Exploration of radiographically normal total knee replacements for unexplained pain.

Twenty-seven patients underwent exploration of their total knee replacements because of severe debilitating pain of an unknown cause. The group was further subdivided into (1) patients who had painful knees with range of motion greater than 80 degrees and (2) patients who had painful knees with decreased range of motion (< 80 degrees arc). At final followup, there were 11 excellent and good results (41%) with 16 fair or poor results (59%). For the 15 patients with decreased range of motion, 9 of 15 knees (60%) had good or excellent results. Range of motion arc improved from a preoperative 43 degrees average to a 81 degrees average. For the pain only group, there were only 2 excellent or good results (17%). Poor results were encountered in 6 of 7 patients (86%) in whom a cementless prosthesis was converted to a cemented prosthesis. If a problem was identified at surgery, only 3 of 12 knees (25%) had successful outcomes.