Mid-thigh Level Research Articles

6613 Liver and Spleen Linked in Hepatic Steatosis during Weight Reduction in Type 2 Diabetes

Abstract Disclosure: K. Han: None. K. Min: None. Splenectomy increased serum lipids, except triglyceride (TG) and high-density lipoprotein (HDL), significantly accelerating hepatic steatosis in animal study. Recently, the concept of a liver-spleen axis has been proposed in nonalcoholic fatty liver disease. The purpose of this study was to investigate change of the liver Hounsfield Units (HU), reflecting the hepatic steatosis, and its relation to spleen HU, central, or peripheral and ectopic adipose tissue during weight reduction in type 2 diabetes. Total 187 women with type 2 diabetes were educated on lifestyle modification. We assessed liver Hounsfield Units(HU) and spleen HU with total abdominal fat(ATAF) , visceral adipose tissue (AVAT), subcutaneous adipose tissue(ASAT) at mid-abdomen level, and total adipose tissue (TTAT)and intramuscular adipose tissue(TIMAT) at midthigh level using nonenhanced computed tomography, at baseline and 12 weeks. We investigated whether changes in liver HD were related to fat in other regions, serum triglycerides, free fatty acids, and adiponectin-leptin ratio (ALR). The participants’ age was 55.2±7.3 years, BMI was 27.3±2.7 kg/m2, Body Weight (BW) 66.8±6.9kg). Baseline liver HU was 54.7±11.5, and spleen HU was 48.5±8.5. At 12 weeks, BW lost 2.4±2.2kg. Liver HU changed with spleen HU (r=0.357, p<0.001, ATAT(r=-0.343, p<0.0001), AVAT (r=0.220, p=.011), ASAT(r=-0.339, p<0.001) and adiponectin-leptin ratio (ALR) (r=-0.174, p=0.047), but no significant relations with TTAT, TIMAT, triglyceride, and free fatty acid. Linear regression analysis showed the best model for change of liver HU (Model R2=0.209, p<0.001) was as follows: Change of Liver HU=0.534 +0.038* change of spleen HU - 0.290* change of ATAF. Higher spleen HU (p<0.001) and lower abdominal fat (p<0.001) predicted higher liver HU (less steatosis). These results suggested that the liver might be metabolically linked to the spleen in hepatic steatosis of type 2 Diabetes. Presentation: 6/2/2024

Independent association of thigh muscle fat density with vascular events in Korean adults

BackgroundWe aimed to explore the associations between thigh muscle fat density and vascular events.MethodsA total of 3,595 adults (mean age, 57.2 years; women, 1,715 [47.7%]) without baseline cardiovascular events from the Korean Atherosclerosis Study-2 were included. Muscle and fat area at the mid-thigh level were measured by computed tomography (CT) using the following Hounsfield Unit range: 0–30 for low density muscle (LDM); 31–100 for normal density muscle (NDM); and − 250 to − 50 for fat.ResultsDuring a median follow-up period of 11.8 (4.3–13.9) years, vascular events occurred in 11.6% of men and 5.9% of women. Individuals with vascular events had a larger LDM area (men: 48.8 ± 15.5 cm2 vs. 44.6 ± 14.5 cm2; women: 39.4 ± 13.2 cm2 vs. 35.0 ± 11.8 cm2, both P < 0.001) compared with those who did not have vascular events during the follow-up of at least 5 years. The LDM/NDM ratio was also independently associated with vascular events after adjusting for cardiometabolic risk factors. Moreover, the LDM/NDM ratio improved the prognostic value for vascular events when added to conventional risk factors.ConclusionsThe current study suggests that a higher thigh muscle fat infiltration is associated with an increased risk of developing vascular events among Korean adults.

Efficacy of collagen conduit wrapping with collagen fibers on nerve regeneration in sciatic nerve injury with partial transection: An experimental study in the rat model.

Peripheral nerve injuries (PNIs) include complete and partial transection, crushing, and chronic compression injuries. Hollow absorbable conduits are used to treat complete transection with short defects, while wrapping the injured part with an absorbent material promotes nerve recovery by inhibiting inflammatory cell infiltration and scar tissue formation in crush injuries. For treatment of partially transected nerve injuries (PTNIs), such as injection-related iatrogenic PNI, whether wrapping the entire nerve, including the injury site, or bridging the transected fascicle with an artificial nerve conduit (ANC) is beneficial remains to be verified. The purpose of this study was to investigate whether wrapping the injured nerve and placing collagen fibers as scaffolds at the nerve defect site contribute to neural recovery in PTNI. A unilateral 5-mm partial nerve defect was created at the mid-thigh level in a rat sciatic nerve injury model. Fifty-four Sprague-Dawley (SD) rats (150-250 g) were divided into three groups (n = 9 each): group 1, collagen fibers were placed in the nerve defect and the sciatic nerve was wrapped with collagen conduit; group 2, the sciatic nerve was wrapped by collagen conduit without collagen fibers; and group 3, nerve defect was reconstructed with collagen-filled conduit. Nerve regeneration was evaluated by analyses of gait, electrophysiology, wet muscle weight, and axon numbers with immunohistochemistry at 12 and 24 weeks. Dorsiflexion angles among all groups improved significantly from 12 to 24 weeks postoperatively. At 24 weeks postoperatively, compound muscle action potential amplitudes (CMAPs) of tibialis anterior were 5.26 ± 4.64, 1.31 ± 1.17, and 0.14 ± 0.24 mV (p < .05), CMAPs of gastrocnemius were 21.3 ± 5.98, 15.4 ± 5.46, and 13.11 ± 3.91 mV in groups 1, 2, and 3, respectively; and the value of group 1 was significantly higher than that of group 3 (p < .05). Axon numbers were 2194 ± 629; 1106 ± 645; and 805 ± 907 in groups 1, 2, and 3, respectively (p < .05). For PTNI reconstruction, artificial nerve wrap (ANW) was superior to ANC. Providing collagen scaffold at the nerve defect site enhanced nerve recovery during reconstruction with ANW.

Paper 31: Quantitative MRI of the Hamstring Muscles Ten Years After Autograft Hamstring ACLR

Paper 31: Quantitative MRI of the Hamstring Muscles Ten Years After Autograft Hamstring ACLR

The relationship between sarcopenia-related measurements and osteoporosis: The SARCOP study.

As muscle and bone are two closely related tissues, we aimed to investigate the association between sarcopenia-related measurements (i.e., sonographic anterior thigh muscle thickness, grip strength, chair stand test (CST), gait speed) and clinical factors, lumbar/femoral BMD, and the presence of osteoporosis (OP) in postmenopausal women. Community dwelling postmenopausal women from two physical and rehabilitation medicine outpatient clinics were consecutively included in this cross-sectional study. Demographic data, age, weight, height, education/exercise status, smoking, and comorbidities were registered. BMD measurements were performed from lumbar vertebrae (L1-4) and femoral neck using dual energy X-ray absorptiometry (DXA). A T-score of ≤ -2.5 SD in the lumbar vertebrae (L1-L4) and/or femoral neck was accepted as OP. Anterior thigh muscle thickness (MT) at the midthigh level was measured sonographically using a linear probe. Grip strength was measured from the dominant side. Physical performance was assessed by CST and gait speed. Among 546 postmenopausal women, 222 (40.7%) had OP. Among sarcopenia-related parameters, grip strength and anterior thigh MT were positively associated with lumbar vertebral BMD. CST performance was positively associated with femoral neck BMD. After adjusting for confounding factors, low grip strength (< 22kg) increased 1.6 times the risk of OP. Loss of muscle mass/function (i.e., sarcopenia) can coexist with loss of trabecular and cortical bone. To this end, grip strength and anterior thigh MT seem to be associated with the lumbar vertebral BMD, while CST is associated with the femoral neck BMD. Lastly, low grip strength might have an association with postmenopausal OP.

Prospective Analysis of Muscle Adiposity in Children With X-linked Hypophosphatemic Rickets vs Control Children.

Children with X-linked hypophosphatemic (XLH) rickets have muscle weakness that severely impairs their function. Intermuscular and intramuscular adipose tissue (IMAT and intraMAT, respectively) may contribute to this muscle weakness. This work aimed to compare IMAT and intraMAT in XLH children vs typically developing (TD) children. A prospective, monocentric cohort study was conducted of XLH (n = 11; aged 10.3 years [6-17]) and TD children (n = 22; aged 10.2 years [5-15.5]). All children underwent magnetic resonance imaging of the lower limbs; IMAT and intraMAT percentages were calculated after manual contouring of each muscle of the thigh and the deep fascia at mid-thigh level. XLH children were comparable in age but shorter and heavier than TD children (P = .001 and P = .03, respectively). They had smaller muscle length and volume than TD children (P < .001) but there was no statistically significant difference in muscle cross-sectional area between the groups (P = .833). The total percentage of IMAT was higher in XLH children (8.66% vs 3.60% in TD children; P < .0001). In addition, though the total percentage of intraMAT did not differ significantly (12.58% and 10.85% in XLH and TD children, respectively; P = .143) intraMAT was statistically significantly higher in XLH children than TD children in 4 of the 13 muscles studied. Our results show that IMAT is higher in young children with XLH, independently of obesity and overweight. Further, these results will facilitate both the early prevention of functional and metabolic consequences of the increase in adipose tissue in XLH children.

Lower-Limb Muscle Activity During Aquatic Treadmill Running in Individuals With Anterior Cruciate Ligament Reconstruction

While anterior cruciate ligament (ACL) tears are commonly managed with ACL reconstruction (ACL-R), 35% of ACL-R individuals fail to return to the preinjury elite sport level. Persistent neuromuscular deficits in the hamstrings and quadriceps have been observed. It has been proposed that aquatic therapy can be used to optimize neuromuscular control after ACL-R. (1)To compare muscle activity in ACL-R individuals during aquatic treadmill (ATM) running at different water depths and (2)to compare muscle activity during ATM running between ACL-R and healthy individuals. A total of 38 participants, including 18 ACL-R individuals (mean postoperative time [SD] = 25.8 [25.0] mo) and 20 healthy individuals were recruited. Muscle activity of biceps femoris (BF), rectus femoris (RF), tibialis anterior, and medial gastrocnemius during land treadmill and ATM running at mid-shin, mid-thigh, and waist levels were recorded using surface electromyography (sEMG). The sEMG signals of the selected muscles were normalized and expressed in % Maximal Voluntary Contraction (%MVC). Muscle activity of the ACL-R, ACL-contralateral, and healthy control limbs at different water depths was compared. Among the 3 groups, the ACL-R group demonstrated the most prominent percentage increase of 101.97% (P = .001) at mid-shin level, 139.66% (P = .001) at mid-thigh level, and 141.97% (P < .001) at waist level, respectively, in %MVC when compared to land. In the ACL-R group, muscle activity of BF in the stance phase (BFSt) was significantly higher than the control group on land at all water depths. Muscle activity of RF in the swing phase (RFSw) in the ACL-R group significantly increased in all water depths immersion when compared to land, respectively. This study showed an increasing trend in muscle activity of BFSt and RFSw in ACL-R individuals during ATM running at increased water depths. ATM running could be implemented as neuromuscular training in rehabilitation after ACL-R.

A Study Comparing Gait and Lower Limb Muscle Activity During Aquatic Treadmill Running with Different Water Depth and Land Treadmill Running.

Aquatic treadmill running is a partial weight-bearing exercise for rehabilitation. The purpose of this study was to investigate the surface electromyography activities of the rectus femoris, tibialis anterior, biceps femoris and medial head of gastrocnemius, and gait kinematics during aquatic treadmill running in water levels at waist, mid-thigh and mid-shin and on land. Seventeen healthy subjects (9 males and 8 females) were recruited by convenience sampling. Participants performed 2-min aquatic treadmill running at a specific speed for each water depth. The test speed was selected based upon the speed that elicited 110 steps per min. The surface electromyography data of lower limb muscles and the joint angles at three different water depths and on land were collected to evaluate the muscle activity and gait kinematics using a waterproofed surface electromyography system and inertial measurement unit for each muscle. Results showed that rectus femoris electromyography was different between depths during the swing and stance phases. Likewise, biceps femoris and tibialis anterior electromyography were different between depths for the swing phase. However, it was not the case for gastrocnemius electromyography. Peak flexion angles in both left and right hips were different between depths. A significant increase in a stance/swing ratio was observed with rising water depths. Water depth influenced muscle activity as well as kinematics. Aquatic treadmill running in the mid-thigh level should be further evaluated for its effectiveness, training value and applicability.

Spatial Distribution and Long-Term Alterations of Peripheral Nerve Lesions in Schwannomatosis.

Purpose To examine the spatial distribution and long-term alterations of peripheral nerve lesions in patients with schwannomatosis by in vivo high-resolution magnetic resonance neurography (MRN). Methods In this prospective study, the lumbosacral plexus as well as the right sciatic, tibial, and peroneal nerves were examined in 15 patients diagnosed with schwannomatosis by a standardized MRN protocol at 3 Tesla. Micro-, intermediate- and macrolesions were assessed according to their number, diameter and spatial distribution. Moreover, in nine patients, peripheral nerve lesions were compared to follow-up examinations after 39 to 71 months. Results In comparison to intermediate and macrolesions, microlesions were the predominant lesion entity at the level of the proximal (p < 0.001), mid- (p < 0.001), and distal thigh (p < 0.01). Compared to the proximal calf level, the lesion number was increased at the proximal (p < 0.05), mid- (p < 0.01), and distal thigh level (p < 0.01), while between the different thigh levels, no differences in lesion numbers were found. In the follow-up examinations, the lesion number was unchanged for micro-, intermediate and macrolesions. The diameter of lesions in the follow-up examination was decreased for microlesions (p < 0.01), not different for intermediate lesions, and increased for macrolesions (p < 0.01). Conclusion Microlesions represent the predominant type of peripheral nerve lesion in schwannomatosis and show a rather consistent distribution pattern in long-term follow-up. In contrast to the accumulation of nerve lesions, primarily in the distal nerve segments in NF2, the lesion numbers in schwannomatosis peak at the mid-thigh level. Towards more distal portions, the lesion number markedly decreases, which is considered as a general feature of other types of small fiber neuropathy.

Evaluation of postoperative analgesic efficacy of dexmedetomidine as adjuvant with ropivacaine in ultrasound guided adductor canal block in patients undergoing unilateral Total Knee Replacement

The aim of anaesthesia in Total knee replacement (TKR) is to provide adequate analgesia and early ambulation. The recent success of adductor canal block in providing post-operative analgesia and achieving early ambulation has evoked interest in studying the effects of local anaesthetic agents and various adjuvants.This study was a randomized three arm parallel group comparative study conducted in a tertiary care center in India on 135 patients undergoing unilateral total knee replacement under spinal anaesthesia. After completion of the surgery, the adductor canal block was performed with ultrasound guidance at mid-thigh level in all three groups. In group A, 20 ml 0.375% ropivacaine was only used but in group B and C Dexmedetomidine was added to ropivacaine (total volume of 20 ml; 0.375%) at a dose of 0.25 µg/kg and 0.50 µg/kg respectively. The primary outcome of the study was to compare duration of analgesia after the adductor canal block. Duration to rescue analgesia (in hours) was significantly longer [Group A: 15.71±4.87; Group B: 16.44±6.21; Group C: 19.78±5.57 (p=0.014)] and total opioid (24 hours tramadol needed in mg) consumption [Group A: 60.00±13.94; Group B: 52.22±18.80; Group C: 33.33±13.95 (p=0.033)] was significantly lower in Group C. NRS scores both at movement and rest were significantly lesser in Group C at 18 and 24 hours timepoints. Patient satisfaction was significantly higher in Group C with 46.67% patient reporting better than expected peri-operative experience (p=0.022).The addition of dexmedetomidine, 0.5 µg/kg to 0.375% ropivacaine in adductor canal block results in longer duration of analgesia, less 24 hours opioid consumption, better motor strength and better patient satisfaction without any adverse effect after unilateral total knee replacement surgery.

A reliable and robust method for the upper thigh muscle quantification on computed tomography: toward a quantitative biomarker for sarcopenia

BackgroundWe aimed to evaluate the feasibility of the upper thigh level as a landmark to measure muscle area for sarcopenia assessment on computed tomography (CT).MethodsIn the 116 healthy subjects who performed CT scans covering from mid-abdomen to feet, the skeletal muscle area in the upper thigh level at the inferior tip of ischial tuberosity (SMAUT), the mid-thigh level (SMAMT), and L3 inferior endplate level (SMAL3) were measured by two independent readers. Pearson correlation coefficients between SMAUT, SMAMT, and SMAL3 were calculated. Inter-reader agreement between the two readers were evaluated using intraclass correlation coefficient (ICC) and Bland-Altman plots with 95% limit of agreement (LOA).ResultsIn readers 1 and 2, very high positive correlations were observed between SMAUT and SMAMT (r = 0.91 and 0.92, respectively) and between SMAUT and SMAL3 (r = 0.90 and 0.91, respectively), while high positive correlation were observed between SMAMT and SMAL3 (r = 0.87 and 0.87, respectively). Based on ICC values, the inter-reader agreement was the best in the SMAUT (0.999), followed by the SMAL3 (0.990) and SMAMT (0.956). The 95% LOAs in the Bland-Altman plots indicated that the inter-reader agreement of the SMAUT (− 0.462 to 1.513) was the best, followed by the SMAL3 (− 9.949 to 7.636) and SMAMT (− 12.105 to 14.605).ConclusionMuscle area measurement at the upper thigh level correlates well with those with the mid-thigh and L3 inferior endpoint level and shows the highest inter-reader agreement. Thus, the upper thigh level might be an excellent landmark enabling SMAUT as a reliable and robust biomarker for muscle area measurement for sarcopenia assessment.

Can the sonographic distal vastus medialis thickness be a useful marker to reflect disease progression of knee OA?

The objective of this study was to evaluate the correlations between radiologic staging and evaluated ultrasound results of the distal portion of VM muscle thickness in knee OA comparing with the previous mid-thigh level study.

Muscle magnetic resonance imaging in patients with LAMA2-related muscular dystrophy

LAMA2-related muscular dystrophy (LAMA2-MD) is classified into congenital muscular dystrophy type 1A (MDC1A) and autosomal recessive limb-girdle muscular dystrophy-23 (LGMDR23). The purpose of this study was to identify the involvement pattern of thigh muscles of LAMA2-MD patients on magnetic resonance imaging. Fourteen MDC1A and 3 LGMDR23 patients were included, with 21 known and 8 novel LAMA2 disease-causing variants. In LAMA2-MD, the gluteus maximus, anterior (quadriceps femoris) and posterior (adductor magnus and biceps femoris) thigh muscles were extensively and severely affected with fatty infiltration, with relatively sparing of the adductor longus. The pattern of muscle involvement was similar between MDC1A and LGMDR23, but more severe in MDC1A, as well as in LAMA2-MD patients without ambulation. The rather peculiar pattern of the adductor magnus and long head of the biceps femoris first and severely affected in the mid-thigh level was found in LGMDR23. Strong correlation between fatty infiltration and age as well as disease duration was observed for the adductor longus in MDC1A. Edema and atrophy selectively involved in some muscles. The pattern of fatty infiltration on thigh muscle MRI of LAMA2-MD could provide important information for the diagnosis, differential diagnosis and assessment of clinical severity.

The Immediate Effects of Foam Rolling and Stretching on Iliotibial Band Stiffness: A Randomized Controlled Trial.

BackgroundIliotibial Band Syndrome (ITBS) is a common clinical condition likely caused by abnormal compressive forces to the iliotibial band (ITB). Stretching interventions are common in ITBS treatment and may predominantly affect tensor fascia latae (TFL). Another ITBS treatment is foam rolling, which may more directly affect the ITB. Shear wave ultrasound elastography (SWUE) measures real-time soft tissue stiffness, allowing tissue changes to be measured and compared.PurposeTo examine effects of foam rolling and iliotibial complex stretching on ITB stiffness at 0˚ and 10˚ of hip adduction and hip adduction passive range of motion (PROM).Study DesignRandomized controlled trial.MethodsData from 11 males (age = 30.5 ± 9.0 years, Body Mass Index (BMI) = 27.8 ± 4.0) and 19 females (age = 23.5 ± 4.9, BMI = 23.2 ± 2.1) were analyzed for this study. Subjects were randomly assigned to one of three groups: control, stretching, and foam rolling. Shear wave ultrasound elastography measurements included ITB Young’s modulus at the mid-thigh, the distal femur and the TFL muscle belly. ITB-to-femur depth was measured at mid-thigh level. Hip adduction PROM was measured from digital images taken during the movement.ResultsNo significant interactions or main effects were found for group or time differences in ITB Young’s modulus at the three measured locations. The ITB stiffness at the mid-thigh and distal femur increased with 10° adduction, but TFL stiffness did not increase. A main effect for adduction PROM was observed, where PROM increased 0.8˚ post-treatment (p = 0.02).ConclusionA single episode of stretching and foam rolling does not affect short-term ITB stiffness. The lack of ITB stiffness changes may be from an inadequate intervention stimulus or indicate that the interventions have no impact on ITB stiffness.Levels of Evidence1b

Diminished Sphenous Compartment Connective Tissue Elasticity has Little Impact on Low Grade Venous Insufficiency: An Ultrasound Shearwave Elastography Study.

BackgroundGreater Saphenous Vein (GSV) courses within saphenous compartment, an adipose-filled space bound by fasciae provides structural support. Ultrasound Shear-Wave Elastography (SWE) provides objective and quantitative data on tissue shear elasticity modulus.ObjectiveThis study aims to analyze possible associations between early stage GSV insufficiency and saphenous intracompartmental SWE measurements.MethodsTwo-hundred consecutive patients, ages 22 to 81 (mean=44.3) years, with venous insufficiency symptoms underwent Doppler and SWE examinations. Patients had no visible or palpable sign of venous disease or had telangiectasia and reticular veins only. Analyses regarding patient age, gender, presence of venous insufficiency of GSV proper and intracompartmental connective tissue elasticity were performed.ResultsNinety-six patients had Doppler evidence for either bilateral or unilateral insufficiency of GSV proper at mid-thigh level. Intracompartmental elasticity of patients with venous insufficiency (mean=4.36±2.24 kilopascals; range 1.55 to 10.44 kPa) did not differ significantly from those with normal veins (mean=4.82±2.61 kPa; range 2.20 to 12.65 kPa) (p=0.231). No threshold for predicting the presence of venous insufficiency could be determined. Neither were there any correlations between age, gender and intracompartmental elasticity. In patients with unilateral insufficiency, however, elastography values around insufficient veins were significantly lower compared to contralateral normal GSV (p<0.001).ConclusionMany intrinsic and patient factors affect intracompartmental connective tissue elastography measurements; thus, cut-off values obtained from specific populations have limited generalizability. Nevertheless, statistically significant intrapatient differences of intracompartmental elasticity among diseased and normal saphenous veins indicate that lack of elastic support from surrounding connective tissues contributes to venous insufficiency in early stages.

MRI quantifies lumbosacral nerve root and sciatic nerve hypertrophy in chronic inflammatory demyelinating polyradiculoneuropathy

PurposeChronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a treatable, immune-mediated condition characterised by progressive or relapsing motor and sensory neurological deficits. The diagnosis is based on a combination of clinical, neurophysiological and supportive criteria, but can be challenging. In this study, we quantified the diameter and cross-sectional area of the lumbosacral nerve roots, and explored the imaging characteristics of the sciatic nerves, in patients with CIDP versus healthy controls using MRI. MethodsMRI of the lumbosacral plexus and both thighs was performed at 3 T. Orthogonal diameter and cross-sectional area of the lumbosacral nerve roots were measured, along with sciatic nerve cross-sectional area at the mid-thigh level. The MRI appearance of the sciatic nerves was also evaluated qualitatively. All measurements were performed by an observer blinded to the diagnosis. Results10 patients with CIDP and 10 healthy controls (age and sex-matched) were studied. Lumbosacral nerve root diameter and cross-sectional area were significantly increased in patients with CIDP compared to controls (mean diameter 6.0 ± 1.1 mm vs 4.8 ± 0.3 mm; p = 0.006), with a high sensitivity (89 %) and specificity (90 %) on ROC analysis. Sciatic nerve cross sectional area was also significantly increased in the CIDP group, and was accompanied by qualitative MRI changes. ConclusionsQuantitative MRI reveals significant hypertrophy of the lumbosacral nerve roots and sciatic nerves in patients with CIDP compared to controls. This study provides further evidence for the inclusion of lumbosacral nerve root and sciatic nerve hypertrophy on MRI as a supportive feature in the diagnostic criteria for CIDP.

Ultrasound-guided sciatic nerve block at the midthigh level in a porcine model: A descriptive study.

Background and ObjectiveThere are a growing number of porcine models being used for orthopaedic experiments for human beings. Therefore, pain management of those research pigs using ultrasound (US)‐guided nerve block can be usefully performed. The aim of this study is to determine optimal US approaches for accessing and localizing the sciatic nerve at the midthigh level, a relevant block site for hindlimb surgery in female Yorkshire pigs.MethodsAs a first step, we dissected the intubated, blood‐washed out pigs (n = 3) and confirmed the anatomical position of the sciatic nerve at midthigh level. After dissection, we found the sciatic nerve, connected with nerve stimulator, and checked the dorsiflexion or plantar flexion of the hindlimb. We matched the sciatic nerve location with the US image. After the pigs were euthanized, the neural structures of the sciatic nerve were confirmed by histological examination with H&E staining. In second step, a main US‐guided sciatic nerve block study was done in the intubated, live pigs (n = 8) based on the above study.ResultsIn lateral position, the effective US‐guided nerve block site was about 6 cm from the patella crease level; immediately proximal to the bifurcation of the sciatic nerve into the tibial nerve and common peroneal nerve. The distal femur was selected as the landmark. There were no vessels or other nerves surrounding the sciatic nerve. The needle‐tip was positioned less than 1 cm lateral from the distal femur and about 2 cm deep to skin. ‘Donut sign’ in US images was confirmed in all 16 nerves.ConclusionsMidthigh level sciatic nerve is located superficially, which enables nerve block to be easily performed using US. This is the first study to describe midthigh sciatic nerve block in the lateral position under US guidance in a porcine model from a clinical perspective.

Changes in fat-free mass and muscle mass at 6 and 12 months after biliopancreatic diversion with duodenal switch surgery.

Bariatric surgery is associated with concomitant loss in both fat and muscle masses. Literature on muscle composition/quality after bariatric surgery is limited. To measure and compare the changes in fat-free mass with the changes in muscle composition after biliopancreatic diversion with duodenal switch surgery (BPD/DS). Bariatric surgery is associated with concomitant loss in both fat and muscle masses. Literature on muscle composition/quality after bariatric surgery is limited. Forty patients underwent BPD/DS and 22 patients are considered as controls. Bioelectrical impedance analysis (body composition) and computed tomography scan at the midthigh and abdominal levels (muscle composition) were performed at baseline, 6, and 12 months. At 6 and 12 months, the BPD/DS group displayed significant reduction in weight (12 months: -46.6 ± 13.5 kg) and fat-free mass (12 months: -8.2 ± 4.4 kg; both P < .001). A significant reduction in abdominal (-15 ± 8%, P < .001) and midthigh muscle areas (-18 ± 7%, P < .001) was observed during the first postoperative 6 months, followed by a plateau after 6 months (abdominal: -1 ± 5%, midthigh: -1 ± 4%, both P > .05). At 6 months, both midthigh fat-infiltrated muscle (-22 ± 10%, P < .001) and normal-density muscle (-16 ± 9%, P < .001) areas decreased. Further reduction at 12 months was only observed in the fat-infiltrated muscle (-11 ± 8%, P < .001) in comparison with an increase in the normal-density muscle area (5 ± 8%, P = .001). There was no significant change for the control group. Reduction in muscle, assessed with computed tomography scans, occurs mostly during the first 6 months postoperatively after BPD/DS. Focus on muscle quantity as well as quality, using precise imaging methods, instead of quantifying total body lean mass, is likely to provide better assessment in body content modulation after BPD/DS.

Distribution of Femoral Metastases; Potential Role for Extended FDG PET/CT Scanning

This study investigates the distribution of femoral metastases in cancer patients, specifically addressing the incidence of distal femoral metastases. PET/CT examinations routinely extend only to mid-thigh level, precluding detection of distal metastases. We found a total of 208 femoral metastases in 112 patients. 30% had distal femoral metastases in addition to other areas of involvement. 7% of patients with femoral metastases had only distal femur disease. 6 patients had distal pathologic fractures. Exclusion of the distal femur during PET/CT may result in a missed or delayed diagnosis that could contribute to the development of a pathologic fracture with increased morbidity.

Ultrasound-Guided Single-Penetration Block for Sciatic and Saphenous Nerve Versus The Traditional Double Penetration Popliteal- Sciatic/Saphenous Technique for Leg and Foot Surgery

Abstract Background A new approach is described to blocking the sciatic and saphenous nerves in the proximal thigh (level of the lesser trochanter or immediately below) using a single-penetration technique. The popliteal-sciatic approach necessitates repositioning of the leg exposing the popliteal fossa and an extra injection for the saphenous nerve (SAN) block at the midthigh level. Aim of the Study The aim of this work is to compare between the new single-penetration block technique for block of the SCN and SAN at proximal thigh and the traditional popliteal sciatic nerve block at popliteal fossa with saphenous nerve block at adductor canal technique for leg and foot surgery. Subjects and Methods This prospective single blinded randomized parallel group study was conducted to compare between the ultrasound guided single penetration block technique for sciatic and saphenous nerve at proximal thigh to the traditional popliteal sciatic nerve block at popliteal fossa and saphenous block at adductor canal. Results Performance time was significantly faster with the single penetration technique median time 6.33 minutes (range, 3-10 minutes) versus 12.57 minutes (range from 8-20 minutes) (P &amp;lt; 0.001), respectively Positioning time was also significantly shorter with the single penetration block technique compared to the traditional block combination technique that is median time 0 minutes (range, 0-0 minutes) versus median time 5.78 minutes (range 3-10 minutes) (P &amp;lt; 0.001), respectively. No other statistically significant differences were recorded. Conclusions The single penetration block resulted in significantly faster performance time and reduced positioning time with statistically equal efficacy in relation to pain assessment, nausea, meperdin demand, dermatomal anesthesia, and motor blockade. The single penetration block is statistically an equally effective alternative to the traditional popliteal-sciatic/saphenous block combination for leg and foot surgery, but it is faster, requires only 1 skin penetration, and does not require repositioning of the leg.