scholarly journals Posterior stability in posterior-stabilized vs medially congruent total knee replacement: A radiological comparison of two polyethylene designs in a single model

2020 ◽  
pp. 221049172097898
Author(s):  
Leonardo Stramazzo ◽  
Nicolo’ Bassi ◽  
Stefano Ghirardelli ◽  
Tommaso Amoroso ◽  
Leonardo Osti ◽  
...  

Objective: The purpose of this radiological study was to assess the posterior laxity of a single model of a total knee arthroplasty design (TKA) having a medially constrained (MC) or a Posterior-Stabilized (PS) polyethylene insert using a well-documented stress x-ray. To the authors knowledge, this is the first report evaluating MC TKA outcomes according to the “kneeling view.” Materials and Methods: Sixty patients with non-traumatic primary knee osteoarthritis undergoing TKA were first matched by age, sex, BMI and diagnosis and then divided in two groups: group A (37 knees) received a MC TKA and group B (23 knees) a PS implant made by the same manufacturer. In all cases the posterior cruciate ligament (PCL) was resected. All patients underwent the same postoperative “kneeling view” and were also clinically evaluated according to the Knee Society Score (KSS) and Oxford Knee Score (OKS). Radiographic measurements were taken by tracing a line along the posterior cortex of the tibia and then measuring the perpendicular distance to a point marked at the posterior corner of Blumensaat’s line. Results: At 12 months minimum FU, no statistically significant differences were found between the two groups in all the clinical scores. There was a statistically significant difference on kneeling view values between the two groups (P = 0.0002): the mean value in the MC group was −1.97 ± 3.8 mm while was −5.6 ± 3.1 mm in the PS group. In both groups, the average position of the posterior cortex of the tibia was anterior to the posterior corner of Blumensaat’s line, showing absence of instability in flexion. Conclusion: This study highlighted that the PCL removal, accompanied by a precise surgical technique, did not increase the instability in flexion in two groups of patients having the same TKA design but polyethylene inserts characterized by different levels of constraint.

2019 ◽  
Vol 101-B (7_Supple_C) ◽  
pp. 33-39 ◽  
Author(s):  
P. F. Lachiewicz ◽  
J. A. O’Dell

Aims There is insufficient evidence to recommend the use of alternative polyethylene bearings in modular, fixed-bearing total knee arthroplasty (TKA). The purpose of this study was to compare standard polyethylene (SP) and highly crosslinked polyethylene (XLP) tibial liners in posterior-stabilized TKA, with osteolysis as the primary outcome and clinical results and the rate of re-operation as the secondary outcomes. Patients and Methods This is a single-surgeon, prospective randomized study involving one design of modular posterior-stabilized TKA. An analysis of 122 TKAs with an SP compression moulded liner and 123 with an XLP liner was performed, with a mean follow-up of six years (2 to 11). Patients were evaluated clinically using the Knee Society score, Lower Extremity Activity Score (LEAS), and the presence of an effusion, and standard radiographs were assessed for radiolucent lines and osteolytic lesions. Results Osteolysis was present in four TKAs (3.3%) in the SP group, and no knees in the XLP group (p = 0.06). There were no significant differences between the Knee Society total score, change in total score, knee function score, change in function score, LEAS, and change in LEAS in the two groups. There was a significant difference in the presence of an effusion (10/122 with SP liners, 1/123 with XLP liners; p = 0.02). There was no significant difference in the rate of re-operation between the two groups (p = 0.36). There were no complications related to the XLP liner. Conclusion At this length of follow-up, there were no advantages and no complications related to the use of this XLP tibial liner. The presence of effusion and small osteolytic lesions was more frequent with SP than XLP liners, but of unknown clinical significance. Cite this article: Bone Joint J 2019;101-B(7 Supple C):33–39


2018 ◽  
Vol 100-B (1_Supple_A) ◽  
pp. 76-82 ◽  
Author(s):  
B. Benjamin ◽  
J. R. T. Pietrzak ◽  
J. Tahmassebi ◽  
F. S. Haddad

AimsThe outcome of total knee arthroplasty (TKA) is not always satisfactory. The purpose of this study was to identify satisfaction and biomechanical features characterising the gait of patients who had undergone TKA with either an anatomical single radius design or a medial pivot design. We hypothesised that the latter would provide superior function.Patients and MethodsThis is a study of a subset of patients recruited into a prospective randomised study of a single radius design versus a medial pivot design, with a minimum follow-up of one year. Outcome measurements included clinical scores (Knee Society Score (KSS) and Oxford Knee Score (OKS)) and gait analysis using an instrumented treadmill.ResultsThere was no statistically significant difference between the two groups for both the KSS and OKS. There was also no statistical significance in cadence, walking speed, stride length and stance time, peak stride, mid support and push-off forces.ConclusionThis study corroborates a previous study by the same authors that showed equally good results in clinical outcome and gait between the conventional single radius and medial pivot designs under stringent testing conditions. Cite this article: Bone Joint J 2018;(1 Supple A)100-B:76–82.


2021 ◽  
Vol 87 (3) ◽  
pp. 487-493
Author(s):  
Irfan Qadir ◽  
Latif Khan ◽  
Jahanzeb Mazari ◽  
Umair Ahmed ◽  
Atiq uz Zaman ◽  
...  

Safety of simultaneous bilateral TKA (simBTKA) and staged BTKA (staBTKA) have been compared in previous systematic reviews but functional outcome remains neglected aspect of the debate. We performed a systematic review of contemporary literature to compare the functional outcome of simBTKA and staBTKA. We searched PubMed/MEDLINE, EMBASE and Cochrane Central Database to identify all articles published between 2000 and July 2020 that evaluated the outcome of patients undergoing BTKA either in simultaneous or staged manner. Ten articles were identified which met the inclusion criteria. Functional outcome was reported in terms of Knee Society score (KSS), range of motion (ROM), Oxford Knee Score (OKS) and Western Ontario and McMaster University score (WOMAC) in seven, five, four and two studies respectively. KSS gained on average 66.6 points (47.5-95.3) for simBTKA and 65.1 points (44.4-97.2) for staBTKA without significant difference between two groups. There was no difference in post-operative ROM (maximum post-operative flexion being 124.4 and 125.1 for simBTKA and staBTKA groups respectively). Mean improvement in OKS ranged from 20 to 32.6 for simBTKA and 21.6 to 33.1 for staBTKA. There was moderate evidence to suggest that both simultaneous BTKA and staged BTKA produce equivalent improvement in functional scores.


2019 ◽  
Vol 7 (6_suppl4) ◽  
pp. 2325967119S0023
Author(s):  
Max Ettinger ◽  
Peter Savov ◽  
Henning Windhagen ◽  
Evelyn Mielke ◽  
Tilman Calliess

Aims and Objectives: The debate of cruciate retaining (CR) versus posterior stabilized (PS) designs in total knee arthroplasty (TKA) is ongoing. With the posterior cruciate ligament retained, the TKA is supposed to function better in terms of proprioception, balance and kinematics. In contrast to that, PS designs are supposed to lead to higher degrees of flexion and a better femoral rollback. It is known, that the preoperative deformity negatively correlates with inferior results following TKA. When balancing a valgus knee, Ranawat et al. suggest to address the PCL in the first place. It is known that in 60% of valgus knees 1-2 soft tissue releases are necessary in order to achieve neutral alignment. Up to date no study exists, reporting the outcome of CR versus PS TKA in valgus knees. Thus, it was purpose of this study to evaluate the mid term outcome of CR versus PS TKA for the treatment of valgus OA in groups between 3°-6° of valgus, 7-10° of valgus and >10° of valgus. Materials and Methods: With the KOOS score as the primary endpoint, a sample size of 117 cases (78 CR and 39 PS) was needed in order to get a statistical power of 80%.Between 01-2011 and 03-2014 a total of 248 patients with a preoperative valgus >3° were treated with a CR TKA (167 cases) or a PS TKA (81 cases) of the same manufacturer (Stryker Triathlon, Stryker, Kalamazoo USA). CR patients were divided into the following groups: Preoperative valgus >3°-6°, 7°-10° and >10°. PS patients were divided into the following groups: Preoperative valgus >3°-6°, 7°-10° and >10°. The KOOS Score and the Oxford Knee score was collected at the time of follow up. For the CR and PS group failure rates and failure etiologies were analyzed. Patients demographics and were collected as well. Results: 141 patients were included into this study (97 CR and 44 PS cases). The CR group had a mean follow up of 57 weeks, the PS group had a follow up of 52weeks. In the CR group, 11/97 (11%) patients were revised due to a.p. instability, whereas 2/44 (5%) patients were revised in the PS group due to infection or aseptic loosening. There was no difference regarding OKS and the KOOS score between the two groups. Further, there was no difference regarding patients demographics and no correlation between the BMI and the clinical outcome. Conclusion: The most important findings of this study are that the CR group showed a significant higher early revision rate, whereas the clinical mid term follow up results are equal. The CR version of the used system showed significantly higher early failure due to a.p. instability.


2017 ◽  
Vol 30 (07) ◽  
pp. 725-729 ◽  
Author(s):  
Akihito Takubo ◽  
Keinosuke Ryu ◽  
Yasuaki Tokuhashi ◽  
Takanori Iriuchishima

AbstractThe purpose of this study was to compare muscle recovery in the lower extremities following the newly developed bi-cruciate substituting (BCS) to posterior stabilized (PS) total knee arthroplasty (TKA) in the Asian population. Forty-one knees in 41 patients undergoing BCS-TKA (41 female, average age: 71 ± 8.8) and 34 knees in 34 patients undergoing PS-TKA (33 female, average age: 73 ± 7.2) were included in this study. The maximum isometric power of the quadriceps and hamstring muscles was measured preoperatively, and at 1, 3, 6, and 12 months after surgery using a handheld dynamometer. Postoperative muscle recovery was calculated regarding preoperative muscle power as 100%. Pre- and postoperative range of knee motion, femorotibial angle, and clinical scores (Knee Society score and function score) were also compared. No significant difference in sex, age, preoperative quadriceps, or preoperative hamstring power was observed between the BCS and PS-TKA groups. When regarding the preoperative muscle power as 100%, quadriceps power at 1, 3, 6, and 12 months following BCS-TKA was 61.2 ± 22%, 86.3 ± 28.3%, 97 ± 27.4%, and 112.4 ± 30.8%, respectively. Quadriceps power at 1, 3, 6, and 12 months following PS-TKA was 72.4 ± 20.8%, 84 ± 16.9%, 95 ± 20.7%, and 110.8 ± 27%, respectively. Hamstring power at 1, 3, 6, and 12 months following BCS-TKA was 96.3 ± 30%, 111.4 ± 35%, 120 ± 37%, and 125 ± 31%, respectively. Hamstring power at 1, 3, 6, and 12 months following PS-TKA was 95 ± 25%, 112.4 ± 27%, 117 ± 38.5%, and 120.4 ± 18.5%, respectively. No significant difference in muscle power recovery was observed at 3 (p = 0.995), 6 (p = 0.944), and 12 (p = 0.917) months after surgery between the two groups. No significant difference of the clinical score was observed between the groups (Knee Society score: p = 0.479, function score: p = 0.342). No significant difference in muscle recovery and clinical score were observed between the BCS and PS-TKA groups. Longer follow-up is needed for the evaluation of efficacy of BCS-TKA in the Asian populations.


Author(s):  
A Galvin ◽  
L M Jennings ◽  
H M McEwen ◽  
J Fisher

Debris-induced osteolysis due to surface wear is a potential long-term problem in total knee replacements (TKRs). Wear between the tibial tray and ultra-high molecular weight polyethylene insert is thought to contribute to the wear. This study investigated the influence of tibial tray design on the wear of fixed-bearing TKRs. Specifically, this study investigated the influence of the material's surface finish and design characteristics of the locking mechanism of the tibial tray on the wear in fixed-bearing knees for both cruciate-retaining (CR) and posterior-stabilized designs. A new fixed-bearing tibial tray design using Co—Cr and with an improved locking mechanism significantly reduced polyethylene wear from 22.8 ± 6.0 mm3 per 106 cycles to 15.9 ± 2.9 mm3 per 106 cycles compared with a previous titanium alloy tray with a CR design. The wear rates were similar to those of a fixed-bearing insert clamped into a tibial tray, suggesting that the decrease in wear was due to a reduction in backside wear. There was no significant difference between the wear rates of a cruciate-retaining design and a posterior-stabilized design under the two kinematic conditions tested.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Dongsheng Hao ◽  
Junjie Wang

Abstract Background The benefits and risks of fixed-bearing and mobile-bearing designs for total knee arthroplasty (TKA) were compared, and long-term functional, clinical and radiological outcomes were analysed. Methods A comprehensive search in the PubMed, EMBASE, Web of Science and Cochrane Central databases was conducted to identify randomized controlled trials (RCTs) comparing fixed-bearing and mobile-bearing designs with no less than 9 years of follow-up. Primary outcome measures were Knee Society Scores (KSSs), range of motion (ROM) in knee joint values, complication rates and revision rates. The final search was performed on 23 April 2021. Results Six RCTs were included. A total of 451 patients with 612 knees met the inclusion criteria. The mobile-bearing design, in contrast to the fixed-bearing design, can clearly increase the KSFSs, especially with posterior cruciate retention. There was no significant difference in the KSKSs, ROM values, revision rates or complication rates between the two bearing design groups. Conclusion After approximately 10 years of follow-up, the mobile-bearing design has advantages in KSFSs over the fixed-bearing design. The mobile-bearing design may also have advantages in the revision rates over the fixed-bearing design when the posterior cruciate ligament is substituted. There may be no clear difference in KSKSs, ROM values or complication rates between these two designs.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Arata Nakajima ◽  
Yasuchika Aoki ◽  
Masazumi Murakami ◽  
Koichi Nakagawa

Achieving correct soft tissue balance and preparing equal and rectangular extension and flexion joint gaps are crucial goals of TKA. Intraoperative gap balances would change postoperatively; however, changes in joint gap balances between pre- and postoperation remain unclear. To explore these changes associated with TKA, we prospectively investigated 21 posterior cruciate ligament retaining TKAs for varus knees. Intraoperative extension gap balance (iEGB) was 2.6 ± 2.0° varus versus postoperative extension gap balance (pEGB) of 0.77 ± 1.8° valgus (P<0.01), while no significant difference between intraoperative flexion gap balance (iFGB) and postoperative flexion gap balance (pFGB) was observed. We also explored correlations between intraoperative and postoperative gap balances but found no significant correlations. These observations indicate that (i) surgeons should avoid excessive release of the medial soft tissue during TKA for varus knees and (ii) intraoperative gap balance may not be necessarily reflected on postoperative gap balance.


Author(s):  
Mehul A. Dharia ◽  
Marc Muenchinger ◽  
Eik Siggelkow ◽  
Jeff E. Bischoff

Posterior stabilization in PCL (Posterior Cruciate Ligament) sacrificing Total Knee Arthroplasty (TKA) can be achieved by two commonly used design concepts. Anteriorposterior (AP) stability can be provided either by the ultracongruent (UC) shape of the tibial articulation or by a posterior cruciate substitution with a central spine on the tibial insert which articulates with a transverse cam on the femoral component [1]. Clinical studies have indicated that the use of UC tibial insert design does not significantly compromise the TKA outcomes when compared with the use of posterior cruciate substituting design [2].


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