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 Total ankle replacement and post-replacement ankle function
Ankle replacement WPI has exact NSW point categories. The result is not just the surgery label; it depends on whether the replacement scores as good, fair or poor under the NSW table.
What injuries can happen to this body part?
- Total ankle replacement after post-traumatic ankle arthritis
- Residual pain, stiffness, instability or poor function after replacement
- Replacement combined with hindfoot alignment, fusion or arthritis questions that require double-counting checks
Symptoms and findings that matter
- Total ankle replacement point score and good/fair/poor category
- ROM, pain, stability, alignment and function forming the score
- Whether another ankle/foot method is more specific or prohibited from combination
- Permanent aid use only if the replacement method does not adequately assess the impairment and gait is legally available
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
- Ankle replacement WPI has exact NSW point categories. The result is not just the surgery label; it depends on whether the replacement scores as good, fair or poor under the NSW table.
- Assessment source: NSW Guidelines Chapter 3 Table 3.3 total ankle replacement point categories.
- 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
- ROM after ankle replacement helps explain function but should be assessed within the replacement scoring method unless another valid method applies.
- Standing, walking, uneven ground and ladder tolerance should be recorded as functional evidence, not substituted for the point category.
NSW Table 3.3 total ankle replacement point categories
Good result, 85 to 100 points12% WPI (30% lower extremity impairment).
Fair result, 50 to 84 points16% WPI (40% lower extremity impairment).
Poor result, less than 50 points20% WPI (50% lower extremity impairment).
NSW corrected Table 17-11 ankle motion rows
Mild ankle motion impairment3% WPI (7% lower extremity impairment; 10% foot impairment): plantar flexion 11-20 degrees, flexion contracture 1-10 degrees, or extension 10-0 degrees to neutral.
Moderate ankle motion impairment6% WPI (15% lower extremity impairment; 21% foot impairment): plantar flexion 1-10 degrees or flexion contracture 11-19 degrees.
Severe ankle motion impairment12% WPI (30% lower extremity impairment; 43% foot impairment): no plantar flexion capability or flexion contracture of 20 degrees or more.
NSW foot and ankle specific rows
Tibia-os calcis angle 110 to 100 degrees5% WPI (12% lower extremity impairment; 17% foot impairment) under NSW Table 3.4.
Tibia-os calcis angle 99 to 90 degrees8% WPI (20% lower extremity impairment; 28% foot impairment) under NSW Table 3.4.
Tibia-os calcis angle below 90 degreesAdd 1% WPI (2% lower extremity impairment; 3% foot impairment) per degree, up to 15% WPI (37% lower extremity impairment; 54% foot impairment).
Persistent plantar fasciitisPersistent symptoms and clinical findings after 18 months are rated at 1% WPI (2% lower extremity impairment).
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.
Practical WPI examples
- Good result, 85-100 points, is verified at 12% WPI.
- Fair result, 50-84 points, is verified at 16% WPI.
- Poor result, less than 50 points, is verified at 20% WPI.
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
- Replacement operation report
- Orthopaedic scoring report
- Weight-bearing X-rays
- ROM and stability notes
- Physiotherapy records
- Work restrictions for standing/walking
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
- Saying ankle replacement always equals one fixed figure
- Ignoring the NSW point category
- Adding gait derangement without checking combination prohibitions
Assessment source
Assessment source: Assessment source: NSW Guidelines Chapter 3 Table 3.3 total ankle replacement point categories.
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 Ankle Replacement WPI Assessment
The assessment scope for Ankle Replacement 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 Ankle Replacement
- 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.