HEMIARTHROPLASTY – DEMOGRAPHICS, REVISIONS AND RISK FACTORS FOR FAILURENATIONAL REGISTRATION OF 12 245 CASES, SWEDEN 2005–07

Abstract

Background: Hemiarthroplasty of the hip is a common procedure, but information about implants and outcome is scarce. In Sweden the number of hemiarthroplasties has increased from 200 in 1998 to 4181 in 2007.

Material and Methods: Nationwide registration started in 2005. 100% of the hospitals participates, and 96% of the hemi-procedures are registrered. An analysis of 12 245 cases operated 2005–07 is presented.

Results: In the Register the mean age at surgery is 84 years (SD 7.0, 73% female). 93% are operated due to acute fracture and 6% due to failed internal fracture fixation. Cemented fixation has been used in 92% and a posterior approach in about half of the cases (52%). The Lubinus and Exeter stems are most common (41 and 23%). The Austin-Moore design has decreased from 9 to 2% during the study period.

3.2% of the patients (hips) have been reoperated, most commonly because of dislocation. Multiple reoperations are common. Male gender, secondary procedure and uncemented stem are associated with increased reoperation risk with 1.2, 1.7 and 1.8 times (1.2, CI: 1.0–1.6; 1.7, 1.3–2.3; 1.8 1.4–2.5). Use of uncemented fixation resulted in increased risk of reoperation, also with exclusion of uncemented Austin-Moore prostheses (1.8 times, 1.1–2.8).

In a separate analysis of the two most frequent designs, use of bipolar head increased the risk of revision twice (1.4–2.8) compared to unipolar head when adjusting for other risk factors. This may reflect that fitter and more active individuals get a bipolar prosthesis and are more prone to become revised should complications occur or a true increase of complications when using bipolar head. A further analysis is in progress.

Use of dorsal approach (1.6, 1.2–2.2), Austin-Moore (1.8, 1.1–3.1) and Thompson prostheses (1.8, 1.5–2.8) increased the risk of revision because of dislocation.

Summary: When treating fracture patients with hemi-arthroplasty we recommend that a well documented cemented implant with different off-set options should be used via an anterolateral approach. Use of bipolar heads may increase the risk of revision.