Woo-Lam Jo

Mid-term results of the BIOLOX delta ceramic-on-ceramic total hip arthroplasty

Aims We conducted a prospective study of a delta ceramic total hip arthroplasty (THA) to determine the rate of ceramic fracture, to characterise post‐operative noise, and to evaluate the mid‐term results and survivorship. Patients and Methods Between March 2009 and March 2011, 274 patients (310 hips) underwent cementless THA using a delta ceramic femoral head and liner. At each follow‐up, clinical and radiological outcomes were recorded. A Kaplan‐Meier analysis was undertaken to estimate survival. Results Four patients (four hips) died and 18 patients (20 hips) were lost to follow‐up within five years. The remaining 252 patients (286 hips) were followed for a mean of 66.5 months (60 to 84). There were 144 men (166 hips) and 108 women (120 hips) with a mean age of 49.7 years (16 to 83) at surgery. The mean pre‐operative Harris Hip Score of 47.1 points improved to 93.8 points at final follow‐up. Six patients reported squeaking in seven hips; however, none were audible. Radiolucent lines involving Gruen zones one and/or seven were seen in 52 hips (18.2%). No hip had detectable wear, focal osteolysis or signs of loosening. One hip was revised because of fracture of the ceramic liner, which occurred due to an undetected malseating of the ceramic liner at the time of surgery. One hip was revised for a periprosthetic fracture of the femur, and one hip was treated for periprosthetic joint infection. The six‐year survivorship with re‐operation for any reason as the endpoint was 99.0% (95% confidence interval 97.8% to 100%). Discussion The rate of delta ceramic fracture was 0.3% (one of 286). While ceramic head fracture was dominant in previous ceramic‐on‐ceramic THA, fracture of the delta ceramic liner due to malseating is a concern.

Frequency, Developing Time, Intensity, Duration, and Functional Score of Thigh Pain After Cementless Total Hip Arthroplasty

BACKGROUND Although thigh pain is an annoying problem after total hip arthroplasty (THA), little information has been known about its natural course. METHODS To determine the frequency, time of onset, and duration of thigh pain after cementless THA, we evaluated 240 patients (240 hips) who underwent primary THA because of femoral head osteonecrosis with the use of a single tapered stem. RESULTS Twenty-seven patients (11.3%) experienced thigh pain during the follow-up of 3-11 years (mean, 84 months). The pain developed 2-78 months (median, 25 months) after THA. The 75% of pain developed within 36 months. In 25 patients, the pain disappeared postoperatively 1 month-64 months (mean, 17.4 months), and 2 patients (7.4%, 2/27) had persistent thigh pain. There were no differences in the latest Harris Hip Score between the thigh pain group and no thigh pain group. CONCLUSION Our results provided basic information about the natural history of thigh pain after cementless THA with a tapered stem design.

Co-transplantation of adipose and bone marrow derived stromal cells for treatment of osteonecrosis of femoral head

Osteonecrosis of femoral head (ONFH) is irreversible disease which treatment is almost depending on total joint replacement. The synergistic effect by co-transplantation of adipose-derived stromal cells (ASCs) in enhancing the osteogenic differentiation of bone marrow stromal cells (BMSCs) proved in critical sized calvarial defect model of rat in our previous study. In this study, porcine ASCs and BMSCs were co-transplanted to ONFH model of minipig. In the results of X-rays and CT, defect of cells transplantation group was complete healed up with new bone tissue while control group had unfilled bone defect. Histological findings also corroborated the radiological findings. We observed very rapid and good quality osteogenesis in combined ASCs and BMSCs implantation group compared with control group.

Rupture of flexor tendons as a complication of a distal radius fracture

Abstract Two cases are reported of flexor tendon rupture of ulnar side fingers as a complication after distal radius fracture. One was associated with a prominent distal volar lip of fracture site, the other with a relatively volarly displaced ulnar head due to the dorsally tilted distal radius due to malunion. These may be unique cases of flexor tendon rupture with conservatively treated patients.

Etiologic Classification Criteria of ARCO on Femoral Head Osteonecrosis Part 1: Glucocorticoid-Associated Osteonecrosis

BACKGROUND Glucocorticoid usage, a leading cause of osteonecrosis of the femoral head (ONFH), and its prevalence was reported in 25%-50% of non-traumatic ONFH patients. Nevertheless, there have been no unified criteria to classify glucocorticoid-associated ONFH (GA-ONFH). In 2015, the Association Research Circulation Osseous addressed the issue of developing a classification scheme. METHODS In June 2017, a task force was set up to conduct a Delphi survey concerning ONFH. The task force invited 28 experts in osteonecrosis/bone circulation from 8 countries. Each round of the Delphi survey consists of questionnaires, analysis of replies, and feedback reports to the panel. After 3 rounds of the survey, the panel reached a consensus on the classification criteria. The response rates were 100% (Round 1), 96% (Round 2), and 100% (Round 3), respectively. RESULTS The consensus on the classification criteria of GA-ONFH included the following: (1) patients should have a history of glucocorticoid use >2 g of prednisolone or its equivalent within a 3-month period; (2) osteonecrosis should be diagnosed within 2 years after glucocorticoid usage, and (3) patients should not have other risk factor(s) besides glucocorticoids. CONCLUSION Association Research Circulation Osseous established classification criteria to standardize clinical studies concerning GA-ONFH.

Incidence, risk factors and prognosis of transient pseudosubluxation after total hip arthroplasty.

Introduction: Pseudosubluxation is a transient separation of the prosthetic femoral head from the acetabular liner during the anaesthetic period after total hip arthroplasty (THA). However, little is known about the frequency, pathomechanism, risk factors or natural history. Methods: To determine the incidence, direction of the displacement, risk factors and subsequent instability of pseudosubluxation, we evaluated 1099 primary cementless THAs (943 patients), which were performed during 8 years at one institution. Immediately after THA, postoperative radiographs were obtained for all hips. If a subluxation was noted, the operated hip was examined by fluoroscope within 1 hour of the detection and repeat radiographs were taken on the postoperative day 1. Results: The pseudosubluxation was identified in 2.6% (28/1059). All of the 28 heads subluxed anteriorly and reduced in flexion-internal rotation. In multivariate analysis: (1) operative decrease of the femoral offset (odds ratio; 1.161 (95% confidence interval [CI]; 1.077–1.251), p = 0.001); and (2) medialisation of acetabular cup (odds ratio; 3.402 (95% CI; 1.482–7.813), p = 0.009) were found as risk factors for pseudosubluxation. None of the 28 hips dislocated during 3- to 8-year follow-up. Conclusions: Our results provide information about the incidence, risk factors and natural history of pseudosubluxation after primary THA. Surgeons should be aware of the risk of pseudosubluxation when performing THA in patients with coxa vara, who have a large femoral offset, and in those with dysplastic or deficient acetabulum, who have a lateral centre of rotation.

The biological response to laser-aided direct metal-coated Titanium alloy (Ti6Al4V)

Objectives Laser-engineered net shaping (LENS) of coated surfaces can overcome the limitations of conventional coating technologies. We compared the in vitro biological response with a titanium plasma spray (TPS)-coated titanium alloy (Ti6Al4V) surface with that of a Ti6Al4V surface coated with titanium using direct metal fabrication (DMF) with 3D printing technologies. Methods The in vitro ability of human osteoblasts to adhere to TPS-coated Ti6Al4V was compared with DMF-coating. Scanning electron microscopy (SEM) was used to assess the structure and morphology of the surfaces. Biological and morphological responses to human osteoblast cell lines were then examined by measuring cell proliferation, alkaline phosphatase activity, actin filaments, and RUNX2 gene expression. Results Morphological assessment of the cells after six hours of incubation using SEM showed that the TPS- and DMF-coated surfaces were largely covered with lamellipodia from the osteoblasts. Cell adhesion appeared similar in both groups. The differences in the rates of cell proliferation and alkaline phosphatase activities were not statistically significant. Conclusions The DMF coating applied using metal 3D printing is similar to the TPS coating, which is the most common coating process used for bone ingrowth. The DMF method provided an acceptable surface structure and a viable biological surface. Moreover, this method is automatable and less complex than plasma spraying. Cite this article: T. Shin, D. Lim, Y. S. Kim, S. C. Kim, W. L. Jo, Y. W. Lim. The biological response to laser-aided direct metal-coated Titanium alloy (Ti6Al4V). Bone Joint Res 2018;7:357–361. DOI: 10.1302/2046-3758.75.BJR-2017-0222.R1.

Level of surgical experience is associated with change in hip center of rotation following cementless total hip arthroplasty: A radiographic assessment.

Objectives After total hip arthroplasty (THA), restoration of hip center of rotation (COR) is essential to ensure stability of the prosthetic hip and longevity of the prosthesis. Our aim was to determine whether, and how, the COR changed postoperatively compared to the native COR following implantation of a cementless acetabular component in anatomical position and to compare the accuracy of cup placement between two surgeons with different levels of surgical experience. Materials and methods We evaluated 145 patients (145 hips) who underwent unilateral primary THA, who had no distorted acetabulum on the affected hip and a normal contralateral hip. Hip reconstruction was radiologically and clinically assessed at a minimum 2-year follow-up. Perioperative change in COR, initial cup position, offset, leg-length discrepancy (LLD), radiographic cup orientation, Harris Hip Score (HHS), component loosening, and dislocations were compared between the highly experienced surgeon and less-experienced surgeon groups. Results The COR was significantly displaced in the superior and medial directions postoperatively. Significant differences were identified in the vertical COR change, initial cup position, LLD, cup inclination, and cups within safe zones, but not in the horizontal COR change, offset parameters, cup anteversion, or HHS. There were no radiographic evidence of component loosening in both groups, but three dislocations (7%) only in the group operated on by the less-experienced surgeon (p = 0.027). Conclusions We found that the postoperative COR tended to be displaced in the superior and medial directions, and that the level of surgical experience strongly affected the accuracy and consistency of cup placement, particularly in COR position and cup inclination.

Diagnosis and Treatment of Inflammatory Joint Disease

Arthritis damages the cartilage within joints, resulting in degenerative changes, including loss of function and joint instability. Ankylosing spondylitis (AS) is a chronic inflammatory condition affecting the spine and bone-to-tendon attachment area within the sacroiliac joint leading to back pain and progressive spinal stiffness. In the final stages, AS causes hyperkyphosis-a condition closely tied to the human leukocyte antigen-B27 gene. Rheumatoid arthritis is a chronic, systemic autoimmune disease characterized by the simultaneous inflammation of the synovium of multiple joints, leading to joint damage (e.g., destruction, deformation and disability). In the past, nonsteroidal anti-inflammatory drugs or conventional disease-modifying antirheumatic drug (DMARDs) have been used for the treatment of these autoimmune diseases, but biologic DMARDs have recently been introduced with excellent results. Gout is a chronic inflammatory disease that causes an alteration of joints resulting in severe pain. Specifically, gout is associated with an accumulation of uric acid within the body resulting from dysregulated purine metabolism, causing recurrent paroxysmal inflammation in the joints. Allopurinol and febuxostat are the primary treatment options for individuals with gout. It is necessary to have an accurate understanding of the pathogenesis, pathological ecology and treatment of AS, rheumatoid arthritis, and gouty arthritis, which are the representative diseases that may cause inflammatory arthritis.