No abstract

Context Postoperative functional and return-to-sport outcomes after anterior cruciate ligament reconstruction (ACLR) differ by sex. However, whether sex disparities are observed in patient-reported outcome measures (PROMS) before return to sport after ACLR is unclear. Objectives To compare common PROMS between young men and women who had not yet returned to sport after ACLR. Design Cross-sectional study. Setting University laboratory. Main Outcome Measure(s) Forty-five young men (age = 18.7 ± 2.7 years, time since surgery = 6.8 ± 1.4 months) and 45 matched for age (±1 year) and time since surgery (±1 month; age = 18.8 ± 2.8 years, time since surgery = 6.9 ± 1.4 months) with ACLR participated. Participants completed the Tegner Activity Scale, ACL Return to Sport After Injury scale, Tampa Scale of Kinesiophobia, International Knee Documentation Committee (IKDC) Subjective Knee Evaluation Score, and Knee Injury and Osteoarthritis Outcome Score (KOOS). The PROMS were compared between men and women using Mann-Whitney U tests. Odds ratios were calculated to evaluate the odds of a male reporting a PROM value above the previously established normative value as compared with a female. Results Sex differences were present for the IKDC score (P = .01) and KOOS Pain score (P = .04) but not for the Tegner activity level (P = .22), ACL Return to Sport after Injury scale score (P = .78), Tampa Scale of Kinesiophobia score (P = .64), or other KOOS subscales (P values = .40 to .52). The odds of reporting values above normative levels differed only for the IKDC score (odds ratio = 2.72, 95% confidence level = 1.16, 6.38). Conclusions After ACLR, young men and women reported similar levels of knee-related function, fear of movement, and readiness for return to sport and were equally likely to meet clinically meaningful normative values before return to sport. Overreliance on patient reports or objective functional outcomes in evaluating patient progress and readiness for return to sport after ACLR may limit clinicians in their ability to comprehensively evaluate and develop individualized interventional approaches that optimize patient outcomes.

Image‐based assessments of quadriceps muscle size facilitate examination of structural changes after anterior cruciate ligament (ACL) injury and reconstruction (ACLR). Understanding the effects of ACLR on muscle size measures may aid in clarifying the contribution of quadriceps atrophy toward quadriceps strength. The purpose of this study was to systematically review the literature examining the effects of ACLR on quadriceps muscle volume and cross‐sectional area (CSA). An online database search was conducted using Web of Science, SportDISCUS, PubMed (Medline), CINHAL (EBSCO), and Cochrane Library limited to articles published after January 1, 1980. Means and standard deviations were extracted for the ACLR limb and the contralateral limb, and sample characteristics from relevant articles. Magnitude of between limb differences were assessed using pooled effect sizes (Hedge's g) and 95% confidence intervals. Eleven articles (five CSA, six muscle volume) were included in this systematic review. Included studies reported negative effective sizes, indicating that the ACLR limb was smaller in CSA or muscle volume compared with the contralateral limb; however, 36% of the included articles reported meaningful difference between the limbs. Quadriceps atrophy may occur following ACL injury and persist after rehabilitation, however, the magnitude of these reductions may not be clinically meaningful and may only partially explain the persistent quadriceps weakness that is ubiquitous among this patient population. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:598–608, 2020

Undernutrition during early life causes chronic disease with specific impairments to the heart and skeletal muscle. The purpose of this study was to determine the effects of early life undernutrition on adult exercise capacity as a result of cardiac and skeletal muscle function. Pups were undernourished during gestation (GUN) or lactation (PUN) using a cross-fostering nutritive mouse model. At postnatal day 21, all mice were weaned and refed a control diet. At postnatal day 67, mice performed a maximal treadmill test. Echocardiography and Doppler blood flow analysis was performed at postnatal day 72, following which skeletal muscle cross-sectional area (CSA) and fiber type were determined. Maximal running capacity was reduced (diet: P = 0.0002) in GUN and PUN mice. Left ventricular mass (diet: P = 0.03) and posterior wall thickness during systole (diet × sex: P = 0.03) of GUN and PUN mice was reduced, causing PUN mice to have reduced (diet: P = 0.04) stroke volume. Heart rate of GUN mice showed a trend (diet: P = 0.07) towards greater resting values than other groups. PUN mice had greater CSA of soleus fibers. PUN had a reduced (diet: P = 0.03) proportion of type-IIX fibers in the extensor digitorum longus (EDL) and a greater (diet: P = 0.008) percentage of type-IIB fibers in the EDL. In conclusion, gestational and postnatal undernourishment impairs exercise capacity.

No abstract