Physical impairments in Adults with Developmental Dysplasia of the Hip (DDH) undergoing Periacetabular osteotomy (PAO): A Systematic Review and Meta-Analysis

BACKGROUND: Developmental dysplasia of the hip (DDH) is a condition associated with hip pain and impairments. Periacetabular osteotomy (PAO) is a common surgical treatment for DDH. Outcomes following PAO have historically been based on radiology or patient reported outcomes, and not physical impairments. OBJECTIVE: To investigate differences in physical impairments in adults with DDH undergoing PAO compared with asymptomatic participants, and to investigate pre- to post-PAO changes in physical impairments. DESIGN: Systematic review with meta-analysis METHODS: A literature search was performed in five databases (MEDLINE, CINAHL, EMBASE, Sports Discuss, and PsychINFO), using the PRISMA checklist. Studies were considered eligible if patients were aged 15 years and older, treated with PAO for DDH and if they included a physical impairment outcome measure. Two independent reviewers performed data extraction and assessed methodological quality, using a modified version of the Downs and Black checklist. RESULTS: Of 5,017 studies, 24 studies were included with 2190 patients. The methodological quality scores ranged from 39% to 88%. With low level of evidence, meta-analysis showed 58% of patients had a positive anterior impingement test (95%CI: 39-76%), prior to PAO and one to three years after PAO. Five years after PAO, the proportion fell to 17% (95%CI: 11-24%). Prior to PAO, patients with DDH walked with a lower peak hip extension angle, compared to asymptomatic participants (SMD 0.65 (95%CI 0.21-1.10). Best evidence synthesis of non-pooled data showed limited evidence of increased walking velocity, stride length and improved hip flexion and extension moment 18-months post-PAO compared to pre-op. Cadence, hip abduction and hip flexion strength did not change. CONCLUSION: Most patients with DDH have a positive hip impingement test, pre-PAO. Compared to asymptomatic participants, patients with DDH demonstrate physical impairments during walking which appear to improve after surgery. Hip abduction and flexion strength did not change pre- to post-PAO. LEVEL OF EVIDENCE: 1b