A pre-operative predictive score for the outcome of eccentric rotational acetabular osteotomy in the treatment of acetabular dysplasia and early osteoarthritis of the hip in adults.
OBJECTIVE
The influence of identifiable pre-operative factors on the outcome of eccentric rotational acetabular osteotomy (ERAO) is unknown. We aimed to determine the factors that might influence the outcome, in order to develop a scoring system for predicting the prognosis for patients undergoing this procedure.


METHODS
We reviewed 700 consecutive ERAOs in 54 men and 646 women with symptomatic acetabular dysplasia or early onset osteoarthritis (OA) of the hip, which were undertaken between September 1989 and March 2013. The patients' pre-operative background, clinical and radiological findings were examined retrospectively. Multivariate Cox regression analysis was performed using the time from the day of surgery to a conversion to total hip arthroplasty (THA) as an endpoint. A risk score was calculated to predict the prognosis for conversion to THA, and its predictive capacity was investigated.


RESULTS
The congruity of the hip, age, the pre-operative minimum width of the joint space and range of abduction were identified as factors predicting conversion to THA. For three groups of patients (scoring 0 to 5, 6 to 7, and 8 to 9 points), the Kaplan-Meier event-free rates of survival at 15 years post-operatively for conversion to THA were 99.6%, 85.2% and 67.3%, respectively.


CONCLUSIONS
These four pre-operative factors are easily measured and predict the prognosis for patients following ERAO. They may be used for decision making when offering surgical treatment to patients with acetabular dysplasia and early onset osteoarthritis. Cite this article: Bone Joint J 2016;98-B:1326-32.
Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
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T
Amano
Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
Y
Y
Hasegawa
Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
T
T
Seki
Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
Y
Y
Takegami
Aichi Medical University, 1-1 Yazakokarimata, Nagakute, 480-1195, Japan.
K
K
Murotani
Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya, 466-8550, Japan.
N
N
Ishiguro
D000077:Acetabulum / Q000000981:diagnostic imaging / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006618:Hip Dislocation, Congenital / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D006621:Hip Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015207:Osteoarthritis, Hip / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D057234:Preoperative Period; D011379:Prognosis; D011859:Radiography; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D013997:Time Factors; D055815:Young Adult
Eccentric peri-acetabular osteotomy; Prognosis prediction; Scoring