Total Knee Arthroplasty with CAOS Augmentation

This study sought to evaluate the efficiency, usage, and accuracy of a novel technology that augments mechanical instrumentation with intraoperative CAOS guidance. Technical reports on 411 primary TKA cases performed using the technology were reviewed. The results demonstrated high surgical efficiency (time) and resection accuracy (alignment and resection depth). Furthermore, it was observed that one fifth of the time, the surgeons placed the cutting block that deviated more than >2°/mm from the ideal position in the coronal plane. Substantial adjustments were found to be required (on average ~10 °/mm per case) to correct the initial placement of the cutting block. The CAOS augmentation minimized the error in cutting block placement and assisted in achieving high accuracy in bony resections. The findings revealed the prevalence of clinical error with manual conventional bony preparation that can be addressed with efficiency and accuracy by adding CAOS augmentation to the mechanical instrumentation.

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The Adjustment of the Rotational Alignment of the Distal End of the Extramedullary Guide to the Anteroposterior Axis of the Proximal Tibia in Total Knee Arthroplasty

The Journal of Knee Surgery ◽

10.1055/s-0040-1722660 ◽

2021 ◽

Author(s):

Hideki Mizu-uchi ◽

Hidehiko Kido ◽

Tomonao Chikama ◽

Kenta Kamo ◽

Satoshi Kido ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Navigation System ◽

Proximal Tibia ◽

Rotational Alignment ◽

Coronal Alignment ◽

Ideal Position ◽

Total Knee ◽

Alignment Guide ◽

The Ideal

AbstractThe optimal placement within 3 degrees in coronal alignment was reportedly achieved in only 60 to 80% of patients when using an extramedullary alignment guide for the tibial side in total knee arthroplasty (TKA). This probably occurs because the extramedullary alignment guide is easily affected by the position of the ankle joint which is difficult to define by tibial torsion. Rotational direction of distal end of the extramedullary guide should be aligned to the anteroposterior (AP) axis of the proximal tibia to acquire optimal coronal alignment in the computer simulation studies; however, its efficacy has not been proven in a clinical setting. The distal end of the guide can be overly displaced from the ideal position when using a conventional guide system despite the alignment of the AP axis to the proximal tibia. This study investigated the effect of displacement of the distal end of extramedullary guide relative to the tibial coronal alignment while adjusting the rotational alignment of the distal end to the AP axis of the proximal tibia in TKA. A total of 50 TKAs performed in 50 varus osteoarthritic knees using an image-free navigation system were included in this study. The rotational alignment of the proximal side of the guide was adjusted to the AP axis of the proximal tibia. The position of the distal end of the guide was aligned to the center of the ankle joint as viewed from the proximal AP axis (ideal position) and as determined by the navigation system. The tibial intraoperative coronal alignments were recorded as the distal end was moved from the ideal position at 3-mm intervals. The intraoperative alignments were 0.5, 0.9, and 1.4 degrees in valgus alignment with 3-, 6-, and 9-mm medial displacements, respectively. The intraoperative alignments were 0.7, 1.2, and 1.7 degrees in varus alignment with 3-, 6-, and 9-mm lateral displacements, respectively. In conclusion, the acceptable tibial coronal alignment (within 2 degrees from the optimal alignment) can be achieved, although some displacement of the distal end from the ideal position can occur after the rotational alignment of the distal end of the guide is adjusted to the AP axis of the proximal tibia.

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Optimal Position for the Artifical Patella During Resurfacing to Decrease Stress and Avoid Pre-Prosthetic Patellar Fracture

ASME 2010 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2010-19419 ◽

2010 ◽

Author(s):

Kwang Won Choi ◽

Farid Amirouche ◽

Mark H. Gonzalez ◽

Wayne Goldstein

Keyword(s):

United States ◽

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

The United States ◽

Patellar Fracture ◽

Optimal Position ◽

Ideal Position ◽

Total Knee ◽

Patellar Fractures ◽

The Ideal

Total knee arthroplasty (TKA) is known to be an excellent solution to patients experiencing considerable pain at the joint and difficulty flexing and extending their knee. Unfortunately, after surgery, cases of peri-prosthetic patellar fracture are possible. The prevalence of this fracture ranges from 0.11% to 21.4% for the over 400,000 TKAs that are conducted in the United States every year and therefore, patellar fracture can become a serious concern. The factors that lead to this are several and many researchers are still investigating this problem. This research shows that the position of the surgically inserted artificial patella, also referred to as the patellar button, influences occurrence of patellar fractures and attempts to derive the ideal position for the button to reduce the risk of patellar fracture.

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Proposal of a New Reference Point to Determine the Tibial Resection Depth during Total Knee Arthroplasty for Valgus Knees

The Open Orthopaedics Journal ◽

10.2174/1874325002115010017 ◽

2021 ◽

Vol 15 (1) ◽

pp. 17-21

Author(s):

Takehiko Sugita ◽

Naohisa Miyatake ◽

Seiya Miyamoto ◽

Akira Sasaki ◽

Ikuo Maeda ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Reference Point ◽

Tibial Resection ◽

Total Knee ◽

Resection Depth

The tibial resection depth during total knee arthroplasty for valgus knees has been variously described and not been standardized yet. Accordingly, it has been proposed in this article, that the sulcus between the medial and lateral intercondylar tibial tubercles can be used as a reference point for the tibial resection depth. The resection can be performed 8 to 9 mm distal to the sulcus.

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Finding and defining the ideal patellar resection plane in total knee arthroplasty

Journal of Biomechanics ◽

10.1016/j.jbiomech.2009.06.021 ◽

2009 ◽

Vol 42 (14) ◽

pp. 2307-2312 ◽

Cited By ~ 16

Author(s):

C. Anglin ◽

C. Fu ◽

A.J. Hodgson ◽

N. Helmy ◽

N.V. Greidanus ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Total Knee ◽

The Ideal

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A Finite-Element Study of Metal Backing and Tibial Resection Depth in a Composite Tibia Following Total Knee Arthroplasty

Journal of Biomechanical Engineering ◽

10.1115/1.4032551 ◽

2016 ◽

Vol 138 (4) ◽

Cited By ~ 1

Author(s):

Susumu Tokunaga ◽

Renee D. Rogge ◽

Scott R. Small ◽

Michael E. Berend ◽

Merrill A. Ritter

Keyword(s):

Finite Element ◽

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Implant Design ◽

Bone Resection ◽

Element Analysis ◽

Term Survival ◽

Tibial Resection ◽

Total Knee ◽

Resection Depth

Prosthetic alignment, patient characteristics, and implant design are all factors in long-term survival of total knee arthroplasty (TKA), yet the level at which each of these factors contribute to implant loosening has not been fully described. Prior clinical and biomechanical studies have indicated tibial overload as a cause of early TKA revision. The purpose of this study was to determine the relationship between tibial component design and bone resection on tibial loading. Finite-element analysis (FEA) was performed after simulated implantation of metal backed (MB) and all-polyethylene (AP) TKA components in 5 and 15 mm of tibial resection into a validated intact tibia model. Proximal tibial strains significantly increased between 13% and 199% when implanted with AP components (p < 0.05). Strain significantly increased between 12% and 209% in the posterior tibial compartment with increased bone resection (p < 0.05). This study indicates elevated strains in AP implanted tibias across the entirety of the proximal tibial cortex, as well as a posterior shift in tibial loading in instances of increased resection depth. These results are consistent with trends observed in prior biomechanical studies and may associate the documented device history of tibial collapse in AP components with increased bone strain and overload beneath the prosthesis.

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Generation and applications of CT images of the ideal standing position for total knee arthroplasty surgery

Modelling in Medicine and Biology X ◽

10.2495/bio130241 ◽

2013 ◽

Author(s):

A. Doi ◽

H. Takahashi ◽

T. Mawatari ◽

S. Ichinohe

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Standing Position ◽

Ct Images ◽

Total Knee ◽

Knee Arthroplasty Surgery ◽

Arthroplasty Surgery ◽

The Ideal

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Total Knee Arthroplasty in Ochronosis Arthropathy: A Case Report and Systematic Review

Case Reports in Orthopedics ◽

10.1155/2019/1871856 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

Wu Chean Lee ◽

Tong Leng Tan ◽

Ying Ho Chan

Keyword(s):

Systematic Review ◽

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Conservative Therapy ◽

Rare Condition ◽

Case Presentation ◽

Outcome Scores ◽

Total Knee ◽

End Stage ◽

The Ideal

Introduction. Ochronosis arthropathy (OcA) is a rare condition which may be treated with total knee arthroplasty (TKA) at the end stage. The condition is often discovered only intraoperatively and the ideal choice of TKA is unknown. Case Presentation. A 54-year-old male with worsening chronic bilateral mechanical knee pain had failed conservative therapy. Posterior stabilised (PS), cemented TKA and patella resurfacing was performed. Intraoperatively, collagenous structures such as the menisci and cartilage were noted to be black. Histological examination showed deposition of large amorphous brown material suggestive of ochronosis. He recovered well and underwent TKA of the contralateral knee the following year. At 2 years postindex TKA, his outcome scores improved and he was satisfied. Discussion and Conclusion. With increasing TKA performed worldwide, a surgeon may eventually be surprised by the above findings once in their lifetime. However, OcA may be considered a likely diagnosis and it is safe to proceed with TKA. There is no particular TKA design that proved to be superior in our systematic review of 19 publications regarding TKA as all reported good outcomes. However, as the pathogenesis of OcA appears to be inflammatory in nature, we suggest using cemented PS TKA with resurfacing of the patella.

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