A retrospective comparative study of infection control rate and clinical outcome between open debridement using antibiotic-impregnated cement beads and a two-stage revision in acute periprosthetic knee joint infection.

The aim of this study was to determine whether the infection control rate of a modified debridement, antibiotics, and implant retention (DAIR) protocol (DAIR with antibiotic-impregnated cement beads) is comparable to that of 2-stage revision for acute periprosthetic joint infection (PJI) after total knee arthroplasty (TKA). We also aimed to determine whether this modified DAIR technique produced better clinical results than those obtained using 2-stage revision in terms of functional outcome, range of motion (ROM), and patient satisfaction at 2 years after surgery.This retrospective comparative study included patients who underwent modified DAIR (7 patients, 9 knees) or 2-stage revision (8 patients, 9 knees) for acute PJI of the knee joint.

Optimal rotational positioning of tibial component in total knee arthroplasty: determined by linker surgical technique using a high definition CT.

Introduction: The rotational alignment of femoral and tibial components is an important determinant of the success of Total Knee Arthroplasty (TKA). The optimal rotational position of the tibial component is still unclear. The purpose of this study was (1) to determine the pre-operative S-TEA (surgical-transepicondylar axis) derived tibialanteroposterior (AP) axis angle and postoperative tibial component axis angle using a "Bird's eye" high-definition CT image in TKA performed by Linker surgical technique; (2) to determine the femorotibial mismatch angle; and (3) to determine the optimal tibial component rotation in a well-aligned femoral and tibial components.

Temporal Value of C-Reactive Protein and Erythrocyte Sedimentation Rate after Total Knee Arthroplasty in Patients with Elevated Preoperative C-Reactive Protein: A Matched-Pair Analysis.

Background: We aimed to determine whether temporal values of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) after total knee arthroplasty (TKA) differ between patients with and without elevated preoperative CRP. We hypothesized that temporal pattern of CRP and ESR change would differ between the two groups.

Materials And Methods: This retrospective study included 30 TKAs with a diagnosis of osteoarthritis with elevated preoperative CRP (>1 mg/dl) without clinical signs and symptoms of infection before surgery (elevated CRP group).

Long-term follow-up and survivorship of single-radius, posterior-stabilized total knee arthroplasty.

Background: We sought to determine the 10-year survivorship of single-radius, posterior-stabilized total knee arthroplasty (TKA) in Asian patients. We also aimed to determine whether the long-term clinical and radiographic results differed between patients with and without patellar resurfacing.

Methods: This retrospective study included 148 (115 patients) consecutive single-radius, posterior-stabilized TKAs.

Clinical performance and survivorship of navigated floating platform mobile-bearing total knee arthroplasty: A minimum 10-year follow-up.

Background: The purpose of this study is to report the outcome of navigation-assisted cruciate-retaining total knee arthroplasty (TKA) using one type of cemented, second-generation, floating-platform (FP), mobile-bearing system.

Methods: Forty-two patients who underwent cruciate retaining TKAs using e.motion-FP prostheses under navigational guidance were retrospectively reviewed.

Safety of simultaneous bilateral total knee arthroplasty using an extramedullary referencing system: results from 2098 consecutive patients.

Introduction: Simultaneous bilateral total knee arthroplasty (TKA) has been associated with a high risk of morbidity and mortality. The orthopedic surgeon must, therefore, decide whether bilateral simultaneous TKA is a safe operation to perform and endeavor to decrease the risk of serious complications or even death.

Methods: This retrospective review included 2098 consecutive patients who underwent bilateral simultaneous TKAs by the protocol used in our institution, including the use of extramedullary instruments to minimize medullary canal invasion and overlapping procedures for both knees to decrease operation time.

Is Total Knee Arthroplasty a Viable Treatment Option in Octogenarians with Advanced Osteoarthritis?

Purpose: This study directly compared clinical assessment scores and short-term systemic complications after total knee arthroplasty (TKA) between a group of patients aged 80 or older (141 patients) and another group of patients aged between 65 and 70 years (616 patients) with advanced osteoarthritis.

Materials And Methods: We retrospectively investigated 757 osteoarthritic patients who underwent primary TKA from January 2007 to January 2011 with a follow-up of 1 year. The surgery was performed using an extramedullary alignment guide instrument without invasion of the intramedullary canal to decrease embolic load and blood loss.

Infrapatellar fat pad preservation reduces wound complications after minimally invasive total knee arthroplasty.

Introduction: The aim of this study was to determine whether pain intensity and wound complication rates differ between patients with and without preservation of the infrapatellar fat pad (IPFP) after minimally invasive total knee arthroplasty (TKA). The authors also sought to determine whether IPFP preservation affects operation time.

Materials And Methods: This retrospective study included 448 knees with primary TKA.

How to minimize rotational conflict between femoral & tibial component in total knee arthroplasty: the use of femoro-tibial axial synchronizer (Linker).

Purpose: The purpose of this study was to investigate the correlation between rotational axes of femur and tibia with the use of Linker.

Materials And Methods: This study was carried out from August 2009 to February 2010 on 54 patients (106 knees), who were diagnosed with simultaneous bilateral total knee arthroplasty. With the use of postoperative computed tomography scans, it was investigated how much the rotational angle of femoral and tibial components matched.

Design modifications of high-flexion TKA do not improve short term clinical and radiographic outcomes.

Background: The prosthesis of contemporary total knee arthroplasty (TKA) has been modified to provide a more familiar environment for higher flexion angle of the replaced knee. The design modifications continue based on evidence reported in the literature. However, whether these modifications of the prosthesis design lead to improvements in clinical results needs further investigation.

Reconstruction of a deficient patella in revision total knee arthroplasty: results of a new surgical technique using transcortical wiring.

This study aimed to report the results of a novel surgical technique for the reconstruction of a deficient patella during revision total knee arthroplasty (TKA). Twenty-eight patients (30 knees) with a deficient patella were treated with an onlay-type prosthesis and bone-augmenting procedure, using acrylic bone cement and transcortical wiring. The technique was indicated when the thickness of remnant patella was less than 8mm with variable amounts of the peripheral rim.

Comparison of cruciate retaining and PCL sacrificing TKA with respect to medial and lateral gap differences in varus knees after medial release.

We aimed to clarify whether the increase in medial gap after medial release is influenced by the retention or sacrifice of posterior cruciate ligament (PCL) during navigation-assisted total knee arthroplasty. After matched pairs were done according to the equality of preoperative varus deformity and medial collateral laxity, 54 knees of each type were available for this study. In the PCL sacrificing group, the mediolateral gap difference significantly increased in both flexion and extension as the preoperative mechanical axis angle increased whereas in the cruciate retaining group, the mediolateral gap difference did not show this tendency.

Prevention of pseudo-patella baja during total knee arthroplasty.

Purpose: Pseudo-patella baja (PPB) is a surgical complication that can arise from total knee arthroplasty and occurs when the patella tendon is not shortened but the level of the femorotibial joint line is elevated. The goal of this study was to assess the performance of a technique specifically designed to prevent the occurrence of PPB and its radiological results.

Methods: Ninety-nine patients undergoing total knee arthroplasty were included.

Relationship between mechanical axis-derived and anatomic landmark-derived femoral rotation in TKA: a three-dimensional CT study.

We sought to determine the relationship between the mechanical axis-derived and the anatomic landmark-derived femoral rotational axes using three dimensional computed tomographic images of 20 lower extremities. The mechanical axis-derived femoral rotational axis was created on the distal articular surface of the femur using coronal mechanical limb axis and the reconstructed images of the femur. Then, we measured the angular difference between mechanical axis-derived and anatomic landmark-derived femoral rotational axes.

Disparate postoperative results in the first and second knees on simultaneous bilateral total knee arthroplasty.

We hypothesized that the circumstances of the two consecutive operations of a simultaneous bilateral total knee arthroplasty (TKA) are different, and could lead to different outcomes of overlapping bilateral TKAs. Both knees of 420 subjects were evaluated in the current study. In the second TKA, there were more incidence rates of outlier in mechanical femoro-tibial angle (16.

Soft tissue laxity should be considered to achieve a constant polyethylene thickness during total knee arthroplasty.

Introduction: In total knee arthroplasty (TKA), the gap expansion effect by soft tissue laxity and bone resection amount influence directly on the proper gap size and ideal polyethylene insert thickness. In this study, we hypothesized if bone resection level could be controlled lesser as gap expansion effect resulted in the effects on gap expansion of the collateral release and lax lateral structure, appropriate gap size would be attained without extensive medial soft tissue release even in severe varus deformed knee. The purpose of this study was to show the usefulness of preoperative calculation of soft tissue laxity for determining the appropriate gap size for the targeted PE thickness in TKA.

Primary total knee arthroplasty in infection sequelae about the native knee.

The aim of this study is to assess the results of primary total knee arthroplasty (TKA) after bone or joint sepsis about the native knee and to analyze the risk factors of periprosthetic infection. Sixty-two patients (62 knees), considered to have prior sepsis history to be resolved, underwent primary TKA and were followed during a mean of 6.1years (range, 2-10.

Physiologic bone remodeling in medial aspect of proximal tibia after under-release of medial soft tissue during total knee arthroplasty.

Introduction: This study was undertaken to investigate the incidence and to identify predictors of physiologic remodeling in the medial aspect of the proximal tibia in varus knees after total knee arthroplasty (TKA).

Materials And Methods: One hundred and sixty-six consecutive patients (221 knees) who underwent navigation-assisted TKA and were followed for a minimum of 2 years were included. Changes in bone radiolucency in the medial aspect of the proximal tibia on the radiographs were investigated at each follow-up.

Outcomes of long retrograde intramedullary nailing for periprosthetic supracondylar femoral fractures following total knee arthroplasty.

Background: The treatment of periprosthetic supracondylar femoral fractures following total knee arthroplasty (TKA) is challenging because of osteopenia and the limited bone available for distal fixation. The purpose of this study was to report the outcomes of periprosthetic supracondylar femoral fractures treated with long retrograde intramedullary nailing.

Methods: We conducted a retrospective review of 25 patients who were treated with a long retrograde intramedullary nail for periprosthetic supracondylar femoral fractures following TKA.

Easy identification of mechanical axis during total knee arthroplasty.

Purpose: We devised an intraoperatively identifiable mechanical axis (IIMA) as a reference of alignment in total knee arthroplasty (TKA).

Materials And Methods: Between February 2010 and January 2011, primary TKAs were consecutively performed on 672 patients (1007 knees) using an IIMA as a reference in the coronal plane.

Results: The alignment of the lower extremity improved from a mean of 11.

Soft Tissue Balancing of Varus Arthritic Knee in Minimally Invasive Surgery Total Knee Arthroplasty: Comparison between Posterior Oblique Ligament Release and Superficial MCL Release.

Purpose: To assess proper soft tissue balancing of the varus arthritic knee between posterior oblique ligament (POL) release group and superficial medial collateral ligament (SMCL) release group.

Materials And Methods: This retrospective study was performed on 186 patients who underwent minimally invasive surgery (MIS) total knee arthroplasty (TKA) from January 2011 to December 2011. Eighty-three patients were in the group of SMCL release and 103 patients were in the POL release group.

Clinical Outcome of IM-Guided Total Knee Arthroplasty with Inappropriate Femoral Resection in Coronal Plane.

Purpose: The purpose of this study was to evaluate clinical results and accuracy of femoral cutting in the coronal plane in total knee arthroplasty (TKA) using a fixed length intramedullary guide.

Materials And Methods: From 2005 to 2008, 101 patients (154 knees) underwent TKA (NexGen LPS implant). The minimal follow-up period was 3 years (mean, 4.

Factors correlated with the reducibility of varus deformity in knee osteoarthritis: an analysis using navigation guided TKA.

Background: We hypothesized that a number of clinical and radiologic parameters could influence the reducibility of varus deformity in total knee arthroplasty. The aim of this study was to identify the factors correlated with reducibility of varus deformity and predict more accurately the amount of medial soft tissue release required in varus deformity total knee arthroplasty.

Methods: One hundred forty-three knees with preoperative varus alignment and medial osteoarthritis were included in this retrospective study.

The comparative efficacies of intra-articular and IV tranexamic acid for reducing blood loss during total knee arthroplasty.

Purpose: Reduction in blood loss during surgery stabilizes hemodynamic status and aids in recovery after total knee arthroplasty (TKA). In this study, the authors examined whether different administration routes of tranexamic acid (TNA) might affect the amount of blood loss after TKA.

Methods: A total of 150 patients were prospectively allocated to each of the three groups (intravenous, intra-articular, and placebo group) and underwent unilateral TKA.

Augmentation with transcortical wiring of an onlay-type prosthesis for a deficient patella during revision total knee arthroplasty.

The management of patellae with a severe bony deficiency during revision total knee arthroplasty is a challenging problem. However, using a technique of augmentation with transcortical wiring of an onlay-type prosthesis allowed the authors to revise a deficient patellae successfully. After making the decision to revise the existing patellar component, the procedure was found to be technically straightforward.