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Knee: R. P. Grelsamer, A. Dubey, and C. H. Weinstein Men and women have similar Q angles: A CLINICAL AND TRIGONOMETRIC EVALUATION J Bone Joint Surg Br 2005; 87-B: 1498-1501 [Abstract] [Full text] [PDF]

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Men and women have similar Q angles: A CLINICAL AND TRIGONOMETRIC EVALUATION

JAGDISH MENON   (23 January 2006)

Men and women have similar Q angles: A CLINICAL AND TRIGONOMETRIC EVALUATION 23 January 2006
JAGDISH MENON, Associate Professor of Orthopaedics Jawaharlal Institue Of Postgraduate Medical Education and Research, Pondicherry, INDIA 605006. Send letter to journal: Re: Men and women have similar Q angles: A CLINICAL AND TRIGONOMETRIC EVALUATION jagdishmenon{at}yahoo.co.uk JAGDISH MENON	Sir, This paper made interesting reading. I have the following observations: 1. The suggested explanation for an increased Q angle in females is the increased femoro-tibial angle (Genu valgum) rather than a wide pelvis. Though the female pelvis is accepted as wider, this usually refers to the pelvic cavity. The distance between the two anterior iliac spines (interspinous distance) is comparable in males and females. Therefore any difference in Q angle between males and females is less likely to be due to a lateralisation of the anterior superior iliac spine. The authors have not addressed the relationship of the patella to the tibial tuberosity, which is a more important determinant of the Q angle. The fact that females have a larger physiological genu valgum (due to their wider pelvises) is well documented. If males and females have identical Q angles, there should be some compensatory measurement to negate the higher genu valgum values in females. Perhaps incorporating femoro-tibial values in the study would have helped. 2. Converting triangle ABC (in Figure 1) into a right-angled triangle gives an incorrect estimation of the Q angle since it assumes that the patella and the tibial tuberosity are in a straight line. In most knees the tibial tuberosity is more laterally placed, thereby adding on to the Q angle. 3. While measuring the Q angle it is best that the knee is extended (zero position), as flexion tends to alter any angulation at the knee (valgum or varum). J. MENON, Associate Professor of Orthopaedics, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry India.