Forearm Deformity and Radial Head Dislocation in Pediatric Patients with Hereditary Multiple Exostoses: A Prospective Study Using Proportional Ulnar Length as a Scale to Lengthen the Shortened Ulna

Short-term outcomes of gradual ulnar lengthening in multiple hereditary osteochondromas of the forearm with monolateral external fixator

Hereditary multiple exostoses is an autosomal dominant genetic condition primarily affecting long bones. Forearm deformities, including wrist ulnar deviation, ulnar shortening, radial or ulnar bowing, and radial head dislocation, are common manifestations. Gradual ulnar lengthening is suggested as a viable treatment option for managing these deformities. This retrospective single-center study included 15 forearms treated with gradual ulnar lengthening using a monolateral external fixator by a single surgeon. Clinical and radiological characteristics were recorded preoperatively and during follow-ups. The Wilcoxon signed-rank test compared preoperative and postoperative radiological and clinical parameters, while McNemar's test assessed changes in radial head dislocation or subluxation. Significant radiological improvements were observed post-treatment. Proportional ulnar length increased from a mean of 0.85 ± 0.10 preoperatively to 1.11 ± 0.03 at the last follow-up (P < 0.001). Ulnar variance decreased from a mean of 17.6 ± 5.58 mm preoperatively to 0.13 ± 1.81 mm at the last follow-up (P < 0.001), while radial bowing decreased from a mean of 0.06 ± 0.02 to 0.05 ± 0.01 at the last follow-up (P < 0.001). In addition, the radioarticular angle decreased significantly from a mean of 29.93 ± 7.34 to 20.20 ± 5.71° (P < 0.001). The incidence of radial head dislocation or subluxation decreased significantly, from 11 patients preoperatively to only one at the last follow-up. These findings demonstrate the effectiveness of gradual ulnar lengthening with a monolateral external fixator in correcting forearm deformities and reducing the incidence of radial head dislocation or subluxation.

Predictors of Radial Head Dislocation in Patients with Multiple Hereditary Exostoses

Background: Radial head dislocation in patients with multiple hereditary exostoses (MHE) is associated with loss of function and cosmetic problems. The treatment of the deformity with radial head dislocation is difficult and the timing of surgical intervention is important. The aim of this study was to evaluate the factors predictive of radial head dislocation in patients with MHE. Methods: Patients diagnosed with forearm deformity due to MHE between 1995 and 2021 were retrospectively evaluated. Radiographic parameters including radial bow (RB), ulnar bow (UB), total radial bow (TRB), total ulnar bow (TUB), percent ulnar length (PUL), ulnar shortening (US), radial articular angle (RAA), modified Masada classification and irregularity of proximal radioulnar joint (PRUJ) of the dislocated group (group D), that is subluxation or dislocation of the radial head, and the located group (group L) were compared. Results: A total of 18 patients and 25 limbs (5 girls and 13 boys) with a mean age of 10.5 years were included. There were significant differences in TUB (22.8° ± 5.6° vs. 10.7° ± 6.5°), PUL (97.5% ± 5.5% vs. 108.2% ± 7.7%) between group D and group L (p < 0.05). Moreover, irregularity of PRUJ on radiographs was more in group D (p < 0.05). Conclusions: It is possible that appropriate radiographic assessment in relation to radial head dislocation may prevent delayed surgical treatment of forearm deformities in MHE. Level of Evidence: Level IV (Diagnostic).

What do we need to address when we treat neglected Monteggia fracture in children

Monteggia fracture is a relatively uncommon injury in pediatric patients, accounting for less than 2% of forearm fractures, characterized by a combination of ulna fracture and radial head dislocation. Neglected Monteggia fractures define as those that have not received treatment within 3 weeks. In children, ulna fractures are easily diagnosed while radial head dislocation may be overlooked, necessitating open reduction after neglecting the Monteggia fracture and potentially causing additional trauma to the child. This study aims to review the pathological characteristics of neglected Monteggia fractures based on the length ratio of the ulna and radius, relative positions between the proximal ends of the ulna and radius, the integrality of annular ligament and the pathological change of proximal radioulnar joint. The findings will provide valuable insights and guidance for managing neglected Monteggia fractures.

Ulnar osteotomy and monolateral external fixator for the treatment of chronic Monteggia fractures in children: comparison between gradual and acute radial head reduction

This study evaluated the outcomes of chronic Monteggia fractures (CMFs) treated by ulnar osteotomy and monolateral external fixator (MEF), and compare the outcome of gradual versus acute radial head reduction. Two groups of patients were identified. Group 1: gradual reduction of the radial head ( n = 13); group 2: acute reduction ( n = 6). Clinical outcome was evaluated by Kim Elbow Score, whereas radiographic outcome was assessed on plain radiographs. The effect of age, side, time from initial trauma to surgery, rate of unplanned surgery, amount of angulation and lengthening, and final outcome were evaluated. Univariate analysis was performed to identify factors associated with good radiographic outcome. Thirteen patients underwent gradual correction of the ulna. The mean duration of correction was 43.4 days (range, 21-82); the mean angulation and lengthening of the ulna were 22.8° (range, 0°-35°) and 22.2 mm (range, 12.2-40.9), respectively. Six patients underwent acute reduction intraoperatively, the mean angulation and lengthening of the ulna were 17.2° (range, 4°-33.9°) and 5.2 mm (range, 2.5-12.2), respectively. CMF treated by ulnar osteotomy and gradual distraction had better radiological outcome (Group 1; 92.3% 12/13) than those treated by acute reduction of the radial head (Group 2; 3/6, 50%) ( P = 0.071). Reoperation rate was found to be significantly correlated with a fair or poor radiographic results ( P = 0.016). Good clinical and radiological outcomes should be expected in CMF patients treated by gradual lengthening and angulation of the ulna with a MEF.

Modified ulnar lengthening for correction of the Masada type 2 forearm deformity in hereditary multiple exostosis

Few articles have reported on the treatment of Masada type 2 forearm deformities in hereditary multiple exostosis, possibly because of the high redislocation rate and other complications. This study precisely declares the use of modified ulnar lengthening by an Ilizarov external fixation with tumour excision for the treatment of Masada type 2 forearm deformities. 20 children with Masada type 2 forearm deformities were admitted for surgical treatment at our hospital from February 2014 to February 2021. There were 13 girls and 7 boys, ranging in age from 3.5 to 15 years (mean: 9 years) at the time of operation. We removed the prominent osteochondromas of the distal ulna and the proximal radius, positioned a classic Ilizarov external fixator on the forearm and then performed ulnar transverse one-third proximal diaphyseal subperiosteal osteotomy. We adopted modified ulnar lengthening postoperatively. The effects of surgical correction of deformity and functional improvement of the limb were assessed via regular follow-up and X-ray. The patients were followed up for 36 months, and the ulna was lengthened 26.99 mm on average; all radial heads remained relocated. The radiographic evaluations, including relative ulnar shortening, radial articular angle, and carpal slip, were improved. The functions of the elbow and forearm were all improved after surgery. Modified ulnar lengthening by an Ilizarov external fixation with tumour excision for the treatment of Masada type 2 forearm deformities in hereditary multiple exostoses has been proven to be an effective and reliable technique in the early stage.

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.

To Angulate or Not to Angulate the Ulna during the Progressive Distraction Period Performed with a Monolateral External Fixator in Paediatric Patients with a Chronic Monteggia Fracture?

Background and Objectives: The purpose of this study was to compare the clinical and radiographic evolution of chronic Monteggia fractures (CMFs) treated by ulnar osteotomy and monolateral external fixators (MEFs) with or without angulation of the ulna during the distraction period. Materials and Methods: This retrospective study evaluated 20 children (14 boys and 6 girls) with CMFs. According to the strategy of ulnar lengthening, two groups of patients were identified: patients undergoing gradual lengthening with (Group A, n = 11) or without ulna angulation (Group B, n = 9). The mean age at the time of surgery was 7.7 years old (range, 5.4−12.9). The mean time from initial trauma to surgery was 26.3 months (range, 1−96), and the mean follow-up was 24.6 months (range, 5.5−45.4). Clinical outcomes were evaluated by Kim et al.’s Elbow Performance Score, while radiographic outcomes were assessed on plain radiographs. Results: Age at surgery, sex, laterality, time between trauma and surgery, and time of follow up in the two groups of patients showed no significant differences. The radial head was successfully reduced in 9 of 9 and 10 of 11 patients in Groups B and A, respectively (p = 1.00). The mean time to achieve radial head reduction was shorter in Group B (18.1 ± 5.3 days) than in Group A (39.2 ± 18.7 days; p = 0.004). The mean angulation of the ulna at the end of treatment was significantly lower in Group B (0.6° ± 1.1°) than in Group A (25.9° ± 6.3°; p < 0.0001). The average ulnar lengthening at the end of treatment in Group B (14.1 ± 5.8 mm) was, on average, 7.7 mm less than that in Group A (21.8 ± 9.7 mm; p = 0.05). The Kim et al. Elbow Performance Score at the last follow-up visit was comparable between the two groups of patients (p = 1.00). Conclusions: A shorter time to achieve radial head reduction and less deformity of the ulna can be expected in paediatric patients with CMFs undergoing intraoperative restoration of ulnar alignment and gradual lengthening without angulation postoperatively.

Outcomes and experience after open reduction for chronic Monteggia fracture in children

BACKGROUND

The treatment of chronic Monteggia fracture-dislocation (CMF) remains controversial and challenging for surgeons. We describe our initial experience with ulnar osteotomy and angulation on correction with modified open surgery and evaluate outcomes from clinical and radiographic findings.

METHODS

We retrospectively reviewed 18 children with a mean age of 6.78±2.67 years old who underwent surgical treatment because of CMF. Electronic medical records of Bado type, complaints, Kim scores, and complications were recorded. Radiographic parameters of maximum interosseous distance (MID), proportional ulnar length (PUL), lengthening, and bending angle of the ulna were summarized. The final reduction statuses of the radial head were reviewed. Parameters were compared at the time of pre-operation and the last follow-up. The relationship between the lengthening and angulation of ulna and the interval was calculated.

RESULTS

The mean interval was 11.1 [1-48] months and the follow-up time was 46.6 [24-96] months. A good reduction was observed in 15 (83.33%) patients, while 3 (16.67%) patients were fair. Postoperatively, the Kim scores were improved, from 59.17±18.17 to 90±6.64 (P=0.000). The mean posterior bending angle was 12.88° (range, 3 to 25°), and the mean amount of elongation of the ulna was 8.78 mm (range, 3.61 to 17.52 mm). The lengthening of the ulna was proportional to the magnitude of angulation of the ulna (r=0.648, P=0.004), and a positive correlation was also seen between the lengthening and the interval (r=0.632, P=0.005) and the angulation and the interval (r=0.502, P=0.034). The PUL and MID were significantly increased from 1.06±0.03 and 1.11±0.26 to 1.13±0.11 (P=0.047) and 1.28±0.27 (P=0.021), separately.

CONCLUSIONS

We highlight ulnar osteotomy as the essential procedure during reconstruction surgeries. Stabilization of the radial head with adequate elongation and balanced angulation of the osteotomy through direct observation is the main way to ensure and maintain satisfactory outcomes. With the extension of the interval, it is more necessary to increase the lengthening and angulation in positive proportion. PUL is a useful parameter in evaluating the mismatch between ulna and radius in CMF.

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.

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.