Impact of late surgical intervention on heterotopic ossification of the hip after traumatic neurological injury

Abstract

Heterotopic ossification (HO) of the hip after injury to the central nervous system can lead to joint ankylosis. Surgery is usually delayed to avoid recurrence, even if the functional status is affected. We report a consecutive series of patients with HO of the hip after injury to the central nervous system who required surgery in a single, specialised tertiary referral unit. As was usual practice, they all underwent CT to determine the location of the HO and to evaluate the density of the femoral head and articular surface. The outcome of surgery was correlated with the pre-, peri- and post-operative findings. In all, 183 hips (143 patients) were included of which 70 were ankylosed. A total of 25 peri-operative fractures of the femoral neck occurred, all of which arose in patients with ankylosed hips and were associated with intra-articular lesions in 18 and severe osteopenia of the femoral head in seven. All the intra-articular lesions were predicted by CT and strongly associated with post-operative complications. The loss of the range of movement before ankylosis is a more important factor than the maturity of the HO in deciding the timing of surgery. Early surgical intervention minimises the development of intra-articular pathology, osteoporosis and the resultant complications without increasing the risk of recurrence of HO.

Troublesome Heterotopic Ossification after Central Nervous System Damage: A Survey of 570 Surgeries

“…For patients with CNS damage, HO causes pain, inflammation and loss of range of motion (ROM) as the joint gradually becomes ankylosed [4], [5], [12], [19], [20]. The condition may have major repercussions on function, with, in many cases, loss of independence [2], [6].…”

“…The condition may have major repercussions on function, with, in many cases, loss of independence [2], [6]. Currently, the only effective treatment is surgery [4], [5], [19], [20], [21]. Indications for surgery have changed recently [4].…”

“…Until recently, surgery was delayed until the HO was fully formed [4], [21], [22], [23], [24], and studies of small samples of patients (analyzed by reviews) have suggested that the rate of recurrence is not affected by HO maturity [4], [25], [26]. Indications for surgery relate to vascular or neurological involvement, effect on function, hygiene (e.g., access to the perineum) and pain [5], [20], [26]. Surgery can be performed as soon as co-morbidity factors are under control, even in patients with major neurologic damage due to the original abnormality (e.g., TBI) [2], [26], [27], [28].…”

Beliefs relating to recurrence of heterotopic ossification following excision in patients with spinal cord injury: a review

“…Moreover, a prolonged delay before excision leads to a negative cascade of events: risk of ankylosis, intra-articular lesions, bone loss in the femoral head and increased risk of fracture during or after surgery. 4,6,16,33 Medical treatments for prevention and cure are still insufficient. Medical treatments for prevention and cure of HO are not very effective, mostly because of the lateness of the diagnosis along with the lack of well-established risk factors.…”

Clarifying the Structure and Bone Mineral Content of Heterotopic Ossification

“…Although HO may develop from rare genetic disorders such as fibrodysplasia ossificans progressiva (FOP) and progressive osseous heteroplasia (POH) [2][3][4], abnormal bone growth has been most frequently reported following trauma [2,[5][6][7][8][9][10][11][12], arthroplasty [13][14][15][16][17][18], burns [19,20], spinal cord injury [21][22][23][24], and traumatic brain injury [23,[25][26][27]. The onset of HO has been noted to occur within 1 to 12 wk from injury [28,29] and may be clinically detectable by swelling, redness, and limited range of motion to the affected area [24]. Properly diagnosing HO remains of utmost importance since misdiagnosis has led to unnecessary tissue damage and amputation of an extremity [30].…”