Imaging Approaches for Accurate Determination of the Quadriceps Angle

Abstract

Objectives A retrospective study was conducted using magnetic resonance image (MRI) and a full‐length standing scanogram (FLSS) to measure the quadriceps angle (Q‐angle) while avoiding soft tissue interference. Methods Two steps were retrospectively carried out in two case series. The first step involved using MRI to define the standardized patellar center (PC) and the tibial tubercle (TT) on the frontal plane of the MRI in one group of 60 consecutive patients (from July 2016 to December 2016, 29 men and 31 women, average of 46 years). The next step was transferring the location of the standardized PC and the TT from the MRI to the FLSS in another group of 100 consecutive patients (from April 2009 to March 2014, 50 men and 50 women, average of 36 years). The pelvis and intact femur, knee, and tibia were used to determine the Q‐angle on the FLSS. Results The standardized PC was positioned 42% from the lateral end of femur trans‐epicondylar line. The TT was 2 cm distal to the tibial articular surface and 37% from the lateral end of tibial width. The average Q‐angle was 9.5° in 100 patients (8.8° in 50 men and 10.1° in 50 women, P = 0.02). The average femoral length was 42.9 cm in 100 patients (44.7 cm in 50 men and 41.1 cm in 50 women, P < 0.001). Women and men had similar pelvic width (27.9 vs 27.8 cm, P = 0.89). Conclusion Using the FLSS may help to accurately determine the Q‐angle. Men and women have similar pelvic width. A larger Q‐angle in women may be mainly due to the shorter femur.

Challenging the assumption of uniformity in patellar tendon structure: Regional patellar tendon morphology and mechanical properties in vivo

“…Males had longer lengths in the lateral region of their patellar tendon compared with the medial and central regions, while females did not. This was expected, considering that females have a static knee position with larger knee abduction angle compared with males 26 . Similar results were observed by Yanke et al 10 that found that the lateral region of the patellar tendon is longer than the medial and central regions in a study with male cadavers.…”

“…This was expected, considering that females have a static knee position with larger knee abduction angle compared with males. 26 Similar results were observed by Yanke et al 10 that found that the lateral region of the patellar tendon is longer than the medial and central regions in a study with male cadavers. This finding may in part explain the differences in prevalence of patellar tendinopathy between sexes.…”

A novel limb‐salvage reconstruction strategy with a custom hemipelvic endoprosthesis and preserved femoral head following the resection of periacetabular tumors: A preliminary study

“…Postoperative functional assessment was performed using the Musculoskeletal Tumor Society (MSTS) Functional Scoring System and the Toronto Extremity Salvage Score (TESS) 24,25 . The measurement of the length of the lower limb was conducted via a full‐length standing scanogram 26 …”

“…24,25 The measurement of the length of the lower limb was conducted via a full-length standing scanogram. 26…”

Patellar malalignment: A common disorder associated with knee pain

“…The causes of PM have been enthusiastically pursued, and three predisposing factors have been advocated: imbalanced peripatellar soft-tissue tension, lower-extremity malalignment, and bone or muscle anomalies ( Table 1 ) [ 17 ]. Among them, the first factor is considered the most important, for which nonsurgical treatment is generally effective.…”