Cementless total hip arthroplasty for secondary traumatic hip arthritis after acetabular fracture fixation

Abstract

Objective To retrospectively analyze short-term outcomes of cementless total hip arthroplasty (THA) in the treatment of secondary traumatic hip arthritis following internal fixation of acetabular fractures in adults. Methods From September 2009 to December 2013, 28 patients were treated with cementless THA for secondary traumatic hip arthritis following internal fixation of acetabular fracture. They were 19 males and 9 females, aged from 23 to 58 years (average, 45.7 years). After surgical debridement and removal of metal implants, all patients underwent intraoperative pathologic analysis of frozen sections. Twenty cases whose neutrophilic granulocyte count ≤ 10 in a high power field received THA at one stage while 8 underwent an antibiotic-loaded cement spacer at the first stage and THA at the second stage when their values of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) became normal. Harris scores were used to evaluate function of the hip. Results All the patients were followed up for an average of 28.5 months (range, from 15 to 58 months). The Harris hip score improved significantly from 52.7±4.7 preoperatively to 93.7±5.7 at the final follow-up (t = 32.341, P= 0.000). No prosthetic dislocation, loosening or periprosthetic osteolysis was found at the last follow-up. By the Engh criteria, bony fusion was achieved at the interface of prosthesis-bone, positions of the acetabular cups were stably fine, and no change occurred in acetabular rotation. No reinfection or periprosthetic fracture occurred after THA. Conclusions THA is an effective salvage procedure for severe posttraumatic hip arthritis following internal fixation of acetabular fracture. Intraoperative pathologic analysis of frozen sections is necessary to judge hip infection. Releasing contracted hip soft tissue, removing metal implants, reconstructing acetabular bone defects and implanting Tantalum monoblock acetabular cup with a high frictional coefficient are essential to good outcomes of THA. Key words: Acetabulum; Fractures, bone; Osteoarthritis, hip; Arthroplasty, replacement, hip