4. How to Recover from a Distal Femoral Osteotomy
Patients who have a distal femoral osteotomy, which is basically a surgical fracture, need to be on crutches until the osteotomy heals sufficiently to start weightbearing. Otherwise, there is a risk that the hinge on the inside part of the knee could crack or the screws could break because too much weight is being placed on them from relying on the plate and screws to hold the fracture apart rather than allowing the bone to heal. In general, we keep patients non-weightbearing for 8 weeks for the distal femoral osteotomy, obtain x-rays at 8 weeks to ensure there is sufficient healing, and then initiate a partial protective weightbearing program, advancing it one-quarter body weight per week until the 3-month point. Further x-rays are obtained at that point to verify healing.
As part of the planning for a distal femoral osteotomy, we like to put most of our patients into a lateral compartment unloader brace. These braces help push the weight towards the inside of the knee, and by doing so, they can help serve as an excellent screen to determine if a patient would benefit from a distal femoral osteotomy. In our hands, almost all patients who benefit from the use of a lateral unloader brace do very well with a later performed distal femoral osteotomy and are able to correct the knock knee condition.
The success rate of distal femoral osteotomies is felt to be about 70% to 75% at 10 years. The success rate also depends upon the amount of arthritis of the lateral compartment, if there is a concurrent meniscal transplant or cartilage resurfacing procedure, and also if the patient is not significantly overweight (with a high body mass index, BMI). In general, patients who smoke are not candidates for a distal femoral osteotomy because bone does not heal very well in smokers and this would generally be a contraindicated surgical procedure in this circumstance.