We retrospectively reviewed 89 consecutive patients (45 men and 44 women) with a mean age at the time of injury of 58 years (18 to 97) who had undergone external fixation after sustaining a unilateral fracture of the distal humerus. Our objectives were to determine the incidence of heterotopic ossification (HO); identify risk factors associated with the development of HO; and characterise the location, severity and resultant functional impairment attributable to the presence of HO.

HO was identified in 37 elbows (42%), mostly around the humerus and along the course of the medial collateral ligament. HO was hazy immature in five elbows (13.5%), mature discrete in 20 (54%), extensive mature in 10 (27%), and complete bone bridges were present in two elbows (5.5%). Mild functional impairment occurred in eight patients, moderate in 27 and severe in two. HO was associated with less extension (p = 0.032) and less overall flexion-to-extension movement (p = 0.022); the flexion-to-extension arc was < 100º in 21 elbows (57%) with HO compared with 18 elbows (35%) without HO (p = 0.03). HO was removed surgically in seven elbows.

The development of HO was significantly associated with sustaining a head injury (p = 0.015), delayed internal fixation (p = 0.027), the method of fracture fixation (p = 0.039) and the use of bone graft or substitute (p = 0.02).HO continues to be a substantial complication after internal fixation for distal humerus fractures.

Cite this article: Bone Joint J 2014;96-B:1681–7.

Heterotopic ossification (HO) is perhaps the single most significant obstacle to independence, functional mobility, and return to duty for combat-injured veterans of Operation Enduring Freedom and Operation Iraqi Freedom. Recent research into the cause(s) of HO has been driven by a markedly higher prevalence seen in these wounded warriors than encountered in previous wars or following civilian trauma. To that end, research in both civilian and military laboratories continues to shed light onto the complex mechanisms behind HO formation, including systemic and wound specific factors, cell lineage, and neurogenic inflammation. Of particular interest, non-invasive in vivo testing using Raman spectroscopy may become a feasible modality for early detection, and a wound-specific model designed to detect the early gene transcript signatures associated with HO is being tested. Through a combined effort, the goals of early detection, risk stratification, and development of novel systemic and local prophylaxis may soon be attainable.

Neurogenic heterotopic ossification (NHO) is a disorder of aberrant bone formation affecting one in five patients sustaining a spinal cord injury or traumatic brain injury. Ectopic bone forms around joints in characteristic patterns, causing pain and limiting movement especially around the hip and elbow. Clinical sequelae of neurogenic heterotopic ossification include urinary tract infection, pressure injuries, pneumonia and poor hygiene, making early diagnosis and treatment clinically compelling. However, diagnosis remains difficult with more investigation needed. Our pathophysiological understanding stems from mechanisms of basic bone formation enhanced by evidence of systemic influences from circulating humor factors and perhaps neurological ones. This increasing understanding guides our implementation of current prophylaxis and treatment including the use of non-steroidal anti-inflammatory drugs, bisphosphonates, radiation therapy and surgery and, importantly, should direct future, more effective ones

The clinical features of eight patients with myositis ossificans progressiva are described and the effects of treatment with the diphosphonate EHDP, together with surgical removal of ectopic bone, are assessed. Early correct diagnosis remains unusual, mainly because the significance of the short great toes is unrecognised, and because myositis may be mistaken for bruising, sarcoma or mumps. The diphosphonate disodium etidronate (EDHP) was given to all patients in an attempt to suppress calcification of new lesions; in five of them ectopic bone was removed during the treatment. EHDP sometimes delayed the mineralisation of newly formed bone matrix after surgical removal but this delay could not be predicted. The variable effect of EHDP may depend particularly on the amount absorbed and on the activity of new bone formation

We have developed a new drug-delivery system using reconstituted bone xenograft to treat chronic osteomyelitis. This material, which has the capabilities of osteoinduction and osteoconduction, was supplemented with up to 2000 times the minimum inhibitory concentration of gentamicin against Staphylococcus aureus to prepare a gentamicin-reconstituted bone xenograft-composite (G-RBX-C). In a rabbit model, we evaluated the release of gentamicin from this composite in vivo, its capability for induction of ectopic bone and the repair of segmental defects of the radius. There was a high level of concentration of antibiotics, which was sustained for at least ten days. In the study of induction of ectopic bone, there was abundant woven bone in the G-RBX-C group two weeks after operation. At 16 weeks after implantation of G-RBX-C the radial defects had been repaired, with the formation of lamellar bone and recanalisation of the marrow cavity. Our findings suggest that G-RBX-C may be useful in the treatment of chronic osteomyelitis

We have examined whether primary human muscle-derived cells can be used in ex vivo gene therapy to deliver BMP-2 and to produce bone in vivo. Two in vitro experiments and one in vivo experiment were used to determine the osteocompetence and BMP-2 secretion capacity of cells isolated from human skeletal muscle. We isolated five different populations of primary muscle cells from human skeletal muscle in three patients. In the first in vitro experiment, production of alkaline phosphatase by the cells in response to stimulation by rhBMP-2 was measured and used as an indicator of cellular osteocompetence. In the second, secretion of BMP-2 was measured after the cell populations had been transduced by an adenovirus encoding for BMP-2. In the in vivo experiment, the cells were cotransduced with a retrovirus encoding for a nuclear localised β-galactosidase gene and an adenovirus encoding for BMP-2. The cotransduced cells were then injected into the hind limbs of severe combined immune-deficient (SCID) mice and analysed radiographically and histologically. The nuclear localised β-galactosidase gene allowed identification of the injected cells in histological specimens. In the first in vitro experiment, the five different cell populations all responded to in vitro stimulation of rhBMP-2 by producing higher levels of alkaline phosphatase when compared with non-stimulated cells. In the second, the five different cell populations were all successfully transduced by an adenovirus to express and secrete BMP-2. The cells secreted between 444 and 2551 ng of BMP-2 over three days. In the in vivo experiment, injection of the transduced cells into the hind-limb musculature of SCID mice resulted in the formation of ectopic bone at 1, 2, 3 and 4 weeks after injection. Retroviral labelling of the cell nuclei showed labelled human muscle-derived cells occupying locations of osteoblasts in the ectopic bone, further supporting their osteocompetence. Cells from human skeletal muscle, because of their availability to orthopaedic surgeons, their osteocompetence, and their ability to express BMP-2 after genetic engineering, are an attractive cell population for use in BMP-2 gene therapy approaches

Aims

To test the hypothesis that reseeded anterior cruciate ligament (ACL)-derived cells have a better ability to survive and integrate into tendon extracellular matrix (ECM) and accelerate the ligamentization process, compared to adipose-derived mesenchymal stem cells (ADMSCs).

1. A patient with ectopic bone in the upper arm associated with multiple congenital anomalies is reported. 2. The previous cases of congenital abnormalities in patients with ectopic bone formation have been indicated and the problem of etiology has been discussed

A case of bilateral myositis ossificans in the biceps femoris muscles causing a sciatic nerve palsy on the left side is described. Complete recovery of the sciatic nerve followed excision of the mass of ectopic bone. It is postulated that the patient's hobby of weight-lifting caused the ossification

1. The phosphonates are simple chemical compounds containing P-C-P bonds which are resistant to the action of naturally occurring phosphatases and pyrophosphatases. They inhibit the formation and dissolution of apatite crystals in vitro and prevent ectopic mineralisation and bone resorption in animals. 2. In man one diphosphonate (EHDP) has been shown to reduce the excessive turnover of bone in Paget's disease and also appears to slow the mineralisation of ectopic bone matrix in myositis ossificans progressiva. 3. The possible uses of the diphosphonates in bone disorders with excessive resorption and in ectopic mineralisation are being further investigated

We have developed an animal model to examine the formation of heterotopic ossification using standardised muscular damage and implantation of a beta-tricalcium phosphate block into a hip capsulotomy wound in Wistar rats. The aim was to investigate how cells originating from drilled femoral canals and damaged muscles influence the formation of heterotopic bone. The femoral canal was either drilled or left untouched and a tricalcium phosphate block, immersed either in saline or a rhBMP-2 solution, was implanted. These implants were removed at three and 21 days after the operation and examined histologically, histomorphometrically and immunohistochemically. Bone formation was seen in all implants in rhBMP-2-immersed, whereas in those immersed in saline the process was minimal, irrespective of drilling of the femoral canals. Bone mineralisation was somewhat greater in the absence of drilling with a mean mineralised volume to mean total volume of 18.2% (. sd. 4.5) versus 12.7% (. sd. 2.9, p < 0.019), respectively. Our findings suggest that osteoinductive signalling is an early event in the formation of ectopic bone. If applicable to man the results indicate that careful tissue handling is more important than the prevention of the dissemination of bone cells in order to avoid heterotopic ossification

Thirty-four patients wtih fibrodysplasia (syn., myositis) ossificans progressiva are described. Marked delay in diagnosis was usual, but all had characteristic skeletal malformations and ectopic ossification. The clinical features included: four types of malformation of the big toe, reduction defects of all digits, deafness, baldness of the scalp, and mental retardation. Progression of disability was erratic in all, but severe restriction of movement of the shoulder and spine was usual by the age of 10 years; the hips were usually involved by the age of 20 years; and most patients were confined to a chair by the age of 30 years. Exacerbating factors included trauma to the muscles, biopsy of the lumps, operations to excise ectopic bone, intramuscular injections, careless venepuncture and dental therapy. Progression of disability did not appear to be influenced by any form of medical treatment and therefore management of the patients must concentrate on the avoidance of exacerbating factors

Aims

The aim of the HIPGEN consortium is to develop the first cell therapy product for hip fracture patients using PLacental-eXpanded (PLX-PAD) stromal cells.

Aims

Heterotopic ossification (HO) is a common complication after elbow trauma and can cause severe upper limb disability. Although multiple prognostic factors have been reported to be associated with the development of post-traumatic HO, no model has yet been able to combine these predictors more succinctly to convey prognostic information and medical measures to patients. Therefore, this study aimed to identify prognostic factors leading to the formation of HO after surgery for elbow trauma, and to establish and validate a nomogram to predict the probability of HO formation in such particular injuries.

Aims

Acquired heterotopic ossification (HO) is a debilitating disease characterized by abnormal extraskeletal bone formation within soft-tissues after injury. The exact pathogenesis of HO remains unknown. It was reported that BRD4 may contribute to osteoblastic differentiation. The current study aims to determine the role of BRD4 in the pathogenesis of HO and whether it could be a potential target for HO therapy.

Post-traumatic elbow stiffness is a disabling condition that remains challenging for upper limb surgeons. Open elbow arthrolysis is commonly used for the treatment of stiff elbow when conservative therapy has failed. Multiple questions commonly arise from surgeons who deal with this disease. These include whether the patient has post-traumatic stiff elbow, how to evaluate the problem, when surgery is appropriate, how to perform an excellent arthrolysis, what the optimal postoperative rehabilitation is, and how to prevent or reduce the incidence of complications. Following these questions, this review provides an update and overview of post-traumatic elbow stiffness with respect to the diagnosis, preoperative evaluation, arthrolysis strategies, postoperative rehabilitation, and prevention of complications, aiming to provide a complete diagnosis and treatment path.

Cite this article: Bone Joint Open 2020;1-9:576–584.

Aims

Heterotopic ossification (HO) is a potentially devastating complication of the surgical treatment of a proximal humeral fracture. The literature on the rate and risk factors for the development of HO under these circumstances is lacking. The aim of this study was to determine the incidence and risk factors for the development of HO in these patients.

Aims

Total ankle arthroplasty (TAA) surgery is complex and attracts a wide variety of complications. The literature lacks consistency in reporting adverse events and complications. The aim of this article is to provide a comprehensive analysis of each of these complications from a literature review, and to compare them with rates from our Unit, to aid clinicians with the process of informed consent.

Aims

Shoulder arthroplasty using short humeral components is becoming increasingly popular. Some such components have been associated with relatively high rates of adverse radiological findings. The aim of this retrospective review was to evaluate the radiological humeral bone changes and mechanical failure rates with implantation of a short cementless humeral component in anatomical (TSA) and reverse shoulder arthroplasty (RSA).