What is the best lateral radiograph positioning technique for assessment of sagittal balance: A biomechanical study on influence of different arm positions.

Purpose: To evaluate the influence of different arm postures from the physiological standing position using force plate analysis of the gravity line.

Methods: Forty healthy volunteered university students were enrolled. Each subject assumed different standing positions including standing with arms resting on the side (control), with fist over the clavicle (clavicular position), with active shoulder flexion in 30°, 60° and 90° with elbows extended (active flexion A), with hand rest on a bar with a static support (passive flexion P), and with hand rest on a bar with a drip stand (passive flexion D).

Effect of anticipation on knee kinematics during a stop-jump task.

Knee stability during a functional assessment of the stop-jump task is a key factor to determine if an athlete is adequately rehabilitated after knee ligamentous injury. This study aimed to investigate knee stability due to the effect of anticipation on landing maneuvers during planned and unplanned stop-jump tasks. Knee kinematics of ten healthy male participants were collected using an optical motion analysis system during stop-jump tasks.

Clinical and biomechanical outcome of minimal invasive and open repair of the Achilles tendon.

Introduction: With evolutions in surgical techniques, minimally invasive surgical (MIS) repair with Achillon applicator has been introduced. However, there is still a lack of literature to investigate into the clinical merits of MIS over open surgery. This study aims to investigate the correlation between clinical outcome, gait analysis and biomechanical properties comparing both surgical methods.

Knee rotational stability during pivoting movement is restored after anatomic double-bundle anterior cruciate ligament reconstruction.

Background: The restoration of knee rotational stability after anatomic double-bundle anterior cruciate ligament (ACL) reconstruction has been demonstrated in the cadaveric model and with passive stress tests on humans but not yet with dynamic functional biomechanical tests performed by human participants.

Purpose: To prospectively investigate the range of tibial rotation of ACL-deficient and ACL-reconstructed knees during a pivoting task. The authors hypothesized that there would be a significant increase in tibial internal rotation in the ACL-deficient knee compared with the contralateral knee and that the increased rotation would return to normal after anatomic double-bundle ACL reconstruction.

Rare ligamentum flavum cyst causing incapacitating lumbar spinal stenosis: Experience with 3 Chinese patients.

Three Chinese patients suffered from severe lumbar spinal stenosis with debilitating symptoms due to a rare condition of ligamentum flavum cysts in the midline of the lumbar spine. This disease is distinct from synovial cyst of the facet joints or ganglion cysts, both intraoperatively and histopathologically. Magnetic Resonance imaging features of the ligamentum flavum cyst are also demonstrated.

Differentiation of ankle sprain motion and common sporting motion by ankle inversion velocity.

This study investigated the ankle inversion and inversion velocity between various common motions in sports and simulated sprain motion, in order to provide a threshold for ankle sprain risk identification. The experiment was composed of two parts: firstly, ten male subjects wore a pair of sport shoes and performed ten trials of running, cutting, jump-landing and stepping-down motions. Secondly, five subjects performed five trials of simulated sprain motion by a supination sprain simulator.

Treatment of an osteoporotic Hoffa fracture.

Two patients with Hoffa fracture of the knee, both suffering from poliomyelitis are reported. Both had unicondylar coronal plane fracture of the medial femoral condyle. The patients were treated with open reduction and screw fixation.

The use of average Pavlov ratio to predict the risk of post operative upper limb palsy after posterior cervical decompression.

Study Design: A retrospective study was conducted to study the post operative upper limb palsy after laminoplasty for cervical myelopathy.

Objective: To identify a reliable and simple preoperative radiological parameter in predicting the risk of post operative upper limb palsy.

Background: Post operative upper limb palsy is one of the causes of patient dissatisfaction after surgery.

Review of knee arthroscopy performed under local anesthesia.

Local anesthesia for knee arthroscopy is a well documented procedure with diagnostic and therapeutic role. Numerous therapeutic procedures including partial menisectomy, meniscus repair, abrasion chondroplasy, synovectomy, loose body removal can be performed safely and comfortably. Appropriate case selection, anesthetic strategy and technical expertise are the key to smooth and successful surgery.

Arthroscopic repair of isolated type II superior labrum anterior-posterior lesion.

The effectiveness of arthroscopic repair of type II superior labrum anterior-posterior lesion (SLAP) was unclear as previous studies examined this treatment with patients of combined types of SLAP lesions. To address this research gap, we evaluated the clinical and functional outcomes of arthroscopic repair for 16 patients (mean=24.2, SD=6.

A mechanical supination sprain simulator for studying ankle supination sprain kinematics.

This study presents a free-fall mechanical supination sprain simulator for evaluating the ankle joint kinematics during a simulated ankle supination sprain injury. The device allows the foot to be in an anatomical position before the sudden motion, and also allows different degrees of supination, or a combination of inversion and plantarflexion. Five subjects performed simulated supination sprain trials in five different supination angles.

A three-pressure-sensor (3PS) system for monitoring ankle supination torque during sport motions.

This study presented a three-pressure-sensor (3PS) system for monitoring ankle supination torque during sport motions. Five male subjects wore a pair of cloth sport shoes and performed 10 trials of walking, running, cutting, vertical jump-landing and stepping-down motions in a random sequence. A pair of pressure insoles (Novel Pedar model W, Germany) was inserted in the shoes for the measurement of plantar pressure at 100Hz.

Estimating the complete ground reaction forces with pressure insoles in walking.

This study presented a method to estimate the complete ground reaction forces from pressure insoles in walking. Five male subjects performed 10 walking trials in a laboratory. The complete ground reaction forces were collected during a right foot stride by a force plate at 1000Hz.

Effect of medial arch-heel support in inserts on reducing ankle eversion: a biomechanics study.

Background: Excessive pronation (or eversion) at ankle joint in heel-toe running correlated with lower extremity overuse injuries. Orthotics and inserts are often prescribed to limit the pronation range to tackle the problem. Previous studies revealed that the effect is product-specific.

Rapid progression of destructive spondyloarthropathy.

Study Design: A case of destructive spondyloarthropathy was reported.

Objectives: To describe the rapid destruction of intervertebral disc and vertebral body as a consequence of destructive spondyloarthropathy in a patients with end-stage renal disease receiving hemodialysis.

Summary Of Background Data: An important facet of this case is that the serial radiographs provide key information about the rapid nature of dialysis associated destructive spondyloarthropathy, a condition which has been increasingly recognized over the last 2 decades.