Sports Update: Acute Patellar Dislocation, Knee Bracing and Patellar Tendinopathy

By Thomas Souza, DC, DACBSP

• Are there characteristics of patients who will suffer acute patellar dislocation?

• What are the effects of protective knee bracing on speed and agility?

• What is the outcome for conservative management of patients with patellar tendinopathy (jumper's knee)?

Patellar dislocation is a common event in sports. Over the years a profile of a young, overweight, sedentary adolescent girl as the prime victim has been developed. This study evaluated and followed 74 patients with acute, lateral patellar dislocation. The results seem to indicate a profile that has some common characteristics, however, that do not meet the stereotype once assumed. The findings are summarized below:

• 69% of patients were under 20 years of age.

• 72% of patients had their dislocation occur with sports; 21% with activities of daily living, and 7% due to a direct blow.

• There was a 50% incidence of patella alta (a high-riding patella).

• All patients demonstrated a lateral hanging patella (patella laterally displaced as seen on a tangential view).

• There was no statistically significant relationship with a history of lower extremity problems as a infant or child, and no apparent relationship to a family history of dislocation.

• At six months, 68% of patients noted limitation with strenuous activities.

There are conflicting reports of the benefit or risk in using prophylactic (used to prevent injury) knee braces. This study compared a number of braces to determine any effect on performance of the 40-yard dash and a four-cone agility drill. Performance was compared to a group not wearing any brace. In addition, they measured the degree of brace migration with these activities. A common complaint of knee braces is that they do not remain in place with activity, usually resulting in superior/inferior migration. The braces used were the DonJoy Legend, Breg Tradition, OMNI-ASK 101W, McDavid Knee Guard, and models I and II of the Air Armor Knee and Thigh Protection System. The results are as follows:

• In the 40-yard dash, the Air-Armor I and the OMNI did not seem to affect performance when compared to the control group (i.e., no brace).

• In the four-cone agility drill, only the Breg Tradition times were significantly slower than controls.

• The Air Armor I and the McDavid Knee Guard demonstrated the least amount of migration with the 40-yard dash compared with the other braces.

• In the four-cone agility drill, the Armor I and II showed less migration compared with the other braces.

Patellar tendinopathy can be a very difficult condition to deal with, given that it occurs in athletes who are high performers. Rest or major modification to activity is often a difficult prescription. As a result, those that try to maintain their level may find themselves in a surgical scenario. This study grouped patients according to a classification system. Stage one designates those individuals who have pain only with activity and have no apparent functional impairment. Stage two designates those with discomfort with activity and after activity, however, the individual can still perform at a satisfactory level. Stage three designates hose individuals who have pain with activity, and pain after activity is more prolonged. Stage three individuals cannot perform at a satisfactory level due to the pain. There were a total of 42 athletes. All were managed with nonsteroidal anti-inflammatory drugs, physical therapy, and exercise.

Exercise for the stage three athletes was initiated with isometric quadriceps contractions and stretching of the quads, hams, and adductors/abductors of the hip. There was also a focus on eccentric training of the quadriceps. At six months, 33 patients were asymptomatic and able to return to sports; nine patients in stage three required surgery. At a mean follow-up of 4.8 years, all patients were doing well. Those with stage two involvement faired better than those with stage three. This may indicate that the earlier the athlete is managed in the course of involvement based on symptoms, the better the outcome.

Thomas Souza,DC,DACBSP
San Jose, California