A Comparison of Outcomes With and Without a

The Journal of Arthroplasty Vol. 00 No. 0 2011

A Comparison of Outcomes With and Without a Tourniquet in Total Knee Arthroplasty A Systematic Review and Meta-analysis of Randomized Controlled Trials Ilhan Alcelik, MRCS,* Raymond D. Pollock, PhD, MPH,* Mohammed Sukeik, MRCS,y Josette Bettany-Saltikov, PhD, MSc, MCSP,z Patrick M. Armstrong, FRCS,* and Peter Fismer, MD*

Abstract: A tourniquet is often used in total knee arthroplasty resulting in improved visualization of structures, reduced intraoperative bleeding and better cementation. The risks include deep vein thrombosis and pulmonary embolism. To quantify the case for or against tourniquet use, we carried out a systematic review and meta-analysis of selected randomized controlled trials. Ten studies were included in the meta-analysis. Of the 8 outcomes analyzed (surgery duration; total, intraoperative, and postoperative blood losses; deep vein thrombosis; pulmonary embolism; and minor/major complications), the total and intraoperative blood losses were less using a tourniquet. Minor complications were more common in the tourniquet group. The remaining outcomes showed no difference between the groups. Using a tourniquet may be beneficial, but long-term studies of outcome are needed. Keywords: tourniquet, total knee arthroplasty, meta-analysis. © 2011 Elsevier Inc. All rights reserved.

field [10]. For some knee surgeons, these benefits outweigh the risks, and they operate without a tourniquet. Systematic review and meta-analysis are an accepted research methodology that quantitatively integrate the results of a collection of studies on a given topic. There has been no published systematic review or metaanalysis on tourniquet use in TKA, apart from a recent analysis [11] that, in our opinion, has methodological weaknesses. This is because of inclusion of studies with incomparable groups and nonrandomized and observational studies. Such studies should not be included in an interventional review because they are likely to have biases that cannot be corrected by meta-analysis. In addition, the authors excluded 8 of their originally included studies in the meta-analysis because of heterogeneity and only made a narrative analysis of that group. Therefore, using a more robust analysis, our aim was to determine whether a tourniquet should be used during TKA in adults so that surgeons can make an evidencebased decision on their use. We have used properly randomized studies only (level I evidence). Our hypothesis is that use of a tourniquet would reduce the duration of surgery reduce intraoperative, postoperative, and total blood losses and improve knee flexion. We also analyzed

Tourniquets are widely used during surgery, but there are complications associated with their use, namely, skin burns, soft tissue and muscle damage, injury of calcified vessels, increased swelling and stiffness of the joints, nerve injury, paralysis, and, rarely, acute pulmonary edema and cardiac arrest after release of a tourniquet [1-8]. Total knee arthroplasty (TKA) is a common procedure that is increasing due to an aging population. In 2010, about 60 000 TKAs were performed in England and whales in the NHS [9]. A tourniquet is often used in TKA to achieve better visualization of the structures and to reduce intraoperative blood loss. Arguably, the main advantage for using a tourniquet is achieving superior cementation due to a relatively blood-free operating

From the *Department of Orthopaedics, West Cumberland Hospital, Whitehaven, UK; yDepartment of Orthopaedics, University College London Hospital, London, UK; and zUniversity of Teesside, School of Health and Social Care, Middlesbrough, UK. Submitted June 1, 2010; accepted April 27, 2011. The Conflict of Interest statement associated with this article can be found at doi:10.1016/j.arth.2011.04.046. Reprint requests: Raymond Pollock, PhD, MPH, Gledsnest, Hawick, TD9 0LF, UK. © 2011 Elsevier Inc. All rights reserved. 0883-5403/0000-0000$36.00/0 doi:10.1016/j.arth.2011.04.046

1

2 The Journal of Arthroplasty Vol. 00 No. 0 Month 2011 the incidence of deep vein thrombosis (DVT), pulmonary embolism (PE), and complications.

Materials and Methods A detailed protocol for the review was prepared in accordance with the guidelines described in the Cochrane Handbook for Systematic Reviews of Interventions [12]. In addition, the meta-analysis was reported according to the quality of reporting of meta-analysis of randomized controlled trials statement [13]. This consists of a flow chart that provides information about the numbers of trials identified, included and excluded and the reasons for exclusion. We also used the quality of reporting of meta-analysis of randomized controlled trials checklist of items that should be included when reporting a metaanalysis. The aim was to quantify how the final studies included in the analysis were identified and combined. The review team consisted of 4 orthopedic surgeons (I.A., M.S., P.A., P.F.), a statistical epidemiologist (R.P.), and a health services researcher (J.B.S.). Searches Finding Existing Systematic Reviews To find existing systematic reviews/meta-analysis on the subject, the following databases were searched (April 2008) using the search terms “knee replacement and tourniquet”: Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database, NHS Economic Evaluation Database, Turning Research Into Practice Database, Health Services/Technology Assessment Text, Aggressive Research Intelligence Facility appraisals, Scottish Intercollegiate Guideline Network Guidelines, National Research Register, and Medline (1950 to date) [14-23]. No systematic review studies were found. Subsequently, during manuscript preparation (July 2009), we discovered a similar meta-analysis on this subject that was in press and that has been subsequently published [11]. We refer to this further in the “Discussion” section. Finding Published Primary Studies Inclusion and Exclusion Criteria. We identified literature that met the following inclusion criteria: (1) randomized controlled trials and (2) comparison of tourniquet use with no tourniquet during TKA surgery. Outcome measures included were duration of surgery, blood loss, range of knee motion, DVT, cases of PE, and minor and major complications. Exclusion criteria were non-English language publications (because of the logistics of obtaining translations), any study comparing usage of tourniquets in dissimilar circumstances (eg,. 2 different anesthetics for each group of patients), and animal studies. Search Strategy. Medline (1950 to date) and EMBASE (1974 to date) were searched by 2 of the authors (I.A. and R.P.) independently to maximize the detection of

relevant studies. Medline and EMBASE are known to cover all areas of health care, and they index journals from all over the world, with an estimated overlap of only 34% [12,24]. A search of reference lists of all retrieved studies to identify any additional studies missed during the database searches was then conducted. This was conducted by I.A. and R.P. independently. Potential suitable studies were reviewed using abstracts. Finding Unpublished Studies An expert informant was contacted for assistance in locating additional studies. To his knowledge, there were no further studies that should be included. (L. Klenerman, letter of discussion on included studies, September 2008). Critical Appraisal The aim of the critical appraisal was to assess the clinical and methodological heterogeneity of the identified studies. This was done in 2 stages; first, a screen for basic eligibility criteria using the abstracts of identified studies, checking, for example, that the study addressed the question and included a control group, and second, a detailed appraisal of quality and validity of potentially eligible studies was performed using the consolidated standards of reporting trials (CONSORT) checklist [25]. This consists of a 22-item checklist used to aid appraisal of randomized controlled trials. Using the full articles, the presence or absence of the item in each study was scored 1 or 0, respectively, giving a score out of 22. Each article abstract was read and scored independently by 2 members of the review team (I.A. and R.P.). A score of 50% (11/22) was defined as a lower limit for inclusion of a study. This percentage was used because this has been reported as the average CONSORT score for surgical trials [26]. Differences between reviewers in the final selection of studies for inclusion in the meta-analysis were resolved by discussion between the reviewers. Data Extraction Outcome data from individual studies selected for inclusion were extracted independently by I.A. and R.P. There were no disagreements between the authors. Statistical Analysis Meta-Analysis Meta-analysis performed using Review Manager (version 5.0; Nordic Cochrane Center, Copenhagen, Denmark) was used to combine the relevant estimates of the effect of interest from the selected studies. This gave a summary estimate of the overall effect in the form of a forest plot. Dichotomous outcomes were expressed as a risk ratio (RR; also called relative risk), and continuous outcomes were expressed as a mean difference. Missing

Outcomes With or Without a Torniquet in TKA Alcelik et al

3

Table 1. Included Studies and Pool of Outcomes Duration of Intraoperative Postoperative Total Knee Minor Major Surgery Blood Loss Blood Loss Blood Loss Flexion DVT PE Complications Complications Total

Study Wakankar et al [27] Abdel-Salam and Eyres [3] Kageyama et al [28] Wauke et al [29] Kato et al [30] Vandenbussche et al [31] Tetro and Rudan [32] Aglietti et al [33] Fukuda et al [34] Matziolis et al [35] Total

√ √ √ √ √ √ √ 7

√

√ √

√

√ √ √ √

√ √ √ √

√ √ √ √ √

5

6

6

standard deviations were calculated from the mean and sample size. Data were analyzed using both fixed- and random-effect models, and the results were compared. Nonidentical results implied the presence of statistical heterogeneity, and results from the random model were used; otherwise, results were from the fixed model.

Results Two hundred seventy seven studies were identified. Two hundred fifty eight were excluded based on the

√ √

√ √ √

√ 3

√

√ √ √

√ √ 6

√ √ 5

√ √

√ √

√ √

√ √

√ 5

4

4 4 4 3 3 8 6 4 6 5

inclusion/exclusion criteria, leaving 19 potentially relevant studies for detailed evaluation. This was further reduced to 10 studies after critical appraisal of the full articles. Table 1 shows the included studies with their contributions to the data pool [3,27-35]. Reasons for exclusion included irrelevant outcome measures (wound oxygenation/hypoxia) and incomparable patient groups. For example, in a study by Kiss et al [36], one group had epinephrine-augmented hypotensive epidural anesthesia with no tourniquet, and the other

Potentially relevant citations identified after screening of the electronic search (1st selection) (n = 277)

Citations excluded with reasons (n = 258)

Studies retrieved for more detailed evaluation (n = 19)

Studies excluded (after evaluation of full text) from systematic review with reasons (2nd selection) (n = 9)

Relevant studies included in systematic review (n = 10)

Studies excluded from meta-analysis (n = 0)

Studies included in meta-analysis (10)

Fig. 1. Flowchart of study selection process.

4 The Journal of Arthroplasty Vol. 00 No. 0 Month 2011 24

16

Matziolis

Fukuda

Aglietti

Tetro

Kato

Wauke

Kayegama

Abdel Salam

4

Wakankar

8

Vandenbussche

12

maximum possible score

20

0

Fig. 2. Consort adherence of studies and arbitrary cutoff point for inclusion.

group was given normotensive epidural anesthesia with a tourniquet. Therefore, the groups were incomparable for the purpose of our study. A flowchart of study selection is shown in Fig. 1. The mean CONSORT adherence score of the studies was 13 (range, 11-15) of a possible maximum score of 22. After the quality assessment, none of the 10 studies were excluded from the systematic review. Fig. 2 shows the results of the CONSORT statement adherence of the included studies as a graph. The CONSORT adherence of the included studies showed great similarities. All the studies reported positively on all aspects of items 1, 2, 4, 5, 12, 17, 20, 21, and 22. That is to say, the description of random allocation was in the abstract, followed by a clear background to the study and a clear description of interventions and objectives in each study. The reporting of statistical methods was flawless, as was the interpretation of the results and generalizability of the study findings. No studies reported positively on items 7, 10, 11, 16, and 18 of the CONSORT statement. All 10 studies failed to show how they decided on the sample size. Allocation concealment and implementation of randomization were again not fully covered in any of the studies. Lastly, the analysis section of the CONSORT adherence for these studies was poor. In 9 of the included studies, the participants were male and female adults with either osteoarthritis or rheumatoid arthritis. In the remaining study, the patients were all female adults with rheumatoid arthritis [29]. In total, 493 patients underwent TKA. Tourniquets were used in 65 (26.1%) male and 184 (73.9%) female patients (total 249), compared with 69 (28.3%) male and 175 (71.7%) female patients (total 244) in which no tourniquet was used. The tourniquet group had a mean age of 70.4 years (range, 38-89 years). In the non–tourniquet group, the mean age was 70.4 years (range, 43-91 years). In all

studies, tourniquet and non–tourniquet groups were similar and comparable. Overall, the clinical heterogeneity of the 10 included studies was minimal. The results of the meta-analysis for the outcomes are shown in the relevant forest plots (Figs. 3-8). Duration of surgery, defined as time (in minutes) from skin incision to closure of wound, was reported in 7 studies. The forest plot (Fig. 3) shows no significant difference between patients with and without a tourniquet (weighted mean difference, −0.36; 95% CI, −4.573.84; n = 299; P = .87). Intraoperative blood loss, defined as blood (in milliliters) on the sponges and swabs and calculated indirectly after measurement of suction and irrigation volumes during surgery, was reported in 5 studies. The forest plot (Fig. 4) shows tourniquet use reduces intraoperative blood loss (weighted mean difference, −161.1: 95% CI, −203 to −119; n = 233; P b .001). All studies showed a reduction in blood loss when a tourniquet was used. Because the duration of tourniquet inflation may have an effect on intraoperative blood loss, we have included details of when deflation occurred (Table 2). There appears to be no correlation between blood loss and tourniquet time. Postoperative blood loss estimated by measuring the blood (in milliliters) in the drains was measured in 6 studies. The forest plot (Fig. 5) shows no difference when a tourniquet was used (weighted mean difference, 49.5; 95% CI, −34 to 133; n = 270; P = .24). It is possible that postoperative blood loss could vary depending on the type of drain used, but this was recorded in only 4 studies [37-40]. Those studies that used a suction drain [31,32,34] had blood drainage volumes of 528, 507, and 467 mL, respectively. This compares with the study by Aglietti et al [33], that recorded a volume of 290 mL without suction. There is also evidence that splintage position reduces postoperative blood drainage, but again, this was recorded in only 2 studies [27,31]. The total blood loss calculated by adding intraoperative and postoperative blood loss (in milliliters) was reported in 6 studies. The forest plot (Fig. 6) shows that tourniquet use reduces the measured blood loss (weighted mean difference, −183.7; 95% CI, −240 to −128; n = 279; P ≤ .001). One of the most important outcomes of TKA is the range of motion of the new joint. Despite its importance, it was only reported in 3 studies. It would appear that there is a better early flexion within the first week in the non–tourniquet group (54° [95% CI, 38-88] vs 70° [95% CI, 45-95]). Temporary loss of function in the compressed thigh muscles was the explanation given for this difference [3,27]. Despite the difference in early flexion, long-term flexion showed no difference. The lack of data (eg, the standard deviation was not given) meant that it was impossible to perform a meta-analysis. There were also few data on knee extension; therefore,

Outcomes With or Without a Torniquet in TKA Alcelik et al Tourniquet Study Aglietti 2000

Mean 90

No tourniquet

SD Total 18

Mean

SD Total Weight

Mean Difference

Mean Difference

IV, Fixed, 95% CI

IV, Fixed, 95% CI

10

96

11

10

10.4%

27

114

13.6

21

16.0%

3.00 [-7.51, 13.51]

21

11

158

23

11

5.2%

5.00 [-13.41, 23.41]

Fukuda 2007

117 23.2

Kageyama 2007

163

Kato 2002

-6.00 [-19.07, 7.07]

111

41

22

111

13

24

5.5%

0.00 [-17.90, 17.90]

Matziolis 2005

85

10

10

93

17.5

10

11.3%

-8.00 [-20.49, 4.49]

Tetro 2001

83

13

33

81

13

30

42.8%

2.00 [-4.43, 8.43]

151

35

40

156

30

40

8.7%

-5.00 [-19.29, 9.29]

146 100.0%

-0.36 [-4.57, 3.84]

Vandenbussche 2002

153

Total (95% CI)

5

Heterogeneity: Chi2 = 3.79, df = 6 (P = .70); I2 = 0%

-20

Test for overall effect: Z = 0.17 (P = .87)

-10

0

Favours tournquet

10

20

Favours no tourniquet

weighted mean difference: -0.36: 95% CI: 4.6 to 3.8; n = 299; P = .87

Fig. 3. Forest plot of duration of surgery.

no meta-analysis could be performed either. The mean knee flexion was 54.3° (n = 87; 49.2%) and 70.6° (n = 90; 50.8%) in the tourniquet and non–tourniquet groups, respectively. Two of the studies, Abdel-Salam and Eyres [3] and Wakankar et al [27] also measured longer-term knee flexion (4 and 12 months, respectively), and the results were very similar. In the study of Wakankar et al, the mean flexion was 102° in the tourniquet group and 105° in the non–tourniquet group. In the study of Abdel-Salam and Eyres, it was exactly 100° in both groups. Neither study reported a significant difference between the means in the 2 groups in the longer term. Six studies looked at the occurrence of DVT (Fig. 7). There were a total of 173 (50.6%) patients in the tourniquet and 169 (49.4%) patients in the non– tourniquet groups. The RR for DVT was 1.17 (95% CI, 0.84-1.64; n = 342; P = .35). Regarding the assessment of DVTs, only Fukuda et al [34] screened all patients before and after the operation even if they had no symptoms. The incidence of postoperative DVT was found to be 77% and 86% in tourniquet and non–tourniquet groups, respectively. The other 5 studies only performed

Tourniquet Study

Mean

No tourniquet

SD Total Mean

screening if the patients were symptomatic. Because of this, the meta-analysis was repeated minus the study of Fukuda et al. This increased the RR to 2.72 (95% CI, 0.81-9.1; n = 294; P = .11). Both meta-analyses showed no statistically significant difference in DVT between tourniquet and non–tourniquet groups. Cases of PE were included in 5 studies (Fig. 8). There were 3 cases in the tourniquet group (incidence, 2.54%) vs 1 (incidence, 0.88%) in the non–tourniquet group. This was not significant between the groups (RR, 1.84; 95% CI, 0.36-9.44; n = 231; P = .46). Minor complications were reported in 5 studies (Fig. 9). Of the 160 patients in each group, there were 23 (14.4%) tourniquet and 9 (5.6%) non–tourniquet patients with minor complications. The difference between the groups was significant (RR, 2.42; 95% CI, 1.21-4.84; n = 320; P = .01). The forest plot shows that the procedure performed without a tourniquet results in fewer minor complications (Fig. 9). Occurrence of major complications was reported in 4 of the studies. Due to the small number of events (1 in the tourniquet group of the study of Abdel-Salam and Eyres [3]), a meta-analysis was inappropriate.

Mean Difference

SD Total Weight

Mean Difference

IV, Fixed, 95% CI

Aglietti 2000

350

12

10

482

97

10

49.0%

-132.00 [-192.58, -71.42]

Fukuda 2007

228 165

27

631

342

21

7.1%

-403.00 [-561.96, -244.04]

Kageyama 2007

177 157

11

347

197

11

8.1%

-170.00 [-318.87, -21.13]

Tetro 2001

148

81

33

295

193

30

32.5%

-147.00 [-221.39, -72.61]

Vandenbussche 2002

706 527

40

895

529

40

3.4%

-189.00 [-420.40, 42.40]

112 100.0%

- 161.13 [-203.52, -118.74]

Total (95% CI)

121

Heterogeneity: Chi2 = 9.99, df = 4 (P = .04); I2 = 60% Test for overall effect: Z = 7.45 (P < .00001)

IV, Fixed, 95% CI

- 500 - 250 Favours tourniquet

weighted mean difference: -188.6: 95% CI: -268 to -109; n = 233; P < .001

Fig. 4. Forest plot of intraoperative blood loss.

0

250 500 Favours no tourniquet

6 The Journal of Arthroplasty Vol. 00 No. 0 Month 2011 Table 2. Tourniquet Deflation and Blood Loss for the Included Studies Study

Mean Intraoperative Blood Loss (mL)

Deflation Point

Abdel-Salam and Eyres [3] After dressing Aglietti et al [33] After cementation Fukuda et al [34] After wound closure Kageyama et al [28] 90 min from the start of surgery Kato et al [30] 108 ± 35 min Matziolis et al [35] Not recorded Tetro and Rudan [32] After the cement had set Vandenbussche et al [31] After dressing Wakankar et al [27] Not recorded Wauke et al [29] Not recorded

350 228 177 – – 148 706 –

Discussion Achieving a bloodless field with a tourniquet should have 2 major effects. First, there should be less bleeding in the operation site and, consequently, less intraoperative blood loss. Second, if there is less bleeding in the wound, the surgeon should spend less time controlling bleeding, and therefore, operating time should be shorter. In the group of studies meta-analyzed, there was no significant difference in the mean duration of operations, but there was significantly more intraoperative bleeding on average in the non–tourniquet group. Although postoperative blood loss showed no evidence of a difference, the mean overall blood loss (intraoperative and postoperative together) was significantly more in the non–tourniquet group. Major limb surgery is a well-known risk factor for DVT. For the tourniquet group, in theory, not only having major extremity surgery but also having a tourniquet potentially increases the risk of DVT due to stasis of venous blood in the lower limb and possible damage to calcified blood vessels. In fact, in a study analyzing 638 cases of TKA performed under tourniquet control [37], the incidence of DVT was 84%. The high incidence of Tourniquet Study

Mean

No tourniquet

SD Total Mean

DVT (81.3%) in both tourniquet and non–tourniquet groups in the study of Fukuda et al [34] was due to the difference in methodology from the other studies included in the meta-analysis. This was the cause of its effect on the forest plot and the difference in RR between the meta-analysis for DVT with (Fig. 7) and without the study of Fukuda et al. Even so, there was no significant difference between the 2 groups in the proportions of DVTs experienced. Even when the same statistical tests were repeated for DVT outcome, without including the results of the study of Fukuda et al, the difference between the groups was still not statistically significant. The main reason for using a tourniquet in TKA is to achieve better cementation. Because there is less blood in the operating field, the bone cement can better adhere to the bone and implant without blood seeping between the bone-cement interface. In theory, this should result in longer implant survival when performed with a tourniquet. However, there were no data on implant survival in any of the studies, so this hypothesis could not be tested. There are some shortcomings in our meta-analysis that should be noted. The literature search was restricted only to the English language; consequently, there is potential for missing some studies. Also, it is difficult to draw firm conclusions from the intermediate quality studies that were included. For example, some of the studies had as few as 10 patients in each arm. The power of the individual studies and, consequently, the strength of the meta-analysis would have been much greater with larger sample sizes. Another issue is that almost all the included studies were deficient on aspects such as randomization, blinding, and participant flow. Furthermore, only one of the experts we contacted in the field of tourniquets responded. As a result, we may have missed unpublished data. Another shortcoming is the timing of tourniquet deflation, which varied between studies (Table 2). This could have a major impact on both intraoperative and postoperative blood loss and makes comparison of the studies less reliable with regard to

Mean Difference

Mean Difference

SD Total Weight

IV, Random, 95% CI

Aglietti 2000

290

54

10

145

50

10

23.5%

Fukuda 2007

467 197

27

457

163

21

18.4%

10.00 [-91.89, 111.89]

Kageyama 2007

769

70

11

618

143

11

19.1%

151.00 [56.91, 245.09]

Tetro 2001

507 317

33

449

226

30

15.2%

58.00 [-77.05, 193.05]

Vandenbussche 2002

528 502

40

661

415

40

10.2%

-133.00 [-334.85, 68.85]

Wauke 2002

346 191

19

424

275

18

13.6%

-78.00 [-231.35, 75.35]

130 100.0%

49.52 [-33.68, 132.72]

Total (95% CI)

140

Heterogeneity: Tau2 = 7113.86; Chi2 = 18.48, df = 5 (P = .002); I2 = 73% Test for overall effect: Z = 1.17 (P = .24)

IV, Random, 95% CI

145. 00 [99.39, 190.61]


weighted mean difference: 49.5: 95% CI: -34 to 133; n = 270; P = .24

Fig. 5. Forest plot of postoperative blood loss.

0


Outcomes With or Without a Torniquet in TKA Alcelik et al Tourniquet Study

Mean

No tourniquet

SD Total Mean

Mean Difference

SD Total W eight

Mean Difference

IV, Fixed, 95% CI

Aglietti 2000

640 120

10

627

142

10

23.7%

13.00 [-102.23, 128.23]

Fukuda 2007

690 273

27 1,088

338

21

10.0%

-398.00 [-575.49, -220.51]

Kageyama 2007

946 113

11

965

170

11

21.7%

-19.00 [-139.63, 101.63]

Kato 2002

67 120

22

510

244

24

26.2%

-443.00 [-552.74, -333.26]

Tetro 2001

654 324

33

742

287

30

13.8%

-88.00 [-238.89, 62.89]

40 1,557

643

40

4.6%

-323.00 [-585.82, -60.18]

136 100.0%

-183.74 [-239.89, -127.59]

Vandenbussche 2002 1, 234 553

143

Total (95% CI)

7

Heterogeneity: Chi2 = 48.03, df = 5 (P < .00001); I2 = 90%

IV, Fixed, 95% CI


Test for overall effect: Z = 6.41 (P < .00001)

0


weighted mean difference: -203.5: 95% CI: -384 to -23; n = 279; P = .03

Fig. 6. Forest plot of total blood loss.

blood loss. For example, in the study of Abdel-Salam and Eyres [3], the tourniquet was released after the application of the dressings, whereas in the study of Tetro and Rudan [32], deflation was after cementation but before wound closure. This may account for the high mean intraoperative blood loss (706 mL) found in the study of Vandenbussche et al [31], in which deflation was after dressing. Possibly, postoperative blood loss could vary depending on the type of drain used. Only 4 studies recorded this information, 3 of which [31,32,34] used suction drains. The remaining study [33] used nonsuction drainage and had a lower blood loss (290 mL) compared with the studies using suction (mean, 500.7 mL), but the sample was too small to test for statistical significance. Another weakness of our review is that knee position during splinting may affect postoperative blood loss, but this was recorded in only 2 studies, so its effect could not be evaluated. It is possible that inflating the tourniquet only during cementation, as practiced by some surgeons, may confound data between tourniquet and non–tourniquet groups. Of the 10 studies, 3 did not record when Tourniquet Study

Events

No tourniquet

Total

Events

Total

tourniquet deflation occurred (Table 2). The remainder either explicitly stated the period as including cementation, or it was implied from the time period of inflation. During manuscript preparation, we discovered another meta-analysis on this subject. At the time, this was a corrected proof of an article in press on the journal Web site of The Knee. This has been subsequently published [11]. Their review included 15 studies compared with our analysis involving 10 of these (Table 3). The authors state that of their 15 selected studies, 8 were heterogeneous and were not included in the meta-analysis but were unclear as to which these studies were. Therefore, only 7 studies were the subject of a meta-analysis, although this is contradicted by their forest plot for the total blood loss that includes 8. In contradiction to our findings that a tourniquet reduces the total blood loss, there was an agreement over the increased risk of complications when a tourniquet is used, although the authors do not appear to have performed a metaanalysis on this. They also failed to include forest plots of all their 10 outcome measures, only including plots of the total and intraoperative blood losses in their study. Risk Ratio

Weight

Risk Ratio

M -H, Fixed, 95% CI

4

40

0

40

2.1%

9.00 [0.50, 161.86]

21

27

18

21

85.3%

0.91 [0.69, 1.18]

Matziolis 2005

0

10

0

10

Vandenbussche 2002

1

40

2

40

8.4%

0.50 [0.05, 5.30]

Wakanker 1999

1

37

0

40

2.0%

3.24 [0.14, 77.06]

Wauke 2002

2

19

0

18

2.2%

4.75 [0.24, 92.65]

169

100.0%

1.17 [0.84, 1.64]

Abdel-Salem 1995 Fukuda 2007

Total (95% CI) Total events

173 29

M-H, Fixed, 95% CI

Not estimable

20


0.002


0.1

Favours tourniquet

risk ratio2: 1.17: 95% CI: 0.84 to 1.64; n = 342; P = .35

Fig. 7. Forest plot of DVT.

1

10

500

Favours no tourniquet

8 The Journal of Arthroplasty Vol. 00 No. 0 Month 2011 Tourniquet Study

No tourniquet

Events Total Events

Total Weight

Risk Ratio

Risk Ratio

M-H, Fixed, 95% CI

M-H, Fixed, 95% CI

Fukuda 2007

1

27

1

21

53.1%

0.78 [0.05, 11.72]

Kato 2002

1

22

0

24

22.6%

3.26 [0.14, 76.10]

Matziolis 2005

0

10

0

10

Vandenbussche 2002

0

40

0

40

Wauke 2002

1

19

0

18

118


3

Not estimable Not estimable 24.2%

2.85 [0.12, 65.74]

113 100.0%

1.84 [0.36, 9.44]

1


0.01 0.1 Favours tourniquet


1


risk ratio: 1.84: 95% CI: 0.36 to 9.44; n = 231; P = .46

Fig. 8. Forest plot of PE.

Their study has other failings. They included studies that were inappropriate. In the study by Kiss et al [36], one group had epinephrine-augmented hypotensive epidural anesthesia without tourniquet, and the other group had normotensive epidural anesthesia with a tourniquet. Therefore, the groups were incomparable for the purpose of a meta-analysis and should not have been included. Again, in the study by Harvey et al [38], patients were randomized into 3 groups with different anticoagulation medications. This is a source of bias, and therefore, it was excluded in our meta-analysis. The study of Nishiguchi et al [39] was excluded in our meta-analysis due to lack of randomization of the patients. In the study by Katsumata et al [40], although there were 2 groups with and without tourniquet, they had not been randomized in any way—just selected from 2 different hospitals. Hence, the trial should not have been included. Similarly in the randomized controlled trial by Padala et al [41], the group without a tourniquet had Tourniquet Study

No tourniquet

Events Total Events

Total Weight

adrenaline and saline infiltration to the skin and subcutaneous tissues but without drains. The group with a tourniquet had drains only. Hence, the groups were not comparable, and the study was again excluded in our meta-analysis. Clarke et al [42] randomized patients into 1 of 3 groups, a control without a tourniquet and 2 groups with a tourniquet at low and high pressures. It was not included in our meta-analysis because it investigated wound oxygenation, which was one of our exclusion criteria. The study of Jarolem et al [43] was a retrospective nonrandomized study. Hence, it was not suitable for inclusion in a meta-analysis. We feel, therefore, that our meta-analysis has been conducted more rigorously using carefully selected studies only. This explains the difference in our results compared with those of Smith and Hing [11]. The other strengths of our review are as follows. First, despite having an important role in any type of extremity surgery, the role of tourniquets in TKA has not been investigated in such detail before. Second, the Risk Ratio

Risk Ratio

M-H, Fixed, 95% CI

M-H, Fixed, 95% CI

Abdel-Salem 1995

4

40

0

40

5.2%

9.00 [0.50, 161.86]

Matziolis 2005

1

10

1

10

10.4%

1.00 [0.07, 13.87]

11

33

5

30

54.4%

2.00 [0.79, 5.09]

Vandenbussche 2002

0

40

0

40

Wakanker 1999

7

37

3

40

30.0%

2.52 [0.70, 9.04]

160

100.0%

2.42 [1.21, 4.84]

Tetro 2001

160


23

Not estimable

9

Heterogeneity: Chi2 = 1.39, df = 3 (P = .71); I2 = 0% Test for overall effect: Z = 2.49 (P = .01)

0.01 0.1 1 10 100 Favours tourniquet Favours no tourniquet

risk ratio: 2.42: 95% CI: 1.21 to 4.84; n = 320; P = .01

Fig. 9. Forest plot of minor complications.

Outcomes With or Without a Torniquet in TKA Alcelik et al Table 3. Comparison of Studies Included in the 2 Meta-Analyses Abdel-Salam and Eyres [3] Aglietti et al [33] Clarke et al [42] Fukuda et al [34] Harvey et al [38] Jarolem et al [43] Kageyama et al [28] Katsumata et al [40] Kato et al [30] Kiss et al [36] Matziolis et al [35] Nishiguchi et al [39] Padala et al [41] Tetro and Rudan [32] Vandenbussche et al [31] Wakankar et al [27] Wauke et al [29]

Smith and Hing [11]

Alcelik et al

√ √ √ √ √ √

√ √

√ √ √ √ √ √ √ √ √ √

√ √ √ √ √ √ √ √

aim of this study was to provide evidence for or against the use of tourniquets in TKA. With the available data at present, this aim has been achieved. In conclusion, our meta-analysis of available studies indicates that the total and intraoperative blood losses are less when using a tourniquet. This should reduce the need for transfusion as well as result in a better cementation due to a clearer field. This has to be balanced against the increased risk of minor complications when using a tourniquet. We hope our metaanalysis presented here will enable surgeons to make an informed decision as to whether to use a tourniquet or not. Suggestions for further research include long-term implant survival studies in addition to outcomes such as range of motion.

Acknowledgment The authors gratefully acknowledge the help of Paul Bassett, a statistician, for his review of the statistical content of our manuscript.

References 1. Adams F. The genuine works of Hippocrates (translated from the Greek). Baltimore: The Williams & Wilkins Company; 1849. 2. Irvine GB, Chan RN. Arterial calcification and tourniquets. Lancet 1986;2:1217. 3. Abdel-Salam A, Eyres KS. Effects of tourniquet during total knee arthroplasty. A prospective randomised study. J Bone Joint Surg [Br] 1995;77:250. 4. Silver R, de la Garza J, Rang M, et al. Limb swelling after release of a tourniquet. Clin Orthop Relat Res 1986;206: 86. 5. Newman RJ. Metabolic effects of tourniquet ischaemia studied by nuclear magnetic resonance spectroscopy. J Bone Joint Surg [Br] 1984;66-B:434.

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6. O'Leary AM, Veall G, Butler P, et al. Acute pulmonary oedema after tourniquet release. Can J Anaesthesiol 1990; 37:826. 7. Gielen M. Cardiac arrest after tourniquet release. Can J Anaesthesiol 1991;38:541. 8. Din R, Geddes T. Skin protection beneath the tourniquet. A prospective randomized trial. ANZ J Surg 2004;74:721. 9. Dixon T, Shaw M, Ebrahim S, et al. Trends in hip and knee joint replacement: socioeconomic inequalities and projections of need. Ann Rheum Dis 2004;63:825. 10. Insall JN, Hass SB. Complications in total knee arthroplasty. In: Install JN, editor. Surgery of the knee, 2nd ed, 2. New York: Churchill Livingstone; 1993. p. 891. 11. Smith TO, Hing CB. Is a tourniquet beneficial in total knee replacement surgery? A meta-analysis and systematic review. Knee 2010;17:141. 12. Higgins JPT, Green S. Cochrane handbook for systematic reviews of interventions 4.2.2. The Cochrane Library, Issue 4. Chichester, UK: John Wiley & Sons, Ltd.; 2006. 13. Moher D, Cook DJ, Eastwood S, et al. Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Quality of reporting of meta-analyses. Lancet 1999;354:1896. 14. Cochrane Database of Systematic Reviews. http://www. cochrane.org/reviews/ (accessed on 20/04/2008). 15. Database of Abstracts of Reviews of Effects. http://www. crd.york.ac.uk/crdweb/ (accessed on 20/04/2008). 16. Health Technology Assessment Database. http://www. ncchta.org/ (accessed on 20/04/2008). 17. NHS Economic Evaluation Database. http://www.homerton. nhs.uk/education/11660052365004.html. 18. Turning Research Into Practice. http://www.tripdatabase. com/index.html (accessed on 10/04/2008). 19. Health Services/Technology Assessment Text. http:// www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=hstat (accessed on 10/04/2008). 20. Aggressive Research Intelligence Facility. http://www.arif. bham.ac.uk/ (accessed on 10/04/2008). 21. Scottish Intercollegiate Guideline Network Guidelines. http://www.sign.ac.uk/ (accessed on 10/04/2008). 22. National Research Register. http://www.nrr.nhs.uk/ (accessed on 10/04/2008). 23. Medline. http://www.datastarweb.com/ (accessed on 10/04/2008). 24. Smith BJ, Darzins PJ, Quinn M, et al. Modern methods of searching the medical literature. Med J Aust 1992;157: 603. 25. Moher D, Schulz KF, Altman DG. The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomised trials. Lancet 2001;357:1191. 26. Rosen R. Perspectives on this issue of the IJS. Int J Surg 2007;5:373. 27. Wakankar HM, Nicholl JE, Koka R, et al. The tourniquet in total knee arthroplasty. A prospective, randomised study. J Bone Joint Surg [Br] 1999;81:30. 28. Kageyama K, Nakajima Y, Shibasaki M, et al. Increased platelet, leukocyte, and endothelial cell activity are associated with increased coagulability in patients after total knee arthroplasty. J Thromb Haemost 2007;4: 738.

10 The Journal of Arthroplasty Vol. 00 No. 0 Month 2011 29. Wauke K, Nagashima M, Kato N, et al. Comparative study between thromboembolism and total knee arthroplasty with or without tourniquet in rheumatoid arthritis patients. Arch Orthop Trauma Surg 2002;122: 442. 30. Kato N, Nakanishi K, Yoshino S, et al. Abnormal echogenic findings detected by transesophageal echocardiography and cardiorespiratory impairment during total knee arthroplasty with tourniquet. J Anesth 2002;97:1123. 31. Vandenbussche E, Duranthon LD, Couturier M, et al. The effect of tourniquet use in total knee arthroplasty. J Int Orthop 2002;26:306. 32. Tetro AM, Rudan JF. The effects of a pneumatic tourniquet on blood loss in total knee arthroplasty. Can J Surg 2001; 44:33. 33. Aglietti P, Baldini A, Vena LM, et al. Effect of tourniquet use on activation of coagulation in total knee replacement. Clin Orthop Relat Res 2000;371:169. 34. Fukuda A, Hasegawa M, Kato K, et al. Effect of tourniquet application on deep vein thrombosis after total knee arthroplasty. Arch Orthop Trauma Surg 2007;127:671. 35. Matziolis G, Drahn T, Schröder JH, et al. Endothelin-1 is secreted after total knee arthroplasty regardless of the use of a tourniquet. J Orthop Res 2005;23:392. 36. Kiss H, Rafl M, Neumann D, et al. Epinephrine augmented hypotensive epidural anesthesia replaces tourniquet use in total knee replacement. Clin Orthop Relat Res 2005;436: 184.

37. Stulberg BN, Insall JN, Williams GW, et al. Deep-vein thrombosis following total knee replacement. An analysis of six hundred and thirty-eight arthroplasties. J Bone Joint Surg Am 1984;66:194. 38. Harvey EJ, Leclerc J, Brooks CE, et al. Effect of tourniquet use on blood loss and incidence of deep vein thrombosis in total knee arthroplasty. J Arthroplasty 1997;12:291. 39. Nishiguchi M, Takamura N, Abe Y, et al. Pilot study on the use of tourniquet: a risk factor for pulmonary thromboembolism after total knee arthroplasty? Thromb Res 2005; 115:271. 40. Katsumata S, Nagashima M, Kato K, et al. Changes in coagulation-fibrinolysis marker and neutrophil elastase following the use of tourniquet during total knee arthroplasty and the influence of neutrophil elastase on thromboembolism. Acta Anaesthesiol Scand 2005;49:510. 41. Padala PR, Rouholamin E, Metha RL. The role of drains and torniquets in primary total knee replacement: a comparative study of TKR performed with drains and tourniquet versus no drains and adrenaline and saline infiltration. J Knee Surg 2004;17:24. 42. Clarke MT, Longstaff L, Edwards D, et al. Tourniquetinduced wound hypoxia after total knee replacement. J Bone Joint Surg Br 2001;83:40. 43. Jarolem KL, Scott DF, Jaffe WL, et al. A comparison of blood loss and transfusion requirements in total knee arthroplasty with and without arterial tourniquet. Am J Orthop 1995;24:906.