A prospective study of prognostic factors concerning the outcome of arthroscopic surgery for anterior ankle impingement.

Sixty-two consecutive patients with painful limited dorsiflexion of the ankle not responding to nonoperative treatment participated in a prospective study. All 42 men and 20 women (average age, 31 years) underwent arthroscopic surgery. Preoperative radiographs were graded according to an osteoarthritic and an impingement classification. Standardized followup took place at 4 months and 1 and 2 years after surgery. Results showed that the degree of osteoarthritic changes is a better prognostic factor for the outcome of arthroscopic surgery for anterior ankle impingement than size and location of the spurs. The hypothesis is that osteophytes without joint space narrowing are not a manifestation of osteoarthritic changes but rather the result of local (micro)trauma. After 2 years, 73% of the patients experienced overall excellent or good results; 90% of those without joint space narrowing had good or excellent results, and 50% of those with joint space narrowing had good or excellent results. At the 2-year followup, the group without joint space narrowing showed significantly better scores in pain, swelling, ability to work, and engagement in sports. This study also revealed that patients with less than 2 years of ankle pain before surgery and spurs located anteromedially were more satisfied with the outcome than when longer periods of preoperative pain were involved and when spurs were located anterolaterally.