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Radial head dislocation and subluxation in osteogenesis imperfecta
Alice Marcdargent Fassier1, Frank Rauch, Mehdi Aarabi
1Pediatric Orthopaedics Clinical Fell, McGill University, 1529 Cedar Avenue, Montreal, QC H3G 1AG, Canada. amarcdargent@shriners.mcgill.ca
Insights
Radial head malalignment is frequent in osteogenesis imperfecta, particularly type V, and is linked to upper limb bowing and function impairment. Surgical correction of bowing may benefit selected patients.
Area of Science:
- Orthopedics
- Pediatric Orthopedics
- Genetics
Background:
- Osteogenesis imperfecta (OI) is a genetic disorder characterized by brittle bones.
- Upper limb deformities in children with OI can significantly impact their functional abilities.
Purpose of the Study:
- To determine the prevalence of radial head malalignment in various types of osteogenesis imperfecta.
- To identify factors associated with radial head malalignment in pediatric OI patients.
Main Methods:
- Retrospective analysis of 489 upper limbs from 254 patients with different types of osteogenesis imperfecta.
- Radiographic assessment for radial head malalignment, associated abnormalities, and limb deformations.
- Measurement of forearm range of motion and grip strength in a subset of patients.
Main Results:
- Radial head malalignment (dislocation or subluxation) was observed in 44 and 39 upper extremities, respectively.
- Malalignment was significantly more common in type V OI (86%) compared to other types (0%-29%).
- Associated factors included capitellum/radial head/neck dysplasia (except type V capitellum), interosseous membrane calcification (type V specific), and radial/ulnar bowing, correlating with reduced function.
Conclusions:
- Radial head malalignment is a frequent complication of osteogenesis imperfecta, especially type V.
- Malalignment is associated with limb bowing and impaired upper limb function.
- Findings support considering surgical correction for radial and ulnar bowing in select osteogenesis imperfecta patients.
Background:
Upper limb deformity in children with osteogenesis imperfecta may substantially impair function. The aims of this retrospective work were to study the prevalence of radial head malalignment (dislocation or subluxation) in different types of osteogenesis imperfecta and to identify factors linked to it.
Methods:
We assessed 489 upper limbs from 254 patients (with a mean age of 9.6 years and including 130 female patients) who had various types of osteogenesis imperfecta. Radiographs representing a single time-point for each patient were assessed for the presence and direction of radial head malalignment and associated abnormalities (dysplasia of the capitellum or of the radial head or neck, calcification of the interosseous membrane, or radioulnar synostosis). Deformations of the humerus, radius, and ulna were assessed with regard to location, direction, and magnitude. The forearm range of motion in pronation and supination and the hand grip force were measured in a subset of patients.
Results:
We observed radial head dislocation or subluxation in forty-four and thirty-nine upper extremities, respectively. The frequency of radial head malalignment was significantly higher in type-V osteogenesis imperfecta (86%) than in the other types (0% to 29%) (p < 0.001). Dysplasia of the humeral capitellum, radial head, or radial neck was associated with malalignment in all types of osteogenesis imperfecta, with the exception of capitellum dysplasia in type V. Malalignment in type V was associated with calcification of the interosseous membrane, an abnormality that was specific for type V. In the other osteogenesis imperfecta types, malalignment was commonly linked with radial and ulnar deformation and was associated with decreased forearm range of motion in supination and pronation and a lower grip force.
Conclusions:
Radial head malalignment is common in osteogenesis imperfecta, especially in type V. Malalignment is associated with bowing characteristics and impaired function of the upper limb. These findings may provide support for surgical correction of radial and ulnar bowing in selected patients with osteogenesis imperfecta.
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