Interactive MCQs Hand and Wrist

Discussion:

The correct answer is d. Central slip rupture. Swan neck deformity is caused by an imbalance between flexors and extensors, with a variable contribution from the intrinsic muscles. Central slip rupture results in a Boutonniere deformity, not a swan neck deformity.

Discussion:

The correct answer is d. Bone, Extensor, Flexor, Artery, Nerve, Vein. When performing a replant of an amputated finger, the correct order of surgery is bone fixation, followed by repair of extensor tendons, then flexor tendons, then arterial repair, then neural repair, and finally venous repair (BE FAN V).

Discussion:

The correct answer is a. A2 and A4. When performing flexor tendon repair, the A2 and A4 pulleys must be preserved in order to prevent bowstringing of the tendons and maintain strong lever arms for their action. Transection of the pulleys can result in weakness of flexion.

Discussion:

The correct answer is b. Adductor aponeurosis interposition between the distally based avulsed ligament impairs ligament healing. A Stener lesion is a condition that occurs when the proximal edge of the adductor aponeurosis is interposed between the distally based avulsed ligament and the bone, preventing complete healing despite a period of immobilization. This commonly occurs in ulnar collateral ligament tears of the thumb.

Discussion:

The correct answer is e. Up to 15º of angulation of the index and middle finger can be accepted. There is still poor consensus on how much deformity to accept for metacarpal neck fractures, but generally up to 70º of angulation is acceptable for the ring and small fingers, whereas up to 15º is acceptable for the index and middle fingers. The Jahss position can be used to immobilize an impacted metacarpal neck fracture by maintaining MCP and PIP flexion at 90º.

Discussion:

The correct answer is c. Extension and supination. When reducing a Smith’s or volar Barton’s fracture, the reduction manoeuvre should include extension and supination to overcome the pronator quadratus and other soft tissue deforming forces.

Discussion:

The correct answer is c. Triangular fibrocartilage complex (TFCC) tear. The mechanism of injury and mechanics are key to understanding the injury. Wrist pain must always be divided into radial, dorsal and ulna. Then according to the anatomy of the region, specific signs and limited special investigations a diagnosis can be made. TFCC tears are either acute or chronic and have been classified by Palmer.

Discussion:

The correct answer is c. Perform a Henry’s approach and a separate carpal tunnel incision. In severe wrist trauma the median nerve may be under a lot of pressure. The wrist crease must always be crossed with an S shape but in this case two separate incisions are key to prevent injury to the palmar cutaneous branch of the median nerve which lies between the flexor carpi radialis and palmaris longus. Safe surgery on the median nerve should not be contemplated from either a very radial or very ulnar approach.

Discussion:

The correct answer is e. Scapholunate angle <60º. The question is a test of the indications for fixation of a scaphoid fracture. The unstable fracture generally needs fixation. Other signs of instability include radiolunate angle >15º, scapholunate angle >60º, intrascaphoid angles >35º and a proximal pole fracture.

Discussion:

The correct answer is a. Brachioradialis and extensor carpi radialis longus (ECRL) in pronation. Wartenburg syndrome is an entrapment neuropathy of the superficial radial nerve in the anatomical region between the brachioradialis and the ECRL. This must not be confused with intersection syndrome, pain associated with the crossing of the first and second dorsal extensor compartments associated with repetitive movements of the wrist (e.g. in rowers).

Discussion:

The correct answer is b. Glomus tumour. A bluish discoloration under the nail, pain, and cold insensitivity are characteristic symptoms of a glomus tumor, a neuromyoarterial apparatus neoplasm that arises from the glomus body. It can typically be excised through nail bed incision.

Discussion:

The correct answer is d. Proximal injury. Proximal injury, where the distance between motor endplates is greater, may hamper the potential for recovery. Young age, low-velocity injury, and sharp (knife) injury are all associated with good prognosis. Early exploration is necessary in the case of neural injuries to identify and treat the lesions, increasing the possibility of a favorable outcome.

Discussion:

The correct answer is d. Natatory ligament. The spiral cord in anatomy, eponymously known as the central band of the extensor expansion, functions to hold the extensor tendon to the phalanx, among other things. Grayson’s ligaments, the spiral band, the lateral sheet, and the pretendinous band, all make up the spiral cord. The natatory ligament, however, is not part of the spiral cord but is the space between the interossei muscles of the hand and the lumbrical muscles.

Discussion:

The correct answer is e. No sensation from tip of acromion to tip of fingers. Avulsion of roots carry a poorer prognosis than rupture or traction injuries. No sensation from the tip of the acromion to the tip of the fingers is not as concerning as the other signs listed, which all suggest severe trauma and may indicate root avulsion.

Discussion:

The correct answer is c. Tendon pull must be synergistic. Rules of tendon transfer include, but are not limited to, the donor muscle being ideally grade 5, joints having adequate mobility with no contracture, tendon pull being synergistic, and the line of pull not being orthogonal. Additionally, the tendon excursion of the flexors (not the extensors) is typically longer than that of the extensors.

Discussion:

The correct answer is d. Scleroderma. The patient described presents with clinical features of scleroderma, such as tight skin, metacarpophalangeal and proximal interphalangeal joint involvement that progresses to distal interphalangeal joint involvement, and a positive prayer sign. Scleroderma is an autoimmune disease marked by skin and connective tissue thickening, as well as fibrosis and small blood vessel changes that can involve many organs.

Discussion:

The correct answer is e. Wrist arthrodesis. Kienbock’s disease is a progressive avascular necrosis of the lunate, which may result in scaphoid abduction. The Lichtman classification system essentially divides Kienbock’s disease into types that can be treated with therapeutic operations such as radial shortening or grafting versus those that need salvage operations such as partial or complete wrist arthrodesis. One of the deciding factors in the type of fusion is the degree of fixed deformity. In the presence of fixed deformity, radial shortening is not an option.

Discussion:

The correct answer is a. Ulnar shortening osteotomy. The best treatment for this would be an ulnar shortening osteotomy. The aim is to reduce this impact. There is no need to address the DRUJ or replace the distal ulna. The Darrach procedure should be reserved for older patients with rheumatoid disease and is associated with ongoing discomfort in the proximal stump.

Discussion:

The correct answer is b. Painful nodules are an indication for surgery. Painful nodules are not necessarily an indication for surgery in Dupuytren’s disease. The long-term recurrence rate of Dupuytren’s disease is indeed 50%, and metacarpophalangeal joint contracture of greater than 30º is indeed an indication for surgery. Myofibroblasts are the offending cells in the etiology of the disease, and carpal tunnel release bears no significant relevance to post-operative flare.

Discussion:

The correct answer is d. Class 1B lesion. TFCC tears are divided into acute (1) and chronic (2) by the Palmer classification. The majority of isolated TFCC injuries do not require early surgical management. The need for treatment is increased when the lesion is associated with fractures, instability, and DRUJ injuries. A class 1B lesion, which involves tears from the ulnar attachment of the meniscus to within 3 mm of the edge of the ulnar head, is the most common type of peripheral tear and typically optimally observed/tested by careful physical examination and MRI arthrogram.

Discussion:

The incorrect statement is a. She has an intrinsic plus hand. The given presentation describes a claw hand where the patient has tight intrinsic muscles and positive Bunnell test as the intrinsic muscles are more powerful than the extrinsic extensors and flexors. The tight intrinsic muscles are treated with distal releases when fibrotic and a proximal slide when spastic. The patient presents with a monkey grip.

Discussion:

The problem described is c. Quadrigia effect. Though this was a bony avulsion, it must be thought of like any other flexor digitorum profundus (FDP) tendon injury. In this case, because of the proximal migration of the tendon, it was probably repaired tightly with an adhesed improperly tensioned FDP. Because the adjacent remaining fingers share a common muscle belly, they cannot flex entirely (quadrigia effect).

Discussion:

The correct answer is a. There is not always a scaphoid fracture. To understand carpal instability, it is essential to appreciate the ligamentous attachments both between the individual carpal bones as well as the extrinsic ligaments that support the wrist. The Mayfield staging is thus summarized: Stage I – scapholunate dissociation/scaphoid fracture, Stage II – lunocapitate dislocation, Stage III – lunotriquetral disruption/triquetrum fracture, and Stage IV – lunate dislocation.

Discussion:

The correct answer is d. Superficial palmar arch. The superficial palmar arch is a continuation of the ulna artery. In the majority of patients (78%), this arch is completed by branches from the deep palmar, radial, or median arteries. This explains why even with significant lacerations to the ulna artery a hand can be well perfused.

Discussion:

The most likely diagnosis is c. Mucoid cyst. This is a common lesion that arises from the osteoarthritic DIP joint. There is usually a disruption of the joint and a cyst develops. They cause deformity of the nail because of pressure on the germinal matrix. If they are large, it may be necessary to perform a local flap at excision (transposition).

Discussion:

The option that is not a recognized treatment for carpal tunnel syndrome is e. Yoga. If symptoms are not severe and there is no significant and progressive neuropathy, then non-operative management must be considered. This includes splinting, hand therapy, steroid injection, and nerve stimulation therapy. Alternatively, a patient could be referred for either open or endoscopic release.

Discussion:

The correct answer is c. Scaphoid extension. In rheumatoid arthritis, the inflammation of the synovium sets off a sequence of events that start with correctable deformity and eventually lead to fixed deformity and destruction of the joints. The synovitis at the DRUJ leads to capsular stretching with ECU subluxation and stretching of the dorsal structures. There is erosion of the radio-scapho-capitate ligament with flexion of the scaphoid. The carpus supinates as it moves in an ulna direction. Rather than the ulna becoming prominent, it is the carpus that slips away from it.

Discussion:

The most likely diagnosis is e. Nail patella syndrome. Nail patella syndrome is a result of an abnormality on chromosome 9. Patients may have subluxed or dislocated radial heads and never realize they have a problem until they have an X-ray. The syndrome can include abnormalities of the patella and nail growth, generalized ligamentous laxity, and bony exostoses.

Discussion:

The correct answer is d. 50%. Because of the morbidity and prolonged rehabilitation associated with tendon repair, it is advisable to repair lacerations over 50% of the tendon width. The exception to this rule is if there is visible triggering under a local anaesthetic block, it may be necessary to address this.

Discussion:

The protein whose defect results in duplication of digits is b. Sonic hedgehog protein. Eight weeks after fertilization, all limb structures are present. It is between 4 and 8 weeks where the majority of congenital disorders in the hand occur. There are many factors involved in limb development; however, there are three key zones responsible for proximodistal, anteroposterior, and dorsoventral development. These are the apical ectodermal ridge, zone of polarizing activity, and Wnt pathway, respectively. These in turn produce fibroblast growth factors, Sonic hedgehog protein, and LMX1, which all work in a coordinated manner to ensure the normal development of the limb.