Computer Navigation and Total Knee Arthroplasty

n Feature Article Computer Navigation and Total Knee Arthroplasty Jingsheng Shi, MA; Yibing Wei, PhD; Siqun Wang, PhD; Feiyan Chen, PhD; Jianguo Wu, MA; Gangyong Huang, PhD; Jie Chen, MA; Licheng Wei, MA; Jun Xia, PhD abstract Full article available online at Healio.com/Orthopedics. Search: 20131219-15 Research has added evidence in favor of computer-navigated techniques over conventional surgery for total knee arthroplasty (TKA). The goal of the current meta-analysis was to compare the outcome of outliers in mechanical axis and postoperative complications in patients undergoing conventional vs computer-navigated techniques for TKA. English literature searches were performed in PubMed, EMBASE, Web of Science, and the Cochrane Library for studies published between January 2002 and August 2012. Randomized, controlled trials comparing computer navigation with conventional surgery for the measurement of mechanical axes in patients with primary osteoarthritis were considered eligible. Fifteen trials were eligible for inclusion. The baseline demographics of 2089 patients (computer-navigated=1111; conventional=978) were well matched. Publication bias was eliminated using the funnel plot. A mechanical axis of more than 30 was considered to be malalignment and an outlier in limb alignment. A significant increase of 16.9 minutes in mean operative time for computer-navigated TKA was observed (P=.046). Although patients undergoing computer-navigated TKA had fewer outliers in mechanical axis (13.4%) compared with the conventional technique (27.4%), the results did not achieve statistical significance (I 2 =0.0%; P=1.000). Fewer complications were observed in patients undergoing computer-navigated TKA (4%) compared with conventional TKA (6.5%). The use of computer-navigated TKA reduced the number of outliers in mechanical axis compared with conventional TKA; however, it did not achieve statistical significance. Additional research with longer follow-up is recommended. The authors are from the Department of Orthopedics, Huashan Hospital, FuDan University Medical College, Shanghai, China. The authors have no relevant financial relationships to disclose. Correspondence should be addressed to: Jun Xia, PhD, Department of Orthopedics, Huashan Hospital, FuDan University Medical College, 12 Wu Lu Mu Qi Middle Rd, Shanghai 200032, China (xia_jun2010@126.com). Received: July 27, 2013; Accepted: August 1, 2013; Posted: January 15, 2014. doi: 10.3928/01477447-20131219-15 JANUARY 2014 Volume 37 Number 1 e39

n Feature Article Computer navigation has gained popularity over the past decade since its introduction in knee prostheses compared with conventional orthopedic surgical techniques. 1 Simply put, computer navigation systems show the live surgical action on a computer screen, which may help improve the alignment of the prosthesis. The need for accuracy in proper prosthetic positioning has led to an increased use of computer navigation systems in total knee arthroplasty (TKA). There are 3 types of computer navigation systems for TKA: intraoperative image-free (no computed tomography [CT] or radiograph); preoperative image-based (CT-based); and intraoperative image-based (radiograph, no CT). 2 Computer navigation has repeatedly demonstrated improvement in the alignment of prosthetic knee components compared with a conventional manual technique. 3-5 Furthermore, a well-positioned prosthesis is directly associated with a good clinical result. 6 A mechanical axis of more than 30 is considered malalignment and an outlier in limb alignment. Despite widespread use, debate is ongoing regarding the risks and benefits of computer navigation systems. Computer navigation increases operative time and adds to the overall cost of surgery due to use of sophisticated equipment. 7 However, the use of computer navigation is a step toward individualization of surgical technology and makes surgeons more apt to deal with complicated surgeries. Computer navigation techniques have advanced technologically over the past decade, especially in the past 5 years. The expertise of orthopedic surgeons and the learning curve in the use of computer navigation have also improved. Considering that computer navigation is rapidly making a place for itself in TKA, the current authors conducted a meta-analysis to assess its accuracy in limb alignment. This study was conducted for randomized, controlled trials to compare the outcome of outliers in mechanical axis in patients undergoing conventional and computernavigated techniques. Postoperative complications were also reviewed. The metaanalysis was reported as per the Quality of Reporting of Meta-analyses (QUOROM) statement. 8 Materials and Methods PubMed, EMBASE, and Web of Sciences electronic databases were searched between January 2002 and August 2012 using the search string (computer OR computer navigation OR navigation) AND (knee arthroplasty OR joint replacement OR joint prosthesis OR arthroplasty). The Cochrane Library was also searched. The study was limited to the English-language literature. All types of navigation systems were included to reduce bias in the use of computer navigation system and type of prosthesis. Inclusion and Exclusion Criteria A study was eligible for inclusion if (1) it was a prospective randomized, controlled trial; (2) patients underwent primary TKA; (3) imageless or CT-based computer navigation was used in comparison with the conventional technique; and (4) the outcome measure was measurement of the mechanical axis. A study was excluded if (1) the knee surgery was bilateral; (2) the outcome of interest was not reported; (3) extrapolation or calculation of the necessary data was not possible from the published results; and (4) it contained previously published data. The abstract of an article was retrieved and reviewed if the title of the article and/ or keywords were relevant. The full-text articles of all potentially relevant articles were read to consider the article for inclusion in the study. The articles that compared mechanical axes and outliers in femoral and tibial angles of computer navigation with conventional TKA were included. The reference lists of the included articles were cross-checked to identify citations that could have been missed in the primary search steps. The articles reporting insufficient data, using nonstandardized scoring systems, or lacking precise comparison methods were rejected. Two authors (J.S.S., Y.B.W.) independently assessed the methodological quality of the included randomized, controlled trials. Study quality was judged on the basis of the randomization procedure, follow-up rates, interventions, and level of evidence (I or II were included). For each eligible study, 2 authors extracted the relevant data, including demographic data (age, sex, and body mass index [BMI]), mechanical axis, deviation from neutral (outliers from the desired target of more than 30 ), and mean operative time. Statistical Analysis Study heterogeneity was assessed, and a P value less than.1 was considered to be suggestive of statistical heterogeneity. Publication bias was assessed with funnel plots, which demonstrate the relationship between the sample sizes of the studies and the precision in estimating the outcome. Bias can be seen if the plots are widely skewed compared with a plot resembling an inverted triangle, which represents no bias. Results were combined using a weighted mean difference for continuous outcomes. For categorical outcomes, the odds ratio or risk difference was calculated as the summary statistics. An odds ratio less than 1 favors the treatment group, and the point estimate of the odds ratio is considered to be statistically significant if the 95% confidence interval does not include the value 1. A randomeffects model was used to pool data to control for increased study heterogeneity. Results A total of 146 studies were identified after the database search and cross-checking of reference lists. Of these, 111 studies were excluded on the basis of title or abstract. The full texts of 32 articles were retrieved and read by 2 independent authors (J.S.S., Y.B.W.). Finally, 15 randomized, e40 ORTHOPEDICS Healio.com/Orthopedics

n Feature Article controlled trials were included in the metaanalysis (Figure A, available at the end of the PDF of this article). 9-23 The study characteristics of the included studies are tabulated in Table A (available at the end of the PDF of this article). The available baseline demographics of patients in the computer-navigated and conventional groups were well matched. patient age was 68.8±2.1 years in the computer-navigated group and 68.3±2.5 years in the conventional group (P=.600). patient BMI was 29.7±1.1 kg/ m 2 in the computer-navigated group and 29.7±1.9 kg/m 2 in the conventional group (P=.987). In both of the groups, the majority of patients were female (computernavigated group, 67.4±19.6; conventional group, 59.4±12.0; P=.734). All included studies compared conventional TKA with computer-navigated TKA. In one study, the authors compared conventional minimally invasive surgery with computer-navigated minimally invasive surgery. Data for the group with minimally invasive surgery were not included. 12 In another study, 13 the conventional technique was compared with computernavigated surgery and computer-navigated minimally invasive surgery. For this study, the data for the 2 types of computer-navigated techniques were pooled. A total of 2089 patients (computernavigated=1111; conventional=978) undergoing TKA for primary osteoarthritis were included in the meta-analysis. The available baseline demographic data were well matched for patients (Table B, available at the end of the PDF of this article). The Figure shows the funnel plot for the 15 included studies reporting outliers in mechanical axis of more than 30. The majority of the studies were within the 95% confidence interval, showing a minimal publication bias. A significant increase of 16.9 minutes in mean operative time was observed in the computer-navigated group (93.1±17.7 minutes) vs the conventional group (76.2±18.2 minutes) (P=.046) (Table A, Figure: Funnel plot of precision by log odds ratio. Abbreviation: Std Err, standard error. available at the end of the PDF of this article). The number of mechanical axis outliers in the computer-navigated group was 149 (13.4%) of 1111, compared with 268 (27.4%) of 978 in the conventional group. Figure B (available at the end of the PDF of this article) shows the forest plot for outliers in mechanical axis as per randomeffects model. The pooled odds ratio for overall outliers in mechanical axis showed no difference between the 2 groups; no heterogeneity was observed (P=1.000; I 2 =0.0%). Femoral and tibial angles were calculated in 7 of the included studies. The pooled data in the random-effects model showed no difference between the 2 groups. No heterogeneity was observed (Figures C-D, available at the end of the PDF of this article). Eight studies presented data regarding complications (Table B, available at the end of the PDF of this article). There was no complication observed in any patient in just 1 of these 8 studies. 14 This study was included in the denominator when analyzing the percentage of complications. Of a total of 1430 patients evaluated for complications (computer-navigated=766; conventional=535), complications were observed in 33 (4%) patients in the computer-navigated group and 35 (6.5%) patients in the conventional group. Common complications observed were deep vein thrombosis, postoperative confusion, and wound-healing problems (eg, superficial infection, delayed healing). Discussion Given that computer-navigated techniques have advanced over the past 10 years, the current meta-analysis of randomized, controlled trials conducted between 2002 and 2012 was performed to compare computer-navigated surgery with conventional surgery. The authors compared conventional surgery with computer-navigated surgery irrespective of the type of equipment or procedure (minimally invasive or normal) and form of navigation (CT-based or imageless) used. This was done to gather all the available evidence for computer navigation compared with conventional surgery, as would be done in clinical practice. The results of this meta-analysis of 15 randomized, controlled trials demonstrated a decreased number of mechanical axis outliers in the computer-navigated group compared with the conventional group, but the results did not achieve statistical significance. Furthermore, no difference was JANUARY 2014 Volume 37 Number 1 e41

n Feature Article observed in femoral and tibial angles between groups. The authors also compared the complications observed in the included studies. Fewer complications were observed in patients treated with computernavigated surgery vs conventional surgery. Computer-navigated surgery is rapidly gaining popularity to help minimize errors in knee prosthesis placement. Two forms of computer-navigated TKA exist: the active robotic technique and the passive system, which includes CT-based and imageless systems, whereby the surgeon navigates instruments and components within a virtual picture intraoperatively. Passive computer navigation offers a preoperative examination of the knee on a computer screen, which helps the surgeon target the affected site more accurately, resulting in better alignment. 15 A mechanical axis of more than 30 was considered to be malalignment and an outlier in limb alignment. Previous studies have reported that a mechanical axis of more than 30 can lead to early loosening 24-26 and reduce the 10-year survival of TKA from 90% to 73%. 27 Thus, proper alignment and a mechanical axis within 30 is a crucial clinical outcome for patients undergoing TKA. When considered individually, a majority of the studies included in the current metaanalysis showed a significant reduction in outliers with computer navigation. The meta-analysis also revealed fewer outliers (13.4%) in the computer-navigated group compared with the conventional group (27.4%). Brin et al 6 conducted a Bayesian meta-analysis of 23 articles that included randomized, controlled trials, nonrandomized cohort studies, retrospective studies, and studies that used a historical cohort. Their meta-analysis showed that the use of imageless computer-navigated TKA significantly reduced the number of outliers in limb mechanical axis and coronal position of the implants by a rate of approximately 80%. 6 Two other metaanalyses investigated the effectiveness of computer-navigated TKA compared with conventional TKA. 7,28 These studies included randomized, controlled trials, quasi-randomized, controlled trials, studies with historical cohorts, and studies investigating the outcome of both CT-based and imageless navigation systems for TKA. These meta-analyses demonstrated better results for computer-navigated TKA. The current meta-analysis included randomized, controlled trials after assessing their methodological quality and included imageless and CT-based navigation systems to compare outliers in mechanical axis with the conventional technique. The inclusion of only randomized, controlled trials was an attempt to eliminate bias in treatment assignment, and randomized, controlled trials have a more valid study design for causal inference compared with an observational study design. Furthermore, the authors did not observe publication bias (Figure A, available at the end of the PDF of this article), which is considered a major reason for including studies other than randomized, controlled trials in meta-analyses. operative time in the current meta-analysis was significantly longer in the computer-navigated group compared with the conventional group (P=.046). There is a paucity of evidence regarding the clinical disadvantages of longer operative time, but theoretical disadvantages of prolonged operative time include increased blood loss and tourniquet-associated ischemia, increased incidence of infection, delayed wound healing, and added cost. However, evidence of these complications was not found in the 2 groups. The main limitation of the current meta-analysis was the inclusion of studies comparing different types of computernavigated techniques with conventional techniques. Although the meta-analysis was well planned, inclusion of a single type of computer-navigated technique could not be achieved due to less evidence. Better outcomes may become available through meta-analyses comparing a single computed-navigated technique and conventional technique with more research in this area. In addition, the follow-up period in the majority of these studies was 6 months but covered the critical time when the benefits of computer-navigated surgery can be observed. Lastly, although a random-effects model was used to compensate for statistical heterogeneity, real clinical heterogeneity cannot be totally ruled out because the included studies had nonuniform definitions, end points, types of implants, and care programs, and also possible differences in baseline demographics, such as severity of the disease. The authors tried to control this heterogeneity by clearly defining inclusion and exclusion criteria and the outcomes to be studied before the meta-analysis. Conclusion This meta-analysis demonstrated fewer mechanical axis outliers with the use of computer-navigated TKA compared with conventional TKA. In addition, the total number of postoperative complications observed in patients who underwent computer-navigated TKA was significantly less than that observed in the conventional group. The results of this meta-analysis provide a platform for further research in this area. There is a need for better designed randomized, controlled trials to facilitate the availability of stronger evidence in favor of computer-navigated surgery. References 1. Picard F, Leitner F, Saragaglia D, Cinquin P. Computer assisted implantation of a total knee prosthesis: about 7 cadaver implantations. Rev Chir Orthop. 1997; 83(Suppl II):31. 2. Merloz P. Computer-assisted knee replacement. European Instructional Course Lectures. 2008; 8:154-159. 3. Miehlke RK, Clemens U, Jens JH, Kershally S. Navigation in knee endoprosthesis implantation: preliminary experiences and prospective comparative study with conventional implantation technique. Z Orthop Ihre Grenzgeb. 2001; 139(2):109-116. 4. Decking R, Markmann Y, Fuchs J, Puhl W, Scharf HP. Leg axis after computer navigated total arthroplasty: a prospective randomized trial comparing computer-navigated and e42 ORTHOPEDICS Healio.com/Orthopedics

n Feature Article manual implantation. J Arthroplasty. 2005; 20(3):282-288. 5. Shinozaki T, Gotoh M, Mitsui Y, et al. Computer-assisted total knee arthroplasty: comparisons with the conventional technique. Kurume Med J. 2011; 58(1):21-26. 6. Brin YS, Nikolaou VS, Joseph L, Zukor DJ, Antoniou J. Imageless computer assisted versus conventional total knee replacement: a Bayesian meta-analysis of 23 comparative studies. Int Orthop. 2011; 35(3):331-339. 7. Bauwens K, Matthes G, Wich M, et al. Navigated total knee replacement: a meta-analysis. J Bone Joint Surg Am. 2007; 89(2):261-269. 8. Moher D, Cook DJ, Eastwood S, Olkin I, Rennie D, Stroup DF. Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Lancet. 1999; 354(9193):1896-1900. 9. Oberst M, Bertsch C, Konrad G, Lahm A, Holz U. CT analysis after navigated versus conventional implantation of TKA. Arch Orthop Trauma Surg. 2008; 128(6):561-566. 10. Chauhan SK, Scott RG, Breidahl W, Beaver RJ. Computer-assisted knee arthroplasty versus a conventional jig-based technique: a randomised, prospective trial. J Bone Joint Surg Br. 2004; 86(3):372-377. 11. Pang HN, Yeo SJ, Chong HC, et al. Computer-assisted gap balancing technique improves outcome in total knee arthroplasty, compared with conventional measured resection technique. Knee Surg Sports Traumatol Arthrosc. 2011; 19(9):1496-1503. 12. Luring C, Beckmann J, Haibock P, et al. Minimal invasive and computer assisted total knee replacement compared with the conventional technique: a prospective, randomised trial. Knee Surg Sports Traumatol Arthrosc. 2008; 16(10):928-934. 13. Van Strien T, van der Linden-van der Zwaag E, Kaptein B, et al. Computer assisted versus conventional cemented total knee prostheses alignment accuracy and micromotion of the tibial component. Int Orthop. 2009; 33(5):1255-1261. 14. Martin A, Wohlgenannt O, Prenn M, Oelsch C, von Strempel A. Imageless navigation for TKA increases implantation accuracy. Clin Orthop Relat Res. 2007; 460:178-184. 15. Ensini A, Catani F, Leardini A, Romagnoli M, Giannini S. Alignments and clinical results in conventional and navigated total knee arthroplasty. Clin Orthop Relat Res. 2007; 457:156-162. 16. Mullaji A, Kanna R, Marawar S, Kohli A, Sharma A. Comparison of limb and component alignment using computer-assisted navigation versus image intensifier-guided conventional total knee arthroplasty: a prospective, randomized, single-surgeon study of 467 knees. J Arthroplasty. 2007; 22(7):953-959. 17. Hiscox CM, Bohm ER, Turgeon TR, Hedden DR, Burnell CD. Randomized trial of computer-assisted knee arthroplasty: impact on clinical and radiographic outcomes. J Arthroplasty. 2011; 26(8):1259 1264. 18. Dutton AQ, Yeo SJ, Yang KY, et al. Computerassisted minimally invasive total knee arthroplasty compared with standard total knee arthroplasty: a prospective, randomized study. J Bone Joint Surg Am. 2008; 90(1):2-9. 19. Matziolis G, Krocker D, Weiss U, Tohtz S, Perka C. A prospective, randomized study of computer-assisted and conventional total knee arthroplasty: three-dimensional evaluation of implant alignment and rotation. J Bone Joint Surg Am. 2007; 89(2):236-243. 20. Sparmann M, Wolke B, Czupalla H, Banzer D, Zink A. Positioning of total knee arthroplasty with and without navigation support: a prospective, randomised study. J Bone Joint Surg Br. 2003; 85(6):830-835. 21. Choong PF, Dowsey MM, Stoney JD. Does accurate anatomical alignment result in better function and quality of life? Comparing conventional and computer-assisted total knee arthroplasty. J Arthroplasty. 2009; 24(4):560-569. 22. Maculé-Beneyto F, Hernández-Vaquero D, Segur-Vilalta JM, et al. Navigation in total knee arthroplasty: a multicenter study. Int Orthop. 2006; 30(6):536-540. 23. Zhang XL, Zhang W, Shao JJ. Rotational alignment in total knee arthroplasty: nonimage-based navigation system versus conventional technique. Chin Med J (Engl). 2012; 125(2):236-243. 24. Jeffery RS, Morris RW, Denham RA. Coronal alignment after total knee replacement. J Bone Joint Surg Br. 1991; 73(5):709-714. 25. Bargren JH, Blaha JD, Freeman MA. Alignment in total knee arthroplasty: correlated biomechanical and clinical observations. Clin Orthop Relat Res. 1983; 173:178-183. 26. Petersen TL, Engh GA. Radiographic assessment of knee alignment after total knee arthroplasty. J Arthroplasty. 1988; 3(1):67-72. 27. Rand JA, Coventry MB. Ten-year evaluation of geometric total knee arthroplasty. Clin Orthop Relat Res. 1988; 232:168-173. 28. Mason JB, Fehring TK, Estok R, Banel D, Fahrbach K. Meta-analysis of alignment outcomes in computer-assisted total knee arthroplasty surgery. J Arthroplasty. 2007; 22(8):1097-1106. JANUARY 2014 Volume 37 Number 1 e43

Table A: Baseline patient demographics and study characteristics. Author Year Randomization Size Size BMI BMI Navigation Assisted Technique Beneyto et al [22] 2006 Not defined 109 93 71.6 72.3 - - 30.4 31.4 Stryker System; Navitrack System; and Orthopilot System Chauhan et al [10] 2004 Block randomization 35 35 - - - - - - Imageless System (Stryker Knee Navigation System) Choong et al [21] 2009 Computer random number generator 57 54 70 69 40 27 29.5 29.5 Modular, Total Condylar Knee Arthroplasty Prosthesis (Press Fit Condylar Sigma, Depuy, Johnson & Johnson, Warsaw, IN)

Table A: Baseline patient demographics and study characteristics. Author Year Randomization Size Size BMI BMI Navigation Assisted Technique Dutton et al [18] 2008 Computer random number generator 52 56 68 67 44 44 27.6 27.1 Mini Medial Parapatellar Approach Combined with an Imageless Computer Navigation System (Ci total knee replacement version 1.0; Depuy/Brainlab, Munich, Germany) Ensini et al [15] 2006 Not defined 60 60 68.8 71.1 30 40 - - Image-free Stryker Knee Navigation System (Stryker Navigation, Kalamazoo, MI) Hiscox et al [17] 2011 Block randomization 61 59 66.8 67.5 37 42 - - Stryker Duracon Total Knee System (Stryker Orthopaedics, Mahwah, NJ)

Table A: Baseline patient demographics and study characteristics. Author Year Randomization Size Size BMI BMI Navigation Assisted Technique Luring et al [12] 2008 Randomized by an independent person by lot 30 30 70 69 - - 31 32 Special MIS Pathway Instruments (intramedullary for femur, extramedullary for tibia) [DePuy, Warshaw, USA] Martin et al [14]] 2007 Assigned patient codes 100 100 70.3 71.1 68 73 30.2 28.2 CT-free VectorVision Knee Navigation System (BrainLAB, Munich, Germany) Matziolis et al [19] 2007 Computer random number generator 32 28 71 70 - - 30.5 31.7 Tricompartmental Plus Solution Type Rotating Platform (TC-PLUS; Endoplus, Marl, Germany)

Table A: Baseline patient demographics and study characteristics. Author Year Randomization Size Size BMI BMI Navigation Assisted Technique Mullaji et al [16] 2007 Random allocation 282 185 65.5 65.9 215 143 - - Ci Navigation System (Brainlab, Munich, Germany) Oberst et al [9] 2008 Not defined 34 35 - - - - - - Vector Vision System (BrainLAB, CT-free software 1.1) Pang H N et al [11] 2011 Randomization tables 70 70 68 70 60 58 29.3 28.5 Identical Cemented Posterior Cruciate Retaining Knee Prosthesis with a Fixed Bearing Tibial Prosthesis (PFC, Depuy orthopaedic International, Leeds, UK)

Table A: Baseline patient demographics and study characteristics. Author Year Randomization Size Size BMI BMI Navigation Assisted Technique Sparmann et al [20] 2003 Availability of navigation system 120 120 67.4 66.1 88 79 - - Knee Navigation System (Stryker Howmedica Osteonics, Allendale, NJ) Strien et al [13] 2009 Computer random number generator 17 21 - - - - - - Brainlab Vector Vision System (Version 1.5.1, Brainlab, Munich, Germany) Zhang et al [23] 2012 Table of random numbers 41 41 66.3 63.3 25 29 - - Scorpio Posterior Stabilized System (Stryker, Mahway, NJ, USA) Abbreviations: Navigation, Conventional, Body Mass Index (BMI)

Table B: Complications observed in patients post-tka Author Year Complications Navigation Technique Conventional (n/n) Technique (n/n) Deep vein thrombosis 1/35 2/35 Superficial infection 1/35 2/35 Chauhan et al [10] 2003 Stiff knee requiring manipulation under anesthesia 1/35 - Acute post-operative confusional state 1/35 10/35 Pulmonary embolism - 1/35 Transient ischemia - 1/35 Pulmonary embolism 1/57 - Deep vein thrombosis 1/57 1/54 Acute myocardial infarction 1/57 1/54 Pneumonia 1/57 - Choong et al [21] 2009 Hemarthrosis 1/57 1/54 Hematoma 1/57 - Poor range of movement 1/57 1/54 Late presentation for deep hematogenous infection 2/57 - Deep infection - 1/54

Confusion - 2/54 Dutton et al [18] 2008 Acute deep wound infection - 1/56 Hiscox et al [17] 2011 Unspecified complications 8/61 1/59 Death 1/61 0/59 Martin et al [14] 2007 Nil 0/100 0/100 Mullaji et al [16] 2007 Acute deep infection 1/282 - Supracondylar fracture 1/282 - Pin track infection around most distal pin site 1/70 - Pang H N et al [11] 2011 Superficial wound infection - 1/70 Proximal deep vein thrombosis in the popliteal vein 1/70 1/70 Transient ischemic attack - 1/70 Deep Infection 1/120 0 Sparmann et al [20] 2003 Thrombosis 1/120 1/120 Delayed would healing 3/120 1/120 Manipulation under anesthesia 1/120 4/120 Zhang et al [23] 2012 Deep vein thrombosis 1/41 3/41 Total Complications (n/n) 33/766 35/535 Abbreviations: Total Knee Arthroplasty (TKA), Patients experiencing post-operative complications (n), and Total Size.

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Figure B

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Figure D