Independent assessment and outcomes of 196 short-tapered stems short-term follow-up and review of the literature.

Abstract

Longer term outcome data are now becoming available for short-tapered femoral stems for cementless total hip arthroplasty. The shorter stem has a metaphyseal fit, loading the bone in this area, leading to physiological bone remodelling. It is also bone preserving, as it is 35 mm shorter. It may be easier to insert through a smaller incision and potentially reduce complication rates. We present a retrospective single surgeon case series of 196 patients (>53% follow-up over 5 years). All patients had the cementless 'Microplasty Taperloc' (Biomet). Primary outcome measures were femoral component revision rates. Secondary outcome measures included complications, patient-reported functional outcome scores (Oxford hip) and radiographic evidence of loosening. Patients were identified using electronic software. All were routinely followed up and assessed in clinic since implant introduction in 2009. Oxford hip scores were routinely obtained. A surgeon who had not carried out the procedure independently assessed radiographs. One hundred ninety-six patients were identified. The revision rate was 0.5% due to an intraoperative peri-prosthetic fracture of the femur identified on post-operative radiograph. The complication rate was 2%, attributable to: subsidence of the prosthesis (one hip), post-operative dislocation (two hips), one of which required acetabular revision. Oxford hip scores increased on average from 21 to 45 (pre- to post-operatively). There were no signs of radiographic loosening. The results show that using the short-tapered stem is proving so far to be a reliable and safe alternative to its longer counterpart, with low complication rates in the short term.