The effect of computer navigation on blood loss and transfusion rate in TKA

The degree of C-reactive protein elevation after total knee arthroplasty is related to bone and medullary injury rather than soft tissue

First, we want to find out whether computer-assisted surgery (CAS) for total knee arthroplasty (TKA), which does not require opening the femoral medullary canal, results in a lesser C-reactive protein (CRP) level increase postoperatively compared to manual TKA. Second, they seek to examine whether the CRP reduction in CAS TKA and manual TKA follows a similar pattern within the first 2 weeks after surgery. Third, the study aims to compare and analyze the CRP levels in 3 different groups: CRP levels in CAS TKA with surgeons who started TKA surgery by CAS, CRP levels in manual TKA by surgeons with little experience, and CRP levels in skillful manual TKA performed after conducting over 200 cases. The 3 patient groups were as follows. Group 1: Patients who underwent non expertized surgeon CAS TKA (N = 63). Group 2: Patients who underwent manual TKA after surgeon CAS TKA experience (N = 108). Group 3: Patients who underwent manual TKA after surgeon 200 cases or more of either CAS TKA or manual TKA experience (more skillful manual TKA) (N = 66). CRP levels were analyzed using electronic medical records for 3 time points: within 3 months before surgery, 5 days after surgery, and 11 days after surgery. There were no statistically significant differences in pre operative CRP values among the 3 groups. At 5 days after surgery, the CRP level were 48.59 ± 32.75 for CAS TKA, 69.82 ± 42.76 for early manual TKA, and 67.73 ± 44.00 for skillful manual TKA, indicating a statistically significant lower CRP level in the CAS TKA group compared to the manual TKA groups (P = .01). At 11 days after surgery, there were no statistically significant differences in CRP level among the 3 groups, with was 12.12 ± 9.74 for CAS TKA, 14.07 ± 13.18 for early manual TKA, and 11.43 ± 11.45 for skillful manual TKA. The degree of CRP elevation after TKA is related to bone and medullary injury rather than soft tissue.

Does the accelerometer-based navigation system reduce blood loss and transfusion in one-stage sequential bilateral total knee arthroplasty? A randomized double-blind controlled trial

BACKGROUND

Total knee arthroplasty (TKA) is associated with significant blood loss and postoperative transfusion. The accelerometer-based navigation (ABN) system guides the bone cutting plane without breaching the intramedullary canal, which may reduce bleeding. This study aimed to investigate blood loss and transfusion compared between the ABN system and the conventional procedure in patients undergoing one-stage sequential bilateral TKA (SBTKA).

METHODS

A total of 66 patients scheduled for SBTKA were randomly allocated to either the ABN or conventional group. Postoperative hematocrit (Hct) level, drainage blood loss, transfusion rate, and amount of packed red cell transfusion were collected. Total red blood cell (RBC) loss was then calculated for the primary outcome.

RESULTS

The mean calculated total RBC loss in the ABN and conventional group was 669.7 and 630.0 mL, respectively (p = 0.572). There was no significant difference between groups for other evaluated outcome parameters, including postoperative Hct level, drainage blood loss, or packed red cell transfusion volume. All patients in the conventional group required postoperative blood transfusion while 96.8% of patients in the ABN group were transfused.

CONCLUSIONS

The total RBC loss and volume of packed red cells transfusion were not significant difference between interventions, which suggest no benefit of the ABN system in reducing blood loss and transfusion in patients undergoing SBTKA.

TRIAL REGISTRATION

The protocol of this study was registered in the Thai Clinical Trials Registry database no. TCTR20201126002 on 26/11/2020.

Computer Navigation Assisted Restricted Kinematic Alignment Improves Short-Term Outcomes in Total Knee Arthroplasty: An Ambispective Cohort Study

OBJECTIVES

Mechanical alignment (MA)-total knee arthroplasty (TKA) has been challenged due to the excessive soft tissue release and the evidence of the clinical outcomes of computer assisted navigation is still limited. The aim of this ambispective cohort study was to: (i) investigate whether computer assisted navigation is capable to achieve restricted kinematic alignment (rKA)-TKA; and (ii) compare the short-term outcomes between rKA-TKA and MA-TKA.

METHODS

We retrospectively included 41 patients diagnosed with osteoarthritis who received MA-TKA between April 2019 and January 2021 and 43 patients diagnosed with osteoarthritis who received rKA-TKA were included in the prospective cohort from January 2021 to September 2021. Demographical, peri-operative, and radiological data were collected and compared. Unpaired two-sample t-test for continuous variables and χ2 test for categorical variables were used to compare various measurements in two groups. The patient-reported outcome measures at baseline, 10 days (T1), and 6 months (T6) after surgery were statistically analyzed by generalized estimating equation (GEE) models.

RESULTS

Fourty-one patients (45 knees) and 43 patients (48 knees) were included in the MA and the rKA group respectively. Three constitutional knee phenotypes (II, I, IV) were the commonest in our population. Navigation improved the surgical accuracy (1.5° vs 3.5°, p < 0.001) and precision (interquartile range 4.0 vs 2.0, p < 0.001) in the rKA group than the MA group. The changes in Knee Injury and Osteoarthritis Outcome Score 12 (KOOS12), EuroQol five-dimension questionnaire (EQ5D) from baseline to T1 and T6 for patients with on-target rKA were larger than on-target MA counterparts (26.053 vs 18.607, P < 0.001(KOOS12, T1) , 0.457 vs 0.367 p < 0.001(EQ5D, T1) ; 51.017 vs 46.896, P = 0.023(KOOS12, T6) , 0.606 vs 0.565, P = 0.01(EQ5D, T6) ). Patients with on-target rKA had better Forgotten Joint Score (FJS) at T1 (54.126 vs 40.965, P = 0.002) compared with on-target MA counterparts.

CONCLUSIONS

Computer assisted navigation achieved the level of accuracy required by rKA-TKA. rKA-TKA offered significantly better short-term outcomes than MA-TKA.

Revisiting Short-term Outcomes of Conventional and Computer-Assisted Total Knee Arthroplasty: A Population-based Study

Background:

Population-based studies showing the advantage of computer-assisted total knee arthroplasty (CATKA) over conventional total knee arthroplasty (TKA) are outdated. More recent institution-based studies with relatively small sample sizes may hinder wider adoption. This cohort-based study aimed to compare postoperative CATKA and TKA in-hospital complications and 90-day all-cause readmissions using 2017-2018 data.

Methods:

Patients who underwent a primary unilateral CATKA or TKA were identified in the New York Statewide Planning and Research Cooperative System database. In-hospital complications were defined based on the 2020 Centers for Medicare & Medicaid Services total hip arthroplasty and TKA complications measure. Ninety-day readmissions were identified using unique patient identifiers. Logistic regression with a generalized estimating equation was used to assess associations of computer assistance with in-hospital complications and 90-day all-cause readmissions.

Results:

A total of 80,468 TKAs were identified during the study period, of which 7,395 (9.2%) were CATKAs. Significantly fewer complications occurred among patients who had CATKAs compared with conventional TKAs (0.4% of total CATKAs vs 2.6% of total conventional TKAs, P < 0.001); patients who had CATKAs had fewer 90-day all-cause readmissions compared with those who underwent TKAs (363 vs 4,169 revisits, P < 0.01). Computer assistance was associated with significantly lower odds of in-hospital complications (odds ratio, 0.15, 95% confidence interval, 0.09 to 0.24; P < 0.05) but not 90-day all-cause readmissions.

Conclusion:

Patients undergoing CATKAs had markedly lower odds of in-hospital complications, compared with patients having TKAs, which has implications for both patient outcomes and hospital reimbursement. These more recent cohort-based findings encourage wider CATKA adoption.

Robotics versus personalized 3D preoperative planning in total knee arthroplasty: a propensity score-matched analysis

Purpose

Lower limb alignment is crucial in total knee arthroplasty (TKA). Previous studies have shown that robotics and personalized three-dimensional (3D) preoperative planning could improve postoperative alignment accuracy compared with conventional TKA, but comparison between the above two techniques has never been reported. The authors hypothesized that robotics may be superior to personalized 3D preoperative planning in terms of postoperative alignment in primary TKA, with similar patient-reported outcome measures (PROMs) but higher cost and longer operative time.

Methods

A consecutive series of patients who received TKA in our center from September 2020 to January 2021 were enrolled retrospectively. After 1:2 matching, 52 and 104 patients were included and divided into study group for robotics and control group for personalized 3D preoperative planning, respectively. Multiple postoperative alignment angles were measured, and clinical features such as operation and tourniquet time, length of hospital stay and hemoglobin (Hb) were recorded. Knee Society Score (KSS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used to evaluate clinical results.

Results

Compared with control group, robotics group had significantly lower frontal femoral component angle (FFC) and frontal tibial component angle (FTC) absolute deviation (P < 0.05). It also had less outliers in hip–knee–ankle angle (HKA), FTC, lateral femoral component angle (LFC) and lateral tibial component angle (LTC) (P < 0.05). Hb loss of robotics group was significantly lower than control group (P < 0.001), while the operation and tourniquet time were longer (P < 0.001). There was no significant difference in KSS and WOMAC scores between two groups.

Conclusion

Compared with control group, patients in robotics group had significantly less malalignment, malposition, Hb loss, but similar PROMs. The operations in robotics group spent longer operation time and cost more compared with control group.

Trial registration: The Chinese Clinical Trial Registry, ChiCTR2000036235. Registered 22 August 2020, http://www.chictr.org.cn/showproj.aspx?proj=59300.

Level of evidence

III.

Navigation assisted total knee arthroplasty in 54,114 patients: No increased risk in acute complications and hospital utilisation

BACKGROUND

The advent of navigation in total knee arthroplasty (TKA) has generated interest in attempt to improve component positioning as desired and clinical outcomes. The aim of this study was to evaluate 90-day complication and cost of navigation-assisted TKAs (NTKA) compared to conventional TKAs (CTKA) using a national database.

METHODS

A retrospective review of national database was conducted on all patients who underwent TKA from 2010 and 2017. The cohort was stratified into NTKA and CTKA subcohorts, excluding cases utilizing robotics.

RESULTS

NTKA was associated with a significant decrease in 90-day postoperative major and minor complications. NTKA was also associated with a decrease in 90-day hospital utilization with lower rates of emergency department visits and readmissions. The cost of hospitalization and total 90-day costs were lower in NTKA, with an average savings of $800.

CONCLUSION

The adoption of navigation in TKA is safe and efficaceous compared to CTKA.

LEVEL OF EVIDENCE

III. Retrospective cohort study.

No definite advantage of a portable accelerometer-based navigation system over conventional technique in total knee arthroplasty: A systematic review and meta-analysis

BACKGROUND

Precise implant alignment is a crucial prognostic factor in total knee arthroplasty (TKA). Portable navigation systems (PN-TKA) were reported to be better than the conventional technique (CON-TKA). We hypothesized that PN-TKA offered greater radiologic precision than CON-TKA in mechanically aligning components. We investigated whether (1) it improved global mechanical alignment, and (2) optimized component placement with respect to the tibial and femoral mechanical axes.

PATIENTS AND METHODS

A systematic literature review compared PN-TKA versus CON-TKA. PubMed, Web of Science and Cochrane Library search retrieved ten studies. Their data were pooled using RevMan 5.3. Odds ratios (OR) for dichotomous data were calculated with 95% confidence intervals (CIs) for each outcome. Statistical heterogeneity was assessed as I² using a standard χ² test. I²>50% denoted significant heterogeneity requiring a random effects model; otherwise, a fixed effects model was applied.

RESULTS

There were significantly fewer outliers for mechanical axis (I²=24%, OR=0.62, 95% CI=0.42-0.91, p=0.02) and coronal femoral component angle (I²=58%, OR=0.31, 95% CI=0.13-0.73, p=0.007) using PN-TKA; however, no significant difference was observed for coronal tibial component angle outliers (I²=0%, OR=0.66, 95% CI=0.38-1.15, p=0.14).

DISCUSSION

Although PN-TKA appeared to improve global alignment, it had no effect on coronal tibial alignment, which is a key factor in predicting the long-term success of component fixation. There thus appeared to be no definite advantage of PN-TKA over CON-TKA.

LEVEL OF EVIDENCE

III.

Agreement of surgical blood loss estimation methods

BACKGROUND

Surgical blood loss is usually estimated by different formulae in studies of strategies aimed at reducing perioperative bleeding. This study assessed and compared the agreement of the main blood loss estimation formulae using a direct measurement of blood loss as the reference method.

STUDY DESIGN AND METHODS

Eighty consecutive patients undergoing urologic laparoscopic surgery were studied. Only optimal conditions for the direct measurement of surgical blood loss were considered. Surgical blood loss was estimated by six formulae at four different postoperative time points. The agreement of the formulae was evaluated by the Concordance correlation coefficient (CCC) and Bland-Altman analyses. An analysis of the agreement's variability regarding different magnitudes of blood loss was also performed.

RESULTS

Directly measured blood loss ranged from 200 to 2200 mL. The formulae studied showed poor agreement with the direct measurement of blood loss; 95% limits of agreement widely exceeded the criterion of ±560 mL. Significant biases were found, which for most of the formulae led to an overestimation of blood loss. For all formulae, agreement remained constant regardless of the amount of blood loss, with limits between -40 and +120% approximately. Among the formulae, the best agreement was achieved by López-Picado's formula at 48 hours (CCC: 0.577), with a bias of +283 mL and 95% limits of agreement between -477 and +1043 mL.

CONCLUSION

Formulae currently used to estimate surgical blood loss differ substantially from direct measurements; therefore, they may not be reliable methods of blood loss quantification in the surgical setting.

Rivaroxaban improves hidden blood loss, blood transfusion rate and reduces swelling of the knee joint in knee osteoarthritis patients after total knee replacement

Osteoarthritis (OA) is the third most common diagnosis made by general practitioners in older patients. The purpose of the current study is to investigate effects rivaroxaban had on both hidden blood loss and blood transfusion rate (BTR) in patients with knee OA (KOA) after going through a total knee replacement (TKR).Between the time periods of December 2011 up until January 2015, a total of 235 patients underwent TKR and were selected to be assigned to either the rivaroxaban or nonanticoagulant groups. Coagulation function indexes before surgery and following administration of rivaroxaban, total blood loss, hidden blood loss, dominant blood loss, blood transfusion volume, hemoglobin reduction, degree of postoperative pain (visual analogue scale), the degree of knee swelling, and range of motion following surgery were all recorded. Hospital for special surgery (HSS) scores offered an objective evaluation for the knee joint functions before surgery at the intervals of 2 weeks and after surgery at intervals of 3 months, 6 months, 12 months, and 24 months.Patients in the rivaroxaban group had shown a higher hidden blood loss, as well as a higher BTR, compared to those involved in the nonanticoagulant group. BTR was found to have been 49.59% in the rivaroxaban group, and 35.09% for the nonanticoagulant group. Patients in the rivaroxaban group had lower degrees of knee swelling than those involved in the nonanticoagulant group. There was no deep vein thrombosis (DVT) detected in the rivaroxaban group, whereas 5 DVT cases were detected in the nonanticoagulant group. In the rivaroxaban group, the HSS scores of the knee joint functions were remarkably higher at the 2-week mark in succession to the surgery than those involved with the nonanticoagulant group.This overall data demonstrated that KOA patients after TKR had presented with a higher hidden blood loss, BRT, and lower swelling degrees of the knee joint after being treated by the rivaroxaban.

No benefit of autologous transfusion drains in total knee arthroplasty

PURPOSE AND HYPOTHESIS

Autologous blood transfusion drains are commonly used to reduce allogeneic blood transfusion rate after total knee arthroplasty. There is conflicting evidence as to whether autologous transfusion drains (ABT drains) were effective when restrictive transfusion triggers were used. The aim of our study was to ascertain where, as a part of a blood management protocol, autologous blood transfusion drains reduce the allogeneic blood transfusion rate after total knee arthroplasty.

METHODS

Two-hundred total knee arthroplasty patients were included in the prospective randomized controlled study. After implantation, a Redon drain without vacuum assistance (control, n = 100) or an autologous blood transfusion drain (ABT group, n = 100) was used. Demographic and operative data were collected. The blood loss, total blood loss, blood values and transfusion rate were documented.

RESULTS

The blood loss in the drains was significantly increased for the ABT group (409 vs. 297 ml, p < 0.001). There was a non-significant trend towards a higher total blood loss for ABT patients (1844 vs. 1685 ml, n.s.). The allogeneic blood transfusion rate was similar for both groups (8 vs. 9%, n.s.). Similarly, the number of transfused blood units was comparable between both groups (0.2U/patient vs. 0.17U/patient n.s.).

CONCLUSION

In combination with restrictive blood transfusion triggers, ABT drains had no positive effect on the allogeneic blood transfusion rate. The blood loss in ABT drains was higher. As a consequence, the use of ABT drains was discontinued.

LEVEL OF EVIDENCE

I.

Computer-Assisted Total Knee Arthroplasty: Is There a Difference Between Image-Based and Imageless Techniques?

BACKGROUND

Image-based and imageless computer-assisted total knee arthroplasty (CATKA) has become increasingly popular. This study aims to compare outcomes, including perioperative complications and transfusion rate, between CATKA and conventional total knee arthroplasty (TKA), as well as between image-based and imageless CATKA.

METHODS

Using the 9th revision of the International Classification of Diseases codes, we queried the Nationwide Inpatient Sample database from 2005 to 2011 to identify unilateral conventional TKA, image-based, and imageless CATKAs as well as in-hospital complications and transfusion rates.

RESULTS

A total of 787,809 conventional TKAs and 13,246 CATKAs (1055 image-based and 12,191 imageless) were identified. The rate of CATKA increased 23.13% per year from 2005 to 2011. Transfusion rates in conventional TKA and CATKA cases were 11.73% and 8.20% respectively (P < .001) and 6.92% in image-based vs 8.27% in imageless (P = .023). Perioperative complications occurred in 4.50%, 3.47%, and 3.41% of cases after conventional, imageless, and imaged-based CATKAs, respectively. Using multivariate analysis, perioperative complications were significantly higher in conventional TKA compared to CATKA (odds ratio = 1.17, 95% confidence interval 1.03-1.33, P = .01). There was no significant difference between imageless and image-based CATKA (P = .34). Length of hospital stay and hospital charges were not significantly different between groups (P > .05).

CONCLUSION

CATKA has low complication rates and may improve patient outcomes after TKA. CATKA, especially the image-based technique, may reduce in-hospital complications and transfusion without increasing hospital charges and length of hospital stay significantly. Large prospective studies with long follow-up are required to verify potential benefits of CATKA.

Usefulness of an accelerometer-based portable navigation system in total knee arthroplasty

Aims

The aim of this study was to evaluate the effects of using a portable, accelerometer-based surgical navigation system (KneeAlign2) in total knee arthroplasty (TKA) on the alignment of the femoral component, and blood loss.

Patients and Methods

A total of 241 consecutive patients with primary osteoarthritis of the knee were enrolled in this prospective, randomised controlled study. There were 207 women and 34 men. The mean age of the patients was 74.0 years (57 to 89). The KneeAlign2 system was used for distal femoral resection in 121 patients (KA2 group) and a conventional intramedullary femoral guide was used in 120 patients (IM group).

Results

One patient (0.8%) in the KA2 group and 19 in the IM group had an alignment which was > 3° away from the neutral mechanical axis (p < 0.01). The mean deviation from neutral alignment was 1.01° (standard deviation (sd) 1.0°) in the KA2 group and 1.93° (sd 1.7°) in the IM group (p < 0.01). Blood loss was significantly less in the KA2 group compared with the IM group (784 ml (sd 357) versus 1071 ml (sd 310), p < 0.001).

Conclusion

The KneeAlign2 system provides a technically straightforward method for identifying the femoral head and performing an accurate distal femoral resection at TKA with significantly less blood loss compared with a conventional intramedullary guide. Cite this article: Bone Joint J 2017;99-B:1047–52.

Computer Navigated Total Knee Arthroplasty: Rates of Adoption and Early Complications

BACKGROUND

When new technologies are introduced, it is important to evaluate the rate of adoption and outcomes compared with preexisting technology. The purpose of this study was to determine the adoption rate of computer-assisted navigation in total knee arthroplasty (TKA), to determine if the short-term complication rate changed over time with navigation, and to compare short-term complication rates of navigated and traditional TKA.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was used to identify 108,277 patients undergoing primary TKA between 2010 and 2014, of which 3573 cases (3.30%) were navigated. Rates of adoption of navigated TKA were determined. Differences in short-term complications by year were compared using propensity score matching.

RESULTS

Navigation utilization decreased from 4.96% in 2010 to 3.06% in 2014. Blood transfusion rates for the entire cohort decreased from 19% in 2011 to 6% in 2014, and was not decreased with navigation compared with traditional TKA in 2014 (P = .1309). Operative time was not increased by navigation, and average 94.2 minutes. There were no significant differences in all-cause complications, reoperation rate, unplanned readmission, or length of stay for any year.

CONCLUSIONS

There was a 38.3% decrease in TKA navigation utilization from 2010-2014. Blood transfusion rates decreased 68% over the 5-year study, and were not decreased with navigation in 2014. Navigation was not found to increase operative time. There were no significant differences in short-term complications, readmission rate, or length of stay between navigated and traditional TKA.

Clinical, radiological and survivorship results after ten years comparing navigated and conventional total knee arthroplasty: a matched-pair analysis

PURPOSE

Our aim was to compare the long-term outcome between navigated and conventional total knee arthroplasty (TKA), which is currently not known.

METHODS

Long-term survivorship, clinical scores and radiographic results of a matched-pair group of 350 patients (350 knees) treated with navigated (n = 157) or conventional (n = 188) TKA for osteoarthritis over a period of 11 years were reviewed retrospectively.

RESULTS

The mean clinical follow-up was ten years. There were no clinically relevant differences with respect to any clinical outcome, patient satisfaction or pain between the two groups. Coronal leg alignment was closer (1.7-3.1°) to the neutral mechanical axis in the navigated group compared with the conventional group (2.6-4.7°). A total of 12 knees (6.4%) in the conventional group and three (1.9%) in the navigated group underwent revision surgery (p = 0.04), resulting in an absolute risk reduction of 4.5% for revision surgery by using navigation. Using any revision as an end point, the ten-year Kaplan-Meier survivorship was 98.1% in the navigated and 92.5% in the conventional group.

CONCLUSIONS

Navigated TKA improves implant survivorship compared with conventional TKA.

Combined Administration of IV and Topical Tranexamic Acid is Not Superior to Either Individually in Primary Navigated TKA

BACKGROUND

In this study, we tried to assess if combined method (intravenous [IV] and topical) of tranexamic acid (TXA) administration, which has been shown to be superior in conventional arthroplasty, has similar effect in navigational arthroplasty compared to administration of drug either individually.

METHODS

In present randomized control trial, 200 patients were randomly divided in one of the 4 groups using computer-generated tables-control, IV, intraarticular, and combined. We studied evident loss through drain, total loss based on Gross method and hemoglobin balance method, hidden losses, hemoglobin and hematocrit drop, functional scores, and all possible complications related to TXA.

RESULTS

Evident loss in combined group was 535.55 mL, not significantly less than IV (585 mL, P = .15) and intraarticular group (514 mL, P = .74). However, these were significantly less than control group (696 mL, P = .000). Functional scores and recovery rates were, however, comparable in all 4 groups. No patients in any group developed symptomatic deep vein thrombosis.

CONCLUSION

Tranexamic use decreases blood loss in navigation-assisted arthroplasty, however, less than that observed for conventional arthroplasty in literature. Further, combined group has no added advantage over other methods of drug administration. We believe that additional amount of TXA administered in combined regimen may not be clinically useful. Further TXA group did not have any advantage in terms of functional recovery over control group.

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

PURPOSE

This meta-analysis was designed to evaluate the effects of computer navigation on blood conservation after total knee arthroplasty (TKA) by comparing postoperative blood loss and need for allogenic blood transfusion in patients undergoing computer navigation and conventional primary TKAs.

METHODS

Studies were included in this meta-analysis if they compared change in haemoglobin concentration before and after surgery, postoperative blood loss via drainage or calculated total blood loss, and/or allogenic blood transfusion rate following TKA using computer navigation and conventional methods. For all comparisons, odds ratios and 95 % confidence intervals (CI) were calculated for binary outcomes, while mean difference and 95 % CI were calculated for continuous outcomes.

RESULTS

Twelve studies were included in this meta-analysis. The change in haemoglobin concentration was 0.39 g/dl lower with computer navigation than with conventional TKA (P = 0.006). Blood loss via drainage was 83.1 ml (P = 0.03) lower and calculated blood loss was 185.4 ml (P = 0.002) lower with computer navigation than with conventional TKA. However, the need for blood transfusion was similar for the two approaches (n.s.).

CONCLUSIONS

The primary TKA with computer navigation was effective in reducing haemoglobin loss and blood loss, but had no effect on transfusion requirement, compared with conventional primary TKA. These findings suggest the importance of analysing several blood loss parameters, because each may not always accurately reflect true postsurgical bleeding.

LEVEL OF EVIDENCE

Meta-analysis, Level III.

Inpatient mortality after elective primary total hip and knee joint arthroplasty in Botswana

PURPOSE

Total hip and knee joint arthroplasty (TJA) rank among the most successful orthopaedic operations. Several developing countries in Africa have started to perform these procedures that are routine in developed countries. The aims of this study were to measure the incidence and assess the determinants of in-hospital mortality after elective primary TJA in our unit and compare it with published data.

METHODS

This was a retrospective study of the first consecutive cohort of patients who underwent elective primary TJA in Princess Marina Hospital, Botswana between March 2009 and October 2015 (6.5 years).

RESULTS

346 elective joint replacements were performed comprising 153 total hip arthroplasties (THA) and 193 total knee arthroplasties (TKA); 36 % of the THA were in female patients and 82 % of TKA were in females. The mean age was 64.5 years (range 26-86). Three patients died giving an inpatient mortality rate of 0.86 %. These three mortalities represent 1.55 % (three out of 193) of all the TKA. There were no deaths after THA. The cause of mortality in two patients was an adverse cardiac event while the third mortality was due to pulmonary embolism.

CONCLUSION

The inpatient mortality rate of 0.86 % following TJA is higher than the reported rates in the developed countries but comparable with data from other developing countries. The inpatient mortality rate following TKA was higher than that following THA and cardiovascular events proved to be the main cause of death. We recommend formal cardiology assessment and close peri-operative monitoring of all patients with a history of cardiovascular disease undergoing TJA.

Thirty-Day Complications of Conventional and Computer-Assisted Total Knee and Total Hip Arthroplasty: Analysis of 103,855 Patients in the American College of Surgeons National Surgical Quality Improvement Program Database

BACKGROUND

Computer-assisted surgery (CAS) has gained popularity in orthopedics for both total knee arthroplasty (TKA) and total hip arthroplasty (THA) in the past decades.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients who underwent a primary, unilateral THA and TKA from 2011 to 2013. Multivariate analysis was conducted to compare the postoperative complications in patients whose surgery involved the use of CAS with those by conventional techniques.

RESULTS

We identified 103,855 patients who had THA and TKA in the database between 2011 and 2013. There were higher overall adverse events (odds ratio [OR], 1.40; CI, 1.22-1.59), minor events (OR, 1.38; CI, 1.21-1.58), and requirements for blood transfusion (OR, 1.44; CI, 1.25-1.67) in the conventional group when compared with CAS for TKA. However, rate of reoperation was higher in the CAS group for TKA (OR, 1.60; CI, 1.15-2.25). The results also showed higher overall adverse events (OR, 2.61; CI, 2.09-3.26), minor events (OR, 2.82; CI, 2.24-3.42), and requirements for blood transfusion (OR, 3.41; CI, 2.62-4.44) in the conventional group when compared to CAS for THA. Nevertheless, superficial wound infections (OR, 0.46; CI, 0.26-0.81) were shown to be higher in the CAS group undergoing THA.

CONCLUSION

The use of CAS in THA and TKA reduced the number of minor adverse events in the first 30 days postoperatively. However, CAS was associated with an increased number of reoperations and superficial infections. The clinical benefits and disadvantages of CAS should be considered when determining the potential benefit-cost ratio of this technology.

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.

Computerized tomography based "patient specific blocks" improve postoperative mechanical alignment in primary total knee arthroplasty

AIM

To compare the postoperative mechanical alignment achieved after total knee arthroplasty (TKA) using computer tomography (CT) based patient specific blocks (PSB) to conventional instruments (CI).

METHODS

Total 80 knees were included in the study, with 40 knees in both the groups operated using PSB and CI. All the knees were performed by a single surgeon using the same cruciate sacrificing implants. In our study we used CT based PSB to compare with CI. Postoperative mechanical femoro-tibial angle (MFT angle) was measured on long leg x-rays using picture archiving and communication system (PACS). We compared mechanical alignment achieved using PSB and CI in TKA using statistical analysis.

RESULTS

The PSB group (group 1) included 17 females and seven males while in CI group (group 2) there were 15 females and eight males. The mean age of patients in group 1 was 60.5 years and in group 2 it was 60.2 years. The mean postoperative MFT angle measured on long-leg radiographs in group 1 was 178.23° (SD = 2.67°, range: 171.9° to 182.5°) while in group 2, the mean MFT angle was 175.73° (SD = 3.62°, range: 166.0° to 179.8°). There was significant improvement in postoperative mechanical alignment (P value = 0.001), in PSB group compared to CI. Number of outliers were also found to be less in group operated with PSB (7 Knee) compared to those operated with CI (17 Knee).

CONCLUSION

PSB improve mechanical alignment after total knee arthroplasty, compared to CI. This may lead to lower rates of revision in the PSB based TKA as compared to the conventional instrumentation.

Four Methods for Calculating Blood-loss after Total Knee Arthroplasty

BACKGROUND

Currently, various calculation methods for evaluating blood-loss in patients with total knee arthroplasty (TKA) are applied in clinical practice. However, different methods may yield different results. The purpose of this study was to determine the most reliable method for calculating blood-loss after primary TKA.

METHODS

We compared blood-loss in 245 patients who underwent primary unilateral TKA from February 2010 to August 2011. We calculated blood-loss using four methods: Gross equation, hemoglobin (Hb) balance, the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula, and Hb-dilution. We determined Pearson's correlation coefficients for the four methods.

RESULTS

There were large differences in the calculated blood-loss obtained by the four methods. In descending order of combined correlation coefficient based on calculated blood-loss, the methods were Hb-balance, OSTHEO formula, Hb-dilution, and Gross equation.

CONCLUSIONS

The Hb-balance method may be the most reliable method of estimating blood-loss after TKA.

The Mark Coventry Award: Custom Cutting Guides Do Not Improve Total Knee Arthroplasty Clinical Outcomes at 2 Years Followup

BACKGROUND

Custom cutting guides (CCGs; sometimes called patient-specific instrumentation [PSI]) in total knee arthroplasty (TKA) use preoperative three-dimensional imaging to fabricate cutting blocks specific to a patient's native anatomy.

QUESTIONS/PURPOSES

The purposes of this study were to determine if CCGs (1) improve clinical outcomes as measured by UCLA activity, SF-12, and Oxford knee scores; and (2) coronal mechanical alignment versus standard alignment guides.

METHODS

This was a retrospective cohort study of patients undergoing primary TKA using the same cruciate-retaining, cemented TKA system between January 2009 and April 2012. Patients were included if they were candidates for a unilateral, cruciate-retaining TKA and met other prespecified criteria; patients were allowed to self-select either an MRI-based CCG procedure or standard TKA. Ninety-seven of 120 (80.8%) patients in the standard and 104 of 124 (83.9%, p = 0.5) in the CCG cohort with a minimum of 1-year followup were available for analysis. The first 95 patients in the standard (mean followup, 3 years; range, 1-4 years) and CCG (mean followup, 2 years; range, 1-4 years) cohorts were compared. The alignment goal for all TKAs was a hip-knee-ankle (HKA) angle of 0°. UCLA, SF-12, and Oxford knee scores were collected preoperatively and at each patient's most recent followup visit. Postoperative, rotationally controlled coronal scout CT scans were used to measure HKA alignment. Independent-sample t-tests and chi-square tests were used for comparisons with a p value ≤ 0.05 considered significant.

RESULTS

At the most recent followup, no differences were present between the two cohorts for range of motion (114° ± 14° in CCG versus 115° ± 15° in standard, p = 0.7), UCLA (6 ± 2 in CCG versus 6 ± 2 in standard, p = 0.7), SF-12 physical (44 ± 12 in CCG versus 41 ± 12 in standard, p = 0.07), or Oxford knee scores (39 ± 9 in CCG versus 37 ± 10 in standard, p = 0.1). No differences were present for the incremental improvement in the UCLA (1 ± 4 in CCG versus 1 ± 3 in standard, p = 0.5), SF-12 physical (12 ± 20 in CCG versus 11 ± 21, p = 0.8), or Oxford knee scores (16 ± 9 in CCG versus 19 ± 10 in standard, p = 0.1) from preoperatively to postoperatively. There was no difference in the percentage of outliers for alignment (23% in standard versus 31% in CCG with HKA outside of 0° ± 3°; p = 0.2) between the two cohorts.

CONCLUSIONS

At a mean followup of greater than 2 years, CCGs fail to demonstrate any advantages in validated knee outcome measure scores or coronal alignment as measured by CT scan versus the use of standard instrumentation in TKA. The clinical benefit of CCGs must be proven before continued implementation of this technology.

LEVEL OF EVIDENCE

Level III, retrospective controlled study.

Modern abbreviated computer navigation of the femur reduces blood loss in total knee arthroplasty

Computer assisted surgery (CAS) optimizes component position in total knee arthroplasty (TKA), yet effects specifically on blood loss are less known. This study purpose was to determine whether a modern abbreviated CAS protocol would reduce blood loss in TKA compared to conventional instrumentation. One hundred consecutive TKAs were retrospectively reviewed comparing abbreviated CAS versus conventional IM instrumentation. Blood loss was determined using drain output, change in hemoglobin, and calculated blood loss. The CAS group demonstrated less hourly drain output (P=0.02), hemoglobin change (P=0.001), and estimated blood loss (P=0.001) versus conventional instrumentation. With proven advantages of accurate component placement and improved functional outcome after TKA, CAS provides additional value by reducing blood loss in TKA.

Surgical and Functional Outcomes in Patients Undergoing Total Knee Replacement With Patient-Specific Implants Compared With "Off-the-Shelf" Implants

Background

Total knee arthroplasty (TKA) instrumentation and implant designs have been evolving, with one of the current innovations being patient-specific implants (PSIs).

Purpose

To evaluate whether there is a significant difference in surgical time, intraoperative blood loss, postoperative range of motion, and length of stay between PSI and conventional TKA.

Study Design

Cohort study; Level of evidence, 3.

Methods

A consecutive series of 621 TKA patients, 307 with PSIs and 314 with conventional implants, was reviewed. Differences in estimated blood loss, length of stay, range of motion, and surgical time/tourniquet time between the 2 cohorts were analyzed.

Results

Linear regression analysis demonstrated that PSI decreased estimated blood loss by 44.72 mL (P < .01), decreased length of stay by 0.39 days (P < .01), decreased postoperative range of motion by 3.90° (P < .01), and had a negligible difference on surgical and tourniquet time.

Conclusion

The use of PSI is associated with decreased estimated blood loss, decreased length of stay, decreased range of motion, and no discernible difference in surgical or tourniquet time, all of which are unlikely to be clinically significant.

Effects of Computer Navigation versus Conventional Total Knee Arthroplasty on Endothelial Damage Marker Levels: A Prospective Comparative Study

Total knee arthroplasty (TKA) inevitably perturbs the femoral medullary canal, which increases blood loss or morbidities associated with marrow embolization postoperatively. Computer navigation TKA reportedly minimizes medullary disturbance to alleviate perioperative blood loss. We performed a prospective comparative study, enrolling 87 patients with osteoarthritic knees from March 2011 to December 2011 in our hospital. The patients were separated into two groups, according to the surgeon they visited. Fifty-four patients underwent computer navigation TKAs and 33 had conventional TKAs. Levels of cell adhesion molecules (CAMs), including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and platelet endothelial cellular adhesion molecule-1 (PECAM-1) in sera and hemovac drainage were measured by ELISA before and 24 hours after the surgery. We showed that patients receiving computer navigation TKAs had less blood loss and lower CAMs in serum and hemovac drainage after the operation. Less postoperative elevation of serum ICAM-1 (p=0.022) and PECAM-1 (p=0.003) from the preoperative baseline after the surgery was also noted. This study provides molecular evidence for the differential extent in vascular injury between conventional and navigation TKAs and sheds light on the possible benefits of computer navigation TKAs.

Comparison of Floseal(r) and electrocautery in hemostasis after total knee arthroplasty

Objective

To evaluate whether hemostasis with eletrocauterization in comparison with Floseal^(r) leads to different bleeding rates during total knee arthroplasty.

Methods

A comparative study was performed between two groups: group with ten consecutive total knee arthroplasties with Floseal^(r) used as hemostatic method and control group with ten consecutive total knee arthroplasties with eletrocauterization as hemostatic method. Bleeding parameters such as debit of the drain, liquid infusion and blood transfusion rate were recorded.

Results

Floseal^(r) group received less blood transfusion, less liquid infusion and lower drainage in absolute numbers compared to the control group. However, no parameter was statistically significant.

Conclusion

Hemostasis with Floseal^(r) is as effective as hemostasis with eletrocauterization, what makes it a viable alternative to patients with contraindication to electric scalpel use. Level of Evidence II, Prospective Comparative Study.

Custom-fit minimally invasive total knee arthroplasty: effect on blood loss and early clinical outcomes

PURPOSE

Recently, new custom-fit pin guides in total knee arthroplasty (TKA) have been introduced. Use of these guides may reduce operating time. Use of the guides combined with the absence of intramedullary alignment jigs may lead to reduced blood loss and improved early outcomes. Our aim was to evaluate blood loss and early clinical outcomes in patients undergoing minimally invasive TKA using custom-fit magnetic resonance imaging (MRI)-based pin guides.

METHODS

A prospective study in 80 patients was carried out. Patients were divided randomly into 2 equal groups. In one group, intramedullary alignment jigs were used. In the second group, custom-fit MRI-based pin guides were used. All patients received the same cemented posterior-stabilized implant through a mini-midvastus approach. The volume in the drain bottles was recorded after 48 h. Hb loss was estimated by subtracting the postoperative from the preoperative Hb level. Transfusion requirements and surgical time were recorded. Outcome measures were Knee Society Scores (KSS), knee flexion, knee swelling and pain.

RESULTS

There was lower mean drainage of blood in the custom-fit group (391 ml vs. 603 ml; p < 0.0001). There was no difference in estimated loss of Hb (3.6 g/dl vs. 4.1 g/dl; n.s.) and in transfusion requirements (7.5 % vs. 10 %; n.s.). Surgical time was reduced in the custom-fit group (12 min less; p = 0.001). KSS measured at week 2, 6 and 12 showed no significant difference between groups. Knee flexion measured on days 7, 10 and at week 6, 12 and knee swelling and pain measured on days 1, 3, 10 and at week 6, 12 showed no significant difference between groups.

CONCLUSIONS

Using custom-fit pin guides reduces blood drainage, but not the estimated Hb loss in minimally invasive TKA and does not affect transfusion rate. Surgical time is reduced. There is no effect on the early clinical outcomes.

LEVEL OF EVIDENCE

Therapeutic study, Level I.

Accelerometer-based, portable navigation vs imageless, large-console computer-assisted navigation in total knee arthroplasty: a comparison of radiographic results

Computer-assisted surgery (CAS) systems improve alignment accuracy in total knee arthroplasty (TKA) but have not been widely implemented. Eighty knees underwent TKA using an accelerometer-based, portable navigation device (KneeAlign 2; OrthAlign Inc, Aliso Viejo, California), and the radiographic results were compared with 80 knees performed using a large-console, imageless CAS system (AchieveCAS; Smith and Nephew, Memphis, Tennessee). In the KneeAlign 2 cohort, 92.5% of patients had an alignment within 3° of a neutral mechanical axis (vs 86.3% with AchieveCAS, P < .01), 96.2% had a tibial component alignment within 2° of perpendicular to tibial mechanical axis (vs 97.5% with AchieveCAS, P = .8), and 94.9% had a femoral component alignment within 2° of perpendicular to the femoral mechanical axis (vs 92.5% with AchieveCAS, P < .01). The mean tourniquet time in the KneeAlign 2 cohort was 48.1 ± 10.2 minutes vs 54.1 ± 10.5 minutes in the AchieveCAS cohort (P < .01). Accelerometer-based, portable navigation is as accurate as large-console, imageless CAS systems in TKA.

Computer-assisted total knee arthroplasty is currently of no proven clinical benefit: a systematic review

BACKGROUND

Navigated total knee arthroplasty (TKA) may improve coronal alignment outliers; however, it is unclear whether navigated TKA improves the long-term clinical results of TKA.

QUESTIONS/PURPOSES

Does the literature contain evidence of better long-term function and lower revision rates with navigated TKA compared with conventional TKA?

METHODS

A systematic literature review was conducted of navigated TKA reviewing articles related to coronal alignment, clinical knee and function scores, cost, patient satisfaction, component rotation, anteroposterior and mediolateral stability, complications, and longer-term reports.

RESULTS

Coronal plane alignment is improved with navigated TKA with fewer radiographic outliers. We found limited evidence of improvements in any other variable, and function was not improved. The duration of surgery is increased and there are unique complications related to navigated TKA. The long-term benefits of additional increase in accuracy of alignment are not supported by any current evidence.

CONCLUSIONS

The findings in reports of navigated TKA should be interpreted with caution. There are few short- and medium- and no long-term studies demonstrating improved clinical outcomes using navigated TKA. Despite substantial research, contradictory findings coupled with reservations about the cost and efficacy of the technology have contributed to the failure of computer navigation to become the accepted standard in TKA. Longer-term studies demonstrating improved function, lower revision rates, and acceptable costs are required before navigated TKA may be widely adopted. In the future, with improvements in study design, methodology, imaging, navigation technology, newer functional outcome tools, and longer-term followup studies, we suspect that navigated TKA may demonstrate yet unrecognized benefits.

Does computer-assisted surgery improve postoperative leg alignment and implant positioning following total knee arthroplasty? A meta-analysis of randomized controlled trials?

PURPOSE

Computer-assisted surgery has been proposed as a technique to improve implant alignment during total knee arthroplasty (TKA). However, there is still a debate over the accuracy of placing the femoral and tibial components using computer-assisted systems in TKA. The aim of this study is to establish whether computer-assisted surgery leads to superior mechanical leg axis and implant positioning than conventional technique in patients with primary TKA.

METHODS

Major electronic databases were systematically searched to identify relevant studies without language restriction. A meta-analysis of 41 randomized controlled trials (RCTs) or quasi-RCTs was performed in a random effects model. A subgroup analysis was conducted by type of navigation system to explore the clinical heterogeneity between these trials. The following radiographic parameters were used to compare computer-assisted surgery with conventional technique: (1) mechanical leg axis, (2) femoral component coronal alignment, (3) tibial component coronal alignment, (4) femoral component sagittal alignment, and (5) tibial component sagittal alignment.

RESULTS

For the mechanical leg axis and coronal positioning of femoral and tibial components, there are statistically significant reductions in the number of patients with malalignment in the CAS group if the outlier cutoff value is ±3 or 2° in the coronal and sagittal planes, respectively. Subgroup analysis demonstrates that CT-free navigation systems provide better alignment than conventional techniques in the coronal and sagittal alignment of femoral components within ±3 and 2°. If the outlier cutoff value for the tibial sagittal alignment is ±2°, the outlier percentages are higher in the CT-free navigation group than in the conventional group. However, there was no significant difference in the tibial sagittal alignment at ±3°.

CONCLUSION

Computer-assisted surgery does improve mechanical leg axis and component orientation in TKAs. However, high-quality RCTs are necessary to determine whether surgeons could use computer-assisted techniques to achieve a targeted tibial slope in TKA.

LEVEL OF EVIDENCE

Therapeutic study (Systematic review of Level I/II studies), Level II.

[Total knee arthroplasty for rheumatoid arthritis]

A total of 150,000 primary total knee arthroplasties are performed in Germany each year. There is only a limited amount of evidence-based data available on possible surgery-related differences between osteoarthritis (OA) and rheumatoid arthritis (RA) of the knee joint. The following review summarizes the recent literature on total knee arthroplasty with a focus on special features of RA patients.

NAVIGATION IN TOTAL KNEE ARTHROPLASTY

Navigation was the most significant advance in instrumentation for total knee arthroplasty over the last decade. It provides surgeons with a precision tool for carrying out surgery, with the possibility of intraoperative simulation and objective control over various anatomical and surgical parameters and references. Since the first systems, which were basically used to control the alignment of bone cutting referenced to the mechanical axis of the lower limb, many other surgical steps have been incorporated, such as component rotation, ligament balancing and arranging the symmetry of flexion and extension spaces, among others. Its efficacy as a precision tool with an effective capacity for promoting better alignment of the lower-limb axis has been widely proven in the literature, but the real value of optimized alignment and the impact of navigation on clinical results and the longevity of arthroplasty have yet to be established.