Janus-Structured Microgel Barrier with Tissue Adhesive and Hemostatic Characteristics for Efficient Prevention of Postoperative Adhesion.

Postoperative adhesion (POA) is a common and serious complication following various types of surgery. Current physical barriers either have a short residence time at the surgical site with a low tissue attachment capacity or are prone to undesired adhesion formation owing to the double-sided adhesive property, which limits the POA prevention efficacy of the barriers. In this study, Janus-structured microgels (Janus-MGs) with asymmetric tissue adhesion capabilities are fabricated using a novel bio-friendly gas-shearing microfluidic platform. The anti-adhesive side of Janus-MGs, which consists of alginate, hyaluronic acid, and derivatives, endows the material with separation, lubrication, and adhesion prevention properties. The adhesive side provided Janus-MGs with tissue attachment and retention capability through catechol-based adhesion, thereby enhancing the in situ adhesion prevention effect. In addition, Janus-MGs significantly reduced blood loss and shortened the hemostatic time in rats, further reducing adhesion formation. Three commonly used rat POA models with different tissue structures and motion patterns are established in this study, namely peritoneal adhesion, intrauterine adhesion, and peritendinous adhesion models, and the results showed that Janus-MGs effectively prevented the occurrence of POA in all the models. The fabrication of Janus-MGs offers a reliable strategy and a promising paradigm for preventing POA following diverse surgical procedures.

Effect of Preoperative Carbohydrate Loading on Postoperative Recovery of Individuals Who Have Type 2 Diabetes After Total Knee Arthroplasty: A Randomized Controlled Trial.

BACKGROUND: Many individuals undergoing surgery involving general anesthesia are asked to fast for a prolonged period to ensure perioperative safety, yet this can initiate stress reactions and insulin resistance, harming postoperative recovery. Such fasting may be particularly problematic for those who have type 2 diabetes. Here, we assessed how giving such individuals' oral carbohydrates before total knee arthroplasty can affect outcomes. METHODS: We randomized 90 patients who had non-insulin-dependent type 2 diabetes mellitus who were scheduled for elective total knee arthroplasty at one medical center between April 2022 and January 2023 to receive oral carbohydrates at two or four hours before surgery or to receive a carbohydrate-free "placebo" drink at four hours before surgery. The three groups were compared in terms of postoperative blood glucose, insulin resistance, ß cell activity, postoperative wound complications, and other clinical outcomes. RESULTS: The group who received oral carbohydrates at two or four hours before surgery showed significantly lower insulin resistance than the placebo group (group at two hours, 9.0 ± 3.4; group at four hours, 15.8 ± 6.9 versus placebo, 30.9 ± 10.5, P < 0.001) and lower ß cell activity (207.7 ± 106.7%; group at four hours, 243.2 ± 114.9% versus 421.5 ± 209.3%, P < 0.001). Those groups were also significantly less likely than the placebo group to experience preoperative hunger or postoperative hyperglycemia. Among patients who received oral carbohydrates, those who received them two hours before surgery showed significantly lower insulin resistance and better glycemic control on postoperative day 1 than those who received carbohydrates four hours before surgery. None of the subjects developed intraoperative aspiration or experienced severe postoperative complications. CONCLUSION: Oral carbohydrates at two to four hours before total knee arthroplasty are safe and can significantly alleviate preoperative hunger while mitigating postoperative insulin resistance and improving glycemic control in patients who have non-insulin-dependent type 2 diabetes mellitus.

Symptomatic Benign Prostatic Hyperplasia: An Optimizable Risk Factor for Periprosthetic Joint Infection After Elective Primary Total Knee Arthroplasty.

BACKGROUND: Whether symptomatic benign prostatic hyperplasia (sBPH), which is common among middle-aged and older men, affects the risk of periprosthetic joint infection (PJI) remains controversial. The present study explored this question among men undergoing total knee arthroplasty and total hip arthroplasty (TKA and THA). METHODS: We retrospectively analyzed medical data from 948 men who underwent primary TKA or THA at our institution between 2010 and 2021. We compared the incidence of postoperative complications such as PJI, urinary tract infection (UTI), and postoperative urinary retention (POUR) between 316 patients (193 hips and 123 knees) who did and 632 patients who did not have sBPH; the 2 groups of patients were matched to each other in a 1:2 ratio based on numerous clinical demographic variables. In the subgroup analyses, we stratified sBPH patients according to whether they began anti-sBPH medical therapy prior to arthroplasty. RESULTS: PJI following primary TKA was significantly more common among sBPH patients than among patients who did not have sBPH (4.1 vs 0.4%; P = .029), as were UTI (P = .029), and POUR (P < .001). Patients who had sBPH also had an increased incidence of UTI (P = .006) and POUR (P < .001) following THA. Among sBPH patients, those who started anti-sBPH medical therapy before TKA suffered significantly lower incidence of PJI than those who did not. CONCLUSION: Symptomatic benign prostatic hyperplasia is a risk factor for PJI after primary TKA among men, and starting appropriate medical therapy before surgery can reduce the risk of PJI following TKA and postoperative urinary complications following TKA and THA.

Plasma fibrinogen: a sensitive biomarker for the screening of periprosthetic joint infection in patients undergoing re-revision arthroplasty.

BACKGROUND: Although serum C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), plasma fibrinogen and neutrophil-lymphocyte ratio (NLR) are promising biomarkers for screening PJI in patients undergoing revision arthroplasty, their efficacy with respect to re-revision arthroplasty remains unclear. METHODS: We included patients who underwent re-revision arthroplasty at our hospital during 2008-2020, and stratified them into two groups whether they had been diagnosed with PJI (infected) or aseptic failure (non-infected) according to the 2013 International Consensus Meeting criteria. We evaluated the diagnostic performance of CRP, ESR, fibrinogen and NLR, both individually and in combinations, based on sensitivity, specificity, and area under the receiver operating characteristic curve. RESULTS: Of the 63 included patients, 32 were diagnosed with PJI. The area under the ROC curve was 0.821 for CRP, 0.794 for ESR, 0.885 for fibrinogen and 0.702 for NLR. CRP gave a sensitivity of 87.5% and specificity of 74.2% with an optimal predictive cut-off of 8.50 mg/mL. ESR gave a sensitivity of 81.3% and specificity of 71.0% with an optimal predictive cut-off of 33 mm/h. Plasma fibrinogen gave a comparatively higher sensitivity of 93.8% and specificity of 77.4% with an optimal predictive cut-off of 3.55 g/L, while NLR gave a moderate sensitivity of 84.4% but low specificity of 54.8% with an optimal predictive cut-off of 2.30. The combination of fibrinogen and CRP gave a high AUC of 0.897, an acceptable sensitivity of 75% and a high specificity 93.5%. CONCLUSIONS: Plasma fibrinogen is a cost-effective, convenient biomarker that can be used to rule out PJI in patients scheduled for re-revision arthroplasty. In combination with CRP, it may be effective in diagnosing PJI in such patients.

Evaluation of the rate of post-operative dislocation in patients with ipsilateral valgus knee deformity after primary total hip arthroplasty.

PURPOSE: There is scant literature on the evaluation of dislocation after total hip arthroplasty (THA) in patients with ipsilateral valgus knee deformity. This study aimed to investigate the post-operative dislocation rate in patients with valgus knee deformity who underwent ipsilateral THA and identify whether ipsilateral valgus knee deformity increases the dislocation rate after THA. METHODS: We retrospectively reviewed patients with valgus knee deformity who underwent ipsilateral THA in our institution from January 2016 to December 2018. Each hip with ipsilateral valgus knee deformity was matched with a hip without valgus knee deformity according to sex, affected side, and date of surgery. The primary outcome was the dislocation rate after THA. Univariate analyses were initially used to compare data between the dislocation group and the non-dislocation group. Independent risk factors for dislocation were determined using multivariate logistic regression. RESULTS: There were 257 THAs with ipsilateral valgus knee deformity (valgus knee group) and 257 THAs without valgus knee deformity (control group). The valgus knee group showed a significantly higher dislocation rate than the control group (9.7% versus 1.6%, p < 0.001). Older age (p = 0.020) and malposition of the acetabular cup (p = 0.048) were independent risk factors of post-operative dislocation. CONCLUSION: Patients with valgus knee deformity have a higher risk of dislocation after ipsilateral THA. If ipsilateral THA and total knee arthroplasty must be performed successively, total knee arthroplasty may have an earlier priority than THA.

Safety and Effectiveness of Robotic-Arm Assisted Total Knee Arthroplasty.

OBJECTIVE: We investigated the advantages of robotic arm-assisted total knee arthroplasty (raTKA) over conventional manual TKA (cmTKA) by comprehensively comparing patients who received raTKA and cmTKA in terms of postoperative pain, function, imaging assessment, and trauma to the body. This study investigated the efficacy and safety of raTKA in patients using the YUANHUA-TKA system. METHODS: In a prospective, randomized single-blind trial, 60 patients undergoing primary unilateral TKA from October 2020 to December 2020 were randomly assigned to either raTKA or cmTKA. Clinical evaluation, including the time of osteotomy and prosthesis model testing, the total operation time, the visual analogue scale at rest, VAS in motion, opioid consumption, white blood cell count, neutrophil ratio, erythrocyte sedimentation rate, C-reactive protein (CRP), passive and active range of motion (pROM, aROM), Western Ontario and McMaster Universities Arthritis Index (WOMAC [stiffness, pain, and function]) score, gait analysis, keen society score (KSS), adverse events, and blood loss were collected by the project nurse, as well as the imaging evaluation, including the lateral tibia component angle (LTC), frontal femoral component angle, frontal tibia component angle (FTC), lateral femoral component angl, and hip-knee-ankle angle (HKA). The student t-test (or the Wilcoxon signed-rank test) and the χ2-test (or the Fisher exact test) were used to determine differences in categorical variables. RESULTS: No significant difference was found between the two groups in pain throughout the whole follow-up period. On the third day postoperatively, the erythrocyte sedimentation rate in the cmTKA group was significantly higher (p = 0.02), as well as the CRP (p = 0.04). No significant difference was found in the WOMAC stiffnes score or pROM. However, the aROM and the flexion range when walking (FRW) were significantly better in the raTKA group throughout the trial (p < 0.05). The KSS at the 1-month follow-up and the WOMAC function score at the 1-year follow-up were both significantly better in the raTKA group (p < 0.05). The HKA and the LTC in the raTKA group closer to the ideal angle, and the difference between the groups was significant (p < 0.05). The total operation time of the raTKA group was significantly longer (p = 0.001). The intraoperative blood loss had no significant difference in the two groups. CONCLUSION: Compared with cmTKA, raTKA with the YUANHUA robot not only avoids extra pain and trauma in patients but promises better functional recovery and improves the accuracy of the prosthesis position and axial alignment reconstruction.

The Long-term Efficacy of Total Knee Arthroplasty on End-stage Kashin-Beck Disease of the Knee in Highland Tibetan Areas Patients: A Retrospective Study with 10-Year Follow-up.

OBJECTIVE: Despite the established success of total knee arthroplasty (TKA) with end-stage osteoarthritis, there is a notable scarcity of research on its long-term outcomes in individuals suffering from end-stage Kashin-Beck disease (KBD). This retrospective study aimed to assess the long-term outcomes and effectiveness of clinical function, quality of life, and complications of TKA and end-stage KBD patients in Tibetan highland areas. METHODS: The retrospective cohort included 43 KBD patients, comprising a total of 59 knees, who had undergone TKA at West China Hospital, Sichuan University between 2008 and 2021. Patients were subsequently followed up for a minimum of 3 years, and received rigorous radiological and clinical assessments at 3, 6, and 12 months post surgery, followed by annual examinations thereafter. The evaluation included various efficacy indices, including visual analogue scale (VAS) scores, hospital for special surgery (HSS) scores, functional score for adult Tibetans with Kashin-Beck disease (FSAT-KBD), and radiographic findings. Comparison of indicators within the same group was conducted using one-way repeated-measures analysis of variance or paired sample t-tests, whereas between-group differences were compared using an independent t-test. RESULTS: Throughout the average follow-up duration of 10.8 years, patients experienced a substantial reduction in knee pain and noteworthy functional improvement. The VAS scores decreased significantly from 77.47 ± 4.12 mm before surgery to 10.91 ± 1.97 mm after surgery, indicating considerable alleviation of knee pain. The HSS scores improved markedly, increasing from 44.26 ± 4.95 preoperatively to 91.26 ± 4.37, indicating enhanced joint function. Similarly, the FSAT-KBD exhibited positive progression, increasing from 25.90 ± 3.12 to 36.95 ± 3.54. Importantly, at the last follow-up, none of the patients presented with periprosthetic infection, prosthesis loosening, or periprosthetic fracture. CONCLUSION: At long-term follow-up, compared with patients in the preoperative period, patients in Tibetan highland areas with KBD of the knee who underwent TKA benefited from a significant reduction in pain, improvement in joint function, and satisfactory improvement in quality of life.

Outcomes of culture-negative or -positive periprosthetic joint infections: A systematic review and meta-analysis.

OBJECTIVES: This study overviewed the current database of studies on periprosthetic joint infections (PJIs) to compare outcomes and antibiotic side effects in culture-negative or culture-positive PJIs and assess treatment options for culture-negative PJIs. PATIENTS AND METHODS: A systematic review and meta-analysis was undertaken using studies published before July 2022 in MEDLINE, EMBASE, and Cochrane Library. All studies comparing treatment of culture-negative or -positive PJIs were included. Afterward, the infection control rate, periprosthetic or spacer fracture, hip joint or spacer dislocation, and antibiotic side effects in different treatment methods of PJI were analyzed. RESULTS: Eleven studies involving 1,747 patients were included. Most studies clearly defined the infection control criteria: no pain or swelling, no wound drainage, normal serology, and normal radiographic findings. Patients were followed until treatment failure, death, or until the last clinical visit without evidence of treatment failure. The two types of PJIs did not differ significantly in infection control rates (culture-negative PJI 79.2% vs. culture-positive PJI 76.6%; odds ratio [OR]=1.20, 95% confidence interval [CI]: 0.84 to 1.70), either after all types of surgical treatment or after two-stage revision arthroplasty (OR=1.12, 95% CI: 0.72 to 1.75), single-stage revision arthroplasty (OR=0.51, 95% CI: 0.19 to 1.37), or debridement, antibiotics, and implant retention (OR=0.88, 95% CI: 0.50 to 1.54). Similarly, we did not find differences in periprosthetic or spacer fracture and hip joint or spacer dislocation. For culture-negative PJIs, the infection control rate was 85.2% after two-stage revision arthroplasty, 90.6% after single-stage revision arthroplasty, and 69.7% after debridement, antibiotics, and implant retention. Data pooled from three studies showed higher incidence of antibiotic side effects for culture-negative PJIs. CONCLUSION: The clinical outcomes of one-stage revision and two-stage revision are comparable. Therefore, both of them can be considered in surgical treatment for culture-negative PJIs. In addition, limited data showed a higher incidence of antibiotic side effects in culture-negative PJIs.

Perioperative Short-Term Glucocorticoids Do Not Increase Incidence of Complications after Total Joint Arthroplasty in Patients with Rheumatoid Arthritis.

OBJECTIVES: The safety and analgesic efficacy of perioperative glucocorticoids have been established for patients without rheumatoid arthritis. Therefore, our study aims to investigate whether similar benefits can be observed in patients with rheumatoid arthritis undergoing total joint arthroplasty. Specifically, we aim to explore the impact of perioperative glucocorticoid use on postoperative complications, opioid consumption, incidence of hypotension, hyperglycemia, 30-day mortality, and 90-day re-admission in this patient population. METHODS: Approval for the study protocol was obtained from the Medical Research Ethics Committee at Sichuan University, aligning with the principles outlined in the Declaration of Helsinki. We retrospectively analyzed a consecutive series of patients with rheumatoid arthritis who underwent total joint arthroplasty at our medical center between November 2009 and April 2021 and who were not on chronic glucocorticoid therapy before surgery. Those who received glucocorticoids at any time during hospitalization were compared to those who did not in terms of acute complications within 90 days after surgery as well as postoperative rescue opioid consumption, hypotension, and hyperglycemia during hospitalization. The two groups were also compared in terms of overall duration of hospitalization, all-cause mortality within 30 days, and readmission for any reason within 90 days. Continuous data were assessed for significance using the independent-samples t test. Categorical data were assessed using the Pearson chi-squared test. RESULTS: Of the 849 patients included in the analysis, 598 administered perioperative glucocorticoids and 251 did not. Prior to surgery, the two groups did not differ significantly in any clinicodemographic variable that we examined. The incidence of acute postoperative complications (2.3% vs. 4.0%, p = 0.187) and acute postoperative infection (2.0% vs. 2.8%, p = 0.482) was comparable between those who received perioperative glucocorticoids and those who did not, but the former group exhibited a significantly lower incidence of rescue opioid use (17.9% vs. 44.6%, p < 0.001) as well as significantly lower total rescue opioid consumption (4.7 ± 2.1 mg vs. 8.9 ± 4.6 mg, p < 0.001). However, the two groups showed similar incidences of postoperative hypotension, hyperglycemia, 30-day mortality, and 90-day re-admission. CONCLUSION: Perioperative glucocorticoids may reduce the need for rescue opioids after total joint arthroplasty of rheumatoid arthritis patients, without increasing the incidence of acute complications, hypotension or hyperglycemia.

Association between disease activity of rheumatoid arthritis and risk of complications following total hip arthroplasty: a retrospective cohort study.

BACKGROUND: Identifying rheumatoid arthritis patients at higher risk of complications after total hip arthroplasty could make perioperative management more effective. Here we examined whether disease activity is associated with risk of such complications. METHODS: We retrospectively analyzed data for 337 rheumatoid arthritis patients at our medical center who underwent primary total hip arthroplasty. Rheumatoid arthritis patients were categorized according to the simplified disease activity index (SDAI), the values of which at admission and follow-up were averaged together. Logistic regression was used to examine associations of mean SDAI with rates of dislocation, infection, periprosthetic fracture and aseptic loosening. As controls, 337 osteoarthritis patients who did not have systemic inflammation and who underwent the same procedure were matched across numerous clinicodemographic variables. RESULTS: Among the 337 rheumatoid arthritis patients, 38 (11.3%) had postoperative complications, the rates of which varied significantly from 0 to 17.5% (p = 0.003) among the four subgroups whose disease activity based on mean SDAI was categorized as high, moderate, low or in remission. Each 1-unit increase in mean SDAI was associated with a significant increase in risk of postoperative complications (OR 1.015, 95% CI 1.001-1.029, p = 0.035). Across all rheumatoid arthritis patients, rate of complications did not differ significantly between patients who received disease-modifying anti-rheumatic drugs or other treatments. Rates of dislocation, of infection or of all postoperative complications combined were significantly lower among osteoarthritis controls than among rheumatoid arthritis patients. CONCLUSION: Greater mean SDAI is associated with higher risk of dislocation, infection and composite postoperative complications after total hip arthroplasty in rheumatoid arthritis patients. These patients show a significantly higher rate of postoperative complications than osteoarthritis patients, likely reflecting the influence of systemic inflammation. Disease activity should be reduced as much as possible in rheumatoid arthritis patients before they undergo total hip arthroplasty.

Comparison of Outcomes in Obese Patients after Total Knee Arthroplasty with Neutral or Mild Varus: A Retrospective Study with 8-Year Follow-Up.

OBJECTIVES: Residual varus after total knee arthroplasty (TKA) can affect functional outcomes, which may worsen in the presence of obesity. However, no studies were found to compare the outcomes of obese patients involving postoperative residual mild varus or neutral. The aim of this study was to compare postoperative complications and prosthesis survival, and functional outcomes for knees of obese patients with neutral or mild varus after TKA. METHODS: We retrospectively reviewed 188 consecutive obese patients (body mass index ≥30 kg/m2) at our hospital who underwent TKA due to varus knee osteoarthritis from January 2010 to December 2015. The mechanical hip-knee-ankle axis angle was measured in all patients at admission and discharge. Knee functions were retrospectively assessed based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society Knee Score (KS-KS), Knee Society Function Score (KS-FS), Forgotten Joint Score (FJS), and range of motion (ROM). Continuous data were compared between knees with neutral or mild varus alignment using analysis of Student's t test or variance or the Kruskal-Wallis test as appropriate. For multiple comparisons of outcomes, we used Bonferroni-Dunn method to adjust p-values. Categorical data were compared using the chi-squared test. RESULTS: Of the 156 knees in 137 obese patients who completed follow-up for a mean of 8.32 ± 1.47 years, 97 knees were corrected from varus to neutral and 54 knees were kept in mild residual varus. Patients with mild varus knees had significantly WOMAC (8.25 ± 8.637 vs. 14.97 ± 14.193, p = 0.009) and better FJS (86.03 ± 15.607 vs. 70.22 ± 30.031, p = 0.002). The two types of knees did not differ significantly in KS-KS, KS-FS, or ROM. Although one patient with a neutral knee had to undergo revision surgery, there was no significant difference between two groups. CONCLUSIONS: For obese patients with osteoarthritis, preservation of residual varus alignment after TKA can improve functional outcomes without compromising prosthesis survival.

Analgesic efficacy of adding the IPACK block to multimodal analgesia protocol for primary total knee arthroplasty: a meta-analysis of randomized controlled trials.

BACKGROUND: Total knee arthroplasty (TKA) is a standard treatment for end-stage degenerative knee disease. Most patients will experience moderate-to-severe postoperative knee pain, significantly affecting rehabilitation. However, controversy remains regarding the efficacy of adding the interspace between the popliteal artery and capsule of the knee (IPACK) into multimodal analgesia protocol. METHODS: PubMed, Medline, Embase, Cochrane Library, and other databases were searched from inception to February 1, 2021. Studies comparing patients receiving IPACK to patients not receiving IPACK were included. The primary outcome was the ambulation pain score on a visual analogue scale (VAS) of 0-10. Secondary outcomes included pain score at rest, morphine usage, functional recovery, clinical outcomes, and complications. RESULTS: Thirteen RCTs involving 1347 knees were included. IPACK was associated with lower ambulation pain scores (weight mean difference [WMD] - 0.49, 95% confidence interval [CI] - 0.72 to - 0.26). The benefits were observed from 2 to 4 h, 6 to 12 h, and beyond one week. IPACK also significantly reduced rest pain scores (WMD - 0.49, 95% CI - 0.74 to - 0.24), and the benefits were observed from 6 to 12 h and beyond one week. IPACK reduced the overall morphine consumption (WMD - 2.56, 95% CI - 4.63 to - 0.49). Subgroup analysis found reduced oral morphine consumption from 24 to 48 h (WMD - 2.98, 95% CI - 5.71 to - 0.24) and reduced rate of morphine requirement from 12 to 24 h (relative risk [RR] = 0.51, 95% CI 0.31 to 0.83). Functional recovery outcomes regarding ambulation distances (on the second postoperative day [POD2]) (WMD = 1.74, 95% CI 0.34 to 3.15) and quadriceps muscle strength (at 0 degree) (WMD = 0.41, 95% CI 0.04 to 0.77) favored IPACK. And IPACK reduced the rate of sleep disturbance (on POD 1) (RR = 0.39, 95% CI 0.19 to 0.81). There was no significant difference in the other outcomes. CONCLUSIONS: Moderate-level evidence confirmed that IPACK was related to better results in pain scores, morphine usage, and functional recovery without increasing the risk of complications. REGISTRATION: CRD42021252156.

Effect of tourniquet use on blood loss, pain, functional recovery, and complications in robot-assisted total knee arthroplasty: a prospective, double-blinded, randomized controlled trial.

BACKGROUND: Robot-assisted total knee arthroplasty (TKA) has been largely studied to confirm its advantages in terms of accurate component positioning, microembolus formation, less blood loss, and so on, but is currently usually performed under tourniquet due to its longer operative time than conventional TKA. The aim of this study was to estimate the effects of tourniquet use in robot-assisted TKA on blood loss, pain, functional recovery, and complications. METHODS: Patients scheduled for robot-assisted TKA were prospectively randomized into a tourniquet or non-tourniquet group (each n = 14). The primary outcome measure was blood loss. The secondary outcome measures were operation time; visual analog scale (VAS) pain scores; time to achieve the first straight-leg raise; swelling of the thigh, knee, and calf; range of motion; Hospital for Special Surgery score; length of stay; and postoperative complications. RESULTS: There was no significant difference in total blood loss between the tourniquet and non-tourniquet groups (738.57 ± 276.158 vs. 866.85 ± 243.422 ml, P = 0.061). The tourniquet group showed significantly lower intraoperative blood loss (P < 0.001), but higher hidden blood loss (P = 0.002). The non-tourniquet group showed better knee range of motion on postoperative days (PODs) 1-3 (all P < 0.001), less thigh swelling on PODs 2 and 3 (P < 0.05), earlier straight-leg raising (P = 0.044), and shorter length of stay (P = 0.044). Thigh pain VAS score at 1 month after surgery was significantly greater in the tourniquet group (P < 0.001), as was knee pain during activity and at rest on PODs 2-3 (all P < 0.05). The tourniquet group also showed a significantly higher rate of tension blisters (28.8% vs. 7.1%, P = 0.038). CONCLUSIONS: Tourniquet use during robot-assisted TKA does not reduce total blood loss, and it appears to increase postoperative pain, aggravate muscle injury, and prolong postoperative recovery. Trial registration ChiCTR, ChiCTR2100041800. Registered 5 January 2021, http://www.chictr.org.cn/index.aspx .

Effect of body mass index on postoperative mechanical alignment and long-term outcomes after total knee arthroplasty: a retrospective cohort study of 671 knees.

Background: A high body mass index (BMI) is associated with increased rates of complications after total knee arthroplasty (TKA). However, no study has examined the effect of BMI on lower limb alignment using the World Health Organization's (WHO) BMI classification. We believe that the WHO's BMI classification allows a uniform standard worldwide. We sought to investigate the potential association between a high BMI and the incidence of postoperative misalignment. We also evaluated whether a higher BMI is associated with worse clinical function. Methods: We retrospectively reviewed the data of 671 patients who underwent primary TKA for varus osteoarthritis between January 2010 and December 2015. The patients were divided into the following 5 groups based on their BMI: normal weight (<25.0 kg/m2), overweight (25.0-29.9 kg/m2), class I obese (30.0-34.9 kg/m2), class II obese (35-39.9 kg/m2), and class III obese (>40 kg/m2). Both weight and height were measured by nurses on admission. Patients' preoperative HKA, gender, age, and side of surgery were collected as baseline. All the patients underwent standing, weight-bearing, full-length radiography before and after surgery to measure the mechanical hip-knee-ankle angle (HKA). We followed up patients by telephone. Among the BMI subgroups, we compared the knee function scores, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society-Knee Score (KS-KS), Knee Society-Function Score (KS-FS), Forgotten Joint Score (FJS), and range of motion (ROM). A multivariate linear regression analysis and a logistic regression was conducted to examine the outcomes. Results: The study had a mean follow-up period of 8.16 years. The multivariate and logistic regression analyses revealed that preoperative alignment (P=0.002) and a higher BMI (P=0.015) were associated with a higher risk of postoperative misalignment. The WOMAC scores were higher in the normal and overweight groups than the other groups (P=0.022). The FJS and KS-KS gradually decreased as BMI increased. Conclusions: A higher BMI is associated with a greater risk of misalignment and worse long-term clinical outcome after TKA. When treating patients with high BMI, we should pay more attention to the adjustment of lower limb alignment intraoperatively.

Robotic arm-assisted total knee arthroplasty improves preoperative planning and intraoperative decision-making.

BACKGROUND: The reliability of robotic arm-assisted total knee arthroplasty (RA-TKA) has been previously reported. In this study, we evaluated the predictive accuracy of the RA-TKA system in determining the required bone resection and implant size preoperatively and its effect on intraoperative decision-making. METHODS: Data on the outcomes of RA-TKA procedures performed in our department were prospectively collected. A three-dimensional model of the femur, tibia, and fibula was reconstructed using standard computed tomography (CT) images. The model was used preoperatively to predict bone required resection for the femur and tibia and implant size. Intraoperatively, the images were registered to the local anatomy to create a patient-specific model for decision-making, including real-time measurement of the medial-to-lateral difference in the extension/flexion gap and TKA component alignment. Differences between predicted and real bone resections and implant size were evaluated, and the post-TKA mechanical axis of the lower limb and difference in medial-to-lateral flexion/extension gap were measured. RESULTS: The analysis was based on the data of 28 patients who underwent TKA to treat severe osteoarthritis. The RA-TKA system successfully predicted the femoral and tibial component within one implant size in 28/28 cases (100%). For the 168 bone resections performed, including both femoral and tibial cuts, the resection was within 1 mm of the predicted value in 120/168 (71%) of the cuts. The actual versus predicted bone resection was statistically different only for the lateral tibial plateau (p = 0.018). The medial-to-lateral gap difference was between - 1 and 1 mm, except in one case. The achieved lower limb alignment was accurate overall, with the alignment being within < 1.0° of the neutral mechanical axis in 13/28 cases (46%) and within < 3.0° in 28/28 cases (100%). CONCLUSIONS: The RA-TKA system provided considerable pre- and intraoperative surgical assistance to achieve accurate bone resection, appropriate component sizing, and postoperative alignment after RA-TKA.