MUNCHMEYER'S DISEASE

Discussion

This syndrome was first described in 1692 by Patin, who reported the case of a young woman who in his words "turned to wood". It was Münchmeyer who reported the first series of cases, and this disorder often is referred to as Münchmeyer's disease.The most frequent presenting symptom is torticollis resulting from a painful, doughy mass within the sternocleidomastoid muscle[2],[3].Ossification proceeds from cranial to caudal direction, from dorsal to ventral, and from axial to appendicular sites[4]. The heart, diaphragm, larynx, tongue, and sphincters are spared, as are all smooth muscle structures. A new episode of ossification frequently is precipitated by minor trauma, injections, or surgery, but the injury is not the primary problem and determines only the site of new ossification. Blood chemistry values, serum alkaline phosphatase concentrations, renal function, and parathyroid hormone levels all are within normal limits. The pathophysiological cause has been suggested because of deposition of calcium salts due to lack of a circulating inhibitor[5],or due to a primary defect in the collagen.

Radiological findings can be categorized into digital anomalies and ectopic ossification. The most common type of digital abnormality is a hallux valgus deformity associated with microdactyly of the first toes, with hypoplasia or synostosis of the phalanges, or both[6].Connor et al.[6] proposed the presence of similar abnormalities of the feet to frequently involve the hands (59 per cent of the 34 reviewed cases).In the hands, small middle phalanges can be observed in the fifth digits with clinodactyly.If the thumbs are involved, the anomalies are less severe than in the toes, and the most common finding is short first metacarpal bone.In our patient too,hallux valgus deformity with short bilateral first metatarsals were present.The digital anomalies in the hands in our case included short first metacarpal and short middle phalanx of the fifth digit.

Involvement of the insertions of fasciae, ligaments, and tendons produces pseudoexostoses (not true osteochondromas) , which arise from the metaphyses of the long bones, the occiput, and the calcaneus[7]. Prominent pseudoexostosis in our case was seen at the external occipital protuberance with involvement of the ligamentum nuchae and soft tissues in the posterior aspect of the neck. Abnormalities in the spine occur as a result of loss of motion.In the majority of cases, ossification of the soft tissues (interspinous ligament, supraspinous ligament, ligamentum nuchae, paraspinal muscles) is followed by fusion of the posterior elements (laminae, spinous processes, apophyseal joints) and finally fusion of the vertebral bodies[8].However,in our case the vertebrae were relatively spared(may be because of the young age of the patient). Other congenital anomalies of the skeleton associated with this disorder are broad femoral necks, bilateral thickening of the medial cortices of the tibiae, an abnormal carrying angle at the elbow, and an increased frequency of spina bifida[6],[7].Evidence of broad femoral necks was also seen in our case. Both CT and MR imaging may be useful diagnostically as a supplement to plain films[9].

Operative intervention or even biopsy has been blamed for accelerating the disease process. Surgical therapy has been combined with pre- and postoperative treatment with disodium etidronate (EHDP) in an effort to prevent recurrence or exacerbation of the disease.