Motor Branching Pattern of the Radial Nerve for Hyperselective Neurectomy: From Anatomy to Clinical Translation.

PURPOSE: Predominant or isolated spasticity of the triceps following upper motor neuron injury is rare and often unmasked once the spastic elbow flexors are addressed. The purpose of this study was to delineate the motor branching pattern of the radial nerve to determine the feasibility of hyperselective neurectomies (HSN) for triceps spasticity. METHODS: Dissections of the motor branch to each triceps head were performed on 11 upper-extremity specimens. The numbers of trunks, branching patterns, and muscle entry points were recorded in reference to the acromion to interepicondylar line. Based on anatomic studies, 10 patients underwent a combined fractional lengthening and HSN procedure for triceps spasticity. Patient demographics, time from diagnosis, and complications were recorded. Preoperative and postoperative Modified Ashworth Scale (MAS) and total active elbow arc of motion were compared. RESULTS: The first branch from the radial nerve was consistently a single trunk to the long triceps head. There were many variations in the branching pattern and number of trunks to the lateral and medial heads of the triceps with motor entry points between 31% and 95% of the acromion to interepicondylar line distance. Ten patients (six men and four women; mean age: 48.5 years) underwent the combined procedure. Mean total active elbow arc of motion improved from 78° before surgery to 111° after surgery, with a 17.5° increase in active elbow flexion. Compared with a mean preoperative triceps MAS of 2.75, nine patients had triceps MAS of 0 at a mean of 10.2 months of follow-up. There was no loss of functional elbow extension and no directly related complications. CONCLUSIONS: Given the variable motor entry points, HSN to each triceps head would require extensive dissection. Therefore, a combined approach consisting of fractional lengthening of the long head and lateral head with HSN of the triceps medial head is recommended to address triceps spasticity. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Validation of the Root Analysis Score for C5 Viability in Patients With Pan-Brachial Plexus Injury.

PURPOSE: Pan-brachial plexus injury patients present a reconstructive challenge. The root analysis score, developed from parsimonious multivariable modeling of 311 pan-brachial plexus injury patients, determines the probability of having a viable C5 nerve based on four categories: positive C5 Tinel test, intact C5 nerve on computed tomography myelogram, lack of hemidiaphragmatic elevation, and absence of midcervical paraspinal fibrillations. METHODS: Root analysis scores were calculated for a separate cohort of patients with pan-brachial plexus injuries. Scores were validated by the presence or absence of a graftable C5 root, based on supraclavicular exploration and intraoperative electrophysiologic testing. Receiver operating characteristic curve, accuracy, and concordance statistic of the scores were calculated. Patients were divided into three root analysis score cohorts: less than 50 (low), 50-75 (average), and 75-100 points (high) based on dividing the score into quartiles and combining the lowest two. The probability, sensitivity, and specificity of each cohort having an available C5 nerve were based on the intraoperative assessment. RESULTS: Eighty patients (mean age, 33.1 years; 15 women and 65 men) were included. Thirty-one patients (39%) had a viable C5 nerve. The root analysis calculator had an overall accuracy of 82.5%, a receiver operating characteristic of 0.87, and a concordance statistic of 0.87, demonstrating high overall predictive value; 6.5% of patients with a score of less than 50 (94% sensitivity and 43% specificity), 16.1% of patients with a score of 50-75 (94% sensitivity and 67% specificity), and 77.4% of patients with a score of 75-100 (77% sensitivity and 90% specificity) had a graftable C5 nerve. CONCLUSIONS: The root analysis score demonstrated high accuracy and predictive power for a viable C5 nerve. In patients with a score of less than 50, the necessity of supraclavicular root exploration should balance patient factors, presentation timing, and concomitant injuries. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnosis II.

Combined Wrist Extensor Tenodesis and Tendon Transfers for Severe Spastic Flexed Wrist Deformity: Surgical Technique and Case Series.

Spastic wrist flexion deformities both limit the functional use of the hand for grasp and pinch producing a stigmatizing appearance. Tendon transfers and total wrist arthrodesis are treatment options for this condition depending on the patient's characteristics, the latter the most commonly used in patients with severe wrist flexion deformities. Tendon transfers alone in this scenario have the tendency for recurrent deformity due to tenorrhaphy failure or soft tissue creep and resultant loss of tension. Total wrist arthrodesis is a more invasive procedure, which can have hardware or fusion problems and that is irreversible. We propose a novel technique that incorporates a distally based wrist extensor tendon slip and suture tape tenodesis to the distal radius. The rationale of this technique is to act as a protective, internal splint to prevent recurrent deformity after primary or revision tendon transfer for moderate to severe spastic flexed wrist deformities, avoiding the need to perform a total wrist arthrodesis.

Injury and Biological Factors Impact Shoulder Function following Autogenous Grafting of Spinal Nerves for Pan-Brachial Plexus Reconstruction.

BACKGROUND: Shoulder function following spinal nerve grafting in pan-brachial plexus injuries(Pan-BPI) is not well described. The purpose of this study was twofold: 1)to evaluate shoulder abduction(ABD) and external rotation(ER) after grafting of viable spinal nerves to the suprascapular nerve(SSN), axillary nerve(AxN), or posterior division of the upper trunk(PDUT); and 2)to determine patient characteristics, injury severity/characteristics, and nerve graft factors that influenced outcomes. METHODS: 362 Pan-BPI reconstruction patients from a single institution were reviewed for those who underwent spinal nerve grafting for shoulder reanimation between 2001 and 2018. Patient demographics, injury severity scores(ISS), graft characteristics, strength, range of motion for shoulder ABD and ER, and patient-reported outcomes were recorded. Patients were divided into three groups based on the recovery of shoulder function: no return, ABD only, and ABD and ER. RESULTS: 110 patients underwent spinal nerve grafting, with 41 meeting inclusion criteria. 17(41.5%) had no return of shoulder function, 14(34.1%) had ABD alone, and 10(24.4%) had ABD and ER. Patients with recovery of both ABD and ER were significantly younger(18.6±5.56), had lower BMI(22.4±4.0), and lower ISS(10.5±6.24, p=0.003). Multivariable analysis found that with increasing age(OR:0.786, 95%CI:0.576,0.941) and ISS(OR:0.820, 95%CI:0.606-0.979), odds for return of ABD and ER significantly decreased. CONCLUSIONS: In Pan-BPI, 24.4% of patients demonstrated return of both ABD and ER following spinal nerve grafting to SSN and either AxN or PDUT. Age, BMI, and ISS were associated with poorer recovery of shoulder function. Careful patient selection and consideration of age, BMI, and ISS may improve outcomes of spinal nerve grafting for shoulder reanimation. LEVEL OF EVIDENCE: III.