Strength Training Effects on Muscular Regeneration after ACL Reconstruction

Friedmann‐Bette, Birgit; Profit, Francesca; Gwechenberger, Thomas; Weiberg, Nadine; Parstorfer, Mario; Weber, Marc‐André; Streich, N.; Barié, Alexander

doi:10.1249/mss.0000000000001564

Cited by 31 publications

(61 citation statements)

References 25 publications

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“…The CSA of quadriceps muscles after ACLR with QT autografts has been reported in only 1 other study in which the CSA increased after eccentric strength training. 6 LSIs in that study were 82% to 84% for CSAs of quadriceps muscles, which are similar to values in our study. It should be noted, however, that comparing graft types was not the primary aim of that study.…”

Section: Discussionsupporting

confidence: 90%

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Quadriceps Recovery After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Versus Patellar Tendon Autografts

Hunnicutt

Gregory

McLeod

et al. 2019

Orthopaedic Journal of Sports Medicine

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Background: Quadriceps tendon (QT) autografts are being increasingly used for anterior cruciate ligament reconstruction (ACLR). A paucity of studies exist that compare QT autografts with alternative graft options. Additionally, concerns exist regarding quadriceps recovery after graft harvest insult to the quadriceps muscle-tendon unit. Purpose/Hypothesis: The purpose of this study was to compare quadriceps recovery and functional outcomes in patients with QT versus bone–patellar tendon–bone (BPTB) autografts. The hypothesis was that those with QT autografts would demonstrate superior outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Active patients with a history of primary, unilateral ACLR with soft tissue QT or BPTB autografts participated. Quadriceps recovery was quantified using variables of strength, muscle size, and activation. Knee extensor isometric and isokinetic strength was measured bilaterally with an isokinetic dynamometer and normalized to body weight. Quadriceps activation was measured with the superimposed burst technique. The maximal cross-sectional area of each quadriceps muscle was measured bilaterally using magnetic resonance imaging. Assessors of muscle size were blinded to the graft type and side of ACLR. Functional tests included hop tests and step length symmetry during walking, measured via spatiotemporal gait analysis. Self-reported function was determined with the International Knee Documentation Committee (IKDC) questionnaire. Neuromuscular and functional outcomes were expressed as limb symmetry indices (LSIs: [surgical limb/nonsurgical limb]*100%). Wilcoxon rank-sum tests were used to compare the LSIs and IKDC scores between groups. Results: There were 30 study participants (19 male, 11 female; median age, 22 years [range, 14-41 years]; median time since surgery, 8 months [range, 6-23 months]), with 15 patients in each group. There were no significant between-group differences in demographic variables or outcomes. LSIs were not significantly different between the QT versus BPTB group, respectively: knee extensor isokinetic strength at 60 deg/s (median, 70 [range, 41-120] vs 68 [range, 37-83]; P = .285), activation (median, 95 [range, 85-111] vs 92 [range, 82-105]; P = .148), cross-sectional area of the vastus medialis (median, 79 [range, 62-104] vs 77 [range, 62-95]; P = .425), single-leg hop test (median, 88 [range, 35-114] vs 77 [range, 49-100]; P = .156), and step length symmetry (median, 99 [range, 93-104] vs 98 [range, 92-103]; P = .653). The median IKDC scores between the QT and BPTB groups were also not significantly different: 82 (range, 67-94) versus 83 (range, 54-94); respectively ( P = .683). Conclusion: Patients with QT autografts demons...

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Section: Discussionsupporting

confidence: 90%

“…Secondary analysis of graft types (QT and hamstring tendon autografts) did not affect results. 6 Interestingly, we studied each of the quadriceps muscles and found varying amounts of limb symmetry between muscles (ie, limb symmetry in rectus muscles was higher than in vastus muscles). This certainly warrants further investigation.…”

Section: Discussionmentioning

confidence: 99%

Quadriceps Recovery After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Versus Patellar Tendon Autografts

Hunnicutt

Gregory

McLeod

et al. 2019

Orthopaedic Journal of Sports Medicine

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“…High-intensity eccentric exercise has been touted as superior to eliciting muscle hypertrophy over concentric exercise, partially due to a greater recruitment of high-threshold type II muscle fibers, which are selectively atrophied after ACLR. 5,19 However, substantially less is known about the effect of high-intensity exercise (either concentric or eccentric) on muscle intramuscular PF, which would be particularly important information for clinicians and researchers. Cadore et al 3 reported reductions in vastus lateralis echo intensity (a surrogate for intramuscular PF) after 6 weeks of progressive isokinetic exercise, but they noted that the magnitude of improvements did not differ between eccentric or concentric training groups.…”

Section: Discussionmentioning

confidence: 99%

Longitudinal Assessment of Quadriceps Muscle Morphology Before and After Anterior Cruciate Ligament Reconstruction and Its Associations With Patient-Reported Outcomes

Garcia

Curran

Palmieri-Smith

2020

Sports Health: A Multidisciplinary Approach

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Background: Reductions in muscle size are common after anterior cruciate ligament reconstruction (ACLR) and may contribute to suboptimal patient outcomes. However, few studies have quantified postoperative alterations in muscle quality and evaluated its associations with patient-reported function. Hypotheses: Rectus femoris cross-sectional area (CSA) will decrease postoperatively but improve at return to activity (RTA), rectus femoris muscle quality (percentage fat [PF]) will increase postoperatively and be greater at RTA compared with preoperative values, and rectus femoris CSA and PF will be associated with International Knee Documentation Committee (IKDC) scores at both postoperative time points. Study Design: Case series. Level of Evidence: Level 4. Methods: A total of 26 individuals who sustained an ACL injury and underwent reconstructive surgery were evaluated preoperatively (T0), 9 weeks post-ACLR (T1), and at RTA. Rectus femoris CSA and PF were evaluated bilaterally via ultrasound imaging, and patient-reported function was assessed using the IKDC score. Results: Bilateral reductions in rectus femoris CSA were noted from T0 to T1 ( P < 0.01). Only the uninvolved limb returned to preoperative CSA ( P = 0.80), as the involved limb failed to return to preoperative levels at RTA ( P = 0.04). No significant changes in rectus femoris PF were observed across time points ( P > 0.05). Lesser PF ( P < 0.01) but not CSA ( P = 0.75) was associated with higher IKDC score at T1. Lesser PF ( P = 0.04) and greater CSA ( P = 0.05) was associated with higher IKDC score at RTA. Conclusion: Substantial atrophy occurs bilaterally after ACLR, and the involved limb does not return to preoperative muscle size despite the patient completing rehabilitation. Quadriceps muscle morphology is associated with patient-reported function and may be an important rehabilitation target after ACLR. Clinical Relevance: Quadriceps atrophy and poor muscle quality may contribute to suboptimal patient functioning and quadriceps dysfunction and may be important in RTA decision making. Assessing muscle morphology using ultrasound may be a feasible and clinically beneficial tool in patients after ACLR.

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“…IGF-1 induces satellite cell proliferation, 16 and increased satellite cell activation is correlated with greater strength gains in resistance training programs, 34 but the satellite cells of patients undergoing ACLR have deficits in activation after resistance exercises. 12 IGF-1 may therefore protect patients undergoing ACLR from muscle weakness in part by promoting satellite cell activity, which could improve strength gains that result from resistance exercises in a postoperative rehabilitation program. Additionally, resistance exercises directly increase myofibrillar protein synthesis and force production in skeletal muscle.…”

Section: Discussionmentioning

confidence: 99%

The Use of Recombinant Human Growth Hormone to Protect Against Muscle Weakness in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Pilot, Randomized Placebo-Controlled Trial

et al. 2020

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Background: Anterior cruciate ligament (ACL) tears are common knee injuries. Despite undergoing extensive rehabilitation after ACL reconstruction (ACLR), many patients have persistent quadriceps muscle weakness that limits their successful return to play and are also at an increased risk of developing knee osteoarthritis (OA). Human growth hormone (HGH) has been shown to prevent muscle atrophy and weakness in various models of disuse and disease but has not been evaluated in patients undergoing ACLR. Hypothesis: Compared with placebo treatment, a 6-week perioperative treatment course of HGH would protect against muscle atrophy and weakness in patients undergoing ACLR. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 19 male patients (aged 18-35 years) scheduled to undergo ACLR were randomly assigned to the placebo (n = 9) or HGH (n = 10) group. Patients began placebo or HGH treatment twice daily 1 week before surgery and continued through 5 weeks after surgery. Knee muscle strength and volume, patient-reported outcome scores, and circulating biomarkers were measured at several time points through 6 months after surgery. Mixed-effects models were used to evaluate differences between treatment groups and time points, and as this was a pilot study, significance was set at P < .10. The Cohen d was calculated to determine the effect size. Results: HGH was well-tolerated, and no differences in adverse events between the groups were observed. The HGH group had a 2.1-fold increase in circulating insulin-like growth factor 1 over the course of the treatment period ( P < .05; d = 2.93). The primary outcome measure was knee extension strength, and HGH treatment increased normalized peak isokinetic knee extension torque by 29% compared with the placebo group ( P = .05; d = 0.80). Matrix metalloproteinase–3 (MMP3), which was used as an indirect biomarker of cartilage degradation, was 36% lower in the HGH group ( P = .05; d = –1.34). HGH did not appear to be associated with changes in muscle volume or patient-reported outcome scores. Conclusion: HGH improved quadriceps strength and reduced MMP3 levels in patients undergoing ACLR. On the basis of this pilot study, further trials to more comprehensively evaluate the ability of HGH to improve muscle function and potentially protect against OA in patients undergoing ACLR are warranted. Registration: NCT02420353 ( ClinicalTrials.gov identifier)

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Strength Training Effects on Muscular Regeneration after ACL Reconstruction

Abstract: CON/ECC leads to significantly greater muscle hypertrophy compared with CON/ECC, but without the hypothesized enhancing effect on SC activation. At the same time, CON/ECC+ induces a less favorable slower muscle phenotype for strong and fast movements.

Cited by 31 publications

References 25 publications

Quadriceps Recovery After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Versus Patellar Tendon Autografts

Quadriceps Recovery After Anterior Cruciate Ligament Reconstruction With Quadriceps Tendon Versus Patellar Tendon Autografts

Longitudinal Assessment of Quadriceps Muscle Morphology Before and After Anterior Cruciate Ligament Reconstruction and Its Associations With Patient-Reported Outcomes

The Use of Recombinant Human Growth Hormone to Protect Against Muscle Weakness in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Pilot, Randomized Placebo-Controlled Trial

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