Ulnohumeral joint static cartilage compression is affected by radial head implant size.

Introduction: Radiocapitellar joint arthroplasty is a commonly performed procedure, which often leads to early failure or instability. Few studies assess the effect of radiocapitellar joint arthroplasty on the ulnohumeral joint. We hypothesized that static forces of contact (compressing cartilage, or cartilage relaxation contact force) would reveal the effect of varying radial head implant size and elbow position on the ulnohumeral joint.

Alterations in tibiotalar joint reaction force following syndesmotic injury are restored with static syndesmotic fixation.

Introduction: Syndesmotic injury alters joint mechanics, which may fail to be restored unless an anatomic reduction is obtained.

Methods: A minimally invasive method of measuring joint forces was utilized that does not require significant dissection or intraarticular placement of sensory instruments. Steinmann pins were placed in the tibia and talus of eight fresh-frozen human cadaveric lower extremities and a baseline joint reaction force was determined.

Spring ligament tear decreases static stability of the ankle joint.

Background: Spring ligament tear is often found in advanced adult acquired flatfoot deformity and its reconstruction in conjunction with the deltoid ligament has been proposed to restore the tibiotalar and talonavicular joint stability. The aim of the present study is to determine the effect of spring ligament injury and subsequent reconstruction on static joint reactive force using a non-invasive method of measurement.

Methods: Ten fresh-frozen human cadaveric lower legs were disarticulated at the knee joint.