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.

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.

Clinical Predictors of C5 Spinal Nerve Viability in Pan-Brachial Plexus Injuries.

BACKGROUNDS: In pan-brachial plexus injury patients, distinguishing between pre-ganglionic and post-ganglionic injuries is crucial to reconstructive planning. This study aimed to identify pre-operative factors that would accurately predict a reconstructible C5 spinal nerve. METHODS: Pan-brachial plexus injury patients from a single institution between 2001 and 2018 were reviewed. Patient demographics, clinical examination, diagnostic imaging, and electrodiagnostic results were recorded. C5 viability was determined based on supraclavicular exploration and intraoperative electrophysiologic testing. Univariate analysis identified significant factors for regression analysis. Multivariable parsimonious model was created using stepwise high performance logistic regression. RESULTS: 311 patients (mean age 29.9 years; 46 females, 265 males; Injury Severity Score 17.2) were included. 134 (43%) had a viable C5 and 50 (12%) patients had a viable C6 nerve. Intact C5 spinal nerve on CT myelogram (OR 5.4), positive Tinel's test (OR 2.6), M ≥ 4 rhomboid (OR 1.3) or M ≥ 4 serratus anterior (OR 1.4), and rhomboid needle EMG (OR 1.8) were predictive of having a viable C5 spinal nerve. The multivariable parsimonious stepwise model (AUC 0.77) included four factors: positive Tinel's test, intact C5 spinal nerve on CT myelogram, hemi-diaphragmatic elevation, and mid-cervical paraspinal fibrillations. CONCLUSIONS: In this cohort of pan-brachial plexus patients with major polytrauma, there was a 43% incidence of viable C5 spinal nerve. A positive Tinel's test (OR 2.1) and intact C5 spinal nerve on CT myelogram (OR 4.9) predicted a viable C5 nerve. In contrast, hemi-diaphragmatic elevation (OR 3.1) and mid-cervical paraspinal fibrillations (OR 2.92) predicted root avulsion.

Factors Associated with Poorer Outcomes from Triceps Motor Branch to Anterior Axillary Nerve Transfer: A Case-Control Study.

INTRODUCTION: We sought to identify predictors of failed triceps motor branch transfer to the anterior division of the axillary nerve (AN) for shoulder abduction reconstruction after a brachial plexus injury (BPI). METHODS: A case-control study of adult AN or brachial plexus patients treated with a triceps motor branch transfer to the anterior division of the AN with a minimum 18 months of follow-up was performed. The failure group (case group) was defined as modified British Medical Research Council muscle scale (mBMRC) postoperative deltoid grade ≤2 and was compared to the successful outcome group (control group), defined as mBMRC postoperative deltoid grade ≥3. Clinical variables, injury mechanism, time from injury to surgery, root avulsion status, electrodiagnostic studies, rotator cuff injuries, scapula fracture, Disabilities of the Arm Shoulder and Hand scores, and preoperative triceps strength were analyzed. Subgroup analysis was performed for patients with isolated AN injuries and those with BPI. RESULTS: A total of 69 patients met inclusion/exclusion criteria, of whom 23 regained ≥M3 deltoid muscle strength and 52° ± 69° of shoulder abduction (successful outcome group) and 46 regained ≤M2 deltoid muscle strength and 27° ± 30° of shoulder abduction (failure group). Preoperative triceps weakness (M ≤4) was significantly more common in the failure group (63% vs. 30%, P = 0.032); preoperative triceps muscle fibrillations were significantly more common in the failure group (61% vs. 30%, P = 0.02). Isolated AN injuries presented better preoperative motion and postoperative outcomes results compared to BPI. CONCLUSIONS: Use of triceps motor branch associated with fibrillations or weakness resulted in statistically poorer outcomes compared to the use of a normal triceps motor branch in the restoration of anterior AN function after nerve transfer.

Persistent and profound peripheral nerve injuries following reverse total shoulder arthroplasty.

BACKGROUND: Peripheral nerve injuries associated with reverse total shoulder arthroplasty (rTSA) are rarely reported and are often dismissed as neuropraxias, particularly in the setting of perioperative nerve blocks. The purpose of this study was to evaluate nerve injuries following rTSA to determine if there is a pattern of injury and to evaluate outcomes of patients who sustain an intraoperative nerve injury. METHODS: A retrospective review was performed identifying patients who underwent rTSA and had a concomitant major nerve injury who were referred to a multidisciplinary peripheral nerve injury clinic. Demographic data, preoperative nerve block use, physical examination, electrodiagnostic studies, injury pattern, and time from injury to referral was collected. Radiographs, Quick Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH) score, and outcomes surveys were obtained at final follow-up. RESULTS: Twenty-two patients were identified with postoperative nerve injuries. Average time from injury to referral was 9.0 months, with 18.8 months' follow-up. Eight patients had undergone prior shoulder surgery, and 11 patients had prior shoulder trauma. Injury patterns were variable and involved diffuse pan-plexopathies with severity localized to the posterior and medial cords (11), the upper trunk (5), lateral cord (2), and axillary nerve (4). The average postoperative acromiohumeral distance (AHD) was 3.7 cm, with an average change of 2.9 cm. The average postoperative lateral humeral offset (LHO) was 1.1 cm, with an average change of 0.2 cm. Seventeen patients were confirmed to have undergone preoperative nerve blocks, which were initially attributed as the etiology of nerve injury. Eighteen patients were initially treated with observation: 11 experienced residual debilitating neuropathic pain and/or disability, and 7 had substantial improvement. One patient underwent nerve transfers, whereas the others underwent procedures for hand dysfunction improvement. The average QuickDASH score was 53.5 at average of 4 years post rTSA. CONCLUSIONS: Although uncommon, permanent peripheral nerve injuries following rTSA do occur with debilitating effects. Preoperative regional blocks were used in most cases, but none of the blocks could be directly attributed to the nerve injuries. Nerve injuries were likely secondary to traction at the time of arthroplasty and/or substantial distalization and lateralization of the implants. Patients with medial cord injuries had the most debilitating loss of hand function. Surgeons should be cognizant of these injuries and make a timely referral to a peripheral nerve specialist.