Biomechanical evaluation of self-cinching stitch techniques in rotator cuff repair: The single-loop and double-loop knot stitches.

In rotator cuff repair, strong and reliable suturing is necessary to decrease failure rates. The biomechanics of two self-cinching stitches - the single-loop knot stitch (SLKS) and the double-loop knot stitch (DLKS) - and the modified Mason-Allen stitch (mMAS) were compared. Twenty-seven porcine infraspinatus tendons were randomized among the three stitches.

Comparison of the double loop knot stitch and Kessler stitch for Achilles tendon repair: A biomechanical cadaver study.

Tendon elongation after Achilles tendon (AT) repair is associated with the clinical outcome. Reliable suture techniques are essential to reduce gap formations and to allow early mobilization. Cyclic loading conditions represent the repetitive loading in rehabilitation.

Sagittal magnetic resonance imaging-scan orientation significantly influences accuracy of femoral posterior condylar offset measurement.

Background: In total knee arthroplasty the femoral posterior condylar offset (PCO) may serve as a potential branch for correct femoral component positioning. The technique of adjusting the sagittal magnetic resonance imaging (MRI)-scan on which it is measured has not been investigated in previous literature, but may be subject to variances due to knee joint positioning or axial localizer scan angulation. The purpose of this study was to investigate the effect of simulated femur rotation on the accuracy of PCO measurement.

Accuracy of femoral tunnel placement in medial patellofemoral ligament reconstruction: the effect of a nearly true-lateral fluoroscopic view.

Background: Reconstruction of the medial patellofemoral ligament (MPFL) is an established operative procedure for patients with recurrent episodes of lateral patellar instability. However, recent articles have reported remarkable complication rates, with nonanatomic femoral tunnel positioning in up to 64% of patients.

Purpose: To evaluate the sensitivity of femoral tunnel placement using lateral fluoroscopic guidance to minor degrees of deviation from the true-lateral view using established radiographic landmarks.

Characteristics of femorotibial joint geometry in the trochlear dysplastic femur.

The medial and lateral tibia plateau geometry has been linked with the severity of trochlear dysplasia. The aim of the present study was to evaluate the tibial slope and the femoral posterior condylar offset in a cohort of consecutive subjects with a trochlear dysplastic femur to investigate whether the condylar offset correlates with, and thus potentially compensates for, tibial slope asymmetry. Magnetic resonance imaging was used to assess the severity of trochlear dysplasia as well as the tibial slope and posterior offset of the femoral condyles separately for the medial and lateral compartment of the knee joint in 98 subjects with a trochlear dysplastic femur and 88 control subjects.

Novel single-loop and double-loop knot stitch in comparison with the modified Mason-Allen stitch for rotator cuff repair.

Purpose: In rotator cuff repair, strong and long-lasting suturing techniques that do not require additional implants are needed. This study examines the ultimate load to failure and the Young's modulus at the suture-tendon interface for a novel single-loop knot stitch and double-loop knot stitch. These values are compared to those of the modified Mason-Allen stitch.

Which patellae are likely to redislocate?

Purpose: The purpose of this study was to identify the risk factors for recurrent lateral patellar dislocations and to incorporate those factors into a patellar instability severity score.

Methods: Sixty-one patients [male/female 35/26; median age 19 years (range 9-51 years)] formed the study group for this investigation. Within the study group, 40 patients experienced a patellar redislocation within 24 months after the primary dislocation, whereas 21 patients, who were assessed after a median follow-up of 37 months (range 24-60 months), had not experienced a subsequent episode of lateral patellar instability.

Radiologically hyperdense zones of the patella seem to be partial osteonecroses subsequent to fracture treatment.

The blood supply to the proximal patella is provided primarily via intraosseous vessels from the inferior patella. Two vascular systems within the patella are distinguished: Tiny arteries penetrate the middle third of the anterior patellar surface via vascular foramina and continue in a proximal direction. Additional vessels enter the patella at its distal pole, between the patellar ligament and the articular surface, and also run proximally.

Influence of tibial slope asymmetry on femoral rotation in patients with lateral patellar instability.

Purpose: The geometry of the tibial plateau and its influence on the biomechanics of the tibiofemoral joint has gained increased significance. However, no quantitative data are available regarding the inclination of the medial and lateral tibial slope in patients with patellar instability. It was therefore the purpose of this study to evaluate tibial slope characteristics in patients with patellar dislocations and to assess the biomechanical effect of medial-to-lateral tibial slope asymmetry on lateral patellar instability.

Bioabsorbable interference screw versus bioabsorbable cross pins: influence of femoral graft fixation on the clinical outcome after ACL reconstruction.

Purpose: The aim of this study was to evaluate the clinical outcome and differences in anterior–posterior laxity of ACL reconstruction using a bioabsorbable interference screw for femoral graft fixation when compared to femoral bioabsorbable cross pin fixation.

Methods: Clinical outcome was evaluated among 59 patients 1 year after arthroscopic ACL reconstruction with hamstrings graft in a prospective, non-randomised study. In 31 cases, femoral fixation of the graft was performed using a bioabsorbable interference screw.

Construction-conditioned rollback in total knee replacement: fluoroscopic results.

Firstly, the way of implementing approximatively the initial rollback of the natural tibiofemoral joint (TFJ) in a total knee replacement (AEQUOS G1 TKR) is discussed. By configuration of the curvatures of the medial and lateral articulating surfaces a cam gear mechanism with positive drive can be installed, which works under force closure of the femoral and tibial surfaces. Briefly the geometric design features in flexion/extension are described and construction-conditioned kinematical and functional properties that arise are discussed.

MRI but not arthroscopy accurately diagnoses femoral MPFL injury in first-time patellar dislocations.

Purpose: The purpose of this study was to investigate whether the femoral part of the medial patellofemoral ligament (MPFL) and its injury can be accurately assessed by standard knee arthroscopy in first-time patellar dislocations or whether preoperative MRI is required to determine injury location in patients where primary MPFL repair is attempted.

Methods: Twelve patients with acute first-time dislocations and MRI-based injury of the femoral MPFL and ten patients with recurrent patellar dislocations underwent knee arthroscopy with the use of a 30-degree optic and standard antero-medial and antero-lateral portals. The femoral origin was marked with a cannula under lateral fluoroscopy.

Total knee replacement with natural rollback.

A novel class of total knee replacement (AEQUOS G1) is introduced which features a unique design of the articular surfaces. Based on the anatomy of the human knee and differing from all other prostheses, the lateral tibial "plateau" is convexly curved and the lateral femoral condyle is posteriorly shifted in relation to the medial femoral condyle. Under compressive forces the configuration of the articular surfaces of human knees constrains the relative motion of femur and tibia in flexion/extension.

Anatomy of lateral patellar instability: trochlear dysplasia and tibial tubercle-trochlear groove distance is more pronounced in women who dislocate the patella.

Background: A trend toward young women being at greatest risk for primary and recurrent dislocation of the patella is evident in the current literature. However, a causative factor is missing, and differences in the anatomical risk factors between men and women are less defined.

Purpose: To identify differences between the sexes in the anatomy of lateral patellar instability.

Patellar dislocations in children, adolescents and adults: a comparative MRI study of medial patellofemoral ligament injury patterns and trochlear groove anatomy.

Purpose: The first aim was to compare medial patellofemoral ligament injury patterns in children and adolescents after first-time lateral patellar dislocations with the injury patterns in adults. The second aim was to evaluate the trochlear groove anatomy at different developmental stages of the growing knee joint.

Materials And Methods: Knee magnetic resonance (MR) images were collected from 22 patients after first-time patellar dislocations.

Early results and patient satisfaction after total hip arthroplasty using a minimally invasive anterolateral approach.

Rehabilitation and patient satisfaction following a modified anterolateral approach for implantation of a total hip replacement (THR) were reviewed following 72 consecutive cases. The Harris Hip and Merle d'Aubigné Scores were recorded at 6 and 12 weeks postoperatively. The patient's satisfaction with regard to the surgical result and the need for analgesia for mobilization were recorded.

Myoclonus-induced bilateral acetabular fracture dislocations.

An uncommon case of myoclonus-induced bilateral central acetabular fracture-dislocation is presented. Although different fracture types due to forceful muscular contractions have been reported, this is an exceedingly uncommon injury pattern. Bilateral total hip arthroplasty, in combination with a reinforcement ring and autologous bone grafting, was performed after open reduction and internal fixation.

Closed reduction and percutaneous Kirschner wire fixation for the treatment of dislocated calcaneal fractures: surgical technique, complications, clinical and radiological results after 2-10 years.

Introduction: To reduce complications, a minimally invasive technique for the treatment of dislocated intraarticular fractures of the calcaneus was used. Therefore previously described closed reduction and internal fixation techniques were combined and modified.

Materials And Methods: Sixty-seven out of 92 calcaneal fractures could be retrospectively evaluated with an average follow-up time of 5.

Minimally invasive orthopedic surgery: first results in navigated total hip arthroplasty.

Minimally invasive hip approaches decrease soft tissue damage but reduce the view of the operating field. The combination of minimally invasive approaches with navigation techniques can resolve this conflict. A modified anterolateral approach was used for minimally invasive implantation of hip endoprostheses, in combination with a navigation technique.

Process optimization in navigated total knee arthroplasty.

Although navigation achieves better alignment results in total knee arthroplasty (TKA), it is generally assumed that navigation also needs more time and effort than conventional surgeries. After optimizing the treatment procedure of navigated TKA, the operation times needed for navigated surgeries were documented and compared with the average time of conventional surgeries, registered before the introduction of the navigation system. Sixty consecutive patients for uncemented TKAs were included in the navigated series.