Navigated, soft tissue-guided total knee arthroplasty restores the distal femoral joint line orientation in a modified mechanically aligned technique

2020 ◽  
Author(s):  
Francesco Zambianchi ◽  
Andrea Giorgini ◽  
Andrea Ensini ◽  
Vincenzo Lombari ◽  
Valerio Daffara ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Joint Line ◽  
Line Orientation ◽  
Total Knee

scholarly journals Personalized alignment in total knee arthroplasty: current concepts

SICOT-J ◽  
2021 ◽  
Vol 7 ◽  
pp. 19
Author(s):  
Sébastien Lustig ◽  
Elliot Sappey-Marinier ◽  
Camdon Fary ◽  
Elvire Servien ◽  
Sébastien Parratte ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Functional Outcomes ◽  
Inverse Kinematic ◽  
Joint Line ◽  
Kinematic Alignment ◽  
Joint Line Obliquity ◽  
Total Knee ◽  
Neutral Alignment

Traditionally in total knee arthroplasty (TKA), a post-operative neutral alignment was the gold standard. This principle has been contested as functional outcomes were found to be inconsistent. Analysis of limb alignment in the non-osteoarthritic population reveals variations from neutral alignment and consideration of a personalized or patient-specific alignment in TKA is challenging previous concepts. The aim of this review was to clarify the variations of current personalized alignments and to report their results. Current personalized approaches of alignment reported are: kinematic, inverse kinematic, restricted kinematic, and functional. The principle of “kinematic alignment” is knee resurfacing with restitution of pre-arthritic anatomy. The aim is to resurface the femur maintaining the native femoral joint line obliquity. The flexion and extension gaps are balanced with the tibial resection. The principle of the “inverse kinematic alignment” is to resurface the tibia with similar medial and lateral bone resections in order to keep the native tibial joint line obliquity. Gap balancing is performed by adjusting the femoral resections. To avoid reproducing extreme anatomical alignments there is “restricted kinematic alignment” which is a compromise between mechanical alignment and true kinematic alignment with a defined safe zone of alignment. Finally, there is the concept of “functional alignment” which is an evolution of kinematic alignment as enabling technology has progressed. This is obtained by manipulating alignment, bone resections, soft tissue releases, and/or implant positioning with a robotic-assisted system to optimize TKA function for a patient’s specific alignment, bone morphology, and soft tissue envelope. The aim of personalizing alignment is to restore native knee kinematics and improve functional outcomes after TKA. A long-term follow-up remains crucial to assess both outcomes and implant survivorship of these current concepts.

Radiographic Findings in Flexion Instability after Total Knee Arthroplasty

2021 ◽  
Author(s):  
Cole M. Howie ◽  
Simon C. Mears ◽  
C. Lowry Barnes ◽  
Erin M. Mannen ◽  
Jeffrey B. Stambough
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Revision Surgery ◽  
Tibial Slope ◽  
Joint Line ◽  
Radiographic Findings ◽  
Radiographic Measurements ◽  
Significant Difference ◽  
Total Knee

AbstractFlexion instability (FI) is one of the leading causes of knee pain and revision surgery. Generally, the biomechanical etiology is considered to be a larger flexion than extension gap. This may be due to mismatch of components sizes to the bone or malalignment. Other factors such as muscle weakness may also play a role, and the diagnosis of FI after total knee arthroplasty (TKA) relies on a combination of patient's complaints during stair descent or walking and physical examination findings. Our study examines the role of implant positioning and sizes in the diagnosis of FI. A retrospective review of 20 subjects without perceived FI and 13 patients diagnosed with FI after TKA was conducted. Knee injury and osteoarthritis outcome scores (KOOS) were documented, and postoperative radiographs were examined. Measurements including included tibial slope, condylar offset, femoral joint line elevation along with surrogate soft-tissue measures for girth and were compared between groups. The FI group was found to have a significantly lower KOOS score compared with the non-FI group (55.6 vs. 73.5; p = 0.009) as well as smaller soft-tissue measurements over the pretubercle region (6.0 mm vs. 10.6 mm; p = 0.007). Tibial slope, condylar offset ratios, and femoral joint line elevation were not significantly different between the FI and non-FI groups. We noted a significant difference in tibial slope in posterior-stabilized implants in subjects with and without FI (6.4° vs. 1.5°; p = 0.003). Radiographic measurements consistent with malalignment were not indicative of FI. X-ray measurements alone are not sufficient to conclude FI as patient symptoms, and clinical examinations remain the key indicators for diagnosis. Radiographic findings may aid in surgeon determination of an underlying cause for an already identified FI situation and help in planning revision surgery.

Is Soft Tissue Laxity Associated with Tissue Metal Concentrations after Total Knee Arthroplasty?

2018 ◽  
Vol 28 (2) ◽  
pp. 79-85
Author(s):  
Meredith Perkins ◽  
Julie Lowell ◽  
Christina Arnholt ◽  
Daniel MacDonald ◽  
Anita L. Kerkhof ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Metal Concentrations ◽  
Soft Tissue Laxity ◽  
Total Knee

scholarly journals Postoperative laxity of the lateral soft tissue is largely negligible in total knee arthroplasty for varus osteoarthritis

2021 ◽  
Vol 29 (1) ◽  
pp. 230949902110020
Author(s):  
Seikai Toyooka ◽  
Hironari Masuda ◽  
Nobuhiro Nishihara ◽  
Takashi Kobayashi ◽  
Wataru Miyamoto ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Varus Deformity ◽  
Varus Knee ◽  
Before And After ◽  
Knee Deformity ◽  
Varus Stress ◽  
Total Knee

Purpose: To evaluate the integrity of lateral soft tissue in varus osteoarthritis knee by comparing the mechanical axis under varus stress during navigation-assisted total knee arthroplasty before and after compensating for a bone defect with the implant. Methods: Sixty-six knees that underwent total knee arthroplasty were investigated. The mechanical axis of the operated knee was evaluated under manual varus stress immediately after knee exposure and after navigation-assisted implantation. The correlation between each value of the mechanical axis and degree of preoperative varus deformity was compared by regression analysis. Results: The maximum mechanical axis under varus stress immediately after knee exposure increased in proportion to the degree of preoperative varus deformity. Moreover, the maximum mechanical axis under varus stress after implantation increased in proportion to the degree of preoperative varus deformity. Therefore, the severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, regression coefficients after implantation were much smaller than those measured immediately after knee exposure (0.99 vs 0.20). Based on the results of the regression formula, the postoperative laxity of the lateral soft tissue was negligible, provided that an appropriate thickness of the implant was compensated for the bone and cartilage defect in the medial compartment without changing the joint line. Conclusion: The severity of varus knee deformity leads to a progressive laxity of the lateral soft tissue. However, even if the degree of preoperative varus deformity is severe, most cases may not require additional procedures to address the residual lateral laxity.

scholarly journals Accuracy of soft tissue balancing in total knee arthroplasty using surgeon-defined assessment versus a gap-balancer or electronic sensor

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ran Zhao ◽  
Yanqing Liu ◽  
Hua Tian
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Sensor Data ◽  
Soft Tissue Balancing ◽  
Electronic Sensor ◽  
Prior Performance ◽  
Cumulative Summation ◽  
Total Knee ◽  
Sensitivity Specificity

Abstract Background Soft tissue balancing is essential for the success of total knee arthroplasty (TKA) and is mainly dependent on surgeon-defined assessment (SDA) or a gap-balancer (GB). However, an electronic sensor has been developed to objectively measure the gap pressure. This study aimed to evaluate the accuracy of soft tissue balancing using SDA and GB compared with a sensor. Methods Forty-eight patients undergoing TKA (60 knees) were prospectively enrolled. Soft tissue balancing was sequentially performed using SDA, a GB, and an electronic sensor. We compared the SDA, GB, and sensor data to calculate the sensitivity, specificity, and accuracy at 0°, 45°, 90°, and 120° flexion. Cumulative summation (CUSUM) analysis was performed to assess the surgeon’s performance during the sensor introductory phase. Results The sensitivity of SDA was 63.3%, 68.3%, 80.0%, and 80.0% at 0°, 45°, 90°, and 120°, respectively. The accuracy of the GB compared with sensor data was 76.7% and 71.7% at 0° and 90°, respectively. Cohen’s kappa coefficient for the accuracy of the GB was 0.406 at 0° (moderate agreement) and 0.227 at 90° (fair agreement). The CUSUM 0° line achieved good prior performance at case 45, CUSUM 90° and 120° showed a trend toward good prior performance, while CUSUM 45° reached poor prior performance at case 8. Conclusion SDA was a poor predictor of knee balance. GB improved the accuracy of soft tissue balancing, but was still less accurate than the sensor, particularly for unbalanced knees. SDA improved with ongoing use of the sensor, except at 45° flexion.

scholarly journals Accuracy of total knee arthroplasty using the modified gap technique based on the bone gap: an evaluation of the bone gap with a distal femoral trial component

Arthroplasty ◽  
2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Goki Kamei ◽  
Shigeki Ishibashi ◽  
Koki Yoshioka ◽  
Satoru Sakurai ◽  
Hiroyuki Inoue ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Distal Femur ◽  
Gap Size ◽  
Flexion Gap ◽  
Gap Technique ◽  
Joint Gap ◽  
Total Knee ◽  
The Mean

Abstract Background In total knee arthroplasty (TKA) using the modified gap technique, the soft-tissue balance is measured after osteotomy of the distal femur and proximal tibia (conventional bone gap). However, after osteotomy, the flexion gap size during 90° knee flexion may be larger than that observed after implantation. The tension of the lateral compartment during 90° flexion may also be reduced after osteotomy of the distal femur. We manufactured a distal femoral trial component to reproduce the condition after implantation and prior to posterior condyle osteotomy. This study aimed to evaluate the effect of the trial component on the flexion gap. Methods This prospective study included 21 consecutive patients aged 78 years with medial osteoarthritis who underwent cruciate-retaining TKA between February 2017 and March 2018. The postoperative flexion gap size and inclination during 90° flexion were compared between cases with and without the trial component. Results The mean joint gap size with the trial component (13.4 ± 0.80 mm) was significantly smaller than that without the trial component (14.7 ± 0.84 mm). The mean gap inclination angle with the trial component (3.7° ± 0.62°) was significantly smaller than that without the trial component (5.5° ± 0.78°). Conclusions In the present study, the joint gap size and medial tension were significantly reduced after the trial component had been set. Accurate measurement of the soft-tissue balance is an important factor in the modified gap technique, and this method using a distal femoral trial component can offer better outcomes than those achieved with conventional methods.

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