Bänder des Kniegelenks

Three-dimensional kinematics of canine hind limbs: in vivo, biplanar, high-frequency fluoroscopic analysis of four breeds during walking and trotting

The first high-precision 3D in vivo hindlimb kinematic data to be recorded in normal dogs of four different breeds (Beagle, French bulldog, Malinois, Whippet) using biplanar, high-frequency fluoroscopy combined with a 3D optoelectric system followed by a markerless XROMM analysis (Scientific Rotoscoping, SR or 3D-2D registration process) reveal a) 3D hindlimb kinematics to an unprecedented degree of precision and b) substantial limitations to the use of skin marker-based data. We expected hindlimb kinematics to differ in relation to body shape. But, a comparison of the four breeds sets the French bulldog aside from the others in terms of trajectories in the frontal plane (abduction/adduction) and long axis rotation of the femur. French bulldogs translate extensive femoral long axis rotation (>30°) into a strong lateral displacement and rotations about the craniocaudal (roll) and the distal-proximal (yaw) axes of the pelvis in order to compensate for a highly abducted hindlimb position from the beginning of stance. We assume that breeds which exhibit unusual kinematics, especially high femoral abduction, might be susceptible to a higher long-term loading of the cruciate ligaments.

Snapping knee syndrome caused by semitendinosus and semimembranosus tendons. A case report

We report the case of a 24-year-old female triathlon athlete with a snapping syndrome of both the distal semimembranosus and the semitendinosus tendon which has not been described so far. The semitendinosus tendon was harvested whereupon snapping has diminished. Tenoscopy and digital palpation showed the semimembranosus tendon to cause the snapping, as well. A careful step-by-step release of the anterior insertion of the tendon was performed with the result of a snapping-free range of motion of the patient's knee.

A symptomatic sesamoid bone in the popliteus muscle (cyamella)

Sesamoid bones of the popliteus muscle, also called cyamellae, are common in primates but rare in humans. They reside as accessory bones in the tendon itself or in the intersection between tendon and bone. They should be clearly distinguished from osteochondral flakes, periosseuos calcifications, osteophytes and the fabella, a common sesamoid bone of the knee. In this case, we report a 25-year-old male with posterior lateral knee pain related to the popliteus tendon where a corresponding cyamella could be demonstrated on X-rays and MRI scans. The clinical findings may be related to the cyamella. Diagnosis and treatment of this rare pathology are discussed.