THE KNEE SOCIETY VIRTUAL FELLOWSHIP CHAPTER 16 LONG-TERM FAILURE MECHANISMS AND SURVIVORSHIP Long-Term Failure Mechanisms and Survivorship Presented by: Michael A. Mont, MD, Assem A. Sultan, MD, and Michael E. Berend, MD
Indiana Michael A. Mont, MD Assem A. Sultan, MD Michael E. Berend, MD
Overview 1 2 3 Long-term survivorship of primary total knee arthroplasty What are the common long-term failure mechanisms? Discussion of each mechanism through available evidence
Mechanisms of TKA failure: short vs. long term mechanisms Short-term failure mechanisms 5 years or less Long-term failure mechanisms 10 to 15 years or more
Mechanisms of TKA failure: short-term mechanisms Fehring et al., 1 analyzed short-term failure mechanisms in 279 patients who required revision within 5 years of the index primary TKA. Causes of failure were infection (38%), prosthetic Instability (27%), cementless ingrowth failure (13%), patellofemoral problems (8%), and component wear and osteolysis (7%) Hossain et al., 2 reported causes of short-term failure in their cohort of 343 patients and mean interval from primary TKA to revision of 7 years. Main causes included infection (32.7%), aseptic loosening (14.9%), and polyethylene wear (12.3%) Bozic et al., 3 in a retrospective review of Medicare database reported infection (25.2%), mechanical loosening (16.1%), and implant failure/breakage (9.7%) as the most common causes of revision TKA (1) Fehring TK, Odum S, Griffin WL, Mason JB, Nadaud M. Early failures in total knee arthroplasty. Clin Orthop Relat Res. 2001;(392):315-318. (2) Hossain F, Patel S, Haddad FS. Midterm Assessment of Causes and Results of Revision Total Knee Arthroplasty. Clin Orthop Relat Res. 2010;468(5):1221-1228. doi:10.1007/s11999-009- 1204-0. (3) Bozic KJ, Kurtz SM, Lau E, et al. The epidemiology of revision total knee arthroplasty in the United States. Clin Orthop Relat Res. 2010;468(1):45-51. doi:10.1007/s11999-009-0945-0.
Mechanisms of TKA failure: short-term mechanisms Sharkey et al. CORR 2002 Mechanisms Percentages (%) Polyethylene wear 25 Loosening 24 Instability 21 Infections 17.5 Arthrofibrosis 15 Malalignment 12 Extensor mechanism failure 7 periprosthetic fracture 3 Sharkey PF, Hozack WJ, Rothman RH, Shastri S, Jacoby SM. Insall Award Paper. Why Are Total Knee Arthroplasties Failing Today? Clin Orthop Relat Res. 2002;(404):7-13.
Mechanisms of TKA failure: short vs. long term mechanisms Short-term* Long-term** vs. Polyethylene wear (25%) Loosening (24%) Instability (21%) Infection (early and late) (17.5%) Arthrofibrosis (15%) Malalignment (12%) Extensor mech failure ( 7%) periprosthetic fracture (3%) Aseptic loosening (30% at 15y) Polyethylene wear (48% at 15y) Less common: Instability, malalignment, late infection *Sharkey Et Al. Clin Ortho 2002 **Schroer WC Et Al., Why Are Total Knees Failing Today? Etiology Of Total Knee Revision In 2010 And 2011. J Arthroplasty. 2013;28(8 Suppl):116-119.
Survivorship of total knee arthroplasty short vs. long-term Studies Year Survivorship (%) F/U (years) Main cause of failure Macheras et al. 2017 98.8 17 *Patellar non-replacement, peri-prosthetic fracture Schiavone et al. 2017 94.7 15 *Infection, aseptic loosening McCalden et al. 2017 96.4 15 *Infection, stiffness Mont et al. 2014 95.6 10 Aseptic loosening Vessely et al. 2006 96 15 Infection,* aseptic loosening and PE wear Sharma et al. 2005 94 16 Aseptic loosening Rodriguez and Ranawat * Short-term causes of failure 2001 90 20 Aseptic loosening
Mechanisms of long-term TKA failure Over the years, aseptic loosening has become the main long-term mechanism of failure Polyethylene wear is becoming less common as a long-term mechanism of failure after 2006. Rarely occur before10 to15 years from index surgery; more predominant after 15 years Other causes: instability, malalignment, late infection Schroer WC et al., Why are total knees failing today? Etiology of total knee revision in 2010 and 2011. J Arthroplasty. 2013;28(8 Suppl):116-119.
Mechanisms of long-term TKA failure Consistent After 15 y/s Schroer WC et al., Why are total knees failing today? Etiology of total knee revision in 2010 and 2011. J arthroplasty. 2013;28(8 suppl):116-119.
What exactly is aseptic loosening? General term used to describe two distinct processes LOMBARDI A V, BEREND KR, ADAMS JB. WHY KNEE REPLACEMENTS FAIL IN 2013: PATIENT, SURGEON, OR IMPLANT? BONE JOINT J. 2014;96-B(11 SUPPLE A):101-104. Implants that were never well-fixed to bone from the time of surgery Most cases of early aseptic loosening Represent a failure of fixation Implants that were once wellfixed to the bone and loosened over time Most cases of late aseptic loosening (True aseptic loosening) Exact mechanism not completely understood, multifactorial Available literature don t stratify reported patients based on mechanism of aseptic loosening
Aseptic loosening: etiologies True long-term aseptic loosening is multifactorial (prosthetic malalignment, implant factors, osteolysis) Recent multicenter study estimated aseptic loosening to cause 40% of failures between 5 to 15 years and 30% after 15 years Failure of tibial component is by far more common than femoral component SCHROER WC ET AL., WHY ARE TOTAL KNEES FAILING TODAY? ETIOLOGY OF TOTAL KNEE REVISION IN 2010 AND 2011. J ARTHROPLASTY. 2013;28(8 SUPPL):116-119.
Aseptic loosening : tibial component Older implants exhibited high rates of tibial component loosening Polycentric and geometric surface articulation (Freeman-Swanson) Surface cement technique : higher loosening rates 1 Cementing the undersurface of the tibial base but not keel All polyethylene tibial components : up to 30% will loosen at 10 years. 2 Implant design factors: Trays with shorter stems more likely to fail 3 Improved implant designs reduced tibial loosening rates : Addition of central fixation pig: reduced loosening observed in various prosthesis 4 Cementing tibial stems Metal backed tibial trays Even distribution of stress Improved long-term survivorship: 97 100 % at 10 to 14 years 5-6 (1) Bert JM, Kelly FB: The incidence of tibial component loosening in cemented total knee arthroplasty when the tibial stem is not cemented. Presented at the American Academy of Orthopaedic Surgery Meeting, Orlando 2000 (2) Faris PM, Ritter MA, Keating EM, et al: The AGC all-polyethylene tibial component: a ten-year clinical evaluation. J Bone Joint Surg Am 85:489, 2003 (3) Foran JRH, Whited BW, Sporer SM. Early aseptic loosening with a precoated low-profile tibial component: a case series. J Arthroplasty. 2011;26(8):1445-1450 (4) Wright J, Ewald FC, Walker PS, et al: Total knee arthroplasty with the Kinematic prosthesis: results after five to nine years: a follow-up note. J Bone Joint Surg Am 72:1003, 1990 (5) Gioe TJ, Stroemer ES, Santos ER: All-polyethylene and metal-backed tibias have similar outcomes at 10 years: a randomized level I [corrected] evidence study. Clin Orthop Relat Res 455:212, 2007 (6) Parsch D, Krüger M, Moser MT, et al: Follow-up of 11 16 years after modular fixed-bearing TKA. Int Orthop 33:431, 2009
Varus component alignment has been reported to increase aseptic tibial component alignment through medial tibial collapse Tibial component alignment (p<0.007) failed: 3.2 o varus survived: 0.2 o varus Overall alignment failed: 1.6 o valgus overall: 3.9 o valgus Berend, et al, CORR, 2004
Varus component alignment has been reported to increase aseptic tibial component alignment through medial tibial collapse in patients with a BMI over 33.7 Berend, et al, Berend, CORR, 2004 et al, CORR, 2004
OPYRIGHT 2016 THE KNEE SOCIETY Fang, Ritter, JOA 2009 Ritter, et al, JBJS, 2011
Aseptic loosening : tibial component Cemented vs. cementless fixation: Historical cementless designs showed early aseptic loosening, revisions, and poor survivorship 1 Cemented fixation remains the gold-standard fixation method when compared to historic cementless Newly introduced cementless implants: excellent survivorship (Short to mid-term 2 10 years) 2 (1) Fehring TK, Griffin WL: Revision of failed cementless total knee implants with cement. Clin Orthop 356:34 38, 1998 (2) Harwin SF, Elmallah RK, Jauregui JJ, Cherian JJ, Mont MA. Outcomes of a Newer-Generation Cementless Total Knee Arthroplasty Design. Harwin SF, ed. Orthopedics. 2015;38(10):620-624. doi:10.3928/01477447-20151002-04.
Cementless vs cemented fixation Cementless: 95.6 % Cemented: 95.3 % 10 year survivorship
Aseptic loosening : femoral component Uncommon when compared to tibial loosening 1 Estimated incidence at 1.4% at 15 years Unique pattern: bone resorption posteriorly causes distal femur to migrate into an anterior and flexed position Posterior and distal region thought to be under severe stress 2 (1) King TV, Scott RD: Femoral component loosening in total knee arthroplasty. Clin Orthop Relat Res 194:285, 1985 (2) Whiteside LA, Pafford J: Load transfer characteristics of a noncemented total knee arthroplasty. Clin Orthop Relat Res 239:168, 1989
Polyethylene wear Used to be leading cause of late TKA failure Over the past 15 years, improved manufacturing technology and implant design has improved longevity 1-2 Cause of 15% of revisions between 5 to 15 years and 48% after 15 years. 1-2 Schroer WC Et Al., Why Are Total Knees Failing Today? Etiology Of Total Knee Revision In 2010 And 2011. J Arthroplasty. 2013;28(8 Suppl):116-119. Lombardi A V, Berend Kr, Adams Jb. Why Knee Replacements Fail In 2013: Patient, Surgeon, Or Implant? Bone Joint J. 2014;96-B(11 Supple A):101-104.
POLYETHYLENE WEAR Longevity Implant factors: Design: Flat disk design: smaller contact = higher stress per unit area Manufacturing and sterilization: Oxidation decrease wear resistance Historically was done with gamma radiation in air environment Cross-Linking: Non-cross linked PE known to release more debris Recently : More conforming designs, better load distribution, highly polished surfaces Sterilization in inert gas environment Annealed Highly Cross-Linked Polyethylene was introduced Chakravarty R, Elmallah R, Cherian J, Kurtz S, Mont M. Polyethylene Wear in Knee Arthroplasty. J Knee Surg. 2015;28(5):370-375. doi:10.1055/s-0035-1551833.
POLYETHYLENE WEAR Surgical techniques: more attention to alignment, availability of image guidance and navigation systems Patient factors: Male, young, and more active patients are more prone to wear Obesity may accelerate polyethylene wear Chakravarty R, Elmallah R, Cherian J, Kurtz S, Mont M. Polyethylene Wear in Knee Arthroplasty. J Knee Surg. 2015;28(5):370-375. doi:10.1055/s-0035-1551833.
(3) Collier MB, Engh CA, McCauley JP, et al: Osteolysis after total knee arthroplasty: influence of tibial baseplate surface finish and sterilization of polyethylene insert. J Bone Joint Surg Am 87:2702, 2005 Osteolysis Inflammatory response to particulate debris Reported at 7% between, 10 to 18 years post-implantation 1 Linked to certain factors : Polyethylene (PE) sterilization method: reduced osteolysis with PE-sterilized in inert gas (vs. air) and non-radiation methods 2 The use of PS knees: associated tibial post impingement Backside wear in modular designs, and backside wear in mobile-bearing knees 3 Younger age is associated with radiographic evidence of osteolysis, but no demonstrated clinical relevance 1 (1) Lachiewicz PF, Soileau ES: The rates of osteolysis and loosening associated with a modular posterior stabilized knee replacement. Results at five to fourteen years. J Bone Joint Surg Am 86:525, 2004 (2) Collier MB, Engh CA, Jr, McAuley JP, et al: Factors associated with the loss of thickness of polyethylene tibial bearings after knee arthroplasty. J Bone Joint Surg Am 89:1306, 2007
Instability Less common cause of long-term failure Responsible for 16% of revisions at 5 to 15 years, which drops to 4.6% after 15 years Vince et al., (2006) reported on progressive late instability to be multifactorial: Repetitive injury from excessive stress on collateral ligaments in obese patient Progressive ligaments loosening with excessive activity VINCE KG, ABDEEN A, SUGIMORI T. THE UNSTABLE TOTAL KNEE ARTHROPLASTY: CAUSES AND CURES. J ARTHROPLASTY. 2006;21(4 SUPPL 1):44-49. DOI:10.1016/J.ARTH.2006.02.101.
Late instability Mulhall et al. (2006) reported instability as one of the predominant causes in their cohort with mean time to revision of 8 years from index procedure, possible linked risk factors: Secondary to PE wear in 44% of instability cases Implant loosening/ migration in 29% Or : late ligamentous failure Overall: on the long-term seems to be a secondary mechanism for failure following aseptic loosening or poly wear MULHALL KJ, GHOMRAWI HM, SCULLY S, CALLAGHAN JJ, SALEH KJ. CURRENT ETIOLOGIES AND MODES OF FAILURE IN TOTAL KNEE ARTHROPLASTY REVISION. CLIN ORTHOP RELAT RES. 2006;446:45-50. DOI:10.1097/01.BLO.0000214421.21712.62.
Periprosthetic fractures Long-term data on the incidence of periprosthetic fractures (after 10 years) is lacking Vessely et al. reported on incidence of peri-prosthetic fractures in a large cohort of 1,000 patients followed for mean of 15.7 years Overall, they reported periprosthetic fractures prevalence rates of femoral (1.4%) and patellar (2.0%) periprosthetic fractures. This may reflect a rising problem with improved implant survivorship in an aging population 36 fractures 15 of 20 patellar occurred within 5 years 8 of 14 supracondylar femur fractures after 10 years VESSELY MB, WHALEY AL, HARMSEN WS, SCHLECK CD, BERRY DJ. THE CHITRANJAN RANAWAT AWARD: LONG-TERM SURVIVORSHIP AND FAILURE MODES OF 1000 CEMENTED CONDYLAR TOTAL KNEE ARTHROPLASTIES. CLIN ORTHOP RELAT RES. 2006;452:28-34.
Periprosthetic late infection Infection is less likely a cause of failure beyond two years Most studies reported on infection as the leading cause of failure in the first two years from the index surgery Some authors reported on septic failure at between 2 to 5 years At 10 to 15 years, it is very rarely reported failure mechanism. However, probably under-reported *Sharkey et al. Clin Ortho 2002 *Lombardi A V, Berend Kr, Adams Jb. Why Knee Replacements Fail In 2013: Patient, Surgeon, Or Implant? Bone Joint J. 2014;96- B(11 Supple A):101-104
Conclusion Long-term survivorship of TKA has been above 90%. Most recent studies report survivorships > 95% recently New cementless prostheses have demonstrated improved long-term success For the last 10 to 15 years, polyethylene wear has become less evident, although still high beyond 15 years Aseptic loosening is a consistently high cause of long-term TKA failure Other less common mechanisms include instability, peri-prosthetic fractures and rarely, late infection
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