Management of immature heterotopic ossification (HO) of the hip

Treatments that are perceived to be helpful for non-neuropathic pain after traumatic spinal cord injury: a multicenter cross-sectional survey

STUDY DESIGN

Cross-sectional survey.

OBJECTIVES

The objective of the study was to identify the treatments that people with traumatic spinal cord injury (SCI) used for their non-neuropathic pains (nonNeuPs) and how they subjectively rated the helpfulness of those treatments.

SETTING

Six centers from the Spinal Cord Injury Model Systems.

METHODS

Three hundred ninety one individuals who were at least 1-year post-traumatic SCI were enrolled. A telephone survey was conducted for pharmacologic and non-pharmacologic treatments utilized in the last 12 months for each participant's three worst pains and the perceived helpfulness of each treatment for each pain.

RESULTS

One hundred ninety (49%) participants reported at least one nonNeuP (Spinal Cord Injury Pain Instrument score < 2) in the previous 7 days. NSAIDs/aspirin, acetaminophen, opioids, and cannabinoids were the most commonly used and helpful pharmacologic treatments for overall nonNeuP locations (helpful in 77-89% of treated pains). Body position adjustment, passive exercise, massage, resistive exercise, and heat therapy were reported as the most commonly used non-pharmacological treatments for nonNeuPs. Heat therapy, aerobic exercise, massage, and body position adjustment were the most helpful non-pharmacological treatments for overall nonNeuP locations (helpful in 71-80% of treated pains). Perceived helpfulness of treatments varied by pain locations, which may be due to different mechanisms underlying pains in different locations.

CONCLUSIONS

Results of the study may help guide clinicians in selecting pain-specific treatments for nonNeuPs. The self-reported helpfulness of heat therapy, exercise, and massage suggests a possible direction for clinical trials investigating these treatments of nonNeuP while limiting the side effects accompanying pharmacologic treatments.

Histopathology of periarticular non-hereditary heterotopic ossification

In the mature adult skeleton, new bone formation is normally restricted to regeneration of osseous tissue at sites of fracture. However, heterotopic ossification, or the formation of bone outside the normal skeleton, can occur within muscle, adipose, or fibrous connective tissue. Periarticular non-hereditary heterotopic ossification (NHHO) may occur after musculoskeletal trauma, following CNS injury, with certain arthropathies, or following injury or surgery that is often sustained in the context of age-related pathology. The histological mechanism of bone development in these forms of heterotopic ossification has thus far been uncharacterized. We performed a histological analysis of 90 bone specimens from 18 patients with NHHO secondary to defined precipitating conditions, including traumatic brain injury, spinal cord injury, cerebrovascular accident, trauma without neurologic injury, and total hip or knee arthroplasty. All bone specimens revealed normal endochondral osteogenesis at heterotopic sites. We defined the order of sequence progression in NHHO lesion formation as occurring through six distinct histological stages: (1) perivascular lymphocytic infiltration, (2) lymphocytic migration into soft tissue, (3) reactive fibroproliferation, (4) neovascularity, (5) cartilage formation, and (6) endochondral bone formation. This study provides the first systematic evaluation of the predominant histopathological findings associated with multiple forms of NHHO and shows that they share a common mechanism of lesion formation.

Cartilage-derived retinoic acid-sensitive protein (CD-RAP): A stage-specific biomarker of heterotopic endochondral ossification (HEO) in fibrodysplasia ossificans progressiva (FOP)

BACKGROUND

Genesis of a cartilaginous scaffold is an obligate precursor to bone formation in heterotopic endochondral ossification (HEO). We tested the hypothesis that cartilage-derived retinoic acid-sensitive protein (CD-RAP) can serve as a plasma biomarker for the pre-osseous cartilaginous stage of HEO. Palovarotene, a retinoic acid receptor-gamma (RARγ) agonist, has been proposed as a possible treatment for fibrodysplasia ossificans progressiva (FOP) and is a potent inhibitor of HEO in mouse models. Current drug development for FOP mandates the identification of stage-specific biomarkers to facilitate the evaluation of clinical trial endpoints.

RESULTS

Here we show in an injury-induced, constitutively-active transgenic mouse model of FOP that CD-RAP levels peaked between day-7 and day-10 during the zenith of histologically-identified chondrogenesis, preceded radiographically apparent HEO, and were diminished by palovarotene. Cross-sectional analysis of CD-RAP levels in plasma samples from FOP patients demonstrated a statistically non-significant trend toward higher levels in the recent flare-up period (three weeks to three months within onset of symptoms). However, in a longitudinal subgroup analysis of patients followed for at least six months after resolution of flare-up symptoms, there was a statistically significant decrease of CD-RAP when compared to levels in the same patients at the time of active or recent exacerbations.

CONCLUSIONS

These data support the further exploration of CD-RAP as a stage-specific biomarker of HEO in FOP.

Association of vitamin D deficiency, secondary hyperparathyroidism, and heterotopic ossification in spinal cord injury

Our objective was to explore the relationship between low vitamin D, secondary hyperparathyroidism, and heterotopic ossification (HO) in patients with spinal cord injury (SCI). Ninety-six subjects with acute or chronic motor complete SCI participated. Levels of serum vitamin D25(OH), calcium, and intact parathyroid hormone (PTH) were collected, and information regarding nutritional patterns and fracture history was obtained from subjects. Evidence of current or previous HO was ascertained through chart review. Of the 96 subjects, 12 were found to have developed HO, 11 with serum vitamin D25(OH) between 5 and 17 ng/mL. Nine subjects exhibited secondary hyperparathyroidism in the range of 72 to 169 pg/mL. Only one subject demonstrated HO in the absence of low vitamin D. However, many subjects with low vitamin D (5-31 ng/mL) did not have hyperparathyroidism or HO. Statistical testing demonstrated a correlation between hyperparathyroidism and HO (p < 0.001) as well as hyperparathyroidism and vitamin D deficiency (<20 ng/mL). Direct correlation between HO and low vitamin D was not observed, but hyperparathyroidism may increase this risk. We believe that those patients who demonstrate low vitamin D and elevated PTH should be screened for HO in addition to beginning vitamin supplementation. Initiating early treatment of low vitamin D to restore therapeutic levels may prevent development of HO.

Sonographic diagnosis of neurogenic heterotopic ossification in patients with severe acquired brain injury in a neurorehabilitation unit

PURPOSE

To illustrate the ultrasonographic (US) and power Doppler US (PDUS) features of neurogenic heterotopic ossification (NHO) in consecutive patients with severe acquired brain injury and to evaluate the role of bedside US in diagnosis of NHO.

METHODS

Ninety-two consecutive patients with severe acquired brain injury underwent clinical and laboratory screening for NHO. In 6 of 92 patients, bedside US confirmed the clinical suspicion of NHO. US diagnosis of NHO was then confirmed by other imaging methods.

RESULTS

The incidence of clinical NHO was 7% (9/92) with one patient having multifocal involvement. In NHO of the hip, US demonstrated the classic pattern of zone phenomenon, and PDUS demonstrated vascular signal within mineralized NHO and in outer hypoechoic area. No vascular signal was observed in the central hypoechoic core. In NHO of the knee, a heterogeneously hypoechoic mass was seen and in the elbow a hyperechoic mineralized mass was visualized, with vascular signals seen within the lesions. Spectral wave analysis demonstrated low resistance vessels in NHO.

CONCLUSIONS

Bedside US is a useful tool in the diagnosis of NHO. PDUS adds data regarding neoangiogenetic activity of NHO.

Bedside ultrasound in early diagnosis of neurogenic heterotopic ossification in patients with acquired brain injury

OBJECTIVE

To illustrate ultrasound (US) and power Doppler US (PDUS) aspects of neurogenic heterotopic ossification (NHO) in consecutive patients with severe acquired brain injury, to evaluate the role of bedside US and PDUS in early diagnosis of NHO, to study incidence and outcome of NHO in this neurorehabilitative setting.

METHODS

Ninety-two consecutive patients with severe acquired brain injury underwent clinical and laboratory screening to pose suspect of NHO. In 6/92 patients bedside US examination confirmed the clinical suspect of NHO. US diagnosis of NHO was then confirmed by other imaging methods. All affected patients started therapy with indometacin, disodium etidronate, 6-methylprednisolone and they were followed-up for 1 year to evaluate the outcome.

RESULTS

The incidence of NHO in this setting was 6.5% (only one patient with multifocal involvement). In hip NHO US demonstrated the classical pattern of zone phenomenon, and PDUS demonstrated vascular signals within mineralized NHO and in the outer hypoechoic area. No vascular signal was observed in the central hypoechoic core. In knee and elbow NHO only a heterogeneously hypoechoic mass or hyperechoic mineralized mass were respectively evident, with vascular signals within the lesions at PDUS. Spectral wave analysis (SWA) demonstrated low resistance vessels in NHO. After 1 year of therapy only one patient showed a severe ankylosis of the hips.

CONCLUSIONS

Bedside US is a safe, cheap and useful tool in diagnosis of NHO and it allows to start therapy in early stages of NHO formation. PDUS adds data about neoangiogenetic activity of early NHO.