Fibrodysplasia ossificans progressiva (FOP) is a rare genetic disorder characterized by congenital bilateral malformation of the large toe and progressive, extensive, and irreversible heterotopic ossification (HO) of soft tissues throughout the body, leading to severe disabilities. FOP is caused primarily by mutations in activin A receptor type 1 (ACVR1), also known as activin-like kinase 2 (ALK2), which encodes a receptor belonging to the bone morphogenetic protein (BMP) type I family. However, the continuous and complex process of HO in FOP is not yet fully understood, which has impeded the development of therapeutic drugs. Despite surgical removal of HO, which often results in recurrence and expansion of ossification, there is currently no definitive drug treatment available to completely prevent, halt, or reverse the progression of HO in FOP. Currently, researchers are intensively studying the pathogenesis of FOP at various stages and developing promising drug candidates, including saracatinib, palovarotene, and rapamycin. This review provides an overview of progress in understanding the mechanism of FOP and the development of therapeutic drugs, with the goal of providing insights for further research and the development of new treatment methods.
Myositis Ossificans/genetics* ; Humans ; Activin Receptors, Type I/genetics* ; Ossification, Heterotopic ; Mutation ; Sirolimus/therapeutic use* ; Quinolones/therapeutic use* ; Benzodioxoles/therapeutic use* ; Animals ; Quinazolines/therapeutic use*

This review aimed to provide a comprehensive analysis of the etiology, epidemiology, pathology, and conventional treatment of heterotopic ossification (HO), especially emerging potential therapies. HO is the process of ectopic bone formation at non-skeletal sites. HO can be subdivided into two major forms, acquired and hereditary, with acquired HO predominating. Hereditary HO is a rare and life-threatening genetic disorder, but both acquired and hereditary form can cause severe complications, such as peripheral nerve entrapment, pressure ulcers, and disability if joint ankylosis develops, which heavily contributes to a reduced quality of life. Modalities have been proposed to treat HO, but none have emerged as the gold standard. Surgical excision remains the only effective modality; however, the optimal timing is controversial and may cause HO recurrence. Recently, potential therapeutic strategies have emerged that focus on the signaling pathways involved in HO, and small molecule inhibitors have been shown to be promising. Moreover, additional specific targets, such as small interfering RNAs (siRNAs) and non-coding RNAs, could be used to effectively block HO or develop combinatorial therapies for HO.
Humans ; Ossification, Heterotopic/genetics*

OBJECTIVE: To explore short-term effectiveness of floating island laminectomy surgery in treating thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum. METHODS: A total of 31 patients with thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum between January 2019 and April 2022 were managed with floating island laminectomy surgery. The patients comprised 17 males and 14 females, aged between 36 and 78 years, with an average of 55.9 years. The duration of symptoms of spinal cord compression ranged from 3 to 62 months (mean, 27.2 months). The lesions affected T _1-6 in 4 cases and T _7-12 in 27 cases. The preoperative neurological function score from the modified Japanese Orthopaedic Association (mJOA) was 4.7±0.6. Surgical duration, intraoperative blood loss, and complications were recorded. The thoracic MRI was conducted to reassess the degree of spinal cord compression and decompression after operation. The mJOA score was employed to evaluate the neurological function and calculate the recovery rate at 12 months after operation. RESULTS: The surgical duration ranged from 122 to 325 minutes, with an average of 204.5 minutes. The intraoperative blood loss ranged from 150 to 800 mL (mean, 404.8 mL). All incisions healed by first intention after operation. All patients were followed up 12-14 months, with an average of 12.5 months. The patients' symptoms, including lower limb weakness, gait disorders, and pain, significantly improved. The mJOA scores after operation significantly increased when compared with preoperative scores ( P<0.05), gradually improving with time, with significant differences observed among 1, 3, and 6 months ( P<0.05). The recovery rate at 12 months was 69.76%±11.38%, with 10 cases exhibiting excellent neurological function and 21 cases showing good. During the procedure, there were 3 cases of dural tear and 1 case of dural defect. Postoperatively, there were 2 cases of cerebrospinal fluid leakage. No aggravated nerve damage, recurrence of ligamentum flavum ossification, or postoperative thoracic deformity occurred. CONCLUSION The floating island laminectomy surgery is safe for treating thoracic spinal stenosis and myelopathy caused by ossification of the ligamentum flavum, effectively preventing the exacerbation of neurological symptoms. Early improvement and recovery of neurological function are achieved.
Humans ; Male ; Spinal Stenosis/diagnostic imaging* ; Female ; Laminectomy/methods* ; Ligamentum Flavum/pathology* ; Middle Aged ; Aged ; Thoracic Vertebrae/surgery* ; Adult ; Decompression, Surgical/methods* ; Treatment Outcome ; Ossification, Heterotopic/surgery* ; Spinal Cord Compression/etiology* ; Spinal Cord Diseases/etiology* ; Magnetic Resonance Imaging

Humans ; Ossification, Heterotopic ; Skin Diseases, Genetic ; Bone Diseases, Metabolic

Humans ; Osteogenesis ; Mesentery/surgery* ; Ossification, Heterotopic/surgery*

Humans ; Ossification, Heterotopic/diagnostic imaging* ; Osteomyelitis/diagnosis*

Patients with burns are predisposed to heterotopic ossification and contracture formation. While radiographs and bone scans are used to detect heterotopic ossification, musculoskeletal ultrasound can be used to diagnose and localize the lesion in patients with contractures. A 14-year-old girl with multiple contractures of the limbs from thermal burn injury sustained three years ago underwent in-patient rehabilitation in a sub-acute burn rehabilitation unit. Despite close monitoring and daily therapy sessions, the patient had minimal improvement in the range of motion of bilateral hips. Musculoskeletal ultrasound demonstrated hyperechogenic focus on the posterolateral aspect of the bilateral hips. This report documents the advantage of diagnostic musculoskeletal ultrasound in localizing and guiding the treatment of heterotopic ossification in a burn patient with contractures.
Diagnostic Imaging ; Ossification, Heterotopic ; Burns ; Rehabilitation ; Pediatrics

Acetabulum/surgery* ; Arthroplasty, Replacement, Hip/adverse effects* ; Femur Head Necrosis/surgery* ; Fracture Fixation, Internal ; Fractures, Bone/surgery* ; Hip Fractures/surgery* ; Humans ; Ossification, Heterotopic/surgery* ; Treatment Outcome

The incidence of heterotopic ossification in adolescents appears to be lower than in adults. There exist very few reports of heterotopic ossification with total bony ankylosis in child or adolescent populations. We describe a case of total bony ankylosis of the elbow secondary to heterotopic ossification, in a 14-year-old female. Total ankylosis of the elbow at 45 degrees of flexion was noted 6 months post-surgery, and complete surgical excision of the heterotopic mass was performed. After an additional one-time dose of radiation therapy and nonsteroidal anti-inflammatory drug medication, full range of motion was obtained without any recurrence or other complications, up to the last follow-up of 30 months.
Adolescent ; Adult ; Ankylosis ; Child ; Dislocations ; Elbow ; Female ; Follow-Up Studies ; Fractures, Bone ; Humans ; Incidence ; Ossification, Heterotopic ; Range of Motion, Articular ; Recurrence

STUDY DESIGN: Prospective observational cohort study. PURPOSE: This study aims to evaluate the safety and efficacy of bone morphogenetic protein-2 (BMP-2) in transforaminal lumbar interbody fusion (TLIF) with regard to postoperative radiculitis. OVERVIEW OF LITERATURE: Bone morphogenetic protein (BMP) is being used increasingly as an alternative to iliac crest autograft in spinal arthrodesis. Recently, the use of BMP in TLIF has been examined, but concerns exist that the placement of BMP close to the nerve roots may cause postoperative radiculitis. Furthermore, prospective studies regarding the use of BMP in TLIF are lacking. METHODS: This prospective study included 77 patients. The use of BMP-2 was determined individually, and demographic and operative characteristics were recorded. Leg pain was assessed using the Visual Analog Scale (VAS) for pain and the Sciatica Bothersome Index (SBI) with several secondary outcome measures. The outcome data were collected at each follow-up visit. RESULTS: Among the 77 patients, 29 were administered with BMP. Postoperative leg pain significantly improved according to VAS leg and SBI scores for the entire cohort, and no clinically significant differences were observed between the BMP and control groups. The VAS back, Oswestry Disability Index, and Short-Form 36 scores also significantly improved. A significantly increased 6-month fusion rate was noted in the BMP group (82.8% vs. 55.3%), but no significant differences in fusion rate were observed at the 12- and 24-month follow-up. Heterotopic ossification was observed in seven patients: six patients and one patient in the BMP and control groups, respectively (20.7% vs. 2.1%). However, no clinical effect was observed. CONCLUSIONS: In this prospective observational trial, the use of BMP in TLIF did not lead to significant postoperative radiculitis, as measured by VAS leg and SBI scores. Back pain and other functional outcome scores also improved, and no differences existed between the BMP and control groups. The careful use of BMP in TLIF appears to be both safe and effective.
Arthrodesis ; Autografts ; Back Pain ; Bone Morphogenetic Proteins ; Cohort Studies ; Follow-Up Studies ; Humans ; Leg ; Lumbosacral Region ; Ossification, Heterotopic ; Outcome Assessment (Health Care) ; Prospective Studies ; Radiculopathy ; Sciatica ; Spinal Fusion ; Spine ; Visual Analog Scale