{"id":"F2018L00188","name":"Statement of Principles concerning popliteal cyst (Reasonable Hypothesis) (No. 31 of 2018)","slug":"statement-of-principles-concerning-popliteal-cyst-reasonable-hypothesis-no-31-of-2018","collection":"legislative_instrument","jurisdiction":"commonwealth","status":"in_force","isInForce":true,"actNumber":null,"makingDate":null,"administeringDepartment":null,"currentVersion":{"id":439497,"registerId":"F2018L00188-fast-fetch-1775955503834","compilationNumber":null,"startDate":"2026-04-12","status":"InForce","reasons":null,"registeredAt":null},"sections":[{"sectionNumber":"1","sectionType":"section","heading":"Statement of Principles concerning popliteal cyst (Reasonable Hypothesis) (No. 31 of 2018)","content":"---\nmeta-content-style-type: text/css\nmeta-content-type: application/xhtml+xml; charset=utf-8\nmeta-generator: Aspose.Words for .NET 20.2\n---\n\n?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"no\"?>\n\n\n\n \n\nStatement of Principles\n\nconcerning\n\nPOPLITEAL CYST (Reasonable Hypothesis)\n\n(No. 31 of 2018)\n\nThe Repatriation Medical Authority determines the following Statement of Principles under subsection 196B(2) of the Veterans' Entitlements Act 1986.\n\n \n\nDated 2 March 2018\n\n \n\n \n\n \n\n \n\n \n\n| The Common Seal of the Repatriation Medical Authority was affixed to this instrument at the direction of:
|\n| --- |\n| 
Professor Nicholas Saunders AO
Chairperson
|\n\n\n \n\n \n\n\nContents\n\n1 Name\n\n2 Commencement\n\n3 Authority\n\n4 Application\n\n5 Definitions\n\n6 Kind of injury, disease or death to which this Statement of Principles relates\n\n7 Basis for determining the factors\n\n8 Factors that must exist\n\n9 Relationship to service\n\n10 Factors referring to an injury or disease covered by another Statement of Principles\n\nSchedule 1 - Dictionary\n\n1 Definitions\n\n \n\n\n\n\n1 Name\n\nThis is the Statement of Principles concerning popliteal cyst (Reasonable Hypothesis) (No. 31 of 2018).\n\n2 Commencement\n\n This instrument commences on 2 April 2018.\n\n3 Authority\n\nThis instrument is made under subsection 196B(2) of the Veterans' Entitlements Act 1986.\n\n4 Application\n\nThis instrument applies to a claim to which section 120A of the VEA or section 338 of the Military Rehabilitation and Compensation Act 2004 applies.\n\n5 Definitions\n\nThe terms defined in the Schedule 1 - Dictionary have the meaning given when used in this instrument.\n\n6 Kind of injury, disease or death to which this Statement of Principles relates\n\n(1) This Statement of Principles is about popliteal cyst and death from popliteal cyst.\n\nMeaning of popliteal cyst\n\n(2) For the purposes of this Statement of Principles, popliteal cyst means a swelling in the popliteal fossa due to enlargement of the gastrocnemius-semimembranosus bursa, where the swelling is associated with clinical manifestations.\n\nNote: Clinical manifestations of a popliteal cyst include a palpable swelling or mass behind the knee, posterior knee pain, knee stiffness, tightness in the popliteal region and limitation of range of motion of the affected knee joint. Pain and swelling may be worsened by prolonged standing or activity. Popliteal cysts may enlarge, dissect or rupture, sometimes resulting in compression or inflammation of adjacent structures.\n\n(3) While popliteal cyst attracts ICD‑10‑AM code M66.0 or M71.2, in applying this Statement of Principles the meaning of popliteal cyst is that given in subsection (2).\n\n(4) For subsection (3), a reference to an ICD-10-AM code is a reference to the code assigned to a particular kind of injury or disease in The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification (ICD-10-AM), Tenth Edition, effective date of 1 July 2017, copyrighted by the Independent Hospital Pricing Authority, ISBN 978-1-76007-296-4.\n\nDeath from popliteal cyst\n\n(5) For the purposes of this Statement of Principles, popliteal cyst, in relation to a person, includes death from a terminal event or condition that was contributed to by the person's popliteal cyst.\n\nNote: terminal event is defined in the Schedule 1 – Dictionary.\n\n7 Basis for determining the factors\n\nThe Repatriation Medical Authority is of the view that there is sound medical‑scientific evidence that indicates that popliteal cyst and death from popliteal cyst can be related to relevant service rendered by veterans, members of Peacekeeping Forces, or members of the Forces under the VEA, or members under the MRCA.\n\nNote: MRCA, relevant service and VEA are defined in the Schedule 1 – Dictionary.\n\n8 Factors that must exist\n\nAt least one of the following factors must as a minimum exist before it can be said that a reasonable hypothesis has been raised connecting popliteal cyst or death from popliteal cyst with the circumstances of a person's relevant service:\n\n(1) having an injury or disease which causes synovitis of the affected knee joint at the time of the clinical onset of popliteal cyst;\n\nNote: Examples of an injury or disease which can cause synovitis of the affected knee joint include:\n\n(a) an acute meniscal tear of the knee;\n\n(b) calcium pyrophosphate deposition disease (pseudogout);\n\n(c) dialysis-related amyloidosis;\n\n(d) gout;\n\n(e) internal derangement of the knee;\n\n(f) Lyme disease;\n\n(g) osteoarthritis;\n\n(h) pigmented villonodular synovitis;\n\n(i) psoriatic arthropathy;\n\n(j) reactive arthritis;\n\n(k) rheumatoid arthritis;\n\n(l) sarcoidosis; and\n\n(m) tuberculosis.\n\n(2) having a partial or total knee replacement before the clinical onset of popliteal cyst;\n\n(3) having an injury or disease which causes synovitis of the affected knee joint at the time of the clinical worsening of popliteal cyst;\n\nNote: Examples of an injury or disease which can cause synovitis of the affected knee joint include:\n\n(a) an acute meniscal tear of the knee;\n\n(b) calcium pyrophosphate deposition disease (pseudogout);\n\n(c) dialysis-related amyloidosis;\n\n(d) gout;\n\n(e) internal derangement of the knee;\n\n(f) Lyme disease;\n\n(g) osteoarthritis;\n\n(h) pigmented villonodular synovitis;\n\n(i) psoriatic arthropathy;\n\n(j) reactive arthritis;\n\n(k) rheumatoid arthritis;\n\n(l) sarcoidosis; and\n\n(m) tuberculosis.\n\n(4) having a partial or total knee replacement before the clinical worsening of popliteal cyst;\n\n(5) for clinical worsening of a popliteal cyst manifesting as rupture of a popliteal cyst only, undertaking physical activity at a minimum intensity of five METS at the time of the clinical worsening of popliteal cyst;\n\nNote: MET is defined in the Schedule 1 - Dictionary. \n\n(6) inability to obtain appropriate clinical management for popliteal cyst.\n\n9 Relationship to service\n\n(1) The existence in a person of any factor referred to in section 8, must be related to the relevant service rendered by the person.\n\n(2) The factors set out in subsections 8(3) to 8(6) apply only to material contribution to, or aggravation of, popliteal cyst where the person's popliteal cyst was suffered or contracted before or during (but did not arise out of) the person's relevant service.\n\n10 Factors referring to an injury or disease covered by another Statement of Principles\n\nIn this Statement of Principles:\n\n(1) if a factor referred to in section 8 applies in relation to a person; and\n\n(2) that factor refers to an injury or disease in respect of which a Statement of Principles has been determined under subsection 196B(2) of the VEA;\n\nthen the factors in that Statement of Principles apply in accordance with the terms of that Statement of Principles as in force from time to time.\n\n \n\n \n\nSchedule 1 - Dictionary \n\nNote: See Section 5\n\n1 Definitions\n\nIn this instrument:\n\n MET means a unit of measurement of the level of physical exertion. 1 MET = 3.5 ml of oxygen/kg of body weight per minute, 1.0 kcal/kg of body weight per hour or resting metabolic rate.\n\n MRCA means the Military Rehabilitation and Compensation Act 2004.\n\n popliteal cyst—see subsection 6(2).\n\n relevant service means:\n\n(a) operational service under the VEA;\n\n(b) peacekeeping service under the VEA;\n\n(c) hazardous service under the VEA;\n\n(d) British nuclear test defence service under the VEA;\n\n(e) warlike service under the MRCA; or\n\n(f) non-warlike service under the MRCA.\n\nNote: MRCA and VEA are also defined in the Schedule 1 - Dictionary.\n\n terminal event means the proximate or ultimate cause of death and includes the following:\n\n(a) pneumonia;\n\n(b) respiratory failure;\n\n(c) cardiac arrest;\n\n(d) circulatory failure; or\n\n(e) cessation of brain function.\n\n VEA means the Veterans' Entitlements Act 1986.\n\n \n\n \n","sortOrder":0}],"analysis":{"flash_summary":{"complexity_score":3,"scope_assessment":{"changed":false,"description":"This Statement of Principles is narrowly targeted to the medical question of when a popliteal cyst (or death from it) can be linked to relevant service under the veterans' compensation legislation. It does not broaden the SoP regime beyond its original purpose of specifying medical factors that raise a 'reasonable hypothesis' of service connection. The instrument remains limited to that single condition, sets a small number of alternative connecting factors, and cross-references existing SoPs where appropriate (sections 6–10). There is no indication the instrument extends scope materially beyond the RMA's usual function."},"complexity_factors":["Short, single-condition Statement (popliteal cyst) with 10 substantive clauses and one Dictionary schedule","6 alternative qualifying factors listed in section 8 (only one required)","Repeated list of 13 example synovitis-causing conditions in sections 8(1) and 8(3)","One quantitative activity threshold (physical activity ≥ 5 METs) in section 8(5)","Cross-reference to other Statements of Principles where factors refer to other injuries/diseases (section 10)","Requirement that factors be related to 'relevant service' introduces a legal link to service definitions in Schedule 1","Use of ICD-10-AM codes referenced but overridden by the textual definition (section 6(3)–(4))","Conditional limitation that some factors (8(3)–8(6)) apply only to material contribution/aggravation of pre-existing cysts (section 9(2))"],"plain_english_summary":"**What this document is and who it affects**\n\n- This is a medical \"Statement of Principles\" (SoP) used in decisions about veteran compensation and rehabilitation claims. It sets out the medical facts and legal tests the Repatriation Medical Authority (RMA) uses to decide whether a popliteal cyst can be linked to a person's \"relevant service\" (service that qualifies under the Veterans' Entitlements Act 1986 or the Military Rehabilitation and Compensation Act 2004). (See sections 3–4, Schedule 1 definitions.)\n\n**What a popliteal cyst means here**\n\n- The instrument defines \"popliteal cyst\" as a swelling behind the knee caused by enlargement of the gastrocnemius–semimembranosus bursa and associated with clinical signs such as a palpable mass, posterior knee pain, stiffness, tightness, or reduced range of motion (section 6(2)). It notes the usual ICD‑10‑AM codes but says the textual definition controls (section 6(3)).\n\n**What the SoP does mechanically**\n\n- Establishes the medical basis for accepting a \"reasonable hypothesis\" that a popliteal cyst (or death from it) is connected to a person's qualifying service (section 7). In practice, RMA has identified the medical circumstances (factors) that, if present and linked to service, are sufficient to raise that reasonable hypothesis (section 8).\n\n- Lists six alternative types of factors; at least one must be present to link the cyst to service on the reasonable hypothesis test (section 8). The factors are:\n - (8)(1) — presence of an injury or disease causing synovitis (inflammation of the joint lining) in the affected knee at the clinical onset of the cyst (with examples such as meniscal tear, osteoarthritis, rheumatoid arthritis, gout, Lyme disease, tuberculosis, etc.).\n - (8)(2) — prior partial or total knee replacement before clinical onset of the cyst.\n - (8)(3) — presence of an injury or disease causing synovitis at the time of clinical worsening of the cyst (examples repeated from (8)(1)).\n - (8)(4) — prior partial or total knee replacement before clinical worsening of the cyst.\n - (8)(5) — where clinical worsening is a rupture of the cyst, the claimant undertaking physical activity at a minimum intensity of 5 METs (a metabolic equivalent measure) at the time of rupture.\n - (8)(6) — inability to obtain appropriate clinical management for the cyst.\n\n- Requires that whichever of those factors is relied on must be \"related to the relevant service\" rendered by the person (section 9(1)). Sections 9(2) and 10 add limits and cross-references: subsections (3)–(6) of section 8 (i.e. aggravation or material contribution factors) only apply where the cyst existed before or during service but did not originate in service; and if a factor refers to another injury or disease that itself has an SoP, that other SoP applies (section 10).\n\n**Why this matters**\n\n- Legal threshold: The SoP defines the medical scenarios that are sufficient to establish a \"reasonable hypothesis\" (a lower evidentiary threshold than \"balance of probabilities\") that the popliteal cyst is connected to qualifying service. That affects whether a veteran's claim can proceed to a compensable finding (sections 4, 7–8).\n\n**How it changes incentives, costs and administrative practice**\n\n- Who pays / who decides: The Department administering veterans' entitlements (and ultimately tribunals or courts) decide claims based on evidence judged against this SoP; the RMA sets the medical rules. The claimant usually bears the immediate cost of assembling medical records and statements proving the listed factor(s) and their service link (sections 8–9).\n\n- Evidence burden and administrative cost: Decision-makers will need relevant clinical records showing synovitis, knee replacement history, activity at time of rupture (including an assessment against the 5 METs threshold), or evidence that appropriate care was unavailable. That creates demand for medical opinions, historical treatment records, and potentially veteran or witness statements about service activities. Estimating METs retrospectively can be imprecise and may require expert interpretation (section 8(5), Schedule 1 definition of MET).\n\n- Interaction with other conditions and SoPs: Where a listed factor is itself another named disease/injury covered by its own SoP, adjudicators must consult that other SoP as well (section 10). This creates dependency between Statements and may lengthen assessments.\n\n- Fiscal and programmatic effects: The SoP potentially increases successful links where a veteran can show one of the listed factors is both present and service‑related, which may increase compensable outcomes and program expense. Conversely, it constrains claims that lack the listed medical connections.\n\n**Implementation risks and trade‑offs**\n\n- Measurement and proof risk: Some factors are straightforward (documented knee replacement); others rely on clinical judgment (synovitis at onset or worsening) or historical reconstruction (whether activity reached ≥5 METs, or whether appropriate care was unavailable). These create uncertainty and potential for dispute.\n\n- Administrative discretion: The RMA sets the SoP, but decision-makers interpret whether evidence meets the listed factors and the service-relationship requirement. Cross-references to other SoPs mean that determinations about one condition can hinge on resolution of another.\n\n- Limited effect beyond veteran claims: The SoP governs entitlement assessments; it does not govern private medical practice or private insurers directly. Private practitioners may be asked to supply evidence, which is an ancillary impact.\n\n**Bottom line**\n\n- This is a narrowly framed, medical‑evidentiary rule for deciding whether a popliteal cyst can reasonably be linked to qualifying service. It lists alternative medical or factual circumstances that, if shown and tied to service, are sufficient to raise that link (section 8), and it requires that the factor be related to the person's relevant service (section 9). The main practical effects are on the type and quality of evidence claimants must supply and on the administrative workload of adjudicators who must apply the SoP and, where necessary, linked Statements for related conditions (sections 8, 9, 10)."},"flash_summary_failed":{"failed":true,"reason":"Unauthenticated. Configure AI_GATEWAY_API_KEY or use a provider module. Learn more: https://ai-sdk.dev/unauthenticated-ai-gateway","source":"analysis-cron"},"kimi_summary":{"content_quality":"ok","complexity_score":4,"scope_assessment":{"changed":false,"description":"This instrument maintains its original narrow scope. It addresses a single specific medical condition (popliteal cyst) and establishes the causal factors required to link it to military service. The structure follows the standard template for Repatriation Medical Authority Statements of Principles without expansion beyond the medical-scientific determination required by subsection 196B(2) of the VEA."},"complexity_factors":["Multiple cross-references to other legislation (VEA, MRCA) and other Statements of Principles","Conditional logic requiring connection between factors and 'relevant service'","Specific medical terminology requiring definition (synovitis, METs, popliteal fossa)","Distinction between 'clinical onset' and 'clinical worsening' with different applicable factors","Nested conditions in section 9(2) limiting application of worsening factors to pre-existing conditions","Reference to external classification system (ICD-10-AM Tenth Edition) with specific ISBN and effective date"],"plain_english_summary":"This Statement of Principles sets when a popliteal (Baker’s) cyst can be accepted as service‑related for claims under the Veterans' Entitlements Act and the Military Rehabilitation and Compensation Act. It affects veterans and defence members seeking compensation, treatment or rehabilitation for a cyst.\n\nIt requires evidence of a service‑connected knee disorder, prior knee replacement, a qualifying activity at rupture, or lack of treatment, and limits worsening claims to cysts already present before service."}},"importantCases":[],"_links":{"self":"/api/acts/statement-of-principles-concerning-popliteal-cyst-reasonable-hypothesis-no-31-of-2018","history":"/api/acts/statement-of-principles-concerning-popliteal-cyst-reasonable-hypothesis-no-31-of-2018/history","analysis":"/api/acts/statement-of-principles-concerning-popliteal-cyst-reasonable-hypothesis-no-31-of-2018/analysis","conflicts":"/api/acts/statement-of-principles-concerning-popliteal-cyst-reasonable-hypothesis-no-31-of-2018/conflicts","importantCases":"/api/acts/statement-of-principles-concerning-popliteal-cyst-reasonable-hypothesis-no-31-of-2018/important-cases","documents":"/api/acts/statement-of-principles-concerning-popliteal-cyst-reasonable-hypothesis-no-31-of-2018/documents"}}