scholarly journals Soft Tissue Envelope Preserving Technique for Computer Navigated Total Knee Arthroplasty

2017 ◽  
Vol 5 (5_suppl5) ◽  
pp. 2325967117S0015
Author(s):  
Gavin Clark ◽  
Luke Mooney
Keyword(s):  
Total Knee Arthroplasty ◽  
Patient Satisfaction ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Mechanical Axis ◽  
Computer Navigation ◽  
Clinical Results ◽  
Short Term ◽  
Soft Tissue Envelope ◽  
Total Knee

Objectives: Current techniques in Total Knee Arthroplasty(TKA) are utilitarian in that all patients are recommended to have the same alignment of neutral mechanical axis. It has been well established that the population has a varied natural alignment with less than 20% of patients naturally neutral. The ability to predictably individualise alignment for patients is hypothesised to result in greater patient satisfaction. This technique aims to modify mechanical axis technique to consider an individual’s soft tissue constraints. Methods: Soft Tissue Envelope Preserving (STEP) is an operative technique for performing TKA that utilises the soft tissue data obtained intra-operatively from computer navigation registration to determine the optimal alignment to provide balanced positioning of implants without the need for soft tissue releases. Hence balance is achieved through bone cuts rather than altering the patient’s soft tissue balance. The technique will be described in detail. Results: The last 100 patients performed with complete data sets including navigation files and both pre-op and one year post operative outcome measures were reviewed. The spread of overall alignments and bony resections have been compiled with no outliers outside 5 degrees of neutral. The clinical results were comparable with other series and patient satisfaction of greater than 90% was reported. There were no MCL or LCL releases performed. Ilio-tibial band partial releases were the only reported soft tissue releases made. Conclusions: This technique is a safe and effective method of performing TKA with good short term outcomes. It minimises the use of soft tissue releases by utilising the patient’s own soft tissue envelope to balance the knee whilst maintaining the basic principles of a measured resection mechanical axis technique. It has resulted in excellent patient satisfaction in the short term.

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 What is a balanced knee replacement?

2018 ◽  
Vol 3 (12) ◽  
pp. 614-619 ◽  
Author(s):  
Lucy C. Walker ◽  
Nick D. Clement ◽  
Kanishka M. Ghosh ◽  
David J. Deehan
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Replacement ◽  
Knee Arthroplasty ◽  
Current Evidence ◽  
Soft Tissue Envelope ◽  
Total Knee ◽  
Uneven Wear ◽  
Definition Of ◽  
Revision Tka

For multifactorial reasons an estimated 20% of patients remain unsatisfied after total knee arthroplasty (TKA). Appropriate tension of the soft tissue envelope encompassing the knee is important in total knee arthroplasty and soft tissue imbalance contributes to several of the foremost reasons for revision TKA, including instability, stiffness and aseptic loosening. There is debate in the literature surrounding the optimum way to achieve balancing of a total knee arthroplasty and there is also a lack of an accepted definition of what a balanced knee replacement is. It may be intuitive to use the native knee as a model for balancing; however, there are many difficulties with translating this into a successful prosthesis. One of the foundations of TKA, as described by Insall, was that although the native knee has more weight transmitted through the medial compartment this was to be avoided in a TKA as it would lead to uneven wear and early failure. There is a focus on achieving symmetrical tension and pressure and subsequent ‘balance’ in TKA, but the evidence from cadaveric studies is that the native knee is not symmetrically balanced. As we are currently trying to design an implant that is not based on its anatomical counterpart, is it possible to create a truly balanced prosthesis or to even to define what that balance is? The authors have reviewed the current evidence surrounding TKA balancing and its relationship with the native knee. Cite this article: EFORT Open Rev 2018;3:614-619. DOI: 10.1302/2058-5241.3.180008.

scholarly journals Patient Satisfaction Outcomes after Robotic Arm-Assisted Total Knee Arthroplasty: A Short-Term Evaluation

2017 ◽  
Vol 30 (09) ◽  
pp. 849-853 ◽  
Author(s):  
Robert Marchand ◽  
Nipun Sodhi ◽  
Anton Khlopas ◽  
Assem Sultan ◽  
Steven Harwin ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Patient Satisfaction ◽  
Physical Function ◽  
Knee Arthroplasty ◽  
Robotic Arm ◽  
Short Term ◽  
Patient Satisfaction Score ◽  
Total Patient ◽  
Total Knee ◽  
The Mean

AbstractRobotic arm-assisted total knee arthroplasty (RATKA) presents a potential, new added value for orthopedic surgeons. In today's health care system, a major determinant of value can be assessed by patient satisfaction scores. Therefore, the purpose of the study was to analyze patient satisfaction outcomes between RATKA and manual total knee arthroplasty (TKA). Specifically, we used the Western Ontario and McMaster Universities Arthritis Index (WOMAC) to compare (1) pain scores, (2) physical function scores, and (3) total patient satisfaction outcomes in manual and RATKA patients at 6 months postoperatively. In this study, 28 cemented RATKAs performed by a single orthopedic surgeon at a high-volume institution were analyzed. The first 7 days were considered as an adjustment period along the learning curve. Twenty consecutive cemented RATKAs were matched and compared with 20 consecutive cemented manual TKAs performed immediately. Patients were administered a WOMAC satisfaction survey at 6 months postoperatively. Satisfaction scores between the two cohorts were compared and the data were analyzed using Student's t-tests. A p-value < 0.05 was used to determine statistical significance. The mean pain score, standard deviation (SD), and range for the manual and robotic cohorts were 5 ± 3 (range: 0–10) and 3 ± 3 (range: 0–8, p < 0.05), respectively. The mean physical function score, SD, and range for the manual and robotic cohorts were 9 ± 5 (range: 0–17) and 4 ± 5 (range, 0–14, p = 0.055), respectively. The mean total patient satisfaction score, SD, and range for the manual and robotic cohorts were 14 points (range: 0–27 points, SD: ± 8) and 7 ± 8 points (range: 0–22 points, p < 0.05), respectively. The results from this study further highlight the potential of this new surgical tool to improve short-term pain, physical function, and total satisfaction scores. Therefore, it appears that patients who undergo RATKA can expect better short-term outcomes when compared with patients who undergo manual TKA.

scholarly journals Correction of Varus Alignment with Peripheral Osteophyte Removal during Total Knee Arthroplasty: An Assessment with Computer Navigation

2021 ◽  
Author(s):  
Nobuhiro Nishihara ◽  
Hironari Masuda ◽  
Naoya Shimazaki ◽  
Seikai Toyooka ◽  
Hirotaka Kawano ◽  
...  
Keyword(s):  
Total Knee Arthroplasty ◽  
Knee Arthroplasty ◽  
Repeated Measures ◽  
Soft Tissues ◽  
Mechanical Axis ◽  
Computer Navigation ◽  
Varus Deformity ◽  
Varus Alignment ◽  
Valgus Stress ◽  
Total Knee

AbstractTechniques for symmetrical balancing in flexion and extension have been described; however, the ideal technique is unclear. This study aimed to clarify whether resection of peripheral osteophytes could restore neutral hip–knee–ankle (HKA) angle of varus deformity of arthritic knees. Data from 90 varus arthritic knees that had undergone total knee arthroplasty (TKA) using a nonimage-based navigation system were analyzed. The change in the coronal mechanical axis, while applying manual valgus stress at extension and 90 degrees of knee flexion, was recorded after the following sequential procedures: (1) anterior cruciate ligament (ACL) sectioning, (2) subperiosteal stripping of the deep medial collateral ligament (MCL) from the underlying osteophytes on the medial tibia, and (3) complete removal of peripheral osteophytes from the proximal medial tibia and distal medial femoral condyle. Repeated measures of analysis of variance (ANOVA) were performed to compare the varus angle among each step, and a post hoc analysis by paired t-test was utilized to compare the parameters between baseline and each step. The varus alignment with valgus stress at extension and 90 degrees of flexion (mean: 6.0 ± 3.6 and 5.2 ± 3.9 degrees of varus, respectively) was significantly corrected to a near-neutral mechanical axis (mean: 0.9 ± 2.4 and 1.4 ± 4.2 degrees of varus, respectively) after peripheral osteophyte resection (p < 0.01, both). In many cases, varus deformity of arthritic knees could be corrected to near-neutral HKA angle by applying manual valgus stress after complete peripheral osteophyte resection. These procedures could facilitate soft tissue balancing in TKA, minimizing the risk of overrelease of the medial soft tissues.

scholarly journals Changes of mediolateral soft tissue gaps in total knee arthroplasty after suturing medial extensor in navigation

2018 ◽  
Vol 26 (3) ◽  
pp. 230949901880251
Author(s):  
Seung Bum Chae ◽  
Myung Rae Cho ◽  
Jae Bum Kwon ◽  
Jae Hyuk Lee ◽  
Won Kee Choi
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Knee Flexion ◽  
Computer Navigation ◽  
Varus Knee ◽  
Total Knee ◽  
The Difference ◽  
Lateral Gaps

Purpose: Aim is to investigate the changes of mediolateral soft tissue gaps in total knee arthroplasty (TKA) after suturing medial extensor. Methods and materials: We compared the differences of medial and lateral gap values that were shown by the computer navigation at 0°, 45°, 90°, and 120° knee flexion during patella in situ and during patella repaired by a towel clip on two constant sites. Fifty consecutive knees (43 patients) scheduled for TKA due to varus knee osteoarthritis, from February 2017 to May 2017, were enrolled in this prospective study. Results: The medial gaps with patella repaired were significantly lower ( p < 0.05) than the medial gaps with patella in situ at 45°, 90°, and 120° knee flexion. Differences in the medial gap were largest at 90, with the difference of 0.87 mm. Twenty-four of 50 cases (48%) showed medial gap differences of 1 mm or over, and 13 of 50 cases (26%) showed medial gap differences of 2 mm or over. The variation in the medial gap at 90° following patellar repair showed significant association (correlation coefficient = 0.78, p = 0.001) with the difference between medial and lateral gaps (medial gap − lateral gap) at 90° of patella in situ. At 90° knee flexion, when the medial and lateral gap difference in patella in situ was 1 mm or less, 73.5% (25/34) of the cases showed variation in the medial gap of less than 1 mm after patellar repair. Conclusion: During TKA, while measuring the medial gap with patella in situ, overestimation might occur, especially in the position of knee flexion. Thus, reevaluation using towel clips should be considered when the medial and lateral gap difference is 1 mm or larger when patella in situ during evaluation of the medial and lateral gaps at 90° knee flexion.

Balancing of total knee arthroplasty by bone cuts achieves accurately balanced soft tissues without the need for soft tissue releases

2018 ◽  
Vol 3 (5) ◽  
pp. 263-268 ◽  
Author(s):  
Ponky Firer ◽  
Brad Gelbart
Keyword(s):  
Total Knee Arthroplasty ◽  
Patient Satisfaction ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Soft Tissues ◽  
Size Difference ◽  
Gap Size ◽  
X Rays ◽  
Coronal Alignment ◽  
Total Knee

IntroductionPatient satisfaction, after mechanically aligned Total Knee Arthroplasty (TKA) is only 80%-85%. There is an inabilty to consistently get perfect soft tissue balance with this technique. It is postulated that soft tissue balance within 2° can be achieved by the boney cuts (Bone Balancing) without soft tissue releases, accepting whatever coronal mechanical alignment (CMA) this produces; that the alignment produced would be similar to natural (constitutional) alignment and that balanced knees would improve patient satisfaction.MethodsWe report on 914 consecutive TKAs using Bone Balancing: the femoral rotation for the flexion gap; the distal femoral cut and valgus angle for the extension gap are adjusted to give equal gap sizes with soft tissue balanced within 2° of medio-lateral laxity. Long leg X-rays were used to measure post-operative coronal alignment. Satisfaction beyond 1 year post operation was assessed by an independent researcher, using a question on satisfaction and a VAS score.Results782(85.5%) TKAs with satisfactory x-rays were available at 2-7 years follow up. Their CMA had a similar distribution profile to reported natural alignment studies. Of these, 672 (86%) had a CMA of 0°±3° (’aligned' group). Overall patient satisfaction was 92.8%, with satisfied patients having a mean (range) VAS score of 9.53 (7.3-10.0) and the dissatisfied patients 3.78 (0.0-6.3) (p<0.0001). There was no difference in satisfaction between ’aligned' knees (92.7%) and those ’outliers', whose CMA was >±3° (93.6%) (p=0.853). All balance measurements were within 3° with 92.2% being ≤2°. Gap size difference between extension and 90° flexion was ≤2mm in 98.7% of cases. Midflexion (45° flexion) balance was within 3° in all cases and the gap size difference was ≤2mm in 89%.ConclusionBalancing by bone cuts is able to achieve accurately balanced soft tissues without the need for soft tissue releases. The coronal alignment profile produced matches that of the normal population. This technique improves satisfaction compared to the literature for mechanically aligned TKAs. Acurate and measured soft tissue balancing needs further consideration in TKAs.Level of EvidenceLevel IV.

Alignment in total knee arthroplasty

2020 ◽  
Vol 102-B (3) ◽  
pp. 276-279 ◽  
Author(s):  
Sam Oussedik ◽  
Matthew P. Abdel ◽  
Jan Victor ◽  
Mark W. Pagnano ◽  
Fares S. Haddad
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Kinematic Alignment ◽  
Hybrid Technique ◽  
Soft Tissue Envelope ◽  
The Past ◽  
Robotic Assisted Surgery ◽  
Total Knee ◽  
Implant Alignment

Dissatisfaction following total knee arthroplasty is a well-documented phenomenon. Although many factors have been implicated, including modifiable and nonmodifiable patient factors, emphasis over the past decade has been on implant alignment and stability as both a cause of, and a solution to, this problem. Several alignment targets have evolved with a proliferation of techniques following the introduction of computer and robotic-assisted surgery. Mechanical alignment targets may achieve mechanically-sound alignment while ignoring the soft tissue envelope; kinematic alignment respects the soft tissue envelope while ignoring the mechanical environment. Functional alignment is proposed as a hybrid technique to allow mechanically-sound, soft tissue-friendly alignment targets to be identified and achieved. Cite this article: Bone Joint J 2020;102-B(3):276–279.

Clinical Results in Valgus Total Knee Arthroplasty With the “Pie Crust” Technique of Lateral Soft Tissue Releases

2005 ◽  
Vol 20 (8) ◽  
pp. 1010-1014 ◽  
Author(s):  
Henry D. Clarke ◽  
Robin Fuchs ◽  
Giles R. Scuderi ◽  
W. Norman Scott ◽  
John N. Insall
Keyword(s):  
Total Knee Arthroplasty ◽  
Soft Tissue ◽  
Knee Arthroplasty ◽  
Clinical Results ◽  
Total Knee
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