Implant arthroplasty in the adult hindfoot.

In patients with mild to moderate valgus deformity and localized pain due to lateral impingement, the subtalar implant has been effective in controlling position and relieving localized pain. When used in conjunction with a talonavicular resurfacing prosthesis in the absence of talonavicular subluxation, the implant has been effective in relieving pain and maintaining the foot in a normal or nearly normal position. In feet with valgus deformity and talonavicular subluxation, both the subtalar implant and the talonavicular prosthesis with a built-in stop must be used. Use of these implants requires that the foot be supple and correctable to at least neutral position at surgery. The valgus hindfoot with a subluxated but otherwise normal talonavicular joint presents a greater problem. In this condition correction can be maintained only if the subtalar implant is used in conjunction with the modified talonavicular joint with a built-in stop. External supports in the shoe have not been routinely used in all patients after operation for a variety of reasons (mostly nonmedical). It may be advisable in patients who have had correction of a deformity to continue to use some sort of support in the shoe for most ambulation. Arthroplasty early in the disease course, before severe deformities develop, may prevent progression of the disorder, but more experience is necessary to validate clinical impressions.