ObjectiveTo investigate the clinical and radiographic results of total hip arthroplasty (THA) for the treatment of hip arthrosis in patients with ankylosing spondylitis (AS). MethodsA retrospective analysis was made on the clinical data from 131 patients (195 hips) who underwent THA for AS between September 2001 and August 2011 with a follow-up period of more than 2 years. There were 100 males (152 hips) and 31 females (43 hips), aged 17-69 years (mean, 33.7 years). The average interval between AS onset and THA was 13.7 years (range, 1-50 years). The left hips were involved in 30 cases, the right hips in 37 cases, and bilateral hips in 64 cases. Preoperative Harris hip score was 18.0±13.7; the sum passive range of motion was (36.2±51.2)°; and the hip passive-flexion arc was (23.4±32.6)°. In 175 hips with passive flexion of less than 90°, 134 hips had flexion contracture. Based on preoperative X-ray films and CT scan, 195 hips were divided into the non-ankylosed subgroup (86 hips), fibrous ankylosed subgroup (43 hips), and bony ankylosed subgroup (66 hips); and the recovery of hip function was compared between subgroups after operation. ResultsIntraoperative complications included linear fractures of femoral calcar in 4 hips, fractures of acetabular posterior column in 1 hip, femoral shaft fractures in 2 hips, and iatrogenic sciatic nerve injury in 3 hips; postoperative complications included anterior dislocation in 2 hips. The average follow-up period was 51.3 months (range, 24-143 months). Bone healing was observed at 3-6 months after operation (mean, 3.9 months). At last follow-up, the average Harris hip score increased to 86.4±14.1, the sum passive range of motion increased to (202.0±28.0)°, and the hip passive-flexion arc increased to (93.2±15.3)°, all showing significant differences when compared with preoperative ones (P<0.05). Based on a four-class scale for subjective satisfaction, the patients were very satisfied, satisfied, and not satisfied with the results of THA in 100, 80, and 15 hips respectively. X-ray films showed radiolucent line (<2 mm) in 5 acetabular components (zones I and II); heterotopic ossification was observed in 49 hips after THA. There was no significant difference in the Harris hip score among 3 subgroups after THA at last follow-up (P>0.05). At last follow-up, the degree of passive flexion in the fibrous ankylosed subgroup and bony ankylosed subgroup was significantly lower than that in the non-ankylosed subgroup (P<0.05), and the sum passive range of motion in the fibrous ankylosed subgroup was significantly lower than that in the non-ankylosed subgroup (P<0.05), but no significant difference was found in the other variables among the 3 sub groups (P>0.05). ConclusionFor severe hip arthrosis in patients with AS, the overall outcomes after THA are ideal with a good midterm prosthetic survivorship, a low complication rate, and a high satisfaction of patients. However the hip function after THA is still less satisfactory.
ObjectiveTo evaluate mid-term results of total hip arthroplasty (THA) for treatment of osteoarthritis secondary to hip sepsis. MethodsBetween February 2003 and January 2009, 62 patients (62 hips) with osteoarthritis secondary to hip sepsis underwent THA. There were 32 males and 30 females with an average age of 39.9 years (range, 18-67 years). The original infection included pyogenic arthritis in 40 hips and tuberculosis in 22 hips. After infection, 35 patients underwent non-operative treatment, and 27 patients received operative management. The average time interval between initial infection and THA was 28.7 years (range, 12-53 years). The preoperative Harris hip score was 24.6±9.2. The Trendelenburg sign was positive in all hips. Leg discrepancy was observed in 25 cases, and the mean discrepancy of bilateral lower extremities was 3.8 cm (range, 2.6-6.5 cm) preoperatively. All hips had no evidence of active hip sepsis. ResultsAll patients were followed up 72 months on average (range, 54-115 months). Intraoperative complications included sciatic nerve injury (2 cases) and femoral shaft fractures (2 cases); postoperative complications included hip anterior dislocation (1 case) and periprosthetic infection (1 case). At last follow-up, 1 hip, 5 hips, 18 hips, and 38 hips were found to have severe pain, moderate pain, slight pain, and no pain respectively. Claudication occurred in 30 patients (mild in 19, moderate in 8, and severe in 3). The Trendelenburg sign was positive in 18 hips. After THA, only 5 patients had a leg length discrepancy of 2.9 cm on average (range, 2.6-3.5 cm). The Harris score was significantly increased to 82.3±11.4 at last follow-up when compared with preoperative one (t=-31.241, P=0.000). The results of subjective satisfaction were very satisfactory in 43 cases, satisfactory in 12 cases, unsatisfactory in 4 cases, and unsatisfactory at all in 3 cases. No sign of aseptic loosening of prosthesis was found during follow-up period. Roentgenographic results showed no radiolucent line or osteolysis in the other patients except 2 patients having local radiolucent. After THA, 12 hips had heterotopic ossification. ConclusionThe mid-term clinical and radiographic results of THA for treatment of osteoarthritis secondary to hip sepsis are good, with the advantages of high satisfactory rate, good function recovery, and low complication incidence.