scholarly journals A NEW PARADIGM FOR THE IN VITRO SIMULATION OF SIDEWAYS FALL LOADING OF THE PROXIMAL HUMAN FEMUR

2014 ◽  
Vol 14 (01) ◽  
pp. 1450005 ◽  
Author(s):  
LORENZO ZANI ◽  
LUCA CRISTOFOLINI ◽  
MATEUSZ MARIA JUSZCZYK ◽  
LORENZO GRASSI ◽  
MARCO VICECONTI
Keyword(s):  
Femoral Head ◽  
Internal Rotation ◽  
Proximal Femur ◽  
High Speed ◽  
External Rotation ◽  
Frontal Plane ◽  
New Paradigm ◽  
Human Femur ◽  
Sideways Fall

Although the direction of loads applied to the proximal human femur is unpredictable during sideways fall, most in vitro and numerical simulations refer to a single loading condition (15° internal rotation; 10° adduction), which has been anecdotally suggested in the 1950s. The aim of the present study was to improve in vitro simulations of sideways falls on the proximal femur. An in vitro setup was developed that allowed exploring a range of loading directions +/-90° internal–external rotation; 0°–50° adduction). To enable accurate control of the loading conditions (direction and magnitude of all load components applied to the femur), the setup included a number of low-friction linear and rotary bearings. The setup was instrumented with an axial and a torsional load cell, three displacement transducers and a rotation transducer to monitor the most significant components of load/displacement during testing. The strain distribution was measured on the bone surface (16 triaxial strain gauges, 2,000 Hz). Fracture was recorded with a high-speed camera. The setup was successfully tested on a cadaveric femur non-destructively (12 loading configurations) and destructively (15° internal rotation; 10° adduction). All measurements were highly repeatable (the displacements of the femoral head varied by < 2% between repetitions; the tilt in the frontal plane by < 0.05°; and strain varied on average 0.34% between repetitions). The displacement of the femoral head varied by over 50% when the same force was applied in different directions. Principal strains at the same location varied by over 70%, depending on the direction of the applied force. The high-speed video enabled the identification of the point of fracture initiation. This study has shown that a new paradigm for testing the proximal femur (including improved testing conditions and a variety of loading configurations) can provide more accurate and more extensive information about the state of strain.

scholarly journals EVALUATION OF THE RANGE OF MOTION OF A HIP ARTHROPLASTY SYSTEM: A COMPUTER SIMULATION STUDY

2021 ◽  
Vol 29 (5) ◽  
pp. 246-248
Author(s):  
GUILHERME GUADAGNINI FALOTICO ◽  
VALÉRIA ROMERO ◽  
RICARDO BASILE ◽  
EDMILSON TAKEHIRO TAKATA
Keyword(s):  
Femoral Head ◽  
Range Of Motion ◽  
Hip Arthroplasty ◽  
External Rotation ◽  
Angular Displacement ◽  
Computational Method ◽  
Technical Standards ◽  
Level Of Evidence ◽  
Mean Values

ABSTRACT Objective: To date, the literature lacks consensus on the most efficient method to measure the range of motion of an in vitro prosthetic system. In this study, we propose the use of a relatively low-cost online software to measure the range of motion of hip prosthetic implants manufactured in Brazil and compare its results with the current technical standards for hip arthroplasty. Methods: Three different diameters of femoral heads were evaluated (28 mm, 32 mm, and 36 mm). The mean values of the angular displacement of the prosthesis in each motion axis were obtained by computer simulations. Results: The range of motion with each femoral head was 28mm (extension/flexion: 148°, internal/external rotation: 179°, adduction/abduction: 107°), 32 mm (152°/185°/114°), and 36 mm (158°/193°/120°). Conclusion: The computational method showed that the larger the femoral head, the greater the range of motion of the hip joint prosthetic system. Additional clinical studies are necessary to compare the physical results obtained with the values found in this study by computational modeling. Level of evidence V, Experimental study.

scholarly journals Strain distribution in the proximal Human femur during in vitro simulated sideways fall

2015 ◽  
Vol 48 (10) ◽  
pp. 2130-2143 ◽  
Author(s):  
Lorenzo Zani ◽  
Paolo Erani ◽  
Lorenzo Grassi ◽  
Fulvia Taddei ◽  
Luca Cristofolini
Keyword(s):  
Strain Distribution ◽  
Human Femur ◽  
Sideways Fall

Rotator Cuff Training for Pitchers

1998 ◽  
Vol 7 (4) ◽  
pp. 285-299 ◽  
Author(s):  
Michael E. Powers
Keyword(s):  
Rotator Cuff ◽  
Internal Rotation ◽  
High Speed ◽  
External Rotation ◽  
Shoulder Abduction ◽  
Muscular Endurance ◽  
Shoulder Injuries ◽  
Three Stages ◽  
Two Stages

This paper reviews the role of the rotator cuff during two key phases of the pitching sequence and presents a training program for these muscles. The program uses a periodization design consisting of three stages, beginning with a high-resistance/low-repetition eccentric strengthening stage. This is followed by a low-resistance/high-repetition stage for training muscular endurance. The core exercises for these two stages are prone external rotation in the 90/90 position, prone horizontal abduction, side-lying D2 flexion pattern, supine internal rotation in the 90/90 position, prone elevation with 100° of shoulder abduction and external rotation, and standing scapular plane elevation. The final stage of the program uses high-speed functional exercises: 90/90 external rotation, 90/90 internal rotation, D2 PNF flexion pattern, D2 PNF extension pattern, supine plyometric 90/90 internal rotation with a medicine ball, and the “arm whip” through the D2 PNF flexion pattern. The goal of this program is to prepare the muscles for the stresses of pitching and prevent shoulder injuries.

The Effect of Femoral Malrotation in Offset Templating for Total Hip Arthroplasty: A Cadaveric Study and Curvilinear Analysis

2021 ◽  
Author(s):  
H. Del Schutte ◽  
Sergio M. Navarro ◽  
Hashim Shaikh ◽  
William R. Barfield ◽  
Jeffrey Conrad ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Internal Rotation ◽  
Hip Arthroplasty ◽  
Proximal Femur ◽  
External Rotation ◽  
Femoral Rotation ◽  
Level Of Evidence ◽  
Total Hip ◽  
Femoral Malrotation ◽  
Cadaveric Model

AbstractTechniques allow assessment of preoperative offset in hip arthroplasty. This study assessed femoral rotation in preoperative offset templating using a cadaveric model. Ten femurs were imaged at degrees of rotation. Offset was measured. A generalizable equation predicting change in offset was derived with a curvilinear model. Statistically significant differences at rotational positions were found. For 30 degrees of internal rotation, 2.1 mm change in adjusted mean offset existed; for 30 degrees of external rotation, 8.4 mm change existed. Improved awareness of malrotation of the proximal femur and templating adjustments may improve total hip arthroplasty outcomes. This study reflects level of evidence III.

Lower extremity static and dynamic relationships with rearfoot motion in gait

1994 ◽  
Vol 84 (4) ◽  
pp. 171-180 ◽  
Author(s):  
KM Knutzen ◽  
A Price
Keyword(s):  
Lower Extremity ◽  
Internal Rotation ◽  
High Speed ◽  
Frontal Plane ◽  
Regression Equations ◽  
High Speed Cinematography ◽  
Foot Strike ◽  
Dynamic Relationships ◽  
Rearfoot Motion ◽  
Hip Internal Rotation

Twenty nonsymptomatic subjects were assessed while walking at a photoelectronically monitored place (2 +/- 0.1 m.s-1) using high speed cinematography (200 Hz) to record the rearfoot motion in the frontal plane, and electrogoniometry (100 Hz) to measure joint kinematics in the lower extremity. The foot type of the subjects was determined statically by using a podiascope and digitization techniques. The results demonstrated that no foot type variables contributed significantly to the variance in either rearfoot angle at foot strike or maximum rearfoot angle (p &gt; 0.05). Regression equations were developed using kinematic variables: rearfoot angle at foot strike = 3.81 + (0.06*time to hip internal rotation) - (0.46*tibia internal rotation) + (0.14*plantarflexion); (R = 0.87, SE = 1.23 degrees); maximum rearfoot angle = 4.02 + (0.52*hip internal rotation) - (0.11*time to hip internal rotation); (R = 0.66, SE = 2.07 degrees). This study identifies hip joint movements as being the most significant contributors to prediction of rearfoot angles produced during walking.

scholarly journals Thirty patients with one-stage hip arthroplasty and multiple drilling decompression for bilateral osteonecrosis of the femoral head:outcomes at two-year follow up

2019 ◽  
Author(s):  
Lu Ding ◽  
Yu-Hang Gao ◽  
Shi Zhang ◽  
Yi-Fan Huang ◽  
Jian-Guo Liu ◽  
...  
Keyword(s):  
Femoral Head ◽  
Total Hip Arthroplasty ◽  
Internal Rotation ◽  
Hip Arthroplasty ◽  
External Rotation ◽  
Radiographic Evaluation ◽  
Two Stage ◽  
Total Hip ◽  
One Stage ◽  
Significant Difference

Abstract Background: To investigate the postoperative outcome of decompresed hip following contralateral replacement in patients with bilateral osteonecrosis of the femoral head (ONFH). M ethods: This study retrospectively reviewed 30 patients with bilateral ONFH who underwent one-stage total hip arthroplasty (THA) and multiple drilling decompression from February 2014 to February 2016. For all patients, alendronate was prescribed. Postoperative Harris Hip Scores (HHSs), Oxford Hip Scores (OHSs), Self-Administered Patient Satisfaction (SAPS), hip internal and external rotation angles, and the time of one-leg standing were evaluated. All patients were followed up for an average of 30.33 months (ranged from 8 months to 48 months). Results: Twenty-four patients had no progression or collapse on radiographic evaluation within 2 years postoperatively. The following scores of the decompressed sides were significantly lower than those of the replaced sides: HHSs (mean: 96.5 versus 98.25, P <0.05), SAPS (mean: 96.35 versus 99.48, P <0.001), internal rotation (mean: 27.58° versus 30.50°, P <0.05), and the time of single-leg standing (mean: 24.17 s versus 31.83 s, P <0.05). There was no significant difference in OHSs and external rotation between the sides. The remaining 6 patients underwent two-stage THA on the decompressed sides within 2 years. Four of them underwent THA for severe pain and femoral head collapse. The other 2 patients showed no progression on radiographic evaluation but complained of an uncomfortable feeling in the joint. Conclusions: One-stage THA and multiple drilling decompression are effective surgical procedures for bilateral ONFH at different stages. However, a few patients with no progression on radiographic evaluation may require two-stage THA on the decompressed sides because of more pain, poorer internal rotation, and weaker gluteal muscle strength when compared with the replaced sides. Keywords: osteonecrosis of the femoral head, postoperative satisfaction, total hip arthroplasty, multiple drilling decompression

IN-VITRO STRAIN DISTRIBUTION DURING SIDEWAYS FALL IN THE PROXIMAL HUMAN FEMUR

2012 ◽  
Vol 45 ◽  
pp. S351 ◽  
Author(s):  
Lorenzo Zani ◽  
Luca Cristofolini ◽  
Mateusz Juszczyk ◽  
Marco Viceconti
Keyword(s):  
Strain Distribution ◽  
Human Femur ◽  
Sideways Fall

Does Capsular Laxity Lead to Microinstability of the Native Hip?

2018 ◽  
Vol 46 (6) ◽  
pp. 1315-1323 ◽  
Author(s):  
Shuyang Han ◽  
Jerry W. Alexander ◽  
Vijai S. Thomas ◽  
Joshua Choi ◽  
Joshua D. Harris ◽  
...  
Keyword(s):  
Femoral Head ◽  
Internal Rotation ◽  
Clinical Symptoms ◽  
External Rotation ◽  
Rotational Laxity ◽  
Full Extension ◽  
Joint Rotation ◽  
Acetabular Fossa ◽  
Femoral Head Center ◽  
Head Translation

Background: Hip “microinstability” is commonly cited as the cause of symptoms that occur in the presence of translation of the femoral head away from conformity with the acetabular fossa. However, there is still no consistent objective criteria defining its presence and biomechanical basis. One hypothesis is that abnormal motion of the articular surfaces occurs because of capsular laxity, ultimately leading to clinical symptoms. Purpose: To determine the relationship between capsular laxity and abnormal rotation and translation of the hip. Study Design: Controlled laboratory study. Methods: Eight cadaveric hips were dissected down to the capsule and mounted in a customized multiaxial hip activity simulator. Each specimen was loaded with 5 N·m of internal and external rotational torque in full extension and 0°, 30°, 60°, and 90° of flexion. During testing, the relative position and rotation of the femur and the pelvis were monitored in real time with a 6-camera motion analysis system. The testing was repeated after capsular laxity was generated by placing a regular array of incisions (“pie crusting”) in the iliofemoral, pubofemoral, and ischiofemoral ligaments. Joint rotation and femoral head translation were calculated with specimen-specific models. A hip microinstability index was defined as the ratio between the length of the locus of the femoral head center and the radius of the femoral head during rotation from extension to 90° of flexion. Results: In intact hips, the components of femoral head translation were within 0.5 mm in positions close to neutral (<30° of flexion). Capsular modification led to significant increases in internal and external rotation ( P < .01) and in the translation of the femoral head center at different positions ( P < .05). Compared with intact hips, the femoral head was inferiorly displaced during external rotation and anteroinferiorly during internal rotation. The length of the locus of the femoral head center increased from 3.61 ± 1.30 mm to 5.35 ± 1.83 mm for external rotation ( P < .05) and from 6.24 ± 1.48 mm to 8.21 ± 1.42 mm for internal rotation ( P < .01). The correlations between rotational laxity and the total translation of the femoral head were not significant, with coefficients of 0.093 and 0.006 in external and internal rotation, respectively. In addition, the hip microinstability index increased from 0.40 ± 0.08 for intact hips to 0.55 ± 0.09 for modified hips ( P < .01). Conclusion: The native hip approximates a concentric ball-and-socket joint within 30° of flexion; however, beyond 30° of flexion, the femoral head translation reached as high as 4 mm. Capsular laxity leads to microinstability of the hip, as indicated by significantly increased joint rotations and femoral head translations and an abnormal movement path of the femoral head center. However, there was no correlation between rotational laxity and the increase in femoral head translation. Clinical Relevance: Capsular laxity alters normal kinematics (joint rotation and femoral head translation) of the hip, potentially leading to abnormal femoral-acetabular contact and joint degeneration.

scholarly journals The Bipolar Hip: Combined Acetabular and Femoral Pathomorphology Determine Hip Motion

2019 ◽  
Vol 7 (7_suppl5) ◽  
pp. 2325967119S0042
Author(s):  
Jessica Shin ◽  
Temitope F. Adeyemi ◽  
Taylor Hobson ◽  
Christopher L. Peters ◽  
Travis G. Maak
Keyword(s):  
Logistic Regression ◽  
Femoral Head ◽  
Internal Rotation ◽  
External Rotation ◽  
Alpha Angle ◽  
Acetabular Version ◽  
Femoral Version ◽  
Hip Flexion ◽  
Hip Internal Rotation ◽  
Head Neck

Objectives: Prior studies have suggested femoral version may outweigh the effect of cam impingement on hip internal rotation; however, the effects of acetabular morphology were considered. This study investigates the influences of acetabular and femoral morphology on hip range of motion (ROM) in patients with femoroacetabular impingement syndrome (FAIS). Methods: With IRB approval, a retrospective chart review and radiographic analysis was performed of patients presenting with hip pain to the clinic of a single surgeon. Patients were included in the study if their hip pain was thought to be intra-articular in origin, had full physical exam documentation (including bilateral hip evaluations and measurements of passive hip ROM), Tönnis grade ≤ 1, and had full imaging including: AP pelvis, 45⁰ Dunn lateral, and false profile radiographs and a CT scan with 3-D reconstructions of the affected hip. Patients were excluded if they had prior hip surgery, prior hip trauma or other underlying hip pathology. Femoral head/neck angle, femoral version, size and clock-face location of the maximum femoral alpha angle, mid-coronal center edge angle (CEA), mid-sagittal CEA, acetabular version at the 1, 2 and 3 o’clock positions and the McKibbin index were measured on CT scan. Univariable and multivariable logistic regression analyses were performed to determine which measurements correlated with hip ROM. Results: 200 hips from 200 patients were included in the final analysis. Mean age was 31.9 ±10 years, 145 (72%) patients were female, and mean BMI of the cohort was 25.2 ± 5. Univariable logistic regression analysis found femoral head/neck angle, mid-sagittal CEA, acetabular version at 1 and 2 o’clock, and McKibbin Index all significantly correlated with hip flexion (all q’s > 0.05 after adjusting for false discovery rate). Femoral head-neck angle, femoral version, and McKibbin index all significantly correlated with external rotation. Femoral neck version, mid-sagittal CEA, acetabular version at all three clock positions, McKibbin index, max femoral alpha angle, and alpha position all significantly correlated with internal rotation. In the multivariate logistic regression analysis mid-sagittal CEA was the only measurement correlating with flexion, femoral head/neck angle and McKibbin index were the only significant variables correlating with external rotation, and McKibbin index and maximum femoral alpha angle were the only variables correlating with internal rotation. The results of the logistic regressions are summarized in Figure 1. Conclusion: Our univariate data supported previous data that suggested femoral version significantly correlated with hip internal rotation. However, multivariate analysis including acetabular version demonstrated that combined acetabular and femoral version significantly correlated with internal and external rotation while femoral version in isolation did not. In contrast to prior studies, an increased cam deformity, as defined by max femoral alpha angle, remained a significant contributor to reduced internal rotation but did not affect hip flexion. Rather, the increased mid-sagittal CEA remained the sole significant contributor to reduced hip flexion in the multivariable analysis. These data suggest that hip ROM is affected in a bipolar fashion and careful multiplanar evaluation of the femoral and acetabular pathomorpohlogy should be conducted prior to attempting to increase hip ROM with corrective osteoplasty or osteotomy. [Figure: see text]

Ankle Instability: In Vitro Kinematics in Response to Axial Load

1994 ◽  
Vol 15 (3) ◽  
pp. 134-140 ◽  
Author(s):  
Joseph R. Cass ◽  
Harry Settles
Keyword(s):  
Internal Rotation ◽  
Axial Load ◽  
Ankle Instability ◽  
External Rotation ◽  
Axial Rotation ◽  
Intact Specimen ◽  
Articular Surfaces ◽  
The Subject ◽  
Talar Tilt

This study was undertaken to elucidate the kinematics of hindfoot instability. An axial load was applied to the inverted hindfoot. Unlike prior studies, axial rotation was not constrained. Using computerized tomography, measurements were made on the axial views of external or internal rotation of the leg, talus, and calcaneus. On the coronal views, tilting of the talus at the ankle and subtalar joints was assessed. No tilting of the talus in the mortise occurred with isolated release of the anterior talofibular (ATF) or calcaneofibular (CF) ligament. In every specimen, talar tilt occurred only after both ligaments were released, averaging 20.6°. External rotation of the leg occurred with inversion averaging 11.1° in the intact specimen. The leg averaged a further external rotation of 4.9° after ATF release and 12.8° further than the intact inverted specimens when both ligaments (ATF-CF) had been released. In earlier reports on the subject, the articular surfaces were believed to be the main constraint against tilting of the talus. In those studies, either axial rotation was constrained while inversion was allowed, or vice versa. Based on the data reported here, the ATF and the CF work in tandem to prevent tilting of the talus, and the articular surfaces do not seem to prevent tilting of the talus in the mortise.

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