Patient-Specific Distal Femoral Guides Optimize Cartilage Topography Matching in Osteochondral Allograft Transplantations.

BACKGROUND

Osteochondral allograft (OCA) transplantation is an important surgical technique for full-thickness chondral defects in the knee. For patients undergoing this procedure, topography matching between the donor and recipient sites is essential to limit premature wear of the OCA. Currently, there is no standardized process of donor and recipient graft matching.

PURPOSE

To evaluate a novel topography matching technique for distal femoral condyle OCA transplantation using 3-dimensional (3D) laser scanning to create 3D-printed patient-specific instrumentation in a human cadaveric model.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Human cadaveric distal femoral condyles (n = 12) underwent 3D laser scanning. An 18-mm circular osteochondral recipient defect was virtually created on the medial femoral condyle (MFC), and the position and orientation of the best topography-matched osteochondral graft from a paired donor lateral femoral condyle (LFC) were determined using an in silico analysis algorithm minimizing articular step-off distances between the edges of the graft and recipient defect. Distances between the entire surface of the OCA graft and the underneath surface of the MFC were evaluated as surface mismatch. Donor (LFC) and recipient (MFC) 3D-printed patient-specific guides were created based on 3D reconstructions of the scanned condyles. Through use of the guides, OCAs were harvested from the LFC and transplanted to the reamed recipient defect site (MFC). The post-OCA recipient condyles were laser scanned. The 360° articular step-off and cartilage topography mismatch were measured.

RESULTS

The mean cartilage step-off and graft surface mismatch for the in silico OCA transplant were 0.073 ± 0.029 mm (range, 0.005-0.113 mm) and 0.166 ± 0.039 mm (range, 0.120-0.243 mm), respectively. Comparatively, the cadaveric specimens postimplant had significantly larger step-off differences (0.173 ± 0.085 mm; range, 0.082-0.399 mm;

CONCLUSION

These findings suggest that the use of 3D-printed patient-specific guides for OCA transplantation has the ability to reliably optimize cartilage topography matching for LFC to MFC transplantation. This study demonstrated substantially lower step-off values compared with previous orthopaedic literature when also evaluating LFC to MFC transplantation. Using this novel technique in a model performing MFC to MFC transplantation has the potential to yield further enhanced results due to improved radii of curvature matching.

CLINICAL RELEVANCE

Topography-matched graft implantation for focal chondral defects of the knee in patients improves surface matching and has the potential to improve long-term outcomes. Efficient selection of the allograft also allows improved availability of the limited allograft sources.

Déclaration de conflit d'intérêts

One or more of the authors has declared the following potential conflict of interest or source of funding: The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) funded this investigation. A.A.E.O. has received financial or material support from Stryker. M.H. has received consulting fees from DJO-Enovis, Moximed, and Vericel; honoraria from Encore Medical; support for education from Arthrex and Foundation Medical; and hospitality payments from Stryker and Medical Device Business Services. B.J.C. has received research support from Aesculap/B.Braun, Arthrex, and Regentis; consulting fees from Arthrex, DJO, and Samumed; royalties from Arthrex; financial or material support from Athletico, JRF Ortho, and Smith & Nephew; and holds stock and stock options in Bandgrip Inc, Ossio, and Regentis. A.B.Y. has received consulting fees from AlloSource, JRF Ortho, and Stryker; research support from Arthrex and Organogenesis; holds stock or stock options in Patient IQ, Sparta Biomedical, and Icarus; and is an unpaid consultant for Patient IQ and Sparta Biomedical. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.