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C-Leg 4 Microprocessor-Controlled
Prosthetic Knee
Reimbursement
Reference Guide
C-Leg Microprocessor-Controlled Prosthetic Knee
Reimbursement Reference Guide (Effective 4/27/2015)
C-Leg
Introduced in 1997, the C-Leg® was the first prosthetic
system to control and adapt to an individual’s gait
pattern. To do this, the C- \Leg actively controls all aspects
of the swing and stance phase with the microprocessorcontrolled hydraulics and adapts to the variation in
walking speeds. The result is a system that recognizes
which phase of gait the patient is in—and adapts in real
time. The new functionality of C-Leg includes patented
technology which provides intuitive standing function
and backward walking recognition and adjustments.
1
C-Leg Coding
The Healthcare Common Procedure Coding System
(HCPCS) for the C-Leg includes the base code and the
respective add-on codes to accurately describe the knee
joints functionality.
PDAC Verification
The first 7 codes are PDAC verified for the C-Leg.2
The base code for C-Leg is:
L5828
Hydraulic Swing and Stance Phase
Knee
The remaining codes describe additional
features/functions:
L5845
Stance flexion feature
L5848
Hydraulic stance extension feature
L5856
Microprocessor control feature, swing
and stance phase, includes sensors
L5920
Alignable system
L5930
High activity knee control frame
(K4 only for Medicare)
L5950/60
Ultralight Material
(Medicare only allows for Sockets)
Additional codes for C-Leg’s new functionality:
L5850
Knee extension assist
L5925
L5999
Manual lock
3,4
Inertial Motion Unit Control Feature for
intuitive standing and walking
backwards.
C-Leg Protective Cover
L5999
C-Leg Custom Protective Cover with
Shield Insert
C-Leg Battery and Charger:
L7367
Lithium Ion Battery, Replacement
L7368
Lithium Ion Battery Charger,
Replacement
Ottobock
800 328 4058
http://professionals.ottobockus.com
2015 Manufacturer Suggested Retail Price
(MSRP)5
MSRP for the Inertial Motion Unit code (L5999) is $5000.
MSRP for the Protective Cover with Shield Insert code
(L5999) is $2400
C-Leg® Practitioner Training
Ottobock lists C-Leg® Trained Practitioners on its
website. These practitioners have taken an online
course, passed the exam and earned CEUs.
FDA Status
Under FDA’s regulations, the C-Leg® MicroprocessorControlled Prosthetic Knee is a Class II device, exempt
from the premarket notification [510(k)] requirements. CLeg prosthetic knee has met all the general control
requirements which include Establishment Registration
(21CFR 807), Medical Device Listing (21 CFR part 807),
Quality System Regulation (21CFR part820), Labeling
(21CFR part 801), and Medical Device Reporting (21 CFR
Part 803). The C-Leg prosthetic knee is listed under
external assembled lower limb prosthesis; Listing Number
is E206060.
Warranty
Three-year manufacturer warranty (extendable to six
years); Repair costs are covered except for those
associated with damages resulting from improper use.
No fixed service inspections are required.
_______________
1
The product/device “Supplier” (defined as an O&P practitioner,
O&P patient care facility, or DME supplier) assumes full
responsibility for accurate billing of Ottobock products. It is the
Supplier’s responsibility to determine medical necessity; ensure
coverage criteria is met; and submit appropriate HCPCS codes,
modifiers, and charges for services/products delivered. It is also
recommended that Supplier’s contact insurance payer(s) for
coding and coverage guidance prior to submitting claims.
Ottobock Coding Suggestions and Reimbursement Guides are
based on reasonable judgment and are not recommended to
replace the Supplier’s judgment. These recommendations may be
subject to revision based on additional information or alphanumeric system changes.
2
The PDAC verification on the DMEPDAC Product Classification
List for C-Leg 3C98 includes the 7 codes identified. The additional
codes for the new functionality are pending PDAC verification &
HCPCS approval.
3
Pending 2016 HCPCS Coding Decision.
4
It is not recommended to bill L5999 to Medicare for
Microprocessor Knees.
3
The manufacturer’s suggested retail pricing (MSRP) is a
suggested retail price only. Ottobock has provided the suggested
MSRP in the event that third-party and/or federal healthcare
payers request it for reimbursement purposes. The practitioner
and/or patient care facility is neither obligated nor required to
charge the MSRP when submitting billing claims for third-party
reimbursement for the product (s).
1
C-Leg Features and Benefits
should be in a low resistance for initiating swing
than any mechanical mechanism. This eliminates
erroneous stance releases that often cause falls in
purely mechanical designs.
Hydraulic Swing and Stance Phase Knee
•
•
Hydraulic swing control allows for adequate
resistance to be applied during heel rise, allowing
65 ± 3 degrees of knee flexion. This ensures
appropriate toe clearance, reduces the chance of
catching the toe in midswing, and offers the patient
security for the next heel strike (does not leave the
patient feeling as if “waiting for the knee to come
through”).
Hydraulic swing control also applies during
extension of the knee preventing terminal impact
by decelerating the limb while restraining the need
for further hip flexion. This resistance mimics the
eccentric contraction of the anatomical hamstrings
and gluteus maximus. Full extension is then
reached in preparation for heel strike.
•
Hydraulic swing control allows patients to vary
cadence. The hydraulic fluid flows through narrow
channels, providing a frictional resistance, which
increases with the speed of compression; a faster
gait speed allows quicker knee extension.
•
With hydraulic stance phase control, resistance
occurs automatically when there is a tendency for
the knee to buckle. This allows the patient to walk
on uneven terrain and results in a more natural
step-over-step pattern when descending inclines
and stairs. This resistance also contributes to the
stance flexion and “stumble recovery.”
Microprocessor Swing and Stance Control
•
The C-Leg’s main microprocessor gathers sensoric
information at a rate of 100 times per second. It
processes this information following programmed
instructions to adjust the valve positions via servo
motors in real time. The valve positions define the
hydraulic fluid resistance of the two independent
valves (extension and flexion valves) and therefore
the resistances of the knee against flexion and
extension separately and variably.
•
During whole gait cycle the programmed
instructions define whether the resistance is high
for securing stance phase support or low for
allowing initiation of swing (Microprocessor Stance
control). Using the programmed instructions the
knee can far more reliably determine if the knee
Ottobock
800 328 4058
http://professionals.ottobockus.com
•
During swing phase the programmed instructions
control the maximal swing angle by adjusting the
flexion valve in real time (Microprocessor Swing
Control). The patient will be able to walk more
naturally and vary cadence with the knee adapting
more accurately and more quickly than without a
microprocessor.
Stance Flexion
•
When the prosthesis initially contacts the ground,
this feature allows the patient to load the knee in a
flexed position. Benefits include shock absorption,
reducing the modulation of the center of gravity
throughout the gait cycle, energy efficiency (less
energy spent on “pulling back” on hamstrings to
lock a fully extended knee), and an overall more
natural gait pattern. Hip and lower back stress will
also be minimized.
•
This feature also allows patients to “ride” the knee
(the knee supports patients’ weight on flexed knee
without buckling and lowers them into desired
position) when sitting into a chair, kneeling, and
when descending stairs and slopes.
•
This resistance will also be there for the patient
should the toe catch during midswing, serving as a
“stumble recovery” feature. As soon as the knee
stops flexing and maximum heel rise is achieved,
this feature is immediately activated; thus, if at any
point the toe catches a supporting resistance is
available. This allows patients enough time to
bring their contralateral side through to catch
themselves, thus preventing a fall and keeping it at
a controlled “stumble.” The newest algorithm in
the updated version of C-Leg® allows this
resistance to be angle dependent, meaning it will
provide additional resistance compared to normal
stance phase resistance. From that point on, the
further the knee bends (or the further the patient is
into the fall) the higher the resistance that will be
provided.
2
C-Leg Features and Benefits
Hydraulic Stance Extension
•
After the knee is flexed during stance phase (stance
flexion), it needs to extend again to advance the
body forward through mid-stance. This feature
provides increased resistance to this extension.
Without this increased resistance the patient will
feel a pronounced “snap back” or “jerk” at the
knee, and will also present with an unnatural
looking gait pattern. Energy is conserved by having
this feature, as the patient will not have to attempt
to use hamstrings to control this motion.
Knee Extension Assist
•
The knee extension assist is used in promoting
knee extension at the beginning of swing phase
extension. This function allows the user to walk
more efficiently at variable cadence since the
spring extension assist mechanically limits the
knee flexion at the end range and begins to bring
the knee into extension for a more symmetrical gait
at faster walking speeds. It also ensures the knee
comes to full extension for the beginning of stance
phase for a more secure loading condition.
Inertial Motion Unit Control Function for Intuitive
Standing and Walking Backwards
•
The Inertial Motion Unit in the C-Leg allows
intuitive standing and backward walking.
•
This patented technology provides stability when
taking steps backwards. (Traditional
microprocessor knees do not accommodate
backward walking, because the knee is
programmed to go into swing when the toe is
loaded, causing the knee to collapse when stepping
backward).
•
Allows the patient to intuitively stand on a flexed
and stable knee on level, uneven, or inclined
surfaces (ramps or hills). With traditional
prosthetic knees people with limb loss must use hip
extension to stabilize the knee or cognitively
ensure that their center of mass stays ahead of their
knee axis to prevent unexpected flexing of the
prosthetic knee.
Activity Report
•
Locking Function
•
The manual lock allows the user to lock the knee in
full extension, e.g. for safer standing or more
comfortable standing due to equal weight
distribution on the prosthetic and sound sides. The
manual lock is activated and deactivated by the
patient by three different methods: motion pattern,
remote, or via a cellular telephone App.
The practitioner is able to print out reports
including:
1. Average. number of steps/day
2. Average. walking speed
3. Number of steps on slopes, ramps and stairs
4. Time totals for walking, sitting, standing
Protective Cover & Shield Insert
High Activity Frame
•
The C-Leg knee is indicated for a restricted outdoor
walker or a non-restricted outdoor walker and is
approved for a patient weight up to 300lbs. The
high weight limit, higher than many knees on the
market, can endure higher loading conditions.
Patient activities may vary, but the knee can
endure the stresses and demands of everyday life
and also higher than normal stresses.
Ottobock
800 328 4058
http://professionals.ottobockus.com
•
The C-Leg Protective Cover is used to provide
greater defense for protecting the knee unit. This
cover is custom designed for this knee unit only
and is able to withstand sudden jolts that may
penetrate the knee unit.
3
C-Leg Bibliography (Recent Studies)
1. Kannenberg A, Zacharias B, Pröbsting E. Benefits of
microprocessor-controlled prosthetic knees to
limited community ambulators: Systematic review.
JRRD, 2014; 51(10): 1469-1496.
2. Highsmith MJ, Kahle JT, Shepard NT, Kaufman KR.
The effects of the C-Leg knee prosthesis on sensory
dependency and falls during sensory organization
testing. Technol Innov, 2014; 1(15): 343-347.
3. Tofts LJ, Hamblin N. C-Leg® improves function and
quality of life in an adolescent traumatic transfemoral amputee - a case study. Prosthet Orthot
Int, 2014; 38(5): 413-417; (ISSN 1746-1553);
DOI: 10.1177/0309364613502354
4. Eberly VJ, Mulroy SJ, Gronley JK, Perry J, Yule WJ,
Burnfield JM. Impact of a stance phase
microprocessor-controlled knee prosthesis on level
walking in lower functioning individuals with a
transfemoral amputation. Prosthet Orthot Int,
2014; 38(6): 447-55 (ISSN: 1746-1553)
5. Thiele J, Westebbe B, Bellmann M, Kraft M. Designs
and Performance of Microprocessor-Controlled
Knee Joints. Biomedizinische Technik/Biomedical
Engineering . Nov 2013; 1–13; ISSN (Online) 1862278X, ISSN (Print) 0013-5585; DOI: 10.1515/bmt2013-0069.
6. Highsmith MJ, Kahle JT, Miro RM and Mengelkoch
LJ. Ramp descent performance with the C-Leg and
interrater reliability of the Hill Assessment Index.
Prosthet Orthot Int, 2013; 37(5): 362-367 (ISSN:
1746-1553) DOI: 10.1177/0309364612470482
7. Wolf EJ, Everding VQ, Linberg AL, Czerniecki JM,
Gambel JM. Comparison of the Power Knee and CLeg during step-up and sit-to-stand tasks. Gait
Posture, Jul 2013; 38(3): 397–402
8. William D, Beasley E, Shaw A. Investigation of the
quality of life of persons with a transfemoral
amputation who use a C-Leg® prosthetic device.
JPO, 2013; 25(3): p 100-109. DOI:
10.1097/JPO.0b013e31829be7bc.
9. Kaufman KR, et.al. Gait asymmetry of transfemoral
amputees using mechanical and microprocessorcontrolled prosthetic knees. Clin Biomech, 2012
Jun; 27(5): 460-465.
Ottobock
800.328.4058
http://professionals.ottobockus.com
10. Theeven P, et al. Influence of Advanced Prosthetic
Knee Joints on Perceived Performance and
Everyday Life Activity Level of Low-Functional
Persons with a transfemoral Amputation or Knee
Disarticulation. J. Rehabil. Med., 2012; 44: 454461.
11. Wolf EJ, Everding VQ, Linberg AL, Schnall BL,
Czerniecki JM, Gambel JM. Assessment of
transfemoral amputees using C-Leg and Power Knee
for ascending and descending inclines and steps.
JRRD, 2012; 49(6): 831-842
12. Wong CK, Benoy S, Blackwell W, Jones S, Rahal R. A
comparison of energy expenditure in people with
transfemoral amputation using microprocessor and
nonmicroprocessor knee prostheses: A systematic
review. JPO, 2012; 24(4): 202-208.
13. Theeven P, et al. Functional Added Value of
Microprocessor-Controlled Prosthetic Knee Joints in
Daily Life Performance of Medicare Functional
Classification Level-2 Amputees. JRRD, 2011;
43:906-915.
14. Highsmith MJ, et al. Safety, Energy Efficiency, and
Cost Efficacy of the C-Leg for Transfemoral
Amputees: A Review of the Literature. Prosthet
Orthot Int, 2010 Dec; 34(4): 362-77; DOI:
10.3109/03093646.2010.520054; Epub 2010 Oct
24.
15. Bellmann M, et al. Comparative Biomechanical
Analysis of Current Microprocessor-Controlled
Prosthetic Knee Joints. Arch Phys Med and Rehabil,
2010; 91(4): 644-52.
16. Hafner BJ. et al. Differences in Function and Safety
between Medicare Functional Classification Level-2
and -3 Transfemoral Amputees and Influence of
Prosthetic Knee Joint Control. JRRD, 2009;
46(3):417-434.
17. Blumentritt S, et al. Safety of C-Leg: Biomechanical
Tests. JPO, 2009; 21(1): 2-17.
18. Berry D, et al. Perceived Stability, Function and
Satisfaction among Transfemoral Amputees using
Microprocessor and Non-microprocessor Controlled
Prosthetic Knees: A Multicenter Study. JPO, 2009;
21(1): 32-42.
4
C-Leg Bibliography (Recent Studies)
19. Highsmith MJ, et al. Decreased Heart Rate in a
Geriatric Client after Physical Therapy Intervention
and Accommodation with the C-Leg. JPO, 2009;
21(1): 43-47.
25. Kaufman KR, et al. Gait and Balance of
Transfemoral Amputees using Passive Mechanical
and Microprocessor-Controlled Prosthetic Knees.
Gait and Posture. 2007; 26: 489-493.
20. Seelen HAM, et al. Costs and Consequences of a
Prosthesis with an Electronically Stance and Swing
Phase Controlled Knee Joint. Technol Disabil,
2009; 21: 25–34.
26. Hafner BJ, et al. Evaluation of Function,
Performance, and Preference as Transfemoral
Amputees Transition from Mechanical to
Microprocessor Control of the Prosthetic Knee. Arch
Phys Med and Rehabil, 2007; 88(2): 207-17.
21. Kahle JT, et al. Comparison of Non-microprocessor
Knee Mechanism versus C-Leg on Prosthesis
Evaluation Questionnaire, Stumbles, Falls, Walking
Tests, Stair Descent, and Knee Preference. JRRD;
2008; 45 (1): 1-14.
22. Brodkorb TH, et al. Cost-effectiveness Of C-Leg
Compared with Non-microprocessor Controlled
Knees: A Modeling Approach. Arch Phys Med and
Rehabil; 2008; 89(1): 24-30.
23. Gerzeli S, et al.Cost Utility Analysis of Knee
Prosthesis with Complete Microprocessor Control
(C-Leg) Compared with Mechanical Technology in
Trans-Femoral Amputees. Eur J Health Econ, 2009;
10: 47-59.
27. Schmalz T, et al. Biomechanical Analysis of Stair
Ambulation in Lower Limb Amputees. Gait Posture,
2007; 25: 267-278.
28. Seymour R, et.al. Comparison between the C-Leg
Microprocessor-Controlled Prosthetic Knee and
Non-Microprocessor Control Prosthetic Knees: A
Preliminary Study of Energy Expenditure, Obstacle
Course Performance, and Quality Of Life Survey.
POI, 2007; 31(1): 51–61.
29. Bunce DJ, et al. The Impact of C-Leg on the Physical
and Psychological Adjustment to Transfemoral
Amputation. Prosthet Orthot Int, 2007; 19(1): 714.
Ottobock
800.328.4058
http://professionals.ottobockus.com
© 2015 Otto Bock HealthCare LP ● 30CLEG.04262015
24. Kaufman KR, et al. Energy Expenditure and
Activity Level of Transfemoral Amputees using
Passive Mechanical and Microprocessor-controlled
Prosthetic Knees. Arch Phys Med and Rehabil,
2008; 89(7): 1380-1385.
5