The Efficacy of Percutaneous Lateral Hemiepiphysiodesis on Angular Correction in Idiopathic Adolescent Genu Varum

Supplementary Fibular-guided Growth in Treatment of Late-onset Blount Disease

Purpose:

Blount disease is due to an idiopathic defect in the posteromedial proximal tibial physis resulting in increasing bowing of the leg in addition to lateral knee thrust with lateral collateral ligament laxity. Our rationale is that Blount disease has a bony and ligamentous laxity element of the lateral collateral ligament that can be corrected simultaneously through hemiepiphysiodesis of the tibia and epiphysiodesis of proximal fibula physis by cannulated screws.

Patients and Methods:

This is a retrospective study conducted on 23 limbs with tibia vara treated between 2010 and 2017 followed up for 2 to 6 years. Ages ranged from 9 to 13 years with a late-onset type of Blount disease. We used a percutaneous transphyseal fully threaded screws traversing the proximal tibial lateral hemiepiphysis, and another screw inserted traversing the proximal fibular epiphysis.

Results:

There was a statistically significant improvement of the radiographic parameters, especially in the form of joint line congruence angle in both supine and standing positions. All patients were clinically and radiographically completely corrected without complications, except 1 patient with a surgical site superficial infection, treated medically.

Conclusion:

Fibular-guided growth surgery with lateral proximal tibia epiphysiodesis is a minimally invasive technique that improves the corrective power of hemiepyphysiodesis of the posterolateral compartment of the knee.

Level of Evidence:

Level IV, retrospective case series.

Coronal plane deformity around the knee in the skeletally immature population: A review of principles of evaluation and treatment

Coronal plane deformity around the knee, also known as genu varum or genu valgum, is a common finding in clinical practice for pediatricians and orthopedists. These deformities can be physiological or pathological. If untreated, pathological deformities can lead to abnormal joint loading and a consequent risk of premature osteoarthritis. The aim of this review is to provide a framework for the diagnosis and management of genu varum and genu valgum in skeletally immature patients.

Hemiepiphyseodesis for Juvenile and Adolescent Tibia Vara Utilizing Percutaneous Transphyseal Screws

BACKGROUND

In juvenile and adolescent tibia vara patients with sufficient growth remaining, implant-controlled hemiepiphyseodesis, or guided growth, can be used to correct deformity. Recent reports have described hardware failure of certain hemiepiphyseodesis implants in overweight patients with tibia vara. We describe our experience using transphyseal screws to correct deformity in this patient population.

METHODS

A retrospective chart and radiograph review was conducted on all juvenile and adolescent tibia vara patients who underwent lateral proximal tibial hemiepiphyseodesis using a single transphyseal screw. Charts were queried for preoperative and postoperative mechanical axis deviation, medial proximal tibial angle, lateral distal femoral angle, and postoperative complications or need for further surgery.

RESULTS

In total, 14 affected limbs in 9 patients (6 males) who underwent lateral proximal tibial transphyseal screw hemiepiphyseodesis were considered. Average chronologic age at implantation was 10.4 years and average body mass index was 31.7 kg/m. At average 23-month follow-up, the average mechanical axis deviation improved from 46 to 0 mm (P<0.001), and the average medial proximal tibial angle improved from 81 to 92 degrees (P<0.001). No limbs underwent further surgery to correct residual deformity. There were no complications or instances of implant failure associated with the transphyseal screws.

CONCLUSIONS

Hemiepiphyseodesis using transphyseal screws is an effective technique to correct deformity in juvenile and adolescent tibia vara patients with sufficient growth remaining. This method can be used safely with few complications and with minimal risk of mechanical failure, even in overweight patients.

LEVEL OF EVIDENCE

Level IV-therapeutic.