Incision placement for intramedullary tibial nailing: An anatomic study

Objectives: For intramedullary nailing of tibial shaft fractures, a recent study has determined that the entry site should be just medial to the lateral tibial spine at the anterior margin of the articular surface. Gaining access to this site is often through a medial parapatellar or transpatellar approach. Several studies have indicated that a transpatellar approach may contribute to anterior knee pain. Our study sought to use anatomic measurement to determine the ideal incision site for insertion of an intramedullary tibial nail. Design: Part I: survey of Orthopaedic Trauma Association (OTA) members. Part II: anatomic study. Setting: A Level 1 trauma center in Sacramento, California. Participants: Part I: OTA members. Part II: a group of 56 healthy volunteers. Intervention: Part I: questionnaire sent to OTA members. Part II: clinical examination and radiographic analysis. Main Outcome Measurements: Part I: responses to questionnaire. Part II: anatomic measurements. Results: Part I: based on a questionnaire, OTA members use at least one or more approaches to access their preferred tibial nail entry site. Fifty-seven percent use only one type of approach in all cases. Part II: the authors performed a clinical and radio-graphic study in 56 volunteers (112 knees) to determine the relationship of the lateral tibial spine to the patellar tendon. On the basis of this information, the tendon was divided into thirds to account for the three most common surgical approaches. The entry site was in the lateral zone in 29 knees, the middle zone in 75 knees, and the medial zone in 8 knees. If divided equally into purely a medial or lateral zone to avoid a transpatellar approach, the starting point fell into the medial zone in 42 knees and the lateral zone in 70 knees. Conclusions: Individual variations in patellar tendon anatomy should be considered when choosing the proper entry site for tibial nailing. Based on the assumption that the ideal entry point for tibial nailing is just medial to the tibial spine at the anterior margin of the articular surface, a preoperative fluoroscopic measurement before incision can guide the surgeon as to whether a medial parapatellar, transpatellar, or lateral parapatellar approach provides the most direct access to this entry site. The routine use of a single approach for all tibial nails may no longer be justified.