TO THE EDITOR:
In "Early Excision of Heterotopic Ossification about the Elbow followed by Radiation Therapy" (79-A: 749—755, May 1997), McAuliffe and Wolfson concluded that the twelve to eighteen-month delay between injury and excision may be eliminated. Additional analysis seems warranted.
In this small study (of eight patients), the authors compared three populations that had distinct responses to the excision of heterotopic ossification. In a patient who has a spinal cord injury or a traumatic brain injury, the recurrence of heterotopic ossification and the functional outcome may be best predicted by the level of neurological involvement and the level of motor recovery1-5. The motor response, the amount of heterotopic ossification, and the outcome of operative intervention are different in a patient who has paraplegia caudad to the level of the fourth cervical nerve root than in a patient who is in a persistent vegetative state or in one who recovers neurological function after a traumatic brain injury. The most important predictor of recurrent heterotopic ossification, and of a good outcome after resection, in a patient who has neurological damage is the motor examination, which unfortunately was not presented in this paper.
Traumatic heterotopic ossification may be excised as early as three to six months after the injury in the general population2. McAuliffe and Wolfson appear to confirm this. The twelve to eighteen-month delay recommended for patients who have neurological involvement allows neurological homeostasis, which seems to diminish the stimulus for heterotopic ossification and allows the patient to participate in postoperative range-of-motion exercises. McAuliffe and Wolfson incorrectly stated that this period is "to allow for maturation of heterotopic bone."
This paper does not necessarily invalidate the concept that a longer delay is necessary for patients who have neurological involvement, as these patients had a decreased range of motion as well as recurrence. Furthermore, it does not give sufficient evidence that radiation prevents recurrence in patients who have persistent neurological damage.
Douglas E. Garland, M.D.: Southern California Center for Sports Medicine, Memorial Orthopaedic Surgical Group, 2760 Atlantic Avenue, Long Beach, California 90806
Dr. McAuliffe and Dr. Wolfson reply:
Although Dr. Garland and others have stated that traumatic heterotopic ossification may be excised as early as three to six months after the injury, we are unaware of previous clinical reports documenting this hypothesis. The generally recommended delay before excision of heterotopic ossification of any etiology is meant primarily to lessen the likelihood of recurrence after excision. Our study suggests that, in certain instances, this delay may be shortened, and we believe that this possibility should be examined further.
We agree that longer delays before excision may be advisable for neurologically impaired patients; however, contrary to Dr. Garland's statement, none of the patients in our series had a recurrence of heterotopic ossification or, we admit, the type of residual neurological deficit that would place them at extraordinarily high risk of a recurrence. Generally, in the absence of cognitive recovery or motor control of the involved extremity, there would be no reason to attempt excision of the heterotopic ossification earlier than the guidelines that were recommended by Dr. Garland. Two of our patients who did not have a complete return of motor function, one because of a brachial plexus injury and one because of an incomplete spinal cord injury, did have limited motion of the affected elbow at the most recent follow-up examination largely because this motion had to be maintained passively. Our clinical expectation of motor recovery in these patients, based on a negative brachial plexus exploration in the first patient and on motor recovery in the contralateral limb in the second, was unfortunately not realized. We do not intend to suggest that heterotopic ossification should routinely be excised before assurance of neurological recovery and motor control, nor do we believe that we have provided evidence that radiation prevents recurrence in patients who have a persistent neurological deficit. Simply stated, we believe that the delay preceding excision of heterotopic ossification may be shortened in many instances and that additional study is needed to better define this interval for specific subsets of heterotopic ossification and to determine whether radiotherapy is necessary to prevent recurrence.
We thank Dr. Garland for his comments and for his efforts to better define the myriad clinical presentations of heterotopic ossification in the various patient populations in which it occurs.
John A. McAuliffe, M.D.: Section of Hand Surgery, Cleveland Clinic Florida, 3000 West Cypress Creek Road, Fort Lauderdale, Florida 33309
Aaron H. Wolfson, M.D.: Department of Radiation Oncology (D-31), University of Miami School of Medicine, 1475 N.W. 12th Avenue, Miami, Florida 33136