Changes in hindfoot alignment after total knee arthroplasty in knee osteoarthritic patients with varus deformity.

Purpose: Hindfoot alignment can affect the weight-bearing kinematics of the knee joint in patients undergoing total knee arthroplasty (TKA). This study evaluated the change in hindfoot alignment after TKA by prospectively analysing the correlation between the knee joint and the hindfoot deformity, the post-operative improvement in the hindfoot deformity, and the long-term post-operative changes in hindfoot alignment.

Methods: This study included 195 knees from 117 patients with osteoarthritis who underwent TKA between 2012 and 2013.

How accurate are orthopedic surgeons in diagnosing periprosthetic joint infection after total knee arthroplasty?: A multicenter study.

Background: The lack of standardized diagnostic criteria for periprosthetic joint infection (PJI) poses a challenge to accurate diagnosis of PJI. Recently, the Musculoskeletal Infection Society (MSIS) proposed diagnostic criteria for PJI. However, it is not known how well these proposed criteria accommodate real clinical scenarios.

Laxity after complete release of the medial collateral ligament in primary total knee arthroplasty.

Purpose: Medial collateral ligament (MCL) release is one of the essential steps toward the achievement of ligament balancing during the total knee arthroplasty (TKA) in patients with varus deformity. When the varus deformity is severe, complete release of the MCL until balanced is often required. However, it is believed that complete MCL release may lead to catastrophic laxity.

Causes, risk factors, and trends in failures after TKA in Korea over the past 5 years: a multicenter study.

Background: Failure after total knee arthroplasty (TKA) may be related to emerging technologies, surgical techniques, and changing patient demographics. Over the past decade, TKA use in Korea has increased substantially, and demographic trends have diverged from those of Western countries, but failure mechanisms in Korea have not been well studied.

Questions/purposes: We determined the causes of failure after TKA, the risk factors for failure, and the trends in revision TKAs in Korea over the last 5 years.

Polymorphonuclear cell count on frozen section is not an absolute index of reimplantation in infected total knee arthroplasty.

We evaluated the outcomes in 15 patients with infected total knee arthroplasty (TKA) who underwent reimplantation following excision arthroplasty in the presence of five to twenty polymorphonuclear cells per high power field (hpf) on intraoperative frozen section. At a minimum of two years of follow-up, we achieved 100% infection eradication rate with normalization of C-reactive protein levels, no radiolucency on plain radiographs and no clinical evidence of recurred infection. Successful reimplantation for infected TKA is possible despite of the presence of five to twenty polymorphonuclear cells per hpf in intraoperative frozen section with clear appearance of the tissues in the operative field.

Evaluation of the chondromalacia patella using a microscopy coil: comparison of the two-dimensional fast spin echo techniques and the three-dimensional fast field echo techniques.

Objective: We wanted to compare the two-dimensional (2D) fast spin echo (FSE) techniques and the three-dimensional (3D) fast field echo techniques for the evaluation of the chondromalacia patella using a microscopy coil.

Materials And Methods: Twenty five patients who underwent total knee arthroplasty were included in this study. Preoperative MRI evaluation of the patella was performed using a microscopy coil (47 mm).

What have we learned from LCS mobile-bearing knee system?

Three hundred and sixty-four low contact stress (LCS) total knee arthroplasties that could be followed up for more than 5 years were clinically and radiographically analyzed. The median postoperative Hospital for Special Surgery score improved from 56 (range 32-77) to 91 (range 64-100) points, but median range of motion did not change from 120° (range 50°-135°) to 120° (range 85°-135°). Complications occurred in 16 cases (4%), and included postoperative polyethylene dislocation and intraoperative tibial condylar fracture, while five knees (1%) required revision surgery due to mechanical reasons.

Should the 'no thumb technique' be the golden standard for evaluating patellar tracking in total knee arthroplasty?

We checked intraoperative patellar tracking with both 'towel clip technique' and the 'no thumb technique' on 97 patients (167 knees) who underwent primary total knee arthroplasty to decide whether to do or not to do lateral retinacular release. Patellar tracking was assessed under pneumatic tourniquet with the no thumb technique first and re-evaluated with the towel clip technique. The tracking was graded as total contact, good contact, lateral contact and subluxation.

The effect of patellar thickness changes on patellar tilt in total knee arthroplasty.

We hypothesized that changes in patellar thickness following patellar resurfacing affect patellar tilt in total knee arthroplasty (TKA) patients. The study enrolled 272 TKAs and categorized them into four groups according to change in patellar thickness: (A) thinner by 1 mm or more, (B) equal or thinner by less than 1 mm, (C) thicker by 1 mm or less, and (D) thicker by more than 1 mm. Patellar tilt angle was measured postoperatively using Merchant radiography.

Interleukin-32gamma enhances the production of IL-6 and IL-8 in fibroblast-like synoviocytes via Erk1/2 activation.

Introduction: In the present study, we examined the effect of the pro-inflammatory cytokine IL-32gamma, the most biologically active isoform, and its related molecules in fibroblast-like synoviocytes (FLS).

Materials And Methods: FLS were isolated from synovial tissues of rheumatoid arthritis (RA) patients. The secretion and expression of IL-6 and IL-8 were examined by ELISA and real-time PCR, and the activation of signaling molecules was evaluated by Western blot, electrophoretic mobility shift assay (EMSA), real-time PCR, and siRNA transfection.

Migration of polyethylene fixation screw after total knee arthroplasty.

Duracon (Howmedica, Rutherford, NJ) posterior stabilized total knee system has a snap fit locking mechanism of a tibial polyethylene, including an additional locking screw for further fixation of polyethylene. We report 13 cases of locking screw migration from tibial component after Duracon posterior stabilized primary total knee arthroplasty. Among 13 knees, screw migration in 10 asymptomatic cases was incidentally detected during regular follow-up, and they were just observed in the outpatient clinic.

Effect of estrogen on the expression of matrix metalloproteinase (MMP)-1, MMP-3, and MMP-13 and tissue inhibitor of metalloproternase-1 in osteoarthritis chondrocytes.

The aim of this study was to evaluate the effect of estrogen on matrix metalloproteinase (MMP)-1, MMP-3, MMP-13, and tissue inhibitor of metalloproteinase (TIMP)-1 in osteoarthritic chondrocytes. Chondrocytes from the knee cartilage of 25 postmenopausal osteoarthritic (OA) patients were cultured under various conditions: 0 pg/mL, 50 pg/mL, 500 pg/mL, and 5,000 pg/mL of 17beta-estradiol, with or without 10-1,000 pg/mL of either interleukin (IL)-1beta or tumor necrosis factor alpha (TNFalpha). MMP-1, MMP-3, MMP-13, and TIMP-1 in the conditioned media were analyzed with immunoblot or enzyme-linked immunosorbent assay (ELISA).