A propensity score-matched analysis between patients with high hip dislocation after childhood pyogenic infection and Crowe IV developmental dysplasia of the hip in total hip arthroplasty with subtrochanteric shortening osteotomy

BACKGROUND: Whether satisfactory clinical and radiological outcomes of total hip arthroplasty (THA) with subtrochanteric shortening osteotomy (SSO) in high hip dislocation after childhood pyogenic infection can be achieved as in Crowe IV developmental dysplasia of the hip (DDH) remains unclear. METHODS: Between September 2009 and December 2016, 151 primary THAs performed at our institution using similar SSO technique and prosthetic design were retrospectively reviewed. After excluding patients who met exclusion criteria, 29 patients were identified as high dislocation (Crowe IV) after childhood infection (HDACI) and 107 as Crowe IV developmental dysplasia of the hip (DDH). Propensity score matching was used to select 29 Crowe IV DDH patients as a control group for the HDACI group with comparable preoperative conditions. Clinical and radiological outcomes and complication were compared and analyzed. The mean follow-up duration of the 2 groups was 5.0 years. RESULTS: The mean Harris hip score (HHS) and the mean score in range of motion (ROM) domain of the modified Merle d’Aubigné-Postel (MAP) were 84.6 and 4.5 in the HDACI group, compared with 88.3 and 4.9 in the DDH group; there was significant difference between the 2 groups in these parameters (P = 0.015 and 0.035, respectively). Meanwhile, in the HDACI group, the median time of osteotomy union was 4 months and osteotomy nonunion rate was 3%; no significant difference was detected in the median time of osteotomy union and osteotomy nonunion rate between the 2 groups (P = 0.388 and 1.000, respectively). And no significant difference was found in the rate of complications between two groups. CONCLUSIONS: HDACI patients who received THA combined with SSO could achieve similar satisfactory results as DDH patients in Crowe type IV. The fixation technique of autogenous cortical bone struts had a positive influence on osteotomy healing of SSO in this specific setting.