Heterotopic ossification (HO) is one of the complications of a cervical cord injury that results in limited range of motion, which can interfere with basic movements and activities of daily living. We encountered a case of a cervical cord injury patient with limited range of motion and mobility due to HO of the hip joint who experienced improvement in both as a result of early surgery and rehabilitation. A 17-year-old boy was diagnosed with a cervical cord injury due to an anterior fracture of the sixth cervical vertebrae following a fall into a pool. It was classified as bilateral C6BII according to the Zancolli's classification for cervical cord injury. The patient presented with limited range of motion in his left hip and was diagnosed with HO four months after the injury. Eight months after the injury, his hip range of motion deteriorated further；consequently, he required continuous transfer assistance. Therefore, surgical HO removal was performed during this period of convalescent rehabilitation. The patient underwent constant post-operative rehabilitation, and the range of motion in his left hip joint improved；thus, he became independent in transfer activities. A concomitant HO after a cervical cord injury can lead to functional impairment in convalescent rehabilitation. In addition, no practice guidelines have been developed that include recommendations on when to perform surgical procedures for HO. Treatment of HO with a combination of immediate surgery and aggressive rehabilitation can be expected to restore function and maximize activity and participation in patients with cervical cord injury with concomitant HO.

Heterotopic ossification (HO) is one of the complications of a cervical cord injury that results in limited range of motion, which can interfere with basic movements and activities of daily living. We encountered a case of a cervical cord injury patient with limited range of motion and mobility due to HO of the hip joint who experienced improvement in both as a result of early surgery and rehabilitation. A 17-year-old boy was diagnosed with a cervical cord injury due to an anterior fracture of the sixth cervical vertebrae following a fall into a pool. It was classified as bilateral C6BII according to the Zancolli's classification for cervical cord injury. The patient presented with limited range of motion in his left hip and was diagnosed with HO four months after the injury. Eight months after the injury, his hip range of motion deteriorated further；consequently, he required continuous transfer assistance. Therefore, surgical HO removal was performed during this period of convalescent rehabilitation. The patient underwent constant post-operative rehabilitation, and the range of motion in his left hip joint improved；thus, he became independent in transfer activities. A concomitant HO after a cervical cord injury can lead to functional impairment in convalescent rehabilitation. In addition, no practice guidelines have been developed that include recommendations on when to perform surgical procedures for HO. Treatment of HO with a combination of immediate surgery and aggressive rehabilitation can be expected to restore function and maximize activity and participation in patients with cervical cord injury with concomitant HO.