Current concepts in the treatment of first-time patella dislocation in children and adolescents

Abstract

Background: Lateral dislocation of the patella is a common injury in children. It can occur in previously healthy and anatomically normal knees, but there are several abnormalities that predispose to patellar instability. Magnetic resonance imaging is an essential part of assessing for associated injuries and risk of further instability. Treatment aims to prevent redislocation, residual instability, osteoarthritis, and allow return to previous activities. The purpose of this review was to assess evidence for management of first-time patella dislocation in children and adolescents.

Methods: Literature review was performed, accompanied by the current best practice by the authors.

Results: Non-operative treatment is preferred, except where there are associated injuries such as osteochondral fractures that would benefit from surgery. The exact method of ideal non-operative management is not clearly defined but should focus on restoration of range of movement and strength with bracing as indicated. There seems to be a trend toward operative intervention that may well be inappropriate.

Conclusion: Further prospective studies are required with focus on the younger patient to fully understand if there is an at-risk group that would benefit from early surgery.

Level of evidence: level III.

Keywords: First-time dislocation; children and adolescents; patella; sport injury; treatment options.

Figure 1.

(a) Patella alta (Figure 1a) can be measured with MRI, using the Caton–Deschamps Index. The length of the patellar articular surface and its shortest distance from the tibia are compared with the normal value (B/A) < 1.3. (b) Patellotrochlea index is another reliable index to measure and evaluate patella alta: The length of the trochlear cartilage overlapping the patellar cartilage (C) is compared to maximal length of the patella (D). The mean patellotrochlear index is 32%. (c) There are several variables describing dysplasia of trochlear sulcus; however, the trochlear depth is among the most important. Measurement is performed 3 cm above the joint line by comparing the highest bone distance (E) and lowest bone distance at the sulcus (F). Sulcus depth >3 mm is taken as normal.

Figure 2.

Example of a patella stabilizing brace that can be used for recovery following a first-time dislocation.