Prevention of Heterotopic Bone Formation in High Risk Patients Post-Total Hip Arthroplasty

Abstract

A retrospective study was carried out to evaluate prophylaxis for heterotopic ossification (HO) about the hip joint post total hip arthroplasty (THA). Between 1990 and 1996, 20 patients with known risk for developing HO were treated prophylactically to prevent this complication. Patients at risk were divided into 3 groups based on risk factors for HO formation (previous ipsilateral hip HO formation, previous contralateral hip HO formation and bilateral hypertrophic osteoarthritis) Single fraction radiotherapy of 600, 700 or 800 cGy was administered postoperatively to all patients. The aim was to irradiate all patients within 72 hours of THA. 12 (60%) patients received in addition a short course of postoperative indomethacin for less than 13 days. Patients in this study were investigated for the following treatment variables: relative risk for forming HO, radiotherapy doses administered, time delays between surgery and irradiation, combined radiotherapy and indomethacin treatment versus radiotherapy alone, and surgical approach used for THA. Heterotopic ossification in patients was measured radiographically by use of the Brooker grading sytem, and was assessed clinically by use of the Harris Hip Score (HHS). A significant difference was found between relative risk groups (p = 0.02). Patients with previous HO formation in the ipsilateral hip joint were at greater risk of developing HO than those with previous contralateral HO formation. Moreover both of these groups were at greater risk than those with advanced bilateral hypertrophic osteoarthritis. Other variables studied showed differences that were not significant due to small sample numbers. This study, though limited by sample number, addresses questions regarding effective radiotherapy dosage, time delays acceptable before irradiation postoperatively, usefulness of short course postoperative indomethacin, and preferred operative approaches to minimise HO.

HO prevention and the combined therapeutic protocol—do we really need it?

“…With a brief literature review, we found studies taking an opposing view to this study in which additional medication to radiotherapy caused no improvement of the clinical outcome [1]. Combined treatments were used post actebular fractures and were found to be effective [4].…”

Amino-bisphosphonates in heterotopic ossification: first experience in five consecutive cases

“…Even with prophylactic radiotherapy a recurrence rate of over 50% has been reported. [27][28][29][30][31][32][33][34] In none of our five cases we found clinical or radiographic evidence for recurrence or new formation of HO following surgery. In addition, biochemical markers such as osteocalcin and alkaline phosphatase were within the normal range in all our patients.…”

“…However, historical data on the natural outcome of excision surgery in this population of patients without treatment indicate a recurrence rate over 50%. [27][28][29][30][31][32][33][34] Accordingly, a recurrence of HO in at least two of our five patients would be anticipated. But in contrast, in none of our five high-risk patients such a recurrence occurred.…”

“…In these high-risk cases a recurrence rate of over 50% has been reported even with prophylactic radiation therapy. 1,[27][28][29][30][31][32][33][34] A protective effect of Etidronate, a first-generation bisphosphonate, in established HO, was found in some but not other studies. 14,[35][36][37][38] A rapidly growing body of literature supports aminobisphosphonates for the treatment of diseases associated with disturbed bone morphogenesis.…”

Assessment and management of chronic pain in patients with stable total hip arthroplasty

“…Clinically relevant ossifications develop in 20-45 % of all THA without prophylaxis compared to less than 5 % under an appropriate prophylaxis. Risk factors for HO include male gender, elderly, post-traumatic or hypertrophic osteoarthritis, rheumatoid arthritis, ankylosing spondylitis and Paget's disease [47][48][49][50]. Treatment of HO-related pain after THA is necessary when the patient experiences any If the nonoperative treatments fail then surgical resection of the ossification is the only therapeutic option [51].…”