If you don't remember your password, you can reset it by entering your email address and clicking the Reset Password button. You will then receive an email that contains a secure link for resetting your password
If the address matches a valid account an email will be sent to __email__ with instructions for resetting your password
Corresponding author: Abby Choke, MBBS, Department of Hand & Reconstructive Microsurgery, Singapore General Hospital, Academia, 20 College Rd., Singapore 169856.
We report a 34-year-old man who presented with hyperostosis of his right elbow associated with an inability to fully extend his elbow. The radiographic assessment revealed a classical dripping candle wax appearance of his proximal ulna suggestive of melorheostosis. Computed tomography was performed to identify the impingement point and aid in surgical planning. A targeted open excision biopsy via a Boyd incision was performed to excise the exophytic component that was causing the functional block. After surgery, he achieved full elbow extension and was able to return to his usual activity.
Melorheostosis, also known as Leri disease, is a rare mesenchymal dysplasia manifested by areas of spontaneous bone sclerosis in long bones of the limbs. It is a benign condition that is asymptomatic in the early stage and often diagnosed incidentally. The radiographic feature of a dripping candle wax appearance is pathognomonic. We report a case of ulna bone melorheostosis in an adult man who presented with unilateral bone enlargement and progressive inability to fully extend his elbow.
Case Report
A 34 year-old man presented with an irregular bony lump over his right posterior elbow that had been present for 7 years. He was right-handed. He had consulted a surgeon when he first noted the mass. Magnetic resonance imaging (MRI) then reported “an undulating cortical hyperostosis of the proximal ulnar bone” with no muscle involvement. At that point, he did not have any functional difficulties. He was told that this was a benign condition not requiring treatment. In the past year, he noticed a gradual enlargement of the mass and a progressive inability to fully extend his elbow. This affected his usual activities, including carrying grocery bags and participating in cricket.
On examination, an area of irregular bony growth was palpable extending from the posterior olecranon to the midposterior forearm. A distinct prominence was felt directly over the olecranon and was tender to palpation. The overlying skin and soft tissue was normal. The range of motion of his elbow joint was to 140° of flexion with a terminal extension block of 10°. Supination and pronation were unaffected, and his motor and sensory function was normal. Serum calcium, phosphate, and alkaline phosphatase were normal. Anteroposterior and lateral radiographs of the elbow and forearm showed a continuous irregular cortical thickening involving the posterior cortex of the midulnar diaphysis to the olecranon, resembling dripping candle wax (Fig. 1). A full-body bone scan demonstrated hyperactivity in the involved ulna bone but did not show activity elsewhere in the body.
Figure 1A, B Radiographs of the right elbow show the classical dripping candle wax appearance of the ulna bone.
A provisional diagnosis of melorheostosis was made based on the clinical presentation and radiographic features. In view of the functional limitations, we recommended targeted excision of the involved bone. We counseled the patient that it was not feasible to remove the entire lesion. A computed tomography scan was performed with the elbow in extension and revealed a 2-cm exophytic component that was impinging against the capitellum of the humerus (Fig. 2). The lesion encroached on the medullary cavity but had not completely obliterated it. The rest of the elbow joint line was well preserved.
Figure 2A, B Melorheostosis appeared densely white on computed tomography imaging. Axial and coronal view revealed the hooklike exophytic component at the radiocapitulate joint, which was the cause of the elbow extension block.
Open excision was performed under general anesthesia with the patient in left lateral position. The right arm was placed on an arm support to allow the elbow the hang (Fig. 3A). A longitudinal skin incision along the ulnar border of the ulna bone skirting the olecranon process was made. Using the Boyd approach, the fascia was incised and the anconeus muscle reflected to expose the bone lesion. The tumor appeared pearly white and lobulated and was hard in consistency (Fig. 3B, C). The exophytic component was carefully exposed. Next, the base of the lesion was drilled multiple times using a 2.0-mm Kirschner wire in line with the posterior cortex of the ulna. Then, the bone tumor was gently chiseled off using an osteotome. The base of the lesion was flattened with a bone bur (Fig. 3D). The ulnar nerve was not encountered during the surgery. Following the procedure, he was able to move his elbow from –5° to 140°, similar to his unaffected elbow. He was referred to the physical therapist for early range of motion exercises to prevent joint stiffness. Postoperative radiographs showed a smooth posterior olecranon (Fig. 4).
Figure 3A The patient was placed in a left lateral position under general anesthesia with his right elbow hanging on an arm support. B, C The lesion was pearly white and lobulated in appearance. The excised portion measured about 4 x 1 cm. D The bone surface was smoothed with a bur after excision of the lesion.
Histological analysis revealed fragments of osteosclerotic bone composed of a mixture of woven and lamellar bone (Fig. 5). There was no evidence of malignancy. At 6-month follow-up, he was able to achieve a full range of elbow motion. He returned to playing cricket within 3 months.
Figure 5A, B The microscopic appearance reveals dense cortical-like bone consisting of lamellar and woven bone. B Higher magnification shows that the osteocytes (arrows) are normal in appearance.
Melorheostosis is derived from the Greek words melos meaning limb, rhein meaning flow, and osto meaning bone, which describe a flowing cortical hyperostosis resembling the wax of a dripping candle in appearance.
Melorheostosis, also known as Leri disease, is a rare benign sclerosing mesodermal disease first described by French neurologists Andrew Léri and J. Joanny in 1922.
The disease is characterized by a linear pattern of bony sclerosis along the axis of the long bones and it is known to cross joint lines to affect an adjacent bone. This condition is more common in childhood and early adolescence, and both males and females are equally affected.
The etiology of this condition remains obscure. Various theories have been proposed, including the possibility of a developmental disorder, infectious process, or vascular insufficiency resulting in failure of intramembranous or endochondral ossification.
The limited literature supports the mosaicism theory, which is the presence of genetically distinct somatic cells within an organism in view of the sporadic occurrence of dysplasia, asymmetrical limb involvement, and equal sex occurrence.
The diagnosis is based on the clinical and radiographic appearance. The condition is often asymptomatic in the initial stages and may be incidentally detected on radiographs. The symptoms may range from localized bone enlargement causing pain, stiffness and loss of movement, to debilitating contractures and may also involve the overlying soft tissue manifested by subcutaneous edema, fibrosis, ectopic bone formation, or muscular atrophy.
For this patient, functional disability did not manifest until a few years after his initial presentation. He did not have any skin or soft tissue changes, and the disease was limited to a single limb.
The radiographic appearance of dripping candle wax is classic for melorheostosis.
The cortical hyperostosis is thick, irregular, and bumpy and typically runs an undulating course where some areas overlap. It can invade the medullary canal and replace it over time. It is important to study the pattern of ossification to rule out diagnoses like osteoid osteoma, myositis ossificans, or parosteal osteosarcoma. Computed tomography imaging can provide valuable information on the degree and pattern of hyperostosis. The lesion does not enhance on MRI but MRI has the added advantage in assessing soft tissue involvement. Histopathological findings for melorheostosis are nonspecific with no pathognomonic feature. It is predominantly made up of dense bony trabeculae that are similar to other conditions associated with hyperostosis.
Our patient presented with symptoms in adulthood. He was predominantly troubled by the inability to fully extend his elbow. The aim of surgery was to restore the elbow function while preserving the forearm structures and to obtain a diagnosis. Because the lesion was extensive, complete excision of the lesion was impractical. Cross-sectional computed tomography imaging was helpful for surgical planning because it accurately identified the area that was causing the impingement. We also considered the use of elbow arthroscopy to assess the joint and assist in debulking, but this was not required because piecemeal excision of the exophytic portion was achieved via the open incision.
Asymptomatic cases of melorheostosis can be monitored radiographically. In symptomatic cases, the lesion can be extensive. The patient should be counseled about the potentially progressive nature of the disease, morbidity from surgery, and the risk of recurrence following surgery.
30766-8&id=gr1.jpg){kind=link}
30766-8&id=gr2.jpg){kind=link}
30766-8&id=gr3.jpg){kind=link}
30766-8&id=gr4.jpg){kind=link}
30766-8&id=gr5.jpg){kind=link}