Reconstruction of forearm deformities in multiple cartilaginous exostoses

The management of complex forearm deformities in patients with multiple cartilaginous exostoses is controversial. The objective of this study is to look into the outcome of treatment with the combined use of ulna lengthening, radial osteotomy, and excision of exostosis in our six patients, who all had Masada type 1 deformity of the forearm. Clinical assessment was performed using the pre- and postoperative range of motion of the wrist, forearm and elbow. The chief symptom each patient had was noted as well as the demographic data of all patients. Radiological assessment was performed by checking the degree of negative ulna variance, the radial articular angle, and the degree of carpal slip. The degree of satisfaction of the patients and their parents were noted. Good clinical and radiological results were obtained at a mean follow-up of 2.5 years. All patients and parents were satisfied and there was no recurrence of deformity in the latest follow-up. The authors believe in early and aggressive treatment of Masada type 1 deformity of the wrist and forearm for multiple cartilaginous exostoses with a combination of excision of exostosis, ulna lengthening and radial osteotomy.     

Disturbed growth in height in multiple cartilaginous exostoses (author's transl)]

Basing on the hypothesis that reduced body height in patients with multiple cartilaginous exostoses would be mainly accounted for by shorter extremities, not by a shorter trunk, the authors clinically examined 19 exostosis patients in respect of thigh, lower leg, upper and lower arm, as well as height of the seated patient. The dimensions were compared by the method of matched pairs, with 19 volunteers without diseased skeleton, who corresponded with one of the exostosis patients in respect of age, sex and height of seated patient. Results were evaluated according to Wilcoxon's test. This showed a statistically significant reduction in length of the extremities in adults with multiple cartilaginous exostoses.     

Correction and lengthening for deformities of the forearm in multiple cartilaginous exostoses

Background Multiple cartilaginous exostoses cause various deformities of the epiphysis. In exostoses of the ulna, the ulna is shortened and the radius acquires varus deformity, which may lead to dislocation of the radial head. In this study, we present the results of exostoses resection, with correction and lengthening with external fixators for functional and cosmetic improvement, and prevention of radial head dislocation. Methods We retrospectively reviewed seven forearms of seven patients who had deformities of the forearm associated with multiple cartilaginous exostoses. One patient had dislocation of the radial head. Operative technique was excision of osteochondromas from the distal ulna, correction of the radius, and ulnar lengthening with external fixation up to 5 mm plus variance. We evaluated radiographs and the range of pronation and supination. Furthermore, we conducted a follow-up of ulnar length after the operation. Results Dislocation of the radial head of one patient was naturally reduced without any operative intervention. At the most recent follow-up, six of the seven patients showed full improvement in pronation–supination. Ulnar shortening recurred with skeletal growth of four skeletally immature patients; however, it did not recur in one skeletally mature patient. Overlength of 5 mm was negated by the recurrence of ulnar shortening about 1.5 years after the operation. Conclusions We treated seven forearms of seven patients by excision of osteochondromas, correction of radii, and gradual lengthening of ulnas with external fixators. The results of the procedure were satisfactory, especially for function of the elbow and wrist. However, we must consider the possible recurrence of ulnar shortening within about 1.5 years during skeletal growth periods in immature patients.     

Long-term results of surgery for forearm deformities in patients with multiple cartilaginous exostoses

BACKGROUND: Surgical treatment of forearm deformities in patients with multiple cartilaginous exostoses remains controversial. The purpose of the present study was to determine the reasonable indications for operative treatment and to evaluate long-term results of forearm surgery in these patients. METHODS: We retrospectively reviewed twenty-three patients (thirty-one forearms) after a mean duration of follow-up of nearly thirteen years. The mean age at the time of the initial procedure was eleven years. The patients underwent a variety of surgical procedures, including excision of exostoses; corrective procedures (lengthening of the radius or ulna and/or corrective osteotomy of the radius and/or ulna) and open reduction or excision of a dislocated radial head. Clinical evaluation involved the assessment of pain, activities of daily living, the cosmetic outcome, and the ranges of motion of the wrist, forearm, and elbow. The radiographic parameters that were assessed were ulnar variance, the radial articular angle, and carpal slip. RESULTS: Four patients had mild pain, and five patients had mild restriction of daily activities at the time of follow-up. Eight patients stated that the appearance of the forearm was unsatisfactory. Radiographic parameters (ulnar variance, radial articular angle, carpal slip) were initially improved; however, at the time of the final follow-up visit, the deformities had again progressed and showed no significant improvement. The only procedure that was associated with complications was ulnar lengthening. Complications included nonunion (three forearms), fracture of callus at the site of lengthening (two forearms), and temporary radial nerve paresis following an ulnar distraction osteotomy (one forearm). Excision of exostoses significantly improved the range of pronation (p = 0.036). CONCLUSIONS: In our patients with multiple cartilaginous exostoses, corrective osteotomy and/or lengthening of forearm bones was not beneficial. The most beneficial procedure was excision of exostoses. Reasonable indications for forearm surgery in these patients are (1) to improve forearm rotation and (2) to improve the appearance.     

The hip in hereditary multiple exostoses

We defined the characteristics of dysplasia and coxa valga in hereditary multiple exostoses (HME) by radiological analysis of 24 hips in 12 patients. The degree and effect of the 'osteochondroma load' around the hip were quantified. We investigated the pathology of the labrum and the incidence of osteoarthritis and of malignant change in these patients. Coxa valga and dysplasia were common with a median neck-shaft angle of 156 degrees, a median centre-edge angle of 23 degrees and Sharp's acetabular angle of 44 degrees. There was overgrowth of the femoral neck with a significantly greater ratio of the neck/shaft diameter in HME than in the control hips (p < 0.05), as well as correlations between the proximal femoral and pelvic osteochondroma load (p < 0.05) and between the proximal femoral osteochondroma load and coxa valga (p < 0.01). Periacetabular osteochondromas are related to Sharp's angle as an index of dysplasia (p < 0.05), but not coxa valga. No correlation was found between dysplasia and coxa valga. These data suggest that HME may cause anomalies of the hip as a reflection of a generalised inherited defect, but also support the theory that osteochondromas may themselves precipitate some of the characteristic features of HME around the hip.     

Manifestations of hereditary multiple exostoses

The solitary osteochondroma, a common pediatric bone tumor, is a cartilage-capped exostosis. Hereditary multiple exostosis is an autosomal dominant disorder manifested by the presence of multiple osteochondromas. Linkage analysis has implicated mutations in the EXT gene family, resulting in an error in the regulation of normal chondrocyte proliferation and maturation that leads to abnormal bone growth. Although exostoses are benign lesions, they are often associated with characteristic progressive skeletal deformities and may cause clinical symptoms. The most common deformities include short stature, limb-length discrepancies, valgus deformities of the knee and ankle, asymmetry of the pectoral and pelvic girdles, bowing of the radius with ulnar deviation of the wrist, and subluxation of the radiocapitellar joint. For certain deformities, surgery can prevent progression and provide correction. Patients with hereditary multiple exostosis have a slight risk of sarcomatous transformation of the cartilaginous portion of the exostosis.     

Cervical myelopathy in hereditary multiple exostoses

Spinal cord compression due to cervical exostoses is a rare but recognized complication of hereditary multiple exostosis (HME), an autosomal dominant disorder. This disease, also called multiple osteochondromatosis, is characterised by osteocartilaginous exostoses, typically involving the juxtaepiphyseal regions of long bones. Complications such as transformation to sarcoma (1 to 5%) or neurological compression (of the spinal cord, 1 to 9%) can arise during the course of the disease. We report the case of a 64-year-old man with progressive difficulties in walking over many years, ascribed to congenital rachitism. A diagnosis of HME was not made until late in the disease course. Investigations revealed cervical myelopathy due to vertebral exostosis as well as multiple exostoses in other sites. His gait was not improved after surgical decompression. A better knowledge of this disease could have prevented this neurological complication.     

Subacromial impingement syndrome in hereditary multiple exostoses

An unusual cause of subacromial pain was observed in a 32-year-old woman with multiple exostoses. The pain was the direct result of the mechanical impingement syndrome from these exostoses. Hereditary multiple exostoses should be investigated systematically, because many other, more common pain-producing conditions are possible. Secondary malignant degeneration of one of the cartilaginous coverings of the exostoses is very rare.     

Cervical spinal cord compression in hereditary multiple exostoses

Spinal cord compression is an extremely serious complication of hereditary multiple exostoses (HME). A case of HME with compression of the cervical spinal cord is reported. Complete recovery following surgery was achieved. A review of the relevant literature revealed 51 previous cases of HME with cord/cauda equina compression. Most patients were under 30 years of age with more men affected than women. The family history was positive in 60%. The cervical and thoracic areas were predominantly affected, with the symptoms usually developing slowly. Recovery following surgery is to be expected in the majority of cases. In patients with HME and suffering from neurological symptoms, the possibility of spinal cord compression should be considered. Prompt diagnosis and surgical excision provide the best prognosis.     

Acute spinal cord compression in hereditary multiple exostoses

Summary Osteocartilaginous exostoses are benign bone tumors frequently found in the metaphysis of long bones but rarely in the spine. Four patients with acute spinal cord decompensation due to vertebral exostoses spinal cord compression have been previously described in the literature. We report an additional case of rapidly evolving spinal cord compression due to a cervical osteochondroma in a patient with hereditary multiple exostoses (HME), also known as Bessel Hagen disease. Careful analysis of the 5 cases suggested to us that patients with HME should have a systematic spinal imaging screening, in order to prevent rapid neurological decompensation. A minimal risk surgical procedure can be performed at a time of election.     

Chondrosarcoma in a family with multiple hereditary exostoses

Multiple hereditary exostoses is an autosomal dominant skeletal disorder in which there are numerous cartilage-capped excrescences in areas of actively growing bone. The condition is genetically heterogeneous, and at least three genes, ext1, ext2 and ext3 are involved. The reported risk for malignant transformation to chondrosarcoma has been from 0.6% to 2.8%. We have reviewed six generations of a family with 114 living adult members, 46 of them with multiple exostoses. Four have had operations for chondrosarcoma, giving the risk for malignant transformation as 8.3% in this family. Clinical and radiological examination revealed two additional patients with a suspicion of malignancy, but in whom the histological findings were benign. Reported elsewhere in detail, genetic linkage analysis mapped the causative gene to chromosome 11 and molecular studies revealed a guanine-to-thymine transversion in the ext2 gene. Patients with multiple hereditary exostoses carry a relatively high risk of malignant transformation. They should be informed of this possibility and regularly reviewed.     

Multiple cartilaginous exostoses and neoplastic degeneration: review of the literature (author's transl)]

In about 10% of patients suffering from multiple osteochondroma a malignant degeneration of one osteochondroma occurs. Data of 59 patients are collected from the literature. The malignant degeneration occurs at the age of 31 in average, mostly on the pelvic girdle, less frequently on the shoulder girdle and on the ribs. The development is slow in most cases, at times interrupted. The first clinical signs are an increase in swelling, rarely pain or neurological symptoms. Radiological findings and prognosis correspond well with those of a proliferative chondroma or a primary chondrosarcoma. Recurrences after local treatment are frequent, metastases are rarely found. Regular check-ups and good information of patients suffering from multiple osteochondroma are recommended.     

Spinal stenosis frequent in children with multiple hereditary exostoses

Purpose

Children with multiple hereditary exostoses (MHE) have numerous osteochondromas, with the most prominent lesions typically over the appendicular skeleton. A recent report noted a high rate of intracanal lesions in this patient population and recommended preventative spinal screening with magnetic resonance imaging (MRI) or computed tomography (CT). We sought to evaluate the prevalence of spinal stenosis from intracanal osteochondromas at our pediatric orthopedic center in order to evaluate if routine screening is warranted.

Methods

All pediatric patients treated for MHE were retrospectively identified. Records were reviewed to determine demographics, previous orthopedic surgery, and indication and results of axial spine imaging (CT or MRI). Imaging studies were reviewed to evaluate the presence of intracanal and compressive spinal lesions.

Results

Between 1990 and 2011, axial imaging was performed in nine patients with MHE due to concerns of pain, weakness, and/or dizziness. These patients had moderate disease involvement, with a mean of 4.9 previous orthopedic surgeries to address skeletal osteochondromas. Two patients with MHE had cervical spinal stenosis secondary to intracanal osteochondromas. Both children successfully underwent spinal decompression. Thus, of our MHE population undergoing axial imaging, 22 % were noted to have intracanal lesions.

Conclusions

Our experience reveals a >20 % rate of compressive intracanal osteochondromas in MHE patients undergoing spinal imaging. These two patients represent 5 % of the MHE patients treated at our center. These lesions may be slow growing, and significant consequences can occur if not identified promptly. Thus, we confer that routine axial screening of the spinal canal may be warranted in these children.     

Hemiepiphyseal stapling for ankle valgus in multiple hereditary exostoses

If left uncorrected, valgus ankle deformity in multiple hereditary exostoses can cause significant disability in skeletally immature children and in adults. Various management methods have been described, including hemiepiphyseal stapling, transphyseal screw placement, fibular-Achilles tenodesis, distal tibial osteotomy, and ablative epiphyseodesis. In this article, we report the cases of 3 skeletally immature children who had undergone hemiepiphyseal stapling of the medial distal tibial epiphysis for correction of valgus ankle deformity in multiple hereditary exostoses. Correction of the tibiotalar axis, in relation to chronological and bone age, was evaluated. Hemiepiphyseal stapling of the medial distal tibial epiphysis provides ipsilateral corrective potential while allowing staple removal for reversal of growth retardation. This procedure is useful in the management of ankle valgus in multiple hereditary exostoses.