BACKGROUND Patellofemoral joint replacement is a successful treatment option for isolated patellofemoral osteoarthritis. However, results of later conversion to total knee replacement may be compromised by periprosthetic bone loss. Previous clinical studies have demonstrated a decrease in distal femoral bone mineral density after patellofemoral joint replacement. It is unclear whether this is d...

2 Chief, Orthopedic Surgery, Duke University Medical Center, Durham, N. C; Chief, Orthopedic and Prosthetic Appliance Clinic Team, Veterans Administration Hospital, Durham, N. C. When it is necessary to use a mechanical knee joint, whether it be in a below-knee prosthesis or a long-leg brace, ideally there should be no relative motion between the patient's limb and the appliance during its use....

In surgical knee replacement, the damaged knee joint is replaced with artificial prostheses. An accurate clinical evaluation must be carried out before applying knee prostheses to ensure optimal outcome from surgical operations and to reduce the probability of having long-term problems. Useful information can be inferred from CT scans of the knee area, that can be used to estimate the stress th...

Abstract. A mathematical model for studying the passive kinematics of condylartype total knee prostheses can be useful in planning and performing total joint replacement. If the insertion location and neutral length of knee ligaments is known, the passive kinematics of the knee can be calculated by minimizing the strain energy stored in the ligaments in any angular configuration of the knee. Th...

Constrained implants are frequently used for primary total knee arthroplasty (TKA) in patients with moderate and severe genu-valgum (>10˚). This deformity presents corrective challenges for ligament release. The lateral-parapatellar approach has been advocated as an alternative to the traditional medial-parapatellar approach. Claimed advantages include better access for release of tight ligamen...

The objective of this study was to examine total knee polyethylene inserts from in vitro simulation to evaluate and display-using a 3D optical scanner-wear patterns and wear rates of inserts exposed to wear by means of simulators. Various sets of tibial inserts have been reconstructed by using optical scanners. With this in mind, the wear behavior of fixed and mobile bearing polyethylene knee c...

BACKGROUND Mobile bearing TKA prostheses were designed to minimize polyethylene wear by increasing implant conformity and reducing stresses between the articulating prosthesis components. It is the purpose of this study to assess the mid-term functionality and clinical outcome associated with a highly congruent mobile platform design, the e.motion(®) UC total knee prosthesis. MATERIAL AND MET...

OBJECTIVE To observe the therapeutic effects of segmental resection and decompression combined with joint prosthesis on continuous knee osteoarthritis (OA). METHODS A total of 130 patients with knee OA were selected and randomly divided into an observation group and a control group (n=65). The control group was treated by segmental resection in combination with joint prosthesis, and the obser...

This paper presents the development of the CYBERLEGs Alpha-Prototype prosthesis, a new transfemoral prosthesis incorporating a new variable stiffness ankle actuator based on the MACCEPA architecture, a passive knee with two locking mechanisms, and an energy transfer mechanism that harvests negative work from the knee and delivers it to the ankle to assist pushoff. The CYBERLEGs Alpha-Prosthesis...