Assessing the role of hip arthrography in the treatment decision making for children with Legg-Calvé-Perthes disease.

OBJECTIVE

The aim of this study was to determine the role of hip arthrography in the treatment decision making for children with Legg-Calvé-Perthes disease (LCPD).

METHODS

A total of 47 consecutive children with LCPD (42 boys, 5 girls; mean age=7.5 years; range=6-10 years) who underwent operative treatment were included in the study. The patient demographics, physical examination findings (pain and hip range of motion [ROM]), standard anteroposterior and Löwenstein lateral hip radiographs, and hip arthrography data were retrospectively collected. The arthrographies were performed immediately before the surgery under general anesthesia. The patients were staged according to the Catterall and Herring classifications and examined in terms of head-at-risk signs before the study. Four sets of patient files were established based on the aforementioned data, with each child in a randomized and blinded order. Ten consultant pediatric orthopedic surgeons randomly assessed the patient files on 4 separate occasions (Set 1 vs Set 2 and Set 3 vs Set 4), with a minimum time interval of 4 weeks. In the first and second sets, the demographic and clinical information, including the age, gender, hip ROM, and hip radiographs, were presented. In the third and fourth sets, hip arthrography was presented in addition to the data from Set 1 and Set 2. The observers were instructed to choose the best treatment options. The percent agreement (PA) and Gwet's AC1 statistics were used to establish a relative level of agreement among the observers.

RESULTS

The mean intra-observer reliabilities ranged from fair to moderate after adding the hip arthrography data (Gwet's AC1 = 0.36 for Set 1 vs Set 2 and 0.42 for Set 3 vs Set 4). The mean PA was 56.6% (range = 29.8% to 78.7%) with a Gwet's AC1 value of 0.51 (range: 0.21 to 0.77) between Set 1 and Set 3 (moderate intra-observer reliability). The decision for the treatment strategy was changed in 43.4% of the patients. For inter-observer reliability, Gwet's AC1 was computed as 0.48 (moderate reliability). The correlation between the intra-observer reliability and stage progression was not significant (p>0.05) for any of the subgroups. Thus, there is a negative correlation with the disease progression.

CONCLUSION

Hip arthrography seems to have a significant role in the treatment decision making for children with LCPD, especially in the advanced stages of the disease.

LEVEL OF EVIDENCE

Level IV, Therapeutic study.