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. 2021 Jun 24;3(4):e1165-e1170.
doi: 10.1016/j.asmr.2021.05.004. eCollection 2021 Aug.

Radiographic Cam Morphology of the Hip May Be Associated with ACL Injury of the Knee: A Case-Control Study

Andrew L Schaver  1 , Kushtrim Grezda  1   2 , Michael C Willey  1 , Robert W Westermann  1
Affiliations

Radiographic Cam Morphology of the Hip May Be Associated with ACL Injury of the Knee: A Case-Control Study

Andrew L Schaver et al. Arthrosc Sports Med Rehabil. .

Abstract

Purpose: To evaluate femoral and acetabular morphology in patients who underwent anterior cruciate ligament reconstruction (ACLR).

Methods: A retrospective review of a prospectively collected ACL registry was performed to identify patients with pelvis radiographs before undergoing either primary or revision ACLR between January 2010 and August 2020. Alpha angle (AA), head-neck offset ratio (HNOR), lateral center edge angle (LCEA), and crossover sign (COS) were measured on the operative side. Values were compared to a negative control group that did not significantly differ in age, sex, or body mass index. Univariate analysis and Pearson's correlation coefficient were used to compare groups with significance defined as P < .05.

Results: In total, 114 patients were included (ACL, n = 38; control, n = 76). Eleven primary and 27 revision ACL reconstructions were identified. The mean AA in patients undergoing primary ACL reconstruction was higher than control (67.45° ± 11.30° vs 51.5° ± 10.8°, P < .001). A significantly elevated AA was also found in those undergoing revision ACL surgery (61.8° ± 7.51° vs 51.5° ± 10.8°, P < .001). In addition, the HNOR was significantly lower in the ACL group (0.12 ± 0.03 vs 0.14 ± 0.04, P = .0304). Acetabular morphology was similar between groups (LCEA, ACL 31.97° ± 5.04° vs control 30.01° ± 5.17°, P = .0549; COS, ACL 9 of 38 (23.7%) vs control 18 of 76 (23.7%), P = 1.00).

Conclusion: An association exists between radiographic cam morphology of the hip and patients who previously underwent ACLR.

Level of evidence: III, retrospective comparison study.

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Figures

Fig 1
Fig 1
Anteroposterior view of the right hip from the same patient. (A) Depiction of alpha angle (72.06°), and (B) head/neck offset ratio (0.07). Measurements were taken using a digital goniometer (PACS Imaging, Vue Motion; Carestream Health, Rochester, NY).
Fig 2
Fig 2
Box and whisker plot of median ± interquartile range (IQR) of alpha angle (AA, °) for control (median 50°, IQR 42.9°-57°) and anterior cruciate ligament (ACL) groups (median 61°, IQR 58.1°-69.6°). Mean AA represented by point X (control, 51.5°; ACL, 63.4°).
See this image and copyright information in PMC

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