[Comparison of the effects of sciatic nerve block combined with continuted femoral nerve block or continuted adductor canal block on pain and motor function after total knee arthroplasty].

Objective: To compare the effect of sciatic nerve block (SNB) combined with continuted femoral nerve block (FNB) or continuted adductor canal block (ACB) on pain and motor function after total knee arthroplasty (TKA). Methods: A total of 60 patients with TKA-treated osteoarthritis of the knee who met the selection criteria were enrolled between November 2020 and February 2021 and randomised allocated into the study group (SNB combined with continuted ACB) and the control group (SNB combined with continuted FNB), with 30 cases in each group. There was no significant difference in gender, age, body mass, height, body mass index, preoperative Hospital for Special Surgery (HSS) score, femoral tibial angle, and medial proximal tibial angle between the two groups ( P>0.05). The operation time, the initial time to the ground, the initial walking distance, and the postoperative hospital stay were recorded. At 2, 4, 6, 12, 24, and 48 hours after operation, the numerical rating scale (NRS) score was used to evaluate the rest pain around the knee joint, the quadriceps femoris muscle strength was evaluated by the freehand muscle strength method, and the knee flexion and extension angles were measured. Results: There was no significant difference in the operation time and initial walking distance between the two groups ( P>0.05); the initial time to the ground and postoperative hospital stay of the study group were significantly shorter than those of the control group ( P<0.05). Except for the 48-hour postoperative NRS score of the study group, which was significantly lower than that of the control group ( P<0.05), there was no significant difference in the NRS scores between the two groups at the remaining time points ( P>0.05). The quadriceps femoris muscle strength from 4 to 24 hours postoperatively and the knee extension angle from 2 to 6 hours postoperatively of the study group were significantly better than those of the control group ( P<0.05); the differences in the quadriceps femoris muscle strength and knee extension and flexion angles between the two groups at the remaining time points were not significant ( P>0.05). Conclusion: SNB combined with either continuted ACB or continuted FNB can effectively relieve pain in patients after TKA, and compared with combined continuted FNB, combined continuted ACB has less effect on quadriceps femoris muscle strength, and patients have better recovery of knee flexion and extension mobility.

Determination of the optimal position of the lower extremity for femoral nerve block with ultrasonographic measurements: a prospective volunteer-based study.

OBJECTIVE: The aim of the study was to determine the optimal position for femoral nerve block (FNB) under ultrasound guidance. PATIENTS AND METHODS: We included fifty volunteers between 18-65 years of age in this study. The distances from the skin to the landmarks, which were taken as a reference for the ultrasound-guided FNB (apex point of the femoral artery = F12, lateral point = F9, and lower point = F6), were measured and compared in 3 different positions given to the lower extremity (neutral position: P1, 45° abduction: P2, and flexed knee: P3). The ease of application and the quality of the ultrasound images were evaluated at each measurement by assigning a subjective observer score and comparing them in three positions. RESULTS: All three measurement points were found to be closest to the skin at position P3. However, the distances from F9 (p = 0.023) and F6 (p = 0.006) to the skin were significant. A significant difference was found between P1 and P3 in terms of the distance from F9 (p = 0.027) and F6 to the skin (p = 0.007). P3 was determined to be the position with the highest score for clarity of the ultrasonography images and ease of detection of the measurement points (p < 0.001). As the scores of ease of access to the femoral nerve (FN) and image clarity increased, the distance from the measurement point to the skin surface decreased, which was statistically significant. CONCLUSIONS: The ideal position for ultrasound-guided FNB is the P3 position. As an alternative for patients with limited mobility, the P2 position can be used.

Femoral and obturator neuropathies.

The femoral and obturator nerves both arise from the L2, L3, and L4 spinal nerve roots and descend into the pelvis before emerging in the lower limbs. The femoral nerve's primary function is knee extension and hip flexion, along with some sensory innervation to the leg. The obturator nerve's primary function is thigh adduction and sensory innervation to a small area of the medial thigh. Each may be injured by a variety of potential causes, many of them iatrogenic. Here, we review the anatomy of the femoral and obturator nerves and the clinical features and potential etiologies of femoral and obturator neuropathies. Their necessary investigations, including electrodiagnostic studies and imaging, their prognosis, and potential treatments, are discussed in this chapter.

Reciprocal inhibition of the thigh muscles in humans: A study using transcutaneous spinal cord stimulation.

Evaluating reciprocal inhibition of the thigh muscles is important to investigate the neural circuits of locomotor behaviors. However, measurements of reciprocal inhibition of thigh muscles using spinal reflex, such as H-reflex, have never been systematically established owing to methodological limitations. The present study aimed to clarify the existence of reciprocal inhibition in the thigh muscles using transcutaneous spinal cord stimulation (tSCS). Twenty able-bodied male individuals were enrolled. We evoked spinal reflex from the biceps femoris muscle (BF) by tSCS on the lumber posterior root. We examined whether the tSCS-evoked BF reflex was reciprocally inhibited by the following conditionings: (1) single-pulse electrical stimulation on the femoral nerve innervating the rectus femoris muscle (RF) at various inter-stimulus intervals in the resting condition; (2) voluntary contraction of the RF; and (3) vibration stimulus on the RF. The BF reflex was significantly inhibited when the conditioning electrical stimulation was delivered at 10 and 20 ms prior to tSCS, during voluntary contraction of the RF, and during vibration on the RF. These data suggested a piece of evidence of the existence of reciprocal inhibition from the RF to the BF muscle in humans and highlighted the utility of methods for evaluating reciprocal inhibition of the thigh muscles using tSCS.

Percutaneous pulsed radiofrequency ablation of articular nerves of the hip joint in patients with chronic hip pain refractory to conventional analgesics.

OBJECTIVES: Total Hip Arthroplasty (THA) may be a risky proposition in patients with comorbidities, and they may require systemic analgesics for chronic hip pain (CHP). Since traditional pain medications may not provide complete pain relief or carry prohibitive adverse effects, pulsed radiofrequency (PRF) treatment of the hip articular nerves (HAN) has been proposed for effective clinical outcomes. We determined the efficacy of PRF-HAN in improvement in CHP compared to baseline pain on conventional systemic analgesics. METHODS: Between August 2015 and December 2021, 31 adult patients with severe comorbid conditions and excruciating chronic hip pain were subjected to a PRF-HAN procedure following a diagnostic block. All 31 patients received PRF of the articular branches of the femoral and obturator nerves. Demographic parameters, numerical rating scale (NRS), Harris Hip Score (HHS), WOMAC scores, the change of these scores from baseline, and any adverse effects were recorded before treatment and on day 1, 1st week, 6 weeks, and 6 months after treatment. RESULTS: All the patients who underwent the PRF-HAN reported a significant improvement in NRS, HHS, and WOMAC scores compared to the baseline values on day 1, at the end of the 1st week, and the 6th week (p<0.001). No adverse events were documented in the study post-procedure until the end of 6 months. CONCLUSION: PRF-HAN is a strong alternative for chronic pain management and augments physical functioning and a return to daily activity in patients who would be deprived of arthroplasty considering associated comorbid conditions.

Comparing quality of recovery and satisfaction between spinal anesthesia and nerve block in orthopedic below-knee surgery: A prospective controlled trial.

BACKGROUND: Postoperative quality of recovery (QoR) and patient satisfaction have gained increasing significance in medical services. This study aimed to compare these 2 parameters between 2 types of regional anesthetics (spinal anesthesia and combined sciatic-femoral nerve block) in orthopedic lower knee surgery. METHODS: A total of 101 patients were classified into 2 groups (combined sciatic-femoral nerve block, group N; spinal anesthesia, group S) according to patient preference. In group N, sciatic and femoral nerve blocks were performed on the popliteal and groin regions, respectively, under ultrasound guidance. Spinal anesthesia was performed in group S. The primary outcomes were QoR and patient satisfaction. QoR was measured using the Korean translation of the QoR-15K. Patient satisfaction was assessed using an 11-point Likert scale (0-10) and a dichotomous question addressing anesthesia preferences for future surgeries. RESULTS: The physical independence of the postoperative QoR-15K was significantly higher in group N than in group S (14.2 vs 12.0, P = .04). On the 11-point Likert scale, group N scored 8.8, and group S scored 7.8 (P = .001). In the dichotomous question, 93.8% of the group N and 52.8% of the group S answered that they would like to choose the same anesthesia method for the next surgery (P < .001). In addition, fewer participants in group N complained of backache than those in group S, and the time to first urination after anesthesia was shorter in group N than in group S (P = .004, <.001, respectively). CONCLUSION: Combined sciatic-femoral nerve block may provide better physical independence and satisfaction than spinal anesthesia in orthopedic below-knee surgeries.

The efficacy of pericapsular nerve group block for reducing pain and opioid consumption after total hip arthroplasty: a systematic review and meta-analysis.

BACKGROUND: Pericapsular nerve group block (PENG) is an emerging regional anesthesia technique for hip surgery. However, its efficacy in total hip arthroplasty (THA) isn't well defined. We perform this meta-analysis aiming to assess the effect of Pericapsular nerve group block on pain control and morphine consumption in patients with total hip arthroplasty. METHODS: We searched four electronic databases (Pubmed, Embase, Cochrane Library, and Web of Science dated from 2018 to October 2023) for published eligible randomized controlled trials (RCTs) comparing PENG with placebo (no block/sham block) after THA. The outcome measurements consisted of pain score, opioid consumption, Time to first opioid, and postoperative complications. All data analyses were performed using STATA 12.0. RESULTS: Five RCTs comprising 808 participants were included. Our meta-analysis showed that there were significant differences between two groups in terms of pain score in PACU (WMD = - 0.598, 95% CI [- 0.886, - 0.310], P < 0.001), pain score at 6 h (WMD = - 0.614, 95% CI [- 0.835, - 0.392], P < 0.001) and time to first opioid (WMD = 5.214, 95% CI [4.545, 5.883], P < 0.001). However, no significant differences were revealed from the pain score at 24 h after THA (WMD = - 0.924, 95% CI [- 1.929, 0.081], P = 0.072). Meanwhile, the meta-analysis indicated that PENG significantly reduced 24-h opioid consumption (WMD = - 6.168, 95% CI [- 6.667, - 5.668], P < 0.001) and 48-h opioid consumption (WMD = - 7.171, 95% CI [- 8.994, - 5.348], P < 0.001). CONCLUSION: Pericapsular nerve group block was effective for pain control up to postoperative 6 h and extending the time to the first opioid after THA. Moreover, it reduced postoperative opioid consumption when compared with a placebo group. Due to the high heterogeneity of the pain score after 24 h and the low-quality evidence, more high-quality RCTs are required to draw a definitive conclusion about pain control.

Incidence and clinical outcome of lateral femoral cutaneous nerve injury after periacetabular osteotomy.

Aims: Lateral femoral cutaneous nerve (LFCN) injury is a complication after periacetabular osteo-tomy (PAO) using an anterior approach, which might adversely affect the outcome. However, no prospective study has assessed the incidence and severity of this injury and its effect on the clinical outcomes over a period of time for longer than one year after PAO. The aim of this study was to assess the incidence and severity of the symptoms of LFCN injury for ≥ three years after PAO and report its effect on clinical outcomes. Methods: A total of 40 hips in 40 consecutive patients who underwent PAO between May 2016 and July 2018 were included in the study, as further follow-up of the same patients from a previous study. We prospectively evaluated the incidence, severity, and area of symptoms following LFCN injury. We also recorded the clinical scores at one year and ≥ three years postoperatively using the 36-Item Short Form Health Survey (SF-36) and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) scores. Results: A total of 20 patients (50%) had symptoms of a LFCN injury at one year after PAO. At ≥ three years postoperatively, the symptoms had completely resolved in seven of these patients and 13 (33%) had persistent symptoms. The severity and area of symptoms did not significantly differ between one and ≥ three years postoperatively. The JHEQ showed significant differences in the patient satisfaction and mental scores between those with and those without sypmtoms of LFCN injury at ≥ three years postoperatively, while there was no significant difference in the mean SF-36 scores. Conclusion: The incidence of LFCN injury after PAO using an anterior approach is high. The outcome of PAO, ≥ three years postoperatively, is poorer in patients with persistent symptoms from a perioperative LFCN injury, in that patient satisfaction and mental health scores are adversely affected.

Comparison of Analgesic Effects of Continuous Femoral Nerve Block, Femoral Triangle Block, and Adductor Block After Total Knee Arthroplasty: A Randomized Clinical Trial.

OBJECTIVES: This study aimed to compare the analgesic effects of continuous femoral nerve block (FNB), femoral triangle block (FTB), and adductor canal block (ACB) following total knee arthroplasty (TKA). The goal was to identify the most effective nerve block technique among these. METHODS: Patients undergoing TKA were randomly assigned to 1 of 3 groups: FNB, FTB, or ACB. Nerve blocks were administered preoperatively, with catheters placed for patient-controlled nerve analgesia (PCNA). The primary end point was the Numeric Rating Scale (NRS) score at movement at 24 hours postsurgery. Secondary end points included NRS scores at rest and movement, quadriceps strength, Timed Up and Go (TUG) test performance, range of motion, effective PCNA utilization, and opioid consumption at various postsurgery time points. RESULTS: Of the 94 valid data sets analyzed (FNB: 31, FTB: 31, ACB: 32), significant differences were observed in the primary end point (H=7.003, P =0.03). Post hoc analysis with Bonferroni correction showed that the FNB group had a significantly lower median pain score (3 [2 to 4]) compared with the ACB group (4 [3 to 5], Bonferroni-adjusted P =0.03). Regarding secondary end points, both the FNB and FTB groups had significantly lower NRS scores than the ACB group at various time points after surgery. Quadriceps strength and TUG completion were better in the FTB and ACB groups. There were no statistically significant differences among the groups for the other end points. DISCUSSION: Continuous FTB provides postoperative analgesia comparable to FNB but with the advantage of significantly less impact on quadriceps muscle strength, a benefit not seen with FNB. Both FTB and ACB are effective in preserving quadriceps strength postoperatively.

Changing Stimulation Frequency Improves Implanted Peripheral Nerve Stimulator Effects After Posttraumatic Total Hip Arthroplasty: A Case Report.

ABSTRACT: Total hip arthroplasty is an effective procedure to improve pain, range of motion, and function for a variety of conditions, including osteoarthritis and posttraumatic arthritis. Up to 28% of patients had persistent pain at the surgical site 12-18 mos after total hip arthroplasty, even in the absence of surgical complications. Currently, there are no widely accepted nonpharmacological treatments for persistent postoperative pain for total hip arthroplasty. This case report details the successful management of a 53-yr-old man with chronic pain and weakness after posttraumatic total hip arthroplasty. He was initially treated with a single-lead percutaneous peripheral nerve stimulator near the right femoral nerve for 4 weeks with 100-Hz frequency sensory-level parameters. Four weeks after implantation, the frequency was changed to 12 Hz with a goal of motor-level stimulation. During the after 3-week time period, his hip flexion strength improved from 10.36 kg to 23.04 kg. His Lower Extremity Functional Scale improved from 35/80 (43.75%) to 54/80 (67.5%) within a 5-wk time period. This case's success demonstrates how peripheral nerve stimulation may help improve postoperative persistent pain and weakness in many patients, including those with posttraumatic arthroplasty.

Peripheral nerve blocks for through-knee amputation in a patient on extracorporeal membrane oxygenation.

A woman in her 40s with an ischaemic right lower limb, who was on extracorporeal membrane oxygenation (ECMO) following cardiopulmonary failure secondary to bilateral alveolar haemorrhage, was scheduled for through-knee amputation. She was under mechanical ventilation and continuous intravenous medications. Considering her significant comorbidities, peripheral nerve blocks were chosen for anaesthesia. Ultrasound-guided traditional nerve blockade techniques of the femoral and sciatic nerves were not possible because of the presence of an ECMO cannula, altered anatomy following previous surgery on the same side and inability to turn the patient to a lateral position. An ultrasound-guided trans fascia iliaca for femoral and anterior approach for sciatic were rather used to accomplish the nerve blockades. Surgery completed without any complications and with reduced postoperative outcomes such as opioid consumption, other morbidities and mortality. This report is unique as the literature on peripheral nerve block approaches for lower limb amputations in ECMO patients is sparse.

Lower extremity peripheral nerve block for total knee arthroplasty in a patient with chronic inflammatory demyelinating polyneuropathy: A case report.

RATIONALE: Chronic inflammatory demyelinating polyneuropathy (CIDP) is an autoimmune disorder that affects the peripheral nerves, leading to weakness and sensory symptoms. CIDP is a rare disease, and few studies have reported on anesthetic management in patients with this condition, especially the peripheral nerve block (PNB). Therefore, a safe and standardized anesthetic approach remains to be established. This case report aims to address this gap in evidence by documenting our experience with PNB in a patient with CIDP undergoing surgery. It contributes significantly to expanding the range of anesthetic options and enhancing perioperative outcomes for patients with CIDP. PATIENT CONCERNS: A 58-year-old woman diagnosed with CIDP was scheduled to undergo left total knee arthroplasty due to osteonecrosis. We anticipated postoperative pain and aggravation of neurological symptoms. DIAGNOSIS: CIDP. INTERVENTIONS: To manage the postoperative pain, we planned a combination of general anesthesia (GA) and lower extremity PNBs, viz. the tibial and femoral nerve blocks, supplemented with intravenous patient-controlled analgesia. An initial dose of fentanyl 50 µg was administered as analgesia. The tibial and femoral nerves were identified using a peripheral nerve stimulator in conjunction with an ultrasonic echo device while the patient was conscious, to minimize the risk of nerve injury. The tibial and femoral nerve blocks were performed with 20 mL of ropivacaine (0.25%) and dexamethasone 2.2 mg, respectively. Subsequently, we administered fentanyl and ketamine and initiated continuous infusion of remifentanil. Thereafter, propofol 120 mg was administered intravenously over a span of 1 minute, followed by continuous infusion at 4 mg/kg/h. Upon confirming loss of consciousness, we induced GA using a supraglottic airway device without using muscle relaxants. For postoperative analgesia, we administered acetaminophen 1000 mg. OUTCOMES: The patient experienced no pain immediately after surgery, and good analgesia was achieved subsequently without worsening of sensory symptoms during rehabilitation. LESSONS: We achieved effective anesthetic management in a patient with CIDP by combining GA with nerve stimulation and ultrasound-guided PNB. It is crucial to devise a personalized anesthesia plan that focuses on the patients' safety and comfort while minimizing risk in patients with CIDP.

Differential Protein Expression between the Motor and Sensory Fascicles in Rat Femoral Nerve Injury.

BACKGROUND AND AIMS: It is important to distinguish between motor and sensory fascicles of the peripheral nerves for nerve alignment in surgery. However, there are no biomarkers currently available for effective identification of motor or sensory fascicles. The objective of this study was to identify differentially expressed proteins between motor and sensory fascicles of rats in response to injury. SETTINGS AND DESIGN: The study was carried out using a rat femoral nerve injury model. MATERIALS: A proteomic analysis was performed to detect differential protein expression using samples of bilateral motor and sensory branches of intact and injured rat femoral nerves through fluorescent two-dimensional difference gel electrophoresis and matrix-assisted laser desorption ionization-time of flight mass spectrometry. STATISTICAL ANALYSIS: Chi-square tests and t-tests were performed for comparison between motor or sensory nerve groups. RESULTS: The data identified six proteins that were differentially expressed between motor and sensory fascicles (>1.5-fold, P < 0.05), including apolipoprotein E, neurofilament light polypepticle, TEC kinase, serine protease inhibitor A3N, peroxiredoxin-2, and TPM1. The proteomic results were consistent with the mRNA expression levels of these genes as determined by quantitative reverse transcription polymerase chain reaction. CONCLUSIONS: Our study suggests that these proteins may play roles in nerve regeneration and repair. Importantly, apolipoprotein E and Serpina3n may serve as specific biomarkers for distinguishing motor and sensory fascicles of the peripheral nerves for nerve alignment in surgery.

Efficacy and Safety of Pericapsular Nerve Group Block for Hip Fracture Surgery under Spinal Anesthesia: A Meta-Analysis.

Objective: To evaluate the effectiveness and safety of pericapsular nerve group (PENG) block for hip fracture surgery under spinal anesthesia. Methods: This meta-analysis was registered on INPLASY (INPLASY202270005). PubMed, Embase, Cochrane, CNKI, and Wanfang databases were searched to collect the randomized controlled trials of the PENG block applied to hip fracture surgery in the setting of spinal anesthesia, with the search period from inception to 1 May 2023. Two independent researchers gradually screened the literature, evaluated the quality, extracted the data, and eventually pooled data using RevMan 5.4. Results: Fifteen articles with 890 patients were enrolled. The combined results showed that the PENG block reduced pain scores during position placement (SMD = -0.35; 95% CI [-0.67, 0.02]; P=0.04; I2 = 0%). Subgroup analyses showed that compared to the unblocked group, the PENG block reduced pain scores at 12 h, 24 h, and 48 h postoperatively. The incidence of postoperative hypokinesia was reduced (RR = 0.11; 95% CI [0.01, 0.86]; P=0.04; I2 = 0.00%). The time to first walking was advanced (SMD = -0.90; 95% CI [-1.17, 0.63]; P < 0.00001; I2 = 0%). Conclusion: The PENG block can reduce postoperative pain and pain during spinal anesthesia positioning, which is helpful to improve the operability and comfort of spinal anesthesia and facilitate postoperative muscle strength recovery and early activity.

Magnetic resonance imaging of femoral nerve injury in the setting of anterior approach total hip arthroplasty.

PURPOSE: To illustrate MRI findings in patients with femoral neuropathy following anterior approach total hip arthroplasty (THA). METHODS: This was a retrospective review of patients who underwent MRI for femoral neuropathy following anterior approach THA between January 1, 2010, and July 1, 2022. Included patients had no preexisting neurologic condition. Clinical and diagnostic data were collected. MRIs were reviewed in consensus by 2 musculoskeletal radiologists. RESULTS: A total of 115 patient records were reviewed, 17 of which were included in the final analysis (mean age 64 years; 11 females). Study subjects presented with weakness with hip flexion and knee extension and pain and numbness in the femoral nerve distribution. In 7 subjects, the femoral nerve appeared normal. In 5 subjects, the femoral nerve was hyperintense on fluid-sensitive fat-suppressed imaging. In 4 patients, mass effect on the femoral nerve by either ill-defined soft tissue edema (n = 2), seroma (n = 1), or heterotopic ossification (n = 1) was detected. Only 1 patient had a nerve transection. Patients were imaged at a median time of 8 months (range: 1 day to 11 years) following arthroplasty placement. Clinical follow-up was available in 8 patients, of whom half had complete symptomatic resolution and half had partial improvement at a mean follow-up time of 39.3 months (SD 51.1). Of these 8, 1 underwent revision arthroplasty, 1 had removal of hardware, and another had excision of heterotopic ossification. CONCLUSION: MRI provides a means to directly evaluate the femoral nerve following anterior approach THA in both the immediate and chronic postoperative periods.

Use of lateral femoral cutaneous nerve blocks by landmark technique is ineffective in decreasing narcotic usage after skin grafts: A retrospective case-control study.

INTRODUCTION: Cutaneous burns are commonly treated with autologous skin grafts. Following skin grafting, many patients complain of pain at the donor site. Donor sites are taken most commonly from the lateral thigh, which is innervated by the lateral femoral cutaneous nerve (LFCN). Use of a LFCN blocks should decrease nociception from the donor site. METHODS: Our group began utilizing LFCN blocks in 2019. Utilizing anatomic landmarks, LFCN blocks were performed on all patients who received autologous skin grafts to reduce perioperative pain. A retrospective cohort study was performed on all patients with 10% or less total body surface areas burns who received an autologous skin graft. A similar cohort from 2016, prior to use of any local or regional analgesia, was used as a historical control. Post-operative enteral and parenteral narcotic analgesics were collected for each post-operative day up to day 5 or discharge (whichever came first) and converted to morphine milligram equivalents (MME) to quantify analgesia after surgery. RESULTS: Chart review identified 55 patients in the 2020 cohort. Fifty-five patients from the 2016 cohort were matched based upon size of skin graft, total body surface area (TBSA) burned, gender, and age. There were no statistically significant differences between the two groups in terms of size of graft, TBSA burned, age, gender, or type of burn. When examining narcotics usage in the immediate perioperative period (days 0-2), we found no difference between the two groups for total MME (113 vs 133, p = 0.28) or IV MME (38 vs 33, p = 0.45). Similar relationships existed in the extended post-operative period (days 1-5) for total MME (149 vs. 188, t = 0.22) or IV MME (37 vs. 50, t = 0.25). Examining daily narcotic usage also yielded no statistically different values. CONCLUSION: Our data shows that use of LFCN block by landmark technique did not reduce narcotic usage in patients that undergo skin grafting procedures. Future studies should consider ultrasound-guided LFCN blocks.

Histochemical Identification of Motor Fascicles Using Cholinesterase Staining in Rats Using a Mixed Nerve Model.

BACKGROUND: Inappropriate matching of motor and sensory fibers after nerve repair or grafting can lead to nerve recovery failure. Identifying the motor and sensory fascicles enables surgeons to match them accurately and correctly align nerve stumps, which is crucial for neural regeneration. Very few methods have been reported to differentiate between the sensory and motor nerve fascicles, and the replicability of these techniques remains unestablished. In this study, we aimed to assess the accuracy of axonal cholinesterase (CE) histochemical staining in distinguishing motor and sensory nerve fibers. METHODS: The femoral and sciatic nerves were harvested from rats. The specimens were immediately cut, frozen in isopentane, and cooled with liquid nitrogen. Nerve serial cross-sections were processed for hematoxylin and eosin staining, followed by CE histochemistry. The staining protocol solutions included acetylthiocholine iodide, phosphate buffer, cobalt sulfate hydrate, potassium phosphate monobasic, sulfuric acid, sodium bicarbonate, glutaraldehyde, and ammonium sulfide. RESULTS: Cross-sections of nerves containing efferent and afferent nerve fibers in segregated fascicles showed that CE activity was confined to motor neurons. A histochemical study revealed that motor fibers with high cholinesterase activity can be differentiated from sensory fibers. The motor branches of the femoral and sciatic nerves showed specific axonal staining, whereas the sensory branch did not show any specific staining. CONCLUSION: CE histochemical staining is a useful technique for distinguishing between motor and sensory nerve fibers. It can be potentially useful in improving the outcomes of nerve grafts or extremity allotransplantation surgery.

Effect of Perineural or Intravenous Betamethasone on Femoral Nerve Block Outcomes in Knee Arthroplasty: A Randomized, Controlled Study.

OBJECTIVES: Despite the use of multimodal analgesia, patients undergoing knee arthroplasty still encounter residual moderate pain. The addition of betamethasone to local anesthetic has been shown to improve postoperative pain. However, it remains uncertain whether the positive effects of perineural or intravenous administration of betamethasone on analgesia outcomes lead to better early mobility and postoperative recovery. METHODS: Between June 2022 and February 2023, a total of 159 patients who were undergoing knee arthroplasty were included in this study. These patients were allocated randomly into three groups: (i) the NS group, received ropivacaine 0.375% and intravenous 3mL 0.9% normal saline; (ii) the PNB group, received ropivacaine 0.375% plus perineural betamethasone (12mg) 3mL and intravenous 3mL 0.9% normal saline; and (iii) the IVB group, received ropivacaine 0.375% and intravenous betamethasone (12mg) 3mL. RESULTS: Both perineural and intravenous administration of betamethasone led to improved median (IQR) numeric rating scale (NRS) scores on the 6-meter walk test, with a score of 1.0 (1.0-2.0) for both groups, compared with 2.0 (1.0-2.0) for the NS group (p = 0.003). Compared to the NS group, both the PNB and IVB groups showed significant reductions in NRS scores at 24 and 36 h after surgery, along with a significant increase in ROM at 24, 36, and 48 h post-operation. Additionally, it exhibited lower levels of cytokine IL-1ß and TNF-α in fluid samples, as well as lower level of HS-CRP in blood samples in the PNB and IVB groups compared to the NS group. CONCLUSION: The administration of perineural and intravenous betamethasone demonstrated an enhanced analgesic effect following knee arthroplasty. Furthermore, it was associated with reduced levels of IL-1ß, TNF-α, and HS-CRP, as well as enhanced knee ROM, which is conducive to early ambulation and postoperative rehabilitation after knee arthroplasty.

Gait analysis of a patient after femoral nerve and malignant soft tissue tumor resections: a case report.

BACKGROUND: Malignant femoral soft tissue tumors are occasionally resected together with the femoral nerves, but this can cause loss of knee extensor muscle activity. To the best of our knowledge, no previous reports have detailed the gait analysis of such cases in combination with electromyography. Herein, we report the gait analysis of a patient who underwent left groin synovial sarcoma and left femoral nerve resection 12 years ago. CASE PRESENTATION: We analyzed the gait of a 38-year-old man who was able to walk unaided after the resection of a synovial sarcoma in the left groin together with the ipsilateral femoral nerve. The muscle activities of the affected medial (MH) and lateral hamstrings (LH), and lateral heads of the gastrocnemius (GL) were increased during 50-75% of the stance phase. The hip flexion angle of the affected limb was smaller, and the ankle plantar flexion angle of the affected limb was larger than that of the non-affected limb. This means that in the affected limb, the hip and ankle angles were adjusted to prevent knee collapse, and the MH, LH, and GL muscles contributed in the mid- and late-stance phases. Moreover, we found that the hamstring and gastrocnemius of the affected limb worked together to keep the ipsilateral knee extended in the mid-stance phase and slightly flexed in the late-stance phase. CONCLUSIONS: Patients capable of walking after femoral nerve resection may control their hamstrings and gastrocnemius muscles collaboratively to prevent ipsilateral knee collapse in the mid- and late-stance phases.