• Complex primary total knee arthroplasty
• Constrained condylar knee
• Patient-specific instrumentation
• Post-traumatic arthritis
• Valgus deformity

• Humans
• Retrospective Studies
• Arthroplasty, Replacement, Knee/methods
• Arthroplasty, Replacement, Knee/instrumentation
• Male
• Female
• Printing, Three-Dimensional
• Middle Aged
• Aged
• Knee Prosthesis
• Knee Joint/surgery
• Knee Joint/diagnostic imaging
• Treatment Outcome
• Knee Injuries/complications
• Knee Injuries/surgery
• Prosthesis Design
• Osteoarthritis, Knee/surgery
• Osteoarthritis, Knee/etiology
• Postoperative Complications/epidemiology
• Arthritis/surgery
• Arthritis/etiology
• Adult
• Aged, 80 and over

• 2023MS011 Nansha District livelihood Science and Technology Program of Guangzhou City

• 3D printing
• In-hospital 3D printing
• PSI
• Patient-specific instrumentation
• TKA
• Total knee arthroplasty

• Individualized alignment
• Patient specific instrumentation
• Personalized medicine
• Robotics
• Total knee replacement

• Humans
• Arthroplasty, Replacement, Knee/methods
• Arthroplasty, Replacement, Knee/instrumentation
• Arthroplasty, Replacement, Knee/trends
• Precision Medicine/methods
• Precision Medicine/trends
• Surgery, Computer-Assisted/trends
• Surgery, Computer-Assisted/methods
• Knee Prosthesis
• Prosthesis Design
• Robotic Surgical Procedures/trends
• Biomechanical Phenomena
• Imaging, Three-Dimensional

• biomechanical loading
• malalignment
• posterior tibial slope
• tibial insert
• total knee arthroplasty

• knee
• patient-specific instrument
• surgical time
• total knee arthroplasty

• Arthroplasty, Replacement, Knee
• Humans
• Bibliometrics
• Periodicals as Topic/statistics & numerical data

• 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

• Humans
• Arthroplasty, Replacement, Knee/instrumentation
• Arthroplasty, Replacement, Knee/methods
• Male
• Female
• Aged
• Reoperation/statistics & numerical data
• Follow-Up Studies
• Knee Prosthesis
• Prospective Studies
• Middle Aged
• Prosthesis Failure
• Patient Reported Outcome Measures
• Retrospective Studies
• Treatment Outcome
• Aged, 80 and over

• Computer-assisted surgery
• Kinematic alignment
• Patient-specific instrument
• Total knee arthroplasty

• Humans
• Arthroplasty, Replacement, Knee/methods
• Knee Joint/surgery
• Femur/diagnostic imaging
• Femur/surgery
• Knee Prosthesis
• Osteoarthritis, Knee/surgery
• Biomechanical Phenomena

• Konyang University

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

• Animals
• Dogs
• Arthroplasty, Replacement, Knee/instrumentation
• Arthroplasty, Replacement, Knee/veterinary
• Femur/surgery
• Knee Joint/surgery
• Printing, Three-Dimensional
• Tibia/surgery
• Random Allocation
• Cadaver

• Humans
• Arthroplasty, Replacement, Knee/methods
• Reoperation
• Surgery, Computer-Assisted
• Knee Prosthesis
• Knee Joint/surgery
• Treatment Outcome

• 3D Printing
• biomaterials
• biomechanics
• bone
• reconstruction
• tissue engineering

• 3D-printed patient-specific guides
• femoral neck osteotomy
• total hip arthroplasty

• 3D-printing
• Additive manufacturing
• Computer assisted planning
• Corrective osteotomy
• Lower extremity
• Malunion

• Zimmer-biomet
• alignment
• customized cutting guides
• functional outcome
• patient-specific instrumentation
• total knee arthroplasty

• Outcome
• Survival
• Tibial component
• Total knee arthroplasty
• Total knee replacement
• Varus alignment

• Arthroplasty, Replacement, Knee
• Case-Control Studies
• Humans
• Knee Joint/surgery
• Knee Prosthesis
• Osteoarthritis, Knee/surgery
• Retrospective Studies

• arthroplasty
• computer navigation
• knee
• osteoarthritis
• replacement
• revision surgery
• surgical navigation
• survivorship
• total knee replacement

• PSI
• TKR
• X-ray based PSI
• Xray-based 3D reconstruction

• arthritis and joint disease
• comorbid conditions
• diagnostic & therapeutic techniques
• forefoot-toe-midfoot
• implant arthroplasty
• implants
• joint replacement
• new technology assessment
• practice management

• Component positioning
• Patient-specific instrumentation
• Patient-specific instruments
• Single-use instruments
• Total knee arthroplasty

The purpose of the study was to develop a deep learning network for estimating and constructing highly accurate 3D bone models directly from actual X-ray images and to verify its accuracy. The data used were 173 computed tomography (CT) images and 105 actual X-ray images of a healthy wrist joint. To compensate for the small size of the dataset, digitally reconstructed radiography (DRR) images generated from CT were used as training data instead of actual X-ray images. The DRR-like images were generated from actual X-ray images in the test and adapted to the network, and high-accuracy estimation of a 3D bone model from a small data set was possible. The 3D shape of the radius and ulna were estimated from actual X-ray images with accuracies of 1.05 ± 0.36 and 1.45 ± 0.41 mm, respectively.

• Knee
• Osteoarthritis
• Total knee arthroplasty

• 3-D printing
• Additive manufacturing
• Biomaterial
• Biomedical
• Lithography (deposition)
• Polymer

• Functional outcomes
• Lower limb alignment
• Patient-reported outcome measures
• Patient-specific instrumentation
• Total knee arthroplasty

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

• Patient-specific instrumentation
• alignment
• radiographs
• total knee arthroplasty
• x-ray

Expectations for limb length differences after TKA are important for patient perception and outcomes. Limb length discrepancies may occur due to postoperative leg length increases, which can lead to decreased patient functionality and satisfaction and even possible litigation. The purpose of this study is to examine the frequency and extent of limb lengthening among various preoperative deformities and between two different implant systems.

Preoperative and postoperative full-length standing radiographs were obtained between August 2018 and August 2019 to measure mechanical axis and limb length of operative limbs. Demographic information such as age, sex, and BMI was also collected. Patients were grouped into categories for pre- and postoperative subgroup analysis: valgus, varus, customized implant, and conventional implant. Regression analysis was performed to evaluate significant relationships.

Of the 121 primary TKAs analyzed, 62% of the knees showed an increase in limb length after TKA, with an average lengthening of 5.32 mm. Preoperative varus alignment was associated with a mean lengthening of 3.14 mm, while preoperative valgus alignment was associated with a mean lengthening of 16.2 mm. Overall, there were no statistically significant differences in limb lengths pre- and postoperatively (p = 0.23) and no significant changes in limb length for any subgroup. Further, no variables were associated with limb length changes (p = 0.49), including the use of customized implants (p = 0.2).

Limb lengthening after TKA is common and, on average, occurs more significantly in valgus knees. No significant difference in limb lengthening could be demonstrated using customized over conventional implants. Preoperative counseling is important to manage patient expectations.

Acetabular fractures pose diagnostic and surgical challenges. They are classified using the Judet-Letournel system, which is based solely on X-ray. However, computed tomography (CT) imaging is now more widely utilized in diagnosing these injuries. The emergence of 3-dimensional (3-D) printing technology in varying orthopedic fields has provided surgeons a solid model that improves their spatial understanding of complex fractures and ability to plan pre-operatively.

To evaluate the reliability of the Judet-Letournel classification system of acetabular fractures, when using either CT imaging or 3-D printed models.

Seven patients with acetabular fractures underwent pelvic CT imaging, which was then used to create solid, 3-D printed models. Eighteen orthopaedic trauma surgeons responded to questionnaires regarding fracture classification and preferred surgical approach. The same questionnaire was completed using only CT imaging, and two weeks later, using only 3-D printed models. The inter- and intra-observer agreement rates were then analyzed.

Inter-observer agreement rates based on CT imaging or 3-D printed models were moderate for fracture classification: κ = 0.44, κ = 0.55, respectively (P < 0.001) and fair for preferred surgical approach: κ = 0.34, κ = 0.29, respectively (P < 0.005). Intra-observer agreement rates for fracture classification and preferred surgical approach comparing CT imaging or 3-D printed models were moderate: κ = 0.48, κ = 0.41, respectively. No significant difference in intra-observer agreement was detected when comparing orthopedic pelvic specialists to general orthopedic traumatologists.

The Judet-Letournel classification demonstrated only moderate rates of agreement. The use of 3-D printed models increased the inter-observer agreement rates with respect to fracture classification, but decreased it with respect to the preferred surgical approach. This study highlights the role of 3-D printed models in acetabular fractures by improving spatial understanding of these complex injuries, thus providing more reliable fracture diagnoses and alternative viewpoints for pre-operative planning.

• Acetabulum
• Pelvic trauma
• Acetabular fracture
• Three-dimensional printing
• Three-dimensional reconstruction
• Judet-Letournel

• Arthroplasty
• Knee
• Osteoarthritis

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

Total knee arthroplasty (TKA) is an effective treatment for severe osteoarthritis. Despite good survival rates, up to 20% of TKA patients remain dissatisfied. Recently, promising new technologies have been developed in knee arthroplasty, and could improve the functional outcomes. The aim of this paper was to present some new technologies in TKA, their current concepts, their advantages, and limitations. The patient-specific instrumentations can allow an improvement of implant positioning and limb alignment, but no difference is found for functional outcomes. The customized implants are conceived to reproduce the native knee anatomy and to reproduce its biomechanics. The sensors have to aim to give objective data on ligaments balancing during TKA. Few studies are published on the results at mid-term of these two devices currently. The accelerometers are smart tools developed to improve the TKA alignment. Their benefits remain yet controversial. The robotic-assisted systems allow an accurate and reproducible bone preparation due to a robotic interface, with a 3D surgical planning, based on preoperative 3D imaging or not. This promising system, nevertheless, has some limits. The new technologies in TKA are very attractive and have constantly evolved. Nevertheless, some limitations persist and could be improved by artificial intelligence and predictive modeling.

• accelerometers
• customized implants
• knee arthroplasty
• new technologies
• patient-specific instrumentation
• robotic-assisted surgery
• sensors

To quantify the effects of the systematic internal and external femoral component rotations and tibial slope on the medial and lateral tibiofemoral gaps in total knee endoprostheses.

Nineteen knee cadaver specimens with an intact ligament apparatus were fixed in a custom frame, facilitating physiological flexion motion. Virtual total knee arthroplasty (TKA) was performed on three-dimensional models obtained from computed tomography ​scans (0° and 90° flexions) with systematically altered femur rotations and tibial slopes.

Both the femur rotation and the tibial slope influenced the medial and lateral tibiofemoral flexion gaps (p ​< ​0.001), and the effects differed between the medial and lateral sides (p ​< ​0.001). The medial tibiofemoral flexion gap increased by 2.90 ​± ​0.34 ​mm and decreased by 2.66 ​± ​0.26 ​mm for 7° external and internal femur component rotations, respectively (both with p ​< ​0.001). The lateral tibiofemoral flexion gap decreased by 3.11 ​± ​0.31 ​mm and increased by 3.29 ​± ​0.33 ​mm for 7° external and internal femur component rotations, respectively (both with p ​< ​0.001).

For established surgical methods, we recommend a neutral femur rotation for a 0° tibial slope and a 3° external femur rotation for a tibial slope of 9–10°. The translational potential of this research shows that while the rotation of the femoral component in extension has no effect on the gap size, owing to the axis of rotation being perpendicular to the gap, for a 90° flexion, we not only observe differences in the gap size between the medial and lateral ​but also unequal differences on either side depending on the inward or outward rotation. The main reason for this is the position of the axis of rotation, which is not precisely half way between the lateral and medial contact points. The results show that rotation of the femoral component always creates an unbalanced flexion gap.

The article points out the differences in the tibiofemoral gap in total knee endoprostheses due to the systematic internal and external femoral component rotation. While in lower leg extension there are no differences seen, in 90° knee-flexion there are unequal differences within the medial and lateral compartment that show a mathematical relationship towards the femoral compartment rotation which needs to be intraoperatively considered.

• Physiological knee motion
• Surgical technique
• Total knee arthroplasty

• Arthroplasty
• Knee
• Outcomes
• Trumatch

Total knee replacement (TKR) is a surgical treatment for final stage gonarthrosis. The lifespan of the prosthetic implants used in TKR surgery is a major interest for the orthopaedic research community.Previously, proper implant alignment of the implants has been advocated for longevity of the TKR surgery. Recently, patient-specific (PSI) instruments have been proposed to improve the mechanical alignment of the TKR by permitting better implant positioning over conventional TKR surgery. The aim of this study is to compare the mechanical alignment results of patients operated with PSIs and conventional instruments.

Two groups of 20 patients chosen in a quasi-random manner have been compared in this study. In the first group femoral distal and tibial osteotomies were made by a PSI which was produced by the patients' computed tomography scans. All osteotomies in the control group were made with the TKR set's routine instruments by conventional means. Patients' preoperative and postoperative mechanical femorotibal angles (mFTA), femoral coronal angles (FCA), tibial coronal angles (TCA) were measured and the number of outliers which showed more than 3° of malalignment were counted in both groups for comparison.

The average postoperative mFTA was found to be 2.09° for the PSI group and in was found to be 2.84° for the control which was not statistically significant. The comparison of postoperative FCA and TCA also did not show significant difference between the groups. The number of outliers showing more than 3° of malalignment per group were found to be 1 out of 20 (5%) for the PSI group and 7 out of 20 (35%) for the control which was statistically significant.

In this study patient-specific instrumentation provided significantly better mechanical alignment compared to conventional TKR for the frequency of outlier cases with malalignment beyond 3°. PSI proved no significant difference when the groups were compared for mFTA, FCA and TCA. Our findings support that PSI may improve TKR alignment by improving the ratio of the outlier patients with marked malalignment.

Level III, Therapeutic Study.

• Mechanical alignment
• Patient matched instruments
• Patient specific instruments
• Total knee arthroplasty
• Total knee replacement

• Aged
• Arthroplasty, Replacement, Knee/adverse effects
• Arthroplasty, Replacement, Knee/instrumentation
• Arthroplasty, Replacement, Knee/methods
• Female
• Humans
• Knee Prosthesis
• Male
• Middle Aged
• Osteoarthritis, Knee/surgery
• Patient-Specific Modeling
• Printing, Three-Dimensional
• Prospective Studies
• Prosthesis Failure
• Prosthesis Fitting/instrumentation
• Prosthesis Fitting/methods
• Surgery, Computer-Assisted/methods
• Tomography, X-Ray Computed/methods

• 3d print
• customized protheses
• osteotomy guide
• pelvic tumor

• Female
• Humans
• Middle Aged
• Neoplasm Metastasis
• Pelvic Neoplasms/pathology
• Pelvic Neoplasms/surgery
• Printing, Three-Dimensional
• Prosthesis Design/methods
• Prosthesis Implantation
• Plastic Surgery Procedures/methods

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

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

• Component alignment
• Intramedullary/extramedullary referencing
• Patient-specific instrumentation
• Tibial alignment
• Total ankle arthroplasty

• CT scan
• PSI
• Total knee artrhoplasty

• Clinical outcome
• Femoral component placement
• Observational study
• Rotation
• TKA
• Total knee arthroplasty
• Total knee replacement

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

• Conventional instruments
• Mid-term
• PROMS
• PSI
• Patient-specific instruments
• RCT
• Randomized controlled trial
• Survival
• TKA
• Total knee arthroplasty