Impingement adversely affects 10-year survivorship after periacetabular osteotomy for DDH.
BACKGROUND
Although periacetabular osteotomy (PAO) for developmental dysplasia of the hip (DDH) provides conceptual advantages compared with other osteotomies and reportedly is associated with joint survivorship of 60% at 20 years, the beneficial effect of proper acetabular reorientation with concomitant arthrotomy and creation of femoral head-neck offset on 10-year hip survivorship remains unclear.


OBJECTIVE
We asked the following questions: (1) Does the 10-year survivorship of the hip after PAO improve with proper acetabular reorientation and a spherical femoral head; (2) does the Merle d'Aubigné-Postel score improve; (3) can the progression of osteoarthritis (OA) be slowed; and (4) what factors predict conversion to THA, progression of OA, or a Merle d'Aubigné-Postel score less than 15 points?


METHODS
We retrospectively reviewed 147 patients who underwent 165 PAOs for DDH with two matched groups: Group I (proper reorientation and spherical femoral head) and Group II (improper reorientation and aspherical femoral head). We compared the Kaplan-Meier survivorship, Merle d'Aubigné-Postel scores, and progression of OA in both groups. A Cox regression analysis (end points: THA, OA progression, or Merle d'Aubigné-Postel score less than 15) was performed to detect factors predicting failure. The minimum followup was 10 years (median, 11 years; range, 10-14 years).


RESULTS
An increased survivorship was found in Group I. The Merle d'Aubigné-Postel score did not differ. Progression of OA in Group I was slower than in Group II. Factors predicting failure included greater age, lower preoperative Merle d'Aubigné-Postel score, and the presence of a Trendelenburg sign, aspherical head, OA, subluxation, postoperative acetabular retroversion, excessive acetabular anteversion, and undercoverage.


CONCLUSIONS
Proper acetabular reorientation and the creation of a spherical femoral head improve long-term survivorship and decelerate OA progression in patients with DDH.
Department of Orthopedic Surgery, Inselspital, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
Christoph E
CE
Albers
Simon D
SD
Steppacher
Reinhold
R
Ganz
Moritz
M
Tannast
Klaus A
KA
Siebenrock
D000077:Acetabulum / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D019644:Arthroplasty, Replacement, Hip; D001696:Biomechanical Phenomena; D002648:Child; D018450:Disease Progression; D005260:Female; D057925:Femoracetabular Impingement / Q000175:diagnosis / Q000209:etiology / Q000601:surgery*; D005270:Femur Head / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006618:Hip Dislocation, Congenital / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects* / Q000379:methods; D016016:Proportional Hazards Models; D011859:Radiography; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D017211:Treatment Failure; D055815:Young Adult