Influence of intentional femoral component flexion in navigated TKA on gap balance and sagittal anatomy

Abstract Background: The aim of the present study was to investigate the influence of sagittal femoral bowing on sagittal femoral component alignment, and whether there was correlation between sagittal femoral component alignment and coronal femoral component alignment.Methods: We retrospectively reviewed 77 knees in 71 patients who had undergone primary TKA for advanced osteoarthritis.All surgeries were performed by using a standard medial parapatellar approach. The osteotomy was performed with a conventional technique using an intramedullar rod for the femur and a mechanical extramedullar guiding system for the tibia. All patients enrolled in the study were evaluated with full-length lower extremity load-bearing standing scanograms and the patients had preoperative and postoperative radiographs of the knees. cFBA(coronal femoral bowing angle), sFBA(sagittal femoral bowing angle),and postoperatively, mTFA(mechanical tibiofemoral angle of the knee), β angle(femoral component flexion angle) were measured. The radiographic results of both groups were compared using Student's t test. A two-sided Pearson correlation coefficient was obtained to identify the correlations between FBA in the coronal and sagittal planes, as well as FBA and age or BMI, sFBA and β angle, cFBA and mTFA. Comparison of FSB incidence between different genders was using chi-square test. The p value <0.05 indicates a statistically significant difference.Results: The mean sFBA, cFBA, β angle, mTFA were 9.34°±3.56°(range 1°-16°), 3.25°±3.79°(range -7°-17°), 3.91°±3.15°(range -1°-13°), 0.60°±1.95°(range -3°-6°), respectively. There was no correlation between age and sFBA(CC=0.192, p=0.194) or cFBA(CC=0.192, p=0.194), similarly, there was no correlation between age and sFBA(CC=0.067, p=0.565) or cFBA(CC=0.069, p=0.549). The sFBA was correlated with cFBA and β angle(CC=0.540, p<0.01; CC=0.543, p<0.01; respectively) and the cFBA was correlated with mTFA(CC=0.430, p<0.01). There was no significant difference(p=0.247) of cFBA between the patients with sFSB and the patients without sFSB. Conclusions: The current study showed that the sFBA was correlated with cFBA in the patients undergoing TKA and the patients with sFSB usually presented non-cFSB. We also found that sFSB could affect the femoral component alignment in the sagittal plane and cFSB could affect the femoral component alignment in the coronal plane. The sFBA or cFBA was not correlated with age, BMI or gender.

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Is the femoral component flexion affected by the sagittal femoral shaft bowing in conventional intramedullary guided TKA?

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02822-7 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Xiaofeng Zhang ◽

Qianjin Wang ◽

Xingquan Xu ◽

Dongyang Chen ◽

Zhengyuan Bao ◽

...

Keyword(s):

Femoral Component ◽

Sagittal Plane ◽

Pearson Correlation ◽

Femoral Shaft ◽

Conventional Technique ◽

Component Alignment ◽

Chi Square ◽

Significant Difference ◽

Femoral Component Flexion ◽

Femoral Bowing

Abstract Background The aim of the present study was to investigate the influence of sagittal femoral bowing on sagittal femoral component alignment, and whether there was correlation between sagittal femoral component alignment and coronal femoral component alignment. Methods We retrospectively reviewed 77 knees in 71 patients who had undergone primary TKA for advanced osteoarthritis. All surgeries were performed by using a standard medial parapatellar approach. The osteotomy was performed with a conventional technique using an intramedullary rod for the femur and a mechanical extramedullary guiding system for the tibia. All patients enrolled in the study were evaluated with full-length lower extremity load-bearing standing scanograms, and the patients had preoperative and postoperative radiographs of the knees. Coronal femoral bowing angle (cFBA), sagittal femoral bowing angle (sFBA), and postoperatively, mechanical tibiofemoral angle of the knee (mTFA), β angle (femoral component flexion angle) were measured. The radiographic results of both groups were compared using Student's t test. A two-sided Pearson correlation coefficient was obtained to identify the correlations between FBA in the coronal and sagittal planes, as well as FBA and age or BMI, sFBA and β angle, cFBA and mTFA. Comparison of FSB incidence between different genders was made using Chi-square test. The p value < 0.05 indicates a statistically significant difference. Results The mean sFBA, cFBA, β angle, mTFA were 9.34° ± 3.56°(range 1°–16°), 3.25° ± 3.79°(range − 7° to −17°), 3.91° ± 3.15°(range − 1° to −13°), 0.60° ± 1.95°(range − 3° to −6°), respectively. There was no correlation between age and sFBA (CC = 0.192, p = 0.194) or cFBA (CC = 0.192, p = 0.194); similarly, there was no correlation between age and sFBA (CC = 0.067, p = 0.565) or cFBA (CC = 0.069, p = 0.549). The sFBA was correlated with cFBA and β angle (CC = 0.540, p < 0.01; CC = 0.543, p < 0.01, respectively), and the cFBA was correlated with mTFA (CC = 0.430, p < 0.01). There was no significant difference (p = 0.247) of cFBA between the patients with sFSB and the patients without sFSB. Conclusions The current study showed that the sFBA was correlated with cFBA in the patients undergoing TKA and the patients with sFSB usually presented non-cFSB. We also found that sFSB could affect the femoral component alignment in the sagittal plane and cFSB could affect the femoral component alignment in the coronal plane. The sFBA or cFBA was not correlated with age, BMI, or gender.

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Influence of Variation in Sagittal Placement of the Femoral Component after Cruciate-Retaining Total-Knee Arthroplasty

The Journal of Knee Surgery ◽

10.1055/s-0039-1696958 ◽

2019 ◽

Author(s):

Yong-Gon Koh ◽

Hyoung-Taek Hong ◽

Hwa-Yong Lee ◽

Hyo-Jeong Kim ◽

Kyoung-Tak Kang

Keyword(s):

Total Knee Arthroplasty ◽

Posterior Cruciate Ligament ◽

Femoral Component ◽

Contact Force ◽

Knee Arthroplasty ◽

Cruciate Ligament ◽

Cruciate Retaining ◽

Total Knee ◽

Quadriceps Force ◽

Femoral Component Flexion

AbstractProsthetic alignment is an important factor for long-term survival in cruciate-retaining (CR) total knee arthroplasty (TKA). The purpose of this study is to investigate the influence of sagittal placement of the femoral component on tibiofemoral (TF) kinematics and kinetics in CR-TKA. Five sagittal placements of femoral component models with −3, 0, 3, 5, and 7 degrees of flexion are developed. The TF joint kinematics, quadriceps force, patellofemoral contact force, and posterior cruciate ligament force are evaluated using the models under deep knee-bend loading. The kinematics of posterior TF translation is found to occur with the increase in femoral-component flexion. The quadriceps force and patellofemoral contact force decrease with the femoral-component flexion increase. In addition, extension of the femoral component increases with the increase in posterior cruciate ligament force. The flexed femoral component in CR-TKA provides a positive biomechanical effect compared with a neutral position. Slight flexion could be an effective alternative technique to enable positive biomechanical effects with TKA prostheses.

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Notching is less, if femoral component sagittal positioning is planned perpendicular to distal femur anterior cortex axis, in navigated TKA

Knee Surgery and Related Research ◽

10.1186/s43019-021-00129-9 ◽

2021 ◽

Vol 33 (1) ◽

Author(s):

Raj Kanna ◽

Chandramohan Ravichandran ◽

Gautam M. Shetty

Keyword(s):

Femoral Component ◽

Distal Femur ◽

Mechanical Axis ◽

Computer Assisted ◽

Therapeutic Level ◽

Level Of Evidence ◽

Anterior Cortex ◽

Level Ii ◽

Navigated Tka ◽

Very High

Abstract Purpose In navigated TKA, the risk of notching is high if femoral component sagittal positioning is planned perpendicular to the sagittal mechanical axis of femur (SMX). We intended to determine if, by opting to place the femoral component perpendicular to distal femur anterior cortex axis (DCX), notching can be reduced in navigated TKA. Methods We studied 171 patients who underwent simultaneous bilateral computer-assisted TKA. Femoral component sagittal positioning was planned perpendicular to SMX in one knee (Femur Anterior Bowing Registration Disabled, i.e. FBRD group) and perpendicular to DCX in the opposite knee (Femur Anterior Bowing Registration Enabled, i.e. FBRE group). Incidence and depth of notching were recorded in both groups. For FBRE knees, distal anterior cortex angle (DCA), which is the angle between SMX and DCX, was calculated by the computer. Results Incidence and mean depth of notching was less (p = 0.0007 and 0.009) in FBRE versus FBRD group, i.e. 7% versus 19.9% and 0.98 mm versus 1.53 mm, respectively. Notching was very high (61.8%) in FBRD limbs when the anterior bowing was severe (DCA > 3°) in the contralateral (FBRE) limbs. Conclusion Notching was less when femoral component sagittal positioning was planned perpendicular to DCX, in navigated TKA. Level of evidence Therapeutic level II.

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Analysis of 18F-FDG uptake patterns in PET for diagnosis of septic and aseptic loosening after total hip arthroplasty

Nuklearmedizin ◽

10.1055/s-0038-1625733 ◽

2003 ◽

Vol 42 (06) ◽

pp. 234-239 ◽

Cited By ~ 21

Author(s):

T. Mumme ◽

P. Reinartz ◽

D. Wirtz ◽

F. U. Niethard ◽

U. Büll ◽

...

Keyword(s):

Aseptic Loosening ◽

Femoral Component ◽

Hip Prosthesis ◽

Prosthetic Infection ◽

Clinical Value ◽

Septic Loosening ◽

Hip Prostheses ◽

Fdg Uptake ◽

Positron Emission ◽

Painful Hip

Summary Aim: Identification of typical patterns for fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) to detect aseptic loosening of hip prosthesis (ace-tabular and/or femoral component) and prosthetic infection. Methods: 18 patients with painful hip prosthesis underwent PET using a dedicated full ring scanner after application of 200-300 MBq FDG. The interface between bone and surrounding soft tissue or bone as displayed on coronal slices was divided into 12 segments in accordance with the classifications of Delee and Gruen. FDG uptake in each of the segments was scored (0-3) by two independent observers. Intraoperative findings were regarded as the gold standard. Results: After surgical revision 14 acetabular components and 9 femoral components were found to be loose and prosthetic infection was present in 7 prostheses. Loosening of the acetabular component was correlated to enhanced uptake in the middle of the acetabular interface, while loosening of the femoral component was correlated to enhanced uptake in the proximal and middle segment of the lateral femoral interface and the proximal segment of the medial femoral interface. A similar pattern was found in prosthetic infection with high uptake along the middle portion of the lateral fe-moral interface. In 6 of 7 infected prostheses loosening of the acetabular and of the femoral component was present. Taking the typical uptake patterns as criteria for loosening and grade 3 uptake as an additional criterion for septic loosening the accuracy of PET imaging in the detection of loosening of the acetabular or the femoral component and of prosthetic infection was 72, 78 and 89%, respectively. Conclusion: This pilot study presents FDG-PET as a promising diagnostic tool for patients with painful hip prostheses. Its clinical value should be evaluated in a larger patient population.

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Isolated Liner Revision for Total Knee Arthroplasty Instability: A Road That Should Remain Less Taken

The Journal of Knee Surgery ◽

10.1055/s-0040-1721091 ◽

2020 ◽

Author(s):

Jason D. Tegethoff ◽

Rafael Walker-Santiago ◽

William M. Ralston ◽

James A. Keeney

Keyword(s):

Total Knee Arthroplasty ◽

Femoral Component ◽

Knee Arthroplasty ◽

Primary Total Knee Arthroplasty ◽

P Value ◽

Surgical Morbidity ◽

Exact Test ◽

Total Knee ◽

Component Revision

AbstractIsolated polyethylene liner exchange (IPLE) is infrequently selected as a treatment approach for patients with primary total knee arthroplasty (TKA) prosthetic joint instability. Potential advantages of less immediate surgical morbidity, faster recovery, and lower procedural cost need to be measured against reoperation and re-revision risk. Few published studies have directly compared IPLE with combined tibial and femoral component revision to treat patients with primary TKA instability. After obtaining institutional review board (IRB) approval, we performed a retrospective comparison of 20 patients treated with IPLE and 126 patients treated with tibial and femoral component revisions at a single institution between 2011 and 2018. Patient demographic characteristics, medical comorbidities, time to initial revision TKA, and reoperation (90 days, <2 years, and >2 years) were assessed using paired Student's t-test or Fisher's exact test with a p-value <0.01 used to determine significance. Patients undergoing IPLE were more likely to undergo reoperation (60.0 vs. 17.5%, p = 0.001), component revision surgery (45.0 vs. 8.7%, p = 0.002), and component revision within 2 years (30.0 vs. 1.6%, p < 0.0001). Differences in 90-day reoperation (p = 0.14) and revision >2 years (p = 0.19) were not significant. Reoperation for instability (30.0 vs. 4.0%, p < 0.001) and infection (20.0 vs. 1.6%, p < 0.01) were both higher in the IPLE group. IPLE does not provide consistent benefits for patients undergoing TKA revision for instability. Considerations for lower immediate postoperative morbidity and cost need to be carefully measured against long-term consequences of reoperation, delayed component revision, and increased long-term costs of multiple surgical procedures. This is a level III, case–control study.

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