FSEM MSK Diploma cheat sheet

Ottawa Ankle Rules: ankle radiography is indicated when there is malleolar pain plus bone tenderness at the posterior edge or tip of either malleolus, or inability to bear weight for four steps both immediately and in the emergency department.

Ottawa Knee Rules: radiography is indicated after knee injury with any of: age ≥55, isolated patellar tenderness, tenderness at the fibular head, inability to flex to 90°, or inability to bear weight four steps.

Canadian C-Spine Rule: imaging is required if age ≥65, dangerous mechanism, or paraesthesia; otherwise assess low-risk factors and active rotation before imaging.

Likelihood ratios: LR+ = sensitivity/(1−specificity); LR− = (1−sensitivity)/specificity. LR+ >10 or LR− <0.1 produce large changes in post-test probability.

Sensitivity and specificity are prevalence-independent, whereas positive and negative predictive values vary with the pre-test probability in the population tested.

Anterior cruciate ligament: Lachman test at about 30° flexion has sensitivity around 0.85–0.95; the pivot shift has high specificity but lower sensitivity and is examiner-dependent.

Lumbar radiculopathy: straight leg raise is sensitive (~0.9) but poorly specific (~0.25); crossed straight leg raise is poorly sensitive but highly specific.

Septic arthritis: aspirate before antibiotics; synovial white cell count >50,000/µL with neutrophil predominance strongly suggests infection, but crystals must also be sought.

Gout diagnosis is confirmed by needle-shaped, negatively birefringent monosodium urate crystals under polarised light microscopy.

Tendinopathy: progressive loading (heavy slow resistance or eccentric) for at least 12 weeks; pain up to 4/10 during exercise is generally acceptable and load is advanced weekly.

ACL reconstruction rehabilitation: return to sport is criteria-based, typically at least 9 months, with quadriceps and hamstring limb symmetry index ≥90% and passed hop tests.

Knee osteoarthritis: exercise and weight loss are core; weight loss of 5–10% of body weight produces moderate-to-large improvement in pain and function.

NICE osteoarthritis sequence: exercise and weight loss, then topical or oral NSAID with gastroprotection if needed, then intra-articular corticosteroid, then joint replacement for severe disease.

Corticosteroid injections give short-term (2–6 week) benefit; repeated injections and peritendinous Achilles injection risk tendon rupture and are avoided.

Blood flow restriction training: cuff at 60–80% of limb occlusion pressure with 20–40% 1RM in a 30-15-15-15 repetition scheme increases strength and hypertrophy at low mechanical load.

PEACE & LOVE for acute soft-tissue injury: Protection, Elevation, Avoid anti-inflammatories, Compression, Education; then Load, Optimism, Vascularisation, Exercise.

Bone stress injuries: low-risk sites (posteromedial tibia, metatarsal shaft) allow relative rest; high-risk sites (femoral neck, anterior tibia, navicular, fifth metatarsal base, sesamoids) need strict offloading and specialist input.

Return to play after hamstring strain is criteria-based: pain-free sprinting, ≥90% strength symmetry, and sport-specific drills; reinjury risk is highest in the first weeks after return.

2010 ACR/EULAR RA classification: score ≥6/10 across joint involvement (0–5), serology (0–3), acute-phase reactants (0–1) and symptom duration ≥6 weeks (0–1).

Rheumatoid factor is about 70% sensitive but poorly specific; anti-CCP is about 95% specific and associated with erosive disease.

RA disease activity is measured with DAS28 (ESR or CRP): remission <2.6, low ≤3.2, moderate 3.2–5.1, high >5.1.

Gout: urate-lowering therapy targets serum urate <360 µmol/L (<300 µmol/L in tophaceous or severe disease); allopurinol is first line, titrated, and continued during flares.

Acute gout flare: NSAID, colchicine or corticosteroid; existing urate-lowering therapy is not stopped during a flare.

Giant cell arteritis: age ≥50, new headache, scalp tenderness, jaw claudication or visual symptoms; start high-dose glucocorticoid immediately and arrange temporal artery ultrasound or biopsy.

Polymyalgia rheumatica: age ≥50, bilateral shoulder and hip girdle pain with morning stiffness, ESR often >40 mm/h; response to prednisolone 15–20 mg daily is typically rapid.

Axial spondyloarthritis: inflammatory back pain, HLA-B27, MRI sacroiliitis; NSAIDs first line, then TNF or IL-17 inhibitors; exercise is a core treatment.

Central sensitisation: pain disproportionate to tissue pathology, spreading, hyperalgesia and allodynia; management is biopsychosocial with graded activity, CBT and sleep intervention.

WHO 2020 guidelines: adults 150–300 min/week moderate or 75–150 min/week vigorous aerobic activity, plus muscle-strengthening on ≥2 days/week; older adults add balance work.

Exercise-induced bronchoconstriction: a ≥10% fall in FEV1 after exercise challenge (or eucapnic voluntary hyperpnoea) confirms diagnosis; warm-up and pre-exercise inhaled bronchodilator reduce symptoms.

Concussion: no same-day return to play; use SCAT6 for assessment and a graded six-step return-to-sport protocol with at least 24 hours per step.

RED-S: low energy availability impairs bone density, menstrual function, immunity and performance; screen with validated tools and involve dietitian and psychology.

Exertional heat stroke: core temperature >40°C plus central nervous system dysfunction; cold-water immersion is the priority and should begin before hospital transfer.

Sudden cardiac death in young athletes: hypertrophic cardiomyopathy is the commonest cause; in older athletes, atherosclerotic coronary disease dominates.

Pre-participation screening: personal and family history, symptoms and physical examination; resting ECG is debated and not universally mandated.

Commotio cordis: a precordial blow during the T-wave vulnerable period triggers ventricular fibrillation; survival depends on immediate CPR and defibrillation.

Hyponatraemia in endurance events is associated with excessive fluid intake and weight gain during the race; restrict fluids and use hypertonic saline if symptomatic.

Hierarchy of evidence: systematic reviews and meta-analyses of RCTs > individual RCTs > cohort > case-control > case series > expert opinion.

GRADE: certainty rated high, moderate, low or very low; recommendations are strong or weak based on balance of benefits and harms, values, resource use and equity.

NNT = 1/ARR, where ARR = control event rate − treatment event rate; NNH = 1/ARI for harm.

Relative risk reduction can look large when absolute risk reduction is small; report both and give baseline risk for shared decisions.

Mental Capacity Act 2005: presume capacity; assess understanding, retention, weighing and communication for the specific decision; if lacking, act in best interests.

Montgomery v Lanarkshire (2015): consent requires disclosure of material risks a reasonable person in that patient's position would want to know.

Duty of candour: statutory and professional duty to inform patients of notifiable safety incidents, apologise, explain and offer support.

Publication bias: positive studies are more likely to be published; funnel plot asymmetry and trial registration help detect it.

Clinical audit compares practice against a standard and closes the loop with re-audit; research generates new generalisable knowledge.