Subvastus and medial parapatellar approaches in total knee arthroplasty

This retrospective study compared the outcome of two consecutive groups of patients having primary total knee arthroplasty, The arthroplasties were pe rformed in the first group (169 arthroplasties in 143 patients) from 1988 t o 1992 using a medial parapatellar approach, and in the second group (167 a rthroplasties in 148 patients) from 1992 to 1996 using a subvastus approach . The patient outcomes were evaluated at 6 months, and were based on clinic al and radiographic measures, occurrence of intraoperative lateral retinacu lar release, and incidence of postoperative patellar subluxation. There wer e no significant differences between the two groups for range of motion, Kn ee Society knee and function scores, and stair climbing ability. The patell a tracked centrally in significantly more knees with the subvastus approach (139 of 167 knees, 83%) than with the parapatellar approach (107 of 169 kn ees, 63%). There were significantly fewer knees in the subvastus group requ iring a lateral retinacular release (62 of 167 knees, 37%), compared with t he parapatellar group (113 of 169 knees, 67%). The authors concluded that t he subvastus approach led to improved patellar tracking and stability. Alth ough the surgical and rehabilitative protocols were identical for both grou ps, the results may have been affected by changing circumstances during the 9-year period of the study.