Review Question - QID 214108

This patient has developed heterotopic ossification (HO) of the elbow following a traumatic brain injury (TBI). As he is only 2-months from his injury, and the acitivity of HO formation is unknown, surgical excision is not recommended.

HO of the elbow usually occurs either spontaneously or following trauma within 2 months of neurologic injury (brain or spinal cord). Patients will often demonstrate limitations in motion. Additionally, due to its proximity to the elbow, the ulnar nerve is particularly vulnerable to compression from HO formation. Laboratory markers may be useful in montioring HO formation. An elevated serum alkaline phosphatase (ALP) is nonspecific and is often elevated. Additionally, normalization of CRP may correlate with maturity of HO formation. Timing of resection is controversial but typically there should be marked decrease in bone scan activity and normalization of ALP. Generally, HO excision is performed 6 months following general trauma and after a year or more following spinal cord injury or TBI, although there is some data that suggests equivalent results when comparing early versus late resection.

Cipriano et al. reviewed neurogenic heterotopic ossification and found that it tends to form at major synovial joints surrounded by spastic muscles. They report that a variety of complications can occur including nerve impingement, joint ankylosis, complex regional pain syndrome, osteoporosis, and soft-tissue infection. They conclude that management of heterotopic ossification is aimed at limiting its progression and maximizing function of the affected joint and that patient selection, timing of excision, and postoperative prophylaxis are important components of proper management.

Lee et al. systematically reviewed literature regarding management and outcomes of surgically treated elbow HO. They report that regardless of the etiology, surgical excision of elbow HO significantly improved functional range of motion. Additionally, they found that the overall complication rate was 22.6% and included HO recurrence, ulnar nerve injury, infection, and delayed wound healing. They concluded that surgical treatment of elbow HO leads to improved functional outcome, whether the etiology of bone formation was direct elbow trauma, brain injury, or thermal injury.

Figure A is the lateral radiograph of an elbow with heterotopic ossification formation

Incorrect Answers:
Answer 1: External beam radiation is used for HO prophylaxis. Typically, a single perioperative dose of 700cGy can be given either 4 hours preoperatively or within 72 hours postoperatively
Answer 2: With mild ulnar nerve symptoms and presumed continued activity of HO formation, isolated ulnar nerve release is not indicated
Answers 3&4: With presumed continued HO formation excision of HO and ulnar nerve release is not indicated at this time. Typically, there should be marked decrease in bone scan activity and normalization of ALP prior to consideration of excision