Role of Arthrodiastasis Using Hinged Monolateral External Fixator Without Soft Tissue Release in Advanced Stage of Legg-Calve-Perthes Disease.

Purpose: Presentation with the advanced stage of Legg-Calve-Perthes disease (LCPD) carries a poor prognosis, regardless of the treatment that the patient receives. The aims of this study are to assess the clinical and radiological outcomes of arthrodiastasis in advanced cases of LCPD using a hinged monolateral external fixator without soft tissue release and to raise safety issues regarding its low rate of complications.

Patients and methods: Six patients with LCPD who were classified as lateral pillar types B and C and were operated on in our department were included in this retrospective study. Data collected from medical files and X-ray measurements were retrospectively reviewed.

Results: A total of six male patients were included in this analysis. The mean age at onset of symptoms was 8.5 years (range 7-10 years). The mean follow-up period was 46 months (range 40-50 months). Five cases were Herring C and one case was Herring B at presentation. The average distraction time was 8 days (range 7-9) and the average duration of external fixator application was 3.1 months (range 2.5-3.5 months). The range of motion of the hip in flexion, abduction and internal rotation were improved postoperatively. Pain score and limping were also improved. At the final follow-up, the mean sphericity deviation score was 10.6. The mean epiphyseal index was improved from 19.3% to 23.8%. In addition, the mean cervical index improved from 99.7% to 89.7% at the last follow-up. Femoral fractures, pin loosening, mechanical failure of the fixator, chondrodiastasis, and hip subluxation were not seen in this group of patients.

Conclusion: Arthrodiastasis with a hinged monolateral external fixator without soft tissue release improved both the clinical and radiological outcomes in this group of patients.