The purpose of this study was to evaluate the anatomical relationships of hamstring tendons to adjacent structures, especially to the saphenous nerve, and to measure the length of the semitendinosus and gracilis tendons in order to determine whether they are of sufficient length to make multiple stranded grafts. Twenty-eight fresh frozen knees(mean ages: 67.9 years) were dissected. The tendons of the sartorius, gracilis, and semitendinosus were exposed. The lengths of the semitendinosus and the gracilis, the widths of the fused portion of each tendon were measured. Also we checked the bifurcation point, the presence of the accessory insertion, cross point of saphenous nerve. The average lengths of the semitendinosus and the gracilis tendons were 32.32+/-2.88cm (mean+/-SI) and 23.14+/-2.79cm, respectively. The upper border of the gracilis tendon was located an average of 1.53cm from the prominence of the tibial tuberosity. The tendons of the gracilis and semitendinosus fused average of 3.66cm from their insertion and firmly adherent to sartorius tendon. The width of conjoined tendon was 2.94cm. The average distance between the saphenous nerve at its cross-over point and the tibial tuberosity was 9.71cm. Several key anatomic points are useful in the harvest of these tendons. Their conjoined insertion site is medial and distal to the tibial tubercle. They become distinct structures at a point that is further medial and slightly proximal. Tendon harvest is facillitated by identifying the tendons proximal to this point. The superficial medial collateral ligament lies deep to the tendons in this area and should not be disturbed. The accessory insertion of the semitendinosus tendon should be identified and transected to avoid tendon damage at harvest. Knee flexion may reduce the risk of injury to the saphenous nerve as it crosses the gracilis tendon. These results should be helpful to surgeon considering using the hamstring tendons as for ligament reconstruction of the knee.
Collateral Ligaments ; Knee ; Ligaments ; Tendons* ; Transplants

Objective: The incidence of pulmonary embolism (PE) and leg deep vein thrombosis (DVT) has increased in recent years in association with aging and an increase in the number of bedridden individuals. We developed an active in-bed leg exercise apparatus labeled the Leg Exercise Apparatus (LEX) for DVT prevention. We compared the effect of leg exercises performed using the LEX to conventional active ankle exercises on increased blood flow.
Materials & Methods: The subjects were eight healthy adult volunteers [five men and three women, aged 20–34 (mean 27.0) years]. Subjects performed two types of exercise; exercise 1 consisted of leg exercises using the LEX, while exercise 2 consisted of in-bed active plantar flexion/dorsiflexion exercises without the device. Measurements were taken 1, 5, 10, 20, and 30 minutes after exercise including common femoral vein blood flow, mean blood flow velocity, maximum blood flow velocity, and vessel diameter using Doppler ultrasound. Statistical procedures included timed measurement data analysis using a linear mixed model. A Bonferroni correction was used for multiple comparisons.
Results: Compared to resting levels, blood flow reached a maximum value 1 minute after exercise for both exercise types, with a significantly greater increase after exercise 1 (1.76-fold increase) compared to exercise 2 (1.44-fold increase) (p = 0.005). There was a significant difference (p = 0.03) between the two exercises for all values from 1 minute to 30 minutes following exercise. There was no significant difference between exercises for peak or mean blood flow velocity. Compared to resting levels, blood vessel diameter reached a maximum value of 1.47-fold greater at 5 minutes post-exercise for exercise 1 and a maximum value of 1.21-fold greater at 1 minute post-exercise for exercise 2.
Conclusions: Exercise using the LEX increased lower leg venous blood flow and vessel diameter. We propose that the LEX may serve as a new DVT prevention tool.

STUDY DESIGN: Retrospective, radiological study. PURPOSE: To determine the relationship between clinical symptoms and the extent of tumor occupation of the spinal canal by cauda equina schwannoma. OVERVIEW OF LITERATURE: Little is known about the relationship between the size of tumors of the cauda equina and the manifestation of clinical symptoms. We analyzed this relationship by estimating the percentage of tumor occupation (PTO) in the spinal canal in cauda equina schwannomas and by correlating this parameter with the presence and severity of clinical symptoms. METHODS: Twenty-two patients (9 men and 13 women; age, 19–79 years; mean age, 55.3 years) who were radiologically diagnosed with schwannomas of the cauda equina between April 2004 and July 2014 were retrospectively analyzed. PTO was measured in axial and sagittal magnetic resonance imaging slices in which the cross-sectional area of the tumor was the largest. Data regarding clinical symptoms and results of physical examinations were collected from patient medical records. PTO differences between symptom-positive and -negative groups were analyzed for each variable. RESULTS: In the 4 cases in which tumor presence was not related to clinical symptoms, PTO was 5%–10% (mean, 9%) in axial slices and 23%–31% (mean, 30%) in sagittal slices. In the 18 cases in which symptoms were associated with the tumor, PTO was 11%–86% (mean, 50%) in axial slices and 43%–88% (mean, 71%) in sagittal slices. PTO in axial slices was significantly higher in the presence of Déjèrine symptoms and/or muscle weakness, a positive straight leg raise test, and a positive Kemp sign. CONCLUSIONS: PTO >20% in axial slices and >40% in sagittal slices can be an indication of symptomatic cauda equina schwannoma.
Cauda Equina* ; Female ; Humans ; Leg ; Magnetic Resonance Imaging ; Male ; Medical Records ; Muscle Weakness ; Neurilemmoma* ; Occupations* ; Physical Examination ; Retrospective Studies ; Spinal Canal*

STUDY DESIGN: Prospective experimental study on humans. PURPOSE: To determine whether postural differences during a low-speed impact are observed in the sagittal and axial views, particularly in a relaxed state. OVERVIEW OF LITERATURE:: Three-dimensional motion capture systems have been used to analyze posture and head-neck-torso kinematics in humans during a simulated low-speed impact, yet little research has focused on the axial view. Since a seatbelt asymmetrically stabilizes a drivers right shoulder and left lower waist into the seat, it potentially creates movement in the axial view. METHODS: Three healthy adult men participated in the experimental series, which used a low-speed sled system. The acceleration pulse created a full sine shape with a maximum acceleration of 8.0 m/s2 at 500 ms, during which the kinematics were evaluated in relaxed and tensed states. The three-dimensional motion capture system used eight markers to record and analyze body movement and head-neck-torso kinematics in the sagittal and axial views during the low-speed impact. Head and trunk rotation angles were also calculated. RESULTS: Larger movements were observed in the relaxed than in the tensed state in the sagittal view. The cervical and thoracic spine flexed and extended, respectively, in the relaxed state. In the axial view, larger movements were also observed in the relaxed state than in the tensed state, and the left shoulder rotated. CONCLUSIONS: During simulated frontal impact, the rotation angle between the head and trunk was significantly larger in the relaxed state. Therefore, we recommend also observing movement in the axial view during impact tests.
Acceleration ; Adult ; Biomechanical Phenomena* ; Head ; Humans ; Imaging, Three-Dimensional ; Male ; Posture ; Prospective Studies ; Shoulder ; Spine* ; Transcutaneous Electric Nerve Stimulation*