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Effects of Suture and Tourniquet on Intraoperative Kinematics in Navigated Total Knee Arthroplasty
The Journal of Arthroplasty xxx (2017) 1e5
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Original Article
Effects of Suture and Tourniquet on Intraoperative Kinematics in Navigated Total Knee Arthroplasty Masanori Tsubosaka, MD a, Kazunari Ishida, MD, PhD b, *, Hiroshi Sasaki, MD, PhD b, Nao Shibanuma, MD, PhD b, Ryosuke Kuroda, MD, PhD a, Tomoyuki Matsumoto, MD, PhD a a b
Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan Department of Orthopaedic Surgery, Kobe Kaisei Hospital, Kobe, Japan
a r t i c l e i n f o
a b s t r a c t
Article history: Received 11 October 2016 Received in revised form 14 January 2017 Accepted 17 January 2017 Available online xxx
Background: To investigate the effects of suture (soft tissue closure) and air tourniquet use on intraoperative kinematics in navigated total knee arthroplasty. Methods: The study included 20 patients with varus-type knee osteoarthritis who underwent primary posterior-stabilized total knee arthroplasty using computed tomography (CT)ebased navigation. Intraoperative tibiofemoral kinematics from maximum extension to maximum flexion were measured using the computed tomographyebased navigation. The measurements were performed 3 times as follows: measurement 1: before suture (tourniquet on), measurement 2: after suture (tourniquet on), and measurement 3: after tourniquet removal. Details of kinematics including knee joint gap, tibiofemoral rotational angles, and anteroposterior (AP) distance between the femur and tibia were compared among the 3 measurements and statistically evaluated. Results: On the medial side, there was no significant difference among the 3 measurements in the extension gap, but measurement 1 showed a significantly larger flexion gap compared with the other 2 measurements. On the lateral side, there was no significant difference between the extension and flexion gaps in all measurements. The anteroposterior distance in measurement 1 showed that the femur was positioned significantly more anterior to the tibia at 10 and 20 of flexion compared with the other 2 measurements after suture. There was no significant difference among the 3 measurements in the tibiofemoral rotation angles. Conclusion: These results found that the effect of suture and tourniquet was minimal, and that intraoperative kinematics can effectively evaluate postoperative passive kinematic conditions. © 2017 Elsevier Inc. All rights reserved.
Keywords: total knee arthroplasty tourniquet soft tissue closure navigation kinematics
Total knee arthroplasty (TKA) is successfully used to treat painful osteoarthritic knees. In recent years, surgeons have been able to obtain information on intraoperative kinematics, soft tissue tension, and rotational adjustments using a navigation system [1-3]. As appropriate kinematics are related to the prevention of postoperative polyethylene wear, protection of soft tissue, and patient satisfaction [2,4,5], this intraoperative information might be useful for the refinement of surgical techniques, as well as anticipating postoperative clinical outcomes [6-9].
No author associated with this paper has disclosed any potential or pertinent conflicts which may be perceived to have impending conflict with this work. For full disclosure statements refer to http://dx.doi.org/10.1016/j.arth.2017.01.033. * Reprint requests: Kazunari Ishida, MD, PhD, Department of Orthopaedic Surgery, Kobe Kaisei Hospital, 3-11-15, Shinohara-Kita, Nada, Kobe 657-0068, Japan. http://dx.doi.org/10.1016/j.arth.2017.01.033 0883-5403/© 2017 Elsevier Inc. All rights reserved.
However, there are many controversies regarding the limitations of intraoperative kinematics [10-12]. It is said that kinematic values obtained using a navigation system tend to be larger than those obtained using fluoroscopic analysis [11,12]. These differences may be regulated by several factors, including the use of anesthesia, tourniquets, and soft tissues incision, which do not reflect the effects of muscle force [10] or passive motion [9]. However, there have been no detailed reports of how suture or tourniquet use affects kinematics during surgery. The present study aimed to investigate the effects of suture of the soft tissues and tourniquet use on intraoperative kinematics in computed tomography (CT)ebased navigated TKA. It is hypothesized that the effect of suture and tourniquet use on passive motion kinematics is minimal and that intraoperative kinematics at postimplantation is useful data that can help evaluate postoperative passive knee kinematics.
2
M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
Materials and Methods This prospective study included 20 consecutive patients (18 female and 2 male patients), with varus-type knee osteoarthritis who underwent primary posterior-stabilized (PS) TKA (DePuy PFC Sigma, fixed bearing type, Warsaw, IN). The mean age of the patients was 77.6 years (±6.4 years), and the mean body mass index was 25.4 kg/m2 (±4.1 kg/m2). The operation was performed by one experienced surgeon who followed a medial parapatellar approach and a measured resection technique using a CT-based navigation system (BrainLAB, Heimstetten, Germany). All the surgeries were performed using an air tourniquet (300 mm Hg) that was inflated with the knee at maximal flexion before skin incision. At the start of the operation, 2 tracker pins were placed on each side through an extra-small skin incision (anterolateral in the femur and anteromedial in the tibia) after blunt muscle dissection. The femoral rotational axis was defined by the navigation system determined by registration. We determined this axis using preoperative 3-dimensional planning software (Athena Knee, SoftCube Co, Ltd, Osaka, Japan), wherein the axis was parallel to the surgical epicondylar axis [13,14]. The tibial rotational axis was defined according to the report of Akagi et al [15], which specified it as being along the line from the medial border of the tibial tubercle to the middle of the posterior cruciate ligament (PCL). Care was taken to balance the flexion and extension gaps and to release any flexion contractures. After the implantation, intraoperative kinematics up to a maximum flexion from maximum extension of the knee joint were collected using a CT-based navigation system, as previously reported [3]. Briefly, while supporting the heel with an open palm and touching the thigh with the opposite hand, the surgeon gently flexed the hip and knee to their final points, with the knee flexion being assisted by gravity. Care was taken not to
apply exterior varus and/or valgus stress, which may influence the kinematics and gap measurement. The measurement was performed 3 times and the average values were analyzed. Primary experiments had already found that the test-retest reliability of these measurements is excellent (interclass and intraclass correlation coefficient, 0.99). The timing of the measurements was as follows: measurement 1: before suture (tourniquet on), measurement 2: after suture (tourniquet on), and measurement 3: after tourniquet removal (Fig. 1). For capsule closure, discontinued stitches with No. 2 polyamide 66 (NUROLON, Ethicon Inc, Somerville, NJ) were used. Then, subcutaneous tissues were roughly approximated with discontinued stitches by No. 0 polyamide 66 (NUROLON, Ethicon Inc). Thereafter, approximation suture 3-0 polyglactin 910 (Coated VICRYL, Ethicon Inc) with discontinued buried knots were performed. The skin was then closed with a skin closer (Steri-strip R1547, 3M Company, Maplewood, MN). Measured parameters were: (1) knee joint gap, (2) tibiofemoral rotational angles, and (3) anteroposterior (AP) distance between the femur and tibia. The knee joint gap was defined as the distance between the cut bone surface of the femur and tibia. Knee joint gaps were measured with the medial and lateral tibiofemoral joint at maximum extension and 90 of flexion. The tibiofemoral rotational angle was defined as the angle between the perpendicular line of the surgical epicondylar axis and Akagi's line [15]. The AP distance was defined as the distance between the distal end of femoral mechanical axis and the proximal end of tibial mechanical axis, in the longitudinal direction. As the kinematic data was affected by the registration point, the results had variance between different patients. Therefore, the data obtained at maximum extension before soft tissue closure was determined to be the reference point, and the results were expressed as differences
Fig. 1. The timing of the measurements. Measured items are (1) knee joint gap, (2) tibiofemoral rotational angles, and (3) anteroposterior (AP) distance between the femur and tibia. (A) Measurement 1 is the timing before suture (tourniquet on). (B) Measurement 2 is the timing after suture (tourniquet on). (C) Measurement 3 is the timing after removal of the tourniquet.
M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
compared with the reference point. The tracker pins were removed after completion of all the measurement procedures. Statistical Analysis Data analyses were performed with a statistical software package (Statview 5.0; Abacus Concepts Inc, Berkeley, CA). In addition, the Shapiro-Wilk-Test (SPSS Statistics 21; IBM Japan, Tokyo, Japan) was performed to analyze normally distributed data. Correlations among the preoperative and postoperative flexion and extension angles were analyzed using paired t tests. We evaluated knee joint gap, tibiofemoral rotational angles, and AP distance between the femur and tibia at each of the measurement points (Fig. 1) using 1-way analysis of variance. These measured parameters among the 3 measurements were evaluated using a repeated measures analysis of variance with a Fisher probable least-squares difference post hoc test for multiple comparisons of paired samples. P values of <.05 were considered statistically significant. The sample size was determined based on the previous study [16], and was further backed up by a post hoc power analysis using the G power 3.1 software (a ¼ 0.05; power level ¼ 80%; each observed effect size and total sample size of 20). Results All 20 patients recovered knee function without changes in the knee maximal flexion angle. The mean preoperative and postoperative maximum flexion angles were 121.9 ± 12.2 and 120.0 ± 4.7, respectively. On the other hand, the mean preoperative and postoperative maximum extension angles were 5.6 ± 6.3 and 0.3 ± 1.2 , respectively. The postoperative maximum extension angles were significantly improved compared with the preoperative angles (P < .01). The results for medial and lateral gaps in extension and flexion among the 3 measurements are shown in Table 1. The results for the medial gap found that there was no significant difference among the 3 measurements in the extension gap. However, measurement 1 showed a significant larger medial flexion gap compared with the other 2 measurements (compared with measurement 2, P ¼ .018; compared with measurement 3, P ¼ .030). The results for lateral gap found that there were no significant differences among the 3 measurements in both the extension and flexion gaps. There was no significant difference among the 3 measurements regarding the tibiofemoral rotational kinematics (Fig. 2). The results for AP distance revealed that the femur was positioned significantly more anterior to the tibia in measurement 1, compared with the other 2 measurements at 10 and 20 of flexion (compared with measurement 2, P ¼ .041 at 10 of flexion and P ¼ .042 at 20 of flexion; compared with measurement 3, P ¼ .042 at 10 of flexion and P ¼ .036 at 20 of flexion; Fig. 3). Table 1 Medial and Lateral Gap in Extension and Flexion Among the 3 Measurements.
Measurement 1: before suture (tourniquet on) Measurement 2: after suture (tourniquet on) Measurement 3: tourniquet off
In Extension
In Flexion
Medial Gap
Lateral Gap
Medial Gap
18.8 ± 2.9
19.1 ± 3.2
*
18.5 ± 2.5
18.7 ± 2.8
Lateral Gap
18.3 ± 4.1
18.4 ± 4.2
19.2 ± 2.6
17.5 ± 4.5
18.0 ± 4.6
19.2 ± 3.4
17.7 ± 4.0
Data were shown as mean ± standard deviation, *P < .05.
*
18.3 ± 4.2
3
Discussion The most important finding of this study was that the suture and tourniquet have almost no effect on intraoperative kinematics, except on the tibiofemoral AP position in the extended position. These results suggest that the intraoperative kinematics at postimplantation could be regarded as postoperative passive motion kinematics. In this study, all patients underwent PS TKA. The PCL acts to maintain a stable joint gap between the femur and tibia, and AP stability beyond 90 flexion [16,17]. The resected PCL is significantly associated with an increase in the flexion gap compared with the extension gap [18]. Here, the PCL and patellar tendon are almost parallel to the longitudinal axis of the tibia when the knee is flexed 90 . Thus, it is likely that the patellar tendon plays a major role in maintaining the joint gap in PS TKA [17,19]. The results found that only the medial flexion gap showed significant separation before soft tissue closure. It can be deduced that the lateral flexion gap was decreased by the combination between patellar tendon and lateral soft tissue structures, such as the vastus lateralis and iliotibial band because of the intact junction between the patellar tendon and lateral soft tissue structures in the medial parapatellar approach. However, the medial side was less affected by the patellar tendon because the approach separated medial soft tissue structures from the patellar tendon. Thus, it can be seen that the patellar tendon plays an important role in maintaining the flexion gap in PS TKA, which lacks the PCL function. Matsumoto et al [20] reported joint gap kinematics in PS TKA measured by an offset-type tensor, and significantly lower gaps were found at 90 flexion with PF joint reduction compared to those with the patella everted. The results also support the present findings, which indicate that the patellar tendon plays an important role in maintaining the flexion gap in PS TKA. On the other hand, it has also been reported that there was no significant change of ligament balance in the varus configuration at 90 flexion with PF joint reduction, compared with patellar eversion in PS TKA [21]. As it is impossible to measure the gap measurement using a tensor after soft tissue closure, it remains unknown whether soft tissue closure affects the gap values. Although a distraction force was not applied to the gap, which is definitely different than the measurement using a tensor, navigation might be a useful tool for the assessment of gap balance after TKA. Regarding the tibiofemoral AP position, the femur shifted anteriorly in the early extension position without suture, compared with after suture. This result suggests that the gravity force was applied rearward to the tibia in midflexion from extension without suture conditions. The conditions in the early extension position, such as the relative instability of knees undergoing PS TKA due to post-cam mechanism usually working from a midflexion position, and a lying passive motion without quadriceps force might influence the results. Some studies have investigated the correlation between intraoperative rotational kinematics and clinical outcomes [3,7,9]. For instance, Matsuzaki et al [7] reported that lateral laxity from midto-deep knee flexion in CR TKA plays a significant role in internal tibial rotation, and the lateral compartment gap was positively correlated with postoperative knee flexion angle at 90 and 120 flexion. These studies suggested that intraoperative kinematics provided important clinical information to estimate postoperative clinical outcomes. However, the discussions in these studies are always limited in terms of intraoperative kinematics because several factors differ in intraoperative conditions compared with postoperative active motion conditions. In the present study, tibiofemoral kinematics were not affected by soft tissue closure and tourniquet. Obviously, the intraoperative kinematics differ
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M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
Fig. 2. Results for tibiofemoral rotational angles among the 3 groups. There was no significant difference among the 3 measurements regarding tibiofemoral rotational kinematics (plus indicates tibial external rotation).
from the postoperative active motion kinematics, although it can be considered that the intraoperative rotational kinematics can be regarded as being similar to postoperative passive motion kinematics. A tourniquet is conventionally used in TKA surgery to provide better visualization, ensure dry surgery, facilitate the cementing procedure, and reduce the duration of surgery [22-24]. However, there were no reports about how a tourniquet affects kinematics during TKA surgery. In this study, there was no significant effect on kinematics by use of a tourniquet. One of the reasons for why there
was no effect of tourniquet on intraoperative kinematics was that the preoperative tourniquet was inflated in the knee maximum flexion position. It is suggested that the condition minimizes the influence of the tourniquet in flexion. The present study has some limitations. First, a single type of PS TKA limited the study. Additional studies using different implant designs are required to further examine the effects of the suture and tourniquet on knee kinematics. Second, although this study is a prospective comparative study, it included a small population based on a previous clinical study and power analysis, so subtle
Fig. 3. The results with AP distance between femur and tibia. In measurement 1, AP distance revealed that the femur was positioned significantly more anterior to the tibia compared with the other 2 measurements at 10 and 20 of flexion (P < .05; plus indicates anterior position of the femur to the tibia).
M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
differences were not detected as significantly different. The kinematic measurement conditions were limited by the use of anesthesia. Although several studies have evaluated postoperative knee kinematics under weight-bearing conditions, the kinematic measurements in this study were of noneweight-bearing passive knee kinematics, which do not reflect the effects of muscle force, and differ from physiological knee kinematics. Furthermore, although navigation-based surgery allowed us to perform constant bony cuts and reduce the outliers from the mechanical axis [25], the correlation between bony cuts, alignment, ligament balancing [26], and kinematic data are out of the scope of this study. Finally, the effect of tracker pins could not be evaluated. Especially femoral tracker pins might influence the kinematics because the pins were placed through the quadriceps muscle. Further studies, such as what factors affect the differences in this study are needed to investigate the detailed explanation of the mechanism. Nevertheless, knowledge about how sutures and tourniquets affect knee kinematics has important clinical relevance. It is suggested that surgeons assess intraoperative knee kinematics carefully based on the present results, although intraoperative kinematics can effectively evaluate postoperative passive kinematic conditions. Conclusion These results indicate that the effects of suture and tourniquet were minimal, and that intraoperative kinematics can be used effectively to evaluate postoperative passive kinematic conditions. References 1. Klein GR, Parvizi J, Rapuri VR, et al. The effect of tibial polyethylene insert design on range of motion: evaluation of in vivo knee kinematics by a computerized navigation system during total knee arthroplasty. J Arthroplasty 2004;19(8):986. 2. Nishio Y, Onodera T, Kasahara Y, et al. Intraoperative medial pivot affects deep knee flexion angle and patient-reported outcomes after total knee arthroplasty. J Arthroplasty 2014;29(4):702. 3. Ishida K, Shibanuma N, Matsumoto T, et al. Navigation-based femorotibial rotation pattern correlated with flexion angle after total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2016;24(1):89. 4. Ho FY, Ma HM, Liau JJ, et al. Mobile-bearing knees reduce rotational asymmetric wear. Clin Orthop Relat Res 2007;462:143. 5. Moschella D, Blasi A, Leardini A, et al. Wear patterns on tibial plateau from varus osteoarthritic knees. Clin Biomech (Bristol, Avon) 2006;21(2):152.
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6. Belvedere C, Ensini A, Leardini A, et al. Tibio-femoral and patello-femoral joint kinematics during navigated total knee arthroplasty with patellar resurfacing. Knee Surg Sports Traumatol Arthrosc 2014;22(8):1719. 7. Matsuzaki T, Matsumoto T, Muratsu H, et al. Kinematic factors affecting postoperative knee flexion after cruciate-retaining total knee arthroplasty. Int Orthop 2013;37(5):803. 8. Siston RA, Giori NJ, Goodman SB, et al. Intraoperative passive kinematics of osteoarthritic knees before and after total knee arthroplasty. J Orthop Res 2006;24(8):1607. 9. Ishida K, Shibanuma N, Matsumoto T, et al. Navigation-based tibial rotation at 90 degrees of flexion is associated with better range of motion in navigated total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2016;24(8):2447. 10. Seon JK, Park JK, Jeong MS, et al. Correlation between preoperative and postoperative knee kinematics in total knee arthroplasty using cruciate retaining designs. Int Orthop 2011;35(4):515. 11. Dennis DA, Komistek RD, Mahfouz MR, et al. A multicenter analysis of axial femorotibial rotation after total knee arthroplasty. Clin Orthop Relat Res 2004;(428):180. 12. Komistek RD, Dennis DA, Mahfouz M. In vivo fluoroscopic analysis of the normal human knee. Clin Orthop Relat Res 2003:69. 13. Chinzei N, Ishida K, Matsumoto T, et al. Evaluation of patellofemoral joint in ADVANCE Medial-pivot total knee arthroplasty. Int Orthop 2014;38(3):509. 14. Tei K, Ishida K, Matsumoto T, et al. Novel image-matching software for postoperative evaluation after TKA. Orthopedics 2012;35(12):e1711. 15. Akagi M, Oh M, Nonaka T, et al. An anteroposterior axis of the tibia for total knee arthroplasty. Clin Orthop Relat Res 2004;(420):213. 16. Mihalko W, Fishkin Z, Krackow K. Patellofemoral overstuff and its relationship to flexion after total knee arthroplasty. Clin Orthop Relat Res 2006;449:283. 17. Komatsu T, Kadoya Y, Nakagawa S, et al. Movement of the posterior cruciate ligament during knee flexioneMRI analysis. J Orthop Res 2005;23(2):334. 18. Kadoya Y, Kobayashi A, Komatsu T, et al. Effects of posterior cruciate ligament resection on the tibiofemoral joint gap. Clin Orthop Relat Res 2001;(391):210. 19. Sasaki H, Kubo S, Matsumoto T, et al. The influence of patella height on intraoperative soft tissue balance in posterior-stabilized total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2012;20(11):2191. 20. Matsumoto T, Muratsu H, Tsumura N, et al. Joint gap kinematics in posteriorstabilized total knee arthroplasty measured by a new tensor with the navigation system. J Biomech Eng 2006;128(6):867. 21. Matsumoto T, Muratsu H, Kubo S, et al. Soft tissue tension in cruciate-retaining and posterior-stabilized total knee arthroplasty. J Arthroplasty 2011;26(5):788. 22. Kvederas G, Porvaneckas N, Andrijauskas A, et al. A randomized double-blind clinical trial of tourniquet application strategies for total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2013;21(12):2790. 23. Vandenbussche E, Duranthon LD, Couturier M, et al. The effect of tourniquet use in total knee arthroplasty. Int Orthop 2002;26(5):306. 24. Dennis DA, Kittelson AJ, Yang CC, et al. Does tourniquet use in TKA affect recovery of lower extremity strength and function? A randomized trial. Clin Orthop Relat Res 2016;474(1):69. 25. Ishida K, Matsumoto T, Tsumura N, et al. Mid-term outcomes of computerassisted total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2011;19(7):1107. 26. Fujimoto E, Sasashige Y, Masuda Y, et al. Significant effect of the posterior tibial slope and medial/lateral ligament balance on knee flexion in total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2013;21(12):2704.
Contents lists available at ScienceDirect
The Journal of Arthroplasty journal homepage: www.arthroplastyjournal.org
Original Article
Effects of Suture and Tourniquet on Intraoperative Kinematics in Navigated Total Knee Arthroplasty Masanori Tsubosaka, MD a, Kazunari Ishida, MD, PhD b, *, Hiroshi Sasaki, MD, PhD b, Nao Shibanuma, MD, PhD b, Ryosuke Kuroda, MD, PhD a, Tomoyuki Matsumoto, MD, PhD a a b
Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, Kobe, Japan Department of Orthopaedic Surgery, Kobe Kaisei Hospital, Kobe, Japan
a r t i c l e i n f o
a b s t r a c t
Article history: Received 11 October 2016 Received in revised form 14 January 2017 Accepted 17 January 2017 Available online xxx
Background: To investigate the effects of suture (soft tissue closure) and air tourniquet use on intraoperative kinematics in navigated total knee arthroplasty. Methods: The study included 20 patients with varus-type knee osteoarthritis who underwent primary posterior-stabilized total knee arthroplasty using computed tomography (CT)ebased navigation. Intraoperative tibiofemoral kinematics from maximum extension to maximum flexion were measured using the computed tomographyebased navigation. The measurements were performed 3 times as follows: measurement 1: before suture (tourniquet on), measurement 2: after suture (tourniquet on), and measurement 3: after tourniquet removal. Details of kinematics including knee joint gap, tibiofemoral rotational angles, and anteroposterior (AP) distance between the femur and tibia were compared among the 3 measurements and statistically evaluated. Results: On the medial side, there was no significant difference among the 3 measurements in the extension gap, but measurement 1 showed a significantly larger flexion gap compared with the other 2 measurements. On the lateral side, there was no significant difference between the extension and flexion gaps in all measurements. The anteroposterior distance in measurement 1 showed that the femur was positioned significantly more anterior to the tibia at 10 and 20 of flexion compared with the other 2 measurements after suture. There was no significant difference among the 3 measurements in the tibiofemoral rotation angles. Conclusion: These results found that the effect of suture and tourniquet was minimal, and that intraoperative kinematics can effectively evaluate postoperative passive kinematic conditions. © 2017 Elsevier Inc. All rights reserved.
Keywords: total knee arthroplasty tourniquet soft tissue closure navigation kinematics
Total knee arthroplasty (TKA) is successfully used to treat painful osteoarthritic knees. In recent years, surgeons have been able to obtain information on intraoperative kinematics, soft tissue tension, and rotational adjustments using a navigation system [1-3]. As appropriate kinematics are related to the prevention of postoperative polyethylene wear, protection of soft tissue, and patient satisfaction [2,4,5], this intraoperative information might be useful for the refinement of surgical techniques, as well as anticipating postoperative clinical outcomes [6-9].
No author associated with this paper has disclosed any potential or pertinent conflicts which may be perceived to have impending conflict with this work. For full disclosure statements refer to http://dx.doi.org/10.1016/j.arth.2017.01.033. * Reprint requests: Kazunari Ishida, MD, PhD, Department of Orthopaedic Surgery, Kobe Kaisei Hospital, 3-11-15, Shinohara-Kita, Nada, Kobe 657-0068, Japan. http://dx.doi.org/10.1016/j.arth.2017.01.033 0883-5403/© 2017 Elsevier Inc. All rights reserved.
However, there are many controversies regarding the limitations of intraoperative kinematics [10-12]. It is said that kinematic values obtained using a navigation system tend to be larger than those obtained using fluoroscopic analysis [11,12]. These differences may be regulated by several factors, including the use of anesthesia, tourniquets, and soft tissues incision, which do not reflect the effects of muscle force [10] or passive motion [9]. However, there have been no detailed reports of how suture or tourniquet use affects kinematics during surgery. The present study aimed to investigate the effects of suture of the soft tissues and tourniquet use on intraoperative kinematics in computed tomography (CT)ebased navigated TKA. It is hypothesized that the effect of suture and tourniquet use on passive motion kinematics is minimal and that intraoperative kinematics at postimplantation is useful data that can help evaluate postoperative passive knee kinematics.
2
M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
Materials and Methods This prospective study included 20 consecutive patients (18 female and 2 male patients), with varus-type knee osteoarthritis who underwent primary posterior-stabilized (PS) TKA (DePuy PFC Sigma, fixed bearing type, Warsaw, IN). The mean age of the patients was 77.6 years (±6.4 years), and the mean body mass index was 25.4 kg/m2 (±4.1 kg/m2). The operation was performed by one experienced surgeon who followed a medial parapatellar approach and a measured resection technique using a CT-based navigation system (BrainLAB, Heimstetten, Germany). All the surgeries were performed using an air tourniquet (300 mm Hg) that was inflated with the knee at maximal flexion before skin incision. At the start of the operation, 2 tracker pins were placed on each side through an extra-small skin incision (anterolateral in the femur and anteromedial in the tibia) after blunt muscle dissection. The femoral rotational axis was defined by the navigation system determined by registration. We determined this axis using preoperative 3-dimensional planning software (Athena Knee, SoftCube Co, Ltd, Osaka, Japan), wherein the axis was parallel to the surgical epicondylar axis [13,14]. The tibial rotational axis was defined according to the report of Akagi et al [15], which specified it as being along the line from the medial border of the tibial tubercle to the middle of the posterior cruciate ligament (PCL). Care was taken to balance the flexion and extension gaps and to release any flexion contractures. After the implantation, intraoperative kinematics up to a maximum flexion from maximum extension of the knee joint were collected using a CT-based navigation system, as previously reported [3]. Briefly, while supporting the heel with an open palm and touching the thigh with the opposite hand, the surgeon gently flexed the hip and knee to their final points, with the knee flexion being assisted by gravity. Care was taken not to
apply exterior varus and/or valgus stress, which may influence the kinematics and gap measurement. The measurement was performed 3 times and the average values were analyzed. Primary experiments had already found that the test-retest reliability of these measurements is excellent (interclass and intraclass correlation coefficient, 0.99). The timing of the measurements was as follows: measurement 1: before suture (tourniquet on), measurement 2: after suture (tourniquet on), and measurement 3: after tourniquet removal (Fig. 1). For capsule closure, discontinued stitches with No. 2 polyamide 66 (NUROLON, Ethicon Inc, Somerville, NJ) were used. Then, subcutaneous tissues were roughly approximated with discontinued stitches by No. 0 polyamide 66 (NUROLON, Ethicon Inc). Thereafter, approximation suture 3-0 polyglactin 910 (Coated VICRYL, Ethicon Inc) with discontinued buried knots were performed. The skin was then closed with a skin closer (Steri-strip R1547, 3M Company, Maplewood, MN). Measured parameters were: (1) knee joint gap, (2) tibiofemoral rotational angles, and (3) anteroposterior (AP) distance between the femur and tibia. The knee joint gap was defined as the distance between the cut bone surface of the femur and tibia. Knee joint gaps were measured with the medial and lateral tibiofemoral joint at maximum extension and 90 of flexion. The tibiofemoral rotational angle was defined as the angle between the perpendicular line of the surgical epicondylar axis and Akagi's line [15]. The AP distance was defined as the distance between the distal end of femoral mechanical axis and the proximal end of tibial mechanical axis, in the longitudinal direction. As the kinematic data was affected by the registration point, the results had variance between different patients. Therefore, the data obtained at maximum extension before soft tissue closure was determined to be the reference point, and the results were expressed as differences
Fig. 1. The timing of the measurements. Measured items are (1) knee joint gap, (2) tibiofemoral rotational angles, and (3) anteroposterior (AP) distance between the femur and tibia. (A) Measurement 1 is the timing before suture (tourniquet on). (B) Measurement 2 is the timing after suture (tourniquet on). (C) Measurement 3 is the timing after removal of the tourniquet.
M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
compared with the reference point. The tracker pins were removed after completion of all the measurement procedures. Statistical Analysis Data analyses were performed with a statistical software package (Statview 5.0; Abacus Concepts Inc, Berkeley, CA). In addition, the Shapiro-Wilk-Test (SPSS Statistics 21; IBM Japan, Tokyo, Japan) was performed to analyze normally distributed data. Correlations among the preoperative and postoperative flexion and extension angles were analyzed using paired t tests. We evaluated knee joint gap, tibiofemoral rotational angles, and AP distance between the femur and tibia at each of the measurement points (Fig. 1) using 1-way analysis of variance. These measured parameters among the 3 measurements were evaluated using a repeated measures analysis of variance with a Fisher probable least-squares difference post hoc test for multiple comparisons of paired samples. P values of <.05 were considered statistically significant. The sample size was determined based on the previous study [16], and was further backed up by a post hoc power analysis using the G power 3.1 software (a ¼ 0.05; power level ¼ 80%; each observed effect size and total sample size of 20). Results All 20 patients recovered knee function without changes in the knee maximal flexion angle. The mean preoperative and postoperative maximum flexion angles were 121.9 ± 12.2 and 120.0 ± 4.7, respectively. On the other hand, the mean preoperative and postoperative maximum extension angles were 5.6 ± 6.3 and 0.3 ± 1.2 , respectively. The postoperative maximum extension angles were significantly improved compared with the preoperative angles (P < .01). The results for medial and lateral gaps in extension and flexion among the 3 measurements are shown in Table 1. The results for the medial gap found that there was no significant difference among the 3 measurements in the extension gap. However, measurement 1 showed a significant larger medial flexion gap compared with the other 2 measurements (compared with measurement 2, P ¼ .018; compared with measurement 3, P ¼ .030). The results for lateral gap found that there were no significant differences among the 3 measurements in both the extension and flexion gaps. There was no significant difference among the 3 measurements regarding the tibiofemoral rotational kinematics (Fig. 2). The results for AP distance revealed that the femur was positioned significantly more anterior to the tibia in measurement 1, compared with the other 2 measurements at 10 and 20 of flexion (compared with measurement 2, P ¼ .041 at 10 of flexion and P ¼ .042 at 20 of flexion; compared with measurement 3, P ¼ .042 at 10 of flexion and P ¼ .036 at 20 of flexion; Fig. 3). Table 1 Medial and Lateral Gap in Extension and Flexion Among the 3 Measurements.
Measurement 1: before suture (tourniquet on) Measurement 2: after suture (tourniquet on) Measurement 3: tourniquet off
In Extension
In Flexion
Medial Gap
Lateral Gap
Medial Gap
18.8 ± 2.9
19.1 ± 3.2
*
18.5 ± 2.5
18.7 ± 2.8
Lateral Gap
18.3 ± 4.1
18.4 ± 4.2
19.2 ± 2.6
17.5 ± 4.5
18.0 ± 4.6
19.2 ± 3.4
17.7 ± 4.0
Data were shown as mean ± standard deviation, *P < .05.
*
18.3 ± 4.2
3
Discussion The most important finding of this study was that the suture and tourniquet have almost no effect on intraoperative kinematics, except on the tibiofemoral AP position in the extended position. These results suggest that the intraoperative kinematics at postimplantation could be regarded as postoperative passive motion kinematics. In this study, all patients underwent PS TKA. The PCL acts to maintain a stable joint gap between the femur and tibia, and AP stability beyond 90 flexion [16,17]. The resected PCL is significantly associated with an increase in the flexion gap compared with the extension gap [18]. Here, the PCL and patellar tendon are almost parallel to the longitudinal axis of the tibia when the knee is flexed 90 . Thus, it is likely that the patellar tendon plays a major role in maintaining the joint gap in PS TKA [17,19]. The results found that only the medial flexion gap showed significant separation before soft tissue closure. It can be deduced that the lateral flexion gap was decreased by the combination between patellar tendon and lateral soft tissue structures, such as the vastus lateralis and iliotibial band because of the intact junction between the patellar tendon and lateral soft tissue structures in the medial parapatellar approach. However, the medial side was less affected by the patellar tendon because the approach separated medial soft tissue structures from the patellar tendon. Thus, it can be seen that the patellar tendon plays an important role in maintaining the flexion gap in PS TKA, which lacks the PCL function. Matsumoto et al [20] reported joint gap kinematics in PS TKA measured by an offset-type tensor, and significantly lower gaps were found at 90 flexion with PF joint reduction compared to those with the patella everted. The results also support the present findings, which indicate that the patellar tendon plays an important role in maintaining the flexion gap in PS TKA. On the other hand, it has also been reported that there was no significant change of ligament balance in the varus configuration at 90 flexion with PF joint reduction, compared with patellar eversion in PS TKA [21]. As it is impossible to measure the gap measurement using a tensor after soft tissue closure, it remains unknown whether soft tissue closure affects the gap values. Although a distraction force was not applied to the gap, which is definitely different than the measurement using a tensor, navigation might be a useful tool for the assessment of gap balance after TKA. Regarding the tibiofemoral AP position, the femur shifted anteriorly in the early extension position without suture, compared with after suture. This result suggests that the gravity force was applied rearward to the tibia in midflexion from extension without suture conditions. The conditions in the early extension position, such as the relative instability of knees undergoing PS TKA due to post-cam mechanism usually working from a midflexion position, and a lying passive motion without quadriceps force might influence the results. Some studies have investigated the correlation between intraoperative rotational kinematics and clinical outcomes [3,7,9]. For instance, Matsuzaki et al [7] reported that lateral laxity from midto-deep knee flexion in CR TKA plays a significant role in internal tibial rotation, and the lateral compartment gap was positively correlated with postoperative knee flexion angle at 90 and 120 flexion. These studies suggested that intraoperative kinematics provided important clinical information to estimate postoperative clinical outcomes. However, the discussions in these studies are always limited in terms of intraoperative kinematics because several factors differ in intraoperative conditions compared with postoperative active motion conditions. In the present study, tibiofemoral kinematics were not affected by soft tissue closure and tourniquet. Obviously, the intraoperative kinematics differ
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M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
Fig. 2. Results for tibiofemoral rotational angles among the 3 groups. There was no significant difference among the 3 measurements regarding tibiofemoral rotational kinematics (plus indicates tibial external rotation).
from the postoperative active motion kinematics, although it can be considered that the intraoperative rotational kinematics can be regarded as being similar to postoperative passive motion kinematics. A tourniquet is conventionally used in TKA surgery to provide better visualization, ensure dry surgery, facilitate the cementing procedure, and reduce the duration of surgery [22-24]. However, there were no reports about how a tourniquet affects kinematics during TKA surgery. In this study, there was no significant effect on kinematics by use of a tourniquet. One of the reasons for why there
was no effect of tourniquet on intraoperative kinematics was that the preoperative tourniquet was inflated in the knee maximum flexion position. It is suggested that the condition minimizes the influence of the tourniquet in flexion. The present study has some limitations. First, a single type of PS TKA limited the study. Additional studies using different implant designs are required to further examine the effects of the suture and tourniquet on knee kinematics. Second, although this study is a prospective comparative study, it included a small population based on a previous clinical study and power analysis, so subtle
Fig. 3. The results with AP distance between femur and tibia. In measurement 1, AP distance revealed that the femur was positioned significantly more anterior to the tibia compared with the other 2 measurements at 10 and 20 of flexion (P < .05; plus indicates anterior position of the femur to the tibia).
M. Tsubosaka et al. / The Journal of Arthroplasty xxx (2017) 1e5
differences were not detected as significantly different. The kinematic measurement conditions were limited by the use of anesthesia. Although several studies have evaluated postoperative knee kinematics under weight-bearing conditions, the kinematic measurements in this study were of noneweight-bearing passive knee kinematics, which do not reflect the effects of muscle force, and differ from physiological knee kinematics. Furthermore, although navigation-based surgery allowed us to perform constant bony cuts and reduce the outliers from the mechanical axis [25], the correlation between bony cuts, alignment, ligament balancing [26], and kinematic data are out of the scope of this study. Finally, the effect of tracker pins could not be evaluated. Especially femoral tracker pins might influence the kinematics because the pins were placed through the quadriceps muscle. Further studies, such as what factors affect the differences in this study are needed to investigate the detailed explanation of the mechanism. Nevertheless, knowledge about how sutures and tourniquets affect knee kinematics has important clinical relevance. It is suggested that surgeons assess intraoperative knee kinematics carefully based on the present results, although intraoperative kinematics can effectively evaluate postoperative passive kinematic conditions. Conclusion These results indicate that the effects of suture and tourniquet were minimal, and that intraoperative kinematics can be used effectively to evaluate postoperative passive kinematic conditions. References 1. Klein GR, Parvizi J, Rapuri VR, et al. The effect of tibial polyethylene insert design on range of motion: evaluation of in vivo knee kinematics by a computerized navigation system during total knee arthroplasty. J Arthroplasty 2004;19(8):986. 2. Nishio Y, Onodera T, Kasahara Y, et al. Intraoperative medial pivot affects deep knee flexion angle and patient-reported outcomes after total knee arthroplasty. J Arthroplasty 2014;29(4):702. 3. Ishida K, Shibanuma N, Matsumoto T, et al. Navigation-based femorotibial rotation pattern correlated with flexion angle after total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2016;24(1):89. 4. Ho FY, Ma HM, Liau JJ, et al. Mobile-bearing knees reduce rotational asymmetric wear. Clin Orthop Relat Res 2007;462:143. 5. Moschella D, Blasi A, Leardini A, et al. Wear patterns on tibial plateau from varus osteoarthritic knees. Clin Biomech (Bristol, Avon) 2006;21(2):152.
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6. Belvedere C, Ensini A, Leardini A, et al. Tibio-femoral and patello-femoral joint kinematics during navigated total knee arthroplasty with patellar resurfacing. Knee Surg Sports Traumatol Arthrosc 2014;22(8):1719. 7. Matsuzaki T, Matsumoto T, Muratsu H, et al. Kinematic factors affecting postoperative knee flexion after cruciate-retaining total knee arthroplasty. Int Orthop 2013;37(5):803. 8. Siston RA, Giori NJ, Goodman SB, et al. Intraoperative passive kinematics of osteoarthritic knees before and after total knee arthroplasty. J Orthop Res 2006;24(8):1607. 9. Ishida K, Shibanuma N, Matsumoto T, et al. Navigation-based tibial rotation at 90 degrees of flexion is associated with better range of motion in navigated total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2016;24(8):2447. 10. Seon JK, Park JK, Jeong MS, et al. Correlation between preoperative and postoperative knee kinematics in total knee arthroplasty using cruciate retaining designs. Int Orthop 2011;35(4):515. 11. Dennis DA, Komistek RD, Mahfouz MR, et al. A multicenter analysis of axial femorotibial rotation after total knee arthroplasty. Clin Orthop Relat Res 2004;(428):180. 12. Komistek RD, Dennis DA, Mahfouz M. In vivo fluoroscopic analysis of the normal human knee. Clin Orthop Relat Res 2003:69. 13. Chinzei N, Ishida K, Matsumoto T, et al. Evaluation of patellofemoral joint in ADVANCE Medial-pivot total knee arthroplasty. Int Orthop 2014;38(3):509. 14. Tei K, Ishida K, Matsumoto T, et al. Novel image-matching software for postoperative evaluation after TKA. Orthopedics 2012;35(12):e1711. 15. Akagi M, Oh M, Nonaka T, et al. An anteroposterior axis of the tibia for total knee arthroplasty. Clin Orthop Relat Res 2004;(420):213. 16. Mihalko W, Fishkin Z, Krackow K. Patellofemoral overstuff and its relationship to flexion after total knee arthroplasty. Clin Orthop Relat Res 2006;449:283. 17. Komatsu T, Kadoya Y, Nakagawa S, et al. Movement of the posterior cruciate ligament during knee flexioneMRI analysis. J Orthop Res 2005;23(2):334. 18. Kadoya Y, Kobayashi A, Komatsu T, et al. Effects of posterior cruciate ligament resection on the tibiofemoral joint gap. Clin Orthop Relat Res 2001;(391):210. 19. Sasaki H, Kubo S, Matsumoto T, et al. The influence of patella height on intraoperative soft tissue balance in posterior-stabilized total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2012;20(11):2191. 20. Matsumoto T, Muratsu H, Tsumura N, et al. Joint gap kinematics in posteriorstabilized total knee arthroplasty measured by a new tensor with the navigation system. J Biomech Eng 2006;128(6):867. 21. Matsumoto T, Muratsu H, Kubo S, et al. Soft tissue tension in cruciate-retaining and posterior-stabilized total knee arthroplasty. J Arthroplasty 2011;26(5):788. 22. Kvederas G, Porvaneckas N, Andrijauskas A, et al. A randomized double-blind clinical trial of tourniquet application strategies for total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2013;21(12):2790. 23. Vandenbussche E, Duranthon LD, Couturier M, et al. The effect of tourniquet use in total knee arthroplasty. Int Orthop 2002;26(5):306. 24. Dennis DA, Kittelson AJ, Yang CC, et al. Does tourniquet use in TKA affect recovery of lower extremity strength and function? A randomized trial. Clin Orthop Relat Res 2016;474(1):69. 25. Ishida K, Matsumoto T, Tsumura N, et al. Mid-term outcomes of computerassisted total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2011;19(7):1107. 26. Fujimoto E, Sasashige Y, Masuda Y, et al. Significant effect of the posterior tibial slope and medial/lateral ligament balance on knee flexion in total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc 2013;21(12):2704.