title: Medial unicompartmental knee arthroplasty in the ACL-deficient knee.
abstract: Symptomatic osteoarthritis (OA) of the knee develops often in association with anterior cruciate ligament (ACL) deficiency. Two distinct pathologies should be recognised while considering treatment options in patients with end-stage medial compartment OA and ACL deficiency. Patients with primary ACL deficiency (usually traumatic ACL rupture) can develop secondary OA (typically presenting with symptoms of instability and pain) and these patients are typically young and active. Patients with primary end stage medial compartment OA can develop secondary ACL deficiency (usually degenerate ACL rupture) and these patients tend to be older. Treatment options in either of these patient groups include arthroscopic debridement, reconstruction of the ACL, high tibial osteotomy (HTO) with or without ACL reconstruction, unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA). General opinion is that a functionally intact ACL is a fundamental prerequisite to perform a UKA. This is because previous reports showed higher failure rates when ACL was deficient, probably secondary to wear and tibial loosening. Nevertheless in some cases of ACL deficiency with end-stage medial compartment OA, UKA has been performed in isolation and recent papers confirm good short- to mid-term outcome without increased risk of implant failure. Shorter hospital stay, fewer blood transfusions, faster recovery and significantly lower risk of developing major complications like death, myocardial infarction, stroke, deep vein thrombosis (as compared to TKA) make the UKA an attractive option, especially in the older patients. On the other hand, younger patients with higher functional demands are likely to benefit from a simultaneous or staged ACL reconstruction in addition to UKA to regain knee stability. These procedures tend to be technically demanding. The main aim of this review was to provide a synopsis of the existing literature and outline an evidence-based treatment algorithm.
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK. fra.mancuso@gmail.com.|Orthopaedics and Traumatology Unit, "Santa Maria della Misericordia" University Hospital, Udine, Piazzale Santa Maria della Misericordia 15, 33100, Udine, UD, Italy. fra.mancuso@gmail.com.
authors.forename: Francesco
authors.identifier: http://orcid.org/0000-0002-2551-5508
authors.initials: F
authors.lastname: Mancuso
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Dodd
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK.
authors.forename: David W
authors.initials: DW
authors.lastname: Murray
authors.affiliation: Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences (NDORMS), University of Oxford, Oxford, UK.
authors.forename: Hemant
authors.initials: H
authors.lastname: Pandit
mesh_terms: D016118:Anterior Cruciate Ligament / Q000503:physiopathology* / Q000601:surgery*; D059549:Anterior Cruciate Ligament Reconstruction / Q000379:methods*; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D006801:Humans; D020370:Osteoarthritis, Knee / Q000503:physiopathology* / Q000601:surgery*; D012307:Risk Factors
keywords: Anterior cruciate ligament deficiency; Anterior cruciate ligament reconstruction; Medial compartment osteoarthritis; Unicompartmental knee arthroplasty