Ultrasound-Guided Ankle Block in Stone Man Disease, Fibrodysplasia Ossificans Progressiva

Monitoring and Management of Fibrodysplasia Ossificans Progressiva: Current Perspectives

Fibrodysplasia ossificans progressiva (FOP), sometimes known as myositis ossificans progressiva, is an ultra-rare disease in which bone is formed in muscular tissue, tendons and ligaments. This is known as heterotopic ossification (HO). FOP is caused by a heterozygous mutation in the highly conserved ACVR1/ALK2 gene which affects about 1 in 1.5–2 million individuals. At birth, patients with the predominant R206H mutation only exhibit a bilateral hallux valgus. During childhood, heterotopic bone formation develops in a typical pattern, affecting the axial muscles first before appendicular body parts are involved. HO can start spontaneously but is often elicited by soft tissue trauma or medical procedures. After soft tissue injury, an inflammatory process called a flare-up can start, followed by the formation of HO. HO leads to a limited range of motion, culminating in complete ankylosis of nearly all joints. As a result of HO surrounding the thorax, patients often suffer from thoracic insufficiency syndrome (TIS). TIS is the most common cause of a limited life expectancy for FOP patients, with a median life expectancy of 56 years. Management is focused on preventing soft-tissue injury that can provoke flare-ups. This includes prevention of iatrogenic damage by biopsies, intramuscular injections and surgery. Anti-inflammatory medication is often started when a flare-up occurs but has a poor basis of evidence. Several forms of potential treatment for FOP are being researched in clinical trials. Progression of the disease is monitored using CT and 18F-NaF PET/CT combined with functional assessments. Patients are regularly evaluated for frequently occurring complications such as restrictive lung disease. Here, we review the current management, monitoring and treatment of FOP.

Fibrodysplasia ossificans progressiva: Diagnosis with ultrasound

Fibrodysplasia ossificans progressiva (FOP) is an extremely rare connective tissue disease, diagnosed by genetic testing. This is the first report in English literature wherein an ultrasound examination suggested this specific diagnosis. In this case, a two month old girl presented with bi-parieto-occipital swellings that were being managed as subgaleal haematoma. The parents were anxious that there was no resolution of the swellings. The suspicion of FOP was raised during the ultrasound examination where a review of the images prompted a questioning of the parents about other lesions in the body. Ultrasound examination of a lump in the thigh revealed calcifications in the vastus lateralis muscle. The appearances on the ultrasound combined with the presence of hallucis valgi suggested a diagnosis of FOP. The diagnosis was subsequently confirmed by genetic studies. This case highlights the need for good communication between the physician, patient and the imaging department.

When Limb Surgery Has Become the Only Life-Saving Therapy in FOP: A Case Report and Systematic Review of the Literature

Fibrodysplasia ossificans progressiva (FOP) is a rare disease in which heterotopic ossification (HO) is formed in muscles, tendons and ligaments. Traumatic events, including surgery, are discouraged as this is known to trigger a flare-up with risk of subsequent HO. Anesthetic management for patients with FOP is challenging. Cervical spine fusion, ankylosis of the temporomandibular joints, thoracic insufficiency syndrome, restrictive chest wall disease, and sensitivity to oral trauma complicate airway management and anesthesia and pose life-threatening risks. We report a patient with FOP suffering from life-threatening antibiotic resistant bacterial infected ulcers of the right lower leg and foot. The anesthetic, surgical and postoperative challenges and considerations are discussed. In addition, the literature on limb surgeries of FOP patients is systemically reviewed. The 44 year-old female patient was scheduled for a through-knee amputation. Airway and pulmonary evaluation elicited severe abnormalities, rendering standard general anesthesia a rather complication-prone approach in this patient. Thus, regional anesthesia, supplemented with intravenous analgosedation and N₂O-inhalation were performed in this case. The surgery itself was securely planned to avoid any unnecessary tissue damage. Postoperatively the patient was closely monitored for FOP activity by ultrasound and [¹⁸F]PET/CT-scan. One year after surgery, a non-significant amount of HO had formed at the operated site. The systematic review revealed seventeen articles in which thirty-two limb surgeries in FOP patients were described. HO reoccurrence was described in 90% of the cases. Clinical improvement due to improved mobility of the operated joint was noted in 16% of the cases. It should be noted, though, that follow-up time was limited and no or inadequate imaging modalities were used to follow-up in the majority of these cases. To conclude, if medically urgent, limb surgery in FOP is possible even when general anesthesia is not preferred. The procedure should be well-planned, alternative techniques or procedures should be tested prior to surgery and special attention should be paid to the correct positioning of the patient. According to the literature recurrent HO should be expected after surgery of a limb, even though it was limited in the case described.

General anesthesia for dental procedures in patients with fibrodysplasia ossificans progressiva: a review of 42 cases in 30 patients

BACKGROUND

Fibrodysplasia ossificans progressiva (FOP) is a rare genetic condition characterized by progressive heterotopic ossification of skeletal muscle and soft connective tissues, leading to progressive ankylosis of all joints of the axial and appendicular skeleton. Cervical spine fusion, ankylosis of the temporomandibular joints, thoracic insufficiency syndrome, restrictive chest wall disease, and sensitivity to oral trauma complicate airway management and anesthesia and pose life-threatening risks.

METHODS

We conducted a retrospective chart review at 1 institution of patients with FOP who underwent general anesthesia (GA) for dental procedures.

RESULTS

Thirty patients underwent 42 general anesthetics. In 35 of 42 cases, GA was induced after the airway was secured by an awake fiberoptic intubation. In 4 of 42 cases, all of them pediatric, GA was first induced with maintenance of spontaneous ventilation, and the trachea was then intubated using a fiberoptic scope. In 2 cases, 1 adult and 1 pediatric, GA was first induced, and the trachea was then intubated using a GlideScope. In 1 case, the patient had a cuffed tracheostomy device in place that was accessed for GA. In 36 of 42 cases, the patients were discharged home on the same day as their dental procedure. No significant postoperative complications were encountered.

CONCLUSIONS

GA can be administered safely to patients with FOP for dental procedures with attention to perioperative and airway management using a multidisciplinary approach. An awake nasal fiberoptic intubation should be considered the first choice for airway management. Most patients can be discharged home on the same day as their dental procedure.

The stone man disease: fibrodysplasia ossificans progressiva: imaging revisited

Fibrodysplasia ossificans progressiva (FOP) is a rare, disabling connective tissue disorder of unknown aetiology. Its occurrence is usually sporadic but may be an inherited autosomal-dominant condition with wide range of expression. FOP is characterised by congenital malformations of the great toes and abnormal progressive heterotopic ossification of striated muscles, tendons, ligaments, fascia and aponeuroses of the trunk and extremities leading to painful swellings. The ossifications typically appear within the first decade of life, resulting in progressive morbidity and severe disability. So far, there has been no effective treatment or prevention. In the early localised phase of disease it may be misdiagnosed, hence the role of correct diagnosis through imaging is essential. Herein, we report a case of a 10-year-old female who was evaluated radiologically and diagnosed as a case of FOP. The findings of plain radiography are described and the role of CT is highlighted.