External Fixator Assisted Genu Varum Correction

Assessment of accuracy of correction of genu varum more than 20 degrees using external fixator assisted plating. Intraoperatively, the operative time needed for completion of accurate correction, torniquet use, blood loss will be assessed. Postoperative complications either early ones like infection, thromboembolic complications, peroneal nerve palsy or late post operative complications like implant failure, delayed union, non union and bone healing time will be assessed..

Malalignment prevents proper transmission of forces across the knee leading to advance or even start the progression of osteoarthritis.Preoperative planning is necessary to identify the level and magnitude of the deformity. Corrections can be performed acutely or gradually. Acute correction can be achieved by opening wedge, closing wedge or dome osteotomies followed by internal fixation. On the other hand, gradual correction can be achieved by osteotomy with external fixation.

Although osteotomy with internal fixation is more convenient to the patient than external fixator, it has many drawbacks. These include the need for large surgical exposure, soft tissue stripping and difficulty executing precise deformity correction. Meticulous preoperative planning is important when internal fixation is planed. It also needs to be executed precisely till fixation is completed. Under-correction or over-correction is possible while executing the procedure. Furthermore, iatrogenic deformity in other planes may also develop. If such a deformity is significant, it may adversely affect the function or may lead to excessive loading on adjacent joints. In some cases, revision of surgery for further correction may be required to correct this residual or iatrogenic deformity.

External fixation can be used for gradual correction of genu varum. In spite of the disadvantages of external fixation like being uncomfortable for the patient, tethering soft tissue, associated pin site infection and irritation , it is re-adjustable postoperatively. This allows controlled accurate correction of the mechanical axis of the lower limb.

Our study is implicated on correction of high degree genu varum which is more than 20 degrees .To correct such deformity, it is difficult to calculate the amount of wedge opening intraoperative. The described trigonometric calculation of the size of the base is described for deformity less than 20 degrees .In this study we are going to use a hybrid technique of both external and internal fixation, so we can make use of the benefits of both internal and external fixation techniques External fixation by limb reconstruction system (LRS) or Taylor Spatial frame(TSF) is used to control and stabilize fragments while performing the desired correction. A locked T plate is then applied to stabilize the fully corrected osteotomy. This allows intraoperative removal of the external fixator without loss of correction. Then we compare the planned correction with the achieved correction.

Eligibility Criteria:
Inclusion Criteria:

1. Age 18years old or more
2. Varus 20 degrees or more

Exclusion Criteria:

1. Contraindication to internal fixation
2. Associated osteoarthritis