Fibulocalcaneal Impingement in a Growing Child With Otherwise Asymptomatic Talocalcaneal Coalition.

Subfibular impingement has been described in patients with flatfoot. It possibly occurs with valgus deformity associated with talocalcaneal coalition. We observed symptomatic unilateral fibular impingement initially on the left foot of an 11-year-old female with an otherwise asymptomatic bilateral talocalcaneal coalition.

The Thrust Plate Hip Prosthesis: A Follow-Up of 15-20 Years With 102 Implants.

Background: Between November 1992 and January 1999, a cohort of 102 thrust plate hip prostheses was implanted.

Methods: We now clinically and radiologically evaluate the remaining 73 prostheses with a mean follow-up of 17.2 years.

The endlock tumor prosthesis with short-length fixation: a clinical study.

Anchorage of segmental replacement prostheses in diaphyseal bone remains a challenge in lower limb reconstructions. We developed and studied a new prosthesis design that features an intramedullary anchorage system for which finite element analysis predicted favorable bone remodeling. We retrospectively analyzed the cases of all patients who underwent implantation of the new stem.

Evolution of open-wedge high-tibial osteotomy: experience with a special angular stable device for internal fixation without interposition material.

Surgical correction of bowed legs should be performed as early as possible. Overload osteoarthritis, even without significant varus deformity of the knee, is a further indication for open-wedge high-tibial osteotomy. Progression of damage to the joint surfaces due to overloading can be significantly retarded by realigning the extremity with the aim to, at least, reduce overload on the medial compartment to a value close to physiological.

Changes in shoulder muscle function with humeral position: a graphical description.

A graphical description of the change in the role played by each of the scapulohumeral muscles with respect to spatial joint position is presented. Moment arms were collected from a biomechanical model using the tendon travel method. Data cover elevation and flexion in a space between the frontal plane and a plane of elevation 60 degrees anterior to this.

The contralateral foot in children with unilateral clubfoot: a study of pressures and forces involved in gait.

The unaffected contralateral side of patients with unilateral clubfeet has sometimes been taken as control in foot pressure measurement studies. However, it has never been shown that the pressure pattern under the contralateral foot is similar to a normal foot. Sixteen patients with unilateral clubfoot and 110 normal subjects took part in this study.

The biomechanical role of the subscapularis in latissimus dorsi transfer for the treatment of irreparable rotator cuff tears.

Inferior functional results of latissimus tendon transfer for the treatment of irreparable rotator cuff tears have been reported in the presence of a subscapularis tendon tear. A biomechanical or experimental explanation for the necessity of an intact subscapularis is unavailable. It was, therefore, the purpose of this investigation to study the biomechanical role of the subscapularis in the treatment of a posterosuperior rotator cuff tear with latissimus dorsi transfer.

Effects of glenoid component version on humeral head displacement and joint reaction forces: an experimental study.

The purpose of this study was to determine whether changes in glenoid version are associated with humeral head displacement and changes in the joint reaction forces, as these might contribute to instability or loosening in total shoulder replacement. A total shoulder prosthesis was implanted in neutral version in 6 cadaveric shoulders. Glenoid version was then changed in steps of 4 degrees toward more anteversion and retroversion.

Forces involved in lower limb lengthening: an in vivo biomechanical study.

Despite improvements in surgical techniques for limb-lengthening procedures, the complication rate remains high. Bone fixators must cope with the forces involved during treatment, providing sufficient strength to maintain integrity of the limb in the course of lengthening, while permitting some "micromotion" across the bone gap that could enhance healing during the final phase of bone consolidation. This study reports on the forces generated during limb lengthening in the distraction and consolidation phases.

Moment arms of forearm rotators.

Background: Rotation about a longitudinal axis of the forearm has been a matter of investigation for over 100 years. However, most studies were limited to only a few muscles and to their action in specific set positions of elbow and forearm rotation. This investigation aims at determining the moment arms of muscles that contribute to pronation and supination at three different angles of elbow flexion throughout the entire range of forearm rotation.

An algorithm for estimation of shoulder muscle forces for clinical use.

Background: The shoulder joint represents an indeterminate mechanical system, making it difficult to predict individual muscle forces required to equilibrate a given arbitrary external force. Although considerable work has been published on this matter, no model exhibits the adaptability required for the analysis involving different positions of the humerus and for any external load. An algorithm involving decision-making loops is developed to predict forces exerted by muscles that cross the shoulder joint in equilibrating a given external force acting in an arbitrary direction, with the humerus in any one of 12 selected positions.

Radiological findings and clinical results of 102 thrust-plate femoral hip prostheses: a follow-up of 2 to 8 years.

We report the radiological and clinical outcome of 102 consecutive femoral hip arthroplasty we prospectively followed up in 84 patients using the third generation of the thrust-plate prosthesis with a mean period of follow-up of 58 (range, 26-100) months. Four implants were revised: 2 because of an infection and 2 because of aseptic loosening. The thrust-plate prosthesis, which allows preservation of part of the femoral neck, was used in younger patients, 80% were younger than 60 years.

In vitro comparison of standard and Knotless metal suture anchors.

Purpose: Clinical experience after failed Knotless suture anchor (Mitek, Westwood, MA) fixations suggested that the Knotless anchor provides considerably less fixation stability than a standard metal anchor. The purpose of this study was to analyze soft tissue fixation to bone comparing a standard and a Knotless metal suture anchor.

Type Of Study: In vitro study.

Coronoid process and radial head as posterolateral rotatory stabilizers of the elbow.

Background: The purpose of this study was to evaluate the role of the radial head and the coronoid process as posterolateral rotatory stabilizers of the elbow and to determine the stabilizing effect of radial head replacement and coronoid reconstruction.

Methods: The posterolateral rotatory displacement of the ulna was measured after application of a valgus and supinating torque (1). in seven intact elbows, (2).

Influence of humeral prosthesis height on biomechanics of glenohumeral abduction. An in vitro study.

Background: During shoulder replacement surgery, the normal height of the proximal part of the humerus relative to the tuberosities frequently is not restored because of differences in prosthetic geometry or problems with surgical technique. The purpose of the present study was to determine the effect of humeral prosthesis height on range of motion and on the moment arms of the rotator cuff muscles during glenohumeral abduction.

Methods: Tendon excursions and abduction angles were recorded simultaneously in six cadaveric specimens during passive glenohumeral abduction in the scapular plane.

The effect of capsular tightening on humeral head translations.

Unlabelled: Idiopathic or surgical tightening of the glenohumeral joint capsule may cause displacement of the humeral head relative to the glenoid fossa and favor the development of instability and/or osteoarthritis. In the present investigation the relative position of the humerus to the glenoid fossa was determined at the end of the ranges of eight different passive movements before and after selective capsular plication in eight cadaveric shoulders to study the effects of selective capsular plications on the kinematics of the shoulder. While the capsule was in its unaltered state, translation of the humeral head was 3.

Fluoroscopically assisted stress radiography for varus-valgus stability assessment in flexion after total knee arthroplasty.

A radiographic technique to quantify varus and valgus joint laxity in flexion after total knee arthroplasty (TKA) was evaluated by means of inter-rater assessment in 12 patients. The test was shown to have good reliability. The simple method helps to detect instability in knee flexion that might be overlooked in a conventional clinical examination.

Mechanical testing of absorbable suture anchors.

Purpose: Absorbable suture anchors offer great advantages but are made of mechanically weak material. The weakest link in the fixation of soft tissue to bone may therefore be the anchor itself. In this study, several commercially available anchors were mechanically tested in vitro.

Mechanical strength of arthroscopic rotator cuff repair techniques: an in vitro study.

Background: Retears after rotator cuff repairs occur relatively frequently and may compromise the functional result. The goal of this study was to analyze the mechanical properties following arthroscopic techniques for rotator cuff repair and to evaluate possible alternative techniques.

Methods: In the first part, five different bone anchors (the Revo screw; Mitek Rotator Cuff anchor, 5.

MR imaging of the forefoot under weight-bearing conditions: position-related changes of the neurovascular bundles and the metatarsal heads in asymptomatic volunteers.

Purpose: To assess practicability of weight-bearing magnetic resonance (MR) imaging of the forefoot, and to demonstrate position-related changes of the neurovascular bundles and the metatarsal heads in asymptomatic volunteers.

Materials And Methods: With an open-configuration MR system, 32 feet of 32 asymptomatic individuals aged 20-60 years were studied in supine and weight-bearing body positions. Transverse T1-weighted spin-echo MR images were performed.

Is impingement the cause of jumper's knee? Dynamic and static magnetic resonance imaging of patellar tendinitis in an open-configuration system.

Background: Chronic overload is considered the main cause of patellar tendinitis, but it has been postulated that impingement of the inferior patellar pole against the patellar tendon during knee flexion could be responsible.

Hypothesis: The role of the patellar pole in patellar tendinitis can be determined by dynamic magnetic resonance imaging.

Study Design: Case-control study.

Avoidance of medial cortical fracture in high tibial osteotomy: improved technique.

A new technique in oblique incomplete high tibial osteotomy that permits an increase of valgus correction while preventing fracture of the medial cortex was investigated. Closing wedge or opening wedge osteotomy was done on 23 tibias from cadavers before loading in an Instron testing machine. In seven specimens (Group 1), lateral oblique wedge osteotomy was done.