Generalized joint laxity and contralateral patellar hypermobility in unilateral recurrent patellar dislocators.

PURPOSE

The purpose of this study was to assess the relation between generalized joint laxity and patellar hypermobility in unilateral recurrent patellar dislocators.

TYPE OF STUDY

Case series.

METHODS

A total of 82 patients (23 male and 59 female patients) with unilateral recurrent patellar dislocation were studied compared with an age- and sex-matched control group. The modified Carter and Wilkinson criteria for generalized joint laxity and lateral patellar hypermobility test were examined.

RESULTS

Generalized joint laxity (score of 4 or 5) was present in 20 patients (24%) with recurrent patellar dislocation in 8 subjects (10%) of the control group. The mean total score was 2.5 (SD, 1.4) in the recurrent patellar dislocators and 1.7 (SD, 1.3) in the control group. The incidence of generalized joint laxity (P = .013) and the mean total score (P = .00004) were statistically significant between the two groups. A hypermobile patella was present in 42 patients (51%) and in 5 subjects (6%) of the control group. There was a large statistically significant difference between the two groups (P < .00001).

CONCLUSIONS

Although a hypermobile patella and generalized joint laxity were significant between the recurrent patellar dislocators and the control group, a hypermobile patella was more significant than generalized joint laxity as the predisposing factors of patellar dislocation.

LEVEL OF EVIDENCE

Level IV, prognostic case series.