Pre-Surgery Hip-Knee-Ankle Angle and Weightbearing Line Percentage Are Nearly Perfectly Correlated to the Miniaci Angle When Planning Open Wedge High Tibial Osteotomies.

PURPOSE: To investigate the conversion formulas between the Miniaci angle, presurgery parameters, and changes in presurgery parameters in open-wedge high tibial osteotomy (OWHTO), including hip-knee-ankle (HKA) angle, weightbearing line (WBL) percentage, mechanical medial proximal tibial angle (mMPTA), ΔHKA angle, ΔWBL percentage, ΔmMPTA, and other parameters. METHODS: From January 2012 to December 2019, 247 lower limbs of 144 patients with medial unicompartmental knee osteoarthritis combined with proximal tibia vara were enrolled. Inclusion criteria were adults, medial unicompartmental knee osteoarthritis, Kellgren-Lawrence classification grade ≤ III, mMPTA ≤ 85°, normal mechanical lateral distal femoral angle (85°-90°), and patella facing anterior in the bipedal standing position. Exclusion criteria were history of fracture, trauma, or orthopaedic surgery; developmental dysplasia of the hip or femoral head necrosis; femoral bowing deformity; deformity of the tibial shaft; and leg length discrepancy. Using standing whole-leg radiographs, an OWHTO simulation was performed to determine the Miniaci angle by delivering the WBL to the Fujisawa point. The relationship of the Miniaci angle, the presurgery parameters, and the changes in presurgery parameters were analyzed by Spearman's correlation and linear regression analyses. The relationship between the postsurgery HKA angle and presurgery parameters was analyzed by multiple linear regression model. RESULTS: The Miniaci angle showed a near-perfect correlation with the presurgery HKA angle (y = -1.05x + 192.10, r2 = 0.99), presurgery WBL percentage (y = -0.25x + 15.14, r2 = 0.97), ΔHKA angle (y = 1.04x - 0.03, r2 = 1.00), ΔWBL percentage (y = 0.25x - 0.52, r2 = 0.97), and ΔmMPTA (y = 1.04x - 0.03, r2 = 1.00). The ΔHKA angle showed nearly perfect correlation with the ΔmMPTA (y = 1.00x, r2 = 1.00), and ΔWBL percentage (y = 0.24x - 0.47, r2 = 0.97). CONCLUSIONS: The presurgery HKA angle, presurgery WBL percentage, ΔHKA angle, ΔWBL, and ΔmMPTA percentage are nearly perfectly correlated to the Miniaci angle, whereas the ΔmMPTA and ΔWBL percentage are nearly perfectly correlated to the ΔHKA angle. With the conversion formulas determined in the current study, surgeons can calculate the Miniaci angle based on the presurgery parameters without the assistance of digital software for complex surgical simulation. The Miniaci angle is closely related to the gap of the medial opening wedge. Based on the Miniaci angle and the depth of the osteotomy, surgeons can calculate the gap required before surgery using trigonometric functions and then simply measure the gap during surgery.

Lateral tibial intercondylar eminence is a reliable reference for alignment correction in high tibial osteotomy.

PURPOSE: The purpose of the study is to determine whether the lateral tibial intercondylar eminence (LTIE) is a reliable reference for alignment correction in high tibial osteotomy (HTO). METHODS: A total of 1954 consecutive standing whole-leg radiography (WLR) examinations of 1373 adult patients with knee osteoarthritis between 2012 and 2019 were reviewed retrospectively; 145 patients were included, 53 males and 92 females, with a mean age of 63.3 years. Virtual simulation of HTO was performed to measure weight-bearing line (WBL) percentages and hip-knee-ankle (HKA) angles when the WBL passed through the Fujisawa, top, bottom, upper 1/3, and middle points of the lateral slope of the LTIE, and the positional relationship between the Fujisawa point and the lateral slope of the LTIE was determined. RESULTS: When the WBL passed through the top, bottom, upper 1/3, and middle points of the lateral slope of the LTIE, the mean WBL percentages were 57.7% ± 2.1%, 74.6% ± 3.3%, 63.4% ± 2.1%, and 66.2% ± 2.3%, respectively, and the mean HKA angles were 182.1° ± 0.5°, 185.9° ± 0.8°, 183.3° ± 0.5°, and 184.0° ± 0.5°, respectively. When the WBL passed through the Fujisawa point, it was passing through 28.6% ± 12.7% of the width of the lateral slope (the top and bottom points were defined as 0% and 100%, respectively). When the WBL passed through the middle and upper 1/3 points of the lateral slope of the LTIE, the majority of cases (96.1%-100%) were within the limits of acceptability, as defined by the widely accepted standard of a postoperative HKA angle ranging from 183° to 186°. CONCLUSION: The upper 1/3 and middle points of the lateral slope of the LTIE are reliable references for guiding the alignment correction in HTO. In clinical application, if 62%-66% of the postoperative WBL percentage is the acceptable target range, the upper 1/3 point of the lateral slope of the LTIE may be a better alternative than the midpoint. If the postoperative HKA angle between 183° and 186° is acceptable, the midpoint of the lateral slope of the LTIE may be better than the upper 1/3 point. These findings are crucial for the accuracy of the traditional intraoperative alignment assessment techniques. LEVEL OF EVIDENCE: IV.

Abnormal subchondral trabecular bone remodeling in knee osteoarthritis under the influence of knee alignment.

OBJECTIVE: This study aimed to investigate the abnormal subchondral trabecular bone (STB) remodeling in knee osteoarthritis (OA) under the influence of knee alignment [hip-knee-ankle (HKA) angle]. DESIGN: Forty-one patients with knee OA underwent radiographic examination before total knee arthroplasty (TKA) for the measurement of HKA angle. Tibial plateau specimens obtained during TKA were used for histomorphometric analyses to assess STB remodeling and cartilage degradation. Tartrate-resistant acidic phosphatase (TRAP) staining was used to test osteoclast activity. Osterix, osteocalcin, and sclerostin expression in the STB were determined using immunohistochemistry. RESULTS: The interaction between HKA angle and side (medial vs lateral of tibial plateau) was the main significant influence factor for STB remodeling and microstructure. The STB with the deviation of the knee alignment was accompanied by obvious abnormal bone remodeling and microstructural sclerosis. Bone volume fraction (BV/TV) was the only significant influence factor for OARSI score, the larger the BV/TV of STB, the higher the OARSI score of cartilage. Moreover, the tibial plateau affected by alignment had more TRAP + osteoclasts, Osterix + osteoprogenitors, and osteocalcin + osteoblasts and fewer sclerostin + osteocytes. CONCLUSIONS: The variation of tibial plateau STB remodeling activity and microstructure was associated with HKA angle and cartilage degradation. Knee malalignment may cause abnormal STB remodeling and microstructural sclerosis, which may potentially affect load stress transmission from the cartilage to the STB, thus resulting in accelerated knee OA progression.

Application of a novel osteotomy instrumentation as a substitute tool in total hip arthroplasty.

BACKGROUND: Mechanical failure, power shortage, and inadvertent contamination of the oscillating saw occasionally occurs in actualizing femoral neck osteotomy during total hip arthroplasty (THA); however, no appropriate alternative solution is currently available. This study aimed to introduce a novel osteotomy instrumentation (fretsaw, jig, cable passer hook) as a substitute tool while the oscillating saw was unavailable during THA. METHODS: This study included 40 patients (40 hips) who underwent femoral neck osteotomy during primary THA using the new osteotomy instrumentation (n = 20) and the oscillating saw (n = 20). Clinical data and intraoperative findings of all patients were evaluated. RESULTS: The mean osteotomy time was 22.3 ± 3.1 s (range, 17-30 s) and 29.4 ± 3.7 s (range, 25-39 s) in the oscillating saw group and in the new osteotomy instrumentation group, respectively (P < 0.001). The Harris Hip Score (HHS) improved in both groups; the mean HSS was 82.3 ± 2.5 and 83.3 ± 3.5 in the oscillating saw group and new osteotomy instrumentation group at 6 months after surgery, respectively (P = 0.297). CONCLUSIONS: The original osteotomy instrumentation can be an ideal substitute tool for femoral neck osteotomy in THA, especially when the oscillating saw is unavailable or malfunctioning.

Positive Correlation Between the Femur Neck Shaft and Anteversion Angles: A Retrospective Computed Tomography Analysis in Patients With Developmental Dysplasia of the Hip.

BACKGROUND: This study aimed to explore the anatomical correlation between the femoral neck shaft angle (NSA) and femoral anteversion angle (AA) in patients with developmental dysplasia of the hip based on the Crowe classification and provide a novel method to estimate the femoral AA on anteroposterior pelvic radiographs. METHODS: A total of 208 patients with dysplastic hips who underwent total hip arthroplasty at our institution were retrospectively included. Preoperative physiological AA and NSA were determined via 3-dimensional computed tomography. Linear regressions and Pearson's coefficients were calculated to assess the correlation between the femoral NSA and femoral AA. RESULTS: A total of 416 hips were divided into 5 subgroups: 99 normal, 143 type I, 71 type II, 63 type III, and 40 type IV hips following the Crowe classification. Dysplastic femurs had significantly higher AAs than normal hips (25.2° vs 31.4° vs 33.3° vs 35.5° vs 41.7°). Significant positive correlations between the AA and NSA were observed in normal (r = 0.635), type I (r = 0.700), type II (r = 0.612), and type III (r = 0.638) hips (P < .001); however, no meaningful correlation was observed in type IV hips (r = 0.218, P = .176). CONCLUSION: The NSA and AA correlated positively and significantly in the normal and dysplastic Crowe type I-III hips. The relationship between the NSA and AA indicates torsion of the proximal femur and offers an opportunity for straightforward estimation of AA based on NSA.

Three-dimensional printing-based personalized limb salvage and reconstruction treatment of pelvic tumors.

BACKGROUND AND OBJECTIVES: The treatment of pelvic tumors is widely recognized to be challenging. The purpose of this study was to evaluate the efficacy of personalized three-dimensional (3D) printing-based limb salvage and reconstruction treatment for pelvic tumors. METHODS: Twenty-eight pelvic tumor patients were enrolled. 3D printing lesion models and osteotomy templates were prepared for surgery planning, prosthesis design, and osteotomy assistance during surgery. 3D printing-based personalized pelvic prostheses were manufactured and used in all 28 patients. Follow-up of postoperative survival, prosthesis survival, imaging examinations, and Musculoskeletal Tumor Society (MSTS) lower limb functional scores were carried out. RESULTS: The mean follow-up period was 32.2 months, during which 16 patients had disease-free survival, 3 survived with the disease, and 9 died. The prostheses were stable, and the mean offset of the center of rotation was 5.48 mm. The prosthesis-bone interface showed good integration. For the 19 surviving patients, the mean MSTS lower limb functional score was 23.2. Postoperative complications included superficial infection in six patients and hip dislocation in three patients. CONCLUSIONS: Personalized 3D printing-based limb salvage and reconstruction was an effective treatment for pelvic tumors. Our patients achieved good early postoperative efficacy and functional recovery.

D-dimer for diagnosis of periprosthetic joint infection: A meta-analysis.

BACKGROUND: The D-dimer test is easily available to detect periprosthetic joint infection (PJI). This study aimed to estimate the diagnostic accuracy of the D-dimer test in PJI diagnosis and identify possible independent factors affecting the diagnostic value of this test. METHODS: MEDLINE and EMBASE databases identified literature until February 2020 that utilized the D-dimer test for PJI diagnosis. The pooled sensitivity, specificity, area under the curve (AUC), diagnostic odds ratio (DOR), positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated to evaluate the diagnostic accuracy of the D-dimer test. Meta-regression and subgroup analyses were performed to assess potential heterogeneity. RESULTS: The databases identified 243 records, and eight studies were included in the final analysis. The pooled sensitivity and specificity of the D-dimer test for PJI diagnosis were 0.78 (95% confidence interval [CI], 0.69-0.84) and 0.74 (95% CI, 0.85-0.99), respectively. The AUCs and DORs of the D-dimer test were 0.83 (95% CI, 0.79-0.86) and 10 (95% CI, 4-24), respectively. The PLR and NLR of the D-dimer test for PJI detection were 3.0 (95% CI, 1.9-4.8) and 0.30 (95% CI, 0.20-0.47), respectively. The results of the meta-regression and subgroup analyses indicated that studies that excluded patients with hypercoagulation disorder had higher sensitivity (0.85 vs 0.86) and specificity (0.83 vs 0.62). The sensitivity of the D-dimer test also improved in studies that excluded patients with inflammatory arthritis (0.81 vs 0.75). CONCLUSION: The D-dimer test is a practical method for PJI diagnosis, especially in patients without history of hypercoagulation disorder and inflammatory arthritis.

Association Between Knee Malalignment and Ankle Degeneration in Patients With End-Stage Knee Osteoarthritis.

BACKGROUND: The association between knee malalignment and ankle degeneration has not been well established. This study aimed at determining whether knee malalignment and compensatory ankle morphology to knee malalignment are associated with the development and progression of ankle osteoarthritis (OA) in patients with end-stage knee OA. METHODS: We retrospectively reviewed 96 patients (106 knees) who underwent total knee arthroplasty. The progression of ankle OA, knee alignment, and ankle morphology were evaluated based on digital radiographs. Alignment deformity of the lower extremity was evaluated with hip-knee-ankle angle and medial proximal tibial angle (MPTA). Ankle morphology was evaluated by the lateral distal tibial angle, talar tilt, tibial plafond inclination angle, and ankle joint line orientation angle. RESULTS: The incidence of radiological ankle OA was observed in 39 of 106 cases. The MPTA (odds ratio = 0.72, P = .0009) and hip-knee-ankle angle (odds ratio = 1.13, P = .0169) were significantly associated with ankle OA. Among patients with tibial varus deformity, 26 of 49 had ankle OA. Among patients with neutral tibial alignment, 13 of 57 had radiological findings of ankle OA. MPTA was the only parameter associated with the progression of ankle OA. No association was observed between compensatory change in ankle morphology and the severity of ankle OA. CONCLUSION: Tibial varus deformity is associated with the development and progression of ankle OA; however, it is unclear whether it causes ankle OA. Due to the high incidence of ankle OA in total knee arthroplasty patients, it is reasonable to consider routine evaluation of the ankle.

Differences between native and prosthetic knees in terms of cross-sectional morphology of the femoral trochlea: a study based on three-dimensional models and virtual total knee arthroplasty.

BACKGROUND: The cross-sectional morphology of the prosthetic knee is crucial to understanding patellar motion and quadriceps strength after total knee arthroplasty. However, few comparative evaluations of the cross-sectional morphology of the femoral trochlea have been performed in the native knee and currently available femoral implants, and the relationship between the trochlear anatomy of prosthetic components and post-operative patellofemoral complications remains unclear. We aimed to investigate the differences in cross-sectional morphology of the femoral trochlea between native knees and prosthetic femoral components. METHODS: Virtual total knee arthroplasty was performed, whereby four different femoral components (medial-pivot, Triathlon, NRG and NexGen) were virtually superimposed onto three-dimensional models of 42 healthy femurs. The following morphological parameters were measured in three cross-sections (0, 45 and 90°) of the femoral trochlea: sulcus height, lateral tilt angle, medial tilt angle and sulcus angle. Only statistically significant differences are described further (p < 0.05). RESULTS: In the 0° cross-section, sulcus height was smaller in the native knee than in the Triathlon, NRG and NexGen components; all prosthetic components had smaller lateral tilt angles and larger medial tilt angles. In the 45° cross-section, sulcus height was larger in the native knee than in the medial-pivot, Triathlon and NexGen components; both lateral and medial tilt angles were smaller in the prosthetic components. In the 90° cross-section, sulcus height was smaller in the native knee than in the medial-pivot component; all prosthetic components had a larger lateral tilt angle and smaller medial tilt angle. In all cross-sections, the sulcus angle was smaller in the native knee. CONCLUSIONS: The discrepancy between native and prosthetic trochlear geometries suggests altered knee mechanics after total knee arthroplasty, but further cadaveric, computational or fluoroscopic investigations are necessary to clarify the implications of this observation. Our findings can be used to optimize biomechanical guidelines for total knee arthroplasty (patellar resurfacing or non-resurfacing) in Chinese individuals so as to decrease the risk of patellar lateral dislocation, to maintain stability and to optimize extensor kinematics.

Do size, shape, and alignment parameters of the femoral condyle affect the trochlear groove tracking? A morphometric study based on 3D- computed tomography models in Chinese people.

BACKGROUND: Our study aimed to investigate whether geometrical features (size, shape, or alignment parameters) of the femoral condyle affect the morphology of the trochlear groove. METHODS: Computed tomography models of 195 femurs (97 and 98 knees from male and female subjects, respectively) were reconstructed into three-dimensional models and categorised into four types of trochlear groove morphology based on the position of the turning point in relation to the mechanical axis (types 45°, 60°, 75°, and 90°). Only subjects with healthy knees were included, whereas individuals with previous knee trauma or knee pain, soft tissue injury, osteoarthritis, or other chronic diseases of the musculoskeletal system were excluded. The size parameters were: radius of the best-fit cylinder, anteroposterior dimension of the lateral condyles (AP), and distal mediolateral dimension (ML). The shape parameters were: aspect ratio (AP/ML), arc angle, and proximal- and distal- end angles. The alignment parameters were: knee valgus physiologic angle (KVPA), mechanical medial distal femoral angle (mMDFA), and hip-knee-ankle angle (HKA). All variables were measured in the femoral condyle models, and the means for each groove type were compared using one-way analysis of variance. RESULTS: No significant difference among groove types was observed regarding size parameters. There were significant differences when comparing type 45° with types 60°, 75°, and 90° regarding aspect ratio and distal-end angle (p < 0.05), but not regarding proximal-end angle. There were significant differences when comparing type 90° with types 45°, 60°, and 75° regarding KVPA, mMDFA, and HKA (p < 0.05). CONCLUSION: Among size, shape, and alignment parameters, the latter two exhibited partial influence on the morphology of the trochlear groove. Shape parameters affected the trochlear groove for trochlear type 45°, for which the femoral condyle was relatively flat, whereas alignment parameters affected the trochlear groove for trochlear type 90°, showing that knees in type 90° tend to be valgus. The morphometric analysis based on trochlear groove classification may be helpful for the future design of individualized prostheses.

Morphological classification of the femoral trochlear groove based on a quantitative measurement of computed tomographic models.

PURPOSE: This study aimed to investigate the natural morphology of the femoral trochlear groove based on quantitative measurement. METHODS: Computed tomographic femur models of 50 male and 50 female healthy Chinese adults (30-60 years) were analysed using three-dimensional software. Coaxial cutting planes (15° increments) rotating about the trochlear groove axis from the proximal to distal point were created, followed by the deepest point of the trochlear groove marked at each cross section. The shape, position, and orientation of the trochlear groove were analysed. RESULTS: The trochlear groove was located laterally relative to the mechanical axis and consisted of the laterally oriented proximal part and medially oriented distal part. Based on the turning points located on different cross sections, the trochlear groove was classified into four types: types 45°, 60°, 75°, and 90°. The mediolateral position relative to the mechanical axis was types 45°, 60°, 75°, and 90°, from the lateral to medial side, while the distal parts of them extended along the same path. The orientation of the trochlear groove was relatively consistent and smooth, which oriented at approximately 1° medially between two adjacent segments, except at approximately 10° medially at the turning point. CONCLUSION: The trochlear groove tracking varies greatly amongst a population that is mainly categorized into four types. This study may be helpful for better understanding of the natural trochlear groove anatomy, prosthetic design modification, and provide the reference value for studying patellofemoral diseases such as patellar maltracking and trochlear dysplasia. LEVEL OF EVIDENCE: Prospective study, Level II.

The intercondylar notch ceiling: an accurate reference for distal femoral resection in total knee arthroplasty for severely degenerated varus knees.

PURPOSE: To measure the distance from the intercondylar ceiling to the lowest point of the medial and lateral femoral condyles in a healthy population so to obtain a clearly discernible and accurate landmark for proper distal femoral resection during total knee arthroplasty (TKA). METHODS: Three-dimensional models of the lower extremities of 100 healthy Chinese subjects were constructed using computed tomography scans. The distance between the distal surface of the medial femoral condyle and the intercondylar notch ceiling, in the direction of the femoral mechanical axis, was measured. RESULTS: The mean distance from the distal surface of the medial femoral condyle to the intercondylar notch ceiling was 9.1 ± 1.4 and 8.2 ± 1.4 mm in male and female subjects, respectively. Interestingly, this distance did not differ significantly with varying sizes of the distal femur. CONCLUSIONS: The intercondylar notch ceiling could be used as an accurate landmark to determine the proper distal femoral resection level during TKA. For the clinical relevance, the distal femoral bone cut should be at the level of the intercondylar notch ceiling when using the most of the current TKA prosthesis systems.

Morphological evaluation of the sagittal plane femoral load-bearing surface in computer-simulated virtual total knee arthroplasty implantation at different flexion angles.

PURPOSE: To examine the effect of implantation of the femoral component of a total knee arthroplasty (TKA) system in 0°, 3°, and 6° of flexion on the sagittal plane morphology of the femoral load-bearing surfaces. It was hypothesized that increasing the flexion angle would result in undersizing of the anterior surface without changing the flexion gap. METHODS: Computer simulation of a TKA using three-dimensional models of 10 healthy knees, matched to three different sized femoral components. Size discrepancy in the sagittal plane anterior, distal, and posterior joint surfaces between the native and prosthetic knees was calculated at 0°, 3°, and 6° of flexion. RESULTS: The required component size varied with the angle of implantation: 0°, size 3/size 4 (N = 7/3), 3°, size 3 (N = 10); and 6°, size 2/size 3 (N = 4/6). Component undersizing ranged between 4.4-6.3 mm at the anterior lateral surface, with a significant difference between 0° and 6° (p < 0.05), and 1.2-3.5 mm at the anterior medial surface. Component oversizing of the distal surface of the lateral condyle (2.9 mm) and undersizing of the medial surface of the posterior condyle (1.6-2.3 mm) were comparable at all three flexion angles of component implantation. CONCLUSIONS: Increasing the flexion angle of implantation increased the incidence of using a smaller size of femoral component without significant interference with the flexion gap. However, the effect of a smaller femoral component on undersizing of the anterior surface of the condyle and the impact on the extensor mechanism need to be considered.

Procalcitonin and α-Defensin for Diagnosis of Periprosthetic Joint Infections.

BACKGROUND: Current methods to diagnose periprosthetic joint infection (PJI) before revision surgery have limited diagnostic accuracy. This meta-analysis was performed to estimate the accuracy of procalcitonin (PCT) and α-defensin for the diagnosis of PJI. METHODS: Articles on the diagnostic value of PCT or α-defensin for PJI diagnosis were searched in the PubMed database. Sensitivity, specificity, diagnostic odds ratio, the area under the curve of summary receiver operating characteristic curves (AUC), the positive likelihood ratio, and the negative likelihood ratio were calculated to evaluate the diagnostic ability of PCT and the α-defensin test for the diagnosis of PJI. RESULTS: The pooled sensitivities for detecting PJI using PCT and α-defensin were 0.53 (95% confidence interval [CI], 0.24-0.80) and 0.96 (95% CI, 0.85-0.99), respectively. The pooled specificities for detecting PJI using PCT and α-defensin were 0.92 (95% CI, 0.45-0.99) and 0.95 (95% CI, 0.89-0.98), respectively. The pooled diagnostic odds ratios for detecting PJI using PCT and α-defensin were 13 (95% CI, 3-70) and 496 (95% CI, 71-3456), respectively. The pooled AUCs for PCT and α-defensin were 0.76 (95% CI, 0.72-0.80) and 0.99 (95% CI, 0.97-0.99), respectively. The positive likelihood ratio and the negative likelihood ratio of PCT were 6.8 (95% CI, 1.0-48.1) and 0.51 (95% CI, 0.31-0.84), respectively, whereas those of α-defensin were 19.6 (95% CI, 8.2-46.8) and 0.04 (95% CI, 0.01-0.17), respectively. CONCLUSION: Synovial fluid α-defensin has a great potential to diagnose PJI.

A comparative, retrospective study of peri-articular and intra-articular injection of tranexamic acid for the management of postoperative blood loss after total knee arthroplasty.

BACKGROUND: Intra-articular injection of tranexamic acid (TXA) is known to be effective in controlling blood loss after total knee arthroplasty (TKA). However, this method has some disadvantages, such as TXA leakage due to soft tissue release. Peri-articular injection provides an alternative to intra-articular administration of TXA. This study aimed to evaluate the effects of peri-articular injection of TXA in reducing blood loss after TKA and compare them to those of intra-articular TXA injection. METHODS: This was a retrospective analysis of 127 patients who underwent primary, unilateral TKA for knee osteoarthritis in our hospital between January 2014 and December 2014. Cases were classified into 3 comparison groups: 49 patients in the peri-articular TXA group, 36 in the intra-articular group, and 42 in the control group (TXA not administered). Demographic variables, hemoglobin (Hb) measured before and after surgery, operation time, total amount of drained volume, time of removing drains, units of blood transfused peri- and postoperatively, estimated volume of blood loss, and preoperative comorbidities were retrieved from the patients' medical charts. Statistical analyses were performed using SPSS 19.0 software. RESULTS: There were no significant differences of demographic variables and operation time among three groups (P > 0.05). Compared to the control group, both TXA groups had a significantly reduced volume of blood loss, postoperative knee joint drainage, hemoglobin concentration, time of removing drains, and need for blood transfusion (P < 0.05). The effects of TXA were comparable for the two methods of injection (P > 0.05). There were no deep venous thrombosis or thromboembolic complications in any group. CONCLUSIONS: Peri-articular injection of TXA is as effective as an intra-articular injection in reducing postoperative blood loss during TKA. Both methods had a statistically significant benefit in reducing the change in Hb concentration, volume of joint drainage, and estimated volume of blood loss when compared to the control group. Peri-articular injection of TXA can significantly reduce the blood transfusion rate compared to the control group.

How the gender or morphological specific TKA prosthesis improves the component fit in the Chinese population?

The purpose of this study was to evaluate how the gender specific or morphological specific total knee prostheses improve the component fit in the distal femur of the Chinese population. The data showed that the perfect fit rate of the femoral component remarkably increased in both the male and female subjects when using the gender specific (Nexgen-LPS GSF, Zimmer) or morphological specific (Advance Stature Knee, Wright Medical Technology) knee prostheses, compared to their standard counterparts. The highest femoral component perfect fit rate was achieved when both the standard and the corresponding gender or morphological specific knee prostheses were available for selection. Additionally, the percentage of the gender or morphological specific prosthesis selection in the females was significantly higher than the males.

A New Method to Predict Postoperative Stem Anteversion in Total Hip Arthroplasty for Developmental Dysplasia of the Hip.

BACKGROUND: Preoperative evaluation of femoral anteversion to predict postoperative stem anteversion aids the selection of an appropriate prosthesis and optimizes the combined anteversion in total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH). The conventional prediction methods are based on the femoral anteversion measurement at the location of the femoral head and/or neck. However, varied differences between femoral anteversion and postoperative stem anteversion were demonstrated. This study investigated the predictive role of a new method based on the principle of sagittal three-point fixation. METHODS: From January 2017 to December 2018, a total of 133 DDH hips that underwent THA were retrospectively analyzed. There were 76 Crowe type I, 27 type II, and 30 type III hips. The single-wedge stem was used in 49 hips, and the double-wedge stem was used in 84 hips. Preoperative native femoral anteversion at the femoral head-neck junction, anterior cortex anteversion at 2 levels of the lesser trochanter, posterior cortex anteversion at 5 levels of the femoral neck, and postoperative stem anteversion were measured using two-dimensional computed tomography. Predictive anteversion by the new method was calculated as the average anteversion formed by the anterior cortex at the lesser trochanter and the posterior cortex at the femoral neck. RESULTS: For hips with different neck heights, different Crowe types, different stem types, or different femoral anteversions, native femoral anteversion showed widely varied differences and correlations with stem anteversion, with differences ranging from -1.27 ± 8.33° to -13.67 ± 9.47° and correlations ranging from 0.122 (p = 0.705, no correlation) to 0.813. Predictive anteversion formed by the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base showed no significant difference with stem anteversion, with less varied differences (0.92 ± 7.52°) and good to excellent correlations (r = 0.826). CONCLUSION: Adopting our new method, predictive anteversion, measured as the average anteversion of the anterior cortex at the lesser trochanter proximal base and posterior cortex 10 mm above the lesser trochanter proximal base, predicted postoperative stem anteversion more reliably than native femoral anteversion.

A Radiographic Analysis of Coronal Morphological Parameters of Lower Limbs in Chinese Non-knee Osteoarthritis Populations.

OBJECTIVES: Analyzing the lower limb coronal morphological parameters in populations without knee osteoarthritis (KOA) holds significant value in predicting, diagnosing, and formulating surgical strategies for KOA. This study aimed to comprehensively analyze the variability in these parameters among Chinese non-KOA populations, employing a substantial sample size. METHODS: A cross-sectional retrospective analysis was performed on the Chinese non-KOA populations (n = 407; 49.9% females). The study employed an in-house developed artificial intelligence software to meticulously assess the coronal morphological parameters of all 814 lower limbs. The parameters evaluated included the hip-knee-ankle angle (HKAA), weight-bearing line ratio (WBLR), joint line convergence angle (JLCA), mechanical lateral-proximal-femoral angle (mLPFA), mechanical lateral-distal-femoral angle (mLDFA), mechanical medial-proximal-tibial angle (mMPTA), and mechanical lateral-distal-tibial angle (mLDTA). Differences in these parameters were compared between left and right limbs, different genders, and different age groups (with 50 years as the cut-off point). RESULTS: HKAA and JLCA exhibited left-right differences (left vs. right: 178.2° ± 3.0° vs. 178.6° ± 2.9° for HKAA, p = 0.001; and 1.8° ± 1.5° vs. 1.4° ± 1.6° for JLCA, p < 0.001); except for the mLPFA, all other parameters show gender-related differences (male vs. female: 177.9° ± 2.8° vs. 179.0° ± 3.0° for HKAA, p < 0.001; 1.5° ± 1.5° vs. 1.8° ± 1.7° for JLCA, p = 0.003; 87.1° ± 2.1° vs. 88.1° ± 2.1° for mMPTA, p < 0.001; 90.2° ± 4.0° vs. 91.1° ± 3.2° for mLDTA, p < 0.001; 38.7% ± 12.9% vs. 43.6% ± 14.1% for WBLR, p < 0.001; and 87.7° ± 2.3° vs. 87.4° ± 2.7° for mLDTA, p = 0.045); mLPFA increase with age (younger vs. older: 90.1° ± 7.2° vs. 93.4° ± 4.9° for mLPFA, p < 0.001), while no statistical difference exists for other parameters. CONCLUSIONS: There were differences in lower limb coronal morphological parameters among Chinese non-KOA populations between left and right sides, different genders, and age.

Matrix stiffness aggravates osteoarthritis progression through H3K27me3 demethylation induced by mitochondrial damage.

Abnormal epigenetics is the initial factor of the occurrence and development of osteoarthritis (OA), and abnormal mechanical load is a key pathogenic factor of OA. However, how abnormal mechanical load affects chondrocyte epigenetics is unclear. Chondrocytes reportedly respond to mechanics through the extracellular matrix (ECM), which has a role in regulating epigenetics in various diseases, and mitochondria are potential mediators of communication between mechanics and epigenetics. Therefore, it is hypothesized that the matrix mechanics of cartilage regulates their epigenetics through mitochondria and leads to OA. The matrix stiffness of OA cartilage on the stress-concentrated side increases, mitochondrial damage of chondrocyte is severe, and the chondrocyte H3K27me3 is demethylated. Moreover, mitochondrial permeability transition pore (mPTP) opens to increase the translocation of plant homeodomain finger protein 8 (Phf8) into the nucleus to catalyze H3K27me3 demethylation. This provides a new perspective for us to understand the mechanism of OA based on mechanobiology.

Hypermethylation of Bmp2 and Fgfr2 Promoter Regions in Bone Marrow Mesenchymal Stem Cells Leads to Bone Loss in Prematurely Aged Mice.

Osteoporosis is an age-related, systemic skeletal disease that poses a significant public health challenge in contemporary society. Development at the epigenetic level is emerging as an important pathogenic mechanism of osteoporosis. Despite indications of a robust association between DNA methylation and osteoporosis development, a comprehensive understanding of the specific role of DNA methylation in osteoporosis remains limited. In this study, significant bone loss was detected at the beginning of eight weeks of age in mouse models of premature aging (SHJHhr mice). We identified a notable upregulation of DNA methyltransferase 3b/3l (Dnmt3b/l) and downregulation of ten eleven translocation dioxygenase 1 (Tet1) in bone marrow mesenchymal stem cells (BMSCs) isolated from SHJHhr mice, along with an increase in the overall 5-methylcytosine (5mC) levels. Moreover, methylation capture sequencing revealed genomic hypermethylation in SHJHhr mice BMSCs. Integrated methylome and transcriptome analyses revealed several crucial methylated genes and networks that are potentially associated with osteoporosis development. Notably, elevated methylation levels of genes linked to the Wnt signaling pathway, particularly bone morphogenetic protein 2 (Bmp2) and fibroblast growth factor receptor (Fgfr2), appeared to compromise the osteogenic differentiation potential of BMSCs. Concurrently, DNA methyltransferase inhibitors attenuated the methylation of the promoter regions of Bmp2 and Fgfr2 and rescued the osteogenic differentiation potential of the BMSCs from SHJHhr mice. In summary, our study provides novel insights into the role of DNA methylation in the development of osteoporosis and suggests promising prospects for employing epigenetic interventions to manage osteoporosis.