1. PPI Ratings. How to achieve a fair, consistent and reliable Permanent Partial Impairment

2. Agenda Define Disability VS. Impairment Maximum Medical Improvement
Subjective vs. Objective
Accurate Diagnosis is the Key
Guides
5th Edition
6th Edition
Case Studies

3. World Health Organization International Classification of Illness
Pathology – underlying disease or diagnosis
Impairment – the physiologic consequences (symptoms and signs)
Disability – the functional consequences, abilities lost
Handicap – social and societal consequences

4. A few Definitions
Maximum Medical Improvement or Quiescence – the point at which a condition has stabilized and is unlikely to change with or without treatment.
Impairment – a loss, loss of use or derangement of any body part, organ system or organ function. Problem involving body structure or function
Disability – alteration of capacity to meet personal, social or occupational demands because of an impairment
Disability is a relational outcome contingent on the environmental conditions which activity performed and the extent of impairment. There is not a linear relationship between Impairment and Disability

5. Subjective vs. Objective
Subjective pain complaints are an element of the impairment determination but by itself have little bearing on final impairment
Objective measures of gait, range of motion (ROM), strength and sensation can all be negatively affected by pain and effort
Depression is a subjective complaint but has objective elements to include observed mood, mentation and quality of movements. Psychiatric conditions can also influence physical objective findings and need to be considered when determining PPI. Severe depression can often cause impairment and disability although rarely is it caused by work exposure or injury

6. Subjective vs. Objective (Symptoms vs. Signs)
Subjective is the subjects report of their symptoms. It is what the patient tells us. Subjective is typically recorded as complaints although can be positive descriptions of the patients condition. It cannot be measured but the complaints should correlate with the diagnosis
Objective is what we as treater's can measure. Objective findings (signs) include physical exam findings, diagnostic tests such as imaging studies or lab results and observations (pain behaviors)
The subjective complaints taken together with the objective findings should lead to an accurate diagnosis

7. More Definitions
Causality – a given event could cause the condition. The symptom chronology is consistent with the event causing the condition. There is not a more plausible explanation or cause. Medical probability is met.
Exacerbation of pre-existing condition – a temporary worsening with return to baseline
Aggravation of pre-existing condition – a permanent worsening without return to baseline

8. AMA Guides to the Evaluation of Permanent Impairment…presently on 6th edition
1st Edition in 1950’s
Revised every 7-8 year years
I started practice (1987) with 3rd Edition.
Every Edition strives to bring consistency and fairness while ensuring interrater reliability.
Prior Edition criticism was failure to provide comprehensive, valid, reliable, unbiased, and evidence based rating system
Prior PPI did not accurately reflect loss of function

9. 6th Edition Advances
Adopts terminology of Inter. Classification of Function, Disability and Health
BECOMES MORE DIAGNOSIS BASED…evidence based where possible
Simplicity and ease of application optimizing inter and intrarater reliability
Functionally Based
Conceptual congruity between organ systems

10. 6th Edition…my experience
More complex calculations to arrive at percentages.
Diagnosis emphasis makes sense and eases process
Function emphasis makes sense
Pain levels considered but only marginally affects score

11. Impairment Classification Grids
Uses Diagnosis Based Impairment (DBI)
Generally under body region or organ function
Class 0-4 determines severity
Grades are modified based on function, exam and clinical studies
With lower extremity (LE) diagnosis ROM is considered in grid
With upper extremity (UE) diagnosis ROM considered as exam modifier or independent determinate “Stand Alone” when grid not successfully representing impairment

12. Steps in performing PPI
1) take history and examine patient and determine at MMI
2) determine accurate reliable diagnosis…can be more than 1
3) use regional grid in appropriate region to determine Class
4) use adjustment grid and grade modifiers to determine Grade within appropriate class
5) determine PPI according to Class and Grade for any allowable diagnosis
6) convert impairments to whole person or like body parts then use Combined Value Chart to combine values if more than one Impairment value (Values are not added unless multiple digit or ROM for same joint)

13. Diagnosis Based Impairment (DBI)
Most Impairments are determined by diagnosis and specific criteria
Impairment is then adjusted by “non-key” factors (grade modifiers) that include functional history (FH),physical exam (PE) and clinical studies (CS)
Using appropriate regional grid find diagnosis and corresponding Class (0-4)
The Grade is then determined using the Grade modifiers or non-key factors. The default Grade is C. It can be modified up (D or E) or down (A or B) depending on the functional history, physical exam and clinical studies.

14. Diagnosis Based Impairment part 2
Grade Modifiers are used in a Net Adjustment Formula
Net adjustments of 1+ or 2+ bring a Grade from default of C to Grade D or E
Net Adjustments of minus 1- or 2- bring Grade C to an A or B
Grade Modifiers allow movement within a Class but will not cause a change in the Class
Subjective Complaints without objective physical findings or significant clinical abnormalities are assigned Class 0 and have no ratable impairment (0% PPI)
The process is repeated for each diagnosis
If multiple diagnosis in same region rate most significant only

15. Upper Extremity Digits/hand Wrist Elbow Shoulder
Consider soft tissue, bones,joints and peripheral nerves
Functional History: QuickDash score (0-100)
Physical exam: positive, negative and nonphysiologic
Clinical studies: MRI, x-ray, EMG

16. Upper Extremity
Most PPI determined by Diagnosis and adjusted by Non-Key Factors which are functional history, exam and clinical studies
Alternative approaches based on peripheral nerve injuries, CRPS, amputations and rarely ROM
In 6th Edition ROM is encouraged as a exam grade modifier and only as PPI determinate when Grid permits
ROM based on active movement and only considered reliable if with 10 degrees of passive in absence of nerve injury
In rare event Diagnosis not listed can use similar Dx explain rational

17. Upper Extremity
Subjective complaints without objective evidence of disease Class 0 or 0% PPI
If 2 diagnosis in same regional grid (RTC tear, Bursitis) use diagnosis with highest PPI. Rarely use 2 diagnosis in same region
For all UE regions if ROM used as PPI determinant it is stand alone
ROM percents in same joint are added

18. UE Conversion factors D1 Thumb to hand 40%
D2-3 Index middle finger to hand 20%
D4-5 ring and small finger to hand 10%
Hand to UE 90%
UE to Whole Person (WP) 60%

19. UE Amputations % based on residual length of digit or extremity
Each digit expressed as percent of than digit.
If multiple digits they are converted to hand PPI and added (rare addition)
If all digits lost at MP joint considered 100% of hand
If distal digit and proximal digit joint lost motion combine those 2 digital PPIs
Sensory Loss affecting amputated part excluded
Need to be provided hand or foot chart

20. UE AROM Stand Alone Rarely use ROM as PPI determinant.
Must be reliable (10 degree rule)
Problem with pain inhibition, diminished effort or active resistance
Motion rounded up to number ending in degrees = 50 Degrees, 55 degrees up to 60.

21. UE CRPS Verify diagnosis with Budapest Criteria
Number of positive elements or points determines severity
PPI based on physical findings
It is stand alone diagnosis so no increase for weakness or decreased ROM

22. Lower Extremity minor differences
Foot and ankle injuries expressed as Lower extremity % PPI.
If PPI needed for toes can be calculated as Great Toe worth 17% of foot/ankle and lesser toes 3%
Foot and ankle converts to LE at 70%
LE to WP at 40%
Conversion tables for these determinants
Most DBI’s have severity include loss motion unlike UE
Amputations per Table expressed as LE PPI

23. Full Thickness RTC tear s/p repair with mild loss of ROM at MMI and severe pain Dash score 65
Table 15-5 page 403
The FH grade Modifier = 3, PE =1 and CS =1
Apply Net Adjustment Formula of 2+ so Grade C moves up to Grade E
PPI of 5% UE for Grade C moves up to 7% for Grade E
7% of UE converts to 4% HPI (60% of UEI = WPI)
Use ROM model only if moderate to severely restricted and as a stand alone

24. s/p C5-6 HNP with Radiculopathy and ACDF, PDQ score of 86, MRI positive with positive Spurling’s
Table 17-2 page 564
AOMSI (fusion) single level with radiculopathy Class 2 Grade C default is 11% WPI
Grade Modifiers are FH = 2, PE = 2, CS = 2 so Net Adjustment is = 0
Maintain in default position C for 11% WPI

25. s/p partial Meniscectomy medial and lateral with normal exam, gait and x-rays
Table 16-3 page 509
Class 1 for partial medial and lateral meniscectomy
Grade Modifiers 0 for FH, PE and CS
Class 1 Grade C is 10% LEI
10% LE converts to 4% WPI as 40% of LE is calculation to WP.

26. Combining last three conditions
Cervical 11% WP
shoulder 7% UE = 4% WP
Knee 10% LE = 4% WP
Combine using CVC page 604
Total combined = 18% WP
Cannot combine unlike body parts. For instance digit and shoulder
Need to convert digit to hand then UE to combine with shoulder (UE)