ELBOW HETEROTOPIC OSSIFICATION
Elbow heterotopic ossification (EHO) is a formation of bone around the elbow joint that usually develops after a traumatic injury and can affect the biomechanics of the elbow joint (Casavant & Hastings, 2006). It should be noted that heterotopic ossification can occur in muscle, skin, subcutaneous tissue, fibrous tissue, yet rarely in the walls of blood vessels, intra- abdominal sites (mesentery). Genetic (fibrodysplasia ossificans progressiva and progressive osseous heteroplasia), post- traumatic, neurogenic (head trauma or spinal cord injuries), post surgical (open reduction, internal fixation or joint replacement surgeries), and reactive to lesions of hands are five clinical settings that the EHO can be developed. In addition, research depicts that there is no systemic effects due to EHO (PhysioPedia, 2010). On the other hand, risk factors that are related to EHO are: circulatory stasis, infection, joint manipulation, post-operative immobilization, and bone demineralization from prolonged bed rest or assisted ventilation (Loma Linda University, 2009).
Following an elbow injury related to trauma, brain injury, and/ or spinal cord injury there is a 10- 20% incidence of clinical EHO significance. Sustained elbow dislocation along the radial head fracture is the most common elbow disorder that EHO can be seen (Casavant & Hastings, 2006). Around 1-3% burn patients are affected, yet the research depicts a prevalence rate between 15-35% (Casavant & Hastings, 2006, Chen et al. 2009, and Loma Linda University, 2009).
3. Pathology Description
The pathogenesis of EHO is still controversial. Two potential mechanisms of ectopic bone formation are though a traumatic brain injury or trauma. In case of traumatic brain injury, firstly systemic factors are released such as bone morphogenetic proteins, growth hormone, growth factor type -1 and basic fibroblast growth factor. Secondly, mesechymal stem cells stimulation occurs, which can result in continued formation of new bone around the injured area (osteoblast formation). Alternatively, in case of direst trauma (fracture), firstly local stimulating factors are released. Secondly, there are environmental and Ph changes (alkalosis) and tissue hypoxia which then can lead to mesenchymal cell stimulation which at the end will result in new bone formation (PhysioPedia, 2010). Limb spasticity, pressure sores and infections can increase EHO. (Loma Linda University, 2009). Ankylosis spondylitis, rheumatoid arthritis, hypertrophic osteoarthritis, Paget’s disease(metabolic bone disease due to activation of osteclasts), paraplegia and quadriplegia are common conditions that EHO can be seen (PhysioPedia, 2010).
4. Clinical signs and symptoms as a consequence of pathological changes
Two weeks after trauma, burn, neurologic insult, or surgery an ectopic ossification can be developed. Localized swelling, increased warmth, tenderness and pain are early clinical symptoms. After early clinical symptoms subside, there is a progressive loss of range of elbow movement in spite of dynamic and/ or static progressive splinting. Initially, there is a soft tissue restriction of elbow flexion and extension. After 3 to 9 months following an injury, there is a rigid end feel (ossification matures) accompanied with pain at the end of range. Nerve palsies can be present of the ulnar (the most common), median and radial nerve lesions or compressions, which can be linked with ectopic ossification at the elbow (Casavant & Hastings, 2006). Anterior (coronoid, humeoulnar/ radial, soft tissue, muscular, and capsular) and Posterior (olecranon fossa, humeroulnar bridge) elbow areas and collateral ligaments (medial and lateral) are common sites of ectopic ossification at the elbow. EHO can be classified into:
Class 1 which contains no functional ROM limitations.
Class 2 which contains limitations in elbow flexion/ extension or supination/ pronation, and
Class 3 which contains ankylosis appearance which prevents elbow flexion/ extension and/ or supination/ pronation (Casavant & Hastings, 2006).
5. Medical Investigation/Diagnostic tools
Diagnostic tools used for EHO are:
Delayed treatment of EHO can be associated with limitation of a simple objective measure (PhysioPedia, 2010).
6. Medical/Surgical/Pharmaceutical/Multidisciplinary Management
The amount of ectopic bone formation, the location and the associated functional limitations of the patient can determine the appropriate management regime for EHO. Prophylactic treatment should be administrated, especially to patients with sustained massive elbow injury or elbow injury accompanied with some risk factors mentioned above. NSAIDS such as Indomethacin and Biophosphonates could be prescribed to prevent the ectopic ossification development (Casavant & Hastings, 2006 and PhysioPedia, 2010).
Furthermore, surgical intervention and radiation therapy are two frequent management EHO approaches used. Surgical intervention goals are mainly to improve range of motion and/ or alter biomechanics of the elbow joint (PhysioPedia, 2010).
The location of the heterotopic bone and its relation to normal structures should guide the surgical procedure. There are 4 main surgical approaches which are the:
Posterior intervention which is suggested to avoid traumatizing previous damaged skin,
Posterolateral intervention which is suggested for extreme flexion in an ankylosis patient,
Medial intervention which is suggested for a heterotopic bone that is extended medially, and
Anterolateral intervention is suggested for post- operative hematomas (Loma Linda University, 2009).
Radiation therapy pre- or postoperative (dosage: 700-800 cGy) on the pluripotential mesencymal cells may prevent EHO, yet can be linked with better functional and radiographic results (Heyd et al. 2010, PhysioPedia, 2010, and Robinson et al. 2009).
Physiotherapy management of EHO right after surgery can be divided into 4 main stages:
Casavant A. & Hastings H. (2006). Heterotopic ossification about the elbow: a ssstherapist’s guide to evaluation and management. Journal of Hand Therapy, 19, 255–sss67.
Chen Hung-Chang, Yang Jui-Yung, Chuang Shiow-Shuh, Huang , Chun-Yuan
sssYang Shih-Yi. Heterotopic ossification in burns: Our experience and
sssliterature reviews. Burns, 35, 857-862.
Heyd R, Buhleier T, Zamboglou N. (2009). Radiation therapy for prevention of sssheterotopic ossification about the elbow. Strahlenther und Onkol,185, 506–11.
Loma Linda University. (2009). Heterotopic ossification about the elbow: repair and sssrehabilitation. California: Kaiser Permanente Southern California
Monday, March 26, 2012
What is Elbow Heterotopic Ossification ?
This is an elbow pathology that I personally prepared for the university. Enjoy!