Patellofixator Rig - Design Specifications of a Device Assisting Medial Patello Femoral Ligament [MPFL] Reconstruction

Abstract

Patella dislocation is one of the most common pathology of the knee joint. Incidence of patellar dislocation is 5.8 to 77.8 in 100000. Medial patella femoral ligament plays a pivot role in patellofemoral instability. All acute dislocations causes some degree of macroscopic MPFL damage and studies shown lateral dislocation is impossible without damage to MPFL. 44% non-conservative treatment patient go on to suffer redislocation, along with painful symptoms of chronic instability. MPFL reconstruction surgeries prevent further dislocation of patella by adopting one of the four surgical techniques. There been no special intra operative method to determine the anatomical location though an intra operative xray image can help in identifying the exact MPFL insertion site but there are high chances of radiation exposure to the patient, surgeon, assistant and other technical staffs.We have designed a zig which can fit to the normal patella of any size and can be adjusted to determine the MPFL attachment site in Patella. The test rig (Patellofixator), which is divided into an upper and lower section, has been designed to be placed for guiding tools for performing the surgical procedure. Its pin slots are located to the MPFL attachment to the patella. Some surgeon prefers the position of the MPFL patella footprint at the Centre. Going through the various papers regarding the anatomy and correct position of the patella foot print our ZIG will help the surgeon to maintain their anatomical location. Considering the chances of the patella fracture as complication we are determined to give the surgeons a zig which will ease their anchor or tunnel placements in the patella. This small and economical device will assist surgeons to adapt to varying patellar size of the patients and effectively reconstructing the medial patella femoral ligament.