Recurrent Patella Dislocation

The patella is normally confined to the Trochlea groove during range of motion. The incidence of recurrent patella dislocation after the first traumatic dislocation is very high. But the term recurrent patella dislocation can be a spectrum of pathologies-

Recurrent dislocations 3 or more
Habitual patella dislocations with every knee flexion
Patella instability or sutle subluxations with spontaneous relocation
Patella abnormal tracking or malalignment
A lot of the literature is misleading because of the varied definition of patella instability. The true incidence of recurrence after a traumatic dislocation can be 25-50%. Cochrane review 2015 on surgical vs nonsurgical management highlights low evidence to suggest one particular treatment though the recurrence is lower at 2-5 years when surgically treated.

Atkin DM, Fithian DC, Marangi KS, et al. Characteristics of patients with primary acute lateral patellar dislocation and their recovery within the first 6 months of injury. Am J Sports Med 2000; 28:472 – 9

Xrays

Blackburne JS, Peel TE. A new method of measuring patellar height. J Bone Joint Surg Br 1977; 59:241 – 2

Dejour H, Walch G, Nove-Josserand L, Guier C. Factors of patellar instability: an anatomic radiographic study. Knee Surg Sports Traumatol Arthrosc. 1994. 2(1):19-26.

Grelsamer RP, Dubey A, Weinstein CH. Men and women have similar Q angles: a clinical and trigonometric evaluation. J Bone Joint Surg Br. 2005 Nov. 87(11):1498-501

Treatment

Physiotherapy

VMO strengthening and core strenghthening

McConnell Taping

Taping improves the onset timing of the VM and VL activity in favour of VMO.
Gilleard W, McConnell J, Parsons D. The effect of patellar taping on the onset of vastus medialis obliquus and vastus lateralis muscle activity in persons with patellofemoral pain. Phys Ther. 1998 Jan. 78(1):25-32

Bracing

The brace cannot replace the need for VMO strengthening. Bracing unloads painful structures, keeps the joint warm, provides proprioceptive feedback, and may assist in improving knee extension neuromuscular patterning

Neptune RR, Wright IC, van den Bogert AJ. The influence of orthotic devices and vastus medialis strength and timing on patellofemoral loads during running. Clin Biomech (Bristol, Avon). 2000 Oct. 15(8):611-8.

Surgical Algorithm

Our surgical algorithm has been in use since 2007. The programme includes adequate prehabilitation, detailed assessment of all clinical and radiological parameters and involves correcting bony (Trochlea dysplasia, Tibial tuberosity offset and patella height) and soft-tissue defects (MPFL repair/reconstruction, lateral release, VMO plasty) combined with articular cartilage management whenever appropriate

Key Questions in management
Immature skeleton vs Mature Skeleton
Dislocation vs pain
Bony and/or soft tissue abnormality
Cootjans K, Dujardin J, Vandenneucker H, Bellemans J. A surgical algorithm for the treatment of recurrent patellar dislocation. Results at 5 year follow-up. Acta Orthop Belg. 2013 Jun. 79(3):318-25