Patient specific, synthetic, partial unipolar resurfacing of a large talar osteochondritis dissecans lesion in a dog

Abstract

AbstractObjectiveTo describe the application and early outcome of a custom‐made unipolar partial tarsal replacement in a dog with an extensive medial talar ridge OCD.AnimalA 7‐month‐old, 25 kg male Rhodesian Ridgeback with progressive left hindlimb lameness (grade III–IV/IV) and diagnosis of talar OCD.MethodsThe dog presented with progressive lameness attributed to extensive medial talar ridge OCD. Due to the severity of the lesion, a resurfacing procedure was chosen. Based on CT data, a bi‐layered resurfacing implant consisting of a titanium socket and a polycarbonate urethane bearing surface was constructed. For intraoperative guidance, a set of matching drill guides were 3D‐printed, along with some models of the affected talus, to allow for dry‐lab training. Surgical implantation using a medial malleolar osteotomy to approach the lesion was without complications. Orthopedic follow‐up examinations were conducted at 10 days, 4 weeks, 6 weeks, 6 months and 12 months. Radiographic examinations were included at the 6‐week, 6‐month, and 12‐month follow‐ups.ResultsFunction improved considerably during the follow‐up period with a lameness grade of 0‐I/IV at the 12‐month follow‐up. ROM differed by 15° in flexion compared to the contralateral side, while there was no difference in extension. Moderate periarticular fibrosis was present at 12 months. Implant positioning was unchanged at follow‐up‐radiographic examination and there was only mild progression of osteoarthritis (OA).ConclusionPatient specific instrumentation ‐ guided tarsal OCD resurfacing with a synthetic patient‐specific implant may be an effective treatment option.