The Effect of Air Tourniquet on Interleukin-6 Levels in Total Knee Arthroplasty

The tourniquet's effects on skeletal muscle during total knee arthroplasty

This study investigates the impact of perioperative tourniquet on skeletal muscle cells during total knee arthroplasty (TKA) and its effects on the gene expression of apoptotic, inflammatory, and angiogenic pathways. The randomized controlled trial included 44 patients undergoing TKA. The patients were randomized to undergo surgery with (n = 23) or without (n = 21) tourniquet. The tourniquet was inflated before skin incision and deflated before wound closure in the tourniquet group. Biopsies from the lateral vastus muscle were obtained from both groups before wound closure and 8 weeks after surgery. The messenger ribonucleic acid (mRNA) expression and protein levels of angiopoietin-like 4 (ANGPTL4), Hypoxia-inducible Factor 1α, and Vascular Endothelial Growth Factor Alpha (VEGF-A) in the biopsies were examined by reverse transcription-quantitative polymerase chain reaction and tissue microarray, respectively. Differences in mean values (ΔCt for mRNA expression and staining positivity for protein expression) were compared with t-tests. The apoptotic marker BID and the angiogenic marker VEGF-A were significantly lower in the tourniquet group compared to the control group (p = 0.03, p = 0.047). However, there was a significant upregulation of VEGF-A 8 weeks after surgery in the tourniquet group compared to perioperative biopsies (p = 0.002), indicating persistent changes. A significant upregulation in protein expression of the angiogenic marker ANGPTL4 was found perioperatively in the tourniquet group (p = 0.02). Our results demonstrate that the angiogenic gene expression is significantly altered by the tourniquet, the effects of which might contribute to postoperative interstitial edema, increased pain, and decreased muscle strength. These effects could lead to delayed rehabilitation and ultimately reduced patient satisfaction after TKA.

The Use of Biomarkers to Quantify Clinical Response to Total Knee Arthroplasty Interventions: A Systematic Review

The primary objective of this review was to determine whether the attenuation of the postoperative inflammatory response (PIR) after total knee arthroplasty (TKA) leads to a notable improvement in clinical outcome scores. The secondary objective of this review was to determine the optimal approach in using inflammatory biomarkers, clinical inflammatory assessments, and imaging to quantify the PIR. A systematic literature search of eight major databases was conducted using a predetermined search strategy. C-reactive protein (CRP), interleukin-6 (IL-6), erythrocyte sedimentation rate (ESR), knee surface temperature (KST), and clinical outcome data were collected and graphically displayed. Eighty-six percent of the studies that reported a statistically significant decrease in inflammatory biomarkers in their treatment group demonstrated a concordant notable improvement in clinical outcome scores. Mean CRP, IL-6, ESR, and KST values peaked on postoperative day (POD) 2, POD1, POD7, and POD 1-3, respectively. The PIR is correlated with early pain and function recovery outcomes. Future studies comparing TKA surgical methodologies and perioperative protocols should assess PIR by incorporating inflammatory biomarkers, such as CRP and IL-6, and clinical inflammatory assessment adjuncts, to provide a more comprehensive comparison.

The optimized tourniquet versus no tourniquet in total knee arthroplasty. Analysis of muscle injury, functional recovery, and knee strength

Background

Tourniquet is widely used in total knee replacement surgery because it reduces intraoperative hemorrhage and provides a comfortable surgical area for the surgeon. It's possible that its use could lead to impaired postoperative functional and motor recovery, as well as local and systemic complications. Our goal was to compare the outcomes of total knee replacement without ischemia using an optimized protocol, consisting of tourniquet inflation before skin incision and deflation after cementing, with a pressure of one hundred millimeters above systolic blood pressure and without postoperative articular suction drains.). We believed that tourniquet effectively would result in no additional muscle damage and no functional or knee strength impairment compared to no tourniquet.

Methods

In a prospective and randomized study, 60 patients with osteoarthritis were evaluated for total knee replacement, divided in two groups: 'without tourniquet' and 'optimized tourniquet'. Outcomes were mean creatine phosphokinase levels, Knee Society Score and knee isokinetic strength. Data were considered significant when p < 0.05.

Results

Creatine phosphokinase levels and functional score were similar between groups. There were no differences between groups regarding knee extension strength on the operated limbs, although the knee flexors' peak torque in the operated limb in the optimized tourniquet group was significantly higher at 6 months relative to preoperative and 3 months assessments.

Conclusions

The optimized tourniquet protocol use in total knee replacement combines the benefits of tourniquet use without compromising functional recovery and without additional muscle damage and strength deficits compared to surgery without its use.

Controlled hypotension technology can improve patient recovery in the early postoperative period after total knee arthroplasty: A prospective, randomized controlled clinical study

OBJECTIVES

The study aimed to analyze the application of controlled hypotension and tourniquets in total knee arthroplasty (TKA) to evaluate their early postoperative period effects in TKA.

PATIENTS AND METHODS

A total of 183 patients (43 males, 140 females; mean age: 67.8±6.4 years; range, 50 to 84 years) with knee osteoarthritis who needed TKA were recruited for this prospective, randomized controlled clinical study between August 2022 and May 2023. The study included a tourniquet group (group T, 94 patients) and a controlled hypotension group (group H, 89 patients). In group T, an inflatable tourniquet was used throughout the operation, with the pressure of the tourniquet set at 300 mmHg. In group H, controlled hypotension was used, with the mean arterial pressure controlled at 55-65 mmHg. The outcome measures of this study included blood loss, coagulation function, inflammatory mediators, knee joint function, permeation thickness of bone cement around the tibial prosthesis, and cognitive function.

RESULTS

The baseline demographics and clinical characteristics of the two groups of patients were comparable (p>0.05). Intraoperative blood loss in group H was higher than that in group T (p<0.05), whereas hemoglobin decrease, postoperative drainage flow, hidden blood loss, and total blood loss in group T were higher than in group H (p<0.05). Fibrinogen, D-dimer, C-reactive protein, and interleukin-6 levels were higher in group T than in group H on the first and third postoperative days (p<0.05). The knee joint function of group H was significantly better than that of group T on the fifth day and one month after the operation (p<0.05). There was no significant difference in the penetration thickness of bone cement around the tibial prosthesis between the two groups (p>0.05). There was no significant difference in Mini-Mental State Examination scores between the two groups on the same day (p>0.05).

CONCLUSION

Controlled hypotension technology in TKA can reduce total blood loss by reducing hidden blood loss and can help to alleviate the postoperative hypercoagulable state, relieve inflammatory reactions, and facilitate early recovery of knee joint function after surgery.

The invasiveness of robot-assisted total hip replacement is similar to that of conventional surgery

Robot-assisted total hip arthroplasty (R-THA) is increasingly being performed throughout the world. The invasiveness of this operation is unknown. We retrospectively reviewed the cohort of consecutive osteonecrosis of the femoral head (ONFH) patients who received primary R-THA or manual THA (M-THA) from January 2020 to January 2022 in our institution. One experienced surgeon performed all procedures. We calculated the propensity score to match similar patients in different groups by multivariate logistic regression analysis for each patient. We included confounders consisting of age, sex, body mass index (BMI), and operation time. Preoperative serum markers and Harris hip scores (HHS), postoperative serum markers at first day and third day, complications rate, postoperative HHS and Forgotten Joint Score (FJS) at 6 months after surgery of different cohorts were compared. We analyzed 218 ONFH patients treated with THA (98 R-THA patients, and 120 M-THA patients). After propensity score matching, we generated cohorts of 95 patients in R-THA and M-THA groups. We found no significant difference in preoperative serum markers and HHS. In the R-THA cohort, the PLT count was significantly lower on the postoperative day 1 (192.36 ± 41.72 × 109/L Vs 210.47 ± 72.85 × 109/L, p < 0.05). The Hb level was significantly lower on the postoperative third day in the R-THA cohort (98.52 ± 12.99 g/L Vs 104.74 ± 13.15 g/L, p < 0.05). There was no significant difference in the other serum markers between the cohorts on postoperative day 1 and 3 (p > 0.05). The FJS was significantly higher in the R-THA than M-THA group (p = 0.01). There was no significant difference in the postoperative HHS or complication rate between the groups (p > 0.05). The R-THA is not associated with a serious invasiveness compared to M-THA. Patients who underwent R-THA had a better early function compared to those who underwent M-THA.

Optimized Tourniquet Use in Primary Total Knee Arthroplasty: A Comparative, Prospective, and Randomized Study

BACKGROUND

The results of recent studies investigating tourniquet (TNQ) use for knee arthroplasty are controversial. Therefore, this study aimed to compare patients undergoing total knee arthroplasty who did not have a TNQ to those in whom an optimized TNQ protocol was applied.

METHODS

We prospectively evaluated 127 patients who had knee osteoarthritis who had undergone total knee arthroplasty and randomized them into two groups: "without TNQ" and "optimized TNQ" (TNQ inflation before skin incision, deflation after cementing, with pressure one hundred millimeters of mercury above the systolic blood pressure, and without articular suction drain usage). The means of surgery and TNQ duration, blood loss, number of blood transfusions, degree of pain, edema, range of motion (ROM), functional score over time, and postoperative complications were compared between the groups. Statistical significance was set at P < .05.

RESULTS

No significant differences were found in terms of surgical timing, blood loss, thigh and knee pain, edema, ROM, functional scores, and complications between the "without TNQ" and "optimized TNQ" groups.

CONCLUSION

The use of an optimized TNQ in primary total knee arthroplasty presents similar clinical results to surgery without a TNQ and did not increase the incidence of postoperative complications. Its use allowed surgery to occur with the benefits of a clean and dry surgical field provided by TNQ without increasing procedure-related comorbidities.

Inflammatory Response in Robotic-Arm-Assisted Versus Conventional Jig-Based TKA and the Correlation with Early Functional Outcomes: Results of a Prospective Randomized Controlled Trial

BACKGROUND

Although the exact etiology of patient dissatisfaction in total knee arthroplasty (TKA) is unclear, the inflammatory response precipitated by surgery may be implicated. Robotic TKA has been shown to result in reduced bone and soft-tissue trauma. The objectives of this study were to compare the inflammatory response in conventional jig-based TKA versus robotic-arm-assisted TKA and to examine the relationship with early functional outcomes.

METHODS

This prospective randomized controlled trial included 15 patients with symptomatic knee osteoarthritis undergoing conventional TKA and 15 undergoing robotic-arm-assisted TKA. Blood samples were collected for up to 28 days postoperatively, and predefined markers of systemic inflammation were measured in serum. The local inflammatory response was assessed by analyzing samples from the intra-articular drain fluid at 6 and 24 hours. Relationships with early functional outcomes were evaluated using the Spearman rank correlation coefficient.

RESULTS

Patients in the robotic TKA group demonstrated lower levels of interleukin (IL)-6 in the drain fluid at 6 hours (798.54 pg/mL versus 5,699.2 pg/mL, p = 0.026) and 24 hours and IL-8 at 6 hours. Robotic TKA was associated with lower pain scores on postoperative days 1, 2, and 7. Patient-reported outcome measures were comparable between the 2 groups at 2 years. Significant correlations were observed between all serum markers except IL-1b and self-reported pain on postoperative day 7; between drain IL-8 levels and pain on postoperative days 1 (r = 0.458), 2, and 7; and between drain IL-6, IL-8, and tumor necrosis factor-alpha levels at 6 hours and knee flexion or extension.

CONCLUSIONS

Robotic-arm-assisted TKA was associated with a reduction in the early postoperative local inflammatory response. We also found a moderate relationship between the inflammatory responses and self-reported pain, knee flexion, and knee extension. Further validation of these findings on a larger scale and using longer-term outcomes will be key to developing the optimal TKA procedure.

LEVEL OF EVIDENCE

Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.

Early Clinical and Radiographic Outcomes of Robot-Assisted Versus Conventional Manual Total Knee Arthroplasty: A Randomized Controlled Study

Objective

Robot‐assisted surgery has been promoted worldwide in recent years. The development of a domestic orthopaedic robot and its clinical application are therefore of great significance. This study aimed to compare the early clinical and radiographic outcomes of domestic robot‐assisted total knee arthroplasty (RA‐TKA) with conventional manual total knee arthroplasty (CM‐TKA).

Methods

A total of 77 patients who underwent primary single‐sided TKA from June to December 2020 were prospectively enrolled; resulting in the inclusion of 72 patients. The patients were randomly divided into the RA‐TKA group (37 cases, with TKA being assisted by the Yuanhua Orthopaedic Robotic System) and the CM‐TKA group (35 cases, with TKA being performed using conventional tools). Knee function was evaluated by the knee range of motion (ROM), the American Knee Society Score (KSS), and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Postoperative radiographic results were evaluated by full‐length weight‐bearing X‐rays of the lower limb and anteroposterior and lateral X‐rays of the knee were obtained preoperatively and at 90 days postoperative. The operative duration, blood loss, postoperative knee function, radiographic outcomes, and incidence of complications were compared by Student's t‐test, Mann–Whitney U test, or chi‐square test. Serum levels of inflammatory markers before the operation and 1, 3, and 30 days after the operation were recorded and compared between the two groups.

Results

The operation was significantly longer in the RA‐TKA group than in the CM‐TKA group (154.3 vs 115.2 min, p < 0.001). There was no significant difference in blood loss (933 vs 863 ml, p = 0.519) between the two groups. The knee ROM, KSS, and WOMAC were significantly improved in both groups 90 days after the operation compared with before the operation (p < 0.05), but there were no significant differences between the two groups (p > 0.05). The incidence of postoperative deep vein thrombosis was not statistically different between the two groups. In the radiographic findings at 90 days postoperatively we found the frequency of lateral tibial component (LTC) angle outliers was significantly lower in the RA‐TKA group (3.0% vs 29.4%, p = 0.003). The neutrophil‐to‐lymphocyte ratio (NLR) was significantly lower in the RA‐TKA group than in the CM‐TKA group on day 1 after surgery (9.9 vs 12.7, p = 0.024).

Conclusions

RA‐TKA requires more time than CM‐TKA, which may be related to the learning curve and intraoperative registration. The short‐term postoperative knee functional outcomes had no differences between the two groups, and RA‐TKA improved the accuracy of tibial component alignment. Further follow‐up studies are required to investigate the long‐term outcomes.

Lower-leg injury and knee arthroscopy have distinct effects on coagulation

Unlike knee arthroscopy, lower-leg injury is associated with increased plasma levels of factor VIII, von Willebrand factor, and D-dimer.

In both situations, coagulation is affected differently, which suggests that there are different pathways toward venous thromboembolism.

It is unknown how lower-leg injury and knee arthroscopy, both associated with venous thromboembolism (VTE), affect coagulation. To study the effect of (1) lower-leg trauma and (2) knee arthroscopy on coagulation, plasma samples of the Prevention of Thrombosis following CAST immobilization (POT-CAST, #NCT01542762) and Prevention of Thrombosis following Knee Arthroscopy (POT-KAST, #NCT01542723) trials were used, which were collected shortly after lower-leg trauma and before/after (<4 hours) knee arthroscopy. For aim 1, 1204 lower-leg injury patients were compared with preoperative samples of 1001 controls. Mean differences/ratios (if ln-retransformed because of skewedness) were adjusted for sex, age, body mass index, comorbidity, malignancy, and oral contraceptives using linear regression. For aim 2, perioperative mean changes of 715 arthroscopy patients were calculated. Plasma levels of fibrinogen, factor (F)VIII, FIX, FXI, von Willebrand Factor (VWF), and D-dimer were measured in all individuals. Parameters of underlying mechanisms (tissue factor, interleukin-6 [IL-6], myeloperoxidase DNA, cell-free DNA) were measured in random subsets. In lower-leg injury patients, coagulation parameter levels increased, especially FVIII, VWF, and D-dimer, that is, adjusted mean differences: FVIII 26.8% (95% confidence interval [CI], 23.7-29.9), FIX 13.8% (95% CI, 11.9-15.6), FXI 5.1% (95% CI, 3.3-7.0), VWF 29.8% (95% CI, 26.0-33.6), fibrinogen 32.5 mg/dL (95% CI, 25.8-39.2), and D-dimer (mean ratio) 3.3 (95% CI, 3.1-3.6). Remaining parameters were unchanged, except for increased IL-6 levels. After arthroscopy, all parameters decreased. Lower-leg trauma is associated with increased procoagulant factor levels in contrast to knee arthroscopy. This suggests that, in both situations, different pathways are involved in development of VTE.

A prospective randomized controlled trial comparing the systemic inflammatory response in conventional jig-based total knee arthroplasty versus robotic-arm assisted total knee arthroplasty

AIMS

The primary aim of this study was to compare the postoperative systemic inflammatory response in conventional jig-based total knee arthroplasty (conventional TKA) versus robotic-arm assisted total knee arthroplasty (robotic TKA). Secondary aims were to compare the macroscopic soft tissue injury, femoral and tibial bone trauma, localized thermal response, and the accuracy of component positioning between the two treatment groups.

METHODS

This prospective randomized controlled trial included 30 patients with osteoarthritis of the knee undergoing conventional TKA versus robotic TKA. Predefined serum markers of inflammation and localized knee temperature were collected preoperatively and postoperatively at six hours, day 1, day 2, day 7, and day 28 following TKA. Blinded observers used the Macroscopic Soft Tissue Injury (MASTI) classification system to grade intraoperative periarticular soft tissue injury and bone trauma. Plain radiographs were used to assess the accuracy of achieving the planned postioning of the components in both groups.

RESULTS

Patients undergoing conventional TKA and robotic TKA had comparable changes in the postoperative systemic inflammatory and localized thermal response at six hours, day 1, day 2, and day 28 after surgery. Robotic TKA had significantly reduced levels of interleukin-6 (p < 0.001), tumour necrosis factor-α (p = 0.021), ESR (p = 0.001), CRP (p = 0.004), lactate dehydrogenase (p = 0.007), and creatine kinase (p = 0.004) at day 7 after surgery compared with conventional TKA. Robotic TKA was associated with significantly improved preservation of the periarticular soft tissue envelope (p < 0.001), and reduced femoral (p = 0.012) and tibial (p = 0.023) bone trauma compared with conventional TKA. Robotic TKA significantly improved the accuracy of achieving the planned limb alignment (p < 0.001), femoral component positioning (p < 0.001), and tibial component positioning (p < 0.001) compared with conventional TKA.

CONCLUSION

Robotic TKA was associated with a transient reduction in the early (day 7) postoperative inflammatory response but there was no difference in the immediate (< 48 hours) or late (day 28) postoperative systemic inflammatory response compared with conventional TKA. Robotic TKA was associated with decreased iatrogenic periarticular soft tissue injury, reduced femoral and tibial bone trauma, and improved accuracy of component positioning compared with conventional TKA. Cite this article: Bone Joint J 2021;103-B(1):113-122.

Total Knee Arthroplasty Using a Medial Pivot or Posterior Cruciate-Stabilizing Prosthesis in Chinese Patients

There is an unmet need for a prosthesis designed according to the anatomical parameters of the Chinese population. This study aims to compare the use of a medial pivot (MP) implant or posterior cruciate ligament (PCL) substitution (posterior-stabilized [PS]) prosthesis for unilateral total knee arthroplasty (TKA) in a Chinese population. The medical records of patients undergoing unilateral TKA with an MP implant (Group A) or a PS prosthesis (Group B) at our institution between January 2010 and December 2011 were retrospectively reviewed. Patients were followed up for 5 years. Preoperatively and at the December 2016 postoperative follow-up, the Hospital for Special Surgery scoring system (HSS knee score) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score were measured to evaluate TKA outcomes. This study included 49 patients in Group A and 51 in Group B. As of December 2016, there were no significant differences in the preoperative/postoperative changes in any category of the HSS knee score or WOMAC score between the groups. There were no postoperative complications in either group during the 5-year follow-up. There were no periprosthetic infections or need for revision surgery. One patient in Group A experienced aching and a small amount of effusion in the articular cavity that was attributed to overexertion. In conclusion, there were no significant differences in midterm outcomes in Chinese patients receiving an MP implant or a PS prosthesis for unilateral TKA. These data suggest that the MP and PCL substitution design are safe and effective for unilateral TKA in China.

Gene expression analysis of vastus medialis cells after tourniquet-induced ischemia during total knee arthroplasty: a randomized clinical trial

PURPOSE

Postoperative quadriceps muscle strength was lowered after tourniquet application during total knee arthroplasty (TKA). Furthermore, tourniquet application results in higher proteolytic activity within vastus medialis cells, without influence on the amount and function of mitochondria. The effects of the commonly utilized intraoperative tourniquet on gene expression within the human skeletal muscle cells are barely examined. The purpose of the present study was to analyze the gene expression within the skeletal muscle cells after tourniquet-induced ischemia to identify differential expressed genes (DEGs) and pathways.

METHODS

As part of a randomized, controlled, monocentric trial (Clinical-Trials.gov NCT02475603) 20 patients, scheduled to undergo primary total knee arthroplasty (TKA), were included. Written informed consent was received and the patients were randomly assigned to Group A (TKA with tourniquet) (n = 10) and Group B (TKA without tourniquet) (n = 10). A muscle biopsie of (5 × 5 × 5 mm) 125 mm³ were obtained from the vastus medialis exactly 60 min after performing the surgical approach. After preparation of a muscle homogenate, RNA extraction was performed (RNeasy Plus Universal Mini Kit Qiagen) and RNA integrity (RIN) was determined (Agilent 2100 Bioanalyzer, RNA 6000 Pico Kit). Gene expression profiling was performed using a validated method (GeneChip™ Human Transcriptome Array 2.0; Affymetrix). Statistical analysis (SPSS-Version 24; SAS JMP10 Genomics, Version 6) included the number of significant DEGs (p < 0.05), the number of DEGs with relative difference > 25% and the number of significant pathway (p < 0.05). The serum C-reactive protein (CRP) and the white blood cell (WBC) count were also perioperatively measured. The protocol was approved by our Institutional Ethics Committee (File reference 2012-334N-MA).

RESULTS

Tourniquet application resulted in a total of 3555 (13.8%) statistically significant DEGs within vastus medialis cells. 76 DEGs (29 upregulated, 47 downregulated) revealed a relative difference of more than 25%. Statistically significant changes occurred in 59 (25.8%) of 229 analyzed pathways. Furthermore, there was no clinically meaningful difference between the groups with regard to CRP and WBC count.

CONCLUSIONS

Tourniquet induced ischemia results in significant changes of the gene expression within cells of vastus medialis including metabolism, genetic information processing and cellular processes. The identified altered expression of genes and pathways might serve as pharmacotherapeutical targets; although further research is needed to clarify the underlying biological processes.

CLINICAL RELEVANCE

These findings add further knowledge and should raise the awareness of surgeons about the effects of tourniquet induced ischemia at the gene expression level. Additional high-quality research may be warranted to examine the short and long term clinical significance of the present data.

LEVEL OF EVIDENCE

Level I.

Do Corticosteroids Attenuate the Peri-Operative Acute Phase Response After Total Knee Arthroplasty?

BACKGROUND

Following tissue injury, the acute phase response (APR) functions to survive and then repair injured tissue. An exuberant APR, which can be evoked by total knee arthroplasty (TKA), results in a hyper-inflammatory state, leading to pain, nausea, venous thromboembolism, or potentially life-threatening complications. Here, we observed the effects of peri-operative dexamethasone on the APR following TKA by trending C-reactive protein (CRP, mg/L) and fibrinogen (mg/dL). We hypothesize that the anti-inflammatory effects of dexamethasone can attenuate the APR after TKA and will be associated with decreased post-operative pain and nausea.

METHODS

A retrospective case-control study was performed on 188 unilateral TKA procedures. The patients were divided into a group receiving dexamethasone (10 mg intra-operatively and on post-operative day [POD] 1) and a group receiving no corticosteroids. Post-operative CRP, fibrinogen, morphine equivalents, and anti-emetic doses were recorded.

RESULTS

Compared to the non-steroid group, patients receiving dexamethasone yielded a significantly decreased CRP on POD0 (5.5 vs 8.3), POD1 (11.8 vs 22.0), and POD2 (85.5 vs 148.9). A significant decrease in fibrinogen in patients receiving dexamethasone was seen on POD2 (460.0 vs 530.2). There was an increase in fibrinogen within the dexamethasone cohort at the 2-week visit (535.4 vs 488.9). Post-operative morphine equivalents administered were significantly decreased in patients receiving dexamethasone, but no difference in anti-emetic use was appreciated.

CONCLUSION

These data support the hypothesis that the APR following TKA can be attenuated pharmacologically by corticosteroids. Further studies are needed to determine whether the attenuation of the APR with the use of corticosteroids prevents complications following TKA.

The Possible Pathophysiological Outcomes and Mechanisms of Tourniquet-Induced Ischemia-Reperfusion Injury during Total Knee Arthroplasty

Ischemia and reperfusion (I/R) injury induced by tourniquet (TQ) application leads to the release of both oxygen free radicals and inflammatory cytokines. The skeletal muscle I/R may contribute to local skeletal muscle and remote organ damage affecting outcomes after total knee arthroplasty (TKA). The aim of the study is to summarize the current findings associated with I/R injury following TKA using a thigh TQ, which include cellular alterations and protective therapeutic interventions. The PubMed database was searched using the keywords "ischemia reperfusion injury," "oxidative stress," "tourniquet," and "knee arthroplasty." The search was limited to research articles published in the English language. Twenty-eight clinical studies were included in this qualitative review. Skeletal muscle I/R reduces protein synthesis, increases protein degradation, and upregulates genes in cell stress pathways. The I/R of the lower extremity elevates local and systemic oxidative stress as well as inflammatory reactions and impairs renal function. Propofol reduces oxidative injury in this I/R model. Ischemic preconditioning (IPC) and vitamin C may prevent oxygen free radical production. However, a high dose of N-acetylcysteine possibly induces kidney injury. In summary, TQ-related I/R during TKA leads to muscle protein metabolism alteration, endothelial dysfunction, oxidative stress, inflammatory response, and renal function disturbance. Propofol, IPC, and vitamin C show protective effects on oxidative and inflammatory markers. However, a relationship between biochemical parameters and postoperative clinical outcomes has not been validated.

[Risk factors associated with interleukin 6 level in serum after total knee arthroplasty]

Objective

To explore the risk factors associated with interleukin 6 (IL-6) level in serum after total knee arthroplasty (TKA).

Methods

A retrospective study was made on the clinical data of 273 patients underwent primary unilateral TKA between July 2015 and April 2017. There were 50 males and 223 females with an average age of 66.3 years (range, 36-89 years), and the body mass index (BMI) was (25.5±3.7) kg/m ². Of them, 256 patients suffered with osteoarthritis, and the other 17 patients with rheumatoid arthritis. Univariate analysis was made to find the related factors between IL-6 level in serum at 1 day after operation and preoperative data including gender, age, BMI, diagnosis, comorbidities, preoperative American Society of Anesthesiologists (ASA) grade, preoperative varus or valgus deformity, range of motion of the knee, preoperative level of C-reactive protein (CRP) and IL-6 in serum, operation time, intraoperative blood loss, usage of drainage tube and catheter, and dosage of tranexamic acid and dexamethasone used on day of operation. Furthermore, the multiple linear regression analysis was performed to identify the risk factors.

Results

The operation time was (79.7±15.6) minutes, and the intraoperative blood loss was (107.8±25.3) mL. Drainage tubes were used in 111 patients and catheters were used in 41 patients after operation. The dosage of tranexamic acid and dexamethasone used on day of operation were (3.2±0.8) g and (15.1±6.6) mg, respectively. The levels of IL-6 in serum were (4.48±3.05), (42.65±37.09), and (28.21±26.44) pg/mL before operation and at 1 and 3 days after operation, respectively. Univariate analysis showed that the level of IL-6 in serum at 1 day after operation was significantly higher in variables as follows: age, diagnosis, history of lung infection, range of motion, preoperative levels of CRP and IL-6 in serum, intravenous dosage of tranexamic acid and dexamethasone on day of operation ( P<0.05). Multiple linear regression analysis showed that range of motion less than 90°, intravenous dosage of tranexamic acid on day of operation less than 3 g, and dosage of dexamethasone on day of operation less than 10 mg were significant risk factors ( P<0.05).

Conclusion

Range of motion less than 90°, intravenous dosage of tranexamic acid on day of operation less than 3 g, and dosage of dexamethasone on day of operation less than 10 mg were independent risk factors that resulted in increased level of IL-6 in serum at 1 day after TKA.