Patellar Instability

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Patellar Dislocation

Patellar instability / patellar dislocation occur, among other things, during the growth phase, e.g. as a result of a sudden twisting of the joint, due to joint malalignments, and through bone malformations.

When is surgery needed?

In the event of an initial patellar dislocation, surgery is performed for cartilage-bone injuries or collateral damage that makes a recurrence likely. Recurrent patellar dislocations are generally treated surgically. Prior to a surgical intervention, the underlying disorder (malalignment of the kneecap, leg axis malalignment, reduced depth of the patellar groove on the femur, general ligamentous laxity, rupture of the patellar retinaculum) must be precisely analysed. The type of surgical procedure depends on the results of this causal analysis.

What happens during surgery?

In milder cases of patellar dislocation, it is usually sufficient to repair or tighten the torn retaining ligaments of the kneecap, or to replace them using one of the patient's own tendons. These operations can be performed with arthroscopic assistance. In complex cases, open surgery involving bone procedures is necessary to correct joint malalignment or to improve patellar tracking.

Aftercare

Following such an operation, partial weight-bearing of the leg using forearm crutches, medicinal thrombosis prophylaxis, and physiotherapeutic treatment are required. The joint is stabilised by a special brace and mobility is restricted for 6 weeks.

Detailed information on patellar dislocation, patellar instability, and MPFL reconstruction can be found here.