Dislocation of the kneecap or patella is rare, but when it happens, it is disabling and can result in complications. The authors of this study found 154 cases of kneecap dislocation written up in the literature and they found that 144 (94 percent) of the patients had undergone surgery. The authors also found that many of the patients experienced complications and needed revisions of the surgery later on.
In this study, the researchers wanted to evaluate the effectiveness of an arthroscopic surgery to fix the dislocated kneecap. This type of surgery requires a couple of small incision for the narrow tools, which are then inserted into the knee to make the repairs. Seven patients with 9 injured knees took part in this study; 6 were women. They were aged from 15 to 38 years, the average age was 25. Three patients had hurt their knees while participating in sports. The time that had passed between the injury and the surgery varied quite a bit, from 6 to 48 months, with the average being 28 months. All of the patients had decreased their level of activity and 5 were severely restricted since the knee injury.
After undergoing the arthroscopic surgery, the patients were told that they could bear weight as they could tolerate and that they should use crutches until they could walk without a limp. They were given exercises and were supervised by a physiotherapist. The patients were allowed to begin, if they wished, to jog, cycle and/or swim 2 months after their surgery, and they could return to their regular sports once they were able to regain full range of motion and full strength in their knees.
The researchers found that the 2 patients who had hurt both knees were so pleased with their surgery outcome on 1 knee that they arranged to have the second knee repaired the same way, one 6 months later, one 18 months later. Of the 9 patients, all were able to regain full range of motion an average of 4 weeks after surgery. The 3 patients who had previously participated in sports were able to resume playing within 6 months of the surgery. After follow-up of between 1 and 8 years (average 2.7 years), none of the patients had any complaints about their repaired knees. There was 1 patient how had re-injured her knee in another accident, 5 years after surgery.
The authors point out that there are weaknesses in the study, including the small number of patients. They also did not have a control group with which to compare the patients. However, the authors conclude that the surgery is successful in treating this type of injury while avoiding the complications that exist with traditional knee repair surgery.