Posterolateral Corner Injuries in Wrestling
John H. Quinn, MS, ATC
quinn1@ntx1.cso.uiuc.edu
The sport of wrestling dates back to the ancient Greek andRoman eras. It is probably safe to say that wrestling is one of the oldest sports still practiced today. Few sports placethe body in continuously precarious situations as does wrestling. Because of this, it is considered a high risk combative sport. The injury rate in wrestling is among the highest in sports, ranking second only to spring football at the collegiate level, and second only to football at the interscholastic level. The most commonly injured body part is the knee.(1) With that in mind, the primary concern of this paper is not on more commonly injured ligaments, such as the anterior cruciate and medial collateral, but that of the posterolateral corner (PL).
As previously mentioned, the frequency of PL injuries is low. However, injuring the PL corner may be more disabling than injuries to remaining structures of the knee.(2,6) Lateral compartment injuries are complex, associated with damage to a number of structures. Most are not isolated and generally associated with injury to the anterior or posterior cruciate ligament.(2,3,6) The PL corner of the knee is the least understood region of the knee, commonly referred to the “dark side” of the knee (2). Variability in the anatomy of static and dynamic stabilizers between patients adds to the confusion of this region.(2,3,6).
Structures most commonly associated with the PL corner include the Iliotibial band, lateral collateral ligament (LCL), popliteus, popliteofibular ligament, popliteotibial fascicle, popliteomeniscal fascicles, middle third of the lateral capsular ligament, fabellofibular ligament, the arcuate ligament, posterior horn of the lateral ligament, and PL joint capsule. (2,3,5,7,8) Attention has more commonly been given to the LCL and popliteofibular ligament for their role in preventing varus laxity and external rotation. It has been shown that the LCL’s primary role is the prevention of varus adduction with limited involvement in preventing external rotation, only assisting in the early ranges of knee flexion before becoming slack. The popliteofibular ligament, due to its orientation, is a primary restraint to external rotation, remaining taut through most flexion angles. (2,7) In association with the PL complex, the posterior cruciate ligament (PCL) is relatively important. Although it is primarily responsible for preventing posterior translation of the tibia, it has been found that at high flexion angles of the knee it provides added varus stability. Prior to 90 degrees of flexion, a majority of the PCL remains slack (2) . After passing this range, it becomes taut, thereby providing additional restraint to varus stress and external rotation while still maintaining its primary role. This information becomes clinically relevant during orthopedic evaluations for suspected PL knee injuries. Due to the complexity of this region and the limitations of this article, a more in depth understanding of the anatomical and biomechanical relevance may be needed at the reader’s discretion.
The most common mechanism of injury to the PL corner is from athletic trauma, motor vehicle accidents, and falls. (2,3) Athletic injuries to the PL corner are generally low velocity injuries, much different that motor vehicle accidents. Although isolated PL injuries may be rare, mechanisms such as a direct PL force on an extended or flexed knee may cause disruption to the structures. Other mechanisms include hyper extension with a PL force, extreme external rotation, extreme varus force, and a PL force with knee flexion and external tibial rotation.(2,3,6,7) The relevance of this to wrestling is the frequency in which these ”mechanisms” come into play during competition or practice.
As with any injury, the mechanism is the key to the evaluation. Understanding the sport of wrestling is very important and often overlooked. Its popularity has significantly diminished over the last 20 years leaving fewer and fewer people that understand the sport. Understanding the athlete’s complaints is crucial the evaluation process. Many maneuvers in the sport of wrestling require or force the athlete’s knee into positional situations predisposing it to PL injury. A majority of these situations come from defensive wrestling positions while resisting their opponent’s offensive moves at the knee and below. The most likely offensive position is the “crab ride”. This position has the offensive opponent’s arms and legs interlaced directly behind his opponent, as if he were a crab riding another. The mechanism is caused when the rider resists his opponent’s attempt to pull his leg toward his chest. In contrast to many acute injuries, whose mechanisms are from abrupt forces, these athletic related mechanisms tend to occur slowly with increased force and resistance.
Acute symptoms include pain on the lateral and PL corner.(2,3,6) Chronic injury may lead to complaints of pain at the medial and lateral joint lines as well as the PL corner. Although not considered a supporting structure of the PL corner, damage to the common peroneal nerve may be associated with the injury leading to complaints of numbness and tingling. (2,3) PL instability is often overlooked during initial evaluations. Signs may be subtle or masked by signs and symptoms from cruciate ligament injuries. If undetected, it has been a potential link for cruciate ligament repair failures and chronic instabilities of the knee.(2,6,7,8)
In addition to the standard special tests performed on the knee, specific tests must be performed to evaluate the PL corner. These tests include the posterior drawer at 30 and 90 degrees, with laxity at 30 degrees indicative of a PL injury; varus stress at 0, 30, and 90 degrees of flexion; tibial external rotation test; reverse pivot shift; PL external rotation test; reverse pivot shift; external rotation recurvatum test; dynamic posterior shift; and the standing apprehension test. (2)
Radiographs and magnetic resonance imaging (MR) are an important tool to assist in determining PL knee injuries. Plain radiographs may show an arcuate fracture. This is an avulsion of the fibular head at the attachment site of the LCL and PL ligaments structures. MR is best used to reveal the extent of soft tissue damage. An additional sign that may be present on radiograph, but more likely seen on MR, is a segond fracture, most commonly referred to as a lateral capsular avulsion fracture.(3,5,7)
Grade I and II injuries to the PL knee are more commonly treated non-operatively and heal relatively well. It is a necessity that Grade III injuries be surgically repaired. To insure the best chance of healing, the repair should be done within the first 2-3 weeks following injury. In contrast to acute injuries, chronic injuries may present a myriad of problems. Extensive scarring and secondary changes to other structures of the knee may greatly compromise the success of surgical repair. (2,3,7) Another highly significant result of a PL injury is the resulting PL thrust. This limb mal-alignment places excess strain on the ACL and PCL, in addition to biomechanical changes to the joint forces about the knee. (2,4,6,8)
The consequences of PL injuries are substantial. Chronic instability, damage to articular cartilage, predisposition to ACL and PCL tears, failure of cruciate ligament reconstruction, and limb alignment abnormalities are many of the long term effects. It is not the purpose of this paper to state that there is an epidemic of PL knee injuries in the sport of wrestling, but rather to bring awareness to the readers that the athletes in the sport of wrestling run a high risk of injury to the PL corner. Each individual wrestler has his/her own style, and may never put himself in situations that place the PL corner at risk. However, there are many wrestlers who do. It is these wrestlers that this article targets. Very rarely will there be an acute Grade III injury to the PL corner. It is the chronic abuse that the PL will endure over the wrestler’s career that comes into question. With this in mind, it is imperative that all lateral and PL injuries receive a proper and detailed evaluation.
(1) Boden BP, Lin W, Young M, Mueller F: Catastrophic injuries in wrestlers. Am J Sports Med 30: 791-795, 2002
(2) Covey DC: Current Concepts Review: Injuries of the posterolateral corner of the knee. J Bone Joint Surg 83; 106-118, 2001
(3) Juhng SK, et al: MR evaluation of the “arcuate” sign of posterolateral instability. Am J Roent 178: 583-588, 2002
(4) LaPrade RF: The effect of injury to the posterolateral structures of the knee on force in a posterior cruciate ligament graft: a biomechanical study. Am J Sports Med 30: 233-238, 2002
(5) LaPrade RF: The magnetic resonance imaging appearance of individual structures of the posterolateral knee. Am J Sports Med 28: 191-199, 2000
(6) Recondo JA, et al.: Lateral stabilizing structures of the knee: functional anatomy and injuries assessed with MR imaging. Radiographics 20: 91-102, 2000
(7) Sugita T: Anatomic and biomechanical study of the lateral collateral and popliteofibular ligaments. Am J Sports Med 29: 466-472, 2001
(8) Wentorf FA, LaPrade RF, Lewis JL, Resig S: The influence of the integrity of posterolateral structures on tibiofemoral orientation when an anterior cruciate ligament graft is tensioned. Am J Sports Med 30: 796-799, 2002
John H. Quinn Jr. MS, ATC/L has been an Assistant Athletic Trainer at the University of Illinois for the past 4 years. He has previously served as a Certified Athletic Trainer at Indiana University and Northwestern University. He has been performing athletic training services for the sport of wrestling in the Big Ten since 1996. He earned his bachelors degree at the University of Florida and his Master of Science degree from Indiana University.
This article has been viewed 3554 times.