Abstract: Role of surgical containment in late onset and healed Perthes is still controversial and ill defined. Untreated and partially treated Perthes disease can progress to osteoarthritis by the fourth decade. The main complication is femoral head deformation. Two important factors contributing to complication:
1. Extruded femoral head
2. Deformed head leads to early onset of osteoarthritis
This study evaluates the clinical and radiological outcome of varus derotation osteotomy (VDRO) in late onset and early healed Perthes with extruded femoral head with remaining growth potential.
Materials and Methods: 30 children (19 males and 11 females) falling in the group of 10-16 years, belonging to modified Elizabethtown classification Stage 4–healed stage / Waldenstrom’s stage 4- residual stage, radiologically – reossified, extruded, deformed femoral head are treated with open wedge VDRO, between 2009 and 2017 were included in this study. 21(70%) are between 10-14yrs, rest are 14 – 16yrs, mean age of osteotomy is 12.37yrs. All patients had limitation of abduction and internal rotation. 14 patients (46.67%) had pain at the hip and 26 patients (86.7%) had limp. Mean time between diagnosis and corrective surgery was 3 weeks.
Results: The evaluation was done using caput index (CI) and epiphyseal quotient (EQ) radiologically, range of motion and Harris Hip Score for clinical outcome.Our minimum follow up was 3yrs and maximum follow up of 10years. We studied Radiological and clinical parameters on 3rd year follow up. All measurement was done on pre-op, post op x-rays at 3rd year follow up and also compared with the contralateral hip. We noted improvement in the clinical outcome and radiologically femoral head attained more spherical contour after containment. In our studies 21 children (70%) had good result with Spherical head and fully contained by acetabulum, 6 children (21%) had fair result with congruent head and acetabulum covering>4/5th of femoral head. Rest 3 children had poor result with clinically symptomatic and extruded deformed head. There was a significant change (P = 0.000) in CI among all the patients after surgery. The final EQ after 3 years of VDRO was 0.685 and was significant (P = 0.0000).
Conclusion: In Healed perthes with extruded and deformed femoral head, containing with VDRO helps to achieve a spherical femoral head, thereby delaying the onset of osteoarthritis. Mould for a spherical femoral head is the acetabulum. Containg the head resumes its growth until achieving skeletal maturity. The remaining growth potential is utilized to mould the head into sphericity.
