Risk Factors for Periprosthetic Femoral Fractures After Cementless Total Hip Arthroplasty.

BACKGROUND: The present study aimed to identify the risk factors of periprosthetic femoral fracture (PFF) after cementless total hip arthroplasty and rank them based on importance. METHODS: The age, sex, body mass index (BMI), osteoporosis, canal flare index (CFI), canal bone ratio (CBR), canal calcar ratio (CCR), stem design, and stem canal fill ratio (P1, P2, P3, and P4) of the proximal femoral medullary cavity of 111 total hip arthroplasty patients who had PFF and 388 who did not have PFF were analyzed. Independent-samples student t-tests were used for continuous variables, and Chi-square tests were used for categorical variables. The importance rankings of influencing factors were assessed using a random forest algorithm. Dimensionally reduced variables were then incorporated into a binary logistic regression model to determine the PFF-related risk factors. RESULTS: The mean age, BMI, CBR, CCR, and incidence of osteoporosis were higher in cases of PFF (all P < .001), while the mean CFI, P1, P2, P3, and P4 were lower in cases of PFF (P < .001, P = .033, P = .008, P < .001, and P < .001, respectively). Additionally, the stem design was also statistically associated with PFF (P < .001). Multivariate logistic regression revealed that advanced age, higher BMI, osteoporosis, stem design, lower CFI, higher CBR, higher CCR, lower P1, lower P2, lower P3, and lower P4 were the risk factors of PFF (P < .001, P < .001, P < .001, P < .001, P < .001, P = .010, P < .001, P = .002, P < .001, P < .001, and P = .007, respectively). The ranked importance of the risk factors for PFF was P3, CFI, osteoporosis, CBR, age, P4, P1, stem design, CCR, BMI, and P2. CONCLUSIONS: Lower P3, lower CFI, osteoporosis, higher CBR, advanced age, lower P4, lower P1, stem design, higher CCR, higher BMI, and lower P2 increased the risk of PFF.

Mechanical alignment tolerance of a cruciate-retaining knee prosthesis under gait loading-A finite element analysis.

Component alignment is one of the most crucial factors affecting total knee arthroplasty's clinical outcome and survival. This study aimed to investigate how coronal, sagittal, and transverse malalignment affects the mechanical behavior of the tibial insert and to determine a suitable alignment tolerance on the coronal, sagittal, and transverse planes. A finite element model of a cruciate-retaining knee prosthesis was assembled with different joint alignments (-10°, -7°, -5°, -3°, 0°, 3°, 5°, 7°, 10°) to assess the effect of malalignment under gait loading. The results showed that varus or valgus, extension, internal rotation, and excessive external rotation malalignments increased the maximum Von Mises stress and contact pressure on the tibial insert. The mechanical alignment tolerance of the studied prosthesis on the coronal, sagittal, and transverse planes was 3° varus to 3° valgus, 0°-10° flexion, and 0°-5° external rotation, respectively. This study suggests that each prosthesis should include a tolerance range for the joint alignment angle on the three planes, which may be used during surgical planning.

Comparison of navigation systems for total knee arthroplasty: A systematic review and meta-analysis.

Background: Component alignment is a crucial factor affecting the clinical outcome of total knee arthroplasty (TKA). Accelerometer-based navigation (ABN) systems were developed to improve the accuracy of alignment during surgery. This study aimed to compare differences in component alignment, clinical outcomes, and surgical duration when using conventional instrumentation (CONI), ABN, and computer navigation (CN) systems. Methods: A comprehensive literature search was carried out using the Web of Science, Embase, PubMed, and Cochrane databases. Articles that met the eligibility criteria were included in the study. Meta-analyses were performed using the Cochrane Collaboration Review Manager based on Cochrane Review Method. The variables used for the analyses were postoperative clinical outcome (PCO), surgical duration, and component alignment, including the hip-knee-ankle (HKA) angle, coronal femoral angle (CFA), coronal tibial angle (CTA), sagittal femoral angle (SFA), sagittal tibial angle (STA), and the outliers for the mentioned angles. The mean difference (MD) was calculated to determine the difference between the surgical techniques for continuous variables and the odds ratio (OR) was used for the dichotomous outcomes. Results: The meta-analysis of the CONI and ABN system included 18 studies involving 2,070 TKA procedures, while the comparison of the ABN and CN systems included 5 studies involving 478 TKA procedures. The results showed that the ABN system provided more accurate component alignment for HKA, CFA, CTA, and SFA and produced fewer outliers for HKA, CFA, CTA, and STA. However, while the ABN system also required a significantly longer surgical time than the CONI approach, there was no statistical difference in PCO for the two systems. For the ABN and CN systems, there was no statistical difference in all variables except for the ABN system having a significantly shorter surgical duration. Conclusion: There was no significant difference in the accuracy of component alignment between the ABN and CN systems, but the ABN approach had a shorter surgical duration and at lower cost. The ABN system also significantly improved the accuracy of component alignment when compared to the CONI approach, although the surgery was longer. However, there was no significant difference in PCO between the CONI, ABN, and CN systems.

Capability of auxetic femoral stems to reduce stress shielding after total hip arthroplasty.

Background: Stress shielding â€‹(SS) is considered the main mechanical cause of femoral stem loosening after total hip arthroplasty (THA). This study introduces an auxetic lattice femoral stem structure with negative Poisson's ratio that can expand laterally, with the intent of transferring more load to surrounding bone and thereby reducing SS. This study aims to evaluate how the geometry profile of different femoral stems with auxetic structures affects the level of SS. Different re-entrant angles for the auxetic unit cells were also evaluated. Methods: This study assessed three commercial femoral stem designs (Mayo, CLS and Fitmore) and three re-entrant angles for the auxetic structures (60°, 70° and 80°). Nine auxetic femoral stems (three M-type, three C-type and three F-type) and three solid femoral stems (control group) were designed. All femoral stems were implanted into a finite element model of the human femur to compare levels of SS between the auxetic stems and their traditional solid counterparts. Results: The results showed that incorporating an auxetic structure into the stem design caused less SS of the surrounding bone than the control models. The M-type stems had the lowest level of SS, followed by the C-type and F-type stems. A re-entrant angle of 70° for the M-type stem, 80° for the C-type stem and 60° for the F-type stem were the designs most capable of reducing SS. Conclusions: This study found that femoral stems with an auxetic lattice structure caused less SS after THA than comparable solid femoral stems. A femoral stem based on the M-type geometry profile is recommended when designing auxetic femoral stems to minimize SS of surrounding bone. The translational potential of this article: The novel solution provided in this study may serve to increase the survival rate of femoral stems by reducing SS after THA.

[Effect of open wedge tibial high osteotomy on patella position and joint function].

OBJECTIVE: To investigate the effect of open wedge tibial high osteotomy on patella position, anterior knee pain and joint function. METHODS: From June 2016 to June 2021, 109 patients (111 knees) with medial knee osteoarthropathy treated by open wedge tibial high osteotomy were included according to the inclusion and exclusion criteria, including 41 males and 68 females;the age ranged from 38 to 78 years old with an average of(57.98±7.07) years;the course of disease ranged from 1 to 36 months with an average of (8.58±6.91) months. The femoral tibial angle(FTA), medial proximal tibial angle(MPTA), weight bearing line(WBL) percentage, Caton Deschamps index (CD index), lateral patella tilt angle (LPTA) and lateral patella shift (LPS) were observed and compared before and after operation. Lysholm score was used to evaluate the knee function, visual analogue scale(VAS) was used to evaluate the degree of anterior knee pain, and Kellgren Lawrence(K-L) grading system was used to evaluate the progress of patellofemoral osteoarthritis. RESULTS: All patients were followed up for 6 to 38 months with an average of (12.41±2.40) months. The preoperative FTA, MPTA, WBL percentage, CD index, and LPTA were significantly different from those at the last follow-up(P<0.05). There was no significant difference between before and after LPS operation(P=0.78). Lysholm score increased from (58.79±7.90) scores to (76.05±7.36) scores (P<0.05). The VAS of anterior knee pain decreased from (3.28±1.95) scores to(1.07±1.75) scores(P<0.05). Knee patellofemoral osteoarthritis showed progressive changes, but there was no significant difference in K-L grading before and after operation (P>0.05). CONCLUSION: After open wedge tibial high osteotomy, the position of patella is lowered and the patella is tilted outward, but the knee function and anterior knee pain are significantly improved. Adverse changes in patella position caused by open wedge tibial high osteotomy may not affect clinical outcomes.

Correlation between component alignment and short-term clinical outcomes after total knee arthroplasty.

Objective: This study aimed to investigate the correlation between component alignment and short-term clinical outcomes after total knee arthroplasty (TKA). Methods: 50 TKA patients from a regional hospital were enrolled in the study. The following component alignments were measured from radiological data acquired within 1 week after surgery: hip-knee-ankle angle (HKA), medial distal femoral angle (MDFA), medial proximal tibial angle (MPTA), femoral flexion-extension angle (FEA), tibial slope angle (TSA), femoral rotational angle (FRA) and tibial rotational angle (TRA). The Hospital for Special Surgery (HSS) knee scoring system was used to assess clinical outcomes after 1 year, with patients being divided into three groups (excellent, good and not good) according to the HSS scores. Difference analysis and linear correlation analysis were used for the statistical analysis. Results: The results showed significant differences in MDFA (p = 0.050) and FEA (p = 0.001) among the three patient groups. It was also found that the total HSS had only a moderate correlation with FEA (r = 0.572, p < 0.001), but FEA had a positive linear correlation with pain scores (r = 0.347, p = 0.013), function scores (r = 0.535, p = 0.000), ROM scores (r = 0.368, p = 0.009), muscle scores (r = 0.354, p = 0.012) and stability scores (r = 0.312, p = 0.028). A larger MDFA was associated with lower FE deformity scores (r = -0.289, p = 0.042) and the TSA had a positive influence on the ROM (r = 0.436, p = 0.002). Also, changes in FRA produced a consequent change in the FE deformity score (r = 0.312, p = 0.027), and the muscle strength scores increased as TRA increased (r = 0.402, p = 0.004). Conclusion: The results show that the FEA plays a significant role in clinical outcomes after TKA. Surgical techniques and tools may need to be improved to accurately adjust the FEA to improve joint functionality and patient satisfaction.

Moderate External Rotation of Tibial Component Generates More Natural Kinematics Than Internal Rotation After Total Knee Arthroplasty.

This study aimed to investigate the influence of tibial malrotation on knee kinematics after total knee arthroplasty (TKA). A symmetric fixed-bearing posterior-stabilized prosthesis was implanted in the validated knee model with different rotational alignments of the tibial component (neutral, 3° external rotation, 5° external rotation, 3° internal rotation, and 5° internal rotation). Computational kinematic simulations were used to evaluate the postoperative kinematics of the knee joint including anteroposterior translation femoral condyles and axial rotation of tibial component during 0°-135° knee flexion. The results revealed that the neutral position of the tibial component was not the closest kinematics to the intact knee, the model with 5° external rotation of the tibial component showed the closest lateral condyle translation and tibial axial rotation, and moderate external rotation could improve the kinematics after TKA.

An Efficient Needleless Grasping Suture Technique for Graft Preparation in Anterior Cruciate Ligament Reconstruction.

Objective: Several needleless techniques have been developed to outcome the inherent disadvantages of the traditional needle stitching technique for graft preparation, such as tendon damage through the needle, time consumption, and the potential risk of needlestick injury. The purpose of the present study is to compare the graft preparation time and the biomechanical performance between an efficient needleless technique and the traditional needle stitching technique for graft preparation in anterior cruciate ligament reconstruction (ACLR). Methods: The time required to perform a complete suture on 20 hamstring tendons during ACLRs was measured. The grafts from one side were prepared using the needle stitching technique. The grafts from the other side used the needleless grasping suture technique. For the second part of the study, 12 fresh-frozen porcine flexor tendons were divided into two groups using two techniques and were mounted in an electric tensile test system. Each group was pretensioned to 100 N to simulate the maximum initial graft tension. The suturing state of sutures and graft (intact and damaged) and the load-elongation curve were recorded for each group. A Student's t-test was used to compare the means of the two groups. Results: In operation, the needleless grasping suture technique group (19.8 ± 4.8, range: 13.5-32.9 s) was significantly faster (p < 0.05) than the needle stitching technique group (52.7 ± 12.7, range: 36.0-87.5 s). The state of sutures in each group was intact. The mean elongation was 11.75 ± 1.38 (range: 9.47-12.99) mm and 10.59 ± 1.02 (range: 9.12-11.76) mm in the needleless stitching technique group and the needle grasping suture technique group, respectively. There was no statistically significant difference in the elongation between the two groups (p > 0.05). Conclusion: The needleless grasping suture technique was a convenient and efficient method for graft preparation in ACLR.

Cannabinoid Use for Pain Reduction in Spinal Cord Injuries: A Meta-Analysis of Randomized Controlled Trials.

Background: Spinal cord injury (SCI) often involves multimodal pain control. This study aims to evaluate the efficacy and safety of cannabinoid use for the reduction of pain in SCI patients. Methods and Findings: This study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement. We searched PubMed, EMBASE, Scopus, Cochrane, Web of Science, and ClinicalTrials.gov for relevant randomized controlled trials (RCTs) reporting the efficacy (e.g., pain relief) or safety (e.g., adverse events) of cannabinoids in patients with SCI, from inception to 25 December 2021. The study quality and the quality of evidence were evaluated by Cochrane ROB 2.0 and the Grading of Recommendations, Assessment, Development, and Evaluations system (GRADE), respectively. We used the random-effects model to perform the meta-analysis. From a total of 9,500 records, we included five RCTs with 417 SCI patients in the systematic review and meta-analysis. We judged all five of the included RCTs as being at high risk of bias. This meta-analysis indicated no significant difference in pain relief between the cannabinoids and placebo in SCI patients (mean difference of mean differences of pain scores: -5.68; 95% CI: -13.09, 1.73; p = 0.13; quality of evidence: very low), but higher odds of adverse events were found in SCI patients receiving cannabinoids (odds ratio: 3.76; 95% CI: 1.98, 7.13; p < 0.0001; quality of evidence: moderate). Conclusion: The current best evidence suggests that cannabinoids may not be beneficial for pain relief in SCI patients, but they do increase the risks of adverse events, including dizziness, somnolence, and dysgeusia, compared to the placebo. Cannabinoids should not be regularly suggested for pain reduction in SCI patients. Updating the systematic reviews and meta-analyses by integrating future RCTs is necessary to confirm these findings.

Hourglass-shaped grafts are superior to conventional grafts for restoring knee stability and graft force at knee flexion angle of 30° following anterior cruciate ligament reconstruction: A finite element analysis.

Background: Anterior cruciate ligament reconstruction (ACLR) using a generally columnar graft is considered the gold standard for treating anterior cruciate ligament ruptures, but such grafts cannot replicate the geometry and mechanical properties of the native anterior cruciate ligament. Purpose: To evaluate the effectiveness of an innovative hourglass-shaped graft versus a traditional columnar graft for restoring joint stability and graft force, while avoiding notch impingement following anterior cruciate ligament reconstruction. Methods: Finite element models of a human knee were developed to simulate ① An intact state, ② anterior cruciate ligament reconstruction using columnar grafts with different diameters (7.5-12 mm in 0.5 mm increments), ③ anterior cruciate ligament reconstruction using columnar grafts with different Young's moduli (129.4, 168.0 and 362.2 MPa) and ④ anterior cruciate ligament reconstruction using hourglass-shaped grafts with different Young's moduli. The knee model was flexed to 30° and loaded with an anterior tibial load of 103 N, internal tibial moment of 7.5 Nm, and valgus tibial moment of 6.9 Nm. The risk of notch impingement, knee stability and graft forces were compared among the different groups. Results: This study found that columnar grafts could not simultaneously restore knee stability in different degree of freedoms (DOFs) and graft force to a level similar to that of the intact knee. The anterior tibial translation and graft force were restored to a near-normal condition when the internal tibial rotation was over-restrained and valgus tibial rotation was lax. A graft diameter of at least 10 mm was needed to restore knee stability and graft force to physiological levels, but such large grafts were found to be at high risk of notch impingement. In contrast, the hourglass-shaped graft was able to simultaneously restore both knee stability and graft force at knee flexion of 30° while also having a much lower risk of impingement. Conclusion: Under knee flexion angle of 30°, an hourglass-shaped graft was better able to restore joint stability and graft force to a near-physiological level than columnar grafts, while also reducing the risk of notch impingement.

Genetic Associations Between IL-6 and the Development of Autoimmune Arthritis Are Gender-Specific.

Objectives: To find out the genetic association between IL6 and autoimmune arthritis. Methods: We performed a two-sample Mendelian randomization (MR) study using multiple genome-wide association studies (GWAS) datasets. Furthermore, a sex-stratified MR study was performed to identify sexual dimorphism in the association between IL6 and autoimmune arthritis. Then, LocusZoom plots were displayed based on the IL6R gene region to present evidence of genetic colocalization between diseases. Results: The MR result denoted a genetic association between the increased level of IL-6 signaling and risk of RA (ß=0.325, 95%CI 0.088, 0.561, p=7.08E-03) and AS (ß=1.240, 95%CI 0.495, 1.980, p=1.1E-03). Accordingly, sIL6R was found to have negatively correlation with the onset of RA (ß=-0.020, 95%CI -0.0320, -0.008, p=1.18E-03) and AS (ß=-0.125, 95%CI -0.177, -0.073, p=2.29E-06). However, no genetic association between IL6/sIL6R and PsA was detected. The gender-stratified MR analysis showed that IL6 was associated with AS in the male population, with RA in the female population, and with PsA in the male population. Additionally, ADAR, a gene identified by a sensitive test, could be the reason for the nonsignificant association between IL6 and PsA in a pooled population. Conclusion: Our findings showed that the overactive IL6 signal pathway led to autoimmune arthritis, especially in RA and AS. Sexual difference was also observed in IL6-intermediate susceptibility to autoimmune arthritis.

Extra-articular migration of PEEK interference screw after anterior cruciate ligament reconstruction: a report of two cases.

BACKGROUND: The interference screw is the most popular device that fixes the graft for anterior cruciate ligament reconstruction, reducing the incidence of windshield effect and bungee effect. For the screw, either metallic, "bioresorbable," or polyetheretherketone (PEEK) material is available. PEEK is popular and extensively used due to its stability, biocompatibility, radiolucency, and elastic modulus. Rare relevant complications were reported, but here, we report two cases of extra-articular migrations of PEEK interference screw from the tibial tunnel after anterior cruciate reconstruction. CASE REPORT: An 18-year-old boy and a 56-year-old woman underwent anterior cruciate ligament reconstruction using a PEEK interference screw to fix the graft in the tibial tunnel. They suffered from screw extrusion from the tibial tunnel after 40 days and six months, respectively, with an incision rupture or palpable subcutaneous mass. They underwent a second operation and recovered well. CONCLUSIONS: The exact incidence of extra-articular migrations of PEEK interference screws is unknown, but it seems to be quite low; despite this and its uncertain cause, the negative effects caused by the PEEK material need to be considered.

Arthroscopic all-inside repair with suture hook for horizontal tear of the lateral meniscus at the popliteal hiatus region: a preliminary report.

BACKGROUND: Arthroscopic surgery procedures vary depending on the types of meniscus tear, including meniscectomy and meniscus repair. Among the several types of meniscus tear, the horizontal tear of the lateral meniscus at the popliteal hiatus region is a common injury, and its surgical treatment is still inconsistent. METHODS: Between January 2018 and October 2018, 20 patients who underwent all-inside repair with suture hook for the horizontal tear of the lateral meniscus at the popliteal hiatus region were recruited. Any operative complication was recorded, and postoperative MRI scans were conducted at the 6 months. The clinical results were graded based on the scale of the Lysholm knee score preoperatively and at follow-up. RESULTS: No operative complications were recorded. Postoperative MRIs at the 6 months showed that there was no re-tear for all patients, though signal intensity remained high in T2-weighted MRI in the lateral meniscus for nine cases. The average preoperative Lysholm knee score was 58.6 ± 10.1, which increased significantly to 89.3 ± 7.8 (t = - 11.01, p = 0.001) at the last follow-up. Recurrence or aggravation of symptoms was not noted at the final follow-up. CONCLUSION: All-inside repair with suture hook may be a good option for the horizontal tear of the lateral meniscus at the popliteal hiatus region which preserves the meniscus; avoids iatrogenic injury on the adjacent popliteal tendon, common peroneal nerve, and inferior lateral geniculate artery.

The Posterolateral Corner-Locked Technique Is Applicable in a Chinese Population Regarding the Tibial Component Rotation Alignment in Total Knee Arthroplasty.

Rotational malalignment between the femoral and tibial components in total knee arthroplasty (TKA) can affect clinical outcomes, but there is no consensus on how to best determine tibia tray orientation. The posterolateral corner-locked (PLCL) technique may be a new method. This study aims to assess the applicability of this technique in a Chinese population. Forty normal Chinese volunteers were recruited and underwent computed tomography (CT) of the lower limbs. Knee model reconstructions and simulated standard tibial osteotomy were conducted digitally. The transepicondylar axis (TEA), the Akagi line, and the line connecting the medial third of the tibial tubercle with the midpoint of the posterior cruciate ligament (PCL) were projected to the tibial cross-section and marked. The PLCL technique was applied using either symmetrical or asymmetrical tibial tray templates, and the anteroposterior (AP) axis of the tibial tray was marked. The angles between the TEA and these lines were calculated, and the statistical differences were analyzed. The angle between the TEA and the Akagi line and between the TEA and the line connecting the medial third of the tibial tubercle with the midpoint of the PCL were 96.90 ± 5.57 and 107.31 ± 5.95 degrees, respectively. The angles between the TEA and the AP axis of the symmetrical and the asymmetrical design tibial trays were 94.01 ± 4.21 and 96.65 ± 4.70 degrees, respectively. Except for the Akagi line and AP axis of the asymmetrical tibial tray, statistical differences were found between all lines (p < 0.05). The PLCL technique is principally suitable for Chinese patients requiring TKA when using the tibial component referred to in this study, although it may result in slight external rotation.

An unusual case of symptomatic deep vein thrombosis and pulmonary embolism after arthroscopic meniscus surgery.

BACKGROUND: Although thrombosis complication is rare after arthroscopic meniscus surgery, deep vein thrombosis and pulmonary embolism can be fatal. The associated risk factors and whether anticoagulant prevention after arthroscopic knee surgery is necessary have not reach consensus. Here we present a case of deep vein thrombosis and pulmonary embolism after a common arthroscopic meniscectomy. CASE PRESENTATION: The patient had no risk factors except ipsilateral leg varicose veins. She present swell at knee and calf from postoperative 3 weeks, and developed dyspnea, palpitation, and nausea on 33th day, pulmonary embolism was confirmed with CT angiography at emergency department. After thrombolysis and anticoagulation therapy were administered, the patient improved well and discharged. And the intravenous ultrasound confirmed thrombosis of popliteal vein and small saphenous vein. Who don't have common risk factors for venous thromboembolism. CONCLUSIONS: Despite the low incidence of thromboembolic complications after simple arthroscopy surgery, its life-threatening and devastating property make clinicians rethink the necessity of thromboprophylaxis and importance of preoperative relative risk factors screening.

Is the posterior cruciate ligament necessary for medial pivot knee prostheses with regard to postoperative kinematics?

PURPOSE: Excellent clinical and kinematical performance is commonly reported after medial pivot knee arthroplasty. However, there is conflicting evidence as to whether the posterior cruciate ligament should be retained. This study simulated how the posterior cruciate ligament, post-cam mechanism and medial tibial insert morphology may affect postoperative kinematics. METHODS: After the computational intact knee model was validated according to the motion of a normal knee, four TKA models were built based on a medial pivot prosthesis; PS type, modified PS type, CR type with PCL retained and CR type with PCL sacrificed. Anteroposterior translation and axial rotation of femoral condyles on the tibia during 0°-135° knee flexion were analyzed. RESULTS: There was no significant difference in kinematics between the intact knee model and reported data for a normal knee. In all TKA models, normal motion was almost fully restored, except for the CR type with PCL sacrificed. Sacrificing the PCL produced paradoxical anterior femoral translation and tibial external rotation during full flexion. CONCLUSION: Either the posterior cruciate ligament or post-cam mechanism is necessary for medial pivot prostheses to regain normal kinematics after total knee arthroplasty. The morphology of medial tibial insert was also shown to produce a small but noticeable effect on knee kinematics. LEVEL OF EVIDENCE: V.