Rare Case of Abnormal Bone Growth Successfully Treated With Surgery, Report Shows

In rare instances, people with hemophilia can grow bones outside their skeletal tissue — with bone growth found in muscles and soft tissues — which significantly limit their range of motion, according to a recent case report.

Surgery can improve the functional outcomes of patients with this abnormal bone growth, but the long-term effects and the likelihood of recurrence remain unknown.

Titled “A rare case of a patient with hemophilia presenting elbow-ankylosing heterotopic ossification: surgery and functional outcomes,” the case report was published in JSES International.

As a result of bleeding into muscle tissue, people with hemophilia can initiate abnormal bone development outside of the skeletal tissue. This rare condition, called heterotopic ossification (HO), is considered an aberrant form of tissue repair. Of note, when HO develops, new bone grows at three times the normal rate, resulting in jagged, painful joints.

While ossification or bone growth outside the skeletal tissue is recognized as a complication of trauma, surgery, and other injuries, its occurrence in hemophiliacs has rarely been reported.

Now, researchers at the University of Pavia, in Italy, reported the case of a 31-year-old male with severe hemophilia A who grew new bone in the muscle surrounding the elbow — without any hemophilia manifestation in the elbow’s joint or trauma to the elbow.

“To our knowledge this is the first case of atraumatic massive elbow muscular HO [heterotopic ossification] described in a hemophiliac patient without joint involvement,” the investigators wrote.

The patient was admitted to a medical facility due to severe stiffening and near-complete right elbow immobility. Pain and limited range of motion had begun about 15 years earlier. The man had no history of trauma that could explain these symptoms.

He did have a history of chronic hemophilic arthropathy, or permanent joint damage due to bleeding in the joints, which affects about 50% of patients with hemophilia. The man also had diabetes and high cholesterol. He received a regular regimen of Elocta (efmoroctocog alfa) — marketed as Eloctate in the U.S. and Canada — an anti-bleeding factor derived from recombinant DNA that is used to treat children and adults with hemophilia A.

A physical examination showed very little elbow function and significant limitations in daily life activities. An X-ray examination showed a well-developed bony bridge between the man’s humerus (the long bone of the upper arm) and the ulna — one of the two bones of the forearm — where they meet at the elbow. The physicians decided to remove the bony bridge surgically.

The patient was given Elocta, as well as tranexamic acid, to prevent bleeding during and immediately after the surgery. The surgeons removed what appeared to be mature cortical bone tissue, which normally forms the bones’ dense outer layer.

The man’s range of motion went from 70 degrees of flexion to 111 degrees following surgery, and from 40 degrees of extension prior to surgery to 14 degrees.

Physical therapy was started the day after surgery and the patient remained in the hospital for three days for optimal bleeding management. The physicians prescribed him celecoxib, once daily for 20 days, to prevent bone growth recurrence.

In addition, to prevent any post-surgical bleeding, the patient was again given tranexamic acid and a more intense regimen of Elocta for 14 days, after which the regular preoperative regimen was resumed. No bleeding-related complications occurred.

Six months after surgery, the patient showed no neurovascular issues and maintained his postoperative elbow flexibility. At this point, elbow function and quality of life had improved considerably, and the original bone growth had not recurred.

“Considering that the incidence of HO [heterotopic ossification] in hemophilia is probably underestimated, HO should be considered a plausible musculoskeletal complication in patients affected by hemophilia, especially when the decrease of range of motion arises in absence of evident acute joint bleeding or traumatic events,” the investigators wrote.

“The short-term result [after surgery] is very satisfactory and suggests that surgery may be considered a good option to treat patients with mature HO lesion and severe disability. However, the long-time results and the possible recurrence are still unknown,” they concluded.