Variety of femoral anteversion and its measurement in cementless total hip arthroplasty: Does robotic technology improve accuracy?

BACKGROUND: High-performance total hip arthroplasty (THA) depends on the accurate position of components. However, femoral anteversion is variable, and current studies only used traditional instruments to evaluate it, such as protractor and spirit level with limited cases. This study aimed to identify the variability in the measured femoral native anteversion and intraoperative stem anteversion under different measurement methods, including intraoperative robotic method. We hypothesized that robotic technology was more accurate than traditional instruments for femoral anteversion evaluation. METHODS: This study included 117 hips of patients who underwent robotic-assisted THA between November 2019 and March 2021. Preoperative native femoral anteversion was measured using a robotic system. Intraoperative femoral stem anteversion was evaluated visually, and then measured with a goniometer and a robotic system, respectively. Variability in the measured femoral native anteversion and intraoperative femoral stem anteversion was calculated and compared. Intraclass correlation coefficient (ICC) and Pearson correlation analysis were used to assess the consistency and correlation of anteversion of different measurements and postoperative CT-measured stem anteversion, respectively. RESULTS: The result of measurement for preoperative native femoral anteversion was more variable than the intraoperative robotic-measured stem anteversion. Intraoperative robotic-measured stem version showed the highest correlation with postoperative CT measurement of stem version (r = 0.806, P < 0.001), while intraoperative surgeon estimation had the lowest correlation coefficient (r = 0.281, P = 0.025). As for the consistency with postoperative CT measurement of femoral stem anteversion, the intraoperative robotic-measured femoral stem version also had the highest value (ICC = 0.892, P < 0.001). CONCLUSION: Native femoral anteversion was variable preoperatively. Using cementless stems, anteversion was also highly variable. Robotic assessment for stem anteversion during surgery was more consistent with the final position than the preoperative assessment and conventional intraoperative estimation.

The Necessity of Implant Removal after Fixation of Thoracolumbar Burst Fractures-A Systematic Review.

BACKGROUND: Thoracolumbar burst fractures are a common traumatic vertebral fracture in the spine, and pedicle screw fixation has been widely performed as a safe and effective procedure. However, after the stabilization of the thoracolumbar burst fractures, whether or not to remove the pedicle screw implant remains controversial. This review aimed to assess the benefits and risks of pedicle screw instrument removal after fixation of thoracolumbar burst fractures. METHODS: Data sources, including PubMed, EMBASE, Cochrane Library, Web of Science, Google Scholar, and Clinical trials.gov, were comprehensively searched. All types of human studies that reported the benefits and risks of implant removal after thoracolumbar burst fractures, were selected for inclusion. Clinical outcomes after implant removal were collected for further evaluation. RESULTS: A total of 4051 papers were retrieved, of which 35 studies were eligible for inclusion in the review, including four case reports, four case series, and 27 observational studies. The possible risks of pedicle screw removal after fixation of thoracolumbar burst fractures include the progression of the kyphotic deformity and surgical complications (e.g., surgical site infection, neurovascular injury, worsening pain, revision surgery), while the potential benefits of pedicle screw removal mainly include improved segmental range of motion and alleviated pain and disability. Therefore, the potential benefits and possible risks should be weighed to support patient-specific clinical decision-making about the removal of pedicle screws after the successful fusion of thoracolumbar burst fractures. CONCLUSIONS: There was conflicting evidence regarding the benefits and harms of implant removal after successful fixation of thoracolumbar burst fractures, and the current literature does not support the general recommendation for removal of the pedicle screw instruments, which may expose the patients to unnecessary complications and costs. Both surgeons and patients should be aware of the indications and have appropriate expectations of the benefits and risks of implant removal. The decision to remove the implant or not should be made individually and cautiously by the surgeon in consultation with the patient. Further studies are warranted to clarify this issue. LEVEL OF EVIDENCE: level 1.

Robotic-assisted revision total joint arthroplasty: a state-of-the-art scoping review.

Background: During the past decades, robotic-assisted technology has experienced an incredible advancement in the field of total joint arthroplasty (TJA), which demonstrated promise in improving the accuracy and precision of implantation and alignment in both primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). However, revision TJA remains a technically challenging procedure with issues of large-scale bone defects and damage to nearby anatomical structures. Thus, surgeons are trying to harness the abilities of robotic-assisted technology for revision TJA surgery. Methods: PubMed, Embase, Cochrane Library, and Google Scholar were comprehensively searched to identify relevant publications that reported the application of robotic-assisted technology in revision TJA. Results: Overall, ten studies reported the use of the robotic system in revision TJA, including active (ROBODOC) and semi-active (MAKO and NAVIO) systems. One clinical case reported conversion from hip fusion to THA, and three studies reported revision from primary THA to revision THA. Moreover, four studies reported that robotic-assisted technology is helpful in revising unicompartmental knee arthroplasty (UKA) to TKA, and two case reports converted primary TKA to revision TKA. In this study, we present the latest evolvements, applications, and technical obstacles of robotic-assisted technology in the revision of TJA and the current state-of-the-art. Conclusion: Current available evidence suggests that robotic-assisted technology may help surgeons to reproducibly perform preoperative plans and accurately achieve operative targets during revision TJA. However, concerns remain regarding preoperative metal artifacts, registration techniques, closed software platforms, further bone loss after implant removal, and whether robotic-assisted surgery will improve implant positioning and long-term survivorship.

Exosomes derived from magnetically actuated bone mesenchymal stem cells promote tendon-bone healing through the miR-21-5p/SMAD7 pathway.

Graft healing after anterior cruciate ligament reconstruction (ACLR) involves slow biological processes, and various types of biological modulations have been explored to promote tendon-to-bone integration. Exosomes have been extensively studied as a promising new cell-free strategy for tissue regeneration, but few studies have reported their potential in tendon-to-bone healing. In this study, a novel type of exosome derived from magnetically actuated (iron oxide nanoparticles (IONPs) combined with a magnetic field) bone mesenchymal stem cells (BMSCs) (IONP-Exos) was developed, and the primary purpose of this study was to determine whether IONP-Exos exert more significant effects on tendon-to-bone healing than normal BMSC-derived exosomes (BMSC-Exos). Here, we isolated and characterized the two types of exosomes, conducted in vitro experiments to measure their effects on fibroblasts (NIH3T3), and performed in vivo experiments to compare the effects on tendon-to-bone integration. Moreover, functional exploration of exosomal miRNAs was further performed by utilizing a series of gain- and loss-of-function experiments. Experimental results showed that both BMSC-Exos and IONP-Exos could be shuttled intercellularly into NIH3T3 fibroblasts and enhanced fibroblast activity, including proliferation, migration, and fibrogenesis. In vivo, we found that IONP-Exos significantly prevented peri-tunnel bone loss, promoted more osseous ingrowth into the tendon graft, increased fibrocartilage formation at the tendon-bone tunnel interface, and induced a higher maximum load to failure than BMSC-Exos. Furthermore, overexpression of miR-21-5p remarkably enhanced fibrogenesis in vitro, and SMAD7 was shown to be involved in the promotive effect of IONP-Exos on tendon-to-bone healing. Our findings may provide new insights into the regulatory roles of IONPs in IONP-Exos communication via stimulating exosomal miR-21-5p secretion and the SMAD7 signaling pathway in the fibrogenic process of tendon-to-bone integration. This work could provide a new strategy to promote tendon-to-bone healing for tissue engineering in the future.

Correlation between tibial valgus deformity and aspect ratio of resected tibial surface in female Chinese patients undergoing total knee arthroplasty.

Background: Morphology of the resected tibial surface is the reference for tibial component design, selection, and implantation in total knee arthroplasty (TKA). This comparative study sought to answer whether valgus deformity of the tibia would affect the morphology of the resected tibial surface in TKA. Methods: Thirty-one female Chinese patients with valgus tibias were retrospectively and consecutively identified from a single-center registration database. Thirty-one patients with well-aligned tibias were matched in terms of gender, height, and weight. Weight-bearing full-length radiographs and computed tomography images of the whole lower limb were obtained for every case. Tibial resection was mimicked perpendicular to the mechanical axis of the tibia in the frontal plane with 3° of posterior slope and a cut level individualized by the actual intraoperative cut. On the resected surface, mediolateral dimension (MLD), medial anteroposterior dimensions (mAPD), and lateral anteroposterior dimensions (lAPD) were measured, and aspect ratios (AR) were calculated. We compared the AR between the two groups. Results: The aspect ratio of resected tibial surface positively correlated with tibial valgus alignment. Patients with valgus tibias had significantly smaller AR (MLD/mAPD) for the medial plateau (1.50 ± 0.06 vs. 1.54 ± 0.07, P = 0.032). However, the AR for the lateral plateau was similar between the two groups (1.63 ± 0.08 vs. 1.65 ± 0.07, P = 0.328). Conclusion: This difference in morphology of resected tibial surface between valgus and well-aligned tibias should be considered in tibial component design, as well as in the selection and placement of TKA implants for knees with valgus tibias.

Bone mineral density, osteopenia, osteoporosis, and fracture risk in patients with atopic dermatitis: a systematic review and meta-analysis.

BACKGROUND: The relationship between atopic dermatitis (AD) and abnormal bone metabolism remains unclear. We performed a systematic review and meta-analysis to determine whether patients with AD were associated with increased risks of low bone mineral density (BMD), osteopenia, osteoporosis, and related fractures. METHODS: We searched PubMed, Embase, and the Cochrane Library through December 2019 to identify studies that investigated the association between AD and abnormal bone metabolism (including BMD, osteopenia, osteoporosis, and related fractures). The predefined primary outcome was related fractures; secondary outcomes included osteoporosis, osteopenia, and BMD. We calculated the summary odds ratios (ORs) and 95% confidence intervals (CIs) using a random-effects model. RESULTS: Ten studies were included in this systematic review. In children and adolescents, four studies investigated the association between AD and BMD; three studies indicated that children and adolescents with AD were associated with an increased risk of low BMD; one study found similar BMD between AD and control groups. In adults, three studies assessed the risk of fracture and were included in the meta-analysis, comprising 562,405 AD patients among 3,171,268 participants. Adults with AD were associated with an increased risk of fracture (OR 1.13; 95% CI, 1.05-1.22; P=0.001). Three studies investigated the association between AD and osteoporosis, which suggested that patients with AD were associated with an increased risk of osteoporosis (OR 1.95; 95% CI, 1.18-3.23; P=0.009). Further, patients with AD were associated with increased risks of osteopenia (OR 1.90; 95% CI, 1.51-2.38; P<0.001) and low BMD at the femur and spine. CONCLUSIONS: Patients with AD were associated with increased risks of low BMD, osteopenia, osteoporosis, and related fractures. Both clinical studies and basic research are needed to clarify the mechanisms of association between AD and abnormal bone metabolism.

Three-dimensional color map: a novel tool to locate the surgical transepicondylar axis.

BACKGROUND: Accurate localization of the surgical transepicondylar axis (sTEA) in total knee arthroplasty (TKA), the most reliable anatomical reference for femoral rotation, has long been a challenge, primarily because it is intractable to locate the center of the sulcus of the medial epicondyle. This study aimed to introduce and verify a novel method to locate the sTEA more precisely. METHODS: This study included 26 adult femoral specimens and 80 adult patients with computed tomography (CT) scan data. Three dimensions (3D) models based on CT scans of the distal femurs were reconstructed with Mimics and imported into Geomagic Studio. The 3D color map method was applied to locate the sTEA. To further verify the accuracy of the method, the identified sTEA was transferred to the femoral specimens and compared with the points identified by the total station machine. We further compared the recognition rate of sTEA between 3D color map method and two-dimensional (2D) CT slices method. The repeatability of this novel method was also evaluated. RESULTS: The 3D color map method located the centers of the sulcus of the medial epicondyle and the most prominent point of the lateral epicondyle of all the femoral specimens, which were further identified and confirmed by patient-specific guide plates and total station machine on femoral specimens. The 3D color map method achieved a recognition rate of up to 96.23%, while the recognition rate of the 2D CT slices method was only 68.87%. The repeatability of this objective method was excellent. CONCLUSIONS: The results of this study indicated that the 3D color map method could be used to accurately and objectively locate the sTEA, with high repeatability and recognition rate. However, the proposed novel method requires further validation in clinical applications.

The necessity of routine postoperative laboratory tests after total hip arthroplasty for hip fracture in a semi-urgent clinical setting.

BACKGROUND: Recent studies suggest that routine postoperative laboratory tests are not necessary after primary elective total hip arthroplasty (THA). This study aims to evaluate the utility of routine postoperative laboratory tests in patients undergoing THA for hip fracture in a semi-urgent clinical setting. MATERIALS AND METHODS: This retrospective study included 213 consecutive patients who underwent primary unilateral THA for hip fractures. Patient demographics, clinical information, and laboratory tests were obtained from the electronic medical record system. Multivariate logistic regression analysis was performed to identify risk factors associated with abnormal laboratory test-related interventions. RESULTS: A total of 207 patients (97.18%) had abnormal postoperative laboratory results, which were mainly due to anemia (190/213, 89.20%) and hypoalbuminemia (154/213, 72.30%). Overall, 54 patients (25.35%) underwent a clinical intervention, 18 patients received blood transfusion, and 42 patients received albumin supplementation. Factors associated with blood transfusion were long operative time and low preoperative hemoglobin levels. Factors associated with albumin supplementation were long operative time and low preoperative albumin levels. Of the 33 patients with abnormal postoperative creatinine levels, 7 patients underwent a clinical intervention. For electrolyte abnormalities, sodium supplementation was not given for hyponatremia, three patients received potassium supplementation, and one patient received calcium supplementation. CONCLUSIONS: This study demonstrated a high incidence of abnormal postoperative laboratory tests and a significant clinical intervention rate in patients who underwent THA for hip fracture in a semi-urgent clinical setting, which indicates that routine laboratory tests after THA for hip fracture are still necessary for patients with certain risk factors. LEVEL OF EVIDENCE: Level III. Trial registration Clinical trial registry number ChiCTR1900020690.

Hospital readmission after anterior cruciate ligament reconstruction: protocol for a systematic review and meta-analysis.

INTRODUCTION: Anterior cruciate ligament (ACL) injury is one of the most common injuries of the knee. ACL reconstruction (ACLR) has been widely performed as a safe and effective treatment for ACL injuries. As there is an increasing trend in the incidence of ACL injury, hospital readmission after ACLR has attracted renewed attention for the financial burden to both patients and the healthcare system. However, information about hospital readmission after ACLR remains fragmented. Therefore, we plan to systematically review the literature to investigate the rate of, causes and risk factors for hospital readmission after ACLR, and summarise interventions to reduce hospital readmission. This article is to provide the protocol for an upcoming systematic review and meta-analysis on this important issue. METHODS AND ANALYSIS: Reporting of this protocol follows the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) checklist. Electronic databases, including PubMed, Embase and the Cochrane Library, will be systematically searched from inception to June 2020. No language restrictions will be applied. Studies will be included if they reported hospital readmission or explored the associated potential causes and risk factors for hospital readmission after ACLR. The primary outcome will be the number and time frame of hospital readmission after ACLR. Secondary outcomes will be reasons for readmission, number and types of complications, risk factors for readmission and preventive measures for readmission after ACLR. Quality assessments will be performed by using the Newcastle-Ottawa Scale (NOS). If possible, study results will be summarised in a forest plot, and heterogeneity will be tested by using the Cochran's Q and I2 statistics. ETHICS AND DISSEMINATION: No ethical approval is required because our study is not related to patients or animals. The results will be published in a peer-reviewed journal. PROSPERO REGISTRATION NUMBER: CRD42020058624.

Approximating the maximum tibial coverage in total knee arthroplasty does not necessarily result in implant malrotation.

Traditionally, the practice of the tibial component placement in total knee arthroplasty has focused on achieving maximum coverage without malrotation. However, the concept of maximizing coverage has not been well defined or researched and yet biased results are often produced. This study aimed to evaluate the effect of a prioritizing maximum coverage positioning strategy on the rotational alignment by using a strict computer algorithm. Computed tomographic scans of 103 tibial specimens were used to reconstruct three-dimensional tibia models. A virtual surgery was performed to generate the resection plane with a posterior slope of 7° on the proximal tibia. Symmetrical and anatomical tibial components were placed and analyzed with an automated program designed for approximating the maximum coverage based on the coherent point drift algorithm. We found that the average tibial coverage achieved across all specimens and implants was 85.62 ± 3.65%, ranging from 83.64 ± 4.10% to 86.69 ± 3.07%. When placed for maximal tibial coverage, the mean degree of rotation related to the Insall line was - 0.73° ± 4.53° for all subjects, 23% of the tibial components were malrotated. The average percentage position of the baseplate anteroposterior axis over the patellar tendon was 26.95 ± 14.71% from the medial edge. These results suggest that with specific design and proper placement of the component, approximating the maximum tibial coverage in total knee arthroplasty does not necessarily result in implant malrotation. The current tibial baseplates have shown good performance on the coverage when aligned parallel to the Insall line with the anteroposterior axis positioned between the medial 1/3 and medial 1/6 of the patella tendon.

Efficacy of a three-day prolonged-course of multiple-dose versus a single-dose of tranexamic acid in total hip and knee arthroplasty.

BACKGROUND: The application of tranexamic acid (TXA) in total hip arthroplasty (THA) and total knee arthroplasty (TKA) has brought momentous changes in blood management. However, the optimal regimen of TXA has not yet been identified. This study aimed to compare the efficacy of a three-day prolonged-course of multiple-dose of TXA with a single pre-operative dose of TXA in patients who undergo THA and TKA. METHOD: We retrospectively analyzed two groups of consecutive patients who received primary unilateral THA and TKA from 2015 to 2017. One group received a three-day prolonged-course of multiple-dose of TXA, while another group received a single-dose of TXA. The primary outcomes included the changes in hemoglobin (Hb), estimated total blood loss (TBL), and transfusion rate; the secondary outcomes included the platelet (PLT) counts, inflammatory markers, and fibrinolysis parameters. RESULTS: A total of 193 THA and 166 TKA procedures were included for comparison. Compared with the patients who received a single-dose of TXA, the patients who received a three-day prolonged-course of multiple-dose of TXA had smaller post-operative drops in Hb levels, which led to consistently significantly higher Hb levels in both THA and TKA. Therefore, the use of multiple-dose of TXA was associated with significantly lower maximum Hb drops and estimated TBL in both THA (24.58±11.43 vs. 30.38±11.33 g/L, P=0.001; 685.88±412.02 vs. 968.94±479.9 mL, P<0.0001) and TKA (18.04±9.75 vs. 27.24±10.99 g/L, P<0.0001; 497.35±291.03 vs. 816.51±354.38 mL, P<0.0001), and marginally reduced transfusion requirements (THA: 1/65 vs. 10/128; TKA: 0/70 vs. 2/96). The multiple-dose group also showed higher PLT counts, continuously reduced inflammatory responses, and significantly and durably attenuated fibrinolytic responses. CONCLUSIONS: A three-day prolonged-course of multiple-dose of TXA was consistently effective in reducing post-operative Hb drops, estimated TBL, inflammatory responses, and fibrinolytic responses, which could be recommended for clinical practice. However, these findings need to be confirmed by prospective studies.

Are Routine Postoperative Laboratory Tests Necessary After Primary Total Hip Arthroplasty?

BACKGROUND: Recently, the practice of ordering routine postoperative laboratory tests in primary total hip arthroplasty (THA) has been challenged. This study aimed to evaluate the utility of routine postoperative laboratory tests after primary elective THA in an Asian population and identify the risk factors associated with abnormal postoperative laboratory test-related intervention. METHODS: We retrospectively reviewed 395 consecutive patients who underwent primary elective THA at a single tertiary academic center. Patient clinical information and laboratory test results were collected for analysis. RESULTS: A total of 349 (88.4%) patients had abnormal postoperative laboratory test results; most patients had anemia and hypoalbuminemia. Twenty-seven (6.8%) patients received clinical intervention. Of the 307 (77.7%) patients with postoperative anemia, 7 patients received blood transfusion. Factors associated with transfusion were female gender, low body mass index, long operation time, and low preoperative hemoglobin levels. Of the 149 (37.7%) patients with postoperative hypoalbuminemia, 16 received albumin supplementation. Factors associated with albumin supplementation were female gender, long operation time, and low preoperative albumin levels. Although 36 patients had abnormal postoperative creatinine, only 1 patient required specialist consultation. For electrolyte abnormalities, hyponatremia was noted; however, no patient received sodium supplementation. Moreover, 14 patients developed hypokalemia, of which 6 required potassium supplementation; 163 patients had hypocalcemia, of which 2 received calcium supplementation. CONCLUSION: Routine laboratory tests after primary elective THA are unnecessary for most of the patients in modern clinical practice. However, for those with identified risk factors, postoperative laboratory tests still should be performed.

Femoral Stress Changes after Total Hip Arthroplasty with the Ribbed Prosthesis: A Finite Element Analysis.

BACKGROUND: A total hip reconstruction is related to the stress distribution throughout the prosthesis, cement, and femur. Researches on reducing the stress in all components to minimize the risk of failure are of great significance. The objective of our study was to determine the biomechanical variation in overall femoral stress and periprosthetic femoral stress distribution after implantation with the Ribbed anatomic prosthesis. METHODS: Three-dimensional finite element models of intact femur and Ribbed prosthesis were developed according to the morphology, while the hip joint loading and the strength of related muscles were applied in the models. The overall stress changes of the intact femur before and after the implantation were analyzed, and the periprosthetic stress distribution especially in the proximal region of the femur was quantified. RESULTS: As a result, the overall stress pattern of the femur did not change after the implantation compared with the intact femur. The region of peak stress value was located in the middle and lower segments of the full length femur, but the stress value level decreased. The final prosthesis resulted in a significant decrease in the equivalent stress level of the periprosthetic bone tissue, and the most severe area appeared at the endmost posterior quadrant. The stress shielding ratio of the Ribbed prosthesis was 71.6%. The stress value level gradually increased towards the distal part of the prosthesis and recovered to physiological level at the end of the prosthesis. CONCLUSIONS: The Ribbed prosthesis can cause significant stress shielding effect in the proximal femur. These results may help optimize prosthetic design to reduce stress shielding effect and improve clinical outcomes.