Formation Of Mature Lamellar Bone Research Articles

Neurovascular Entrapment Due to Combat-Related Heterotopic Ossification in the Lower Extremity

Heterotopic ossification is the ectopic formation of mature lamellar bone in nonosseous tissue. The prevalence of heterotopic ossification following combat injuries is much higher than civilian data would suggest. In certain cases, the aberrant bone formation can envelop major neurovascular structures in the lower extremity, leading to symptomatic neurovascular entrapment. We describe five consecutive cases of heterotopic ossification leading to symptomatic neurovascular entrapment in the lower extremity as a result of blast trauma and present our method of patient assessment, preoperative planning, and surgical excision. Heterotopic bone was successfully excised without neurovascular injury in all patients. At a mean of twenty months (range, eight to forty-five months) postoperatively, all patients demonstrated continued improvement of their pre-excision function. All patients who had neuropathic pain had a decrease in the pain. Those with decreased joint motion regained motion once their wounds were stable. Sensory deficits resolved before motor deficits did. There was no recurrence of clinically relevant heterotopic ossification in this series. Excision of heterotopic bone, particularly with concurrent neurovascular entrapment, can be associated with major short-term and long-term complications. With use of our treatment algorithm, involving careful preoperative planning and meticulous operative excision, heterotopic bone entrapping major neurovascular structures following severe extremity trauma can be safely excised with subsequent clinical improvement.

Insights into posttraumatic heterotopic ossification in extremity war injuries

Heterotopic ossification (HO) denotes the formation of mature lamellar bone in nonosseous or soft tissue. HO is a well-known complication of trauma; however, in the war-wounded population the incidence is much higher than that in the civilian population. While the pathophysiology and molecular biology of HO are subjects of continued investigation, the current model stipulates that high-energy trauma causes a chronic inflammatory state facilitating a fibrous osteoinductive environment leading to endochondral ossification. There is no standard prophylaxis regimen for combat-related HO since conventional therapies such as radiation and nonsteroidal antiinflammatory drugs carry a higher risk of complications compared with that in the civilian population. Treatment of symptomatic HO begins with conservative management and eventually surgical excision in the appropriately selected patient. Through improved understanding of the pathophysiology and basic science of the disorder, recent investigative efforts have focused on development of an appropriate prophylactic agent, as well as treatment therapy, for this condition in the war-wounded. This article reviews the current literature on combat-related HO and describes the experience with this disease process at our institution.

Nasofrontal Heterotopic Ossification Following Lymphangioma Resection

Heterotopic ossification (HO) is the formation of mature lamellar bone in soft tissues. Heterotopic ossification can occur locally following surgical trauma, most commonly after total hip arthroplasty. Periosteal stripping, organizing hematoma, and extensive soft tissue dissection have been associated with subsequent HO. Craniomaxillofacial HO is rare and almost always associated with injury to the muscles of mastication. We present a report of biopsy-established HO of the cranium. An 18-month-old boy presented with a soft, compressible mass in the forehead midline, which did not extend intracranially on computed tomography scan. Surgical exploration revealed a poorly marginated lymphangioma infiltrating the periosteum of the nasofrontal region. This was debulked to restore nasofrontal contour. Two months postoperatively, after minor accidental trauma, the patient developed a subperiosteal hematoma that was evacuated in the clinic. Eight months postoperatively, the patient returned with a visible nasofrontal prominence overlying a firm immobile mass. Computed tomography scan revealed a 3-cm horn-like osseous structure extending inferiorly from the frontal bone across the nasofrontal junction. The bony mass was resected via a coronal approach and confirmed as HO with hematopoietically active marrow.

Heterotopic Ossification Revisited

Heterotopic ossification is the abnormal formation of mature lamellar bone within extraskeletal soft tissues where bone does not exist. Heterotopic ossification has been classified into posttraumatic, nontraumatic or neurogenic, and myositis ossificans progressiva or fibrodysplasia ossificans progressive. The pathophysiology is unknown. Anatomically, heterotopic ossification occurs outside the joint capsule without disrupting it. The new bone can be contiguous with the skeleton but generally does not involve the periosteum. Three-phase technetium-99m (99mTc) methylene diphosphonate bone scan is the most sensitive imaging modality for early detection and assessing the maturity of heterotopic ossification. Nonsurgical treatment with indomethacin and radiation therapy is appropriate for prophylaxis or early treatment of heterotopic ossification. Although bisphosphonates are effective prophylaxis if initiated shortly after the trauma, mineralization of the bone matrix resumes after drug discontinuation. During the acute inflammatory stage, the patient should rest the involved joint in a functional position; once acute inflammatory signs subside, passive range of motion exercises and continued mobilization are indicated. Surgical indications for excision of heterotopic ossification include improvement of function, standing posture, sitting or ambulation, independent dressing, feeding and hygiene, and repeated pressure sores from underlying bone mass. The optimal timing of surgery has been suggested to be a delay of 12 to 18 months until radiographic evidence of heterotopic ossification maturation and maximal recovery after neurological injury. The ideal candidate for surgical treatment before 18 months should have no joint pain or swelling, a normal alkaline phosphatase level, and 3-phase bone scan indicating mature heterotopic ossification.

WITHDRAWN: Pharmacological interventions for treating acute heterotopic ossification.

Heterotopic ossification (HO) is the formation of mature lamellar bone in soft tissue sites outside the skeleton. HO frequently complicates burns, arthroplasty, fractures, and spinal cord and brain injuries. It can impair joint function. To determine the efficacy of medications to treat acute HO on radiological, symptomatic, functional impairment, and disability outcomes. We searched the Cochrane Bone, Joint and Muscle Trauma Group specialised register, the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 2, 2004), MEDLINE (1966 to August 2004), EMBASE (1980 to August 2004), CINAHL (1982 to August 2004), other databases, reference lists of articles, and contacted trialists and drug companies. No language restrictions were applied. All randomised or quasi-randomised controlled trials that assessed the efficacy of any medication for treating acute HO (confirmed by bone scintigraphy, radiography, ultrasonography, or biopsy) and which used radiography to grade post-treatment HO severity. Two reviewers independently assessed the study quality and extracted data. We analysed two dichotomous outcomes: no progression in HO grade (versus progression) and improvement in HO grade (versus no improvement). Two randomised trials comparing disodium etidronate versus placebo were included (Ono 1988; Stover 1976), from which ninety-two participants with spinal cord injury had radiographically-proven HO at baseline. At the completion of the 12 week intervention, the Ono study but not the Stover study, suggested that disodium etidronate was associated with a significantly greater likelihood of successfully preventing the progression of radiographic HO grade, (relative risk (RR) 1.50; 95% confidence interval (CI) I 1.16 to 1.93; and RR 1.48; 95% CI 0.78 to 2.84 respectively) and a significantly greater likelihood of improvement in HO grade (RR 2.78; 95% CI 1.66 to 4.66; and RR 0.71; 95% CI 0.20 to 2.53 respectively). There was evidence of statistical heterogeneity for the latter outcome. Longer term radiographic, clinical or side effect outcomes were unavailable. Data was not pooled due to this heterogeneity and the inadequate duration of follow up. Given the absence of long term radiographic outcomes in the included studies, there is insufficient evidence to recommend the use of disodium etidronate or other pharmacological agents for the treatment of acute HO. It has been previously suggested that disodium etidronate acts by delaying, rather than preventing, the mineralization of HO, and that mineralization may occur after treatment cessation in many cases, thereby negating the benefit of disodium etidronate on eventual HO grade. Further studies are required to assess all pharmacological treatments for acute HO with sufficient follow-up duration.

Risk factors for major joints heterotopic ossification after thermal injury

Heterotopic ossification (HO), a disabling condition of mature lamellar bone formation in soft tissues, particularly periarticular, may complicate the course of thermal injury1. Despite significant improvements in burns care, effective prevention of HO is still lacking. Epidemiological analysis of the phenomenon including optimal diagnosis approach is a preliminary condition for future therapeutic perspective. The aim of this retrospective study was to identify early risk factors for HO.

Heterotopic Ossification in the Maxillary Sinus

We report a case of heterotopic ossification of the maxillary sinus in a 30-year-old female who was treated surgically in our department. Heterotopic ossification (HO) refers to the formation of mature lamellar bone in nonosseous tissues. We present the radiographic and computed tomographic appearance, and discuss the surgical treatment, histopathologic results, and differential diagnosis. To the best of our knowledge, no other case of HO of the maxillary sinus has been reported yet.

Heterotopic Ossification of the Distal Portion of Biceps Femoris

Heterotopic ossification is the formation of mature lamellar bone in soft tissue. We report a very unusual case of heterotopic ossification arising in the distal portion of the biceps femoris muscle. A 29-year-old woman presented with knee pain after playing golf. She had had no apparent history of trauma. Radiography of the knee showed a calcified mass adjacent to the lateral side of her knee joint. The radiological diagnosis was calcification of the lateral collateral ligament. The pain soon disappeared without treatment. At the age of 45 years, she complained of a growing mass in her left knee that was occasionally painful. Computed tomography and magnetic resonance imaging demonstrated a well matured ossified mass in the lateral side of her left knee. Radiologically and macroscopically, it was found to be in continuity with the distal part of biceps femoris. The mass was excised en bloc. Microscopically, the lesion was mainly composed of well-matured lamellar bone with bone marrow and islands of cartilage showing enchondral ossification. No apparent zoning was found. Cellular atypia was not observed. Extraskeletal osteosarcoma was ruled out. The mass was diagnosed as a heterotopic ossification arising from the distal part of biceps femoris.

Heterotrophic Ossification after Total Knee Arthroplasty: A Case Report

Heterotrophic ossification (HO) is a reactive disease that is defined as the formation of mature lamellar bone in the soft tissue but it is rarely associated with loss of motion and stiffness. The reported incidence of HO after total knee arthroplasty (TKA) ranges from 1% to 42%. We experienced a case of HO adversely affecting the ambulation of the patient as a result of the severe ankylosis of the knee after TKA. We report this case with a review of the relevant literature.

Bone formation and inflammation in cardiac valves.

For nearly a century, the mechanical failure of calcified heart valves was attributed to a passive degenerative process. Recently, several case reports described bone formation in surgically excised heart valves and suggested an unexpected process of tissue repair. We studied the prevalence and pathology of heterotopic ossification in 347 surgically excised heart valves (256 aortic, 91 mitral) in 324 consecutive patients (182 men, 142 women; mean age 68 years) who underwent cardiac valve replacement surgery between 1994 and 1998. The valves were examined microscopically to determine the prevalence and features of bone formation and remodeling. Two hundred eighty-eight valves (83%) had dystrophic calcification. Mature lamellar bone with hematopoietic elements and active bone remodeling were present in 36 valves (13%) with dystrophic calcification. Endochondral bone formation, similar to that seen in normal fracture repair, was identified in 4 valves. Microfractures were present in 92% of all valves with ossification. Neoangiogenesis was found in all valves with ossification. Bone morphogenetic proteins 2 and 4 (BMP 2/4), potent osteogenic morphogens, were expressed by myofibroblasts and preosteoblasts in areas adjacent to B- and T-lymphocyte infiltration in valves where ossification was identified. Mast cells were present in calcified and ossified valves and were especially prominent in atheromatous regions. Heterotopic ossification consisting of mature lamellar bone formation and active bone remodeling is a relatively common and unexpected finding in end-stage valvular heart disease and may be associated with repair of pathological microfractures in calcified cardiac valves.

Response of Bone Marrow Stroma Cells to Demineralized Cortical Bone Matrix in Experimental Spinal Fusion in Rabbits

The effect of autogeneic bone marrow (BM) cells and allogeneic demineralized bone matrix (DBM), alone or combined, as transplantation materials was studied in an experimental posterior thoracic spinal fusion model in rabbits. Transplantation of composite grafts composed of BM and DBM showed the first signs of fusion between two spinal segments after four weeks, reaching 86% after 20 weeks. Late fusion results achieved with DBM alone were similar. The capacity of BM per se to build up a spinal fusion was insignificant. Calcified tissue, documented roentgenographically, was shown to develop locally with time, and the earliest bridging of an interspace was noted after four weeks. Histologically, formation of new bone and cartilage was observed after two weeks, showing mature lamellar bone formation between thoracic segments after 20 weeks. Furthermore, increased 45Ca activity was still observed in the fused tissues after 20 weeks. Although, with grafting materials used, this model for experimental spinal fusion gave promising results, further investigations with other fusion techniques could give still better effects.