Arthroscopically Assisted Particulated Juvenile Allograft Cartilage Implantation and Bone Grafting for Treatment of Large Cystic Osteochondral Lesions of the Talus: A Case Series

Abstract

Category: Ankle; Arthroscopy; Basic Sciences/Biologics; Sports; Trauma Introduction/Purpose: Osteochondral lesions of the talus (OCLT) are common traumatic injuries and can be difficult to treat. Conventional methods consist of arthroscopic debridement and bone marrow stimulation techniques including microfracture, curettage, abrasion chondroplasty and antegrade/retrograde drilling predominantly leading to fibrocartilage formation. These methods have proved effective for small lesions; however, larger lesions with accompanying subchondral bone cysts require more invasive treatment with osteochondral allografts or autologous chondrocyte implantation. These procedures can require harvesting of osteochondral grafts from the knee or malleolar osteotomies, which have associated donor site morbidities and complications of osteotomy healing. We describe an alternative method, an all-arthroscopic technique to treat these large cystic OCLTs, and sought to determine long-term quality of life metrics for a cohort of patients. Methods: From 2010-2012, six patients with difficult to treat OCLTs underwent arthroscopic-assisted implantation of particulated juvenile allograft cartilage with viable chondrocytes (DeNovo NT) along with autogenous bone grafting from the calcaneus by a single surgeon. These lesions all had associated cystic changes requiring bone graft to fill the defect. Other inclusion criteria included at least two of the following: 1) shoulder lesions, 2) lesion size > 200 mm 2 , 3) failed previous microfracture treatment, or 4) age > 40 with a Body Mass Index (BMI) > 25 kg/m 2 . These six patients were fully evaluated using physical examination, patient interviews, and outcome score measures. Follow-up was completed at 2 years, 4 years, and between 6-9 years at their most recent visit. Pre-operative and post-operative functional outcome scores were compared with Wilcoxon Signed Ranked Test. Results: Six patients (age: 43.8 + 14.0 years, BMI: 28.4 + 6.7 kg/m 2 ) had average lesion sizes of 188.5 + 50.9 mm 2 (range: 125-260 mm 2 ) and most recent follow-up of 8.4 + 1.2 years (range: 6.0-9.3 years). Post-operatively, average VAS pain scores decreased by 4.2 points, 95% CI [1.6-6.8]. FAAM ADL scores improved from 41.8 to 72.5, 95% CI [11.3-50.1]. SF-36 Physical Component Scores also showed significant improvement by 37.8 points, 95% CI [20.8-54.8]. FAAM Sports (p = 0.055) and AOFAS (p = 0.066) scores clinically improved from 13.3 to 39.2 and 57.7 to 86.3, respectively, and approached statistical significance. There were no intraoperative or perioperative complications with calcaneal bone grafting. Conclusion: A small cohort of patients followed over the course of ~8 years after implantation of particulated juvenile allograft cartilage (DeNovo NT) and autogenous calcaneal bone graft for cystic OCLTs had positive post-operative, self-reported functional outcomes. Patients significantly improved compared to pre-operative measures, with no complications observed. This may be an effective long-term treatment for patients with difficult to treat OCLTs.