In Vivo Arthroscopic Behavior of the Infrapatellar Plica of the Knee
In Vivo Arthroscopic Behavior of the Infrapatellar Plica of the Knee
Anterior knee pain has been an enigmatic problem for orthopedic surgeons. Recent studies, as
 well as the clinical observation of the principle investigator have suggested that
 arthroscopic resection of the infrapatellar plica (IPP), a vestigial remnant from embryonic
 development of no known clinical or biological significance, may eliminate this pain. The
 mechanism whereby this pain is related to the IPP is unclear. This study will document the
 mechanical behavior of the IPP, its kinematics, as recorded on video among a group of
 subjects who are undergoing arthroscopy. Radiographic visualization of the observed behavior
 will be obtained by injection of contrast material, and then fluoroscopic recording of a
 standard series of motions. The plica will then be resected to avoid any possibility of
 residual symptoms related to its presence. Further fluoroscopy of the knee without plical
 attachment, will allow the kinematic behavior to be assessed. The procedure will then be
 terminated.
The infrapatellar plica (IPP) of the human knee is vestigial remnant of the embryologic
 division between the medial and lateral compartments of the knee, present in 85.5% of knees1,
 felt by some to be of no clinical significance other than acting as a block to visualization
 an movement during arthroscopy.2 S.J. Kim 3,4, C.R. Boyd 5, and B. Demirag 2006 have
 documented successful relier of anterior knee pain after resection of the IPP. This study
 seeks to assess the relationship between knee motion, activation of the extensor apparatus,
 and the IPP, in essence, the kinematics of the contents of the anterior compartment of the
 knee. The hypothesis to be evaluated is:

 the infrapatellar plica is a structure of fundamental biomechanical significance, allowing
 the transmission of force from the extensor apparatus to the distal femur through the fat
 pad, and acting as a restraint and a modulator of fad pad mobility.

 Subjects will be identified by the PI at their office visit. The subject will be consented.
 The consent will be discussed and verified in a second office visit before surgery. The
 subject will undergo arthroscopy specifically directed toward identifying and treating known
 pathology. Once this is finished, if an IPP is present, it will be injected with radiographic
 contrast material. A series of maneuvers will be performed involving passive and active
 motion of the knee and active contraction of the quadriceps apparatus. Videotape recording
 and fluoroscopy will be undertaken. The plica will be removed. Another fluoroscopy will be
 performed. The patient will be followed according to the standard practice for arthroscopy
 and the defined pathology.
must be Healthy subject must be >18 years of age, skeletally mature must bePending knee
 joint arthroscopy.

 may not have Active infection