What's new in hip arthroplasty

Extended trochanteric osteotomy followed by cemented impaction allografting in revision hip arthroplasty

The aim of this study is to present the medium- to long-term results of all cases of femoral impaction allografting revision at our institution that required an extended trochanteric osteotomy (ETO) at the time of surgery. Eighteen patients with a mean age of 60 years were evaluated. Indication for revision was aseptic loosening in all cases. The mean follow-up was 123 months (51-170). Charnley-D'Aubigné-Postel scores, stem length, ETO length, ETO healing, and complications were recorded. No patient was lost to follow-up. Signs of clinical healing were noted within the first 6 postoperative months. The difference between the preoperative and postoperative clinical scores was statistically significant. No nonunion of the ETO was observed in any case. These results give support to the combined use of these techniques.

Automated assessment of polyethylene wear in cemented acetabular components using anteroposterior radiographs of total hip replacements

Polyethylene wear in the acetabular components of hip prostheses is implicated in loosening and failure. Radiographic measurement of wear is used to identify patients at risk and to assess prosthesis designs. This paper focuses on analysis of prostheses with cemented acetabular cups from anteroposterior (AP) radiographs. The articular surface of the femoral head and the acetabular rim marker are modelled as spherical and circular respectively, resulting in elliptical image projections. Methods for automatically localising these structures in radiographs are presented using robust ellipse fitting and various error functions. Special attention is paid to the acetabular marker since this often projects as a highly eccentric ellipse. Robust fitting enables successful localisation in the presence of clutter without the need for user interaction. Finally, the use of these ellipses as reference structures for wear estimation is investigated and the effect of eccentricity errors is highlighted.

Extended femoral osteotomy for revision of hip arthroplasty: results and complications

Seventy-five revision total hip arthroplasties (73 patients) performed using an extended greater trochanteric osteotomy for exposure and an extensively porous-coated uncemented stem were reviewed after 2 years (range, 1 to 5). The mean osteotomy length was 14 cm (range, 7 to 19 cm) and fixation was with at least 2 cables. One stem was revised at 4 months for stem subsidence and loosening. Of the remaining 74 osteotomies, 73 healed without further procedures. A single nonunion was reoperated at 4 months and healed. Sixty-eight of 73 osteotomies healed with no migration and 5 did with less than 5 mm of proximal migration of the osteotomy fragment. Complications included 3 intraoperative and 1 postoperative osteotomy fragment fractures. Extended trochanteric osteotomy, executed preserving the fragment's vascularity and fixed with rigid fixation, can be performed with a low rate of complications.

Influence of surface finish in total hip arthroplasty

The influence of femoral component surface finish was investigated by comparing 2 finishes, precoat and satin finish, for 1 cemented total hip arthroplasty (THA) system using 1 acetabular cup design. All surgeries were performed by a single surgeon in 2 consecutive series. Minimum 2-year follow-up outcomes (36 precoat, 25 satin) were compared using Harris Hip Scores, radiographs, and survivorships. The precoat population experienced significantly more radiographic and debonding failures than the satin-finish population, and significantly more pain (P <.05). Comparing failures and nonfailures within the precoat population disclosed neither significant preoperative nor significant cement-grade differences. Because of failure performance of the precoat surface finish, this surgeon no longer implants these components.