Age-adjusted 5-factor modified frailty index as a valuable tool for patient selection in bilateral simultaneous total knee arthroplasty.

Although bilateral simultaneous total knee arthroplasty (BSTKA) is an effective treatment for bilateral knee osteoarthritis, safety concerns and lack of precise patient selection criteria persist. The purpose of this retrospective study was to determine the complication rate and the role of frailty in patient selection for BSTKA. We analyzed data from 434 patients who underwent BSTKA between February 2012 and January 2021, examining demographic factors and preoperative blood test results. Complications occurred in 77 patients (18%), with anemia requiring transfusion being the most common (26 patients, 5.9%). In the univariate analysis, age ≥ 75 years, age-adjusted Charlson Comorbidity Index ≥ 5, age-adjusted 5-factor modified Frailty Index (aamFI-5) ≥ 3, hemoglobin ≤ 11.0 g/dL, albumin ≤ 3.5 g/dL, estimated glomerular filtration rate < 45 ml/dl/1.73 m2, and D-dimer ≥ 2.0 µg/mL contributed to postoperative complications (p < 0.05). Multivariate analysis identified aamFI-5 ≥ 3 as an independent risk factor (p = 0.002). Our findings underscore the practical utility of aamFI-5 in predicting complications after BSTKA, providing valuable guidance to surgeons in the selection of BSTKA candidates and ultimately improving clinical outcomes.

Analgesic Effect of Passive Range-of-Motion Exercise on the Healthy Side for Pain after Total Knee Arthroplasty: A Prospective Randomized Trial.

Background: Exercise can reduce the pain threshold momentarily and induce analgesia, which is called exercise-induced hypoalgesia (EIH). Exercise therapy for inducing EIH may be an effective treatment option for pain. We aimed at investigating whether continuous passive motion (CPM) on both healthy and affected sides could induce EIH and reduce pain in the operated knee in patients after unilateral total knee arthroplasty (TKA). Patients and Methods. In this prospective randomized controlled trial, participants were randomly assigned to two groups: a bilateral group that received bilateral exercise on the operated and healthy sides and a unilateral group that received exercise therapy only on the affected side. We enrolled 40 patients aged ≥60 years who were scheduled to undergo unilateral TKA. Visual analogue scale (VAS) scores and range of motion (ROM) on the operated side were measured immediately before and after CPM on postoperative days 2, 4, 7, and 14. The primary outcome was the difference in the VAS scores before and after CPM on postoperative day 14. The secondary outcome was the difference in the ROM before and after CPM on postoperative day 14. Results: Comparison of VAS scores before and after CPM showed no significant intergroup differences on all measurement dates. However, there was a significant difference in values on day 14 (P < 0.05). Both groups showed an increase in ROM after CPM, with significant increments observed on days 2 and 4 in the bilateral group and on day 14 in the unilateral group. There was no significant difference in values on postoperative day 14. Conclusion: Post-TKA pain was reduced by performing the same exercise on the healthy knee during CPM therapy. This could be due to EIH, and the results indicated that EIH can also influence postoperative pain immediately after surgery.

Development of Silver-Containing Hydroxyapatite-Coated Antimicrobial Implants for Orthopaedic and Spinal Surgery.

The prevention of surgical site infections is directly related to the minimization of surgical invasiveness, and is in line with the concept of minimally invasive spine therapy (MIST). In recent years, the incidence of postoperative infections has been increasing due to the increased use of spinal implant surgery in patients at high risk of infection, including the elderly and easily infected hosts, the limitations of poor bone marrow transfer of antibiotics, and the potential for contamination of surgical gloves and instruments. Thus, the development of antimicrobial implants in orthopedic and spinal surgery is becoming more and more popular, and implants with proven antimicrobial, safety, and osteoconductive properties (i.e., silver, iodine, antibiotics) in vitro, in vivo, and in clinical trials have become available for clinical use. We have developed silver-containing hydroxyapatite (Ag-HA)-coated implants to prevent post-operative infection, and increase bone fusion capacity, and have successfully commercialized antibacterial implants for hip prostheses and spinal interbody cages. This narrative review overviews the present status of available surface coating technologies and materials; describes how the antimicrobial, safety, and biocompatibility (osteoconductivity) of Ag-HA-coated implants have been demonstrated for commercialization; and reviews the clinical use of antimicrobial implants in orthopedic and spinal surgery, including Ag-HA-coated implants that we have developed.

Fragility fracture following total hip arthroplasty.

BACKGROUND: While periprosthetic fractures following total hip arthroplasty (THA) are a well-known phenomenon for orthopedic surgeons, fragility fractures following THA are also a significant, though less studied, concern. Furthermore, patients who have undergone THA have several additional risk factors for fragility fractures, including motor weakness, bone atrophy, and limping. The aims of this study were to evaluate the incidence of fragility fractures following THA and to clarify the characteristics of these fractures. METHODS: This study included 5678 primary THA procedures in 4589 female patients. This study evaluated body morphology data, disease type leading to THA, Japanese Orthopaedic Association hip score, range of motion of the hip joint, and medical history. Distal radius and patella fractures were defined as fragility fractures. Risk factors for fragility fractures after THA were calculated by comparing the fragility fracture group with the non-fracture group. RESULTS: Fifty-three fragility fractures were confirmed in 53 patients (distal radius fracture: 32 fractures in 32 patients, patella fracture: 21 fractures in 21 patients). In the univariate analysis, the following eight risk factors for fragility fractures were significantly different between the groups: height, weight, follow-up period, developmental dysplasia of the hip, primary osteoarthritis, abduction before THA, internal rotation before THA, and external rotation before THA. Medical histories were not significantly different between the groups. There was no difference in any study factor and in the time of occurrence between the radius fractures and patella fractures analyzed as fragility fractures. CONCLUSIONS: This study revealed that there are significant preoperative factors of fragility fractures following THA. These factors will serve as useful data for THA treatment strategies, preoperative explanations, and future studies.

Periarticular analgesic injection containing a corticosteroid after total hip arthroplasty may prevent deep venous thrombosis: a retrospective comparative cohort study.

BACKGROUND: Of late, periarticular analgesic injection (PAI) has become a common alternative treatment for pain following total hip arthroplasty (THA). However, the systemic effects of PAI containing corticosteroids in patients subjected to THA have not been investigated. This study evaluated the analgesic efficacy and systemic effects of PAI containing a corticosteroid in patients subjected to THA. METHODS: This single-center, retrospective cohort study enrolled patients undergoing unilateral, primary THA. A total of 197 patients (200 hips) were included in the final analyses, with 87 hips in the PAI group and 113 hips in the control group. Numeric Rating Scale (NRS) and laboratory data were assessed preoperatively and on postoperative days (POD) 1 and 7. Pearson's correlation coefficients were obtained to assess the correlations between the D-dimer level on POD 7 and each outcome measure on POD 1. RESULTS: The postoperative white blood cell count (WBC) was significantly higher in the PAI group than in the control group. Postoperative NRS, creatine phosphokinase (CK), and C-reactive protein (CRP) levels were significantly lower in the PAI group. D-dimer levels were significantly lower in the PAI group on POD 7. Postoperative aspartate transaminase (AST), alanine aminotransferase, blood urea nitrogen, and creatinine levels were within reference ranges. D-dimer levels on POD 7 showed a significant negative correlation with WBC on POD 1 (r=-0.4652) and a significant positive correlation with the NRS score and AST, CK, CRP, and D-dimer levels on POD 1 (r = 0.1558, 0.2353, 0.2718, 0.3545, and 0.3359, respectively). CONCLUSIONS: PAI containing a corticosteroid may be an effective treatment for pain and inflammation after THA, and it does not seem to cause drug-induced liver or kidney injury. Moreover, corticosteroid PAI can may accelerate early ambulation, which prevents the elevation of postoperative D-dimer levels, and may reduce the risk of deep venous thrombosis.

Conventional cementless total hip arthroplasty in patients with dwarfism with height less than 140 cm and minimum 10-year follow up: A clinical study.

BACKGROUND: Orthopedic complications can cause issues and severe disability in patients with dwarfism. Thus, these individuals frequently undergo total hip arthroplasty to mitigate decline in daily functioning. Although studies have reported on the difficulties of orthopedic surgery in patients with dwarfism, many do not clearly define dwarfism and have a short follow-up period. We aimed to retrospectively investigate the clinical and radiographic results of total hip arthroplasty for patients with dwarfism. METHODS: A total of 68 hips of 49 patients with height <140 cm and at least 10-year follow-up periods were enrolled. All patients had conventional cementless implants. All hips were evaluated using the Japanese Orthopaedic Association hip score. RESULTS: The main hip disease etiologies were primary hip osteoarthritis (58%) and secondary osteoarthritis due to developmental dysplasia (31%). Rheumatoid arthritis, rapidly destructive coxarthrosis, spondyloepiphyseal dysplasia, childhood infection, and femoral head aseptic necrosis were also causative pathologies. Hip scores significantly improved from 44 to 82 out of 100. Overall implant-associated survival rate after 10 years was 94.1%. Cup loosening was observed in 2 hips, and subsidence >5 mm was observed in 9 hips. Presence of Crowe IV in hips was a significant risk factor for total hip arthroplasty in patients with dwarfism (p < 0.05); leg lengthening had a weak but significant correlation (r = 0.253, p < 0.05). CONCLUSIONS: Total hip arthroplasty using conventional cementless implants for patients with dwarfism shows good clinical and radiological outcomes and has a relatively low perioperative risk.

Total hip arthroplasty using hydroxyapatite-coated cementless cup for rapidly destructive coxarthrosis: Minimum 10-year follow-up.

BACKGROUND: Performing total hip arthroplasty (THA) as early as possible is recommended for rapidly destructive coxarthrosis (RDC) as it causes pain that becomes progressively more severe. However, acetabular bone loss remains an issue in THA. Special devices, such as a Kerboull-type plate, may be used for acetabular bone defects, but the procedure is highly invasive and often the patients are elderly, further complicating matters. We retrospectively investigated the clinical and radiographic results of THA using conventional hydroxyapatite-coated cementless cup in RDC. METHODS: A total of 32 patients (35 hips) with RDC were enrolled in the study with a minimum 10-year follow-up. All THAs were performed using conventional hydroxyapatite-coated cementless cup. All patients were evaluated clinically according to the Harris hip score (HHS). Acetabular bone deficiency was classified according to the American Academy of Orthopaedic Surgeons (AAOS) classification. RESULTS: Eleven hips (31%) were AAOS type III, and none were type IV. Total HHS significantly improved from 36.5 to 79.4 (p < 0.01). Two cups exhibited loosening. The overall implant-associated survival rate after 10 years was 91.4%. CONCLUSIONS: Clinical results of THA using conventional cementless implants for patients with RDC were acceptable. Thus, THA using conventional cementless implant is an effective and safe surgery for patients with RDC, minimizing surgical stress.

First experience with a thermal-sprayed silver oxide-containing hydroxyapatite coating implant in two-stage total hip arthroplasty for the treatment of septic arthritis with hip osteoarthritis: A case report.

INTRODUCTION: Septic arthritis of the hip joint in adults is a rare and potentially devasting disease. To the best of our knowledge, there have been no reports of two-stage total hip arthroplasty (THA) for the treatment of septic arthritis of the hip joint with a cementless hip implant that has antibacterial properties. PRESENTATION OF CASE: We present a case of two-stage THA with a thermal-sprayed silver oxide-containing hydroxyapatite coating (Ag-HA) implant to treat septic arthritis of the hip joint with hip osteoarthritis in an 80-year-old woman. There was no complication or recurrence at 28 months follow-up after 2nd-stage operation. DISCUSSION: Ag-HA implants were found to have antibacterial activity within the subcutaneous tissues and bone, osteoconductive properties, and no adverse reactions in vivo. Moreover, no adverse events due to silver were reported in a clinical or radiographic study. CONCLUSION: To further reduce infection after two-staged THA for septic arthritis of the hip joint, antibacterial implants, such as an Ag-HA implant, may be used.

Traumatic boutonniere deformity of the second toe caused by sumo wrestling: A case report.

INTRODUCTION: Traumatic boutonniere deformities of the fingers are well documented unlike those of the lesser toes. With few existing reports on boutonniere deformities of the lesser toes, the related pathology and treatment guidelines remain unclear. PRESENTATION OF CASE: We present a case of traumatic boutonniere deformity of the second toe caused by sumo wrestling in a 23-year-old man. A flexion deformity of the proximal interphalangeal joint and hyperextension of the distal interphalangeal joint of the right second toe were observed, including a torn central slip and plantarly displaced lateral bands during surgery. Surgical repair of the extensor mechanism and temporary pinning led to good clinical results. DISCUSSION: Acute traumatic boutonniere deformity of the interphalangeal joint of the lesser toe is very rare. The mechanism of boutonniere deformity in this case is thought to be due to forced passive flexion exerted on an actively extended PIP joint, which is similar to that seen in fingers. CONCLUSION: We describe the pathophysiology of a case of boutonniere deformity of the lesser toe and suggest the effectiveness of surgical treatment.

Conventional Cementless Total Hip Arthroplasty for Hip Osteoarthritis after Distal Trochanteric Transfer: A Report of Two Cases.

Distal trochanteric transfer (DTT) has been widely performed to treat developmental dysplasia of the hip or Perthes disease. Total hip arthroplasty (THA) following DTT in patients with hip osteoarthritis is one of the most challenging procedures for hip surgeons, because great care must be taken regarding anatomical abnormalities of the greater trochanter and the soft tissue attached to the greater trochanter. To the best of our knowledge, there are no reports on THA after DTT. We herein report two cases of patients who underwent THA post DTT using cementless components. After THA, both patients developed abduction temporary contraction because of leg length extension and gluteus medius hypertension. However, in both cases, the contraction was reversible within two months and the final clinical result was good. Therefore, THA can be considered an effective and safe choice for treating osteoarthritis after DTT.

Bone ongrowth of a cementless silver oxide-containing hydroxyapatite-coated antibacterial acetabular socket.

BACKGROUND: The silver oxide-containing hydroxyapatite-coated socket (KYOCERA, Osaka, Japan) is a cementless antibacterial implant that has both the osteoconductivity of the HA and the antibacterial activity of silver. The silver oxide-containing hydroxyapatite coating was shown to have good osteoconductivity and new bone formation in vitro and in vivo. However, the histological bone ongrowth of this implant has not been proven in a clinical study. METHODS: We analyzed bone ongrowth using two silver oxide-containing hydroxyapatite-coated sockets that were removed in revision total hip arthroplasty for recurrent dislocation. A histomorphometric analysis was performed using a scanning electron microscope (SEM) connected to a CCD camera and an elemental analysis was performed by energy-dispersive elemental spectrometry (EDS). RESULT: A white structure thought to be osseous tissue was attached to the retrieved socket surface macroscopically, and histological bone ongrowth of the silver oxide-containing hydroxyapatite coating of the socket was confirmed by SEM. In addition, the presence of silver in the silver oxide-containing hydroxyapatite coating was confirmed in an elemental analysis by EDS. CONCLUSION: Histologically, the silver oxide-containing hydroxyapatite-coated socket presented bone ongrowth in this clinical study.

The Direct Anterior Approach is Associated With Early Revision Total Hip Arthroplasty.

BACKGROUND: The direct anterior approach for total hip arthroplasty (THA) has generated increased interest recently. The purpose of this study was to compare the duration to failure and reasons for revision of primary THA performed elsewhere and subsequently revised at our institution after the direct anterior vs other nonanterior surgical approaches to the hip. METHODS: All primary THAs performed elsewhere and referred to our institution for revision were divided into the direct anterior approach (30 cases) or nonanterior approach groups (100 cases, randomly selected from 453 cases) based on the original surgical approach. Because all primary direct anterior THAs were originally performed after 2004 to eliminate temporal bias, we identified a subset of the nonanterior group in which the primary THA was performed after 2004 (known as the recent nonanterior group, 100 cases, randomly selected from 169 available cases). RESULTS: The mean duration from primary to revision THA was 3.0 ± 2.7 years (direct anterior approach), 12.0 ± 8.8 years (nonanterior approach), and 3.6 ± 2.8 years (recent nonanterior), respectively. There was a significant difference in time to revision between the direct anterior and nonanterior approach groups (P < .001). Aseptic loosening of the stem was significantly more frequent with the direct anterior approach group (9/30, 30.0%) when compared with the nonanterior group (8/100, 8.0%, P = .007) and the recent nonanterior group (7/100, 7.0%, P = .002). CONCLUSION: Revision of the femoral component for aseptic loosening is more commonly associated with the direct anterior approach in our referral practice.

First Clinical Experience With Thermal-Sprayed Silver Oxide-Containing Hydroxyapatite Coating Implant.

BACKGROUND: Prosthetic joint infection is a serious complication of implant therapy. To prevent prosthetic joint infection, we previously reported the features of silver oxide-containing hydroxyapatite (Ag-HA), which was prepared by mixing silver (a metal with antimicrobial activity) with HA. In this study, we evaluated the potential issues of total hip arthroplasty (THA) with an Ag-HA-coated implant. METHODS: We prepared an implant for THA that was coated with Ag-HA. In this study, the implant contained silver at a maximum quantity of 2.9 mg/implant. In this prospective interventional study, we performed THA with this implant in 20 patients and investigated the effects of silver. RESULTS: Blood silver levels peaked at 2 weeks after THA and gradually decreased thereafter. The highest blood silver level recorded during the postoperative follow-up was 6.0 ng/mL, which was within the normal range. The Harris Hip Scores increased in all cases, and activities of daily living improved markedly after THA with Ag-HA-coated implants. Implant failure was absent on radiography. No adverse reaction to silver was noted, and argyria was not observed in any case. No patients have developed infection after surgery. CONCLUSION: This is the first clinical study of Ag-HA-coated implants in THA. Our Ag-HA-coated implants markedly improved patients' activities of daily living without causing any adverse reactions attributable to silver in the human body. Ag-HA is expected to reduce postoperative infections and prevent decreased quality of life in patients undergoing prosthetic arthroplasty, thus leading to more favorable outcomes.

Silver-Containing Hydroxyapatite Coating Reduces Biofilm Formation by Methicillin-Resistant Staphylococcus aureus In Vitro and In Vivo.

Biofilm-producing bacteria are the principal causes of infections associated with orthopaedic implants. We previously reported that silver-containing hydroxyapatite (Ag-HA) coatings exhibit high antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA). In the present study, we evaluated the effects of Ag-HA coating of implant surfaces on biofilm formation. Titanium disks (14-mm diameter, 1-mm thickness), one surface of which was coated with HA or 0.5%-3.0% Ag-HA with a thermal spraying technique, were used. In vitro, the disks were inoculated with an MRSA suspension containing 4 × 105 CFU and incubated for 1-2 weeks. In vivo, MRSA-inoculated HA and 3% Ag-HA disks (8.8-10.0 × 108 CFU) were implanted subcutaneously on the back of rats for 1-7 days. All disks were subsequently stained with a biofilm dye and observed under a fluorescence microscope, and biofilm coverage rates (BCRs) were calculated. The BCRs on the Ag-HA coating were significantly lower than those on the HA coating at all time points in vitro (p < 0.05). Similar results were observed in vivo (p < 0.001) without argyria. Ag-HA coating reduced biofilm formation by MRSA in vitro and in vivo; therefore, Ag-HA coating might be effective for reducing implant-associated infections.

Silver oxide-containing hydroxyapatite coating supports osteoblast function and enhances implant anchorage strength in rat femur.

Antibacterial silver with hydroxyapatite (Ag-HA) is a promising coating material for imparting antibacterial properties to implants. We previously reported that 3% (w/w) silver with HA (3% Ag-HA) has both antibacterial activity and osteoconductivity. In this study, we investigated the effects of Ag-HA on the in vitro osteoblast function and the in vivo anchorage strength and osteoconductivity of implants. Production of the osteoblast marker alkaline phosphatase, but not cytotoxicity, was observed in cells of the osteoblast cell line MC3T3-E1 cultured on the 3% Ag-HA-coated surface. These results were similar to those observed with silver-free HA coating. In contrast, a significant high level of cytotoxicity was observed when the cells were cultured on a 50% Ag-HA-coated surface. The anchorage strength of implants inserted into the femur of Sprague-Dawley (SD) rats was enhanced by coating the implants with 3% Ag-HA. On the 3% Ag-HA-coated surface, both metaphyseal and diaphyseal areas were largely covered with new bone and had adequate osteoconductivity. These results suggest that 3% Ag-HA, like conventional HA, promotes osteogenesis by supporting osteoblast viability and function and thereby contributes to sufficient anchorage strength of implants. Application of 3% Ag-HA, which combines the osteoconductivity of HA and the antibacterial activity of silver, to prosthetic joints will help prevent postoperative infections.

Acute and subacute toxicity in vivo of thermal-sprayed silver containing hydroxyapatite coating in rat tibia.

To reduce the incidence of implant-associated infection, we previously developed a novel coating technology using hydroxyapatite (HA) containing silver (Ag). This study examined in vivo acute and subacute toxicity associated with the Ag-HA coating in rat tibiae. Ten-week-old rats received implantation of HA-, 2% Ag-HA-, or 50% Ag-HA-coated titanium rods. Concentrations of silver in serum, brain, liver, kidneys, and spleen were measured in the acute phase (2-4 days after treatment) and subacute phase (4-12 weeks after treatment). Biochemical and histological examinations of those organs were also performed. Mean serum silver concentration peaked in the acute phase and then gradually decreased. Mean silver concentrations in all examined organs from the 2% Ag-HA coating groups showed no significant differences compared with the HA coating group. No significant differences in mean levels of glutamic-oxaloacetic transaminase, glutamic-pyruvic transaminase, lactate dehydrogenase, creatinine, or blood urea nitrogen were seen between the three groups and controls. Histological examinations of all organs revealed no abnormal pathologic findings. No acute or subacute toxicity was seen in vivo for 2% Ag-HA coating or HA coating. Ag-HA coatings on implants may represent biologically safe antibacterial biomaterials and may be of value for reducing surgical-site infections related to implantation.