Optimising femoral-head osteochondral allograft transplantation in a preclinical model

Abstract

SummaryBackground/ObjectiveOsteochondral autografting and allografting of the femoral head have been described as treatments for avascular necrosis without segmental collapse, fracture, osteochondritis dissecans, and tumours. One long-term study reported that 80% of nonsteroid-treated patients had successful outcomes. Most data are compiled from small case reports or series. Although these results are encouraging, to the authors’ knowledge, there is no basic scientific evidence regarding optimal graft source or technique reported in the peer-reviewed literature. The objective of this study was to create a translational canine model to compare femoral-head osteochondral autografts and allografts with respect to safety and efficacy.MethodsWith Institutional Animal Care and Use Committee approval, skeletally mature hound-mix dogs (n = 6) weighing >20 kg underwent aseptic surgical implantation of osteochondral grafts using a craniolateral approach to the hip, without dislocation. Three graft options were evaluated: small auto (n = 3), 6-mm-diameter autograft from the trochlear ridge of the ipsilateral knee; small allo (n = 3), 6-mm-diameter fresh (21-day storage) allograft from a size-matched canine femoral head; or large allo (n = 3), 14-mm-diameter fresh (21-day storage) allograft from a size-matched canine femoral head. Small grafts were implanted into the same femoral head of three dogs, and large grafts were implanted alone in the other three dogs. The dogs were allowed unrestricted activity in their runs, and were walked on a leash for 15 minutes 5 times/wk. The outcome measures included functional, radiographic, and arthroscopic assessments at 8 weeks, and functional, chondrocyte viability, and histologic assessments at 6 months after surgery. The pre- and postoperative data were compared for statistically significant (p < 0.05) differences. Based on data from the canine study, four human patients underwent fresh (<28-day storage) osteochondral allografting using large (>30-mm diameter) size-matched femoral-head grafts. The radiographic, quality of life, and functional assessments were captured postoperatively.ResultsAll grafts had >80% chondrocyte viability at the time of implantation. All grafts showed radiographic evidence for integration into host bone. Small auto and small allo showed significant (p < 0.05) loss in range of motion, chondrocyte viability, and articular-cartilage integrity 8 weeks after implantation, whereas large allo maintained viability and structural integrity throughout the study period. The large-allo dogs maintained full hip range of motion and hindlimb function. A similar type of large allograft (>30 mm) was performed in the four human patients. Due to the defect size, three out of the four human patients required two large allografts at the time of implantation. At the time of this manuscript's acceptance, patient follow-up ranged from 4 months to 18 months. All human patients were full weight-bearing without an assistive device, and showed no evidence of graft failure or progressi...

Outcomes Associated With Osteochondral Allograft Transplantation in Dogs

“…Many treatment options for cartilage damage are used in both human and canine medicine, including non-surgical management, osteochondral autografting, or synthetic resurfacing with focal, unicompartmental, or total joint replacement systems (8)(9)(10)(11)(12)(13)(14). However, osteochondral allograft (OCA) transplantation is a treatment option used in people, which has not been described for use in clinical canine patients (15)(16)(17)(18).…”

“…Osteochondral allograft transplantation has been reported to be effective for resurfacing cartilage defects in the human knee, ankle, hip, shoulder, and elbow (17,18,(24)(25)(26). Resurfacing is most commonly performed using cylindrical OCA cores, or "plugs, " using essentially the same equipment and techniques used for osteochondral autograft transfer (OAT).…”

“…Resurfacing is most commonly performed using cylindrical OCA cores, or "plugs, " using essentially the same equipment and techniques used for osteochondral autograft transfer (OAT). As surgical techniques have advanced, OCA transplantation has been used to treat larger portions of joints and more complex cases including total biologic joint resurfacing (17,18,27). Outcomes after OCA transplantation in people are significantly affected by a number of factors including underlying pathologic change, specific joint treated, chondrocyte viability at time of implantation, patient age, body mass index, tobacco use, number of grafts transplanted, and comorbidities (28)(29)(30)(31).…”

Translational study of orthopaedic biomaterials and devices

“…It is a promising approach to regenerating a biological joint, but whether it can become a cost-effective approach that can replace osteochondral allograft transplantation—a well-accepted surgical treatment—remains for further investigation. The objective of Crist et al’s study presented in this issue of the journal was to compare femoral head osteochondral autografts and allografts in a canine model [13] . The authors reported that there was a significant loss in range of motion, chondrocyte viability and articular cartilage integrity 8 weeks after implantation of both small autografts and allografts, whereas chondrocytes in the large allografts maintained their viability and structural integrity throughout the study period.…”

Restoration of osteochondral defects by implanting bilayered poly(lactide-co-glycolide) porous scaffolds in rabbit joints for 12 and 24 weeks

“…Lacking of blood supply and innervation, articular cartilage has a very limited capacity for self-healing once damaged [1], [2]. To treat the cartilage defects, early clinical intervention includes bone marrow stimulation techniques, cartilage plug transplant, and expanded autologous chondrocyte or mesenchymal stem cell implantation [2], [3], [4]. Given the limitations of current surgical approaches to treat articular cartilage lesions, tissue engineering has been pursued extensively in recent decades and exhibited promising applications in clinical treatment [5], [6], [7], [8].…”