The anatomical basis for surgical intervention in myositis ossificans-A systematic review.

Myositis ossificans (MO) is a benign condition characterized by heterotrophic bone formation, most commonly within muscle tissue. Multiple types have been described, the most predominant being myositis ossificans circumscripta, which occurs in response to trauma. Myositis ossificans cases reported in the literature were reviewed systematically. The aim of the review was to examine how the condition and its management are influenced by the anatomical structures involved. The Medline and Ovid Embase online databases were searched for all papers relevant to MO between Jan 1972 and Dec 2020. Duplicate and unobtainable records were removed. The remaining records were manually assessed for relevance by three independent reviewers, initially by abstract and then by full-text screening, to ensure that all papers were suitable. Acceptance of articles was not limited by case features or study design. In total, 77 papers from the literature search were included. They contained information on 89 patients diagnosed with MO. The average age of the patients was 26.17 years (range 13 weeks to 72 years, a 71.75 year range) and 65.17% were male. The lower limb was affected more than the upper limb or spine, the most common site being the thigh. Muscle was the most commonly affected tissue, the quadricep femoris being most often involved. Diagnostic imaging varied widely among cases; X-ray alone was the most common method, followed by a combination of X-ray and MRI. Lesions in the lower limb had larger diameters than those in the upper limb or spine. More cases in the upper limb (47.83%) than in the lower limb (33.33%) required surgery. All instances of MO in the jaw, hand, and foot were symptomatic, and all required surgical management. The findings were consistent with previous research showing MO to be a predominantly male disease, with most patients being under 30 years of age. Trauma was involved in 52.81%, lower than previously reported. In this study, the vastus lateralis of the quadriceps was most often affected. MO lesions were less common and smaller in the upper limb but more required surgery. Anatomically confined sites such as the hand and foot always required surgery, probably because of earlier onset or more severe functional effects of symptoms. Further work is needed to review the anatomical predilection of MO to help identify patients who could benefit from earlier consideration of surgery. A national registry of MO cases could contribute to further research on this disease.