We have evaluated the clinical effectiveness
of a metal resurfacing inlay implant for osteochondral defects of
the medial talar dome after failed previous surgical treatment.
We prospectively studied 20 consecutive patients with a mean age
of 38 years (20 to 60), for a mean of three years (2 to 5) post-surgery.
There was statistically significant reduction of pain in each of
four situations (i.e., rest, walking, stair climbing and running;
p ≤ 0.01). The median American Orthopaedic Foot and Ankle Society
ankle-hindfoot score improved from 62 (interquartile range (IQR)
46 to 72) pre-operatively to 87 (IQR 75 to 95) at final follow-up
(p <
0.001). The Foot and Ankle Outcome Score improved on all
subscales (p ≤ 0.03). The mean Short-Form 36 physical component
scale improved from 36 (23 to 50) pre-operatively to 45 (29 to 55)
at final follow-up (p = 0.001); the mental component scale did not
change significantly. On radiographs, progressive degenerative changes
of the opposing tibial plafond were observed in two patients. One
patient required additional surgery for the osteochondral defect.
This study shows that a metal implant is a promising treatment for
osteochondral defects of the medial talar dome after failed previous
surgery. Cite this article:
It has been suggested that a supramalleolar osteotomy can return the load distribution in the ankle joint to normal. However, due to the lack of biomechanical data, this supposition remains empirical. The purpose of this biomechanical study was to determine the effect of simulated supramalleolar varus and valgus alignment on the tibiotalar joint pressure, in order to investigate its relationship to the development of osteoarthritis. We also wished to establish the rationale behind corrective osteotomy of the distal tibia. We studied 17 cadaveric lower legs and quantified the changes in pressure and force transfer across the tibiotalar joint for various degrees of varus and valgus deformity in the supramalleolar area. We assumed that a supramalleolar osteotomy which created a varus deformity of the ankle would result in medial overload of the tibiotalar joint. Similarly, we thought that creating a supramalleolar valgus deformity would cause a shift in contact towards the lateral side of the tibiotalar joint. The opposite was observed. The restricting role of the fibula was revealed by carrying out an osteotomy directly above the syndesmosis. In end-stage ankle osteoarthritis with either a valgus or varus deformity, the role of the fibula should be appreciated and its effect addressed where appropriate.
