The difference in bone mineral density between femur and tibia is related to tibia deformation in endstage knee osteoarthritis.

Background: This study investigated bone mineral density (BMD) around the knee joint to clarify the mechanism by which tibia deformation exceeds that of the femur in patients with end-stage knee osteoarthritis (KOA).

Methods: We retrospectively analyzed 193 patients who underwent total knee arthroplasty for end-stage KOA with varus alignment. Preoperative T-score of the femur neck and femur total using dual-energy X-ray absorptiometry (DXA) and hounsfield units (HU) of the distal femur and proximal tibia using computed tomography (CT) were measured to asess the BMD.

Valgus Arthritic Knee Responds Better to Conservative Treatment than the Varus Arthritic Knee.

: Clinically, it is beneficial to determine the knee osteoarthritis (OA) subtype that responds well to conservative treatments. Therefore, this study aimed to determine the differences between varus and valgus arthritic knees in the response to conservative treatment. We hypothesized that valgus arthritic knees would respond better to conservative treatment than varus arthritic knees.

Estimation of the proper gap ratio using preoperative radiography for posterior tibial slope maintenance in biplanar open wedge high tibial osteotomy.

Background: This study aimed to estimate the ratio of the anterior and posterior gaps before surgery that can minimize the posterior tibial slope (PTS) change through preoperative radiography, and to confirm whether the use of the block helps maintain the PTS during open wedge high tibial osteotomy (OWHTO).

Methods: Patients who underwent OWHTO between 2015 and 2018 were included. To measure optimal anterior gap (AG) and posterior gap (PG) ratio, hinge to medial tibial tuberosity length (HTL), total osteotomy length (TOL), and PTS were measured using knee AP X-ray.

The effect of Parkinson's disease on total knee arthroplasty: a systematic review and meta-analysis.

Purpose: The purpose of this systematic review was to determine the effect of Parkinson's disease (PD) on clinical outcomes and complications after total knee arthroplasty (TKA). Our systematic review was conducted to answer the following questions: (1) does TKA negatively affect clinical outcomes in patients with PD? and (2) does TKA cause more complications in patients with PD?

Methods: A rigorous and systematic approach was used, and each selected study was evaluated for methodological quality. Data on study design, total number of cases enrolled, follow-up duration, PD severity, clinical outcome, and complications after TKA were analyzed.

Quadriceps muscle volume has no effect on patellofemoral cartilage lesions in patients with end-stage knee osteoarthritis.

Purpose: The quadriceps muscle has a positive effect on anterior knee pain. However, its effect on the patellofemoral (PF) cartilage in patients with end-stage knee osteoarthritis is unknown. The present study aimed to evaluate whether the quadriceps muscle area had a positive effect on the PF cartilage and whether this muscle had a positive effect on the clinical scores.

Risk of stroke after unilateral or bilateral TKA (simultaneous and staged without discharge) in 327,438 matched patients using data from the National Health Insurance Claims for South Korea.

Purpose: This study aims to investigate the incidence rate and risk factors of stroke in patients treated with bilateral TKA compared with patients with unilateral TKA.

Methods: In this retrospective nationwide cohort study, we compared patients undergoing unilateral TKA or bilateral TKA using data from the Korean National Health Insurance claims database between January 1, 2009 and August 31, 2017 and included patients older than 40 years of age who underwent primary TKA by the index date as documented primary diagnosis and first additional diagnosis without a history of stroke during the preceding 1 year. We used matched Cox regression models to compare the incidence rate and risk factors of newly acquired stroke among patients treated with unilateral TKA or bilateral TKA after propensity score (PS) matching.

Allogeneic Umbilical Cord Blood-Derived Mesenchymal Stem Cell Implantation Versus Microfracture for Large, Full-Thickness Cartilage Defects in Older Patients: A Multicenter Randomized Clinical Trial and Extended 5-Year Clinical Follow-up.

Background: There is currently no optimal method for cartilage restoration in large, full-thickness cartilage defects in older patients.

Purpose: To determine whether implantation of a composite of allogeneic umbilical cord blood-derived mesenchymal stem cells and 4% hyaluronate (UCB-MSC-HA) will result in reliable cartilage restoration in patients with large, full-thickness cartilage defects and whether any clinical improvements can be maintained up to 5 years postoperatively.

Study Design: Randomized controlled trial; Level of evidence, 1.

Increased external rotation of the osteoarthritic knee joint according to the genu varum deformity.

Purpose: To evaluate the rotational profile of the lower extremity using computed tomography (CT) in accordance with the degree of varus deformity in medial condyle-affected knee joint osteoarthritis (OA).

Methods: This retrospective study included 1036 patients (872 lower extremities) with end-stage knee OA. The coronal alignment of the lower extremity was measured using standing anteroposterior radiography.

Differentiating Nutrient Artery Canals of the Femur versus Fracture Lines in Patients with Total Hip Arthroplasty on Plain Radiographs.

Background: Nutrient artery canals of the femur are often visible on plain radiographs as radiolucent lines which may mimic fracture lines. The purpose of this study was to distinguish nutrient artery canals from fracture lines on plain radiographs.

Materials And Methods: Ninety-three patients (102 hips) with an average age of 65.

Comparative Analysis of Diaphyseal versus Metaphyseal tracker Placement in Imageless Navigation Systems for Total Knee Arthroplasty.

This work was designed to compare the intraoperative parameters and clinical and radiologic outcomes of total knee arthroplasty (TKA) during a minimum follow-up period of 2 years and to discuss the pros and cons of two different tracker placement (diaphyseal and metaphyseal) navigation systems. The null hypothesis was that there would be no clinical or radiologic difference between the two different systems. Primary TKA was performed in a total of 100 knees using the two different image-free navigation systems (group 1: diaphyseal tracker placement and group 2: metaphyseal tracker placement) with the strict gap balancing technique.

Risk of Revision Following Total Knee Arthroplasty or High Tibial Osteotomy: A Nationwide Propensity-Score-Matched Study.

Background: High tibial osteotomy (HTO) is often performed to postpone or avoid the need for subsequent total knee arthroplasty (TKA). We designed the present study to investigate the incidence rate and risk factors for subsequent revision in patients treated with HTO compared with those managed with TKA.

Methods: In this retrospective nationwide cohort study, we reviewed the South Korean National Health Insurance claims database from January 1, 2009, to August 31, 2017.

Correction: Rotating hinge knee versus constrained condylar knee in revision total knee arthroplasty: A meta-analysis.

[This corrects the article DOI: 10.1371/journal.pone.

Rotating hinge knee versus constrained condylar knee in revision total knee arthroplasty: A meta-analysis.

There is debate in the literature whether rotating hinge knee (RHK) or constrained condylar knee (CCK) prostheses lead to better clinical outcomes and survival rates in patients undergoing revision total knee arthroplasty (RTKA). The purpose of this meta-analysis is to compare the survivorship and clinical outcomes of RHK and CCK prostheses. In this meta-analysis, we reviewed studies that evaluated pain and function scores, range of motion (ROM), complications, and survival rates in patients treated with RHK or CCK with short-term (<5 years) or midterm (5-10 years) follow-up.

Spinal Accessory Nerve Injury Induced by Manipulation Therapy: A Case Report.

Spinal accessory nerve (SAN) injury mostly occurs during surgical procedures. SAN injury caused by manipulation therapy has been rarely reported. We present a rare case of SAN injury associated with manipulation therapy showing scapular winging and droopy shoulder.

Snapping Phenomenon after Revisional Total Knee Arthroplasty.

The cases of revision total knee arthroplasty (TKA) are increasing. In this report, snapping phenomenon after final implantation of revision TKA has been presented. Snapping was caused by adhered iliotibial band (ITB) impinging against the lateral part of femoral component.

Intra-Articular Injection of Bone Marrow-Derived Mesenchymal Stem Cells Leading to Better Clinical Outcomes without Difference in MRI Outcomes from Baseline in Patients with Knee Osteoarthritis.

Purpose: Bone marrow (BM) is frequently used as a source of mesenchymal stem cells (MSCs) because they have a high potential for differentiation. However, it is unclear whether BM-derived MSCs lead to better clinical and magnetic resonance imaging (MRI) outcomes postoperatively.

Materials And Methods: This meta-analysis compared the clinical and MRI outcomes in patients with knee osteoarthritis (OA) treated with BM-derived MSCs.

Reference Value for Infrapatellar Branch of Saphenous Nerve Conduction Study: Cadaveric and Clinical Study.

Objective: To determine the optimal stimulation and recording site for infrapatellar branch of saphenous nerve (IPBSN) conduction studies by a cadaveric study, and to confirm that obtained location is practically applicable to healthy adults.

Methods: Twelve lower limbs from six cadavers were studied. We defined the optimal stimulation site as the point IPBSN exits the sartorius muscle and the distance or ratio were measured on the X- and Y-axis based on the line connecting the medial and lateral poles of the patella.

Quantitative Measurement of Muscle Atrophy and Fat Infiltration of the Supraspinatus Muscle Using Ultrasonography After Arthroscopic Rotator Cuff Repair.

Objective: To investigate the utility of ultrasonography to objectively examine morphological changes (i.e., muscle atrophy and fatty infiltration) of the supraspinatus muscle.

Effect of shape on bone cement polymerization time in knee joint replacement surgery.

Background: Although many factors are known to influence the polymerization time of bone cement, it remains unclear which bone cement shape predicts the precise polymerization time. The purpose of this study was to investigate whether different cement shapes influenced polymerization time and to identify the relationship between cement shape and ambient operating theater temperature, relative humidity, and equilibration time.

Methods: Samples were gathered prospectively from 237 patients undergoing primary total knee arthroplasty.

Unsatisfactory clinical outcomes of second-generation mobile bearing floating platform total knee arthroplasty: comparing outcomes with fixed bearing after five years minimum.

Background: The purpose of this retrospective study was to analyze and compare the clinical and radiologic outcomes of fixed bearing ultracongruent (UC) insert total knee arthroplasty (TKA) and mobile bearing (MB) floating platform TKA using the navigation-assisted gap balancing technique with a minimum follow-up of five years.

Methods: The study retrospectively enrolled 105 patients who received the UC type fixed bearing insert (group 1) and 95 patients who received the floating platform MB insert (group 2) during the period from August 2009 to June 2012. All surgery was performed using the navigation-assisted gap balancing technique.

Posterior-stabilized inserts are preferable to cruciate-substituting ultracongruent inserts due to more favourable kinematics and stability.

Purpose: It is unknown whether the conforming superiority of ultracongruent (UC) inserts over posterior stabilized (PS) inserts, due to an increased anterior lip for prevention of anterior displacement of the condyles during knee flexion, leads to better knee scores or greater knee stability in arthroplasty patients. This meta-analysis compared clinical outcomes, intraoperative kinematics, sagittal stability, and range of motion (ROM) between groups with either UC or PS inserts in primary total knee arthroplasty (TKA).

Methods: Studies that recorded clinical outcomes, intraoperative kinematics, sagittal stability, and ROM in patients who underwent primary TKA with UC or PS inserts were included in the meta-analysis.

Unicompartmental knee arthroplasty fails to completely restore normal gait patterns during level walking.

Purpose: Gait analysis is a valuable instrument for measuring function objectively after unicompartmental knee arthroplasty (UKA). However, most gait analysis studies have reported conflicting results for functional assessment after UKA. This meta-analysis compared the gait patterns of UKA patients and healthy controls during level walking.

Correction to: Use of autogenous onlay bone graft for uncontained tibial bone defects in primary total knee arthroplasty.

After the publication of this article [1] it came to the attention of the authors that there were 2 errors in the results section: 0.0.856 should be 0.

Diagnostic accuracy of interleukin-6 and procalcitonin in patients with periprosthetic joint infection: a systematic review and meta-analysis.

Purpose: Many studies have found associations between laboratory biomarkers and periprosthetic joint infection (PJI), but it remains unclear whether these biomarkers are clinically useful in ruling out PJI. This meta-analysis compared the performance of interleukin-6 (IL-6) versus procalcitonin (PCT) for the diagnosis of PJI.

Methods: In this meta-analysis, we reviewed studies that evaluated IL-6 or/and PCT as a diagnostic biomarker for PJI and provided sufficient data to permit sensitivity and specificity analyses for each test.