International Orthopaedics December 2011, Volume 35, Issue 12, pp 1791–1797

Comparison of five patellar height measurement methods in 90° knee flexion

Anagnostakos, K., Lorbach, O., Reiter, S. et al.
Knee

Purpose

The aim of this prospective study was to evaluate the patellar height in 90° knee flexion.

Methods

A total of 85 patients with 95 knee joints were included in the study. Patellar height was measured according to the Blackburne-Peel, Labelle-Laurin, Insall-Salvati, Linclau, and Caton-Deschamps methods in the whole group and in subgroups based on age, gender, and side.

Results

The BP-ratio showed a patella norma in 45 cases, and in 25 cases a patella alta and infera, respectively. The Labelle-Laurin method determined a patella norma in eight knees, in 35 a patella alta and in 52 a patella infera. The IS-ratio revealed a patella norma in 52 patients, a patella alta in six and in 37 a patella infera. The Linclau method demonstrated in 52 cases a patella norma, in 17 a patella alta and in 26 a patella infera. The CD-ratio showed the highest values of a patella norma among all tested methods in 67 knees, whereas a patella alta was evident in 13 and a patella infera in 15 cases. In the subgroups, discrepancies depended on the subgroup and method used.

Conclusions

Our results demonstrate a method-dependent discrepancy in the measurement of patellar height. A future study should evaluate this effect in a direct comparison between 30° and 90° knee flexion.


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