Various Types of Medial Tibial Bone Resorption after Total Knee Arthroplasty Using a Thick Cobalt Chromium Tibial Baseplate

Author(s):  
Sang Jun Song ◽  
Hyun Woo Lee ◽  
Se Gu Kang ◽  
Dae Kyung Bae ◽  
Cheol Hee Park

AbstractRecent literature has implicated a thick cobalt chromium baseplate as a potential source of stress shielding and medial tibial bone resorption after total knee arthroplasty (TKA) in a Western population. The purpose was to calculate the incidence of various types and severity of medial tibial bone resorption utilizing a novel classification system after TKA with a thick cobalt chromium baseplate in Asian patients. Five hundred TKAs using Attune prostheses with mean follow-up of 3.4 years were evaluated, using the prospective radiographic data. The mean age was 71.3 years. The preoperative mechanical axis was varus, 11.2 degrees. The type and severity of medial tibial bone resorption were categorized as type U (resorption under the tibial baseplate up to 50% [U1] or beyond 50% [U2] of medial tibial tray width), C (resorption around the penetrated cement under the baseplate), and M (resorption on the medial tibial cortex without extension to the baseplate). Bone resorption of medial proximal tibia was observed in 96 knees (19.2%). Types U1 and U2 were seen in 46 and 28 knees, respectively. Type C was observed in 12 knees and type M in 10 knees. The type U resorption group had significantly more preoperative varus deformity (varus 12.9 vs. 10.9 degrees, p = 0.017). Medial tibial bone resorption after TKAs using a thick cobalt chromium baseplate is not uncommon and has various locations, types, and severities. The medial tibial bone resorption might be related to various causes, including stress shielding, thermal necrosis from cement in the bony hole, and bony devascularization. The type-U resorption has to be closely observed in patients with preoperative severe varus deformity. This is a Level IV study.

2017 ◽  
Vol 32 (1) ◽  
pp. 79-82 ◽  
Author(s):  
J. Ryan Martin ◽  
Chad D. Watts ◽  
Daniel L. Levy ◽  
Todd M. Miner ◽  
Bryan D. Springer ◽  
...  

2018 ◽  
Vol 27 (4) ◽  
pp. 1270-1279 ◽  
Author(s):  
ShiZhong Gu ◽  
Shinichi Kuriyama ◽  
Shinichiro Nakamura ◽  
Kohei Nishitani ◽  
Hiromu Ito ◽  
...  

Author(s):  
Lennert de Ruiter ◽  
Dennis Janssen ◽  
Adam Briscoe ◽  
Nico Verdonschot

The current study was designed to investigate the mechanical response of a polyetheretherketone-on-polyethylene total knee replacement device during a deep squat. Application of this high-demand loading condition can identify weaknesses of the polyetheretherketone relative to cobalt-chromium. This study investigated whether the implant is strong enough for this type of loading, whether cement stresses are considerably changed and whether a polyetheretherketone femoral component is likely to lead to reduced periprosthetic bone loss as compared to a cobalt-chromium component. A finite element model of a total knee arthroplasty subjected to a deep squat loading condition, which was previously published, was adapted with an alternative total knee arthroplasty design made of either polyetheretherketone or cobalt-chromium. The maximum tensile and compressive stresses within the implant and cement mantle were analysed against their yield and fatigue stress levels. The amount of stress shielding within the bone was compared between the polyetheretherketone and cobalt-chromium cases. Relative to its material strength, tensile peak stresses were higher in the cobalt-chromium implant; compressive peak stresses were higher in the polyetheretherketone implant. The stress patterns differed substantially between polyetheretherketone and cobalt-chromium. The tensile stresses in the cement mantle supporting the polyetheretherketone implant were up to 33% lower than with the cobalt-chromium component, but twice as high for compression. Stress shielding was reduced to a median of 1% for the polyetheretherketone implant versus 56% for the cobalt-chromium implant. Both the polyetheretherketone implant and the underlying cement mantle should be able to cope with the stress levels present during a deep squat. Relative to the cobalt-chromium component, stress shielding of the periprosthetic femur was substantially less with a polyetheretherketone femoral component.


2021 ◽  
Vol 29 (1) ◽  
pp. 230949902110020
Author(s):  
Seikai Toyooka ◽  
Hironari Masuda ◽  
Nobuhiro Nishihara ◽  
Takashi Kobayashi ◽  
Wataru Miyamoto ◽  
...  

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.


Author(s):  
Masanori Tsubosaka ◽  
Tomoyuki Kamenaga ◽  
Yuichi Kuroda ◽  
Koji Takayama ◽  
Shingo Hashimoto ◽  
...  

AbstractSeveral studies have reported better clinical outcomes following kinematically aligned total knee arthroplasty (KA-TKA) than mechanically aligned TKA. Consistent reproduction of a KA-TKA is aided by accurate tibial bone resections using computer navigation systems. This study compares an accelerometer-based portable navigation system with a conventional navigation system on tibial bone resection and clinical outcomes in KA-TKA. This study included 60 knees of patients who underwent primary KA-TKA between May 2015 and September 2017. They were randomly assigned to the OrthoPilot and iASSIST groups. A tibial bone cut was performed with 3 degree varus and 7 degree posterior slope in relation to the mechanical axis in all cases. The tibial component angle (TCA) and posterior slope angle (PSA) were evaluated by postoperative radiography, and those that deviated more than 2 degree were set as outliers. The clinical outcomes were the knee range of motion (ROM) and 2011 Knee Society Score (KSS) evaluated at 1 year postoperation. The groups were compared in terms of the TCA, PSA, number of outliers, ROM, and 2011 KSS (p < 0.05). No significant difference was observed between the groups in terms of the mean TCA, PSA, number of outliers, ROM, and categories of the 2011 KSS (objective knee indicators, symptoms, satisfaction, expectations, and functional activities). Although tibial bone cuts were performed with 3 degree varus and 7 degree posterior slope, no significant difference was observed between the OrthoPilot and iASSIST groups in terms of the accuracy of cuts or postoperative clinical result. The iASSIST was found to be a simple and useful navigation system for KA-TKA.


2005 ◽  
Vol 20 (5) ◽  
pp. 550-561 ◽  
Author(s):  
Arun B. Mullaji ◽  
Vinod Padmanabhan ◽  
Gaurav Jindal

Author(s):  
Mohammadreza Minator Sajjadi ◽  
Mohammad Ali Okhovatpour ◽  
Yaser Safaei ◽  
Behrooz Faramarzi ◽  
Reza Zandi

AbstractThe aim of this study was to assess the predictive value of the femoral intermechanical-anatomical angle (IMA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibia angle (MPTA), femorotibial or varus angle (VA), and joint line convergence angle (CA) in predicting the stage of the medial collateral ligament (MCL) during total knee arthroplasty (TKA) of varus knee. We evaluated 229 patients with osteoarthritic varus knee who underwent primary TKA, prospectively. They were categorized in three groups based on the extent of medial soft tissue release that performed during TKA Group 1, osteophytes removal and release of the deep MCL and posteromedial capsule (stage 1); Group 2, the release of the semimembranosus (stage 2); and Group 3, release of the superficial MCL (stage 3) and/or the pes anserinus (stage 4). We evaluated the preoperative standing coronal hip-knee-ankle alignment view to assessing the possible correlations between the knee angles and extent of soft tissue release. A significant difference was observed between the three groups in terms of preoperative VA, CA, and MPTA by using the Kruskal–Wallis test. The extent of medial release increased with increasing VA and CA as well as decreasing MPTA in preoperative long-leg standing radiographs. Finally, a patient with a preoperative VA larger than 19, CA larger than 6, or MPTA smaller than 81 would need a stage 3 or 4 of MCL release. The overall results showed that the VA and MPTA could be useful in predicting the extent of medial soft tissue release during TKA of varus knee.


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