We investigated the early results of modular porous metal components used in 23 acetabular reconstructions associated with major bone loss. The series included seven men and 15 women with a mean age of 67 years (38 to 81), who had undergone a mean of two previous revisions (1 to 7). Based on Paprosky’s classification, there were 17 type 3A and six type 3B defects. Pelvic discontinuity was noted in one case. Augments were used in 21 hips to support the shell and an acetabular component-cage construct was implanted in one case. At a mean follow-up of 41 months (24 to 62), 22 components remained well fixed. Two patients required rerevision of the liners for prosthetic joint instability. Clinically, the mean Harris Hip Score improved from 43.0 pre-operatively (14 to 86) to 75.7 post-operatively (53 to 100). The mean pre-operative Merle d’Aubigné score was 8.2 (3 to 15) and improved to a mean of 13.7 (11 to 18) post-operatively. These short-term results suggest that modular porous metal components are a viable option in the reconstruction of Paprosky type 3 acetabular defects. More data are needed to determine whether the system yields greater long-term success than more traditional methods, such as reconstruction cages and structural allografts.
Thirty-five patients with habitual dislocation of the patella in flexion were reviewed; eight were bilaterally affected. Each had undergone quadricepsplasty with an average follow-up of 6 years 9 months. Bands or contractures, most commonly in vastus lateralis, the iliotibial tract and rectus femoris were seen in each. Redislocation was seen in 12 knees. At review, 79% of the knees were normal. Quadriceps lengthening is an essential part of treatment and must be performed proximally. Causes for failure include reformation of contractures and failure to correct the initial abnormality fully.