Coronal Correction for Severe Deformity Using Robotic-Assisted Total Knee Arthroplasty

Abstract

Although robotic-assisted total knee arthroplasty (TKA) has the potential to accurately reproduce neutral alignment, it is still unclear if this correction is attainable in patients who have severe varus or valgus deformities. Therefore, the purpose of this study was to assess a single surgeon's experience with correcting coronal deformities using the robotic-assisted TKA device. Specifically, we looked at correction of varying degrees of varus and valgus deformity in patients who underwent robotic arm-assisted TKA. A total of 330 robotic-assisted TKA cases performed by a single surgeon were analyzed. Preoperative CT scans were registered to the robotic-assisted software to create a three-dimensional rendering from which coronal alignment was measured. Postoperative coronal alignment measurements were taken in the operating room using the robotic-assisted device after trial component placement. The robotic-assisted device uses optical tracking from navigation probes placed on the distal femur and proximal tibia. The robotic-assisted software can register these probes as bony landmarks to measure coronal alignment in the distal plane of the femoral component and proximal plane of the tibial component. A total of 261 cases were of varus knees, 46 cases were of valgus knees, and 23 cases had 0° preoperative alignment. Severe deformity was defined as 7° or greater deformity. Preoperative neutral alignment was defined as 0°, while postoperative neutral alignment was defined as 0° ± 3°. There were 129 patients with and initial severe varus and 7 patients with an initial severe valgus deformity of 7° or greater. Patients were divided into varus or valgus cohorts, and analysis was performed on the overall cohort, as well as nonsevere (<7°) and severe (7° or greater) deformity cohorts.

All 132 knees with initial varus deformity of less than 7° were corrected to neutral (mean 1°, range -1–3°). A total of 82 knees (64%) with 7° or greater varus deformity were corrected to neutral (mean 2°, range 0–3°). However, roughly 30% of patients with severe deformity who were not corrected to neutral were still corrected within a couple of degrees of neutral. There were seven knees with 7° or greater valgus deformity, and all were corrected to neutral (mean 2°, range 0–3°). This study demonstrated that all knees were corrected in the appropriate direction within a few degrees of neutral, and no knees were overcorrected. The implication of this ability to achieve alignment goals on clinical outcomes will need to be evaluated in future studies. The results from this study demonstrate the potential for the robotic-assisted device during TKA in helping surgeons achieve a preoperatively planned desired neutral alignment.

Keywords

total knee arthroplasty - coronal alignment - robotic-assisted TKA

Note

This work was not sponsored or supported by Stryker Inc., although some authors are paid consultants for Stryker Inc.

• References

• 1 Cherian JJ, Kapadia BH, Banerjee S, Jauregui JJ, Issa K, Mont MA. Mechanical, Anatomical, and Kinematic Axis in TKA: Concepts and Practical Applications. Curr Rev Musculoskelet Med 2014; 7 (02) 89-95
• 2 Rajgopal A, Vasdev A, Dahiya V, Tyagi VC, Gupta H. Total knee arthroplasty in extra articular deformities: a series of 36 knees. Indian J Orthop 2013; 47 (01) 35-39
• 3 Apostolopoulos AP, Nikolopoulos DD, Polyzois I. , et al. Total knee arthroplasty in severe valgus deformity: interest of combining a lateral approach with a tibial tubercle osteotomy. Orthop Traumatol Surg Res 2010; 96 (07) 777-784
• 4 Schiraldi M, Bonzanini G, Chirillo D, de Tullio V. Mechanical and kinematic alignment in total knee arthroplasty. Ann Transl Med 2016; 4 (07) 130
• 5 Kim MS, Koh IJ, Choi YJ, Kim YD, In Y. Correcting Severe Varus Deformity Using Trial Components During Total Knee Arthroplasty. J Arthroplasty 2017; 32 (05) 1488-1495
• 6 Teeny SM, Krackow KA, Hungerford DS, Jones M. Primary total knee arthroplasty in patients with severe varus deformity. A comparative study. Clin Orthop Relat Res 1991; (273) 19-31
• 7 Rossi R, Rosso F, Cottino U, Dettoni F, Bonasia DE, Bruzzone M. Total knee arthroplasty in the valgus knee. Int Orthop 2014; 38 (02) 273-283
• 8 Song E-K, Seon J-K, Yim J-H, Netravali NA, Bargar WL. Robotic-assisted TKA reduces postoperative alignment outliers and improves gap balance compared to conventional TKA. Clin Orthop Relat Res 2013; 471 (01) 118-126
• 9 Siebert W, Mai S, Kober R, Heeckt PF. Technique and first clinical results of robot-assisted total knee replacement. Knee 2002; 9 (03) 173-180
• 10 Hampp EL, Chughtai M, Scholl LY, Bhowmik-Stoker M, Jacofsky DJ, Mont MA. Robotic-arm assisted total knee arthroplasty demonstrated improved accuracy and precision compared to manual technique. Poster presented at: Orthopaedic Research Society; 2017 March 19–22; San Diego, CA
• 11 van der List JP, Chawla H, Joskowicz L, Pearle AD. Current state of computer navigation and robotics in unicompartmental and total knee arthroplasty: a systematic review with meta-analysis. Knee Surg Sports Traumatol Arthrosc 2016; 24 (11) 3482-3495
• 12 Bellemans J, Vandenneucker H, Vanlauwe J. Robot-assisted total knee arthroplasty. Clin Orthop Relat Res 2007; 464 (464) 111-116
• 13 Liow MHL, Chin PL, Tay KJD, Chia SL, Lo NN, Yeo SJ. Early experiences with robot-assisted total knee arthroplasty using the DigiMatch™ ROBODOC® surgical system. Singapore Med J 2014; 55 (10) 529-534
• 14 Urish KL, Conditt M, Roche M, Rubash HE. Robotic Total Knee Arthroplasty: Surgical Assistant for a Customized Normal Kinematic Knee. Orthopedics 2016; 39 (05) e822-e827
• 15 Liow MHL, Xia Z, Wong MK, Tay KJ, Yeo SJ, Chin PL. Robot-assisted total knee arthroplasty accurately restores the joint line and mechanical axis. A prospective randomised study. J Arthroplasty 2014; 29 (12) 2373-2377