scholarly journals The medial condylar wall is a reliable landmark to kinematically align the femoral component in medial UKA: an in-silico study

2021 ◽  
Author(s):  
Benjamin Preston ◽  
Simon Harris ◽  
Loic Villet ◽  
Collin Mattathil ◽  
Justin Cobb ◽  
...  
Keyword(s):  
Femoral Component ◽  
Anatomical Landmark ◽  
Axial Plane ◽  
Medial Wall ◽  
Kinematic Alignment ◽  
Anatomical Landmarks ◽  
Medial Condyle ◽  
Axial Alignment ◽  
Cylindrical Axis ◽  
The Ideal

Abstract Purpose Kinematic alignment (KA) aligns the femoral implant perpendicular to the cylindrical axis in the frontal and axial plane. Identification of the kinematic axes when using the mini-invasive sub-quadricipital approach is challenging in unicompartmental knee arthroplasty (UKA). This study aims to assess if the orientation of condylar walls may be suitable for use as an anatomical landmark to kinematically align the femoral component in medial UKA. It was hypothesised that the medial wall of the medial condyle would prove to be a reliable anatomical landmark to set both the frontal and axial alignment of the femoral component in medial UKA. Methods 73 patients undergoing medial UKA had pre-operative CT imaging to generate 3D models. Those with osteophytes that impaired visualisation of the condylar walls were excluded. 28 patients were included in the study. The ideal KA was determined using the cylindrical axis in the frontal and axial plane. Simulations using the medial wall of the medial condyle (MWMC) and the lateral wall of the medial condyle (LWMC) were performed to set the frontal alignment. To set the axial alignment, the MWMC, LWMC, medial wall of the lateral condyle (MWLC), and medial diagonal line (MDL) anatomical landmarks were investigated. Differences between the ideal measured KA values and values obtained using landmarks were investigated. Results Use of the MWMC let to similar frontal alignment compared to the ideal KA (2.9° valgus vs 3.4° valgus, p = 0.371) with 46.4% (13/28) of measurements being $$\le $$ ≤ 1.0° different from the ideal KA and only 1 simulation with greater than 4.0° difference. Use of the MWMC led to very similar axial alignments compared to the ideal KA (0.5° internal vs 0.0°, p = 0.960) with 75.0% (21/28) of measurements being $$\le $$ ≤ 1.0o different from the ideal KA, and a maximum difference of 3.0°. Use of the MWLC and MDL was associated with significant statistical differences when compared to the ideal KA (p < 0.001 for both). Conclusions The native orientation of the medial condylar wall seems to be a reliable anatomical landmark for aligning the femoral component in medial KA UKA in both the axial plane and frontal planes. Other assessed landmarks were shown to not be reliable. Clinical and radiographic assessments of the reliability of using the MWMC to set the frontal and axial orientation of the femoral component when performing a medial KA UKA are needed.

scholarly journals Defining the limits of caesarean scar niche repair: new anatomical landmarks

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Tanushree Rao ◽  
Neera Lambert ◽  
Bhaswati Ghosh ◽  
Timothy Chang
Keyword(s):  
Laparoscopic Repair ◽  
Anatomical Landmark ◽  
Anatomical Landmarks ◽  
Video Presentation ◽  
Surgical Method ◽  
Caesarean Scar ◽  
Reproducible Technique ◽  
The Ideal

Abstract Background Caesarean scar niche is increasingly being seen due to the rise in the number of caesarean sections worldwide. Indications and the ideal route for niche repair are still being researched. If the residual myometrium is less than 3 mm thick and potential fertility is needed, laparoscopy is the ideal surgical method for caesarean scar niche repair. The aim of this video presentation is to demonstrate techniques of identifying new anatomical landmarks during laparoscopic uterine niche repair. Results As seen in the video, Caesarean scar niche repair can be done in a step-by-step manner, with lateral bands serving as anatomical landmarks. Conclusions Lateral bands are a consistent anatomical landmark which identify the level and width of the uterine niche and thus simplify the laparoscopic repair making this a reproducible technique.

scholarly journals The kinematic alignment technique for TKA reliably aligns the femoral component with the cylindrical axis

2017 ◽  
Vol 103 (7) ◽  
pp. 1069-1073 ◽  
Author(s):  
C. Rivière ◽  
F. Iranpour ◽  
S. Harris ◽  
E. Auvinet ◽  
A. Aframian ◽  
...  
Keyword(s):  
Femoral Component ◽  
Kinematic Alignment ◽  
Alignment Technique ◽  
Cylindrical Axis

scholarly journals Transsphenoidal Optic Canal Decompression for Traumatic Optic Neuropathy Assisted by a Computed Tomography Image Postprocessing Technique

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
J. Li ◽  
Q. S. Ran ◽  
B. Hao ◽  
X. Xu ◽  
H. F. Yuan
Keyword(s):  
Optic Nerve ◽  
Sphenoid Sinus ◽  
Uncinate Process ◽  
Medial Wall ◽  
Optic Canal ◽  
Wide Field ◽  
Anatomical Landmarks ◽  
Invasive Approach ◽  
Ethmoidal Sinus ◽  
Less Invasive

The endoscopic transethmoidal approach is favored for the lack of external scars, a wide field of view, and rapid recovery time. But the effect of iatrogenic trauma should not be ignored due to the removal of the uncinate process and anterior and posterior ethmoidal sinus. Anatomically, the optic nerve is close to the sphenoid sinus and Onodi cell. In order to preserve the uncinate process and ethmoidal sinus, we perform endoscopic transsphenoidal optic canal decompression (ETOCD), which is less invasive. However, the anatomy of sphenoid sinus is quite variable, and the anatomical landmarks are rare. Therefore, identifying the position of optic canal is particularly important during surgery. To solve this, we use a postprocessing technique to identify the position of the optic nerve and internal carotid artery on the sphenoid sinus wall. Our results find that VA in 13 patients improved, with a total improve rate of 59.1%. No serious complications were found. We also found that the length of optic canal is different and the medial wall of the optic canal was the longest (p<0.05). The middle section of the optic canal is the narrowest, which was significantly different from cranial mouth and orbital mouth (p<0.05). We assumed that decompression may not require removal of all medial wall. If we remove the length of the shortest wall on the medial wall of the optic canal, the compression may be relieved. Thus, ETOCD was a feasible, safe, effective, and less-invasive approach for patients with TON. The CT postprocessing imaging facilitated recognition of the optic canal during surgery. The decompression length of the medial wall may not need to be completely removed, especially near the cranial mouth.

Adjusting Insert Thickness and Tibial Slope Do Not Correct Internal Tibial Rotation Loss Caused by PCL Resection: In Vitro Study of a Medial Constraint TKA Implanted with Unrestricted Calipered Kinematic Alignment

2021 ◽  
Author(s):  
Alexander J. Nedopil ◽  
Peter J. Thadani ◽  
Thomas H. McCoy ◽  
Stephen M. Howell ◽  
Maury L. Hull
Keyword(s):  
Internal Rotation ◽  
Cruciate Ligament ◽  
Tibial Slope ◽  
Kinematic Alignment ◽  
Tibial Rotation ◽  
Medial Condyle ◽  
Maximum Extension ◽  
Posterior Tibial ◽  
Internal Tibial Rotation ◽  
Lift Off

AbstractMost medial stabilized (MS) total knee arthroplasty (TKA) implants recommend excision of the posterior cruciate ligament (PCL), which eliminates the ligament's tension effect on the tibia that drives tibial rotation and compromises passive internal tibial rotation in flexion. Whether increasing the insert thickness and reducing the posterior tibial slope corrects the loss of rotation without extension loss and undesirable anterior lift-off of the insert is unknown. In 10 fresh-frozen cadaveric knees, an MS design with a medial ball-in-socket (i.e., spherical joint) and lateral flat insert was implanted with unrestricted calipered kinematic alignment (KA) and PCL retention. Trial inserts with goniometric markings measured the internal–external orientation relative to the femoral component's medial condyle at maximum extension and 90 degrees of flexion. After PCL excision, these measurements were repeated with the same insert, a 1 mm thicker insert, and a 2- and 4-mm shim under the posterior tibial baseplate to reduce the tibial slope. Internal tibial rotation from maximum extension and 90 degrees of flexion was 15 degrees with PCL retention and 7 degrees with PCL excision (p < 0.000). With a 1 mm thicker insert, internal rotation was 8 degrees (p < 0.000), and four TKAs lost extension. With a 2 mm shim, internal rotation was 9 degrees (p = 0.001) and two TKAs lost extension. With a 4 mm shim, internal rotation was 10 degrees (p = 0.002) and five TKAs lost extension and three had anterior lift-off. The methods of inserting a 1 mm thicker insert and reducing the posterior slope did not correct the loss of internal tibial rotation after PCL excision and caused extension loss and anterior lift-off in several knees. PCL retention should be considered when using unrestricted calipered KA and implanting a medial ball-in-socket and lateral flat insert TKA design, so the progression of internal tibial rotation and coupled reduction in Q-angle throughout flexion matches the native knee, optimizing the retinacular ligaments' tension and patellofemoral tracking.

scholarly journals Femoral Component Alignment Boundaries for Tibia First Gap Balancing using Digital Tensioning Tool

10.29007/9p46 ◽  
2020 ◽  
Author(s):  
Edgar Wakelin ◽  
Sami Shalhoub ◽  
Jeffrey Lawrence ◽  
John Keggi ◽  
Jeffrey DeClaire ◽  
...  
Keyword(s):  
Los Angeles ◽  
Femoral Component ◽  
Patient Outcomes ◽  
Component Alignment ◽  
Small Deviations ◽  
Gap Balancing ◽  
Axial Alignment ◽  
Outcome Scores ◽  
Total Knee ◽  
Tibiofemoral Alignment

Achieving a balanced knee is a critical aspect of Total Knee Arthroplasty (TKA). Coronal and axial boundaries for femoral component placement to achieve balance however, are not well defined. Our aim is to investigate the effect of femoral component and long leg coronal and axial alignment on patient outcomes when using a tibia-first gap balancing technique.All surgeries were performed using the OMNIBotics robot-assisted TKA platform and BalanceBot device. A total of 197 patients were prospectively enrolled into this study and received TKA surgery using the OMNIBotics platform and completed 1-year KOOS outcome scores. Femoral component and tibiofemoral alignment were categorized as inliers or outliers in the coronal and axial planes. Knee Injury and Osteoarthritis Outcome Score (KOOS), and University of California at Los Angeles Activity Scale (UCLA) was collected at 1-year post-op.No significant differences were found between the KOOS subscores or UCLA outcome and femoral coronal or tibiofemoral coronal and axial alignment. Significant differences were found between the KOOS pain and sports sub-scores and femoral axial alignment (∆ = 5.4, p = 0.007, ∆ = 8.3, p = 0.03 respectively), in which outlier femoral rotation reported higher scores.Component alignment limits for improved survival and patient outcomes are a source of ongoing debate. The data presented here indicates that when utilizing a tibia-first gap balancing technique, small deviations outside of traditional ±3°alignment boundaries did not negatively affect KOOS or UCLA outcomes, indicating balance may have a stronger link to patient outcome than alignment.

Intraoperative placement of total hip arthroplasty components with robotic-arm assisted technology correlates with postoperative implant position

2018 ◽  
Vol 100-B (10) ◽  
pp. 1303-1309 ◽  
Author(s):  
S. R. Nodzo ◽  
C-C. Chang ◽  
K. M. Carroll ◽  
B. T. Barlow ◽  
S. A. Banks ◽  
...  
Keyword(s):  
Total Hip Arthroplasty ◽  
Ct Scan ◽  
Femoral Component ◽  
Hip Arthroplasty ◽  
Mean Deviation ◽  
Robotic Assistance ◽  
Anatomical Landmarks ◽  
Hip Reconstruction ◽  
Robotic Assisted ◽  
Total Hip

Aims The aim of this study was to evaluate the accuracy of implant placement when using robotic assistance during total hip arthroplasty (THA). Patients and Methods A total of 20 patients underwent a planned THA using preoperative CT scans and robotic-assisted software. There were nine men and 11 women (n = 20 hips) with a mean age of 60.8 years (sd 6.0). Pelvic and femoral bone models were constructed by segmenting both preoperative and postoperative CT scan images. The preoperative anatomical landmarks using the robotic-assisted system were matched to the postoperative 3D reconstructions of the pelvis. Acetabular and femoral component positions as measured intraoperatively and postoperatively were evaluated and compared. Results The system reported accurate values for reconstruction of the hip when compared to those measured postoperatively using CT. The mean deviation from the executed overall hip length and offset were 1.6 mm (sd 2.9) and 0.5 mm (sd 3.0), respectively. Mean combined anteversion was similar and correlated between intraoperative measurements and postoperative CT measurements (32.5°, sd 5.9° versus 32.2°, sd 6.4°; respectively; R2 = 0.65; p < 0.001). There was a significant correlation between mean intraoperative (40.4°, sd 2.1°) acetabular component inclination and mean measured postoperative inclination (40.12°, sd 3.0°, R2 = 0.62; p < 0.001). There was a significant correlation between mean intraoperative version (23.2°, sd 2.3°), and postoperatively measured version (23.0°, sd 2.4°; R2 = 0.76; p < 0.001). Preoperative and postoperative femoral component anteversion were significantly correlated with one another (R2 = 0.64; p < 0.001). Three patients had CT scan measurements that differed substantially from the intraoperative robotic measurements when evaluating stem anteversion. Conclusion This is the first study to evaluate the success of hip reconstruction overall using robotic-assisted THA. The overall hip reconstruction obtained in the operating theatre using robotic assistance accurately correlated with the postoperative component position assessed independently using CT based 3D modelling. Clinical correlation during surgery should continue to be practiced and compared with observed intraoperative robotic values. Cite this article: Bone Joint J 2018;100-B:1303–9.

The Relationship of Transepicondylar Width with the Distal and Posterior Femoral Condyles and Its Clinical Implications: A Three-Dimensional Study

2020 ◽  
Author(s):  
Merrill Lee ◽  
Jade Pei Yuik Ho ◽  
Jerry Yongqiang Chen ◽  
Chung Kia Ng ◽  
Seng Jin Yeo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Ct Images ◽  
Revision Total Knee Arthroplasty ◽  
Joint Line ◽  
Lower Limbs ◽  
Anatomical Landmarks ◽  
Medial Condyle ◽  
Lateral Epicondyle ◽  
Femoral Condyles

Abstract Background Restoration of the anatomical joint line, while important for clinical outcomes, is difficult to achieve in revision total knee arthroplasty (rTKA) due to distal femoral bone loss. The objective of this study was to determine a reliable method of restoring the anatomical joint line and posterior condylar offset in the setting of rTKA based on three-dimensional (3D) reconstruction of computed tomography (CT) images of the distal femur. Methods CT scans of 50 lower limbs were analyzed. Key anatomical landmarks such as the medial epicondyle (ME), lateral epicondyle, and transepicondylar width (TEW) were determined on 3D models constructed from the CT images. Best-fit planes placed on the most distal and posterior loci of points on the femoral condyles were used to define the distal and posterior joint lines, respectively. Statistical analysis was performed to determine the relationships between the anatomical landmarks and the distal and posterior joint lines. Results There was a strong correlation between the distance from the ME to the distal joint line of the medial condyle (MEDC) and the distance from the ME to the posterior joint line of the medial condyle (MEPC) (p < 0.001; r = 0.865). The mean ratio of MEPC to MEDC was 1.06 (standard deviation [SD]: 0.07; range: 0.88–1.27) and that of MEPC to TEW was 0.33 (SD: 0.03; range: 0.25–0.38). Conclusions Our findings suggest that the fixed ratios of MEPC to TEW (0.33) and that of MEPC to MEDC (1.06) provide a reliable means for the surgeon to determine the anatomical joint line when used in combination.

scholarly journals Femoral Component Sizing in Oxford Unicompartmental Knee Replacement: Existing Guidelines Do Not Work for Indian Patients

2018 ◽  
Vol 32 (03) ◽  
pp. 205-210
Author(s):  
Rajesh Malhotra ◽  
Sahil Gaba ◽  
Vijay Kumar ◽  
Deep Srivastava ◽  
Hemant Pandit ◽  
...  
Keyword(s):  
Femoral Component ◽  
Knee Replacement ◽  
Unicompartmental Knee Replacement ◽  
Component Size ◽  
Component Sizing ◽  
Indian Patients ◽  
Study Population ◽  
Gender Based ◽  
And Gender ◽  
The Ideal

AbstractOxford unicompartmental knee replacement (OUKR) has shown excellent long-term clinical outcomes as well as implant survival when used for correct indications with optimal surgical technique. Anteromedial osteoarthritis is highly prevalent in Indian patients, and OUKR is the ideal treatment option in such cases. Uncertainty prevails about the best method to determine femoral component size in OUKR. Preoperative templating has been shown to be inaccurate, while height- and gender-based guidelines based on European population might not apply to the Indian patients. Microplasty instrumentation introduced in 2012 introduced the sizing spoon, which has the dual function of femoral component sizing and determining the level of tibia cut. We aimed to check the accuracy of sizing spoon and also to determine whether the present guidelines are appropriate for use in the Indian patients. A total of 130 consecutive Oxford mobile bearing medial cemented UKR performed using the Microplasty instrumentation were included. The ideal femoral component size for each knee was recorded by looking for overhang and underhang in post-operative lateral knee radiograph. The accuracy of previous guidelines was determined by applying them to our study population. Previously published guidelines (which were based on Western population) proved to be accurate in only 37% of cases. Hence, based on the demographics of our study population, we formulated modified height- and gender-based guidelines, which would better suit the Indian population. Accuracy of modified guidelines was estimated to be 74%. The overall accuracy of sizing spoon (75%), when used as an intraoperative guide, was similar to that of modified guidelines. Existing guidelines for femoral component sizing do not work in Indian patients. Modified guidelines and use of intraoperative spoon should be used to choose the optimal implant size while performing OUKR in Indian patients.

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