Exeter small femoral stem for patients with small femurs

Abstract

Purpose: To report the long-term results of total hip arthroplasty (THA) using small size Exeter femoral stems.

Methods: Eight men and 34 women aged 60 to 83 (mean, 70) years underwent 45 THAs using the Exeter small stem with offsets of 30 mm (n=3), 33 mm (n=15), and 35.5 mm (n=27). The Harris hip score was assessed pre- and post-operatively. Stem alignment and axial subsidence of the stem were measured. Radiolucent lines around the femur were recorded at 14 Gruen zones. Completeness and thickness of the cement mantle and cement fractures were also noted. Ectopic ossification, if present, was graded. Stem loosening was based on the Olsson definitions.

Results: The mean follow-up was 9 (range, 5-12) years. The mean Harris hip score improved from 37 (range, 13-61) to 80 (range, 47-96) [p<0.001]. At the latest follow-up, the score was excellent (90-100) in 8 (18%) of the hips, good (80-89) in 21 (47%), fair (70-79) in 9 (20%), and poor (<70) in 7 (16%). All hips had a complete cement mantle of 2 mm or more. All stems were inserted without intramedullary reaming. 11 (24%) of the hips developed stem subsidence of <2 mm; all stabilised within 2 years. None of these patients had pain or other radiological signs of loosening. Six stems showed radiolucent lines of <1 mm in the upper zones, which were not progressive. No cement fracture or subsidence was noted. Using revision for any cause as an endpoint, the overall survival rate of Exeter small femoral stem was 100% at 10 years and 89% at 12 years.

Conclusion: The results of Exeter small stems for patients with small femurs are good.