adolescents Undergoing Meniscal Allograft Transplantation Using the Bridge-In-Slot Technique at Midterm Follow-Up

To report midterm outcomes after primary medial and lateral meniscal allograft transplantation (MAT) withfresh-frozen allografts implanted with the bridge-in-slot technique in the adolescent patient population. Adolescent patients less than 18 years old at the time of primary MAT from 1999 to 2016 were retrospectively identified. International Knee Documentation Committee (IKDC) subjective form, Lysholm, and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales scores were collected before surgery and at 1-year, 2-year, and a minimum 5-year follow-up. Thresholds for achieving clinically significant outcomes were calculated, and the proportion of patients achieving minimal clinically important difference (MCID), patient-acceptable symptomatic state (PASS), and substantial clinical benefit (SCB) was determined. Meniscus reoperation (partial, subtotal, or total meniscectomy, repair, or failure) and failure (revision MAT or conversion to arthroplasty) rates were determined. Forty-four (female n= 33; male n= 11) of 62 identified patients met inclusion criteria and were followed for a mean of 9.5 ± 3.8 years (range, 5.0-17.7). Lateral MAT was performed in most patients (n= 35/44 [80%]). Isolated MAT was performed in 27 (61%) patients. Common concomitant procedures included osteochondral allograft transplantation (32%), autologous chondrocyte implantation (18%), and anterior cruciate ligament reconstruction (14%). MCID, PASS, and SCB were achieved by patients at a minimum 5-year follow-up for IKDC (62%; 76%; 31%), Lysholm (62%; 79%; 23%), and KOOS questionnaires (Pain [65%; 81%; 41%], Symptoms [58%; 81%; 47%], Activities of Daily Living [53%; 77%; 35%], Sport [86%; 75%; 50%], and Quality of Life [59%; 81%; 59%]), respectively. Fourteen patients (32%) underwent reoperation at an average of 5.0±4.3 years (range, 0.8-14.0) after MAT. Three (7%) patients met criteria for failure, requiring revision MAT an average of 3.8 ± 1.1 years (range, 2.8-4.9) after transplantation. No patients underwent arthroplasty. Overall survival free from failure at 1, 2, 5, and 10 years was 100%, 100%, 93%, and 93%, respectively. At the time of final follow-up, 80% of patients reported satisfaction with their current physical status. Primary MAT in adolescent patients resulted in significant and durable functional improvements at mid- to long-term follow-up. At an average of 9.5 years after surgery, meniscal reoperation rate was 32% whereas graft survival free of revision MAT was 93%. Adolescents undergoing MAT demonstrated similar functional outcomes and graft survivability when compared to available adult MAT literature. Level IV, retrospective case series.

Treatment of Chondral Lesions in the Knee.

Articular cartilage injuries are common and lead to early joint deterioration and osteoarthritis. Articular cartilage repair techniques aim at forming a cartilaginous neo-tissue to support the articular load and prevent progressive degeneration. Several techniques are available for this purpose, such as microfracture and chondrocyte transplantation. However, the procedural outcome is often fibrocartilage, which does not have the same mechanical resistance as cartilaginous tissue. Procedures with autologous osteochondral graft have a morbidity risk, and tissue availability limits their use. As such, larger lesions undergo osteochondral transplantation using fresh or frozen grafts. New techniques using minced or particulate cartilage fragments or mesenchymal stem cells are promising. This paper aims to update the procedures for treating chondral lesions of the knee.

Update in diagnosis, treatment, and prevention of osteochondritis dissecans of the capitellum.

Osteochondritis dissecans of the capitellum is debilitating and is a potentially sports career-ending injury in a young and athletic population. Osteochondritis dissecans typically occurs in patients between the ages of 10 and 24 years, and boys are more commonly affected than girls. Conventional radiographs have low diagnostic accuracy, and magnetic resonance imaging (with or without contrast) or computed tomography may aid in accurate diagnosis. The primary indication for non-operative treatment is the presence of an intact cartilage cap on magnetic resonance imaging, indicating a "stable lesion." However, if operative treatment is necessary, various surgical procedures are available when operative treatment for an osteochondritis dissecans of the capitellum is considered, including open or arthroscopic removal of loose bodies, with or without microfracturing, fragment fixation, osteochondral autograft transplantation, and osteochondral allograft transplantation. The decision-making process for selecting the appropriate treatment considers factors such as the patient's characteristics, functional limitations, and lesion morphology.

Ankle arthritis: joint-preserving surgery and total ankle arthroplasty

Ankle arthritis affects approximately 1% of the adult population worldwide and represents a serious global disease burden. However, compared with hip arthritis and knee arthritis, the clinical understanding and treatment of ankle arthritis are still in their infancy. For end-stage ankle arthritis, ankle arthrodesis was considered as the "gold standard" in the past. However, ankle arthrodesis will result in loss of joint mobility, altered gait, limited daily activities, and accelerated degeneration of adjacent joints. Therefore, how to preserve the range of motion of the ankle joint while relieving pain is the key to the treatment of ankle arthritis. Currently, the surgical treatment of ankle arthritis includes arthroscopic debridement, periarticular osteotomies, osteochondral transplantation, ankle distraction arthroplasty, ankle arthrodesis, and total ankle arthroplasty. The choice of treatment should be individualized and based on various factors such as the patient's symptoms, signs, imaging performance, complaints, and financial situation. However, there are no guidelines that give clear treatment recommendations. Therefore, it is necessary to conduct extensive and in-depth discussions on the diagnosis and treatment of ankle arthritis.

Bioinspired gradient scaffolds for osteochondral tissue engineering.

Repairing articular osteochondral defects present considerable challenges in self-repair due to the complex tissue structure and low proliferation of chondrocytes. Conventional clinical therapies have not shown significant efficacy, including microfracture, autologous/allograft osteochondral transplantation, and cell-based techniques. Therefore, tissue engineering has been widely explored in repairing osteochondral defects by leveraging the natural regenerative potential of biomaterials to control cell functions. However, osteochondral tissue is a gradient structure with a smooth transition from the cartilage to subchondral bone, involving changes in chondrocyte morphologies and phenotypes, extracellular matrix components, collagen type and orientation, and cytokines. Bioinspired scaffolds have been developed by simulating gradient characteristics in heterogeneous tissues, such as the pores, components, and osteochondrogenesis-inducing factors, to satisfy the anisotropic features of osteochondral matrices. Bioinspired gradient scaffolds repair osteochondral defects by altering the microenvironments of cell growth to induce osteochondrogenesis and promote the formation of osteochondral interfaces compared with homogeneous scaffolds. This review outlines the meaningful strategies for repairing osteochondral defects by tissue engineering based on gradient scaffolds and predicts the pros and cons of prospective translation into clinical practice.

Dual-tissue transplantation versus osteochondral autograft transplantation in the treatment of osteochondral defects: a porcine model study

BackgroundOsteochondral injury is a common sports injury, and hyaline cartilage does not regenerate spontaneously when injured. However, there is currently no gold standard for treating osteochondral defects. Osteochondral autograft transplantation (OAT) is widely used in clinical practice and is best used to treat small osteochondral lesions in the knee that are < 2 cm2 in size. Autologous dual-tissue transplantation (ADTT) is a promising method with wider indications for osteochondral injuries; however, ADTT has not been evaluated in many studies. This study aimed to compare the radiographic and histological results of ADTT and OAT for treating osteochondral defects in a porcine model.MethodsOsteochondral defects were made in the bilateral medial condyles of the knees of 12 Dian-nan small-ear pigs. The 24 knees were divided into the ADTT group (n = 8), OAT group (n = 8), and empty control group (n = 8). At 2 and 4 months postoperatively, the knees underwent gross evaluation based on the International Cartilage Repair Society (ICRS) score, radiographic assessment based on CT findings and the magnetic resonance observation of cartilage repair tissue (MOCART) score, and histological evaluation based on the O'Driscoll histological score of the repair tissue.ResultsAt 2 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score were significantly better in the OAT group than the ADTT group (all P < 0.05). At 4 months postoperatively, the ICRS score, CT evaluation, MOCART score, and O'Driscoll histological score tended to be better in the OAT group than the ADTT group, but these differences did not reach statistical significance (all P > 0.05).ConclusionsIn a porcine model, ADTT and OAT are both effective treatments for osteochondral defects in weight bearing areas. ADTT may be useful as an alternative procedure to OAT for treating osteochondral defects.

Young Age and Concomitant or Prior Bony Realignment Procedures are Associated with Decreased Risk of Failure of Osteochondral Allograft Transplantation in the Knee: A Nationwide Database Study.

Osteochondral allograft (OCA) transplantation is a restorative surgical option for large, full-thickness chondral or osteochondral defects in the knee. Variability in outcomes reporting has led to a broad range of graft survival rates. Using rate of salvage surgery following OCA as a failure metric, the purpose of this study was to analyze the incidence and risk factors for failure in a nationwide cohort. The M151Ortho PearlDiver database was queried for patients aged 20 to 59 who underwent primary OCA between 2010 and 2020. Patients with prior cartilage procedures or arthroplasty were excluded. Kaplan-Meier survival analysis was performed to characterize cumulative rate of salvage surgery, defined as any patient subsequently undergoing revision OCA, autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), unicompartmental knee arthroplasty (UKA), or total knee arthroplasty (TKA). Multivariable logistic regression was used to determine the effect of several variables on odds of salvage surgery. Around 6,391 patients met inclusion criteria. Cumulative 5-year salvage rate was 1.71%, with 68.8% in the first 2 years. Age 20 to 29 and concomitant or prior bony realignment procedures were associated with significantly decreased rate of salvage surgery (age-adjusted odds ratio [aOR] = 0.49, 95% confidence interval [CI], 0.24-0.99, P = 0.046; realignment-aOR = 0.24, 95% CI, 0.04-0.75, P = 0.046). In the largest OCA cohort studied to date, less than 2% of patients required salvage surgery. Young age and bony realignment were protective. These findings suggest that OCA in the knee is a durable cartilage-restoration procedure, especially in young patients with corrected alignment.

Paper 52: Pre- and Post-operative Patient Management by an Integrated Care Team Reduces Postoperative Failure Rates Following Osteochondral Allograft Transplantation in the Knee

Objectives: To assess the effects of an integrated care team including a health behavior psychologist on postoperative adherence and associated outcomes for patients undergoing osteochondral and/or meniscus allograft transplantation in the knee. Methods: With IRB approval and documented informed consent, patients were prospectively enrolled into a registry dedicated to following outcomes after OCA and meniscus allograft transplantation surgery between January of 2016 and April of 2021. Patients undergoing primary osteochondral and/or meniscus allograft transplantation to address symptomatic full-thickness cartilage loss and/or meniscus deficiency were included. Patient adherence rates and outcomes were compared based on two cohorts: patients that did not see a behavioral health psychologist preoperatively, and patients that met preoperatively identify potential barriers to adherence, set expectations for postoperative protocols, and identify a plan to moderate risk factors to non-adherence. Patients in both cohorts met preoperatively with the rest of the integrated care team specializing in joint preservation. Data were collected preoperatively, and at all follow-up visits at 3 months, 6 months, and yearly post-operatively. Visual analog scale (VAS) pain scores, International Knee Documentation Committee scores, PROMIS Global Health, and PROMIS Pain interference scores were collected. Treatment failure was defined as any reoperation to revise any of the osteochondral and/or meniscus allografts (revision) or for conversion to arthroplasty in the affected knee. Functional survival (success) was defined as patient- reported pain and function scores improved from pre-operative levels without need for revision or arthroplasty. Patients were categorized as nonadherent when documented evidence of a break from the physical therapy protocol was recounted to a member of the healthcare team by the patient or their physical therapy provider. Data were included for analyses when applicable registry data were available for at least one year following surgery. Chi-square or Fisher’s exact tests were used to analyze differences in proportions, while unpaired t-Tests, one-way analysis of variance tests, or rank sum tests were used to assess significant differences in variables with continuous data. Significance was set a priori at p &lt; 0.05. Results: For patients in the study (n=213), 23.4% were documented to be nonadherent. Of those who were nonadherent, 4 (8.0%) were in the Health Psych cohort versus 46 (92.0%) who were not. Patients in the No Health Psych cohort were significantly more likely to be nonadherent to postoperative rehabilitation protocols (p = .023, OR = 3.4). Tobacco use (p&lt;.001, OR = 7.9), higher preoperative PROMIS Pain Interference score (p&lt;.001), lower preoperative PROMIS Mental Health score (p&lt;.001), older age (p&lt;.001) and higher BMI (p&lt;.001) were also significantly associated with nonadherence. 81.6% of adherent patients had successful outcomes (mean final follow-up 46.7 months, range 12-75), while 40% of nonadherent patients required revision or total knee arthroplasty during the study period, such that nonadherent patients were 3x more likely (p = .004) to experience treatment failure. In this cohort of patients, male sex (p&lt;.001, OR = 3.4) and bipolar OCA transplantation surgeries (p&lt;.001, OR = 5.0) were also significantly associated with increased risk for treatment failure. Conclusions: Preoperative education and postoperative support for patients provided by an integrated care team including a health psychologist can significantly improve adherence and outcomes following osteochondral and meniscal allograft transplantation in the knee.

Poster 365: Initial outcomes after unicompartmental tibiofemoral bipolar osteochondral and meniscus allograft transplantation in the knee using high-viability tissues

Objectives: To report initial outcomes for unicompartmental tibiofemoral bipolar osteochondral allograft transplantation (OCAT) with meniscus allograft transplantation (MAT) using fresh high-cell- viability tissues for treatment of knee articular cartilage defects with meniscus deficiency. The study was designed to test the hypothesis that primary OCAT and MAT using high-viability tissues will be associated with successful short-term (2 to 6 years) outcomes based on statistically significant and clinically meaningful improvements in pain and function in the majority of patients. Methods: With IRB approval and documented informed consent, patients who underwent primary OCAT and MAT for large articular cartilage defects with meniscus deficiency involving at least one femoral condyle, tibial plateau, and meniscus, all of which were opposing (bipolar). Surgeries were defined as Uni when patients underwent OCAT and MAT involving one femoral condyle, tibial plateau, and meniscus in the same compartment or Uni-Plus when patients underwent Uni OCAT and MAT with at least one other OCA transplant to treat a large (&gt;2.5cm2) grade III or IV focal articular cartilage defect of the patella, trochlea, femoral condyle, or tibial plateau. Patients who had at least 2-year follow up data regarding complications, failures, adherence, and patient reported outcome measures (PROMs) were analyzed. Patients who required OCA and/or MAT revision or artificial arthroplasty were defined as treatment failures. Patient reported outcome measures (PROMs) including VAS pain, IKDC, SANE, PROMIS Global Health and Physical Function, were collected at 3 and 6 months and then yearly after transplantation. Outcomes were compared based on patient sex, age, and BMI, tobacco use, previous and concurrent procedures, differences in number of surfaces transplanted (Uni vs Uni-Plus), and adherence. Significance was set at P &lt; 0.05. Differences in PROMs were also assessed for minimum clinically important differences. Results: Seventy-six patients (n=52 males; 68%) met inclusion criteria (mean followup = 52 months; median = 56 months; range, 24-70 months). Mean age was 41.1 years (range, 15-69 years) and mean body mass index (BMI) was 28.9 kg/m2 (range, 17-46). Forty-eight patients underwent OCAT(s) in addition to Uni (Uni-Plus). Eight patients (10.5%) underwent concurrent ACL reconstruction, and 28 patients (36.8%) underwent ipsilateral lower extremity osteotomy in order to address co-morbidities. Twenty-three patients (30.3%) were documented to be non-adherent during the first year after transplantation. Initial (&gt;2-year) success rate was 77.6% with 8 patients (10.5%) undergoing OCA and/or MAT revision and 9 patients (11.8%) converted to arthroplasty. Variables associated with increased risk for treatment failure (revision or arthroplasty) included ipsilateral osteotomy (p = .046; OR = 3.3), ipsilateral concurrent procedure (p = .0057; OR = 5.5), and non-adherence (p = .0009; OR = 7.2). None of the patients undergoing OCA and/or MAT revision surgery in the present study required arthroplasty at the time of data analysis such that overall success rate for primary and revision unicompartmental bipolar OCA plus MAT was 88.2%. There were statistically significant (p &lt; .0001) and clinically important improvements from preoperative levels for all patient reported outcomes at each annual follow-up time point. Conclusions: Unicompartmental tibiofemoral bipolar osteochondral and meniscus allograft transplantation can result in successful short-term (2 to 6 years) outcomes and satisfaction in the majority (78%) of patients. Primary MOPS-preserved OCAT and MAT for treatment of femoral condyle and tibial plateau articular cartilage defects with concurrent meniscus deficiency was associated with statistically significant and clinically meaningful improvements in patient-reported measures of pain and function.

Poster 254: Osteochondral Allograft Transplantation Using Dowell Technique for the Treatment of Steroid-Associated Osteonecrosis of the Femoral Condyles: Arthroplasty-Free Survival at 5 and 10 Years

Objectives: Steroid-associated osteonecrosis of the femoral condyles is a known complication of long- term or high dose steroid exposure. This is a not infrequent situation for patients with inflammatory conditions such as Lupus or Ulcerative Colitis and in patients with malignancies leukemia requiring bone marrow transplant. Historically, osteonecrosis was a contraindication for osteochondral allograft transplantation (OATS), however, recent evidence has indicated OATS maybe a durable treatment option. While results using the shell OATS technique has been reported in the steroid-associated osteonecrosis population, there is a dearth of information on the long-term survival for the newer dowel OATS technique. The aim of this study was to retrospectively analyze survival of OATS using the dowel technique for the treatment of steroid-associated osteonecrosis of the femoral condyles. Methods: Institutional database was queried to identify eligible patients. Inclusion criteria included diagnosis of aseptic or secondary osteonecrosis of the distal femur, osteochondral allograft transplantation surgical treatment, dowel OATS technique, and history of steroid use for a medical condition. Exclusion criteria included previous cartilage restoration or arthroplasty surgery and incomplete records. No age criteria were used to exclude patients. Patient charts were reviewed for demographic details, information about underlying pathologic condition and steroid exposure, surgical details, and revision OATS or conversation to arthroplasty. Primary outcomes were arthroplasty-free survival and revision-free survival. Results: 27 knees in 25 patients with an average age of 27.6 years (range 16-59 years) were identified with an average follow up of 6.2 years (range 0.7-22 years). Medical conditions included 10 malignancies (5 post-bone marrow transplant) and 13 autoimmune diseases. Distribution of osteonecrosis of the femoral condyles included 1 isolated medial condyle, 5 isolated lateral condyles, 21 medial and lateral condyles. All patients underwent dowel OATS technique. Patients received on average of 2.2 grafts (range 1-5 grafts) with an average combined graft area of 6.67 cm2 (range 1.5 to 20.4 cm2). 10 patients had concomitant procedures and 10 patients had supplemental graft fixation. All patients were treated between 2006 and 2020. Arthroplasty-free survival was 88%, 85%, 60% at 5, 8, 10 years. Revision OATS or arthroplasty free survival was 81%, 77%, 55% at 5, 8, 10 years. Graft failures included 1 revision OATS at 7.7 years secondary to cartilage delamination and 4 conversions to total knee arthroplasty at 1.6, 1.9, 8.7, 9.5 years. Conclusions: Osteochondral Allograft Transplantation is an acceptable and durable treatment option in patients with steroid-associated osteonecrosis with 88% arthroplasty-free survival at 5 years and 60% arthroplasty-free survival at 10 years. Future studies should capture patient reported outcomes and investigate factors leading to arthroplasty conversion such as age at time of OATS, etiology of osteonecrosis, extent of osteonecrosis. [Table: see text]