There is no optimal treatment for osteochondral defects of the talus after failed primary surgical treatment. To treat these patients, a 15-mm diameter metal implant was developed for the medial talar dome. The present study was undertaken to evaluate the clinical effectiveness of the metal implantation technique for osteochondral lesions of the medial talar dome.

This is a prospective case series. The inclusion criteria were the combination of a large OCD (ϕ >12 mm) of the medial talar dome, persistent complaints >1 year after treatment, and clinically relevant pain levels. The exclusion criteria were: age <18 years, OCD size >20 mm, ankle osteoarthritis grade 2 or 3, concomitant ankle pathology, and diabetes. The primary outcome measure was the Numeric Rating Scale pain (NRS) rest, walking, running, and stair climbing. Secondary outcome measures were: Foot Ankle Outcome Score (FAOS), American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot score, and clinical and radiographic complications. The Wilcoxon signed ranks test was used to calculate p-values.

Between October 2007 and March 2009 10 patients were included. The median follow-up was 2 years (range, 2–3 years). On preoperative CT scanning, the median lesion size was 15 (range, 12–20) × 11 (range, 8–14) mm. The NRS rest improved from a median of 3 (0–7) preoperatively to 0.5 (0–2) at final follow-up (p = 0.017), NRS walking from 6.5 (4–8) to 1 (0–4) (p = 0.005), NRS running from 9 (6–10) to 3 (0–10) (p = 0.024), and NRS stair climbing from 6 (4–8) to 1 (0–7) (p = 0.012). The FAOS improved significantly on four of five subscales. The AOFAS improved from a median of 70 (47–75) before surgery to 89 (69–100) at final follow-up (p = 0.008). There were three temporary complications: hyposensibility about the scar in two and a superficial wound infection in one. There were no radiographic complications.

Objectives

Osteochondral ankle defects (OCDs) mainly occur in a young, active population. In 63% of cases the defect is located on the medial talar dome. Arthroscopic debridement and microfracture is considered the primary treatment for defects up to 15 mm. To treat patients with a secondary OCD of the medial talar dome, a 15-mm diameter metal implant (HemiCAP ®) was developed. The set of 15 offset sizes was designed to correspond with the anatomy of various talar dome curvatures. Recently, two independent biomechanical cadaver studies were published, providing rationale for clinical use. The present study was undertaken to evaluate the clinical effectiveness and safety of the metal implantation technique for osteochondral lesions of the medial talar dome in a prospective study.