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Medical and Behavioral Health Policy
Section: Surgery
Policy Number: IV-122
Effective Date: 03/23/2015
Blue Cross and Blue Shield of Minnesota medical policies do not imply that members should not receive specific services
based on the recommendation of their provider. These policies govern coverage and not clinical practice. Providers are
responsible for medical advice and treatment of patients. Members with specific health care needs should consult an
appropriate health care professional.
KNEE ARTHROPLASTY (KNEE REPLACEMENT)
Description:
Knee arthroplasty (also known as knee replacement) is a surgical
procedure in which the worn and/or damaged surfaces of the knee
joint are replaced with a prosthesis made of metal, ceramic material, or
high-density plastic. It is most commonly performed for advanced knee
joint disease caused by osteoarthritis (OA); however, it may also be
performed for joint disease resulting from rheumatoid arthritis (RA),
juvenile rheumatoid arthritis, post-traumatic arthritis, and
osteonecrosis. The primary indications for knee arthroplasty are
significant loss or erosion of cartilage to bone, accompanied by pain
and limited function.
Definitions:
Three compartments of the knee:
 Patellofemoral: area behind the kneecap riding over the end of
the femur “trochlea/sulcus” groove
 Medial: the area of joint contact between the femur and tibia on
the “inside” or medial aspect of the knee
 Lateral: the area of joint contact between the femur and tibia on
the “outside” or lateral aspect of the knee
Total knee arthroplasty (also known as TKA, or total knee
replacement): Performed when one or more of the three
compartments of the knee is affected by advanced joint disease. TKA
involves removal of a thin layer of subchondral bone and overlying
articular cartilage, with anatomic resurfacing of all three compartments
and insertion of the implant and bearing surface.
Unicompartmental knee arthroplasty (also known as UKA or
partial knee arthroplasty): May be performed in patients with
advanced joint disease limited to a single compartment (i.e., medial,
lateral, or patellofemoral).
 UKA of the medial or lateral compartment requires a smaller
incision that does not interrupt the anterior and posterior cruciate
ligaments which are the main structures stabilizing the knee.

UKA of the patellofemoral compartment treats degenerative
disease underneath the patella and involves implantation of a
prosthesis to resurface the articulating surfaces of the patella and
femur.
Bicompartmental knee arthroplasty: Replacement of the medial
and patellofemoral compartments, with sparing of the cruciate
ligaments.
Bi-unicompartmental knee arthroplasty: UKA performed in the
contralateral compartment of a knee previously treated with a UKA.
Unicondylar interpositional spacers (e.g., UniSpacer™): Metallic
implants are inserted into the joint space between the affected tibial
plateau and femoral condyle. Instead of being fixed, the spacers are
held in place by the geometry of the curved implant, ligament tension,
and surrounding soft tissue structures.
Grading Systems for Knee Osteoarthritis:
 The Kellgren-Lawrence Grading System is a method of
determining the extent of cartilage damage, based on x-ray
imaging.
Grade 0: Normal
Grade 1: Doubtful narrowing of joint space and possible
osteophytic lipping
Grade 2: Definite osteophytes, definite narrowing of joint space
Grade 3: Moderate multiple osteophytes, definite narrowing of
joint space, some sclerosis and possible deformity of bone
contour
Grade 4: Large osteophytes, marked narrowing of joint space,
severe sclerosis and definite deformity of bone contour.
Policy:

The Modified Outerbridge Classification is a method of
determining the extent of cartilage damage, based on magnetic
resonance imaging (MRI) or arthroscopy.
Grade 0: Normal
Grade I: Cartilage with softening and swelling by arthroscopy OR
signal intensity alterations with an intact surface of the articular
cartilage compared with the surrounding normal cartilage by MRI
Grade II: Partial-thickness defect with fissures on the surface that
do not reach subchondral bone or exceed 1.5 centimeters (cm) in
diameter
Grade III: Fissuring to the level of subchondral bone in an area
with a diameter more than 1.5 cm
Grade IV: Exposed subchondral bone head. Subchondral bone is
the bone underneath the joint cartilage
I.
Total knee arthroplasty (also known as total knee
replacement) may be considered MEDICALLY NECESSARY for
ANY of the following indications:
A. Primary and secondary tumors of the distal femur or proximal
tibia; OR
B. Displaced fractures of the distal femur or proximal tibia; OR
C. Failed previous knee fracture fixation; OR
D. Failed previous unicompartmental knee arthroplasty; OR
E. Failed previous knee osteotomy; OR
F. Advanced knee joint disease, when EITHER of the following
criteria are met:
1. Diagnostic imaging and/or arthroscopic evidence, obtained
within the previous 12 months, of complete cartilage
destruction (i.e., modified Outerbridge grade IV or KellgrenLawrence grade 4) AND both of the following:
a. Moderate to severe persistent knee pain; AND
b. Clinically significant functional limitation resulting in
impaired, age-appropriate activities of daily living and
diminished quality of life.
OR
2. Diagnostic imaging and/or arthroscopic evidence, obtained
within the previous 12 months, of cartilage damage (i.e.,
modified Outerbridge grade III or Kellgren-Lawrence grade
3) when ALL of the following criteria are met:
a. Moderate to severe persistent knee pain despite use of
BOTH of the following:
i. Medical management with nonsteroidal antiinflammatory agents (NSAIDS) or other analgesic
medications; AND
ii. Physical therapy, including strengthening exercises:
6 week course
NOTE: If a patient is unable to complete physical
therapy (PT) due to progressively, worsening pain
and disability, the case will be reviewed on an
individual basis by an internal physician reviewer
(See Documentation Submission section);
AND
b. Clinically significant functional limitation resulting in
impaired, age-appropriate activities of daily living and
diminished quality of life.
II.
Unicompartmental knee arthroplasty (also known as partial
knee replacement) may be considered MEDICALLY
NECESSARY for the treatment of advanced knee joint disease
limited to a single compartment (i.e., medial, lateral, or
patellofemoral), when EITHER of the following criteria are met:
A. Diagnostic imaging and/or arthroscopic evidence, obtained
within the previous 12 months, of complete cartilage
destruction (i.e., modified Outerbridge grade IV or KellgrenLawrence grade 4) AND ALL of the following:
1. Moderate to severe persistent knee pain localized to the
affected compartment (i.e., medial, lateral, or
patellofemoral); AND
2. Clinically significant functional limitation resulting in
impaired, age-appropriate activities of daily living and
diminished quality of life; AND
3. Involved knee demonstrates adequate alignment and
ligamentous stability
OR
B. Diagnostic imaging and/or arthroscopic evidence, obtained
within the previous 12 months, of cartilage damage (i.e.,
modified Outerbridge grade III or Kellgren-Lawrence grade 3)
AND ALL of the following:
1. Moderate to severe persistent knee pain localized to the
affected compartment (i.e., medial, lateral, patellofemoral)
despite use of BOTH of the following:
a. Medical management with nonsteroidal antiinflammatory agents (NSAIDS) or other analgesic
medications; AND
b. Physical therapy, including strengthening exercises:
6 week course
NOTE: If a patient is unable to complete physical
therapy (PT) due to progressively, worsening pain and
disability, the case will be reviewed on an individual
basis by an internal physician reviewer (See
Documentation Submission section);
AND
2. Clinically significant functional limitation resulting in
impaired, age-appropriate activities of daily living and
diminished quality of life.
AND
3. Involved knee demonstrates adequate alignment and
ligamentous stability.
III. Revision of knee arthroplasty may be considered MEDICALLY
NECESSARY for ANY of the following indications:
A. Instability of the prosthetic components or aseptic loosening;
OR
B. Periprosthetic fractures; OR
C. Fracture or dislocation of the patella; OR
D. Infection of the implant.
IV. The following knee procedures are considered INVESTIGATIVE
due to a lack of evidence demonstrating an impact on improved
health outcomes:
A. Bicompartmental knee arthroplasty and bi-unicompartmental
knee arthroplasty;
B. Unicondylar interpositional spacer.
Documentation
Submission:
Documentation supporting the medical necessity criteria described
in the policy must be included in the prior authorization, when prior
authorization is required. In addition, the following documentation
must also be submitted for initial knee arthroplasty (total or
unicompartmental) due to advanced knee joint disease:
1. Interpretive report within the past 12 months that describes the
extent of articular cartilage damage, as determined by at least
one of the following methods:
a. Knee arthroscopy report that utilizes or can be correlated
with the modified Outerbridge classification system of
articular cartilage injury; OR
b. Knee x-ray report that utilizes or can be correlated with the
Kellgren-Lawrence grading system of osteoarthritis; OR
c. Knee MRI report from a radiologist that utilizes or can be
correlated with the modified Outerbridge or similar
classification system related to articular cartilage injury and
osteoarthritis.
Further information on these classification systems is provided
in the ‘Definitions’ and ‘Policy’ sections of this document; AND
2. Clinical notes describing:
a. Severity of knee pain; AND
b. Functional limitations related to knee symptoms; AND
c. For modified Outerbridge grade III or Kellgren-Lawrence
grade 3 cartilage damage, documentation must also be
submitted for the following:
 Medical management with nonsteroidal antiinflammatory agents (NSAIDS) or other analgesics;
AND
 Physical therapy.
If a patient is unable to complete physical therapy (PT)
due to progressively, worsening symptoms of pain and
disability, the case will be reviewed on an individual
basis by an internal physician reviewer. Documentation
must include clinical notes from the physical therapist
describing the patient’s inability to complete PT.
3. For unicompartmental knee arthroplasty: an orthopedic
assessment of knee alignment and ligamentous stability.
Coverage:
This policy does not apply to the following lines of business:
1. Federal Employee Plan (FEP); OR
2. Government Programs products; OR
3. Medicare Primary products.
Blue Cross and Blue Shield of Minnesota medical policies apply
generally to all Blue Cross and Blue Plus plans and products. Benefit
plans vary in coverage and some plans may not provide coverage for
certain services addressed in the medical policies.
Medicaid products and some self-insured plans may have additional
policies and prior authorization requirements. Receipt of benefits is
subject to all terms and conditions of the member’s summary plan
description (SPD). As applicable, review the provisions relating to a
specific coverage determination, including exclusions and limitations.
Blue Cross reserves the right to revise, update and/or add to its
medical policies at any time without notice.
For Medicare NCD and/or Medicare LCD, please consult CMS or
National Government Services websites.
Refer to the Pre-Certification/Pre-Authorization section of the Medical
Behavioral Health Policy Manual for the full list of services,
procedures, prescription drugs, and medical devices that require Precertification/Pre-Authorization. Note that services with specific
coverage criteria may be reviewed retrospectively to determine if
criteria are being met. Retrospective denial of claims may result if
criteria are not met.
Coding:
The following codes are included below for informational purposes
only, and are subject to change without notice. Inclusion or exclusion
of a code does not constitute or imply member coverage or provider
reimbursement.
CPT:
27438 Arthroplasty, patella; with prosthesis
27440 Arthroplasty, knee, tibial plateau;
27441 Arthroplasty, knee, tibial plateau; with debridement and partial
synovectomy
27442 Arthroplasty, femoral condyles or tibial plateau(s), knee;
27443 Arthroplasty, femoral condyles or tibial plateau(s), knee; with
debridement and partial synovectomy
27445 Arthroplasty, knee, hinge prosthesis (eg, Walldius type)
27446 Arthroplasty, knee, condyle and plateau; medial OR lateral
compartment
27447 Arthroplasty, knee, condyle and plateau; medial AND lateral
compartments with or without patella resurfacing (total knee
arthroplasty)
27486 Revision of total knee arthroplasty, with or without allograft; 1
component
27487 Revision of total knee arthroplasty, with or without allograft;
femoral and entire tibial component
ICD-9 Procedure:
00.80 Revision of knee replacement, total (all components)
00.81 Revision of knee replacement, tibial component
00.82 Revision of knee replacement, femoral component
00.83 Revision of knee replacement, patellar component
81.54 Total knee replacement
81.55 Revision of knee replacement, not otherwise specified
Policy History:
Developed April 11, 2012
Most recent history:
Reviewed April 10, 2013
Revised January 8, 2014
Revised January 14, 2015
Cross
Reference:
Current Procedural Terminology (CPT®) is copyright 2014 American Medical
Association. All Rights Reserved. No fee schedules, basic units, relative values, or
related listings are included in CPT. The AMA assumes no liability for the data
contained herein. Applicable FARS/DFARS restrictions apply to government use.
Copyright 2015 Blue Cross Blue Shield of Minnesota.