Hip Function Was Not Associated with the Incidence of Preoperative Deep Vein Thrombosis in Patients Undergoing Primary Total Hip Arthroplasty.

The prevalence of preoperative deep vein thrombosis (DVT) has been reported to be relatively high in patients undergoing total hip arthroplasty. We investigated the prevalence of DVT, the association between hip function and preoperative DVT, and the effect of a history of surgery in patients who underwent primary total hip arthroplasty. We retrospectively analyzed the cases of the patients who underwent primary total hip arthroplasty between April 2013 and February 2020 at our institution. We evaluated the prevalence of preoperative DVT based on the results of the patients' ultrasound screening. We performed univariate and multivariate analyses to investigate the association between the incidence of DVT and patient factors including age, sex, hip function, medical histories, and American Society of Anesthesiologists Physical Status classification. We analyzed 451 patients (494 hips). The prevalence of DVT was 14.2% (64 patients). The multivariate analysis demonstrated that increased age was an independent significant risk factor for DVT. The prevalence of preoperative DVT was relatively high among patients who underwent primary total hip arthroplasty. Preoperative DVT tended to be more prevalent in older patients. Hip function was not associated with the incidence of DVT.

Influence of the knot position on the union of the greater trochanter after bipolar hip arthroplasty via the modified Dall approach: a prospective non-randomized study.

BACKGROUND: In our institute, all elderly patients with displaced femoral neck fracture were treated with cemented bipolar hemiarthroplasty (BHA) using the modified Dall approach. To our knowledge, there are no reports on the knot position of the greater trochanter reattachment. The aim of this study was to determine influence of two knot positions (anterior or posterior) on the complications of the greater trochanter. METHODS: This is a prospective non-randomized study conducted on 95 elderly patients (95 hips) from September 2013 to December 2017. The knot position was changed from anterior to posterior alternately. The X-ray images obtained immediately after the operation were compared with those obtained at 3 months postoperatively; thereafter, the status of the greater trochanter was classified into three types: type A, no apparent shifting and fracture; type C, over 1-mm shifting of the fragment; and type F, fracture of the greater trochanter. RESULTS: Regarding age at operation, sex, BMI, size of the greater trochanteric fragment, stem type, and surgeon, there was no significant difference between two groups. In the anterior group, 34 hips (72.3%), 5 hips (10.6%), and 8 hips (17.0%) were classified under type A, C, and F, respectively. In the posterior group, 44 hips (91.7%), 1 hip (2.1%), and 3 hips (6.3%) were classified under type A, C, and F, respectively. There were significantly fewer greater trochanteric complications in the posterior group. CONCLUSIONS: The posterior knot position improved the union of the greater trochanter after BHA compared with the anterior knot position. TRIAL REGISTRATION: We had approved IRB at our hospital clinical research review committee. Retrospectively registered.

Long-term outcome of cemented total hip arthroplasty with the Charnley-type femoral stem made of titanium alloy.

BACKGROUND: Total hip arthroplasty is a successful treatment for hip diseases including osteoarthritis, osteonecrosis of the femoral head, and rheumatoid arthritis. Various designs of cemented femoral stems made of stainless steel and titanium alloy have been used. Among them, Charnley-type femoral stems made of stainless steel have often been reported to have good long-term outcome. However, the long-term outcome of the Charnley-type femoral stem made of Ti alloy is yet to be reported. We conducted a retrospective study to assess the long-term outcome of cemented primary total hip arthroplasty with the Charnley-type femoral stem made of Ti alloy. METHODS: Between October 1988 and February 1997, 341 cemented primary total hip arthroplasties with the Charnley-type femoral stem made of Ti alloy were consecutively performed in our hospital. Among these, 164 patients (211 hips) who underwent this procedure were followed up for more than 12 years, and the surgical hips were analysed clinically and radiologically. The mean follow-up period was 20.6 years. Kaplan-Meier survival analyses were performed to assess femoral component survival. Factors affecting stem revision for aseptic loosening were also investigated using log-rank tests. RESULTS: In the functional assessment, the preoperative Japanese Orthopaedic Association score significantly improved from 47.2 points preoperatively to 79.0 points at the final follow-up. Eventually, 33 femoral stems were revised, of which 12 were revised for aseptic loosening. In the Kaplan-Meier survival analysis, the 20-year survival rates with stem revision for aseptic loosening and radiological stem loosening at the end points were 95.9% and 97.1%, respectively. Original diagnosis (non-osteoarthritis) was the only significant factor for aseptic loosening of the femoral stem. CONCLUSIONS: Cemented primary total hip arthroplasty with the Charnley-type femoral stem made of Ti alloy showed excellent outcomes for more than 20 years.

A high body mass index tilts the pelvis caudally in the lateral decubitus position for total hip arthroplasty.

BACKGROUND: Accurate cup placement is essential for obtaining excellent outcomes in total hip arthroplasty (THA). We evaluated the pelvic lateral tilt of the patient (which affects the incline of the acetabular cup in THA) and investigated the factors affecting it. METHODS: We reviewed the medical records of THA procedures performed at our hospital between October 2015 and January 2021 for which an anteroposterior pelvic radiograph was always taken preoperatively once the patient was placed in the lateral decubitus position. These radiographs were used to measure the lateral pelvic tilt in each case. We analysed whether patient factors (sex, body mass index [BMI], range of motion of abduction or adduction in both hips, surgical history of both hips, and lumbar Cobb angle) influenced the tilt. RESULTS: We reviewed 363 cases (341 primary, 22 revision). The mean pelvic lateral tilt was 4.1°, and the operated hip was located on the caudal side compared to the unoperated hip. Statistical analyses revealed that the patient BMI and surgical history of the operated and unoperated hips significantly influenced tilt. CONCLUSIONS: The pelvis in the lateral decubitus position leaned 4.1° to the caudal side, most commonly due to a high BMI. Surgeons should consider this when performing acetabular cup implantation in THA.

Good result for twelve years after bilateral hip and knee arthroplasties for ankylosis with juvenile idiopathic arthritis: a case report.

Juvenile idiopathic arthritis (JIA) can lead to joint deformity and bone destruction, which can cause gait disturbances. To the best of our knowledge, there are no case reports with over 10 years of follow-up on quadruple joint arthroplasties (QJA) for bilateral hip and knee ankylosis associated with JIA. We present the case of a 29-year-old woman with JIA. The patient suffered from bilateral ankylosis of the hips and knees and developed a swing gait requiring double crutches. We performed staged QJA with careful attention to postoperative rehabilitation and her physical features, which included excessive pelvic anteversion, poor bone quality, and short statue of bones. Twelve years after surgery, the patient was able to walk without any support and showed good clinical functional scores. In addition, no radiological loosening following QJA was observed. We hereby introduce a surgical strategy for total hip arthroplasty for excessive pelvic anteversion, which involves two methods to calculate pelvic tilt on a pelvic anteroposterior radiograph. These methods were able to approximately predict postoperative pelvic changes.

The influence of anterior and posterior knot placement on hip function after total hip arthroplasty using a modified Dall's approach: a prospective non-randomised comparative study.

BACKGROUND: The direct lateral modified Dall's approach for total hip arthroplasty (THA) provides an excellent vision of the hip joint by osteotomising the greater trochanter (GT). A robust method for the reattachment of osteotomised fragments is essential to prevent complications around the GT. Ultra-high molecular weight polyethylene cables are reported to be useful for reattachment; but the optimal suture method of these cables is unknown. The purpose of this study was to investigate the influence of the knot position on hip function after primary THA. METHODS: In a prospective non-randomised study 216 primary THA were included, being scheduled for an operation with a modified Dall's approach. They were divided into 2 groups, anterior (A) and posterior (P) according to the knot position for the GT. Hip function was assessed using the Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ), pain visual analogue scale (VAS), satisfaction VAS and Merle d'Aubigne-Postel hip score at 3 and 6 months postoperatively. A logistic regression analysis was used to investigate factors influenced by the knot position. RESULTS: Patient demographics were comparable between the 2 groups. Differences of the knot position did not affect the radiological failure rate of GT reattachment. Regression analysis showed a significantly positive impact on pain VAS and flexion range at 6 months postoperatively for posterior knot position. CONCLUSIONS: For the reattachment of osteotomised fragments, the posterior knot may be superior to the anterior knot.

Generation of Monkey Induced Pluripotent Stem Cell-Derived Cartilage Lacking Major Histocompatibility Complex Class I Molecules on the Cell Surface.

Due to the poor capacity for articular cartilage to regenerate, its damage tends to result in progressively degenerating conditions such as osteoarthritis. To repair the damage, the transplantation of allogeneic human induced pluripotent stem cell (iPSC)-derived cartilage is being considered. However, although allogeneic cartilage transplantation is effective, immunological reactions can occur. One hypothetical solution is to delete the expression of major histocompatibility complex (MHC) class I molecules to reduce the immunological reactions. For this purpose, we deleted the ß2 microglobulin (B2M) gene in a cynomolgus monkey (crab-eating monkey [Macaca fascicularis]) iPS cells (cyiPSCs) to obtain B2M-/- cyiPSCs using the CRISPR/Cas9 system. Western blot analysis confirmed B2M-/- cyiPSCs lacked B2M protein, which is necessary for MHC class I molecules to be transported to and expressed on the cell surface by forming multimers with B2M. Flow cytometry analysis revealed no B2M-/- cyiPSCs expressed MHC class I molecules on their surface. The transplantation of B2M-/- cyiPSCs in immunodeficient mice resulted in teratoma that contained cartilage, indicating that the lack of MHC class I molecules on the cell surface affects neither the pluripotency nor the chondrogenic differentiation capacity of cyiPSCs. By modifying the chondrogenic differentiation protocol for human iPSCs, we succeeded at differentiating B2M+/+ and B2M-/- cyiPSCs toward chondrocytes followed by cartilage formation in vitro, as indicated by histological analysis showing that B2M+/+ and B2M-/- cyiPSC-derived cartilage were positively stained with safranin O and expressed type II collagen. Flow cytometry analysis confirmed that MHC class I molecules were not expressed on the cell surface of B2M-/- chondrocytes isolated from B2M-/- cyiPSC-derived cartilage. An in vitro mixed lymphocyte reaction assay showed that neither B2M+/+ nor B2M-/- cyiPSC-derived cartilage cells stimulated the proliferation of allogeneic peripheral blood mononuclear cells. On the contrary, osteochondral defects in monkey knee joints that received allogeneic transplantations of cyiPSC-derived cartilage showed an accumulation of leukocytes with more natural killer cells around B2M-/- cyiPSC-derived cartilage than B2M+/+ cartilage, suggesting complex mechanisms in the immune reaction of allogeneic cartilage transplanted in osteochondral defects in vivo. Impact statement The transplantation of allogeneic induced pluripotent stem cell (iPSC)-derived cartilage is expected to treat articular cartilage damage, although the effects of major histocompatibility complex (MHC) in immunological reactions have not been well studied. We succeeded at creating B2M-/- cynomolgus monkey (cy)iPSCs and cyiPSC-derived cartilage that lack MHC class I molecules on the cell surface. B2M-/- cyiPSC-derived cartilage cells did not stimulate the proliferation of allogeneic peripheral blood mononuclear cells in vitro. On the contrary, the transplantation of B2M-/- cyiPSC-derived cartilage into osteochondral defects in monkey knee joints resulted in survival of transplants and accumulation of leukocytes, including natural killer cells, suggesting complex mechanisms for the immune reaction.

Inverted reamer technique for bone grafting of the acetabulum: technical note.

BACKGROUND: Socket fixation with bone grafting for dysplastic hips is technically demanding, and inadequate coverage of the socket may cause poor results in patients with severely dysplastic hips. An accurate technique to form a bone graft to fit into the defect is necessary. We aim to introduce the simple method of bone grafting, "inverted reamer technique" in cemented total hip arthroplasty (cTHA). METHODS: After acetabular preparation with a normal acetabular reamer, the bone graft was prepared from the resected femoral head with the inverted reamer. The graft can be press-fit into the defect of the acetabulum with good compatibility through this method. Then, the bone graft was fixed with 1-3 screws and the socket was implanted with bone cement. RESULTS: The "inverted reamer technique" can easily and automatically create a well-fit graft. This method is simple and technically less demanding; it can be performed by every surgeon, including trainee and inexperienced surgeons. CONCLUSION: This method can improve the outcome of cTHA for dysplastic hips by preserving bone stock and increasing bone coverage of the socket implanted in the anatomic position.

Hip-Spine Syndrome: Acetabular Anteversion Angle Is Associated with Anterior Pelvic Tilt and Lumbar Hyperlordosis in Patients with Acetabular Dysplasia: A Retrospective Study.

BACKGROUND: Hip-spine syndrome was originally described by Offierski and MacNab, who argued that the flexion deformity of the hip rotated the pelvis forward, causing the spine symptoms. We additionally hypothesized that in patients who have osteoarthritis (OA) of the hip, the pelvis is tilted anteriorly to compensate for the anterior acetabular coverage defect. We investigated the hip factors associated with anterior pelvic tilt (PT) in patients who had OA of the hip due to acetabular dysplasia. METHODS: We retrospectively reviewed the medical records of patients who had undergone total hip arthroplasty between January 2009 and December 2017 to identify those who had unilateral secondary OA due to acetabular dysplasia. Patients who had spinal imbalance, a history of spinal or lower limb fracture or surgery, bilateral OA of the hip, or a severely subluxated hip were excluded, leaving 100 eligible patients. We defined the indicators of an anterior acetabular coverage defect, flexion deformity of the hip, and anterior PT as the acetabular anteversion angle (AAA), extension range of motion (ROM), and anterior tilt of the pelvis, respectively. We measured hip factors and spinal parameters on radiographs and the standardized axial and coronal planes on 3-dimensional computed tomography with reference to the anterior pelvic plane. Hip factors associated with PT were investigated. RESULTS: Univariate analysis showed a significant correlation between PT and both AAA (r = -0.389, p < 0.001) and combined anteversion angle (r = -0.272, p = 0.03). Multivariate regression analysis identified AAA (ß = -0.385, p < 0.001) and extension ROM (ß = 0.212, p = 0.0496) as independent factors associated with PT. Lumbar lordosis and pelvic incidence minus lumbar lordosis were significantly correlated with AAA, but sagittal vertical axis was not. CONCLUSIONS: When treating patients who have acetabular dysplasia, surgeons should recognize the relationship between the anterior acetabular coverage and anterior PT. Correcting hyperlordosis of the lumbar spine can induce progression of hip OA because it may decrease the acetabular anterior coverage.

A long-term comparative study between two different designs of cemented stems: Distal-cylindrical versus distal-taper.

INTRODUCTION: The aim of this study was to calculate the wear rate of highly cross-linked polyethylene (HXLPE) and investigate long-term clinical and radiographic outcomes related to two femoral stem designs, the distal-cylindrical (DC) and distal-taper (DT) stems. MATERIALS AND METHODS: Outcomes for the DC and DT stems were evaluated in 110 patients, who underwent total hip arthroplasty using an HXLPE socket, over a 5-year follow-up period. There were 56 hips (53 patients) in the DC group and 60 hips (57 patients) in the DT group. Clinical outcomes were measured using the Japanese Orthopaedic Association (JOA) score and radiographic changes. Polyethylene wear rate was calculated using a computer software. RESULTS: The mean follow-up period was 135.7 and 124.0 months for the DC and DT groups, respectively. Both stem designs improved hip function. On radiographic assessment, osteolysis around the tip of the stem was more frequent in the DC than in the DT group. Three cases of aseptic loosening of the stem were identified in the DC group, and no cases were identified in the DT group. The 10-year stem survival, using aseptic loosening as the primary endpoint, was 94.1% and 100% for the DC and DT groups, respectively (p = 0.06). The polyethylene wear rate was comparable for both stem groups. CONCLUSION: Better clinical outcomes were obtained with the DT stem than with the DC stem regardless of the equivalent polyethylene wear rate for the two designs. The DC shape of the stem may increase the risk of aseptic loosening.

A Japanese case of vertebral sarcoidosis.

We herein report the first Japanese case of vertebral sarcoidosis diagnosed using multiple imaging modalities and a biopsy. CT, MRI and (18)F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) detected multiple vertebral lesions, and a vertebral biopsy guided by the PET findings confirmed the diagnosis of vertebral sarcoidosis. Although the disease was refractory to corticosteroids, treatment with methotrexate (MTX) achieved a good response. Our case suggests that MRI and 18F-FDG PET are useful for determining the site for a biopsy and that MTX is effective for treating vertebral sarcoidosis.