Clinical Results after Design Modification of Lospa Total Knee Arthroplasty System: Comparison between Posterior-Stabilized (PS) and PS Plus Types.

Background: Lospa posterior-stabilized (PS) Plus type is a modified version of Lospa PS, in which the polyethylene insert shape is modified to reinforce stability and prevent patella-post impingement compared to Lospa PS. However, studies comparing the clinical and radiographic results of the two designs have not been reported yet. This study aimed to compare the clinical results of total knee arthroplasty (TKA) using the existing PS type and the modified Lospa PS Plus type. Methods: A retrospective study was performed on 558 knees of 342 patients who underwent TKA using the Lospa PS or PS Plus types and were followed up for at least 2 years. Cases were divided into two groups according to the implant used: 212 cases in the PS group and 346 cases in the PS Plus group. For clinical outcome assessment, knee range of motion (ROM), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, and Knee Society Score (KSS) were recorded before surgery and at the 2-year follow-up. Radiographic outcomes were evaluated according to the American Knee Society method. The incidence of postoperative complications and survival rates were compared between the two groups. Results: Both groups showed significant clinical improvement after surgery. The average KSS significantly improved from 53.4 points in the PS group and 52.3 points in the PS Plus group preoperatively to 91.3 points and 93.2 points after surgery, respectively (p < 0.001). The average WOMAC score improved from 50.4 points in the PS group and 52.3 points in the PS Plus group before surgery to 15.6 points and 14.8 points after surgery, respectively (p < 0.001). There was no significant difference between the two groups in ROM, the alignment of the lower limbs, and the implant position after surgery. The complication rates were also similar between the groups (p = 0.167). Conclusions: The Lospa PS Plus model is a modified design that improves the post structure from the previous PS type. Compared to the PS type, the PS Plus type showed similar statistical results at 2-year follow-up and good clinical results. The short-term average survival rate was over 98%, showing promising results.

Hip Arthroplasty Using the Bencox® Hip System: An Evaluation of a Consecutive Series of One Thousand Cases.

PURPOSE: This is a report on the outcomes associated with a consecutive series of 1,000 cementless hip arthroplasties utilizing the Bencox® hip stem-the first Korean-developed hip prosthesis. MATERIALS AND METHODS: A consecutive series of 1,000 hip arthroplasties using the Bencox® hip stem were analyzed, starting from its initial release (September 2006) until June 2014. Patients in this consecutive series underwent surgery for fractures (n=552), arthritis (n=155), avascular necrosis (n=209), and revisions (n=84). Of these 1,000 cases, patients with a minimum follow-up of at least 1 year (n=616) were retrospectively analyzed for radiographic and clinical outcomes (i.e., Harris hip score). The stability of the prosthesis was evaluated by examining subsidence. RESULTS: During the follow-up period (mean follow-up period of 54.8 months), there were 2 cases requiring revision of the femoral stem-both were caused by periprosthetic fractures and neither involved stem loosening. The mean Harris hip score during follow-up was 95.5. Bone ongrowth occurred in 95% of patients; no cases of subsidence or aseptic loosening of the stem were detected, and no cases of postoperative complications such as ceramic breakage were observed. CONCLUSION: Clinical and radiographic evaluations of hip arthroplasty using the Bencox® hip stem revealed excellent outcomes with an average of 54.8 month follow-up in a consecutive series of 1,000 cases.

A Protocol to Acquire the Degenerative Tenocyte from Humans.

Tendinopathy, a painful condition that develops in response to tendon degeneration, is on the rise in the developed world due to increasing physical activity and longer life expectancy. Despite its increasing prevalence, the underlying pathogenesis still remains unclear, and treatment is generally symptomatic. Recently, numerous therapeutic options, including growth factors, stem cells, and gene therapy, were investigated in hopes of enhancing the healing potency of the degenerative tendon. However, the majority of these research studies were conducted only on animal models or healthy human tenocytes. Despite some studies using pathological tenocytes, to the best of our knowledge there is currently no protocol describing how to obtain human degenerative tenocytes. The aim of this study is to describe a standard protocol for acquiring human degenerative tenocytes. Initially, the tendon tissue was harvested from a patient with lateral epicondylitis during surgery. Then biopsy samples were taken from the extensor carpi radialis brevis tendon corresponding to structural changes observed at the time of surgery. All of the harvested tendons appeared to be dull, gray, friable, and edematous, which made them visually distinct from the healthy ones. Tenocytes were cultured and used for experiments. Meanwhile, half of the harvested tissues were analyzed histologically, and it was shown that they shared the same key features of tendinopathy (angiofibroblastic dysplasia or hyperplasia). A secondary analysis by immunocytochemistry confirmed that the cultured cells were tenocytes with the majority of the cells having positive stains for mohawk and tenomodulin proteins. The qualities of the degenerative nature of tenocytes were then determined by comparing the cells with the healthy control using a proliferation assay or qRT-PCR. The degenerative tenocyte displayed a higher proliferation rate and similar gene expression patterns of tendinopathy that matched previous reports. Overall, this new protocol might provide a useful tool for future studies of tendinopathy.

Acetabular Cup Revision Arthroplasty Using Morselized Impaction Allograft.

The rate of acetabular cup revision arthroplasty is gradually rising along with an increased risk of osteolysis and prosthesis loosening over time and an increase in life expectancy. The goals of revision total hip arthroplasty are: i) implant stability through reconstruction of large bone defects, ii) restoration of range of motion and biomechanics of the hip joint, and iii) normalization of uneven limb lengths. In acetabular cup revision arthroplasty, stable fixation of acetabular components is difficult in the presence of severe bone loss (e.g., evidence suggests that it is challenging to achieve satisfactory results in cases of Paprosky type 3 or higher bone defects using conventional techniques). The author of this study performed acetabular revision to manage patients with large areas of defective bones by filling in with morselized impaction allografts. These allografts were irradiated frozen-stored femoral heads acquired from a tissue bank, and were applied to areas of an acetabular bone defect followed by insertion of a cementless cup. When this procedure was insufficient to obtain primary fixation, a tri-cortical or structural allograft using a femoral head was carried out. Structural stability and bone incorporation were confirmed via long-term follow-up. This study aims to review conventional surgical techniques and verify the utility of surgical procedures by analyzing the author's surgical methods and discussing case reports.

Treatment of Periprosthetic Femoral Fractures Following Hip Arthroplasty.

PURPOSE: This study was performed to assess potential improvements in clinical outcomes when applying recent advanced hip arthroplasty surgical techniques and understand the potential relationship between bone mineral density (BMD) and surgical outcomes. MATERIALS AND METHODS: Among 37 cases of periprosthetic femoral fractures after hip arthroplasty treated between March 2014 and September 2016, all included a follow-up of at least one year and were included in this study. Outcomes were evaluated using the Beals and Tower's criteria. BMD was examined in 27 of 37 cases and the relationship between osteoporosis and treatment outcomes was analyzed. Advanced hip arthroplasty surgical approaches varied depending on the fracture type: i) open reduction with wiring for Vancouver A, ii) open reduction with double plate fixation for Vancouver B1, iii) revision THA with long stem for Vancouver B1-Nonunion, B2 and B3, and iv) open reduction with double plate fixation for Vancouver C. RESULTS: When assessed using the Beals and Tower's criteria, 33 out of 37 (89.2%) patients were excellent and 4 (10.8%) were poor. These outcomes were an improvement compared with series I (81.8%). When analyzed according to the Vancouver classification, patients with type A (n=8), type B1 (n=16), and type B2 (n=2) were all excellent, the patients with type B3 were excellent (n=1) and poor (n=1), and the patients with type C were excellent (n=6) and poor (n=3). The mean BMD was -2.6 (T-score) in 27 of 37 cases and -4.4 in 4 cases with poor prognosis. Osteoporosis was statistically correlated to those classified as poor by Beals and Tower. CONCLUSION: The results of the analysis suggest that applying new surgical hip arthroplasty treatment approaches leads to improved outcomes compared with the author's previous study. When treating periprosthetic femoral fractures following total hip arthroplasty, an appropriate internal fixation method should be selected, at least in part based on the Vancouver classification. In addition, osteoporosis may be a major prognostic factor for the outcomes of surgical treatment.

Down-Regulation of Transglutaminase 2 Stimulates Redifferentiation of Dedifferentiated Chondrocytes through Enhancing Glucose Metabolism.

Expansion of chondrocytes for repair of articular cartilage can lead to dedifferentiation, making it difficult to obtain a sufficient quantity of chondrocytes. Although previous studies have suggested that culture in a three-dimensional environment induces redifferentiation of dedifferentiated chondrocytes, its underlying mechanisms are still poorly understood in terms of metabolism compared with a two-dimensional environment. In this study, we demonstrate that attenuation of transglutaminase 2 (TG2), a multifunctional enzyme, stimulates redifferentiation of dedifferentiated chondrocytes. Fibroblast-like morphological changes increased as TG2 expression increased in passage-dependent manner. When dedifferentiated chondrocytes were cultured in a pellet culture system, TG2 expression was reduced and glycolytic enzyme expression up-regulated. Previous studies demonstrated that TG2 influences energy metabolism, and impaired glycolytic metabolism causes chondrocyte dedifferentiation. Interestingly, TG2 knockdown improved chondrogenic gene expression, glycolytic enzyme expression, and lactate production in a monolayer culture system. Taken together, down-regulation of TG2 is involved in redifferentiaton of dedifferentiated chondrocytes through enhancing glucose metabolism.

Wiring Techniques for the Fixation of Trochanteric Fragments during Bipolar Hemiarthroplasty for Femoral Intertrochanteric Fracture: Clinical Study and Technical Note.

PURPOSE: Femoral intertrochanteric fractures are common in the elderly. Appropriate surgical fixation of trochanteric fracture fragments can restore normal anatomical structure and ambulation, and can aid in the recovery of biomechanical function of the hip. We evaluated clinical outcomes of bipolar hemiarthroplasty using a wiring technique for trochanteric fracture fragment fixation. MATERIALS AND METHODS: From September 2006 to February 2015, a total of 260 cases underwent simultaneous bipolar hemiarthroplasty and wire fixation. A total of 65 patients (69 hips) with an average age of 78 years and more than one year of follow-up was included in the study. Using pre-, postoperative and follow-up radiograms, we evaluated wire fixation failure and also assessed changes in walking ability. RESULTS: Loosening or osteolysis around the stem was not observed; however, we did observe bone growth around the stem (54 cases), cortical hypertrophy (6 cases), a wide range of sclerotic lines but no stem subsidence (1 case), wire breakage (9 cases), and fracture fragment migration with no significant functional deficiency (2 cases). CONCLUSION: Our study showed that additional wiring for trochanteric fracture fragment fixation following bipolar hemiarthroplasty can help restore normal anatomy. The added stability results in faster rehabilitation, and good clinical and radiographic outcomes. We recommend this procedure in this type of fracture.

Enhancement of Matrix Metalloproteinase-2 (MMP-2) as a Potential Chondrogenic Marker during Chondrogenic Differentiation of Human Adipose-Derived Stem Cells.

Human adipose-derived stem cells (hASCs) have a capacity to undergo adipogenic, chondrogenic, and osteogenic differentiation. Recently, hASCs were applied to various fields including cell therapy for tissue regeneration. However, it is hard to predict the direction of differentiation of hASCs in real-time. Matrix metalloproteinases (MMPs) are one family of proteolytic enzymes that plays a pivotal role in regulating the biology of stem cells. MMPs secreted by hASCs are expected to show different expression patterns depending on the differentiation state of hASCs because biological functions exhibit different patterns during the differentiation of stem cells. Here, we investigated proteolytic enzyme activity, especially MMP-2 activity, in hASCs during their differentiation. The activities of proteolytic enzymes and MMP-2 were higher during chondrogenic differentiation than during adipogenic and osteogenic differentiation. During chondrogenic differentiation, mRNA expression of MMP-2 and the level of the active form of MMP-2 were increased, which also correlated with Col II. It is concluded that proteolytic enzyme activity and the level of the active form of MMP-2 were increased during chondrogenic differentiation, which was accelerated in the presence of Col II protein. According to our findings, MMP-2 could be a candidate maker for real-time detection of chondrogenic differentiation of hASCs.

Acetabular revision total hip arthroplasty using an impacted morselized allograft and a cementless cup: minimum 10-year follow-up.

This study was undertaken to analyze the clinical and radiologic results of acetabular revision arthroplasty using an impacted morselized allograft and a cementless cup and was performed on 71 hips of 62 patients who were followed up for a minimum of 10 years (10 years to 14 years 8 months; mean, 12 years). The acetabular bone defects were classified using the American Academy of Orthopaedic Surgeons Committee on the Hip and Paprosky classifications. Cementless hemispherical cups were inserted via a press-fit technique, using an impacted morselized allograft. The mean Harris hip score at the last follow-up visit was 92. Only 3 cases were re-revised, and the 12-year survival rate was thus 95.8%. The study shows that acetabular revision arthroplasty using an impacted morselized allograft and a cementless cup is an excellent treatment option.

Comparison of hydroxyapatite-coated and non-hydroxyapatite-coated noncemented total hip arthroplasty in same patients.

The comparison between standard blasted and hydroxyapatite (HA)-coated cementless femoral stems (CLS stem) was made in the same patients who have bilateral late-stage osteonecrosis. Clinical and radiographic evaluations were performed in 20 patients (among 29 patients) with the minimum follow-up of 10 years (range, 123-168 months). Endosteal bone formation was found in all patients of both stems, and no radiolucent line was observed. The mean of initial stem subsidence was 1.27 +/- 0.95 mm with the standard stem and 0.59 +/- 0.56 mm with the HA-coated stem. Other results, such as hip score, endosteal bone formation, cortical hypertrophy, osteolysis, and heterotopic ossification showed no statistical differences. These have suggested that the fixation obtained by the cementless stem with a corundum-blasted surface is stable enough to get excellent clinical and radiographic results without the HA coating.