Myositis Ossificans of the Quadriceps


Myositis Ossificans is a benign, meta-plasmatic, mostly self-limiting process in which bone or bone-like tissue formation takes place in skeletal muscle. It occurs mostly in large skeletal muscles such as quadriceps,brachialis & adductor of thigh.It may arise with or without trauma.But its common in young active athlete after a single traumatic injury[1].

These different causes of myositis ossificans (MO)divide the disorder into two subgroups:

  • -Myositis Ossificans Traumatica (MOT) also called the non-hereditaryy myositis ossificans(associated with burns, haemophilia and neurological disorders)
  • -Myositis Ossificans Progressiva (MOP), also called Fibroplasia Ossificans Progressiva (FOP).

Epidemiology /Etiology

MOP resulting from a direct blow or repeated injury is the most common representing 60-75% of total cases.[2]

Post-traumatic MO occurs in about 20% of cases reported with large muscle hematoma associated with contusion or trauma. It lasts for an average of 1.1 years.[3]It may also occur due to repetitive injury to the same area.

It's found in both contacts as well as non-contact sports. Its exact cause is unknown but mostly it's an error in the healing process where normal muscle cells known as fibroblast are replaced by immature bone cells[4].[5]

Characteristics/Clinical Presentation

  1. Pain;-Aching type of pain lasting for more time than in case of a simple muscle contusion.
  2. Swelling;-Localised swelling on the anterior thigh or in some cases it may be in the whole limb.
  3. Decrease ROM;-Gradual loss of ROM(Range of motion[2][6]

Along with the above symptoms,a careful history of injury gives an indication to diagnose MO

Differential Diagnosis

Malignant tumors of thigh such as lymphoma, osteosarcoma and rhabdomyosarcoma have similar symptoms.

Diagnostic Procedures

MRI is a gold standard investigation for any soft tissue mass,it helps to identify early developing cases.

Earlier Ultrasonography also helps to detect calcifying hematoma. Plain Radiograph shows calcified mass only in the advanced stage.CT scan or bone scans can also be performed to differentiate myositis ossificans from other conditions.[6][7]

Outcome Measures

Lower Extremity Functional Scale (LEFS),may be used as outcome measure for condition.



As MO can only be accurately diagnosed about two weeks after onset and generally requires investigation beyond a standard clinical examination, Consequently, initial presentation may follow that of a quadriceps contusion. Following acute injury the following signs & symptoms may be noted[8]:

  • Anterior thigh pain
  • Sharp pain during activity (particularly when kicking, jumping, or changing directions in athletes)
  • Localized swelling and loss of motion

MO should be suspected under the following circumstances[8]:

  • Worsening of symptoms after 2-3 weeks accompanied by loss of knee flexion
  • Persistent swelling

Physical Examination

As ossifying lesions mature, physical examination can reveal noteworthy findings. The table below matches parts of the clinical examination with possible findings related to MO :

Testing Domain Findings
Observation Swelling, increased thigh circumference
Palpation Painful soft tissue mass, usually with no signs of inflammation[9]
Range of Motion Restricted knee flexion[8][9], pain with passive stretching
Strength Decreased quadriceps strength with pain during static & dynamic contraction[9]

Medical Management

Most cases of MO can be successfully managed with conservative treatment[10]. This typically includes the prescription of NSAIDs, rest, and exercise therapy. Operative removal of the ossification is only indicated for progressive disease or persistent cases in which conservative treatment has not been successful[10].

Physical Therapy Management

Physiotherapy can be used to guide patients through a supervised rehabilitation program. Given the rarity of MO of the quadriceps, little evidence exists to guide treatment. Many case studies and reviews advocate an initial period of stretching, range of motion & gentle exercise (ex. isometric quadriceps contraction and terminal knee extension) followed by the addition of more aggressive strengthening, proprioceptive retraining, aerobic conditioning, and return to activity[10].

A small number of case studies[3][11] suggest that Extracorporeal Shockwave Therapy (ESWT) may be an effective adjunct to traditional conservative measures.


  1. Devilbiss Z, Hess M, Ho GW. Myositis Ossificans in Sport: A Review. Current sports medicine reports. 2018 Sep 1;17(9):290-5.
  2. 2.0 2.1 McCarthy EF, Sundaram M. Heterotopic ossification: a review. Skeletal radiology. 2005 Oct 1;34(10):609-19.
  3. 3.0 3.1 Torrance DA. Treatment of post-traumatic myositis ossificans of the anterior thigh with extracorporeal shock wave therapy. The Journal of the Canadian Chiropractic Association. 2011 Dec;55(4):240.
  4. Beiner JM, Jokl P. Muscle contusion injury and myositis ossificans traumatica. Clinical Orthopaedics and Related Research (1976-2007). 2002 Oct 1;403:S110-9.
  5. Jacobsen S. Traumatic myositis ossificans. Posttraumatic non-neoplastic heterotopic ossification. Ugeskrift for laeger. 1995 Sep;157(39):5385-8.
  6. 6.0 6.1 Srikanth IM, Vishal A, Kiran KR. Myositis ossificans of rectus femoris: a rare case report. Journal of orthopaedic case reports. 2015 Jul;5(3):92.
  7. Devilbiss Z, Hess M, Ho GW. Myositis Ossificans in Sport: A Review. Current sports medicine reports. 2018 Sep 1;17(9):290-5.
  8. 8.0 8.1 8.2 Kary JM. Diagnosis and management of quadriceps strains and contusions. Current reviews in musculoskeletal medicine. 2010 Oct 1;3(1-4):26-31.
  9. 9.0 9.1 9.2 Marques JP, Pinheiro JP, Costa JS, Moura D. Case Report: Myositis ossificans of the quadriceps femoris in a soccer player. BMJ case reports. 2015;2015
  10. 10.0 10.1 10.2 Devilbiss Z, Hess M, Ho GW. Myositis Ossificans in Sport: A Review. Current sports medicine reports. 2018 Sep 1;17(9):290-5.
  11. 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 Medicine & Biology. 2010 Mar 1;36(3):397-409.