Novel susceptibility loci for steroid-associated osteonecrosis of the femoral head in systemic lupus erythematosus.

Osteonecrosis of the femoral head (ONFH) involves necrosis of bone and bone marrow of the femoral head caused by ischemia with unknown etiology. Previous genetic studies on ONFH failed to produce consistent results, presumably because ONFH has various causes with different genetic backgrounds and the underlying diseases confounded the associations. Steroid-associated ONFH (S-ONFH) accounts for one-half of all ONFH, and systemic lupus erythematosus (SLE) is a representative disease underlying S-ONFH. We performed a genome-wide association study (GWAS) to identify genetic risk factors for S-ONFH in patients with SLE. We conducted a two-staged GWAS on 636 SLE patients with S-ONFH and 95 588 non-SLE controls. Among the novel loci identified, we determined S-ONFH-specific loci by comparing allele frequencies between SLE patients without S-ONFH and non-SLE controls. We also used Korean datasets comprising 148 S-ONFH cases and 37 015 controls to assess overall significance. We evaluated the functional annotations of significant variants by in silico analyses. The Japanese GWAS identified 4 significant loci together with 12 known SLE susceptibility loci. The four significant variants showed comparable effect sizes on S-ONFH compared with SLE controls and non-SLE controls. Three of the four loci, MIR4293/MIR1265 [odds ratio (OR) = 1.99, P-value = 1.1 × 10-9)], TRIM49/NAALAD2 (OR = 1.65, P-value = 4.8 × 10-8) and MYO16 (OR = 3.91, P-value = 4.9 × 10-10), showed significant associations in the meta-analysis with Korean datasets. Bioinformatics analyses identified MIR4293, NAALAD2 and MYO16 as candidate causal genes. MIR4293 regulates a PPARG-related adipogenesis pathway relevant to S-ONFH. We identified three novel susceptibility loci for S-ONFH in SLE.

Artificial Intelligence-Based Surgery Support Model Using Intraoperative Radiographs for Assessing the Acetabular Component Angle.

BACKGROUND: This study aimed to develop an artificial intelligence-based surgical support model for assessing the acetabular component angle using intraoperative radiographs during total hip arthroplasty and verify its accuracy. METHODS: A total of 268 hips were analyzed. At first, 268 preoperative and intraoperative anteroposterior pelvic radiographs were amplified to 536. These radiographs were used to create a learning model to estimate the acetabular component angle from the radiographs intraoperatively. The ground truth was the anteversion and inclination angles obtained from the computed tomography-based navigation system intraoperatively. Bone landmarks on the preoperative and intraoperative radiographs were manually annotated. The distances and angles between each landmark were used as predictor variables. The estimation accuracy was assessed for internal and external test datasets. Mean absolute error (MAE) and R2 values were used as accuracy measures. RESULTS: The MAE and R2 for the internal test set showed 2.19 and 0.850 for anteversion, and 1.18 and 0.805 for inclination, respectively. The MAE and R2 for the external test set showed 2.78 and 0.789 for anteversion, and 1.56 and 0.744 for inclination, respectively. CONCLUSIONS: We developed an artificial intelligence-based surgical support model for accurately assessing the acetabular component angle using intraoperative radiographs. Excellent estimation accuracy was confirmed for the external test set. In the future, the model may help to reduce the risk of adverse postoperative events.

Influence of greater trochanteric bone density and three-dimensional morphology on perioperative greater trochanteric fracture following total hip arthroplasty via an anterolateral approach.

BACKGROUND: Perioperative greater trochanteric fracture following total hip arthroplasty (THA) using the anterolateral approach is a recognized perioperative complication. There was no previous study to determine the relationship between bone mineral density (BMD) and three-dimensional greater trochanter morphology for perioperative greater trochanter fractures. The purpose of this study is to identify the influence of greater trochanteric bone density and three-dimensional morphology on perioperative greater trochanteric fracture following THA using the anterolateral approach. METHODS: We investigated 209 hips done primary THA using the anterolateral approach and preoperative BMD test for the proximal femoral bone with a minimum of 6 months follow-up. We picked up all patients who had perioperative greater trochanteric fractures. Multivariate analysis was done in order to investigate the influence of the greater trochanter young adult mean (YAM) and three-dimensional morphology on perioperative greater trochanteric fractures. RESULTS: There were 10 joints (10/209, 4.8%) with perioperative greater trochanteric fractures. Osteosynthesis was required only in one joint (1/209, 0.5%) because the bone fragments were significantly displaced proximally by the gluteus medius. Multivariate analysis showed the combination of Type B femoral shape (in cases where the top of the great trochanter was inside the longitudinal central axis of the planned femoral stem in computed tomography (CT)- based three-dimensional templating) and a YAM of < 80% was the only risk factor for fracture. CONCLUSIONS: The preoperative greater trochanter BMD test (YAM < 80%) and three-dimensional femoral morphology (Type B femoral shape) provide useful information to mitigate the occurrence of perioperative greater trochanter fractures associated with THA using the anterolateral approach.

Risk factor analysis on perioperative greater trochanteric fracture of total hip arthroplasty via anterolateral approach.

INTRODUCTION: A greater trochanteric fracture is a perioperative complication of primary total hip arthroplasty (THA) via an anterolateral approach. Although surgeons determine risk factors in the preoperative planning phase, no study explored the relationship between the planned femoral implant and greater trochanter. This study attempts to determine the risk factors for perioperative greater trochanteric fractures in primary THA via an anterolateral approach. MATERIALS AND METHODS: This retrospective single-institution study enrolled 440 patients (66 males and 374 females) who underwent primary THA via an anterolateral approach with a minimum follow-up of six months. First, we selected patients with perioperative greater trochanteric fractures, regardless of the need for additional surgery. Second, we investigated the risk factors for perioperative greater trochanteric fractures using the patients' demographic data, operative data, and femoral geometry data via univariate and multivariate analyses. RESULTS: Perioperative greater trochanteric fractures occurred in 30 joints (30/440, 6.8%), and all cases were reported in women. Multivariate analysis revealed that in cases where the top of the great trochanter was inside the longitudinal central axis of the planned femoral stem in three-dimensional templating (Type B) was the only independent risk factor for perioperative greater trochanteric fracture (odds ratio, 14.6; 95% confidence interval, 5.88-36.1; P < 0.001). CONCLUSION: This study identified female sex and Type B femoral geometry as risk factors for perioperative greater trochanteric fracture via an anterolateral approach. Our results may reduce the incidence of perioperative greater trochanteric fractures associated with primary THA.

Risk factors that hinder locomotive syndrome improvement following surgery for musculoskeletal diseases in older patients: A multicentre prospective study.

OBJECTIVES: This study aimed to evaluate preoperative and post-operative locomotive syndrome (LS) in older adults undergoing surgical treatment for musculoskeletal diseases of the lumbar spine and lower extremities and identify risk factors that impede LS improvement after surgery. METHODS: The baseline evaluation included 471 patients 65 years or older [276 in the pre-old-age (65-74 years) group; 195 in the old-age (75 years or older) group] and examined the preoperative and post-operative LS data. The second evaluation performed to identify risk factors, including anthropometric measurements, comorbidity, and frailty, that hinder LS improvement after surgery included 378 patients with preoperative LS Stage 3. RESULTS: Preoperatively, 80% of the patients had LS Stage 3; this rate decreased to 40% post-operatively. Half of the patients exhibited post-operative LS improvement. The LS improvement rate was higher in the pre-old-age group than in the old-age group. According to the multiple logistic regression analysis, old age, high body mass index, weak hand grip strength, and high 5-factor modified frailty index score were significant risk factors that hinder LS improvement after surgery. CONCLUSIONS: Ageing, obesity, weak muscle strength, and frailty can hinder LS improvement in older patients who undergo surgery.

Large intraosseous chronic expanding hematoma after total hip arthroplasty presenting with chronic disseminated intravascular coagulation: a case report and literature review.

BACKGROUND: A chronic expanding hematoma (CEH) is a rare complication caused by surgery or trauma; it mostly affects the soft tissues, such as those in the trunk or extremities. We present the first case of a large intraosseous CEH presenting with chronic disseminated intravascular coagulation (DIC), 22 years after total hip arthroplasty (THA); the CEH was treated with a single-stage excision and revision THA. CASE PRESENTATION: A 67-year-old man presented to our hospital with left thigh pain and an enlarging mass. He had no history of trauma, anticoagulant use, or a collagen vascular disorder. The patient initially declined surgery. Two years later, radiographs and computed tomography images revealed progressive osteolysis, marginal sclerosis, and calcification in the left femur, in addition to loosening of the femoral component. Laboratory data revealed anemia and chronic DIC of unknown causes. Magnetic resonance imaging revealed a "mosaic sign" on the mass, indicating a mix of low- and high-signal intensities on T2-weighted images. Needle biopsy prior to surgery revealed no infection or malignant findings. An intraosseous CEH was suspected due to extensive osteolysis and loosening of the femoral component. No other factors that could induce chronic DIC were identified, such as sepsis, leukemia, cancer, trauma, liver disease, aneurysms, or hemangiomas. Therefore, we speculated that the anemia and chronic DIC were caused by the large intraosseous CEH. A single-stage revision THA with surgical excision was performed to preserve the hip function and improve the chronic DIC. The postoperative histopathological findings were consistent with an intraosseous CEH. The anemia and chronic DIC improved after 7 days. There was no recurrence of intraosseous CEH or chronic DIC at the 6-month follow-up. The left thigh pain improved, and the patient could ambulate with the assistance of a walking frame. CONCLUSIONS: The loosening of the femoral component caused persistent movement, which may have caused intraosseous CEH growth, anemia, and chronic DIC. It is important to differentiate CEHs from malignant tumors with hematomas. Furthermore, the "mosaic sign" noted in this case has also been observed on magnetic resonance images in other cases of CEH.

Does Dosage or Duration of Concurrent Oral Corticosteroid Influence Elevated Risk of Postoperative Complications After Total Joint Arthroplasty?

BACKGROUND: This report seeks to clarify whether the dosage and duration of preoperative concurrent corticosteroid use influence postoperative complications after primary total joint arthroplasty (TJA). METHODS: This retrospective single institutional study enrolled 1128 primary TJA cases, including 905 total hip arthroplasties and 223 total knee arthroplasties at a minimum 6 months of follow-up. Mean follow-up period was 51.9 ± 34.1 months (range 6-146). Of all joints, 120 joints (10.6%) were associated with chronic concurrent oral corticosteroid use. Multivariate analysis was performed to identify whether chronic concurrent oral corticosteroid use elevated the risk of postoperative complications including surgical site infection/periprosthetic joint infection, delayed wound healing, periprosthetic fracture, and implant loosening. For chronic concurrent oral corticosteroid user, we determined whether the dosage and duration of preoperative concurrent corticosteroid use influenced postoperative complications and have an effective threshold for postoperative complications using receiver operating characteristic curve analysis. RESULTS: The multivariate analysis revealed that American Society of Anesthesiologist Physical Status 3 was an independent risk factor for postoperative complications, while concurrent oral corticosteroid use was not an independent risk factor. When we compared joints with (n = 13) and without (n = 107) postoperative complications in chronic concurrent oral corticosteroid user, there was no statistical difference in the dosage (P = .97) and duration (P = .69) between the 2 groups. Area under the curve values for the oral corticosteroid dosages and duration were 0.482 and 0.549, respectively. CONCLUSION: This study revealed that neither dosage nor duration of concurrent oral corticosteroid use was predictive of postoperative complications after TJA. American Society of Anesthesiologist Physical Status 3 is a major factor in postoperative complications after TJA.

Does intraoperative periprosthetic occult fracture of the acetabulum affect clinical outcomes after primary total hip arthroplasty?

INTRODUCTION: The frequency of intraoperative periprosthetic occult fracture of the acetabulum (IPOA) in primary total hip arthroplasty (THA) is relatively high. However, the effect of this fracture on clinical outcome and survival of primary THA remains unknown. This study aimed to determine the impact of IPOA on the outcomes of primary THA during a minimum follow-up of 5 years. MATERIALS AND METHODS: This retrospective case-control study compared the outcomes of primary THA with or without IPOA during a minimum 5-year follow-up. Thirty-eight patients who underwent primary THA with IPOA (O group) were matched to 76 patients without IPOA (C group) between 2004 and 2013 based on age, sex, body mass index, primary diseases, cup diameter, cup design, and additional dome screw. Both groups underwent the same rehabilitation programs after surgery. We evaluated the Japanese Orthopaedic Association clinical outcomes score; postoperative complications, such as nerve injury, dislocation, heterotopic ossification, iliopsoas impingement, or infection; and radiographic outcomes. Additionally, we performed Kaplan-Meier survival analysis with cup aseptic loosening, cup failure revision, and all-cause revision as the endpoints. RESULTS: There were no significant differences in the pre- and postoperative clinical scores, postoperative complication rates, and cup sagittal rotation between the two groups. Radiographic evaluations showed no aggravation of cases to overt fractures. Bone ingrowth was observed in all cases, and none of the acetabular cups had a progressive radiolucent line ≥ 2 mm in all the 3 acetabular zones. Ten-year survival rates for cup aseptic loosening and cup failure revision were 100% in both groups; those for all-cause revision were 97.4% (92.0-100%) and 100% in the O and C groups, respectively (p = 0.157). CONCLUSIONS: Primary THA with IPOA provides favorable mid- to long-term outcomes. On IPOA diagnosis, although radiographic follow-up is necessary, additional treatments or rehabilitation programs are not required. Furthermore, postoperative computed tomography images for the detection of IPOA may be unnecessary.

Evaluation of locomotive syndrome in patients receiving surgical treatment for degenerative musculoskeletal diseases: A multicentre prospective study using the new criteria.

OBJECTIVES: This study aimed to evaluate the condition of patients with locomotive syndrome (LS) and their improvement after undergoing surgery for degenerative musculoskeletal diseases using the new criteria, including stage 3. METHODS: In total, 435 patients aged ≥40 years (167 middle-aged and 268 older) were divided into four groups based on the disease location: the lumbar (n = 118), hip (n = 191), knee (n = 80), and foot and ankle (n = 46) groups. Patients were evaluated by pre- and 1 year postoperative LS risk tests, including the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale. RESULTS: The pre- and postoperative prevalence of LS stage 3 were 78% and 29%, respectively. The postoperative LS stage improved in 62% of patients (77% and 53% in the middle-aged and older groups, respectively). Overall, the knee group showed the worst results, and the foot and ankle groups showed the best pre- and postoperative results. The pre- and postoperative prevalence of LS stage 3 according to the 25-Question Geriatric Locomotive Function Scale were comparable to those based on the total assessment. CONCLUSIONS: The new LS stage criteria are appropriate, and the 25-Question Geriatric Locomotive Function Scale is a good option for evaluating patients requiring surgery.

The prevalence and impact of sarcopenia in females undergoing total hip arthroplasty: A prospective study.

OBJECTIVES: Although both sarcopenia and hip disease decrease physical function, few studies have investigated the association. We investigated the prevalence of sarcopenia in patients awaiting total hip arthroplasty for osteoarthritis and examined the impact of sarcopenia on pre- and postoperative outcomes. METHODS: This prospective study included 96 females. Participants were classified using two criteria. Cases defined as having sarcopenia by the Asian Working Group for Sarcopenia (AWGS) criteria were categorized as the AWGS-sarcopenia (A-S) group, and others were categorized as the AWGS-non-sarcopenia (A-NS) group. Those classified by hand grip strength (HGS) constituted the lower-HGS (L-H) and normal-HGS (N-H) groups. Patient demographics, physical function, and Japanese Orthopaedic Association (JOA) score were compared between each group. RESULTS: The prevalence of the AWGS sarcopenia was 33.3%. In the pre- and postoperative analyses, the L-H group had significantly poorer physical function and JOA score than the N-H group. Postoperatively, the A-S group only demonstrated poorer HGS. CONCLUSION: Preoperative physical function and JOA score was significantly poorer in the L-H group; physical function was significantly poorer even postoperatively. A HGS test is useful for detecting a decline in the pre- and postoperative physical function in females with hip osteoarthritis.

Antibacterial Activity in Iodine-coated Implants Under Conditions of Iodine Loss: Study in a Rat Model Plus In Vitro Analysis.

BACKGROUND: We developed iodine-coated titanium implants to suppress microbial activity and prevent periprosthetic joint infection (PJI); their efficacy was demonstrated in animal and in vitro models. The iodine content in iodine-coated implants naturally decreases in vivo. However, to our knowledge, the effect of reduced iodine content on the implant's antimicrobial activity has not been evaluated to date. QUESTIONS/PURPOSES: (1) How much does the iodine content on the implant surface decrease after 4 and 8 weeks in vivo in a rat model? (2) What effect does the reduced iodine content have on the antimicrobial effect of the implant against multiple bacteria in an in vitro model? METHODS: This experiment was performed in two parts: an in vivo experiment to determine attenuation of iodine levels over time in rats, and an in vitro experiment in which we sought to assess whether the reduced iodine content observed in the in vivo experiment was still sufficient to deliver antimicrobial activity against common pathogens seen in PJI. For the in vivo experiment, three types of titanium alloy washers were implanted in rats: untreated (Ti), surface-anodized to produce an oxide film (Ti-O), and with an iodine layer on the oxidation film (Ti-I). The attenuation of iodine levels in rats was measured over time using inductively coupled plasma-mass spectrometry. Herein, only the Ti-I washer was used, with five implanted in each rat that were removed after 4 or 8 weeks. For the 4- and 8-week models, two rats and 15 washers were used. For the in vitro study, to determine the antibacterial effect, three types of washers (Ti, Ti-O, and Ti-I) (nine washers in total) were implanted in each rat. Then, the washers were removed and the antibacterial effect of each washer was examined on multiple bacterial species using the spread plate method and fluorescence microscopy. For the spread plate method, six rats were used, and five rats were used for the observation using fluorescence microscopy; further, 4- and 8-week models were made for each method. Thus, a total of 22 rats and 198 washers were used. Live and dead bacteria in the biofilm were stained, and the biofilm coverage percentage for quantitative analysis was determined using fluorescence microscopy in a nonblinded manner. Ti-I was used as the experimental group, and Ti and Ti-O were used as control groups. The total number of rats and washers used throughout this study was 24 and 213, respectively. RESULTS: Iodine content in rats implanted with Ti-I samples decreased to 72% and 65% after the in vivo period of 4 and 8 weeks, respectively (p = 0.001 and p < 0.001, respectively). In the in vitro experiment, the Ti-I implants demonstrated a stronger antimicrobial activity than Ti and Ti-O implants in the 4- and 8-week models. Both the median number of bacterial colonies and the median biofilm coverage percentage with live bacteria on Ti-I were lower than those on Ti or Ti-O implants for each bacterial species in the 4- and 8-week models. There was no difference in the median biofilm coverage percentage of dead bacteria. In the 8-week model, the antibacterial activity using the spread plate method had median (interquartile range) numbers of bacteria on the Ti, Ti-O, and Ti-I implants of 112 (104 to 165) × 105, 147 (111 to 162) × 105, and 55 (37 to 67) × 105 of methicillin-sensitive Staphylococcus aureus (Ti-I versus Ti, p = 0.026; Ti-I versus Ti-O, p = 0.009); 71 (39 to 111) × 105, 50 (44 to 62) × 105, and 26 (9 to 31)× 105 CFU of methicillin-resistant S. aureus (Ti-I versus Ti, p = 0.026; Ti-I versus Ti-O, p = 0.034); and 77 (74 to 83) × 106, 111 (95 to 117) × 106, and 30 (21 to 45) × 106 CFU of Pseudomonas aeruginosa (Ti-I versus Ti, p = 0.004; Ti-I versus Ti-O, p = 0.009). Despite the decrease in the iodine content of Ti-I after 8 weeks, it demonstrated better antibacterial activity against all tested bacteria than the Ti and Ti-O implants. CONCLUSION: Iodine-coated implants retained their iodine content and antibacterial activity against methicillin-sensitive S. aureus, methicillin-resistant S. aureus, and P. aeruginosa for 8 weeks in vivo in rats. To evaluate the longer-lasting antibacterial efficacy, further research using larger infected animal PJI models with implants in the joints of both males and females is desirable. CLINICAL RELEVANCE: Iodine-coated titanium implants displayed an antibacterial activity for 8 weeks in rats in vivo. Although the findings in a rat model do not guarantee efficacy in humans, they represent an important step toward clinical application.

The influence of pelvic tilt on stress distribution in the acetabulum: finite element analysis.

BACKGROUND: Finite element analysis (FEA) has been previously applied for the biomechanical analysis of acetabular dysplasia and osteotomy. However, until now, there have been little reports on the use of FEA to evaluate the effects of pelvic tilt on stress distribution in the acetabulum. METHODS: We used the Mechanical Finder Ver. 7.0 (RCCM, Inc., Japan) to construct finite element models based on 3D-CT data of patients, and designed dysplasia, borderline, and normal pelvic models. For analysis, body weight was placed on the sacrum and the load of the flexor muscles of the hip joint was placed on the ilium. The pelvic tilt was based on the anterior pelvic plane, and the pelvic tilt angles were -20°, 0°, and 20°. The load of the flexor muscle of the hip joint was calculated using the moment arm equation. RESULTS: All three models showed the highest values of von Mises stress in the -20° pelvic tilt angle, and the lowest in the 20° angle. Stress distribution concentrated in the load-bearing area. The maximum values of von Mises stress in the borderline at pelvic tilt angles of -20° was 3.5Mpa, and in the dysplasia at pelvic tilt angles of 0° was 3.1Mpa. CONCLUSIONS: The pelvic tilt angle of -20° of the borderline model showed equal maximum values of von Mises stress than the dysplasia model of pelvic tilt angle of 0°, indicating that pelvic retroversion of -20° in borderline is a risk factor for osteoarthritis of the hip joints, similar to dysplasia.

The efficacy of total hip arthroplasty on locomotive syndrome and its related physical function in patients with hip osteoarthritis.

BACKGROUND: Locomotive syndrome (LS) is a predictive factor of future motor dysfunction. Our aim was to evaluate the change in the total LS grade and, its the association with the Japanese Orthopaedic Association (JOA) hip score after total hip arthroplasty (THA) among patients with hip osteoarthritis. METHODS: This was a prospective case-control study of 72 patients who underwent primary THA. The functional outcomes were measured before, and at 6 and 12 months after THA. LS was evaluated using the following tests: stand-up test, 2-step test, and 25-question Geriatric Locomotive Function Scale (GLFS-25). In addition, factors affecting the improvement of LS grade were examined. RESULTS: Prior to THA, 7% and 93% of patients were classified as LS grades 1 and 2. At 6 months after THA, an improvement in the total LS grade was observed in 57% of patients, with this percentage further increasing to 65% at 1 year. Only the preoperative GLFS-25 was correlated with the preoperative JOA hip scores. The postoperative GLFS-25 and the two-step test were correlated with the postoperative JOA hip scores. The preoperative functional reach test (FRT) was significantly correlated with the total LS grade improvement. CONCLUSIONS: THA can improve the total LS grade in 65% of patients at 1 year postoperatively. Improvement was largely achieved in the first 6 months after THA, with a change from LS grade 2 to grade 1. FRT could be used an indicator of the total LS grade improvement.

Comparison of mid-term clinical results between cementless and cemented femoral stems in total hip arthroplasty with femoral shortening osteotomy for Crowe type IV hips.

INTRODUCTION: This report is the first study to compare the clinical outcomes between cementless and cemented femoral prostheses in total hip arthroplasty (THA) with subtrochanteric femoral shortening osteotomy for Crowe type IV hips. MATERIALS AND METHODS: We identified 26 hips in 20 patients who had undergone cemented (n = 13) or cementless (n = 13) THA with subtrochanteric femoral shortening osteotomy for Crowe type IV hips with a minimum follow-up period of 2 years. The mean follow-up period was 60.8 ± 33.9 months (24-120 months). We compared radiological findings, postoperative clinical recoveries, postoperative complications, and implant survival rates. RESULTS: In both groups, there were no cases of aseptic loosening for the acetabular and femoral implant. In terms of bone union at the osteotomy site, the mean duration was significantly longer in the cemented group (9.8 ± 4.2 months) than in the cementless group (5.0 ± 1.9 months). The clinical hip score in gait and pain at 3 months postoperatively was significantly higher in the cemented group than in the cementless group, while there were no significant changes at other timepoints between two groups. The number of postoperative complications was not significantly different between the two groups. The implant survival rate was 92% in the cementless group and 100% in the cemented group at 5 years postoperatively (P = 0.31). CONCLUSIONS: The cemented femoral prosthesis is superior to the cementless femoral prosthesis for early clinical recovery, while the duration required to achieve bone union at the osteotomy site is longer in the cemented femoral prostheses. It is possible for surgeons to perform successful hip reconstructions, regardless of the fixation method used for THA with shortening femoral osteotomy.

Accuracy of different navigation systems for femoral and tibial implantation in total knee arthroplasty: a randomised comparative study.

PURPOSE: It remains to be established whether optical computed tomography (CT)-free and acceleration-based navigation systems differ in terms of implantation accuracy and clinical outcomes for total knee arthroplasty. This randomised prospective study compared the implantation accuracy of these two navigation systems in total knee arthroplasty. METHODS: Optical CT-free navigation (ExactechGPS) or acceleration-based navigation (KneeAlign2) was randomly assigned to the left or right knee of 45 patients who underwent a single-stage bilateral total knee arthroplasty: the ExactechGPS (n = 45) and KneeAlign2 groups (n = 45) were compared. Component alignments were evaluated using three-dimensional computed tomography and radiography at pre- and post-surgery. Implantation accuracy of the component alignment, proportion of outliers, postoperative range of motion, and Japanese Orthopaedic Association (JOA) score were compared between the systems. RESULTS: The implantation accuracies of the lower-extremity mechanical alignment, coronal femoral component angle, coronal tibial component angle, sagittal femoral component, axial femoral angle, and axial tibial angle had no significant difference between the groups. The implantation accuracy of the sagittal tibial component angle was superior in the ExactechGPS than the KneeAlign2 group (1.3° vs. 1.8°, P = 0.034). The proportions of outliers, range of motion, and JOA score had no significant difference between the groups. CONCLUSION: In the tibial sagittal plane, there was a significant difference in the implantation accuracy, but its difference did not affect the clinical outcomes. Both navigation systems have clinically acceptable implantation accuracy.

Gradual exacerbation of knee flexion angle after total knee arthroplasty in patients with diabetes mellitus.

OBJECTIVES: This study aimed to investigate the effect of diabetes mellitus (DM) on knee extension/flexion angle and its early clinical course after total knee arthroplasty (TKA). METHODS: Patients who received TKA were retrospectively divided into two groups based on haemoglobinA1c level; the DM group (23 knees) and the control group (23 knees matched for baseline characteristics). The passive knee extension/flexion angle, gait speed and Japanese Orthopaedic Association (JOA) score were evaluated preoperatively and at 1, 6 and 12 months postoperatively. RESULTS: There was no significant difference in the passive knee flexion angle at 1 and 6 months postoperatively between the groups (p = .302, p = .160, respectively). The passive knee flexion angle was significantly lower at 12 months postoperatively in the DM group than the control group (p = .014). In the DM group, the passive knee flexion angle at 6 and 12 months significantly decreased compared with that at 1 month postoperatively (p = .021, p < .001, respectively). There were no significant differences in the knee extension angle, gait speed and JOA score between the groups. CONCLUSION: Patients with DM are likely to experience passive knee flexion angle exacerbating from 1 to 6 months after TKA.

Patient-reported outcomes following primary total hip arthroplasty in Crowe type III or IV developmental dysplasia are comparable to those in Crowe type I: a case-control study of 96 hips with intermediate-term follow-up.

BACKGROUND: A few previous studies have investigated patient satisfaction after total hip arthroplasty (THA) according to the degree of pelvic deformity. This study compared patient-reported outcomes after primary THA for Crowe types III, IV and I dysplasia. METHODS: This retrospective, single-center, single-surgeon case-control study included patients who underwent primary THA between 2008 and 2016. We sent postal questionnaires to 38 patients with Crowe type III and IV dysplasia. Among the questionnaire respondents, 23 patients, excluding those with a follow-up period of < 1 year, were enrolled as the H group. The control group included 46 patients with Crowe type I, matched for sex, age, body mass index and surgical approach. To investigate the influence of femoral shortening osteotomy, the H group was divided according to whether femoral shortening osteotomy was performed. Ten patients underwent THA with femoral shortening osteotomy (FO group), while 12 patients underwent THA without femoral shortening osteotomy (N-FO group). Patient demographics, mean follow-up period, surgical information, pre- and postoperative leg length discrepancy (LLD), and perioperative complications were investigated. Clinical evaluations were performed using the Japanese Orthopaedic Association (JOA) scores, 36-item short-form survey (SF-36), net promotor score (NPS), visual analogue scale (VAS), and questionnaires. The VAS and SF-36 scores were determined only at final follow-up. RESULTS: The H and control groups were not significantly different in the postoperative JOA scores and SF-36. In the H group, VAS at the final follow-up was significantly higher, and significantly more patients felt that postoperative rehabilitation was serious, expressing that they underwent THA for LLD correction. In addition, the VAS scores in the FO group was higher than those in the N-FO group. Postoperative LLD was significantly greater in the H group than in the control group. Each group had an NPS of > 50. CONCLUSION: The postoperative VAS score was higher in Crowe type III and IV dysplasia than in Crowe type I dysplasia, but no significant differences were detected in the postoperative satisfaction, JOA score, and SF-36 score. These findings may help explain the effects of THA preoperatively to patients with Crowe type III and IV dysplasia. LEVEL OF EVIDENCE: Therapeutic Level 3b.

Improvement of locomotive syndrome with surgical treatment in patients with degenerative diseases in the lumbar spine and lower extremities: a prospective cohort study.

BACKGROUND: The epidemiology, risk factors, and prevention of locomotive syndrome (LS) have been reported. However, the number of clinical studies about the efficacy of LS treatment, including surgery, has been limited. This study aimed to evaluate LS and its improvement in patients undergoing surgeries for degenerative disease of the lumbar spine and lower extremities, and to discuss the effects of surgery on LS and the issues of LS assessment in these patients. METHODS: We enrolled 257 patients aged ≥60 years that underwent surgery for degenerative diseases of the lumbar spine and lower extremities and agreed to participate in the preoperative and 6- and 12-month postoperative LS examinations. According to the disease location, patients were divided into the lumbar (n = 81), hip (n = 106), knee (n = 43), and foot and ankle (n = 27) groups. Patients underwent LS risk tests, including the stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale (GLFS-25) assessment. RESULTS: The preoperative prevalence of LS stage 2 was 95%. Only the hip group showed significant improvements in the stand-up test. The knee group showed the worst results in the stand-up and two-step tests at all time points. All four groups had significant improvements in GLFS-25 scores. Approximately 40% of all patients had improvement in their LS stage postoperatively. However, > 90% of the patients in the knee group had LS stage 2 postoperatively. CONCLUSION: Nearly all elderly patients requiring surgeries for degenerative diseases of the lumbar spine and lower extremities had advanced conditions (LS stage 2). Surgeries could be beneficial in alleviating LS. The LS stage 3 criteria should be established, and the use of the GLFS-25 assessment can be appropriate for advanced LS patients with severe musculoskeletal diseases requiring surgeries.

Periodic injections of adipose-derived stem cell sheets attenuate osteoarthritis progression in an experimental rabbit model.

BACKGROUND: Subcutaneous adipose tissue represents an abundant source of multipotent adult stem cells named as Adipose-derived stem cells (ADSCs). With a cell sheet approach, ADSCs survive longer, and can be delivered in large quantities. We investigated whether intra-articular ADSC sheets attenuated osteoarthritis (OA) progression in a rabbit anterior cruciate ligament transection (ACLT) model. METHODS: Fabricating medium containing ascorbate-2-phosphate was used to enhance collagen protein secretion by the ADSCs to make ADSC sheets. At 4 weeks after ACLT, autologous ADSC sheets were injected intra-articularly into the right knee (ADSC sheets group), and autologous cell death sheets treated by liquid nitrogen were injected into the left knee (control group). Subsequent injections were administered once weekly. Femoral condyles were compared macroscopically and histologically. RESULTS: Macroscopically, OA progression was significantly milder in the ADSC sheets than in the control groups. Histologically, control knees showed obvious erosions in the medial and lateral condyles, while cartilage was retained predominantly in the ADSC sheets group. Immunohistochemically, MMP-1, MMP-13, ADAMTS-4 were less expressive in the ADSC sheets than in the control groups. CONCLUSIONS: Periodic ADSC sheets injections inhibited articular cartilage degeneration without inducing any adverse effects. A large quantity of autologous ADSCs delivered by cell sheets homed to the synovium and protected chondrocytes.

The feasibility of iodine-supported processing for titanium with different surfaces.

BACKGROUND: The reduction of microbial infections can substantially improve the success of implant surgery. The iodine-supported implants that were developed by us for infection prevention were featured at the recent International Consensus Meeting on Musculoskeletal Infection and were partly incorporated into the consensus guidelines. For future clinical application, we examined (1) whether iodine can be added to metals with different surface roughness, (2) differences in surface roughness before and after processing, and (3) the effect of sterilization on the iodine content. METHODS: Four Ti-6Al-4V metals were prepared with different surface roughness values by polishing, blasting and plasma spraying. Before and after processing, the surface structure of metals was observed using a scanning electron microscope and stylus instruments. Before and after sterilization, iodine contents were measured by X-ray fluorescence spectroscopy. RESULTS: After processing, sufficient iodine contents with an antimicrobial effect were detected for each metal. These iodine contents decreased after sterilization but were higher than the lowest content of iodine observed to have an antimicrobial effect in a previous study, indicating that the antimicrobial effect persists even after sterilization. After processing, surface roughness was greater for polishing metal. With general surface processing, iodine processing was possible. CONCLUSIONS: Our results indicated that surface roughness is affected by the processing method and that the iodine content should be set according to the sterilization method. Considering these factors, iodine processing can be used for clinical applications.