EARLY SURGERY IN RARE KNEE HETEROTOPIC OSSIFICATION LEADS TO SUCCESSFUL FUNCTIONAL OUTCOME: A CASE REPORT.

Background: Heterotopic ossification is a common complication after joint replacement surgery, such as hip or knee arthroplasty. In the intensive care unit, it is most commonly associated with traumatic brain injury or spinal cord injury. To prevent recurrence, surgical resection of heterotopic ossification is recommended once the ectopic bone has fully matured, which is estimated to occur after at least 12 months.

Case presentation: This case describes a young woman with no relevant previous medical history who developed severe bilateral heterotopic ossification on the anteromedial sides of her knees after an intensive care unit stay. Passive flexion of both knees was limited to 50°. X-ray was a simple diagnostic tool. Predisposing factors were extended immobilization, prolonged systematic inflammatory condition and mechanical ventilation. Due to the failure of initial conservative therapy, the heterotopic ossification was resected early, 4 months after onset of first symptoms. Following an intensive rehabilitation program, a normal, pain-free gait and full range of motion of both knees were achieved 9 months after surgery.

Conclusion: This case report demonstrates that early resection of heterotopic ossification can result in a good clinical and functional outcome.