Comparison of Short Stems Versus Straight Hip Stems: A Biomechanical Analysis of the Primary Torsional Stability.

Cementless straight stems show very good survival rates. However, the more distal force application of straight stems may lead to release-related proximal stress-shielding. Nevertheless, this technical brief had the objective of conducting a biomechanical in vitro analysis comparing short stems with established straight stems with respect to their primary torsional stability.

How screw connections influence the primary stability of acetabular cups under consideration of different bone models.

Introduction: Good osteointegration of implants requires sufficient primary stability. Aim of this study was to examine the influence of screw fixation on the primary stability of press-fit cups.

Methods: Two press-fit acetabular cups were tested with regard to the influence and number of screws and their primary stability.

Outcome of short- to medium-term migration analysis of a cementless short stem total hip arthroplasty using EBRA-FCA: a radiological and clinical study.

Introduction: Stress shielding may lead to aseptic loosening which is a common reason for implant failure. An established method to identify implants with risk of implant failure caused by aseptic loosening is to measure early migration of the stem with the "Ein Bild Roentgen Analyse" femoral component analysis (EBRA-FCA). Therefore, the aim of this study was to measure the migration of a cementless short stem prosthesis via EBRA-FCA to predict the future performance.

Biomechanical testing of various suture techniques for Achilles tendon repair with and without augmentation by using synthetic polyester grafts.

Following surgical Achilles tendon reconstruction surgery, there is a distinct trend towards an early and faster rehabilitation protocol to avoid muscle atrophy. However, this procedure involves the risk of a higher complication rate. In order to reduce the occurrence of re-ruptures and pathological tendon extensions, a tendon reconstruction with the highest possible primary stability is desirable.

In vitro examination of the primary stability of three press-fit acetabular cups under consideration of two different bearing couples.

Backround: For preclinical statements about the anchoring behavior of prostheses, the primary stability of the prosthesis is of special importance. It was the aim of this study to examine and compare the relevant relative micromotions of three different acetabulum prostheses by introducing three-dimensional torques.

Methods: The cups were implanted under standard conditions into an anatomical artificial bone model.

Development of periprosthetic bone mass density around the cementless Metha® short hip stem during three year follow up-a prospective radiological and clinical study.

Purpose: The purpose of this study was to check the concept of the cementless Metha® short hip stem in order to find out whether proximal physiological load transfer can be achieved.

Methods: Fourty-three patients were included. Epidemiological factors were established.

Analysis of the elastic bending characteristics of cementless short hip stems considering the valgus alignment of the prosthetic stem.

Background: The resultant hip force causes a varus torque which must be compensated by a shear force couple depending on the stem alignment of the prosthesis. Since the prosthesis is substantially less flexible than the bone, the interior of the femur is stiffened over the entire prosthesis length. The present study thus aims at analyzing short-stem prostheses for its elastic bending characteristics, considering inappropriate valgus alignment of the prosthetic stem.

Sports activities before and after medial unicompartmental knee arthroplasty using the new Heidelberg Sports Activity Score.

Purpose: The purpose of our study was to investigate the change of sports activities before and after medial unicompartmental knee arthroplasty (UKA) with the use of the Heidelberg Sports Activity Score (HAS).

Methods: The Heidelberg Sports Activity Score (HAS) as well as FFb-H-OA, Oxford-12-Score, Tegner, UCLA and ACS were carried out to assess sports activities in 157 patients with medial osteoarthritis of the knee joint before and after UKA. The newly developed HAS also records the important duration and the sporting activity.