Current therapeutic strategies of heterotopic ossification--a survey amongst orthopaedic and trauma departments in Germany

Fulminant Heterotopic Ossification of the Lower Extremity After Gunshot Injury and Blunt Trauma: A Case Report

Traumatic heterotopic ossification (HO) of the lower extremity is relatively rare but is of major importance in clinical practice. They are defined as posttraumatic abnormal formations of bone within soft tissue outside of the skeletal system. This article describes the clinical case of a 31-year-old male patient who suffered 2 traumatic events within 12 months-a gunshot wound in the lumbar spine/gluteal region followed by a severe traumatic brain injury with intracranial hemorrhage in a traffic accident as a pedestrian. Clinically, the patient was bedridden because of complete stiffening of the lumbar spine, both hip joints, and the left knee joint. After preoperative diagnosis, 3 surgical ablations of the HO were performed on both the hip joints and the left knee joint. In addition, physiotherapeutic exercise, postoperative nonsteroidal anti-inflammatory drug administration (25 mg of indomethazine for 6 weeks, 3 times a day), and perioperative radiation with 7 Gy for each operation were advised. After 4 years of follow-up, the patient showed significant improvement. In HO treatment, prophylactic local radiotherapy (pre- and postoperative radiation with a local single dose of 7 Gy) and postoperative administration of nonsteroidal anti-inflammatory drugs are often recommended. For therapeutic purposes, surgical resection is still indicated for pronounced cases.

Classification and Incidence of Heterotopic Ossifications in Relation to NSAID Prophylaxis after Elbow Trauma

Heterotopic ossification (HO) after elbow trauma can be responsible for significant motion restrictions. The study's primary aim was to develop a new X-ray-based classification for HO of the elbow. This retrospective study analyzed elbow injury radiographs from 138 patients aged 6-85 years (mean 45.9 ± 18) who underwent operative treatment. The new classification was applied at 6 weeks, 12 weeks, and 6 months postoperatively. The severity of HO was graded from 0 to 4 and localization was defined as r (radial), p (posterior), u (ulnar) or a (anterior) by two observers. The patients were categorized based on injury location and use of non-steroidal anti-inflammatory drugs (NSAIDs) for HO prophylaxis. The correlations between the generated data sets were analyzed using Chi-square tests (χ2) with a significance level of p < 0.05. The inter- and intraobserver reliability was assessed using Cohen's Kappa. In 50.7% of the evaluated X-rays, the formation of HO could be detected after 12 weeks, and in 60% after 6 months. The analysis showed a significant correlation between the injury's location and the HO's location after 12 weeks (p = 0.003). The use of an NSAID prophylaxis did not show a significant correlation with the severity of HO. The classification showed nearly perfect inter- (κ = 0.951, p < 0.001) and intrareliability (κ = 0.946, p < 0.001) according to the criteria of Landis and Koch. Based on the presented classification, the dimension and localization of HO in the X-ray image can be described in more detail compared to previously established classifications and, thus, can increase the comparability of results across studies.

Inflammation-Responsive Hydrogel Spray for Synergistic Prevention of Traumatic Heterotopic Ossification via Dual-Homeostatic Modulation Strategy

Traumatic heterotopic ossification (THO) represents one of the most prominent contributors to post-traumatic joint dysfunction, which currently lacks an effective and definitive preventative approach. Inflammatory activation due to immune dyshomeostasis during the early stages of trauma is believed to be critical in initiating the THO disease process. This study proposes a dual-homeostatic modulation (DHM) strategy to synergistically prevent THO without compromising normal trauma repair by maintaining immune homeostasis and inducing stem cell homeostasis. A methacrylate-hyaluronic acid-based hydrogel spray device encapsulating a curcumin-loaded zeolitic imidazolate framework-8@ceric oxide (ZIF-8@CeO2, CZC) nanoparticles (CZCH) is designed. Photo-crosslinked CZCH is used to form hydrogel films fleetly in periosteal soft tissues to achieve sustained curcumin and CeO2 nanoparticles release in response to acidity and reactive oxygen species (ROS) in the inflammatory microenvironment. In vitro experiments and RNA-seq results demonstrated that CZCH achieved dual-homeostatic regulation of inflammatory macrophages and stem cells through immune repolarization and enhanced efferocytosis, maintaining immune cell homeostasis and normal differentiation. These findings of the DHM strategy are also validated by establishing THO mice and rat models. In conclusion, the CZCH hydrogel spray developed based on the DHM strategy enables synergistic THO prevention, providing a reference for a standard procedure of clinical operations.

Heterotopic Ossification Remodeling After Acetabular Surgery: A Natural History Case Report

CASE

A 30-year-old woman presented with a transverse plus posterior wall acetabular fracture and underwent operative fixation through a Kocher-Langenbeck approach. Shared decision was made for no heterotopic ossification (HO) prophylaxis. The patient developed symptomatic HO and was scheduled for resection, which was delayed because of the pandemic. She returned with interval remodeling of HO and symptom resolution. No surgery was required.

CONCLUSION

HO is a common complication after acetabular injury. Resection is the treatment of choice for symptomatic HO. We are not aware of other reports of spontaneous remodeling of symptomatic HO such that it no longer required surgery.

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.

Young Adolescent With Restricted Arm Motion During a Preparticipation Physical Exam

A healthy 15-year-old right-hand dominant football player presented to the clinic for a preparticipation examination (PPE) with an exam notable for reduced right shoulder range of motion. The patient reported no complaints, including no pain. Upon questioning, he noted a remote non-sports related injury to that shoulder with unremarkable radiographs at that time. Subsequent X-ray imaging showed a bony abnormality thought to be consistent with an osteochondroma. However, advanced imaging identified it as a heterotrophic ossification center that required a complex, multidisciplinary surgical team to correct. This case of a high school football player's routine PPE that resulted in surgery highlights not only whether sport participation is safe, but also the importance of direct, specific language that asks about the history of any injuries, rather than specifically sports related.

Bilateral hip heterotopic ossification with sciatic nerve compression on a paediatric patient–An individualized surgical approach: A case report

BACKGROUND

Neurogenic heterotopic ossification is an acquired serious complication described in patients with central nervous system disorders and defined by bone formation in non-osseous tissue.

CASE SUMMARY

We present an unusual case of a 13-yr-old boy presenting with hip pain and severe gait impairment 5 mo after the diagnosis of hemiplegia following a spontaneous intracerebral haemorrhage. Computed tomography revealed bilateral heterotopic ossification of both the paretic and the non-paretic limbs, with entrapment of the sciatic nerve. The choice of surgical or nonsurgical management of such patients depends on the timing of diagnosis, the symptoms, and the extent of maturation of the ossified lesions. Surgical resection remains the only treatment with proven, evidence-based effectiveness. The choice of surgical approach largely depends on the location of the ossified lesions.

CONCLUSION

We believe the plane of dissection presented is a satisfactory option for resection of a posteromedial mass and sciatic nerve release.

The Treatment of Heterotopic Ossification With a Dual Mobility Total Hip Replacement System: A Case Report

Heterotopic ossification (HO) is the formation of bone within extraskeletal soft tissue. The development of mature lamellar bone within soft tissues can be acquired in cases like trauma. Clinical manifestations of HO primarily include pain at the site of the extraskeletal ossification and limited range of motion or function when it involves a joint. This case report presents a 56-year-old man with severe HO. His past medical history included a traumatic hip dislocation in 1996. He denied any other past medical, family, or surgical history. This patient had severely limited range of motion and difficulty performing activities of daily living like going up and down the stairs and getting up from a seated position. After failing conservative therapy with non-steroidal anti-inflammatory drugs (NSAIDs) and physical therapy, a non-cemented dual mobility hip replacement system was used to treat this patient. A non-cemented dual mobility hip replacement system was chosen because the patient had significant bone loss and was relatively young. The dual mobility system significantly reduces the risk of dislocation and is a good option for younger patients who require more stability in their hips. The patient progressed well with a full range of motion and no pain. There was no evidence of HO recurrence. Treatment of HO with a total hip replacement, let alone a dual mobility system, is not prevalent throughout the literature. Furthermore, cemented total hip arthroplasty has been associated with increased recurrence of HO, which is why we elected to use a non-cemented technique. Osteoplasty is typically the mainstay of treatment for HO. The purpose of this case report is to introduce an incident of HO treated with a non-cemented dual mobility system and emphasize its use in young, middle-aged, or active patients who have bone loss and require increased stability.

Heterotopic ossification in the post cruciate ligament of the knee: a case report and literature review

Background

Heterotopic ossification (HO) is noted most frequently in periarticular muscles and has not yet been reported in the cruciate ligaments of the knee. We present a rare case of symptomatic ossification of the posterior cruciate ligament (PCL).

Case presentation

A 59-year-old woman had a 2-year history of knee pain that was getting worse during knee motion and had restricted knee motion for 1 year. X-rays could not show the lesion clearly. Multi-planar computed tomography demonstrated ossification within the PCL with mild osteoarthritic changes and excluded any other intra-articular pathology. The patient underwent arthroscopic debridement and then experienced immediate relief of pain and complete recovery of range of motion.

Conclusion

This is the first report of HO in the PCL as a possible cause of knee pain and restricted knee motion. On the basis of literature review, this case elaborates the difference between HO and calcification in the ligaments, the related factors inducing HO and the undefined pathogenesis, and favorable prognosis after adequate treatment.

A review of the biomarkers and in vivo models for the diagnosis and treatment of heterotopic ossification following blast and trauma-induced injuries

Heterotopic ossification (HO) is the process of de novo bone formation in non-osseous tissues. HO can occur following trauma and burns and over 60% of military personnel with blast-associated amputations develop HO. This rate is far higher than in other trauma-induced HO development. This suggests that the blast effect itself is a major contributing factor, but the pathway triggering HO following blast injury specifically is not yet fully identified. Also, because of the difficulty of studying the disease using clinical data, the only sources remain the relevant in vivo models. The aim of this paper is first to review the key biomarkers and signalling pathways identified in trauma and blast induced HO in order to summarize the molecular mechanisms underlying HO development, and second to review the blast injury in vivo models developed. The literature derived from trauma-induced HO suggests that inflammatory cytokines play a key role directing different progenitor cells to transform into an osteogenic class contributing to the development of the disease. This highlights the importance of identifying the downstream biomarkers under specific signalling pathways which might trigger similar stimuli in blast to those of trauma induced formation of ectopic bone in the tissues surrounding the site of the injury. The lack of information in the literature regarding the exact biomarkers leading to blast associated HO is hampering the design of specific therapeutics. The majority of existing blast injury in vivo models do not fully replicate the combat scenario in terms of blast, fracture and amputation; these three usually happen in one insult. Hence, this paper highlights the need to replicate the full effect of the blast in preclinical models to better understand the mechanism of blast induced HO development and to enable the design of a specific therapeutic to supress the formation of ectopic bone.

The Survey of Cells Responsible for Heterotopic Ossification Development in Skeletal Muscles-Human and Mouse Models

Heterotopic ossification (HO) manifests as bone development in the skeletal muscles and surrounding soft tissues. It can be caused by injury, surgery, or may have a genetic background. In each case, its development might differ, and depending on the age, sex, and patient's conditions, it could lead to a more or a less severe outcome. In the case of the injury or surgery provoked ossification development, it could be, to some extent, prevented by treatments. As far as genetic disorders are concerned, such prevention approaches are highly limited. Many lines of evidence point to the inflammatory process and abnormalities in the bone morphogenetic factor signaling pathway as the molecular and cellular backgrounds for HO development. However, the clear targets allowing the design of treatments preventing or lowering HO have not been identified yet. In this review, we summarize current knowledge on HO types, its symptoms, and possible ways of prevention and treatment. We also describe the molecules and cells in which abnormal function could lead to HO development. We emphasize the studies involving animal models of HO as being of great importance for understanding and future designing of the tools to counteract this pathology.

Investigating the incidence and magnitude of heterotopic ossification with and without joints involvement in patients with a limb fracture and mild traumatic brain injury

Objectives

This study seeks to evaluate the incidence rate of heterotopic ossification (HO) formation in patients afflicted by an isolated limb fracture (ILF) and a concomitant mild traumatic brain injury (mTBI).

Methods

The current study is an observational study including ILF patients with or without a concomitant mTBI recruited from an orthopedic clinic of a Level 1 Trauma Hospital. Patients were diagnosed with a mTBI according to the American Congress of Rehabilitation Medicine (ACRM) criteria. Radiographs taken on average 3 months post-trauma were analyzed separately by two distinct specialists for the presence of HO proximally to the fracture site (joints or extra joints). Both raters referred to Brooker's and Della's Valle's classification to establish signs of HO. First, analyses were conducted for the full sample. Secondly, a matched cohort was used in order to control for specific factors, namely age, sex, type of injury, and time elapsed between the accident and the analyzed radiograph.

Results

The full sample included a total of 183 patients with an ILF (94 females; 47.5 years old), of which 50 had a concomitant mTBI and 133 without. Radiographic evidence of HO was significantly higher in patients with an ILF and a mTBI compared to ILF patients (X² = 6.50; p = 0.01). The matched cohort consisted of 94 participants (i.e.; 47 patients from the ILF + mTBI group and 47 patients from the ILF group). Again, ILF + mTBI patients presented significantly higher rates of HO signs in comparison to ILF patients (X² = 3.69; p = 0.04). Presence of HO was associated with prolonged delays to return to work (RTW) only in ILF + mTBI patients (F = 4.055; p = 0.05) but not in ILF patients (F = 0.823; p = 0.37).

Conclusions

Study findings suggest that rates of HO are significantly higher proximally to fracture sites when ILF patients sustain a concomitant mTBI, even after controlling for factors known to influence HO. Moreover, results show that HO is associated with a prolonged RTW only in ILF patients with a concomitant mTBI but not in ILF-only patients. The impact of mTBI on HO formation warrants further attention to detect early signs of HO, to identify shared physiopathological mechanisms and, ultimately, to design targeted therapies.

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Rates of HO are significantly higher in patients with a fracture and a mTBI compared to patients with a fracture only.

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Factors such as sex, age, joint involvement, and surgical procedures were unrelated to the detection of signs of HO

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Presence of HO negatively impacted RTW delays in patients with a concomitant mTBI

Heterotopic Ossification: A Comprehensive Review

Heterotopic ossification (HO) is a diverse pathologic process, defined as the formation of extraskeletal bone in muscle and soft tissues. HO can be conceptualized as a tissue repair process gone awry and is a common complication of trauma and surgery. This comprehensive review seeks to synthesize the clinical, pathoetiologic, and basic biologic features of HO, including nongenetic and genetic forms. First, the clinical features, radiographic appearance, histopathologic diagnosis, and current methods of treatment are discussed. Next, current concepts regarding the mechanistic bases for HO are discussed, including the putative cell types responsible for HO formation, the inflammatory milieu and other prerequisite “niche” factors for HO initiation and propagation, and currently available animal models for the study of HO of this common and potentially devastating condition. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Gαs signaling in skeletal development, homeostasis and diseases

Skeletal development is exquisitely controlled both spatially and temporally by cell signaling networks. Gα_s is the stimulatory α-subunit in a heterotrimeric G protein complex transducing the signaling of G-protein-coupled receptors (GPCRs), responsible for controlling both skeletal development and homeostasis. Gα_s, encoded by the GNAS gene in humans, plays critical roles in skeletal development and homeostasis by regulating commitment, differentiation and maturation of skeletal cells. Gα_s-mediated signaling interacts with the Wnt and Hedgehog signaling pathways, both crucial regulators of skeletal development, remodeling and injury repair. Genetic mutations that disrupt Gα_s functions cause human disorders with severe skeletal defects, such as fibrous dysplasia of bone and heterotopic bone formation. This chapter focuses on the crucial roles of Gα_s signaling during skeletal development and homeostasis, and the pathological mechanisms underlying skeletal diseases caused by GNAS mutations.

Selective COX-2 inhibitor versus non-selective COX-2 inhibitor for the prevention of heterotopic ossification after total hip arthroplasty: A meta-analysis

BACKGROUND

Whether selective non-steroidal anti-inflammatory drugs (NSAIDs) has equally efficacy with non-selective NSAIDs in preventing heterotopic ossification (HO) after total hip arthroplasty (THA) was controversial. The purpose of this meta-analysis was to assess the efficacy and safety of selective NSAID versus non-selective NSAIDs for the prevention of HO after THA.

METHODS

PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science, Google Search Engine, and China National Knowledge Infrastructure databases was searched for randomized controlled trials (RCTs) were comparing selective NSAID versus non-selective NSAIDs for preventing HO after THA. The primary outcomes were overall HO incidence, Brooker classification HO incidence, gastrointestinal side effects, the occurrence of excessive bleeding and discontinuation caused by gastrointestinal side effects (DGSE). Data were analyzed using Stata 12.0.

RESULTS

A total of 8 RCTs involving 1636 patients were included in the meta-analysis. There was no significant difference between the nonselective NSAIDs group and the selective NSAIDs group in the overall incidence of HO (relative risk, RR = 0.91, 95% confidence intervals, CI 0.78-1.06, P = .203), Brooker I HO (RR = 1.02, 95% CI 0.85-1.23, P = .794), Brooker II HO (RR = 1.00, 95% CI 0.66-1.52, P = .996). Brooker III HO (RR = 0.98, 95% CI 0.37-2.62, P = .971). And the occurrence of excessive bleeding (RR = 0.67, 95% CI 0.24-1.92, P = .458). The selective NSAIDs group was associated with a significant decrease in gastrointestinal side effects (RR = 0.35, 95% CI 0.18-0.71, P = .004) and discontinuation caused by gastrointestinal side effects compared with the nonselective NSAIDs group (RR = 0.28, 95% CI 0.11-0.66, P = .004).

CONCLUSION

The available evidence indicates selective NSAIDs were as effective as non-selective NSAIDs in preventing HO after THA. And selective NSAIDs were associated with less gastrointestinal side effects than non-selective NSAIDs. Considering the limitation of current meta-analysis, more RCTs need to identify the optimal NSAIDs drug for HO after THA.

Incidence and factors associated with development of heterotopic ossification after damage control laparotomy

INTRODUCTION

The incidence of heterotopic ossification (HO) following damage control laparotomy (DCL) is unknown. Abdominal wall reconstruction may prove more challenging in patients with HO. This study examines the incidence and factors associated with HO in patients with an open abdomen following DCL.

METHODS

A retrospective review of all patients with an open abdomen after DCL at a level 1 trauma centre from 2009 to 2015 was conducted. Demographics and peri-operative outcomes of patients with and without HO were compared. Univariate and multivariable binary logistic regression models were used to determine the association of peri-operative factors with the development of HO.

RESULTS

68 patients were included, of which 36 (53%) developed HO. On univariate analysis, development of HO was significantly associated with hollow viscus injury (OR, 3.89; CI 1.42-10.7), greater number of abdominal surgeries prior to definitive closure (OR, 1.84; CI, 1.10-3.05), non-fascial closure (OR, 4.33; CI, 1.44-13.1) and higher peak ALP (OR 1.01; CI, 1.00-1.02). The presence of a hollow viscus injury remained an independent predictor of HO on multivariable analysis after adjusting for covariates (OR, 3.77; CI, 1.22-11.6).

CONCLUSION

Heterotopic ossification develops in a high proportion of trauma patients following damage control laparotomy, particularly in the presence of hollow viscus injury. Its impact on delayed abdominal wall reconstruction and the efficacy of prophylaxis strategies merit further investigation.