Sports-related peripheral nerve injuries of the upper limb.

Peripheral nerve injuries in athletes affect the upper limb more commonly than the lower limb. Common mechanisms include compression, traction, laceration, and ischemia. Specific sports can have unique mechanisms of injury and are more likely to be associated with certain neuropathies. Familiarity with these sport-specific variables and recognition of the common presentations of upper limb neuropathic syndromes are important in assessing an athlete with a suspected peripheral nerve injury. Evaluation may require imaging modalities and/or electrodiagnostic testing to confirm a nerve injury. In some cases, diagnostic injections may be needed to differentiate neuropathic versus musculoskeletal etiology. Early and accurate diagnosis is essential for treatment/management and increases the likelihood of a safe return-to-sport and avoidance of long-term functional consequences. Most nerve injuries can be treated conservatively, however, severe or persistent cases may require surgical intervention. This monograph reviews key diagnostic, management, and preventative strategies for sports-related peripheral nerve injuries involving the upper limb.

Differential Diagnosis of "Foot Drop": Implications for Peripheral Nerve Surgery.

BACKGROUND: At least 128,000 patients in the United States each year suffer from foot drop. This is a debilitating condition, marked by the inability to dorsiflex and/or evert the affected ankle. Such patients are rendered to a lifetime of relying on an ankle-foot orthosis (AFO) for walking and nighttime to prevent an equinovarus contracture. METHODS: This narrative review explores the differential diagnosis of foot drop, with a particular focus on clinical presentation and recovery, whether spontaneously or through surgery. RESULTS: Contrary to popular belief, foot drop can be caused by more than just insult to the common peroneal nerve at the fibular head (fibular tunnel). It is a common endpoint for a diverse spectrum of nerve injuries, which may explain its relatively high prevalence. From proximal to distal, these conditions include lumbar spine nerve root damage, sciatic nerve palsy at the sciatic notch, and common peroneal nerve injury at the fibular head. Each nerve condition is marked by a unique clinical presentation, frequency, likelihood for spontaneous recovery, and cadre of peripheral nerve techniques. CONCLUSION: The ideal surgical technique for treating foot drop, other than neurolysis for compression, remains elusive as traditional peripheral nerve procedures have been marred by a wide spectrum of functional results. Based on a careful understanding of why past techniques have achieved limited success, we can formulate a working set of principles to help guide surgical innovation moving forward, such as fascicular nerve transfer.

3D mapping of phrenic nerve course for radiofrequency pulmonary vein isolation.

INTRODUCTION: Phrenic nerve (PN) injury is a rare but severe complication of radiofrequency (RF) pulmonary vein isolation (PVI). The objective of this study was to characterize the typical intracardiac course of the PN with a three-dimensional electroanatomic mapping system, to quantify the need for modification of the ablation trajectory to avoid delivering an ablation lesion on sites with PN capture, and to identify very circumscribed areas of common PNC on the routine ablation trajectory of a RF-PVI, allowing fast and effective PN screening for everyday usage. METHODS: We enrolled 137 consecutive patients (63 ± 9 years, 64% men) undergoing PVI. A detailed high output (20 mA) pace-mapping protocol was performed in the right (RA) and left atrium (LA) and adjacent vasculature. RESULTS: The right PN was most commonly captured in the superior vena cava at a lateral (50%) or posterolateral (23%) position before descending along the RA either straight (29%) or with a posterolateral bend (20%). In the LA, beginning deep within the right superior pulmonary vein (RSPV), the right PN is most frequently detectable anterolateral (31%), then descends to the lateral proximal RSPV (23%), and further towards the lateral antral region (15%) onto the medial LA wall (12%). To avoid delivering an ablation lesion on sites with PN capture, modification of ablation trajectory was necessary in 23% of cases, most commonly in the lateral RSPV antrum (81%). No PN injury occurred. CONCLUSION: PN mapping frequently reveals the close proximity of the PN to the ablation trajectory during PVI, particularly in the lateral RSPV antrum. Routine PN pacing should be considered during RF PVI procedures.

Traumatic peripheral nerve injuries: a classification proposal.

BACKGROUND: Peripheral nerve injuries (PNIs) include several conditions in which one or more peripheral nerves are damaged. Trauma is one of the most common causes of PNIs and young people are particularly affected. They have a significant impact on patients' quality of life and on the healthcare system, while timing and type of surgical treatment are of the utmost importance to guarantee the most favorable functional recovery. To date, several different classifications of PNIs have been proposed, most of them focusing on just one or few aspects of these complex conditions, such as type of injury, anatomic situation, or prognostic factors. Current classifications do not enable us to have a complete view of this pathology, which includes diagnosis, treatment choice, and possible outcomes. This fragmentation sometimes leads to an ambiguous definition of PNIs and the impossibility of exchanging crucial information between different physicians and healthcare structures, which can create confusion in the choice of therapeutic strategies and timing of surgery. MATERIALS: The authors retrospectively analyzed a group of 24 patients treated in their center and applied a new classification for PNI injuries. They chose (a) five injury-related factors, namely nerve involved, lesion site, nerve type (whether motor, sensory or mixed), surrounding tissues (whether soft tissues were involved or not), and lesion type-whether partial/in continuity or complete. An alphanumeric code was applied to each of these classes, and (b) four prognostic codes, related to age, timing, techniques, and comorbidities. RESULTS: An alphanumeric code was produced, similar to that used in the AO classification of fractures. CONCLUSIONS: The authors propose this novel classification for PNIs, with the main advantage to allow physicians to easily understand the characteristics of nerve lesions, severity, possibility of spontaneous recovery, onset of early complications, need for surgical treatment, and the best surgical approach. LEVEL OF EVIDENCE: according to the Oxford 2011 level of evidence, level 2.

Traumatic peripheral nerve injuries: diagnosis and management.

PURPOSE OF REVIEW: To review advances in the diagnostic evaluation and management of traumatic peripheral nerve injuries. RECENT FINDINGS: Serial multimodal assessment of peripheral nerve injuries facilitates assessment of spontaneous axonal regeneration and selection of appropriate patients for early surgical intervention. Novel surgical and rehabilitative approaches have been developed to complement established strategies, particularly in the area of nerve grafting, targeted rehabilitation strategies and interventions to promote nerve regeneration. However, several management challenges remain, including incomplete reinnervation, traumatic neuroma development, maladaptive central remodeling and management of fatigue, which compromise functional recovery. SUMMARY: Innovative approaches to the assessment and treatment of peripheral nerve injuries hold promise in improving the degree of functional recovery; however, this remains a complex and evolving area.

Traumatic injury to peripheral nerves.

This article reviews the epidemiology, classification, localization, prognosis, and mechanisms of recovery of traumatic peripheral nerve injuries (PNIs). Electrodiagnostic (EDx) assessments are critical components of treating patients with PNIs. In particular, motor and sensory nerve conduction studies, needle electromyography, and other electrophysiological methods are useful for localizing peripheral nerve injuries, detecting and quantifying the degree of axon loss, and contributing toward treatment decisions as well as prognostication. It is critical that EDx medical consultants are aware of the timing of these changes as well as limitations in interpretations. Mechanisms of recovery may include recovery from conduction block, muscle fiber hypertrophy, distal axonal sprouting, and axon regrowth from the site of injury. Motor recovery generally reaches a plateau at 18 to 24 months postinjury. When patients have complete or severe nerve injuries they should be referred to surgical colleagues early after injury, as outcomes are best when nerve transfers are performed within the first 3 to 6 months after onset.

Role of electrodiagnosis in nerve transfers for focal neuropathies and brachial plexopathies.

Over the past 2 decades, the surgical treatment of brachial plexus and peripheral nerve injuries has advanced considerably. Nerve transfers have become an important surgical tool in addition to nerve repair and grafting. Electrodiagnosis has traditionally played a role in the diagnosis and localization of peripheral nervous system injuries, but a different approach is needed for surgical decision-making and monitoring recovery. When patients have complete or severe injuries they should be referred to surgical colleagues early after injury, as outcomes are best when nerve transfers are performed within the first 3 to 6 mo after onset. Patients with minimal recovery of voluntary activity are particularly challenging, and the presence of a few motor unit action potentials in these individuals should be interpreted on the basis of timing and evidence of ongoing reinnervation. Evaluation of potential recipient and donor muscles, as well as redundant muscles, for nerve transfers requires an individualized approach to optimize the chances of a successful surgical intervention. Anomalous innervation takes on new importance in these patients. Communication between surgeons and electrodiagnostic medicine specialists (EMSs) is best facilitated by a joint collaborative clinic. Ongoing monitoring of recovery post-operatively is critical to allow for decision making for continued surgical and rehabilitation treatments. Different electrodiagnostic findings are expected with resolution of neurapraxia, distal axon sprouting, and axonal regrowth. As new surgical techniques become available, EMSs will play an important role in the assessment and treatment of these patients with severe nerve injuries.

Molecular Changes in the Dorsal Root Ganglion during the Late Phase of Peripheral Nerve Injury-induced Pain in Rodents: A Systematic Review.

The dorsal root ganglion is widely recognized as a potential target to treat chronic pain. A fundamental understanding of quantitative molecular and genomic changes during the late phase of pain is therefore indispensable. The authors performed a systematic literature review on injury-induced pain in rodent dorsal root ganglions at minimally 3 weeks after injury. So far, slightly more than 300 molecules were quantified on the protein or messenger RNA level, of which about 60 were in more than one study. Only nine individual sequencing studies were performed in which the most up- or downregulated genes varied due to heterogeneity in study design. Neuropeptide Y and galanin were found to be consistently upregulated on both the gene and protein levels. The current knowledge regarding molecular changes in the dorsal root ganglion during the late phase of pain is limited. General conclusions are difficult to draw, making it hard to select specific molecules as a focus for treatment.

State of the Art and Advances in Peripheral Nerve Surgery.

This review is intended to describe and actualize the basic knowledge of the three basic entities that affect the peripheral nerve system and can be treated by surgery: nerve trauma, chronic nerve compressions, and tumors.Regarding trauma, emphasis is given on the timing of surgery, given the fact that the moment in which the surgery is performed and the employed microsurgical reconstruction technique are the most important factors in the final result. Open lesions with associated nerve injury should be managed with an early exploration carried out before 7 days. Closed injuries are usually deferred, with few exceptions, from 3 to 6 months after the trauma.In turn, chronic compressions require an appropriate clinical, neurophysiological, and imaging diagnosis. Isolated sensory symptoms can be treated actively though without surgery: motor signs like atrophy should be regarded as a sign for immediate surgery, as a deferred treatment might cause an irreversible nerve and muscular damage. Endoscopic approaches are a valuable tool for treatment in selected neuropathies.Finally, nerve tumors demand a thorough preoperative evaluation, as benign tumors are treated in a very different way when compared to malignant lesions. Benign tumors can usually be safely and completely resected without sacrificing the nerve of origin. When malignancy is confirmed, extensive resection to optimize patient survival is the main objective, potentially at the expense of neurological function. This may then be followed by adjuvant radiation and/or chemotherapy, depending on the nature of the tumor and the completeness of resection attained. The role of nerve biopsy remains controversial, and several modern diagnostic techniques might be helpful.

Interpreting Electrodiagnostic Studies for the Management of Nerve Injury.

Nerve injuries are common after trauma and can be life-altering for patients. Electrodiagnostic studies are the gold standard for diagnosing and prognosticating nerve injuries. However, most surgeons are not trained in the interpretation of these studies; rather, they rely on the interpretation provided by the electrodiagnostician, who in turn is unlikely to be trained in nerve reconstruction. This discrepancy between the interpretation of these studies and the management of nerve injuries can lead to suboptimal surgical planning and patient outcomes. This review aims to provide a framework for surgeons to take a more active role in collaborating with their colleagues in electrodiagnostic medicine in the interpretation of these studies, with an ultimate goal of improved patient care. The basics of nerve conduction studies, electromyography, and relevant terminology are reviewed. The relationship between the concepts of demyelination, axon loss, Wallerian degeneration, nerve regeneration, collateral sprouting, and clinical function are explained within the framework of the Seddon and Sunderland nerve injury classification system. The natural evolution of each degree of nerve injury over time is illustrated, and management strategies are suggested.

Peripheral Nerve Injury Treatments and Advances: One Health Perspective.

Peripheral nerve injuries (PNI) can have several etiologies, such as trauma and iatrogenic interventions, that can lead to the loss of structure and/or function impairment. These changes can cause partial or complete loss of motor and sensory functions, physical disability, and neuropathic pain, which in turn can affect the quality of life. This review aims to revisit the concepts associated with the PNI and the anatomy of the peripheral nerve is detailed to explain the different types of injury. Then, some of the available therapeutic strategies are explained, including surgical methods, pharmacological therapies, and the use of cell-based therapies alone or in combination with biomaterials in the form of tube guides. Nevertheless, even with the various available treatments, it is difficult to achieve a perfect outcome with complete functional recovery. This review aims to enhance the importance of new therapies, especially in severe lesions, to overcome limitations and achieve better outcomes. The urge for new approaches and the understanding of the different methods to evaluate nerve regeneration is fundamental from a One Health perspective. In vitro models followed by in vivo models are very important to be able to translate the achievements to human medicine.

Complex regional pain syndrome: an evolving perspective.

BACKGROUND: Complex regional pain syndrome (CRPS) is a heterogenous and poorly understood condition that can be provoked by quite minor injuries. The symptoms and signs of CRPS persist, long after the patient has recovered from the inciting event. In some cases, there is a clear association with a peripheral nerve injury. The degree of disability produced by CRPS is often out of proportion to the scale of the original insult and the condition is associated with protracted recovery times and frequent litigation. METHODS: We have performed a PubMed literature search, referenced landmark papers in the field and included a national expert in peripheral nerve injury and repair in our team of authors. RESULTS AND CONCLUSIONS: The diagnostic criteria for CRPS have changed repeatedly over the last two centuries and much of the historical literature is difficult to compare with more recent research. In this review article, we consider how our understanding of the condition has evolved and discuss its pathogenesis, its apparent heterogenicity and the various investigations and treatments available to the clinician.

Incidence of peripheral nerve injury in revision total shoulder arthroplasty: an intraoperative nerve monitoring study.

BACKGROUND: The incidence of nerve injuries in revision total shoulder arthroplasty (TSA) is not well defined in the literature and may be higher than that in primary procedures, with 1 study reporting a complication rate of 50% for shoulder revisions. Given that continuous intraoperative nerve monitoring (IONM) can be an effective tool in diagnosing evolving neurologic dysfunction and preventing postoperative injuries, the purpose of this study was to report on IONM data and nerve injury rates in a series of revision TSAs. METHODS: A retrospective cohort review of consecutive patients who underwent revision TSA was performed from January 2016 to March 2020. Indications for revision included infection (n = 7); failed total arthroplasty and hemiarthroplasty secondary to pain, dysfunction, and/or loose components (n = 36); and periprosthetic fracture (n = 1). Of the shoulders, 32 underwent revision to a reverse TSA, 6 underwent revision to an anatomic TSA, and 6 underwent spacer placement. IONM data included transcranial electrical motor evoked potentials (MEPs), somatosensory evoked potentials, and free-run electromyography. The motor alert threshold was set at ≥80% signal attenuation in any peripheral nerve. Patients were screened for neurologic deficits immediately following surgery, prior to administration of an interscalene nerve block, and during the first 2 postoperative visits. Additional data collection included surgical indication, sex, laterality, age at surgery, procedure performed, body mass index, history of tobacco use, Charlson Comorbidity Index, medical history, and preoperative range of motion. RESULTS: A total of 44 shoulders in 38 patients were included, with a mean age of 63.2 years (standard deviation, 13.0 years). Of the procedures, 22.4% (n = 10) had an MEP alert, with 8 isolated to a single nerve (7 axillary and 1 radial) and 1 isolated to the axillary and musculocutaneous nerves. Only 1 patient experienced a major brachial plexus alert involving axillary, musculocutaneous, radial, ulnar, and median nerve MEP alerts, as well as ulnar and median nerve somatosensory evoked potential alerts. Age, sex, body mass index, Charlson Comorbidity Index, and preoperative range of motion were not found to be significantly different between cases in which an MEP alert occurred and cases with no MEP alerts. In the postoperative period, no minor or major nerve injuries were found whereas distal peripheral neuropathy developed in 4 patients (9.1%). CONCLUSION: Among 44 surgical procedures, no patients (0%) had a major or minor nerve injury postoperatively and 4 patients (9.1%) complained of distal peripheral neuropathy postoperatively. In this study, we have shown that through the use of IONM, the rate of minor and major nerve injuries can be minimized in revision shoulder arthroplasty.

[Functional reconstruction in traumatic paralysis]. / Funktionelle Rekonstruktionen bei traumatischen Lähmungen.

BACKGROUND: Traumatic nerve injuries are associated with a high morbidity and long rehabilitation times. The extent of a nerve lesion and the related regeneration potential can often only be estimated during the course, whereby the time window for successful surgical interventions is limited. OBJECTIVE: The incidence and distribution of traumatic nerve lesions are reported. Algorithms for treatment decisions are presented. MATERIAL AND METHODS: Statistics from the German TraumaRegister DGU® as well as international registers were evaluated. The results of basic research and expert recommendations for diagnostics and treatment are discussed. RESULTS AND CONCLUSION: A strategic approach to conservative and surgical treatment of traumatic nerve injuries depending on the extent of injury and resulting regeneration potential is recommended. In conjunction with the clinical course, electrophysiology and imaging diagnostics, e.g. nerve sonography, can help to differentiate between neurapraxia, axonotmesis and neurotmesis.

Phrenic nerve injury in atrial fibrillation ablation using balloon catheters: Incidence, characteristics, and clinical recovery course.

AIMS: Systematic data on phrenic nerve palsy (PNP) associated with contemporary balloon ablation techniques (cryoballoon [CBA] vs laser balloon [LBA]) are sparse. We aimed to investigate the incidence, characteristics, and clinical recovery course in patients with PNP who underwent CBA or LBA. METHODS AND RESULTS: A total of 2433 consecutive patients who underwent balloon-based pulmonary vein isolation (CBA: n = 1720 and LBA: n = 713) were retrospectively identified. PNP was classified into (a) transient (recovery before discharge) or (b) persistent (within 6 months, 6-12 months, and >12 months) according to clinical recovery course. In general, PNP occurred significantly more often in CBA 71/1720 (4.2%) than LBA 11/713 (1.5%) (P = .003). The rate of transient PNP was significantly higher in CBA (3.0%, n = 45) than LBA (0.1%, n = 1, P = .004). The rate of persistent PNP did not significantly differ between two groups (CBA: 1.2% vs LBA: 1.4%, P = .89). The rate of persistent PNP which recovered within 6 months was similar (CBA: 17.4% vs LBA 18.2%, P = 1.000). However, the rates of persistent PNP which recovered within 6 to 12 months (CBA: 2.9% vs LBA 27.3%, P = .0171) and more than 12 months (CBA: 7.3% vs LBA 45.5%, P = .0034) were significantly higher in LBA. CONCLUSION: PNP occurred more often in CBA than LBA, however, the majority of PNP in CBA was transient whereas the majority of PNP in LBA was persistent. Either balloon technology is not superior in terms of long-term PNP.

Efficacy of electrical stimulation of denervated muscle: A multicenter, double-blind, randomized clinical trial.

BACKGROUND: This was a multicenter, double-blind, randomized clinical trial to investigate the efficacy of electrical stimulation of denervated muscle (ESDM) on recovery of patients with peripheral nerve injuries. METHODS: We enrolled 38 patients with traumatic peripheral nerve injuries with axonal damage and clinical impairment of two muscles, who were randomly treated with real or sham electrical stimulation (ES). Clinical and neurophysiological examinations were performed before treatment, at the end of treatment, and 3 mo posttreatment, by the same physician who was blinded to the ES allocation. RESULTS: All patients improved but there was no significant beneficial effect of ESDM compared with sham treatment. CONCLUSIONS: This study failed to demonstrate the efficacy of ESDM for peripheral nerve injuries. However, given the large number of variables related to ES and the heterogeneity in disease etiologies and clinical manifestations, future studies on homogeneous populations using different stimulation protocols may be useful.

Natural History of Mixed and Motor Nerve Cryoablation in Humans-A Cohort Analysis.

Eight patients who underwent percutaneous cryoablation of mixed and/or motor nerves over a period of 5 years were identified. Distances from the ablation sites to origins of distal musculature were measured, and times to initial clinical recovery were collected. Strength progression over time following muscle activation was also collected and analyzed. All patients demonstrated activation of all muscles distal to the ablation, and the calculated mean rate of nerve regeneration based on distance to the origin of the assessed musculature and time to muscle activation for the group was 1.5 mm/day ± 1.1.

Utility of Motor and Somatosensory Evoked Potentials for Neural Thermoprotection in Ablations of Musculoskeletal Tumors.

PURPOSE: To characterize the utility of monitoring transcranial electrical motor evoked potentials (TCeMEPs) and somatosensory evoked potentials (SSEPs) for neural thermoprotection during musculoskeletal tumor ablations. MATERIALS AND METHODS: Retrospective review of 29 patients (16 male; median age, 46 y; range, 7-77 y) who underwent musculoskeletal tumor radiofrequency ablation (n = 8) or cryoablation (n = 22) with intraprocedural TCeMEP and SSEP monitoring was performed. The most common tumor histologies were osteoid osteoma (n = 6), venous malformation (n = 5), sarcoma (n = 5), renal cell carcinoma (n = 4), and non-small-cell lung cancer (n = 3). The most common tumor sites were spine (n = 22) and lower extremities (n = 4). Abnormal TCeMEP change was defined by 100-V increase above baseline threshold activation for a given myotome; abnormal SSEP change was defined by 60% reduction in baseline amplitude and/or 10% increase in latency. RESULTS: Abnormal changes in TCeMEP (n = 9; 30%) and/or SSEP (n = 5; 17%) occurred in 12 procedures (40%) and did not recover in 5 patients. Patients with unchanged TCeMEP/SSEP activities throughout the procedure (n = 18) did not have motor or sensory symptoms after the procedure; 3 (60%) with unrecovered activity changes and 2 (29%) with transient activity changes had new motor (n = 1) or sensory (n = 4) symptoms. Relative risk for neurologic sequelae for patients with unrecovered TCeMEP/SSEP changes vs those with transient or no changes was 7.50 (95% confidence interval, 1.66-33.9; P = .009). CONCLUSIONS: Abnormal activity changes of TCeMEP or SSEP during percutaneous ablative procedures correlate with postprocedural neurologic sequelae.

The Utility of Diagnostic Tests for Digital Nerve Injury.

PURPOSE: The purpose of this study was to present the sensitivity and specificity of 6 clinical tests for the diagnosis of digital nerve injury. The clinical tests are as follows: light touch, pinprick, static and dynamic 2-point discrimination (D2PD), Semmes-Weinstein monofilament, and wrinkle test. METHODS: We reviewed the charts of all the patients who were admitted to our department with hand lacerations and/or suspicions of digital nerve injury that were examined before surgery with the 6-sensation test, comparing the results to the surgical findings. RESULTS: The study included 70 patients with 85 injured nerves overall. Of the 85 nerves, 51 were found with full cut, 9 with partial cut, and 25 with no cut. Only 2 variables were significantly associated with the study outcome: D2PD > 4 (P = 0.0141, odds ratio = 3.9, 95% confidence interval = 1.3-11.8, sensitivity = 80.7%, specificity = 48%) and wrinkle test (P = 0.0098, odds ratio = 4.0, 95% confidence interval = 1.4-11.6, sensitivity = 69.5%, specificity = 62.5%).Multivariable logistic regression included these variables and revealed the predictive probability for a nerve injury to be 92% if both risk factors exist and 43% if none of these risk factors exist. If one risk factor exists, the predictive probability for a cut is still very high (75%). CONCLUSIONS: The combination of positive wrinkle test and D2PD > 4 gave a predictive probability for a nerve injury as 92% in the cases in our study and should be considered in the evaluation of patients with hand lacerations and suspicions of digital nerve injury.

Anatomic lectures on structures at risk prior to cadaveric courses reduce injury to the superficial peroneal nerve, the commonest complication in ankle arthroscopy.

PURPOSE: To assess the effectiveness of cadaveric ankle arthroscopy courses in reducing iatrogenic injuries. METHODS: A total of 60 novice surgeons enrolled in a basic cadaveric ankle arthroscopy course were divided into two groups. Group A (n = 32) was lectured on portal placement and use of the arthroscope, whereas group B (n = 28) was in addition lectured on specific portal-related complications. Following the performance of anterior ankle arthroscopy and hindfoot endoscopy, the specimens were dissected and carefully assessed for detection of any iatrogenic injuries. RESULTS: The rate of injury to the superficial peroneal nerve (SPN) was reduced from 25 to 3.6%, in group A compared with B (p = 0.033). Injuries to the peroneus tertius or extensor digitorum longus, the flexor hallucis longus and the tibial nerve or the Achilles tendon were also reduced in group B. Overall, the number of uninjured specimens was 50% (n = 30) and higher in group B (57%) than group A (44%). Lesions to the plantaris tendon, the sural nerve or the posterior tibial artery were more common in group B, however, without reaching statistical significance. Overall, 25 (13.9%) anatomic structures were injured in anterior arthroscopy compared to 18 (5%) in hindfoot endoscopy, out of a potential total of 180 and 360, respectively (p = 0.001). CONCLUSION: Dedicated lectures on portal-related complications have proven useful in reducing the risk of injury to the SPN, the commonest iatrogenic injury encountered in ankle arthroscopy. Hindfoot endoscopy is significantly safer than anterior ankle arthroscopy in terms of injury to anatomical structures.