Case Study: Chronic Knee Dislocations Due to Work Injury

A 31 year old male patient came into the office complaining of continuous knee pain. He also complained that his kneecap would “give out”. During the examination, we determined the problems began back in 2008 following a work injury. The patient explained that during the incident, he had twisted his knee at work, which had caused his knee to dislocate.

At the time, the patient had been treated with physical therapy and a brace. He was able to return to work following the injury but continued to suffer with the symptoms described above for years. Upon examination, it was determined that he was suffering from chronic patella instability and multiple dislocations.

As part of the examination, we noted the following:

•           Knee swelling

•           Increased patella laxity

•           Positive patellar apprehension sign

•           Increased Q angle

Before determining the exact treatment protocol, the increased Q angle indicated the need to perform a CT scan to measure the distance between the tibial tubercle and the trochlear groove. This is referred to as the T-T distance. A T-T distance greater than 2.0 cm requires the anteromedial transfer of the tibial tubercle and will decrease the T-T distance. This will encourage improved stability of patella.

It was determined that the best treatment approach was to combine two surgical procedures at the same time. The first procedure is referred to as MPFL reconstruction. The medial patellofemoral ligament or MPFL is a thin band of tissue that attaches the kneecap to the inner part of the knee. When the kneecap dislocates, it often tears the MPLF on the inside of the knee, which is important for stability in the knee. During the procedure, the MPFL is reconstructed and re-attached in the most anatomically correct position. To do this, we used a hamstring allograft and replaced the torn MPFL.

The second procedure is referred to as anterio-medialization of the tibal tubercle. The operation focuses on recentering the patella and reduces patellofemoral contact pressure. This improves the Q angle and reduces lateral vector force on the reconstructed MPFL.

The surgery proved to be a success. Following surgery, the patient was in a hinged brace and utilized crutches for 4 weeks. He then completed 12 weeks of physical therapy that was focused on edema control, range of motion and strength training. He was able to return to his job as a laborer 3 months post-op. He is currently doing extremely well and no longer suffers from patellar instability. He currently works 50-60+ hours per week without difficulty. 

Why are women more susceptible to ACL tears?

In recent years, there has been discussion on why women and young girls are more susceptible to ACL tears. There are many theories on the reasons why, but today we will examine a main anatomic difference between men and women that is a contributing factor: the Q-Angle and wider pelvis.

The Q-angle is the angle at which the femur (upper leg bone) meets the tibia (lower leg bone). The Q-angle is determined by three areas of the human anatomy – the Anterior Superior Iliac Spine (ASIS), the center of the kneecap (patella) and the tibia tubercle.  The Q-angle is basically a line drawn from the ASIS down to the center of the kneecap to the tibia tubercle (see picture below).

The Q-angle in women is greater because women are anatomically built with a wider pelvis than men.  A normal Q-angle in men is 14 degrees, while women have a normal angle of 17 degrees. The greater the angle, the more at risk the person is for knee injuries, including ACL tears.

The fact that the q-angle is more pronounced in women than men leads to more stress on the knee joint and makes it less stable when put under stress. For this reason, when a woman participates in sports involving jumping, running or pivoting, she is naturally more likely to suffer an ACL tear. 

What can we do to prevent ACL tears in women?

Recently, emphasis is being placed on neuromuscular training programs.  Neuromuscular training teaches the body better biomechanic movements to improve the control of the dynamic knee stabilizers (the ACL and major ligaments that surround the knee).  Exercises that are included in a neuromuscular training program include stretching, plyometrics and strength training.  The goal of these programs is to teach athletes how to land, pivot and control the knee without placing as much force on the ACL.  One program was developed by the Santa Monica Sports Medicine Research Foundation and is known as the PEP Program: Prevent Injury and Enhance Performance. To learn more about this program, please visit http://smsmf.org/files/PEP_Program_04122011.pdf.  

If you suspect that you have an ACL tear or other orthopedic injury, it is important to see an Orthopedic Surgeon.  Skyview Orthopedic, the office of John Vitolo, MD is available to treat all your orthopedic injuries and concerns.  Our office is focused on treating each patient individually and offering the highest quality orthopedic care.  John Vitolo, MD holds dual board certification in Orthopedic Surgery and Sports Medicine. For more information call the office, 973-300-1553 or visit us online at www.skyvieworthopedic.com.