Myositis ossificans of psoas muscle: magnetic resonance imaging findings

Massive Heterotopic Ossification of the Tensor Fascia Lata in a Bodybuilder Leading to Severe Hip Dysfunction: A Case Report

CASE

A 42-year-old bodybuilder with no history of trauma presented to our clinic with persistent right hip pain and rapidly advancing joint stiffness. Imaging confirmed massive, mature heterotopic ossification predominantly involving the right tensor fascia lata. Six months after a tailored surgical removal, there were no signs of disability, pain, or clinical signs of recurrence, and the patient regained proper joint function.

CONCLUSION

In massive heterotopic ossification, tailored surgical removal of the part of the lesion that is limiting function may result in a complete functional recovery.

Nontraumatic Myositis Ossificans as an Uncommon Cause of Scoliosis: Case Report and Review of the Literature

BACKGROUND

A 5-year-old pediatric patient developed scoliosis associated with nontraumatic myositis ossificans in the lumbar region. Although there have been reports in literature of syndromes leading to widespread muscle ossifications resulting in shoulder deformities owing to impaired movement in the facet joints, to the best of our knowledge there has been no report of scoliosis associated with myositis ossificans.

CASE DESCRIPTION

The case presented is of a 5-year-old girl who developed scoliosis associated with nontraumatic myositis ossificans in the lumbar region. On the thoracolumbar radiograph, a hyperintense lesion was seen at the right-side L2-L3 level and scoliosis with a Cobb angle of 16.2° to the right side. The decision for surgery was made with the consideration of the existing scoliosis and that the complaints were associated with paravertebral calcified lesions adjacent to the facet joints. After surgery, the scoliosis improved.

CONCLUSIONS

Nontraumatic, paravertebral myositis ossificans at an early age is a very rare pathology. Therefore, it must be recognized that spine deformities such as scoliosis and kyphosis can develop in neglected cases of paravertebral myositis ossificans. In addition, there is a high risk of confusion with malignant pathologies, such as osteosarcoma, in this area. Removal of the mass eliminates both the pain of myositis ossificans and prevents the development of scoliosis.

Myositis ossificans circumscripta of the psoas muscle due to overuse in an adolescent gymnast

Myositis ossificans is a pseudoinflammatory tumour that originates from skeletal muscle and corresponds to a heterotopic, metaplastic, nonmalignant bone tumour. The purpose of this article is to report the case of myositis ossificans circumscripta (MOC) of the psoas muscle due to overuse in an adolescent gymnast. A 16-year-old female athlete presented at our outpatient orthopaedic clinic for evaluation of a 1-month history of low back pain. Initial plain radiographs were initially interpreted as negative, and laboratory values were normal. MRI imaging demonstrated a circumscribed mass with associated oedema in the psoas muscle. Computed tomography-guided percutaneous biopsy was performed and histology confirmed the diagnosis of MOC. Conservative treatment was initiated with rest and anti-inflammatory drugs (indomethacin). The patient had a resolution of pain and function after 3 months of conservative treatment. At 6 months' follow-up, MRI demonstrated complete resolution of the lesion and she gradually returned to her sports activity. At last follow-up she was asymptomatic. MOC is a rare lesion in the paediatric-adolescent population. To our knowledge, this is the first report of MOC in the psoas muscle produced by overuse. MRI is very sensitive in detecting oedema during the acute phase of the lesion. Conservative treatment should be considered, especially at the early stage of the disease. Spontaneous resolution can be expected in most cases.

Pericytes: multitasking cells in the regeneration of injured, diseased, and aged skeletal muscle

Pericytes are perivascular cells that envelop and make intimate connections with adjacent capillary endothelial cells. Recent studies show that they may have a profound impact in skeletal muscle regeneration, innervation, vessel formation, fibrosis, fat accumulation, and ectopic bone formation throughout life. In this review, we summarize and evaluate recent advances in our understanding of pericytes' influence on adult skeletal muscle pathophysiology. We also discuss how further elucidating their biology may offer new approaches to the treatment of conditions characterized by muscle wasting.

Bilateral simultaneous heterotopic ossification of the reflected head of rectus femoris muscle: a case report and review of the literature

Lamellar bone formation in an abnormal location is defined as heterotopic ossification. It commonly occurs around the hip joint and most often involves the abductor muscles. It is a benign condition; however, its etiology remains largely unknown. Most previously reported cases have been due to trauma or intramuscular hemorrhage. In this paper, we present a case of bilateral heterotopic ossification of the reflected head of rectus femoris muscle without antecedent trauma or any other known cause, as the first and unique case in the literature. She was treated by excision of the right symptomatic bony mass via a modified Smith-Petersen approach. Postoperatively, she received 75 mg indomethacin daily for six weeks. She was pain-free and obtained full range of motion 3 weeks after the first intervention.

Myositis ossificans in psoas muscle after lumbar spine fracture

STUDY DESIGN

A case report.

OBJECTIVE

To report a case of myositis ossificans in the psoas muscle after lumbar spine fracture.

SUMMARY OF BACKGROUND DATA

Myositis ossificans is a benign condition of heterotopic bone formation in skeletal muscle. It predominantly occurs in large muscles of extremities following injury. Occurrence in the psoas muscle is rare with no previous reports of this condition associated with vertebral fracture in patients without hematologic abnormality.

METHODS

A 56-year-old man was referred to our hospital for a mass located in the left psoas muscle and an L3 compression fracture. He complained of low back and left leg pain after a fall 2 weeks previously. Magnetic resonance (MR) imaging obtained 12 days after trauma showed an L3 compression fracture with a left psoas mass with low T1 and high T2 signal intensity, associated edema, and enhancement. Computed tomography (CT) scans showed a suspicious slightly high-density mass in the left psoas area. The radiologic features of the mass were consistent with a hematoma.

RESULTS

After 1 week, CT scans showed calcification at the hematoma site. Histologic examination following CT-guided biopsy demonstrated new bone formation, atrophy of skeletal muscle fibers, and fibrosis. Lymphocytes were focally infiltrating. Irregularly anastomosing bony trabeculae and fibroblastic cell proliferation were noted. On follow-up MRI and CT scans 2 months later, the previous calcified mass was no longer evident.

CONCLUSION

Myositis ossificans usually occurs in extremities and is very uncommon in the psoas muscle. We report psoas myositis ossificans that developed from hemorrhage and edema associated with a lumbar fracture and required only 2 months to regress completely. When one finds a soft tissue mass with surrounding edema in the psoas muscle combined with a vertebral compression fracture, myositis ossificans should be included in the differential diagnosis.

Post-traumatic myositis ossificans circumscripta: an unusually large example

A 66-year-old woman presented with painful gait and a large, firm, nonmobile mass in her right foot. She had undergone four previous surgeries to remove a recurring "calcified hematoma" that resulted from an injury sustained 3 decades previously. An unusually large ossific mass (7.0 x 7.0 x 2.0 cm) consistent with post-traumatic myositis ossificans circumscripta was excised. After 3 years of follow-up, there was no return of the symptoms or the mass.

MR Imaging of Iliopsoas Musculotendinous Injuries

The literature describing iliopsoas compartment injuries is based on case reports and small patient series, mostly in the orthopedic literature.Nevertheless, in recent years, there has been a growing recognition of these injuries. Because many intra-articular and extra-articular bony and soft tissue injuries in the groin may clinically mimic each other, because two or more pathologic entities may coexist, and because athletes are highly motivated to continue with their physical activity, diagnosis of iliopsoas injury is often delayed. Thus, cross-sectional imaging is highly important. MR imaging is most accurate for diagnosing nondynamic diseases of the iliopsoas compartment as well as for ruling out other abnormalities of the hip joint and surrounding structures. When a snapping hip is being investigated or corticosteroid injection is warranted, US can be of help in providing a dynamic study and by guiding the injection.