This study examined the clinical and radiographic outcomes of uncemented bipolar hemiarthroplasty for femoral neck fractures in elderly patients with osteoporosis

Between March 2002 and July 2004, 48 uncemented bipolar hemiarthroplasty procedures (Zweymuller, Plus Orthopedics AG, Rotkreuz, Switzerland) for femoral neck fractures were performed in 47 patients older than 75 years of age. Of the 48 patients, 1 patient died during the follow-up period. There were 11 men and 36 women. The mean age of the patients at the time of surgery was 81 years (range, 75 ~ 94 years), and the mean follow up period was 42 months(range, 24 ~ 58 months). The bone mineral density and canal flare index of the proximal femur were measured in all patients.

The mean bone mineral density (T score) was -3.9 points (range, -2.9 ~ -5.3) and the proximal femoral morphology showed stove pipe shapes in 33 hips. At the last follow up, the mean Harris hip scores and visual analogue scale score was 85 (range, 75~93) and 2.7 (range, 1 ~ 6)points, respectively. Inguinal pain was observed in thirteen hips, among which the degree of pain was moderate in 1 and mild in 12. Radiologically, none of the stems showed evidence of osteolysis and aseptic loosening, and remained well osseointegrated without subsidence.

Uncemented bipolar hemiarthroplasty using a Zweymuller stem in elderly patients associated with osteoporosis can provide favorable clinical and radiographic results because the stem imparts good primary stability due to its rectangular tapered shape and long-term secondary stability due to excellent osseointegration on the gritblasted surface.