Structure your ABFAS Foot Surgery Part I preparation around the classification and staging systems that determine operative choices in each syllabus region. Work through branch-point scenarios per region, drill the complication profile of each index procedure, and use a self-check rubric as a learning milestone — not a pass prediction. Check registration and exam logistics directly with ABFAS.
Why staging systems should anchor your Part I review, not procedure lists
Treat each syllabus region as a decision tree rather than a procedure catalog. Named classifications — Coughlin-Shurnas, Eichenholtz, Johnson-Strom/Myerson, Danis-Weber, Torg — are the branch points that determine which operations are appropriate, so studying them organizes everything else.
Each major classification in foot and ankle surgery exists to answer one question: what stage is this condition in, and what does that stage permit? Coughlin-Shurnas grading for hallux rigidus separates joint-preserving from joint-sacrificing options. Eichenholtz staging for Charcot arthropathy separates offloading phases from reconstruction windows. Johnson-Strom, as modified by Myerson, splits posterior tibial tendon dysfunction into flexible and rigid phases with entirely different plans. When you learn a classification, you are really learning the boundary lines of surgical decision-making in that region.
The Part I examination has two components per ABFAS: a didactic examination and a computer-based patient simulation (CBPS). The didactic format rewards precise, discrete knowledge; the simulation format asks you to apply that knowledge in sequence through patient cases. Building your review around the same decision trees serves both components at once — the fact you memorize for a didactic item becomes the branch point you recognize in a simulated case. One integrated map beats two separate review tracks.
- Map every syllabus region to its controlling classification before opening any procedure text.
- For each stage, write down which operations are indicated and which are explicitly not.
- Reuse each decision tree in scenario practice so didactic and simulation preparation reinforce each other.
Hallux rigidus versus hallux valgus: the grade decides the operation
First-ray surgery is a branch-point problem. The rigidus grade, the valgus deformity severity, first-ray mobility, and joint cartilage status each select between cheilectomy, osteotomy, Lapidus-type correction, and arthrodesis. Operator preference comes only after the stage-based decision is settled.
Worked scenario: a 62-year-old presents with painful hallux limitus, a large dorsal bony prominence, and motion restricted to a painful arc; radiographs show roughly two-thirds joint space loss. A plausible mistake is planning a cheilectomy because the instinct is 'hallux rigidus equals cheilectomy' without formally grading the joint. In classic teaching, Coughlin-Shurnas grade III — severe cartilage loss with marked restriction — points toward a more definitive intervention such as first MTP arthrodesis in a suitable candidate, because a cheilectomy in an advanced joint invites persistent pain and revision. The better decision is to grade the joint first, then match the procedure to the grade.
Contrast that with a deformity-dominant presentation: hallux valgus with interphalangeus, where the distal joint rather than the metatarsophalangeal joint drives the problem, may call for an Akin-type osteotomy instead of metatarsal work. Similarly, valgus with first-ray hypermobility is the setting in which Lapidus-type first tarsometatarsal fusion enters the discussion. The exercise is to write, for each hallux procedure you review, the specific anatomic finding that selects it — and the finding that rules it out. If two procedures share an indication on your sheet, you have not yet found the branch point.
PTTD staging: how flexibility changes the flatfoot plan
Posterior tibial tendon dysfunction staging controls which structures you address: tenosynovitis alone in stage I, osteotomies with tendon transfer for flexible stage II, fusion for rigid stage III, and ankle involvement in stage IV.
The Johnson-Strom system, as modified by Myerson, is worth mastering as a complete decision table because each stage adds an anatomic finding that changes the operative logic. The clinical discriminators — whether the arch restores on single-leg heel rise, whether the too-many-toes sign is present, whether the deformity is passively correctable — are the observations a simulated case will ask you to make. Subtalar joint involvement and fixed hindfoot valgus are what distinguish the rigid stages, and fixed deformity is what removes corrective osteotomy from the table in favor of fusion.
A plausible error is treating a stage II flatfoot plan as adequate for stage III: an isolated flexor digitorum longus transfer with a medializing calcaneal osteotomy addresses a flexible deformity, but a fixed, arthritic stage III hindfoot cannot be corrected through those means in standard teaching — it requires realignment fusion. Mis-staging therefore changes the entire operation, not a step within it. Stage IV adds ankle valgus from deltoid insufficiency, which extends the plan proximally. Rehearse the physical examination maneuvers as decision inputs, not as isolated facts.
| Stage | Key finding | Typical operative logic | Pitfall if mis-staged |
|---|---|---|---|
| I | Tenosynovitis, no deformity | Tendon-addressing treatment, no bony correction | Operating on bone that does not need it |
| II | Flexible flatfoot, correctable | Osteotomies plus tendon transfer | Under-correcting by ignoring bony work |
| III | Rigid hindfoot, subtalar arthritis | Realignment fusion of affected joints | Trying tendon transfer or osteotomy on a fixed deformity |
| IV | Stage III findings plus ankle valgus | Extends the plan to the ankle | Stopping at the hindfoot and missing ankle valgus |
The Charcot versus osteomyelitis branch point in the diabetic foot
Acute Charcot arthropathy and diabetic foot infection can both present as a warm, swollen, insensate foot, but they demand opposite pathways: offloading and protection versus debridement and antimicrobial management. Distinguishing them is a core simulation-style decision.
Worked scenario: a diabetic patient presents with a warm, edematous midfoot after a trivial twisting injury; radiographs show fragmentation and subluxation at the tarsometatarsal joints, and plain films are reported as showing 'destructive change.' A plausible mistake is reading the fragmentation as osteomyelitis and steering the plan toward prolonged antimicrobial therapy and urgent surgical debridement. The better decision is to place the presentation against the Eichenholtz framework — stage 0 prodromal injury through consolidation — recognize the injury-triggered acute neuroarthropathy pattern, and prioritize protected offloading with structured interval imaging, escalating only if a distinct infection picture emerges. The two pathways diverge from the first decision onward, which is why the distinction matters.
Build your discrimination checklist around named, defensible elements: Eichenholtz stages and their radiographic signatures, the distribution of fragmentation relative to a known injury, the presence or absence of a contiguous ulcer or probe-to-bone finding, and the role of interval serial radiographs when early images are inconclusive. Remember the teaching that MRI findings can be confounded in the neuropathic foot, so imaging is interpreted alongside the clinical trajectory rather than in isolation. Practicing this as a time-sequence — presentation, first step, reassessment — mirrors how a simulated case unfolds and forces the branch point to surface early.
Fifth metatarsal and ankle trauma: classifications that predict the next step
In trauma, classification is not academic labeling — it predicts healing potential and stability, and therefore the treatment. Zone anatomy for fifth metatarsal fractures, Torg typing, and the Weber and Lauge-Hansen frameworks each change the next decision.
Worked scenario: a 22-year-old athlete has an acute proximal fifth metatarsal fracture at the metaphyseal-diaphyseal junction — a zone 2 Jones-type fracture — with sclerosis at the fracture line suggesting pre-existing stress. A plausible mistake is managing it like a zone 1 avulsion, which has abundant healing potential and usually does well with protected weight-bearing in standard teaching. The better decision is to recognize that zone 2 and zone 3 fractures in this Torg type have a documented tendency toward delayed union, making intramedullary screw fixation a serious consideration for a patient who needs to return reliably. The classification did the work: same bone, three zones, three different plans.
The same logic runs through the ankle. Danis-Weber classifies by fibular fracture level relative to the syndesmosis, while Lauge-Hansen reconstructs the injury mechanism and predicts associated ligamentous damage in sequence. The practical skill a case rewards is combining them: a fibular pattern that looks benign may be unstable if deep deltoid competence is in question, so mortise alignment and stability assessment — historically including stress views — drive the nonoperative-versus-fixation decision. Write out, for each fracture classification you study, what the classification predicts about stability and healing, because that prediction is the reason the classification exists.
Perioperative reasoning: studying complications as case responses
The perioperative and complications domain is best studied as response sequences: for each index procedure, know what typically fails, when failure presents, and what the first diagnostic or management step is. That structure maps directly onto how a simulated case progresses.
Take a Lapidus-type first tarsometatarsal fusion. The complication profile includes nonunion, malalignment, and hardware irritation, each with a characteristic timing: a nonunion announces itself with persistent pain and a radiographically unconsolidated site at follow-up, while immediate postoperative problems center on wound issues and malposition recognized on early films. A midfoot Charcot reconstruction raises an entirely different set — fixation failure, ulceration over new prominences, and progression of neuroarthropathy if offloading lapses. When you study the complication, study its timeline and its first response together; the pair is what a case asks you to demonstrate.
A workable drill: for each of your index procedures, write the three most-discussed complications, the typical window of presentation, and the single first step in response — be that imaging, offloading, wound management, or return to the operating room. This converts a scattered list of adverse events into a callable routine. It also exposes gaps quickly: if you cannot name the first response to a complication you just listed, that procedure is not yet finished from a review standpoint. Revisit any procedure where the response column stays blank.
A four-week rotation and a 24-point readiness rubric
Rotate through the syllabus in four passes: map classifications, work branch-point scenarios, drill complication sequences, then run timed self-testing. Weigh each pass by your rubric scores so weak regions get a second rotation rather than an equal share.
A realistic sequence: in week one, for each region — forefoot, midfoot, hindfoot and ankle, trauma and reconstruction, biomechanics and gait, perioperative care — write the controlling classifications and the branch points they create. In week two, build and work written scenarios for every branch point, deliberately including the mistake you would plausibly make, as done throughout this article. In week three, complete the complication-response sheets from the previous section. In week four, run timed self-testing across regions, then re-rotate one week for whichever two regions scored lowest. Repeat or stretch the cycle to fit the time you actually have; the order, not the calendar, is the point.
Practical exercise with expected observations: select twelve index conditions spanning all six regions — for example, hallux rigidus grade III, hallux valgus with first-ray hypermobility, PTTD stage II, PTTD stage III, Eichenholtz stage 0, established midfoot Charcot, a zone 2 fifth metatarsal fracture, a Weber-type ankle fracture, and three perioperative complication presentations of your choosing. For each condition, in under five minutes, write the classification and stage, one branch-point decision with its justification, and one complication with its first response. Then score the whole condition 0–2 against your source material: 0 if any element is blank or clearly wrong, 1 if partial or vague, 2 if all three elements are specific and internally consistent. This yields a 24-point total (twelve conditions, up to two points each). A total of 18 of 24 or better suggests you are ready to move to timed practice; anything below 14 marks the regions to re-rotate. These scores are learning milestones only — they indicate where to spend the next rotation, not whether you will pass.
For registration windows, exam dates, eligibility, and the current examination format, rely on the credentialing board directly; administrative details change and are published at the issuer's site rather than in study materials.
- Week 1: classification maps per region, including which procedures each stage permits and excludes.
- Week 2: written branch-point scenarios with the plausible mistake built in.
- Week 3: complication-response sheets — failure, timing, first step — for every index procedure.
- Week 4: timed cross-region self-testing, then re-rotate the two lowest-scoring regions.
- Rubric benchmark: 18 of 24 on the twelve-condition exercise before advancing to timed practice.
References and further reading
Use these references to explore the concepts and check the latest information from the relevant organizations.