Heterotopic ossification in the setting of neuromuscular blockade

Heterotopic Ossification of Bilateral Hips Post-COVID-19 and Prolonged Immobilization: A Case Report

CASE

A 43-year-old healthy man developed hip pain post-coronavirus disease 2019 (COVID-19) immobilization. Imaging confirmed bilateral bridging heterotopic ossification (HO) of the hips, Brooker Class IV. Bilateral HO caused functional arthrodesis (45° flexion: -20° internal rotation). Bilateral HO resection resulted in almost full mobility at 1-year follow-up (90° flexion; 30° internal rotation).

CONCLUSION

Many cases of HO after immobilization for COVID-19 have been reported, but as far as we know, this is the first case report describing surgical intervention as an adequate treatment option for severe restricted mobility caused by HO due to COVID-19-induced prolonged immobilization. Caution and preoperative 3D planning are recommended of HO formation near neurovascular structures.

[18F]FDG-PET/CT in mechanically ventilated critically ill patients with COVID-19 ARDS and persistent inflammation

Purpose

We report the findings of four critically ill patients who underwent an [18F]FDG-PET/CT because of persistent inflammation during the late phase of their COVID-19.

Methods

Four mechanically ventilated patients with COVID-19 were retrospectively discussed in a research group to evaluate the added value of [18F]FDG-PET/CT.

Results

Although pulmonary PET/CT findings differed, bilateral lung anomalies could explain the increased CRP and leukocytes in all patients. This underscores the limited ability of the routine laboratory to discriminate inflammation from secondary infections. Based on PET/CT findings, a secondary infection/inflammatory focus was suspected in two patients (pancreatitis and gastritis). Lymphadenopathy was present in patients with a detectable SARS-CoV-2 viral load. Muscle uptake around the hips or shoulders was observed in all patients, possibly due to the process of heterotopic ossification.

Conclusion

This case series illustrates the diagnostic potential of [18F]FDG-PET/CT imaging in critically ill patients with persistent COVID-19 for the identification of other causes of inflammation and demonstrates that this technique can be performed safely in mechanically ventilated critically ill patients.

Idiopathic Spontaneous Occurrence of Heterotrophic Occurrence During Pregnancy

Heterotopic ossification (HO) typically presents in the hip, knee, and elbow joints in the setting of trauma or postsurgical intervention. Less commonly, it may occur secondary to neurologic dysfunction or underlying genetic conditions, but idiopathic HO is rare. Most cases of HO are managed nonoperatively with surgical resection remaining a controversy due to high recurrence rates. We describe a case of idiopathic HO of the shoulder that occurred in the absence of trauma, neurologic dysfunction, or underlying genetic disorder that was treated with surgical excision.

Early diagnosis of heterotopic ossification among patients admitted to a neurological Post-Intensive Care Rehabilitation Unit

BACKGROUND

Heterotopic ossification (HO) is defined as the formation of endochondral bone within soft tissue. Non-genetic forms, mainly corresponding to a consequence of bone, brain or spinal cord injury, are the most common. HO leads to important functional limitations and alteration of quality of life. To our knowledge, the time between brain, bone, or spinal cord injury and clinical suspicion of HO has never been studied. By admitting patients with severe neurological disorders, we hypothesized that the prevalence of HO in neurological post-intensive care rehabilitation units (PICRU) might be significant as these patients have recognized risk factors for HO.

AIM

This study aimed to investigate HO among patients admitted to a neurological PICRU with two objectives: 1) to describe the prevalence of HO in PICRU; 2) to assess the time between neurological disorder, clinical suspicion of HO and radiological diagnosis.

DESIGN

A monocentric retrospective cohort study.

SETTING

PICRU in our public university teaching hospital. This inpatient referral department is specifically dedicated to the early discharge from Intensive Care Units (ICU) of patients with severe neurological impairment who need rehabilitation.

POPULATION

We study all patients admitted between April 2016 and January 2019. One hundred twenty-five subjects were admitted for a rehabilitation program after neuro-trauma or stroke. We included all first-time stays in PICRU lasting 7 days or longer.

METHODS

Retrospective data extraction using administrative data from an electronic patient management program was done to select eligible subjects. Included subjects were then identified by a retrospective review of electronic inpatient medical records after patient discharge. Data of interest were collected from these same medical records.

RESULTS

Forty-four HO were diagnosed in 24 subjects (24/125; 19%), with a median number of 2 [1; 2] HO per subject. Neurological trauma was the main reason for admission to ICU (89/125; 71%) and half of patients had a traumatic brain injury (TBI) (67/125; 54%). The diagnosis of HO was made in PICRU in 75% of cases. Clinical suspicion of HO (autonomic dysfunction, local inflammatory signs, pain, or reduced joint range of motion) was made 6 [5; 7] weeks after admission to ICU. Radiological confirmation of clinical suspicion or fortuitous diagnosis by imaging (50% of the cases) occurred 8 [7; 12] weeks after admission to ICU. The median time of clinical suspicion or radiological diagnosis was 1 week after admission to PICRU.

CONCLUSIONS

HO is a sub-acute complication which develops in patients admitted to ICU for severe central nervous system disorders as clinical suspicion or radiological confirmation of diagnosis was made within the first week after admission in neurological PICRU (i.e. 6 to 8 weeks after ICU admission).

CLINICAL REHABILITATION IMPACT

As treatment for HO may at least partially improves rehabilitation and quality of life, we recommend a systematic screening in PICRU patients for HO by clinical examination supplemented by imaging in case of suspicion.

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.

Brain injury severity and autonomic dysregulation accurately predict heterotopic ossification in patients with traumatic brain injury

Objective : To assess brain injury severity, autonomic dysregulation and systemic infection as risk factors for the occurrence of heterotopic ossification in patients with severe traumatic brain injury.

Design : Historic cohort study.

Setting : Radboud University Medical Centre.

Subjects : All consecutively admitted patients with severe traumatic brain injury (admission Glasgow Coma Scale score 8 or less) during the years 2002—2003.

Main measures : The development of clinically relevant heterotopic ossification, defined as painful swelling of joints with redness and decreased range of motion, confirmed radiographically.

Results : Seventy-six (64%) of the 119 patients survived and were eligible for further follow-up. Nine patients (12%) developed 20 symptomatic heterotopic ossifications, in one or more joints. Patients with heterotopic ossification had sustained more severe brain injuries, compared to the group without heterotopic ossification. The mean coma duration in the heterotopic ossification group was 28.11 days (SD 20.20) versus 7.54 days (SD 7.47) in the patients without heterotopic ossification (P < 0.001). The occurrence of autonomic dysregulation (relative risk (RR) 59.55, 95% confidence interval (CI) 8.39—422.36), diffuse axonal injury (RR 20.68, 95% CI 4.92—86.91), spasticity (RR 16.96, 95% CI 3.96—72.57) and systemic infection (RR 13.12, 95% CI 3.01—57.17) were all associated with an increased risk of developing symptomatic heterotopic ossification. However, only autonomic dysregulation had a high positive (88.9%, 95% CI 51.7—99.7) and negative (98.5%, 95% CI 91.9—99.9) predictive value with regard to heterotopic ossification.

Conclusions : The occurrence of autonomic dysregulation may predict the chance of developing heterotopic ossification in patients with severe head injury.

Risk Factors in Hospitalized Patients With Burn Injuries for Developing Heterotopic Ossification--A Retrospective Analysis

The aims of this study were to identify the risk factors for developing heterotopic ossification in patients with burns injuries and, second, to review the outcomes associated with the treatment disodium etidronate. Patients with heterotopic ossification were identified using the burns unit computer database. The control group was the patients who were the next admission after admission of the patient who subsequently developed heterotopic ossification. Demographic and clinical data were collected. Univariate and multivariate techniques were used to identify risk factors for heterotopic ossification. We reviewed 337 patients admitted over a 5-year period and identified 19 patients with heterotopic ossification (5.6%). A further 19 burn injury patients were included as controls. Heterotopic ossification developed clinically and radiologically after a median time of 37 days (interquartile range [IQR], 30-40) and 49 days (IQR, 38-118), respectively. In univariate analysis, heterotopic ossification was associated with a greater %TBSA, inhalation injury, use of mechanical ventilation, number of surgical procedures, sepsis, and longer time to active movement. In a multivariate analysis that adjusted for severity of burn injury by means of the Belgian Outcome in Burn Injury score, time to active movement was recognized as an independent risk factor for heterotopic ossification (odds ratio 1.48, 95% confidence interval 1.09-2.01). Elevations in serum calcium concentrations were the only observed adverse effects for disodium etidonrate. This study has demonstrated that %TBSA, inhalation injury, and the need for ventilatory support and the use of multiple surgical procedures are predictive of the development of heterotopic ossification.

[Hip joint arthrolysis due to heterotopic ossification]

OBJECTIVE

Restoration of joint mobility with preservation of femoral head perfusion and warranty of joint stability. Pain reduction. Enhancement of the autonomous daily mobility (if possible regarding the cognitive status) as well as the ability to sit. For nonambulatory, bedridden patients ease of sanitary tasks and improvement of patients' convenience.

INDICATIONS

Joint stiffness with limitation of the quality of life. Pain. Joint deformity, especially in cases of progressive subluxation.

CONTRAINDICATIONS

Relative: radiologically and scintigraphically immature heterotopic ossification (HO) with moderate limitation of motion and patients who are not able to tolerate the demanding postoperative management.

SURGICAL TECHNIQUE

The patient is positioned depending on size and location of ectopic bone. Ectopic bone is released from surrounding soft tissue or by making use of a gap between original bone and ectopic bone from the femur or pelvis. If ectopic bone is close to neurovascular structures, these have to be identified and protected.

POSTOPERATIVE MANAGEMENT

Postoperative irradiation in patients > 50 years. Generally, medicamentous prevention for recurrent cases with nonsteroidal anti-inflammatory drugs. Intensive and aggressive physical therapy, especially in patients with neurologic disorders. Depending on the extent of arthrolysis and the cause of HO, full, partial, or no weight bearing of the extremity over the first 6 postoperative weeks.

RESULTS

The literature does not allow to draw firm conclusions regarding the occurrence of HO. The incidence of HO after primary total hip arthroplasty is estimated at 42%. In 9% of these cases, a severe HO with major limitation of motion or ankylosis occurs. In patients with neurologic injuries (brain injuries, spinal cord injuries) the incidence varies between 20-40%, but only one third of these patients show limited function or ankylosis. After surgical arthrolysis, the recurrence rate amounts to 25-30% at a mean follow-up of 6 years.

Heterotopic Ossification in Guillain-Barré Syndrome: Incidence and Effects on Functional Outcome With Long-Term Follow-Up

OBJECTIVE

To define the incidence, effects on functional abilities, and possible causation of heterotopic ossification (HO) in Guillain-Barré syndrome (GBS) patients admitted for inpatient rehabilitation.

DESIGN

Long-term prospective study on neurologic and functional outcome of GBS patients admitted for rehabilitation.

SETTING

Rehabilitation department, inpatient and outpatient, within a university-affiliated medical center.

PARTICIPANTS

All GBS patients admitted for rehabilitation and followed for a minimum of 3 years.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Presence of HO, factors that may be etiologically significant, and effects on functionality. Data included: medical interventions, Disability Grading Scale, need for assisted ventilation, electrodiagnostic findings, autonomic function, standard neuro-musculo-skeletal evaluation, and hospital length of stay.

RESULTS

Four (6%) of 65 patients had HO, 24 of whom required mechanical ventilation. All had decreased range of motion in the involved hips that affected mobility.

CONCLUSIONS

Even though it has been rarely reported, HO does occur in GBS and affects functional outcome.

Heterotopic ossification: a review

Heterotopic ossification is the formation of bone in the soft tissues. Soft tissue bone deposition may range from the minimal and inconsequential to massive and clinically significant. In some clinical settings it is a predictable finding with an unpredictable course and in other settings it may be diagnostically confounding. Heterotopic ossification may be encountered in clinically disparate disease processes and circumstances. We review the genetic, neurogenic, post-traumatic, post-surgical and "reactive" causes of heterotopic ossification and discuss some current concepts of its pathogenesis.

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.

Heterotopic ossification in critical illness and cancer: a report of 2 cases

Heterotopic ossification is the abnormal development of bone tissue within periarticular soft tissue. We present 2 Turkish patients with malignant thoracic cancer who underwent extensive thoracic surgery and required prolonged postoperative chemical paralysis and cardiorespiratory support for respiratory complications. Both patients were found by the physiatrist to have multiple, extensive heterotopic ossifications. Clinical findings in both patients included joint swelling and severe limitation in range of motion (ROM) associated with pain. The diagnoses were confirmed radiographically. After an extended length of inpatient rehabilitation, both patients improved their cumulative FIM instrument motor scores by 23 and were discharged with a trained family member. Our findings suggested that heterotopic ossification should be suspected in patients presenting with decreased ROM, increased pain, and joint swelling after prolonged immobilization. Serum alkaline phosphatase might be used as an effective screening tool.

Influence of etiology in heterotopic bone formation of the hip

OBJECTIVE

Heterotopic ossification (HO) in periarticular tissue can appear after brain or local joint trauma. The aim of this study was to investigate differences of manifestation and outcome after surgical therapy of patients suffering from HO of the hip after isolated brain injury (n = 18), local hip trauma (n = 21), or the combination of both (n = 25). HO can cause progressive lost of joint movement; once mature, the only therapy to improve joint mobility is the excision.

METHODS

All patients underwent surgical removal of HO and postoperative irradiation therapy. On the basis of plain radiographic findings, we evaluated the recurrent ossification after 1-year and 5-year follow-up periods. Within this prospective study, clinical performance status was scored according to the classification of d'Aubigne and a planimeter was used to evaluate the area of heterotopic bone formation in standard x-rays films.

RESULTS

The severity of brain trauma observed by Glasgow Coma Scale correlated with the ossification size (square centimeters). Correlation was noticed as well between severity of brain injury and functional outcome. The evaluation of an average 1-year and 5-year follow-up period showed relief of pain and clear improvement of range of motion in all patients. There was mild recurrence of heterotopic bone growth within the first postoperative year without deterioration of the functional results.

CONCLUSION

The severity of brain trauma has an influence on the extent of HO near the hip joint and also on the rehabilitation process. The histologic findings and recurrence of HO after excision were not affected by the localization of initial trauma. There was only mild recurrence of heterotopic bone growth between the first and fifth postoperative year. For objective evaluation of heterotopic bone formation in standard x- ray films, planimetric measurement is a useful method.

Polyarticular heterotopic ossification complicating critical illness

A patient with generalized heterotopic ossification (HO) complicating critical illness due to necrotizing pancreatitis is described; data on two other cases with HO are briefly presented. The clinical features, prevention and therapy of HO are discussed. The effect of surgical therapy of the HO in our three patients was good.