The patella or knee cap is a lens shaped bone situated at the front of the knee. It is incorporated into the tendon of the quadriceps muscles of the thigh and moves within a groove at the lower end of the thigh bone (femur). Patellar dislocation occurs when the patella completely moves out of this groove. It commonly occurs in young and physically active people, often during sporting activities.
When the patella dislocates, injury to the soft tissues of the knee joint occurs, which requires a period of rehabilitation. This may include treatments such as immobilisation and bracing to limit knee movement, exercises, manual therapy, taping and electrotherapeutic modalities. Some surgeons have suggested that people may have a better outcome if surgical procedures repairing or reconstructing the injured soft tissues, or carrying out other procedures to restrain the knee cap from dislocating again.
This Cochrane review included five studies (339 participants) which have looked at the results of surgery compared with non-surgical treatment alone for people who have sustained a knee cap dislocation. All the trial participants were being treated for a primary (first-time) dislocation. These studies were small and had some weaknesses in their design and conduct.
Based on pooled data from all five studies, the review found no significant differences between surgical and non-surgical management for risk of recurrent dislocation or in the scores of a condition-related knee outcome measure. The pooled data from three studies indicated no difference between the treatment groups for the need for subsequent operations. The only study reporting complications reported that all four treatment complications occurred in the surgical management group.
The review concluded that there was insufficient evidence to confirm a significant difference in outcome between surgical or non-surgical initial management of people who have sustained a patellar dislocation. Further research is recommended.