Journal of Knee Surgery

BACKGROUND: Mobile-bearing (MB) unicompartmental knee arthroplasty (UKA) has high conformity between the femoral articular surface and the meniscal bearing; therefore, the surface and subsurface contact stress is reduced. Additionally, the survival rate is high. However, the in vivo kinematics of MB UKA knees during high-flexion activities of daily living remains unknown. The aim of this study was to investigate in vivo the 3-dimensional kinematics of MB UKA knees during high-flexion activities of daily living...

Introduction One of the critical steps in total knee arthroplasty (TKA) is femoral component positioning and sizing. Historically, there was wider variability between femoral component sizes, necessitating the concepts of anterior referencing (AR) and posterior referencing (PR). With the introduction of smaller increments between sizes, the concept of anatomic referencing has been introduced to replace AR and PR. The intent of this study was to validate the concept of anatomic referencing and show that with 2mm increments in femoral sizes, the femoral component can be placed flush to the anterior cortex while maintaining posterior condylar offset (PCO)...

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No abstract text is available yet for this article.

An estimated 10 to 15% of total knee arthroplasties (TKAs) are implanted for a diagnosis of arthritis when a valgus deformity is present. There are various techniques and considerations that must be considered for a successful TKA in a patient with a valgus deformity. This article provides a detailed summary of the anatomy, pathology, bone preparation, soft tissue management, implant selection, and complications when performing a TKA in a patient with valgus deformity.

Periprosthetic joint infection (PJI) following revision total knee arthroplasty (TKA) for aseptic failure is associated with poor outcomes, patient morbidity, and high health care expenditures. The aim of this study was to develop novel machine learning algorithms for the prediction of PJI following revision TKA for patients with aseptic indications for revision surgery. A single-institution database consisting of 1,432 consecutive revision TKA patients with aseptic etiologies was retrospectively identified...

Over 25% of patients with rheumatoid arthritis (RA) are expected to undergo a joint replacement during their lifetime. Current practice guidelines recommend withholding biologic therapy 1 week prior to total hip arthroplasty, given its immunosuppressive effects. Most patients are on a regimen including biologic and nonbiologic therapy; however, the individual influences of these therapies are not well understood in the setting of total knee arthroplasty (TKA). Therefore, we sought to compare biologic, nonbiologic, and recipients of both types of therapy in patients with RA undergoing TKA...

Although the accuracy of other types of robotic systems for total knee arthroplasty (TKA) has been assessed in cadaveric studies, no investigations have been performed to evaluate this newly advanced active robotic system. Therefore, the authors aimed to analyze the accuracy of bone resection in terms of thickness and alignment in a cadaveric study. Three cadaveric specimens (six knees) and an active robotic system (CUVIS Joint, CUREXO) were used in the study. Three surgeons with different experiences in robotic TKAs performed this cadaveric study using the same robotic protocol with two different implant designs...

In staged bilateral total knee arthroplasty (BTKA), the intersurgical time is yet to be determined. This study aimed to (1) test for differences in in-hospital metrics between the index and contralateral TKA and (2) determine the safest intersurgical time interval to minimize adverse outcomes after the contralateral surgery. The National Readmissions Database was queried for patients who received staged BTKA (2016-2017). A total of 20,279 patients were included. Demographics, comorbidities, baseline determinants, and intersurgical time between index and contralateral TKAs (≤ 3 month, 4-6 months, 7-9 months, and 10-12 months intervals) were captured...

The effect of osteotomy type on the initial stiffness of the bone-implant construct in lateral opening-wedge distal femoral osteotomy (LOWDFO) using a uniplanar compared to a biplanar technique has been investigated. However, no study has explored the biomechanical risk factors for medial hinge fracture. This study aimed to compare the biomechanical strength of uniplanar versus biplanar LOWDFO in terms of the risk for medial hinge fracture during gap opening. Twelve composite femora were divided into two groups (6 in each group) based on the distal femoral osteotomy technique: uniplanar vs biplanar LOWDFO...

INTRODUCTION: As obesity becomes more prevalent, more patients are at risk of lower extremity osteoarthritis and subsequent total knee arthroplasty (TKA). This study aimed to test 1) the association of preoperative weight change with healthcare utilization; and 2) the association of pre- and postoperative weight changes with failure to achieve satisfaction and minimal clinically important difference (MCID) in Knee injury and Osteoarthritis Outcome Score for pain (KOOS-Pain) and function (KOOS-PS) 1-year after TKA...

INTRODUCTION: Soft tissue balancing is an important factor in primary total knee arthroplasty (TKA), with 30 to 50% of TKA revisions attributed to technical operative factors including soft-tissue balancing. Robotic-assisted TKA (RATKA) offers opportunities for improved soft-tissue balancing methods. This study aimed to evaluate the repeatability and reproducibility of ligamentous laxity assessments during RATKA using a digital tensioner. METHODS: Three experienced RATKA surgeons assessed pre-resection and trialing phases of twelve human cadaveric knees with varying degrees of arthritis...

INTRODUCTION: Longitudinal data on patient trends in body mass index (BMI) and the proportion that gain or lose significant weight before and after total knee arthroplasty (TKA) is scarce. This study aimed to observe patients longitudinally for a two-year period and determine 1) clinically significant BMI changes during the one-year before and one-year after TKA; and 2) identify factors associated with clinically significant weight changes. METHODS: A prospective cohort of 5,388 patients who underwent primary TKA at a tertiary healthcare institution between January 2016 and December 2019 were analyzed...

INTRODUCTION: Distal femur fractures (DFF) are common injuries with significant morbidity. Surgical options include open reduction and internal fixation (ORIF) with plates and/or intra-medullary devices or a distal femur endoprosthesis (DFR). A paucity of studies exist that compare the two modalities. The present study utilized a 1:2 propensity score match to compare 30-day outcomes of geriatric patients with distal femur fractures who underwent an ORIF or DFR. METHODS: The NSQIP data from 2008 to 2019 was utilized to identify all patients who sustained a DFF and underwent either ORIF or DFR...

Extended oral antibiotic prophylaxis (EOAP) has been suggested to reduce rates of periprosthetic joint infection (PJI) postoperatively after total joint arthroplasty (TJA). The purpose of this multicenter study is to define how many TJA patients are considered high risk for developing PJI based on published EOAP criteria and determine whether this status is associated with socioeconomic or demographic factors. All primary and aseptic revision TJAs performed in 2019 at three academic medical centers were reviewed...

Revision anterior cruciate ligament reconstruction (ACLR) can be achieved in a single-stage or two-stage approach. Single-stage revisions have several advantages, including one less operation, decreased cost, and a quicker recovery for patients. Revision ACLR can be complicated by malpositioned or dilated bone tunnels, which makes a single-stage revision more challenging or sometimes necessitates a two-stage approach. The use of fast-setting bone graft substitutes (BGS) has been described in recent literature as a strategy to potentially help address this problem in the setting of single-stage revision ACLR...

No abstract text is available yet for this article.

Knee pain is a common presenting problem in the general population. Radiographs and MRI are the cornerstones of imaging in current clinical practice. With advancements in technology, there has been increasing utilization of other modalities to evaluate knee disorders. Dynamic assessment utilizing computed tomography and portable ultrasounds have demonstrated the capacity to accurately assess and reproducibly quantify kinematics of knee disorders. Cartilage physiology can be further evaluated with magnetic resonance imaging...

The conventional approach for total knee arthroplasty (TKA) is a medial parapatellar approach (MPA). We aimed to study patient outcomes and kinematics with a quadriceps sparing lateral subvastus lateralis approach (SLA). Patients with neutral/varus alignment undergoing primary TKA were consented to undergo the SLA. At 1-year postoperative, patients underwent radiostereometric analysis. Patients were administered the Short Form 12 (SF-12), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and Knee Society Score (KSS)...

Anticipating implant sizes before total knee arthroplasty (TKA) allows the surgical team to streamline operations and prepare for potential difficulties. This study aims to determine the correlation and derive a regression model for predicting TKA sizes using patient-specific demographics without using radiographs. We reviewed the demographics, including hand and foot sizes, of 1,339 primary TKAs. To allow for comparison across different TKA designs, we converted the femur and tibia sizes into their anteroposterior (AP) and mediolateral (ML) dimensions...