Thirteen studies were included in the review (566 patients, 626 hips). Mean follow-up ranged from 2.9 to 12 years.
Radiographic results showed that mean change in acetabular inclination ranged from 4.5 degrees to 25.9 degrees. Mean changes in anterior angles ranged from 16 degrees to 51 degrees and lateral centre-edge from 20 degrees to 44.6 degrees. Mean change in medial translation of the hip centre ranged from 5mm to 10mm. These results indicated that PAO was successful in achieving deformity correction. Clinical outcomes showed improvements in pain relief and hip function; the latter indicated by improvements ranging from 14.5 points to 33 points in the Harris hip score (eight studies).
Range of motion was reported in three studies. Reductions were noted for: flexion (range 12 degrees to 18 degrees); abduction (six degrees); adduction (three degrees to six degrees); external rotation (six degrees to 21 degrees); and internal rotation (five degrees to 21 degrees). Conversion to total hip arthroplasty was reported in 0% to 17% of patients. Most of the clinical failures were associated with patients who had moderate to severe preoperative osteoarthritis. Most studies did not attempt to correlate radiographic and clinical outcomes.
Major complications were reported in 6% to 37% of cases (12 studies). The most frequent were symptomatic heterotopic ossification, wound haematomas, nerve palsies, intra articular osteotomies, loss of fixation and malreductions. Moderate complications were largely connected with symptomatic hardware needing removal (10 studies).