Evaluation and management of heterotopic ossification in patients with spinal cord injury

Impact of Heterotopic Ossification on Functional Recovery in Acute Spinal Cord Injury

Objective: In spinal cord injury (SCI), heterotopic ossification is a frequent secondary complication, commonly associated with limited range of motion of affected joints, which could lead to secondary disability in activities of daily living. Additionally, heterotopic ossifications might challenge the effect of regeneration-promoting therapies on neurological and functional recovery. This study evaluated the impact of heterotopic ossification on clinical recovery within the first year after SCI.

Methods: The study was conducted as a monocentric longitudinal paired cohort study. Recruitment was based on consecutive sampling in the framework of the European Multicenter about Spinal Cord Injury (EMSCI). Recovery profiles were determined using standardized neurological and functional clinical assessments within the 1st year following SCI. All study participants underwent at least two comprehensive standardized neurological and functional clinical examinations according to the International Standards for Neurological Classification of SCI and the Spinal Cord Independence Measure, respectively. Data regarding the diagnosis and treatment of heterotopic ossification were obtained by reviewing the patient medical records. The most similar “digital twin” from the entire EMSCI database were matched in terms of age, acute neurological and functional status to each individual with SCI, and heterotopic ossification.

Results: Out of 25 participants diagnosed with heterotopic ossification, 13 individuals were enrolled and matched to control individuals. Most individuals presented with motor complete injury (75%). Ossifications were most frequently located at the hip joints (92%) and mainly occurred within the first 3 months after SCI. Individuals with heterotopic ossification achieved around 40% less functional improvement over time compared to their matched counterparts, whereas neurological recovery was not altered in individuals with SCI and heterotopic ossification.

Conclusion: Heterotopic ossification—a common complication of SCI—unfavorably affects functional recovery, which in the end is most relevant for the best possible degree of independence in activities of daily living. Upon presentation with heterotopic ossification, neurological improvement achieved through potential restorative therapies might not translate into clinically meaningful functional improvement. Diagnostic algorithms and effective early prevention/treatment options for heterotopic ossification need to be established to ensure the best possible functional outcome.

Clinical Trial Registration: NCT01571531 (https://clinicaltrials.gov).

Pelvic MRI in spinal cord injury patients: incidence of muscle signal change and early heterotopic ossification

STUDY DESIGN

Prospective observational study.

OBJECTIVE

To evaluate pelvic MRI muscle signal changes and their association with early heterotopic ossification (HO) in patients with spinal cord injuries.

SETTING

National Spinal Injuries Unit, Stoke Mandeville, UK.

METHODS

Forty patients were imaged with at least two interval magnetic resonance (MR) studies of the pelvis in the first 6 months following a spinal cord injury. Scans were reviewed and scored for heterotopic ossification, muscle signal change and extent of muscle involvement.

RESULTS

Muscle signal change was present in 28 (70%) on the initial MRI and 31 (77%) by the second study. Six patients developed MR changes of prodromal or immature heterotopic ossification (15%). No restricted diffusion was demonstrated and no patient developed mature HO. Patients developing MR changes of early HO were more likely to have grade 3 muscle changes.

CONCLUSION

Increased T2 muscle signal is common following cord injury, is frequently progressive in the subacute period and is associated with complete injury and early MR signs of heterotopic ossification.

Surgical treatment of hip ankylosis due to heterotopic ossification secondary to spinal cord injury

OBJECTIVES

To expose our experience in the diagnostic and surgical treatment of neurogenic heterotopic ossification of the hip.

MATERIAL AND METHODS

We designed an observational retrospective descriptive study including 20 patients (30 hips) with neurogenic heterotopic ossification of the hip secondary to spinal cord injury attended in our institution in the last 10 years, with a minimum of one year follow-up. Medical files and imaging studies were reviewed. The study variables analyzed were: type and localization of neurogenic heterotopic ossification, pre-post excision range of motion, level and aetiology of spinal cord injury, ASIA score, smoking history, surgical approach and complications associated with surgery.

RESULTS

A total of 20 patients were treated with resection of heterotopic ossification in 30 hips. 16 patients presented ASIA A spinal cord injury and 4 ASIA B spinal cord injury. Preoperatively all the patients had severe ankylosis in the hip that made sitting in a wheel chair and activities such as repositioning and hygiene difficult. The average postoperative motion at the follow-up evaluation was 90° in flexion, 20° of internal rotation and 40° of external rotation. Immediately after surgery all the patients followed a specific intensive physiotherapy regime for the hip and celecoxib 200 mg was administrated daily orally for a month to prevent recurrence of heterotopic bone formation. None of the patients reviewed suffered a recurrence of heterotopic bone formation.

CONCLUSIONS

Surgical excision of hip ossification in order to achieve functional ROM of the hip is the best treatment for patients with neurogenic heterotopic ossification of the hip.

Acquired heterotopic ossification of the temporomandibular joint

Although the risk factors and diagnosis of heterotopic ossification (HO) are discussed in the orthopedics literature, the etiology of HO, as well as its prevention and management, remain theoretical. Furthermore, there is a lack of information in the literature regarding HO in temporomandibular joint replacement (TMJR). This article provides a qualitative review of information relative to the etiology, diagnosis, and management of HO to inform and encourage further investigation in TMJR. The orthopedic HO literature considered for this qualitative review was drawn from a comprehensive examination of the subject published previously by one of the authors. Using the key words "heterotopic ossification" or "heterotopic bone", citations in the PubMed database from both the dental and oral and maxillofacial surgery literature were reviewed. Based on this, it appears that the etiology, diagnosis, imaging, laboratory testing, risk factors, prophylaxis, and non-surgical and surgical options available for the management of TMJR-related HO are similar to those for orthopedic HO, but further elucidation is required for TMJR. There is a lack of published information in the literature on TMJR. Therefore, using the literature from this review as a foundation, studies should be developed and reported so that alloplastic TMJ surgeons have evidence-based protocols that will lead to the early detection and potential prevention of HO.

A preliminary investigation on the effect of extracorporeal shock wave therapy as a treatment for neurogenic heterotopic ossification following traumatic brain injury. Part I: Effects on pain

INTRODUCTION

Neurogenic heterotopic ossification (NHO) is a complication of a neurological injury following traumatic brain injury (TBI) and may be present around major synovial joints. It is often accompanied by severe pain, which may lead to limitation in activities of daily living. Currently, a common intervention for NHO is surgery, which has been reported to carry many additional risks. This study was designed to assess the effect of extracorporeal shock wave therapy (ESWT) on pain in patients with TBI with chronic NHO.

METHODS

A series of single-case studies (n = 11) was undertaken with patients who had TBI and chronic NHO at the hip or knee. Each patient received four applications of high-energy EWST delivered to the affected joint over 8 weeks. Two-weekly follow-up assessments were carried out, and final assessments were made 3 and 6 months post-intervention. Pain was measured using the Faces Rating Scale, and X-rays were taken at baseline and 6-months post-intervention to physiologically measure the size of the NHO.

RESULTS

The application of high-energy ESWT was associated with significant overall reduction of pain in patients with TBI and NHO (Tau-0.412, 95% confidence interval -0.672 to -0.159, p = 0.002).

CONCLUSIONS

ESWT is a novel non-invasive intervention for reducing pain resulting from NHO in patients with TBI.

A preliminary investigation on the effect of extracorporeal shock wave therapy as a treatment for neurogenic heterotopic ossification following traumatic brain injury. Part II: Effects on function

INTRODUCTION

Neurogenic heterotopic ossification (NHO) occurs as a complication of traumatic brain injury (TBI). Management of clinically significant NHO remains variable. Complications of mature NHO include limitation of mobility. The effect of the extracorporeal shock wave therapy (ESWT) on range of motion at hip and knee, and function in patients with TBI with chronic NHO was investigated.

METHODS

A series of single-case studies applying ESWT to chronic NHO at the hip or knee of 11 patients with TBI were undertaken at a rehabilitation hospital. Participants received four applications of high-energy EWST delivered to the affected hip or knee over a period of 8 weeks. Two-weekly follow- up assessments were carried out; final assessments were made 3 and 6 months post-intervention. Range of motion (ROM) and Functional Reach (FR) or Modified Functional Reach (MFR) were measured.

RESULTS

Application of high-energy ESWT was associated with significant improvement in ROM (flexion) of the NHO-affected knee (Tau = 0.833, 95% CI 0.391-1.276, p = 0.002) and significant improvement of FR (Overall Tau 0.486, 95% CI 0.141-0.832, p = 0.006); no significant improvement in hip ROM or MFR.

CONCLUSIONS

ESWT may improve mobility and balance of patients with TBI who have chronic NHO.

The sensitivity of ultrasound screening examination in detecting heterotopic ossification following spinal cord injury

STUDY DESIGN

Retrospective chart review.

OBJECTIVE

To analyze the role of sonography in detecting heterotopic ossification (HO) following spinal cord injury (SCI).

SETTING

Department of Spinal Cord Injury and Department of General and Trauma Surgery, BG University Hospital Bergmannsheil Bochum, Ruhr University Bochum, Germany.

METHODS

Between January 2003 and December 2013, 217 patients with HO of the hips met the inclusion criteria and were included in the final analyses. The diagnosis of HO was carried out in all cases using our hospital protocol. Primary outcome measure was to calculate the sensitivity of ultrasound screening examination in detecting HO following SCI.

RESULTS

The diagnosis of HO was confirmed in 217 patients after a mean interval of 64.8 days (range from 8 to 295; s.d.=40.4) via computerized tomography or magnetic resonance imaging scan. In 193 out of 217 patients, suspicious HO signs were noted in the ultrasound screening examination (sensitivity=88.9%).

CONCLUSIONS

The use of ultrasound for screening for HO in SCI patients is reliable and has a high sensitivity.

Association between alendronate, serum alkaline phosphatase level, and heterotopic ossification in individuals with spinal cord injury

CONTEXT/OBJECTIVE

Only sparse evidence exists regarding the effectiveness of oral alendronate (ALN) in the prevention of heterotopic ossification (HO) in patients with spinal cord injury (SCI). The objective of this study is to investigate the protective effect of oral ALN intake on the appearance of HO in patients with SCI.

STUDY DESIGN

Retrospective database review.

SETTING

A Spinal Cord Unit at a Rehabilitation Hospital.

PARTICIPANTS

Two hundred and ninety-nine patients with SCI during acute inpatient rehabilitation.

INTERVENTIONS

Administration of oral ALN.

OUTCOME MEASURES

The incidence of HO during rehabilitation was compared between patients with SCI receiving oral ALN (n = 125) and patients with SCI not receiving oral ALN (n = 174). The association between HO and/or ALN intake with HO risk factors and biochemical markers of bone metabolism were also explored.

RESULTS

HO developed in 19 male patients (6.35%), however there was no significant difference in the incidence of HO in patients receiving oral ALN or not. The mean odds ratio of not developing versus developing HO given ALN exposure was 0.8. Significant correlation was found between abnormal serum alkaline phosphatase (ALP) levels and HO appearance (P < 0.001) as well as normal serum ALP and ALN intake (P < 0.05).

CONCLUSION

Even though there was no direct prevention of HO in patients with SCI by oral ALN intake, abnormal serum ALP was found more frequently in patients with HO development and without oral ALN intake. This evidence could suggest that ALN may play a role in preventing HO, especially in patients with acute SCI with increasing levels of serum ALP.

Neurogenic heterotopic ossification: epidemiology and morphology on conventional radiographs in an early neurological rehabilitation population

OBJECTIVE

To retrospectively evaluate neurogenic heterotopic ossification in an early neurological rehabilitation population (phases B and C) with respect to epidemiology and morphology on conventional radiographs.

MATERIALS AND METHODS

Over a 4-year period, 1,463 patients treated at a clinic for early neurological rehabilitation were evaluated for clinical symptoms of neurogenic heterotopic ossification. In case of clinical suspicion, plain radiographs of the expected sites were obtained. If heterotopic ossification was detected, the initial and subsequent radiographs were retrospectively analyzed for sites, size, and morphology. Immature lesions were categorized as small (<10 mm) or large (10-100 mm).

RESULTS

The prevalence rate of neurogenic heterotopic ossification was 2.05%. The condition was most common in young male adults. The hip was the most common site accounting for more than half of the cases. Two or more ossifications were seen in 56.7% of the affected patients with approximately two-thirds showing bilateral symmetric involvement of corresponding joint regions. The size of ossifications strongly varied interindividually. Small immature lesions demonstrated less progression in size than large lesions during maturation (P < 0.05).

CONCLUSION

Standard radiographs, as a fast and inexpensive technique, allow the expected size progression of heterotopic ossifications during maturation to be estimated, which is relevant in terms of therapeutic decisions, patient mobilization, and neurological rehabilitation.

The changing landscape of spinal cord injury

In the past quarter century, spinal cord injury medicine has welcomed the proliferation of new medications and technologies that improve the survival and quality of life for people with spinal cord injury, but also endured the failure of strategies we hoped would salvage the cord in the acute phase. Surgical decompression and spinal stabilization should be pursued whenever indicated and feasible; however, there is no compelling evidence that early decompression facilitates neurological improvement. Methylprednisolone, the subject of over two decades of trials, has proven to be of marginal benefit in improving functional outcome. Recent advances in the management of the respiratory, cardiovascular, autonomic, endocrine, skeletal and integumentary systems have not only changed morbidity and survival of spinal cord injury patients but also improved quality of life. Progress has been made in the early diagnosis and effective treatment of cardiac arrhythmias, neurogenic shock, autonomic dysreflexia and orthostatic hypotension. Aggressive respiratory care for high cervical level of injury patients should include an option for phrenic nerve pacing as it is a viable rehabilitative strategy for appropriately selected patients. Pressure ulcers remain a significant psychological, financial, and functional burden for many people with SCI and for healthcare providers. This area will continue to require further work on early prevention and education. Despite extensive scientific and clinical data on neurogenic osteoporosis, there is no consensus regarding the best pharmacotherapeutic agents, dosing regimens, or rehabilitative strategies for prevention and treatment of bone loss. This chapter will focus on the advances.

A comparison of heterotopic ossification treatment within the traumatic brain and spinal cord injured population: An evidence based systematic review

BACKGROUND

To compare the treatment of heterotopic ossification (HO) within the traumatic brain and spinal cord injured populations.

METHODS

MEDLINE/Pubmed, CINAHL, EMBASE, and PsycINFO databases were searched for articles addressing treatment of HO post-injury. Articles were constrained to: English language and human subjects. Studies were included if: n ≥ 50% of the subjects had a spinal cord injury (SCI) or a traumatic brain injury (TBI), n ≥ 3 SCI or TBI subjects, and study subjects participated in a treatment or intervention. Study quality, for randomized control trials (RCTs), were assessed using the PEDro assessment scale, while non-RCTs was assessed using the Downs and Black evaluation tool. A modified Sackett scale was used to apply levels of evidence for each intervention.

RESULTS

In total 26 studies (NTBI = 12; NSCI = 14) met inclusion criteria. The majority of studies (10/12) conducted in the TBI population were surgical interventions. Studies conducted with the SCI population investigated diverse pharmacological treatments including: bisphosphonates, non-steroidal anti-inflammatory drugs (NSAIDs) and Warfarin. Non-pharmacological studies investigated the benefits of pulse low-intensity electromagnetic field therapy, surgical excision, and radiotherapy in the treatment of HO.

CONCLUSIONS

Within the SCI literature, NSAIDs showed the greatest efficacy in the prevention of HO when administered early after a SCI, and biphosphonates were found to be the most effective treatment strategy. In the TBI population, surgical excision was the most effective treatment.

[Imaging features of neurologic and orthopedic complications from severe trauma]

Cranial and spinal trauma are a frequent cause of disability in the general population. Post-traumatic paraplegia or quadriplegia or hemiplegia from vascular injury (CVA) can lead to early complications (respiratory, cardiovascular, urinary, cutaneous, infectious...) that may have an impact on the immediate prognosis. Neurologic and orthopedic complications occur later and further impair the quality of life of patients. Orthopedic complications include: neurogenic paraosteoarthropathy (NPOA) or neurogenic osteoma or myositis ossificans (NMO). The nomenclature currently in use is NMO; Osseous complications: osteoporosis and secondary insufficiency fractures; Joint complications: degenerative arthropathy and stiffness; Overuse mechanical complications; Muscular complications; Infectious complications: arthritis and myositis complicating skin ulcers and bed sores. The purpose of this paper is to describe these neuro-orthopedic complications and review their imaging features.

Heterotopic ossification following traumatic brain injury and spinal cord injury

Heterotopic ossification associated with neurologic injury, or neurogenic heterotopic ossification, tends to form at major synovial joints surrounded by spastic muscles. It is commonly associated with traumatic brain or spinal cord injury and with other causes of upper motor neuron lesions. Heterotopic ossification can result in a variety of complications, including nerve impingement, joint ankylosis, complex regional pain syndrome, osteoporosis, and soft-tissue infection. The associated decline in range of motion may greatly limit activities of daily living, such as positioning and transferring and maintenance of hygiene, thereby adversely affecting quality of life. Management of heterotopic ossification is aimed at limiting its progression and maximizing function of the affected joint. Nonsurgical treatment is appropriate for early heterotopic ossification; however, surgical excision should be considered in cases of joint ankylosis or significantly decreased range of motion before complications arise. Patient selection, timing of excision, and postoperative prophylaxis are important components of proper management.

From brain to bone: evidence for the release of osteogenic humoral factors after traumatic brain injury

PRIMARY OBJECTIVE

The aetiology of the increased osteogenesis associated with severe traumatic brain injury (TBI) remains incompletely understood. The purpose of this article is to review the available evidence regarding the release of osteogenic humoral factors after TBI.

RESEARCH DESIGN

This study is presented in the form of a literature review.

METHODS AND PROCEDURES

To obtain suitable references, Pubmed was searched using keywords 'heterotopic ossification', 'brain', 'trauma', 'injury', 'aetiology'.

MAIN OUTCOMES AND RESULTS

Evidence from both clinical and laboratory investigations points to centrally released osteogenic factor(s) that enter the systemic circulation following TBI.

CONCLUSIONS

Further investigation into the identification of these putative osteogenic factor(s), using human tissues and new techniques, is indicated to better understand this phenomenon.

The use of eidronate disodium in the prevention of heterotopic ossification in burn patients

Heterotopic ossification (HO) is a well-known complication of moderate and severe burn injuries. The development and progression of HO in burn patients are poorly understood phenomena at this time. Numerous measures aimed at preventing or minimizing HO have been described, but no definitive prophylactic modality has been found. Biphosphonate compounds are known to inhibit calcification, but previous studies are equivocal regarding their effectiveness in preventing HO in burn patients. We retrospectively reviewed the effect of etidronate disodium (EDHP), a bisphosphonate, on the development of HO in severely burned patients. We found that not only was EDHP ineffective in preventing HO, the group of patients treated with EDHP demonstrated an increased incidence of HO over that seen in a comparison group. This was true after controlling for age, sex, and %TBSA burned. Based on the results of this study, the routine use of etidronate disodium to prevent HO in burn patients cannot be recommended.

Management of heterotopic ossification and venous thromboembolism following acquired brain injury

OBJECTIVE

To evaluate the effectiveness of interventional strategies for the common complications of heterotopic ossification (HO) and venous thromboembolism (VTE) following acquired brain injury (ABI).

METHODS AND MAIN OUTCOMES

A systematic review of the literature from 1980-2005 was conducted focusing on interventions for HO and VTE in the ABI population. Nineteen studies examining a variety of treatment approaches were evaluated.

RESULTS

The majority of interventions are supported by limited evidence, defined as an absence of randomized controlled trials (RCTs). All of the treatment approaches for HO are supported with limited evidence. For VTE, there is moderate evidence, defined as at least one positive RCT, indicating that low-molecular-weight heparin is more effective than low-dose unfractionated heparin in preventing VTE, low-molecular-weight heparin is as effective and safe as unfractionated heparin for the prevention of pulmonary thromboembolism, low-molecular-weight heparin combined with compression stockings is more effective than compression stockings alone for the prevention of VTE and intermittent pneumatic compression devices are as effective as low-molecular-weight heparin for the prevention of VTE.

CONCLUSIONS

There are a variety of intervention and prophylactic strategies that have been postulated to treat and reduce the incidence of these complications, with the goal of improving rehabilitation outcomes. It is therefore important to investigate the efficacy of these treatment strategies to provide guidance for clinical practice based on the best available evidence.

False-negative triple-phase bone scans in spinal cord injury to detect clinically suspect heterotopic ossification: a case series

BACKGROUND/OBJECTIVE

Heterotopic ossification (HO) is a complication seen in patients after spinal cord injury (SCI). Triple-phase nuclear bone scanning is the most sensitive test for the detection of HO. This retrospective study assesses whether patients with clinically suspected HO but negative triple-phase nuclear bone scans develop delayed positive nuclear bone scans.

CASE SERIES

A cohort of patients with SCI and clinically suspected HO who underwent triple phase nuclear bone scans over a period of 2 years was identified from retrospective chart review of an acute inpatient SCI rehabilitation service. A subgroup of 7 patients with initially negative but subsequently positive triple-phase nuclear bone scans was identified, and the following data were collected: date, mechanism, admission level, and admission completeness of injury as well as date, number, and results of bone scans. Laboratory studies were also collected during the time of imaging.

RESULTS

Over a 2-year period, 343 patients were admitted to the SCI rehabilitation service; 60 patients were suspected of having HO and underwent a total of 85 triple-phase nuclear bone scans. Seven patients were identified with initially negative but subsequently positive bone scans.

CONCLUSIONS

In patients with clinically suspicious HO but negative bone scans, follow-up scans are indicated to identify initial false-negative studies.

Transforming growth factor-beta (TGF-β) in acute injuries of the spinal cord

Injuries to the spinal cord may be associated with increased healing of fractures. This can be of benefit, but excessive bone growth can also cause considerable adverse effects.

We evaluated two groups of patients with fractures of the spinal column, those with neurological compromise (n = 10) and those without (n = 15), and also a control group with an isolated fracture of a long bone (n = 12). The level of transforming growth factor-beta (TGF-β), was measured at five time points after injury (days 1, 5, 10, 42 and 84).

The peak level of 142.79 ng/ml was found at day 84 in the neurology group (p < 0.001 vs other time points). The other groups peaked at day 42 and had a decrease at day 84 after injury (p ≤ 0.001).

Our findings suggest that TGF-β may have a role in the increased bone turnover and attendant complications seen in patients with acute injuries to the spinal cord.

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

STUDY DESIGN

Retrospective, observational study in five consecutive cases.

OBJECTIVES

The management of heterotopic ossification (HO), a frequent complication after spinal cord injury (SCI) and after orthopaedic surgery, is a therapeutic challenge with high recurrence rates of over 50%. Conflicting data were reported for Etidronate. The use of the more potent new generation of amino-bisphosphonates has been put forward in different inflammatory, dysmorphogenic bone disease. In order to try and halt the underlying dysfunctional bone metabolism we have studied the action of pamidronate in five consecutive high-risk patients with established HO of different etiology undergoing surgical removal.

SETTING

University Hospital of Basel, Switzerland, Division of Endocrinology, Diabetology and Clinical Nutrition and the Department of Orthopedic Surgery.

METHODS

In all five patients, ranging from 47 to 68 years of age, we used continuous pamidronate infusions perioperatively at a dosage of 120 mg in the first 12 h and subsequent reduction to 75-60-30-15 mg/12 h over a period of 10-14 days.

RESULTS

None of these patients showed clinical, radiographical and laboratory signs of HO recurrence or new forming HO in the follow-up 5-54 month after surgery. Potential side effects of high-dose bisphosphonate therapy such as osteoporosis and osteomalacia were not reported in any case.

CONCLUSION

We postulate that pamidronate might have pronounced beneficial effects in high-risk patients with established HO undergoing excision surgery. Since the therapeutic window of amino-bisphosphonates has not yet been defined and the minimal necessary doses for preventing new HO are unknown, further studies are encouraged to confirm our findings and to identify the necessary dosage and duration of treatment and to pinpoint, which patients will benefit most from this treatment.

Influence of brain injury on early posttraumatic bone metabolism

BACKGROUND

Various clinical studies and observations demonstrate enhanced osteogenesis in patients sustaining traumatic brain injury. It is presumed that the induction of this process starts early after trauma. The purpose of our study was to investigate humoral markers of bone metabolism during the early posttraumatic period, with special regard to traumatic brain injury.

METHODS

Serum concentrations of biochemical markers of bone metabolism (calcium, inorganic phosphorus, carboxyl-terminal propeptide of type 1 procollagen, pyridinoline cross-linked telopeptide domain of type 1 collagen, Ostase, osteocalcin, intact parathyroid hormone, and calcitonin) were measured in three different groups of 80 patients during the first posttraumatic week. Patients were categorized into three groups: group I, fractures only; group II, isolated traumatic brain injury; and group III, traumatic brain injury in combination with fractures.

RESULTS

Osteocalcin levels were significantly lower in the presence of traumatic brain injury (p < .05). Elevated pyridinoline cross-linked telopeptide domain of type 1 collagen levels expressed enhanced bone resorption in all groups, but levels were significantly higher in the absence of traumatic brain injury (p < .05). Intact parathyroid hormone levels were significantly higher on days 0 and 1 in the combined presence of traumatic brain injury plus fractures.

CONCLUSION

These results demonstrate an imbalance of bone formation and resorption parameters in patients with traumatic brain injury during the early posttraumatic period, suggesting a central regulation in bone formation. The lower levels of osteocalcin detected in this study may play an important role in patients with brain injury and the later development of posttraumatic heterotopic ossification.

Prevention of heterotopic ossification after spinal cord injury with COX-2 selective inhibitor (rofecoxib)

STUDY DESIGN

A randomized, prospective, double-blind, placebo-controlled clinical trial.

OBJECTIVES

To determine the effect of COX-2-selective inhibitor on the prevention of heterotopic ossification (HO) after spinal cord injury (SCI).

SETTING

County and University Teaching Hospital, Miami, FL, USA.

METHODS

A total of 76 patients were enrolled in the study. Among them, 39 patients received placebo, and 37 received COX-2-selective inhibitor rofecoxib 25 mg daily for a period of 4 weeks. Prevention was started 3 weeks after spinal cord injury (SCI). In both groups of patients there was similar age as well as the level of SCI and ASIA impairment scale. Two methods were used to diagnose early HO, clinical symptoms and bone scintigraphy. Radiography was used for diagnosis of late stages of HO development.

RESULTS

A significantly lower incidence of HO was found in the rofecoxib group (13.4%) than in the placebo group (33.3%: P<0.05). In patients receiving rofecoxib, there was a 2.5 times lower relative risk of developing HO than in the placebo group (95% CI, 2.3-6). There were no patients who discontinued the study due to adverse effects of medication.

CONCLUSION

Our data suggest that COX-2-selective inhibitor rofecoxib is an effective medication in prevention of HO after SCI.

Deep vein thrombosis and heterotopic ossification in spinal cord injury: a 3 year experience at the Swiss Paraplegic Centre Nottwil

STUDY DESIGN

Retrospective review of patient data.

OBJECTIVES

(i) To determine the incidence and time of deep vein thrombosis (DVT) under low molecular weight heparin (LMWH) prophylaxis in spinal cord injury (SCI), (ii) to determine the incidence and time of heterotopic ossification (HO) and (iii) to assess a possible aetiologic relationship in the pathogenesis of DVT and HO.

SETTING

Swiss Paraplegic Centre, Nottwil.

METHODS

We analyzed the incidence of DVT and HO in 1209 SCI patients (275 first rehabilitations) at the Swiss Paraplegic Centre Nottwil from 1998 to 2000. Clinical files and laboratory data were scrutinised for particularities preceding DVT and HO.

RESULTS

The incidence of DVT was 6.55% for first rehabilitation compared to only 1.59% in all patients hospitalised. DVT was complicated by pulmonary embolism (PE) in 1.45% and 0.47% respectively. Incidence of HO was 8% for first rehabilitation and 1.82% for all patients hospitalised. In first rehabilitation patients the peak for DVT occurred around day 30 contrary to HO with a peak around day 120. In single patients HO was identified by MRI as a rapidly progressing process. Laboratory profiles were inflammatory in both HO and DVT. Increased physical activity preceding HO was observed in four patients. In two patients acute HO was complicated by ipsilateral DVT.

CONCLUSION

Prophylaxis with LMWH and elastic stockings significantly reduces the frequency of DVT during first rehabilitation in SCI. DVT and HO are both associated with laboratory parameters of non-infectious inflammation. The later onset of HO coinciding with ongoing mobilisation, argues for a different pathogenetic mechanism. Acute HO of the hip region appears to favour ipsilateral DVT by well known thrombogenic mechanisms.

Management of immature heterotopic ossification (HO) of the hip

A case of extensive heterotopic ossification involving the left hip in a 16 year old girl who sustained non traumatic spinal paralysis at T4 ASIA scale A. This case demonstrates the practical difficulties facing clinicians involved in the rehabilitation of this paraplegic patient who required intervention before full maturation of her left hip heterotopic ossification (HO). The patient was developing a rapidly progressive fixed scoliosis and severe difficulty in achieving a proper seating posture. In addition there was difficulty with the application of a suitable orthosis to try and limit the progression of scoliosis as a result of the HO. Discussants will comment on heterotopic ossification in general and the course of action in this particular case.

Neurogenic heterotopic ossification in spinal cord injury

Neurogenic heterotopic ossification (NHO) is a frequent complication in spinal cord injury (SCI) that is often difficult to treat. This review emphasizes the incidence, risk factors and clinical signs of NHO in SCI patients. Although the exact pathophysiology underlying NHO in neurologic patients is not yet understood, different pathogenic mechanisms have been proposed in the literature. A selection of the most important theories will be given and discussed. Moreover the different diagnostic, therapeutic, and preventive methods currently used in NHO management after SCI will be reviewed.

Imaging in chronic spinal cord injury--indications and benefits

As most patients who have suffered spinal cord injury can now expect a normal life span, the late complications of these injuries are seen increasingly frequently. Regular surveillance of both the renal tract and the central nervous system (CNS) is important as the treatment of impending, potentially fatal complications can be implemented before damage has progressed too far. Renal tract complications are particularly dangerous as they are often clinically silent but regular surveillance to detect early deterioration in renal function, particularly from reversible causes such as reflux or obstruction can pre-empt problems. Follow-up protocols depend on the bladder management regime but most centres advocate regular ultrasound with less frequent isotope function studies. With the increasing ability to diagnose and treat the neurological complications, surveillance of the state of the spinal cord with MRI is also important and many centres now advocate checks every few years with sagittal midline T2W sections are sufficient unless changes are noted, when axial T1W sections can be added without significant examination time penalty. Imaging is critical in acute problems. In addition to suffering from the usual normal conditions, patients with spinal cord injury suffer others peculiar to, or particularly related to, the injury, which may be missed as their symptomatology is greatly altered by their paraplegic or quadriplegic status and they may often present as generally unwell but with no obvious cause. This review discusses the role of radiology in routine surveillance of the CNS and the renal tract as well as in assessing specific conditions such as deteriorating neurology or renal function, pain, spinal instability, pressure sores, ectopic ossification, muscular spasm, spinal instability, airway problems and elective operations on the renal tract.

Spinal cord injury medicine. 2. Medical complications after spinal cord injury: Identification and management

This is a self-directed learning module that reviews medical complications associated with spinal cord injury (SCI). It is part of a chapter on SCI medicine in the Self-Directed Physiatric Educational Program for practitioners and trainees in physical medicine and rehabilitation. This article includes discussion of common medical complications that impact rehabilitation and long-term follow-up for individuals with SCI. Issues addressed include the rehabilitation approach to SCI individuals with pressure ulcers, unilateral lower-extremity swelling (deep venous thrombosis, heterotopic ossification, fractures), along with the pathophysiology, assessment, and treatment of spasticity, autonomic dysreflexia, orthostatic hypotension, and pain.

OVERALL ARTICLE OBJECTIVE

To describe diagnostic and treatment approaches for medical complications common to individuals with SCI.

Pelvic heterotopic ossification: MR imaging characteristics

PURPOSE

To evaluate the magnetic resonance (MR) signal intensity characteristics of pelvic heterotopic ossification (HO) in various stages of maturation.

MATERIALS AND METHODS

Thirty-six patients with HO proved at computed tomography (CT) (n = 17) or radiography (n = 19) who underwent 1.5-T pelvic MR imaging within 3 months were included. HO was defined at CT or radiography as grade 1, fluid attenuation without calcification at CT; grade 2, calcification; grade 3, immature ossification; or grade 4, mature ossification. The location and MR signal intensity of all HO sites were noted.

RESULTS

HO was determined to be grade 1 at 20 of 141 sites, grade 2 at 39, grade 3 at 30, and grade 4 at 52. With increasing HO grade, the following findings were observed: (a) decreasing T2 signal intensity (grade 1, 70%; grade 2, 58%; grade 3, 44%; grade 4, 4%), (b) increasing fat and cortical bone signal intensity at T1-weighted imaging (grade 1, 0%; grade 2, 3%; grade 3, 13%; grade 4, 86%), and (c) decreasing contrast enhancement (from 100% for grade 1 to 20% for grade 4). Fifteen (88%) patients with CT correlation had HO in the anatomic area of the trochanteric or iliopsoas bursa (55 [60%] of 91 sites).

CONCLUSION

With progressive maturity of HO, T2 signal intensity and contrast enhancement decrease, but fat and cortical bone-equivalent signal intensity increases.

Microvascular changes in the lower extremities of paraplegics with heterotopic ossification

OBJECTIVES

To investigate the morphological aspects of blood microvasculature of the skin and subcutaneous tissues in subjects with paraplegia with heterotopic ossification (HO).

METHODS

In two patients with traumatic spinal cord injury and HO, punch biopsies of skin and hypodermic soft tissue in the region of HO near the hip were studied with histological and ultrastructural methods.

RESULTS

Alterations of endothelial cell and basement membrane of capillaries and small vessels were observed. Hyperactive endothelium, thickening and reduplication of the basement membrane, changes of the perivascular connective tissues and microcalcifications in the subcutaneous fat tissue were also seen.

CONCLUSIONS

This present study indicates microvascular changes in the skin and subcutaneous tissue in the region of HO near the hip of two subjects with paraplegia. In our opinion the described vascular changes may induce hypoxiemic alterations of the soft para-articular tissues leading metabolic changes which may contribute to the development of HO. Therefore, it cannot be concluded whether these changes are directly responsible for HO induction.

Prevention of heterotopic ossification after spinal cord injury with indomethacin

STUDY DESIGN

A randomized, prospective, double-blind, placebo-controlled clinical trial.

OBJECTIVES

To determine the effect of indomethacin on the prevention of heterotopic ossification (HO) following spinal cord injury (SCI).

SETTING

County Hospital, Miami, Florida, USA.

METHODS

Sixteen patients were treated with slow-release indomethacin 75 mg daily and 17 patients received placebo for a period of 3 weeks. Prevention was started 21+/-14 days after SCI. In both groups of patients there was similar age of the patients as well as the level of SCI and ASIA impairment scale. Two methods were used to diagnose HO, bone scintigraphy and radiographic examination. Bone scintigraphy with technetium labeled methylene-diphosphonate was used for diagnosis of early stage, while radiography was used for diagnosis of late stage of HO development.

RESULTS

A significantly lower incidence of early HO was found in the indomethacin group (25%) than in the placebo group (65%; P<0.001). Similarly there was a significant reduction of late HO in the indomethacin group (12.5%) as compared to the placebo group (41%; P<0.001).

CONCLUSION

Our data suggest that indomethacin used during the first 2 months after SCI is effective in prevention of HO in a significant number of patients.

Treatment of osteoporosis with bisphosphonates

Several bisphosphonates are effective for preventing bone loss associated with estrogen deficiency, glucocorticoid treatment, and immobilization, and for at least partially reversing bone loss in patients with postmenopausal osteoporosis and steroid-induced osteoporosis. The most promising of these agents are etidronate, alendronate, risedronate, and ibandronate. These drugs should have an important role in the prevention and treatment of osteoporosis; however, more research is needed regarding optimal doses and regimens (continuous versus intermittent, oral versus parenteral), comparisons with other agents, and their use in combination with other agents.