Partial and Total Knee Replacement

Mark G. Freeman, MD

Assistant Professor and Chief, Division of Adult Reconstruction

Department of Orthopaedic Surgery University of Tennessee COM Chattanooga

Medical Director and Staff Surgeon

UT Erlanger Orthopaedics / Erlanger Orthopaedic Institute

April 8, 2017

Disclosures

•  Consultant, Depuy •  Consultant, Medtronic •  Consultant, Smith and Nephew •  HealthTrust PG Orthopaedic Advisory Board

Goals for Knee Reconstruction

•  Pain Relief •  Improved Function

–  Good Stability –  Good ROM

•  Durable •  Reproducible •  Efficient •  Cost-effective

The knee is three articular compartments!

With complex ligament dynamics!

Remember: What are we treating? •  Arthritis = joint destruction = PAIN

– Osteoarthritis –  Inflammatory – Post-traumatic

•  Stiffness / Loss of ROM •  Instability / Ligament Dysfunction •  Deformity

Follow pioneers… but not blindly!

Partials cannot…

•  Take away pain from a global joint problem •  Improve significant contractures •  Improve significant deformities •  Improve cruciate ligament dysfunction •  Improve collateral ligament dysfunction

How many patients do not have any of these problems?

Tire Analogy

•  If out of alignment, tread gone everywhere = TKA

•  If, and only if, reasonable alignment, isolated disease, intact stability, then partial is successful…

Indications for a Uni – 5%

“Intraoperative findings in varus osteoarthritis of the knee”

Ritter, et. al., JBJS 86-B, 2004. •  4021 patients with preop isolated varus OA •  247 patients (6%) intraop isolated medial disease •  168 patients (4.3%) met clinical criteria

Possibly more Uni’s •  Retrospective Analysis of Total Knee Arthroplasty Cases

for Visual, Histological, and Clinical Eligibility of Unicompartmental Knee Arthroplasties

–  Sally Arno, MSc,* Diana Maffei, BA,* Peter S. Walker, PhD,* Ran Schwarzkopf, MD,* Panna Desai, MD,y and German C. Steiner, Mdy

–  Journal of Arthroplasty in press

•  97 patients undergoing TKA, 7 surgeons •  Visual look at lateral and Patellofemoral •  Histology •  Absence of contraindications for UNI •  21% were candidates for UNI

DeBoer’s Warning….

•  Very few patients meet the strict criteria for Unicondylar knee replacement.

•  Most inferior results occur when the surgeon expands the indications for partial knee replacement

TKA Results

•  Pubmed search – Long term results of TKA •  Greater than 30 English articles •  Usually 10 – 20 years •  Survivorship 80% +, often > 90%! •  Knee scores mid 90’s

– All this means: many “happy patients”

Why bother with partials?

•  Minimally invasive? – Less blood loss, faster recovery, shorter inpatient stay

•  Remember these are people with less disease •  TKA is a big operation, but getting better and better

•  More natural kinematics: normal feeling knee? •  TKA’s do feel mechanical, but designs are improving

•  Categories of patients that are not great for TKA? –  Elderly: low demand, high risk from operation –  Young: high demand, high risk for TKA wear: “bridge”

Partials often fall short (aka contraindications)

•  Inflammatory arthritis •  ACL insufficiency (will wear) •  Multiple compartment wear •  Cannot correct deformity •  Stiffness •  Subluxation •  Obesity (tibial loosening)

UNI Results

•  10+ article of 5-13 year results, not as long F/U •  Excellent outcome scores, lower survivorship:

–  around 80 to 95% at ten years across studies •  Early failures related to patient selection / surgeon •  Late failures due to progression of OA •  Outcomes much more implant & surgeon specific

–  Design, Generation / Evolution, Instrumentation

Volume Effects

•  Oxford Uni results – Low volume surgeons (< 10 uni’s / yr) – 15-25%

failures less than 5 years – High volume surgeons (> 30 uni’s / yr) - < 5% failures

at 8 years. – Overall around 90% survivorship at ten years

•  Confirmed across all UNI designs in Norwegian registry data, Furnes, JBJS 2007 –  Data collected from 1994 to 2004

Revision UNI to TKA

•  Not so simple! •  Barrett WP, Scott RD. Revision of failed unicondylar

unicompartmental knee arthroplasty. J Bone Joint Surg Am. 1987;69:1328-35.

–  50% of cases required long stems and revision implants. •  Springer BD, Scott RD, Thornhill TS. Conversion of failed

unicompartmental knee arthroplasty to TKA. Clin Orthop Relat Res. 2006; (446):214-220. 9-23% metal augmentation 27-45% bone grafting

By Keith R. Berend, MD; Joseph George, MD; Adolph V. Lombardi Jr., MD ORTHOPEDICS 2009; 32:684

•  13% to 75% required stems and metallic augments –  Revision reason –  UNI type

By Keith R. Berend, MD; Joseph George, MD; Adolph V. Lombardi Jr., MD ORTHOPEDICS 2009; 32:684

Uni Revision to TKA

•  Int Orthop. 2010 Jun;34(5):649-53. –  Järvenpää J, Kettunen J, Miettinen H, Kröger H. –  49 pts, pain and stiffness higher in uni revisions – WOMAC scores worse than primary TKA

UNI Revision to TKA 2012

•  Revision of Minimal Resection Resurfacing Unicondylar Knee Arthroplasty to Total Knee Arthroplasty: Results Compared With Primary Total Knee Arthroplasty. –  O'Donnell TM, Abouazza O, Neil MJ. J Arthroplasty. 2012 Jul 16.

–  2 to 4% stems and augments –  40% bone grafting

•  Unicompartmental knee arthroplasties revised to total knee arthroplasties compared with primary total knee arthroplasties. –  Rancourt MF, Kemp KA, Plamondon SM, Kim PR, Dervin GF. J Arthroplasty.

2012 Sep;27(8 Suppl):106-10. Epub 2012 Apr 13.

TKA in Young Patients 174. Ranawat CS, Padgett DE, Ohashi Y. Total knee arthroplasty for patients younger than 55 years. Clin Orthop. 1989;248:27-33. 175. Stern SH, Bowen MK, Insall JN, Scuderi GR. Cemented total knee arthroplasty for gonarthrosis in patients 55 years old or younger. Clin Orthop. 1990;260:124-9. 176. Dalury DF, Ewald FC, Christie MJ, Scott RD. Total knee arthroplasty in a group of patients less than 45 years of age. J Arthroplasty. 1995;10:598-602. 177. Gill GS, Chan KC, Mills DM. 5- to 18- year follow-up study of cemented total knee arthroplasty for patients 55 years old or younger. J Arthroplasty. 1997; 12:49-54. 178. Diduch DR, Insall JN, Scott WN, Scuderi GR, Font-Rodriguez D. Total knee replacement in young, active patients. Long-term follow-up and functional outcome. J Bone Joint Surg Am. 1997;79:575-82.

Compare UNI vs. TKA

•  Furnes et al. Failure Mechanisms After Unicompartmental and Tricompartmental Primary Knee Replacement with Cement J. Bone Joint Surg. Am., Mar 2007; 89: 519 – 525

•  Kuipers et al. Factors associated with reduced early survival in the Oxford phase III medial unicompartment knee replacement. Knee. 2009 Aug 27.

•  Parratte et al. Medial unicompartmental knee replacement in the under-50s. J Bone Joint Surg Br. 2009 Mar;91(3):351-6.

•  Mont MA et al. Different surgical options for monocompartmental osteoarthritis of the knee: HTO versus UNI versus TKA: indications, techniques, results, and controversies. Instr Course Lect. 2004;53:265-83. Review.

Octagon Matchup…20th round

•  Unicompartmental versus total knee arthroplasty database analysis: is there a winner?

–  Lyons MC, MacDonald SJ, Somerville LE, Naudie DD, McCalden RW. –  Clin Orthop Relat Res. 2012 Jan;470(1):84-90.

•  Isolated Unicompartment OA •  Intact ACL •  Varus Deformity < 10 degrees (deformity should be

passively correctable after removal of osteophytes)

•  Valgus Deformity <15 degrees •  Flexion contracture < 5 degrees •  Weight < 80 kg (180 lbs) •  ROM > 90 degrees Kozinn & Scott, JBJS- 71A, 1989.

Save the partials for these guys!

Why TKA is Preferred to Uni

1.  Ideal indications for a Unicondylar Arthroplasty are uncommon (The general orthopaedic surgeon would have 2 to 3 candidates per year)

2.  The long-term survivorship have been inferior when compared to TKA, especially in young patients.

3.  The surgical technique is more difficult than with tricompartment arthroplasty.

4.  Revision to conventional TKA can be complex.

Performance to patient expectations

•  2 Arms (TKA v Normal Knee) •  Age and Gender matched arms Clin Orthop Relat Res. 2005 Feb;431:157-165: Noble PC, Gordon MJ … Mathis KB

•  243 TKA Patients v 257 individuals •  Performance to expectations was poor

Performance/Satisfaction of TKA’s v THA?

•  Post THA: sports activities increased from 36% to 52%

•  Post TKA: sports activities decreased from 42% to 34%

The Ulm Osteoarthritis Study- K Huch

•  Up to 20% of patients are not satisfied with the outcome following total knee replacement

•  Only 82% to 89% of primary TKA patients are satisfied

J Bone Joint Surg Br. 2010 Sep;92(9): Scott CE, Howie CR, MacDonald D, Biant LC Clin Orthop Relat Res. 2010 Jan;468(1):57-63: Bourne RB, Chesworth BM, Davis AM, Mahomed NN, Charron KD

•  Velocity ↓

•  Stride length ↓

•  Mid-stance knee flexion (quad avoidance gait)

•  ↓ Max knee flexion during stance and swing phases

Dorr, CORR 1988 Kramers, JOA 1997 Saari, Acta Orthop 2005 Andriacchi, JBJS-A 1982

Is gait altered after TKA?

•  Consistent greater quadriceps muscular effort on the Conventional TKA versus non-operated leg (7231.1 vs 2547.3 at p=0.0267)

•  The average EMG amplitude

was greater for the Conventional TKA versus the non-operated leg (43 vs 16 at p=0.035)

•  Conventional TKA displayed 3x quad effort versus non-operated leg

Lester DK. Objective Sagittal Instability of CR-TKA by Functional EMG During Normal Walking. AAOS. 2012; Presentation No. 810

Does any of this affect muscles?

Why Uni is Preferred to TKA

1.  Less Risk: infection, stiffness, bleeding, DVT/PE

2.  Faster Recovery less pain, off aids, back to work

3.  Higher postoperative function 4.  Feels better with more normal kinematics 5.  Higher patient satisfaction

The Future

•  More randomized, controlled trials •  Mixed compartment resurfacing •  Knee reconstruction with preservation of

ligamentous structures to improve kinematics •  Better Uni, Dual, and Tricompartmental Designs! •  Have to balance new theoretical improvements

with long-term success rates: – Patient Outcome Measures and Survivorship

Back to the Present… basic needs are unchanged

•  Good patient selection, right operation •  Good technical execution •  Appropriate postoperative care

– Medical – Surgical – Physical Therapy – Psychosocial

•  Postoperative Care – AVOID

•  Infection •  Wound breakdown •  DVT / PE •  Stiffness

– GAIN •  Pain control •  Independence •  ROM, stability, strength, and function

Knee Recovery Priorities

1)  Avoid medical complications 2)  Avoid wound problems / drainage / infection

Hold ROM / PT 24-48 hours and restart when dry 3)  Gain ROM (100 degrees by 4 weeks, 120 by 8)

4)  Gain function / independence 5)  Gain strength

Summary

•  Both UNI and TKA improve patient outcome measures significantly

•  UNI is less morbid operation with faster recovery •  TKA survivorship is better than partial knees! •  Conversion of Uni is a complex (not primary) TKA •  Patient selection, implant design, surgical technique

and postoperative care are critical for success!

Thank You

Chattanooga, Tennessee

Erlanger Medical Center

The “Scenic City”