This study reports the results of hybrid stem fixation in difficult revision hip arthroplasties where proximal femoral bone stock loss was severe.

Twenty-six revision arthroplasties (21 women and 5 men, aged from 58 to 86 years), were performed between 1998 and 2008. The indication for surgery was aseptic loosening. In all cases, stabilization of the stem presented problems because of severe proximal femoral bone stock loss (due to extensive periprosthetic osteolytic defects), or because of iatrogenic defects or surgical procedures (attempts to remove the stem and cement with fenestration or extended osteotomy). The average follow-up was 48 months (range 16 to 120).

Primary stability is necessary for the successful definite fixation of a cementless implant by bone. When this was not possible (because of proximal cortical insufficiency), we used a modular distally cemented long stem, bypassing the area of bone defect for at least 6–7 cm. Proximally bone defects were grafted and osteotomy was closed with cerclage wires.

Four stems (15%) had an asymptomatic subsidence (3 stems subsided less than 3–4 mm and 1 stem about 15mm). No stem was revised to date. Major complications did not occur. The mean Harris hip score improved from 32 points preoperatively to 82.3 points (at the most recent evaluation).

Hybrid fixation offers the advantage of initial and secure stability of the cemented stem on the short term, until stabilization of the entire implant by bone occurs. Thus early subsidence and loosening is avoided and on the long term benefits of the cementless fixation are attained. Our results support the method of hybrid fixation in patients with severe femoral bone loss (and consequently problematic stabilization), when primary stability is needed.

Aims: This is a retrospective study, comparing prosthesis survivorship, complications and functional results in geriatric patients treated with different types of prosthetic replacement for subcapital fractures of the hip. Methods: In the years 1985–1999, 292 elderly (aged 65–80 years) patients with displaced, nonpathologic sub-capital hip fractures were operated on. Of those, 143 were lost to follow-up; therefore, prospectively collected data of 149 patients were retrospectively reviewed. 54 patients received a unipolar, 48 a bipolar prosthesis and 47 underwent a primary total hip arthroplasty (THA). Mean follow-up was 5.3 years. The patients did not differ in pre-injury characteristics. Analysis of variance was used to compare the three patient groups in terms of early and late complications, need for revision surgery, and functional outcome. Results: A statistically signiþ-cant difference was noted, regarding need for revision surgery, since 5 (9.25%) of the unipolar and 5 (10.4%) of the bipolar prostheses had to be re-operated, compared to 2 (4.25%) from the THA group. Of note, 4 of the revised bipolar prostheses had loose stems. The THA group also proved superior, when recovery of instrumental activities was investigated. Conclusions: Elderly patients, whose biologic age poses high functional demands on them, with a displaced subcapital hip fracture, should receive a total hip arthroplasty. Stem loosening seems more likely, as a mode of failure, in bipolar prostheses, than acetabular erosion.

Aims: The purpose of this roentgenographic study is to quantify patellar tilt after total knee arthroplasty and substantiate which factors might affect it. Methods: We reviewed the þles of 446 patients with 485 primary total knee arthroplasties, solely on the diagnosis of degenerative osteoarthritis. Mean follow-up approximated 8.5 (range, 5–20) years. Resurfacing-type prostheses were exclusively used. Patellar resurfacing was accomplished in 51 (11.4%) knees. Patellar tilt was measured pre- and postoperatively using standard Merchant views. Chi-square analysis was used in an attempt to disclose any relationship of patellar tilt with variables like button positioning, lateral release, patellar thickness, limb alignment, joint line elevation, patellar height and posterior cruciate ligament retention or sacriþce. Results: Pre-operatively, 27%, 40% and 33% of patellae demonstrated neutral, lateral and medial tilt respectively. These þgures subsequently changed to 49%, 19% and 32% immediately post-op. However, at þnal follow-up, patellar tilt pattern looked much like the pre-operative one, namely, 31%, 38% and 31% respectively. A statistically signiþcant positive correlation was only documented for patellar thickness, buttonmedialization and pre-operative tilt. The rest of the parameters tested were found not to have any statistical signiþcance with post-operative tilt values. Conclusions: After knee arthroplasty, the patella has, on the long term, a tendency to revert laterally. Lateral release does not seem to ameliorate this tendency. Finally, pre-operative tilt does not correlate to post-operative external mechanism complications.