12-phase flow (12)

1. 1FRAME
   Tendinopathy is a load-related continuum doctrine, not a single diagnosis; phenotype = site + continuum stage (reactive → disrepair → degenerative); pain/structure/function are dissociated and imaging structure does NOT track symptoms; use ICON 2019 terminology "tendinopathy", not "tendinitis" (Cook & Purdam 2009 PMID 18812414; Cook/Rio 2016 PMID 27127294; Scott ICON 2019 PMID 31399426)
   inputs: tendon_site, symptom_duration_and_continuum_stage
   advance: Scope framed: load-related continuum, site + stage, ICON terminology adopted
2. 2ENTRY
   Load-related localised tendon pain (Achilles mid-portion/insertional, lateral elbow with grip, inferior-patellar-pole with jumping, lateral-hip greater-trochanter), recent load-spike, drug-trigger flag, or chronic-tendinopathy review (JOSPT Achilles 2018/2024; JOSPT Lateral Elbow 2022 Lucado; Mellor LEAP 2016)
   inputs: tendon_site, load_history_and_activity_exposure
   advance: Engine entered via a recognised site-specific trigger
3. 3CONTEXT
   Capture site, load/activity exposure (training-load spike, repetitive gripping, jumping), age/sex/menopausal status (gluteal female-predominant 40–60 y; FQ rupture risk ↑ >60 y), continuum stage, fluoroquinolone/aromatase-inhibitor/statin exposure, glucocorticoid use, diabetes/metabolic syndrome, eGFR/GI/CVD for NSAID gating (Cook & Purdam 2009; Mellor LEAP 2016; Sangiorgio 2024; Koumou 2021)
   inputs: tendon_site, load_history_and_activity_exposure, age, fluoroquinolone_aromatase_inhibitor_statin, ckd_gi_cvd_status, glucocorticoid_or_diabetes_or_metabolic, symptom_duration_and_continuum_stage
   advance: Pre-test prior + load driver + drug-trigger + comorbidity profile captured
4. 4RED_FLAGS
   Full/partial TENDON RUPTURE (Achilles: positive Simmonds–Thompson calf-squeeze, palpable gap, loss of resting plantarflexion tone — high LR; partial elsewhere) → urgent referral; ENTHESITIS of spondyloarthritis (inflammatory rhythm, multi-site enthesopathy, psoriasis/IBD/uveitis, raised inflammatory markers) → route rheum.axial-spondyloarthritis.core.v1; INFECTION (hot, systemically unwell — septic bursitis/tenosynovitis); REFERRED (lumbar radiculopathy mimicking gluteal/hamstring; radial-tunnel/cervical mimicking lateral elbow); DRUG-INDUCED rupture risk (fluoroquinolone, esp. ofloxacin RR 10.1; ↑ by renal failure + glucocorticoid + age >60) (JOSPT Achilles 2018 Martin; van der Linden 1999 PMID 10510157; Sangiorgio 2024 PMID 38949172)
   inputs: sudden_pop_or_loss_of_function, inflammatory_rhythm_or_multisite_enthesopathy, fluoroquinolone_aromatase_inhibitor_statin
   actions: panel.inflammation
   advance: Rupture, spondyloarthritis enthesitis, infection, referred and drug-induced causes screened and escalated/deprescribed if present
5. 5INITIAL_WORKUP
   Clinical exam is primary: site-specific provocative-test battery scored with LR± (§5.5.2). ACHILLES RUPTURE (Maffulli 1998 PMID 9548122, prospective n=174 vs surgical/imaging reference, rupture-suspicion population): calf-squeeze (Simmonds–Thompson) sens 0.96 / spec 0.93 → LR+ 13.7, LR− 0.04; Matles knee-flexion test sens 0.88 / spec 0.85 → LR+ 5.9, LR− 0.14; gap palpation sens 0.73 (0.81 under anaesthesia) / spec 0.89 → LR+ 6.6, LR− 0.30; O’Brien needle / Copeland cuff sens ~0.80. The COMPOSITE rule-IN cluster (calf-squeeze + Matles + palpable gap ALL positive) was positive (≥2 of any tests positive) in 100% of true ruptures and in 0% of the 28 intact-tendon controls → composite LR+ ≥20 (rule-IN). CONDITIONAL DEPENDENCE — calf-squeeze, Matles and gap-palpation all interrogate the SAME loss of musculotendinous continuity, so their LRs are NOT conditionally independent; the combined LR is sub-multiplicative (closer to the strongest single test, not the naive product) and is co-modified by US/MRI continuity (T_test). Lateral elbow: Maudsley / Cozen / Mill (ECRB provocation, sensitive cluster, moderate specificity — a fully negative cluster with painless resisted extension drops post-test probability toward the radial-tunnel/cervical pivot); patellar: single-leg decline squat (high-sensitivity inferior-pole provocation in jumping athletes; Malliaras 2013 PMID 23494258); gluteal: focal greater-trochanter palpation + resisted hip abduction / external-de-rotation + single-leg-stance ≥30 s + FABER (Grimaldi & Fearon 2015 PMID 26381486). Inflammatory panel ONLY if spondyloarthritis suspicion. NO routine imaging — structure does not track symptoms (JOSPT Achilles 2018 Martin; JOSPT Lateral Elbow 2022 Lucado; Cook/Rio 2016 PMID 27127294)
   inputs: site_specific_provocative_tests, inflammatory_markers
   actions: workup.tendinopathy, workup.shoulder_pain, workup.plantar_heel_pain, panel.inflammation
   advance: Site-specific provocative-test cluster scored, rupture screen done, inflammatory panel only if indicated
6. 6BRANCHING_WORKUP
   T_test threshold — Ultrasound OR MRI ONLY when the result changes management: suspected complete/partial rupture (continuity assessment — note the calf-squeeze LR is conditional on this continuity finding, so US/MRI here is the conditional-dependence resolver, not a routine test), atypical/refractory course after an adequate loading trial, or surgical planning. Inflammatory enthesitis features → route rheum.axial-spondyloarthritis.core.v1 (HLA-B27 / sacroiliac imaging context). Rotator-cuff overlap → workup.shoulder_pain → msk.shoulder-pain.core.v1. Patellar–patellofemoral overlap or adjacent-joint OA driving load intolerance → workup.knee_pain → msk.knee-pain.core.v1 / msk.osteoarthritis.core.v1. Drug-induced confirmation (temporal relationship, molecule, risk multipliers). Imaging restraint otherwise (Cook/Rio 2016 PMID 27127294; JOSPT CPGs)
   inputs: ultrasound_or_mri_tendon
   actions: workup.tendinopathy, workup.shoulder_pain, workup.knee_pain
   advance: Imaging done only where it changes management (conditional-dependence resolver for the rupture cluster); SpA / cuff-overlap / patellar–PFJ–OA / drug-induced routing resolved
7. 7DIFFERENTIAL
   MECE: site-specific tendinopathy (continuum stage) vs full/partial RUPTURE (tendon-continuity pivot) vs ENTHESITIS of spondyloarthritis (inflammatory pivot) vs REFERRED (lumbar radicular for gluteal/hamstring; radial-tunnel/cervical for lateral elbow) vs DRUG-INDUCED (orthogonal modifier — fluoroquinolone/aromatase-inhibitor/statin raises rupture probability irrespective of site). CONDITIONAL DEPENDENCIES modelled as data (§5.5.2): (1) the calf-squeeze rupture LR is conditional on tendon continuity — a positive squeeze with a palpable gap and lost resting tone is near-pathognomonic (Maffulli 1998 PMID 9548122 composite LR+ ≥20) but a positive squeeze with INTACT continuity on US/MRI collapses to a low post-test probability; (2) calf-squeeze, Matles and gap-palpation are NOT conditionally independent (shared loss-of-continuity mechanism) so the cluster LR is sub-multiplicative; (3) the site-test cluster (Maudsley/Cozen/Mill; single-leg decline squat; trochanter palpation + single-leg-stance + FABER) is internally correlated — a single positive provocation adds little once the cluster is positive, and the cluster’s post-test value is conditional on the pre-test prior (activity/age/sex/load-spike); (4) the drug-induced rupture LR is conditional on exposure — it only multiplies rupture probability when fluoroquinolone/aromatase-inhibitor/statin exposure is present, and is itself co-multiplied by renal failure + glucocorticoid + age >60 (Sangiorgio 2024 PMID 38949172; Koumou 2021 PMID 34285735). Co-existence handled: degenerative tendinopathy can co-exist with a superimposed acute partial tear; widespread-pain amplification can co-exist (route msk.fibromyalgia.core.v1); adjacent joint OA can co-drive load intolerance (route msk.osteoarthritis.core.v1 / msk.knee-pain.core.v1 for patellar–PFJ overlap); drug-induced changes overlay pre-existing degeneration (Cook & Purdam 2009; ICON 2019 Scott)
   inputs: site_specific_provocative_tests, sudden_pop_or_loss_of_function
   advance: Terminal phenotype assigned with the continuity + inflammatory pivots, the drug-induced modifier, and the four modelled conditional dependencies resolved
8. 8RISK_STRATIFICATION
   Continuum stage (reactive/disrepair/degenerative), chronicity band, functional/occupational/sport demand, the SITE PRE-TEST PRIOR that conditions every provocative-test LR (Achilles enriched in runners/jumpers + load-spike; lateral elbow in repetitive-gripping/racquet 40–60 y; patellar in jumping athletes; GLUTEAL markedly female-predominant peri/post-menopausal — LEAP cohort 167/204 women, mean age 54.8 y, Mellor 2018 PMID 29720374; Grimaldi & Fearon 2015 PMID 26381486 — "trochanteric bursitis" is a misnomer for gluteal tendinopathy), drug-induced rupture-risk multipliers (offending molecule + renal failure + glucocorticoid + age >60 — ofloxacin highest, Sangiorgio 2024 AT/ATR 1.40% vs ~0.17% levo/cipro), and NSAID-comorbidity risk (eGFR/GI/CVD) (Cook/Rio 2016; Sangiorgio 2024 PMID 38949172)
   inputs: symptom_duration_and_continuum_stage, fluoroquinolone_aromatase_inhibitor_statin
   actions: calc.ckd_epi_2021
   advance: Continuum-stage + chronicity + drug-risk + NSAID-comorbidity tier documented
9. 9TREATMENT
   Education + progressive/eccentric or heavy-slow-resistance (HSR) tendon-loading + load management + RELATIVE rest is FIRST-LINE at every site (Alfredson 1998 PMID 9617396 — 15/15 returned to running vs 0/15 conventional; Kongsgaard 2009 PMID 19793213 / 2010 PMID 20154324 — HSR & eccentric durable, corticosteroid good short-term but worse long-term; Malliaras 2013 PMID 23494258 — eccentric-only non-response up to 45%, eccentric-concentric/HSR equivalent-or-superior so the eccentric component need not be isolated; Silbernagel 2007 PMID 17307888 — continued loading under a pain-monitoring model is safe, not strict rest; definitive LEAP RCT Mellor 2018 PMID 29720374 — education+exercise vs wait-and-see 8-wk NNT 2.0 (risk diff 49.1%, 95% CI 34.6–63.5), education+exercise vs CSI 52-wk NNT 4.9 (risk diff 20.4%, 95% CI 4.9–35.9): education+exercise > CSI > wait-and-see for gluteal, durable to 52 wk). AVOID routine peritendinous corticosteroid — Coombes JAMA 2013 PMID 23385272: 1-yr complete recovery 83% CSI vs 96% placebo (RR 0.86, 99% CI 0.75–0.99); 1-yr recurrence 54% vs 12% (RR 0.23, 99% CI 0.10–0.51). Adjuncts: ESWT modest/uncertain (Gatz 2021 PMID 33586526 — no significant benefit vs placebo over loading); GTN patch site-dependent (rxcui omitted); topical/oral NSAID + acetaminophen short analgesic bridge only, comorbidity-gated. PRP NOT beneficial for Achilles (de Vos 2010 PMID 20068208). DEPRESCRIBE the offending fluoroquinolone / review aromatase inhibitor / statin (drug-induced axis). Surgery is LAST-line after a long adequate loading trial (JOSPT Achilles 2018/2024; JOSPT Lateral Elbow 2022 Lucado)
   inputs: ckd_gi_cvd_status, fluoroquinolone_aromatase_inhibitor_statin, symptom_duration_and_continuum_stage
   advance: Progressive-loading-first plan set, adjuncts gated, offending drug deprescribed, surgery deferred to last-line
10. 10DISPOSITION
    Almost all outpatient. Urgent orthopaedic referral for suspected complete tendon rupture; rheumatology referral / route for inflammatory enthesitis of spondyloarthritis; ED for infection / systemic illness; surgical opinion only after an adequate progressive-loading trial (JOSPT Achilles 2018 Martin; ICON 2019 Scott)
    advance: Level of care + specialty routing set
11. 11MONITORING
    Track validated site outcomes (VISA-A Achilles, VISA-P patellar, PRTEE lateral elbow, VISA-G gluteal) and load tolerance using the pain-monitoring model (Silbernagel 2007 PMID 17307888); expect SLOW recovery (≥3 months loading at most sites); NSAID renal/GI/CVD safety review (calc.ckd_epi_2021); enforce any corticosteroid-injection ceiling; confirm offending-drug deprescription and screen for delayed rupture after fluoroquinolone (van der Linden 1999; Sangiorgio 2024)
    inputs: ckd_gi_cvd_status, fluoroquinolone_aromatase_inhibitor_statin
    actions: calc.ckd_epi_2021
    advance: Trajectory on track under pain-monitoring model or non-responder flagged for re-phenotyping / imaging
12. 12FOLLOWUP
    Loading maintenance + graded return-to-load / return-to-sport / return-to-work; recurrence and drug-avoidance counselling (avoid future fluoroquinolone where alternatives exist; tendon-pain return precautions on any future fluoroquinolone/aromatase inhibitor); re-evaluate persistent / worsening symptoms for re-phenotyping, delayed imaging or surgical opinion (ICON 2019 Scott; JOSPT Achilles 2018/2024)
    advance: Long-term loading self-management + return plan + drug-avoidance counselling in place