What should be checked before relying on a WPI figure?
Check maximum medical improvement, the body area, objective findings, the NSW Guideline chapter and any NSW modification before relying on a percentage.
Can this page calculate your percentage?
No. WPI depends on an assessor, maximum medical improvement, objective findings and the NSW Guidelines. This page is general information only.
Permanent impairment assessment
How permanent impairment is assessed for Meniscus tear, meniscectomy and residual knee symptoms
Meniscus WPI depends on the residual knee condition and whether an adopted diagnosis-based estimate, ROM, arthritis or another method is the specific valid pathway. A tear seen on MRI is not the same as a meniscectomy row.
What injuries can happen to this body part?
- Medial or lateral meniscal tear after twisting, squatting, kneeling or impact
- Partial or total meniscectomy
- Locking, catching, swelling or persistent joint-line symptoms
- Meniscal deficiency contributing to joint-space narrowing or arthritis
Symptoms and findings that matter
- Whether the tear was treated by partial or total meniscectomy
- Whether residual symptoms are better assessed as arthritis/cartilage loss, ROM loss or instability
- Whether both medial and lateral menisci are involved
- Whether the same impairment is being double counted with arthritis or gait
What investigations are usually relevant?
- Treating specialist report and final impairment assessment at maximum medical improvement
- Imaging, pathology, audiology, ophthalmology, respiratory, nerve or functional testing that fits the body system
- Operative reports, discharge summaries, rehabilitation records and objective clinical measurements where relevant
How WPI is assessed for this body part
- Meniscus WPI depends on the residual knee condition and whether an adopted diagnosis-based estimate, ROM, arthritis or another method is the specific valid pathway. A tear seen on MRI is not the same as a meniscectomy row.
- Assessment source: NSW Guidelines Chapter 3 lower extremity and AMA5 Table 17-33 diagnosis-based estimates where adopted and not modified by NSW.
- The assessor should explain maximum medical improvement, the body-system chapter, the method selected, any NSW modification, and why the objective findings fit that method.
How movement affects the assessment
- Meniscus problems can restrict squatting, kneeling, pivoting and stairs.
- ROM is not automatically added to a meniscectomy estimate; the selected method must be valid and not double count the same impairment.
Meniscus diagnosis-based examples where AMA5 is adopted
Partial medial or lateral meniscectomy1% WPI (2% lower extremity impairment) where the adopted AMA5 diagnosis-based estimate applies.
Total medial or lateral meniscectomy3% WPI (7% lower extremity impairment) where the adopted AMA5 diagnosis-based estimate applies.
Partial medial plus partial lateral meniscectomy4% WPI (10% lower extremity impairment) where the adopted AMA5 diagnosis-based estimate applies.
Total medial and lateral meniscectomy9% WPI (22% lower extremity impairment) where the adopted AMA5 diagnosis-based estimate applies.
Not scan-onlyA meniscal tear on MRI does not equal the meniscectomy row if no meniscectomy or qualifying residual condition is present.
NSW arthritis and cartilage-loss rules
Cartilage loss definitionOsteoarthritis for lower limb WPI is assessed as cartilage loss, usually through radiologically determined joint-space intervals in AMA5 Table 17-31 as adopted by NSW.
Knee compartmentsThe knee has three compartments. The major impairment compartment is used; compartments are not added or combined.
Cannot combine with some methodsArthritis rating cannot be combined with gait disturbance, muscle atrophy, muscle strength or ROM.
Patello-femoral cautionPatello-femoral arthritis/crepitus is not added again when assessing arthritis of the knee joint itself.
Resurfacing proceduresNSW gives no additional impairment for resurfacing procedures for localised cartilage lesions or defects in major joints.
NSW lower limb global rules
Most specific method firstUse the method that most specifically addresses the lower limb impairment where possible, rather than a broad fallback label.
Highest valid assessmentWhere more than one valid lower limb method applies, the NSW Guidelines generally require the assessment that gives the highest valid rating, unless a specific rule prevents it.
Do not exceed amputation valueA lower limb part or region cannot exceed the applicable amputation value. The whole lower limb maximum is 40% WPI, except where a specific gait table gives WPI directly.
Gait derangement is last resortGait derangement should be used only as a last resort and cannot be combined with other lower extremity assessment methods.
Permanent walking aid onlyIf a walking aid is relied on, the evidence should show permanent use, not a temporary aid during treatment or recovery.
ROM reliabilityROM can be unreliable where effort, pain behaviour or inconsistency affects measurement. The opposite side should be compared where relevant.
Arthritis needs imagingArthritis/cartilage loss must be radiologically assessed. Pain, crepitus or a broad MRI comment is not enough by itself.
Lower limb ROM and consistency rules
Use ROM only where validROM should be used only where the measurements are consistent and clinically reliable.
Same joint planesMultiple valid planes within the same lower limb joint are added, not combined, under the NSW lower limb method.
Opposite side comparisonIf the opposite side has reduced average mobility, the assessor should explain whether baseline deduction or comparison is needed.
Knee varus/valgus with arthritisVarus or valgus deformity due to compartment arthritis is not combined with ROM; both are calculated and the greater valid value is used.
Practical WPI examples
- A partial meniscectomy may have an adopted diagnosis-based estimate, but a scan-only meniscal tear may not fit that row.
- If meniscal loss has caused joint-space narrowing, the arthritis/cartilage method may be the more specific issue.
- Persistent locking after surgery should be supported by treating or specialist records, not just broad pain complaints.
Evidence checklist
- A clear diagnosis and the body area being assessed
- Records showing the condition has reached maximum medical improvement, if that is the issue
- Specialist reports, imaging reports and treating notes relied on by the assessor
- Objective findings on examination, not only symptoms described by the injured person
- A work and treatment chronology explaining the injury, treatment, surgery and recovery path
- Any previous injury, degeneration, congenital issue or non-work cause that needs apportionment considered
- MRI report
- Arthroscopy or operative report
- Orthopaedic review
- Joint-line findings
- ROM records
- Weight-bearing X-rays if cartilage loss is alleged
What usually does not increase WPI
- Assuming a scan result automatically gives a WPI percentage
- Confusing pain, disability or inability to work with permanent impairment
- Ignoring maximum medical improvement before arranging an assessment
- Using an AMA5 table without checking whether the NSW Guidelines modify or replace it
- Double counting the same impairment through two methods when the Guidelines require one method
- Using meniscectomy values without surgery evidence
- Adding meniscus and arthritis figures for the same compartment without checking NSW rules
- Assuming locking/catching always means ratable WPI
Assessment source
Assessment source: Assessment source: NSW Guidelines Chapter 3 lower extremity and AMA5 Table 17-33 diagnosis-based estimates where adopted and not modified by NSW.
This section is source-backed general information. It is not a WPI assessment and is not legal advice.
- SIRA NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment: Source for the NSW assessment framework, MMI, AMA5 adoption, NSW modifications and exclusions.
- SIRA lower extremity chapter: Source for NSW lower extremity assessment rules, gait derangement limits and NSW-modified lower limb tables.
Related injury and claim pages
Need a practical claim check?
If an impairment percentage, medical assessment or insurer decision is affecting your NSW injury claim, send the decision or report for a practical review. This is general information only and does not guarantee any result.
Request a free claim checkAssessment scope for Meniscus WPI Assessment
The assessment scope for Meniscus WPI Assessment should be stated precisely before any percentage is considered. The file should identify whether that label describes the primary diagnosed condition, a symptom of another injury, a regional overview or one component of a broader impairment. Findings from another body area or diagnosis should not be transferred without explanation. The report should connect the stated condition to the correct NSW Guideline chapter, objective findings, treatment history and any permitted combination or apportionment method. This distinction is particularly important where similar page labels cover different clinical questions.
- Confirm the diagnosis and body area being assessed as Meniscus
- Separate condition-specific findings from overlapping symptoms or injuries in another body area
- Check that the selected NSW Guideline chapter and method match the condition actually assessed
- Explain any combination, apportionment or exclusion rather than relying on the page label alone
Start with maximum medical improvement
Permanent impairment should generally be assessed when the condition is stable and unlikely to change substantially in the next year. Treatment, surgery and rehabilitation history may affect whether the timing is appropriate.
Use the NSW Guidelines first
The NSW Guidelines adopt AMA5 in many areas, but NSW modifications prevail. Do not assume an AMA5 table applies without checking the NSW chapter and any public SIRA clarification.
Keep the assessment practical
A useful assessment file separates diagnosis, objective findings, surgery history, work capacity issues, apportionment questions and the body-area method used by the assessor.
Ask about an impairment issueDocuments and records
Injury evidence to organise early
The useful records depend on how the injury happened, when symptoms were recorded and how treatment or work capacity changed.
- Date, location and short description of the injury event
- Medical certificates, reports, scans, treatment records or hospital documents
- Employer, insurer, police, incident or venue records where relevant
- Photos, witness details, dashcam or other supporting material if available
- Income, superannuation, work capacity or leave records where relevant
- Letters, emails, claim numbers and decisions already received
Common questions
Injury evidence questions
Short general answers only. The right next step depends on the facts, dates and documents.
Is WPI the same as being unable to work?
No. WPI is a medical impairment measure. Work capacity, weekly payments, damages, treatment disputes and TPD issues are separate questions, although the evidence may overlap.
Does pain alone create a WPI percentage?
Not by itself. NSW workers compensation excludes AMA5 Chapter 18 on pain. Chronic pain is assessed through the underlying diagnosed condition where the Guidelines permit it.
Can secondary psychological symptoms be added to physical WPI?
In NSW workers compensation, secondary psychiatric or psychological impairment is not assessed as permanent impairment. Primary psychological impairment is assessed separately and is not combined with physical WPI.
Injury pathway enquiry
Not sure which claim type matches the injury?
Start with how the injury happened, what medical records exist and how work or daily activity has changed. The same injury can sit in different pathways.