The biceps tendon as a measure of rotational deformity in residual brachial plexus birth palsy

Quantitative Musculoskeletal Imaging of the Pediatric Shoulder

ABSTRACT

Pediatric acquired and congenital conditions leading to shoulder pain and dysfunction are common. Objective, quantitative musculoskeletal imaging-based measures of shoulder health in children lag recent developments in adults. We review promising applications of quantitative imaging that tend to be available for common pediatric shoulder pathologies, especially brachial plexus birth palsy and recurrent shoulder instability, and imaging-related considerations of musculoskeletal growth and development of the shoulder. We highlight the status of quantitative imaging practices for the pediatric shoulder and highlight gaps where better care may be provided with advances in imaging technique and/or technology.

The morphologic change of the elbow with flexion contracture in upper obstetric brachial plexus palsy

BACKGROUND

Contracture of the elbow after obstetric brachial plexus palsy (OBPP) is well known; however, details of the 3-dimensional (3D) morphologic changes in the elbow joint in OBPP have not been clarified. This study aimed to clarify the 3D morphologic changes in the elbow joint by focusing on the distal humerus with flexion contracture in upper OBPP. We tested the hypothesis that the shape of the distal humerus with flexion contracture in upper OBPP is hypoplastic in the trochlea, capitellum, and olecranon fossa.

METHODS

We retrospectively studied 20 patients with elbow flexion contracture and residual OBPP. The approximate radius of the distal humerus, the shortest distance between the olecranon and coronoid fossa, and the size of the olecranon fossa were measured and compared between the affected and normal sides using 3D bone models to assess the distal humerus morphology.

RESULTS

The average radius of the distal humerus was smaller on the affected side than on the normal side. Furthermore, the average distance between the olecranon and coronoid fossa was greater and the average size of the olecranon fossa was smaller on the affected side than on the normal side. The size of the distal humerus was significantly smaller and the olecranon fossa was significantly shallower on the affected side.

CONCLUSIONS

Consistent with our original hypothesis, the distal humerus with flexion contracture in upper OBPP was hypoplastic. The shallow olecranon fossa might prevent full extension of the elbow even though soft tissue contracture release is performed. We recommend evaluation of the morphology of the olecranon fossa to determine the treatment plan for elbow flexion contracture with OBPP.

Three-dimensional humeral morphologic alterations and atrophy associated with obstetrical brachial plexus palsy

BACKGROUND

Obstetrical brachial plexus palsy (OBPP) is a common birth injury, resulting in severe functional losses. Yet, little is known about how OBPP affects the 3-dimensional (3D) humeral morphology. Thus, the purpose of this study was to measure the 3D humeral architecture in children with unilateral OBPP.

METHODS

Thirteen individuals (4 female and 9 male patients; mean age, 11.8 ± 3.3 years; mean Mallet score, 15.1 ± 3.0) participated in this institutional review board approved study. A 3D T1-weighted gradient-recalled echo magnetic resonance image set was acquired for both upper limbs (involved and noninvolved). Humeral size, version, and inclination were quantified from 3D humeral models derived from these images.

RESULTS

The involved humeral head was significantly less retroverted and in declination (medial humeral head pointed anteriorly and inferiorly) relative to the noninvolved side. Osseous atrophy was present in all 3 dimensions and affected the entire humerus. The inter-rater reliability was excellent (intraclass correlation coefficient, 0.96-1.00).

DISCUSSION

This study showed that both humeral atrophy and bone shape deformities associated with OBPP are not limited to the axial plane but are 3D phenomena. Incorporating information related to these multi-planar, 3D humeral deformities into surgical planning could potentially improve functional outcomes after surgery. The documented reduction in retroversion is an osseous adaptation, which may help maintain glenohumeral congruency by partially compensating for the internal rotation of the arm. The humeral head declination is a novel finding and may be an important factor to consider when one is developing OBPP management strategies because it has been shown to lead to significant supraspinatus inefficiencies and increased required elevation forces.

Advanced imaging and arthroscopic management of shoulder contracture after birth palsy

Modern imaging techniques applied to the pediatric glenohumeral joint have advanced understanding of the anatomic changes that occur secondary to muscular imbalance after brachial plexus birth palsy. A better understanding of the progression and timing of glenohumeral dysplasia has also increased awareness and vigilance of this problem. Early detection of glenohumeral joint subluxation is now possible, allowing for prompt treatment with closed, arthroscopic, or open joint reduction with and without tendon transfers. Dynamic ultrasound imaging, Botox, and arthroscopic techniques have expanded treatment options, providing minimally invasive methods to successfully manage glenohumeral joint dysplasia.

Current concepts in the management of brachial plexus birth palsy

Brachial plexus birth palsy, although rare, may result in substantial and chronic impairment. Physiotherapy, microsurgical nerve reconstruction, secondary joint corrections, and muscle transpositions are employed to help the child maximize function in the affected upper extremity. Many present controversies regarding natural history, microsurgical treatment, and secondary shoulder reconstructive surgery remain unresolved in infants with brachial plexus birth palsies. Recent literature has enhanced our understanding of the pathoanatomy and natural history of the injury as well as the surgical indications, expected outcomes, and complications; this literature has led to improved care of these patients. Based on the present evidence, recommendations for both microsurgery and shoulder reconstruction with tendon transfer and arthroscopic and open reductions are presented.