Outcomes of glenohumeral dysplasia after brachial plexus birth injury using the Sup-ER orthosis

We investigated the efficacy of the supination-external rotation ('Sup-ER') orthosis, designed as a non-operative treatment to maintain normal anatomical growth of the shoulder, on the progression of glenohumeral dysplasia in patients with brachial plexus birth injuries. The Sup-ER orthosis was fabricated for 20 infants diagnosed with glenohumeral dysplasia after brachial plexus birth injuries and its success in correcting glenohumeral dysplasia was confirmed by objective calculations of the alpha angle on serial ultrasound findings and improvement in Active Movement Scale scores. Of the 20 patients, 14 had successful resolution of glenohumeral dysplasia, confirmed by shoulder abduction, shoulder flexion, external rotation and supination, Active Movement Scale scores and improving alpha angle measurements. Failure to rectify glenohumeral dysplasia, evidenced by worsening ultrasound findings and Active Movement Scale scores, necessitated a change to operative management in six patients.Level of evidence: IV.

Management of Brachial Plexus Birth Injury: The SickKids Experience

This article describes the approach utilized by the multidisciplinary team at Sick Kids Hospital to evaluate and treat patients with brachial plexus birth injury (BPBI). This approach has been informed by more than 30 years of experience treating over 1,800 patients with BPBI and continues to evolve over time. The objective of this article is to provide readers with a practical overview of the Sick Kids approach to the management of infants with BPBI.

Outcomes of Botulinum Toxin Injection for Shoulder Internal Rotation Contractures in Infants with Brachial Plexus Birth Injury

PURPOSE

Shoulder internal rotation contractures (IRC) are common sequela of brachial plexus birth injuries (BPBI). Botulinum toxin A (BTX-A) injection into targeted muscles has been described to facilitate functional improvement at the shoulder joint and prevent glenohumeral dysplasia. The purpose of this study was to assess the outcomes of BTX-A injections on shoulder IRC in children with BPBI.

METHODS

We conducted a retrospective analysis of 47 children with shoulder IRC due to BPBI, who were treated with BTX-A. Shoulder passive external rotation in adduction and Active Movement Scale external rotation scores were recorded before and after BTX-A injection. We also recorded the number of children who underwent secondary surgical balancing procedures to improve shoulder motion after BTX-A injection.

RESULTS

Mean age at the time of injection was 12 months (range, 5-23 months). Subjects demonstrated a significant increase in passive external rotation of 46° (range, 10° to 90) at 4 months; an average improvement of 18° (range, -30° to 80°) persisted at 11 months after injection. A total of 28 patients (60%) underwent subsequent external rotation tendon transfer. At 5-year follow-up, 7 patients (15%) had adequate functional shoulder range of motion and did not undergo external rotation tendon transfer.

CONCLUSIONS

Botulinum toxin A injections result in improvement in IRC due to BPBI, which is sustained beyond the expected half-life of 3 months. As many as 15% of patients who have this treatment avoid external rotation tendon transfer.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic IV.

Development of the glenohumeral joint after subscapular release and open relocation in children with brachial plexus birth palsy: long-term results in 61 patients

BACKGROUND

We present the long-term results of remodeling of the glenohumeral joint after open subscapularis elongation and relocation of the humeral head in patients with an internal rotation contracture and joint incongruity due to brachial plexus birth palsy.

METHODS

In this before-and-after study, 61 patients who underwent open subscapularis elongation and reduction of the glenohumeral joint were evaluated with respect to joint remodeling, with a mean follow-up period of 10.2 years (range, 7-16 years). The mean age at operation was 3.2 years (range, 8 months to 15 years). Measurements of the percentage of the humeral head anterior to the midscapular line (PHHA), glenoid version, and diameter of the humeral head were recorded using magnetic resonance imaging, comparing the affected joints preoperatively vs. postoperatively (n = 31) and comparing the operated vs. unaffected sides postoperatively (n = 61).

RESULTS

The mean increase in PHHA was 27.6 percentage points (95% confidence interval, 22.4-32.7 percentage points; P < .01), from 13.2% to 40.8%. The glenoid retroversion changed by 14.8° (95% confidence interval, 11.1°-18.4°; P < .01), from 25.4° to 10.6°, approaching a normal value. All patients, even those older than 5 years, showed a clear benefit from surgery.

CONCLUSIONS

Our study confirms that open subscapularis lengthening with joint repositioning, up to the age of 5 years, gives consistent remodeling of incongruent shoulders with surprisingly small differences between the operated and unaffected shoulders at long-term follow-up. The findings indicate that open reduction is useful also in adolescents and challenges the notion that older children should be treated with derotational humeral osteotomy.

Adding Value to the Magnetic Resonance Examination in a Case of Brachial Plexus Birth Palsy

We report a case of brachial plexus birth palsy in an infant with the inability to move the left upper limb since birth. There was neither history of birth trauma nor any complications during delivery. Magnetic resonance imaging (MRI) of brachial plexus showed postganglionic injury with musculoskeletal abnormalities. The child underwent surgical repair of the plexus and is on physical rehabilitation. In this case report, we discuss the utility of a single MRI examination with an elaborate discussion on various MRI signs of brachial plexus injury including secondary musculoskeletal manifestations. The case reiterates the significance of two-in-one approach while imaging these cases with MRI. Apart from reporting the damage to the brachial plexus, the radiologist should actively search for glenohumeral dysplasia. Awareness of classification and assessment of glenohumeral dysplasia should be routinely included as an integral part of imaging report as it adds incremental value to the overall patient management and functional outcome.

The Surgical Strategy to Correct the Rotational Imbalance of the Glenohumeral Joint after Brachial Plexus Birth Injury

In upper brachial plexus birth injury, rotational balance of the glenohumeral joint is frequently affected and contracture in medial rotation of the arm develops, due to a severe palsy or insufficient recovery of the lateral rotators. Some of these children present with a severe glenohumeral joint contracture in the first months, although regular physiotherapy has been provided, a condition associated with a posteriorly subdislocated or dislocated humeral head. These conditions should be screened early by a pediatrician or specialized physiotherapist. Both aspects of muscular weakness affecting the lateral rotators and the initial or progressive glenohumeral deformity and/or subdislocation must be identified and treated accordingly, focusing on the reestablishment of joint congruence and strengthening of the lateral rotators to improve rotational balance, thus working against joint dysplasia and loss of motor function of the shoulder in a growing child. Our treatment strategy adapted over the last 20 years to results from retrospective studies, including biomechanical aspects on muscular imbalance and tendon transfers. With this review, we confront our actual concept to recent literature.

The role of subscapularis muscle denervation in the pathogenesis of shoulder internal rotation contracture after neonatal brachial plexus palsy: a study in a rat model

We assessed the role of subscapularis muscle denervation in the development of shoulder internal rotation contracture in neonatal brachial plexus injury. Seventeen newborn rats underwent selective denervation of the subscapular muscle. The rats were evaluated at weekly intervals to measure passive shoulder external rotation. After 4 weeks, the animals were euthanized. The subscapularis thickness was measured using 7.2T MRI axial images. The subscapularis muscle was then studied grossly, and its mass was registered. The fiber area and the area of fibrosis were measured using collagen-I inmunostained muscle sections. Significant progressive decrease in passive shoulder external rotation was noted with a mean loss of 58° at four weeks. A significant decrease in thickness and mass of the subscapularis muscles in the involved shoulders was also found with a mean loss of 69%. Subscapularis muscle fiber size decreased significantly, while the area of fibrosis remained unchanged. Our study shows that subscapularis denervation, per se, could explain shoulder contracture after neonatal brachial plexus injury, though its relevance compared to other pathogenic factors needs further investigation.

The role of muscle imbalance in the pathogenesis of shoulder contracture after neonatal brachial plexus palsy: a study in a rat model

BACKGROUND

An internal rotation contracture of the shoulder is common after neonatal brachial plexus injuries due to subscapularis shortening and atrophy. It has been explained by 2 theories: muscle denervation and muscle imbalance between the internal and external rotators of the shoulder. The goal of this study was to test the hypothesis that muscle imbalance alone could cause subscapularis changes and shoulder contracture.

MATERIALS AND METHODS

We performed selective neurectomy of the suprascapular nerve in 15 newborn rats to denervate only the supraspinatus and the infraspinatus muscles, leaving the subscapularis muscle intact. After 4 weeks, passive shoulder external rotation was measured and a 7.2-T magnetic resonance imaging scan of the shoulders was used to determine changes in the infraspinatus and subscapularis muscles. The subscapularis muscle was weighed to determine the degree of mass loss. An additional group of 10 newborn rats was evaluated to determine the sectional muscle fiber size and muscle area of fibrosis by use of images from type I collagen immunostaining.

RESULTS

There was a significant decrease in passive shoulder external rotation, with a mean loss of 66°; in the thickness of the denervated infraspinatus, with a mean loss of 40%; and in the thickness and weight of the non-denervated subscapularis, with mean losses of 28% and 25%, respectively. No differences were found in subscapularis muscle fiber size and area of fibrosis between shoulders after suprascapular nerve injury.

CONCLUSIONS

Our study supports the theory that shoulder muscle imbalance is a cause of shoulder contracture in patients with neonatal brachial plexus palsy.

Geometry of the proximal humeral articular surface in young children: a study to define normal and analyze the dysplasia due to brachial plexus birth palsy

BACKGROUND

Little is known regarding the morphology of the proximal humerus in growing children. This study reports bilateral magnetic resonance imaging measurements in children with internal rotation contractures from birth palsy, hypothesizing that dysplasia alters normal humeral sphericity and symmetry.

METHODS

We studied 25 children with unilateral internal rotation contractures (mean age, 3.7 years) for humeral shape by bilateral magnetic resonance imaging studies at the mid-glenoid level. Local radii of curvature were compared for symmetry and orientation.

RESULTS

Neither side showed uniform radii (sphericity), but normal humeri showed symmetry lost in dysplasia. Internal rotation contractures were correlated with flattening of the anterior humeral head (P = .0002). All heads were flatter in the region of articular contact. The skew axis (the largest cross-sectional diameter of the proximal humerus) was collinear with the articular surface centerline in normal humeri, an alignment often lost with dysplasia, resulting in a skew axis angle. The severity of glenoid deformity correlated with progressive posterior displacement of the humeral head center (P < .0003).

CONCLUSION

The normal humeral articular surface in the young child is not spherical and is flatter in the middle than at the periphery but is symmetric about its central axis. Internal rotation contractures result in loss of this symmetry with characteristic flattening of the anterior humeral head and development of a skew axis angle.

CLINICAL RELEVANCE

Posterior displacement of the humeral head center of rotation beyond 50% of the calculated head radius warrants vigilance and possibly surgical intervention because there is a high likelihood for development of a pseudoglenoid.

Shoulder function and anatomy in complete obstetric brachial plexus palsy: long-term improvement after triangle tilt surgery

PURPOSE

Untreated complete obstetric brachial plexus injury (COBPI) usually results in limited spontaneous recovery of shoulder function. Older methods used to treat COBPI have had questionable success, with very few studies being published. The purpose of the current study was to examine the results of triangle tilt surgery on shoulder function and development in COBPI individuals.

METHODS

This study was conducted as a retrospective chart review. Inclusion criteria were COBPI patients that had undergone the triangle tilt procedure from 2005 to 2009 and were between the ages of 9 months and 12 years. COBPI was defined as permanent injury to all five nerve roots (C5-T1), with significant degradation in development and function of the hand. Twenty-five patients with a mean age of 5 (0.75-12) years were followed up clinically for more than 2 years.

RESULTS

The triangle tilt procedure resulted in demonstrable clinical enhancements with appreciable improvements in shoulder function, glenoid version, and humeral head congruity. There was a significant increase in the overall Mallet score (2.4 points, p < 0.0001) following surgical correction in patients that were followed up for more than 2 years.

CONCLUSIONS

The results of this study demonstrate that COBPI patients who develop SHEAR and medial rotation contracture deformities can benefit from the triangle tilt surgery, which improves shoulder function and anatomy across a range of pediatric ages. Despite these patients presenting late for surgery in general (5 years), significant improvements were observed in their glenohumeral (GH) dysplasia and their ability to perform shoulder and arm movements following surgery.