Posterior Cruciate Ligament Injury
- Author: Charles S Peterson, MD; Chief Editor: Craig C Young, MD more...
The posterior cruciate ligament (PCL) is described as the primary stabilizer of the knee by many authors. PCL injuries are less common than anterior cruciate ligament (ACL) injuries, and they often go unrecognized. The PCL is broader and stronger than the ACL and has a tensile strength of 2000 N. Injury most often occurs when a force is applied to the anterior aspect of the proximal tibia when the knee is flexed. Hyperextension and rotational or varus/valgus stress mechanisms also may be responsible for PCL tears. Injuries may be isolated or combined with other ligamentous injuries. A PCL tear can result in varying degrees of disability, from no impairment to severe impairment. PCL injury has been overly simplified, and the functional disability of PCL injury may be underestimated. The radiographs belowdemonstrate the results of suchinjuries, comparing a normal knee with one that has a damaged PCL.
The primary function of the PCL is to prevent posterior translation of the tibia on the femur. The PCL also plays a role as a central axis controlling and imparting rotational stability to the knee. This injury has received little attention in the past, compared with the ACL; however, this emphasis on the ACL has stimulated increased interest in the treatment of PCL injuries. Controversy regarding treatment of isolated PCL injuries exists in the literature, with recommendations supporting both operative and nonoperative therapy. Current management of PCL injuries unfortunately can yield relatively poor clinical outcomes, whether surgically or conservatively treated.
True incidence in the United States is unknown. In National Football League predraft physical examinations, a 2% incidence of isolated, asymptomatic, and unknown PCL injuries was found; operated, isolated, and combined PCL injuries were reported at an incidence of 3.5-20%. On the KT-1000 stress test examination, a 7% incidence of PCL injuries was found, of which 40% were isolated and unidirectional and 60% were multidirectional.
As demonstrated in the images below, the PCL originates from the intercondylar notch of the femur on the roof of the medial femoral condyle. The insertion is central on the posterior aspect of the tibial plateau, on a depression between the tibial plateaus, extending 1 cm below the articular surface. The ligament is composed of a larger anterolateral bundle and a smaller posteromedial bundle. The anterior component is tightest in the midarc of flexion and the posterior fibers are tight in extension and deep flexion.
In addition, variable anterior and posterior meniscofemoral ligaments of Humphrey and Wrisberg attach distally and proximally to the PCL, respectively. The meniscofemoral ligaments attach distally to the posterior horn of the lateral meniscus, in a slanting orientation, providing resistance to the tibial posterior drawer. The PCL is an extrasynovial structure that lies behind the intra-articular portion of the knee. The primary function of the PCL is to resist posterior displacement of the tibia in relation to the femur; its secondary function is to prevent hyperextension and limit internal and varus/valgus rotation.
Sport Specific Biomechanics
Disruption may occur with forced hyperextension while the foot is planted in dorsiflexion. A force applied to the anteromedial aspect of the knee, as during a football tackle, results in a posteriorly directed force and a varus hyperextension force, leading to PCL and posterolateral capsular ruptures.
Wang CJ. Injuries to the posterior cruciate ligament and posterolateral instabilities of the knee. Chang Gung Med J. 2002 May. 25(5):288-97.
Margheritini F, Rihn J, Musahl V, Mariani PP, Harner C. Posterior cruciate ligament injuries in the athlete: an anatomical, biomechanical and clinical review. Sports Med. 2002. 32(6):393-408.
Sheps DM, Otto D, Fernhout M. The anatomic characteristics of the tibial insertion of the posterior cruciate ligament. Arthroscopy. 2005 Jul. 21(7):820-5.
Amis AA, Gupte CM, Bull AM, Edwards A. Anatomy of the posterior cruciate ligament and the meniscofemoral ligaments. Knee Surg Sports Traumatol Arthrosc. 2006 Mar. 14(3):257-63.
Servant CT, Ramos JP, Thomas NP. The accuracy of magnetic resonance imaging in diagnosing chronic posterior cruciate ligament injury. Knee. 2004 Aug. 11(4):265-70.
Nha, KW, Bae, JH, Kwon, JH, et al. Arthroscopic posteromedial drive-through test in posterior cruciate ligament insufficiency: a new diagnostic test. Knee Surg Sports Traumatol Arthrosc. February 2014. [Medline].
[Guideline] Pierce CM, O'Brien L, Griffin LW, Laprade RF. Posterior cruciate ligament tears: functional and postoperative rehabilitation. Knee Surg Sports Traumatol Arthrosc. 2012 Apr 8. [Medline].
Chen B, Gao S. Double-bundle posterior cruciate ligament reconstruction using a non-hardware suspension fixation technique and 8 strands of autogenous hamstring tendons. Arthroscopy. 2009 Jul. 25(7):777-82. [Medline].
Lim HC, Bae JH, Wang JH, et al. Double-bundle PCL reconstruction using tibial double cross-pin fixation. Knee Surg Sports Traumatol Arthrosc. 2010 Jan. 18(1):117-22. [Medline].
Lenschow S, Zantop T, Weimann A, Lemburg T, Raschke M, Strobel M. Joint kinematics and in situ forces after single bundle PCL reconstruction: a graft placed at the center of the femoral attachment does not restore normal posterior laxity. Arch Orthop Trauma Surg. 2006 May. 126(4):253-9.
Kim SJ, Kim TE, Jo SB, et al. Comparison of the clinical results of three posterior cruciate ligament reconstruction techniques. J Bone Joint Surg Am. 2009 Nov. 91(11):2543-9. [Medline].
Jung TM, Höher J, Weiler A. Screw fixation of a 4 1/2-year-old PCL avulsion injury. Knee Surg Sports Traumatol Arthrosc. 2006 May. 14(5):469-72.
Ahn JH, Yoo JC, Wang JH. Posterior cruciate ligament reconstruction: double-loop hamstring tendon autograft versus Achilles tendon allograft--clinical results of a minimum 2-year follow-up. Arthroscopy. 2005 Aug. 21(8):965-9.
Ahn JH, Nha KW, Kim YC, Lim HC, Nam HW, Wang JH. Arthroscopic femoral tensioning and posterior cruciate ligament reconstruction in chronic posterior cruciate ligament injury. Arthroscopy. 2006 Mar. 22(3):341.e1-4.
Jung YB, Jung HJ, Tae SK, Lee YS, Yang DL. Tensioning of remnant posterior cruciate ligament and reconstruction of anterolateral bundle in chronic posterior cruciate ligament injury. Arthroscopy. 2006 Mar. 22(3):329-38.
Sekiya JK, West RV, Ong BC, Irrgang JJ, Fu FH, Harner CD. Clinical outcomes after isolated arthroscopic single-bundle posterior cruciate ligament reconstruction. Arthroscopy. 2005 Sep. 21(9):1042-50.
Goudie EB, Will EM, Keating JF. Functional outcome following PCL and complex knee ligament reconstruction. Knee. 2009 Sep 29. [Medline].
Hermans S, Corten K, Bellemans J. Long-term results of isolated anterolateral bundle reconstructions of the posterior cruciate ligament: a 6- to 12-year follow-up study. Am J Sports Med. 2009 Aug. 37(8):1499-507. [Medline].
Strobel MJ, Weiler A, Schulz MS, Russe K, Eichhorn HJ. Arthroscopic evaluation of articular cartilage lesions in posterior-cruciate-ligament-deficient knees. Arthroscopy. 2003 Mar. 19(3):262-8.
Baker CL Jr, Norwood LA, Hughston JC. Acute combined posterior cruciate and posterolateral instability of the knee. Am J Sports Med. 1984 May-Jun. 12(3):204-8. [Medline].
Bergfeld JA, McAllister DR, Parker RD, et al. The effects of tibial rotation on posterior translation in knees in which the posterior cruciate ligament has been cut. J Bone Joint Surg Am. 2001 Sep. 83-A(9):1339-43. [Medline].
Browner BD. Skeletal Trauma: Fractures, Dislocations, Ligamentous Injuries. Philadelphia, Pa: WB Saunders Co; 1998.
Cain TE, Schwab GH. Performance of an athlete with straight posterior knee instability. Am J Sports Med. 1981 Jul-Aug. 9(4):203-8. [Medline].
Clancy WG Jr, Shelbourne KD, Zoellner GB, et al. Treatment of knee joint instability secondary to rupture of the posterior cruciate ligament. Report of a new procedure. J Bone Joint Surg Am. 1983 Mar. 65(3):310-22. [Medline].
Cosgarea AJ, Jay PR. Posterior cruciate ligament injuries: evaluation and management. J Am Acad Orthop Surg. 2001 Sep-Oct. 9(5):297-307. [Medline].
Cross MJ, Powell JF. Long-term followup of posterior cruciate ligament rupture: a study of 116 cases. Am J Sports Med. 1984 Jul-Aug. 12(4):292-7. [Medline].
Daniel DM, Stone ML, Barnett P, Sachs R. Use of the quadriceps active test to diagnose posterior cruciate-ligament disruption and measure posterior laxity of the knee. J Bone Joint Surg Am. 1988 Mar. 70(3):386-91. [Medline].
Delee JC. Orthopaedic Sports Medicine, Principles and Practice. Philadelphia, Pa: WB Saunders Co; 1994. Vol 2:
Donovan. Posterior cruciate ligament injury on artificial turf. Orthop. 1977. 1:20.
Fowler PJ, Messieh SS. Isolated posterior cruciate ligament injuries in athletes. Am J Sports Med. 1987 Nov-Dec. 15(6):553-7. [Medline].
Harner, Miller. Complex topics in knee surgery. Clin Sports Med. 1999. 18(1):
Janousek AT, Jones DG, Clatworthy M, et al. Posterior cruciate ligament injuries of the knee joint. Sports Med. 1999 Dec. 28(6):429-41. [Medline].
Ogata K, McCarthy JA, Dunlap J, Manske PR. Pathomechanics of posterior sag of the tibia in posterior cruciate deficient knees. An experimental study. Am J Sports Med. 1988 Nov-Dec. 16(6):630-6. [Medline].
Paddu G, Gianni E, Chambat P. The axial view in evaluating tibial translation in cases of insufficiency of the posterior cruciate ligament. Arthroscopy. 2000. 16(2):217-220.
Parolie JM, Bergfeld JA. Long-term results of nonoperative treatment of isolated posterior cruciate ligament injuries in the athlete. Am J Sports Med. 1986 Jan-Feb. 14(1):35-8. [Medline].
Safran MR, Allen AA, Lephart SM, et al. Proprioception in the posterior cruciate ligament deficient knee. Knee Surg Sports Traumatol Arthrosc. 1999. 7(5):310-7. [Medline].
Shelbourne KD, Davis TJ, Patel DV. The natural history of acute, isolated, nonoperatively treated posterior cruciate ligament injuries. A prospective study. Am J Sports Med. 1999 May-Jun. 27(3):276-83. [Medline].
Shelbourne KD, Jennings RW, Vahey TN. Magnetic resonance imaging of posterior cruciate ligament injuries: assessment of healing. Am J Knee Surg. 1999. 12(4):209-13. [Medline].
Siliski JM. Traumatic Disorders of the Knee. New York, NY: Springer-Verlag; 1994.
St Pierre P, Miller MD. Posterior cruciate ligament injuries. Clin Sports Med. 1999 Jan. 18(1):199-221, vii. [Medline].
Veltri DM, Warren RF. Isolated and combined posterior cruciate ligament injuries. J Am Acad Orthop Surg. Nov 1993. 1(2):67-75.