The Parapatellar Approach to Intramedullary Tibial Nailing

Overview

This project will address the incidence of anterior knee pain in the approaches used for tibial nailing. A parapatellar approach, with nail insertion in relative extension, will be compared to the approaches in which nail insertion requires the knee to be placed in flexion. The incidence of anterior knee pain will be compared in each group to assess whether the compared approaches result in similar levels of anterior knee pain. Patients will be given the 2000 IKDC Subjective Knee Evaluation Form to assess anterior knee pain. The 2000 IKDC Subjective Knee Evaluation Form is a newer assessment tool created by the International Knee Documentation Committee. It has been validated for use with broad patient populations dealing with various knee disorders.19

In the population affected by orthopaedic injury, fractures of the tibial shaft are the most common of all long bone fractures. This fracture pattern occurs approximately 26 times per 100,000 people and accounts for 77,000 hospitalizations per annum.(1, 2) Intramedullary nailing is the most common operative treatment choice for fractures of the diaphyseal tibia (tibial shaft). Intramedullary nailing is also commonly used for shaft fractures that extend into the metaphyses (excluding fractures that extend into the knee and/or exhibit comminution at the ankle joint). Tibial nails are inserted at or about the knee. Three different insertion approaches are used as standard of care at this institution, including the transtendinous, peritendinous, and parapatellar approach. In all three techniques, the nail is placed in the tibia in the same manner: after fracture reduction, the proper entry point in the proximal tibia is found and the tibia is sequentially reamed until a suitable nail can be passed and locked in place with interlocking screws. The three named approaches vary the (1) angulation of the knee at the time of insertion and the (2) location of the incision and soft tissue dissection, relative to the patellar tendon, necessary to locate the proper entry point for the nail. Tibial nails are inserted with the knee in flexion (bent to \~90°) for the transtendinous and peritendinous approaches, and in relative extension (less than 30°) for the parapatellar approach. For insertion, the transtendinous and peritendinous approaches require dissections that allow the nail to be passed through or around the patellar tendon. In the parapatellar technique, dissection is carried out juxtaposed to the patella. Anterior knee pain is the most common complication of intramedullary tibial nailing. It has been reported in a range of 10% to 86% with average follow up of two years.(3) Review of current literature regarding the subject of anterior knee pain and tibial nailing reveals four commonly attributable causes: skin incision location,(4,5) approach in reference to the patellar tendon,(6-9) nail insertion site,(10) and nail prominence.(11-13) No study has specifically examined whether knee angulation at the time of insertion impacts anterior knee pain.