Myositis ossificans traumatica is a relatively common injury associated with sports especially those involving contact. It continues to frustrate both athlete and health practitioner alike due to its continued lack of treatment options and a lengthy natural history. This case study chronicles the observation of a 34 year old recreational ice hockey player who presented 7 years post-trauma, was diagnosed with myositis ossificans traumatica and was followed up on 8 years later (15 years post-trauma). This case report is suspected to be the first published case study of its kind. The literature review outlines the various types of myositis ossificans, its incidence, pathogenesis, differential diagnoses including osteosarcoma, and the various methods/modalities reported in its treatment.
myositis ossificans traumatica; heterotopic ossification; post-traumatic myositis ossificans; ice hockey; deltoid ligament; myosite ossifiante traumatique; ossification hétéropique; myosite ossifiante post-traumatique; hockey sur glace; ligament deltoïde
Myositis ossificans circumscripta (MOC) is an extra-osseous non- neoplastic growth of a new bone. It occurs most commonly in the second and the third decade of life, while it is rare in children. The etiology of MOC is unknown and the quadriceps and brachials are the most affected. The occurrence of traumatic MOC in tissues of the neck is uncommon. We are presenting below a rare case of traumatic myositis ossificans occurring in sternocleidomastoid and trapezius muscles in a 17-year-old girl.
neck muscles; local trauma and children
Myositis ossificans is a self-limiting ossifying process that most often develops following mechanical trauma to skeletal musculature. It chiefly affects the skeletal muscles of extremities of young athletically active adult males. Myositis ossificans is rare in children except for children affected by heritable disorder known as progressive myositis ossificans (fibrodysplasia ossificans progressiva). Children with this disorder develop ossification of muscles and associated soft tissue in early childhood without prior history of trauma. Traumatic form of myositis ossificans also known as myositis ossificans circumscripta (MOC) is rarely encountered in the head and neck musculature. We report a case of MOC within the buccinator which developed as a postoperative complication of mandibular third molar surgery. During extraction of a left mandibular third molar in a 16-year old male, a tooth fragment was accidently displaced into the adjacent soft tissue. Retrieval of this tooth fragment caused significant soft tissue trauma. Eighteen months after his third molar surgery, the patient continued to have pain and tenderness anterior to the left mandibular ramus. Radiographic imaging revealed a well-defined ovoid radiopaque mass within the left buccinator muscle. The lesion was surgically removed and the post-surgical course of the patient was uneventful. Histological findings of the mass were characteristic for myositis ossificans.
Myositis ossificans; Buccinator muscle; Third molar surgery; Postoperative complications
We report a case of true trilineage haematopoiesis in an excised area of heterotopic ossification from an upper mid-line laparotomy scar. Heterotopic ossification is a rare complication of abdominal surgery and usually occurs when upper mid-line incisions are utilised. Whereas cases of heterotopic ossification in abdominal incisions are not exceedingly rare, true trilineage haematopoiesis in such an area of heterotopic ossification, to our knowledge, has only been previously reported once in the English literature.
Extramedullary haematopoiesis; Heterotopic ossification; Myositis ossificans
A patient developed ossifying skeletal muscle metastases from a primary gastric mucin-producing adenocarcinoma. The unusual nature of skeletal muscle metastases and the inflammatory-like syndrome associated with heterotopic ossification is reviewed. It is suggested that this case of 'neoplasm-induced post-traumatic myositis ossificans' may be caused by the interaction of local haemorrhage and thrombosis, mucin-producing tumour implants, and the presence of large quantities of gamma-carboxyglutamic acid, an amino acid associated with the calcification of bone matrix formation.
A 58-year-old man who had had three laparotomies for gastric surgery, developed a painful mass in the abdominal wall scar. Radiology confirmed bone formation in the scar. The bone was excised and the wound repaired. Histology confirmed metaplastic mature bone formation. This case draws the attention to the clinical condition of bone formation in midline scars. Clinically, it should be differentiated from scar recurrence following surgery for abdominal malignancy.
Keywords: myositis ossificans; heterotopic ossification
Heterotopic ossification is the abnormal formation of lamellar bone in soft tissue. Its presence jeopardizes functional outcome, impairs rehabilitation and increases costs due to subsequent surgical interventions.
We present a case of a 32-year-old African-American man with trisomy 8 mosaicism who developed severe heterotopic ossification of his right extensor mechanism subsequent to repair of a patellar tendon rupture.
To the best of our knowledge there are no prior reports of heterotopic ossification as a complication of patellar tendon repair. This case may suggest an association between trisomy 8 mosaicism and increased risk of heterotopic ossification.
Fibrodysplasia ossificans progressiva (FOP) is an autosomal dominant severe musculoskeletal disease characterized by extensive new bone formation within soft connective tissues and unique skeletal malformations of the big toes which represent a birth hallmark for the disease. Most of the isolated classic cases of FOP showed heterozygous mutation in the ACVR1 gene on chromosome 2q23 that encodes a bone morphogenetic protein BMP (ALK2). The most common mutation is (c.617G > A) leading to the amino acid substitution of arginine by histidine (p.Arg206His). We currently report on an Egyptian infant with a sporadic classic FOP in whom c.617G > A mutation had been documented. The patient presented with the unique congenital malformation of big toe and radiological evidence of heterotopic ossification in the back muscles. The triggering trauma was related to the infant's head, however; neither neck region nor sites of routine intramuscular vaccination given during the first year showed any ossifications. Characterization of the big toe malformation is detailed to serve as an early diagnostic marker for this rare disabling disease.
Fibrodysplasia ossificans progressiva (FOP), a rare and disabling genetic condition of congenital skeletal malformations and progressive heterotopic ossification (HO), is the most catastrophic disorder of HO in humans. Episodic disease flare-ups are precipitated by soft tissue injury, and immobility is cumulative. Recently, a recurrent mutation in activin receptor IA/activin-like kinase 2 (ACVR1/ALK2), a bone morphogenetic protein (BMP) type I receptor, was reported in all sporadic and familial cases of classic FOP, making this one of the most highly specific disease-causing mutations in the human genome. The discovery of the FOP gene establishes a critical milestone in understanding FOP, reveals a highly conserved target for drug development in the TGF-β/BMP signalling pathway, and compels therapeutic approaches for the development of small molecule signal transduction inhibitors for ACVR1/ALK2. Present management involves early diagnosis, assiduous avoidance of iatrogenic harm, and symptomatic amelioration of painful flare-ups. Effective therapies for FOP, and possibly for other common conditions of HO, may potentially be based on future interventions that block ACVR1/ALK2 signalling.
fibrodysplasia ossificans progressiva (FOP); heterotopic ossification; bone morphogenetic protein; BMP; ACVR1; ALK2
Myositis Ossificans (MO) is an unusual pathological entity still largely unknown, characterized by dystrophic calcification leading to heterotopic ossification of intramuscular connective tissue. The masticatory muscles are exceptionally involved.
Four distinct types of myositis ossificans have been described: MO Progressiva, which is a genetic disorder involving several muscular groups; MO Circumscripta, limited to a single muscle and generally due to calcification of an intramuscular haematoma following severe trauma and progressive ossification; MO Pseudo-malignant limited to soft tissue and not associated to any trauma; MO associated to paraplegia.
A case of circumscribed myositis ossificans of the masseter muscle in a 62 years-old woma is reportedn.
Myositis ossificans; Circumscribed Myositis Ossificans; Masseter muscle
Heterotopic ossification is a common postoperative complication of acetabular fracture. However, functionally significant heterotopic ossification with associated late bone defects in the posterior wall of the acetabulum is rare and challenging to treat. When heterotopic ossification is a late complication of failed acetabular fracture operation, it is disabling and may only be treated by THA. THA is highly susceptible to premature failure in young and active patients and may require numerous revisions.
This article describes a 40-year-old man with massive heterotopic ossification associated with late bone defects in the posterior wall of the acetabulum after a failed acetabular fracture operation. The primary fracture type was a 62-A2.3 fracture according to the AO/OTA Classification.Surgical excision and anatomical reconstruction of the acetabular wall using heterotopic ossific bone were performed 10 months after the fracture repair. Postoperatively, indomethacin was administered for prophylaxis against recurrence of heterotopic ossification, and hip range of motion was progressively increased. At 5 years and 6 months follow-up, the patient’s pain was relieved and hip function had recovered. Though radiography and CT showed minimal subchondral cysts and mild joint-space narrowing, there was no evidence of graft resorption, progressive posttraumatic osteoarthritis or necrosis of the femoral head.
To the authors’ knowledge, this is the first case of such a challenging condition. Although it is an extremely rare case, it provides an attractive option for avoiding THA, as the long-term follow-up shows a satisfactory outcome.
Heterotopic ossification; Late bone defects; Posterior wall; Acetabulum; Acetabular fracture
Myositis ossificans (MO) is a benign condition of non-neoplastic heterotopic bone formation in the muscle or soft tissue. Trauma plays a role in the development of MO, thus, non-traumatic MO is very rare. Although MO may occur anywhere in the body, it is rarely seen in the lumbosacral paravertebral muscle (PVM). Herein, we report a case of non-traumatic MO in the lumbosacral PVM. A 42-year-old man with no history of trauma was referred to our hospital for pain in the low back, left buttock, and left thigh. On physical examination, a slightly tender, hard, and fixed mass was palpated in the left lumbosacral PVM. Computed tomography showed a calcified mass within the left lumbosacral PVM. Magnetic resonance imaging (MRI) showed heterogeneous high signal intensity in T1- and T2-weighted image, and no enhancement of the mass was found in the postcontrast T1-weighted MRI. The lack of typical imaging features required an open biopsy, and MO was confirmed. MO should be considered in the differential diagnosis when the imaging findings show a mass involving PVM. When it is difficult to distinguish MO from soft tissue or bone malignancy by radiology, it is necessary to perform a biopsy to confirm the diagnosis.
Myositis ossificans; Lumbosacral spine; Paravertebral muscle
Myositis ossificans circumscripta is a form of heterotopic ossification that is benign in nature associated to a trauma, but may appear clinically and radiologically as a malignant neoplasm. We describe a rare case of calcifying of myositis ossificans not associated to trauma in a 35-year-old woman with a mass in her upper third and external of right thigh. We discuss some of the difficulties of diagnosis and histological evolution of the lesion.
Myositis ossificans; Thigh; Differential diagnosis; Nontraumatic
Fibrodysplasia ossificans progressiva is a rare and disabling genetic condition characterized by congenital malformation of the great toes and by progressive heterotopic ossification in specific anatomic patterns. Most patients with fibrodys-plasia ossificans progressiva are misdiagnosed early in life before the appearance of heterotopic ossification and undergo diagnostic procedures that can cause lifelong disability. Recently, the genetic cause of fibrodysplasia ossificans progressiva was identified, and definitive genetic testing for fibrodysplasia ossificans progressiva is now available before the appearance of heterotopic ossification.
We recently evaluated 7 children for diagnosis of fibrodysplasia ossificans progressiva before the onset of heterotopic ossification. A medical history, physical examination, and skeletal survey were obtained on all of the patients, as well as clinical genetic testing for the canonical fibrodysplasia ossificans progressiva mutation.
All 7 of the children (4 girls and 3 boys; ages 3 months to 6 years) had congenital malformations of the great toes, but none had radiographic evidence of heterotopic ossification at the time of evaluation. Five of the 7 children had soft tissue lesions of the neck and back, suggestive of early fibrodysplasia ossificans progressiva flare-ups, 3 of whom had undergone invasive diagnostic procedures that exacerbated their condition. Two children had no history or signs of soft tissue swelling or flare-ups. DNA sequence analysis found that all 7 of the children had the recurrent fibrodysplasia ossificans progressiva missense mutation, a single nucleotide substitution (c.617G>A) at codon 206 in the glycine-serine activation domain of activin receptor IA, a bone morphogenetic protein type 1 receptor.
Clinical suspicion of fibrodysplasia ossificans progressiva early in life on the basis of malformed great toes can lead to early clinical diagnosis, confirmatory diagnostic genetic testing, and the avoidance of additional harmful diagnostic and treatment procedures. This is the first report of genetic confirmation of fibrodysplasia ossificans progressiva before the appearance of heterotopic ossification. Pediatricians should be aware of the early diagnostic features of fibrodysplasia ossificans progressiva, even before the appearance of heterotopic ossification. This awareness should prompt early genetic consultation and testing and the institution of assiduous precautions to prevent iatrogenic harm.
fibrodysplasia ossificans progressiva; heterotopic ossification; malformed great toes; bone morphogenetic protein; ACVR1
Fibrodysplasia ossificans progressiva (FOP, MIM 135100) is a rare genetic disorder characterized by congenital great toe malformations and progressive heterotopic ossification transforming skeletal muscles and connective tissues to bone following a well-defined anatomic pattern of progression. Recently, FOP has been associated with a specific mutation of ACVR1, the gene coding for a bone morphogenetic protein type I receptor. The identification of ACVR1 as the causative gene for FOP now allows the genetic screening of FOP patients to identify the frequency of the identified recurrent ACVR1 mutation and to investigate genetic variability that may be associated with this severely debilitating disease. We report the screening for mutations in the ACVR1 gene carried out in a cohort of 17 Italian patients. Fifteen of these displayed the previously described c.617G>A mutation, leading to the R206H substitution in the GS domain of the ACVR1 receptor. In two patients, we found a novel mutation c.774G>C, leading to the R258S substitution in the kinase domain of the ACVR1 receptor. In the three-dimensional model of protein structure, R258 maps in close proximity to the GS domain, a key regulator of ACVR1 activity, where R206 is located. The GS domain is known to bind the regulatory protein FKBP12 and to undergo multiple phosphorylation events that trigger a signaling cascade inside the cell. The novel amino-acid substitution is predicted to influence either the conformation/stability of the GS region or the binding affinity with FKBP12, resulting in a less stringent inhibitory control on the ACVR1 kinase activity.
FOP; ACVR1; heterotopic ossification; BMPs
Myositis ossificans is a rare condition characterized by non-neoplastic heterotopic bone formation in soft tissue and skeletal muscle. It is a benign and often self-limiting disease with no need for surgery. Here, we describe a young female swimmer with myositis ossificans circumscripta of the triceps due to overuse. Because of the benign character of the lesion, conservative treatment was initiated with rest and anti-inflammatory drugs. She obtained complete resolution after 6 months and was able to return to normal sporting activities. Myositis ossificans circumscripta is a rare benign lesion with an excellent prognosis. Most lesions in athletes occur due to contusions or strains; however, overuse is now described as well. Spontaneous resolution is seen in almost all cases. Cases in which, despite conservative treatment, a painful mass persists, surgical excision can be considered.
Myositis ossificans circumscripta; overuse; soft tissue tumor; triceps
We report the case of a parosteal osteosarcoma of the distal ulna, treated with wide resection without reconstruction. The patient developed lung metastasis and a mass in the interosseus membrane of the forearm proximally to the osteotomy. The lung mass was found to be a metastasis from parosteal osteosarcoma and the biopsy of the forearm mass revealed a myositis ossificans. The suspicion of a recurrence of parosteal osteosarcoma, already metastatic, led to a second wide resection with no reconstruction. A slice of the radial cortex was taken during this second procedure. From a histological point of view, good margins were achieved and diagnosis of myositis ossificans was confirmed. Two months later, a radius fracture occurred and a synthesis, with plate and screws, as added with poly(methyl methacrylate) (PMMA) to reconstruct the bone loss, was performed. Indication of the reconstructive technique and the complication after distal ulna resection in oncologic surgery are discussed in this paper.
Distal ulna resection; Parosteal osteosarcoma; Ulna; Ulna reconstruction
Fibrodysplasia ossificans progressiva (FOP), a rare, disabling condition caused by gain-of-function mutations of a bone morphogenetic protein (BMP) type I receptor, leads to episodes of heterotopic ossification and resultant immobility. Neurological problems have not been associated with FOP, but neurological symptoms are commonly reported by FOP patients. To determine the prevalence of neurological symptoms and their characteristics in individuals with FOP, we conducted a survey of the 470 patient members of the International FOP Association (IFOPA) using a questionnaire about neurological symptoms. There were 168 responses (105 females, 63 males; age 1.5–68 years) from 30 countries representing 36 % of IFOPA members. Chronic neurological symptoms were reported by 86 (51 %). Prevalence of neuropathic pain (NP) was significantly increased (P < 0.001) compared to the general population, and tenfold more common in females (15 %) than males (1.6 %). Of those with NP, 94 % reported other sensory abnormalities. Prevalence of recurrent severe headaches (HA) (26 %) was similar to that in the general population, but prevalence in females with FOP (36 %) was almost fourfold greater than in males. Prevalence of NP, HA, and other sensory abnormalities was substantially higher in post-pubertal females; 33 % reported symptoms worsened during menstrual periods. Worsening of neurological symptoms during FOP flare-ups was reported by 23 %. Three patients with FOP (1.8 %) reported myoclonus, a prevalence much greater than reported in the general population (P < 0.001). Our worldwide survey indicates that neurological symptoms are common in FOP. We speculate that these symptoms are related to effects of dysregulated BMP signaling on the central and/or peripheral nervous systems.
ACVR1; Bone morphogenetic protein 4; Substance P
Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder of progressive heterotopic ossification (HO) caused by a recurrent activating mutation of ACVR1/ALK2, a bone morphogenetic protein (BMP) type I receptor. FOP is characterized by progressive HO, which is associated with inflammation in the setting of dysregulated BMP signaling, however, a variety of atypical neurologic symptoms are also reported by FOP patients. The main objective of this study is to investigate the potential underlying mechanism that is responsible for the observed atypical neurologic symptoms. We evaluated two mouse models of dysregulated BMP signaling for potential CNS pathology through noninvasive magnetic resonance imaging (MRI) studies and histological and immunohistochemical approaches. In one model, BMP4 is over-expressed under the control of the neuron-specific enolase promoter; the second model is a knock-in of a recurrent FOP mutation of ACVR1/ALK2. We also retrospectively examined MRI scans of four FOP patients. We consistently observed demyelinated lesions and focal inflammatory changes of the CNS in both mouse models but not in wild-type controls, and also found CNS white matter lesions in each of the four FOP patients examined. These findings suggest that dysregulated BMP signaling disturbs normal homeostasis of target tissues, including CNS where focal demyelination may manifest as the neurologic symptoms frequently observed in FOP.
Fibrodysplasia ossificans progressiva (FOP); Animal model; Demyelination; Bone morphogenetic protein (BMP); ACVR1/ALK2; Magnetic resonance imaging (MRI)
Heterotopic ossification is a pathologic condition in which bone tissue is formed outside of the skeleton, within soft tissues of the body. The extraskeletal bone that forms in these disorders is normal; the cellular mechanisms that direct cell fate decisions are dysregulated. Patients with fibrodysplasia ossificans progressiva (FOP), a rare human genetic disorder of extensive and progressive heterotopic ossification, have malformations of normal skeletal elements, identifying the causative gene mutation and its relevant signaling pathways as key regulators of skeletal development and of cell fate decisions by adult stem cells. The discovery that mildly activating mutations in ACVR1/ALK2, a bone morphogenetic protein (BMP) type I receptor, is the cause of FOP has provided opportunities to identify previously unknown functions for this receptor and for BMP signaling and to develop new diagnostic and therapeutic strategies for FOP and other more common forms of heterotopic ossification, as well as tissue engineering applications.
Activin A type I receptor; ACVR1; Activin-like kinase 2; ALK2; Bone morphogenetic proteins; BMP; BMP receptors; BMP signaling; Endochondral ossification; Fibrodysplasia ossificans progressiva; FOP; Heterotopic ossification; Extraskeletal bone formation
The objective of this study was to evaluate the degree of improvement in the range of movement in the knee joint, sitting ability, and overall ambulation in patients with heterotopic ossification of the knee joint who underwent surgical excision of ectopic bone. Between 1999 and 2006, 14 patients (23 joints) with significant heterotopic ossification of the knee joint that required surgery were evaluated. We compared the range of movement in the knee joint, sitting ability, and overall ambulation in the preoperative and postoperative periods using the Fuller and Keenan classification systems. Range of movement increased in 82% of cases (19 knee joints). Sitting ability improved in 13 patients (93%). Postoperatively, ambulation in eight patients (57%) was remarkably superior. In conclusion, resection of heterotopic ossification may significantly improve the range of movement in the knee joint, sitting ability, and overall ambulation.
Myositis ossificans (MO) is a benign, progressive, ossifying lesion that displays a characteristic zonal histological appearance. MO traumatica is a localized form of heterotopic bone formation, associated with repetitive micro- and/or macrotrauma in the majority of cases. The importance of imaging to differentiate MO from sarcomatous change and to determine maturity of the lesion is identified because suboptimal operative intervention on immature MO inevitably results in recurrence. A severe case of MO in a 24-year-old paraplegic man with chronic bilateral greater trochanteric pressure sores is presented, and the importance of the MO in the etiology and treatment of this case is discussed. An extensive review of the literature is included and integrated.
Heterotopic ossification; Myositis ossificans; Paraplegic; Pressure sore
The myositis ossificans around shoulder in military recruits are not reported yet. Three young male soldiers presented with complaints of palpable mass at the anterior aspect of shoulder; tenderness around the superior part of deltopectoral groove close to acromioclavicular joint; and restriction of shoulder motion. They also noticed ecchymosis and pain around the coracoid process and anterior shoulder region during regular firing exercises. Plain X-rays and computerized tomography showed extra-capsular, dense, irregular structure in the space between pectoralis and deltoid muscles which correlated with heterotopic bone. One patient refused surgical intervention because of the completion of his military serving period. Surgical excision was performed for the other two patients. During surgical exploration, both ossified masses were found in deltopectoral region and mostly in fibers of clavicular and acromial parts of deltoid muscle. Pathological reports confirmed the structure of masses as mature trabecular bone. Postoperatively indomethacin treatment and active shoulder exercises were started until the full range of motion was regained. Mini soft bag was used on the rifle contact area of the shoulder. No complications or recurrences were observed during the 24 months of followup period.
Heterotopic ossification; military exercises; shoulder
To present a rare case of multiple compressive thoracic intradural cysts with pathologic arachnoid ossification, review the literature and present the surgical options.
Summary of background data
Few reports have identified the existence of arachnoid calcifications and intrathecal cysts causing progressive myelopathy. The literature regarding each of these pathologies is limited to case reports. Their clinical significance is not well studied, although known to cause neurologic sequelae.
An 81-year-old female clinically presents with rapidly progressive myelopathy. Pre-operative magnetic resonance imaging identified multiple compressive thoracic intrathecal cysts. Surgical exploration and decompression of these cysts identified calcified plaques within the arachnoid. Histopathologic examination revealed fibrocalcific tissue undergoing ossification with bone marrow elements.
Due to progressive myelopathy, the thoracic cysts were decompressed and calcified plaques were excised, once identified intra-operatively.
On last examination, the patient’s neurologic status had not improved, but had stabilized. The rate of neurologic improvement from excision and decompression is variable, but it may still be warranted in the face of progressive neurologic deficits.
Arachnoid ossification; Intrathecal cysts; Myelopathy; Osseous metaplasia
Pulmonary adenocarcinoma is a common malignancy that often involves calcification; however, bone formation in primary lung adenocarcinoma is extremely rare. In ten cases of primary pulmonary adenocarcinoma with heterotopic ossification, we detected immunoreactivity against TGF-β1, osteopontin, osteocalcin and Runx2 in the fibroblastic stroma and tumor cells within the area of ossification. Our results suggest that in primary pulmonary adenocarcinoma, heterotopic ossification occurs via intramembranous bone formation. To our knowledge, only 11 other cases of pulmonary adenocarcinoma with heterotopic ossification have been reported. Here, we present ten cases of pulmonary adenocarcinoma showing heterotopic ossification with a description of previously published results and the histogenesis of heterotopic bone formation.
Lung Neoplasms; Adenocarcinoma; Choristoma; Immunohistochemistry; Metaplasia; Ossification