Sensory Nerve Injury Research Articles

Neuropathic Pain and Itch Mechanisms Underlying Allergic Conjunctivitis.

Among the constellation of symptoms that characterizes allergic conjunctivitis, many (eg, burning and stinging) can be attributed to chronic neuropathic pain. Cumulative data support that these hallmark symptoms might be linked to the effects of allergen-induced neuromodulation. This review investigates the key characteristics of neuropathic itch and pain in allergic conjunctivitis and their underlying pathogenic mechanisms. A literature review was conducted using a PubMed search focusing on allergic conjunctivitis, neurogenic inflammation, neuropathic itch, and neuropathic pain. Articles were reviewed, and those discussing clinical course, pathophysiology, and neuronal regulation of chronic neuropathic symptoms as related to allergic disease were summarized. Recent evidence suggests that some symptoms of allergic conjunctivitis may be better represented as a chronic neuropathic disorder. We found that neurogenic mechanisms may have a significant role in chronic ocular surface inflammation from allergic inflammation. Manifestations may be associated with repeated ocular sensory nerve injury leading to an acute-to-chronic transition, which is in turn associated with neuropathologic changes (peripheral and central sensitization), neuronal dysfunction, and spontaneous ocular pain. Current goals in the management of allergic conjunctivitis aim to minimize the inflammatory cascade associated with the allergic response in the initial stages of the pathogenic mechanism. Based on the mechanistic data reviewed herein, the recognition that neuronal inflammation explains many of the symptoms in allergic conjunctivitis opens new frontiers for drug discovery.

Pain, Dryness, and Itch Sensations in Eye Surface Disorders Are Defined By a Balance Between Inflammation and Sensory Nerve Injury.

Patients with corneal and conjunctival disorders report an array of ocular surface symptoms including stinging, foreign body sensation, and itching. The intensity and perceptual quality of these sensations and their duration, from brief intervals to long-term symptoms, also vary. We hypothesize that symptomatic differences across disorders reflect differences in the balance between ocular inflammation and nerve injury, with different conditions resulting from predominant effects of one of these, or a combined effect. This article provides an overview of corneal and conjunctival nerve cells, such as nociceptors and thermoreceptors, with descriptions of their morphological and molecular characteristics and their nerve-firing patterns and evoked sensations, as determined by earlier studies in animals and humans. Detailed descriptions of the changes in neuronal responses (such as abnormal responsiveness and spontaneous firing) due to local inflammation and nerve injury are provided, and assorted ocular surface disorders are discussed. Eye conditions in which inflammation is predominant include allergic conjunctivitis and photokeratitis, whereas nerve injury is the primary factor underlying complaints of dry eye after photorefractive keratectomy and in elderly patients. Both factors contribute substantially to dry eye disease and varicella-zoster infections. This model of the combined effects of inflammation and nerve injury serves to explain the different sensations reported in various eye surface disorders, including short-term versus chronic pain and dysesthesias, and may help to improve diagnoses and treatment methods.

Ultrasound-Guided de Quervain's Tendon Release, Feasibility, and First Outcomes.

Background de Quervain's syndrome is one of the main tendonitis of the wrist. The hypothesis of authors was that de Quervain's syndrome could be successfully treated with a specific ultrasound-guided percutaneous procedure, as it is for trigger finger. Surgical Technique Identification of the subcompartmentalization of the first extensor compartment was performed first, using the Hiranuma's classification, prior to the surgery. Then, we assessed precisely the positions of the sensory branches of the radial nerve and drew the landmarks. Through a continuous ultrasound in-plane control, we performed a percutaneous retrograde section of each part of the first compartment of the extensors, using a dedicated surgical blade. Methods In a cadaveric study, authors proposed to assess the feasibility and safety of a new and specific procedure and then assessed their first clinical cases. Fourteen specimen wrists were analyzed with ultrasound and the procedure was performed prior to an open control of the efficiency of the release, and safety for the superficial nerves. Then, we reported the results of the 22 first patients included in the clinical series. Results In a cadaver laboratory, authors were able to identify with ultrasound the type of first compartment septation (subcompartmentalization) in 13 cases ( n = 14). The misidentification induced one incomplete release. No damages of the superficial radial nerve were observed despite close relationship. In the small series ( n = 22), the duration of surgery was 8 minutes (range: 4-18 minutes). It was performed in office surgery and no morbidities were noticed. All patients improved, from quickDASH preoperative score of 59 (range: 28-71) to quichDASH postoperative score of 9 (range: 0-25). Conclusion Ultrasound-guided percutaneous release in the de Quervain's disease is a safe and reliable procedure without specific morbidity. Great care should be taken to avoid sensory nerve injuries and to identify the correct type of subcompartmentalization with a precise ultrasound evaluation.

Complications of Third Molar Extraction: A retrospective study from a tertiary healthcare centre in Oman.

ObjectivesThis retrospective study aimed to investigate complications associated with the extraction of third molars at a tertiary healthcare centre in Oman.MethodsAll consecutive patients who underwent extraction of one or more impacted third molars under general anaesthesia at Sultan Qaboos University Hospital, Muscat, Oman, between January 2007 and December 2017 were included. Age, gender, indication for extraction, teeth removed, procedure and complications were recorded.ResultsA total of 1,116 third molars (56% mandibular and 44% maxillary) were extracted and the majority (67.7%) were from female patients. The mean age at extraction was 24 ± 5 years and most patients (77.7%) were 20–29 years old. The intraoperative and postoperative complication rates were 3.7% and 8.3%, respectively. The intraoperative complications included tuberosity fracture (1.2%), root fracture (1.1%), bleeding (0.7%), soft tissue injury (0.5%) and adjacent tooth damage (0.2%). Postoperative complications were sensory nerve injuries (7.2%), swelling/pain/trismus (0.6%) and dry socket (0.5%). Nerve injury was temporary in 41 patients and permanent in four cases. A statistically significant relationship was observed between those aged 30–39 years and dry socket (P = 0.010) as well as bone removal and all postoperative complications (P = 0.001).ConclusionMost complications resulting from third molar extractions were minor and within the reported ranges in the scientific literature. However, increased age and bone removal were associated with a higher risk of complications. These findings may help to guide treatment planning, informed consent and patient education.

GPR34 in spinal microglia exacerbates neuropathic pain in mice

BackgroundNeuropathic pain is caused by sensory nerve injury, but effective treatments are currently lacking. Microglia are activated in the spinal dorsal horn after sensory nerve injury and contribute to neuropathic pain. Accordingly, molecules expressed by these cells are considered potential targets for therapeutic strategies. Our previous gene screening study using a mouse model of motor nerve injury showed that the G-protein-coupled receptor 34 gene (GPR34) is induced by nerve injury. Because GPR34 is now considered a microglia-enriched gene, we explored the possibility that it might be involved in microglial activation in the dorsal horn in a mouse model of neuropathic pain.MethodsmRNA expression of GPR34 and pro-inflammatory molecules was determined by quantitative real-time PCR in wild-type and GPR34-deficient mice with L4 spinal nerve injury. In situ hybridization was used to identify GPR34 expression in microglia, and immunohistochemistry with the microglial marker Iba1 was performed to examine microglial numbers and morphology. Mechanical sensitivity was evaluated by the von Frey hair test. Liquid chromatography–tandem mass spectrometry quantified expression of the ligand for GPR34, lysophosphatidylserine (LysoPS), in the dorsal horn, and a GPR34 antagonist was intrathecally administrated to examine the effect of inhibiting LysoPS-GPR34 signaling on mechanical sensitivity.ResultsGPR34 was predominantly expressed by microglia in the dorsal horn after L4 nerve injury. There were no histological differences in microglial numbers or morphology between WT and GPR34-deficient mice. However, nerve injury-induced pro-inflammatory cytokine expression levels in microglia and pain behaviors were significantly attenuated in GPR34-deficient mice. Furthermore, the intrathecal administration of the GPR34 antagonist reduced neuropathic pain.ConclusionsInhibition of GPR34-mediated signal by GPR34 gene deletion reduced nerve injury-induced neuropathic pain by suppressing pro-inflammatory responses of microglia without affecting their morphology. Therefore, the suppression of GPR34 activity may have therapeutic potential for alleviating neuropathic pain.

Evaluation of Long-term Outcomes of Facial Sensation following Cranial Vault Reconstruction for Craniosynostosis.

Cranial vault reshaping to correct craniosynostosis in infants may injure terminal branches of the trigeminal nerve, namely the supraorbital, supratrochlear, zygomaticofacial, and zygomaticotemporal nerves, especially if a fronto-orbital advancement is performed. Despite numerous studies demonstrating successful esthetic outcome after FOA, there are no long-term studies assessing facial sensation after possible damage to these nerves as the result of surgery. A cross-sectional case-control research design was used to evaluate facial sensory threshold in the trigeminal branches after cranial vault reconstruction in children with isolated, nonsyndromic metopic, and unicoronal craniosynostosis, compared with those with sagittal craniosynostosis and age-matched nonaffected controls. Study participants were recruited from the Hospital for Sick Children between the ages of 6 and 18 years. Sensory outcome was determined using the Weinstein Enhanced Sensory Test, the Ten Test, and self-reported facial sensibility function questionnaire. The sensory outcomes of 28 patients and 16 controls were examined at an average age of 9.6 years and 10.3 years, respectively. No subjective or objective sensory deficit was noted in supraorbital, supratrochlear, zygomaticofacial, or zygomaticotemporal nerve distributions between groups. Qualitative reports of facial sensibility function indicated no difference in subjective sensation, protective sensation, or motor behavior between groups. These results suggest that while sensory nerve injury during routine FOA may occur, it does not result in a quantifiable nor clinically significant long-term sensory deficit threshold. Patients do not develop long-term neuropathic pain following surgical intervention.

Améliorer l’issue des lésions nerveuses sensorielles traumatiques de la main par l’utilisation supplémentaire d’un tube nerveux de chitosane dans la réparation du nerf primaire — un essai bicentrique contrôlé randomisé

Peripheral sensory nerve injuries are a major problem of acute hand trauma surgery. Standard treatment is microsurgical end-to-end repair of these nerves whenever possible. If surgery fails, a permanent loss of sensibility and the formation of painful neuroma are consequences. The objective of this study was to evaluate whether the additional use of a chitosan nerve tube in primary nerve repair influences the sensory convalescence. A randomized controlled bicenter trial with parallel group design and double blinded assessment was conducted to show superiority of the additional use of a chitosan nerve tube compared to microsurgical nerve repair alone. 74 participants were enrolled. The ability of static 2-point-discrimanation (2PD) 6 months after surgery was the primary outcome parameter. Considerable secondary outcome parameters were filament recognition (Semmes Weinstein) testing, pain, appearance of neuroma and the Disabilities of the Arm, Shoulder and Hand (DASH)–score. In Intervention group both sensibility (expressed by 2PD) and tactile gnosis (expressed by Semmes Weinstein testing) could be increased significantly. Mean 2PD in control group at 6-month follow-up was 8 (2–20) mm and 6.3 (1–15) mm in intervention group (P = 0.029). 2PD correlated with DASH-score. In control group, 3 neuroma were found whereas none in intervention group. There were no implant-associated complications. Peripheral sensory nerve regeneration can be improved significantly by additional use of a chitosan nerve tube. An augmented ability of static 2-point discrimination has clinical relevancy.

SIV-Induced Immune Activation and Metabolic Alterations in the Dorsal Root Ganglia During Acute Infection.

Human immunodeficiency virus-associated sensory neuropathy (HIV-SN) remains a frequent neurologic complication of HIV infection. Little is known about alterations in the peripheral nervous system during the early stages of HIV, a time when neuroprotective interventions may be most beneficial. We performed Nanostring gene expression analysis on lumbar dorsal root ganglia (DRG) from 6 simian immunodeficiency virus (SIV)-infected pigtailed macaques killed at 7 days post-inoculation and 8 uninfected controls. We found significant upregulation of many genes involved in immune signaling and activation in the DRG. Among genes related to glutamate metabolism, there was significant upregulation of glutamine synthetase (GS), while glutaminase (GLS) was downregulated. Several genes involved in the oxidative stress response also showed significant differential regulation in the DRG of 7d SIV-infected animals, with superoxide dismutase-2 (SOD2) showing the greatest median fold change compared to controls. Novel findings in the DRG were compared to corresponding brain data and further investigated at the protein level by Western blotting and immunohistochemistry. Together with our previous finding of significant epidermal nerve fiber loss at 14 days post-SIV infection, results of this study demonstrate that immune activation and altered cellular metabolism at in the DRG precede and likely contribute to early sensory nerve injury in HIV-SN.

Tooth pulp injury induces sex-dependent neuronal reshaping in the ventral posterolateral nucleus of the rat thalamus

Orofacial injuries often result in persistent pain and are therefore considered a common health problem worldwide. Considerable evidence suggests that peripheral sensory nerve injury results in diverse plastic changes in the central nervous system (CNS). Tooth pulp is innervated by trigeminal afferents which extend to the trigeminal brainstem sensory nuclear complex and send input to higher level neurons in the CNS, including the ventral posterolateral nucleus of the thalamus (VPL). In the present study, we examined the long term effects of pulpal injury on neuronal arborization in the VPL using morphological analysis via Golgi-Cox staining. In addition, we examined these effects in both male and female rats due to the major prevalence of oral pain in women. Quantitative morphological analysis revealed that pulpal injury induced neuronal hypertrophy in VPL neurons of female rats. In clear contrast, pulpal injury increased arborization close to the soma and reduced arborization distal to the soma without modification of total dendritic length in male rats. As a result, we show, for the first time, sex-dependent morphological alterations in VPL neurons after orofacial peripheral injury. Since dental injuries are readily reproducible in rat dental molars and closely mimic the clinical setting in humans, this model represents a useful tool to further understand mechanisms of orofacial pain.

Trigeminal nerve injuries

AbstractTrigeminal nerve injury is the most problematic consequence of dental surgical procedures with major medico‐legal implications. In trigeminal nerve injuries related to dentistry, 70% are reported to have chronic neuropathic post‐traumatic pain. Neuropathic pain states require different therapeutic approaches such as anticonvulsants, which are not effective in nociceptive pain. Major causes of nerve injuries in the orofacial region are endodontics and administration of local anaesthetics. Endodontic treatment of premolar and mandibular teeth has the potential to damage the inferior alveolar nerve via direct trauma, pressure or neurotoxicity. Persistent pain after endodontics has been reported to occur in 3–13% of patients, whilst surgical endodontics resulted in chronic neuropathic pain in 5% of patients. Most sensory nerve injuries related to dentistry are permanent; only local anaesthetic nerve injuries have a 75% likelihood of recovery. Nerve injury from local anaesthetics shows an incidence of 1 in 14 000 with 25% permanent injury from general dental restorative procedures and 1 in 3300 with 29% permanence from oral surgery.

Enhancing the Outcome of Traumatic Sensory Nerve Lesions of the Hand by Additional Use of a Chitosan Nerve Tube in Primary Nerve Repair: A Randomized Controlled Bicentric Trial.

Peripheral sensory nerve injuries present a significant yet common challenge in acute hand trauma surgery. Standard treatment remains microsurgical end-to-end nerve repair where appropriate. Permanent loss of sensitivity and painful neuroma formation are typical sequelae of unsuccessful surgery. The objective of this study was to evaluate whether the additional use of a chitosan nerve tube in primary nerve repair positively influences sensory recovery. A randomized, controlled, two-center trial with parallel group design and double-blind assessment was conducted to demonstrate the superiority of the additional use of a chitosan nerve tube compared with microsurgical nerve repair alone. Seventy-four participants were enrolled. The primary outcome parameter used was degree of static two-point discrimination at 6 months after surgery. Additional secondary outcome parameters included filament recognition testing (Semmes-Weinstein); pain; neuroma development; and the Disabilities of the Arm, Shoulder and Hand score. Nerve repair with additional use of chitosan nerve tubes (intervention group) significantly increased both tactile gnosis (expressed by two-point discrimination) and sensitivity (expressed by Semmes-Weinstein testing). The mean two-point discrimination at 6-month follow-up was 8 mm (range, 2 to 20 mm) in the control group and 6.3 mm (range, 1 to 15 mm) in the intervention group, respectively (p = 0.029). Two-point discrimination correlated with the Disabilities of the Arm, Shoulder and Hand score. In the control and intervention groups, respectively, three versus zero neuromas were found. Peripheral sensory nerve regeneration can be improved significantly by additional use of a chitosan nerve tube. An improved ability of static two-point discrimination is clinically relevant. Therapeutic, I.

No difference in sensory outcome between vertical and oblique incisions for hamstring graft harvest during ACL reconstruction.

To compare the incidence, extent of sensory loss, its clinical effect and natural course caused by sensory nerve injury, during two different skin incisions used for autogenous hamstring graft harvest during ACL reconstruction. This randomized prospective study was carried out on 84 patients, divided into two groups, all of them underwent arthroscopic ACL reconstruction using hamstring tendon graft with two incisions; a vertical incision used in 43 patients, and an oblique incision in 41 patients. The location and area of sensory loss were evaluated during follow-up as well as the degree of improvement and patient satisfaction. The average age in this study was 29.8 ± 7.2 in the vertical group and 29.9 ± 6.3 in the oblique group. Both semitendinosus and gracilles were harvested in 34 patients, semitendinosus in 49 patients and gracilles in one patient. In the vertical group, a higher incidence of sensory loss was recorded with 21 patients (51.2%), relative to the oblique group with 18 patients (41.9%). However, there was no statistically significant difference (p = n.s). Most of the sensory loss affected the distribution of the IPBSN (infrapatellar branch of saphenous nerve) in 27 patients (69.2%) in both groups, and to a lesser extent in the lower medial area [distribution of SBSN (sartorial branch of saphenous nerve)] in 12 patients (30.8%). This study clearly revealed the high incidence of nerve injury particularly the IPBSN during hamstring graft harvest, but did not prove a difference between oblique and vertical incisions, with regard to postoperative sensory loss. It was clear that harvesting the semitendinosus alone is not a factor that can diminish nerve injury. II.

Post-operative Complications Following Distal Biceps Tendon Repairs: A Prospective Study

Ownership Interest: Matador Medical, Dimension Orthotics LLC, Wright Medical (Beredjiklian) The reported incidence of post-operative complications following distal biceps tendon repairs (DBTR) has been largely determined by retrospective and small prospective studies.1-4 We hypothesized that a large prospective cohort study of DBTRs performed at our institution would demonstrate similar complication rates. All patients undergoing a primary DBTR by a surgeon from our institution were followed prospectively. The repair technique, post-operative protocol, and follow-up intervals were determined by the individual surgeons’ protocols. At each visit, the surgeon evaluated the patient for any complication, which included infection, wound dehiscence, sensory nerve injury, motor nerve injury, heterotopic ossification, re-rupture, and others. Demographic and surgical data was collected. Descriptive statistics were performed. Sixty patients (59 male, 1 female) underwent 60 distal biceps repairs by 25 orthopaedic surgeons over the course of 6 months. The mean age of the patients was 47 years (Range: 28 - 62), and the mean Body Mass Index (BMI) was 32 (Range: 23 to 54). Surgical techniques included one-incision tension-slide (33 cases), two-incision Modified Boyd Anderson (26 cases), and one-incision suture anchor (1 case). The average time to surgery was 2.9 weeks (Median: 2, Range: 0.5 - 10), the average post-operative length of immobilization was 1.5 weeks (Range: 0 - 4), and the average follow-up was 12 weeks (Range: 6 - 27). The overall complication rate was 23%. There were 14 sensory nerve injuries: 8 lateral antebrachial cutaneous nerves, 2 superficial radial nerves, 1 non-specific hand numbness, and 3 non-specific forearm numbness. Thirteen of 14 sensory nerve injuries occurred with single-incision techniques (38% of one-incision cases vs 4% of two-incision cases). While there was not a single infection, 1 patient had wound blisters, and 1 patient developed olecranon bursitis. Finally, 1 patient re-ruptured his biceps tendon, which required revision surgery. •Patients treated with a one-incision technique have a higher rate of complication than those treated with a two-incision technique.•Sensory nerve injury, specifically to the lateral antebrachial cutaneous nerve, is the most common complication.•The prospective incidence of complications is similar to that obtained retrospectively and reported in the literature.

Endovenous laser ablation therapy in children: applications and outcomes

BackgroundEndovenous laser ablation is well recognized as the first-line treatment for superficial venous reflux with varicose veins in adults. It is not widely reported and is not an established practice in pediatric patients.ObjectiveTo illustrate a variety of pediatric venous conditions in which endovenous laser ablation can be utilized and to demonstrate its feasibility and safety in children.Materials and methodsWe conducted a retrospective review of endovenous laser ablation procedures performed between January 2007 and July 2014 at two large pediatric institutions.ResultsWe included 35 patients (17 males) who underwent endovenous laser ablation to 43 veins. Median age at first treatment was 14 years (range: 3–18 years). Median weight was 56 kg (range: 19–97 kg). Underlying diagnoses were common venous malformation (15), Klippel–Trenaunay syndrome (8), superficial venous reflux with varicose veins (5), verrucous hemangioma-related phlebectasia (4), venous varix (2) and arteriovenous fistula (1). The most common aim of treatment was to facilitate sclerotherapy. Thirty-four patients had treatment in the lower limbs and one patient in an upper limb. Ten of the veins treated with endovenous laser ablation had an additional procedure performed to close the vein. Complications attributable to endovenous laser ablation occurred in two patients (6%). One patient experienced post-procedural pain and one patient developed a temporary sensory nerve injury. Median clinical follow-up was 13 months (range: 28 days–5.7 years). The aim of the treatment was achieved in 29 of the 35 (83%) patients.ConclusionEndovenous laser ablation is technically feasible and safe in children. It can be used in the management of a range of pediatric venous diseases with good outcomes.

Nerve injury during anterior cruciate ligament reconstruction: A comparison between patellar and hamstring tendon grafts harvest

BackgroundTendon harvesting for anterior cruciate ligament reconstruction often injures sensory branches of the saphenous nerve. The reports on the prevalence of these injuries are scarce, while the implications on patient satisfaction are not known. Our objective was to compare the prevalence of sensory nerve injuries in patellar to hamstring autograft harvesting for anterior cruciate ligament reconstructions and follow up their postoperative course. MethodsBetween 2012 and 2014, patients who had a primary anterior cruciate ligament reconstruction with bone patellar tendon bone or hamstring autografts were included (n=94). We evaluated and compared demographic details, level of activity and postoperative sensation disturbances between both groups. Data was analyzed retrospectively. ResultsThe mean postoperative follow-up time was 23months. At the last follow-up 46 (77%) patients of the patellar tendon group and 22 (58%) of the hamstring tendons group reported on reduced sensation; however, in both groups a quarter of these patients experienced full recovery within an average of seven to eight months. There were more patients in the hamstring tendons group that reported on partial recovery. In most cases midline incisions for patellar tendons harvesting injured the infrapatellar branch and medial incisions for hamstring tendons harvesting injured the sartorial branch of the saphenous nerve. ConclusionsHarvesting tendon autografts for anterior cruciate ligament reconstructions by vertical incisions had high prevalence of saphenous nerve branches injury with a minor possibility for complete recovery within the first year. The loss of sensation was perceived by patients as a minor complication. Level of evidenceLevel IV, therapeutic case series.

Afferent Fiber Remodeling in the Somatosensory Thalamus of Mice as a Neural Basis of Somatotopic Reorganization in the Brain and Ectopic Mechanical Hypersensitivity after Peripheral Sensory Nerve Injury.

Plastic changes in the CNS in response to peripheral sensory nerve injury are a series of complex processes, ranging from local circuit remodeling to somatotopic reorganization. However, the link between circuit remodeling and somatotopic reorganization remains unclear. We have previously reported that transection of the primary whisker sensory nerve causes the abnormal rewiring of lemniscal fibers (sensory afferents) on a neuron in the mouse whisker sensory thalamus (V2 VPM). In the present study, using transgenic mice whose lemniscal fibers originate from the whisker sensory principle trigeminal nucleus (PrV2) are specifically labeled, we identified that the transection induced retraction of PrV2-originating lemniscal fibers and invasion of those not originating from PrV2 in the V2 VPM. This anatomical remodeling with somatotopic reorganization was highly correlated with the rewiring of lemniscal fibers. Origins of the non-PrV2-origin lemniscal fibers in the V2 VPM included the mandibular subregion of trigeminal nuclei and the dorsal column nuclei (DCNs), which normally represent body parts other than whiskers. The transection also resulted in ectopic receptive fields of V2 VPM neurons and extraterritorial pain behavior on the uninjured mandibular region of the face. The anatomical remodeling, emergence of ectopic receptive fields, and extraterritorial pain behavior all concomitantly developed within a week and lasted more than three months after the transection. Our findings, thus, indicate a strong linkage between these plastic changes after peripheral sensory nerve injury, which may provide a neural circuit basis underlying large-scale reorganization of somatotopic representation and abnormal ectopic sensations.

Prevalence and clinical implications of nerve injury during bone patellar tendon bone harvesting for anterior cruciate ligament reconstruction

Tendon harvesting for anterior cruciate ligament (ACL) reconstruction often injure sensory branches of the saphenous nerve (SN). Our purpose was to estimate the prevalence and postoperative course of sensory nerve injuries in bone patellar tendon bone (BPTB) autograft harvesting for ACL reconstruction. Between 2012 and 2014, patients who had primary ACL with BPTB autograft were included ( n = 60) and interviewed specifically for sensory loss and its recovery. The surface area of sensory loss was documented. Evaluation also included demographic details, level of activity, and description of postoperative sensation disturbances. The mean postoperative follow-up time was 24 ± 14 months. At the last follow-up, 46 (77%) patients reported on postoperative reduced sensation; however, only 35 (58%) remained with sensation loss. The most involved region of reduced sensation was of the infrapatellar branch of the SN. Three patients claimed they regret to have had the surgery specifically because of sensation loss and kneeling difficulties, while all others did not. Primary ACL reconstruction using the midline incision for harvesting the middle third of the patellar tendon autograft has a high prevalence of sensory nerve injury with a minor possibility for complete recovery within the first year. However, sensory loss secondary to this injury does not impair normal daily activities in these patients.

Tibial Bone Grafting for Wrist Reconstruction.

Background Iliac crest bone graft harvesting is routinely performed for upper extremity orthopedic procedures despite high complication rates associated with sensory nerve injury, hematoma, chronic pain, and fracture. Description of Technique Cancellous bone graft is harvested from the proximal tibia using a medial approach, minimizing donor site morbidity. Patients and Methods A retrospective review was undertaken of 14 patients who underwent cancellous proximal tibia bone graft harvesting to augment healing of wrist reconstruction, with 2 months minimum follow-up. We report donor limb tourniquet time, time to union, visual analog scale (VAS) pain score, and complications. Patients were also contacted by phone to administer a retrospective questionnaire and record experiences with the harvesting technique. Results Average donor site VAS for the immediate postoperative period was 7.4. Average tourniquet time was 28 minutes. Average time to union of the recipient site was 45 days. One patient experienced delayed union after corrective osteotomy, attributed to osteoporosis. Two patients underwent hardware removal from the operative wrist, unrelated to bone graft harvesting. One patient with a history of chronic neuropathy and foot drop developed dysesthesia and allodynia about the ipsilateral ankle, but was asymptomatic at the proximal tibia donor site; ankle symptoms resolved 3 weeks postoperatively. No patient reported any residual donor site difficulties 24.2 months postoperatively. Conclusion In consideration of the minimal complication rate, favorable clinical parameters, and excellent patient tolerance, we advocate proximal tibia bone graft harvesting as opposed to iliac crest harvesting for wrist reconstruction when a moderate amount of autogenous cancellous graft is needed. Level of Evidence IV.

75. Intraoperative monitoring in minimally invasive lateral transpsoas approach: Our experience

The minimally invasive lateral transpsoas approach to the lumbar and spine has become an increasingly popular approach for achieving interbody fusion. The reported advantages include minimally invasive access to the spine, absent manipulation of aorta and vena cava, less blood loss compared to open procedures, decreased operative times, shorter hospital stays, less postoperative pain. The patient is placed in the lateral decubitus position. A lateral X-ray confirms that the patient is in a truly lateral position. A series of tubes and dilators are used to identify the mid-position of the disk to be incised. The dilator is introduced through a small incision and the surgeon’s index finger directs the dilator through the retroperitoneal space to the psoas muscle. Due to the location of the lumbar nerve root contribution to the lumbosacral plexus within the psoas muscle, the risk of motor and sensory nerve injury is present when traversing the lumbosacral plexus with the dilator or during retractor positioning over the disk space. Neural monitoring (Free-Run EMG L2-S1 and intraoperative monopolar electrical stimulation, PEM and PES) is believed to be critical in localizing the lumbosacral plexus during positioning of the retractor system. We monitorized 15 patients with no complications.

Superficial radial sensory neuropathy: Medial and lateral branch injury.

Superficial radial sensory nerve (SRN) injury may involve the main nerve or its distal medial or lateral branch. We investigated the utility of SRN conduction studies on the medial and lateral branches in patients with suspected SRN injury. Fifteen patients with symptoms of SRN neuropathy were studied. Their clinical and electrophysiological findings were assessed according to sensory symptom areas. Three active recording electrode positions were used: snuff box (position A); medial branch (position B); and lateral branch (position C). In 7 patients with medial area symptoms, abnormal findings were seen in position B (100%) and position A (71%). In 3 patients with medial and lateral area symptoms, abnormal findings were seen in all positions. In 5 patients with lateral symptoms, abnormal findings were seen in position C only. Nerve conduction studies for each branch of the SRN are useful in patients with suspected SRN neuropathy.