Abstract

The introduction of multihole mega cup has proposed innovative answers in the management of acetabular impediments that ensued from the use of bipolar hemiarthroplasty. This study bestows a prospective analysis of the outcome of conversion surgery from bipolar hemiarthroplasty to total hip replacement in patients with acetabular complications.

Forty-two patients, 22 men and 20 women, with a mean age of 59 years (range 46-69 years) who experienced complex acetabular deficiencies following bipolar hemiarthroplasty, were converted to total hip replacement between January 2008 and June 2010. Pain was the main complaint in all cases. It was primarily confined to the groin region. Limping due to shortening of the affected limb was the second main complaint (30 cases). All cases had erosion of the acetabulum with varying degrees of protrusion. Cementless mutihole cups with augmentation by autogenous bone graft from the iliac crest and large metal heads’ sizes were used for conversion in all cases.

After a minimum follow-up of 36 months, Harris hip scores (HHS) improved from a mean of 36.8 ± 6.8 (range 21-59) preoperatively to a mean of 85.9 ± 5.6 (range 71 to 94) postoperatively. Thirty six (85.7%) patients experienced no groin pain postoperatively while six patients (14.3%) described limited improvement. Postoperative complications included ; dislocation in two cases which were reduced and did not result in a poor outcome later on. No patients were lost to follow-up.

Conclusion : Short-term results at minimum three years follow-up of multihole mega cup were encouraging regarding high capability of acetabular reconstruction with less morbidity of recipient site. Significant pain and functional improvement were noticeable, however further longer term studies are consequently recommended.