Alteration of the coronal plane soft tissues of the knee by osteoarthritis and total knee arthroplasty and the impact of this on surgical outcomes

Abstract Background Total knee arthroplasty is known to successfully alleviate pain and improve function in endstage knee osteoarthritis. However, there is some controversy with regard to the influence of obesity on clinical benefits after TKA. The aim of this study was to investigate the impact of body mass index (BMI) on improvement in pain, function and general health status following total knee arthroplasty (TKA). Methods A single-centre retrospective analysis of primary TKAs performed between 2006 and 2016 was performed. Data were collected preoperatively and 12-month postoperatively using WOMAC score and EQ-5D. Longitudinal score change was compared across the BMI categories identified by the World Health Organization. Results Data from 1565 patients [mean age 69.1, 62.2% women] were accessed. Weight distribution was: 21.2% BMI < 25.0 kg/m2, 36.9% BMI 25.0–29.9 kg/m2, 27.0% BMI 30.0–34.9 kg/m2, 10.2% BMI 35.0–39.9 kg/m2, and 4.6% BMI ≥ 40.0 kg/m2. All outcome measures improved between preoperative and 12-month follow-up (p < 0.001). In pairwise comparisons against normal weight patients, patients with class I-II obesity showed larger improvement on the WOMAC function and total score. For WOMAC pain improvements were larger for all three obesity classes. Conclusions Post-operative improvement in joint-specific outcomes was larger in obese patients compared to normal weight patients. These findings suggest that obese patients may have the greatest benefits from TKA with regard to function and pain relief one year post-op. Well balanced treatment decisions should fully account for both: Higher benefits in terms of pain relief and function as well as increased potential risks and complications. Trial registration This trial has been registered with the ethics committee of Eastern Switzerland (EKOS; Project-ID: EKOS 2020–00,879)

Download Full-text

The Impact of Gastric Bypass Surgery Compared to Total Knee Arthroplasty on Knee Symptoms

journal of Clinical & Experimental Orthopaedics ◽

10.4172/2471-8416.100058 ◽

2018 ◽

Vol 04 (02) ◽

Author(s):

Hafiz Kassam ◽

Allan Okrainec ◽

Timothy Jackson ◽

Michael G Zyweil ◽

Anthony V Perruccio ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Gastric Bypass ◽

Knee Arthroplasty ◽

Bypass Surgery ◽

Gastric Bypass Surgery ◽

Total Knee ◽

The Impact

Download Full-text

Bone ingrowth in total knee arthroplasty: The impact of HA-coatings and the relation with mechanical stability

Journal of Biomechanics ◽

10.1016/s0021-9290(98)80055-9 ◽

1998 ◽

Vol 31 ◽

pp. 26

Author(s):

L. Labey ◽

H. Van Campenhout ◽

J. Vander Sloten ◽

R. Van Audekercke ◽

G. Van der Perre ◽

...

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Mechanical Stability ◽

Bone Ingrowth ◽

Total Knee ◽

The Impact

Download Full-text

Why knees move like they do: A simulation of the effect of varying distal femoral and proximal tibial anatomy on coronal kinematic curve morphology

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117s00163 ◽

2017 ◽

Vol 5 (5_suppl5) ◽

pp. 2325967117S0016

Author(s):

Peter McEwen

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Proximal Tibia ◽

Coronal Plane ◽

Curve Shape ◽

Femoral Rotation ◽

Full Extension ◽

Reciprocal Effect ◽

Maximal Deviation ◽

Total Knee

Objective: Computer assisted total knee arthroplasty (CA TKA) platforms can provide detailed kinematic data that is presented in various forms including a coronal plane graphic that maps the flexion arc from full extension to deep flexion. Graphics obtained from normal tibiofemoral articulations reveal varied and complex kinematic patterns that have yet to be explained. An understanding of what drives curve variation would allow prediction of how a preoperative curve would be altered by total knee arthroplasty. Implant position could then be tailored to maintain a desirable curve or avoid an undesirable one. Methods: An articulated lower limb saw bone with a stable hip pivot was obtained. Adjustable osteotomies were created so that femoral torsion, femoral varus-valgus and tibial varus-valgus could be altered independently. The saw bone limb was registered with a CA TKA navigation system using the posterior condyles as a rotational axis. Axial and coronal plane morphology of the distal femur and coronal plane morphology of the proximal tibia were systematically altered and a kinematic curve obtained for each morphologic combination. Femoral rotational position was varied from 100 of internal torsion to 100 of external torsion in 20 increments. Similarly, femoral coronal position was varied from 20 of varus to 60 of valgus and tibial coronal position was varied from 5.50 of varus to 10 of valgus. Curves were obtained by manually flexing the joint through a full range of motion with the femoral condyles in contact with proximal tibia at all times. Results: Varying femoral rotation has no effect in full extension but drives the curve away from neutral as the knee flexes. Maximal deviation is seen at around 900 of flexion. Internal torsion drives the curve into valgus as the knee flexes and external torsion has a reciprocal effect. Varying femoral varus-valgus causes maximal deviation from neutral in full extension. Femoral varus drives the curve from varus in extension towards valgus as the knee flexes with the effect peaking in maximal flexion. Femoral valgus has a reciprocal effect. Varying tibial varus-valgus has no effect on curve shape but does move the curve either side of neutral. Complex (parabolic) curves are caused by large rotations or the opposing effects of femoral varus-valgus and femoral rotation. The modal human anatomy of slight femoral internal rotation, slight femoral valgus and slight tibial varus produces a straight neutral curve. Conclusion: Kinematic curve shape is driven by distal femoral anatomy. The typical changes made to distal femoral articular anatomy in TKA by externally rotating a neutrally orientated femoral component will bring many native curves towards neutral. Externally rotating when the preoperative curve begins neutral and drives into varus as the knee flexes will drive the curve harder into varus. Conversely, kinematic femoral placement will reconstitute the premorbid curve morphology. Which outcome is preferable has yet to be determined.

Download Full-text

Effect of Gait on Patellofemoral Mechanics

ASME 2008 Summer Bioengineering Conference, Parts A and B ◽

10.1115/sbc2008-192451 ◽

2008 ◽

Author(s):

Jeffrey E. Bischoff ◽

Justin S. Hertzler

Keyword(s):

Total Knee Arthroplasty ◽

Knee Arthroplasty ◽

Clinical Studies ◽

Patellofemoral Joint ◽

Knee Kinematics ◽

Component Design ◽

Total Knee ◽

The Impact ◽

Reconstructed Knee

Computational modeling of the reconstructed knee is an important tool in designing components for maximum functionality and life. Utilization of boundary conditions consistent with in vivo gait loading in such models enables predictions of knee kinematics and polyethylene damage [1–4], which can then be used to optimize component design. Several recent clinical studies have focused on complications associated with the patellofemoral joint [5–6], highlighting the need to better understand the mechanics of this compartment of total knee arthroplasty (TKA). This study utilizes a computational model to characterize the impact of gait loading on the mechanics of the patella in TKA.

Download Full-text