• 2D–3D reconstruction
• MRI
• PSI
• Patient-specific instrumentation
• Preoperative planning
• Total knee arthroplasty
• X-ray

• Robot-assisted surgery
• guide plate navigation
• virtual fixtures

• Osteotomy/methods
• Humans
• Robotic Surgical Procedures/methods
• Surgery, Computer-Assisted/methods
• Robotics
• Bone Plates

• evidence-based
• knee arthroplasty
• level of evidence
• methodological
• most-cited
• study metrics

• Arthroplasty, Replacement, Knee/statistics & numerical data
• Arthroplasty, Replacement, Knee/trends
• Humans
• Bibliometrics
• Evidence-Based Medicine
• Periodicals as Topic

• Ankle volume
• Demographics
• Femoral component
• Implant size
• Tibial component
• Total knee arthroplasty

• Humans
• Middle Aged
• Aged
• Arthroplasty, Replacement, Knee/adverse effects
• Arthroplasty, Replacement, Knee/methods
• Retrospective Studies
• Knee Prosthesis
• Knee Joint/diagnostic imaging
• Knee Joint/surgery
• Tibia/surgery

• 3d printing
• additive manufacturing
• custom-made implants
• patient-specific instrumentation (psi)
• total knee arthroplasty (tka)

Over the past years, patient specific instrumentation (PSI) for total knee arthroplasty (TKA) has been implemented and routinely used. No clear answer has been given on its associated cost and cost-effectiveness when compared to conventional instrumentation (CI) for TKA.

To compare the cost and cost-effectiveness of PSI TKA compared to CI TKA.

A literature search was performed in healthcare, economical healthcare, and medical databases (MEDLINE, EMBASE, CINAHL, Web of Science, Cochrane Library, EconLit). It was conducted in April 2021 and again in January 2022. Relevant literature included randomised controlled trials, retrospective studies, prospective studies, observational studies, and case control studies. All studies were assessed on methodological quality. Relevant outcomes included incremental cost-effectiveness ratio, quality-adjusted life years, total costs, imaging costs, production costs, sterilization associated costs, surgery duration costs and readmission rate costs. All eligible studies were assessed for risk of bias. Meta-analysis was performed for outcomes with sufficient data.

Thirty-two studies were included into the systematic review. Two were included in the meta-analysis. 3994 PSI TKAs and 13267 CI TKAs were included in the sample size. The methodological quality of the included studies, based on Consensus on Health Economic Criteria-scores and risk of bias, ranged from average to good. PSI TKA costs less than CI TKA when considering mean operating room time and its associated costs and tray sterilization per patient case. PSI TKA costs more compared to CI TKA when considering imaging and production costs. Considering total costs per patient case, PSI TKA is more expensive in comparison to CI TKA. Meta-analysis comparing total costs for PSI TKA, and CI TKA showed a significant higher cost for PSI TKA.

Cost for PSI and CI TKA can differ when considering distinct aspects of their implementation. Total costs per patient case are increased for PSI TKA when compared to CI TKA.

• Total knee arthroplasty
• Patient specific instrumentation
• Instrumentation for total knee arthroplasty
• Cost-effectiveness
• Systematic review

Patient-specific cutting guides (PSGs) and single-use disposable instrumentation (SUI) have emerged as potential beneficial innovations for total knee arthroplasty. The aim of this study was to evaluate the impact of PSG and SUI for total knee arthroplasty on operating room (OR) and sterilization times.

A monocentric, prospective, interventional, full factorial design study, including 136 patients, compared patient-specific (PSG, n = 68) to conventional cutting guides (n = 68) and SUI (n = 68) to conventional instrumentation (CVI, n = 68). In the OR, we recorded the number of instrument trays, operating time, and room occupancy time. In the central sterile services department, the total sterilization duration was assessed. The primary outcome was operating time and sterilization duration. Secondary outcomes were difference in the number of trays, Oxford Knee Score, and postoperative mechanical axis.

The median operating time was 80 minutes (Q1-Q3: 73-90) and was significantly increased for SUI compared to that for CVI (+5 minutes, P = .0072). The median sterilization duration was 1261 minutes (Q1-Q3: 934-1603). It was significantly in favor of SUI (936 minutes) over CVI (1565 minutes) (+629 minutes, P < .0001). The total number of instrument trays was 404 for 136 patients: 252 for CVI and 152 for SUI (P < .0001) and 189 for PSG and 215 for conventional cutting guides (P = .0006). There was no significant difference in OKS (P = .86) nor in the postoperative alignment which was between 177° and 183° (75% patients, P = .24).

SUI lowers the number of instrument trays and sterilization duration. PSG is not associated with significant OR or sterilization time reduction. The use of SUI could reduce the risk of noncompliance of instrument trays.

• Arthroplasty
• Efficiency
• Patient-specific
• Single-use

• 3D printing
• Additive manufacturing
• Functionally graded parts
• Implants
• Medical applications
• Orthopedics

• TKA
• alignment
• malalignment
• outcomes
• patient-reported outcomes
• total knee arthroplasty

• cost-effect
• cost-utility
• obese
• patient specific instrumentation
• total knee arthroplasty

• Complex total knee arthroplasty
• Custom cutting guides
• Extra-articular deformities
• Patient-specific instrumentation
• Retained hardware

• 3 dimensional printing
• 3D
• Hip arthroplasty
• Knee arthroplasty
• PSI
• Patient specific instrumentation

Total knee arthroplasty (TKA) is most frequently planned using conventional two-dimensional weight-bearing lower limb radiographs and is performed with conventional femoral and tibial cutting guides. Questions have been raised about the accuracy of conventional TKA instrumentation and planning for an anatomically standard or complex joint. Use of computed tomography (CT)-based three-dimensional (3D) templating and patient-specific cutting guides printed in 3D has shown improved postoperative lower limb alignment parameters. This case-control study compared costs and operative times of using CT-based, patient-specific, single-use instruments versus conventional metal instruments for TKA.

In this case-control, retrospective chart review, all TKAs were performed by one senior surgeon, using the F.I.R.S.T. posterior-stabilised knee prosthesis (Symbios, CH), with a similar protocol and identical operating room setup. Group A included 51 TKAs performed with patient-specific cutting guides and conventional metal instruments. Group B included 49 TKAs performed with patient-specific cutting guides and patient-specific, single-use instrumentation. Operation duration, number of instrumentation trays and sterilisation costs were evaluated.

The groups were similar for age, body mass index, hip-knee-ankle angle and operation duration. The mean number of instrumentation trays was 8.0 ± 0.8 for group A (controls) and 5.1 ± 0.9 for group B (p<0.001). The mean sterilisation costs were 380 ± 47 Swiss Francs (CHF) for group A and 243 ± 55 CHF for group B (p<0.001), for a mean cost reduction of 130.50 CHF per intervention in group B. The time interval between two consecutive surgeries was 24 min for group A and 18 min for group B. There were no adverse events or complications, instrument-related or otherwise.

Compared to conventional instrumentation, use of patient-specific, single-use instruments for TKA reduced the number of instrumentation trays by more than one-third and saved 36% in sterilisation costs. If fabrication costs of single-use instruments are included by the company, the total cost is significantly diminished. There was no operative time advantage for single-use instrumentation.

• Disposable instrumentation
• Operative time
• Patient-specific cutting guide
• Patient-specific instrumentation
• Single-use
• Sterilisation cost
• Total knee arthroplasty

Bony resection is the primary step during total knee arthroplasty. The accuracy of bony resection was highly addressed because it was deemed to have a good relationship with mechanical line. Patient-specific instruments (PSI) were invented to copy the bony resection references from the preoperative surgical plan during a total knee arthroplasty (TKA); however, the accuracy still remains controversial. This study was aimed at finding out the accuracy of the bony resection during PSI-assisted TKA.

Forty-two PSI-assisted TKAs (based on full-length leg CT images) were analyzed retrospectively. Resected bones of every patient were given a CT scan, and three-dimensional radiographs were reconstructed. The thickness of each bony resection was measured with the three-dimensional radiographs and recorded. The saw blade thickness (1.27 mm) was added to the measurements, and the results represented intraoperative bone resection thickness. A comparison between intraoperative bone resection thickness and preoperatively planned thickness was conducted. The differences were calculated, and the outliers were defined as >3 mm.

The distal femoral condyle had the most accurate bone cuts with the smallest difference (median, 1.0 mm at the distal medial femoral condyle and 0.8 mm at the distal lateral femoral condyle) and the least outliers (none at the distal medial femoral condyle and 1 (2.4%) at the distal lateral femoral condyle). The tibial plateau came in second (median difference, 0.8 mm at the medial tibial plateau and 1.4 mm at the lateral tibial plateau; outliers, none at the medial tibial plateau and 1 (2.6%) at the lateral tibial plateau). Regardless of whether the threshold was set to >2 mm (14 (17.9%) at the tibial plateau vs. 12 (14.6%) at the distal femoral condyle, p > 0.05) or >3 mm (1 (1.3%) at the tibial plateau vs. 1 (1.2%) at the distal femoral condyle, p > 0.05), the accuracy of tibial plateau osteotomy was similar to that of the distal femoral condyle. Osteotomy accuracy at the posterior femoral condyle and the anterior femoral condyle were the worst. Outliers were up to 6 (15.0%) at the posterior medial femoral condyle, 5 (12.2%) at the posterior lateral femoral condyle, and 6 (15.8%) at the anterior femoral condyle. The percentages of overcut and undercut tended to 50% in most parts except the lateral tibial plateau. At the lateral tibial plateau, the undercut percentage was twice that of the overcut.

The tibial plateau and the distal femoral condyle share a similar accuracy of osteotomy with PSI. PSI have a generally good accuracy during the femur and tibia bone resection in TKA. PSI could be a kind of user-friendly tool which can simplify TKA with good accuracy. Level of Evidence. This is a Level IV case series with no comparison group.

The objective of this experimental study was to develop and evaluate a three-dimensionally printed custom surgical guide system for performing bipolar coxofemoral osteochondral allograft transplantation in dogs. Five cadaver dogs, weighing 20–38 kg were used in the study. Custom surgical guides were designed and three-dimensionally printed to facilitate accurate execution of a surgical plan for bipolar coxofemoral osteochondral allograft transplantation. Guide-assisted technique was compared to freehand technique in each cadaver. Surgical time was recorded and postoperative computed tomography and three-dimensional segmentation was performed. Femoral version and inclination angles, femoral neck length, and gap present at the femoral and acetabular donor-recipient interface was compared between the virtual surgical plan and postoperative outcome for both techniques. One-tailed paired t-test (P < .05) was used for statistical analysis. When compared to free-hand preparation, mean donor femoral preparation time was 10 minutes longer and mean recipient preparation time was 2 minutes longer when using guides (p = 0.011 and p = 0.001, respectively). No difference in acetabular preparation time was noted between groups. Gap volume at the acetabular and femoral donor-recipient interface was not different between groups. Mean difference between the planned and postoperative version angle was 6.2° lower for the guide group when compared to the freehand group (p = 0.025). Mean femoral neck length was 2 mm closer to the plan when using guides than when performing surgery freehand (p = 0.037). Accuracy for femoral angle of inclination was not different between groups. Custom surgical guides warrants consideration in developing bipolar coxofemoral osteochondral allograft transplantation as an alternative surgical technique for managing hip disorders in dogs.

• Allografts
• Animals
• Bone Transplantation/methods
• Dogs
• Femur/surgery
• Printing, Three-Dimensional
• Surgery, Computer-Assisted

Accurate sizing is critical for the overall success of a total knee arthroplasty (TKA). This study's primary purpose was to investigate the ability to predict the tibial and femoral component size in a single implant system from patient demographics and anthropometric data. A secondary goal was to compare the predicted tibial and femoral component sizes from our statistical model with a previously validated electronic application used to predict the implant size.

A consecutive series of 484 patients undergoing a primary TKA at a single institution was reviewed. Data on height, weight, body mass index, sex, age, and component size were collected. A proportional odds model was developed to predict tibial and femoral component sizes. The relationship between the proportional odds model predictions was also compared with the component sizes determined by the Arthroplasty Size Predictor electronic application.

Weight, height, and sex predicted the implanted component size with an accuracy of 54.0% (n = 247/484) for the tibia and 51.1% (n = 231/484) for the femur. The accuracy improved to 94.4% (n = 457/484) for the tibia and 93.4% (n = 452/484) for the femur within ±1 component size. Our data are highly correlated to the Arthroplasty Size Predictor for the predicted tibial component size (ρ = 0.91, P < .001) and femoral component size (ρ = 0.89, P < .001).

Our novel templating model may improve operative efficiency for a single TKA system. Our findings have a high concordance with a widely available electronic application used to predict implant sizes for a variety of TKA systems.

• Anthropometric
• Arthritis
• Frame size
• Knee
• Templating
• Total knee arthroplasty

We present a case report of a patient with osteopetrosis and refractory bilateral knees osteoarthritis who underwent bilateral total knee arthroplasties (TKAs). After conservative management has failed, surgical treatment with arthroplasty is an excellent alternative with satisfactory outcomes. TKA in patients with osteopetrosis has only been described in 6 other case studies, none of which underwent bilateral TKA. To perform this procedure, additional attention should be directed toward the presurgical planning because of the amplified difficulty of the procedure and the altered bone biology that increases the risks of intraoperative fractures and markedly extends the time of surgery. This report describes a case of osteopetrosis with refractory osteoarthritis managed with bilateral TKA, the surgical technique and special considerations, complications, and future recommendations.

• Arthroplasty
• Osteoarthritis
• Osteoclast
• Osteopetrosis
• Periprosthetic fracture

• 3d printing
• Anatomic models
• Cost-savings
• Personalized medicine
• Radiology
• Surgical guides
• Three-dimensional printing

• Humans
• Models, Anatomic
• Operating Rooms
• Orthopedics
• Printing, Three-Dimensional
• Surgery, Oral

• T32 EB021955 NIBIB NIH HHS

• accelerometry
• arthroplasty
• computer-assisted
• knee
• replacement
• surgery

• Isolated knee exercise
• Joint biomechanics
• Surface kinematics
• Three-dimensional fluoroscopy

• Aged
• Arthroplasty, Replacement, Knee
• Biomechanical Phenomena
• Female
• Femur/physiopathology
• Fluoroscopy
• Humans
• Image Processing, Computer-Assisted
• Imaging, Three-Dimensional
• Knee/physiopathology
• Knee Joint/physiopathology
• Knee Prosthesis
• Male
• Middle Aged
• Minimally Invasive Surgical Procedures
• Osteoarthritis, Knee/diagnostic imaging
• Prosthesis Design
• Range of Motion, Articular
• Reproducibility of Results
• Weight-Bearing

• computer-assisted total joint arthroplasty
• imaging
• incidental finding(s)
• total hip arthroplasty
• total knee arthroplasty

The purpose of this study was to compare restoration of mechanical limb alignment and three-dimensional component-positioning between conventional and patient-specific instrumentation in total knee arthroplasty.

Radiographic data of patients undergoing mobile-bearing total knee arthroplasty (n = 1257), using either conventional (n = 442) or patient-specific instrumentation (n = 812), were analyzed. To evaluate accuracy of axis restoration and 3D-component-positioning between conventional and patient-specific instrumentation, absolute deviations from the targeted neutral mechanical limb alignment and planned implant positions were determined. Measurements were performed on standardized coronal long-leg and sagittal knee radiographs. CT-scans were evaluated for accuracy of axial femoral implant rotation. Outliers were defined as deviations from the targeted neutral mechanical axis of > ± 3° or from the intraoperative component-positioning goals of > ± 2°. Deviations greater than ± 5° from set targets were considered to be severe outliers.

Deviations from a neutral mechanical axis (conventional instrumentation: 2.3°± 1.7° vs. patient-specific instrumentation: 1.7°± 1.2°; p < 0.001) and numbers of outliers (conventional instrumentation: 25.8% vs. patient-specific instrumentation: 10.1%; p < 0.001) were significantly lower in the patient-specific instrumentation group. Significantly lower mean deviations and less outliers were detected regarding 3D-component-positioning in the patient-specific instrumentation compared to the conventional instrumentation group (all p < 0.05).

Patient-specific instrumentation prevented from severe limb malalignment and component-positioning outliers (> ± 5° deviation). Use of patient-specific instrumentation proved to be superior to conventional instrumentation in achieving more accurate limb alignment and 3D-component positioning, particularly regarding femoral component rotation. Furthermore, the use of patient-specific instrumentation successfully prevented severe (> 5° deviation) outliers.

• Accuracy
• Outliers
• Patient-specific instrumentation
• Three-dimensional component position
• Total knee arthroplasty

• computer navigation
• extra-articular deformity
• mechanical axis alignment
• total knee arthroplasty

Patient-specific 3-D printing cutting blocks (PSI) have been used instead of traditional intramedullary cutting guides. We hypothesized that PSI would lead to significantly decreased operating room (OR) time and significant cost savings to our institution with noninferior radiographic outcomes and no difference in expected vs actual implant size when compared with standard referencing (SR).

Patients who had undergone total ankle replacements at our institution from 2013 through 2016 were included in the study. Associations between demographic variables and postoperative alignment in the SR vs PSI group were calculated using the Wilcoxon rank-sum test and the intraclass correlation coefficient. The cost of the operation was calculated using both an institutionally based fixed cost of OR time and using Time Driven Activity Based Cost (TDABC) accounting. A total of 43 patients were included in the study, 13 in the SR group and 30 in the PSI group.

Operative time (168 vs 137 minutes) and tourniquet time (123 vs 113 minutes) were significantly lower in the PSI vs the SR group. PSI predictions were accurate 100% of the time for tibial components and 83% of the time for talar components. Average costs of TAA using PSI were significantly reduced by $7597.00 when using traditional OR accounting, whereas PSI was $836.00 more expensive on average using TDABC accounting.

Further research is needed to determine the cost-effectiveness of PSI vs SR in TAA; however, it does appear to save time intraoperatively. The long-term effect on clinical outcomes requires further study.

Level III, case-control study.

• cost-effectiveness
• patient-specific instrumentation
• standard referencing
• total ankle arthroplasty
• value-based care

• Aged
• Arthroplasty, Replacement, Knee/adverse effects
• Arthroplasty, Replacement, Knee/instrumentation
• Blood Transfusion
• Female
• Hemoglobins/metabolism
• Humans
• Length of Stay
• Male
• Operative Time
• Patient Discharge
• Postoperative Complications/etiology
• Postoperative Period
• Pulmonary Embolism/etiology
• Risk Factors
• Venous Thrombosis/etiology

• efficiency and economic benefits
• postdischarge complications
• single-use instruments
• sterilization
• total knee arthroplasty

• demographics
• electronic application
• preoperative planning
• templating
• total knee arthroplasty

• alignment
• blood loss
• patient-specific instrumentation
• rotation
• time
• total knee arthroplasty

• Aged
• Arthroplasty, Replacement, Knee/instrumentation
• Blood Loss, Surgical/statistics & numerical data
• Female
• Femur/surgery
• Humans
• Intraoperative Complications
• Knee Joint/surgery
• Knee Prosthesis
• Male
• Middle Aged
• Operative Time
• Precision Medicine
• Prospective Studies
• Rotation
• Surgery, Computer-Assisted
• Tibia/surgery
• Tomography, X-Ray Computed

• Arthroplasty
• Artroplastia
• Instrumentación
• Instruments
• Knee
• Rodilla
• Tiempo
• Time

• Aged
• Arthroplasty, Replacement, Knee/instrumentation
• Arthroplasty, Replacement, Knee/methods
• Female
• Humans
• Knee Prosthesis
• Male
• Middle Aged
• Operative Time
• Osteoarthritis, Knee/surgery
• Retrospective Studies
• Surgery, Computer-Assisted/instrumentation
• Surgery, Computer-Assisted/methods
• Treatment Outcome

• Patient-specific instrumentation (PSI)
• knee
• total knee arthroplasty (TKA)
• total knee replacement (TKR)

To investigate whether patient-specific instrumentation (PSI) and single-use instrumentation (SUI) improve operating room efficiency in terms of time and cost to the healthcare provider over conventional/reusable instrumentation (CVR) when performing total knee arthroplasty (TKA).

Patients requiring TKA were randomised into one of four surgical groups: CVR, CVS (conventional/SUI), PSR (PSI/reusable) and PSS (PSI/SUI). All surgical procedures were video recorded to determine specific surgical time intervals. Other variables reported included the number of instrument trays used, missing equipment, direct instrument costs and the weight of the instruments the staff had to handle. Oxford Knee Score (OKS), estimated blood loss and lengths of hospital stay were also recorded as markers of patient experience.

PSR was significantly quicker in all the recorded time intervals, used less trays, experienced less missing equipment and resulted in lower blood loss and shorter hospital stays. SUI reported significantly slower operating room times and resulted in higher blood loss, but SUI was 88% lighter and 20% cheaper on average when compared with their reusable counterparts. Despite the economic advantages of PSI and SUI, the patients who reported greatest improvements in OKS were those allocated to the CVR group, but no clinically meaningful difference in OKS was found at any time point.

PSI and SUI for TKA have the potential of reducing operating room times over conventional, reusable sets. This reduction will benefit theatre personnel ergonomically, while presenting the healthcare provider with potential cost-saving benefits in terms of reduced sterilisation costs and surgical times.

• cost-effectiveness
• qualitative research
• randomised controlled trial
• surgery

• Patient-specific instrumentation
• Tibial cut accuracy
• Total knee arthroplasty

• 3D-printed anatomic templates
• customized cutting blocks
• implant complications
• pelvic reconstruction
• pelvic tumor

• Alignment
• Patient-specific instrumentation, PSI
• Standard instrumentation, SI
• Total knee arthroplasty, TKA

• extramedullary
• femur
• intramedullary
• meta-analysis
• total knee arthroplasty

• Alignment
• Computer navigation
• Knee
• Low-volume
• Patient-specific TKA
• Total knee Arthroplasty