Medial Head Research Articles

Proximal Medial Gastrocnemius Release: Surgical Technique.

PMGR is performed with the patient in the prone position. A thigh tourniquet is not utilized. We prefer to use spinal anesthesia, but local anesthesia could be applied along with sedation. A posteromedial incision is made on or just below the posterior knee crease. The crural fascia is divided, and the proximal insertion of the medial gastrocnemius is identified. Performing the "hook maneuver" with a curved dissector is helpful at this step. Only the white fibers are sectioned in order to allow for a lengthening of the muscular fibers that is completed with forceful ankle dorsiflexion. After proper hemostasis has been achieved, the subcutaneous layer and skin are closed, leaving the fascia open. Nonoperative treatment should be the first option, including analgesics, insoles, heel cups, calf-stretching, injections, and extracorporeal shock wave therapy8. Some authors have also suggested that application of a walking cast for 3 to 6 weeks should be attempted9,10. Once all of these treatment options have failed, operative treatment is appropriate. Historically, open plantar fasciotomy was offered to patients with recalcitrant plantar fasciitis, and this treatment continues to be a surgical option. Other procedure, like the Strayer, Vulpius, or Baumann techniques, involve the calf system and are called "gastrocnemius recession." However, these techniques act in the more distal aspect of the calf system compared with PMGR. PMGR offers patients with recalcitrant plantar fasciitis rapid recovery and good results. This procedure obviates the complications associated with plantar fasciotomy, in which the medial aspect of the proximal plantar fascia is divided to relieve the overload. A plantar fasciotomy (either open or endoscopic11) risks lateral column overload12 or a painful flatfoot if >50% of the fascia is divided. A long recovery period following plantar fasciotomy has also been described7. On the other hand, other procedures have been utilized to lengthen the Achilles-calcaneus-plantar system to an even greater extent. Techniques like the Silfverskiöld (i.e., medial and lateral proximal gastrocnemius release) or Strayer (i.e., division of the distal aspect of the gastrocnemius fascia) technique present a higher rate of complications (up to 38%), specifically nerve injuries13,14. We consider these procedures (classified as gastrocnemius recession procedures) more properly indicated for patients with neurological diseases or with an equinus contracture. The medial gastrocnemius is the more powerful of the 2 bellies. Releasing the medial head alone offers a robust decrease in tension and is safer than approaching the lateral head of the gastrocnemius15. At the same time, this technique provides a quick recovery for the patient. PMGR can also help those patients with other clinical signs related to gastrocnemius tightness, such as calf cramps and pain or repeated muscle injuries. Moreover, it can be effective in patients with second-rocker metatarsalgia or midportion Achilles tendinitis1,16. PMGR has a reported rate of satisfaction of >80%. Most patients undergoing this procedure experience substantial pain relief within the first 2 to 3 months6,17. PMGR is an outpatient procedure with a short operative time and a rapid return to recreational and labor activities. The complication rate is low, and the most common complications are calf hematomas and delayed wound healing. The present article demonstrates a reduction in pain and good functional results. An improvement in the perception of health-related quality of life, especially in the physical and pain domains of the Short Form-36 questionnaire, was also observed. The prone position allows for direct access to the proximal medial head of the gastrocnemius. Preferably, perform PMGR without a tourniquet in order to assure proper hemostasis. Keep the ankle joint free at the end of operating table because ankle dorsiflexion is a helpful maneuver at some stages in this procedure. Digital (index finger) dissection should be performed among the medial head of the gastrocnemius, the hamstrings, and the posterior aspect of the proximal tibia. The hook maneuver, performed with use of a blunt dissector, is helpful to identify all of the white fibers. Only white fibers should be divided. The surgeon must also make sure to cut the more anterior part of the aponeurosis that is hidden by red fibers. After cutting the white fibers, forceful ankle dorsiflexion is required to obtain full lengthening of the muscle. Proper hemostasis should be achieved to prevent formation of a calf hematoma. Advise the patient to do calf-stretches as soon as pain permits in order to prevent a contracting muscle scar. PMGR = proximal medial gastrocnemius releaseESWT = extracorporeal shock wave therapySD = standard deviation.

Use of Weight-Bearing Computed Tomography in the Evaluation of Abnormal Hindfoot Morphology in Charcot-Marie-Tooth Patients

Category:Hindfoot; OtherIntroduction/Purpose:The hindfoot deformity seen in Charcot-Marie-Tooth disease (CMT) is poorly understood, and the contribution of abnormal bone morphology has never been conclusively demonstrated. The purpose of this study was to compare the three-dimensional (3D) bone morphology of the talus, calcaneus and navicular in a cohort of CMT patients versus a control population. We used the data obtained from weight-bearing computed tomography (WBCT) to reconstruct the geometric shape of each bone using 3D surface meshing techniques. Surface mesh analysis of this type is commonly used in engineering to evaluate and optimize 3D geometries and structures.Methods:A total of 17 WBCTs from 15 patients (average age 24) with CMT who underwent WBCT without previous surgeries, degenerative changes or open physes were included. These were compared to 20 healthy control WBCTs. Calcaneal measurements included the radius of curvature and the angle between the posterior tuberosity and posterior facet in the sagittal plane. Talar measurements include axial and sagittal declination between the body and neck as well as coronal rotation of the talar head relative to the body. Surface-mesh model analysis was performed comparing the average of the CMT cohort to the controls using CT analysis software (Disior Bonelogic). Means were compared with a t test (p<0.05).Results:CMT patients had significantly less sagittal declination (plantarflexion) versus controls (14.9 versus 25.1 degrees respectively) (p<0.01). Similarly, CMT patients had less talar head coronal rotation versus controls (30.2 versus 42.5 degrees respectively) (p<0.001). There was no difference in axial rotation of the talar neck versus body between the groups (p=0.88). The calcaneal radius of curvature in CMT patients was significantly smaller than the control population (716.6 versus 2143.5 mm respectively) (p<0.05). Angular differences were also significant between the posterior tuberosity and posterior facet of the subtalar joint in the sagittal plane (CMT 57.7 degrees, control 67.9 degrees) (p<0.001). Additionally, surface-mesh model analysis demonstrated the largest differences in morphology at the navicular tuberosity, medial talar head, sustentaculum tali and anterior process of the calcaneus (Figure 1).Conclusion:This is the first study to quantify the morphologic differences in osteology seen in CMT patients. The decreased sagittal declination of the talar neck is seen with a reciprocal decreased slope of the posterior facet of the calcaneus. The coronal rotation of the talar head and abnormal navicular tuberosity morphology shows changes seen in patients with CMT and may be attributed to unbalanced pull of the posterior tibial tendon during development. These findings will help refine, and potentially revolutionize the surgical reconstruction of cavovarus deformity in CMT patients.

Pathohistological characteristics of muscles in patients with chronic lower limb ischemia

To assess the signs of damage (the extent of necrosis and apoptosis, capillary density (CD)) and regeneration (the cross-sectional muscle fiber area (CSMFA), the proportion of centrinucleated muscle fibers (CNMFs), and that of connective tissue), by using the gastrocnemius medial head biopsy specimens obtained from patients with heterogeneous forms of chronic lower limb obliterating diseases (CLLODs). The investigation included the biopsy specimens obtained from 44 men under 65 years of age (their mean age was 54±9.8 years) with Stage IIB-IV chronic limb ischemia (according to the A.V. Pokrovsky-Fontaine classification) with its history of at least six months. The nosological entities were atherosclerotic lesion in 33 patients (distal atherosclerosis n=13), multistage lesion (n=8), and Leriche's syndrome (n=12); autoimmune-mediated vascular injury in 11 patients (Buerger's disease (n=7) and nonspecific aortoarteritis (n=4)). The similar muscle fragments obtained during autopsy from the deceased without obvious signs of cardiovascular system diseases were examined as a control. It was found that there was a statistically significant difference between the nosological entities, as compared to the control in terms of CD and CSMFA (a decrease), the proportion of CNMFs and that of connective tissue (an increase). No substantial differences were found in the studied parameters between the nosological entities. The findings may suggest the universal mechanism for damage to striated muscle tissue because of circulatory hypoxia, regardless of its etiology and the common character of tissue compensatory-adaptive responses (regeneration).

Reliability of lower leg muscle thickness measurement along the long axis of the muscle using ultrasound imaging, in a sitting position.

[Purpose] To verify the reliability and validity of lower leg muscle thickness (MT) assessment along the muscle’s long axis using ultrasound imaging (USI) in a sitting position. [Participants and Methods] Twenty healthy adult female participants (aged, 20.3 ± 0.9 years) were included in the study. Intra- and inter-examiner reliability of the proximal, middle, and distal MT of the tibialis anterior (TA) and medial head of the gastrocnemius (GM) were verified using USI in a sitting position. Additionally, the relationship between MT measurement using USI and muscle cross-sectional area (MCSA) measurement using magnetic resonance imaging (MRI), as well as the ankle joint’s maximum muscle strength, were examined. [Results] The reliability of TA and GM MT measurement using USI was high for all regions. The relationship between MCSA measurement using MRI and MT measurement using USI showed a significant correlation in all the regions for both muscles. The relationship between ankle muscle strength and USI of MT was not significantly correlated in any region for both muscles. [Conclusion] Measurement of MT using USI is reliable and valid for MCSA, but must be combined with assessments of other factors for muscle strength.

Comparison of a Simple Anatomic Landmark-Based Achilles Tendon Measurement with Ultrasound and MRI Measurements

Category:Ankle; TraumaIntroduction/Purpose:Achilles tendon ruptures (ATRs) occurred with an incidence of 2.5 per 100,000 person-years in 2016. This rate has been increasing over the last decade and it has been postulated that this is due to the increasing activity level of an aging population. With a high and increasing incidence of this significant injury, further investigation must be done to optimize the treatment of ATRs. The degree of tendon lengthening has been correlated with clinical outcomes, with greater elongation being associated with worse outcomes. MRI and ultrasound (US) techniques have been validated in Achilles tendon measurements. We sought to develop a reliable, reproducible, and accurate measurement technique utilizing the manual palpation of anatomic landmarks that will be cost effective as well as convenient to perform, particularly intraoperatively.Methods:Both lower legs of 10 healthy subjects without history of Achilles tendon injury were examined. For US and anatomic landmark-based (ALB) measurements, subjects' ankles were held at 90o with the lateral aspect of the lower leg resting on the exam table. The length from the medial head of the gastrocnemius to the bottom of the non-compressed heal pad was measured by three raters using the US and ALB techniques. Two of those raters repeated the measurements one week later. MRI studies were obtained with ankles held at 90o. Using imaging software, the above measurements were made in sagittal and coronal series. A repeated measures mixed model method was utilized to model the measurement type and the length of the Achilles tendon. The length of the Achilles tendon measured by each measurement type was estimated with least square means. All pairwise comparisons were considered.Results:The Achilles tendon length was similar on the left [23.4 cm (95% CL: 22.3 cm, 24.5 cm)] and right [23.5 cm (95% CL: 22.4 cm, 24.6 cm)] legs. The average Achilles tendon length measured with the ALB technique was 23.2 cm (95% CL: 21.9 cm, 24.6 cm). The average Achilles tendon length measured with the US technique was 22.4 cm (95% CL: 21.0, 23.8). The average Achilles tendon length measured on the sagittal view of MRI was 24.1 cm (95% CL: 22.7, 25.4). The average Achilles tendon length measured on the coronal view of MRI was 24.2 cm (95% CL: 22.8, 25.5). Pairwise comparisons of the measurement types were not significantly different from 0.Conclusion:The ALB measurements were not statistically different from MRI or US. With orthopaedic surgeons in need of simple, noninvasive, and cost-effective methods to assess tendon length, the authors propose this ALB technique or US as valid ways to monitor that variable both during and after repair. These results set the stage for further evaluation of this measurement technique in the operating room in subjects undergoing ATR repair.

Variant anatomy of the muscles of the anterior compartment of the leg in human fetuses at 4-6 months

The objective is to find out the variant anatomy of the muscles of the anterior compartment of the leg in human fetuses at 4-6 months.Material and methods. The study was performed on 28 preparations of human fetuses of 81.0-230.0 mm parietal-coccygeal length (PCL) using macro-microscopic preparation, morphometry and statistical analysis.Results. The study of the structure and topography of the muscles of the anterior compartment of the leg in 26 human fetuses at 4-6 months revealed the classic sites of origin and attachment, the typical shape, and the number of muscles. Rare variants of the muscles of the anterior compartment of the leg have been found in two fetuses.Conclusions. The individual characteristics of the muscles of the anterior compartment of the lower leg in human fetuses are variations in their structure, shape, number, place of origin, and attachment. In most of the fetuses studied, the muscles of the anterior compartment of the lower leg had a classical origin, but the length and area of attachment varied with a tendency to lengthen and expand. The fetus of 105.0 mm PCL lateral and medial heads of the tibialis anterior muscle were detected, and an additional lower head of the long extensor muscle of the fingers was observed in the fetus of 175.0 mm PCL.

Anatomic variability of the nerves of the triceps surae in early human fetuses

Background. Establishing fetal anatomical variability of intramuscular nerves and their connections plays an important role in the search for and development of new methods for the diagnostic and treatment posterior region of the leg. Objective – to find out the topographic and anatomical features of the innervation of the triceps surae in human fetuses 4-6 months. Methods. The study was performed on 46 human fetuses 81.0-230.0 mm crown-rump length (CRL) length using macromicroscopic preparation, vascular injection, and morphometry. Results. In early human fetuses, the anatomical variability of the distribution of intramuscular nerves in the thickness of the triceps surae was established, which is due to the variability of the structure and topography of the tibial nerve, structural and functional organization of triceps surae, arterial branching and interneural connections in the thickness of the heads of the gastrocnemius and soleus in fetuses of different and the same age groups, and sometimes in the same fetus. Conclusion. The main source of innervation of the triceps surae is the tibial nerve, which can be presented by a single trunk, main and additional trunks, or several independent trunks. The nerves in the thickness of the triceps are unevenly distributed. The highest concentration of muscular branches of the tibial nerve is determined in the medial head of the gastrocnemius and the medial part of the soleus. Information on fetal topography of intramuscular nerves in the thickness of the right and left triceps surae, as well as forms of their anatomical variability, both in fetuses of different and the same age and sometimes in the same fetus, due to structural-functional organization of the components of the triceps surae, the type of branching of arteries and nerves in the thickness of the heads of the gastrocnemius and soleus. Atypical variants of the topography of the tibial nerve and common fibular nerve in early fetuses, as well as interneural connections in the thickness of the components of the triceps surae, are more common on the right lower leg.

Predicting Forefoot-Orthosis Interactions in Rheumatoid Arthritis Using Computational Modelling.

Foot orthoses are prescribed to reduce forefoot plantar pressures and pain in people with rheumatoid arthritis. Computational modelling can assess how the orthoses affect internal tissue stresses, but previous studies have focused on a single healthy individual. This study aimed to ascertain whether simplified forefoot models would produce differing biomechanical predictions at the orthotic interface between people with rheumatoid arthritis of varying severity, and in comparison to a healthy control. The forefoot models were developed from magnetic resonance data of 13 participants with rheumatoid arthritis and one healthy individual. Measurements of bony morphology and soft tissue thickness were taken to assess deformity. These were compared to model predictions (99th% shear strain and plantar pressure, max. pressure gradient, volume of soft tissue over 10% shear strain), alongside clinical data including body mass index and Leeds Foot Impact Scale–Impairment/Footwear score (LFIS-IF). The predicted pressure and shear strain for the healthy participant fell at the lower end of the rheumatoid models’ range. Medial first metatarsal head curvature moderately correlated to all model predicted outcomes (0.529 < r < 0.574, 0.040 < p < 0.063). BMI strongly correlated to all model predictions except pressure gradients (0.600 < r < 0.652, p < 0.05). There were no apparent relationships between model predictions and instances of bursae, erosion and synovial hypertrophy or LFIS-IF score. The forefoot models produced differing biomechanical predictions between a healthy individual and participants with rheumatoid arthritis, and between individuals with rheumatoid arthritis. Models capable of predicting subject specific biomechanical orthotic interactions could be used in the future to inform more personalised devices to protect skin and soft tissue health. While the model results did not clearly correlate with all clinical measures, there was a wide range in model predictions and morphological measures across the participants. Thus, the need for assessment of foot orthoses across a population, rather than for one individual, is clear.

Abnormal Bone Morphology in Charcot-Marie-Tooth Disease.

Although long suspected, it has yet to be shown whether the foot and ankle deformities of Charcot-Marie-Tooth disease (CMT) are generally associated with abnormalities in osseous shape. Computed tomography (CT) was used to quantify morphologic differences of the calcaneus, talus, and navicular in CMT compared with healthy controls. Weightbearing CT scans of 21 patients (27 feet) with CMT were compared to those of 20 healthy controls. Calcaneal measurements included radius of curvature, sagittal posterior tuberosity-posterior facet angle, and tuberosity coronal rotation. Talar measurements included axial and sagittal body-neck declination angle, and coronal talar head rotation. Surface-mesh model analysis of the hindfoot was performed comparing the average of the CMT cohort to the controls using a CT analysis software (Disior Bonelogic 2.0). Means were compared with a t test (P < .05). CMT patients had significantly less talar sagittal declination vs controls (17.8 vs 25.1 degrees; P < .05). Similarly, CMT patients had less talar head coronal rotation vs controls (30.8 vs 42.5 degrees; P < .001). The calcaneal radius of curvature in CMT patients was significantly smaller than controls (822.8 vs 2143.5 mm; P < .05). CMT sagittal posterior tuberosity-posterior facet angle was also significantly different from that of controls (60.3 vs 67.9 degrees respectively; P < .001).Surface-mesh model analysis demonstrated the largest differences in morphology at the navicular tuberosity, medial talar head, sustentaculum tali, and anterior process of the calcaneus. This is the first study to quantify the morphologic differences in hindfoot osteology seen in CMT patients. Patients identified with osseous changes of the calcaneus, especially a smaller axial radius of curvature, may benefit from a 3-dimensional osteotomy for correction.

Muscle Electrical Impedance Properties and Activation Alteration After Functional Electrical Stimulation-Assisted Cycling Training for Chronic Stroke Survivors: A Longitudinal Pilot Study

Electrical impedance myography (EIM) is a sensitive assessment for neuromuscular diseases to detect muscle inherent properties, whereas surface electromyography (sEMG) is a common technique for monitoring muscle activation. However, the application of EIM in detecting training effects on stroke survivors is relatively few. This study aimed to evaluate the muscle inherent properties and muscle activation alteration after functional electrical stimulation (FES)-assisted cycling training to chronic stroke survivors. Fifteen people with chronic stroke were recruited for 20 sessions of FES-assisted cycling training (40 min/session, 3–5 sessions/week). The periodically stimulated and assessed muscle groups were quadriceps (QC), tibialis anterior (TA), hamstrings (HS), and medial head of gastrocnemius (MG) on the paretic lower extremity. EIM parameters [resistance (R), reactance (X), phase angle (θ), and anisotropy ratio (AR)], clinical scales (Fugl-Meyer Lower Extremity (FMA-LE), Berg Balance Scale (BBS), and 6-min walking test (6MWT)] and sEMG parameters [including root-mean square (RMS) and co-contraction index (CI) value] were collected and computed before and after the training. Linear correlation analysis was conducted between EIM and clinical scales as well as between sEMG and clinical scales. The results showed that motor function of the lower extremity, balance, and walking performance of subjects improved after the training. After training, θ value of TA (P = 0.014) and MG (P = 0.017) significantly increased, and AR of X (P = 0.004) value and AR of θ value (P = 0.041) significantly increased on TA. The RMS value of TA decreased (P = 0.022) and a significant reduction of CI was revealed on TA/MG muscle pair (P < 0.001). Significant correlation was found between EIM and clinical assessments (AR of X value of TA and FMA-LE: r = 0.54, P = 0.046; X value of TA and BBS score: 0.628, P = 0.016), and between sEMG and clinical scores (RMS of TA and BBS score: r = −0.582, P = 0.029). This study demonstrated that FES-assisted cycling training improved lower limb function by developing coordinated muscle activation and facilitating an orderly myofiber arrangement. The current study also indicated that EIM can jointly evaluate lower extremity function alteration with sEMG after rehabilitation training.Clinical Trail Registration: The study was registered on the Clinical Trial Registry (trial registration number: NCT 03208439, https://clinicaltrials.gov/ct2/show/NCT03208439).

Dry Needling of the Medial Gastrocnemius as Novel Treatment for Type-VI Functional Popliteal Artery Entrapment Syndrome

Popliteal artery entrapment syndrome is rare, commonly overlooked, and characterized by the compression of the popliteal artery via the surrounding myofascial structures. Presented is a 28-year-old active-duty male service member with unilateral exertional left lower extremity pain, paresthesia, and discoloration. Popliteal musculoskeletal and Doppler ultrasound showed normal anatomy with functional compression of the popliteal artery by the medial head of the gastrocnemius. This is the first case in current literature to report ultrasound-guided dry needling to the medial head of the gastrocnemius as novel treatment for functional popliteal artery entrapment syndrome.

The anatomy of the anconeus nerve redefined.

The anconeus nerve is the longest branch of the radial nerve and suitable as a donor for the neurotization of the axillary nerve. The aim of this study was to map its topographical course with reference to palpable, anatomical landmarks. The anconeus nerve was followed in 15 cadaveric specimens from its origin to its entry to the anconeus. It runs between the lateral and the medial head of the triceps before entering the medial head and running intramuscularly further distal. Exiting the muscle, it lies on the periosteum and the articular capsule of the elbow, before entering the anconeus muscle. Two types of anconeus nerve in relation to branches innervating triceps were found: nine nerves also innervated the lateral triceps head, while the other six only contributed two branches to its innervation. The course of the anconeus nerve is important for harvesting as a donor nerve and to protect the nerve in surgical elbow approaches.

A critical appraisal of ankle rehabilitative interventions

ABSTRACT Introduction Lateral ankle sprain is a common musculoskeletal pathology. Functional exercise progression is vital to restore full function. Aim The aim of this study was to compare the electromyographical response to a standard balance task on one stable and four unstable surfaces. Participants Twenty subjects (5 male, 15 females; age at 23 ± 7.1 years) were recruited to participate in the study. Methods A gym-based single session cross over design was used to compare peak and mean surface EMG (sEMG) activity of the Peroneus Longus, Tibilais Anterior and medial head of the gastrocnemius muscles whilst performing a standardized balance task on one stable surface and four unstable surfaces stable surface. Results A significant main effect for surface was found. Post-hoc testing revealed that the Floor and Trampoline (Trampet) elicited similar mean sEMG response. Discussion The results of the study propose a safe and stepwise progressive rehabilitation regime following ankle injury whilst considering the healing process of the injured structure.

Transdeltoid Approach to Axillary Nerve Repair: Anatomical Study and Case Series

In cases of isolated paralysis of the axillary nerve, dissection of the distal stump at the posterior deltoid border can be difficult because of scarring from an injury or previous surgery. To overcome this, we propose dissecting the anterior division of the axillary nerve (ADAN) using a deltoid-splitting approach. We investigated the anatomy of the ADAN as it pertains to the transdeltoid approach and report the clinical application of this approach in 9 patients with isolated axillary nerve injury. The axillary nerve and its branches were dissected in 9 fresh cadaver specimens. In the clinical series, 1 patient with a lesion confined to the ADAN underwent nerve grafting. In the remaining 8 patients, the ADAN was repaired by transferring the triceps lower medial head and anconeus (TLMA) motor branch via a single-incision or double-incision posterior arm approach. The posterior division of the axillary nerve does not travel around the humerus. It innervated the posterior deltoid and teres minor muscles. At the posterior margin of the humerus, the ADAN ran adjacent to the teres minor tendon. The ADAN's trajectory on the lateral side of the humerus was 65 mm (SD ± 8 mm) from the midpoint of the acromion. One centimeter from the origin, the ADAN offered a prominent branch to the middle deltoid and wound around the humerus anteriorly at the surgical neck just distal to the infraspinatus tendon. A transdeltoid approach was feasible in all our patients. The TLMA was reached without any tension in the ADAN. Middle deltoid strength in 1 patient who had received a graft scored M3, while anterior and middle deltoid strength in the remaining patients who underwent nerve transfers scored M4. With axillary nerve lesions, reinnervation of the ADAN is a priority. The transdeltoid approach between the posterior and middle deltoid offers a direct and feasible approach to the ADAN. Therapeutic V.

Investigation of Motor Point Shift and Contraction Force of Triceps Brachii for Functional Electrical Stimulation.

Functional electrical stimulation (FES) has been used for neurorehabilitation of individuals with paralysis due to spinal cord injuries or stroke aftereffects. The biceps brachii is often adopted in studies on FES because of the ease of stimulation, while there are few studies on the triceps brachii. Stimulation of the triceps brachii is important because the biceps brachii tends to be spastic. The aim of this study is to investigate the position shift of the motor points (MPs) of the three main muscle groups in triceps brachii with respect to the elbow joint angle, and the contraction force of the muscle groups. Firstly, MPs were measured in 6 healthy individuals using an MP pen at 5 elbow joint angles. The MPs of the long and lateral heads shifted distally and laterally, and the MPs of the medial head shifted distally and medially as the arm extended. The MPs of the long head shifted farthest of all. Secondly, the contraction force was measured in 9 healthy individuals using a force gauge at elbow joint angle of 90 degrees. Three different voltages were applied: 4, 8, and 12 V. The results showed that the medial head yields a sufficient contraction force although the medial head is situated deeper than the other two muscle groups. These findings will help to better understand the stimulation of the triceps brachii and improve the efficiency of electrical stimulation therapy.

What are the significant factors affecting pain in patients with Hartofilakidis type \u0399 developmental dysplasia of the hip?

ObjectiveTo explore the influencing factors of age at onset of pain and severe pain in patients with Hartofilakidis type I developmental dysplasia of the hip (DDH).MethodsA retrospective study of 83 patients with DDH treated at our hospital from January 2017 to June 2021 was conducted. The age at onset of pain, patients’ demographic data, and radiographic parameters were collected. Multiple linear regression was used to determine the influencing factors of age at onset of pain. Cox regression analysis was used to determine the influencing factors of severe pain attacks.ResultsAccording to the results of multiple linear regression analysis, when the distance between the medial femoral head and the ilioischial line increased by one millimetre, the age at onset of pain decreased by 1.7 years (β = − 1.738, 95% CI − 1.914–[− 1.561], p < 0.001). When the sharp angle increases by one degree, the age at onset of pain decreases by 0.3 years (β = − 0.334, 95% CI − 0.496–[− 0.171], p < 0.001). According to the results of the Cox regression analysis, for each additional degree of the lateral centre-edge angle (LCEA), the probability of severe pain was reduced by 5% (Exp [β]: = 0.947, 95% CI 0.898–0.999, p = 0.044). For each additional millimetre in the distance between the medial femoral head and the ilioischial line, the likelihood of severe pain increased by 2.4 times (Exp [β]: 2.417, 95% CI 1.653–3.533, p < 0.001).ConclusionLarger distances between the medial femoral head and the ilioischial line and sharp angle can lead to an earlier age at onset of pain in patients with DDH. Small LCEA and excessive distance between the medial femoral head and the ilioischial line are risk factors for severe pain.

Cross-sectional imaging of popliteal artery entrapment syndrome

A 63-year-old asymptomatic man with unlimited exercise tolerance is investigated for suspected popliteal aneurysms, due to absent pedal pulses and prominent popliteal pulsations. Contrast-enhanced computed tomography (CT) shows occlusion of the left popliteal artery with geniculate collaterals surrounding the popliteal vein (A). The medial head of gastrocnemius separates the popliteal vein and the occluded (entrapped) popliteal artery. CT also shows entrapment of the right popliteal artery, due to extrinsic compression by the abnormally sited tendon of the medial head of gastrocnemius, which separates the artery and vein, mirroring the muscular anatomy on the left (B). A second 55-year-old man, normally walking 10-12 miles per day without restriction, presents with acute right leg claudication at 200 m. Contrast-enhanced CT demonstrates left popliteal artery stenosis with post-stenotic dilatation and right distal popliteal embolic occlusion due to a popliteal aneurysm with thrombus secondary to bilateral popliteal entrapment syndrome (PAES) (C). Axial balanced flow fast field echo magnetic resonance images and corresponding CT axial images demonstrate that the left medial head of gastrocnemius passes between the popliteal artery and popliteal vein. However, the aneurysmal right popliteal artery and the right popliteal vein are both located medial to, and are not separated by, the medial head of gastrocnemius (D). PAES is an uncommon cause of occlusive arterial disease, which is often bilateral. It is caused either by abnormal muscular insertions, typically of the medial head of gastrocnemius or the popliteus muscle, or by anomalous fibrous bands (types II, III, and IV, according to the modified Whelan classification).1Rich N.M. Collins G.J. McDonald P.T. Kozloff L. Clagett G.P. Collins J.T. Popliteal vascular entrapment: its increasing interest.Arch Surg. 1979; 114: 1377-1384Google Scholar Less commonly, an abnormal course of the popliteal vessels around normally inserted muscles is responsible for the entrapment (type I). Arteriovenous (type V) and functional entrapments have also been described. As illustrated, cross-sectional studies are very useful in demonstrating the abnormal anatomy. These two cases also show that muscular abnormalities are not always symmetrical in bilateral PAES (all limbs presenting as type II, except for the right leg of the second patient, which can be classed as type I, due to the medial course of the artery around a normal insertion of the medial head of gastrocnemius). Both patients consented to the publication of the case details and relative images.

A Unilateral Variation in Triceps Brachii Muscle Demonstrating a Fourth Head

Introduction Triceps brachii muscle is the only muscle of posterior compartment of arm, consisting of three heads—long, lateral, and medial. Radial nerve and profunda brachii artery run in the radial groove that separate lateral and medial head. Evolutionarily, triceps has many subheads which either fused or disappeared. Therefore, the knowledge of muscle is essential anthropologically and clinically, and this study aims to study the anatomical variations of triceps brachii muscle. Case Report In the present case, during routine dissections of undergraduate MBBS students, a fourth head of origin of triceps brachii muscle was seen in a male cadaver in the right arm. The variation was seen only unilaterally in cadaver. The origin was tendinous arising from the posteromedial aspect of upper part of the shaft of the humerus close to the surgical neck above the radial groove. This tendon was arching over the neurovascular bundle containing radial nerve and profunda brachii artery. Discussion and Conclusion The variations of triceps brachii muscles are mentioned in literature but are uncommon and if tendinous fourth head is present over the neurovascular bundles, it may lead to compression syndrome. Hence, these variations are of great importance to the radiologists, surgeons, and orthopaedicians while dealing with posterior compartment of arm.

Venous popliteal entrapment syndrome

Popliteal entrapment syndrome (PES) describes a set of symptoms related to compression of the neurovascular bundle in the popliteal fossa, with popliteal artery involvement the most widely recognized variation. Popliteal vein entrapment is a rare variation which can easily go undiagnosed. This is most commonly due to an anomaly of the medial head of the gastrocnemius muscle, but other etiologies include excess adipose tissue or cysts within the popliteal fossa, popliteal artery aneurysm, fibrous bands, thickened perivenous fascia, compression by the popliteus muscle or muscular hypertrophy independent of anomalous anatomy, or variant origin of the short saphenous vein. However, with improving awareness, it is a condition which should be increasingly considered in patients presenting with unexplained lower extremity swelling or other symptoms of lower extremity thrombosis. The initial test of choice is typically ultrasound with flexion and extension maneuvers. Venography is the gold standard for diagnosis, but MRI offers a noninvasive option for both diagnosis and evaluation of etiology and should be considered in the work-up of popliteal venous entrapment. Management is based on severity and type of symptoms, ranging from conservative management with compression stockings to surgical management if there is popliteal artery involvement or more severe symptoms. Endovascular therapy such as angioplasty or stenting has also been reported with good results.

Cross-correlated fractal components of H-wave amplitude fluctuations in medial gastrocnemius and soleus muscles

The time series of the H-wave amplitude in soleus muscle (SOL) shows fractal (long-range) correlation, which is attributed to input from supraspinal centers. However, whether such long-range power-law correlated input also contributes to the synergistic muscles remains unclear. The purpose of this study was therefore to examine the correlation in the fractal components of H-wave amplitude fluctuations between the synergistic muscles used for plantar flexion, i.e., the medial head of the gastrocnemius muscle (MG) and SOL. In eight young male participants, consecutive H-reflexes were recorded almost simultaneously from the MG and SOL at a stimulation frequency of 0.5 Hz for 30 min. We performed detrending moving-average cross-correlation analysis (DMCA) for each of the H- and M-wave amplitude time series between MG and SOL to assess the existence of a common noise input contributing to these long-range correlations. The cross-correlation coefficient ρDMCA (−1 to 1) was calculated to quantify the strength of the correlation between two different time series. The results indicated a significant long-range power-law correlation between H-wave amplitudes in MG and SOL (ρDMCA: 0.50 (0.22) and 0.22 (0.17), mean (standard deviation) for the original and randomly shuffled surrogate data, respectively, P < 0.05). This was not the case for M-wave amplitudes (ρDMCA: 0.29 (0.23) and 0.20 (0.15), P > 0.05). We conclude that there is a common noise input governing these synergistic muscles, possibly due to supraspinal origin, causing long-range power-law correlations in monosynaptic reflexes.