Adjustable Slot Cutting Guide for Improved Accuracy During Bone Resection in Total Knee Arthroplasty

2013 ◽  
Vol 7 (4) ◽  
Author(s):  
Thomas P. James ◽  
Owen P. McGonigle ◽  
Imran S. Hasan ◽  
Eric L. Smith
Keyword(s):  
Computer Navigation ◽  
Cutting Plane ◽  
Bone Resection ◽  
Cutting Guide ◽  
Blade Thickness ◽  
Flexion Extension ◽  
Cutting Error ◽  
Cutting Guides ◽  
Total Knee ◽  
Slot Cutting

Slotted cutting guides are used by orthopaedic surgeons to improve the accuracy of bone resection during total knee replacement. Accuracy of the saw cuts has an effect on patient mobility and on implant survival time. While computer navigation systems have improved the accuracy of cutting guide placement, the contribution to cutting error from blade toggle within the slots of the cutting guide persists. In this research, equations were derived to quantify angular cutting error based on the parameters affecting blade and cutting guide geometry. Analytically, the relationship between cutting plane error and blade thickness was determined to be linear. A smaller gap, due to thicker blades with minimal tooth offset, results in less cutting error. From an experimental standpoint, six commercially available cutting guides were tested for femoral plane cutting accuracy by resection of synthetic bone under the guidance of computer navigation. The results indicate an average flexion/extension error of 3.8 deg for a 0.89 mm thick blade and 2.0 deg for a 1.27 mm blade. Varus/valgus error due to twisting of the blade within the slot was less than 1.0 deg, regardless of blade thickness. To improve upon cutting accuracy, an adjustable slot cutting guide was designed and tested. From more closely matching slot width to blade thickness, the results indicate that cutting plane error can be reduced to less than 1.0 deg in both the flexion/extension and varus/valgus planes.

scholarly journals The use of imageless navigation to quantify cutting error in total knee arthroplasty

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Ran Schwarzkopf ◽  
Morteza Meftah ◽  
Scott E. Marwin ◽  
Michelle A. Zabat ◽  
Jeffrey M. Muir ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Bone Resection ◽  
Cutting Guide ◽  
Imageless Navigation ◽  
Valgus Angle ◽  
Flexion Extension ◽  
Cutting Error ◽  
Total Knee ◽  
Implant Alignment ◽  
Resection Depth

Abstract Purpose Navigated total knee arthroplasty (TKA) improves implant alignment by providing feedback on resection parameters based on femoral and tibial cutting guide positions. However, saw blade thickness, deflection, and cutting guide motion may lead to final bone cuts differing from planned resections, potentially contributing to suboptimal component alignment. We used an imageless navigation device to intraoperatively quantify the magnitude of error between planned and actual resections, hypothesizing final bone cuts will differ from planned alignment. Materials and methods A retrospective study including 60 consecutive patients undergoing primary TKA using a novel imageless navigation device was conducted. Device measurements of resection parameters were obtained via attachment of optical trackers to femoral and tibial cutting guides prior to resection. Following resection, optical trackers were placed directly on the bone cut surface and measurements were recorded. Cutting guide and bone resection measurements of both femoral and tibial varus/valgus, femoral flexion, tibial slope angles, and both femoral and tibial medial and lateral resection depths were compared using a Student's t-test. Results Femoral cutting guide position differed from the actual cut by an average 0.6 ± 0.5° (p = 0.85) in the varus/valgus angle and 1.0 ± 1.0° (p = 0.003) in the flexion/extension angle. The difference between planned and actual cut measurements for medial and lateral femoral resection depth was 1.1 ± 1.1 mm (p = 0.32) and 1.2 ± 1.0 mm (p = 0.067), respectively. Planned cut measurements based on tibial guide position differed from the actual cut by an average of 0.9 ± 0.8° (p = 0.63) in the varus/valgus angle and 1.1 ± 1.0° (p = 0.95) in slope angle. Measurement of medial and lateral tibial resection depth differed by an average of 0.1 ± 1.8 mm (p = 0.78) and 0.2 ± 2.1 mm (p = 0.85), respectively. Conclusions Significant discrepancies between planned and actual femoral bone resection were demonstrated for flexion/extension angle, likely the result of cutting error. Our data highlights the importance of cut verification postresection to confirm planned resections are achieved, and suggests imageless navigation may be a source of feedback that would allow surgeons to intraoperatively adjust resections to achieve optimal implant alignment.

scholarly journals Accuracy of bone resection in total knee arthroplasty using CT assisted-3D printed patient specific cutting guides

SICOT-J ◽  
2018 ◽  
Vol 4 ◽  
pp. 29 ◽  
Author(s):  
Ikram Nizam ◽  
Ashish V. Batra
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Patient Specific ◽  
Surgical Patient ◽  
Bone Resection ◽  
Patient Specific Instrumentation ◽  
Medial Pivot ◽  
Cutting Guides ◽  
3D Printed ◽  
Total Knee

Introduction: We conducted this study to determine if the pre-surgical patient specific instrumented planning based on Computed Tomography (CT) scans can accurately predict each of the femoral and tibial resections performed through 3D printed cutting guides. The technique helps in optimization of component positioning determined by accurate bone resection and hence overall alignment thereby reducing errors. Methods: Prophecy evolution medial pivot patient specific instrumented knee replacement systems were used for end stage arthrosis in all consecutive cases over a period of 20 months by a single surgeon. All resections (4 femoral and 2 tibial) were measured using a vernier callipers intraoperatively. These respective measurements were then compared with the preoperative CT predicted bone resection surgical plan to determine margins of errors that were categorized into 7 groups (0 mm to ≥2.6 mm). Results: A total of 3618 measurements (averaged to 1206) were performed in 201 knees (105 right and 96 left) in 188 patients (112 females and 76 males) with an average age of 67.72 years (44 to 90 years) and average BMI of 32.3 (25.1 to 42.3). 94% of all collected resection readings were below the error margin of ≤1.5 mm of which 90% showed resection error of ≤1 mm. Mean error of different resections were ≤0.60 mm (P ≤ 0.0001). In 24% of measurements there were no errors or deviations from the templated resection (0.0 mm). Conclusion: The 3D printed cutting blocks with slots for jigs accurately predict bone resections in patient specific instrumentation total knee arthroplasty which would directly affect component positioning.

scholarly journals The Effect of Femoral Cutting Guide Design Improvements for Patient-Specific Instruments

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Oh-Ryong Kwon ◽  
Kyoung-Tak Kang ◽  
Juhyun Son ◽  
Yun-Jin Choi ◽  
Dong-Suk Suh ◽  
...  
Keyword(s):  
Motion Artifacts ◽  
Patient Specific ◽  
Bone Resection ◽  
Cutting Guide ◽  
Patient Specific Instruments ◽  
Mri Scans ◽  
Total Knee ◽  
Magnetic Resonance Imaging Mri ◽  
The Cost ◽  
Implant Alignment

Although the application of patient-specific instruments (PSI) for total knee arthroplasty (TKA) increases the cost of the surgical procedure, PSI may reduce operative time and improve implant alignment, which could reduce the number of revision surgeries. We report our experience with TKA using PSI techniques in 120 patients from March to December 2014. PSI for TKA were created from data provided by computed tomography (CT) scans or magnetic resonance imaging (MRI); which imaging technology is more reliable for the PSI technique remains unclear. In the first 20 patients, the accuracy of bone resection and PSI stability were compared between CT and MRI scans with presurgical results as a reference; MRI produced better results. In the second and third groups, each with 50 patients, the results of bone resection and stability were compared in MRI scans with respect to the quality of scanning due to motion artifacts and experienced know-how in PSI design, respectively. The optimized femoral cutting guide design for PSI showed the closest outcomes in bone resection and PSI stability with presurgical data. It is expected that this design could be a reasonable guideline in PSI.

scholarly journals Bone Cement Solidifiliation Influence the Limb Alignment and Gap Balance during TKA

2015 ◽  
Vol 2015 ◽  
pp. 1-3 ◽  
Author(s):  
Dongquan Shi ◽  
Xingquan Xu ◽  
Anyun Guo ◽  
Jin Dai ◽  
Zhihong Xu ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Bone Cement ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Statistical Significance ◽  
Mechanical Alignment ◽  
Early Loosening ◽  
Flexion Extension ◽  
Before And After ◽  
Total Knee

Introduction. Mechanical alignment deviation after total knee arthroplasty is a major reason for early loosening of the prosthesis. Achieving optimum cement penetration during fixation of the femoral and tibial component is an essential step in performing a successful total knee arthroplasty. Bone cement is used to solidify the bone and prosthesis. Thickness imbalance of bone cement leads to the deviation of mechanical alignment. To estimate the influence of bone cement, a retrospective study was conducted.Materials and Methods. A total of 36 subjects were studied. All the TKA were performed following the standard surgical protocol for navigated surgery by medial approach with general anaesthesia. Prostheses were fixed by bone cement.Results. We compared the mechanical axis, flexion/extension, and gap balance before and after cementation. All the factors were different compared with those before and after cementation. Internal rotation was reached with statistical significance (P=0.03).Conclusion. Bone cement can influence the mechanical axis, flexion/extension, and gap balance. It also can prompt us to make a change when poor knee kinematics were detected before cementation.

scholarly journals Patients' Perception of Bone and Tissue Excision, and the Size and Weight of Prostheses at Total Knee Arthroplasty

2017 ◽  
Vol 03 (03) ◽  
pp. e110-e112
Author(s):  
Benjamin Rossi ◽  
Narlaka Jayasekera ◽  
Fionnuala Kelly ◽  
Keith Eyres
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Postoperative Recovery ◽  
Patient Perception ◽  
Femoral Bone ◽  
Bone Resection ◽  
Orthopaedic Literature ◽  
Total Knee ◽  
A Prospective Study ◽  
Revision Tka

AbstractThe aim of this study is to ascertain patients' perception of the amount of bone and tissue excision and size and weight of their implanted prostheses at total knee arthroplasty (TKA). To our knowledge, no prior study in the English orthopaedic literature has analyzed these parameters against patient perception of TKA. In a prospective study of eight consecutive TKA (six primary and two single-stage revision TKA procedures) by a single surgeon, patients estimated the weight of their implanted knee. We assessed actual weights of their implants and bone cement. Patients estimated the size of their prostheses by sketching the tibial and femoral bone cuts upon a printout of an anteroposterior and lateral radiographs of their preoperative knee. We utilized an articulated plastic model knee for patient reference. Our study shows almost half a kilogram of weight is added postoperatively to the surgical site as a result of tissue excision, explanted material, and implanted prosthesis and cement. All patients overestimated the weight of their implanted prostheses and extent of bone excision. Thus, even ‘well-informed’ patients overestimate their bone resection and weight of implanted prosthesis at TKA. We postulate such misconceptions among TKA patients are common, and may impact negatively upon patient perception of TKA, their postoperative recovery and outcome.

Surgical Variability of Resection Parameters During Total Knee Arthroplasty

2012 ◽  
Author(s):  
Yifei Dai ◽  
Adam Henderson ◽  
Joern Seebeck ◽  
Jeffrey E. Bischoff
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Morphological Analysis ◽  
Bone Resection ◽  
Component Placement ◽  
Clinical Applicability ◽  
Component Design ◽  
Total Knee ◽  
Computational Analyses ◽  
Single Set

There is intrinsic surgical variability in the practice of total knee arthroplasty (TKA), and thus computational analyses of TKA should account for this variability to ensure clinical applicability and robustness of results. Statistical inputs within computational analyses have been used to assess the biomechanical characteristics of TKA implants [1], and such methodologies are promising when applied to morphological analysis of TKA in order to motivate component design, assess current designs, and improve the understanding of surgical outcomes. Analyses to date either directly use actual TKA component placement or bone resection data [2], or assume a single set of parameters for placement and resection across the entire specimen group that was investigated [3], and thus do not account for surgical variability. This could be due to a lack of available data to quantify clinical variability in TKA component placement.

DOES NAVIGATION TOTAL KNEE REPLACEMENT REALLY MAKE A DIFFERENCE?

2013 ◽  
Vol 16 (02) ◽  
pp. 1350007
Author(s):  
P. Motwani ◽  
A. Jariwala ◽  
N. Valentine
Keyword(s):  
Total Knee Replacement ◽  
Tibial Component ◽  
Sagittal Plane ◽  
Computer Navigation ◽  
Component Alignment ◽  
Tibial Component Alignment ◽  
Significant Difference ◽  
Total Knee ◽  
The Mean

Background: Computer Navigation in Total Knee Replacement (TKR) has completed more than a decade since its inception. From that time, numerous studies have been done to see its effect on the variables of surgery and its outcome. Some studies have shown that it is definitely beneficial while others have negated its superiority over conventional techniques. This is an early outcome study on the results of navigation TKR in terms of alignment and clinical outcome at three years post-operatively. Methods: In the present study, 128 patients who had undergone navigation TKR (128 TKR) between January 2006 and November 2009 were included. The navigation system used was orthoPilot®. Patients were assessed post-operatively at one and three year using knee society score (KSS) and knee function score (KFS). All patients completed one year follow-up and 55 patients completed three year follow-up. From 128 patients, 40 navigated TKR patients operated between November 2007 and 2009 and were compared with 40 patients operated by conventional TKR operated between July 2007 and December 2008. Results: The mean KSS at 1 year post-operatively was 85.60 and at 3 years was 85.87. The mean KFS at 1 year post-operatively was 69.30 and at 3 years was 68.00. There was no statistically significant difference between navigation TKR and conventional TKR in terms of anatomical femoro-tibial alignment, femoral component alignment in coronal and sagittal plane and tibial component alignment in coronal plane. However, there was statistically significant difference between tibial component alignment in sagittal plane (p = 0.000) between both the groups. Conclusion: Computer navigation TKR affords a possibility to place both the femoral and tibial component very precisely without the risk of any greater axis deviation from ideal value. It helps in reducing the outliers in alignment of the limb and that of component and that improves the overall implant survival for a long time post-operatively.

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