Unicompartmental Knee Arthroplasty: Indications and

Current ResultsNatasha Holder MD, MSc

PGY-1

Objectives

Classic indications

Expanding indications

UKR vs. TKR: current outcome studies

Unicompartmental Knee Arthroplasty

Preservation of normal kinematics

Lower perioperative morbidity

Accelerated patient rehabilitation

Preservation of bone stock

Classic Indications

Diagnosis of unicompartmental arthritis

Age >60 with low demand for activity

Weight <82 kg

ROM arc >90° with <5° flexion contracture

Angular deformity of <15°Kozinn et al. JBJS 1989:145-150

Contraindications

Inflammatory arthritis

Patient age < 60

High patient activity level

Patellofemoral pain

Kozinn et al. JBJS 1989:145-150

UKA and Age

Pennington et al. (JBJS, 2003) Retrospective study, 46 UKA, age <60 Survivorship of 92% at 11 years

Price et al. (JBJS (Br), 2005) Case Series, 564 UKA, compared 2 age groups Age <60 – Survivorship of 91% at 10 years Age >60 Survivorship of 96% at 10 years

Cartier et al. (Ortho, 2007) Case Series, 161 UKA, age <60 Survivorship of 94% at 10 years, 88% at 12 years

UKA and Age

Kort et al. (Knee, 2007) Case Series, 46 UKA, age <60, 2-6 yr F/U Improved KSS and WOMAC scores Obesity can affect outcome i.e. technical failure

Berend et al. (Orthopedics, 2007) Case Series, 318 UKA, age 33-90, 6w-28 mo F/U Early survivorship 98.1%, age <60 was not

predictive of early failure

UKA and Obesity

Berend et al. (Orthopedics, 2007)Prospective study, 318 UKA, weight 51-

158kg, 150 UKA BMI >32, 6w-28 mo F/U

Early surviorship 98.1%, weight >82 or BMI >35 was not predictive of early failure

UKA and ACL Deficiency

Pandit et al. (JBJS (Br), 2006)Prospective Study, compared 15 UKA

with ACL reconstruction to 15 UKA with intact ACL (age, gender, F/U matched)

Oxford Knee score, KSS, Tegner activity level score, radiological assessment

UKA and ACL Deficiency

Pandit et al. (JBJS (Br), 2006)ACLR had greater postoperative

Oxford knee scores than ACLI No pathological radiolucencies or

component subsidence in either group

UKA vs TKA

Lombardi et al. (Clin Ortho Relat Res, 2009) Retrospective cohort, 115 UKA and 115 TKA,

matched for age, gender, BMI, bilaterality UKA selection: anteromedial OA, intact ACL,

flexion deformity <15°, varus deformity <15° TKA selection: unicompartmental OA or more

extensive OA Outcomes: ROM, KSS, LOS

UKA vs TKA

Newman et al. (JBJS (Br), 2009 Prospective randomized control trial (1989-1992)

with a 15 year follow up 102 knees Criteria: unicompartmental, intact cruciate

ligaments, flexion deformity ≤ 15°, varus/valgus deformity ≤15°

Outcome: Bristol knee score Failure: revision, Bristol score < 60

UKA 89.8% Survival rate

TKA 78.7% Survival rate

UKA results are comparable to TKA and have no greater tendency to fail at 15 years

Summary

In appropriately selected patients UKA is a successful procedure Indications are expanding with

satisfactory resultsEqual survivorship to TKA in first decade Improved functional resultsFewer complications

Thank you