{"doi":"10.1002/jor.25065","title":"Skeletal muscle cellular contractile dysfunction after anterior cruciate ligament reconstruction contributes to quadriceps weakness at 6‐month follow‐up","abstract":"Muscle dysfunction following anterior cruciate ligament reconstruction (ACLR) may evolve from alterations in muscle contractility at the myofilament protein level. Using a prospective, within-subject case-control design, we evaluated cellular-level contractility, cross-sectional area (CSA), and myosin heavy chain (MHC) isoform expression on single muscle fibers 3 weeks post ACLR, and evaluated their relationship to whole muscle strength and patient-oriented outcomes 6 months post operation. Biopsies of the vastus lateralis were performed 3 weeks post ACLR in 11 subjects (5 females, mean age ± SD = 24.7 ± 6.5 years, height = 172.7 ± 8.2 cm, mass = 75.7 ± 12.5 kg) following first-time ACL rupture and whole muscle strength and self-reported pain, function, and quality of life assessed 6 months post ACLR. At 3 weeks post ACLR, force production was reduced (p < 0.01) in MHC I (-36%) and IIA (-48%) fibers compared with the non-injured leg. When force production was expressed relative to CSA to account for fiber atrophy, reductions remained in MHC IIA fibers (-40%; p < 0.001), but MHC I fibers showed only a trend toward being lower (-13%; p = 0.09). Finally, skeletal muscle fiber functional deficits at 3 weeks post ACLR were associated with whole muscle weakness and less favorable patient-reported outcomes at 6-month follow-up. Thus, ACLR promotes early cellular contractile dysfunction that may contribute to decreased whole muscle strength and patient function, and increased patient-reported symptoms, at 6-month follow-up.","journal":"Journal of Orthopaedic Research®","year":2021,"id":189973,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":14,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9602,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":302909,"name":"Thomas B. Voigt","orcid":"0000-0003-2217-897X","position":1,"is_corresponding":false},{"id":302910,"name":"Rebecca H. Choquette","orcid":"0000-0001-6808-1781","position":2,"is_corresponding":false},{"id":302912,"name":"Mathew Failla","orcid":"0000-0003-0786-7400","position":3,"is_corresponding":false},{"id":303632,"name":"Nathan K. Endres","orcid":null,"position":4,"is_corresponding":false},{"id":303633,"name":"James R. Slauterbeck","orcid":null,"position":5,"is_corresponding":false},{"id":302913,"name":"Bruce D. Beynnon","orcid":"0000-0002-1205-3674","position":6,"is_corresponding":false},{"id":302907,"name":"Michael J. Toth","orcid":"0000-0003-0668-1911","position":7,"is_corresponding":false},{"id":302908,"name":"Timothy W. Tourville","orcid":"0000-0002-6087-6894","position":0,"is_corresponding":true}],"reference_count":54,"raw_metadata":null,"created_at":"2026-07-18T23:49:22.671571Z","pmid":"33969521","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}