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

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*

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

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

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

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

Distal humerus fractures require stable fixation and early joint motion, similar to other intra-articular fractures, but are difficult to treat adequately because of the anatomical complexity, severe comminution, and accompanying osteoporosis. In most cases, surgical treatment is performed using two supporting plates. Plate fixation can be divided into right angle plate fixation and parallel plate fixation. In addition, depending on the type of fracture, surgical procedures can be performed differently, and autologous bone grafting can be required in the case of severe bone loss. The elbow joint is vulnerable to stiffness, so it is important to start joint movement early after surgery. Postoperative complications, such as nonunion, ulnar nerve compression, and heterotopic ossification, can occur. Therefore, accurate and rigid fixation and meticulous manipulation of soft tissues are required during surgery.
Bone Transplantation ; Elbow Joint ; Humerus ; Intra-Articular Fractures ; Joints ; Ossification, Heterotopic ; Osteoporosis ; Postoperative Complications ; Rehabilitation ; Ulnar Nerve ; Ulnar Nerve Compression Syndromes

BACKGROUND: Heterotopic ossification (HO) is a known complication of hip arthroscopy. We investigated incidence of HO after hip arthroscopy and determined whether revision for HO improved outcome. METHODS: A retrospective study was conducted on 242 patients (140 men and 102 women, mean age: 36.2 ± 9.5 years) who underwent hip arthroscopy for femoroacetabular impingement (FAI) between January 2016 and January 2018. The average follow-up period was 22.88 ± 11.74 months (range: 11-34 months). Thirteen (5.37%) cases of HO (six men and seven women, five left hips and eight right hips; mean age: 37.5 ± 4.7 years) were observed. Among them, four cases with HO with obvious pain symptoms and persistent non-remission underwent revision surgery to remove HO. Monthly follow-up was conducted. Visual analog scale (VAS), modified Harris Hip Score (mHHS), and non-Arthritis Hip Score (NAHS) were evaluated and compared between HO and non-HO patients. Independent sample t test, Mann-Whitney U test and the Chi-square test were used for inter-group comparisons. HO degree was evaluated using Brooker classification. Symptoms and function were evaluated before and after revision. RESULTS: A total of 242 patients were involved in this study. Thirteen cases (5.4%) had imaging evidence of HO. Nine (9/13) were classified as Brooker stage I, three (3/13) Brooker stage II, and one (1/13) Brooker stage III. HO was detected by ultrasonography as early as 3 weeks after operation. After primary surgery, the mHHS of the HO group and non-HO group increased by 13.00 (8.50, 25.50) and 24.00 (14.00, 34.50) points (Z = -1.80, P = 0.08), NAHS increased by 18.00 (9.50, 31.50) and 26.00 (13.50, 36.00) points (Z = -1.34, P = 0.18), and VAS decreased by 3.00 (2.00, 4.00) and 4.00 (3.00, 4.50) points (Z = -1.55, P = 0.12). Average follow-up time after revision was 9.00 ± 2.94 months; mHHS increased by 34.75 points (t = -55.23, P < 0.01) and NAHS by 28.75 points (t = -6.03, P < 0.01), and VAS decreased by 4 points (t = 9.80, P < 0.01). HO and non-HO patients were similar for demographic and surgical data, and clinical and functional scores. CONCLUSION HO incidence after arthroscopic treatment of FAI is similar to that found in previous studies. Most HO have no effect on clinical symptoms. Patients who undergo revision HO resection show improvement in pain and joint function.
Adult ; Arthroscopy ; adverse effects ; Female ; Femoracetabular Impingement ; surgery ; Hip Joint ; pathology ; surgery ; Humans ; Male ; Middle Aged ; Ossification, Heterotopic ; diagnosis ; etiology ; Retrospective Studies ; Treatment Outcome