Abstract
Introduction
Traditionally the use of small diameter femoral head (22mm) with the posterior approach has been perceived as an increased risk of dislocation. We present this prospective study of 400 consecutive total hip replacements performed using a 22mm femoral head and the posterior approach.
Materials/Methods
Between March 2000 and November 2005 364 patients underwent 400 total hip replacements with a small diameter 22mm head under the care of four different consultants, using a standard posterior approach. All of the femoral implants were cemented using modular C-stems (Depuy Ltd.) and all of the acetabular components were cemented flanged monobloc all-polyethylene components with long posterior wall with a third generation cementing technique. A standard posterior approach was used in all cases, with direct repair of the capsule and short external rotators.
Results
There were 252 female and 112 male patients. The average age at the time of surgery was 71.3 years (range 25–92 years) and the average duration of follow-up for surviving patients is 98 months (58–127 months).
The average acetabular abduction angle was 43.2 degrees (30–62) and the average femoral offset was 46mm (35–54). Five patients (1.25%) suffered dislocations. Four occurred on a single occasion and were stable on initial reduction and only one required further surgery for recurrent dislocations. Skirted femoral heads had been used in four of these cases, reducing the head/neck ratio (1.76).
Conclusion
Total hip replacement using small diameter femoral heads and a posterior approach has provided excellent results and implant longevity, with a low complication rate. Dislocation was the most common complication, occurring in only 1.25% of cases and was associated with the use of a skirted head. This is the largest prospective series coming from single centre, using same approach and same implant design in total hip replacement with 22 mm head.
