Percutaneous osteotomy and simple monolateral frame for treatment of developmental coxa vara

Objectives
Although subtrochanteric valgus osteotomy is considered the standard surgical management of developmental coxa vara, the method of fixation of the osteotomy is still a debate. This study aimed to assess the results and to evaluate the efficacy of percutaneous osteotomy and fixation by monolateral external fixator for the treatment of developmental coxa vara.


Patients and methods
Between December 2017 and February 2020, we conducted a prospective study that involved 10 cases (four females and six males). The patients’ ages at the time of presentation ranged from 4.5 to 12 years with a mean of 6.7 years. All patients underwent percutaneous osteotomy and fixation by a monolateral external fixator. The mean follow-up period was 21 months (range, 14–28 months). Radiological evaluation depended on epiphyseal Hilgenreiner angle and neck-shaft angle, clinical evaluation depended on the IOWA score (it is the hip score of University of IOWA in USA).


Results
There was a significant improvement of the mean values of epiphyseal Hilgenreiner angle (80.6–29.1°), neck-shaft angle (86.9–129°), and IWOA score (58.4–92.2), there was one case of postoperative abductor tightening treated by abductor release and two cases of superficial pin-tract discharge treated by oral antibiotics and all three cases had excellent IOWA score at the last follow-up.


Conclusion
Using percutaneous valgus osteotomy and fixation by monolateral frame provides a reliable, less-invasive, low-cost option for the treatment of developmental coxa vara.