Myositis ossificans traumatica of the deltoid ligament in a 34 year old recreational ice hockey player with a 15 year post-trauma follow-up: a case report and review of the literature.
Abstract: Myositis ossificans traumatica is a relatively common injury associated with sports especially those involving contact. It continues to frustrate both athlete and health practitioner alike due to its continued lack of treatment options and a lengthy natural history. This case study chronicles the observation of a 34 year old recreational ice hockey player who presented 7 years post-trauma, was diagnosed with myositis ossificans traumatica and was followed up on 8 years later (15 years post-trauma). This case report is suspected to be the first published case study of its kind. The literature review outlines the various types of myositis ossificans, its incidence, pathogenesis, differential diagnoses including osteosarcoma, and the various methods/modalities reported in its treatment.

(JCCA 2010; 54(4):229-242)

KEY WORDS: myositis ossificans traumatica, heterotopic ossification, post-traumatic myositis ossificans, ice hockey, deltoid ligament

La myosite ossifiante traumatique est une blessure relativement courante liee a la pratique des sports, particulierement les sports de contact. Elle continue de frustrer les athletes et les professionnels de la sante en raison de l'absence d'options de traitement et du fait qu'elle existe depuis longtemps. Cette etude de cas raconte l'observation d'un joueur de hockey sur glace de ligue recreative de 34 ans qui recut un diagnostic de myosite ossifiante traumatique apres 7 ans, et qu'on examina ensuite 8 ans plus tard (15 ans apres le traumatisme), Cette etude de cas est probablement la premiere en son genre. Une analyse de la documentation a ce sujet souligne les divers types de myosite ossifiante, sa frequence, sa pathogenie, les differents diagnostics, notamment l'osteosarcome, et les diverses methodes/ modalites signalees dans son traitement.

(JCCA 2010; 54(4):229-242)

MOTS CLES : myosite ossifiante traumatique, ossification heteropique, myosite ossifiante posttraumatique, hockey sur glace, ligament deltoide
Article Type: Case study
Subject: Hockey players (Health aspects)
Myositis (Case studies)
Myositis (Care and treatment)
Myositis (Diagnosis)
Author: Muir, Brad
Pub Date: 10/01/2010
Publication: Name: Journal of the Canadian Chiropractic Association Publisher: Canadian Chiropractic Association Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2010 Canadian Chiropractic Association ISSN: 0008-3194
Issue: Date: Oct, 2010 Source Volume: 54 Source Issue: 4
Geographic: Geographic Scope: Canada Geographic Code: 1CANA Canada
Accession Number: 259589965
Full Text: Introduction

Myositis ossificans traumatica (MOT) is often defined as heterotopic, non-neoplastic proliferation of bone in an area previously exposed to trauma and hematoma. (1,2)

The most common areas that are affected by MOT are the quadriceps femoris, brachialis anticus, and the adductor muscles of the thigh (3) although it may occur anywhere. It can happen at any age, but occurs most frequently in adolescents and young athletes, with over half of the cases occurring in the third decade. (1,3) MOT is considered rare in children under 10 years of age (1) and males are more often affected than females. (3)

The incidence of MOT following quadriceps contusions is reported at varying percentages depending on the severity of the injury. Mild contusions have shown an incidence of MOT of 0-9%, moderate to severe 17-72% and recurrent contusion 100%. (4,5) Contusions of the thigh are generally graded according to the subsequent loss of range of motion at the knee joint. Contusions are graded as mild (active ROM greater than 90[degrees]), moderate (45-90[degrees]) and severe (less than 45[degrees]). (5) Arrington6 grades thigh contusions as: mild--near normal ROM, local tenderness, no gait abnormality; moderate--swollen tender muscle, 75% ROM, antalgic gait; and severe--marked tenderness/ swelling, 50% ROM with a severe limp. Muscle contusion injuries are second only to strain injuries as a major cause of morbidity in the modern athlete. (2)



This paper presents a case study of a 34 year old recreational ice hockey player who was diagnosed with MOT of the deltoid ligament of the ankle 7 years post-trauma and followed up on 8 years later (15 years post-trauma).

Case Report


A 34 year old recreational hockey player presented with an unusual bony lump just anterior and inferior to his left medial malleolus (see Figure 1 and 2). He reported that the lump had started following blocking a shot in a hockey game 7 years previously. He was able to finish the game and had partial weightbearing following the game. The foot became increasingly swollen and was treated with rest and ice. No radiographs were taken at the time of the initial injury. He reported that the lump had increased in size slowly over the next few years. Two years after the injury, he had returned to play competitive hockey and didn't recall any limitation although the lump had not resolved. Four years post injury, he began to notice the lump was larger and was becoming increasingly irritated from the direct pressure of tightening his skate laces. He was also getting sharp pain in his foot with pivoting while skating and noticed decreased range of motion especially in dorsiflexion. Seven years post-injury, he began to notice increased pain when turning around pylons while demonstrating drills as a hockey coach. Stopping, and backward skating had also become painful and pivoting was still difficult due to pain. He also noted increasing difficulty going up stairs and felt he had to lift his leg higher to get his foot flat on the next stair. At this point, he presented to the clinic for examination and possible imaging.

There was no history of recent infection, sudden unexplained weight loss or night pain. Systems review revealed a history of seasonal bronchitis but was otherwise unremarkable. Previous medical history revealed a previous right shoulder surgery for recurrent subluxation but no other major traumas or motor vehicle accidents. He did not report any previous injury to the left foot or ankle. Family history did not reveal anything relevant. He is an otherwise healthy individual who exercises regularly and does not smoke. This patient is a factory worker and a part-time hockey coach.


He did not report any numbness or tingling in his foot or ankle.

Physical examination

Upon examination, the patient was able to ambulate normally. A visible prominence was noted anterior and inferior to the medial malleolus of his left foot. Active and passive range of motion revealed a decrease of 40% in dorsiflexion, inversion and eversion due to restriction not pain. Plantar flexion was decreased 10-20% due to soft tissue restrictions. (The patient felt he could go further but was tight and no bony end feel was noted.) Joint play of the midtarsal joints was within normal limits. Other ranges of motion were full and pain free. Strength was slightly decreased compared to the right side in all ranges but there was no pain. Palpation of the bony mass revealed some point tenderness but the foot and ankle were otherwise pain free. Radiographs and a CT were ordered for this patient at this point in the examination (see Figure 3-6).


The patient was subsequently diagnosed with myositis ossificans traumatica of the left deltoid ligament of the ankle.


Plan of management

The initial plan of management for this patient was to rule out any insidious diagnosis, including osteosarcoma, with the imaging. The diagnosis of osteosarcoma was unlikely due to the slow, progressive nature of the injury and its lack of pain but it was felt imaging was prudent in this case. Following the diagnosis, the patient was informed of the natural history of MOT and that there were few proven treatment options available at that time. Due to the relatively minor irritation experienced during hockey and activities of daily living the patient was not interested in surgery and decided to treat the area symptomatically with ice and rest as needed. A "wait and see" approach was taken with instructions that if the lump was increasing in size and/or pain that the patient was to return for further examination.

15 Year Follow-up

The patient, now 42 years old, was contacted to follow-up on his status. The patient reported that he felt there was little change in the size of the lesion on his left ankle. He still had similar restrictions with regard to his on-ice activities including quick pivoting and demonstrating drills and his activities of daily living including going up stairs. He felt these activities were difficult due to his decreased ability to dorsiflex his ankle. The patient reported that he had learned to avoid certain aggravating activities because of the length of time of his injury. No follow-up physical exam was performed. Radiographic images were obtained at follow-up. The follow-up radiographs show that little change has occurred in the size of the MOT as visualized (see Figure 7 and 8).



Types of Myositis Ossificans

Heterotopic bone formation in soft tissue has historically been classified as myositis ossificans. Many authors now consider the term myositis ossificans to be a misnomer arguing that there is no inflammatory process and the condition may or may not involve bone or muscle tissue. (7,8) Myositis ossificans consists of three main types--congenital, idiopathic, and traumatic (see chart 1). Myositis ossificans traumatica (MOT) is also known in the literature by specific names given to MOT in specific areas of the body (see chart 2). (3,7,9,10) Arrington (6) classifies MOT into three types as does Mestan and Bassano (see chart 3). (10)

The pathogenesis of this injury remains unclear at this time. Some of the common theories include: (10)


1. transformation of muscle hematoma to bone;

2. hematoma calcification;

3. intramuscular bone formation from detached periosteal flaps;

4. osteoblast proliferation from periosteal rupture;

5. metaplasia of intramuscular connective tissue cells;

6. individual predisposition.

It is believed that blunt trauma to the extremity creates a compression wave travelling through soft-tissue crushing the deepest muscle against the bone. The force is transmitted through the fluid compartment of all of the layers of muscles but the damage usually occurs in the layer that is next to the bone. (5)


Wang (7) suggests that there are several steps following the injury to the tissue that leads to the development of MOT. There is cellular damage causing necrotic debris that is subsequently removed through the invasion of histiocytes. Fibroblasts from the endomysium then assail the injured cells and mesenchymal cells begin to proliferate. The fibroblasts and mesenchymal cells produce osteoid and chondroid tissue that lays down the groundwork for the formation of bone within the damaged tissue. This can occur as early as 4 to 5 days after the injury has occurred.


A particularly important aspect of MOT occurs at this stage and is critical to the differentiation of MOT and osteosarcoma. The previously mentioned steps begin in the least damaged area moving toward the area of most damage. As a result, lamellar new bone is laid down in a centripetal pattern that is referred to as "the zonal phenomenon" (see Figure 9). (7,11)

Zonal phenomenon seems to be first mentioned by Ackerman in 1958.11 He states, "I have been impressed by what I have designated as zone phenomena (inner, middle and outer zones)." He further states, "... they are well documented in examples of classic myositis ossificans, but no one has mentioned it, probably because the process is often recognized by typical histories and locations." (11)

Beginning in the second week to second month, bone is formed surrounding the area and then moves inward toward the site of injury giving layers of varying tissue activity. Moving inward, the outside layer is bone, the middle layer is an area of extensive osteoblastic and fibroblastic activity, and the central layer is an area of highly cellular tissue with a lot of cell differentiation and necrotic cells. (7,8) Osteosarcoma does not show this zonal phenomenon. The calcification seen with osteosarcoma begins in the central areas of the tumour. Unfortunately, if a biopsy of the area is done and the majority of the cells come from the middle and central layers, an incorrect diagnosis of osteosarcoma can been made and improper treatment has followed, including amputation. (3,12)


Typical Patient Presentation

A typical patient presentation includes a history of trauma to the affected area with increased difficulty in moving and using the affected limb. In football, an opposing player's helmet to the thigh and in hockey and soccer, an opposing players knee to the thigh are common mechanisms of injury. (12) Trauma (direct and repetitive) is reported in 60-70% of the cases. (3) As previously mentioned the onset seems to be related to the severity of the injury.

In our case, the athlete reported a severe, yet common cause of trauma (blocking a shot). However, he did not feel it was severe enough to get a radiograph or seek treatment at the time of the injury.

A clinician should initially suspect the early stages of MOT if the pain, swelling and tenderness of the affected area has not responded to conservative management within the first 4-5 days. (12) This suspicion should increase further if the athlete reports that the symptoms have not improved significantly or have worsened within 10-14 days of the injury. (12)

A physical examination of an athlete suspected of having MOT begins with observation. If the injury is to the lower limb, particularly the thigh, an antalgic gait with limited weight bearing of the affected limb will often be noted as the athlete enters the treating room. The athlete will often have difficulty getting into the seated position due to an inability to flex the adjacent joints. A significant superficial hematoma is often noted with palpable tenseness of the affected area. However, a deep intramuscular hematoma may not produce visual signs of injury but should be suspected in cases of a severe blow to the limb.

Active, passive and resisted range of motion will be notably decreased in the affected limb with more severe injuries. In our case, the athlete's ankle range of motion was restricted but he was still able to function in his activities of daily living. While playing hockey, he reported that he was still able to play but certain movements while skating were difficult. Booth reports that muscle atrophy may be noted with persistent local tenderness and loss of range of motion. (12) There was no muscle atrophy noted in our case.

Beauchesne reported a case of MOT of the piriformis in a patient that fell down the stairs. (13) The patient presented with radicular symptoms of the lower limb including paresthesias and decreased sensation on the lateral border of the left foot as well as weakness in the left ankle. Our patient did not present with any lack or change in sensation.

Hyder reported a case of MOT of the tibialis anterior in a 31 year old man 14 years post injury. (14) The man presented with extreme limitation of ankle movements with some pain in the leg, especially with walking.

In another case report by Mestan and Bassano, a 54 year old man presented with acute pain localized to the middle aspect of his left lower leg after a log rolled onto it.10 The patient was subsequently diagnosed with a fracture of a previous heterotopic bone formation secondary to a karate injury 32 years previously.

Booth identifies three important criteria to consider when diagnosing MOT. (12) These include:

1. a history of significant local injury;

2. clinical and radiological evidence of ossification within 2 months of the initial injury;

3. the location of the lesion in proximal limb areas more commonly associated with MOT including the brachialis anticus and quadriceps femoris.

Other reasonable differential diagnoses include: (8) extraosseous osteosarcoma, synovial osteosarcoma, osteochondroma, posttraumatic periostitis, osteomyelitis, and tumoral calcinosis. There have been cases of osteosarcoma that have developed from traumatic myositis ossificans but it is very rare. (1) Aboulafia reported a case of osteosarcoma arising from heterotopic ossification that occurred as a result of an electrical burn 10 years previous. (15) (Chart 3 provides a differential diagnoses between MOT and osteosarcoma).

There are several risk factors that have been identified in those athletes that have developed MOT. These are described in Table 1.


Natural History

MOT is generally considered to be a self-limiting condition and can have spontaneous resolution. (1,3,16) Hamida reports that without treatment the radiological and clinical findings will have stabilized and/or resolved within 1.5 to 3 years following the onset of symptoms. (16) Danchik notes that within 4 to 6 months, the lesion has stabilized. (3) Full reabsorption can take place especially in lesions occurring within the muscle belly. (3) Lesions located near an origin or insertion of a muscle are less likely to reabsorb and may result in functional impairment. (3) Parikh reports that full reabsorption is more likely to occur in smaller upper extremity lesions compared to a larger lesion located in the lower extremity. (1) Le Roux noted that smaller upper extremity lesions were more likely to reabsorb except for those lesions occurring at the elbow. (8) There are several medical management options that are used for MOT. These are listed in Table 2.


There is little to be done once the process of MOT has been initiated. (10,12) However, as a sport medicine clinician that may be responsible for the diagnosis and treatment of MOT in athletes, there are several areas in which the proper management of the risk factors may decrease the possibility of its onset. These include:

1. early consideration of MOT as a differential diagnosis and the proper management of the hematoma (see Post Injury Protocol);

2. protection of the athlete from recurrent injury to the area by restriction of return to play and the addition of extra padding when the athlete does return. Some authors recommend extra protection 3 to 6 months post injury; (17)

3. education of the athletes on the causes and consequences of MOT and the importance of early treatment in its possible prevention. This should occur after an injury and also prior to the season before serious contusions are likely to occur.

Fracture of the myositis ossificans is rare but has been reported. (10) Care should be taken to protect existing cases of MOT from fracture in those athletes that have returned to play and are at an increased risk of significant injury to the area.

Post Injury Protocol

Ryan investigated post injury protocols and the incidence of myositis in 117 contusions at West Point. (5) In a previous study done by Jackson and Feagin at West Point in 1973, early knee extension was emphasized. (4) In the 1991 study, early return of knee flexion was emphasized in an effort to reduce the disability and incidence of myositis ossificans.

Of the 117 contusions, 71 were mild, 38 were moderate and 8 were classified as severe. Their protocol consisted of 3 phases: Phase I--the limitation of hemorrhage with RICE. Weightbearing was to tolerance with crutches if necessary. The hip and knee were immobilized in flexion to pain tolerance as opposed to extension. The patient was advanced to the next phase when they were pain-free at rest and their thigh girth had stabilized; Phase II--the restoration of motion with emphasis on knee flexion and continued RICE as necessary. The patient was advanced to the next phase when their pain-free active knee range of motion was greater than 120[degrees] and their thigh girth was equal bilaterally; Phase III--functional rehabilitation emphasizing the return of strength and endurance with always pain free cycling, swimming, walking and jogging. The patient was advanced to full activities if they had full active range of motion, full squat, and all other activities were pain free. They were to wear extra thigh protection for 3 to 6 months for all contact sports. It is interesting to note that mild and moderate quadriceps contusions were treated daily and severe contusions were treated twice daily. (5)

The results of this study showed that average disability time was reduced for moderate (19 versus 56 days) and severe (21 versus 72 days) contusions but increased for mild contusions (13 versus 7 days). The incidence of MOT occurring was 11 of 117 (9%) following contusions overall (mild contusion 3 of 71 (4%), moderate 7 of 38 (18%) and severe 1 of 8 (13%)). Compared to the 1973 study, there was a reduction in overall incidence from 20% to 9% and in severe contusions 72% to 13%. (4,5)

Extracorporeal Shock Wave

In a prospective study done by Buseli et al in 2010, three sessions of extracorporeal shock wave therapy was performed over a 6 week period occurring once every 2 weeks. (18) The shockwave was administered at 100 impulses per [cm.sup.2] of ossification at a medium power setting of 0.13 to 0.23 mJ/[mm.sup.2] in an effort to keep pain at a tolerable level. The shockwave treatments were started an average of 4 2.09 months after the trauma and treatment effectiveness evaluations were made at 1,2,3,6 and 12 months after the last treatment.

There was a complete clinical and functional resolution in 21 of the 24 athletes. Return to previous sport activity in these athletes occurred within the 12 months of follow-up. Interestingly, there were statistically significant improvements in range of motion and pain (visual analogue and Fischer algometer) but no significant difference in the size of the lesion with radiographic follow-up.

In our case, the athlete did not seek any assessment of the injury until 7 years post-trauma. Prior to that, he did not feel that his activities were restricted enough to seek assessment and/or treatment but now felt assessment was warranted.


The reporting of myositis ossificans traumatica (MOT) in the medical literature is, in general, a series of case reports that most commonly involve athletes but can range from injuries as a result of college fraternity hazing (19) to repetitive physical assault and battery found at autopsy (20) to subcutaneous injections (21) to falling down the stairs on the buttocks. (13) Previous MOT of the ankle in athletes has been reported as heterotopic ossification involving the interosseous membrane following a syndesmotic sprain in football players. (22) To our knowledge, the present case study is the first report of MOT involving the deltoid ligament of the ankle following blunt trauma from a hockey puck in a recreational ice hockey player.

MOT must be carefully examined and must be properly diagnosed due to its similarity in presentation to osteosarcoma. (10,17,23) An inappropriate diagnosis can lead to devastating results for the patient.

Until recently, there have been very few new approaches to the treatment of MOT other than prevention (10,12) and a proper post injury protocol (5). Buselli et al have shown extracorporeal shock wave to have some real potential as a viable treatment option for athletes suffering from MOT. (18) More studies are needed in an effort to determine the most effective dose/response ratio for the use of shock wave in its treatment of MOT.


(1) Parikh J, Hyare H, Saifuddin A. The imaging features of post-traumatic myositis ossificans, with emphasis on MRI. Clin Radiol. 2002; 57(12):1058-66.

(2) Beiner JM, Jokl P. Muscle contusion injury and myositis ossificans traumatica. Clin Orthop. 2002; 403S:S110-9.

(3) Danchik JJ, Yochum TR, Aspegren DD. Myositis ossificans traumatica. J Manipulative Physiol Ther. 1993; 16(9):605-14.

(4) Jackson DW, Feagin JA. Quadriceps contusions in young athletes. J Bone Joint Surg [Am]. 1973; 55-A:95-105.

(5) Ryan JB, Wheeler JH, Hopkinson WJ, Arciero RA, Kolakowski KR. Quadriceps contusions. West Point update. Am J Sports Med. 1991 May-Jun;19(3):299 304.

(6) Arrington ED, Miller MD. Skeletal muscle injuries. Orthop Clin North Am. 1995; 26(3):411-22.

(7) Wang SY, Lomasney LM, Demos TC, Hopkinson WJ. Radiologic case study. Traumatic myositis ossificans. Orthopedics. 1999; 22(10):1000, 991-5.

(8) Le Roux DA. Chondrosarcoma and myositis ossificans. J Manipulative Physiol Ther. 1998; 21(9):640-648.

(9) Patton, C., Tew, M. Periarticular heterotopic ossification after multiple knee ligament reconstructions: a report of three cases. Am J Sports Med. 2000; 28(3):398-401.

(10) Mestan MA, Bassano JM. Fractured heterotopic bone in myositis ossificans traumatica. J Manipulative Physiol Ther. 2001; 24(4):296-9.

(11) Ackerman LV. Extra-osseous localized non-neoplastic bone and cartilage formation (so-called myositis ossificans): clinical and pathological confusion with malignant neoplasms. J Bone Joint Surg Am. 1958; 40:279-298.

(12) Booth DW, Westers BM. The management of athletes with myositis ossificans traumatica. Can J Sport Sci. 1989; 14(1):10-6.

(13) Beauchesne RP, Schutzer SF. Myositis ossificans of the piriformis muscle: an unusual cause of piriformis syndrome. A case report. J Bone Joint Surg Am. 1997; 79(6):906-10.

(14) Hyder N, Shaw DL, Bollen SR. Myositis ossificans: calcification of the entire tibialis anterior after ischaemic injury (compartment syndrome). J Bone Joint Surg [Br]. 1996; 78-B:319-320.

(15) Aboulafia AJ, Brooks F, Piratzky J, Weiss S. Osteosarcoma arising from heterotopic ossification after an electrical burn: a case report. J Bone Joint Surg [Am]. 1999; 81-A (4):564-570.

(16) Ben Hamida KS, Hajri R, Kedadi H, Bouhaouala H, Salah MH, Mestiri A, Zakraoui L, Doughi MH. Myositis ossificans circumscripta of the knee improved by alendronate. Joint Bone Spine. 2004; 71(2):144-146.

(17) Larson CM, Almekinders LC, Karas SG, Garrett WE. Evaluating and managing muscle contusions and myositis ossificans. The Physician and Sportsmedicine. 2002; 30(2):41-48.

(18) Buselli P, Coco V, Notarnicola A, Messina S, Saggini R, Tafuri S, Moretti L, Moretti B. Shock waves in the treatment of post-traumatic myositis ossificans. Ultrasound in Med & Biol. 2010; 36(3):397-W9.

(19) Sodl JF, Bassora R, Guffman GR, Keenan M. Case report: traumatic myositis ossificans as a result of college fraternity hazing. Clin Orthop Relat Res. 2008; 466:225230.

(20) Takahashi S, Kanetake J, Kanawaku Y, Funayama M. Adult autopsy case with marked myositis ossificans: association with repetitive physical assault and battery. Legal Medicine. 2008; 10:274-276.

(21) Gunduz B, Erhan B, Demir Y. Subcutaneous injections as a risk factor of myositis ossificans traumatica in spinal cord injury. Int J Rehab Res. 2007; 30:87-90.

(22) Taylor DC, Englehardt DL, Bassett FH. Syndesmosis sprains of the ankle: the influence of heterotopic ossification. Am J Sports Med. 1992; 20(2):146-150.

(23) Kaeding CC, Sanko WA, Fischer RA. Myositis Ossificans. Minimizing Downtime. The Physician and Sportsmedicine. 1995; 23(2):77-82.

(24) Job-Deslandre C. Inherited ossifying diseases. Joint Bone Spine. 2004; 71(2):98-101.

(25) Tsuno MM, Shu GJ. Myositis ossificans. J Manipulative Physiol Ther. 1990; 13(6):340-2.

(26) Sencimen M, Gulses A, Ogretir O, Gunham O, Ozkaynak O, Okcu KM. Dystrophic calcifications arising in the masseter muscle: a case report. Quintessence Int. 2010; Apr; 41(4):295-7.

(27) Geschickter CF, Maseritz IH. Myositis Ossificans. J Bone Joint Surg [Am]. 1938; 20:661-674.

(28) Kulowski J. Pellegrini-Stieda's disease: a report of one case surgically treated. J Am Med Assoc. 1933; 100(13):1014-1017.

(29) Wieder DL. Treatment of traumatic myositis ossificans with acetic acid iontophoresis. Phys Ther. 1992; 72(2):133-7.

Dr. Brad Muir, HBSc(Kin), DC, FCCSS(C) *

* Assistant Professor, Canadian Memorial Chiropractic College, 177 Carnwith Drive East, Brooklin, ON L1M 2J5. Tel: (416) 482-2546 ext. 123 (CMCC), (905) 428-9370 (practice) [C] JCCA 2010
Chart 1 Types of Myositis Ossificans

1. Congenital (24)

* three inherited diseases that are characterized by heterotopic
bone formation (24)

* these are: fibrousdysplasia ossificans progressive (FOP),
progressive osseous heteroplasia (POH), and
Albright's hereditary osteodystrophy (AHO)

* although rare, they should be included in children presenting
with myositis ossificans of an idiopathic nature.

Fibrousdysplasia ossificans
progressiva (FOP):

* also called "stone man
disease" and myositis
ossificans progressive

* first described in the late 17th

* characterized by the
formation of bone in tendons
and muscles.

* manifests itself in childhood
and is slowly progressive
resulting in the formation
of a "second skeleton" in

* very uncommon occurring in
approximately 1 in 2 million.

Progressive osseous
heteroplasia (POH):

* first described by Kaplan in

* originally thought to be
atypical FOP

* in contrast to FOP,
ossification begins in the
dermis and spreads to the
subcutaneous tissue and
fascia with no skeletal

* POH is very rare and begins
in childhood, similar to FOP.

Albright's hereditary
osteodystrophy (AHO):

* manifests with a certain
phenotypical presentation
along with subcutaneous
calcifications about the limb

* phenotypical features
includes: short stature, a
round facies, hypertelorism,
and shortness of the 4th and
5th digits.

* mental retardation is also
common in these patients.

2. Idiopathic

* controversy regarding the idiopathic nature of myositis
ossificans and its naming.

* some authors use the term myositis ossificans circumscripta
(MOC) to describe the heterotopic ossification of soft tissue
of an idiopathic nature (25)

* other authors use MOC as synonymous with myositis ossificans
traumatica (8, 16)

* has been reported following burns, tetanus, and polio and
neurogenic injuries including spinal cord injuries, closed head
injuries, central nervous system infections, and stroke (1,9)

3. Traumatic

* difficult to adequately research MOT due to its many

* these include post-traumatic myositis ossificans, myositis
ossificans circumscripta, pseudomalignant heterotopic
ossification, pseudomalignant myositis ossificans,
pseudomalignant osseous tumor of soft tissue, extraosseous
localized non-neoplastic bone or cartilage formation3

* some radiologists consider the traumatic ossification
of ligaments specifically to be called dystrophic

* dystrophic calcification is defined as "calcium salt
deposits in the presence of normal calcium/phosphorus
metabolism involving tissues that do not physiologically
calcify" (26) which may not adequately describe our case

Chart 2 Specific Areas of MOT with Specific Names (3,1,10,21,28)

"Rider's Bone",      * found in the hip adductors in horseback riders
Prussian's Disease   and jockeys from the pressure of the saddle
or "Saddle Tumor"    against upper/inner thigh.

                     * described by Geschickter and Maseritz in
                     1938 (27) as ossification in the thighs of
                     cavalry men.

                     Author's Note: the terms Prussian's Disease and
                     saddle tumor were attributed to Ackerman11 by
                     Danchik et al. (3) but no mention of these terms
                     were found when examining the Ackerman paper. A
                     subsequent literature search of these terms did
                     not reveal any articles on PubMed.

Pelligrini-Stieda    * found in the medial collateral ligament of the

Disease              * first described by Pellegrini in 1905. Kohler
                     reported a similar case in 1905 as well. Stieda,
                     unaware of the previous works of Pellegrini or
                     Kohler reported a similar case in 1907. (28)

                     * most commonly found in football players.

"Rider's Bone"       * found near the attachment of the hamstrings at
                     the ischial tuberosity.

                     * Danchik et al. (3) suggests it is secondary to
                     hypervascularity following an avulsion of the

                     * has also been called "Rider's Bone" due to the
                     proclivity of this injury in horseback riders (3)

                     * Common in sprinters, hurdlers and cheerleaders

                     Author's Note: in checking Danchik's reference of
                     Ackerman11 no mention of "Rider's Bone" was found
                     suggesting that the "Rider's Bone" mentioned may
                     be similar to the aforementioned with "Prussian's
                     Disease" and the ischial tuberosity injury as
                     described is misnamed.

"Rifle Shoulder"     * found in the pectoralis major or anterior
                     deltoid muscle due to the repeated kickback
                     of a rifle or due to carrying the rifle on
                     the shoulder.

                     * most common in soldiers particularly the

                     * described by Geschickter and Maseritz in 1938
                     (27) as the "rifle shoulders" of infantry men.

"Fencer's Bone"      * found in the brachialis anticus due to the
                     overextension of the forearm (7)

                     * most common in fencers and baseball pitchers.

"Dancer's Bone"      * found in the soleus muscle (7)

                     Author's Note: a subsequent literature search of
                     the terms "Fencer's Bone" and "Dancer's Bone"
                     did not reveal any articles on PubMed.

Chart 3 Classification of MOT

Arrington Classification (6)

1. stalk         there is a stalk attachment
                 to the underlying bone

2. periosteal    there is total continuity
                 between the underlying
                 bone and the heterotopic

3. broad-based   is a large base of
                 attachment to the
                 underlying muscle

Mestan and Bassano Classification (10)

1. parosteal     the ossification is found near or
                 against bone

2. periosteal    the periosteum is torn away
                 from the underlying cortex due
                 to the trauma. The resulting
                 injury may have a sunburst

                 Note: 60% of MOT's have a
                 periosteal reaction secondary to
                 the trauma. (12)

3. extraosseus   the heterotopic bone is found
                 in the substance of the involved

Chart 4 Myositis Ossificans Traumatica and Osteosarcoma
A comparison of the two conditions includes the folling: (23)

Myositis Ossificans Traumatica       Osteosarcoma

* history of trauma                  * no history of trauma (although
* found in the diaphysis               trauma can occur in up to 40%
                                       of cases) (17)
* cortex usually intact even         * found in the metaphysis
  with a periosteal reaction         * cortex often violated
* pain and mass decrease with time   * pain and mass increase with time
* activity-related pain              * night pain alkaline phosphatase
* alkaline phosphatase levels          levels elevated
  often normal but can be
  elevated (2)

Table 1 Risk Factors for developing MOT (3,4,5)

1.   Severity of the injury. Although MOT has occurred following
     relatively minor trauma or even repetitive microtrauma, the
     more severe the initial injury, the greater the likelihood
     of developing MOT.

2.   Localized tenderness and swelling.

3.   Knee flexion <120[degrees]. In a study at West Point (5)
     no athlete with a contusion in which knee range of motion
     in flexion was greater than 120[degrees] developed MOT.

4.   Re-injury during the recovery phase. Although having a small
     sample size, Jackson and Feagin (4) reported those athletes
     with recurrent contusions to the same area during recovery
     developed MOT in 100% of cases.

5.   Delay in treatment >72 hours.

6.   Improper management of the muscle contusion. (3)

Table 2 Medical Management of MOT

Aspiration                * early aspiration of the hematoma with
                          subsequent injection of steroids,
Booth (12) reported on    lysosomal enzymes, and xylocaine.
a study done by Molloy
and McGuirk in 1976.      * able to return the majority of patients
                          to full activity

                          * intervention did not prevent the onset of
                          MOT or the reabsorption of mature lesions.

                          * efficacy in reducing the incidence of MOT
                          is questionable.

Alendronate (Fosamax)     * started on Alendronate six months post
Case report. (16) A 22
year old police officer   * six months later the symptoms had
and judoist presented     resolved although a smaller ossified mass
following a period of     was still present in the affected tissue.
intense training.
                          * larger trial necessary to rule out the
                          effects of natural history of MOT

NSAIDs (17,23)            * Indomethacin (25 mg, 3 X/day for 6 weeks)
                          suggested for prevention of heterotopic
                          ossification post surgery.

                          * Indomethacin and naproxen sodium are
                          effective if used for 2 to 6 weeks but
                          not effective with shorter-term usage.

                          * NSAID therapy is especially endorsed
                          following hip replacement surgery.

                          * common side effects include the spectrum
                          of gastrointestinal distress to bleeding
                          ulcers and death, make their usage a less
                          viable option.

Acetic acid               * 2% acetic acid solution was used with
iontophoresis             iontophoresis in an attempt to decrease
                          the size and progression of the calcium

                          * treatment initiated 4 weeks post injury

Case report. (29)         * consisted of iontophoresis, ultrasound
                          and passive pain free ROM 3X/wk for 3
16 year old male          weeks.
that developed MOT
following a diving        * after 3 week period, a follow-up
accident.                 radiograph showed a 98.9% decrease
                          in the size of the mass

                          * athlete regained full ROM and full,
                          pain free ADL's.

                          * a randomized control trial needed to
                          rule out natural history.

                          Author's Note: Iontophoresis involves
                          the movement of an electrically charged
                          substance (in this case acetic acid)
                          through the skin using low electrical
                          current. This is not to be confused with
                          phonophoresis that involves the use of

Surgery (2,17)            * surgery may be necessary if the lesion
                          has not resorbed and functional disability

                          * universally accepted that if surgery is
                          performed, it is only after the lesion has
                          reached osseous maturity as indicated on
                          bone scan or radiograph. This usually
                          occurs 6 to 12 months post-injury.

                          * lesion is likely to reoccur if excised
                          prior to osseous maturity and even in up
                          to 67% of cases after maturity.
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