Patient-specific design for articular surface conformity to preserve normal knee mechanics in posterior stabilized total knee arthroplasty

2018 ◽  
Vol 29 (4) ◽  
pp. 401-414 ◽  
Author(s):  
Yong-Gon Koh ◽  
Juhyun Son ◽  
Oh-Ryong Kwon ◽  
Sae Kwang Kwon ◽  
Kyoung-Tak Kang
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Articular Surface ◽  
Patient Specific ◽  
Posterior Stabilized ◽  
Specific Design ◽  
Normal Knee ◽  
Knee Mechanics ◽  
Total Knee

Can a gait-dependent model predict wear on retrieved total knee arthroplasty components?

2020 ◽  
Vol 102-B (6_Supple_A) ◽  
pp. 129-137
Author(s):  
Christopher B. Knowlton ◽  
Hannah J. Lundberg ◽  
Markus A. Wimmer ◽  
Joshua J. Jacobs
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Patient Specific ◽  
Lateral Side ◽  
Volumetric Wear ◽  
Wear Rates ◽  
Medial Side ◽  
Knee Mechanics ◽  
Gait Mechanics ◽  
Total Knee

Aims A retrospective longitudinal study was conducted to compare directly volumetric wear of retrieved polyethylene inserts to predicted volumetric wear modelled from individual gait mechanics of total knee arthroplasty (TKA) patients. Methods In total, 11 retrieved polyethylene tibial inserts were matched with gait analysis testing performed on those patients. Volumetric wear on the articular surfaces was measured using a laser coordinate measure machine and autonomous reconstruction. Knee kinematics and kinetics from individual gait trials drove computational models to calculate medial and lateral tibiofemoral contact paths and forces. Sliding distance along the contact path, normal forces and implantation time were used as inputs to Archard’s equation of wear to predict volumetric wear from gait mechanics. Measured and modelled wear were compared for each component. Results Volumetric wear rates on eight non-delaminated components measured 15.9 mm3/year (standard error (SE) ± 7.7) on the total part, 11.4 mm3/year (SE ± 6.4) on the medial side and 4.4 (SE ± 2.6) mm3/year on the lateral side. Volumetric wear rates modelled from patient gait mechanics predicted 16.4 mm3/year (SE 2.4) on the total part, 11.7 mm3/year (SE 2.1) on the medial side and 4.7 mm3/year (SE 0.4) on the lateral side. Measured and modelled wear volumes correlated significantly on the total part (p = 0.017) and the medial side (p = 0.012) but not on the lateral side (p = 0.154). Conclusion In the absence of delamination, patient-specific knee mechanics during gait directly affect wear of the tibial component in TKA. Cite this article: Bone Joint J 2020;102-B(6 Supple A):129–137.

scholarly journals Early outcomes of patient-specific posterior stabilized total knee arthroplasty implants

2019 ◽  
Vol 16 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Benjamin Wheatley ◽  
Kyle Nappo ◽  
Jesse Fisch ◽  
Laura Rego ◽  
Molly Shay ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Patient Specific ◽  
Posterior Stabilized ◽  
Total Knee

scholarly journals Bone Preservation in a Novel Patient Specific Total Knee Replacement.

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
William B. Kurtz ◽  
John E. Slamin ◽  
Scott W. Doody
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Revision Surgery ◽  
Patient Specific ◽  
Total Knee Arthroplasties ◽  
Posterior Stabilized ◽  
Patient Specific Implants ◽  
Bone Preservation ◽  
Total Knee ◽  
Bone Remains

Background: The volume of total knee arthroplasty procedures is growing rapidly and, correspondingly, it is expected that the volume of revision procedures will grow rapidly as well.  Revision surgery is most successful when adequate bone remains on both the tibia and femur to allow for the least invasive revision.  We hypothesized that total knee arthroplasty with a patient-specific implant would result in significant bone preservation as compared to standard total knee arthroplasty with “off-the-shelf” implants. Methods: We evaluated 100 total knee arthroplasties which utilized patient-specific implants, versus 37 standard posterior stabilized and 32 standard posterior cruciate retaining total knee arthroplasties.  Bone resection was quantified utilizing intra-operative measurements of actual resected bone. Additionally we performed a virtual, CAD-based analysis of resections via CT imaging on 15 knees.  Findings: We found that patients had significantly less bone resected in all zones measured, on both the femur and tibia, when patient-specific implants with patient-specific jigs were used.  When assessed volumetrically with CAD imaging, standard implants resected 12-49% more bone than did patient-specific implants, depending on the size of the implant utilized. Interpretations: Utilizing patient-specific implants in total knee arthroplasty results in significant bone sparing as compared to standard total knee arthroplasty. This has the potential for less invasive revision surgery in the future, possibly obviating the need for dedicated revision implants or augments and other bone substituting devices.

Higher Component Malposition Rates with Patient-Specific Cruciate Retaining TKA than Contemporary Posterior Stabilized TKA

2020 ◽  
Author(s):  
Prakrit Kumar ◽  
Jacob Elfrink ◽  
James P. Daniels ◽  
Ajay Aggarwal ◽  
James A. Keeney
Keyword(s):  
Total Knee Arthroplasty ◽  
Surgical Technique ◽  
Knee Arthroplasty ◽  
Demographic Characteristics ◽  
Patient Specific ◽  
Posterior Stabilized ◽  
Component Alignment ◽  
Cruciate Retaining ◽  
Femoral Notching ◽  
Total Knee

AbstractCustomized individually manufactured total knee arthroplasty (CIM-TKA) was developed to improve kinematic total knee arthroplasty (TKA) performance. Component placement accuracy may influence the success of CIM-TKA designs. We performed this study to compare radiographic component alignment and revision rates of a cruciate retaining (CR) CIM-TKA and a contemporary posterior stabilized TKA (PS-TKA). After obtaining Institutional Review Board approval, we identified 94 CR CIM-TKAs (76 patients) and 91 PS-TKAs (82 patients) performed between July 1, 2013 and December 31, 2014 with a minimum 2-year follow-up (mean 41.1 months, range 24–59 months). We performed a retrospective electronic medical record review to identify patient demographic characteristics and revision procedures performed. Postoperative plain radiographs were reviewed to assess component alignment including cruciate ligament imbalance, femoral overhang, and femoral notching. Demographic characteristics, component malalignment, and revision surgery rates were assessed using a student's t-test or two-tailed Fisher's exact test, with a p-value < 0.05 designating significance. Technical errors were more commonly identified with CR CIM-TKA (29.8 vs. 9.9%, p < 0.001), including higher rates of tibiofemoral instability (13.8 vs. 1.1%, p < 0.01), femoral notching (12.8 vs. 3.3%, p = 0.03), and patellofemoral malalignment (20.2 vs. 7.7%, p = 0.02). CR CIM-TKA had more frequent coronal plane malposition (26.6 vs. 9.9%, p < 0.01) or sagittal plane reconstruction > 3 degrees outside of an optimized range (20.2 vs. 9.9%, p = 0.06). Aseptic revisions occurred more frequently with the CR CIM-TKA design (9.6 vs. 3.3%, p = 0.13). Demographic characteristics were not significantly different between the treatment groups. CR CIM-TKA may improve kinematic performance for patients undergoing knee replacement surgery. However, our study observations suggest that careful attention to surgical technique is important for optimizing implant survivorship with the CR CIM-TKA design. Additional study is needed to determine whether higher revision rates identified during this study are related to patient selection, surgical technique, or implant design.

Revision Total Knee Arthroplasty Using a Constrained Condylar Knee Prosthesis Combined with a Posterior Stabilized Articular Surface

2017 ◽  
Vol 31 (02) ◽  
pp. 197-201
Author(s):  
Shang-Wen Tsai ◽  
Cheng-Fong Chen ◽  
Po-Kuei Wu ◽  
Chao-Ming Chen ◽  
Wei-Ming Chen
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Knee Prosthesis ◽  
Articular Surface ◽  
Womac Score ◽  
Revision Total Knee Arthroplasty ◽  
Functional Score ◽  
Posterior Stabilized ◽  
Total Knee ◽  
The Mean

AbstractIntraoperative assessment of valgus–varus stability is crucial for choosing articular surfaces with different levels of constraint. Legacy constrained condylar knee (CCK) prostheses are readily available to assemble and use with a CCK articular surface or a posterior stabilized (PS) articular surface in revision knee arthroplasty surgeries. We wanted to validate outcomes of revision total knee arthroplasty (TKA) using legacy CCK prostheses combined with a PS articular surface. Thirty-seven patients were enrolled and followed up for more than 2 years. Range of motion (ROM), the Knee Society score (KSS), the Knee Society functional score (KSS-F), and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were used to evaluate outcomes. Follow-up was a mean of 86.5 months (range: 28–152 months). The mean age of the participants was 69.8 years (range: 31–86 years). The mean ROM was 110.5 degrees, the KSS was 86.2 points, the KSS-F was 68.3 points, and the WOMAC score was 22.6 points. Seven participants had implant failures: five because of delayed infections and two because of posterior dislocations. In conclusion, revision TKA using a CCK prosthesis combined with a PS articular surface might provide satisfactory mid-term outcomes. Delayed infection was the most common cause of implant failure. Dislocation might occur in middle-old or older patients despite careful intraoperative examination of valgus–varus stability, extension–flexion gap balancing, and signs of recurvatum.

Total Hospital Costs and Readmission Rate of Patient-Specific Instrument in Total Knee Arthroplasty Patients

2020 ◽  
Author(s):  
Stephen Thomas ◽  
Ankur Patel ◽  
Corey Patrick ◽  
Gary Delhougne
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Hospital Cost ◽  
Readmission Rate ◽  
Hospital Costs ◽  
Patient Specific ◽  
P Value ◽  
Total Hospital Cost ◽  
Total Hospital ◽  
Total Knee

AbstractDespite advancements in surgical technique and component design, implant loosening, stiffness, and instability remain leading causes of total knee arthroplasty (TKA) failure. Patient-specific instruments (PSI) aid in surgical precision and in implant positioning and ultimately reduce readmissions and revisions in TKA. The objective of the study was to evaluate total hospital cost and readmission rate at 30, 60, 90, and 365 days in PSI-guided TKA patients. We retrospectively reviewed patients who underwent a primary TKA for osteoarthritis from the Premier Perspective Database between 2014 and 2017 Q2. TKA with PSI patients were identified using appropriate keywords from billing records and compared against patients without PSI. Patients were excluded if they were < 21 years of age; outpatient hospital discharges; evidence of revision TKA; bilateral TKA in same discharge or different discharges. 1:1 propensity score matching was used to control patients, hospital, and clinical characteristics. Generalized Estimating Equation model with appropriate distribution and link function were used to estimate hospital related cost while logistic regression models were used to estimate 30, 60, and 90 days and 1-year readmission rate. The study matched 3,358 TKAs with PSI with TKA without PSI patients. Mean total hospital costs were statistically significantly (p < 0.0001) lower for TKA with PSI ($14,910; 95% confidence interval [CI]: $14,735–$15,087) than TKA without PSI patients ($16,018; 95% CI: $15,826–$16,212). TKA with PSI patients were 31% (odds ratio [OR]: 0.69; 95% CI: 0.51–0.95; p-value = 0.0218) less likely to be readmitted at 30 days; 35% (OR: 0.65; 95% CI: 0.50–0.86; p-value = 0.0022) less likely to be readmitted at 60 days; 32% (OR: 0.68; 95% CI: 0.53–0.88; p-value = 0.0031) less likely to be readmitted at 90 days; 28% (OR: 0.72; 95% CI: 0.60–0.86; p-value = 0.0004) less likely to be readmitted at 365 days than TKA without PSI patients. Hospitals and health care professionals can use retrospective real-world data to make informed decisions on using PSI to reduce hospital cost and readmission rate, and improve outcomes in TKA patients.

Sign in / Sign up

Export Citation Format

Share Document