Computer navigation is effective in reducing blood loss but has no effect on transfusion requirement following primary total knee arthroplasty: a meta-analysis

Comparative analysis of acute blood loss anemia in robotic assisted vs. manual instrumented total knee arthroplasty

Introduction

Robotic assisted total knee arthroplasty has become an increasingly popular technique over the past several years. Manual total knee arthroplasty can be associated with acute blood loss anemia. Instrumentation of the femoral canal with the alignment guide may in part contribute to this blood loss. Because the femoral canal is not entered during robotic assisted total knee arthroplasty, the blood loss may be lower compared to that seen in manual total knee arthroplasty. The purpose of this study was to determine if acute blood loss is greater in manually instrumented total knee arthroplasty versus robotic assisted total knee arthroplasty.

Materials and methods

This retrospective cohort study was performed in a large tertiary academic hospital network by two fellowship trained surgeons. Patients underwent either robotic assisted or manually instrumented total knee arthroplasty and were assessed for postoperative acute blood loss anemia, defined as hemoglobin <13 g/dL for males or <12 g/dL for females plus a 2 g/dL drop from preoperative levels, as well as postoperative drop in hemoglobin.

Results

A total of 75 patients were included in each study arm. There was no significant difference (p > 0.05) in postoperative hemoglobin in robotic assisted (2.1 g/dL) compared to manually instrumented total knee arthroplasty (2.1 g/dL). There was no significant difference in the incidence of postoperative acute blood loss anemia between robotic assisted (45 %) and manually instrumented total knee arthroplasty (39 %). Higher BMI and increased age were protective against postoperative drop in hemoglobin. These protective effects were not significant when controlling for confounding variables. Surgical time was significantly longer for robotic assisted (99 min) versus manually instrumented total knee arthroplasty (86 min) (p < 0.001).

Conclusions

There is no significant difference in acute blood loss when comparing patients undergoing robotic assisted and manually instrumented total knee arthroplasty.

Blood Management for the Orthopaedic Surgical Patient

Prevention and management of anemia and blood loss in the orthopaedic patient undergoing surgery is a major concern for healthcare providers and patients. Although transfusion technology can be lifesaving, there are risks to blood products that have led to increased awareness of blood management and development of hospital patient blood management programs. Use of patient blood management can be effective in addressing preoperative anemia, a major modifiable risk factor in patients undergoing surgery. In this informational article, evidence-based practice guidelines for perioperative blood management are addressed. A case scenario is introduced focusing on a patient whose religious preference is Jehovah's Witness having "no blood wishes" undergoing elective orthopaedic surgery. Orthopaedic nurses can facilitate optimal patient blood management through multidisciplinary collaboration.

Avoiding Femoral Canal Instrumentation in Computer-Assisted Total Knee Arthroplasty With Contemporary Blood Management Had Minimal Differences in Blood Loss and Transfusion Rates Compared to Conventional Techniques

BACKGROUND

Computer-assisted surgery that does not utilize femoral canal instrumentation is theorized to have less blood loss. However, there is a paucity of data on this, particularly in the era of tranexamic acid use. We sought to analyze the association of computer navigation with total calculated blood loss and transfusion rate in patients undergoing primary total knee arthroplasty (TKA).

METHODS

We identified 14,890 patients who underwent unilateral primary TKA at a single institution from 2016 to 2020. Computer-assisted surgery in the form of an accelerometer or robotics was utilized in 4,165 TKAs (28%). Drains were utilized in 4,860 TKAs (32%). We used multivariate logistic regression analysis to determine if computer navigation reduced the rate of blood transfusion and linear regression analysis to determine the impact of computer navigation on blood loss.

RESULTS

In total, 542 patients (3.6%) underwent a transfusion. The average change in hemoglobin (Hgb) was 2.1 g/dL (standard deviation [SD] 0.91) and average total calculated blood loss was 310 mL (SD = 154). In a multivariate regression model, computer navigation was not protective of transfusion (odds ratio [OR] 1.04, P = .73). Preoperative Hgb <10 (OR 10.5, P < .0001) and drain use (OR 2.25, P < .0001) were the most significant risk factors for transfusion. In a linear regression model, computer navigation reduced blood loss by 19 mL (SD 2.94, P < .0001) per case.

CONCLUSION

In this large retrospective cohort analysis of contemporary TKA patients, computer-assisted surgery that eliminates intramedullary femoral canal instrumentation during primary TKA was not associated with reduced transfusion rates and had minimal differences in overall blood loss.

The association between bone mineral density and postoperative drainage volume following cruciate-substituting primary total knee arthroplasty: a cross-sectional study

Background

The prevalence of osteoporosis in patients who undergo a primary total knee arthroplasty (TKA) is increasing. Low bone mineral density (BMD) is related to unfavorable outcomes following TKA such as migration of uncemented tibial components. Postoperative blood loss in TKA is an important complication. Non-modifying predicting factors for postoperative blood loss in patients undergoing primary TKA need further elucidation. Studies on the association between BMD and blood loss after TKA are limited. We aimed to demonstrate the relationship between BMD and postoperative drainage volume following primary TKA.

Methods

A cross-sectional study was conducted between January 2014 and August 2020. A total of 119 primary varus osteoarthritis knees with BMD results were included in the study. Patients with secondary causes of osteoporosis were excluded.

Results

The median postoperative drainage volume of participants in the normal total hip BMD group and the normal trochanter BMD group was higher than that of patients in the low total hip BMD group and the low trochanter BMD group (285.0 ml vs 230.0 ml, P = 0.003; 282.5 ml vs 240.0 ml, P = 0.013, respectively). Multivariate regression analyses showed that operative time, spinal anesthesia, and normal total hip BMD status were significant predictive factors associated with increased postoperative drainage volume (P = 0.014, 0.022, and 0.013, respectively). No association was identified between the lumbar spine BMD status and postoperative drainage volume.

Conclusions

The relationship between BMD and postoperative blood loss in primary TKA was identified in this study. Normal total hip BMD was found to be associated with an increased postoperative drainage volume after primary TKA compared with low BMD.

Total Knee Arthroplasty in Octogenarians: Should We Still Be so Restrictive?

Demand for total knee arthroplasty (TKA) in octogenarians will increase in subsequent years as society ages. We conducted a retrospective observational study in octogenarians operated on with TKA between 2015 and 2019, comparing preoperative and postoperative Knee Society Score (KSS), Knee Society Function Score (KSFS), extension and flexion balance, and radiologic alignment using a paired Student t-test. A chi-squared test was used to correlate mortality with Charlson comorbidities index score and with ASA scale. Kaplan-Meier analysis was performed to calculate patient survival. In this period 36 patients ≥80 years underwent TKA, with a mean age of 81.6 years. Of these, 24 patients (66.7%) were classified as ASA II and 12 (33.3%) as ASA III. Sixteen patients (44.4%) were Charlson 0, 14 (38.9%) Charlson 1, two (5.6%) Charlson 2, and four (11.1%) Charlson 3. KSS, KSFS, flexion and extension range, and radiologic alignment were statistically significant (p < 0.001) when comparing preoperatory and post-operatory data. No correlation (p > 0.05) was found between mortality and ASA or Charlson score. Seven patients (19.4%) suffered a medical complication and two patients experienced surgical complications. Four patient died (11.1%) during follow-up. The mean patient survival was 67.4 months. Patients ≥80 years achieve clinical improvement after TKA. Comorbidities, not age, are the burden for surgery in older patients.

Reduced postoperative morbidity in computer-navigated total knee arthroplasty: A retrospective comparison of 225,123 cases

BACKGROUND

Total knee arthroplasty (TKA) is one of the most common elective surgical procedures in the United States, with more than 650,000 performed annually. Computer navigation technology has recently been introduced to assist surgeons with planning, performing, and assessing TKA bone cuts. The aim of this study is to assess postoperative complication rates after TKA performed using computer navigation assistance versus conventional methods.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried for unilateral TKA cases from 2008 to 2016. The presence of the CPT modifier for use of computer navigation was used to separate cases of computer-navigated TKA from conventional TKA. Multivariate and propensity-matched logistic regression analyses were performed to control for demographics and comorbidities.

RESULTS

There were 225,123 TKA cases included; 219,880 were conventional TKA (97.7%) and 5,243 were navigated (2.3%). Propensity matching identified 4,811 case pairs. Analysis demonstrated no significant differences in operative time, length of stay, reoperation, or readmission, and no differences in rates of post-op mortality at 30 days postoperatively. Compared to conventional cases, navigated cases were at lower risk of serious medical morbidity (18% lower, p = 0.009) within the first 30 days postoperatively.

CONCLUSION

After controlling for multiple known risk factors, navigated TKA patients demonstrated lower risk for medical morbidity, predominantly driven by lower risk for blood transfusion. Given these findings, computer-navigation is a safe surgical technique in TKA.

Clinical Trial Registry Use in Orthopaedic Surgery Systematic Reviews

BACKGROUND

Results from systematic reviews and meta-analyses, which have the highest level of evidence (Level I), often drive clinical decision-making and health policy. Often, unpublished trial data are omitted from systematic reviews, raising concerns about the extent of the reliability and validity of results that have been drawn from systematic reviews. We aimed to determine the extent to which systematic review authors include searches of clinical trial registries for unpublished data when conducting systematic reviews in orthopaedic surgery.

METHODS

Systematic reviews and/or meta-analyses were gathered from the top 5 orthopaedic surgery journals based on the h5-index from Google Scholar Metrics. Systematic reviews that had been published in the Cochrane Database of Systematic Reviews, which requires the inclusion of a clinical trial registry search, served as controls. For the primary outcome, each systematic review from the top 5 orthopaedic journals was screened to determine whether the authors of each study searched for unpublished data in clinical trial registries. We then compared the rate of registry searches with those in the control group. For the secondary analysis, a search of ClinicalTrials.gov was performed for unpublished trial data for 100 randomized systematic reviews.

RESULTS

All 38 of the Cochrane systematic reviews (100%) included clinical trial registry searches, while the top 5 orthopaedic journals had only 31 of 480 studies (6.5%) that looked at clinical trial registries. The secondary analysis yielded 59 of 100 systematic review articles (59.0%) that could have included unpublished clinical trial data from ≥1 studies to their sample.

CONCLUSIONS

Systematic reviews that have been published in the top orthopaedic surgery journals seldom included a search for unpublished clinical trial data.

CLINICAL RELEVANCE

The exclusion of clinical trial registry searches potentially contributes to publication bias within the orthopaedic literature. Moving forward, systematic review authors should include clinical trial registry searches for unpublished clinical trial data to provide the most accurate representation of the available evidence for systematic reviews and meta-analyses.

Usefulness of an accelerometer-based navigation system in bilateral one-stage total knee arthroplasty

Background

Bilateral one-stage total knee arthroplasty (BTKA) have increased because it provides a number of advantages. Recently, Accelerometer-based navigation (ABN) system which guide the cutting plane without intramedullary disturbance might result in less endothelial and microvascular damage. Therefore, we hypothesized that the ABN may reduce blood loss, reduce postoperative pain, and better restore BTKA alignment compared to conventional instruments.

Methods

We retrospectively compared 44 consecutive patients receiving ABN assisted BTKA (iBTKA) to 57 patients with conventional instruments (cBTKA). Identical pre- and post-operative care was utilized to all patients. The outcome measures assessed were hemoglobin (Hb), calculated blood loss (CBL), blood transfusion, VAS score for pain, morphine consumption, knee flexion angle, and length of stay (LOS). Radiographic assessment included mechanical axis (MA) and component positioning at 3–6 months of follow up.

Results

Both iBTKA and cTKA groups had equivalent demographic data. Postoperative Hb of the cBTKA group was significantly lower than those in the iBTKA group at 24 h (p = 0.02), but there was no significant difference in drain volume, CBL, and blood transfusion rate. For radiographic measures, the iBTKA group had more accurate MA and component orientation, and had a lower number of outliers than those in the cBTKA group (p ≤ 0.01), except for the sagittal femoral component angle.

Conclusion

The ABN assisted BTKA could not reduce blood loss or postoperative pain more than cBTKA, nor improve functional recovery. However, the ABN significantly improved the accuracy of MA and prostheses positioning.

Trial registration

The protocol of this study was registered in the Thai Clinical Trials Registry database No. TCTR20180731001# on 25 July 2018.

Is TKA with computer-assisted navigation associated with less blood loss? A comparative study between computer-navigated and conventional method

The aim of this study is to evaluate whether computer-assisted navigated TKA reduces perioperative blood loss. Patients were randomly divided into 2 groups and underwent either a conventional TKA (n = 40) or a TKA with computer-assisted navigation (n = 40). Perioperative blood loss was evaluated by laboratory parameters, postoperative drain output and number of required transfusions. Change in hemoglobin concentration and in hematocrit levels was similar. Also, there was no statistically significant difference in drain output and in the number of transfused units. The results of this study showed that TKA with computer-assisted navigation is similar to the conventional TKA regarding perioperative hemorrhage.

One-Stage Sequential Bilateral Total Knee Arthroplasty: An Effective Treatment for Advanced Bilateral Knee Osteoarthritis Providing High Patient Satisfaction

BACKGROUND

The mortality and risks of bilateral total knee arthroplasty (BTKA) have been reported to be far greater than in unilateral total knee arthroplasty (UTKA). This study aimed to determine whether this remains the case using contemporary anesthetic and surgical techniques for one-stage single anesthetic sequential BTKA.

METHODS

Two cohorts of 394 patients were created by propensity matching for gender, age, body mass index, American Society of Anesthesiologists grade, and Veterans Rand-12 health survey scores. Primary outcome was morbidity and mortality, with satisfaction measures using patient-reported outcome measures.

RESULTS

The mortality rate was low with one case after BTKA. Major complications were also low; however, a pulmonary embolism rate of 2% in BTKA patients was significantly higher than 0.3% after UTKA (P < .05), and associated with an American Society of Anesthesiologists grade ≥3. The rate of minor complications between the 2 cohorts was comparable (P = .95). Blood transfusions were uncommon and not significantly different between cohorts (2.5% vs 1.3%, P = .3). BTKA patients stayed in hospital a mean 1.3 days longer with greater rehabilitation requirements. At final follow-up, patient satisfaction was high with all patient-reported outcome measures significantly improved and comparable between cohorts.

CONCLUSION

BTKA is safe and effective in the majority of patients. Transfusion rates were far lower than historically reported and major complications were rare after both UTKA and BTKA. A significant increase in the rate of pulmonary embolism after BTKA was observed, especially in high risk patients. At minimum 1-year postoperatively, cohorts had the same significant clinical improvement and high level of satisfaction.

An umbrella review comparing computer-assisted and conventional total joint arthroplasty: quality assessment and summary of evidence

Background

Systematic reviews (SRs) of computer-assisted (CA) total knee arthroplasty (TKA) and total hip arthroplasty (THA) report conflicting evidence on its superiority over conventional surgery. Little is known about the quality of these SRs; variability in their methodological quality may be a contributing factor. We evaluated the methodological quality of all published SRs to date, summarized and examined the consistency of the evidence generated by these SRs.

Methods

We searched four databases through December 31, 2018. A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2) was applied to assess the methodological quality. Evidence from included meta-analyses on functional, radiological and patient-safety outcomes was summarized. The corrected covered area was calculated to assess the overlap between SRs in including the primary studies.

Results

Based on AMSTAR 2, confidence was critically low in 39 of the 42 included SRs and low in 3 SRs. Low rating was mainly due to failure in developing a review protocol (90.5%); providing a list of excluded studies (81%); accounting for risk of bias when discussing the results (67%); using a comprehensive search strategy (50%); and investigating publication bias (50%). Despite inconsistency between SR findings comparing functional, radiological and patient safety outcomes for CA and conventional procedures, most TKA meta-analyses favored CA TKA, whereas most THA meta-analyses showed no difference. Moderate overlap was observed among TKA SRs and high overlap among THA SRs.

Conclusions

Despite conclusions of meta-analyses favoring CA arthroplasty, decision makers adopting this technology should be aware of the low confidence in the results of the included SRs. To improve confidence in future SRs, journals should consider using a methodological assessment tool to evaluate the SRs prior to making a publication decision.

Strategies to minimize intraoperative blood loss during major surgery

Background

Reducing operative blood loss improves patient outcomes and reduces healthcare costs. The aim of this article was to review current surgical, anaesthetic and haemostatic intraoperative blood conservation strategies.

Methods

This narrative review was based on a literature search of relevant databases up to 31 July 2019 for publications relevant to reducing blood loss in the surgical patient.

Results

Interventions can begin early in the preoperative phase through identification of patients at high risk of bleeding. Directly acting anticoagulants can be stopped 48 h before most surgery in the presence of normal renal function. Aspirin can be continued for most procedures. Intraoperative cell salvage is recommended when anticipated blood loss is greater than 500 ml and this can be continued after surgery in certain situations. Tranexamic acid is safe, cheap and effective, and routine administration is recommended when anticipated blood loss is high. However, the optimal dose, timing and route of administration remain unclear. The use of topical agents, tourniquet and drains remains at the discretion of the surgeon. Anaesthetic techniques include correct patient positioning, avoidance of hypothermia and regional anaesthesia. Permissive hypotension may be beneficial in selected patients. Promising haemostatic strategies include use of pharmacological agents such as desmopressin, prothrombin complex concentrate and fibrinogen concentrate, and use of viscoelastic haemostatic assays.

Conclusion

Reducing perioperative blood loss requires a multimodal and multidisciplinary approach. Although high-quality evidence exists in certain areas, the overall evidence base for reducing intraoperative blood loss remains limited.

Tranexamic Acid Reduces Total Blood Loss and Inflammatory Response in Computer-Assisted Navigation Total Knee Arthroplasty

Introduction

Tranexamic acid (TXA) is an effective blood salvage agent that reduces perioperative blood loss in conventional total knee arthroplasty (TKA). As computer-assisted surgery for TKA (CAS-TKA) results in a lower perioperative blood loss than conventional TKA, the additional effect of blood conservation by TXA might be mitigated. This study aimed to evaluate the efficacy of TXA in CAS-TKA.

Methods

We retrospectively reviewed 222 consecutive patients who underwent CAS-TKA. Intravenous TXA was administered in 103 patients (TXA group) at a dosage of 20 mg/kg 15 min before deflation of the tourniquet. The other 119 patients did not receive TXA (control group). Patient demographic data including age, gender, BMI, DM, and hypertension were collected. The primary outcomes were the estimated total blood loss (ETBL) and perioperative data, including tourniquet duration, preoperative and postoperative day 1 (POD1) and day 3 (POD3) serum D-dimer, CRP, hemoglobin (Hb), and hematocrit (Hct) levels. Secondary outcomes including transfusion rate and 90-day complications were recorded.

Results

The ETBL was lower in the TXA group on both POD1 (404.34 ± 234.77 vs. 595.47 ± 279.04, p < 0.001) and POD3 (761.39 ± 260.88 vs. 987.79 ± 326.58, p < 0.001). The TXA group also demonstrated a lower level of CRP on POD1 (p=0.02) and lower levels of CRP and serum D-dimer on POD3 (p=0.008 and p < 0.001). Consumption of fibrinogen was higher in the control group on both POD1 (p=0.013) and POD3 (p < 0.001). Length of hospital stay was lower in the TXA group (5.42 ± 1.21 vs. 6.25 ± 1.49, p < 0.001). The transfusion rate and perioperative complications were not significantly different between the two groups.

Conclusion

Administration of TXA is not only effective in reducing perioperative blood loss and length of hospital stay but also exerts an anti-inflammatory effect following CAS-TKA without causing major complications.

Advanced Age Is Not a Barrier to Total Knee Arthroplasty: A Detailed Analysis of Outcomes and Complications in an Elderly Cohort Compared With Average Age Total Knee Arthroplasty Patients

BACKGROUND

Life expectancy and higher complication rates have made the routine use of total knee arthroplasty (TKA) in elderly patients disputed by some authors. The purpose of this study was to assess patient and implant survivorship, complication and revision rates, and patient-reported outcomes (PROMS) in a cohort of patients aged above 80 years undergoing TKA. A comparison with a propensity matched cohort of patients of average age within our database for TKA was performed.

METHODS

A retrospective review of prospectively collected data identified 644 patients over the age of 80 years undergoing a TKA within a 14-year period. After calculating the average age of all TKA patients within the reviewed database, a cohort deemed average age was created within 1 standard deviation of the average age and matched using the following criteria: gender, surgeon, diagnosis, procedure type, and year. The primary outcomes were survivorship of the implant and the patient. The secondary outcomes were complications, transfusion rates, discharge destination, and PROMS.

RESULTS

The revision rate was low for both groups (P = .051). Implant survivorship at 10 years was similar (P = .07). Mortality rate was higher in the elderly (P < .001). General complication rate was higher in the elderly (P = .031). Surgical complications rates were similar (P = .702). The PROMS at final follow-up were 4% lower in the elderly (P < .001).

CONCLUSION

TKA in the elderly is a safe procedure. With measures minimizing the perioperative complications and blood loss, the outcome can be expected to be similar to patients of average age. The projected implant and patient survivorship in the elderly cohort is long enough to suggest that TKA in the elderly could have a high impact on remaining quality of life. Level III retrospective study.

Single-Use Custom Instrumentation in Total Knee Arthroplasty: Effect on In-Hospital Complications, Length of Stay, and Discharge Disposition

Total knee arthroplasty (TKA) is a quality surgical intervention with rapidly increasing use. This growth has brought with it a host of new technologies, including custom instrumentation (CI). With the current emphasis on value-based health care, the clinical benefit of CI TKA must be evaluated. The goal of this study was to compare CI and conventional TKA regarding multiple quality metrics, in-hospital complications, length of stay, and discharge destination. The authors propensity score matched 231 conventional TKAs to 231 consecutive CI TKAs for age, sex, and body mass index. Preoperative risk factors analyzed were age, sex, body mass index, and preoperative hemoglobin. Perioperative factors included transfusion rate, hemoglobin drop, hemovac output, operative time, length of stay, discharge disposition, deep venous thrombosis and pulmonary embolism rates, and in-hospital vital sign data. There were no differences in preoperative demographics between groups. Postoperatively, there was no difference between conventional and CI TKA in operative time, transfusion rate, discharge hemoglobin, length of stay, discharge disposition, or in-hospital venous thromboembolism rates. In the conventional and CI groups, length of stay was 2.6 and 2.5 days (P=.43) and discharge disposition was 82% home and 83% home (P=.90), respectively. Although CI TKA is commonly implemented, in this analysis, compared with conventional TKA, it was not associated with any difference in length of stay, discharge disposition, operative time, transfusion rate, or in-hospital complications. [Orthopedics. 2019; 42(5):299-303.].

Blood management in total knee arthroplasty: state-of-the-art review

Total blood loss from primary total knee arthroplasty may exceed 2 L with greater blood loss during revision procedures. Blood loss and allogeneic transfusion are strongly associated with adverse outcomes from surgery including postoperative mortality, thromboembolic events and infection. Strategies to reduce blood loss and transfusion rates improve patient outcomes and reduce healthcare costs. Interventions are employed preoperatively, intraoperatively and postoperatively. The strongest predictor for allogeneic blood transfusion is preoperative anaemia. Over 35% of patients are anaemic when scheduled for primary and revision knee arthroplasty, defined as haemoglobin <130 g/L for men and women, and the majority of cases are secondary to iron deficiency. Early identification and treatment of anaemia can reduce postoperative transfusions and complications. Anticoagulation must be carefully managed perioperatively to balance the risk of thromboembolic event versus the risk of haemorrhage. Intraoperatively, tranexamic acid reduces blood loss and is recommended for all knee arthroplasty surgery; however, the optimal route, dose or timing of administration remains uncertain. Cell salvage is a valuable adjunct to surgery with significant expected blood loss, such as revision knee arthroplasty. Autologous blood donation is not recommended in routine care, sealants may be beneficial in select cases but further evidence of benefit is required, and the use of a tourniquet remains at the discretion of the surgeon. Postoperatively, restrictive transfusion protocols should be followed with a transfusion threshold haemoglobin of 70 g/L, except in the presence of acute coronary syndrome. Recent studies report no allogeneic transfusions after primary knee arthroplasty surgery after employing blood conservation strategies. The current challenge is to select and integrate different blood conserving interventions to deliver an optimal patient pathway with a multidisciplinary approach.

Optimizing Intraoperative Blood Management for One-Stage Bilateral Total Knee Arthroplasty

BACKGROUND

Effective blood management strategies are a major determinant of successful outcomes after one-stage bilateral total knee arthroplasty (BTKA). Proper patient selection with preoperative optimization and intra- and postoperative interventions can reduce transfusion risk and associated morbidity in these patients.

QUESTIONS/PURPOSES

The purpose of this study was to evaluate intraoperative blood management modalities based on three keystone questions: (1) What is the role of the anesthesiologist?, (2) Which are the surgeon-dependent strategies?, and (3) Is there any place for pharmacologic interventions?

METHODS

We searched the established electronic literature database MEDLINE. After critical appraisal, 94 studies were deemed eligible from which to draw documented evidence.

RESULTS

A number of blood-conserving methods are currently implemented in patients undergoing one-stage BTKA. Among them, regional anesthesia, tourniquet use, and tourniquet deflation after wound closure, femoral canal sparing or femoral canal plugging, avoidance of drains, and tranexamic acid use were the intraoperative strategies with documented efficacy in blood conservation.

CONCLUSION

Combined proper intraoperative anesthesiologic, surgical, and pharmacologic interventions reduce blood loss and need for transfusion in BTKA patients. However, contemporary relevant literature is lacking evidence-based guidelines.

Computer assisted total knee arthroplasty: a real navigation to better results?

BACKGROUND AND AIM OF THE WORK

Computer assisted surgery in knee replacement is still in discussion, but majority of papers affirm an increase of the accuracy in alignment. Aim of our study is to evaluate the accuracy of mechanical axis, the posterior tibial slope and the femoral component rotation with navigation, x-ray and CT data.

METHODS

We have analysed 145 patients who underwent total knee arthroplasty between January 2012 and December 2014. We have checked each patient at 6, 12 and 24 months of follow-up. During each visit, we did a clinical evaluation checking the ROM and a clinical score (KOOS). At 2 years, we did a CT evaluation and a plain x-ray evaluation.

RESULTS

125 patients have completed the follow-up. Mean follow-up time was 2,6 years. Both ROM and KOOS values increased during follow-up. About the mechanical axis, both x-ray and CT data showed a mean deviation <2° from the target. About posterior tibial slope and femoral component rotation, CT data showed a mean deviation of <3° from the target. Mean difference between navigation and CT data was <1°.

CONCLUSIONS

According to literature data, our data confirm that computer assisted surgery in knee replacement have a good accuracy of coronal alignment, rotational alignment and posterior tibial slope.

Computer-assisted stereotaxic navigation improves the accuracy of mechanical alignment and component positioning in total knee arthroplasty

INTRODUCTION

This study reports on a novel computer-assisted stereotaxic navigation (CASN) system that attempts to combine the accuracy of computer navigation with familiarity of conventional methods. We hypothesize that CASN would improve mechanical alignment and component positioning when compared to conventional instrumentation.

MATERIALS AND METHODS

145 patients (192 knees) retrospectively matched for age, BMI, gender and pre-operative scores, underwent total knee arthroplasty (TKA) using CASN (n = 92) or conventional instrumentation (n = 100). Pre- and post-operative radiological alignment [Acceptable ranges: mechanical axis (MA) 0° ± 3°, coronal femoral-component angle (CFA) and coronal tibia-component angle (CTA) 90° ± 3°] and clinical outcomes (Knee Society Scores, Oxford Knee Score and Short Form-36) at 6 months were examined.

RESULTS

The CASN group had significantly improved mean MA (1.9° ± 1.4°, versus 2.8° ± 2.0° in the conventional group, p = 0.001), CFA (1.6° ± 1.3°, versus 2.1° ± 1.5° in the conventional group, p = 0.035) and CTA (1.6° ± 1.2°, versus 2.1° ± 1.5° in the conventional group, p = 0.024). 91.3 % of knees in the CASN group were within 3° of a neutral mechanical axis, versus 74 % in the conventional group (p < 0.001). The duration of surgery was significantly longer in the CASN group (84 ± 22 vs 73 ± 15 min, p = 0.001) and cost an additional USD 850 per operation. There were no significant differences in clinical outcomes or satisfaction rates at 6 months post-operatively (p > 0.05).

CONCLUSIONS

CASN improved TKA mechanical alignment and component positioning, however, resulted in longer and costlier surgery with no benefits in short-term functional outcomes, despite providing familiarity to surgeons accustomed to conventional instrumentation.

LEVEL OF EVIDENCE

III.