Accuracy and reliability of distal femoral rotation measurements using the transepicondylar axis in total knee arthroplasty: A cadaver study

Objective: Computer assisted total knee arthroplasty (CA TKA) platforms can provide detailed kinematic data that is presented in various forms including a coronal plane graphic that maps the flexion arc from full extension to deep flexion. Graphics obtained from normal tibiofemoral articulations reveal varied and complex kinematic patterns that have yet to be explained. An understanding of what drives curve variation would allow prediction of how a preoperative curve would be altered by total knee arthroplasty. Implant position could then be tailored to maintain a desirable curve or avoid an undesirable one. Methods: An articulated lower limb saw bone with a stable hip pivot was obtained. Adjustable osteotomies were created so that femoral torsion, femoral varus-valgus and tibial varus-valgus could be altered independently. The saw bone limb was registered with a CA TKA navigation system using the posterior condyles as a rotational axis. Axial and coronal plane morphology of the distal femur and coronal plane morphology of the proximal tibia were systematically altered and a kinematic curve obtained for each morphologic combination. Femoral rotational position was varied from 100 of internal torsion to 100 of external torsion in 20 increments. Similarly, femoral coronal position was varied from 20 of varus to 60 of valgus and tibial coronal position was varied from 5.50 of varus to 10 of valgus. Curves were obtained by manually flexing the joint through a full range of motion with the femoral condyles in contact with proximal tibia at all times. Results: Varying femoral rotation has no effect in full extension but drives the curve away from neutral as the knee flexes. Maximal deviation is seen at around 900 of flexion. Internal torsion drives the curve into valgus as the knee flexes and external torsion has a reciprocal effect. Varying femoral varus-valgus causes maximal deviation from neutral in full extension. Femoral varus drives the curve from varus in extension towards valgus as the knee flexes with the effect peaking in maximal flexion. Femoral valgus has a reciprocal effect. Varying tibial varus-valgus has no effect on curve shape but does move the curve either side of neutral. Complex (parabolic) curves are caused by large rotations or the opposing effects of femoral varus-valgus and femoral rotation. The modal human anatomy of slight femoral internal rotation, slight femoral valgus and slight tibial varus produces a straight neutral curve. Conclusion: Kinematic curve shape is driven by distal femoral anatomy. The typical changes made to distal femoral articular anatomy in TKA by externally rotating a neutrally orientated femoral component will bring many native curves towards neutral. Externally rotating when the preoperative curve begins neutral and drives into varus as the knee flexes will drive the curve harder into varus. Conversely, kinematic femoral placement will reconstitute the premorbid curve morphology. Which outcome is preferable has yet to be determined.

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Comparison of robot-assisted and conventional total knee arthroplasty: A controlled cadaver study using multiparameter quantitative three-dimensional CT assessment of alignment

Computer Aided Surgery ◽

10.3109/10929088.2012.654408 ◽

2012 ◽

Vol 17 (2) ◽

pp. 86-95 ◽

Cited By ~ 38

Author(s):

Young-Wan Moon ◽

Chul-won Ha ◽

Kwan-Hong Do ◽

Chang-Young Kim ◽

Jeong-Hoon Han ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Three Dimensional ◽

Cadaver Study ◽

Robot Assisted ◽

Total Knee ◽

Conventional Total Knee Arthroplasty

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Robotic-Arm Assisted Total Knee Arthroplasty Demonstrated Soft Tissue Protection

10.29007/8bxp ◽

2018 ◽

Author(s):

Emily Hampp ◽

Manoshi Bhowmik-Stoker ◽

Laura Scholl ◽

Jason Otto ◽

David Jacofsky ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Soft Tissue ◽

Knee Arthroplasty ◽

Cadaver Study ◽

Patellar Ligament ◽

Robotic Arm ◽

Collateral Ligament ◽

Tissue Protection ◽

Total Knee ◽

Patellar Eversion

Total knee arthroplasty (TKA) typically addresses end-stage osteoarthritis. While TKA procedures have demonstrated clinical success, occasionally intraoperative complications can occur. This cadaver study examined the potential benefits of soft tissue protection in robotic-arm assisted TKA (RATKA). Six cadaver knees were prepared using RATKA by a single surgeon from a high-volume TKA joint center with no former clinical robotic experience, and compared to seven manually performed cases as a control. The presence of soft tissue disruption was assessed by having the surgeon perform visual evaluation and palpation of the medial collateral ligament (MCL), lateral collateral ligament (LCL), posterior cruciate ligament (PCL), and the patellar ligament after the procedures. The amount of tibial subluxation and patellar eversion was recorded for each case.For all RATKA cases, there was no visible evidence of disruption of any of the ligaments. All RATKA cases were successfully left with a bone island on the tibial plateau, which protected the PCL. Tibial subluxation and patellar eversion were not required for visualization. In two of the seven MTKA cases, there was slight disruption noted of the PCL, although this did not lead to any apparent change in the functional integrity of the ligament. All MTKA cases required tibial subluxation and patellar eversion to achieve optimal visualization.Aspects of soft tissue protection were noted in this cadaver study for RATKA. Standard retraction techniques during cutting are recommended. This is the first study to have soft tissue injury parameters assessed for RATKA, and may serve as a platform for future studies.

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Title Anterior Prominence of the Femoral Condyle Varies among Prosthesis Designs and Surgical Techniques in Total Knee Arthroplasty

10.21203/rs.3.rs-731593/v1 ◽

2021 ◽

Author(s):

Junya Itou ◽

Umito Kuwashima ◽

Masafumi Itoh ◽

Ken Okazaki

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Surgical Simulation ◽

Femoral Condyle ◽

Surgical Techniques ◽

Planning System ◽

Implant Design ◽

Transepicondylar Axis ◽

Limited Range Of Motion ◽

Total Knee

Abstract BackgroundPatellofemoral overstuffing after total knee arthroplasty can cause limited range of motion and anterior knee pain. This study compared anterior prominence of femoral components among different prothesis designs in surgical simulation models utilizing the anterior reference (AR) and posterior reference (PR) techniques.MethodsSurgical simulations were performed using preoperative computed tomography data of 30 patients on a three-dimensional planning system. Four implant models were used: Attune, Persona, Journey II, and Legion. Rotational alignment was set parallel to the transepicondylar axis and size selection was based on absence of notch formation in the femoral anterior cortex and best fit to the shape of the medial posterior femoral condyle. For each combination of surgical technique (AR or PR method) and implant model, measurements were taken of the maximum medial, central, and lateral prominence of the implant from the anterior femoral cortex (mm).ResultsUsing either the AR or PR method, the medial and central prominences were significantly lower with Journey II than with other models. The lateral prominence was the lowest with Attune in the AR method. The AR method was associated with significantly less prominence than the PR method, regardless of implant model.ConclusionsDegree of anterior prominence of the femoral implant is affected by implant design when the AR method is used. The PR method is associated with greater anterior prominence compared with the AR method, with size pitch an additional influencing factor. Journey II is associated with the least anterior prominence when using either method.

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