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.

OSTEOCHONDRAL ALLOGRAFTING IN THE SKELETALLY IMMATURE KNEE: HIGH RATES OF INCORPORATION AND EXCELLENT EARLY OUTCOMES

Background: While an excellent option for osteochondral defects in the adult knee, outcomes following fresh osteochondral allograft (OCA) the skeletally immature are limited. Purpose: To compare radiographic and patient reported outcomes (PROs) in mature and skeletally immature adolescents following OCA of the knee. Methods: An IRB-approved review of fresh size-matched OCA treatment of knee lesions in patients aged < 19 years within a pediatric sports medicine practice from 1/2006-3/2019 was completed. Following exclusion of patients with less than 12 months follow-up, demographics, lesion characteristics, reoperations, and PROs were evaluated. A novel grading scale (k= 0.832) was utilized to evaluate radiographic OCA incorporation: A=complete, B= >50%, or C= <50% healed. Results: Forty-four patients [15.5 years (9.6-19.8) treated with OCA of the distal femur or patella (LFC= 18, MFC=17, Trochlea=6, Patella=3), 24 with open and 20 with closed physes, with 2.2 year follow up (range 1-5.3 years) were evaluated. Overall average graft size was 4.76cm2 and did not differ significantly between groups. Thirty-nine patients underwent at least one prior procedure to the ipsilateral knee, most frequently for attempted osteochondral lesion healing (77%), followed by realignment (22.7%), and meniscal pathology (15.9%). Graft failure occurred in only one skeletally immature patient with a trochlear lesion. Those with open physes were more likely to demonstrate complete graft incorporation (66.6%, p=0.001). 21(88%) patients with open physes and 17(85%) patients with closed physes had radiographic healing grades of A or B one year post-operatively. There was no difference in healing grade based on graft size, depth, or location within the knee. There was no difference in pre-operative PROs or activity scores. At final follow-up, open physes OCA patients demonstrated better KOOS scores (KOOS daily living 97.0 vs 89.5, p=0.02; KOOS pain 95.7 vs 84.6, p= 0.04; KOOS quality of life 157.2 vs 59.6, p= 0.005). Final activity scores did not vary by skeletal maturity (Pedi-IKDC 75.8 vs 77.99; Pedi-FABS 17.2 vs 13.5,) or radiographic healing grade. Daily living and pain scores were better in those with more radiographic healing (KOOS daily living 98.6 vs 86,2, p= 0.02; KOOS pain 96.7 vs 82.3, p= 0.048). Conclusion: Fresh osteochondral allograft treatment in the young knee may be expected to yield good early results. Despite relatively large graft size, when indicated for patients with open physes, equivalent or improved healing and patient reported outcomes may be expected.

Rehabilitation and Return-to-Play Criteria After Fresh Osteochondral Allograft Transplantation: A Systematic Review

Background: Fresh osteochondral allograft (OCA) is a treatment option that allows for the transfer of size-matched allograft cartilage and subchondral bone into articular defects of the knee. Although long-term studies show good functional improvement with OCA, there continues to be wide variability and a lack of consensus in terms of postoperative rehabilitation protocols and return to sport. Purpose: To systematically review the literature and evaluate the reported rehabilitation protocols after OCA of the knee, including weightbearing and range of motion (ROM) restrictions as well as return-to-play criteria. Study Design: Systematic review; Level of evidence, 4. Methods: PubMed, EMBASE, Cumulative Index of Nursing Allied Health Literature, SPORTDiscus, and Cochrane databases were searched according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines for studies on knee OCA. Studies were included if they reported return-to-play data or postsurgical rehabilitation protocols. Results: A total of 62 studies met the inclusion criteria, with a total of 3451 knees in 3355 patients. Concomitant procedures were included in 30 of these studies (48.4%). The most commonly cited rehabilitation protocols included weightbearing restrictions and ROM guidelines in 100% and 90% of studies, respectively. ROM was most commonly initiated within the first postoperative week, with approximately half of studies utilizing continuous passive motion. Progression to weightbearing as tolerated was reported in 60 studies, most commonly at 6 weeks (range, immediately postoperatively to up to 1 year). Of the 62 studies, 37 (59.7%) included an expected timeline for either return to play or return to full activity, most commonly at 6 months (range, 4 months to 1 year). Overall, 13 studies (21.0%) included either objective or subjective criteria to determine return to activity within their rehabilitation protocol. Conclusion: There is significant heterogeneity for postoperative rehabilitation guidelines and the return-to-play protocol after OCA of the knee in the literature, as nearly half of the included studies reported use of concomitant procedures. However, current protocols appear to be predominantly time-based without objective criteria or functional assessment. Therefore, the authors recommend the development of objective criteria for patient rehabilitation and return-to-play protocols after OCA of the knee.

A Systematic Review of Fresh Osteochondral Allograft Transplantation for Osteochondral Lesions of the Talus

Category: Ankle Introduction/Purpose: The term osteochondral lesion of the talus (OLT) refers to any pathology of the talar articular cartilage and corresponding subchondral bone. In general, OLTs can pose a formidable treatment challenge to the orthopaedic surgeon due to the poor intrinsic ability of cartilage to heal as well as the tenuous vascular supply to the talus. Although many treatment options exist, including microfracture, retrograde drilling, autologous chondrocyte implantation (ACI), and osteochondral autograft transfer system (OATS) these options may be inadequate to treat large cartilage lesions. Osteochondral allografts have demonstrated promise as the primary treatment for OLTs with substantial cartilage and bone involvement. To our knowledge, this is the first systematic review of outcomes after fresh osteochondral allograft transplantation for OLTs. Methods: PudMed, the Cochrane Central Register of Controlled Trials, EMBASE, and Medline were searched using PRISMA guidelines. Studies that evaluated outcomes in adult patients after fresh osteochondral allograft transplantation for chondral defects of the talus were included. Operative results, according to standardized scoring systems, such as the AOFAS Ankle/Hindfoot scale and the Visual Analog Scale were compared across various studies. The methodological quality of the included studies was assessed using the Coleman methodology score. Results: There were a total of 12 eligible studies reporting on 191 patients with OLTs with an average follow-up of 56.8 months (range 6-240). The mean age was 37.5 (range 17-74) years and the overall graft survival rate was 86.6%. The AOFAS Ankle/Hindfoot score was obtained pre- and postoperatively in 6 of the 12 studies and had significant improvements in each (P<0.05). Similarly, the VAS pain score was evaluated in 5 of the 12 studies and showed significant decreases (P<0.05) from pre- to postoperatively with an aggregate mean preoperative VAS score of 7.3 and an aggregate postoperative value of 2.6. The reported short-term complication rate was 0%. The overall failure rate was 13.4% and 21.6% percent of patients had subsequent procedures. Conclusion: The treatment of osteochondral lesions of the talus remains a challenge to orthopaedic surgeons. From this systematic review, one can conclude that osteochondral allograft transplantation for osteochondral lesions of the talus results in predictably favorable outcomes with an impressive graft survival rate and high satisfaction rates at intermediate follow-up. [Table: see text]

Fresh Osteochondral Allograft Transplants in the Knee: Bipolar and Beyond

Knee patients who have sustained chondral and osteochondral lesions suffer from debilitating pain, which can ultimately lead to posttraumatic osteoarthritis and whole-joint disease. Older, nonactive patients are traditionally steered toward total knee arthroplasty (TKA), but younger, active patients are not good candidates for TKA based on implant longevity, complications, morbidity, and risk for revision, such that treatment strategies at restoring missing hyaline cartilage and bone are highly desired for this patient population. Over the past four decades, fresh osteochondral allograft (OCA) transplantation has been developed as a treatment method for large (> 2.5 cm2) focal full-thickness articular cartilage lesions. This article documents our own institutional OCA journey since 2016 through enhanced graft preservation techniques (the Missouri Osteochondral Preservation System, or MOPS), technical improvements in surgical techniques, use of bone marrow aspirate concentrate, bioabsorbable pins and nails, and prescribed and monitored patient-specific rehabilitation protocols. Further follow-up with documentation of long-term outcomes will provide insight for continued optimization for future applications for OCA transplantation, potentially including a broader spectrum of patients appropriate for this treatment. Ongoing translational research is necessary to blaze the trail in further optimizing this treatment option for patients.