What is a recurrent patella dislocation? Well, if your patella (knee cap) shifts out of its position in the knee (dislocates) for more than once, then it is called recurrent patella dislocation. This condition is extremely painful. The dislocation may be transient and the patella may get back to its original position on its own, or sometimes the patella stays dislocated and it has to be relocated to its natural position by a physical maneuver by your doctor.
This mainly happens in two different scenarios. The first one is due to acute traumatic injures which may consist of sports injuries, road traffic accidents, or even trivial trauma while slipping and falling while walking. These individuals are usually normal individuals with normal anatomy of the bone, and with an absolutely normal knee before the traumatic event. The most common age group for such an injury would be in the second to the fourth decade. These individuals basically have a normal bony constitution, and the traumatic event leads to the tear of the medial stabilizer of the knee called and MPFL (Medial Patella Femoral Ligament). When there is a loss of medial stabilizer, the patella has a tendency to shift laterally and dislocate.
The other subset of individuals is the ones who are having developmental changes around the knee, which may predispose the patella to shift and dislocate on the outer aspect. This may be due to structural problems in the bone, alignment, rotation, the soft tissue structure around the knee, and often a combination of more than one of the above problems. Patients may present with multiple episodes of patella dislocation, pain on the anterior aspect of the knee, or J-Sign (dislocation of the patella or a lethal shift every time the patient straightens the knee).
The second subset of patients needs to be assessed carefully regarding getting the exact cause and the nature of the problem. Such patients may have generalized laxity of the ligaments. The position of the patella may be high than normal leading to inadequate engagement of the groove. Such patients may have bony issues like torsion of the thigh bone, excessive angulation of the knee leading to the increased stress of the patella. There may be a defect in the slot where the patella sits the socket of the thigh bone (femoral groove). It may also be due to defects in the formation of knee condyles. As you can see, the result depends on a thorough assessment of the patient by your doctor and understanding the nature of the injury in detail.
When you visit your doctor, they will perform a comprehensive assessment with clinical tests and investigations to provide you an individualized line of management. In acute scenarios, the knee may be swollen and tensed, and it may need to be decompressed. There is usually tenderness over the attachments of the MPFL ligament. The patella may sometimes be dislocated and such a patella has to be manually reduced into its natural position to relieve the pain. In chronic situations, your knee will be assessed for patellar position and stability by tests like patellar glide and patellar tilt. Patients have a typical apprehension of dislocation which can be demonstrated by shifting the patella laterally, also called as apprehension test.
After thorough clinical evaluation, patella dislocation often needs to evaluate with a combination of X-rays, CT scans,s and MRI scans. All these investigations have a specific role in diagnosis and choosing the best line of treatment for every patient. X-rays and CT scan help us identify the bony problems along with the presence of fractures or loose bodies, whereas MRI would identify the soft tissue irregularities and MPFL integrity.
As per, Dr. Abhishek Nerurkar, Consultant Orthopaedic Surgeon, first-time dislocations can be given a nonoperative trial, consisting of anti-inflammatory medicines, activity modification, and physical therapy. In severe cases, we can give short-term immobilization followed by 6 weeks of controlled motion. There is an emphasis on strengthening of quadriceps group of muscles, core and hip muscles.
Recurrent dislocators would often require a surgical intervention to get their problems resolved. An arthroscopy (keyhole surgery) is routinely performed to look for patella position under magnification. It also helps us to evaluate the concomitant knee problems under magnification and treat them at the same time. If there are any loose bodies or free bony fragments, then they are traced and removed by Arthroscopy.
If there is an injury to the medial stabilizer (MPFL), then we need to reconstruct the ligament with a soft tissue graft like a hamstring. Bony issues are corrected with various osteotomies and realignment procedures to restore the anatomy and dynamics of the knee. If there is a developmental problem in groove formation, then we need to create the groove by a procedure called trochleoplasty. A combination of all these procedures is done to give the best functional knee to the patient.
If you have recurrent patella dislocations, then a thorough assessment of the cause of your dislocation and a 360-degree comprehensive treatment of the knee would be the key to success to a well-performing and long-lasting knee. Visit your Orthopaedic doctor immediately to find the best solution for your knee to stay healthy and active !!
Dr. Abhishek Arun Nerurkar,
M.S. Orthopaedics., D.N.B. Orthopaedics.,
F. Sports Medicine and Arthroscopy, Germany,
F. Advanced Hip and Knee Joint Reconstruction (SICOT)