Egyptian Board Plastic Surgery cheat sheet

Skin layers: epidermis (avascular, keratinocytes), dermis (papillary and reticular; collagen I > III, elastin), subcutaneous fat; dermal appendages are the source of epidermal regeneration after superficial injury.

Burn depth by anatomy: superficial partial-thickness injures papillary dermis and blanches with intact pain; deep partial-thickness reaches reticular dermis with sluggish or absent blanching; full-thickness is insensate and leathery.

Wound healing phases: hemostasis (minutes-hours), inflammation (days 1-3, neutrophils then macrophages), proliferation (days 3-21: fibroblasts, angiogenesis, granulation, epithelialization), remodeling (weeks-months; type III collagen replaced by type I).

Collagen synthesis requires hydroxylation of proline and lysine, dependent on vitamin C, iron, and alpha-ketoglutarate; deficiency causes impaired cross-linking and weak scars (scurvy, Ehlers-Danlos variants).

Normal wound tensile strength: about 5% at 1 week, 20% at 3 weeks, 70-80% of unwounded skin by 3 months; never exceeds roughly 80% of original strength.

Langer lines (cleavage lines) follow dermal collagen bundle orientation; incisions parallel to them reduce tension and scar hypertrophy, whereas perpendicular incisions gape and widen.

Skin blood supply: random pattern perfusion via dermal and subdermal plexuses fed by musculocutaneous and septocutaneous perforators; angiosome concept underlies flap design and choke-vessel dilation.

Nerve injury classification (Seddon): neurapraxia (conduction block, recovery weeks), axonotmesis (axon loss, intact endoneurium, spontaneous regeneration), neurotmesis (transected nerve, requires repair); regeneration proceeds about 1 mm/day.

Hypertrophic scar versus keloid: hypertrophic scar stays within the original wound boundary and often regresses; keloid extends beyond the wound, rarely regresses, and recurs after excision alone.

Z-plasty: two triangular flaps transposed to lengthen a contracture along the central limb; a 60-degree angle yields about 75% theoretical lengthening, 45 degrees about 50%, 30 degrees about 25%.

W-plasty and geometric broken line closure break up a linear scar into irregular segments to camouflage it against relaxed skin tension lines; best for broad, flat scars in mobile areas.

Dog-ear correction options: extend the incision, perform a Burow triangle excision, or use a half-circle (M-plasty) excision of redundant tissue.

Suture selection: monofilament non-absorbable (nylon, polypropylene) for skin; absorbable (polyglactin 910, polyglecaprone, polydioxanone) for deep layers; polydioxanone retains strength longest among absorbable monofilaments.

Undermining should be at a consistent plane (subcutaneous or sub-SMAS) to preserve perforators; excessive undermining increases hematoma, seroma, and flap necrosis risk.

Tissue expansion: fill volume relative to expander capacity, weekly or biweekly inflation after initial healing; capsule forms around the device and provides additional tissue for reconstruction.

Local anesthetic maximum doses: lidocaine 7 mg/kg with epinephrine (4.5 mg/kg plain); bupivacaine 3 mg/kg; epinephrine-containing solutions reduce bleeding and prolong block duration.

Surgical triangle principle: choose flap or graft based on defect size, vascularity of bed, donor availability, and need for color and texture match; local flaps for small defects over vascular beds, grafts for avascular beds.

Graft survival: split-thickness and full-thickness skin grafts survive by plasmatic imbibition (24-48 h), inosculation, and revascularization; full-thickness grafts need a well-vascularized bed and take less reliably on bone or tendon.

Skin graft contraction: split-thickness grafts contract more (secondary contraction) than full-thickness grafts; full-thickness grafts give better color and texture match and less contracture.

Flap classification: by blood supply (random, axial), by composition (cutaneous, fasciocutaneous, musculocutaneous, muscle, osseous), and by movement (local, regional, distant, free).

Free flap monitoring: clinical assessment of color, capillary refill, temperature, and bleeding plus handheld Doppler or implantable Doppler; venous congestion presents as dark, tense, brisk bleeding, arterial failure as pale and cool.

Common free flaps: radial forearm (thin, pliable, good for head and neck), anterolateral thigh (versatile, long pedicle), fibula (bone for mandible), latissimus dorsi (large, reliable), deep inferior epigastric perforator (breast reconstruction).

Microsurgery principles: tension-free anastomosis, vessel diameter match, adequate pedicle length, avoid twisting or kinking, and use of vein grafts when pedicle length is insufficient.

Perforator flaps rely on a single perforating vessel; preoperative mapping with handheld Doppler or CT angiography reduces flap loss and donor-site morbidity.

Replantation indications: sharp amputations, thumb, multiple digits, children, and proximal amputations; absolute contraindications include severe crush, prolonged warm ischemia, and unstable patient.

Nerve repair timing: primary repair within days for clean sharp injuries; delayed repair for contaminated wounds; nerve grafts (sural) for gaps; conduit for short gaps in small sensory nerves.

Parkland formula: 4 mL/kg/% total body surface area burn of lactated Ringer's in the first 24 h, half in the first 8 h from injury time; urine output goal 0.5-1 mL/kg/h in adults.

Burn depth classification: superficial (epidermis only, erythema, painful), superficial partial-thickness (blisters, moist, painful), deep partial-thickness (pale, decreased sensation), full-thickness (leathery, insensate, charred).

Rule of nines in adults: head 9%, each arm 9%, each leg 18%, anterior trunk 18%, posterior trunk 18%, perineum 1%; in children the head is proportionally larger and legs smaller.

Escharotomy indications: circumferential full-thickness burns with compromised perfusion or ventilation; perform along midlateral lines, avoiding neurovascular structures.

Inhalation injury: suspect with facial burns, singed nares, hoarseness, carbonaceous sputum, or closed-space fire; early intubation before airway edema progresses.

Burn wound excision and grafting: early tangential or fascial excision within 48-72 h reduces sepsis and improves survival; autograft coverage preferred, with allograft or xenograft as temporary coverage.

Hypertrophic burn scar management: pressure garments (15-25 mmHg), silicone sheeting, intralesional corticosteroids, and early splinting; contracture release with Z-plasty or skin grafting when function is limited.

Electrical burns: deep tissue injury may exceed surface appearance; monitor for cardiac arrhythmia, rhabdomyolysis, and compartment syndrome; urine output goal higher (about 1 mL/kg/h) with myoglobinuria.

Face lift planes: subcutaneous (skin and SMAS elevated together), deep-plane, and subperiosteal; SMAS plication or imbrication improves jawline and neck contour and longevity compared with skin-only lift.

Rhinoplasty: dorsal reduction, osteotomies for width, tip support via columellar strut or spreader grafts; avoid over-resection of the dorsum leading to saddle deformity and internal valve collapse.

Blepharoplasty: upper lid skin excision with conservative fat removal; lower lid via transconjunctival or transcutaneous approach; assess for dry eye and lagophthalmos risk preoperatively.

Breast augmentation: implant selection by base width, projection, and tissue coverage; dual-plane technique improves upper pole coverage; risk of capsular contracture, anaplastic large cell lymphoma (BIA-ALCL), and implant rupture.

Breast reduction: superomedial or inferior pedicle techniques; pedicle choice depends on nipple-areola complex viability and planned resection volume; free nipple graft for very large reductions.

Abdominoplasty: rectus plication, umbilical transposition, and limited undermining to reduce seroma; simultaneous ventral hernia repair requires mesh consideration and infection risk assessment.

Liposuction: tumescent technique with dilute lidocaine and epinephrine reduces blood loss and pain; limit total aspirate and lidocaine dose; risk of fat embolism and fluid shifts.

Body contouring after massive weight loss: staged procedures, address circumferential truncal laxity, and correct nutritional deficiencies before elective surgery.

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

Cleft palate repair techniques: von Langenbeck (bipedicled mucoperiosteal flaps), Bardach (two-flap), and Furlow double-opposing Z-plasty for soft palate lengthening.

Craniosynostosis: premature suture fusion; sagittal synostosis causes scaphocephaly, coronal causes plagiocephaly, metopic causes trigonocephaly; surgical release (strip craniectomy or cranial vault remodeling) relieves raised intracranial pressure.

Pierre Robin sequence: micrognathia, glossoptosis, and cleft palate; airway management includes prone positioning, nasopharyngeal airway, or mandibular distraction.

Hemifacial microsomia: unilateral mandibular hypoplasia, ear anomalies, and soft tissue deficiency; graded by Pruzansky-Kaban; treatment staged from distraction to reconstruction.

Craniofacial syndromes: Crouzon and Apert syndromes involve coronal synostosis with midface hypoplasia; Apert also has syndactyly; Le Fort III advancement addresses midface retrusion.

Fronto-orbital advancement: for coronal synostosis to increase cranial volume and reshape the forehead; timing often within the first year.

Vascular anomalies: infantile hemangioma proliferates then involutes (propranolol first-line); vascular malformations (capillary, venous, lymphatic, arteriovenous) do not involute and require intervention based on type.

Head and neck squamous cell carcinoma: risk factors tobacco and alcohol, HPV-associated oropharyngeal cancer has better prognosis; staging guides resection margins and neck dissection.

Neck dissection levels: I submental/submandibular, II upper jugular, III mid jugular, IV lower jugular, V posterior triangle; selective dissection preserves structures based on nodal risk.

Mandibular reconstruction: fibula free flap is the workhorse for segmental defects; plate and soft tissue flap for poor candidates; dental rehabilitation planned with osseointegrated implants.

Tongue and floor of mouth defects: radial forearm free flap for thin pliable coverage; anterolateral thigh for larger defects; maintain tongue mobility and oral competence.

Radial forearm flap: fasciocutaneous, thin, reliable pedicle (radial artery and venae comitantes); donor site requires tendon coverage and may need skin graft; Allen test preoperatively.

Pharyngoesophageal reconstruction: jejunum free flap or anterolateral thigh tubed flap; consider tracheostomy and swallowing rehabilitation.

Facial nerve sacrifice: immediate cable graft (sural) if proximal stump available; static or dynamic reanimation options including temporalis transfer and nerve transfer.

Oncologic margins: clear margins (commonly 1-2 cm for skin and mucosal cancers) with frozen section; adjuvant radiotherapy for positive margins, perineural invasion, or nodal disease.

Kanavel signs of flexor tenosynovitis: fusiform swelling, tenderness along the flexor sheath, pain on passive extension, and finger held in slight flexion.

Dupuytren contracture: palmar fascia fibrosis, nodules and cords; treatment options include needle aponeurotomy, collagenase injection, and limited fasciectomy; recurrence is common.

Carpal tunnel syndrome: median nerve compression; night pain, thenar atrophy, positive Tinel and Phalen tests; release of the transverse carpal ligament.

Scaphoid fracture: tenderness in the anatomic snuffbox; risk of avascular necrosis of the proximal pole; immobilization and imaging (CT or MRI for occult fractures).

Hand infections: paronychia, felon, and web space infections require drainage; deep space infections (thenar, midpalmar) need surgical drainage and antibiotics.

Tendon repair zones: flexor zone II (no man's land) repairs require core suture plus epitendinous repair and early controlled mobilization to limit adhesions.

Nerve injuries of the hand: median nerve (thenar muscles, sensation radial 3.5 digits), ulnar nerve (intrinsic muscles, ulnar 1.5 digits), radial nerve (wrist extension); repair or graft based on gap.

Replantation and revascularization: cooling the amputated part, avoiding direct ice contact, and prompt transfer; absolute contraindications include severe crush and multiple-level injury.

Informed consent elements: diagnosis, proposed procedure, alternatives including no treatment, material risks, benefits, and the patient's right to withdraw consent at any time.

WHO surgical safety checklist: sign in before induction, time out before incision, sign out before leaving the operating room; reduces wrong-site surgery and communication errors.

Venous thromboembolism prophylaxis: risk-stratify with Caprini score; use mechanical and pharmacologic prophylaxis in high-risk aesthetic and reconstructive cases; consider timing around regional anesthesia.

Wrong-site surgery prevention: marking the site with the patient awake when possible, verifying imaging and consent, and a formal time-out with the full team.

Confidentiality: patient information protected; disclosure permitted with consent, legal requirement, or public health exception; teach-back and documentation support ethical practice.

Conflict of interest: disclose financial relationships and industry support; avoid incentives that influence clinical decisions; institutional review for research conflicts.

Professionalism: honesty in documentation, appropriate boundaries, cultural competence, and reporting impaired colleagues through proper channels.

Fire safety in the operating room: fire triad (fuel, oxidizer, ignition); stop oxygen before electrocautery near the face; use wet drapes and appropriate laser precautions.

Study designs: randomized controlled trial is the strongest for causality; cohort and case-control for observational associations; case series and case reports are hypothesis-generating only.

Levels of evidence: systematic reviews and meta-analyses of RCTs at the top; then RCTs, cohort studies, case-control, case series, and expert opinion at the bottom.

Sensitivity and specificity: sensitivity is true positives divided by all diseased; specificity is true negatives divided by all non-diseased; predictive values depend on prevalence.

Confidence interval interpretation: a 95% CI excludes the null value if the interval does not include 1 for ratios or 0 for differences; wider intervals reflect less precision.

Number needed to treat: 1 divided by absolute risk reduction; lower NNT means greater clinical benefit; NNH is the reciprocal of absolute risk increase.

Bias types: selection, information, confounding, and publication bias; randomization and blinding reduce selection and information bias; adjustment or matching addresses confounding.

Quality improvement: Plan-Do-Study-Act cycles, run charts, and control charts track process and outcome measures; measure baseline before intervention to demonstrate change.

Critical appraisal: assess validity, results, and applicability to the patient; systematic reviews should report heterogeneity (I-squared) and risk of bias assessment.

Face lift planes: subcutaneous, deep-plane, and subperiosteal; SMAS plication or imbrication improves jawline and neck contour and longevity compared with skin-only lift.

Rhinoplasty: dorsal reduction, osteotomies for width, tip support via columellar strut or spreader grafts; avoid over-resection leading to saddle deformity and internal valve collapse.

Blepharoplasty: upper lid skin excision with conservative fat removal; lower lid via transconjunctival or transcutaneous approach; assess dry eye and lagophthalmos risk preoperatively.

Breast augmentation: implant selection by base width, projection, and tissue coverage; dual-plane technique improves upper pole coverage; risks include capsular contracture, BIA-ALCL, and rupture.

Breast reduction: superomedial or inferior pedicle techniques; pedicle choice depends on nipple-areola complex viability and planned resection volume; free nipple graft for very large reductions.

Abdominoplasty: rectus plication, umbilical transposition, and limited undermining to reduce seroma; simultaneous ventral hernia repair requires mesh consideration and infection risk assessment.

Liposuction: tumescent technique with dilute lidocaine and epinephrine reduces blood loss and pain; limit total aspirate and lidocaine dose; risk of fat embolism and fluid shifts.

Body contouring after massive weight loss: staged procedures, address circumferential truncal laxity, and correct nutritional deficiencies before elective surgery.

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

Cleft palate repair techniques: von Langenbeck (bipedicled mucoperiosteal flaps), Bardach (two-flap), and Furlow double-opposing Z-plasty for soft palate lengthening.

Craniosynostosis: premature suture fusion; sagittal synostosis causes scaphocephaly, coronal causes plagiocephaly, metopic causes trigonocephaly; surgical release relieves raised intracranial pressure.

Pierre Robin sequence: micrognathia, glossoptosis, and cleft palate; airway management includes prone positioning, nasopharyngeal airway, or mandibular distraction.

Hemifacial microsomia: unilateral mandibular hypoplasia, ear anomalies, and soft tissue deficiency; graded by Pruzansky-Kaban; treatment staged from distraction to reconstruction.

Craniofacial syndromes: Crouzon and Apert syndromes involve coronal synostosis with midface hypoplasia; Apert also has syndactyly; Le Fort III advancement addresses midface retrusion.

Fronto-orbital advancement: for coronal synostosis to increase cranial volume and reshape the forehead; timing often within the first year.

Vascular anomalies: infantile hemangioma proliferates then involutes (propranolol first-line); vascular malformations do not involute and require intervention based on type.

Head and neck squamous cell carcinoma: risk factors tobacco and alcohol; HPV-associated oropharyngeal cancer has better prognosis; staging guides resection margins and neck dissection.

Neck dissection levels: I submental/submandibular, II upper jugular, III mid jugular, IV lower jugular, V posterior triangle; selective dissection preserves structures based on nodal risk.

Mandibular reconstruction: fibula free flap is the workhorse for segmental defects; plate and soft tissue flap for poor candidates; dental rehabilitation planned with osseointegrated implants.

Tongue and floor of mouth defects: radial forearm free flap for thin pliable coverage; anterolateral thigh for larger defects; maintain tongue mobility and oral competence.

Radial forearm flap: fasciocutaneous, thin, reliable pedicle (radial artery and venae comitantes); donor site requires tendon coverage and may need skin graft; Allen test preoperatively.

Pharyngoesophageal reconstruction: jejunum free flap or anterolateral thigh tubed flap; consider tracheostomy and swallowing rehabilitation.

Facial nerve sacrifice: immediate cable graft (sural) if proximal stump available; static or dynamic reanimation options including temporalis transfer and nerve transfer.

Oncologic margins: clear margins (commonly 1-2 cm for skin and mucosal cancers) with frozen section; adjuvant radiotherapy for positive margins, perineural invasion, or nodal disease.

Kanavel signs of flexor tenosynovitis: fusiform swelling, tenderness along the flexor sheath, pain on passive extension, and finger held in slight flexion.

Dupuytren contracture: palmar fascia fibrosis, nodules and cords; treatment options include needle aponeurotomy, collagenase injection, and limited fasciectomy; recurrence is common.

Carpal tunnel syndrome: median nerve compression; night pain, thenar atrophy, positive Tinel and Phalen tests; release of the transverse carpal ligament.

Scaphoid fracture: tenderness in the anatomic snuffbox; risk of avascular necrosis of the proximal pole; immobilization and imaging (CT or MRI for occult fractures).

Hand infections: paronychia, felon, and web space infections require drainage; deep space infections (thenar, midpalmar) need surgical drainage and antibiotics.

Tendon repair zones: flexor zone II (no man's land) repairs require core suture plus epitendinous repair and early controlled mobilization to limit adhesions.

Nerve injuries of the hand: median nerve (thenar muscles, sensation radial 3.5 digits), ulnar nerve (intrinsic muscles, ulnar 1.5 digits), radial nerve (wrist extension); repair or graft based on gap.

Replantation and revascularization: cooling the amputated part, avoiding direct ice contact, and prompt transfer; absolute contraindications include severe crush and multiple-level injury.

Informed consent elements: diagnosis, proposed procedure, alternatives including no treatment, material risks, benefits, and the patient's right to withdraw consent at any time.

WHO surgical safety checklist: sign in before induction, time out before incision, sign out before leaving the operating room; reduces wrong-site surgery and communication errors.

Venous thromboembolism prophylaxis: risk-stratify with Caprini score; use mechanical and pharmacologic prophylaxis in high-risk aesthetic and reconstructive cases; consider timing around regional anesthesia.

Wrong-site surgery prevention: marking the site with the patient awake when possible, verifying imaging and consent, and a formal time-out with the full team.

Confidentiality: patient information protected; disclosure permitted with consent, legal requirement, or public health exception; teach-back and documentation support ethical practice.

Conflict of interest: disclose financial relationships and industry support; avoid incentives that influence clinical decisions; institutional review for research conflicts.

Professionalism: honesty in documentation, appropriate boundaries, cultural competence, and reporting impaired colleagues through proper channels.

Fire safety in the operating room: fire triad (fuel, oxidizer, ignition); stop oxygen before electrocautery near the face; use wet drapes and appropriate laser precautions.

Study designs: randomized controlled trial is the strongest for causality; cohort and case-control for observational associations; case series and case reports are hypothesis-generating only.

Levels of evidence: systematic reviews and meta-analyses of RCTs at the top; then RCTs, cohort studies, case-control, case series, and expert opinion at the bottom.

Sensitivity and specificity: sensitivity is true positives divided by all diseased; specificity is true negatives divided by all non-diseased; predictive values depend on prevalence.

Confidence interval interpretation: a 95% CI excludes the null value if the interval does not include 1 for ratios or 0 for differences; wider intervals reflect less precision.

Number needed to treat: 1 divided by absolute risk reduction; lower NNT means greater clinical benefit; NNH is the reciprocal of absolute risk increase.

Bias types: selection, information, confounding, and publication bias; randomization and blinding reduce selection and information bias; adjustment or matching addresses confounding.

Quality improvement: Plan-Do-Study-Act cycles, run charts, and control charts track process and outcome measures; measure baseline before intervention to demonstrate change.

Critical appraisal: assess validity, results, and applicability to the patient; systematic reviews should report heterogeneity (I-squared) and risk of bias assessment.