Rehabilitation Program
Physical Therapy
The treatment of heterotopic ossification (HO) often is quite challenging and, in many cases, unsatisfactory. Therefore, emphasis should be placed on the importance of understanding the natural history of HO in developing treatment strategies. Most cases of HO occur within 3 months after spinal cord injury. Most roentgenographic evaluation occurs during a 6-month period, and the progress of HO is related to the severity of injury. In patients with severe injuries, roentgenographic progression has been found to subside by 6 months and serum alkaline phosphatase and bone scan activity to become normal or significantly decreased. In patients with more severe deficits, larger amounts of bone formation that progressed for more than 1 year has been seen, and elevated alkaline phosphatase levels and increased bone scan activity have been observed for up to 2 years or longer.
The role of physical therapy in patients with HO is controversial. The major goal of treatment is to maintain ROM and thereby preserve function; however, opinions differ regarding ROM exercises for patients with HO.
Several authors have reviewed the literature that compares opposing philosophies. One theory is that an aggressive regimen of passive ROM exercises may predispose the patient to the development of HO because of microtrauma or local hemorrhage. Several authors suggest that passive stretching and ROM exercises are contraindicated after HO is suggested, but they recommend active exercise within the pain-free range. Other authors stress the importance of ROM exercises to maintain joint mobility and to prevent or retard fibrous ankylosis. They found no evidence for increased HO or decreased ROM with passive ROM exercises.
Forceful manipulation of joints with preexisting HO under anesthesia helps to maintain useful joint ROM and to prevent ankylosis. A study by Garland and colleagues found that 64% of affected joints maintained or gained ROM with rehabilitation after manipulation. [12] Some patients required repeated manipulations; none had a detectable increase in HO. The literature generally supports the common use of active ROM exercises and gentle, passive ROM exercises to maintain available joint motion and to avoid progressive contractures. If ankylosis seems inevitable despite exercises, it is best for the patient if it occurs in the most functional position.
Medical Issues/Complications
In a patient with a severe head injury, problems (such as deforming spasticity and contracture) often have time to develop because of the time needed to handle prolonged complications in acute care (eg, craniotomy facial bone surgeries, cholecystitis, pneumonia or other infections). In addition, if the head-injury patient displays a low level of responsiveness during much of the hospital course, this often casts doubt in the mind of acute care personnel about the individual's suitability for rehabilitation. Aggressive measures to prevent deformities may be given a lesser priority, especially if staff members are dealing with complications that have a greater medical priority. The resulting deformities may be quite advanced by the time the patient reaches acute rehabilitation, making intervention more difficult.
Surgical Intervention
In cases of heterotopic ossification (HO), surgery for removal of ectopic bone should be undertaken only for clear functional goals, such as for improved standing posture or ambulation or for independent dressing and feeding. In general, surgery is not undertaken earlier than 18 months after injury.
Excision should be considered for patients in whom shoulder motion is severely limited by extensive heterotopic bone, especially if dynamic electromyography studies reveal volitional capacity for the various shoulder muscles. Excision may also be undertaken to improve passive shoulder functions.
HO that restricts elbow motion is excised surgically at maturation. Maturation of HO is determined by the radiographic appearance of a defined cortex and by a normal level of serum alkaline phosphatase. Additional prognostic indicators for successful HO excision are good cognitive recovery (Rancho scale level VI or greater) and selective motor control in the extremity. Time since onset of brain injury alone is not an accurate prognosticator. [13, 14]
An observational, retrospective, descriptive study by Romero-Muñoz et al supported the efficacy of surgical excision in HO of the hip. Patients who underwent the procedure for spinal cord injury–related hip HO had, at minimum 1-year follow-up, average flexion, internal rotation, and external rotation of 90°, 20°, and 40°, respectively. Patients were rehabilitated postsurgically with intensive physical therapy, along with a month-long regimen of daily, orally administered celecoxib 200 mg for recurrence prevention. [15]
lf joint deformity from HO results in significant functional limitations such as difficulty with hygiene, sitting, or ambulation, surgical resection of HO may be indicated. Surgery may also be appropriate if an underlying bone mass contributes to repeated pressure sores. Various recommendations have been made for the timing of surgery. Surgery is contraindicated in patients with clinical, laboratory, or radiographic evidence of active ossification. Waiting for the maturation of heterotopic bone before operating may take 1-2 years. Heterotopic bone should be excised when it significantly restricts joint ROM and limits function and rehabilitation. Other authors have said that the process is stabilized after 6-8 months and that surgery is of benefit after that time, although the authors did not state whether radiation treatments were given to the patients studied.
Traditionally, surgery should be delayed for 18 months after brain injury. Patients with good neurologic recovery, good motor control, normal or slightly elevated levels of alkaline phosphatase, and a mature lesion may be candidates for surgery before the 18 months. In more severely compromised patients, if motor control is still improving and laboratory test values still indicate abnormalities, surgery should be delayed longer than 18 months. With such patients, the major indication for surgery is limb positioning. Once HO has matured, at 12-18 months or more after injury, it can be removed surgically or partially resected if clinically indicated. Postexcision, low-dose radiation or the use of etidronate disodium (EHDP) can prevent its recurrence. [16, 17, 18, 19, 20, 21]
However, several case series suggest that earlier resection results in improved function without significant risk of recurrence. Although diphosphonates are an effective means of prophylaxis if initiated shortly after the trauma, mineralization of the bone matrix resumes after drug discontinuation, making this traditional practice also controversial.
Consultations
See the list below:
-
Physiatrists - To plan the best rehabilitative approach
-
Neurologists - To rule out other neurologic impairments
-
Orthopedic surgeons - If any surgical treatment is necessary
Other Treatment
Forceful joint manipulation appeared to enhance formation of HO, and it has been postulated that the force generated by muscle spasticity may promote its development.
-
This radiograph clearly demonstrates fairly extensive heterotopic ossification at the bilateral hip regions. The extensive bone formation shown here makes it easy for the viewer to understand why a patient with HO could present with complaints such as pain, swelling, palpable mass, and decreased range of motion.
