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Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 43 - 43
1 Feb 2020
Mont M Kinsey T Zhang J Bhowmik-Stoker M Chen A Orozco F Hozack W Mahoney O
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Introduction

Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence prosthetic survivorship and clinical outcomes. Robotic-assisted (RA) total knee arthroplasty has demonstrated improved accuracy to plan in cadaver studies compared to conventionally instrumented (manual) TKA, but less clinical evidence has been reported.

The objective of this study was to compare the three-dimensional accuracy to plan of RATKA with manual TKA for overall limb alignment and component position.

Methods

A non-randomized, prospective multi-center clinical study was conducted to compare RATKA and manual TKA at 4 U.S. centers between July 2016 and August 2018. Computed tomography (CT) scans obtained approximately 6 weeks post-operatively were analyzed using anatomical landmarks. Absolute deviation from surgical plans were defined as the absolute value of the difference between the CT measurements and surgeons’ operative plan for overall limb, femoral and tibial component mechanical varus/valgus alignment, tibial component posterior slope, and femoral component internal/external rotation. We tested the differences of absolute deviation from plan between manual and RATKA groups using stratified Wilcoxon tests, which controlled for study center and accounted for skewed distributions of the absolute values. Alpha was 0.05 two-sided. At the time of this abstract, data collections were completed for two centers (52 manual and 58 RATKA).


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_11 | Pages 9 - 9
1 Oct 2019
Kinsey T Chen AF Hozack WJ Mont MA Orozco F Mahoney OM
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Introduction

Component position and overall limb alignment following total knee arthroplasty (TKA) have been shown to influence prosthetic survivorship and clinical outcomes1. The objective of this study was to compare the accuracy to plan of three-dimensional modeled (3D) TKA with manual TKA for component alignment and position.

Methods

An open-label prospective clinical study was conducted to compare 3D modeling with manual TKA (non-randomized) at 4 U.S. centers between July 2016 and August 2018. Men and women aged > 18 with body mass index < 40kg/m2 scheduled for unilateral primary TKA were recruited for the study. 144 3DTKA and 86 manual TKA (230 patients) were included in the analysis of accuracy outcomes. Seven high-volume, arthroplasty fellowship-trained surgeons performed the surgeries. The surgeon targeted a neutral (0°) mechanical axis for all except 9 patients (4%) for whom the target was within 0°±3°. Computed tomography (CT) scans obtained approximately 6 weeks post-operatively were analyzed using anatomical landmarks to determine femoral and tibial component varus/valgus position, femoral component internal/external rotation, and tibial component posterior slope. Absolute deviation from surgical plan was defined as the absolute value of the difference between the CT measurement and the surgeon's operative plan. Smaller absolute deviation from plan indicated greater accuracy. Mean component positions for manual and 3DTKA groups were compared using two-sample t tests for unequal variances. Differences of absolute deviations from plan were compared using stratified Wilcoxon tests, which controlled for study center and accounted for skewed distributions of the absolute values. Alpha was 0.05 two-sided. At the time of this report, CT measurements of femoral component rotation position referenced from the posterior condylar axis were not yet completed; therefore, the current analysis of femoral component rotation accuracy to plan reflects one center that exclusively used manual instruments referencing the transepicondylar axis (TEA).


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_34 | Pages 75 - 75
1 Dec 2013
Howard M Anthony D Hitt K Jacofsky D Smith E Orozco F
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Introduction:

Revision total knee arthroplasty (TKA) can be very complex in nature with difficulties/obstacles involving bone and soft tissue deficits, visualization and exposure, as well as alignment and fixation. Auxiliary devices such as augmentation and offset adapters help address these issues; however they increase the complexity of the reconstruction. The objective of this study was to show that use of a single radius revision TKA system allowing for minimal auxiliary revision devices can yield positive early clinical outcomes.

Methods:

This data was collected as part of a prospective, post-market, multicenter study. One hundred and twenty-five single radius revision TKA cases were evaluated. Surgical details were reviewed and cases were grouped based on type of auxiliary devices used. Group 1 included cases that used only femoral and/or tibial augments. Group 2 used femoral and/or tibial augments in conjunction with femoral and/or tibial offset adapters. Early clinical outcomes, operative data and radiographic findings were used to compare cases.


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 73 - 73
1 Mar 2009
Harrison F Orozco F Parvizi J Purtill J Rothman R
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Introduction: The use of coumadin for prophylaxis against thromboembolism (TE) following total joint arthroplasty is the standard of care. In light of recent publication of the American College of Chest Physicians (ACCP), we altered our anticoagulation protocol to be compliant with the recommendations. This study evaluates the incidence of TE and bleeding complications following TJA when low dose coumadin vs. regular dose coumadin was administered.

Methods: 987 consecutive patients undergoing total joint arthroplasty by a single surgeon between the years of 2004–2005 were included. 446 patients operated on during the 2004 received low dose coumadin (intended INR 1.5–1.7) whilst 541 patients undergoing TJA during 2005 were given regular dose coumadin (intended INR 2–2.5).

Results: The mean INR for patients operated during the year 2005 was significantly higher than the INR for patients receiving TJA in 2004. There were more complications in 2005. There were 13 PE, 44 wound drainage, 4 DVT, and 11 hematoma formation (requiring surgical evacuation) during the year 2005 compared to 10 PE, 26 wound drainage, 6 DVT, and 5 hematoma formation in 2004. The difference for all complications except DVT was significant.

Conclusion: This study confirms the commonly held belief that aggressive anticoagulation does carry a higher incidence of complications such as wound drainage and bleeding. It appears that administering higher dose coumadin increased the bleeding complications without conferring additional protection against thromboembolic disease.