Management of instability after primary total knee arthroplasty: an evidence-based review

Abstract Background Instability is one of the most common reasons for revision after a total knee replacement. It accounts for 17.4% of all single-stage revision procedures performed in the UK National Joint Registry. Through a careful patient evaluation, physical assessment and review of investigations one can identify the likely type of instability. Aims To critically examine the different types of instability, their presentation and evidence-based management options. Method A comprehensive literature search was conducted to identify articles relevant to the aetiology and management of instability in total knee replacements. Results Instability should be categorised as isolated or global and then, as flexion, mid-flexion, extension or recurvatum types. By identifying the aetiology of instability one can correctly restore balance and stability. Conclusion With careful judgement and meticulous surgical planning, instability can be addressed and revision surgery can provide patients with successful outcomes.

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Is there a need for early post-operative x-rays in primary total knee replacements? Experience of a centre in the UK

Annals of The Royal College of Surgeons of England ◽

10.1308/003588412x13171221501780 ◽

2012 ◽

Vol 94 (3) ◽

pp. 199-200 ◽

Cited By ~ 7

Author(s):

S Hassan ◽

A Wall ◽

B Ayyawamy ◽

S Rogers ◽

SP Mills ◽

...

Keyword(s):

Tibial Fracture ◽

Operative Management ◽

X Rays ◽

Inferior Pole ◽

Total Knee Replacements ◽

Knee Replacements ◽

Total Knee ◽

The Uk ◽

Primary Total Knee

INTRODUCTION Early post-operative x-rays are often taken in total knee replacements (TKRs). Patient mobilisation may be delayed until these x-rays are obtained and this may prolong discharge. The aim of this study was to assess the value of such early x-rays and whether they influenced the early post-operative management of these patients. METHODS A total of 624 consecutive TKRs performed at the Blackpool Victoria Hospital over a 34-month period were evaluated. Plain anteroposterior and lateral x-rays were examined. RESULTS Two patients were found to have significant abnormalities: an undisplaced peri prosthetic tibial fracture and a partial inferior pole patellar avulsion. Neither of these required further treatment or influenced mobility. No other complications were noted that changed routine post-operative management. CONCLUSIONS These results question the need for immediate x-rays in primary TKRs.

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Effect of body mass index on functional outcome in primary total knee arthroplasty - a single institution analysis of 2180 primary total knee replacements

World Journal of Orthopedics ◽

10.5312/wjo.v7.i10.664 ◽

2016 ◽

Vol 7 (10) ◽

pp. 664 ◽

Cited By ~ 7

Author(s):

Shane C O’Neill ◽

Joseph S Butler ◽

Adam Daly ◽

Darren F Lui ◽

Patrick Kenny

Keyword(s):

Body Mass Index ◽

Total Knee Arthroplasty ◽

Functional Outcome ◽

Knee Arthroplasty ◽

Primary Total Knee Arthroplasty ◽

Single Institution ◽

Total Knee Replacements ◽

Knee Replacements ◽

Total Knee ◽

Primary Total Knee

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Outcome & Survival Analysis of Conventional Measured Resection, Neutral Alignment Attune TKA vs CAS Anatomic Tibia, Balanced Femur, Constitutional Alignment Attune TKA

Orthopaedic Journal of Sports Medicine ◽

10.1177/2325967117s00156 ◽

2017 ◽

Vol 5 (5_suppl5) ◽

pp. 2325967117S0015 ◽

Cited By ~ 2

Author(s):

Mark Clatworthy

Keyword(s):

Mechanical Axis ◽

Computer Assisted ◽

Joint Registry ◽

Total Knee Replacements ◽

Balanced Approach ◽

Measured Resection ◽

Knee Replacements ◽

Total Knee ◽

Neutral Alignment ◽

Oxford Score

Objectives: Arthroplasty knee surgeons have traditionally performed a measured resection technique with a neutral mechanical axis. We have recently developed a new total knee arthroplasty technique whereby the tibia is cut anatomically and the femoral component position is determined using a balanced approach utilizing a computer assisted ligament tension device with aim of restoring constitutional alignment. This study compares the Oxford scores and survival of these two techniques for Attune TKA’s. Method: The New Zealand Joint Registry has requested Oxford Knee Scores at six months on all Attune Total Knee Replacements performed. 1088 scores have been returned. 716 have been performed using a conventional measured resection technique aiming for a neutral mechanical axis. 362 have been performed using the CAS anatomic tibia, balanced femur (ATBF) technique aiming for constitutional alignment. Oxford scores are compared alone and with a multivariate analysis including age, sex, surgeon level, fixed vs mobile, public vs private, operative time and cruciate retaining vs cruciate substituting Results: Mean Oxford Conventional TKA univariate Oxford Score is 38.1 Mean Oxford CAS ATBF TKA univariate Oxford Score is 40.7 p=<0.001 Mean Oxford Conventional TKA multivariate Oxford Score is 36.9 Mean Oxford CAS ATBF TKA multivariate Oxford Score is 39.1 p=<0.001 The CAS ATBF had 10% less poor and fair scores and 15% more excellent scores Non infection conventional TKA has 0.71 failures per 100 component years Non infection CAS ATBF TKA has 0.25 failures per 100 component years. Conclusion: The CAS assisted anatomic tibia balanced femur TKA has a significantly higher Oxford score with a three times lower non infection failure rate at three years

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Three-Dimensional Dynamic Simulation of Total Knee Replacement Motion During a Step-Up Task

Journal of Biomechanical Engineering ◽

10.1115/1.1406950 ◽

2001 ◽

Vol 123 (6) ◽

pp. 599-606 ◽

Cited By ~ 93

Author(s):

Stephen J. Piazza ◽

Scott L. Delp

Keyword(s):

Activity Patterns ◽

Equations Of Motion ◽

Three Dimensional ◽

Knee Kinematics ◽

Prosthetic Knee ◽

Total Knee Replacements ◽

Contact Points ◽

Flexion Extension ◽

Knee Replacements ◽

Total Knee

A three-dimensional, dynamic model of the tibiofemoral and patellofemoral articulations was developed to predict the motions of knee implants during a step-up activity. Patterns of muscle activity, initial joint angles and velocities, and kinematics of the hip and ankle were measured experimentally and used as inputs to the simulation. Prosthetic knee kinematics were determined by integration of dynamic equations of motion subject to forces generated by muscles, ligaments, and contact at both the tibiofemoral and patellofemoral articulations. The modeling of contacts between implants did not rely upon explicit constraint equations; thus, changes in the number of contact points were allowed without modification to the model formulation. The simulation reproduced experimentally measured flexion–extension angle of the knee (within one standard deviation), but translations at the tibiofemoral articulations were larger during the simulated step-up task than those reported for patients with total knee replacements.

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