Less Is More: Ulnar Lengthening Alone without Radial Corrective Osteotomy in Forearm Deformity Secondary to Hereditary Multiple Exostoses

Ulnar lengthening for children with forearm deformity from hereditary multiple exostoses: a retrospective study from a tertiary medical center

BACKGROUND

Patients with hereditary multiple exostosis (HME) usually present with forearm deformity with or without radial head dislocation. Ulna lengthening has been proposed to address this condition. Exostosis resection plus ulna lengthening has been adopted in our hospital since 2008, and patients with this condition were retrospectively reviewed. Herein, we aimed to investigate the optimal timing and clinical outcomes of this surgical approach.

METHODS

In all, thirty-five patients (40 forearms), including 22 boys and 13 girls, were enrolled in our study from July 2014 to September 2020. We divided the patients into 4 groups based on the age when they received surgery and the status of the radial head. Pronation and supination of the forearm, flexion and extension of the elbow, wrist ulnar deviation and wrist radial deviation, and radiological parameters including ulnar length (UL), ulnar variance (UV), the percentage of radial bowing (RB/RL), radio articular angle (RAA) and carpal slip (CS), were assessed and recorded.

RESULTS

The mean UL was significantly improved after surgery in four Groups (P<0.05). In patients with radial head dislocation, we found significant improvement in forearm, wrist function and elbow flexion (p < 0.05). For the patients with radial head dislocation, the juniors demonstrated better improvement in % RB and RAA (p<0.05, p = 0.003 and 0.031).

CONCLUSION

Exostosis resection and ulna lengthening with unilateral external fixation can effectively improve the function and radiological parameters of forearm deformity in HME children. For patients with radial head dislocation, early surgery can achieve better results. For patients not associated with radial head dislocation, we recommend regular follow-up and surgical treatment after 10 years of age.

Distraction osteogenesis at the proximal third of the ulna for the treatment of Masada type I/IIb deformities in children with hereditary multiple exostoses: a retrospective review of twenty cases

BACKGROUND

Ulna distraction by monolateral external fixator (MEFix) is a good option for the treatment of Masada type I and IIb deformities in children with hereditary multiple exostoses (HMEs). However, there is no consensus regarding where to perform ulnar osteotomy. Our hypothesis is that osteotomy at the proximal third of the ulna and progressive distraction with MEFix can simultaneously correct elbow and wrist deformities in patients with HME.

METHODS

We retrospectively reviewed patients with HME who underwent ulna distraction osteogenesis from June 2014 to March 2019. The carrying angle (CA), radial articular angle (RAA), ulnar variance (UV), radial variance (RV) and range of motion (ROM) of the affected forearm and elbow were clinically assessed before lengthening and at the last follow-up visit. The total ulna lengthening distance (LD) and radiographic outcome were also recorded.

RESULTS

Nineteen patients (20 forearms) with HME aged 9.1 ± 2.4 years at the time of surgery were retrospectively reviewed. The mean follow-up period was 26.1 ± 5.6 months. There were 11 patients (12 forearms) with Masada type I deformities and eight patients (8 forearms) with Masada type IIb deformities. Patients with type IIb deformity had higher RV, lower CA values, less elbow flexion and forearm pronosupination than those with type I deformity (p < 0.05); RV was an independent risk factor for radial head dislocation, with the cut off at RV > 15.5 mm. The mean LDs in patients with type I and type IIb deformities were 33.6 ± 6.6 mm and 41.4 ± 5.4 mm, respectively. The mean CA, UV, RV, forearm pronation and ulna deviation at the wrist improved significantly following surgery in all patients. In particular, five of eight patients (62.5%) with type IIb deformities had concentric reduction of the radiocapitellar joint, while no radial head subluxation was detected in patients with type I deformities at the last follow-up. Three complications were recorded: two pin-track infections and one delayed union.

CONCLUSIONS

Distraction osteogenesis at the proximal third of the ulna provides satisfactory clinical and radiological outcomes in patients with Masada type I and IIb deformities. Early treatment of Masada type I deformities is indicated before progression to more complex type IIb deformities.

Lengthening of the ulna by callotasis in children with multiple hereditary exostoses: comparison of methods with and without internal fixation

PURPOSE

The goal of this retrospective study was to compare the gradual lengthening of the ulna in children with multiple hereditary exostoses with and without an elastic intramedullary nail.

METHODS

Between 1998 to 2018, the ulna was lengthened in 28 forearms in 21 patients (aged 7.1 to 16.6 years) using a monolateral external fixator when relative ulnar shortening exceeded 15 mm. In total, 16 forearms were lengthened with the external fixator (group I) and 12 forearms with the addition of an intramedullary elastic nail (group II). Subjective assessment of function, range of movement (ROM) of the wrist and elbow and complications were compared. Ulnar shortening, radial head dislocation, radial articular angle (RAA) and percentage of carpal slip and radial bowing were followed radiographically. The difference between the groups has been evaluated statistically.

RESULTS

The function of the extremity improved partially in 81% of patients in group I and in 83% of patients in group II. ROM was not improved except for radial deviation. Radial head position did not change. The values in group II in comparison with group I are higher for gain of length and lower for bone lengthening index and for bone healing index. Carpal slip decreased insignificantly. The RAA and radial bowing decreased, the comparison of values between groups and age under and over ten years were not statistically significant. Complications were more common in group I. No permanent complications were noted.

CONCLUSION

The addition of an intramedullary nail during the gradual ulnar lengthening improves the gain, bone healing index and rate of complications.

LEVEL OF EVIDENCE

III.

Limb Length Discrepancy and Angular Deformity due to Benign Bone Tumors and Tumor-like Lesions

Benign bone tumors and tumor-like lesions are frequently diagnosed in children and adolescents. The immature skeleton is at risk for growth disturbances and deformity because of the effects of the lesions on normal bone architecture and the physis. The development, manifestation, and severity of the limb length inequality and deformity differs between the various bone pathologies. Distraction osteogenesis, osteotomy, and guided growth are key tools in the treatment of limb inequality and deformity using a combination of external and internal fixation devices.

An unusual example of hereditary multiple exostoses: a case report and review of the literature

Background

Hereditary multiple exostoses (HME) is a rare skeletal disorder characterised by a widespread.

distribution of osteochondromas originating from the metaphyses of long bones.

Case presentation

This case study examines a 55-year-old male cadaver bequeathed to the University of Liverpool who suffered from HME, thus providing an exceptionally rare opportunity to examine the anatomical changes associated with this condition.

Conclusions

Findings from imaging and dissection indicated that this was a severe case of HME in terms of the quantity and distribution of the osteochondromas and the number of synostoses present. In addition, the existence of enchondromas and the appearance of gaps within the trabeculae of affected bones make this a remarkable case. This study provides a comprehensive overview of the morbidity of the disease as well as adding to the growing evidence that diseases concerning benign cartilaginous tumours may be part of a spectrum rather than distinct entities.

Gradual ulnar lengthening in Masada type I/IIb deformity in patients with hereditary multiple osteochondromas: a retrospective study with a mean follow-up of 4.2 years

BACKGROUND

Gradual ulnar lengthening is the most commonly used procedure in the treatment of Masada type I/II deformity in patients with hereditary multiple osteochondromas. However, the treatment remains controversial for the recurrence of deformity in growing children. This study aims to evaluate the clinical and radiological outcomes of ulnar gradual lengthening in our clinic.

METHODS

We retrospectively reviewed patients who underwent ulnar lengthening by distraction osteogenesis from June 2008 to October 2017. The carrying angle (CA) and range of motion (ROM) of the forearm and elbow were clinically assessed, and the radial articular angle (RAA) and ulnar shortening (US) were radiologically assessed before lengthening, 2 months after external frame removal, and at the last follow-up.

RESULTS

The current study included 15 patients (17 forearms) with a mean age of 9.4 ± 2.3 years at the index surgery. The mean follow-up period was 4.2 ± 2.4 years. There were 9 patients (10 forearms) with Masada type I deformity and 6 patients (7 forearms) with Masada type IIb deformity. The mean amount of ulnar lengthening was 4.2 ± 1.2 cm. The mean RAA improved from 37 ± 8 to 30 ± 7° initially (p = 0.005) and relapsed to 34 ± 8° at the last follow-up (p = 0.255). There was a minimal deterioration of US yet significant improvement at the last follow-up compared to pre-op (p < 0.001). At the last follow-up, the mean forearm pronation and elbow flexion increased significantly (p < 0.001 and p = 0.013, respectively), and the mean carrying angle also improved significantly (p < 0.001). No patient with type IIb deformity achieved a concentric radial head reduction.

CONCLUSIONS

Gradual ulnar lengthening significantly reduces cosmetic deformity and improves function in patients with Masada type I/IIb deformity. Our results supported early ulnar lengthening for patients with a tendency of dislocation of the radial head.