In the past patella dislocation was primarily treated conservatively with close reduction (reducing a bone without surgery) followed by immobilisation in a brace for up to 6 weeks. Treatment involved physiotherapy and rehabilitation with a strong focus on:
• Quadriceps, VMO strengthening exercises.
• Inner range quads exercises with knee at 0-30°.
• Stretching of hamstrings, ITB, and retinaculum.
• Patellar taping, proprioceptive exercises.
• Behavioural modification.
If conservative treatment failed and the patient continued to complain of pain or developed recurrent dislocations of the patella, then surgical management was the next step. There are more than 100 procedures described to treat patella malalignment, which suggests there is no one proven technique to be the best in treating this condition.
A/Prof Munjed Al Muderis’ approach:
It is common that there is intra-articular damage resulting from patella dislocation. A physical examination can reveal instability of the knee but the best current method of identifying a torn or damaged medial patellofemoral ligament (MPFL) is by using both plain radiograph and MRI scans in order to reach the appropriate diagnosis.
If surgery is indicated then the best evidence based medicine suggests restoration of anatomy and early mobilisation provides the best outcome. A/Prof Al Muderis applies this principle by reconstructing the ruptured MPFL thus restoring anatomy. Early rehabilitation starts the first week after surgery with the primary aim to increase the range of movement. The aim is to achieve more than 90 degrees of flexion in the first six weeks as well as restoring the muscle strength during this same period.
This type of aggressive rehabilitation can only be achieved by using a strong reliable graft such as the LARS (Ligament Augmentation and Reconstruction System) ligament, which is strong enough to provide initial stability of the joint and a scaffold for the natural ligament to heal and grow back over the graft. This technique has been used with a high success rate and minimal adverse outcome.
LARS ligaments are artificial ligaments used for the intra or extra-articular reconstruction of ruptured ligaments. Used to reconstruct a torn MPFL they are designed to mimic the normal anatomic ligament fibres in the knee. The intra-articular longitudinal fibres resist fatigue and allow fibroblastic growth. The extra-articular woven fibres provide strength and resistance to stretch.
LARS ligaments can be used in conjunction with suturing to the remaining section of the ruptured ligament, or as a stand-alone reconstruction.
The ligaments are precisely selected according to the weight and activity level of each patient.
Using LARS ligaments can reduce surgery time considerably because no additional harvesting of grafts is needed. Thus the patient can expect a faster return to full function compared to after MPFL reconstruction using hamstring tendon grafts. This is largely due to LARS allowing the original ligament tissues to heal in the absence of traction.
Traditional surgeries such as tibial tubercule osteotomy, patellar tendon transfer, VMO advancement and trochealioplasty all involve significant modification to the patient anatomy, which may make future surgery such as knee arthroplasty much more difficult and this may eventually lead to a poor outcome. However, the MPFL Reconstruction using LARS ligaments does not involve any major alteration to the patient’s anatomical structures, which makes it easy to perform any further surgeries in the future if they are required.