Myositis Ossificans Also known as localized myositis ossificans, extra osseous localized non neoplastic bone and cartilage formation, myositis ossificans traumatica, myo-osteosis, myositis ossificans circumscripta, traumatic ossifying myositis and ossifying haematoma. Reactive lesion occurring in soft tissues and at times near bone and periosteum.

Myositis Ossificans It is characterized by fibrous, osseous and cartilaginous proliferation and by metaplasia. The term myo and itis is a misnomer because skeletal muscle is often not involved and inflammatory changes are rarely evident. Also in early phase of evolution, formation of bone may not be observed, so term ossificans is not always applicable.

Myositis Ossificans Most if not all, have a history of trauma, simple severe blow or series of repeated minor traumas. Condition may be classified according to its location as extra osseous, periosteal or parosteal. Haematoma seems to be necessary prerequisite. Muscles most often involved are brachialis, quadriceps femoris and adductor muscles of thigh. It is significant that these muscles gain attachment to bone over a wide surface area, suggesting that periosteum participates to some extent in the process.

Myositis Ossificans Young athletic men are predisposed. Region of elbow is a favorite site, and when the process appears to restrict elbow motion progressively, ill advised forcible manipulation will cause a widespread involvement.

Pathogenesis Muscle is commonly but not invariably involved, and fascia, tendon and periosteum can also be the site. Process is peculiar alteration within the ground substance of connective tissue, associated with striking proliferation of undifferentiated mesenchymal cells.

Pathogenesis Initially there is degeneration and necrosis, in case of muscle, disrupted muscle fibers retract. In 3 to 4 days, fibroblasts from endomysium invade

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damaged area and rapidly form broad sheets of immature fibroblasts. At the same time, primitive mesenchymal cells proliferate within injured connective tissue. Intense cellular proliferation of fibroblasts and mesenchymal cells produces a histological picture that may be erroneously diagnosed as fibrosarcoma or myosarcoma.

Pathogenesis Ground substance becomes homogeneous or glassy or waxy, suggesting some type of edema. It increases in in amount and encloses some of mesenchymal cells, which then assume the morphological characteristic of osteoblasts. Mineralization follows and bone is formed. This events typically takes place first within least damaged part i.e. periphery. As the process of osteoid formation and mineralization changing in mature bone evolves, it progressively extends towards the central, severely damaged area.

Pathogenesis Any trauma that produces haematoma beneath the periosteum or damages it sufficiently to elevate it, will produce highly cellular proliferation in space between periosteum and bone; osteoid develops and is rapidly converted to bone. When myositis is not removed and is allowed to mature, it becomes oriented and covered by a cartilaginous cap, because of muscle action over the lesion. This is called post traumatic osteochondroma and is common in region of knee joint.

Clinical picture Result of single or repeated trauma. Brachialis is a favorite site after posterior dislocation of elbow. Elbow is quite swollen and tender and active as well as passive motion is restricted. As pain and swelling decreases, a circumscribed, indurated, later hard tumor mass is palpable. Active extension of joint is limited due to inelasticity of muscle, and flexion is prevented by obstruction by the mass.

Clinical picture Ossification in deltoid is common in foot soldiers due to trauma caused by carrying a rifle. The constant pressure of saddle against the adductors in riders causes ossification in adductors. This syndrome is known as Prussian disease. Myositis ossificans is self limited, undergoes maturation and may persist as a hard ossified mass, usually within a muscle or fixed to adjacent long bone. In some cases it undergoes almost complete regression.

Diagnosis Totally excised lesion or deep biopsy will demonstrate zoning effect. Central area with numerous cells of various shapes and sizes and occasional mitotic figures. Next zone shows osteoid

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formation with a fibrovascular background. This is more advanced stage, cells are more uniform, indicating a benign lesion. In outer zone, trabeculae of well formed bone and more mature fibrous stroma are observed.

Treatment Growth should not be removed in premature stage as it is disastrous. The ossification becomes exuberant, infiltrates beyond the original site, and compresses the soft tissues around beyond hope of repair. When after serial x-rays the mass is dense, well delineated, and at a stand still, it may be safely removed. It may be possible to prevent myositis by aspirating the original haematoma.

Myositis ossificans progressiva Congenital condition that starts without antecedent trauma before or shortly after birth. Consists of frequently repeated episodes of sudden extension of ossification in muscles, fascia, tendons and aponeuroses. Raised eosinophil count. Ossification usually starts with the upper back muscles, trapezius, latissimus dorsi, and spreads distally involving soft tissue structures throughout the body.

Myositis ossificans progressiva IP joint of thumb, large toe and spine are liable to fuse. All joint motion is finally lost and patient dies of inter current infection. This condition is very rare. There is no known effective treatment. Corticotrophin seems to have some deterrent effect on heterotrophic bone formation. Eosinophil count drops and joint motion may even increase.

Tennis elbow Chronic disabling pain in elbow, around radio humeral joint, is called tennis elbow rather than epicondylitis or radio humeral bursitis in view of lack of specificity regarding its origin.

Tennis elbow-Etiology Common in people whose occupation require frequent rotary motion of forearm e.g. tennis players, pipe fitters and carpenters.

Tennis elbow-Clinical picture Onset is gradual.

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Pain appears over outer aspect of elbow and is referred to forearm. It is persistent and intensified by grasping or twisting motions. In short, all muscles required for grasping and supination which originate from lateral epicondyle, epicondylar ridge and a few fibers from anterior capsule of elbow joint.

Tennis elbow-Clinical picture Well localized point of tenderness at either epicondylar ridge, lateral epicondyle, lower edge of capitellum anteriorly, laterally over radio humeral space or one area in the circumference of radial head during rotation of forearm. Range of motion is normal. There is weak grasp and dropping of objects particularly with forearm pronated.

Tennis elbow-Clinical picture Pain can be reproduced by completely extending the elbow, pronating forearm and forcibly flexing wrist. Active attempts of dorsiflexion of the wrist and supinate the forearm against resistance will likewise intensify the pain. The condition infrequently involves the medial epicondyle where pain is intensified by strong grasping, active flexion of wrist and pronation of forearm against resistance. This is called Golfer’s elbow or medial epicondylitis.

Tennis elbow-X-Ray X-rays are usually negative. Occasionally a small flake of bone anterior to the epicondyle suggests an avulsion or surface of epicondyle may be roughened as an indication of Peri Osteitis.

Tennis elbow-Pathology Actual pathology is unknown. May be caused by tearing of tendon fibers from their attachment to epicondyle . The constant muscle contractions prevent healing, creating a traumatic Peri Osteitis. Annular ligament undergoes hyaline degeneration and may be the source of pain.

Tennis elbow-Treatment Conservative treatment is effective in most cases but recurrence is common. Rest : Complete rest with posterior moulded cast or splint, maintaining relaxation of extensors by flexion at elbow, supination and extension at wrist. This should be removed daily for gentle exercises to avoid elbow stiffness.

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Tennis elbow-Treatment Heat : Moist compresses or SWD is used. LAHC : Multiple punctures are made in tender area and either steroid alone or a combination of steroid and local anesthetic is injected and repeated at intervals of 1 to 2 weeks for 3 to 4 doses. Radiation therapy : 3 sittings of 200 rads in air to each of three fields-anterior, posterior and lateral. One field is treated every other day.

Tennis elbow-Treatment Manipulation : Principle is to convert the partial tear of conjoined tendon into a complete tear, thereby detaching the tendon from chronically inflamed periosteum. Technique : Elbow flexed and forearm supinated, epicondyle is massaged for 10 minutes. Then elbow is fully extended and forearm forcibly adducted to create varus position. This is repeated every 2 or 3 days; about 4 treatments are sufficient to provide relief.

Tennis elbow-Treatment Technique : While the fingers and wrist are held fully flexed and forearm pronated, the elbow is forced into full extension while firm pressure is applied with thumb over the tender epicondyle. Miscellaneous : Ultrasonic therapy gives equivocal results. Phenylbutazone produces excellent results but it is not recommended due to its potential toxicity.

Tennis elbow-Treatment Surgical treatment usually gives immediate and lasting relief. It is indicated when conservative treatment fails. Technique : Under tourniquet, curved linear longitudinal incision made just posterior to lateral epicondyle. Deep Fascial covering over conjoined tendon is divided transversely. IM septum is also divided. Conjoined tendon is severed at the epicondyle, epicondylar ridge and remaining fibers detached by subperiosteal elevation.

Tennis elbow-Treatment Conjoined tendon and extensor muscles are allowed to displace distally. Lateral incision into joint anterior to collateral ligament exposes the capitellum and radial head. A portion of annular ligament is cut. Only skin and SC tissue are closed and elastic compression bandage is applied and immediate joint motion permitted. Removal of annular ligament is optional and does not affect stability.

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Tennis elbow-Treatment Denervation : Under cover of brachioradialis muscle, radial N gives off a branch that can be traced to periosteum of lateral epicondyle. After exposure of radial N, it is lifted gently and articular branches are identified and excised from anterior and lateral surface of epicondyle. Postoperatively injection of periosteal and articular branches are blocked with local anesthetic to test the effectiveness of denervation.

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