No Association Between Hamstrings-to-Quadriceps Strength Ratio and Second ACL Injuries After Accounting for Prognostic Factors: A Cohort Study of 574 Patients After ACL-Reconstruction

Sports Medicine - Open

Table 3 Hamstrings-to-quadriceps strength ratio for the odds of sustaining an ipsilateral and contralateral anterior cruciate ligament injury

	Value	n (%) of event	Univariable*		Area under ROC curve (95%CI)	Multivariable**
	Value	n (%) of event	OR (95%CI)	p value	Area under ROC curve (95%CI)	OR (95%CI)	p value
Ipsilateral ACL injuries
HQ-ratio (ACL reconstructed side) (%)	30.9–< 52.9	19 (10.4%)
	52.9–< 61.1	7 (3.8%)
	61.1–139.0	10 (5.5%)	0.97 (0.94–1.00)	0.051	0.60 (0.51–0.70)	0.97 (0.94–1.01)	0.12
Tegner preinjury n (%)	6–< 8	6 (3.5%)
	8–< 9	13 (5.5%)
	9–10	17 (7.4%)	1.28 (0.96–1.71)	0.097	0.58 (0.49–0.66)	1.10 (0.79–1.53)	0.58
Contralateral ACL injuries
HQ-ratio (uninjured side) (%)	32.0–< 51.6	14 (7.8%)
	51.6–< 57.7	6 (3.3%)
	57.7–104.3	8 (4.5%)	0.97 (0.92–1.02)	0.19	0.58 (0.45–0.70)	0.97 (0.92–1.02)	0.24
Tegner preinjury n (%)	6–< 8	3 (1.8%)
	8–< 9	10 (7.0%)
	9–10	15 (6.6%)	1.37 (0.98–1.92)	0.063	0.60 (0.52–0.68)	1.39 (0.99–1.95)	0.056

A bold p-value indicates a significance (p < 0.05). ACL anterior cruciate ligament, CI confidence intervals, HQ hamstrings-to-quadriceps, n numbers, OR odds ratio, ROC receiver operating curve, Tegner Tegner activity scale
*All analyses were performed with univariable logistic regression
**Multivariable logistic regression model including hamstrings-to-quadriceps strength ratio (ACL reconstructed side) and Tegner preinjury. Area under the ROC curve with 95% CI for multivariable model = 0.66 (0.57–0.74)