Total hip arthroplasty in hereditary multiple exostosis patients: literature review and evaluation of 10 cases

Background: Acquired hip deformities in patients affected by hereditary multiple exostosis (HME) may incur in early hip osteoarthritis and functional limitation requiring primary total hip arthroplasty (THA). Characteristic coxo-femoral joint dysmorphisms in HME may pose a challenge for the orthopaedic surgeon. Here we report our experience in a series of patients with HME treated in our hospital with THA. Methods: With a mean follow-up of 5 years, 10 primary THAs were reviewed; proximal femur deformities, acetabular dysplasia and joint osteoarthritis has been assessed through x-rays and CT-scan evaluation. In all cases hemispheric press-fit cups were used; 4 stem had metaphyseal engagement, 5 had proximal diaphyseal engagement and 1, with anatomical geometry, had metaphyseal fixation. 2 cases required stem cementation, 3 modular neck and 1 lateralised. The clinical data, complications and clinical outcomes, were recorded and analysed. Results: The mean Harris Hip Score (HHS) increased from 34 preoperative to 86 postoperative; preoperative mean neck shaft angle (NSA) was 150°, head/neck ratio 0.6, offset 31 mm; Wiberg angle 28°, Sharp angle 38°, 1 patient had subluxation grade 4 according to Crowe, 8 hips showed osteoarthritis (Tönnis grade ⩾2 ); 5 femurs were classified as Dorr type C, 2 as type B and 3 as type A. Perioperative complications were not observed. Conclusions: Primary THA in HME significantly improved clinical and functional outcomes. Press-fit cup fixation together with metaphyseal and proximal diaphyseal stem engagement on reliable bone quality femur, represents a valid option in HME patients with normal acetabular morphology, wide broaden neck and valgus NSA.

Older age and multi-joint external fixator are two risk factors of complications in ulnar lengthening in children with hereditary multiple exostosis

Objectives Hereditary multiple exostosis (HME) often involves forearm deformities. The aim of this study was to present the clinical results of 37 children who underwent ulnar lengthening with two different types of unilateral external fixators and to investigate the risk factors of complications. Methods We evaluated 37 children with forearm deformities caused by HME treated in our hospital from January 2008 to July 2019. The surgical procedures included resection of exostosis, osteotomy of the ulna, and gradual lengthening of the ulna with a unilateral external fixator. According to the type of fixator they received, the children were divided into two groups: group A received monorail fixators and group B received multi-joint fixators. Radiographic and functional parameters were assessed. Complications were recorded. Results All patients were followed-up for an average of 4.6 years (3.0 to 6.5). In both group A and group B, the ulna shortening (US), radial articular angle (RAA), carpal slip (CS), elbow flexion, forearm pronation, supination, and Mayo Elbow Performance Score (MEPS) values improved significantly from preoperatively to postoperatively (p < 0.05). However, the ulnar deviation was observed in 4 cases in group B and no cases in group A. According to logistic regression, the difference was only related to age (p < 0.05) and the type of external fixator (p < 0.05). Conclusions Ulnar lengthening with unilateral external fixation is a safe and effective procedure for the treatment of HME. Regarding complications, deviation of the ulna axis was more likely to occur in older children with multi-joint external fixators.

Older age and multi-joint external fixator are two risk factors of complications in ulnar lengthening in children with hereditary multiple exostosis

Objectives: Hereditary multiple exostosis (HME) often involves forearm deformities. The aim of this study was to present the clinical results of 37 children who underwent ulnar lengthening with two different types of unilateral external fixators, and to investigate the risk factors of complications. Methods: We evaluated 37 children with forearm deformities caused by HME treated in our hospital from January 2008 to July 2019. The surgical procedures included resection of exostosis, osteotomy of the ulna, and gradual lengthening of the ulna with a single arm external fixator. According to the type of external fixator they received, the children were divided into two groups: group A received monorail fixators, and group B received multi-joint fixators. Radiographic and functional parameters were assessed. Complications were recorded. Results: All patients were followed up for an average of 4.6 years (3.0 to 6.5). In both group A and group B, the ulna shortening (US), radial articular angle (RAA), carpal slip (CS), elbow flexion, forearm pronation, supination, and Mayo Elbow Performance Score (MEPS) values improved significantly from preoperatively to postoperatively ( p < 0.05). However, ulnar deviation was observed in 4 cases in group B and no cases in group A. According to logistic regression, the difference was only related to age ( p <0.05) and the type of external fixator ( p <0.05). Conclusions: Ulnar lengthening with unilateral external fixation is a safe and effective procedure for the treatment of HME. Regarding complications, deviation of the ulna axis was more likely to occur in older children with multi-joint external fixators.

Gradual Lengthening of the Ulna for the Treatment of Forearm Deformities in Children with Hereditary Multiple Exostosis: A Retrospective Study

Objectives: Hereditary multiple exostosis (HME) often involves forearm deformities. The aim of this study was to present the clinical results of 37 children who underwent the surgical procedure of ulnar lengthening with two different types of single arm external fixators.Methods: We evaluated 37 children with forearm deformities caused by HME treated in our hospital from January 2008 to July 2019. The surgical procedures included resection of exostosis, osteotomy of the ulna, and gradual lengthening of the ulna with a single arm external fixator. According to the type of external fixator they received, the children were divided into two groups: group A received monorail fixators, and group B received multi-joint fixators. Radiographic and functional parameters were assessed. Complications were recorded.Results: All patients were followed up for an average of 4.6 years (3.0 to 6.5). In both group A and group B, the ulna shortening (US), radial articular angle (RAA), carpal slip (CS), elbow flexion, forearm pronation, supination, and Mayo Elbow Performance Score (MEPS) values improved significantly from preoperatively to postoperatively (p < 0.05). However, ulnar deviation was observed in 4 cases in group B and no cases in group A. According to logistic regression, the difference was only related to age (p<0.05) and the type of external fixator (p<0.05). Conclusions: Ulnar lengthening with unilateral external fixation is a safe and effective procedure for the treatment of HME. Regarding complications, deviation of the ulna axis was more likely to occur in older children with multi-joint external fixators.

A 40-Year-Old Male Presenting with Hereditary Multiple Exostosis: Management and Considerations

Hereditary multiple exostosis is a rare condition in which numerous benign osteochondromas form throughout the body, typically in areas of high bone turnover such as the metaphyseal plates of long bones. While many of these lesions remain clinically asymptomatic, other growth locations can lead to excruciating pain, limit a joint’s range of motion, and compromise neurovascular structures. These patients undergo multiple surgeries throughout their lifetime in order to remove symptomatic osteochondromas. Due to deformities and changes in bone structure, these patients also suffer from significant arthritis which may also require surgery. It is important that a skilled orthopedic surgeon follow these patients in order to help them make informed decisions and limit the number of surgeries within their lifetime. The purpose of this case report is to discuss one instance in which a patient’s significant arthritis was operatively managed in the setting of hereditary multiple exostosis.