Muscle morphometric effect of anterior cruciate ligament injury measured by computed tomography: aspects on using non-injured leg as control

Abstract

BackgroundAnterior cruciate ligament (ACL) tears are common, functionally disabling, and predispose to subsequent injuries and early onset of osteoarthritis in the knee. Injuries result in muscular atrophy and impaired muscular activation. To optimize surgical methods and rehabilitation strategies, knowledge of the effects of ACL injuries on muscles size and function is needed. Asymmetry due to limb dominance implies that the effect of ACL-injury might be different in right-sided and left-sided injuries which, should be taken in account when evaluating the effect of an injury. Evaluation of the effects of injuries is usually made with the contralateral leg as control. The aim of this study is to describe the effect of ACL-injuries on thigh muscle size and also to analyze feasibility of using contralateral limb as control.MethodsSixty-two patients scheduled to undergo ACL reconstruction were examined with computed tomography (CT). Muscle cross sectional area (CSA) was recorded for quadriceps, hamstrings, gracilis and sartorius 15 cm above the knee joint. Comparisons were made between the injured and non-injured side and between individuals separated by gender and side of injury. Comparisons were also made for patients with or without concomitant meniscal tear, for patients differing in time between injury and examinations and for patients with different level of physical activity after the injury.ResultsQuadriceps CSA was 5% smaller on the injured side. There was an indication that the muscles of the right thigh were generally bigger than those of the left thigh. The difference between the injured and the non-injured side was larger for right-sided injuries than for left-sided. There was also a greater difference in semimembranosus for women than for men. There were no differences related to meniscal injury, time since injury or physical activity.ConclusionThe use of contralateral leg for evaluating the effect of ACL-injury is often the only available alternative but our study indicates that the difference in CSA between injured and non-injured side does not necessarily reflect the true degree of atrophy, as there are side differences both in muscle size in general and in the effect of an ACL-injury on muscle size.

Asymmetries in explosive strength following anterior cruciate ligament reconstruction

“…The underlying assumption has been that the legs were equal regarding the muscle size and strength prior to injury, while the properties of the uninvolved leg do not change over the rehabilitation period. However, this approach has been criticized since strength of the uninvolved side often decreases over time due to the cross-over inhibition of motor activation, as well as due to either de-conditioning or insufficient reconditioning [2, 29, 33, 49]. This concept is clearly supported by our findings where standard asymmetries in the quadriceps explosive strength were significantly lower than the corresponding real asymmetries.…”

Previous injury is associated with heightened countermovement jump force‐time asymmetries in professional soccer players

“…Further, medium effect sizes for other variables appear to indicate that at least with respect to bilateral CMJ performance, non‐dominant limb injuries may be associated with larger asymmetries. Few studies have examined this interaction, but Strandberg, Lindström, Wretling, Aspelin, Shalabi reported a larger inter‐limb quadricep cross‐sectional asymmetry area after a right side (typically the dominant limb) than a left side ACL injury in footballers awaiting surgery for reconstruction. Given these apparently contradictory findings which may need consideration in the rehabilitation process, the interaction between side of injury and magnitude of asymmetry/deficit warrants further investigation.…”

Quadriceps Muscle Size Following ACL Injury and Reconstruction: A Systematic Review

“…Three studies reported quadriceps CSA for both the ACL‐injured and contralateral limb prior to ACLR. In comparing the ACL‐injured limb to the contralateral limb, one study demonstrated a large, negative effect, one study demonstrated a moderate, negative effect, and one study demonstrated a small, negative effect. The effect size CIs of the two studies demonstrating a negative moderate or large, effect size did not cross zero indicating a meaningful difference, while the effect size CI of the study with a small, negative effect size did cross zero.…”

“…Using the modified Downs and Black checklist, assessment of the methodological quality of the 11 studies categorized five of the studies as low quality, 24,[41][42][43] five studies as moderate quality, 12,25,28,[44][45][46] and one study as high quality. 47 Table 2 (muscle volume) and Table 3 (CSA) contain a detailed description of the methodological quality assessment of each included article.…”