Session VII - Tibia

Arthroscopically Diagnosed Knee Injuries in Association with Tibial Shaft Fractures: A Prospective Study

Raffy Mirzayan, MD; Vahé Panossian, MD; C. Thomas Vangsness, Jr, MD; Christopher J. Shean, MD; Lane E. Shepherd, MD, University of Southern California School of Medicine, Los Angeles, CA

Introduction: Intramedullary nailing is the treatment of choice for unstable closed and low-grade open fractures. Anterior knee pain is the most common complication following nailing. Its etiology is unclear; possible causes include associated and iatrogenic injuries and nail factors. The purpose of this prospective study was to arthroscopically document the incidence and extent of knee injuries associated with tibial shaft fractures, as well as iatrogenic injuries incurred at the time of intramedullary nailing which may account for the knee pain.

Methods: Fifty patients with 52 tibial shaft fractures (6 cm from knee and ankle joints) resulting from blunt trauma and requiring surgical stabilization were enrolled in the study with approval of the Institutional Review Board. After stabilization (with 48 intramedullary (IM) nails, 4 external fixators) of the fracture, the knee was examined under anesthesia (EUA) and a standard diagnostic arthroscopy was performed. A senior arthroscopist, who was blinded to patient demographics and radiographs, reviewed all of the videotapes.

The average age of the patients was 33.6 years, and there were 42 males and 8 females. There were 30 closed fractures and 3 type I, 10 type II, 2 type IIIA, and 7 type IIIB open fractures. There were 22 type A, 17 type B, and 13 type C fractures based on the OTA fracture classification.

Results: Nine of 52 (17%) patients had an anterior cruciate ligament (ACL) tear, 12 of 52 (22%) had meniscal tears, and 7 of 52 (13.5%) had chondral injuries. In addition, 9 of 48 patients (19%) had an intra-articular starting point with the anterior horn of the medial meniscus being incarcerated in the entry point. All fractures violated the footprint of the ACL, and a medial peritendinous approach was used in all cases.

Discussion: We found no prospective studies documenting arthroscopic knee findings in association with tibial shaft fractures in the literature. Our study found significant intra-articular findings 36.5% of the time, which cannot be diagnosed at the time of injury nor with an examination under anesthesia. Furthermore, there was a 19% incidence of iatrogenic injury as a result of surgical stabilization. We do not recommend routine arthroscopy of the knee joint following intramedullary nailing of tibial shaft fractures. However, if a patient has knee pain at the time of follow-up, intra-articular knee injury should be strongly considered and accordingly treated.