Pseudoarthrosis in heterotopic ossification in spinal cord-injured patients

Heterotopic ossification (HO) of proximal joints is a common complication of spinal cord injury, traumatic brain injury, and burns, and is also seen among an array of other clinical conditions. Of the patients with HO, 3-8% develop ankylosis of the joint involved. Although the etiology of HO is not known, the main goal in its management is to retain the maximum possible functional range of movement in the joint involved. Toward this end, surgical resection of HO with etidronate disodium treatment to mobilize ankylosed joints has been reported, as has forceful joint manipulation in head-injured adults with HO. This paper presents two cases of extensive HO formation around hip and knee joints in patients who developed pseudoarthrosis. Cinradiographic assessment of the joints involved revealed pseudoarthrosis formation at the same axis as the normal anatomical plane of the joint, thus permitting functional range of movement.