Abstract
Revision total hip arthroplasty, with retention of well fixed femoral and acetabular components and exchange of modular femoral heads and acetabular liners, is seeing increasing usage, primarily for the treatment of osteolysis or recurrent dislocations. The purpose of this study was to determine the dislocation rate after this procedure.
From January 1993 to December 2000, 54 patients underwent isolated head and liner exchange performed by two surgeons. These patients have been followed bi-annually with clinical and radiographic evaulation. There were 36 males and 18 females. Diagnoses at the time of revision surgery were recurrent dislocations in 27 and osteolysis in 27.
The overall dislocation rate was 11% (6/54). In the 49 non-constrained revisions, a 28 mm diameter femoral head was used in 27 and a 32 mm head in 22. At the time of revision, 60% of the femoral heads were lengthened, 40% were increased in diameter, and 25% were increased in both dimensions. Hooded or later-alised liners were used in 55% of the revisions. Operative stability was documented in all operative notes, and in 85% Ranawat’s sign was used to determine liner placement based on relative component version. The dislocation rate in the non-constrained revisions was 8% (4/49). Two out of five constrained revisions, performed for recurrent dislocations, subsequently dislocated. In this study isolated head and liner revision had a comparable dislocation rate to full revision total hip arthroplasty.
The abstracts were prepared by Nico Verdoschot. Correspondence should be addressed to him at Orthopaedic Research Laboratory, Universitair Medisch Centrum, Orthopaedie / CSS1, Huispost 800, Postbus 9101, 6500 HB Nijmegen, Th. Craanenlaan 7, 6525 GH Nijmegen, The Netherlands.
