Mid-Term Outcome of Total Hip Arthroplasty in Patients With Progressive Pseudorheumatoid Dysplasia

Background: Progressive pseudorheumatoid dysplasia (PPD) is a rare disease that causes musculoskeletal deformities. There has been no detailed report on the outcome of PPD patients who undergo total hip arthroplasty (THA). The aim of this study was to investigate the clinical and radiological outcome of PPD patients undergoing THA after middle-term follow-up.

Methods: This was a medical records review study. Patients with the diagnosis of PPD who underwent THA were enrolled. The PPD diagnosis was confirmed by genetic sequencing. Baseline clinical data were retrieved. The patients were followed for the Harris Hip Score, visual analogue score, range of hip motion, and postoperative complication. Life quality was evaluated with the Short Form 36. Plain x-ray films were used for radiographic evaluation.

Results: Four cases were identified from the patient database in our institute. All the patients presented arthropathy of both hips and underwent 1-stage bilateral THA. All the patients had WISP3 mutation after genetic sequencing. The cases were followed at average 47.9 months (range, 18-93 months). Harris Hip Score increased from 39.67 ± 9.73 points preoperatively to 91.67 ± 4.32 points postoperatively (p < 0.05); Short Form 36 increased from 19.67 ± 1.53 points preoperatively to 71.33 ± 3.06 postoperatively (p < 0.05). The hip range of hip motion was significantly improved after operation. X-ray films showed no obvious radiolucent lines or aseptic loosening at the latest follow-up.

Conclusions: This study indicated that THA was effective to treat the PPD patients complicated with hip arthropathy with satisfactory clinical and radiological outcome after mid-term follow-up.