Non-removable offloading with adherence proof, probe-plus-X-ray osteomyelitis workup with duration ladder, and WIfI-quartile revascularisation with amputation honesty

Model answer

(A) The 58-year-old needing non-removable offloading — ladder, cast, adherence proof, honest bounds (4 marks). Recite the IWGDF ladder: non-removable knee-high first, removable knee-high or ankle-high second on contraindication or intolerance, footwear-plus-felt third — with failed forefoot offloading earning Achilles lengthening, metatarsal-head resection, arthroplasty or osteotomy.^[18] Prove the cast with Armstrong TCC (63 superficial non-infected non-ischaemic ulcers): 89.5% TCC against 65.0% walker and 58.3% half-shoe at 12 weeks (OR 5.4), with TCC patients taking 600 against 1462 steps.^[20] Prove adherence is the mechanism with iTCC (50 Texas-1A ulcers): wrapping the walker lifts healing from 51.9 to 82.6% and cuts time from 58.0 to 41.6 days.^[21] Bound the claim honestly: Faglia equivalence at 73.9 versus 72.7% is a 45-patient finding, not a ladder inversion; Lavery finds TCC 69.6% against boot 22.2% and sandal 44.5%; Bus ties three removables at 58/60/70% with adherence and stride counts as the explanation — and the pools agree at RRp 1.43 over removable and 1.68 over shoes with TCC equal to instant TCC at 1.06.^{[22][23][24][25]}

(B) The 64-year-old with possible osteomyelitis — combine before scanning, biopsy before committing, shorten by the ladder (3 marks). Start at the bedside: ulcer over 2 cm² (LR 7.2), positive probe (LR 6.4) and ESR over 70 (LR 11) each move the probability, and at 12% prevalence the probe's positive value is only 0.57 against a 0.98 negative — positive rules little in, negative rules out.^[28][29] Combine probe with X-ray before MRI: sequential sensitivity 0.97 with specificity 0.92 (LR 12.8/0.02) and only 6.6% double-negative disease — pooled 0.94 with DOR 82, MRI-comparable and inexpensive but expertise-dependent.^[32][31] Discipline the MRI: preferred test at 0.90/0.79 sensitivity/specificity, yet 29.3% go unconfirmed at biopsy with 12 false positives — so biopsy with culture or histology stays gold with an integrated clinic-radiologist-biopsy approach.^[33][35][28] Shorten antibiotics to the tested floors as study regimens: 6 weeks equals 12 at 65% remission with gut events 15 versus 45%; 3 equals 6 post-debridement at 84 versus 73%; 10 days equals 20 for soft tissue at 77 versus 71% — disclosing the 23-versus-16% new-osteomyelitis tail on the shortest course.^[36][37][38]

(C) The 71-year-old WIfI-4 heel ulcer — quartile first, trials second, amputation counselled not dictated (3 marks). Stage benefit before promising salvage: Q4 limbs face 25.7% one-year amputation against 7.2% in Q1 at hazard 4.26, with over half amputated despite patent revascularisation — wound and infection burden decide.^[12] Quote strategy by PLAN: BASIL-2 infrapopliteal randomisation (345) favours endovascular-first on amputation-free survival (HR 1.35 against vein-first, death-driven) with £1690 saved — while BEST-CLI-diabetes (1777, 69.2% diabetic) prices late WIfI presentation at 73.7 versus 45.9% with amputation 1.75-fold and death 1.63-fold independent.^[43][44][45] Counsel the level: deep infection with pulses favours below-ankle healing yet nothing alone excludes it — minor amputations heal below-ankle in 64% (79% of survivors) at 26 median weeks — but transmetatarsal honesty prices pooled major amputation at 30.16% with re-amputation at 28.37%, so the first forefoot cut consents the proximal ladder.^[53][52][50]