scholarly journals The evaluation of the distance between the popliteus tendon and the lateral collateral ligament footprint and the implant in Total Knee Arthroplasty using a 3-dimensional template.

2020 ◽  
Author(s):  
Akihito Takubo ◽  
Keinosuke Ryu ◽  
Takanori Iriuchishima ◽  
Masahiro Nagaoka ◽  
Yasuaki Tokuhashi ◽  
...  

Abstract Background The popliteus tendon (PT) or lateral collateral ligament (LCL) stabilizes the postero-lateral aspects of the knees. When surgeons perform total knee arthroplasty (TKA), PT and LCL iatrogenic injuries are a risk because the femoral attachments are relatively close to the femoral bone resection area. The purpose of this study was to evaluate the distance between the PT or LCL footprint and the TKA implant using a 3D template system and to evaluate any significant differences according to the implant model.Methods Eighteen non-paired formalin fixed cadaveric lower limbs were used (average age: 80.3). Whole length lower limbs were resected from the pelvis. All the surrounding soft tissue except the PT, knee ligaments and meniscus were removed from the limb. Careful dissection of the PT and LCL was performed, and the femoral footprints were detected. Each footprint periphery was marked with a 1.5 mm K-wire. Computed tomography (CT) scanning of the whole lower limb was then performed. The CT data was analyzed with a 3D template system. This simulation models for TKA were the Journey II BCS and the Persona PS. The area of each footprint, and the length between the most distal and posterior point of the lateral femoral condyle and the edge of each footprint were measured. Matching the implant model to the CT image of the femur, the shortest length between each footprint and the bone resection area were calculated.Results PT and LCL footprint were detected in all knees. The area of the PT and LCL footprints was 38.7±17.7mm2 and 58.0±24.6mm2, respectively. The length between the most distal and posterior point of the lateral femoral condyle and the edge of the PT footprint was 10.3±2.4mm and 14.2±2.8mm, respectively. The length between most distal and most posterior point of the lateral femoral condyle and the edge of the LCL footprint was 16.3±2.3mm and 15.5±3.3mm, respectively. Under TKA simulation, the shortest length between the PT footprint and the femoral bone resection area for the Journey II BCS and the Persona PS was 4.3±2.5mm and 3.2±2.9mm, respectively. The shortest length between the LCL footprint and the femoral bone resection area for the Journey II BCS and the Persona PS was 7.2±2.3mm and 5.6±2.1mm, respectively. The PT attachment was damaged by the bone resection of the Journey II BCS and the Persona PS TKA in 3 and 9 knees, respectively.Conclusion The PT and LCL femoral attachments existed close to the femoral bone resection area of the TKA. To prevent postero-lateral instability in TKA, careful attention is needed to avoid damage to the PT and LCL during surgical procedures.

2020 ◽  
Author(s):  
Akihito Takubo ◽  
Keinosuke Ryu ◽  
Takanori Iriuchishima ◽  
Masahiro Nagaoka ◽  
Yasuaki Tokuhashi ◽  
...  

Abstract Background When surgeons perform TKA, popliteus tendon (PT) and lateral collateral ligament (LCL) iatrogenic injuries are a risk because the femoral attachments are relatively close to the bone resection area. The purpose of this study was to evaluate the distance between the PT or LCL footprint and the TKA implant using a 3D template system and to evaluate any significant differences according to the implant model. Methods Eighteen non-paired formalin fixed cadaveric lower limbs were used. All the surrounding soft tissue except the PT, ligaments and meniscus were removed from the knee. Careful dissection of the PT and LCL was performed, and the femoral footprints were detected. Each footprint periphery was marked with a K-wire. CT scanning was then performed. The data was analyzed with a 3D template system. This simulation models for TKA were the Journey II BCS and the Persona PS. The area of each footprint, and the length between the most distal and posterior point of the lateral femoral condyle and the edge of each footprint were measured. Matching the implant model to the CT image, the shortest length between each footprint and the osteotomy area were calculated. Results The area of the PT and LCL footprints was 38.7±17.7mm 2 and 58.0±24.6mm 2 . The length between the most distal and posterior point of the lateral femoral condyle and the edge of the PT footprint was 10.3±2.4mm and 14.2±2.8mm. The length between these same points and the edge of the LCL footprint was 16.3±2.3mm and 15.5±3.3mm. Under TKA simulation, for the Journey II BCS and the Persona PS, the shortest length between the PT footprint and the osteotomy area was 4.3±2.5mm and 3.2±2.9mm, and the shortest length between the LCL footprint and the osteotomy area was 7.2±2.3mm and 5.6±2.1mm. The PT attachment was damaged by the bone resection of the Journey II BCS and the Persona PS TKA in 3 and 9 knee. Conclusion The PT and LCL femoral attachments existed close to the femoral bone resection area of the TKA. Careful attention is needed to avoid damage to the PT and LCL during surgical procedures.


2020 ◽  
Author(s):  
Akihito Takubo ◽  
Keinosuke Ryu ◽  
Takanori Iriuchishima ◽  
Masahiro Nagaoka ◽  
Yasuaki Tokuhashi ◽  
...  

Abstract Background When the surgeons perform total knee arthroplasty (TKA), PT and LCL iatrogenic injury are worried because those femoral footprints are relatively close to the bone resection lesion. The purpose of this study was to evaluate the distance between PT or LCL footprint and TKA implant using the three-dimensional (3D) template system.Methods Eighteen non-paired formalin fixed cadaveric lower limbs were used. All the surrounded soft tissue except the PT and knee ligaments were removed from the limb. Careful dissection of the PT and LCL was performed, and those femoral footprints were detected. Each footprint was periphery marked with a K-wire. CT scanning of the whole lower limb was then performed. The CT data was analyzed with 3D template system. Simulated models of TKA were Journey II BCS and Persona PS. The area of each footprint, and the length between most distal or posterior point of femur and the edge of each footprint were measured. When the implant model was matched to the CT image, the shortest length between each footprint and the bone resection were evaluated.Results The area of PT and LCL footprint were, 38.7±17.7mm 2 , and 58±24.6mm 2 , respectively. The length between most distal or posterior point of femur and the edge of the PT footprint were 10.3±2.4mm, and 14.2±2.8mm, respectively. The length between most distal or posterior point of femur and the edge of the LCL footprint were 16.3±2.3mm, and 15.5±3.3mm, respectively. When simulated the TKA, the shortest length between PT footprint and bone resection lesion of Journey II BCS and Persona PS were, 4.3±2.5mm, and 3.2±2.9mm, respectively. The shortest length between PT footprint and bone resection lesion of Journey II BCS and Persona PS were, 7.2±2.3mm, and 5.6±2.1mm, respectively. PT footprint was suffered by the bone resection of Journey II BCS TKA in 3 knees, and also by the Persona PS’s bone resection in 9 knees.Conclusion The PT and LCL femoral footprint existed close to the femoral bone resection lesion of the TKA. Careful attention is needed not to injure the PT and LCL in the surgical procedures.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Liang Yuan ◽  
Bin Yang ◽  
Xiaohua Wang ◽  
Bin Sun ◽  
Ke Zhang ◽  
...  

Purpose. Bony resection is the primary step during total knee arthroplasty. The accuracy of bony resection was highly addressed because it was deemed to have a good relationship with mechanical line. Patient-specific instruments (PSI) were invented to copy the bony resection references from the preoperative surgical plan during a total knee arthroplasty (TKA); however, the accuracy still remains controversial. This study was aimed at finding out the accuracy of the bony resection during PSI-assisted TKA. Methods. Forty-two PSI-assisted TKAs (based on full-length leg CT images) were analyzed retrospectively. Resected bones of every patient were given a CT scan, and three-dimensional radiographs were reconstructed. The thickness of each bony resection was measured with the three-dimensional radiographs and recorded. The saw blade thickness (1.27 mm) was added to the measurements, and the results represented intraoperative bone resection thickness. A comparison between intraoperative bone resection thickness and preoperatively planned thickness was conducted. The differences were calculated, and the outliers were defined as >3 mm. Results. The distal femoral condyle had the most accurate bone cuts with the smallest difference (median, 1.0 mm at the distal medial femoral condyle and 0.8 mm at the distal lateral femoral condyle) and the least outliers (none at the distal medial femoral condyle and 1 (2.4%) at the distal lateral femoral condyle). The tibial plateau came in second (median difference, 0.8 mm at the medial tibial plateau and 1.4 mm at the lateral tibial plateau; outliers, none at the medial tibial plateau and 1 (2.6%) at the lateral tibial plateau). Regardless of whether the threshold was set to >2 mm (14 (17.9%) at the tibial plateau vs. 12 (14.6%) at the distal femoral condyle, p > 0.05 ) or >3 mm (1 (1.3%) at the tibial plateau vs. 1 (1.2%) at the distal femoral condyle, p > 0.05 ), the accuracy of tibial plateau osteotomy was similar to that of the distal femoral condyle. Osteotomy accuracy at the posterior femoral condyle and the anterior femoral condyle were the worst. Outliers were up to 6 (15.0%) at the posterior medial femoral condyle, 5 (12.2%) at the posterior lateral femoral condyle, and 6 (15.8%) at the anterior femoral condyle. The percentages of overcut and undercut tended to 50% in most parts except the lateral tibial plateau. At the lateral tibial plateau, the undercut percentage was twice that of the overcut. Conclusion. The tibial plateau and the distal femoral condyle share a similar accuracy of osteotomy with PSI. PSI have a generally good accuracy during the femur and tibia bone resection in TKA. PSI could be a kind of user-friendly tool which can simplify TKA with good accuracy. Level of Evidence. This is a Level IV case series with no comparison group.


2017 ◽  
Vol 03 (03) ◽  
pp. e110-e112
Author(s):  
Benjamin Rossi ◽  
Narlaka Jayasekera ◽  
Fionnuala Kelly ◽  
Keith Eyres

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.


2021 ◽  
Vol 29 (5) ◽  
pp. 249-252
Author(s):  
MARCEL FARACO SOBRADO ◽  
CAMILO PARTEZANI HELITO ◽  
LUCAS DA PONTE MELO ◽  
ANDRE MARANGONI ASPERTI ◽  
RICCARDO GOMES GOBBI ◽  
...  

ABSTRACT Objective: To analyse the distances between the femoral insertions of the popliteus tendon (PT) and the lateral collateral ligament (LCL) through dissections of cadaveric specimens in a mixed population. Methods: Fresh cadavers were dissected, and the anthropometric data of all specimens were recorded. The distances from the origin of the PT to the LCL in the femoral region and the diameter of each structure were measured using a digital calliper. Results: In total, 11 unpaired knees were dissected, eight men and three women, with an average age of 71.5 ± 15.2 years, weight of 57.2 ± 15.6 kg, and a mean height of 170.5 ± 8.2 cm. The distance from the center of the femoral footprint of the LCL to the PT was 10.0 ± 2.4 mm. The distances between the edges closest to each other and those more distant from each other were 3.1 ± 1.1 mm and 16.3 ± 2.4 mm, respectively. Conclusion: The distance between the midpoints of the PT and the LCL in our mixed population is smaller than the distances often reported in the literature. PLC reconstruction with separate tunnels for the LCL and PT may not be technically possible for individuals of any population. Level of Evidence III, Diagnostic studies.


2019 ◽  
Vol 33 (03) ◽  
pp. 284-293 ◽  
Author(s):  
Kyoung-Tak Kang ◽  
Yong-Gon Koh ◽  
Ji Hoon Nam ◽  
Sae Kwang Kwon ◽  
Kwan Kyu Park

AbstractKinematic alignment (KA), which co-aligns the rotational axes of the components with three kinematic axes of the knee by aligning the components to the prearthritic joint lines, has been a recently introduced surgical technique. However, whether KA and cruciate retaining (CR) implants provide better biomechanical function during activities than mechanical alignment (MA) in posterior stabilized (PS) implants is unclear. We evaluated the biomechanical functions during the stance phase gait and deep knee bend, with a computer simulation and measured forces in the medial and lateral collateral ligaments and medial and lateral contact stresses in the polyethylene insert and patellar button. The forces on the medial collateral ligament in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions, whereas those on the lateral collateral ligament did not show any difference between the two surgical alignment techniques in the stance phase gait condition. The maximum contact stresses on the medial PE inserts in KA were lower than those in MA in both CR and PS TKA in the stance phase gait and deep knee bend conditions. However, the maximum contact stresses on the lateral PE inserts and the patellar button did not differ between MA and KA. The biomechanical function was superior in KA TKA than in MA TKA, and KA was more effective in CR TKA. This comparison could be used as a reference by surgeons to reduce the failure rates by using KA TKA instead of MA TKA.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yong-Gon Koh ◽  
Juhyun Son ◽  
Oh-Ryong Kwon ◽  
Sae Kwang Kwon ◽  
Kyoung-Tak Kang

The purpose of this study is to investigate post-cam design via finite element analysis to evaluate the most normal-like knee mechanics. We developed five different three-dimensional computational models of customized posterior-stabilized (PS) total knee arthroplasty (TKA) involving identical surfaces with the exception of the post-cam geometry. They include flat-and-flat, curve-and-curve (concave), curve-and-curve (concave and convex), helical, and asymmetrical post-cam designs. We compared the kinematics, collateral ligament force, and quadriceps force in the customized PS-TKA with five different post-cam designs and conventional PS-TKA to those of a normal knee under deep-knee-bend conditions. The results indicated that femoral rollback in curve-and-curve (concave) post-cam design exhibited the most normal-like knee kinematics, although the internal rotation was the closest to that of a normal knee in the helical post-cam design. The curve-and-curve (concave) post-cam design showed a femoral rollback of 4.4 mm less than the normal knee, and the helical post-cam design showed an internal rotation of 5.6° less than the normal knee. Lateral collateral ligament and quadriceps forces in curve-and-curve (concave) post-cam design, and medial collateral ligament forces in helical post-cam design were the closest to that of a normal knee. The curve-and-curve (concave) post-cam design showed 20% greater lateral collateral ligament force than normal knee, and helical post-cam design showed medial collateral ligament force 14% greater than normal knee. The results revealed the variation in each design that provided the most normal-like biomechanical effect. The present biomechanical data are expected to provide useful information to improve post-cam design to restore normal-like knee mechanics in customized PS-TKA.


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