Normal Glenoid Ossification in Pediatric and Adolescent Shoulders Mimics Bankart Lesions: A Magnetic Resonance Imaging-Based Study

Sex-Related Differences in Shoulder Complex Joint Dynamics Variability During Pediatric Manual Wheelchair Propulsion

More than 80% of adult manual wheelchair users with spinal cord injuries will experience shoulder pain. Females and those with decreased shoulder dynamics variability are more likely to experience pain in adulthood. Sex-related differences in shoulder dynamics variability during pediatric manual wheelchair propulsion may influence the lifetime risk of pain. We evaluated the influence of sex on 3-dimensional shoulder complex joint dynamics variability in 25 (12 females and 13 males) pediatric manual wheelchair users with spinal cord injury. Within-subject variability was quantified using the coefficient of variation. Permutation tests evaluated sex-related differences in variability using an adjusted critical alpha of P = .001. No sex-related differences in sternoclavicular or acromioclavicular joint kinematics or glenohumeral joint dynamics variability were observed (all P ≥ .042). Variability in motion, forces, and moments are considered important components of healthy joint function, as reduced variability may increase the likelihood of repetitive strain injury and pain. While further work is needed to generalize our results to other manual wheelchair user populations across the life span, our findings suggest that sex does not influence joint dynamics variability in pediatric manual wheelchair users with spinal cord injury.

Normal ossification of the glenoid mimicking a glenoid fracture in an adolescent patient: a case report

A 13-year-old male was diagnosed with a glenoid fracture following direct shoulder trauma, for which surgical treatment was considered. After referral to a center for pediatric orthopedic care, physical examination, contralateral shoulder X-ray, and detailed computed tomography examination ruled out the presence of fracture; these findings were later confirmed by magnetic resonance imaging. Normal ossification patterns in the adolescent shoulder may simulate a fracture in traumatic settings. To accurately diagnose and manage pediatric shoulder pathology, orthopedic surgeons must be aware of the normal anatomy of the growing shoulder, its secondary ossification centers, and growth plates.

Dynamic pediatric shoulder instability: Etiology, pathogenesis and treatment

Dynamic shoulder instability in children or adolescents, whose glenohumeral growth plates are still open, is a rare condition with an etiology that is hard to decipher. Atraumatic and recurrent forms are most common, contrary to adults. Disruptions to capsule and ligament maturation, muscle balance or bone growth can lead to glenohumeral instability. The etiology assessment, which needs to be multidisciplinary in atraumatic forms, aims to collect the medical history, analyze the direction of the instability, determine whether it is voluntary or involuntary, and look for a history of trauma, connective tissue abnormality, psychological disorder, neuromuscular pathology or congenital malformation. The initial treatment is conservative. It requires a multidisciplinary team when the shoulder instability is voluntary. Surgical treatment is reserved for symptomatic forms that do not respond to conservative treatment and have an impact on daily life and/or sports participation after a minimum of 6 months of well-conducted rehabilitation. The results of surgical stabilization mainly depend on the features of the instability, the anatomical structures damaged and the etiology. Episodes of recurrent instability in children/adolescents with open glenohumeral growth plates can fade in adulthood or can get worse with the development of structural damage. Early detection of poor outcomes and suitable treatment will help to limit the occurrence of osteoarthritis in the medium and long term. LEVEL OF EVIDENCE: Expert opinion.

The Influence of Age at Pediatric-Onset Spinal Cord Injury and Years of Wheelchair Use on Shoulder Complex Joint Dynamics During Manual Wheelchair Propulsion

Objective

To assess the association of age at pediatric-onset spinal cord injury (SCI) and years of manual wheelchair use with shoulder dynamics.

Design

Upper extremity kinematics and hand-rim kinetics were obtained during manual wheelchair propulsion. An inverse dynamics model computed three-dimensional acromioclavicular, sternoclavicular, and glenohumeral joint dynamics. Linear mixed effects models evaluated the association of age at injury onset and years of wheelchair use with shoulder dynamics.

Setting

Motion laboratory within a children's hospital.

Participants

Seventeen manual wheelchair users (N=17; 6 female, 11 male; mean age: 17.2 years, mean age at SCI onset: 11.5 years) with pediatric-onset SCI (levels: C4-T11) and International Standards for Neurological Classification of SCI grades: A (11), B (3), C (2), and N/A (2).

Interventions

Not applicable.

Main Outcome Measures

Acromioclavicular, sternoclavicular, and glenohumeral angles and ranges of motion, and glenohumeral forces and moments.

Results

We observed a decrease in maximum acromioclavicular upward rotation (ß [95% confidence interval {CI}]=3.02 [0.15,5.89], P=.039) and an increase in acromioclavicular downward/upward rotation range of motion (ß [95% CI]=0.44 [0.08,0.80], P=.016) with increasing age at SCI onset. We found interactions between age at onset and years of use for maximum glenohumeral abduction (ß [95% CI]=0.16 [0.03,0.29], P=.017), acromioclavicular downward/upward rotation range of motion (ß [95% CI]=-0.05 [-0.09,-0.01], P=.008), minimum acromioclavicular upward rotation (ß [95% CI]=-0.34 [-0.64,-0.04], P=.026). A decrease in glenohumeral internal rotation moment (ß [95% CI]=-0.09 [-0.17,-0.009], P=.029) with increasing years of use was found.

Conclusions

Age at injury and the years of wheelchair use are associated with shoulder complex biomechanics during wheelchair propulsion. These results are noteworthy, as both age at SCI onset and years of wheelchair use are considered important factors in the incidence of shoulder pain. These results suggest that investigations of biomechanical changes over the lifespan are critical.

Normal Humeral Head Ossification in Pediatric and Adolescent Shoulders Can Mimic Hill-Sachs Lesions: A Magnetic Resonance Imaging-based Study

BACKGROUND

The sequential maturation of the humeral head (HH) as viewed on magnetic resonance imaging (MRI) has not been described to date. Proper assessment may be complicated by the presence of physeal tissue in pediatric patients. Past studies suggest that skeletally immature patients may also have a higher risk of a false-positive diagnosis of Hill-Sachs lesion on MRI. The purpose of this study was to define pediatric HH developmental patterns using MRI and to investigate for any associations with findings of known false-positive Hill-Sachs.

METHODS

Picture Archiving and Communication System (PACS) records at an urban academic tertiary care musculoskeletal facility from 2014 to 2020 were queried for shoulder MRI in patients aged 0 to 15 years. Patients were excluded if they had a history of glenohumeral instability, fracture, growth arrest, brachial plexus injury, surgery, or infection. All images were independently evaluated by a musculoskeletal fellowship-trained radiologist. Each HH was staged based on skeletal maturity.

RESULTS

For both sexes, HHs matured in a predictable manner with increasing chronological age associated with a higher ossification stage. False Hill-Sachs lesions were observed in girls aged 4 to 7 and boys aged 5 to 14, exclusively during stage I to II ossification.

CONCLUSIONS

False Hill-Sachs lesions were visualized on MRI in stage I to II proximal humerus ossification. Due to differential timing of skeletal maturation, males present with false Hill-Sachs lesions at a later age than females on average. When interpreting shoulder MRI for glenohumeral instability, clinicians should be cautious of false Hill-Sachs lesions, especially in younger patients with distinct greater tuberosity and HH ossification centers (stage I to II ossification).

LEVEL OF EVIDENCE

Level III.

Editorial Commentary: Bankart Lesion in an Adolescent Athlete? Not So Fast

With the desire to remain athletically competitive, many adolescent athletes with shoulder instability are turning to early surgical invention. But is surgical repair always necessary and are all Bankart lesions identical? Using 3-dimensional, frequency-selective, fat-suppressed gradient recalled echo magnetic resonance imaging (MRI) scans, the authors noted that the anterior glenoid rim secondary ossification center peaks at age 16 years in male patients but is only fused in 70% of male patients at age 17 years. Therefore, relying on MRI alone to guide surgical treatment may result in procedures that may otherwise be avoided because normal glenoid development may be mistaken for a bony Bankart lesion. A thorough history and physical examination are still essential in adolescents with shoulder injuries. Relying on MRI alone to guide surgical treatment may result in procedures that may otherwise be avoided.