A 16-year-old Caucasian boy with a diagnosis of spinal dysraphism at the L5 level presented with a two-month history of a recurrent right ischial pressure ulcer. His surgical history included debridement and flap reconstruction of previous sacral and right ischial ulcers. On physical examination, a stage IV pressure ulcer was present overlying the right ischium in the setting of local postsurgical scarring. Computed tomography confirmed right ischial osteomyelitis. The patient was treated with wide surgical debridement of the involved soft tissues, ostectomy of the right ischial tuberosity and right gluteus maximus myocutaneous flap reconstruction, with postoperative care in the prone and lateral positions. Three months postoperatively, the patient complained of limited hip mobility; a plain pelvis radiograph confirmed bilateral heterotopic ossification (HO) of the iliac crests to the femurs (Figure 1). The patient was subsequently treated with a six-month course of aggressive physical therapy (twice a day treatment sessions) and oral bisphosphonate (etidronate 20 mg/kg three times a day), which resulted in significant clinical and radiographic improvement of bilateral hip range of motion (Figure 2).
DisCUssionHO has traditionally been a challenging diagnosis to successfully treat. Surgical excision has been described as the treatment of choice for symptomatic HO (1,2). As with all invasive surgical procedures, there is a risk of infection and blood loss (1), a considerable rehabilitation process and accumulation of scar tissue. Furthermore, due to the high recurrence rates, if surgical resection is performed on an immature lesion, treatment is often delayed for months before operative intervention is performed on mature lesions (3).Another option is radiation treatment, which can be used for both therapeutic and prophylactic purposes in HO (4-6). The therapeutic use of radiation therapy in established HO was first described by Schaeffer and Sosner (5) in 1995, who found that giving a 2 gray dose of radiation for several consecutive days resulted in improved range of motion. For prophylactic therapy, a single dose of 700 centigray administered within 48 h postoperatively is effective at reducing the recurrence rate of HO (7). Side effects of radiation therapy are common and present an obvious limitation to this treatment modality. An alternative postoperative prophylactic option is a course of a nonsteroidal anti-inflammatory Heterotopic ossification (HO) is a process whereby lamellar bone forms in the soft tissues surrounding a joint. The most common type of HO is traumatic myositis ossificans, which develops following traumatic injuries, burns or arthroplasty. A variety of other forms of HO also exist, such as those associated with central nervous system injury and systemic forms that can manifest at other joints simultaneously. Clinically, patients can present with decreased range of motion, pressure ulcers, nerve compression, swelling, pain or asymptomatically. Symptomatic patients are most commonly treated ...