ABPS Plastic Surgery cheat sheet

Wound tensile strength follows collagen deposition: ~5% at 1 week, ~20% at 3 weeks, ~70-80% of final at 6 weeks; never regains 100% of unwounded skin.

Collagen type III predominates early (granulation tissue) and is replaced by type I during remodeling; net collagen equals synthesis minus degradation (collagenase/MMPs).

Normal wound healing phases: hemostasis (minutes-hours), inflammation (days 1-5), proliferation (days 5-21), remodeling (weeks to >1 year).

Langer lines (relaxed skin tension lines) follow dermal collagen orientation; incisions parallel to them reduce tension and scar spread.

Hypertrophic scar: within wound boundaries, regresses over months; keloid: extends beyond original wound, recurs after excision, common on ears/presternum/shoulders.

Random-pattern flap length-to-width safety ratio is approximately 1:1 (up to 2:1 in some axial-rich regions); axial pattern flaps use a named direct cutaneous artery and exceed this.

Skin graft survival: plasmatic imbibition (first 24-48 h), inosculation (48-72 h), then revascularization; graft take requires a well-vascularized, non-infected bed.

Full-thickness grafts contract less (primary contraction and secondary contraction) than split-thickness grafts, which re-epithelialize from retained adnexal epithelium.

Pressure injury staging: Stage 1 non-blanchable erythema; Stage 2 partial-thickness dermal loss; Stage 3 full-thickness to fascia; Stage 4 to bone/tendon/muscle; unstageable if eschar obscures.

Breast reconstruction timing: immediate vs delayed; expander/implant-based vs autologous (DIEP, TRAM, latissimus, SGAP); autologous flaps avoid implant complications and tolerate radiation better.

DIEP flap is perforator-based off the deep inferior epigastric system, preserving rectus abdominis; TRAM sacrifices rectus muscle and carries higher hernia/bulge risk.

Carpal tunnel syndrome: median nerve compression; nocturnal paresthesias in thumb-index-middle distribution; Tinel and Phalen signs; thenar atrophy is late.

Dupuytren disease: palmar fascia fibrosis with nodules and cords; MCP joint contracture addressed before PIP; recurrence is common after fasciectomy.

Cleft lip repair timing ~3-6 months (rule of 10s: ~10 weeks, 10 lb, 10 g/dL hemoglobin); cleft palate repair ~9-12 months to support speech before phonation.

Mandible fracture management: anatomic reduction and fixation (ORIF with plates) for displaced/unstable fractures; condylar fractures often managed closed unless severely displaced.

Burn resuscitation: Parkland formula 4 mL/kg/%TBSA lactated Ringer's over 24 h from burn time (half in first 8 h); urine output goal ~0.5 mL/kg/h adults.

Free flap monitoring: clinical assessment (color, capillary refill, temperature, turgor, Doppler signal); venous congestion is often the earliest sign of flap compromise.

Reduction mammaplasty techniques: inferior peduncle (Wise pattern), superomedial peduncle, and vertical (Lejour) patterns; nipple-areola complex viability depends on preserved dermal/ductal blood supply.

Craniosynostosis: premature suture fusion; sagittal (scaphocephaly), coronal (plagiocephaly), metopic (trigonocephaly), lambdoid; surgery relieves elevated intracranial pressure and restores skull shape.

Syndromic craniosynostosis (Crouzon, Apert, Pfeiffer) involves FGFR mutations; Apert syndrome includes syndactyly (mitten hands) and midface hypoplasia.

Z-plasty: lengthens scar along its central limb by ~75% at 60-degree angles; used to release contractures and reorient scars along relaxed skin tension lines.

Hand infection: flexor tenosynovitis (Kanavel signs: finger held in flexion, fusiform swelling, tenderness along sheath, pain on passive extension) requires urgent surgical drainage.

Digital nerve repair: epineurial repair for clean sharp lacerations; nerve gap >2-3 cm may require nerve graft or conduit; sensory recovery best in young patients and distal injuries.

Rhinoplasty: dorsal reduction, tip support via lower lateral cartilage adjustment; spreader grafts prevent internal nasal valve collapse; septal cartilage is preferred graft.

Abdominoplasty: rectus plication and skin excision; risk of seroma, wound dehiscence, and thromboembolism; umbilical stalk preservation avoids necrosis.

Lipedema vs lymphedema: lipedema is bilateral, symmetric fat deposition in legs sparing feet, painful, non-pitting; lymphedema is unilateral/asymmetric with pitting and dorsal foot involvement (Stemmer sign).

Skin cancer reconstruction: basal cell carcinoma (most common, locally destructive, rarely metastasizes); squamous cell carcinoma (higher metastasis risk); melanoma staged by Bresenham depth and sentinel node biopsy for depth >0.8-1.0 mm.