A Flexible Intramedullary Guide Can Reduce the Anteroposterior Oversizing of Femoral Components Used in Total Knee Arthroplasty in Patients with Osteoarthritis and Severe Distal Femoral Sagittal Bowing

2021 ◽  
Author(s):  
Do Weon Lee ◽  
Joonhee Lee ◽  
Junpyo Lee ◽  
Du Hyun Ro ◽  
Myung Chul Lee ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Clinical Outcomes ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
Sagittal Alignment ◽  
Primary Tkas ◽  
Functional Scores ◽  
Total Knee ◽  
Intramedullary Rod ◽  
Rigid Rod

AbstractTraditionally, a rigid intramedullary rod has been used as the reference guide for femoral cutting in total knee arthroplasty (TKA). However, correct positioning of this rigid rod is difficult, especially in the knees with severe distal femoral sagittal bowing. A flexible intramedullary rod has been developed to address this problem. This study was performed to compare the sagittal alignment and clinical outcomes of TKAs performed with flexible and rigid femoral intramedullary guides. Thirty-eight knees that underwent primary TKAs with flexible intramedullary rods as femoral cutting guides were matched according to patient height and sex with 38 knees that underwent TKAs using conventional rigid rods. Clinical outcomes, including the range of motion and functional scores, and radiological variables, including the distal femoral bowing angle (DFBA), femoral component flexion angle (FFA), and mediolateral overhang and anteroposterior (AP) oversizing of femoral components, were evaluated. Clinical and radiological outcomes did not differ significantly between the flexible rod and conventional rigid rod groups. A subgroup analysis of knees with severe distal femoral sagittal bowing (DFBA >4 degrees) showed that the FFA was significantly larger in the flexible rod group than in the rigid rod group, with an average difference of 3 degrees (5.2 ± 2.4 vs. 2.2 ± 1.6 degrees, respectively, p = 0.022). In addition, the incidence of AP oversizing of femoral components was lower in the flexible rod group than in the rigid rod group (11.1 vs. 60.0%, respectively, p = 0.027). Relative to TKA with a rigid rod, TKA performed with a flexible femoral intramedullary guide resulted in more flexed sagittal alignment of femoral components in patients with severe distal femoral sagittal bowing. This greater flexion of the femoral component resulted in less AP oversizing. However, the use of a flexible rod had no impact on short-term clinical outcomes.

Excessive flexed position of the femoral component was associated with poor new Knee Society Score after total knee arthroplasty with the Bi-Surface knee prosthesis

2020 ◽  
Vol 102-B (6_Supple_A) ◽  
pp. 36-42
Author(s):  
Kohei Nishitani ◽  
Shinichi Kuriyama ◽  
Shinichiro Nakamura ◽  
Naoki Umatani ◽  
Hiromu Ito ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Clinical Outcomes ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
Knee Society Score ◽  
Sagittal Alignment ◽  
Knee Prosthesis ◽  
Rear Surface ◽  
Functional Activities ◽  
Total Knee

Aims This study aimed to evaluate the association between the sagittal alignment of the femoral component in total knee arthroplasty (TKA) and new Knee Society Score (2011KSS), under the hypothesis that outliers such as the excessive extended or flexed femoral component were related to worse clinical outcomes. Methods A group of 156 knees (134 F:22 M) in 133 patients with a mean age 75.8 years (SD 6.4) who underwent TKA with the cruciate-substituting Bi-Surface Knee prosthesis were retrospectively enrolled. On lateral radiographs, γ angle (the angle between the distal femoral axis and the line perpendicular to the distal rear surface of the femoral component) was measured, and the patients were divided into four groups according to the γ angle. The 2011KSSs among groups were compared using the Kruskal-Wallis test. A secondary regression analysis was used to investigate the association between the 2011KSS and γ angle. Results According to the mean and SD of γ angle (γ, 4.0 SD 3.0°), four groups (Extended or minor flexed group, −0.5° ≤ γ < 2.5° (n = 54)), Mild flexed group (2.5° ≤ γ < 5.5° (n = 63)), Moderate flexed group (5.5° ≤ γ < 8.5° (n = 26)), and Excessive flexed group (8.5° ≤ γ (n = 13)) were defined. The Excessive flexed group showed worse 2011KSSs in all subdomains (Symptoms, Satisfaction, Expectations, and Functional activities) than the Mild flexed group. Secondary regression showed a convex upward function, and the scores were highest at γ = 3.0°, 4.0°, and 3.0° in Satisfaction, Expectations, and Functional activities, respectively. Conclusion The groups with a sagittal alignment of the femoral component > 8.5° showed inferior clinical outcomes in 2011KSSs. Secondary regression analyses showed that mild flexion of the femoral component was associated with the highest score. When implanting the Bi-Surface Knee prosthesis surgeons should pay careful attention to avoiding flexing the femoral component extensively during TKA. Our findings may be applicable to other implant designs. Cite this article: Bone Joint J 2020;102-B(6 Supple A):36–42.

Reliable outcomes and survivorship of primary total knee arthroplasty for osteonecrosis of the knee

2019 ◽  
Vol 101-B (11) ◽  
pp. 1356-1361 ◽  
Author(s):  
Brian P. Chalmers ◽  
Kapil G. Mehrotra ◽  
Rafael J. Sierra ◽  
Mark W. Pagnano ◽  
Michael J. Taunton ◽  
...  
Keyword(s):  
Risk Factors ◽  
Total Knee Arthroplasty ◽  
Aseptic Loosening ◽  
Clinical Outcomes ◽  
Knee Arthroplasty ◽  
Primary Total Knee Arthroplasty ◽  
Cox Regression Analysis ◽  
Primary Tkas ◽  
Total Knee ◽  
The Mean

Aims Knee osteonecrosis in advanced stages may lead to joint degeneration. Total knee arthroplasty (TKA) for osteonecrosis has traditionally been associated with suboptimal results. We analyzed outcomes of contemporary TKAs for osteonecrosis, with particular emphasis on: survivorship free from aseptic loosening, any revision, and any reoperation plus the clinical outcomes, complications, and radiological results. Patients and Methods In total, 156 patients undergoing 167 primary TKAs performed for osteonecrosis between 2004 and 2014 at a single institution were reviewed. The mean age at index TKA was 61 years (14 to 93) and the mean body mass index (BMI) was 30 kg/m2 (18 to 51) The mean follow-up was six years (2 to 12). A total of 110 TKAs (66%) were performed for primary osteonecrosis and 57 TKAs (34%) for secondary osteonecrosis. Overall, 15 TKAs (9%) had tibial stems, while 12 TKAs (7%) had femoral stems. Posterior-stabilized designs were used in 147 TKAs (88%) of TKAs. Bivariate Cox regression analysis was conducted to identify risk factors for revision and reoperation. Results Survivorship free from aseptic loosening, any revision, and any reoperation at ten years was 97% (95% confidence interval (CI) 93 to 100), 93% (95% CI 85 to 100), and 82% (95% CI 69 to 93), respectively. No factors, including age, sex, BMI, primary versus secondary osteonecrosis, stem utilization, and constraint, were identified as risk factors for reoperation. Four TKAs (2%) underwent revision, most commonly for tibial aseptic loosening (n = 2). Excluding revisions and reoperations, there was a total of 11 complications (7%), with the most common being a manipulation under anaesthesia (six TKAs, 4%). Mean Knee Society Scores (Knee component) significantly improved from 57 (32 to 87) preoperatively to 91 (49 to 100) postoperatively (p < 0.001). No unrevised TKAs had complete radiolucent lines or radiological evidence of loosening. Conclusion Contemporary cemented TKAs with selective stem utilization for osteonecrosis resulted in durable survivorship, a low complication rate, and reliable improvement in clinical outcomes. Cite this article: Bone Joint J 2019;101-B:1356–1361.

Femoral component malrotation is not correlated with poor clinical outcomes after total knee arthroplasty

2020 ◽  
Vol 28 (12) ◽  
pp. 3879-3887 ◽  
Author(s):  
Katia Corona ◽  
Simone Cerciello ◽  
Michele Vasso ◽  
Giuseppe Toro ◽  
Adriano Braile ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Clinical Outcomes ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
Total Knee

Variation in Optimal Sagittal Alignment of the Femoral Component in Total Knee Arthroplasty

Orthopedics ◽  
2016 ◽  
Vol 40 (2) ◽  
pp. 102-106 ◽  
Author(s):  
Brandon Hood ◽  
Laura Blum ◽  
Sven A. Holcombe ◽  
Stewart C. Wang ◽  
Andrew G. Urquhart ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Femoral Component ◽  
Knee Arthroplasty ◽  
Sagittal Alignment ◽  
Total Knee

scholarly journals Comparison of the Radiologic, Morphometric, and Clinical Outcomes between Kinematically and Mechanically Aligned Total Knee Arthroplasty: A Propensity Matching Study

2021 ◽  
Author(s):  
Tae Woo Kim ◽  
Jae Ik Lee ◽  
Han Gyeol Choi ◽  
Hyun Jin Yoo ◽  
Kyu Tae Kim ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Clinical Outcomes ◽  
Knee Arthroplasty ◽  
Tilt Angle ◽  
Patellar Tilt ◽  
Functional Scores ◽  
Propensity Matching ◽  
Total Knee ◽  
Preoperative Status ◽  
Patellar Tilt Angle

AbstractThe purpose of this study was to compare radiologic, morphometric, and clinical outcomes between kinematically aligned (KA) and mechanically aligned (MA) total knee arthroplasty (TKA) in Korean patients. Overall, 168 patients who underwent primary TKA were retrospectively reviewed, and propensity matching (age, sex, and body mass index) was performed as 1:3 ration (KA TKAs [n = 42]: MA TKAs [n = 126]). Joint-line orientation angle (JLOA), coronal and axial alignments of implants, hip–knee–ankle (HKA) angle, and patellar tilt angle were assessed using full-length standing radiograph, axial computed tomography (CT) scan, and plain radiographs. Morphometric assessment was performed by analyzing the intraoperative measurement of the femoral cut surface and femoral components fitting in five zones. Clinical outcomes more than 2 years of follow-up were evaluated with the Knee Society (KS) knee and functional scores, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores, and the Short-Form Health Survey (SF-36). In radiologic results, JLOA was more parallel to the floor in KA TKAs (KA: medial tilt 0.9 ± 1.5 degrees; MA: lateral tilt 1.7 ± 1.5 degrees, p < 0.05), and patellar tilt angle was closer to preoperative status after KA TKA (KA: 2.0 ± 1.6 degrees; MA;0.3 ± 1.2 degrees, p < 0.05). HKA angle and rotational mismatch were similar between two groups. In morphometric analysis, entire overhang of anterior femoral cutting surface was reduced in KA TKA compared with MA TKA (KA: 11.7 ± 6.2 mm; MA: 14.4 ± 5.9 mm, p < 0.05). However, both of MA and KA TKAs showed underhang in mediolateral dimension without difference. There were no significant differences in clinical scores between two groups. KA TKA showed more parallel JLOA to floor, closer patellar tilt to preoperative status, and better anterior flange fitting that can reproduce more natural knee kinematics compared with MA TKA. Although clinical outcomes assessed by conventional evaluating tools were similar between two groups, further evaluation focusing on the patellofemoral symptoms or unawareness of TKA is necessary to clarify the clinical benefit of KA TKA.

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