Comparing functional outcome of triangle tilt surgery performed before versus after two years of age.

BACKGROUND: Many patients each year who are born with obstetric brachial plexus injuries eventually do not achieve complete recovery. As a result of the primary nerve injuries, these patients will often develop bony deformities involving the shoulder joint as a secondary consequence. The triangle tilt surgery has been shown to be an effective procedure to correct these deformities and has been performed on patients ranging in age from less than a year old to adolescence. The purpose of this retrospective study is to compare outcomes of triangle tilt surgery performed on patients before the age of 2 years versus after 2 years of age to determine an optimal age to operate on these children. METHODS: 36 patients with deformities developed secondarily from the initial obstetric brachial plexus injury in this study were divided into 2 groups. Group 1, those who had undergone triangle tilt surgery at < 2 yrs of age (16 patients). Group 2, those who were operated at > 2 yrs of age (20 patients). Group 1 age range: 9 months to 23 months, average: 18 months. Group 2 age range: 26 months to 9 years, average: 6 years. RESULTS: Significant differences were found between the 2 groups (0-2 yrs vs > 2yrs) in regards to overall changes (pre- to post-op) in Mallet score, external rotation score, hand-to-mouth score, and supination angle. DISCUSSION: This study demonstrates that triangle tilt surgery had better outcomes on clinical functioning if performed before the age of 2 years, however, improvement in clinical functioning can still be achieved if the triangle tilt surgery is performed after the age of 2 years as well. A possible mechanism to explain this phenomenon is the increased potential for anatomical remodeling if the triangle tilt surgery is performed at a younger age, thereby leading to significant functional improvement.

Triangle tilt and steel osteotomy: similar approaches to common problems.

BACKGROUND: Each year, thousands of children worldwide suffer obstetric brachial plexus nerve injuries resulting not only in primary nerve injury, but also in development of secondary muscle and bone deformities of the shoulder. The triangle tilt surgery has been developed and shown to effectively address these deformities. The triangle tilt procedure was initially designed by the lead author (RKN) to follow the concepts of joint normalization featured in the Steel pelvic osteotomy used to correct developmental dysplasia of the hip joint, and indeed ultimately bears a striking resemblance to the Steel osteotomy. Prior to performing these bony surgical procedures, soft tissue procedures are performed to release the muscle contractures of the shoulder and hip. The purpose of this article is to compare and analyze the similarities between the indications, surgical techniques, involved anatomy, and outcomes of these operative procedures. METHODS: A literature review was conducted using PubMed to identify articles pertaining to triangle tilt surgery and the Steel pelvic osteotomy. Functional parameters and surgical strategies were compared. Pre- and post-operative CTs were analyzed to compare anatomical results of the procedures. RESULTS: Similarities were found between both procedures in terms of indications, involved anatomy, surgical techniques, and outcomes. The triangle tilt surgery is indicated to correct the developmental dysplasia of the glenohumeral joint in obstetric brachial plexus injury patients. Steel pelvic osteotomy is performed to correct the subluxation and dislocation of the hip innominate bone in patients with congenital dysplasia, cerebral palsy myelodysplasia, and poliomyelitis. The involved anatomy of both procedures is similar in that both involve limb girdles and ball-and-socket joints, namely the shoulder and hip. Both procedures are also triple osteotomies, the triangle tilt involving the acromion, clavicle and scapula while the Steel osteotomy involves the iliac spine, ischial and pubic ramus of the innominate bone. Surgical techniques also bear likenesses in that both can theoretically be done percutaneously. Post-operative CT outcomes of both surgeries showed improved anatomical positioning of the ball-and-socket joint congruency, and therefore better functional outcomes. DISCUSSION: The similarities between the triangle tilt surgery and Steel pelvic osteotomy could potentially be useful as a model system in developing other procedures that involve the shoulder and hip. Future clinical applications include the development and implementation of new surgical procedures based on comparisons and adaptations from the hip to the shoulder and vice versa.

Triangle tilt surgery: effect on coracohumeral distance and external rotation of the glenohumeral joint.

OBJECTIVE: Shoulder muscle imbalances and bone deformities that develop secondary to obstetric brachial plexus injury have been extensively studied. Less emphasis has focused on coracohumeral distance, a small value potentially being linked to impaired shoulder external rotation. The purpose of this study is to analyze coracohumeral distances and shoulder external rotation in obstetric brachial plexus injury patients before and after triangle tilt surgery. METHODS: Twenty patients with deformities secondary to obstetric brachial plexus injury were included. Coracohumeral distances were measured on computed tomographic images. Clinical functioning was evaluated through video recordings by using a modified Mallet scale. Paired Student t tests were used to determine statistical significance of anatomic and functional parameters, pre- and postoperatively. RESULTS: Coracohumeral distance (P < .0006), total Mallet score (P < .0001), supination angle (P < .0001), and individual Mallet scores for all external rotation parameters including hand-to-mouth (P < .0001), supination (P = .0010), external rotation (P < .0001), hand-to-neck (P < .0001), and hand-to-spine (P = .0064) were significantly higher postoperatively than preoperatively for affected shoulders. Hand-to-mouth angles were significantly lower postoperatively than preoperatively (P < .0001). Coracohumeral distance in unaffected shoulders remained unchanged. CONCLUSIONS: Triangle tilt surgery significantly improves coracohumeral distance and clinical functioning in obstetric brachial plexus injury patients. Coracohumeral distance plays a key role in shoulder external rotation. Increasing coracohumeral distance significantly improves all external rotation parameters and total Mallet scores. The triangle tilt surgery relieves excessive tightness of the anterior stabilizing complex, widens coracohumeral distance, and improves external rotation of shoulder.

Coracoid abnormalities and their relationship with glenohumeral deformities in children with obstetric brachial plexus injury.

BACKGROUND: Patients with incomplete recovery from obstetric brachial plexus injury (OBPI) usually develop secondary muscle imbalances and bone deformities at the shoulder joint. Considerable efforts have been made to characterize and correct the glenohumeral deformities, and relatively less emphasis has been placed on the more subtle ones, such as those of the coracoid process. The purpose of this retrospective study is to determine the relationship between coracoid abnormalities and glenohumeral deformities in OBPI patients. We hypothesize that coracoscapular angles and distances, as well as coracohumeral distances, diminish with increasing glenohumeral deformity, whereas coracoid overlap will increase. METHODS: 39 patients (age range: 2-13 years, average: 4.7 years), with deformities secondary to OBPI were included in this study. Parameters for quantifying coracoid abnormalities (coracoscapular angle, coracoid overlap, coracohumeral distance, and coracoscapular distance) and shoulder deformities (posterior subluxation and glenoid retroversion) were measured on CT images from these patients before any surgical intervention. Paired Student t-tests and Pearson correlations were used to analyze different parameters. RESULTS: Significant differences between affected and contralateral shoulders were found for all coracoid and shoulder deformity parameters. Percent of humeral head anterior to scapular line (PHHA), glenoid version, coracoscapular angles, and coracoscapular and coracohumeral distances were significantly lower for affected shoulders compared to contralateral ones. Coracoid overlap was significantly higher for affected sides compared to contralateral sides. Significant and positive correlations were found between coracoscapular distances and glenohumeral parameters (PHHA and version), as well as between coracoscapular angles and glenohumeral parameters, for affected shoulders. Moderate and positive correlations existed between coracoid overlap and glenohumeral parameters for affected shoulders. On the contrary, all correlations between the coracoid and glenohumeral parameters for contralateral shoulders were only moderate or relatively low. CONCLUSIONS: These results indicate that the spatial orientation of the coracoid process differs significantly between affected and contralateral shoulders, and it is highly correlated with the glenohumeral deformity. With the progression of glenohumeral deformity, the coracoid process protrudes more caudally and follows the subluxation of the humeral head which may interfere with the success of repositioning the posteriorly subluxed humeral head anteriorly to articulate with the glenoid properly.

Nitric oxide signaling and neural stem cell differentiation in peripheral nerve regeneration.

OBJECTIVE: The objective was to examine whether nitric oxide signaling plays a role in human embryonic stem cell differentiation into neural cells. This article reviews current literature on nitric oxide signaling and neural stem cell differentiation for potential therapeutic application to peripheral nerve regeneration. METHODS: Human embryonic H9-stem cells were grown, maintained on mitomycin C-treated mouse embryonic fibroblast feeder layer, cultured on Matrigel to be feeder-free, and used for all the experiments. Fluorescent dual-immunolabeling and confocal image analysis were used to detect the presence of the neural precursor cell markers nestin and nitric oxide synthase-1. Fluorescence-activated cell sorting analysis was used to determine the percentage of expression. RESULTS: We have shown the confocal image of stage 1 human embryonic stem cells coexpressing nestin and nitric oxide synthase-1. Fluorescence-activated cell sorting analysis indicated 24.3% positive labeling of nitric oxide synthase-1. Adding retinoic acid (10(-6) M) to the culture medium increased the percent of nitric oxide synthase-1 positive cells to 33.9%. Combining retinoic acid (10(-6) M) with 8-brom cyclic guanosine monophosphate (10(-5) M), the fluorescence-activated cell sorting analysis demonstrated a further increase of nitric oxide synthase-1 positive cells to 45.4%. Our current results demonstrate a prodifferentiation potency of nitric oxide synthase-1, stimulated by retinoic acid with and without cyclic guanosine monophosphate. CONCLUSION: We demonstrated for the first time how nitric oxide/cyclic guanosine monophosphate signaling contributes to the development of neural precursors derived from human embryonic stem cells and enhances the differentiation of precursors toward functional neurons for peripheral nerve regeneration.

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.