Long-term outcomes of triangle tilt surgery for obstetric brachial plexus injury

Abstract

Aim: The purpose of this study was to evaluate long-term shoulder functional outcomes from a triangle tilt procedure on obstetric patients, who initially presented with medial rotation contracture and scapular deformity secondary to obstetric brachial plexus injury.

Methods: We retrospectively studied long-term outcomes both functionally and anatomically in 61 patients (age ranging from 2 to 12 years). Functional movements were evaluated and scored using a modified Mallet scale at different time intervals: preoperatively, 1 year and 2 year following triangle tilt surgery. Shoulder anatomy was examined on radiologic images to evaluate the severity of shoulder deformities preoperatively and anatomical improvement after the surgery.

Results: All shoulder functional movements were significantly improved at 1 and 2 year follow-ups. Functional improvements were maintained in shoulder abduction, external rotation and hand-to-mouth movements beyond the first year, and continued in hand-to-neck and hand-to-spine movements past 2 years. Remarkable glenohumeral remodeling or reservation of glenoid congruence was observed in all patients over a mean time of 27 months postoperatively.

Conclusion: The triangle tilt procedure, which addresses scapular and glenohumeral joint abnormalities characteristic of Erb's palsy, improves shoulder functional movements and anatomical structure in patients over the long-term.

Fig. 1

Comparisons of individual functional movements of external rotation (a), hand-to-neck (b), hand-to-spine (c), hand-to-mouth (d), apparent supination (e), and total modified Mallet score (f), in patients with obstetric brachial plexus injury at different time intervals: preoperative, 1 year follow-up and 2 year follow-up. *p < 0.05, **p < 0.01, ***p < 0.001

Fig. 2

Comparisons of pre- and postoperative hand-to-mouth movement for patients with obstetric brachial plexus injury. a Preoperative photograph of a 10-year-old boy demonstrating limitation of hand-to-mouth function with typical Bugler’s position; b same patient, 24 months after triangle tilt surgery. c Preoperative photograph of a 7-year-old girl demonstrating limitation of hand-to-mouth function; d same patient, 27 months after triangle tilt surgery

Fig. 3

Comparisons of pre- and postoperative apparent supination movement for patients with obstetric brachial plexus injury. a Preoperative photograph of a 10-year-old boy demonstrating limitation of apparent supination movement; b same patient, 24 months after triangle tilt surgery. c Preoperative photograph of a 7-year-old girl demonstrating limitation of apparent supination movement; d same patient, 27 months after triangle tilt surgery

Fig. 4

Comparisons of pre- and postoperative shoulder anatomical structure for a 5-year-old patient with obstetric brachial plexus injury. a Preoperative axial CT diagram demonstrating the right glenohumeral joint deformity (with −8% of humeral head anterior to the scapula line and 40° of glenoid retroversion). b Preoperative 3D CT image demonstrating the right scapular deformity (with 31% of the scapula above the clavicle relative to the unaffected left scapula). Twenty-six months after the triangle tilt surgery, c postoperative axial CT diagram demonstrating improvement in the right glenohumeral joint alignment (with 40% of humeral head anterior to the scapula line and 12° of glenoid retroversion), and d postoperative 3D CT image demonstrating reduction in the right scapular elevation (with 5% of the scapula above the clavicle relative to the unaffected left scapula)