The Role of Hip Arthrodiastasis in Management of Late-Onset Legg-Calvé-Perthes Disease: A Prospective Case Series.

BACKGROUND

Late-onset Legg-Calvé-Perthes disease (LCPD), defined as onset after the age of 8 years or younger, is associated with a poor prognosis and limited remodeling potential. The role of hip arthrodiastasis in this age group remains controversial.

METHODS

This prospective case series enrolled patients consecutively and collected data at predefined follow-up intervals. It included 24 patients with late-onset LCPD treated with articulated hip arthrodiastasis using a hinged Ilizarov external fixator combined with percutaneous adductor tenotomy. This reflects a deliberate institutional shift in treatment strategy rather than selective case allocation, which may reduce selection bias but limits the availability of a contemporary control group. All patients were older than 8 years at disease onset and classified as Herring lateral pillar B or C. Clinical outcomes were assessed using the Harris Hip Score (HHS) and range of motion (ROM). Radiographic evaluation included the Sharp acetabular angle, Reimer uncoverage index, epiphyseal index, and modified Stulberg classification at final follow-up.

RESULTS

The mean follow-up was 24 months (range: 18 to 30). The mean HHS improved significantly from 47.2 preoperatively to 86.7 at final follow-up (P<0.001). Significant improvements were observed in hip flexion, abduction, and internal rotation (all P<0.001). Radiographically, mean femoral head uncoverage improved from 33.3% to 25.0% (P<0.001), and the Sharp acetabular angle decreased from 42.3 to 37.6 degrees (P<0.001). According to the modified Stulberg classification, 19 hips (79%) had good outcomes (Stulberg II to III), while 5 hips (21%) had poor outcomes (Stulberg IV to V). Complications included pin-tract infections managed with local care and oral antibiotics, as well as a small number of patients requiring additional secondary procedures.

CONCLUSION

Articulated hip arthrodiastasis with adductor tenotomy resulted in favorable short-term clinical and radiographic outcomes in most patients with late-onset LCPD. This technique improved hip motion and radiographic parameters suggestive of improved femoral head containment, without the need for femoral or pelvic osteotomy, and may represent a useful treatment option in this challenging patient population.

LEVEL OF EVIDENCE: Level IV-therapeutic case series.