Patello-Femoral Injury and Replacement NSW

Overview for NSW injured workers

Start with the dispute, not just the diagnosis

May be relevant when

The applicable test depends on the legal characterisation. A personal injury generally must arise out of or in the course of employment, with employment a substantial contributing factor; a disease or disease aggravation generally requires employment to be the main contributing factor.

Benefits to check

Medical expenses, weekly payments, suitable duties, treatment requests, WPI and any dispute notice already received.

Legal help is useful when

The insurer denies liability, refuses treatment, relies on an IME, reduces weekly payments or disputes permanent impairment.

How this affects your claim in practice

In a patello-femoral injury and replacement claim, the diagnosis is only the starting point. The records should connect MRI and weight-bearing or patello-femoral X-rays and records of patellar dislocation, translocation, instability or direct trauma with the worker's practical limits, including standing, walking, stairs, kneeling, squatting, driving and load carrying and safe duties that avoid unsafe mobility demands. If the insurer disputes whether symptoms are patello-femoral, meniscal, arthritic or referred, the response should address that reason directly.

This information is general in nature and is not legal advice. You should obtain advice about your own circumstances.

Assessment source

NSW Guidelines for the Evaluation of Permanent Impairment, paras 1.8-1.12: NSW Guidelines control the assessment method and AMA5 is used only where adopted and not modified.
NSW Guidelines para 1.12: AMA5 Chapter 18 pain is excluded; chronic pain is assessed through the underlying diagnosed condition, while CRPS is assessed under the relevant NSW method.
NSW Guidelines para 1.15: assessment should usually wait until maximum medical improvement, meaning the condition is stable and unlikely to change substantially in the next year.
NSW Guidelines Chapter 3 applies AMA5 Chapter 17 only as modified by NSW. Paragraphs 3.2-3.7 require the most specific valid method, selection of the highest valid evaluation where more than one method applies, common units before combination, and a 40% WPI lower-limb maximum.
NSW Guidelines para 1.24: activities of daily living must not be used to increase or reduce a calculated lower-extremity impairment. Functional examples explain the measurement; they are not an extra percentage.
NSW Guidelines paras 3.8-3.15 and corrected AMA5 Tables 17-4 and 17-6: true leg length, gait, unilateral atrophy and manual muscle testing each have their own measurement and non-combination requirements.
NSW Guidelines paras 3.16-3.18: inconsistent range-of-motion findings are invalid; values from different movement planes within one joint are added; joint ankylosis uses the corrected NSW optimum-position table and positional additions.
NSW Guidelines paras 3.19-3.24: arthritis means radiological cartilage loss for impairment purposes. It cannot be assumed from pain, and the arthritis method cannot be combined with gait, atrophy, strength or range of motion.
NSW Guidelines paras 3.10-3.15 and 3.32-3.35: gait is a last resort; gait, atrophy, muscle testing and peripheral-nerve methods can duplicate lower-limb function and must follow Table 17-2 non-combination rules; CRPS uses the NSW Chapter 17 method rather than AMA5 Chapter 18 pain.
NSW Guidelines paras 3.26-3.30 and Tables 3.2-3.4: NSW modifies diagnosis-based estimates, tibial plateau fracture, patello-femoral and ankle replacement, tibia-os calcis angle and persistent plantar fasciitis. Hip and total-knee replacements use AMA5 Tables 17-33 to 17-35 subject to the NSW corrections.

What injuries or conditions may be assessed?

Patello-femoral injury can involve direct anterior trauma, patellar translocation or dislocation, focal chondral loss and an isolated patello-femoral joint replacement.

An isolated patello-femoral replacement is not the same operation as a total knee replacement and does not use the total-knee replacement points worksheet.
The ordinary valid knee assessment is completed first, then the special isolated-replacement value is combined as directed by NSW paragraph 3.28.

Symptoms and findings that matter

The operation report must confirm an isolated patello-femoral replacement. The assessor separately records the valid underlying knee findings and applies the non-combination rules before using the replacement row.

For patello-femoral injury and replacement, range of motion is normally measured three times in each relevant plane and the greatest valid result is used. If repeated readings or findings between examinations are materially inconsistent, ROM is not a valid impairment parameter.

If true leg length is relevant to patello-femoral injury and replacement, manual measurement is an exception to the greatest-reading rule: three readings are averaged. The opposite joint or limb is also compared where it provides a valid baseline.

Where patello-femoral injury and replacement is assessed through manual muscle weakness, the examiner uses the six Medical Research Council grades from 0 to 5. Those grades are ordinal rather than evenly spaced, and the NSW method uses AMA5 Table 17-8; electrodiagnostic results do not replace the manual muscle test.

An impairment report for patello-femoral injury and replacement may need a diagnosis-based estimate, radiological cartilage-loss method, replacement score, true limb-length difference, unilateral atrophy, muscle grade, named-nerve deficit or gait method instead of, or in a limited case alongside, ROM.

What investigations are usually relevant

Investigations for patello-femoral injury and replacement may include weight-bearing X-rays, CT, MRI, ultrasound or operation records identifying the actual joint, fracture, tendon, ligament, cartilage, prosthesis or nerve condition and repeat goniometer measurements, stability tests, alignment findings and comparison with the unaffected side where that comparison is valid. Each result should answer a defined clinical question and be read with the examination, diagnosis and history.

Orthopaedic, rehabilitation and physiotherapy records showing whether the condition has reached maximum medical improvement.
Certificates of capacity and duties evidence about walking, standing, stairs, kneeling, squatting, driving, lifting and uneven ground. These explain claim impact but do not alter the WPI calculation.

How WPI is assessed for this body part

For an isolated patello-femoral replacement, NSW paragraph 3.28 directs the assessor to complete the usual valid knee assessment and combine it with 9% WPI (22% LEI). This is not the total-knee replacement scoring method.

For patello-femoral injury and replacement, NSW Guidelines Chapter 3 applies AMA5 Chapter 17 subject to NSW corrections. The most specific valid method is used, and where more than one valid method applies the highest valid evaluation is generally selected unless Table 17-2 permits a combination.

If ROM is valid for patello-femoral injury and replacement, values in different planes of the same joint are added. Regional values in the same limb are expressed in the same unit and combined before conversion to WPI.

For patello-femoral injury and replacement, knee flexion means bending and extension means straightening. A flexion contracture prevents full passive and active straightening; an extension lag prevents active full extension despite greater passive extension. Varus and valgus describe inward or outward alignment.

Arthritis in an assessment of patello-femoral injury and replacement requires radiologically measured cartilage loss. For a knee, only the most impaired compartment is used. Arthritis cannot be combined with gait, atrophy, strength or ROM for the same loss.

For patello-femoral injury and replacement, gait remains a last-resort standalone method. Atrophy, manual muscle testing, peripheral nerve impairment and gait can duplicate strength loss and cannot be stacked. A diagnosis-based estimate is combined only where Table 17-2 permits it.

The calculation for patello-femoral injury and replacement cannot be changed because of activities of daily living under NSW paragraph 1.24. Functional descriptions help explain the evidence but are not an uplift or deduction.

Table and value examples

Isolated patello-femoral joint replacement

Assess knee impairment in the usual way and combine with 9% WPI (22% lower extremity impairment)

This applies to isolated patello-femoral joint replacement and should not be treated as a rating for every patella or knee pain claim.

Source: NSW Guidelines para 3.28

Cartilage resurfacing procedures

No additional impairment

No extra WPI is awarded for resurfacing procedures used for localised cartilage lesions and defects in major joints.

Source: NSW Guidelines para 3.28

Worked assessment illustrations

These examples paraphrase the assessment reasoning in the source material. They explain method only and are not predicted outcomes.

Illustration 1

Patello-femoral injury and replacement: isolated replacement combination

Assumed facts: Assume the usual valid knee assessment produces 5% WPI and the operation report confirms an isolated patello-femoral replacement.

Method: NSW paragraph 3.28 says to combine the usual knee result with 9% WPI (22% LEI) for the isolated replacement. The Combined Values Chart combines 9% and 5% to 14% WPI after rounding.

Illustrative outcome: The 14% result follows only from the assumed 5% underlying knee value and the verified isolated replacement. Ordinary anterior knee pain is not calculated this way. This is an illustration only.

Source: NSW Guidelines para 3.28; Combined Values Chart

What usually does not increase WPI

A patella procedure, resurfacing or pain presentation that is not an isolated patello-femoral replacement does not attract the special 9% WPI component.

Pain, tenderness, swelling or difficulty walking does not create a percentage without a valid lower-limb method.

A scan label, surgery name or recommendation for surgery is not a fixed WPI result.

Work restrictions, weekly payments and inability to resume the pre-injury job are important claim issues but are not themselves impairment measurements.

Activities of daily living cannot be used to increase or reduce the calculated lower-extremity rating.

Evidence checklist

The records for patello-femoral injury and replacement should include the accepted injury description, date and any insurer decision limiting the body part or diagnosis and imaging and operation reports, including the relevant side, level, compartment and procedure. They are most useful when the diagnosis, examination and practical restrictions are consistent.

Repeat movement, stability, alignment, circumference, limb-length or neurological measurements required by the selected method.
A calculation worksheet identifying the table, regional unit, permitted combinations, conversion and rounding.

How this injury commonly happens at work

Work-related patello-femoral injury and replacement can arise through a direct blow or fall onto the front of the knee and patellar dislocation or translocation during a work incident. The chronology should identify the actual task or event and when symptoms or function changed.

Work-related patello-femoral injury and replacement can arise through repeated kneeling, stairs or squatting that aggravates accepted patello-femoral pathology. The chronology should record the actual task or event and the point at which symptoms or function changed.

Common insurer disputes

For patello-femoral injury and replacement, an insurer may dispute whether symptoms are patello-femoral, meniscal, arthritic or referred and whether the NSW footnote criteria for pain or crepitation are met. The written decision should be answered with evidence directed to those reasons.

Further disputes about patello-femoral injury and replacement may concern whether replacement was isolated or part of a total knee procedure and whether kneeling, stairs and standing duties are sustainable. The decision notice should identify which issue is relied on and the evidence said to support it.

Treatment and surgery issues

Depending on the diagnosis and treating opinion, management of patello-femoral injury and replacement may involve physiotherapy, bracing, injections, realignment or replacement where treating evidence supports it. The request should explain the expected functional benefit and its connection to the accepted injury.

Weekly payments and work capacity

Capacity evidence for patello-femoral injury and replacement should address standing, walking, stairs, kneeling, squatting, driving and load carrying and safe duties that avoid unsafe mobility demands. Proposed duties must be sustainable for the proposed hours, not merely possible once.

For patello-femoral injury and replacement, capacity evidence should address travel to work and medication effects where relevant and weekly payment decisions where partial capacity is overstated. The question is whether those activities can be performed safely, reliably and for the proposed hours—not whether a task can be attempted once.

How NSW Work Injury Claim can help

For patello-femoral injury and replacement, a claim review can help to clarify diagnosis and mechanism of injury and compare work duties with medical restrictions. The purpose is to identify the precise decision and the evidence needed for the next available step, not to promise an outcome.

For patello-femoral injury and replacement, a claim review can help to respond to treatment or work capacity disputes and prepare WPI evidence when the condition becomes stable. The purpose is to identify the precise decision and the evidence needed for the next available step, not to promise an outcome.

Common questions about patello-femoral injury and replacement claims

How can work cause or aggravate patello-femoral injury and replacement?

For patello-femoral injury and replacement, the relevant work history may include a direct blow or fall onto the front of the knee, patellar dislocation or translocation during a work incident, and repeated kneeling, stairs or squatting that aggravates accepted patello-femoral pathology. A claim still depends on the actual chronology and medical evidence. The records should identify what changed, when symptoms began or worsened, and how the diagnosed condition affects the worker's duties.

How is WPI assessed for patello-femoral injury and replacement?

For patello-femoral injury and replacement, for an isolated patello-femoral replacement, NSW paragraph 3.28 directs the assessor to complete the usual valid knee assessment and combine it with 9% WPI (22% LEI). This is not the total-knee replacement scoring method. The operation report must confirm an isolated patello-femoral replacement. The assessor separately records the valid underlying knee findings and applies the non-combination rules before using the replacement row. The assessor must apply the NSW Guidelines to the accepted, stable condition; the diagnosis or an operation does not by itself determine a percentage.

Which records are most useful for a patello-femoral injury and replacement assessment?

A patello-femoral injury and replacement assessment commonly needs the accepted injury description, date and any insurer decision limiting the body part or diagnosis, imaging and operation reports, including the relevant side, level, compartment and procedure, repeat movement, stability, alignment, circumference, limb-length or neurological measurements required by the selected method, and a calculation worksheet identifying the table, regional unit, permitted combinations, conversion and rounding. Those records are most useful when they describe the same diagnosis, examination findings, treatment history and practical work restrictions.

What does an insurer commonly dispute about patello-femoral injury and replacement?

For patello-femoral injury and replacement, common issues include whether symptoms are patello-femoral, meniscal, arthritic or referred, whether the NSW footnote criteria for pain or crepitation are met, and whether replacement was isolated or part of a total knee procedure. The response should address the insurer's stated reason with the relevant chronology, clinical findings, investigations and duties evidence rather than relying on the diagnosis alone.

How can patello-femoral injury and replacement affect weekly payments and suitable duties?

Capacity evidence for patello-femoral injury and replacement may need to address standing, walking, stairs, kneeling, squatting, driving and load carrying, safe duties that avoid unsafe mobility demands, and travel to work and medication effects where relevant. A certificate should describe what the worker can do safely and sustainably. Proposed duties should then be checked against those restrictions and the real demands of the job.

Does patello-femoral injury and replacement automatically receive a fixed WPI percentage?

No. For patello-femoral injury and replacement, one verified example is isolated patello-femoral joint replacement: Assess knee impairment in the usual way and combine with 9% WPI (22% lower extremity impairment), under NSW Guidelines para 3.28. That value applies only when its stated criteria are met. A patella procedure, resurfacing or pain presentation that is not an isolated patello-femoral replacement does not attract the special 9% WPI component.

Request a calm claim position review

If you have received an insurer decision or you are unsure how your injury evidence fits together, we can help you identify the issue, organise the documents and consider the next step. Where ILARS funding is approved, eligible legal costs and necessary disbursements may be covered.

Request a claim review Call (02) 7233 3661

Patello-femoral injury and replacement workers compensation NSW

Key legal and assessment sources