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.
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.
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.
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.

OBJECTIVE: Approximately 30% of patients with hereditary multiple osteochondromas (HMO) have forearm deformity and dysfunction. The aim of this retrospective study was to review our experience with the surgical treatment of children with HMO and Masada IIb forearm deformities.
METHODS: Data of eight children treated for HMO Masada IIb forearm deformity at our hospital between 2015 and 2019 were collected from the hospital records and retrospectively reviewed. All patients underwent ulnar lengthening by distraction osteogenesis using either the Orthofix or Ilizarov external fixator. Range of movements at the elbow and wrist joints, and forearm supination/pronation, before and after the operation were recorded. Radiographs were evaluated by the Fogel method, and wrist joint function by the Krimmer method.
RESULTS: Follow-up radiographs showed significant improvement in relative ulnar shortening after treatment (pre-operative 9.23 ± 5.21 mm; post-operative 0.33 ± 4.13 mm). Changes in radial articular angle (pre-operative 33.55° ± 3.88° to 32.78° ± 6.57°) and carpal slip (pre-operative 45.00% ± 19.09%; post-operative 43.13% ± 16.68%) were not significant. Elbow flexion and extension, wrist flexion and extension, ulnar and radial deviation at wrist, and forearm rotation were significantly improved after surgery. Wrist function was graded as excellent in seven patients and as good in one patient. One patient treated with the Ilizarov external fixator had poor radial head reduction.
CONCLUSIONS: Ulnar lengthening with distraction osteogenesis is an effective treatment for HMO Masada IIb deformities. The optimum site for ulnar osteotomy appears to be at the proximal one-third to one-fourth of the ulna.

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

OBJECTIVE: Forearm deformity is common in hereditary multiple osteochondromas (HMO). The results of ulnar lengthening and osteochondroma excision are generally favorable, both clinically and radiographically. This study aimed to assess the clinical, radiographic, and functional results of forearm reconstruction in patients with Masada type I deformity (osteochondroma in the distal ulna with radial bowing, without radial head dislocation).
METHODS: A retrospective review was performed on patients with HMO who underwent surgical reconstruction for a Masada type I forearm deformity over a 10-year period. Eleven forearms in 10 patients underwent gradual ulnar lengthening with an external fixator. Age at the time of surgery was 5 to 12 years. Radiographic evaluation included ulnar shortening, radial articular angle, and carpal slip. Clinical evaluation included range of motion of the elbow and wrist. Functional outcomes were evaluated with the Disabilities of the Arm, Shoulder, and Hand questionnaire and the Short Form-36 survey.
RESULTS: At an average follow-up of 37.5 months, significant improvement was observed in ulnar shortening, the radial articular angle, and carpal slip. Preoperative average Disabilities of the Arm, Shoulder, and Hand score of 24.2 improved to 17.3. Significant improvement was observed in 3 measures of the Short Form-36 survey: general health, social functioning, and health change.
CONCLUSIONS: In agreement with the literature, surgical reconstruction yielded favorable clinical and radiographic results in Masada type I forearm deformities. The main functional improvement was observed in scales of mental health. The baseline physical impairment was minimal in the absence of radial head dislocation, but although it improved with treatment, it was not necessarily clinically relevant. This study can assist surgeons and families in setting realistic goals and expectations for surgery. There may also be additional long-term benefits to forearm lengthening in HMO, including prevention of radial head dislocation, improved range of motion, and better cosmesis, which future research may help to clarify.
METHODS: Therapeutic V.

Ulnar lengthening has gained popularity in treating forearm deformity due to hereditary multiple exostoses (HME). Whether a simultaneous radius angular correction is necessary for bowing deformity remains debatable. We aimed to evaluate effectiveness and safety of ulnar lengthening alone in HME children. HME patients with forearm deformity who underwent ulnar lengthening between 2011 and 2016 were included. Patients were divided into two groups: eight juniors (age ≤ 10 years) and six seniors (>10 years). The mean age of two groups was 8.1 ± 2.5 and 16.7 ± 4.4 years, respectively. The juniors underwent ulnar lengthening alone, and the seniors received an additional radial corrective osteotomy. Pre-operative and post-operative parameters of supination, pronation, ulnar variance (UV), radial articular angles (RAA), and carpal slip (CS) were assessed. The juniors rather the seniors had an improvement in supination (p < 0.05 and p = 0.109, respectively). The juniors and seniors improved in pronation (p < 0.05). UV, RAA, and CS were corrected in the seniors (p < 0.05). In the juniors, parameters improved in UV, RAA, and CS (p < 0.05). For HME children, ulnar lengthening alone can restore radiologic anatomy and functions, providing comparable surgical outcomes in cosmetic results and clinical parameters.

OBJECTIVE: To report on the outcomes of using ulnar lengthening combined with acute angular correction for the treatment of forearm deformities in patients affected by multiple hereditary exostoses (MHE). Our hypothesis was that this procedure would improve both radiographic measurements and clinical outcomes with minimal complications.
METHODS: A retrospective chart review was performed on patients who had a diagnosis of MHE and had undergone ulnar lengthening via a uniplanar external fixator over a 12-year period. Clinical outcomes such as range of motion, pain, and surgical complications were assessed. Radiographic changes were measured using interval radiographs.
RESULTS: The series included 17 patients. Median age at surgery was 7 years (range, 3-14 years). Median follow up was 55 months (range, 5-125 months). Improvements occurred in radial and ulnar radii of curvature, carpal slip, ulnar variance, and carrying angle at the elbow. There was 1 major pin track infection. There were 2 failures of the external fixator requiring exchange. Premature consolidation occurred in 1 case. Elbow, forearm, and wrist motion was not affected. Radiocapitellar joint congruency did not change. No patient reported pain at final follow-up.
CONCLUSIONS: Our approach of using distraction osteogenesis of the ulna with angular correction in the radius and ulna as needed is able to correct carpal slip as well as to improve forearm bowing and elbow carrying angle. All of the patients maintained congruency of the radiocapitellar joint with no postoperative dislocations. Because of the low complication rate, the resolution of pain in patients who presented with pain, and the improvement of forearm bowing, this approach should be considered as a treatment option for children with MHE who are at risk for radiocapitellar dislocation.
METHODS: Therapeutic IV.

OBJECTIVE: Deformities of the forearm and shortening of the ulna occur in 30 % of patients with hereditary multiple exostoses (HME), leading to radial head dislocation and loss of movement. Several surgical techniques have been described for treatment, and the aim of our study was to present clinical and radiographic results at skeletal maturity in 15 children that underwent the surgical procedure of ulnar lengthening with external fixators.
METHODS: We evaluated 15 patients with ulnar shortening and radial head dislocation that underwent external fixation procedures. Radiographic assessment included measurement of radial articular angle, carpal slip, and ulnar shortening. Clinical evaluation included range of motion, MAYO Elbow Score, assessment function of the extremity as described by Stanton, the visual analog scale (VAS) for pain, and SF-12 to evaluate quality of life.
RESULTS: The average follow-up period was 77 months and took place when each patient had reached skeletal maturity. MAYO Elbow Score improved from 34.7 to 93.3 points, while the average preoperative functional assessment criteria score was 1.6 points and improved to 4.4. The preoperative average VAS ranged from 8.2 to 2.3, while the SF-12 in its physical (PCS) and mental (MCS) components resulted, respectively, as 53.3 and 54.2. Pronation and supination improved from a preoperative average value of 35.6° and 51.3° to 70° and 80.6°, respectively, at the most recent follow-up visit. Flexion and extension ranged, respectively, from 143° and 2° to 146.7° and 3°. Ulnar shortening improved from 24 mm preoperative to 3 mm, and radial articular angle varied from 37.7° preoperative to 26° at the last follow-up. Only one complication occurred in our group, and one patient completely healed from a case of nonunion of the ulna.
CONCLUSIONS: Ulnar lengthening is a safe and reliable procedure for the treatment of HME that provides good to excellent results and reduces radial head dislocation.