The proximal part of the tibia consists of the medial and lateral tibia plateaus and the tibia spines where the anterior and posterior cruciate ligaments attach.
ACL Avulsion Fractures
ACL Avulsion Fractures
Tibia plateau
Coronal view of left knee
Sagittal view of left knee
ACL avulsion fractures
Injury mechanism:
- ACL avulsion fractures may be due to motor vehicle accidents, sports-related injuries and less often household or occupational-related injuries.
- Typical mechanism of injury include a strong valgus force that causes the knee to pivot shift with the tibia in external rotation or the femur in internal rotation
Associated injuries:
- Meniscus tears
- Collateral ligament tears
- Second fractures (lateral capsular avulsion injury)
Presentation
- Pain to the knee area
- Pain may be aggravated with weight bearing
- Soft tissues swelling around knee area
- Knee swelling
- Knee instability
Meyers and McKeever Classification
Presentation include:
- Type Ⅰ: nondisplaced
- Type Ⅱ: displaced anterior margin with seated posterior margin
- Type Ⅲ: completely displaced
- Type Ⅳ: fragment comminution
Associated meniscus tears
Examples of meniscus tear patterns
Associated Knee ligament tears
Management
- Nondisplaced (Type Ⅰ) fractures can be managed non-operatively with brace/cast
- Displaced fractures (Type Ⅱ-Ⅳ) requires surgical fixation
Surgery fixation include screw/wires/anchor fixation techniques
Arthroscopic ACL avulsion surgery repair
Surgery technique:
- Reduce ACL avulsion after clearing avulsion bed
- Create bone tunnels
- Secure ACL avulsion with stitch across the avulsion fracture
- Tie ACL avulsion stitch to button
Outcome of arthroscopic ACL repair has shown that this technique restores knee function and stability with a 92% excellent/good outcome result (Dung et al 2019)
Authors Modified Arthroscopic ACL avulsion surgery repair for small or comminuted ACL avulsion fragment (Type IV)
Surgery technique:
- ACL avulsion stitch
- Create bone tunnels
- Tie ACL avulsion to button
Rehabilitation
Post surgery guideline management:
- After surgery brace knee in full extension for 4 weeks
- Crutches for 1-2 weeks with tolerable weight bearing
- Remove brace after 4 weeks and start knee range of motion (ROM) and introduce quadriceps closed chain exercises
- At 8 weeks consider low level straight line running
- Perform pivot-test routines after 12 weeks
Physiotherapy
- Rehabilitation include ongoing strength and sport specific training with completion of battery of testing before return to sport
Knee range of motion (ROM) brace allows the degree of knee ROM to be set
Foot ROM with brace on, pre and/or post-surgery allowing lower limb circulation
Download ASSIC Performance Fingerprint or Strength & Conditioning apps to create or download guideline (pre and post surgery) rehab routines
References
- Arthroscopic fixation of ACL avulsion fracture in the Saint Paul Hospital: a review of treatment outcomes. Tran Trung Dung, Hoang Gia Du, Nguyen Hoang Long, Le Manh Son, Dao Xuan Thanh, Dinh Ngoc Son, Nguyen Tuyen, Do Van Minh, Nguyen Huy Phuong, Vu Tu Nam, Pham Trung Hieu, Ma Ngoc Thanh. Eur J Othop Surg Traumatol. 2019Oct;29(7): 1485-1491.
- Arthroscopic fixation of ACL avulsion fracture in the saint pault hospital: A review of treatment outcomes: Cohort study. Tran Trung Dung, Hoang Gia Du, Nguyen Hoang Long, Le Manh Son, Dao Xuan Thanh, Dinh Ngoc Son, Nguyen Tuyen, Do Van Minh, Nguyen Huy Phuong, Vu Tu Nam, Pham Trung Hieu, Ma Ngoc Thanh. Ann Med Surg (Lond). 2019 Dec;48: 91-94.
- Osseous Injury Associated with Ligamentous Tear of the Knee. Chee Hwee Lee, Chih Feng Tan, Okwha kim, Kyung Jin Suh, Min-Szu Yao, Wing P. Chan, Jim S. Wu. Canadian Association of Radiologists Journal Volume 67, Issue 4, November 2016: 379-386.
