Fresh Osteochondral Allograft Transplantation Research Articles

Outcomes After Osteochondral Allograft Transplantation of the Medial Femoral Condyle in Patients With Varus and Nonvarus Alignment

Background: Fresh osteochondral allograft (OCA) transplantation is an effective technique for the treatment of focal chondral and osteochondral defects in the knee. Coronal-plane malalignment leads to increased contact forces within a compartment and subsequently the cartilage repair site and may lead to higher failure rates. However, the magnitude of the effect of coronal-plane malalignment on graft survivorship and clinical outcomes has not been well characterized. Purpose: To evaluate how varus malalignment affects graft survival and patient-reported outcomes after isolated OCA transplantation of the medial femoral condyle (MFC). Study Design: Cohort study; Level of evidence, 3. Methods: A total of 70 patients (74 knees) who underwent primary OCA transplantation of the MFC between 2005 and 2019 were identified from a prospectively collected single-surgeon cartilage registry with a minimum 2-year follow-up. Coronal-plane alignment was evaluated utilizing standing hip-to-ankle radiographs. OCA failure, defined as removal of the graft or conversion to arthroplasty, and reoperations were recorded. Patient-reported outcomes were obtained preoperatively and postoperatively using the International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, modified Merle d’Aubigné–Postel score, and overall patient satisfaction score. Results: The mean mechanical tibiofemoral angle for patients with varus alignment was 3.9° of varus (range, 1.1° to 8.9°) and for patients with nonvarus alignment it was 0.02° of valgus (range, 3.6° varus to 4.6° valgus). Graft survivorship was 95.3% in the varus group and 95.8% in the nonvarus group (P = .918) at 5 years postoperatively. Reoperations after OCA transplantation occurred in 14.0% of the varus group and 22.6% of the nonvarus group (P = .336). The mean International Knee Documentation Committee total score improved from 45.2 preoperatively to 74.8 at latest follow-up in the varus group and from 40.5 preoperatively to 72.3 at latest follow-up in the nonvarus group. Patient satisfaction was >85%. Conclusion: Patients undergoing isolated OCA transplantation of the MFC had high rates (>90%) of graft survivorship and significant improvements in pain and function. Patients with mild preexisting varus malalignment were found to have no difference in the failure rate or clinical outcomes compared with patients with nonvarus alignment.

Fresh Osteochondral Allograft Transplantation of the Capitellum for the Treatment of Osteochondritis Dissecans

Background: Osteochondritis dissecans (OCD) of the humeral capitellum is a rare and challenging condition to treat. Several surgical options exist, but in the last few years, the pendulum has swung from debridement and microfracture to restoration of the articular surface. Osteochondral autografts from the rib and knee have been described, but donor-site morbidity is a concern. Purpose: To expand the results of fresh osteochondral allograft transplantation (FOCAT) in a previously published report with inclusion of additional patients and a longer follow-up period. Study Design: Case series; Level of evidence, 4. Methods: After institutional review board approval, the charts of patients who underwent FOCAT for OCD of the capitellum between 2006 and 2022 by a single surgeon were reviewed. The majority of cases (94%) had unstable lesions (Minami grades 2 and 3). A trial of nonoperative treatment had failed in all. All patients underwent diagnostic arthroscopy, followed by a mini-open, ligament-sparing approach with grafting using commercially available guides and instruments. Results: A total of 35 patients were identified, of whom 25 were male. The mean age was 16 ± 3.9 years (range, 11-32 years). There were 24 baseball players (19 pitchers and 5 position players), 5 gymnasts, 3 cheerleaders/tumblers, 1 tennis player, 1 student (who did not participate in athletics), and 1 patient with avascular necrosis from chemotherapy. Eighteen patients had a mean flexion contracture of 14.1°± 11.9°. A single osteochondral allograft plug was used in 23 patients (mean diameter, 11.3 ± 2.8 mm), and 12 patients required 2 plugs (Mastercard technique). The mean follow-up was 92.6 ± 54.5 months (range, 24-204 months). There was significant improvement in Oxford (from 25.5 ± 4.9 to 46.7 ± 3.5; P < .00001) and visual analog scale for pain (from 7.5 ± 2 to 0.3 ± 1.0; P < .0001) scores. The mean Single Assessment Numeric Evaluation score at the time of follow-up was 90.6 ± 10.8 (range, 60-100). In overhead athletes, there was significant improvement in the Kerlan-Jobe Orthopaedic Clinic score (from 40.8 ± 11.8 to 90.6 ± 10.8; P < .00001). A postoperative magnetic resonance imaging scan was obtained in 16 (46%) patients at a mean of 32.6 months. In all cases, the graft was incorporated. All overhead athletes were able to return to their sport and perform at the same level or higher for >2 years. Two elbows required a subsequent arthroscopy for loose-body removal; otherwise, there were no other complications. Conclusion: FOCAT is an excellent option for treating OCD lesions of the humeral capitellum. Excellent outcomes and high return-to-sport rates were observed, with midterm follow-up showing no graft failures. FOCAT eliminates donor-site morbidity.

Fresh osteochondral allograft transplantation for knee full-thickness articular cartilage lesions using femoral head of living donors: short-term results.

Fresh osteochondral allograft transplantation is a good treatment option of cartilage defects. However, this treatment option is not available in all countries due to limited graft availability and tissue banks limitations. The purpose of this study is to assess the short term functional and imaging outcomes of fresh osteochondral allograft transplantation in the knee using the femoral head of living donors. Fresh osteochondral allografts from the femoral heads of living donors is a valid graft source for management of distal Femur cartilage defects. This technique can improve functional knee scores with good radiological outcomes. Prospective case series. Fifteen patients with full thickness cartilage defects of the distal femur underwent osteochondral allograft transplantation from the femoral heads of living donors. Grafts were transplanted by both shell and multiple dowels techniques. The average follow up duration was 18.3 months (range, 12-25 months). Patients were evaluated by Lysholm and International Knee Documentation Committee (IKDC) scores, radiography and MR imaging using Osteochondral Allograft MRI Scoring System (OCAMRISS). There was a statistically significant improvement (P < 0.001) in both Lysholm and IKDC average scores at 6 months and 12 months postoperative. Postoperative MRI was done at an average 6.8 months (range, 5-11 months) postoperative. The mean total OCAMRISS score was 3.4 (range, 1-7). A second look arthroscopy was done in four patients and showed intact articular cartilage in all three patients. Femoral head of living donors is a valid new source for fresh osteochondral allograft transplantation of knee osteochondral lesions. Short term results showed improvement in clinical assessment scores. Follow up imaging showed graft incorporation and good MRI scores.

Paper 49: Osteochondral Allograft Transplantation for Capitellar Osteochondritis Dissecans: Excellent Patient Reported Outcomes Scores and High Return to Sports

Objectives: Unstable osteochondritis dissecans of the capitellum (OCD-C) is treated surgically, most commonly with loose body removal and marrow stimulation. This treatment has historically been associated with suboptimal return to high-demand upper extremity sports (baseball and gymnastics) and persistent elbow pain. Fresh osteochondral allograft transplantation (OAlloT) is an alternative treatment which restores subchondral bone and articular cartilage without donor site morbidity associated with autograft harvest. The purpose of this study was to evaluate the outcomes of osteochondral allograft transplantation in pediatric patients with unstable OCD-C 10mm or greater in size. Methods: A single-center prospective study was performed of consecutive pediatric patients, less than 19 years of age, with unstable OCD-C 10mm or greater in size treated with primary fresh OCAlloT using pre-cut 10mm, 12mm, or 16mm cores. Imaging, including radiographs and MRI were obtained preoperatively to assess OCD size and characteristics, as well as postoperatively to assess incorporation of the OCA. Patient reported outcome scores (PROs), including sport data, were obtained preoperatively and annually following surgery. Minimum follow-up duration was 2 years. Results: 26 elbows in 24 patients, mean age 13.4 years (11.3 – 17.1 years) met inclusion. The most common primary sport was gymnastics in 11 elbows (42%), baseball/softball in 7 elbows (27%), and cheer in 3 elbow (12%). The majority of patients (88%) played at a competitive level. Median symptom duration prior to presentation was 3 months. The most common presenting symptoms were pain (85%) and mechanical symptoms (81%). Sixteen elbows (62%) presented with a &gt;5° loss of elbow extension compared to the contralateral side. The capitellar physis was open in 23 elbows (88%). OCD location was central in 17 elbows (65%) and far lateral in 9 elbow (35%). Mean MRI size of the OCD was 11 mm in coronal width, 12 mm in sagittal length, and 6 mm in depth. Twelve elbows (48%) had a loose body on MRI. The majority of elbows (22, 85%) were treated with a single allograft plug, while 4 elbows had two allograft plugs transplanted. Median OCA size was 12 mm. There were no infections nor arthrofibrosis. Two elbows (8%) had a secondary surgery, both underwent partial synovectomy and chondroplasty at 14- and 16-months following the primary surgery. Postoperative MRIs were obtained in 15 elbows (58%) and had a mean BOGIE (Boston Osteochondral Graft Incorporation in the Elbow) score of 11, thus documenting a high degree of incorporation. Mean follow-up duration was 40 months (range 25 – 60 months). All patients had preoperative, 1-year, and 2-year PROs (Table 1). 21 elbows (81%) had returned to sports at 1-year postoperatively9, and all but 1 patient had returned to sports by 2 years following surgery. Forty-five percent of gymnasts returned to gymnastics, while the remaining pursued different sports. Five of 6 baseball players (83%) returned to baseball. Conclusions: OCAlloT as a treatment for OCD-C is a procedure associated with low rates of complications, excellent graft incorporation, high elbow function and patient satisfaction, and overall high rates of return to sports at 2-years. Return to sports, particularly among gymnasts was less than 50% in this series, which we attribute to a combination of factors, including loss of training and competition time at a critical time for an elite gymnast as well as physician counseling on alternative sports with less stress on the elbow. Continued patient follow-up is ongoing and will be critical to the assessment of this treatment on the mid- and long-term outcomes in these young athletes. [Figure: see text]

Outcomes of Osteochondral Allograft Transplantation for Femoral Head Cartilage Lesions: Minimum 2-Year Follow-Up

BackgroundThe surgical management of large osteochondral lesions of the femoral head in young, active patients remains controversial. Fresh osteochondral allograft (OCA) transplantation can be a highly effective treatment for these lesions in some patients. This study investigated survivorship as well as clinical and radiographic outcomes after fresh OCA transplantation at a minimum 2-year follow-up (mean, 6.6 years; range, 0.6 to 13.7 years). MethodsA retrospective review of 29 patients who underwent plug OCA transplantation for focal femoral head osteochondral lesions between 2008 and 2021 was performed. Patients were assessed clinically using the modified Harris Hip score (mHHS) preoperatively and at each follow-up visit. Postoperative radiographs were evaluated for graft integrity and osteoarthritis severity. Kaplan-Meier survivorship analyses with 95% confidence intervals (CIs) were performed for the endpoint of conversion to total hip arthroplasty (THA). ResultsOverall graft survivorship for included patients was 78.4% (95% CI: 62.9 to 93.9) and 62.7% (95% CI: 39.6 to 85.8) at 5 and 10 years, respectively. There were ten patients (34.5%) who underwent conversion to THA. There was a significant difference using the log-rank test between survival for patients who had a preoperative diagnosis of osteonecrosis (ON) versus those who had other diagnoses (P = .002). The ten-year survival for those who had ON was 41.8% (95% CI: 4.8 to 78.8), and the ten-year survival for diagnoses other than ON was 85.7% (95% CI: 59.8 to 100). The mean mHHS score improved significantly (P < .001) from 48.9 (19 to 84) preoperatively to 77.4 (35 to 100) at the final follow-up. There were twenty patients (69.0%) who had mHHS ≥ 70 at the latest follow-up. Arthritic progression, indicated by an increase in the Kellgren and Lawrence grade, occurred in 7 hips (26.9%). ConclusionsAn OCA transplantation is a viable treatment option for osteochondral defects of the femoral head in young, active patients who have minimal preexisting joint deformity. It may delay the progression of arthritis and the need for THA. Patients who had a preoperative diagnosis of ON had worse clinical outcomes than those who had other diagnoses.

Treatment of Medial Patellar Instability With Bipolar Patellofemoral Cartilage Lesions: Staged De-rotational Distal Femoral Osteotomy Followed by Bipolar Osteochondral Allograft Transplantation and Tibial-Tubercle Osteotomy

Background: Patellar instability with symptomatic cartilage lesions in young patients is a challenging problem to treat. The use of osteotomies to correct malalignment and fresh osteochondral allograft transplantation (OCA) to address cartilage lesions and patellofemoral dysplasia is a viable treatment option for carefully selected patients. Indications: The patient is a 22-year-old woman with medial patellar instability caused by iatrogenic distal femoral external rotation and uncontained grade IV patellofemoral lesions. The patient was indicated for OCA because the lesions were too large for an osteochondral autograft transfer system (OATS) and were uncontained and not amenable to autologous chondrocyte implantation. Bipolar OCA also addresses the patient’s patellofemoral dysplasia by restoring a more morphologically normal patellofemoral joint. The external rotation and mild varus deformity are corrected with a biplanar distal femoral osteotomy. Correction of malalignment is necessary prior to OCA transplantation to avoid abnormal graft loading and thereby decrease the risk of graft failure. Technique Description: (1) Diagnostic arthroscopy and fluoroscopic examination under anesthesia. (2) Lateral closing wedge de-rotational distal femoral osteotomy. (3) Bipolar OCA with tibial tubercle osteotomy and removal of hardware. Results: In this case, the patient had significant improvement in her symptoms and had full knee range of motion with a normal gait at 3 months after surgery. Depending on a patient’s preoperative function and the specific pathology, full recovery can take considerably longer. A successful outcome is considered return to activities of daily living without significant pain. Return to higher level athletic activities is significantly more unpredictable. Graft survival of bipolar patellofemoral OCA is variable, and the literature is limited by the small number of procedures performed, but published series range from 60% to 85% at 5 years. Discussion/Conclusion: A successful outcome in these unique, complex cases depends on good patient selection, preoperative planning, and surgical execution. Patellar instability can be reliably treated when the predisposing anatomical factors are appropriately corrected. Bipolar OCA can provide significant improvement in pain and function, but continues to have the highest rate of graft failure compared with other sites within the knee, and should be considered a salvage operation for patients with significant limitations in activities of daily living. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Participation in Sports or Recreational Activities After Osteochondral Allograft Transplantation of the Talus

Background: Fresh osteochondral allograft (OCA) transplantation is a viable treatment option for osteochondral defects of the talus. However, sufficient data are not available on patients’ participation in sports or recreational activities after the procedure. Purpose: To assess whether patients undergoing OCA transplantation of the talus participated in sports or recreational activities postoperatively. Study Design: Case series; level of evidence, 4. Methods: A total of 36 ankles in 34 patients underwent OCA transplantation of the talus. At a mean follow-up of 9.2 years, information on participation in sports or recreational activities pre- and postoperatively was obtained, as well as postoperative pain, function, and satisfaction. Results: The mean age at the time of surgery was 36.1 years (range, 20.5-57.7 years), and 50% of patients were men. The mean graft size was 3.6 cm2 (range, 1-7.2 cm2) or 41.1% of the talar dome. Before the injury, 63.9% of patients (23/36 ankles) reported being highly competitive athletes or well trained and frequently sporting; 36.1% of patients (13/36 ankles) reported sometimes sporting or were nonsporting. Also, 66.7% of patients (24/36 ankles) were able to participate in sports or recreational activities after OCA transplantation and 50% (18/36 ankles) were still participating in sports or recreational activities at the latest follow-up. In a subset of well-trained or highly competitive athletes, 73.9% (17/23 ankles) were able to return to sports or recreational activities at any point after OCA transplantation, and 65.2% (15/23 ankles) were still participating at the latest follow-up. Further surgery occurred in 16.7% of patients (6/36 ankles). Graft survivorship was 94.3% at 5 years and 85.3% at 10 years. There was a significant improvement in the mean Olerud-Molander Ankle Scores, and the mean Foot and Ankle Ability Measure scores were high postoperatively. Moreover, 79.4% of patients (27/34 ankles) were either satisfied or extremely satisfied with the allograft surgery. Conclusion: Fresh OCA transplantation is a reasonable surgical option for osteochondral defects of the talus for young, active patients who have failed previous operative management or have massive defects.

Osteochondral Allograft Transplantation in the Knee

Osteochondral injuries of the knee can be a frequent source of debilitating pain and dysfunction. Significant chondral (>1.5-2 cm2) lesions of the femoral condyles can be especially difficult to manage with nonsurgical measures. Fresh osteochondral allograft (OCA) transplantation has been shown to be a reliable surgical procedure to manage a wide array of high-grade focal chondral lesions, with or without subchondral bone involvement. OCA transplantation affords the transfer of a size-matched allograft of mature hyaline cartilage with its associated subchondral bony scaffold. Indications include primary or secondary management of large, high-grade chondral or osteochondral defects secondary to trauma, developmental malformation, osteonecrosis, or other focal degenerative disease. Contraindications include end-stage osteoarthritis, uncorrected malalignment, ligament or meniscus deficiency, and inflammatory joint disease. Improvements in surgical technique, allograft storage, and tissue availability have created more reproducible clinical results and increased chondrocyte viability. Long-term (>10 year) graft survival rates have been shown to be between 70% and 91%, and the procedure has been shown to be cost-effective based on cost per quality-adjusted life year. Finally, OCA transplantation has been shown to provide excellent return to play rate for athletes with medium-to-large cartilage lesions. OCA transplantation is therefore an important option in the treatment algorithm of articular cartilage injuries.

Treatment of osteochondral injuries of the humeral head using fresh osteochondral allograft transplantation

BackgroundLarge osteochondral lesions of the humeral head can result from locked posterior dislocations, avascular necrosis, and osteochondritis dissecans. Fresh osteochondral allograft (OCA) transplantation is a treatment option for young patients with focal osteochondral defects of the humeral head. The purpose of this case series was to assess graft survivorship, subjective patient-reported outcomes (PROMs), and satisfaction among seven patients who underwent OCA transplantation of the humeral head. MethodsWe identified seven patients who underwent humeral head OCA transplantation between 2008 and 2017. A custom questionnaire for patient reported outcome measures including ASES, QuickDASH, Likert satisfaction, and reoperations was mailed to each patient. Clinical failure was defined as further surgery that involved removal of the allograft. ResultsMedian follow-up duration was 10 years (range, 4.6 to 13.5 years) with a median age of 21.6 years (range, 18.5 to 43.5 years). Most patients (86%) reported improved function and reduced pain. At final follow-up, 71% of patients reported ongoing problems with their shoulder including pain, stiffness, clicking/grinding, limited range of motion, and instability. Return to recreational activities was high at 86% but 43% expressed limitations with activity due to their shoulder. Overall satisfaction was high at 71% with mean ASES and QuickDASH scores at 62.4 and 29.2 respectively. Reoperation after OCA occurred in one patient (14%). ConclusionsAmong this case series of seven patients who underwent OCA transplantation of the humeral head, patient satisfaction was high at 10 year follow-up and most returned to recreational activity although most also had persistent shoulder symptoms.

Combined Trochlear, Patellar, Medial and Lateral Condyle Fresh Osteochondral Allograft Transplantation: A Case Report

Background: This is a case report of a 41-year-old man with torsional knee trauma in 2019 and chondral lesions. Previous microfracture had failed, and the patient presented with a dull pain and knee effusion. Imaging revealed multiple focal lesions including trochlea, patella, medial condyle, and lateral condyle. Fresh osteochondral allograft (OCA) transplantation is a versatile treatment for large defects as it is based on mature, living hyaline cartilage attached to a bone interface. A patient with multiple chondral lesions is rare, and this report presents a case with multiple symptomatic large focal lesions in the knee that underwent a fresh OCA in all 3 knee compartments. Indications: Osteochondral allograft is indicated for patients who present with activity-related pain and recurrent knee effusion. Contraindications are patient clinical conditions that may lead to complications, such as tobacco use, inflammatory arthritis, or septic arthritis. Technique Description: After the chondral defect is exposed, an appropriate allograft Mega-OATS sizer (15-30 mm) is chosen. Cartilage and the subchondral bone are drilled until the desired depth. The donor allograft is drilled in the desired diameter, and excess bone is removed according to the previous measurements of the recipient site. The graft is advanced with firm pressure into the created socket. Postoperative rehabilitation includes a limited range of motion and proprioceptive weightbearing in the first 2 weeks but expected total weightbearing and a full range of motion by the sixth week. Results: Range of motion was full by 6 weeks of surgery. The effusion lasted for 2 months after the surgery. Fresh OCA is a good surgical option for patients with multiple large chondral defects. Discussion/Conclusion: Patient satisfaction is high since the mature cartilage leads to a fast rehabilitation compared with the other surgical procedures for large chondral defects. This technique appears to be effective also for multiple focal lesions as presented in this article. Patient Consent Disclosure Statement: The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form.

Paper 69: Do Patients Participate in Sports or Recreational Activity After Osteochondral Allograft Transplantation of the Talus?

Objectives: Fresh osteochondral allograft (OCA) transplantation has been reported as a viable treatment option for chondral lesions of the talus, but there is insufficient data regarding patients’ participation in sports or recreational activity following the procedure. The purpose of this study was to assess the frequency of patients who participated in sports or recreational activity following OCA of the talus. Methods: We identified 36 ankles in 34 patients (70% well trained or highly competitive athletes) who underwent OCA transplantation of the talus. Mean age was 36 years and 50% were male. Postoperatively, participation in sport or recreational activity, foot and ankle ability measure (FAAM) scores, American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot scores, and patient satisfaction with the results of surgery were assessed. Further surgery on the ankle was captured, and OCA failure was defined as any operation that involved removal of the allograft. Results: At a mean follow up of 8.6 years, 67% of patients reported that they had participated in sports or recreational activity after the OCA transplantation. Among those who participated in sport or recreation, 68% returned to their pre-injury sport, 21% played in competitive sports, and 95% participated in regular exercise. Following the OCA transplantation, 17% of ankles required further surgery and 11% were classified as OCA failures (underwent revision OCA transplantation or fusion). There was significant improvement in FAAM and AOFAS ankle-hindfoot scores, and 79% of patients were either satisfied or extremely satisfied with the results of surgery. Survivorship of the OCA transplantation was 94% at five years and 85% at ten years. Conclusions: Fresh OCA transplantation is a reasonable surgical option for osteochondral defects of the talus for young, active patients who have failed non-operative management. Most patients participate in sports or recreational activity following OCA transplantation of the talus.

Early Postoperative CT Scan Provides Prognostic Data on Clinical Outcomes of Fresh Osteochondral Transplantation of the Knee

Background: There is a lack of information regarding the ability of imaging studies to predict clinical outcomes after fresh osteochondral allograft (FOCA) transplantation of the knee. Purpose: To determine the value of computed tomography (CT) scans to predict the clinical outcome of FOCA transplantation using the assessment computed tomography osteochondral allograft (ACTOCA) score. Study Design: Cohort study; Level of evidence, 3. Methods: We prospectively collected data from all consecutive patients who underwent FOCA transplantation for osteochondral knee lesions at one institution between August 2017 and August 2019. All patients were followed up for a minimum of 2 years. CT scans performed 6 months after surgery were evaluated by a musculoskeletal radiologist using the ACTOCA scoring system. The radiologist was blinded to the patient’s medical history. Clinical outcomes were assessed preoperatively and at 12 and 30 months postoperatively using the International Knee Documentation Committee (IKDC) score, the Kujala score, the Tegner activity scale, and the Western Ontario Meniscal Evaluation Tool (WOMET) score. Results: A total of 38 cases were included. The ACTOCA score at 6 months after surgery showed a statistically significant correlation with clinical results at 12 and 30 months. The correlation was better at 30 months, showing a high negative correlation with the IKDC score (−0.663) and a moderate negative correlation with the Kujala, WOMET, and Tegner scores (−0.593; −0.547, and −0.593, respectively) (P < .001). Conclusion: A statistically significant correlation between the mean ACTOCA score on CT scans at 6 months and the clinical results measured by the IKDC, Kujala, WOMET, and Tegner scores at 30 months confirmed the predictive value of the ACTOCA score for use in clinical practice.

Paper 42: Effects of Blood Type Mismatching on Functional Graft Survival after Osteochondral Allograft Transplantation

Objectives:To explore a factor that may contribute to potentially detrimental sub-rejection immune responses, we compared donor and recipient blood types following osteochondral allograft (OCA) transplants from a subset of patients in an IRB-approved dedicated lifelong registry to determine potential relationships for blood type mismatches with documented graft failures. The study was designed to test the hypothesis that OCA transplantation patients receiving blood type mismatched allografts would be more likely to require OCA revision or artificial arthroplasty surgery compared to those receiving donor-recipient matched allografts.Methods:A subset of patients was selected from those enrolled (n=414) in our center’s IRB-approved lifelong registry for OCA transplantation clinical outcomes. This subset included patients with complete donor and recipient ABO and Rh Factor data available such that there was a 2:1 ratio of successful versus failed outcomes for age-, BMI-, and joint-matched OCA transplant recipients for statistical analyses. Donor blood type information was obtained from the respective tissue banks. Recipient blood type information was obtained from electronic medical records. Patients who required OCA revision or artificial arthroplasty were defined as graft failures. Outcomes were assessed for all patients included in the blood type mismatching analyses. Osteochondral tissues that were resected from the knee, hip, and ankle of patients undergoing standard-of-care revision or arthroplasty surgeries, and that otherwise would be discarded, were recovered for histologic assessments. Subjective histologic assessments were performed by a pathologist who was blinded to patient demographics, blood typing information, outcomes data, and tissue source. When aggregates of lymphocytes and plasma cells were observed surrounding small blood vessels (consistent with an immune response), immunohistochemistry for CD3, CD8, and CD20 was performed to further characterize the lymphocytes (T cell marker, cytotoxic T lymphocytes, and B cell marker, respectively) for subjective assessment of relevant immune responses. Subjects were grouped by ABO blood type, Rh Factor, and both. Histologically evaluated failures were separated by immune response as positive or negative. Fisher’s exact tests were used for statistical analyses with a p-value of less than 0.05 set a priori to define statistical significance.Results:A total of 103 patients were included for analysis with 33 of these requiring OCA revision or artificial arthroplasty. Of the clinical failures, 18 had previously transplanted osteochondral allograft tissues recovered for histological assessment. Twelve (66%) of these recovered OCAs had aggregates of CD3+, CD8+, and CD20+ lymphocytes around small blood vessels in the bone marrow spaces and adipose/collagenous tissue of the previously transplanted allograft. The remaining resected OCAs (34%) did not show a similar pattern of T- and B-cell infiltrates around blood vessels. Other histologic abnormalities associated with failed OCAs included avascular necrosis, subchondral micro and macro fractures, subchondral collapse, and/or articular cartilage erosion or delamination. No statistically significant differences in proportions for success versus failure based on mismatches for ABO type, Rh Factor, or both were noted. Similarly, no statistically significant differences in proportions for positive versus negative immune responses based on mismatches for ABO type, Rh Factor, or both were noted.Conclusions:Donor-recipient mismatches for ABO blood type and/or Rh Factor were not associated with higher likelihood for patients to require OCA revision or artificial arthroplasty surgery. Similarly, donor-recipient mismatches for ABO blood type and/or Rh Factor were not associated with higher likelihood for positive immune responses in previously implanted OCA tissues recovered from patients who required revision or artificial arthroplasty surgeries. However, two-thirds of the tissues recovered from graft failure cases had T- and B-cell infiltrates, suggesting sub-rejection immune responses occur after OCA transplantation that should be further investigated to determine potential mechanistic relationships with graft failures. The results of the present study support current clinical practice for transplantation of fresh OCAs, which does not require HLA or blood type matching or immunosuppressive medication for recipients. However, histologic assessments suggest that sub-rejection immune responses may play a role in graft failures and should be further investigated.

Midterm Prospective Evaluation of Structural Allograft Transplantation for Osteochondral Lesions of the Talar Shoulder.

In cases of large osteochondral lesions of the talus (OLTs), fresh structural or bulk osteochondral allograft transplantation has yielded favorable outcomes in several retrospective and few prospective case series. The purpose of this study was to prospectively evaluate patients who received fresh structural allograft transplantation of the talar shoulder. A prospective evaluation of patients who received a fresh structural allograft of an OLT was performed. Preoperative imaging included magnetic resonance imaging (MRI) and/or computed tomography (CT) with plain radiographs. The following patient-reported outcomes questionnaires were administered preoperatively and yearly after surgery: 36-Item Short-Form Health Survey (SF-36), visual analog scale (VAS) for pain, and the Short Musculoskeletal Functional Assessment (SMFA). Preoperative and postoperative imaging were evaluated for allograft assimilation, evidence of arthritic changes, or functional range of motion abnormalities. Thirty-one patients with a mean age of 41.4 years (±14.1, range 18-69) underwent structural fresh osteochondral allograft transplantation to the talar shoulder and were included in this study. The mean follow-up was 56.2 months (±36.1, range 24-142). The majority of patients were female (n=17, 54.8%), reported some history of prior ankle trauma (n=21, 67.7%), and underwent prior ankle surgery (n=23, 74.2%). The mean lesion size on CT scan was 1879 mm3 (n = 27) compared to the mean lesion size of 3877 mm3 (n = 21) on MRI. There was a significant improvement in the mean preoperative VAS score (P < .0001), SF-36 score (P < .0005), SMFA bother index (P < .0015), and the SMFA function index (P < .0001) at final follow-up. A total of 15 (48.4%) patients underwent an additional surgery following their osteochondral allograft transplant, most commonly arthroscopic debridement or removal of hardware, performed at an average of 25.2 (±13.0) from their index procedure. There was one failure that required a total ankle replacement. The overall graft survival rate was 96.8%. Fresh, structural allograft transplantation resulted in significant improvement in patient-reported postoperative pain and function in patients suffering from OLTs. The graft survival rate was 96.8% at a mean of 56.2 months follow-up, with half of patients requiring a second procedure. Level IV, prospective case series.

Osteochondral Allograft Transplantation for a Cartilage Defect of the Humeral Capitellum

Background: Cartilage defects of the humeral capitellum most frequently present as osteochondritis dissecans (OCD) in young overhead athletes, such as baseball players. Historically, surgical options have included debridement, marrow stimulation, and osteochondral autograft transplantation. Fresh osteochondral allograft (OCA) transplantation comprises an additional treatment option that can structurally restore osteochondral defects and has demonstrated satisfactory outcomes without the donor-site morbidity associated with osteochondral autograft transplantation. Indication: OCA transplantation provides structural restoration of the articular surface and can be used for large (&gt;1 cm diameter) lesions not amenable to refixation. Additionally, OCA transplantation can address both chondral and subchondral pathology and is suited for the treatment of failed previous surgical interventions, such as debridement or marrow stimulation. Technique Description: Following diagnostic arthroscopy, an anconeus splitting mini-open approach was performed to expose the capitellar defect. The defect was measured to be 10 mm, and a central guide pin was placed. A 10-mm reamer was used to prepare the defect bed to a depth of 8 mm. An OCA plug was then cut from a fresh femoral hemicondyle to match the prepared defect. The graft was soaked in bone marrow aspirate concentrate harvested from the iliac crest, and the plug was then inserted into the defect and tamped to be concentric with the surrounding articular cartilage. Results: OCA transplantation of the capitellum allows for the restoration of the articular surface with a structural graft and can be used for large defects and revision cases. While OCA transplantation is well described in the knee with long-term efficacy, the application of this technique to the capitellum is relatively recent. Recent case series for the capitellum have displayed significant improvements in patient-reported outcome measures and predictable return to sports. Discussion/Conclusion: OCA transplantation for the humeral capitellum provides an effective treatment option for large, unstable cartilage lesions not amenable to refixation. The procedure allows for restoration of the articular surface and can provide improvements in pain and function as well as return to sport.

Computerized tomography scan evaluation after fresh osteochondral allograft transplantation of the knee correlates with clinical outcomes

PurposeTo determine the correlation between the assessment computed tomography osteochondral allograft (ACTOCA) scoring system and clinical outcomes scores. The hypothesis was that the ACTOCA score would show sufficient correlation to support its use in clinical practice.MethodsWe prospectively collected data from all consecutive patients who underwent cartilage restitution with fresh osteochondral allograft (FOCA) transplantation for osteochondral lesions of the knee and had a minimum follow-up of two years. CT scans were performed at three, six and 24 months post-operatively. A musculoskeletal radiologist blinded to the patients’ medical history evaluated the scans using the ACTOCA scoring system. Clinical outcomes collected preoperatively and at three, six and 24 months postoperatively were evaluated using the International Knee Documentation Committee (IKDC), Kujala, the Western Ontario Meniscal Evaluation Tool (WOMET), and the Tegner Activity Scale.ResultsThe mean total ACTOCA score showed a statistically significant correlation with the clinical outcome. The correlation was optimal at 24 months. We found a high negative correlation with the IKDC, Kujala and Tegner (− 0.737; − 0.757, and − 0.781 respectively), and a moderate negative correlation with WOMET (− 0.566) (p < 0.001). IKDC, Kujala, WOMET, and Tegner scores showed a significant continuous improvement in all scores (p < 0.001).ConclusionThe mean total ACTOCA score showed a linear correlation with clinical results in IKDC, Kujala, WOMET, and Tegner scores, being the highest at 24 months post-surgery. This finding supports the use of ACTOCA to standardize CT scan reports following fresh osteochondral allograft transplantation in the knee.

Posterior Approach for the Treatment of an Osteochondral Defect on the Posterior Lateral Femoral Condyle

Osteochondral defects of the knee often occur as a result of traumatic injury, repetitive microtrauma, or genetic predisposition. Smaller lesions can be treated nonoperatively in younger patient populations; however, large symptomatic lesions require surgical intervention using a fresh osteochondral allograft transplant. Although osteochondral defects classically appear on the lateral aspect of the medial femoral condyle, there have been cases in which the lesion is located on the posterior aspect of the lateral femoral condyle. To access these posteriorly located lesions, the surgeon must utilize a complex posterior approach in order to successfully manage these lesions. While care must be taken to protect the neurovascular bundle in this area, this technique allows for excellent exposure and optimal graft placement.

Mid-Term Prospective Evaluation of Structural Allograft Transplantation for Osteochondral Lesions of the Talar Shoulder

Category:AnkleIntroduction/Purpose:The management of large osteochondral lesions of the talar shoulder remains a clinical challenge. Their size, three-dimensional geometry, and subchondral cystic degeneration often preclude treatment with traditional measures such as microfracture and osteochondral autograft transplantation. Structural or bulk osteochondral allograft transplantation has demonstrated efficacy in several retrospective reviews. The purpose of this study was to prospectively evaluate patients who received fresh structural allograft transplantation to the talus.Methods:A prospective evaluation of consecutive patients who underwent fresh structural allograft transplantation for an OLT form 2010 to 2019 was performed under Institutional Review Board approval. All patients failed a minimum of 6 months of conservative management. Preoperative MRI and/or CT, as well as plain radiographs were obtained on all patients. The following patient reported outcomes questionnaires were administered preoperatively and yearly after surgery: 100mm VAS pain scale, AOFAS Ankle-Hindfoot Scale, SF-36, and the Short Musculoskeletal Functional Assessment (SMFA). Pre- and postoperative radiographs were assessed for allograft incorporation and the development of arthritis.Results:27 patients underwent fresh osteochondral allograft transplantation and were followed for a minimum of 2 years. The mean follow-up was 5 years (range 2-11). The average size of the OLT was 2,269 mm3 (range 813-8,366) based on CT imaging and 5,797 mm3 (range 1,136-12,489) based on MRI imaging. There was significant improvement in the VAS pain score, AOFAS Ankle- Hindfoot Scale score, the SF-36 total score, and the SMFA functional and bother indices (Figure 1). Thirteen (48%) of the patients required subsequent surgery. Twelve underwent removal of hardware and joint debridement and one patient underwent isolated joint debridement. At the time of these surgeries, two grafts demonstrated cartilage delamination. One of these patients had continued pain and progression of arthritis without additional surgery and one was converted to an ankle replacement. Therefore, the failure rate was 7%.Conclusion:Significant improvement in pain and function can be achieved with structural allograft transplantation for large OLTs. However, it is important to council patients that painful hardware and stiffness can occur in approximately one-half of patients. An unstable graft and cartilage delamination are indicators of subsequent failure. The use of a structural allograft does not preclude subsequent ankle arthrodesis or arthroplasty.

Fresh Osteochondral Allograft Transplantation in Osteochondritis Dissecans in the Knee Joint

Osteochondritis dissecans (OCD) is a chronic and painful joint condition that can occur from childhood through to adult life. Microtrauma, vascular insufficiency, or abnormal endochondral ossification are the most common causes of OCD. Reconstructive techniques for OCD of the knee are typically necessary when either non-operative or reparative/regenerative operative treatments fail, or when the OCD is irreversible. To analyze the clinical outcomes and failure rates of fresh osteochondral allograft transplantation (FOCA) used as a reconstructive strategy in OCD patients, an in-depth search was carried out on the PubMed, Scopus, and Web of Science databases concerning the existing evidence related to the use of FOCA for OCD patients in the knee joint. A total of 646 studies were found through the search and 2 studies were added after a cross-referenced examination of the articles within the bibliography. Six studies with a total of 303 OCD lesions treated with FOCA, with a mean follow-up of 6.3 years, were included. Although a limited number of low-level evidence studies on this topic are available in previous research, satisfactory clinical results and survival rates of the reconstruction are reported. However, to better define the real advantages of FOCA in the healing process of OCD lesions, comparative studies with different techniques are needed.

Histological and Inflammatory Cytokine Analysis of Osteochondral Lesions of the Talus After Failed Microfracture: Comparison With Fresh Allograft Controls.

Background:The most common first-line treatment of osteochondral lesions of the talus (OLTs) is microfracture. Although many patients do well with this procedure, a number fail and require reoperation. The mechanism of failure of microfracture is unknown, and to our knowledge there has been no research characterizing failed microfracture regarding histological and inflammatory makeup of these lesions that may contribute to failure.Purpose:To characterize the structural and biochemical makeup of failed microfracture lesions.Study Design:Case series; Level of evidence, 4.Methods:Specimens from 8 consecutive patients with symptomatic OLTs after microfracture who later underwent fresh osteochondral allograft transplantation were analyzed. For each patient, the failed microfracture specimen and a portion of the fresh allograft replacement tissue were collected. The allograft served as a control. Histology of the failed microfracture and the allograft replacement was scored using the Osteoarthritis Research Society International (OARSI) system. Surface roughness was also compared. In addition, tissue culture supernatants were analyzed for 16 secreted cytokines and matrix metalloproteinases (MMPs) responsible for inflammation, pain, cartilage damage, and chondrocyte death.Results:The OARSI grade, stage, and total score as well as surface smoothness were significantly worse in the failed microfracture sample, indicating better cartilage and bone morphology for the allografts compared with the failed microfracture lesions. Analyzed cytokines and MMPs were significantly elevated in the microfracture tissue culture supernatants when compared with fresh osteochondral tissue supernatants.Conclusion:These data demonstrate a significantly rougher cartilage surface, cartilage and subchondral bone histology that more closely resembles osteoarthritis, and elevated inflammatory cytokines and MMPs responsible for pain, inflammation, cartilage damage, and chondrocyte death when compared with fresh osteochondral allografts used as controls.