Iatrogenic upper limb nerve injuries: a systematic review

Impact of arm position compared to tourniquet and general anesthesia on peripheral vein width in supine adult patients: a prospective, monocentric, cross-sectional study

BACKGROUND

IV access is a commonly performed procedure that is often taught based on tradition rather than evidence. The effect of arm retroflexion on vein width, either alone or in combination with a tourniquet or general anesthesia (GA), remains unclear. In this case, the sonographically measured vein width is a surrogate parameter for the success of the puncture.

METHODS

Prospective, cross-sectional study involving 57 patients scheduled for surgery in general anesthesia. We analyzed the impact of arm retroflexion, tourniquet, general anesthesia, and their combinations on the antebrachial veins in supine patients by ultrasound. Measurements were taken awake and during general anesthesia, each with and without the application of a tourniquet, and in three different arm positions (0°, 30°, and max° retroflexion) each. Data are presented as median and interquartile range [IQR].

RESULTS

Tourniquet application (AT) had the greatest single effect on Cubital vein outer diameter compared to the baseline value of all measures (3.9 mm [3.4-5.1]; 4.8 mm [4.1-5.7], P = 0.001, r = 0.515). This effect was surpassed by the combination of AT and GA (5.1 mm [4.6-6.6], P = 0.001, r = 0.889). In contrast, retroflexion alone did not result in an increase at either 30° (4.2 mm [3.7-5.1], p = 1.0, r = 0.12) or max° (4.2 mm [3.6-4.9], p = 0.72, r = 0.23). With GA and AT, no further enlargement was measurable by 30° (5.4 mm [4.6-6.6], p = 1.0, r = 0.15) or max° (5.4 mm [4.6-6.6], p = 1.0, r = 0.07) retroflexion compared to GA-AT-0° (5.1 mm [4.6-6.6], p = 1.0, r = 0.15).

CONCLUSIONS

This study provides evidence that retroflexion of the arm in supine patients, whether alone or in addition to a tourniquet or general anesthesia, does not have any additional effect on vein width as a surrogate parameter for successful IV success. It shows for the first time that general anesthesia effectively increases vein diameter.

TRIAL REGISTRATION

DRKS00029603 (date of registration 07.07.2022).

Increasing Awareness of Complications of Nerve Injury Following Shoulder Surgery: Preventing Delays in Referral and Treatment

BACKGROUND

Nerve injuries remain a challenging complication after shoulder surgery. While most resolve spontaneously, some require surgical intervention. This study describes the characteristics of patients sustaining nerve injuries following shoulder surgery, evaluates referral patterns to nerve surgeons, and characterizes nerve surgeries performed and their outcomes. Increased awareness of these injuries allows patients and providers to be better informed regarding the appropriate management when these complications occur.

METHODS

A retrospective review of referrals with nerve injuries following shoulder surgery between 2007 and 2015 was performed. The final analysis included 65 patients. Data reviewed included demographics, procedure and anesthesia type, and diagnosis of nerve injury. Time to referral to nerve surgeon and proportional changes in the Disabilities of the Arm, Shoulder, and Hand (DASH) scores were determined. Outcomes were categorized as failed, partially successful, and successful based on final follow-up.

RESULTS

Patients were referred following arthroscopic shoulder surgeries (35.4%), shoulder arthroplasties (24.6%), open shoulder procedures (21.5%), and combined open and arthroscopic procedures (18.5%). The mean time to referral was 7.6 months. Nerve injuries involved brachial plexus (33) and individual and multiple peripheral nerve branches (23 and 7, respectively). Twenty-five (38%) nerve injuries demonstrated spontaneous recovery. Thirty-five patients underwent surgical intervention, of which 27 were successful, 3 were partially successful, and 3 failed.

CONCLUSIONS

This is the largest series of patients with iatrogenic nerve injury following shoulder surgeries to date. Our data demonstrate a lack of timely referral to nerve surgeons, especially after arthroscopy. There continues to be a variable injury pattern even among similar surgeries. Despite this, timely surgical intervention, when indicated, can lead to favorable outcomes.

Evaluation of brachial plexus stiffness in different arm and head positions by sonoelastography

Intraoperative positioning-related nerve injuries, particularly those affecting the brachial plexus, are concerning complications believed to arise from stretching and/or compression of peripheral nerves. Although sonoelastography, a new ultrasound technology, is emerging as a valuable tool in the musculoskeletal system, its utility in evaluating peripheral nerves remains unclear. This study aimed to utilize sonoelastography to assess the brachial plexus during surgery, specifically investigating changes in its stiffness values in relation to different head and arm positions. In this prospective cohort study, bilateral brachial plexuses of 8 volunteers in 3 different positions were enrolled. Using a high-frequency linear probe, the stiffness of the brachial plexus was quantitatively measured in kilopascals (kPa) under 3 different positions: neutral, head rotated, and head rotated with arm hyperabducted. Intra-class agreement was evaluated. The stiffness of the brachial plexus was 7.39 kPa in the neutral position (NP), 10.28 kPa with head rotation, and 17.24 kPa when the head was turned, and the ipsilateral arm was hyperabducted. Significant increases were observed in stiffness values when the head was turned, whether ipsilaterally or contralaterally, and during hyperabduction of the arm while the head was turned (for all P < .001). Strong intra-class correlations were found for the measurements of stiffness values (ICC = 0.988-0.989; P < .001; Cronbach Alpha = 0.987-0.989). Sonoelastography revealed significant increases in the stiffness of the brachial plexus with various head rotations and arm positions compared to the neutral state. These findings suggest that sonoelastography could potentially serve as a valuable tool for assessing the risk of brachial plexus injury during surgery and for guiding optimal patient positioning. Further research with larger sample sizes is needed to establish definitive clinical applications.

The surgical anatomy of the axillary approach for nerve transfer procedures targeting the axillary nerve

PURPOSE

The exact relational anatomy for the anterior axillary approach, targeting the axillary nerve for nerve transfers/grafts, has not been fully investigated. Therefore, this study aimed to dissect and document the gross anatomy surrounding this approach, specifically regarding the axillary nerve and its branches.

METHODS

Fifty-one formalin-fixed cadavers (98 axilla) were bilaterally dissected simulating the axillary approach. Measurements were taken to quantify distances between identifiable anatomical landmarks and relevant neurovascular structures encountered during this approach. The musculo-arterial triangle, described by Bertelli et al., to aid in identification on localization of the axillary nerve, was also assessed.

RESULTS

From the origin of the axillary nerve till (1) latissimus dorsi was 62.3 ± 10.7 mm and till (2) its division into anterior and posterior branches was 38.8 ± 9.6 mm. The origin of the teres minor branch along the posterior division of the axillary nerve was recorded as 6.4 ± 2.9 mm in females and 7.4 ± 2.8 mm in males. The musculo-arterial triangle reliably identified the axillary nerve in only 60.2% of the sample.

CONCLUSION

The results clearly demonstrate that the axillary nerve and its divisions can be easily identified with this approach. The proximal axillary nerve, however, was situated deep and therefore challenging to expose. The musculo-arterial triangle was relatively successful in localising the axillary nerve, however, more consistent landmarks such as the latissimus dorsi, subscapularis, and quadrangular space have been suggested. The axillary approach may serve as a reliable and safe method to reach the axillary nerve and its divisions, allowing for adequate exposure when considering a nerve transfer or graft.

A review of 100 iatrogenic nerve injuries: delays in referrals remain significant

INTRODUCTION

This is a retrospective study of 100 consecutive patients with iatrogenic nerve injuries, as seen in a tertiary referral centre over a six-year period.

MATERIALS AND METHODS

Patients who presented with new-onset nerve palsy involving a motor or mixed motor/sensory nerve following an operation were studied.

RESULTS

There were 44 male and 56 female patients with a mean age of 53 years (range 5-87 years). The median duration from the index procedures to referral was six months (range 0 days to 12 years). Approximately one third of referrals were made over 12 months since the index procedures. Twenty patients recovered spontaneously and were managed expectantly. Eighty patients underwent secondary interventions.

DISCUSSION

There remains a significant delay in referring postoperative nerve palsy to a nerve specialist. The majority of these cases will warrant secondary reconstructive surgery and delay in treatment may have a negative effect on the ultimate outcomes.

Brachial Plexopathy After Modified Radical Mastectomy: A Case Report

Introduction: Brachial plexus injury (BPI) is not a common complication of surgery and anesthesia, which may happen with varied mechanisms like over-abduction, no appropriate positioning, and upper limb stretching. The overall prognosis of BPIs is commonly satisfactory, but the poor function of the upper limb may not be fully recovered in all cases and may end in the permanent sequel in serious injuries. Case Presentation: This study reported a woman with breast cancer. She developed a right brachial plexopathy following a modified radical mastectomy. Upon conservative treatment, full recovery was achieved and normal function of the right upper limb was observed 3 months following the operation. Conclusions: The arm's extremely abnormal positioning during intraoperative manipulation and axillary retraction or hyper abduction can lead to BPI. Nerve injury can occur even in diabetic patients, whose blood glucose is well controlled and have no other risk factors. If the nerve structure is intact, spontaneous recovery can be expected with conservative management.

Iatrogenic Nerve Injuries of the Upper Extremity: A Critical Analysis Review

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Iatrogenic nerve injuries may occur after any intervention of the upper extremity.

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Causes of iatrogenic nerve lesions include direct sharp or thermal injury, retraction, compression from implants or compartment syndrome, injection, patient positioning, radiation, and cast/splint application, among others.

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Optimal treatment of iatrogenic peripheral nerve lesions relies on early and accurate diagnosis.

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Advanced imaging modalities (e.g., ultrasound and magnetic resonance imaging) and electrodiagnostic studies aid and assist in preoperative planning.

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Optimal treatment of iatrogenic injuries is situation-dependent and depends on the feasibility of direct repair, grafting, and functional transfers.

Acromion-axillary nerve distance and its relation to the arm length in the prediction of the axillary nerve position: a clinical study

Background

Because of the broad anatomic variation in the course of the axillary nerve, several cadaveric studies have investigated the acromion-axillary nerve distance and its association with the humeral length to predict the axillary nerve location. This study aimed to analyze the acromion-axillary nerve distance (AAND) and its relation to the arm length (AL) in patients who underwent internal plate fixation for proximal humerus fractures.

Methods

The present prospective study involved 37 patients (15 female, 22 male; the mean age = 51 years, age range 19–76) with displaced proximal humerus fractures treated by open reduction and internal fixation. After anatomic reduction and fixation were achieved, the following parameters were measured in each patient before wound closure without making an extra incision or dissection: (1) the distance from the anterolateral edge of the acromion to the course of the axillary nerve was recorded as the acromion-axillary nerve distance and (2) the distance from the anterolateral edge of the acromion to the lateral epicondyle of the humerus was recorded as arm length. The ratio of AAND to AL was then calculated and recorded as the axillary nerve index (ANI).

Results

The mean AAND was 6 ± 0.36 cm (range 5.5–6.6), and the mean arm length was 32.91 ± 2.9 cm (range 24–38). The mean axillary nerve ratio was 0.18 ± 0.02 (range 0.16 to 0.23). There was a significant moderate positive correlation between AL and AAND (p = 0.006; r = 0.447). The axillary nerve location was predictable in only 18% of the patients.

Conclusion

During the anterolateral deltoid-splitting approach to the shoulder joint, 5.5 cm from the anterolateral edge of the acromion could be considered a safe zone to prevent possible axillary nerve injury.

The prevention of pressure injuries in the positioning and mobilization of patients in the ICU: a good clinical practice document by the Italian Society of Anesthesia, Analgesia, Resuscitation and Intensive Care (SIAARTI)

BACKGROUND

The aim of this document is to support clinical decision-making concerning positioning and mobilization of the critically ill patient in the early identification and resolution of risk factors (primary prevention) and in the early recognition of those most at risk (secondary prevention). The addresses of this document are physicians, nurses, physiotherapists, and other professionals involved in patient positioning in the intensive care unit (ICU).

METHODS

A consensus pathway was followed using the Nominal Focus Group and the Delphi Technique, integrating a phase of focused group discussion online and with a pre-coded guide to an individual phase. A multidisciplinary advisory board composed by nine experts on the topic contributed to both the phases of the process, to reach a consensus on four clinical questions positioning and mobilization of the critically ill patient.

RESULTS

The topics addressed by the clinical questions were the risks associated with obligatory positioning and therapeutic positions, the effective interventions in preventing pressure injuries, the appropriate instruments for screening for pressure injuries in the ICU, and the cost-effectiveness of preventive interventions relating to ICU positioning. A total of 27 statements addressing these clinical questions were produced by the panel. Among the statements, nine provided guidance on how to manage safely some specific patients' positions, including the prone position; five suggested specific screening tools and patients' factors to consider when assessing the individual risk of developing pressure injuries; five gave indications on mobilization and repositioning; and eight focused on the use of devices, such as positioners and preventive dressings.

CONCLUSIONS

The statements may represent a practical guidance for a broad public of healthcare professionals involved in the management of critically ill patients.

Medical Malpractice in Nerve Injury of the Upper Extremity

Background: Medical malpractice accounts for more than $55 billion of annual health care costs. Updated malpractice risk to surgeons and physicians related to upper extremity peripheral nerve injury has not been published. Methods: A comprehensive database analysis of upper extremity nerve injury claims between 1995 and 2014 in the United States was conducted using the Medical Professional Liability Association Data Sharing Project, representing 24 major insurance companies. Results: Nerve injury in the upper extremity accounted for 614 (0.3%) malpractice claims (total of 188 323). Common presenting diagnoses included carpal tunnel syndrome (41%), upper extremity fractures (19%), and traumatic nerve injuries to the shoulder or upper limb (8%). Improper performance (49% of total claims) and claims without evidence of medical error (19%) were the most common malpractice suits. Orthopedic surgeons were the most frequently targeted specialists (42%). In all, 65% of nerve injury claims originated from operative procedures in a hospital, 59% of claims were dismissed or withdrawn prior to trial, and 30% resulted in settlements. Thirty-three percent of claims resulted in an indemnity payment to an injured party, with an average payout of $203 592 per successful suit. Only 8% of claims resulted in a completed trial and verdict, and verdicts were overwhelmingly in favor of the defendant (83%). Conclusions: Most malpractice claims from peripheral nerve injuries in the United States arise from the management of common diagnoses, occur in the operating room, and allege improper performance. Strategies to reduce malpractice risk should emphasize the management of common conditions and patient-physician communication.

The Prevention of Positioning Injuries During Gynecologic Surgery. Guideline of the DGGG, OEGGG and SGGG (S2k Level, AWMF Registry Number 015/077, October 2020)

Purpose Positioning injuries are relatively common, forensically highly relevant complications of gynecologic surgery. The aim of this official AWMF S2k-guideline is to provide statements and recommendations on how to prevent positioning injuries using the currently available literature. The literature was evaluated by an interdisciplinary group of experts from professional medical societies. The consensus on recommendations and statements was achieved in a structured consensus process. Method The current guideline is based on the expired S1-guideline, which was updated by a systematic search of the literature and a review of relevant publications issued between February 2014 and March 2019. Statements were compiled and voted on by a panel of experts. Recommendations The guideline provides general and specific recommendations on the prevention, diagnosis and treatment of positioning injuries.

Lead Optimization of Nerve-Specific Fluorophores for Image-Guided Nerve Sparing Surgical Procedures

Nerve damage is a major complication of surgery, causing pain and loss of function. We have identified novel near-infrared nerve-specific fluorophores that provide excellent nerve contrast with the ability to identify buried nerve tissue.

Iatrogenic nerve injuries: a potentially serious medical and medicolegal problem. About a series of 42 patients and review of the literature

OBJECTIVE

To analyze the management of iatrogenic nerve injuries (iNI) in 42 patients.

METHODS

Retrospective analysis of the charts.

RESULTS

The iNI occurred mostly during a surgical procedure (n = 39), either on a nerve or plexus (n = 13), on bone, joint, vessel or soft tissue (n = 24) or because of malpositioning (n = 2). The most commonly injured nerves were the brachial plexus, radial, sciatic, femoral, or peroneal nerves. 42.9% of the patients were referred later than 6 months. A neurological deficit was present in 37 patients and neuropathic pain in 17. Two patients were lost to follow-up. Conservative treatment was applied in 23 patients because of good spontaneous recovery or compensation or because of expected bad prognosis whatever the treatment. Surgical treatment was performed in 17 patients because of known nerve section (n = 2), persistent neurological deficit (n = 12) or invalidating neuropathic pain (n = 3); nerve reconstruction with grafts (n = 8) and neurolysis (n = 8) were the most common procedures. Outcome was satisfactory in 50%. Potential reasons of poor outcome were a very proximal injury, placement of very long grafts, delayed referral and predominance of neuropathic pain. According to the literature delayed referral of iNI for treatment is frequent. We provide an illustrative case of a young girl operated on at 6.5 months for femoral nerve reconstruction with grafts while nerve section was obvious from the operative note and pathological tissue analysis. Litigation claims (n = 10) resulted in malpractice (n = 2) or therapeutic alea (n = 5) (3 unavailable conclusions). i CONCLUSIONS: NI can result in considerable disability, pain and litigation. Optimal management is required.

MRI evaluation of axillary neurovascular bundle: Implications for minimally invasive proximal humerus fracture fixation

Background

Percutaneous fixation of proximal humeral fractures places the axillary nerve and posterior humeral circumflex artery at risk for injury. Safe operative zones for the axillary nerve are described based on external measurements from anatomic landmarks, but no study to date has incorporated advanced imaging to help guide surgical procedures in the region of the axillary neurovascular bundle (ANVB). We sought to define the location and trajectory of the ANVB in relation to osseous landmarks using magnetic resonance imaging (MRI) measurements.

Methods

Retrospective review of 750 consecutive MRI studies was performed with 55 imaging studies meeting inclusion criteria for patient positioning, image alignment, and quality. Five measurements were performed including the distance from mid-lateral acromion to lateral ANVB, mid-lateral acromion to medial ANVB, greater tuberosity to lateral ANVB, vertical distance between inferior anatomic neck and lateral ANVB, and angle the ANVB crosses the humerus. Height, gender, and age were recorded. Analysis was performed using ANOVA and Pearson correlation tests.

Results

The lateral ANVB was below the inferior articular margin of the humeral head by an average of 12.9 ± 3.9 mm and within a 22 mm window. It was an average of 57.4 ± 5.1 mm from the lateral mid-acromion, and 34.7 ± 4.3 mm below the greater tuberosity. The angle formed by the ANVB crossing the humerus averaged 19.5 ± 3.9 degrees upward from medial to lateral. Height and gender directly impacted measurements.

Conclusions

The use of the inferior humeral head articular margin provides a radiographic landmark to aid intraoperative lateral ANVB assessment which may be helpful during percutaneous fracture fixation.

Nerve Ultrasound in Traumatic and Iatrogenic Peripheral Nerve Injury

Peripheral nerve injury is a potentially debilitating disorder that occurs in an estimated 2–3% of all patients with major trauma, in a similar percentage of medical procedures. The workup of these injuries has traditionally been clinical, combined with electrodiagnostic testing. However, this has limitations, especially in the acute phase of the trauma or lack of any recovery, when it is very important to determine nerve continuity and perform surgical exploration and repair in the case of the complete transection or intraneural fibrosis. Ultrasound can help in those situations. It is a versatile imaging technique with a high sensitivity of 93% for detecting focal nerve lesions. Ultrasound can assess the structural integrity of the nerve, neuroma formation and other surrounding abnormalities of bone or foreign bodies impeding the nerve. In addition, this can help to prevent iatrogenic nerve injury by marking the nerve before the procedure. This narrative review gives an overview of why and how nerve ultrasound can play a role in the detection, management and prevention of peripheral nerve injury.

Characteristics of Iatrogenic Nerve Injury from Orthopedic Surgery Correlate with Time to Subspecialty Presentation

There is no current literature examining iatrogenic nerve injury resulting from orthopedic procedures across subspecialties and anatomic areas. This study uses a single peripheral nerve surgeon’s experience to investigate the variable time to presentation of adult patients with iatrogenic nerve injury after orthopedic surgery.

Conditions and Injuries Affecting the Nerves Around the Elbow

Sports-related peripheral neuropathies account for 6% of all peripheral neuropathies and most commonly involve the upper extremity. The routes of the median, radial, and ulnar nerves are positioned in arrangements of pulleys and sheaths to glide smoothly around the elbow. However, this anatomic relationship exposes each nerve to risk of compression. The underlying mechanisms of the athletic nerve injury are compression, ischemia, traction, and friction. Chronic athletic nerve compression may cause damage with moderate or low pressure for long or intermittent periods of time.

Near-infrared nerve-binding fluorophores for buried nerve tissue imaging

Nerve-binding fluorophores with near-infrared (NIR; 650 to 900 nm) emission could reduce iatrogenic nerve injury rates by providing surgeons precise, real-time visualization of the peripheral nervous system. Unfortunately, current systemically administered nerve contrast agents predominantly emit at visible wavelengths and show nonspecific uptake in surrounding tissues such as adipose, muscle, and facia, thus limiting detection to surgically exposed surface-level nerves. Here, a focused NIR fluorophore library was synthesized and screened through multi-tiered optical and pharmacological assays to identify nerve-binding fluorophore candidates for clinical translation. NIR nerve probes enabled micrometer-scale nerve visualization at the greatest reported tissue depths (~2 to 3 mm), a feat unachievable with previous visibly emissive contrast agents. Laparoscopic fluorescent surgical navigation delineated deep lumbar and iliac nerves in swine, most of which were invisible in conventional white-light endoscopy. Critically, NIR oxazines generated contrast against all key surgical tissue classes (muscle, adipose, vasculature, and fascia) with nerve signal-to-background ratios ranging from ~2 (2- to 3-mm depth) to 25 (exposed nerve). Clinical translation of NIR nerve-specific agents will substantially reduce comorbidities associated with surgical nerve damage.

Risk of Axillary Nerve Injury in Standard Anterolateral Approach of Shoulder: Cadaveric Study

Introduction: The anterolateral acromion approach of the shoulder is popular for minimally invasive plate osteosynthesis (MIPO) technique. However, there are literatures describing the specific risks of injury of the axillary nerve using this approach. Nevertheless, most of the studies were done with Caucasian cadavers. So, the purpose of this study was to evaluate the risk of iatrogenic axillary nerve injury from using the anterolateral shoulder approach and further investigate the location of the axillary nerve, associated with its location and arm length in the Asian population that have shorter arm length compared to the Caucasian population.

Materials and Methods: Seventy-nine shoulders in fourty-two embalmed cadavers were evaluated. The bony landmarks were drawn, and a vertical straight incision was made 5cm from tip of the acromion (anterolateral approach), to the bone. The iatrogenic nerve injury status and the distance between the anterolateral edge of the acromion to the axillary nerve was measured and recorded.

Results: In ten of the seventy-nine shoulders, the axillary nerve were iatrogenically injured. The average anterior distance was 6.4cm and the average arm length was 30.2cm. The anterior distance and arm length ratio was 0.2.

Conclusion: Our results demonstrated that the recommended safe zone at 5cm from tip of acromion was not suitable with Asian population due to shorter arm length, compared to Caucasian population. The location of axillary nerve could be predicted by 20% of the total arm-length.

A review of main anatomical and sonographic features of subcutaneous nerve injuries related to orthopedic surgery

Lesion to subcutaneous nerves is a well-known risk of orthopedic surgery and a significant cause of postoperative pain and dissatisfaction in patients. High-resolution ultrasound can be used to visualize the vast majority of small subcutaneous nerves of the upper and lower limbs. Ultrasound detects nerve abnormalities such as focal hypoechoic thickening, stump neuroma, and scar encasement, and provides information not only about the peripheral nerve itself but also about its relationship to adjacent anatomical structures. The purpose of this review is to provide an overview of the anatomy of the main subcutaneous nerves damaged during orthopedic surgery, recall at-risk procedures, and offer useful anatomic landmarks to help the sonographer identify and follow the nerves when an iatrogenic lesion is suspected.

Preventing brachial plexus injury during shoulder surgery: a real-time cadaveric study

BACKGROUND

Brachial plexopathy is not uncommon after shoulder surgery. Although thought to be due to stretch neuropathy, its etiology is poorly understood. This study aimed to identify arm positions and maneuvers that may risk causing brachial plexopathy during shoulder arthroplasty.

METHODS

Tensions in the cords of the brachial plexuses of 6 human cadaveric upper limbs were measured using load cells while each limb was placed in different arm positions and while they underwent shoulder hemiarthroplasty and revision reverse arthroplasty. Arthroplasty procedures in 4 specimens were performed with standard limb positioning (unsupported), and 2 specimens were supported from under the elbow (supported). Each cord then underwent biomechanical testing to identify tension corresponding to 10% strain (the stretch neuropathy threshold in animal models).

RESULTS

Tensions exceeding 15 N, 11 N, and 9 N in the lateral, medial, and posterior cords, respectively, produced 10% strain. Shoulder abduction >70° and combined external rotation >60° with extension >50° increased medial cord tension above the 10% strain threshold. Medial cord tensions (mean ± standard error of the mean) in unsupported specimens increased over baseline during hemiarthroplasty (sounder insertion [4.7 ± 0.6 N, P = .04], prosthesis impaction [6.1 ± 0.8 N, P = .04], and arthroplasty reduction [5.0 ± 0.7 N, P = .04]) and revision reverse arthroplasty (retractor positioning [7.2 ± 0.8 N, P = .02]). Supported specimens experienced lower tensions than unsupported specimens.

CONCLUSIONS

Shoulder abduction >70°, combined external rotation >60° with extension >50°, and downward forces on the humeral shaft may risk causing brachial plexopathy. Retractor placement, sounder insertion, humeral prosthesis impaction, and arthroplasty reduction increase medial cord tensions during shoulder arthroplasty. Supporting the arm from under the elbow protected the brachial plexus in this cadaveric model.

Best care paradigm to optimize functionality after extra-articular distal humeral fractures in the young patient

For younger patients with extra-articular distal humerus fractures closed management is plagued with high rates of malunion, suboptimal functional outcomes, extended immobilization with loss of early motion, a delay in return to work, and a general period of lost productivity. Surgical management offers an appealing alternative. Maintaining respect for the triceps musculature and minimizing iatrogenic injury to the radial nerve are primary concerns with operative treatment. Accordingly, use of a triceps-sparing approach and single column plating may be the optimal treatment paradigm in the young patient presenting with an extra-articular distal humerus fracture.

Arms Down Cone Beam CT Hepatic Angiography Performance Assessment: Vascular Imaging Quality and Imaging Artifacts

INTRODUCTION

The practice of positioning patients' arms above the head during catheter-injected hepatic arterial phase cone beam CT (A-CBCT) imaging has been inherited from standard CT imaging due to image quality concerns, but interrupts workflow and extends procedure time. We sought to assess A-CBCT image quality and artifacts with arms extended above the head versus down by the side.

METHODS

We performed an IRB approved retrospective evaluation of reformatted and 3D-volume rendered images from 91 consecutive A-CBCTs (43 arms up, 48 arms down) acquired during hepatic tumor arterial embolization procedures. Two interventional radiologists reviewed all A-CBCT imaging and assigned vessel visualization scores (VVS) from 1 to 5, ranging from non-diagnostic to optimal visualization. Streak artifacts across axial images were rated from 1 to 3 based on resulting image quality (none to significant). Presence of respiratory or cardiac motion during acquisition, body mass index and radiation dose area product (DAP) were also recorded and analyzed. Univariate and multivariate analyses were used to assess the impact of arm position on VVS and imaging artifacts.

RESULTS

VVS were not significantly associated with arm position during A-CBCT imaging. One reader reported more streak artifacts across axial images in the arms down group (p = 0.005). DAP was not statistically different between the groups (23.9 Gy cm² [6.1-73.4] arms up, 26.1 Gy cm² [4.2-102.6] arms down, p = 0.54).

CONCLUSION

A-CBCT angiography performed with the arms above the head is not superior for clinically relevant hepatic vascular visualization compared to imaging performed with the arms by the patient's side.

Guideline Implementation: Positioning the Patient

Every surgical procedure requires positioning the patient; however, all surgical positions are associated with the potential for the patient to experience a positioning injury. The locations and types of potential injuries (eg, stretching, compression, pressure injury) depend on the position. Factors that may increase the patient's risk for an injury are the length of the procedure and risk factors inherent to the patient (eg, weight, age, frailty). AORN's updated "Guideline for positioning the patient" provides guidance on injury prevention practices for all surgical positions including supine, Trendelenburg, reverse Trendelenburg, lateral, lithotomy, prone, and sitting positions and modifications of these positions. This article focuses on the key points of the guideline covering the use of prophylactic dressings, neurophysiological monitoring, and safely positioning the patient in the supine and prone positions. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

Mechanisms, Treatment, and Patient Outcome of Iatrogenic Injury to the Brachial Plexus-A Retrospective Single-Center Study

BACKGROUND

Injury to the brachial plexus is a devastating condition, with severe impairment of upper extremity function resulting in distinct disability. There are no systematic reports on epidemiology, causative mechanisms, treatment strategies. or outcomes of iatrogenic brachial plexus injury (iBPI).

METHODS

We screened all cases of iatrogenic nerve injuries recorded between 2007 and 2017 at a single specialized institution. Mechanism of iBPI, type of previous causative intervention, location and type of the lesion as well as the type of revision surgery and functional patient outcome were analyzed.

RESULTS

We identified 14 cases of iBPI, which all presented with significant impairment of upper extremity motor function (at least 1 muscle Medical Research Council grade 0). Neuropathic pain was present in most patients (11/14). Orthopedic shoulder procedures such as rotator cuff fixation, arthroplasty, and repositioning of a clavicle fracture accounted for iBPI in 7 of 14 patients. Other reasons for iBPI were resection or biopsy of a peripheral nerve sheath tumor in 3 patients or lymph node situated at the cervicomediastinal area in 2 patients. Mechanisms also included transaxillary rib resection in one and sternotomy in another patient. The treatment of iBPI was conducted according to each individual's needs and included neurolysis in 4, nerve grafting in 9, and nerve transfers in 1 patient. We found improved symptoms after treatment in most patients (11/14).

CONCLUSIONS

Most common causes for iBPI were shoulder surgery and resection or biopsy of peripheral nerve sheath tumor and lymph nodes. Early referral to specialized peripheral nerve centers may help to improve functional patient outcome.

Nerve Regeneration and Functional Recovery With Neurorrhaphy Performed at the Early Distraction Osteogenesis: An Experimental Study

Distraction osteogenesis is widely used in many clinical situations, but distraction in cases accompanying nerve injury has been avoided due to concern of unfavorable effect on nerve regeneration by traction. This study evaluated the feasibility of early distraction lengthening after neurorrhaphy. Thirty-six rats were evenly distributed into 3 groups (12 rats in each group); neurorrhaphy and distraction (group I), neurorrhaphy and osteotomy without distraction (group II), and only distraction without neurorrhaphy (group III), respectively. After osteotomy on the right tibia, distraction started after 1 week and was continued for 40 days with 0.25 mm per day. Histological evaluation was carried out to identify nerve regeneration at 4, 8, and 12 weeks after surgery. Walking tract analysis was performed to assess the functional recovery preoperatively and 1, 4, 8, and 12 weeks postoperatively. Histologically, axon number ratio was significantly impaired in group I (0.48 ± 0.14) and group II (0.53 ± 0.13) compared with group III (0.88 ± 0.04) at 4 weeks (P = 0.020). There was no significant difference at both 8 and 12 weeks. Walking tract analysis showed significant differences between groups I and III (-40.5 ± 4.3), and groups II and III (-35.5 ± 5.0) at 1 week (P = 0.001), but no difference was observed at 8 and 12 weeks. Distraction osteogenesis in early stage after nerve repair is safe and effective, when performed at a rate of 0.25 mm per day in rats.

The design of and chronic tissue response to a composite nerve electrode with patterned stiffness

OBJECTIVE

As neural interfaces demonstrate success in chronic applications, a novel class of reshaping electrodes with patterned regions of stiffness will enable application to a widening range of anatomical locations. Patterning stiff regions and flexible regions of the electrode enables nerve reshaping while accommodating anatomical constraints of various implant locations ranging from peripheral nerves to spinal and autonomic plexi.

APPROACH

Introduced is a new composite electrode enabling patterning of regions of various electrode mechanical properties. The initial demonstration of the composite's capability is the composite flat interface nerve electrode (C-FINE). The C-FINE is constructed from a sandwich of patterned PEEK within layers of pliable silicone. The shape of the PEEK provides a desired pattern of stiffness: stiff across the width of the nerve to reshape the nerve, but flexible along its length to allow for bending with the nerve. This is particularly important in anatomical locations near joints or organs, and in constrained compartments. We tested pressure and volume design constraints in vitro to verify that the C-FINE can attain a safe cuff-to-nerve ratio (CNR) without impeding intraneural blood flow. We measured nerve function as well as nerve and axonal morphology following 3 month implantation of the C-FINE without wires on feline peripheral nerves in anatomically constrained areas near mobile joints and major blood vessels in both the hind and fore limbs.

MAIN RESULTS

In vitro inflation tests showed effective CNRs (1.93  ±  0.06) that exceeded the industry safety standard of 1.5 at an internal pressure of 20 mmHg. This is less than the 30 mmHg shown to induce loss of conduction or compromise blood flow. Implanted cats showed no changes in physiology or electrophysiology. Behavioral signs were normal suggesting healthy nerves. Motor nerve conduction velocity and compound motor action potential did not change significantly between implant and explant (p  >  0.15 for all measures). Axonal density and myelin sheath thickness was not significantly different within the electrode compared to sections greater than 2 cm proximal to implanted cuffs (p  >  0.14 for all measures).

SIGNIFICANCE

We present the design and verification of a novel nerve cuff electrode, the C-FINE. Laminar manufacturing processes allow C-FINE stiffness to be configured for specific applications. Here, the central region in the configuration tested is stiff to reshape or conform to the target nerve, while edges are highly flexible to bend along its length. The C-FINE occupies less volume than other NCEs, making it suitable for implantation in highly mobile locations near joints. Design constraints during simulated transient swelling were verified in vitro. Maintenance of nerve health in various challenging anatomical locations (sciatic and median/ulnar nerves) was verified in a chronic feline model in vivo.

Radial nerve palsy

As a result of its proximity to the humeral shaft, as well as its long and tortuous course, the radial nerve is the most frequently injured major nerve in the upper limb, with its close proximity to the bone making it vulnerable when fractures occur.Injury is most frequently sustained during humeral fracture and gunshot injuries, but iatrogenic injuries are not unusual following surgical treatment of various other pathologies.Treatment is usually non-operative, but surgery is sometimes necessary, using a variety of often imaginative procedures. Because radial nerve injuries are the least debilitating of the upper limb nerve injuries, results are usually satisfactory.Conservative treatment certainly has a role, and one of the most important aspects of this treatment is to maintain a full passive range of motion in all the affected joints.Surgical treatment is indicated in cases when nerve transection is obvious, as in open injuries or when there is no clinical improvement after a period of conservative treatment. Different techniques are used including direct suture or nerve grafting, vascularised nerve grafts, direct nerve transfer, tendon transfer, functional muscle transfer or the promising, newer treatment of biological therapy. Cite this article: Bumbasirevic M, Palibrk T, Lesic A, Atkinson HDE. Radial nerve palsy. EFORT Open Rev 2016;1:286-294. DOI: 10.1302/2058-5241.1.000028.

Iatrogenic Injury to the Median Nerve During Palmaris Longus Harvest: An Overview of Safe Harvesting Techniques

Background: A rare and disastrous complication of harvesting a tendon graft is the misidentification of the median nerve for the palmaris longus. Methods: The authors report a referred case in which the median nerve was harvested as a free tendon graft. Results: Few reports of this complication are found in the literature despite the frequency of palmaris longus tendon grafting and the proximity of the palmaris tendon to the median nerve. Given the obvious medicolegal implications, the true incidence of this complication is difficult to assess. Discussion: Safe harvesting of the palmaris longus mandates a thorough understanding of the relevant anatomy, in particular the proper differentiation between nerve and tendon and recognition of when the palmaris longus tendon is absent. Techniques to facilitate proper identification of the palmaris longus are outlined.

Iatrogenic lesions of peripheral nerves

Iatrogenic nerve lesions (INLs) are an integral part of peripheral neurology and require dedicated neurologists to manage them. INLs of peripheral nerves are most frequently caused by surgery, immobilization, injections, radiation, or drugs. Early recognition and diagnosis is important not to delay appropriate therapeutic measures and to improve the outcome. Treatment can be causative or symptomatic, conservative, or surgical. Rehabilitative measures play a key role in the conservative treatment, but the point at which an INL requires surgical intervention should not be missed or delayed. This is why INLs require close multiprofessional monitoring and continuous re-evaluation of the therapeutic effect. With increasing number of surgical interventions and increasing number of drugs applied, it is quite likely that the prevalence of INLs will further increase. To provide an optimal management, more studies about the frequency of the various INLs and studies evaluating therapies need to be conducted. Management of INLs can be particularly improved if those confronted with INLs get state-of-the-art education and advanced training about INLs. Management and outcome of INLs can be further improved if the multiprofessional interplay is optimized and adapted to the needs of the patient, the healthcare system, and those responsible for sustaining medical infrastructure.

Safer Surgery by Learning from Complications: A Focus on Robotic Prostate Surgery

BACKGROUND

The uptake of robotic surgery has led to changes in potential operative complications, as many surgeons learn minimally invasive surgery, and has allowed the documentation of such complications through the routine collection of intraoperative video.

OBJECTIVE

We documented intraoperative complications from robot-assisted radical prostatectomy (RARP) with the aim of reporting the mechanisms, etiology, and necessary steps to avoid them. Our goal was to facilitate learning from these complications to improve patient care.

DESIGN, SETTING, AND PARTICIPANTS

Contributors delivered videos of complications that occurred during laparoscopic and robotic prostatectomy between 2010 and 2015.

SURGICAL PROCEDURE

Surgical footage was available for a variety of complications during RARP.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Based on these videos, a literature search was performed using relevant terms (prostatectomy, robotic, complications), and the intraoperative steps of the procedures and methods of preventing complications were outlined.

RESULTS AND LIMITATIONS

As a major surgical procedure, RARP has much potential for intra- and postoperative complications related to patient positioning, access, and the procedure itself. However, with a dedicated approach, increasing experience, a low index of suspicion, and strict adherence to safety measures, we suggest that the majority of such complications are preventable.

CONCLUSIONS

Considering the complexity of the procedure, RARP is safe and reproducible for the surgical management of prostate cancer. Insight from experienced surgeons may allow surgeons to avoid complications during the learning curve.

PATIENT SUMMARY

Robot-assisted radical prostatectomy has potential for intra- and postoperative complications, but with a dedicated approach, increasing experience, a low index of suspicion, and strict adherence to safety measures, most complications are preventable.

The Prevention of Positioning Injuries during Gynecologic Operations. Guideline of DGGG (S1-Level, AWMF Registry No. 015/077, February 2015)

Purpose: Official guideline published and coordinated by the German Society of Gynecology and Obstetrics (DGGG). Positioning injuries after lengthy gynecological procedures are rare, but the associated complications can be potentially serious for patients. Moreover, such injuries often lead to claims of malpractice and negligence requiring detailed medical investigation. To date, there are no binding evidence-based recommendations for the prevention of such injuries. Methods: This S1-guideline is the work of an interdisciplinary group of experts from a range of different professions who were commissioned by DGGG to carry out a systematic literature search of positioning injuries. Members of the participating scientific societies develop a consensus in an informal procedure. Afterwards the directorate of the scientific society approves the consensus. The recommendations cover.

Intraoperative peripheral nerve injury in colorectal surgery. An update

Intraoperative peripheral nerve injury during colorectal surgery procedures is a potentially serious complication that is often underestimated. The Trendelenburg position, use of inappropriately padded armboards and excessive shoulder abduction may encourage the development of brachial plexopathy during laparoscopic procedures. In open colorectal surgery, nerve injuries are less common. It usually involves the femoral plexus associated with lithotomy position and self-retaining retractor systems. Although in most cases the recovery is mostly complete, treatment consists of physical therapy to prevent muscular atrophy, protection of hypoesthesic skin areas and analgesics for neuropathic pain. The aim of the present study is to review the incidence, prevention and management of intraoperative peripheral nerve injury.

Cadaveric investigation on radial nerve strain using different posterior surgical exposures for extraarticular distal humeral ORIF: merits of nerve decompression through a lateral paratricipital exposure

OBJECTIVE

To determine whether the type of posterior surgical approach for distal humeral fracture open reduction and internal fixation influenced radial nerve strain during simulated operative retraction in a cadaveric model.

METHODS

Three different posterior surgical exposures: triceps splitting, lateral paratricipital, and paratricipital with release of the lateral intermuscular septum were used. Radial nerve strain was measured using a microDVRT, while traction was applied with a digital force gauge at forces 0.1-0.3 kg.

RESULTS

The lateral paratricipital with nerve decompression was superior to both the triceps splitting approach (P < 0.048) and paratricipital method without decompression (P < 0.036). There was no significant difference between the triceps splitting method and paratricipital exposure without intermuscular septum release.

CONCLUSIONS

Radial nerve decompression through release of the lateral intermuscular septum through a lateral paratricipital exposure ideally decreases nerve strain during humeral open reduction and internal fixation in our cadaveric model.

Perioperative upper extremity peripheral nerve traction injuries

Peripheral nerve traction injuries may occur after surgical care and can involve any of the upper extremity large peripheral nerves. In this review, injuries after shoulder or elbow surgical intervention are discussed. Understanding the varying mechanisms of injury as well as classification is imperative for preoperative risk stratification as well as management.

Brachial plexus palsy after a left-side modified radical mastectomy with immediate latissimusdorsi flap reconstruction: report of a case

Brachial plexus injury is a rare complication during operation and anesthesia; it can occur as a result of various mechanisms such as inappropriate positioning, over-abduction and stretching the upper limbs. Brachial plexus injury can cause the poor function of the upper limb before recovery, and sometimes serious injury is unable to completely recovered the function permanently. Here, we report a female breast cancer patient who sustained a left brachial plexus palsy after modified radical mastectomy with immediate breast reconstruction with latissimusdorsi flap (LDF). The patient had fully recovered with normal function of her left upper limb six months postoperation after conservative treatment.