Tibial Spine Fracture in Adults

A lateral knee radiograph of a 22-year-old man sustaining motor vehicle collision demonstrates an oval bone fragment (arrow) in the intercondylar region of the knee. There is complete separation between the fragment and the donor site with superior displacement of the fragment. Note hemarthrosis (asterisk).

Facts:

• Classically described in pediatric patients and considered the childhood equivalent of anterior cruciate ligament (ACL) ruptures in adults
• Forceful hyperextension of the knee resulting in avulsive force/tension on ACL, which inserts into the anterior tibial spine. Possibly with valgus stress or rotation. 
• In adults, most injuries occur in road-traffic accidents and are isolated
• Adults more likely to have associated tear of medial collateral ligament (MCL) or intra-articular fracture

Classification (Meyers and McKeever)

• Based on degree of displacement. Type II & III are most common
• Type I = incomplete avulsion of tibial spine without displacement
• Type II = incomplete avulsion with anterior elevation of the fragment
• Type IIIA = complete separation of fragment
• Type IIIB = rotated and comminuted fragment
• Generally, types I and II are managed conservatively while type III fractures are managed arthroscopically or with open reduction

References:

Kendall NS, et al. Fracture of the tibial spine in adults and children. J Bone J Surg [Br] 1992;74-B:848-52.

Rosen's Emergency Medicine - Concepts and Clinical Practice