Biomechanical characterization of cadaveric brachial plexus regions using uniaxial tensile tests.

INTRODUCTION: The proximal regions of the brachial plexus (roots, trunks) are more susceptible to permanent damage due to stretch injuries than the distal regions (cords, terminal branches). A better description of brachial plexus mechanical behavior is necessary to better understand deformation mechanisms in stretch injury. The purpose of this study was to model the biomechanical behavior of each portion of the brachial plexus (roots, trunks, cords, peripheral nerves) in a cadaveric model and report differences in elastic modulus, maximum stress and maximum strain. METHODS: Eight cadaveric plexi, divided into 47 segments according to regions of interest, underwent cyclical uniaxial tensile tests, using a BOSE® Electroforce® 3330 and INSTRON® 5969 material testing machines, to obtain the stress and strain histories of each specimen. Maximum stress, maximum strain and elastic modulus were extracted from the load-displacement and stress-strain curves. Statistical analyses used 1-way ANOVA with post-hoc Tukey HSD (Honestly Significant Difference) and Mann-Whitney tests. RESULTS: Mean elastic modulus was 8.65 MPa for roots, 8.82 MPa for trunks, 22.44 MPa for cords, and 26.43 MPa for peripheral nerves. Differences in elastic modulus and in maximum stress were statistically significant (p < 0.001) between proximal (roots, trunks) and distal (cords, peripheral nerves) specimens. CONCLUSIONS: Proximal structures demonstrated significantly smaller elastic modulus and maximum stress than distal structures. These data confirm the greater fragility of proximal regions of the brachial plexus.

Biomechanical characterization of cadaveric brachial plexus microstructure.

INTRODUCTION: Peripheral nerves consist of axons and connective tissue. The amount of connective tissue in peripheral nerves such as the brachial plexus varies proximally to distally. The proximal regions of the brachial plexus are more susceptible to stretch injuries than the distal regions. A description of the mechanical behavior of the peripheral nerve components is necessary to better understand the deformation mechanisms during stretch injuries. The purpose of this study was to model the biomechanical behavior of each component of the peripheral nerves (fascicles, connective tissue) in a cadaveric model and report differences in elastic modulus, maximum stress and maximum strain. METHODS: Forty-six specimens of fascicles and epi-perineurium were subjected to cyclical uniaxial tensile tests to obtain the stress and strain histories of each specimen, using a BOSE® Electroforce® 3330 and INSTRON® 5969 materials testing machines. Maximum stress, maximum strain and elastic modulus were extracted from the load-displacement and stress-strain curves, and analyzed using Mann-Whitney tests. RESULTS: Mean elastic modulus was 6.34 MPa for fascicles, and 32.1 MPa for connective tissue. The differences in elastic modulus and maximum stress between fascicles and connective tissue were statistically significant (p < 0.001). CONCLUSIONS: Peripheral nerve connective tissue showed significantly higher elastic modulus and maximum stress than fascicles. These data confirm the greater fragility of axons compared to connective tissue, suggesting that the greater susceptibility to stretch injury in proximal regions of the brachial plexus might be related to the smaller amount of connective tissue.

Advances in Imaging of Compressive Neuropathies.

Ultrasound and magnetic resonance neurography are useful modalities to aid in the assessment of compressive neuropathies, although they are still limited in their resolution of nerve microstructure and their capacity to monitor postoperative nerve recovery. Optical coherence tomography, a preclinical imaging modality, is promising in its ability to better identify structural and potential physiologic changes to peripheral nerves, but requires additional testing and research prior to widespread clinical implementation. Further advances in nerve imaging may elucidate the ability to visualize the zone of nerve injury intraoperatively, monitor the progression of nerve regeneration, and localize problems during nerve recovery.

A Prospective Randomized Pilot Study: One-Year Outcomes of Ligament Reconstruction Tendon Interposition Versus Suture Tape Suspensionplasty for Thumb Carpometacarpal Joint Arthritis.

PURPOSE: We performed a randomized controlled trial assessing patient-reported outcome measures following trapeziectomy with ligament reconstruction and tendon interposition (LRTI) or suture tape suspensionplasty (STS) for treatment of thumb carpometacarpal joint osteoarthritis. METHODS: Patients undergoing surgery for thumb carpometacarpal joint osteoarthritis were prospectively randomized to LRTI or STS. Outcome measures were collected at 2 weeks, 4 weeks, 3 months, and 1 year and included visual analog scale pain, Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity, return to work/activity, range of motion, grip/pinch strength, and complications. RESULTS: Thirty-one patients (32 thumbs) were randomized from 51 patients offered participation over two years. One-year follow-up was 97%. Both groups had a decrease in visual analog scale pain scores at all postoperative time points. The trajectory of postoperative Patient-Reported Outcomes Measurement Information System Upper Extremity scores was similar, and both groups achieved the meaningful clinically important difference for improvement in PROMIS Upper Extremity by three months. Grip strength was substantially increased in both groups at one year. Return to work/activity and surgical complications favored the LRTI group. CONCLUSIONS: Our study did not suggest any clinically relevant differences in the postoperative patient-reported outcome measures or objective clinical measurements between LRTI and STS, although LRTI patients had a faster return to work/activity and lower complication rates. TYPE OF STUDY/LEVEL OF EVIDENCE: Prospective randomized clinical trial, level IIB clinical.

Development and Assessment of a Patient "Journey Guide" for Adult Traumatic Brachial Plexus Injury.

BACKGROUND: Patients with a traumatic brachial plexus injury (BPI) have previously identified the need for improved patient education tools, emphasizing the importance of communicating outcome expectations, providing attention to the emotional aspects of the injury and the treatment of pain, and acknowledging the needs of caregivers. We created a journey guide, a BPI-specific educational tool, to address these deficiencies. In this study, we determined the acceptability of the journey guide through surveys of and semistructured interviews with patients with a BPI. METHODS: The journey guide was created by a multidisciplinary team focusing on previously defined areas for the improvement of patient education and care delivery related to BPI. To assess the acceptability of the journey guide, we recruited 19 participants from the brachial plexus clinic of our institution and the United Brachial Plexus Network to complete a series of surveys and semistructured interviews. Participants completed surveys regarding their satisfaction with the journey guide, and we conducted semistructured interviews to assess patient BPI experiences and impressions of the journey guide and to seek feedback. Interview transcripts were qualitatively analyzed to determine common themes for improvement. RESULTS: A total of 19 participants with a mean age of 44.7 years were included. The cohort was predominantly male (13 participants) and White (16 participants). The mean time since BPI was 12.9 years, ranging from 2.0 to 39.7 years. On a visual analog scale, satisfaction with the journey guide was given a mean score of 8.4; expected usefulness when a patient is first injured, 8.7; potential for continued use, 7.3; and the fit for the BPI community, 8.8. Qualitative analysis demonstrated a primarily positive view of the guide and identified 4 major themes: (1) visuals and quotes improve clarity and engagement, (2) the journey guide would be most useful immediately following an injury, (3) the journey guide is an effective organizational tool, and (4) it is difficult to orient patients toward future hardships. CONCLUSIONS: The journey guide successfully filled a gap in the current care for BPI and was largely deemed acceptable by patients with a BPI. Specifically, participants found the journey guide to be a concise educational resource and an effective organizational tool. Participants also indicated that areas for improvement include the increased use of graphics and images and recognition of the greater BPI community with which patients can engage.

Trapeziectomy with Ligament Reconstruction/ Suspensionplasty Compared to Suture Tape Suspensionplasty for the Surgical Treatment of Advanced Thumb Carpometacarpal Osteoarthritis.

Purpose: Trapeziectomy with tendon reconstruction/suspensionplasty (TRS) is the most commonly performed surgical procedure in the United States for treatment of thumb carpometacarpal (CMC) osteoarthritis (OA). Trapeziectomy with suture tape suspensionplasty (STS) has been used recently at the study institution as an alternative surgical treatment option with perceived benefits of earlier return to function and reduced operative time. The purpose of this study was to compare patient outcomes following TRS versus STS for treatment of thumb CMC OA. Methods: All patients who underwent primary, isolated TRS or STS for treatment of thumb CMC OA between 1/1/2014 and 9/1/2020 were analyzed. We assessed demographics and preoperative and postoperative patient-rated outcome scores including Patient-reported outcomes measurement information system scores as well as pain outcomes, satisfaction, and appearance at a mean of 2.6 years after surgery (minimum 6 months). Time to return to work and activities was compared between groups. Bivariate statistics compared outcomes between groups. Results: Ninety-four patients were included in the final study cohort, of which 53 underwent TRS and 41 underwent STS. There were no differences in preoperative, postoperative, or final patient-rated outcome scores between groups. Patients reported high global and appearance satisfaction scores at final follow-up in both groups. Mean tourniquet time was 15 minutes (26%) shorter and return to work was on average 3 weeks faster for the STS group. Conclusions: There were no differences in postoperative patient-rated outcome scores between the STS and TRS groups. The STS group had a shorter surgical time and faster return-to-work after surgery. Type of study/level of evidence: Therapeutic III.

Toward peripheral nerve mechanical characterization using Brillouin imaging spectroscopy.

Significance: Peripheral nerves are viscoelastic tissues with unique elastic characteristics. Imaging of peripheral nerve elasticity is important in medicine, particularly in the context of nerve injury and repair. Elasticity imaging techniques provide information about the mechanical properties of peripheral nerves, which can be useful in identifying areas of nerve damage or compression, as well as assessing the success of nerve repair procedures. Aim: We aim to assess the feasibility of Brillouin microspectroscopy for peripheral nerve imaging of elasticity, with the ultimate goal of developing a new diagnostic tool for peripheral nerve injury in vivo. Approach: Viscoelastic properties of the peripheral nerve were evaluated with Brillouin imaging spectroscopy. Results: An external stress exerted on the fixed nerve resulted in a Brillouin shift. Quantification of the shift enabled correlation of the Brillouin parameters with nerve elastic properties. Conclusions: Brillouin microscopy provides sufficient sensitivity to assess viscoelastic properties of peripheral nerves.

Mechanomyography as a Surgical Adjunct for Treatment of Chronic Entrapment Neuropathy: A Case Series.

BACKGROUND: Chronic entrapment neuropathy results in a clinical syndrome ranging from mild pain to debilitating atrophy. There remains a lack of objective metrics that quantify nerve dysfunction and guide surgical decision-making. Mechanomyography (MMG) reflects mechanical motor activity after stimulation of neuromuscular tissue and may indicate underlying nerve dysfunction. OBJECTIVE: To evaluate the role of MMG as a surgical adjunct in treating chronic entrapment neuropathies. METHODS: Patients 18 years or older with cubital tunnel syndrome (n = 8) and common peroneal neuropathy (n = 15) were enrolled. Surgical decompression of entrapped nerves was performed with intraoperative MMG of the hypothenar and tibialis anterior muscles. MMG stimulus thresholds (MMG-st) were correlated with compound muscle action potential (CMAP), motor nerve conduction velocity, baseline functional status, and clinical outcomes. RESULTS: After nerve decompression, MMG-st significantly reduced, the mean reduction of 0.5 mA (95% CI: 0.3-0.7, P < .001). On bivariate analysis, MMG-st exhibited significant negative correlation with common peroneal nerve CMAP ( P < .05), but no association with ulnar nerve CMAP and motor nerve conduction velocity. On preoperative electrodiagnosis, 60% of nerves had axonal loss and 40% had conduction block. The MMG-st was higher in the nerves with axonal loss as compared with the nerves with conduction block. MMG-st was negatively correlated with preoperative hand strength (grip/pinch) and foot-dorsiflexion/toe-extension strength ( P < .05). At the final visit, MMG-st significantly correlated with pain, PROMIS-10 physical function, and Oswestry Disability Index ( P < .05). CONCLUSION: MMG-st may serve as a surgical adjunct indicating axonal integrity in chronic entrapment neuropathies which may aid in clinical decision-making and prognostication of functional outcomes.

The Influence of Psychosocial Factors on Disability and Expected Improvement Before Surgery for Adult Traumatic Brachial Plexus Injury.

PURPOSE: Psychosocial factors influence pain and recovery after extremity trauma and may be targets for early intervention. This may be of particular interest for patients with adult traumatic brachial plexus injury (BPI), given the broad and devastating impact of the injury. We hypothesized that there would be an association between depressive symptoms, anxiety, and pain interference with preoperative disability and expectations for improvement after BPI surgery. METHODS: We enrolled 34 patients into a prospective multicenter cohort study for those undergoing surgery for adult traumatic BPI. Before surgery, participants completed Patient-Reported Outcome Measurement Information System scales for pain interference, anxiety, and depressive symptoms, and a validated BPI-specific measure of disability and expected improvement. We performed Pearson correlation analysis between pain interference, anxiety symptoms, and depressive symptoms with (A) disability and (B) expected improvement. We created separate linear regression models for (A) disability and (B) expected improvement including adjustment for severity of plexus injury, age, sex, and race. RESULTS: Among 34 patients, there was a moderate, statistically significant, correlation between preoperative depressive symptoms and higher disability. This remained significant in a linear regression model adjusted for severity of plexus injury, age, sex, and race. There was no association between severity of plexus injury and disability. Depressive symptoms also were moderately, but significantly, correlated with higher expected improvement. This remained significant in a linear regression model adjusted for severity of plexus injury, age, sex, and race. CONCLUSIONS: Depressive symptoms are associated with greater disability and higher expected improvement before BPI surgery. Screening for depressive symptoms can help BPI teams identify patients who would benefit from early referral to mental health specialists and tailor appropriate expectations counseling for functional recovery. We did not find an association between severity of BPI and patient-reported disability, suggesting either that the scale may lack validity or that the sample is biased. LEVEL OF EVIDENCE: Prognostic II.

Future Considerations in the Diagnosis and Treatment of Compressive Neuropathies of the Upper Extremity.

Compressive neuropathies of the upper extremity are among the most common conditions seen by hand surgeons. The diagnoses of carpal tunnel syndrome and cubital tunnel syndrome have traditionally been made by a combination of history, physical examination, and electrodiagnostic testing. However, findings can be nonspecific and electrodiagnostic testing is invasive for the patient. The diagnosis of compressive neuropathies continues to evolve as technology advances, and newer diagnostic modalities predominantly focus on preoperative diagnostic imaging with ultrasound and magnetic resonance imaging/neurography. With the advent of cheaper, faster, and less invasive imaging, the future may bring a paradigm shift away from electrophysiology as the gold standard for the preoperative diagnosis of compressive neuropathies. Intraoperative imaging of nerve health is an emerging concept that warrants further investigation, whereas postoperative imaging of nerve recovery with ultrasound and magnetic resonance imaging currently has a limited role because of nonspecific findings and potential for misinterpretation. Advances in surgical treatment of compressive neuropathies appear to center around the use of imaging for less invasive neurolysis techniques and other adjunctive treatments with nerve decompression. The management of failed peripheral nerve decompressions and recurrent compressive neuropathies remains challenging.

Factors Influencing Patient Experience After Cubital Tunnel Syndrome Surgery.

PURPOSE: The purpose of this study was to use qualitative methodology to better understand patient experiences after cubital tunnel surgery, with the goal of identifying areas of improvement in delivery of care. METHODS: Patients who underwent surgery (in situ decompression or anterior transposition) for cubital tunnel syndrome within the last 12 months, which was performed by one of three fellowship-trained hand surgeons, were identified. Participants were invited to an interview regarding "their experiences with ulnar nerve surgery." An interview guide with semistructured, open-ended questions regarding the decision for surgery, treatment goals, and the recovery process was used. Interim data analyses were conducted to assess emerging themes, and interviews were continued until thematic saturation was achieved. RESULTS: Seventeen participants completed interviews; the mean age of study participants was 57 years, and 71% were women. The mean time between surgery and the interview was 6 months. Participants identified the following two key areas that could improve their surgical experience: (1) the need for detailed preoperative education about the surgery and recovery process, (2) and the importance of discussing treatment goals and expectations. Participants suggested providing both written and online resources to patients, including specific details about incision size and recovery process in education materials, and setting expectations for symptom resolution. CONCLUSIONS: Although the overall patient experience after cubital tunnel surgery was positive, participants noted that there is a need for providing improved educational resources and counseling before surgery. CLINICAL RELEVANCE: Addressing education and counseling needs before cubital tunnel surgery will help surgeons to improve delivery of care.

Catastrophic Health Care Expenditure Following Brachial Plexus Injury.

PURPOSE: Brachial plexus injuries (BPIs) are devastating to patients not only functionally but also financially. Like patients experiencing other traumatic injuries and unexpected medical events, patients with BPIs are at risk of catastrophic health expenditure (CHE) in which out-of-pocket health spending exceeds 40% of postsubsistence income (income remaining after food and housing expenses). The individual financial strain after BPIs has not been previously quantified. The purpose of this study was to assess the proportion of patients with BPIs who experience risk of CHE after reconstructive surgery. METHODS: Administrative databases were used from 8 states to identify patients who underwent surgery for BPIs. Demographics including age, sex, race, and insurance payer type were obtained. Inpatient billing records were used to determine the total surgical and inpatient facility costs within 90 days after the initial surgery. Due to data constraints, further analysis was only conducted for privately-insured patients. The proportion of patients with BPIs at risk of CHE was recorded. Predictors of CHE risk were determined from a multivariable regression analysis. RESULTS: Among 681 privately-insured patients undergoing surgery for BPIs, nearly one-third (216 [32%]) were at risk of CHE. Black race and patients aged between 25 and 39 years were significant risk factors associated with CHE. Sex and the number of comorbidities were not associated with risk of CHE. CONCLUSIONS: Nearly one-third of privately-insured patients met the threshold for being at risk of CHE after BPI surgery. CLINICAL RELEVANCE: Identifying those patients at risk of CHE can inform strategies to minimize long-term financial distress after BPIs, including detailed counseling regarding anticipated health care expenditures and efforts to optimize access to appropriate insurance policies for patients with BPIs.

Limitations of Computed Tomography Angiography in Preoperative Planning of Peroneus Brevis Rotational Flap.

The distally based peroneus brevis (PB) rotational flap has been shown to be a reliable method of coverage of distal third tibial wounds. The flap is perfused via retrograde flow from distal PB perforators located within 8 cm of the lateral malleolus. The ability to assess patency of these vessels preoperatively facilitates surgical planning, and computed tomography angiography (CTA) has been used for perforator assessment of other lower extremity flaps. The purpose of the present study is to establish the potential utility of standard CTA for locating distal PB perforators by examining uninjured lower extremities. Methods: Twenty-five patients who underwent bilateral lower extremity CTAs using standard lower extremity protocol were retrospectively identified. Axial two-dimensional images were scanned craniocaudally using our institution's standard CT image viewing software, Merge Radsuite (Merge Healthcare, Hartland, Wis.). Results: The average location of distal-most PB perforators identified on CT angiogram was 13.1 ± 5.1 cm proximal to the distal fibula, or 34.5% ± 13.5% of total fibular length. Standard CTA was only able to locate a pedicle within 8 cm of the lateral malleolus (20.9% of fibular length) in three of 25 patients (12%). Conclusions: Previous studies have described a reliable pedicle within 8 cm of the distal fibular tip upon which to design a distally based PB rotational flap. The absence of such perforators in the CT angiogram suggests that standard CT angiogram is not a reliable technique for identifying the patency of such perforators when evaluating the utility of a distally based PB flap.

Expectant Management, Tendon Transfer, or Nerve Transfer Surgery for Radial Nerve Injury: A Qualitative Study Exploring Patient Expectations, Goals, and Treatment Experiences.

BACKGROUND: After a radial nerve injury, patients must weigh a complicated set of advantages and disadvantages to observation or surgery. We conducted semistructured interviews to characterize the decision-making process that these patients undertake. METHODS: We recruited participants who were treated with expectant management (nonoperatively), received only a tendon transfer, or received a nerve transfer. Participants completed a semistructured interview that was transcribed and coded to identify recurring themes, to describe the influence of qualitative findings on treatment decision-making. RESULTS: We interviewed 15 participants (5 expectant management, 5 tendon transfer only, and 5 nerve transfer). Participants' primary concerns were returning to work, hand appearance, regaining motion, resuming activities of daily living, and enjoying hobbies. Delayed diagnosis and/or insurance coverage led 3 participants to change treatment from nerve transfer to isolated tendon transfer. Interactions with providers early in diagnosis and treatment had strong effects on how members of the care team were perceived. The hand therapist was the primary person who shaped expectations, provided encouragement, and prompted referral to the treating surgeon. Participants valued debate among the care team members regarding treatment, provided that medical terminology was explained. CONCLUSIONS: This study highlights the importance of initial, collaborative care in setting expectations for patients with radial nerve injuries. Many participants named returning to work and hand appearance as primary concerns. Hand therapists were the primary source of support and information during recovery. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Factors Associated with the Success and Timing of Orthopaedic Surgery Resident Research Thesis Project Publication.

Scholarship and research are important aspects of orthopaedic surgery training. Many orthopaedic surgery residency programs have developed dedicated research curricula, often culminating in a capstone thesis project with the intended goal of peer-reviewed publication. However, data on the success of these programs are scarce. The purpose of the current study was to determine the success rate and time to publication of resident research thesis projects at our own institution while evaluating factors associated with these outcomes. Methods: Resident research thesis projects performed over the past 15 years were aggregated and reviewed. Additional data regarding the projects and former trainees who performed them were collected using public resources which included measures of current academic aptitude (i.e., H-index and number of publications) as well as project and publication characteristics. Cox and linear regression analyses were conducted to assess the relation between numerous predictor variables and the success and time to publication. All analyses were conducted at the 95% confidence interval (CI) level. Results: Sixty-eight (n = 68; 83%) resident research thesis projects were published an average of 2,582.8 days, or roughly 7 years from the start of their residency training. Graduate adjusted H-index was associated with increased success and decreased time to publication (hazard ratio 1.183 [95% CI: 1.059-1.322], p = 0.003). A lower journal impact factor was associated with taking significantly shorter time to reach publication (F(1,66) = 7.839, p = 0.007; Β1 = 146.45, p = 0.007). Study type (clinical vs. laboratory), posttraining practice setting (academic vs. private), and whether the research topic was within the same area of the trainee's matched fellowship(s) did not predict publication success. Discussion/Conclusion: Over the past 15 years, 83% of orthopaedic resident research thesis projects at our institution were published. A higher adjusted H-index was associated with greater completion and faster timing to publication. A lower journal impact factor was also associated with quicker publication. These data highlight the publication metrics of a formalized resident research program and identify factors associated with success and timing of publication.

'Being a patient the rest of my life'- The influence of patient participation during recovery after brachial plexus injury.

BACKGROUND: Given the modest functional outcomes seen after surgical reconstruction and subsequent therapy, increasing attention is being directed to patient satisfaction and psychological aspects of recovery after brachial plexus injury (BPI). PURPOSE: To better understand the recovery course after surgical reconstruction for BPI, we used qualitative interviews and focused on common points of frustration for patients. STUDY DESIGN: Qualitative, interpretive description study METHODS: We conducted semi-structured interviews with BPI patients who were 6+ months post-surgical reconstruction. The interview focused on the patients' experience with BPI, focusing on emotional aspects of recovery. Interviews were transcribed and independently coded by 2 researchers. We used inductive and deductive analysis to organize codes into themes. Once thematic saturation was reached, no additional interviews were conducted. RESULTS: We interviewed 15 BPI patients at median 13 months after surgery (range: 6-43 months). Our analysis revealed: (1) BPI patients expressed variable degrees of participation during recovery, with the indeterminate state of function making it difficult to adjust to life after BPI. (2) The uncertainty while waiting for improved function is frustrating to BPI patients, with many patients expressing concern for activities and moments they are missing due to injury. (3) While many BPI patients feel left out of decision-making, those who felt engaged in the process expressed less frustration and more acceptance of their status. CONCLUSION: Traumatic BPI patients those who felt engaged in decision-making were more receptive to adjustment to their new state of function. When coordinating multidisciplinary care, measures to encourage patients to feel agency over their outcome and to develop self-management skills have the potential to improve patient satisfaction.

Trends in Brachial Plexus Surgery: Characterizing Contemporary Practices for Exploration of Supraclavicular Plexus.

BACKGROUND: There is variability in treatment strategies for patients with brachial plexus injury (BPI). We used qualitative research methods to better understand surgeons' rationale for treatment approaches. We hypothesized that distal nerve transfers would be preferred over exploration and nerve grafting of the brachial plexus. METHODS: We conducted semi-structured interviews with BPI surgeons to discuss 3 case vignettes: pan-plexus injury, upper trunk injury, and lower trunk injury. The interview guide included questions regarding overall treatment strategy, indications and utility of brachial plexus exploration, and the role of nerve grafting and/or nerve transfers. Interview transcripts were coded by 2 researchers. We performed inductive thematic analysis to collate these codes into themes, focusing on the role of brachial plexus exploration in the treatment of BPI. RESULTS: Most surgeons routinely explore the supraclavicular brachial plexus in situations of pan-plexus and upper trunk injuries. Reasons to explore included the importance of obtaining a definitive root level diagnosis, perceived availability of donor nerve roots, timing of anticipated recovery, plans for distal reconstruction, and the potential for neurolysis. Very few explore lower trunk injuries, citing concern with technical difficulty and unfavorable risk-benefit profile. CONCLUSIONS: Our analysis suggests that supraclavicular exploration remains a foundational component of surgical management of BPI, despite increasing utilization of distal nerve transfers. Availability of abundant donor axons and establishing an accurate diagnosis were cited as primary reasons in support of exploration. This analysis of surgeon interviews characterizes contemporary practices regarding the role of brachial plexus exploration in the treatment of BPI.

Gray-Scale and Power Doppler Ultrasound Findings Predictive of Cubital Tunnel Syndrome Severity.

BACKGROUND: The use of ultrasound in the diagnosis of cubital tunnel syndrome (CuTS) is an attractive alternative to electrodiagnostic (EDX) studies, but its utility is binary with poor severity correlation. We hypothesize that increasing ulnar nerve cross-sectional area (CSA) and power Doppler measurement of intraneural vascularity may predict the extent of disease. METHODS: We identified 20 elbows from patients with a history of CuTS and 20 elbows in 10 asymptomatic controls. Electrodiagnosis was performed for symptomatic patients. Gray-scale ultrasound and power Doppler ultrasound were performed to measure CSA and intraneural vascularity in all participants. Functional measures, Boston Carpal Tunnel Questionnaire (BCTQ), and Patient-Reported Outcomes Measurement Information System surveys were also completed. RESULTS: A strong positive correlation was found between CSA and motor nerve conduction velocity (MNCV) decrease between elbow and forearm, which increased when BCTQ >2 was used as a screening criterion. Increased CSA also demonstrated a high positive predictive value (PPV) in predicting MNCV changes, but poor ability to predict axonal loss. In contrast, power Doppler ultrasound demonstrated 100% PPV and 94% negative predictive value (NPV) in predicting severe CuTS (defined as compound motor action potential [CMAP] amplitude <6 mV and electromyography [EMG] findings). CONCLUSIONS: Cross-sectional area is a sensitive method for identifying changes in MNCV and amplitude but does not stratify disease severity, as defined by diminished CMAP amplitude and/or evidence of denervation on EMG. The presence of increased intraneural vascularity is relatively sensitive but highly specific for axonal loss. The combination of nerve CSA, BCTQ screening, and power Doppler ultrasound may provide an alternative means for CuTS assessment.

Early Expression of MMP-9 Predicts Recovery of Tibialis Anterior after Sciatic Nerve Crush Injury.

Background: The purpose of this study was to assess the expression of molecular markers and epineural blood flow after differing degrees of nerve injury to identify potential tools to predict nerve recovery in a rat sciatic nerve model. Methods: A total of 72 rats were divided into nine groups. Each group was subjected to one of three crush injuries, created by applying one of three vascular clamps for 30 seconds. Vascularity was assessed with laser Doppler flowmetry before and after crush, and at nonsurvival surgery. Nonsurvival surgeries were performed 6 hours, 2 weeks, or 6 weeks later with nerve conduction studies and muscle strength testing. Expression of matrix metalloproteinase 9 (MMP-9) and matrix metalloproteinase 2 (MMP-2) in each nerve was quantified using with enzyme linked immunosorbent analysis. Results: Persistent hyperemia was noted in the zone of injury compared with baseline at 2 weeks and 6 weeks in the groups that displayed incomplete recovery. Expression of MMP-9 at 6 hours increased with increasing severity of crush and was inversely related to tibialis anterior muscle force recovery. The ratio of MMP-9:MMP-2 expression correlated well with recovery of compound nerve action potential amplitude at 6 weeks. Conclusions: Resolution of nerve hyperemia may correlate with nerve recovery from trauma, but early measures of nerve blood flow after injury are not prognostic of recovery. Ratio of MMP-9:MMP-2 expression 6 hours after injury correlates with recovery of compound nerve action potential at 6 weeks, while MMP-9 expression alone predicts tibialis anterior recovery. These findings together suggest that increased MMP-9 expression is a potentially useful marker of more severe nerve injury.

Team Approach: Management of Brachial Plexus Injuries.

¼: Traumatic brachial plexus injuries are relatively rare but potentially devastating injuries with substantial functional, psychological, and economic consequences. ¼: Prompt referral (ideally within 6 weeks of injury) to a center with a team of experts experienced in the diagnosis and management of these injuries is helpful to achieving optimal outcomes. ¼: Preoperative and intraoperative decision-making to diagnose and plan reconstructive procedures is complex and must take into account a number of factors, including the time from injury, concomitant injuries, preservation of cervical nerve roots, and the availability of intraplexal and extraplexal donor nerves for nerve transfer. ¼: A team approach is essential to ensure accurate localization of the pathology before surgery and to maximize rehabilitation after surgery, necessitating close contact between the surgical team, physiatrists, radiologists, and therapists.