Varus-valgus constrained insert with posterior-stabilized femoral components in complex primary total knee arthroplasties

Aims Varus-valgus constrained (VVC) devices are typically used in revision settings, often with stems to mitigate the risk of aseptic loosening. However, in at least one system, the VVC insert is compatible with the primary posterior-stabilized (PS) femoral component, which may be an option in complex primary situations. We sought to determine the implant survivorship, radiological and clinical outcomes, and complications when this VVC insert was coupled with a PS femur without stems in complex primary total knee arthroplasties (TKAs). Methods Through our institution’s total joint registry, we identified 113 primary TKAs (103 patients) performed between 2007 and 2017 in which a VVC insert was coupled with a standard cemented PS femur without stems. Mean age was 68 years (SD 10), mean BMI was 32 kg/m2 (SD 7), and 59 patients (50%) were male. Mean follow-up was four years (2 to 10). Results The five-year survivorship free from aseptic loosening was 100%. The five-year survivorship free from any revision was 99%, with the only revision performed for infection. The five-year survivorship free from reoperation was 93%. The most common reoperation was treatment for infection (n = 4; 4%), followed by manipulation under anaesthesia (MUA; n = 2; 2%). Survivorship free from any complication at five years was 90%, with superficial wound infection as the most frequent (n = 4; 4%). At most recent follow-up, two TKAs had non-progressive radiolucent lines about both the tibial and femoral components. Knee Society Scores improved from 53 preoperatively to 88 at latest follow-up (p < 0.001). Conclusion For complex primary TKA in occasional situations, coupling a VVC insert with a standard PS femur without stems proved reliable and durable at five years. Longer-term follow-up is required before recommending this technique more broadly. Cite this article: Bone Jt Open 2021;2(11):921–925.

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Early outcomes of a modern cemented total knee arthroplasty

The Bone & Joint Journal ◽

10.1302/0301-620x.103b6.bjj-2020-1972.r1 ◽

2021 ◽

Vol 103-B (6 Supple A) ◽

pp. 51-58

Author(s):

JaeWon Yang ◽

Nathanael D. Heckmann ◽

Cindy R. Nahhas ◽

Michael B. Salzano ◽

Gregory P. Ruzich ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Aseptic Loosening ◽

Knee Arthroplasty ◽

Joint Infection ◽

Posterior Stabilized ◽

Cruciate Retaining ◽

Primary Tkas ◽

Total Knee ◽

The Impact

Aims Recent total knee arthroplasty (TKA) designs have featured more anatomical morphologies and shorter tibial keels. However, several reports have raised concerns about the impact of these modifications on implant longevity. The aim of this study was to report the early performance of a modern, cemented TKA design. Methods All patients who received a primary, cemented TKA between 2012 and 2017 with a minimum two-year follow-up were included. The implant investigated features an asymmetrical tibial baseplate and shortened keel. Patient demographic details, Knee Society Scores (KSS), component alignment, and the presence of radiolucent lines at final follow-up were recorded. Kaplan-Meier analyses were performed to estimate survivorship. Results A total of 720 of 754 primary TKAs (95.5%) were included with a mean follow-up of 3.9 years (SD 1.3); 562 (78.1%) were cruciate-retaining and 158 (21.9%) were posterior-stabilized. A total of 11 (1.5%) required reoperation for periprosthetic joint infection and seven (1.0%) for aseptic tibial loosening (five cruciate-retaining, two posterior-stabilized). Loosening occurred at a mean of 3.3 years (0.9 to 6.5). There were no cases of loosening in the 33 patients who received a 14 mm × 30 mm tibial stem extension. All-cause survivorship was 96.6% at three years (95% confidence interval (CI) 95.3% to 98.0%) and 96.2% at five years (95% CI 94.8% to 97.7%). Survivorship with revision for aseptic loosening was 99.6% at three years (95% CI 99.1% to 100.0%) and 99.1% at five years (95% CI 98.4% to 99.9%). Tibial components were in significantly more varus in those with aseptic loosening (mean 3.4° (SD 3.7°) vs 1.3° (SD 2.0°); p = 0.015). There were no other differences in demographic, radiological, or surgical characteristics between revised and non-revised TKAs for aseptic loosening (p = 0.293 to 1.00). Mean KSS improved significantly from 57.3 (SD 9.5) preoperatively to 92.6 (SD 8.9) at the final follow-up (p < 0.001). Conclusion This is the largest series to date of this design of implant. At short-term follow-up, the rate of aseptic tibial loosening is not overly concerning. Further observation is required to determine if there will be an abnormal rate of loosening at mid- to long-term follow-up. Cite this article: Bone Joint J 2021;103-B(6 Supple A):51–58.

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Incidence and Causes of Tibial Component Loosening Based on Level of Obesity in a Large Consecutive Cohort of Cemented Primary TKAs without Stem Extensions

Proceedings of IMPRS ◽

10.18060/24699 ◽

2020 ◽

Vol 3 ◽

Author(s):

Lilly Longawa ◽

Leonard Buller ◽

Mary Ziemba-Davis ◽

R. Michael Meneghini

Keyword(s):

Aseptic Loosening ◽

Medical Records ◽

Tibial Component ◽

Low Viscosity ◽

Primary Tkas ◽

Total Knee ◽

Potential Impact ◽

Component Loosening ◽

Component Revision

Background and Hypothesis: Aseptic loosening is one of the most common failure mechanisms of total knee arthroplasty (TKA) requiring revision. The influence of obesity on tibial component aseptic loosening remains unknown. Some surgeons advocate the addition of a tibial stem extension to reduce the risk of loosening. The purpose of this study was to quantify the incidence and causes of revision for tibial component loosening in a large consecutive cohort of cemented primary TKAs without stem extensions based upon level of obesity. Experimental Design or Project Methods: 534 consecutive cemented primary TKAs performed between 2016 and 2018 by one surgeon were retrospectively reviewed. Procedures were performed using consistent surgical, perioperative medical, and pain-control protocols. All tibial implants were tapered thin keeled designs without stem extensions and implanted with low viscosity cement. Medical records were examined and all-cause revisions of the index surgery were documented. Results: After exclusions for confounds, 525 TKAs were analyzed. Mean age and BMI were 67.8 years and 33.9kg/m2 respectively and 72% were female. Mean follow-up was 19.1 (SD 10.5) months and 48% had minimum two-year follow-up. 41.3% of patients had a BMI greater than 35kg/m2 and 21.9% above 40kg/m2. There were 11 revisions in 10 patients, 1.9% out of all TKAs performed. Five TKAs required both-component revision and three involved the femoral component only. No tibial component revisions were performed for aseptic loosening. Conclusion and Potential Impact: None of the standard tibial implants with a keeled design without stem extensions failed in a patient population with greater than 40% obesity. Despite some suggesting tibial stem extensions should be used in obese TKA patients, these findings suggest that tibial component failure in obese patients may be design specific and routinely utilizing stem extensions may not be warranted and could result in deleterious bone loss at revision if required for reasons other than aseptic loosening.

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Early Clinical and Radiological Outcomes of the Metaphyseally Fixed Totally Stabilized Knee Prosthesis in Primary Total Knee Arthroplasty

The Journal of Knee Surgery ◽

10.1055/s-0039-1683976 ◽

2019 ◽

Vol 33 (07) ◽

pp. 678-684 ◽

Cited By ~ 1

Author(s):

Fahad Hossain ◽

Sujith Konan ◽

Babar Kayani ◽

Christina Kontoghiorghe ◽

Toby Barrack ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Knee Prosthesis ◽

Oxford Knee Score ◽

Primary Total Knee Arthroplasty ◽

Primary Tkas ◽

Total Knee ◽

The Mean ◽

Primary Total Knee

AbstractThe use of valgus–varus constrained (VVC) implant designs in primary total knee arthroplasty (TKA) is considered in situations of severe deformities, bone loss, and inadequate soft tissue balance. It is not known whether the use of such prosthesis designs may predispose to reduced function owing to its constraining design. The components are usually implanted with diaphyseal stem extensions to dissipate the increased forces. The totally stabilized (TS) implant is a contemporary VVC design with metaphyseal fixation only. It has a conforming articulation with increased rotational freedom compared with conventional VVC designs. The aim of this study was to assess whether the use of the contemporary TS implant with its metaphyseally fixed components would be associated with inferior outcomes compared with conventional standard primary posterior stabilized (PS) implants. We reviewed 38 consecutive complex primary TKAs performed using the metaphyseally fixed TS implant and 76 matched patients receiving primary PS TKA, at a minimum follow-up of 24 months. The mean follow-up was 61.1 months (24–102). Only patients with osteoarthritis were included. Clinical outcome was assessed using range of motion (ROM) and Oxford knee score (OKS). Radiographic assessment was performed using the femorotibial angle (FTA) at 6 weeks followed by assessment of bone–implant interface lucencies at final follow-up. There were no major early postoperative complications. The mean postoperative ROM in the TS and PS groups were 114.1 and 112.0, respectively. There was no difference in the mean ROM and OKS between the two groups. The mean FTA for patients in both groups was within 3° of the expected. There was no evidence of progressive lucencies or implant migration at final follow-up. The metaphyseally fixed TS knee design achieves comparable short-term functional outcomes when compared with conventional PS designs in primary knee arthroplasty. Long-term follow-up studies are required to assess survivorship.

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Five-Year Follow-up of Primary Optetrak Posterior Stabilized Total Knee Arthroplasties in Osteoarthritis

The Journal of Arthroplasty ◽

10.1016/j.arth.2005.04.028 ◽

2005 ◽

Vol 20 (7) ◽

pp. 927-931 ◽

Cited By ~ 17

Author(s):

Raymond P. Robinson

Keyword(s):

Total Knee Arthroplasties ◽

Posterior Stabilized ◽

Total Knee

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Validation of Lithuanian Arthroplasty Register Telephone Survey of 2769 Patients Operated for Total Knee Replacement

Medicina ◽

10.3390/medicina55060310 ◽

2019 ◽

Vol 55 (6) ◽

pp. 310

Author(s):

Egle Terteliene ◽

Kazimieras Grigaitis ◽

Otto Robertsson ◽

Narunas Porvaneckas ◽

Jolanta Dadoniene ◽

...

Keyword(s):

Total Knee Replacement ◽

Telephone Survey ◽

Total Knee Arthroplasties ◽

Telephone Number ◽

Arthroplasty Register ◽

Primary Surgery ◽

Primary Tkas ◽

Total Knee ◽

Revision Tkas ◽

Primary Total Knee

Background and objectives: The aim of our study is to validate the registration of knee arthroplasty revisions in the Lithuanian Arthroplasty Register (LAR) and thus give an indication of the accuracy of the published revision rates. Materials and methods: A total of 4269 primary total knee arthroplasties (TKAs) registered in the LAR between 2013 and 2015 were included. Two years after surgery the patients were contacted by phone in order to inquire if they had been subject to revision. The information from the patients was then cross checked against what had been registered in the LAR, and in case of a revision not having been registered hospital charts were investigated. Thus, the patients were followed up with regarding revision and/or death until 2017. A true revision was defined as an addition, exchange, or removal of one or all components. Results: Out of 4269 primary TKAs, we managed to contact and interview 2769 patients. Nine small hospitals were not able to provide contact details (telephone numbers) for 533 patients (549 knees). Sixty-seven patients (67 knees) were deceased (data from the Lithuanian National Census Register) and a further 438 patients (565 knees) appeared to have a wrong or non-valid telephone number, leaving 3031 (3091 knees) patients being contacted. Of those, 262 patients (266 knees) refused to participate in the study which left 2769 responders (2825 knees). Sixty-one patients said that reoperation had been performed on the index knee within two years of their primary surgery. After checking with the clinics, 10 were surgical procedures on the knee but not true revisions by our criteria. Out of the 51 true revisions we found that 46 were registered to the LAR as revised, while five (9.8%) revisions were missing. Conclusions: We conclude that the Lithuanian Arthroplasty Register has a good completeness of registered revision TKAs as only 9.8% of revisions were missing.

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