An in vitro model for postoperative cranial nerve dysfunction and a proposed method of rehabilitation with N-acetylcysteine microparticles.

PURPOSE: When operating near cranial motor nerves, transient postoperative weakness of target muscles lasting weeks to months is often observed. As nerves are typically intact at a procedure's completion, paresis is hypothesized to result from a combination of neurapraxia and axonotmesis. As both neurapraxia and axonotmesis involve Schwann cell injury and require remyelination, we developed an in vitro RSC96 Schwann cell model of injury using hydrogen peroxide (H2O2) to induce oxidative stress and investigated the efficacy of candidate therapeutic agents to promote RSC96 viability. As a first step in developing a long-term local administration strategy, the most promising of these agents was incorporated into sustained-release microparticles and investigated for bioactivity using this assay. METHODS: The concentration of H2O2 which reduced viability by 50% was determined to establish a standard for inducing oxidative stress in RSC96 cultures. Fresh cultures were then co-dosed with H2O2 and the potential therapeutics melatonin, N-acetylcysteine, resveratrol, and 4-aminopyridine. Schwann cell viability was evaluated and the most efficacious agent, N-acetylcysteine, was encapsulated into microparticles. Eluted samples of N-acetylcysteine from microparticles was evaluated for retained bioactivity. RESULTS: 100 µM N-acetylcysteine improved the viability of Schwann cells dosed with H2O2. 100 µM Microparticle-eluted N-acetylcysteine also enhanced Schwann cell viability. CONCLUSION: We developed a Schwann cell culture model of iatrogenic nerve injury and used this to identify N-acetylcysteine as an agent to promote recovery. N-acetylcysteine was packaged into microparticles and demonstrated promise as a locally administrable agent to reduce oxidative stress in Schwann cells.

Neurapraxia in patients with trigeminal neuralgia but no identifiable neurovascular conflict during microvascular decompression: a retrospective analysis of 26 cases.

BACKGROUND: Microvascular decompression (MVD) is the first choice in patients with classic trigeminal neuralgia (TGN) that could not be sufficiently controlled by pharmacological treatment. However, neurovascular conflict (NVC) could not be identified during MVD in all patients. To describe the efficacy and safety of treatment with aneurysm clips in these situations. METHODS: A total of 205 patients underwent MVD for classic TGN at our center from January 1, 2015 to December 31, 2019. In patients without identifiable NVC upon dissection of the entire trigeminal nerve root, neurapraxia was performed using a Yasargil temporary titanium aneurysm clip (force: 90 g) for 40 s (or a total of 60 s if the process must be suspended temporarily due to bradycardia or hypertension). RESULTS: A total of 26 patients (median age: 64 years; 15 women) underwent neurapraxia. Five out of the 26 patients received prior MVD but relapsed. Immediate complete pain relief was achieved in all 26 cases. Within a median follow-up of 3 years (range: 1.0-6.0), recurrence was noted in 3 cases (11.5%). Postoperative complications included hemifacial numbness, herpes labialis, masseter weakness; most were transient and dissipated within 3-6 months. CONCLUSIONS: Neurapraxia using aneurysm clip is safe and effective in patients with classic TGN but no identifiable NVC during MVD. Whether this method could be developed into a standardizable method needs further investigation.

Predictors of traumatic nerve injury and nerve recovery following humeral shaft fracture.

INTRODUCTION: Nerve palsy is common after humeral shaft fracture, with the radial nerve being the most commonly injured nerve. Isolated nerve injuries usually recover spontaneously, and operative intervention is rarely indicated. Our goal was to study the predictors of traumatic nerve injury and recovery in a large cohort of patients with humeral shaft fractures. METHODS: A total of 376 patients with humeral shaft fracture, including 96 patients with documented traumatic nerve palsy and 280 with intact neurovascular examination on presentation, were retrospectively included in the study. The primary outcome was incidence of a traumatic nerve palsy, and the secondary outcome was nerve recovery. RESULTS: Nerve palsy was present in 96 patients (25.5%) at the time of injury. Radial nerve was the most commonly injured nerve (93.6%), followed by the ulnar (5.1%) and axillary (1.2%) nerves. Seventeen patients (17.7%) had multiple nerves palsies. A multivariable regression analysis revealed that the concomitant vascular injury (odds ratio [OR] 52, 95% confidence interval [CI] 5.6-480.6), distal one-third fractures (OR 6.3, 95% CI 2.7-14.7), and middle one-third (OR 2.8, 95% CI 1.2-6.5) vs. proximal fractures, open fracture (OR 2.1, 95% CI 1.1-4.4), and high-energy trauma (OR 1.7, 95% CI 1.1-2.9) were independent predictors of nerve palsy. Iatrogenic nerve injury was detected in 7 patients (4.6%), all affecting the radial nerve. Spontaneous recovery of traumatic nerve injuries was detected in 87 patients (91%), with 19% partial and 72% complete recovery. The initial sign of recovery was observed at median times of 7 and 9 weeks for those managed conservatively or fracture fixation. Operative treatment of the fracture had no effect on the outcome of nerve recovery (88.5% vs. 100%, P = .14). Ten patients (14.1%) had transected nerves at the time of exploration and open fractures (22.7% vs. 6.8%, P = .04), and concomitant vascular injury (33.3% vs. 7.3%, P = .02) were associated with nerve transection, portending a worse prognosis for nerve recovery compared with nerves in continuity (40% vs. 95.3%, P = .004). DISCUSSION: The incidence of nerve injury after humeral shaft fracture was 25%, reflecting an abundance of high-energy and open injuries in this cohort. Ninety-one percent of patients experienced improvement in their nerve function with a median time to recovery of 7-9 weeks. Operative treatment of the fracture did not change the rate of nerve recovery. Patients with multiple nerve palsies and concurrent vascular insult had worse nerve recovery. We recommend nerve studies if no sign of recovery is observed by 9 weeks.

Nailing femoral shaft fracture with postless distraction technique: a new technique enabled by shape-conforming pad.

BACKGROUND: Femoral shaft fractures are usually treated with nailing using a traction table and a perineal post, but this may occasionally result in various groin-related complications, including pudendal nerve neurapraxia. Although most of them are transient, complication rates of up to 26% are reported. Recently, postless distraction technique has been described for elective hip arthroscopy. In this study we compared post and postless distraction technique in femoral shaft fracture nailing in terms of (1) quality of reduction, (2) outcome, and (3) complications. METHODS: We reviewed 50 patients treated with postless distraction nailing technique for femoral shaft fractures and compared them with our historical case series (95 patients). The following data were collected for all patients: age, gender, weight, height, diagnoses (fractures were classified according to the 2018 revision of AO classification), type and size of nail surgical timing, Trendelenburg angles during surgery, quality of reduction according to Baumgaertner and Thoresen classifications, Modified Harris Hip Scores at 6 months, and perineal complications. RESULTS: Median age was 53 years, and median weight was 70 kg (range 50-103 kg). We found no significant difference in terms of quality of reduction (72 versus 74% "excellent" reduction for subtrochanteric fractures, while 81 versus 79% "excellent" reduction for femoral shaft fractures) and functional outcomes (Modified Harris Hip Score 74 versus 79). One patient in the control group had a failure of the fixation, and one patient in the postless group had a deep infection. Two patients in the control group reported pudendal nerve neurapraxia for 4 months, while none reported complication linked to the postless technique. CONCLUSIONS: Our results using the postless distraction technique show a sufficient distraction to allow reduction and internal fixation of the femoral fracture with a standard femoral nail. LEVEL OF EVIDENCE: IV.

Sequelae of bilateral luxatio erecta in the acute post-reduction period demonstrated by MRI: a case report and literature review.

Luxatio erecta humeri (LEH), also known as inferior shoulder dislocation, is uncommon, comprising about 0.5% of all cases of shoulder dislocation. Synchronous bilateral LEH is exceedingly rare and, to our knowledge, there are no descriptions of axillary nerve injury on magnetic resonance imaging (MRI) following LEH. We present a case of traumatic bilateral LEH in a 59-year-old woman who fell from a fast-moving mobility scooter and sustained direct axial loading forces on the fully abducted shoulders. Both shoulders were successfully reduced using the traction-countertraction technique in the emergency department. In this article, we describe the characteristic features of LEH on plain radiography and the pattern of acute soft-tissue injuries on MRI. We emphasize the importance of reviewing the axillary neurovascular bundle, which by virtue of its location beneath the shoulder joint, is prone to injury in inferior shoulder dislocation and thus has a substantial impact on functional recovery. This important complication is unfortunately not routinely examined by radiologists, partly because of the paucity of literature highlighting its clinical significance.

A Prospective Evaluation of Early Postoperative Complications After Distal Biceps Tendon Repairs.

PURPOSE: The reported incidence of postoperative complications after distal biceps tendon repairs (DBTRs) has been determined largely by retrospective studies. We hypothesized that a large prospective cohort study of DBTRs would demonstrate increased complication rates relative to existing literature values. Secondarily, we hypothesized that most complications would be transient and self-limiting, regardless of the surgical technique employed for the repair. METHODS: Consecutive patients undergoing acute, primary DBTR from July 2016 to December 2017 were enrolled. The repair technique, postoperative protocol, and follow-up intervals were determined by the individual surgeons' protocols. Demographic information, surgical data, and complications were tabulated prospectively. Exclusion criteria included chronic DBTRs, secondary DBTRs requiring allograft, DBTRs of partial tears, and postoperative follow-up of less than 12 weeks. We included 212 repairs performed by 37 orthopedic surgeons in 3 different subspecialties. RESULTS: Sixty-five patients (30.7%) had 73 complications. Fifty patients (44.6%) in the 1-incision group experienced complications compared with 15 (15.0%) in the 2-incision group. Sixty patients (28.3%) developed a minor complication. Fifty-seven patients (26.9%) had sensory neurapraxias, 47 after a 1-incision procedure and 10 after a 2-incision procedure, a statistically significant difference. Of the patients with neurapraxias, 94.7% were resolved or improving at the time of the latest follow-up. Five patients (2.4%) developed a major complication, defined as a return to the operating room in the postoperative period due to deep infection or rerupture. CONCLUSIONS: The complication rate after DBTR appears to be higher than 2 other retrospective studies and is predominantly in the form of transient neurapraxias. This study confirms that there is a higher complication rate in 1-incision techniques as compared with 2-incision techniques. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Sonographic evaluation of peripheral nerve pathology in the emergency setting.

High-resolution sonography has a growing role in both the diagnosis and management of traumatic and atraumatic peripheral nerve pathology. Sonography not only affords a cost-effective and time-efficient approach to interrogating long segments of peripheral nerves but also possesses unique advantages in terms of its dynamic, real-time nature with few clinical contraindications and limitations. In this review, we will initially discuss imaging techniques and characteristics of normal neural sonohistology, then address specific features and pitfalls pertaining to the spectrum of post-traumatic peripheral nerve injury. Additionally, we will highlight the more common sonographic applications in the clinical work-up of patients presenting with symptoms of dynamic neural impingement and entrapment. Finally, illustrative and clinical features of the more frequently encountered peripheral neural neoplastic pathologies will be addressed.

Surgical anatomy of the radial nerve in the deltopectoral approach for revision shoulder arthroplasty and periprosthetic fracture fixation: a cadaveric study.

BACKGROUND: Radial nerve injury is a rare but clinically significant complication of revision shoulder arthroplasty and fixation of native and periprosthetic proximal humeral fractures. Understanding of the anatomic relationship between the radial nerve as it enters the humeral spiral groove and anterior shoulder landmarks in a deltopectoral approach is necessary to avoid iatrogenic radial nerve injury. METHODS: Eight forequarter cadaveric specimens were dissected through a deltopectoral approach. Distances between the radial nerve entry into the proximal spiral groove and the coracoid process, distal lesser tuberosity/inferior subscapularis insertion, superior latissimus insertion, and inferior latissimus insertion were measured. Means, standard deviations, and ranges were determined for each distance. RESULTS: The radial nerve entry into the proximal spiral groove averaged 133.1 mm (range, 110.3-153.0 mm) from the coracoid process, 101.9 mm (range, 76.5-124.3 mm) from the distal lesser tuberosity/inferior subscapularis insertion, 81.0 mm (range, 63.4-101.5 mm) from the superior latissimus insertion, and 39.6 mm (range, 25.5-55.4 mm) from the inferior latissimus insertion. The proximal spiral groove was distal to the inferior latissimus insertion in all specimens. CONCLUSION: The risk of iatrogenic injury to the radial nerve at the spiral groove may be minimized through proper identification and protection or avoidance of circumferential fixation. However, if encircling fixation with cerclage cables is necessary, instrumentation proximal to the inferior edge of the latissimus dorsi insertion may reduce the risk of radial nerve injury.

Technical feasibility of robot-assisted minimally-invasive neurolysis of the lateral cutaneous nerve of thigh: About a case.

To limit the risk of iatrogenic neuroma and recurrence after surgical treatment of meralgia paresthetica, some authors have recently developed a technique of endoscopic neurolysis of the lateral cutaneous nerve of thigh (LCNT) below the level of the inguinal ligament. We report the case of a robot-assisted endoscopic technique underneath the inguinal ligament. A 62-year-old patient suffering of idiopathic meralgia paresthetica for the past 18 months received a Da Vinci robot-assisted minimally-invasive 10cm long neurolysis, of which 1/3 was situated above the level of the inguinal ligament and 2/3 below it. The patient was discharged the following day without complications. At 6-months follow-up the pain was rated 0/10 compared to 5/10 pre-operatively. Robot-assisted endoscopic neurolysis of the LCNT retains the advantages of conventional endoscopy and enables to approach the nerve in the most frequently compressed zone underneath the inguinal ligament. The three-dimensional view offered by robotic surgery facilitates the dissection. The superiority of this technique remains to be demonstrated by comparing it to conventional techniques.

Pelvic nerve injury negatively impacts female genital blood flow and induces vaginal fibrosis-implications for human nerve-sparing radical hysterectomy.

OBJECTIVE: This study sought to develop a novel animal model to study the impact of nerve-sparing radical hysterectomy (NSRH) on female genital blood flow. DESIGN: In vivo animal study. POPULATION: Thirty Sprague-Dawley female rats. MATERIALS AND METHODS: Female rats underwent either unilateral pelvic nerve (PN) crush (PNC; n = 9), or crush of both the PNs and all efferent nerves in the pelvic plexus ('clock-nerve crush', CNC; n = 9). Under anaesthesia, we electrically stimulated the crushed PN at 3 and 10 days after crush while monitoring blood pressure and recording clitoral and vaginal blood flows by laser Doppler. Uninjured PNs were stimulated as an internal control. Twelve additional rats were assigned either to bilateral PNC or sham surgery, and genital tissues were processed 10 days after injury for in vitro analysis. MAIN OUTCOME MEASURES: Genital blood flow, nNOS, eNOS, collagen I-III. RESULTS: Stimulation of the crushed PN in both groups subjected to PNC and CNC induced significantly lower peak genital blood flow at 3 and 10 days (P < 0.05) compared to stimulation of the non-crushed control PN. The immunofluorescence and Western blot analyses revealed that all injured rats exhibited more vaginal collagen III and collagen I than rats did that ad undergone sham surgeries (P < 0.05). PCN reduced nNOS expression in both clitoral and vaginal tissue. CONCLUSIONS: Based on our study it may be hypothesised that NSRH might cause reductions of genital blood flow and vaginal fibrosis due to neurapraxia of the pelvic nerve and reductions of nNOS nerve fibres in clitoral and distal vaginal tissue. TWEETABLE ABSTRACT: Pelvic nerve neurapraxia during nerve-sparing radical hysterectomy could lead to sexual arousal dysfunction.

Surfer's neurapraxia - an uncommon surfing injury of the saphenous nerve.

Surfer's neurapraxia is a rare surfing injury of the saphenous nerve secondary to persistent compression of the saphenous nerve along the medial thigh by the surfboard when paddling prone and while sitting upright on the board waiting for a wave. Symptoms may be nonspecific and consist of pain in the medial thigh with or without radiation along the saphenous nerve distribution (medial leg, medial ankle, medial arch of the foot). The saphenous nerve tension test can be utilized to reproduce the symptoms of surfer's neurapraxia. Treatment consists of conservative management while refractory cases may benefit from injection with local anesthetic. The authors propose the Obana Plan (WATER) for prevention of surfer's neurapraxia, consisting of Wetsuits, Abduction, Timing, Exercise, and Rest. Overall, surfer's neurapraxia is a benign condition that can be prevented and managed conservatively.

A Prospective Comparison of Groin-Related Complications After Hip Arthroscopy With and Without a Perineal Post.

BACKGROUND: Previous studies have demonstrated various groin-related nerve and soft tissue complications in patients undergoing hip arthroscopy with a perineal post. PURPOSE: To prospectively compare groin-related nerve and soft tissue complications between patients undergoing hip arthroscopy with and without the use of a perineal post. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: A prospective single-surgeon cohort study was performed on all patients undergoing hip arthroscopy by the senior author between January 2020 and March 2022. A post-free hip distraction system was used at 1 center in which the senior author operates, and a system with a large padded perineal post was used at another surgical location. Patients completed a survey at the first postoperative visit (7-10 days) to determine if they had experienced any groin-related complications after surgery (groin numbness, sexual/urinary dysfunction, skin tears). Patients with a positive survey response repeated the survey at each follow-up visit (6 weeks, 3 months, 6 months) until the symptoms resolved. The rate and duration of groin-related complications were then compared between the groups. RESULTS: A total of 87 patients were included in the study who underwent hip arthroscopy: 53 with a perineal post and 34 without. No differences were found between the post and postless groups in terms of age at surgery, sex, body mass index, or traction time. We found that 16 patients (30%) in the perineal post group experienced groin numbness versus 0 (0%) in the postless group (P < .0001). On average, groin numbness lasted 5 ± 3 days (mean ± SD) in the perineal post group. Three patients in the perineal post group experienced sexual dysfunction for a mean 7 days, as compared with none in the postless group. Seventeen patients (32%) in the perineal post group experienced foot numbness versus 4 (12%) in the postless group (P = .04). One patient in the perineal post group reported a superficial skin tear. CONCLUSION: Postless hip arthroscopy resulted in no risk of groin-related complications as compared with traditional hip arthroscopy with a perineal post.

Are complications related to the perineal post on orthopaedic traction tables for surgical fracture fixation more common than we think? A systematic review.

BACKGROUND: Traction tables have long been utilized in the management of fractures by orthopaedic surgeons. The purpose of this study was to systematically review the literature to determine the complications inherent to the use of a perineal post when treating femur fractures using a traction table. METHODS: A systematic review was conducted using PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) using PubMed, EMBASE, and Cochrane Library. The search phrase used was "fracture" AND "perineal" AND "post" AND ("femur" OR "femoral" OR "intertrochanteric" OR "subtrochanteric"). Inclusion criteria for this review were: level of evidence (LOE) of I - IV, studies reporting on patients surgically treated for femur fractures, studies reporting on patients treated on a fracture table with a perineal post, and studies that reported the presence or absence of perineal post-related complications. The rate and duration of pudendal nerve palsy were analyzed. RESULTS: Ten studies (2 prospective and 8 retrospective studies; 2 LOE III and 8 LOE IV) were included consisting of 351 patients of which 293 (83.5%) were femoral shaft fractures and 58 (16.5%) were hip fractures. Complications associated with pudendal nerve palsies were reported in 8 studies and the mean duration of symptoms ranged between 10 and 639 days. Three studies reported a total of 11 patients (3.0%) with perineal soft tissue injury including 8 patients with scrotal necrosis and 3 patients with vulvar necrosis. All patients that developed perineal skin necrosis healed through secondary intention. No permanent complications relating to pudendal neurapraxia or soft tissue injuries were reported at final follow-up timepoints. CONCLUSION: The use of a perineal post when treating femur fractures on a fracture table poses risks for pudendal neurapraxia and perineal soft tissue injury. Post padding is mandatory and supplemental padding may also be required. Appropriate perineal skin examination prior to use is also important. Occurring at a higher rate than previously thought, appropriate post-operative examination for any genitoperineal soft tissue complications and sensory disturbances should not be ignored.

Long-Term Motor versus Sensory Lumbar Plexopathy After Lateral Lumbar Interbody Fusion: Single-Center Experience, Intraoperative Neuromonitoring Results, and Multivariate Analysis of Patient-Level Predictors.

BACKGROUND: Although lateral lumbar interbody fusion (LLIF) is an effective surgical option for lumbar arthrodesis, postoperative plexopathies are a common complication. We characterized post-LLIF plexopathies in a large cohort and analyzed potential risk factors for each. METHODS: A single-institutional cohort who underwent LLIF between May 2015 and December 2019 was retrospectively reviewed for postoperative lumbar plexopathies. Plexopathies were divided based on sensory and motor symptoms and duration, as well as by laterality relative to the surgical approach. We assessed these subgroups for associations with patient and surgical characteristics as well as psoas dimensions. We then evaluated risk of developing plexopathies after intraoperative neuromonitoring observations. RESULTS: A total of 127 patients were included. The overall rate of LLIF-induced sensory or motor lumbar plexopathy was 37.8% (48/127). Of all cases, 42 were ipsilateral to the surgical approach (33.1%); conversely, 6 patients developed contralateral plexopathies (4.7%). Most (31/48; 64.6%) resolved with a follow-up interval of 402 days in the plexopathy group. Of ipsilateral cases, 24 patients experienced persistent (>90 days) postoperative sensory symptoms (18.9%), whereas 20 experienced persistent weakness (15.7%). More levels fused predicted persistent sensory symptoms (odds ratio, 1.714 [1.246-2.359]; P = 0.0085), whereas surgical duration predicted persistent weakness (odds ratio, 1.004 [1.002-1.006]; P = 0.0382). Psoas anatomic variables were not significantly associated with plexopathy. Nonresolution of intraoperative evoked motor potential alerts was a significant risk factor for developing plexopathies (relative risk, 2.29 [1.17-4.45]). CONCLUSIONS: Post-LLIF plexopathies are common but usually resolve. Surgical complexity and unresolved neuromonitoring alerts are possible risk factors for persistent plexopathy.

Prevalence, management, and outcomes of nerve injury after shoulder arthroplasty: a case-control study and review of the literature.

Background: Neurologic injury is a rare and potentially devastating complication of shoulder arthroplasty. Patients typically present with a mixed plexopathy or mononeuropathy, most commonly affecting the axillary and radial nerves. Given the paucity of studies available on the topic, our goal was to elucidate the prevalence of nerve injury after shoulder arthroplasty and to describe the treatment course and outcomes of neurologic injuries. Methods: This is a retrospective case-control study performed at a single, urban, academic institution. Consecutive patients who underwent anatomic total shoulder arthroplasty (TSA) or reverse shoulder arthroplasty (RSA) by a single surgeon from 2014 to 2020 were reviewed, and patients with a documented nerve injury were identified. A control group of patients without nerve injury were selected in a 2:1 ratio controlling for age and procedure type (TSA vs. RSA; primary vs. revision). Data collected included demographics, comorbidities as per the Charlson Comorbidity Index, radiographic evaluations, surgical and implant details, patient-reported outcome measures, and perioperative complications. Results: Of 923 patients, 33 (3.6%) sustained an iatrogenic nerve injury: 10 (2.1%) after TSA, 23 (5.0%) after RSA, and 3 (7.8%) after revision arthroplasty. Axillary mononeuropathy was most common (42%), followed by brachial plexopathies (18%). There was no significant difference in age, sex, race, body mass index, and preoperative diagnoses between groups. Patients with nerve injury had fewer comorbidities (Charlson Comorbidity Index <3, 33 vs. 65%, P<.001). Patients with nerve injury had higher rates of cervical spine pathology (15 vs. 6%; P = .15) and increased postoperative lateralization (8.9 mm [7.2] vs. 5.5 mm [7.3]; P<.06). The majority (91%) were managed with observation alone. Three (9%) underwent an additional procedure: carpal tunnel release (1, 3%), ulnar nerve decompression (1, 3%), and ulnar nerve transposition (1, 3%) for peripheral compressive neuropathies. At the final follow-up, 19 (57%) nerves fully recovered, and 14 (43%) showed mild residual sensorimotor dysfunction. The mean time to first sign of recovery and ultimate recovery were 11 (7.2) and 36 (23.5) weeks, respectively. At the final follow-up, patients with nerve injury performed worse on patient-reported outcomes, including visual analog score pain (2.2 vs. 1.0, P<.001), American Shoulder and Elbow Surgeons score (67.8 vs. 84.8, P<.001), and Single Assessment Numeric Evaluation scores (62 vs. 77, P = .009). Discussion: Nerve injury after shoulder arthroplasty is rare, occurring in 3.6% of our patient population. Axillary mononeuropathy and brachial plexopathies are the most common. Most patients can be managed expectantly with observation and will recover at least partial nerve function, although clinical outcomes remain inferior to those without nerve complication.

Acute Carpal Tunnel Syndrome and Median Nerve Neurapraxia: A Review.

Prompt diagnosis and treatment of acute injury to the median nerve after wrist trauma are paramount to a successful outcome. Neuropathy can occur primarily at the time of injury, secondary to unreduced fracture fragments or callus, or from prolonged immobilization in palmar flexion. Acute carpal tunnel syndrome is a surgical emergency that requires decompression. Progressively worsening pain and sensory disturbances in the median nerve distribution are findings that will distinguish an acute carpal tunnel syndrome from the less severe median nerve neurapraxia. This article describes the key differences between neurapraxia and acute compartment syndrome and their respective treatment.

A Cadaveric Study Measuring Femoral Nerve Tension During Anterior Total Hip Arthroplasty Approach.

Femoral nerve palsy is a rare but devastating complication of anterior total hip arthroplasty. Its etiology is still unknown, but several studies have suggested that anterior acetabular retractors may place the femoral nerve at increased risk. This study hypothesized that hip extension and traction places tension on the femoral nerve, offering an additional explanation for the development of femoral nerve palsy. A spring device was secured across 6 transected femoral nerves from 5 lower extremity cadavers and the hip was extended and pulled into traction with and without retractor placement. The change in spring length was used to determine femoral nerve tension. The average spring length changed +8.83 mm with hip extension, +3.73 mm with traction, -0.7 mm with traction and placement of the anterior acetabular retractor, and -1.15 mm with extension and placement of the femoral retractor. Femoral nerve tension was greatest with hip extension followed by traction. Acetabular and femoral retractor placement decreased average femoral nerve tension in both traction and hip extension. This may be due to medialization of the femoral nerve by the retractors, reducing the overall distance traveled, and thereby reducing tension. Previous studies have found femoral nerve pressure to be greatest during anterior acetabular retractor placement. It is likely that both pressure and tension contribute to femoral nerve palsy. Careful retractor placement, staying safely on anterior acetabular bone, and efficient femoral preparation to decrease time under hip extension and traction may help to minimize the risk of femoral nerve palsy.

Recurrent spinal stenoses after implant removal: A case report.

Introduction and importance: Cervical spinal stenoses is becoming more and more common due to the aging population. The degenerative changes in the spine including discopathy or spondylosis will constrict and narrow the spinal canal and the usual site for the stenoses is in the cervical and lumbar region. The mainstay of the treatment is surgical, however there still a controversy regarding which approach is the best for the patient with cervical stenoses. Case presentation: In this case reports we present a case of 63-year-old male who came to our center due to weakness of arms and legs due to cervical spinal stenoses and underwent treatment after which the implant was removed, and the symptoms worsens. Clinical discussion: We performed Anterior Cervical Discectomy and Fusion (ACDF) and insertion of a cages to stabilize the spine. ACDF associated with lower intraoperative blood loss, similar surgical duration, and complication rate compared with laminoplasty. From the radiological outcome, ACDF showed a better-preserved cervical lordosis, which could affects patient's quality of life. Conclusion: ACDF is one of the viable methods for the treatment of the cervical stenoses with lower complication rate and good clinical outcomes.

Outpatient outcomes of patients with femoral nerve neurapraxia after prone lateral lumbar interbody fusion at L4-5.

OBJECTIVE: Single-position prone lateral lumbar interbody fusion (LLIF) improves the efficiency of staged minimally invasive lumbar spine surgery. However, laterally approaching the lumbar spine, especially L4-5 with the patient in the prone position, could increase the risk of complications and presents unique challenges, including difficult ergonomics, psoas migration, and management of the nearby lumbar plexus. The authors sought to identify postoperative femoral neurapraxia after single-position prone LLIF at L4-5 to better understand how symptoms evolve over time. METHODS: This retrospective analysis examined a prospectively maintained database of LLIF patients who were treated by two surgeons (J.S.U. and J.D.T.). Patients who underwent single-position prone LLIF at L4-5 and percutaneous pedicle screw fixation for lumbar stenosis or spondylolisthesis were included if they had at least 6 weeks of follow-up. Outpatient postoperative neurological symptoms were analyzed at 6-week, 3-month, and 6-month follow-up evaluations. RESULTS: Twenty-nine patients (16 women [55%]; overall mean ± SD age 62 ± 11 years) met the inclusion criteria. Five patients (17%) experienced complications, including 1 (3%) who had a femoral nerve injury with resultant motor weakness. The mean ± SD transpsoas retractor time was 14.6 ± 6.1 minutes, the directional anterior electromyography (EMG) threshold before retractor placement was 20.1 ± 10.2 mA, and the directional posterior EMG threshold was 10.4 ± 9.1 mA. All patients had 6-week clinical follow-up evaluations. Ten patients (34%) reported thigh pain or weakness at their 6-week follow-up appointment, compared with 3/27 (11%) at 3 months and 1/20 (5%) at 6 months. No association was found between directional EMG threshold and neurapraxia, but longer transpsoas retractor time at L4-5 was significantly associated with femoral neurapraxia at 6-week follow-up (p = 0.02). The only case of femoral nerve injury with motor weakness developed in a patient with a retractor time that was nearly twice as long as the mean time (27.0 vs 14.6 minutes); however, this patient fully recovered by the 3-month follow-up evaluation. CONCLUSIONS: To our knowledge, this is the largest study with the longest follow-up duration to date after single-position prone LLIF at L4-5 with percutaneous pedicle screw fixation. Although 34% of patients reported ipsilateral sensory symptoms in the thigh at the 6-week follow-up evaluation, only 1 patient sustained a nerve injury; this resulted in temporary weakness that resolved by the 3-month follow-up evaluation. Thus, longer transpsoas retractor time at L4-5 during prone LLIF is associated with increased ipsilateral thigh symptoms at 6-week follow-up that may resolve over time.