Dupuytren's disease, congenital hand and miscellaneous Flashcards
What is the surgical dissection sequence encountered when repairing a suspected Stener lesion of the thumb MCP joint?
Skin → Sagittal bands → Adductor aponeurosis → Ulnar collateral ligament → Volar plate.
This sequence enables identification and management of the displaced ulnar collateral ligament, classically prevented from reattachment due to interposition of the adductor aponeurosis, characteristic of a Stener lesion.
In a suspected Stener lesion, which structure is typically interposed, preventing healing of the ulnar collateral ligament?
The adductor aponeurosis is interposed, preventing spontaneous healing of the ligament and necessitating surgical intervention.
Why must the sagittal bands and adductor aponeurosis be carefully managed during surgical repair of a Stener lesion?
Sagittal bands stabilize the extensor pollicis longus tendon, while the adductor aponeurosis must be divided carefully to reveal the underlying displaced ulnar collateral ligament, facilitating accurate repair and ligament reattachment.
What is the recommended age range for pollicisation in patients with Type IIIb hypoplastic thumb (pouce flottant)?
Between 6 months and 3 years of age.
This timing balances anesthesia safety, ease of technical procedure, and optimal cortical plasticity for thumb-index finger reassignment.
Why is pollicisation generally avoided in the first few months of life for hypoplastic thumb management?
Early pollicisation (under 3 months) has increased anesthetic risk due to potential incomplete cardiac and pulmonary development, and technical difficulty due to tiny anatomical structures.
Which Blauth classification type of thumb hypoplasia is described as a small, vestigial thumb held by a thin stalk of soft tissue (“pouce flottant”)?
Blauth Type IV thumb, requiring excision followed by pollicisation to restore hand function effectively.
What is the optimal surgical sequence for replantation of multiple digits amputated at the same anatomical level?
“Part by part” sequence: Bone → Flexor tendon → Extensor tendon → Nerves → Arteries → Veins.
This sequence ensures maximum efficiency and protects delicate vascular and neural structures from potential intraoperative damage.
Why is digit-by-digit replantation generally not recommended when multiple digits are amputated at the same level?
Digit-by-digit replantation is less efficient because completing each structure sequentially across all digits reduces overall ischemia time and enhances the viability of replanted digits.
During multiple digit replantation, why are arterial repairs completed before venous repairs?
Arterial repair precedes venous repair because restoring arterial inflow first allows identification of optimal veins through venous filling, aiding successful venous anastomosis and tissue reperfusion.
What is the appropriate management step upon discovering “rice bodies” and granulomas around flexor tendons during hand surgery?
Perform acid-fast cultures of the tenosynovium and urgently consult microbiology, as these findings suggest tuberculous tenosynovitis, typically from Mycobacterium marinum.
What is the most common causative organism of tuberculous tenosynovitis in the hand?
Mycobacterium marinum, typically causing chronic tenosynovitis presenting with “rice bodies” and granulomas.
Why is immediate histology insufficient in diagnosing tuberculous tenosynovitis?
Histology alone usually reveals non-specific tenosynovitis, thus requiring microbiological confirmation via acid-fast bacilli cultures to establish diagnosis.
What is the initial recommended treatment step for a high-flow arteriovenous malformation (AVM) in the hand?
Highly selective intralesional embolization of the predominant artery (radial artery), reducing lesion size and facilitating safer subsequent surgical resection.
Why is ligation alone ineffective for treatment of high-flow AVMs in the hand?
Ligation causes collateral vascular channels to rapidly form, resulting in recurrence. Selective embolization aims to eradicate the nidus, preventing recurrence and facilitating effective surgical resection.
Why is sclerotherapy typically ineffective in managing high-flow AVMs?
Sclerotherapy is more effective for low-flow venous malformations. High-flow AVMs require selective embolization, which targets the lesion’s arterial supply more effectively.
What is the appropriate treatment for a hypertrophic scar after excision of ulnar-sided polydactyly in a 3-month-old infant?
Scar massage and observation, reassuring caregivers as hypertrophic scars typically improve spontaneously without intervention.
Why are intralesional steroid injections contraindicated in managing hypertrophic scars in young infants?
Intralesional steroids are inappropriate in young infants due to potential complications and because hypertrophic scars generally resolve spontaneously.
How can hypertrophic scars be clinically differentiated from keloids in pediatric patients?
Hypertrophic scars remain confined to the original wound margins, while keloids overgrow the original boundaries, typically appearing months after the initial injury.
Which finding is the most significant indication for surgical intervention in Dupuytren’s disease?
Extension deficit at the proximal interphalangeal joint (PIPJ), as PIP joint contractures are prone to permanent deformity, recurrence, and functional impairment if untreated.
Why are palmar nodules not typically an indication for surgical intervention in Dupuytren’s disease?
Palmar nodules alone do not usually lead to significant functional impairment, unlike joint contractures, and thus do not justify surgical risks.
Why is the presence of an abductor digiti minimi cord significant in Dupuytren’s disease?
An abductor digiti minimi cord involvement can cause significant functional impairment, particularly limiting hand span and grip function, indicating surgical consideration.
Following revascularization of severe forearm trauma with prolonged ischemia, what is the immediate surgical priority?
Perform fasciotomies to prevent compartment syndrome from reperfusion injury and subsequent muscle swelling.
Why is primary nerve repair not the immediate priority following severe ischemic forearm trauma?
Initial priority is restoring circulation and preventing compartment syndrome. Nerve repairs typically occur later once tissue viability is stabilized.
Why is immediate split-thickness skin grafting inappropriate in severe ischemic soft-tissue trauma?
Immediate grafting is inappropriate due to potential ongoing swelling, tissue viability uncertainty, and likely need for subsequent reoperation after compartmental pressure reduction.
What is the recommended management for a stable infantile haemangioma on a toddler’s hand?
Observation and reassurance, as most infantile haemangiomas regress spontaneously over time without intervention.
Why is oral propranolol not immediately initiated for a small stable infantile haemangioma without functional impairment?
Propranolol carries systemic risks requiring close monitoring; conservative management is preferable for stable lesions without functional issues.
How is an infantile haemangioma clinically distinguished from congenital haemangioma?
Infantile haemangiomas are not present at birth, appear in weeks after birth, and exhibit rapid initial growth followed by gradual spontaneous regression.
What is the correct approach to managing a tourniquet that has been applied for 2 hours in a polytrauma patient undergoing limb surgery?
The correct approach is to deflate the tourniquet for 20 minutes, reinflate it, and then proceed with repairs.
This technique minimizes ischemic injury while maintaining a controlled surgical field. Releasing the tourniquet completely after 2 hours can lead to a surge of toxic metabolites and potential systemic complications, whereas intermittent deflation balances tissue perfusion and controlled blood loss.
Why is immediately proceeding with surgical repairs without deflating a tourniquet after prolonged ischemia dangerous?
Keeping the tourniquet inflated beyond safe limits can cause irreversible ischemic damage to muscles and nerves. It also increases the risk of compartment syndrome and metabolic acidosis upon sudden reperfusion due to the release of ischemic byproducts.
What are the potential systemic effects of prolonged tourniquet use followed by sudden deflation in a polytrauma patient?
Sudden deflation after prolonged ischemia (>2 hours) can lead to reperfusion syndrome, characterized by hypotension, metabolic acidosis, hyperkalemia, and rhabdomyolysis, potentially leading to cardiac arrhythmias and multi-organ dysfunction.
Gradual deflation with intermittent reinflation helps mitigate these effects.
What is the most appropriate management for an 11-month-old with a fixed flexion deformity of the thumb IP joint and a palpable firm lump at the A1 pulley?
Observation and follow-up.
Pediatric trigger thumb, often associated with Notta’s nodule, typically resolves spontaneously between 1-3 years of age. Surgical release is reserved for persistent cases beyond 3 years.
Why is surgical release of the A1 pulley not recommended for infants under 3 years with trigger thumb?
Most cases resolve spontaneously, and early surgery carries risks of neurovascular injury due to volarly placed structures. Intervention is only considered if the condition persists beyond 3 years.
How can pediatric trigger thumb be differentiated from congenital camptodactyly?
Trigger thumb is characterized by a fixed flexion deformity at the IP joint with a firm nodule (Notta’s nodule), whereas camptodactyly affects the PIP joint, often due to abnormal lumbrical or superficial flexor insertion.
An 11-year-old boy presents with atrial fibrillation and an isolated hypoplastic thumb. What is the most likely diagnosis?
Holt-Oram syndrome.
This autosomal dominant disorder is associated with cardiac septal defects, conduction abnormalities, and upper limb malformations, particularly radial longitudinal deficiencies.
How does Holt-Oram syndrome differ from TAR (thrombocytopenia-absent radius) syndrome?
Holt-Oram syndrome presents with cardiac conduction abnormalities and radial deficiencies, whereas TAR syndrome is associated with thrombocytopenia and absent radius, typically without major cardiac defects.
Why should all children with radial-sided upper limb anomalies undergo early pediatric cardiology evaluation?
Conditions like Holt-Oram syndrome frequently involve cardiac septal defects or conduction abnormalities, which may be asymptomatic initially but can lead to arrhythmias or heart failure later in life.
What is the most appropriate wound coverage option for an 8-year-old with a full-thickness volar forearm burn and a 5 cm segmental ulnar nerve defect?
Flap coverage of the wound.
The wound is too large for a skin graft, and vascularized tissue coverage is necessary to protect exposed structures and facilitate nerve healing.
Why is direct skin grafting not ideal for an exposed ulnar nerve in a burn injury?
Skin grafting directly over an injured nerve can cause tethering and neuroma formation, leading to chronic pain and dysfunction.
When is nerve grafting appropriate in pediatric ulnar nerve injuries following burns?
Nerve grafting is considered only if the nerve develops a neuroma in continuity, as immediate nerve repair is challenging due to unpredictable long-term nerve recovery in young children.
Which clinical finding is most indicative of compartment syndrome in a patient with a swollen and tense hand after metacarpal fixation?
Severe pain on passive adduction and abduction of the fingers.
This suggests intrinsic muscle compartment involvement, as stretching affected compartments exacerbates ischemic pain.
Why is reduced sensation on the dorsum of the hand not an early indicator of hand compartment syndrome?
Sensory loss is a late sign, whereas severe pain with passive movement is the most reliable early indicator of impending compartment syndrome.
What is the definitive management for suspected hand compartment syndrome?
Urgent fasciotomies to relieve increased compartmental pressure and prevent irreversible muscle necrosis and nerve damage.
Which muscle assumes the function of abductor pollicis brevis after pollicization in Blauth IV thumb hypoplasia?
First dorsal interosseous muscle.
Following pollicization, this muscle takes over the function of thumb abduction, enhancing prehension and grip.
Which anatomical structure is repositioned to function as the extensor pollicis longus after pollicization?
The extensor indicis proprious of the index finger becomes the new EPL to maintain thumb extension.
Why is pollicization preferred over prosthetic thumb reconstruction in Blauth IV thumb hypoplasia?
Pollicization provides functional opposition and grip strength using native tissue, whereas prosthetic reconstruction lacks dynamic motor control and sensory feedback.
Which congenital hand anomaly requires preoperative hematological evaluation due to its association with systemic syndromes?
Radial longitudinal deficiency.
This condition is associated with syndromes such as Holt-Oram, VACTERL, TAR (thrombocytopenia-absent radius), and Fanconi anemia, which may involve life-threatening hematological or cardiac abnormalities.
Why is surgery contraindicated in patients with Fanconi anemia or TAR syndrome until hematological abnormalities are addressed?
Fanconi anemia can lead to pancytopenia and marrow failure, while TAR syndrome involves neonatal thrombocytopenia, making surgical intervention risky due to bleeding complications.
What other systemic conditions should be assessed in a patient with radial longitudinal deficiency before surgical correction?
Cardiac anomalies (Holt-Oram syndrome), vertebral and renal abnormalities (VACTERL), and thrombocytopenia (TAR syndrome). These can significantly impact perioperative management.
What is the most definitive surgical procedure for a 50-year-old with severe Dupuytren’s contracture and high recurrence risk?
Dermofasciectomy.
In high-risk patients (Caucasian males, bilateral disease, younger onset, family history), this procedure removes the affected fascia and replaces it with a skin graft, reducing recurrence.
Why is needle aponeurotomy not ideal for high-risk Dupuytren’s disease cases?
While minimally invasive, needle aponeurotomy has a high recurrence rate, making it unsuitable for patients with aggressive, extensive disease.
What key prognostic indicators suggest higher recurrence risk in Dupuytren’s disease?
Early onset (<50 years), bilateral involvement, strong family history, ectopic fibromatosis (e.g., Garrod’s pads), and male gender. These factors predict a more aggressive disease course.
Which anatomical structure is primarily responsible for distal interphalangeal (DIP) joint contractures in Dupuytren’s disease?
Retrovascular cord.
This cord originates from the periosteum of the proximal phalanx and inserts on the lateral aspect of the distal phalanx, leading to DIP joint contractures.
How does the retrovascular cord differ from the central cord in Dupuytren’s disease?
The central cord contributes to MCP and PIP contractures, while the retrovascular cord is responsible for DIP contractures by tethering the distal phalanx.
What is the appropriate surgical approach for a DIP joint contracture due to a retrovascular cord?
Selective cord excision.
This involves removing the pathological cord to restore DIP joint extension.
Which clinical feature is most indicative of complex regional pain syndrome (CRPS)?
Sweating asymmetry between the two hands.
This is part of the Budapest criteria, which includes sensory, vasomotor, sudomotor/edema, and motor/trophic changes.
What is the difference between CRPS type I and type II?
• CRPS Type I (Reflex Sympathetic Dystrophy): No identifiable nerve injury.
• CRPS Type II (Causalgia): Clear peripheral nerve injury.
What is the first-line treatment approach for early-stage CRPS?
Multimodal therapy, including graded physical therapy, pain control (NSAIDs, neuropathic agents), and desensitization techniques. Early intervention prevents chronic pain progression.
What is the best reconstructive option for large exposed tendons after excision of a major burn with no available free flap donor sites?
Dermal regeneration template.
This provides a biodegradable matrix for vascularization and requires a secondary skin graft for full coverage.
Why is skin allograft not a viable long-term solution in severe burns?
Allografts are temporary and will be rejected within weeks due to the host immune response.
Why are tissue expansion and regional pedicled flaps not suitable in this case?
• Tissue expansion is ineffective due to reduced skin elasticity after severe burns.
• Regional pedicled flaps are not available as adjacent tissues are also burned.
Which racial group has the highest incidence of subungual melanoma?
Darker-skinned populations (African, Asian).
Subungual melanoma is a type of acral lentiginous melanoma, which is more common in non-Caucasian groups.
What clinical sign is pathognomonic for subungual melanoma?
Hutchinson’s sign – Pigmentation extending to the eponychium or lateral nail folds.
What is the standard surgical management for confirmed subungual melanoma?
Wide excision with ≥1 cm margins and sentinel lymph node biopsy.
Amputation at the interphalangeal joint may be necessary due to periosteal proximity.
What is the most effective pharmacological treatment for adrenaline-induced digital ischemia?
Phentolamine injection.
As an alpha-adrenergic blocker, phentolamine reverses vasoconstriction within 1–1.5 hours.
Why is hyaluronidase injection not useful in treating epinephrine-induced vasoconstriction?
Hyaluronidase disperses anesthetic agents but does not counteract vasospasm.
When should surgical exploration and revascularization be considered for digital ischemia?
Only if ischemia persists despite pharmacologic reversal, as digits are highly tolerant of transient ischemia.
Which tumor presents with intermittent sharp pain, cold intolerance, and pinpoint tenderness under the nail matrix?
Glomus tumor.
Classic signs include “Love Sign” (focal pressure pain) and Hildreth’s Sign (pain relief with tourniquet application).
What is the best imaging modality for diagnosing a glomus tumor?
MRI – Clearly delineates the tumor and guides surgical excision.
How does subungual melanoma differ clinically from a glomus tumor?
Subungual melanoma presents with progressive dark streaking (Hutchinson’s sign) and lacks paroxysmal pain seen in glomus tumors.
What is the best initial management for a non-healing ulcer with a violaceous border in a patient with ulcerative colitis?
Referral to dermatology for medical treatment.
Pyoderma gangrenosum is an autoimmune neutrophilic dermatosis, requiring steroids or immunomodulators.
Why is debridement contraindicated in pyoderma gangrenosum?
Surgical trauma exacerbates the ulcer, leading to pathergy (worsening ulceration).
What systemic conditions are associated with pyoderma gangrenosum?
Inflammatory bowel disease (IBD), rheumatoid arthritis, and hematologic malignancies.
What is the most common cause of contracture at the proximal interphalangeal joint in Dupuytren’s disease?
Central cord
Which pathological structure arises from the periosteum of the proximal phalanx and causes distal interphalangeal joint contracture in Dupuytren’s disease?
Retrovascular cord
Which anatomical structure contributes to the formation of Dupuytren’s disease by involving the lateral digital sheath?
Spiral cord
Which structure in Dupuytren’s disease is vertical and sometimes involved in disease progression?
Septa of Legueu and Juvara
Which pathological structure causes contractures of the proximal interphalangeal joint of the little finger in Dupuytren’s disease?
Abductor digiti minimi cord
Which consumptive coagulopathy is life-threatening and associated with large vascular anomalies?
Kassabach-Merritt syndrome
Which condition is an angiosarcoma that can develop after years of chronic lymphoedema?
Stewart-Treves syndrome
Which painful neuritis can result in paralysis of upper limb muscles?
Parsonage-Turner syndrome
Which syndrome has symptoms that can be confused with carpal tunnel syndrome?
Hand Arm Vibration Syndrome
Which syndrome can result in a loss of function in patients with rheumatoid arthritis?
Vaughn-Jackson Syndrome
Which sign is elicited by exsanguinating the digit and applying a tourniquet, resulting in pain relief of a glomus tumour?
Hildreth’s sign
Which sign is used to differentiate a pre-ganglionic from a post-ganglionic brachial plexus injury?
Froment’s sign
Which sign indicates a poor prognosis in a ring avulsion injury?
Red streak sign
Which sign is a result of dysfunction of the third palmar interosseous?
Wartenberg’s sign
Which sign can be a prodrome to Vaughn-Jackson Syndrome?
Piano key sign
What is one of the recognised procedures to deal with a duplicate thumb?
Bilhaut-Cloquet procedure
Which congenital hand difference requires ruling out cardiac and haematological conditions?
Radial longitudinal deficiency
Which condition corresponds to a neurological pattern, most often in the median nerve or its branches?
Macrodactyly
What condition is associated with a delta phalanx seen on radiographs?
Clinodactyly
Which congenital hand condition can cause acrosyndactyly with fenestrations between two digits?
Constriction Band Syndrome
Which agent is used to treat lidocaine toxicity from an overdose?
20% lipid emulsion
Which local anaesthetic is a class IB anti-arrhythmic and can be used to treat ventricular arrhythmias?
Lidocaine hydrochloride
Which agent, along with lidocaine, makes up the constituents of the topical EMLA cream?
Tetracaine
Which is an ester class of local anaesthetic and an effective topical anaesthetic?
Prilocaine
Which agent can cause precipitation if used in the wrong quantities when combining local anaesthetics?
Sodium bicarbonate
What is the most appropriate immediate management for doxorubicin extravasation in a patient on an oncology ward?
The best immediate management is to aspirate the canula, remove it, and start intravenous dexrazoxane. Doxorubicin is a DNA-binding vesicant, and dispersing it with flushing or hyaluronidase can increase tissue necrosis. Dexrazoxane is the most effective antidote, preventing surgery in over 98% of cases.
Why is hyaluronidase contraindicated in anthracycline extravasation injuries?
Hyaluronidase is generally used to dilute and disperse extravasated agents, but in anthracycline extravasation (e.g., doxorubicin), dispersing the drug can lead to a larger area of necrosis. DNA-binding vesicants like doxorubicin should be localized and neutralized, making intravenous dexrazoxane the preferred treatment.
When should surgical debridement and skin grafting be considered for anthracycline extravasation injuries?
Surgical debridement and grafting should only be considered if necrosis has already developed and conservative measures, including dexrazoxane administration, have failed. Early intervention with dexrazoxane significantly reduces the need for surgery and allows continued chemotherapy without interruption.
