Factors predisposing to patellar chondropathy and patellar apicitis in athletes.

Factors predisposing to patellar chondropathy (the PC group) and inferior patellar apicitis (jumper's knee - the PA group) were sought by means of a questionnaire, detailed quantitative physical measurements and radiological examination in male athletes. There were 20 athletes in the two groups who had typical symptoms and signs of each disorder. A group of 20 high-level athletes without knee symptoms served as a control group. The factors found in the PC group which differed significantly from those in the control group included increased anterior drawer sign (p less than 0.05), increased passive mediolateral patellar range of movement (p less than 0.001) and increased hyperextension (p less than 0.05). More leg length inequality (p less than 0.001) and patella alta (p less than 0.05) was observed in the PA group than in the controls. There was statistically significant positive correlation between the different measurements of knee laxity (anterior drawer sign, passive mediolateral patellar movement and hyperextension) in the 60 cases. The correlation coefficient between the length of the patellar tendon and passive mediolateral patellar movement was 0.82 (p less than 0.001).