PCL injury

PCL (Posterior Cruciate ligament) is attached to posterior intercondyloid fossa of the tibia and to the posterior portion of the lateral meniscus. PCL is stronger but shorter and prevents the tibia from shifting posteriorly. PCL injuries often occur with other knee injuries such as ACL, MCL, LCL and meniscus tear. However, it can happen in isolation. Isolated PCL injury is uncommon (about 2 % of the knee injury *2,3). Severe PCL injuries are(Grade 3 tear) often associated with knee ligament injuries. *4

Aetiology

• High energy trauma (ex. car accident)
• Sports related (soccer, football, gymnastics, handball) *2
• Chronic (2-3 %)

Mechanism

PCL injuries occur when tibia gets some impacts from anterior aspect to posterior with knee flexed.

In sports, it happens when landed on the knee with plantar flexion of the ankle.

Signs and symptoms

• Pain
• Swelling
• Instability
• Shuffling when walking

Special test

• Quadriceps active test
• Posterior drawer
• Sag sign

Isolated PCL injuries decrease posterior tibial translation with internal rotation of the tibia as superficial medial collateral ligament and posterior oblique ligament get tighten up which support posterior tibial shift.

Severity *1

• Grade 1: 0-5mm of posterior tibial shift
• Grade 2: 6-10mm of posterior tibial translation
• Grade 3: more than 10mm of posterior tibial shift

*End feel is often soft due to no resistance of PCL

Treatment 

• Nonoperative treatment
• Operative treatment (less reliable than nonoperative)

Severe PCL injuries in professional and semi-professional athletes performed nonoperative treatment such as bracing and individualized rehabilitation program. They went back to training 10.6 weeks on average and mean time to return to play sports was 16.4 weeks. 91.3% patients were playing at same or higher lever before the injury. *5

68 patients with acute and isolated PCL injuries were treated without operation or surgery and followed 10 up years. Quadriceps strength was as strong as non-injured leg and all patients had full knee ROM. *6

Goal of rehabilitation *1

·      Phase 1: protective phase (week 1-6)

The aim of this phase is to increase knee ROM, normalize the gait and strengthen the muscle around the knee. Hyperextension of the knee and posterior tibial translation should be avoided. Swelling, knee pain and stiffness are prevalent in this phase. When patients can perform straight leg raise without sag sign, then it is good time to walk without crutches. Knee flexion may be limited to 90 degrees for a few weeks. Quads and gluts exercises are vital to unload the knee. Once patients can perform more than 120 degrees of knee flexion, it is ok to perform bike riding without resistance.

·      Phase 2: Transitional phase: (week 6-12)

The goal of this phase is to enhance muscles around the knee and restore full knee ROM. Patients should be able to perform weight bearing exercises without compensation.

·      Phase 3: Functional phase (week 12-16)

Patients can begin running, perform 90 degrees of weight bearing knee flexion. Isolated hamstrings exercises and single leg should be executed before starting jogging.

·      Phase 4: Return to sports (week16-24)

This is the phase to prepare for returning to play sports. Exercises are compound and as close as sports related movements are such as functional exercises and agilities.

*Some researches reported that it causes chronic instability when the injured ligament is in elongated position. *7

References

1. Dean Wang, Jessica Graziano and Kristofer J. Jones Nonoperative treatment of PCL injuries: Goals of Rehabilitation and Natural History of Conservative care 2018 Curr Rev Musculoskeletal Med. 11(2): 290-297
2. Majewski M, Susanne H and Klaus S Epidemiology of athletic knee injuries: A 10-years study 2006 knee 13(3): 184-188
3. Sanders TL, Pareek A, Barrett IJ, Kremers HM, Bryan AJ, Stuart MJ, et al. Incidence and long-term follow-up of isolated posterior cruciate ligament tears. Knee Surg Sports Traumatol Arthrosc. 2017;25(10):3017–3023.
4. Becker EH, Watson JD, Dreese JC. Investigation of multiligamentous knee injury patterns with associated injuries presenting at a level I trauma center. J Orthop Trauma. 2013;27(4):226–231
5. Agolley D, Gabr A, Benjamin-Laing H, Haddad FS. Successful return to sports in athletes following non-operative management of acute isolated posterior cruciate ligament injuries: medium-term follow-up. Bone Joint J. 2017;99-B(6):774–778
6. Shelbourne KD, Clark M, Gray T. Minimum 10-year follow-up of patients after an acute, isolated posterior cruciate ligament injury treated nonoperatively. Am J Sports Med. 2013;41(7):1526–1533
7. Pierce CM, O’Brien L, Griffin LW, Laprade RF. Posterior cruciate ligament tears: functional and postoperative rehabilitation. Knee Surg Sports Traumatol Arthrosc. 2013;21(5):1071–1084