(Kiosk 2) Bilateral Derotation Osteotomies of the Tibia and Fibula in a 55-year-old Female with Dystonic Cerebral Palsy

Case Diagnosis: Dystonic cerebral palsy with bilateral external tibial torsion and flexion contracture of bilateral knees

Case Description: A 55-year-old female with a past medical history of dystonic cerebral palsy with crouch gait, bilateral external tibial torsion, excessive ankle dorsiflexion, and semitendinosus dystonia/spasticity causing severe bilateral knee pain and knee flexion contractures. Patient had a bilateral semitendinosus transfer to the adductor magnus tendon with the aim of decreasing the knee flexion and improving knee pain and gait at least marginally.

Discussion: After one year, patient continued to have bilateral knee pain that had failed conservative treatment with pain medications as needed and prior surgery, distal tibial and fibular osteotomies with plate and screw fixation of both distal tibial osteotomies were performed to address tibial torsion which is a recognized cause of patellofemoral pain.

Setting: Inpatient Rehabilitation.

Assessment/Results: The patient was discharged to Acute Rehabilitation for 3 weeks with the plan to keep bilateral below-the-knee casts and Darco shoes fitted over the casts for about 8 weeks, weight bearing was as tolerated. Patient tolerated physical and occupational therapy. Pain management included ice, standing doses of gabapentin, acetaminophen, and diazepam. The patient is expected to have a three-dimensional gait analysis after two years to allow for full recovery of both the osteotomies and semitendinosus transfer.

Conclusion: Tibial/fibular derotation surgeries are not frequently seen at this age, for which, data about surgical complications or rehabilitation outcomes is limited. Tibial rotation contributes to the knee deformity in a coronal plane, in this case, derotation osteotomy of the tibiae and fibula aims to improve the biomechanics of her gait and to decrease forces going across the knees and this theoretically should help alleviate pain. In contrast to tibial osteotomies, fibulae osteotomies are not fixated internally and often patients feel a clicking that can disappear once the fibula has a solid union.