Alignment in total knee arthroplasty — A comparison of patient-specific implants with the conventional technique

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.

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The Use of Customized Total Knee Arthroplasty Implants to Increase Efficiency in the Operating Room and Improve Patient Outc

Medical Research Archives ◽

10.18103/mra.v9i7.2474 ◽

2021 ◽

Vol 9 (7) ◽

Author(s):

Raj Sinha

Keyword(s):

Total Knee Arthroplasty ◽

Operating Room ◽

Knee Arthroplasty ◽

Patient Reported Outcomes ◽

Knee Kinematics ◽

Anatomic Reconstruction ◽

Patient Specific ◽

Patient Specific Implants ◽

Patient Reported ◽

Total Knee

Operating room efficiency during surgical procedures saves time and money, reduces waste of hospital resources and improves staff morale. Surgical efficiency in orthopaedic surgery can decrease medical complications, such as periprosthetic infection and venous thromboembolic disease, but also must be associated with equivalent or improved longer term patient reported outcomes. In total knee arthroplasty, the instruments used for bone preparation are excessive in number, are frequently redundant, and rely upon achieving average alignment and rotational parameters. As a result, approximately 15-25% of patients report dissatisfaction with their knee reconstructions. Patient specific customized instruments and patient specific implants improve intraoperative efficiency by reducing surgical steps and eliminating redundant steps. Further, because the customized instruments and implants provide anatomic reconstruction of each individual patient, patient reported outcomes have been higher. Additional demonstrated benefits include improved knee alignment and knee kinematics. This paper addresses the various sources of operating room inefficiency, provides suggestions to overcome them, and discusses the first decade of experience with the customized guides for customized implants as a method to improve efficiency.

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

The Journal of Knee Surgery ◽

10.1055/s-0040-1713353 ◽

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.

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