Which of the following regarding metacarpal neck fractures is true? metacarpal neck fracture.
When reducing a Smith’s or volar Barton’s fracture, the reduction manoeuvre should include?
Extension and supination. This question tests the understanding of the deforming forces of a fracture. Extension and supination are necessary to overcome the pronation rotatory deformity that the volar displaced fragment undergoes.
A 22-year-old medical student was slightly intoxicated and fell onto his extended wrist while his forearm was pronated. He has pain and a clicking sensation on the ulnar side of his wrist. X-rays and nerve conduction studies are normal. The most likely diagnosis is?
Triangular fibrocartilage complex (TFCC) tear. Once again 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: Class 1 – Traumatic A – central perforation or tear B – ulnar avulsion with or without ulnar styloid fracture C – distal avulsion D – radial avulsion with or without sigmoid notch fracture Class 2 – Degenerative stage A – TFCC wear B – TFCC wear with lunate and/or ulnar chondromalacia C – TFCC perforation with lunate and/or ulnar chondromalacia D – TFCC perforation with lunate and/or ulnar chondromalacia and lunotriquetral (LT) ligament perforation E – TFCC perforation with lunate and/or ulnar chondromalacia, LT ligament perforation, and ulnocarpal arthritis
If a 28-year-old male motorbiker had a complex distal radius fracture (volar fixation required) and acute severe carpal tunnel syndrome, which of the following surgical approaches would be correct? carpal tunnel.
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. It is not acceptable to watch and wait as there will only be more swelling post-operatively. 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.
Which of the following is not a sign of an unstable scaphoid fracture?
Scapholunate angle <60º. This 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 >15, scapholunate angle >60, intrascaphoid angles >35 and a proximal pole fracture.
In Wartenburg syndrome the compression takes place between? 5
Brachioradialis and extensor carpi radialis longus (ECRL) in pronation. The superficial branch of the radial nerve is compressed as it is squeezed between the brachioradialis and ECRL in pronation. 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). 18
A patient presents with pain and cold insensitivity at the fingertip. There is a bluish discolouration under the nail. The most likely diagnosis is?
Glomus tumour. The give away is the bluish colour under the nail. This is typical for the glomus tumour; this is a rare benign neoplasm arsing from the glomus body (a neuromyoarterial apparatus). It can be excised by lifting the nail up (if under the nail plate) with repair of the nail bed afterwards.
The following are all good prognosis after nerve injury except?
Proximal injury. A more distal low velocity injury with a sharp object will have a better potential for healing. The long distance to the motor endplate from a proximal injury may preclude recovery. Younger patients have far higher potential for full recovery than adults.
All of the following make up the spiral cord except?
Natatory ligament. This key question is a test of anatomy. Before considering surgery a thorough knowledge of local structures is important. The distortion of the normal anatomy results in displacement of the neurovascular structures, and explains the significant risk in Dupuytren’s disease surgery.
Which of the following is not a poor prognostic indicator in traumatic brachial plexus injury?
No sensation from tip of acromion to tip of fingers. The prognosis for avulsion of the roots is far worse than just rupture or traction. All of these markers suggest severe trauma and may point to root avulsion. Numbness on its own is not as worrying as the other signs.
Which of the following is a rule of tendon transfer?
Tendon pull must be synergistic. These rules must be appreciated and short cuts will only lead to disaster. Donor muscles must be expendable and have adequate power, ideally MRC grade 5. Joints must be mobile with no contracture.
A 56-year-old obese man presents with a painless deterioration in bilateral hand function. Initially it was the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints that were involved and now it is the distal interphalangeal (DIP) joints. He has thick tight skin and a positive prayer sign. The most likely disease is? 6
Diabetic cheirarthropathy. This is a poorly understood condition. It is thought to be as a result of a muscular or tendon imbalance with soft tissue disruption. There is a microangiopathy of the dermal and subcutaneous blood vessels. It is more common in Type 1 diabetics and can affect 8–50% of the population. Loss of function is painless, and progresses from distal to proximal. The prayer sign is an inability to oppose palmar surfaces.
A 38-year-old man presents with dorsal wrist pain. He has a stiff wrist with very limited range of motion and can’t work as a mechanic. Plain films reveal Grade IV Kienbock’s disease. He should be treated with?
Wrist arthrodesis. 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. It is also not an option in the more uncommon scenario of the ulnar positive wrist. The Lichtman classification, based on radiographs, is as follows: Stage 1 – normal (may have a linear or a compression fracture) Stage 2 – sclerosis but no collapse Stage 3A – collapse of entire lunate without fixed scaphoid rotation Stage 3B – collapse of entire lunate with fixed scaphoid rotation Stage 4 – stage III with generalized degenerative changes in the carpus 19
A 41-year-old woman sustained a distal radius fracture whilst hiking in the Andes. It was treated in plaster by a local missionary doctor and went on to malunion. She presents with ulnar-sided pain and on examination she impacts on the ulnar side, with a negative grind test at the distal radioulnar joint (DRUJ). The best treatment would be?
Ulnar shortening osteotomy. It is uncommon for younger people to present with significant radial shortening as their fractures are usually well managed. In this case there is ulna impaction syndrome. The aim is to reduce this impaction. 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. It is associated with ongoing discomfort in the proximal stump and certainly not the first choice in this scenario.
Which of the following is not true of Dupuytren’s disease? for surgery.
Painful nodules are an indication for surgery. The disease is usually in its early phases. The stages, according to Luck’s classification, are proliferative, involutional and finally residual. Early surgery will certainly lead to recurrence and can stimulate the disease process. Carpal tunnel surgery must be performed at a separate occasion for a similar reason. Unfortunately in the long term recurrence rates are high (50%).
A 17-year-old snowboarder fell onto his outstretched pronated hand. He presents with ongoing ulnar-sided wrist pain. He is tender over the ulnar fovea and has no click. The distal radioulnar joint (DRUJ) is stable. Plain films are normal and a MR arthrogram show a triangular fibrocartilage complex (TFCC) defect adjacent to the ulna. How is this classified according to the Palmer classification?
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 16-year-old girl had multiple fractures in her forearm and hand. One year later after fracture healing she presents with trouble gripping things. When the metacarpophalangeal (MCP) joint is extended you cannot passively flex the proximal interphalangeal (PIP) joint. When the MCP joint is flexed it is possible to passively flex the PIP joint. Her extensors are at a good length. Which of the following is incorrect? 7
She has a claw hand. She has tight intrinsic muscles and her Bunnell test is positive as the intrinsic muscles are more powerful than her extrinsic extensors and flexors. The tight intrinsic muscles are treated with distal releases when fibrotic and a proximal slide when spastic. An intrinsic minus hand is one where there is a loss of function in the ulna and sometimes the median nerve (claw). The patient presents with a monkey grip.
A 23-year-old cricketer had an avulsion of the flexor digitorum profundus (FDP) tendon of his ring finger. This was diagnosed early and despite proximal migration he had it reinserted with a button technique. Six months later he complains that he can’t close his fingers tightly over a cricket ball. This problem is?
Quadrigia effect. Though this was a bony avulsion it must be thought of like any other 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).
Which of the following is true regarding a Mayfield Stage I injury?
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 Stage IV – lunate dislocation
A 23-year-old was intoxicated at a wedding and fell through a glass window. He presents to the emergency department with a radial wrist laceration with arterial bleeding. With regards to the timing of surgery the major blood supply to the hand is provided by which of the following?
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. 20
A 41-year-old man presents with a swelling at the level of his distal interphalangeal (DIP) joint on his right middle finger. What is the most likely diagnosis?
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).
Which of the following is not a recognized treatment for carpal tunnel syndrome? 8
Nerve stimulation therapy. If symptoms are not severe and there is not significant and progressive neuropathy then non-operative management must be considered. This includes splintage, hand therapy, steroid injection and even yoga has been proven to be beneficial. Alternatively a patient could be referred for either open or endoscopic release.
All of the following contribute to the wrist and hand deformity in rheumatoid arthritis except?
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.
A 13-year-old boy is referred to you after a trivial fall onto his elbow. Radiographs reveal a dislocated radial head. He does not have much pain. His mother says she has always had joint pains with abnormal knee caps. She keeps pointing to her knees in an excited manner with long fake nails. The most likely diagnosis is?
Nail patella syndrome. This 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.
A 43-year-old woman presents with decreased digital flexion and an injury in Zone 2 of her left hand. On exploration what percentage laceration of the flexor tendon would you repair?
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.
With regards to radioulnar limb formation and the zone of polarizing activity, defects in which protein will result in duplication of digits? 9
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. 21 1. The term internal impingement is used in throwers to describe a condition where the posterosuperior glenoid labrum impinges on which structure? a. The anterior glenohumeral ligaments. b. The posterior glenohumeral ligaments. c. The biceps tendon. d. The anterior rotator cuff. e. The posterior rotator cuff. 2. The biomechanical advantage of a reverse total shoulder arthroplasty compared to a standard arthroplasty is what? a. Centre of rotation more superior. b. Centre of rotation more medial. c. Centre of rotation more lateral. d. Increased lateral humeral offset. e. Decreased deltoid muscle fibre tension. 3. Posterior glenohumeral dislocations occur more frequently than anterior dislocations in which group of patients? a. Rugby players. b. Ehlers–Danlos patients. c. Hypermobile patients. d. Epileptics. e. None of the above. 4. A football player sustains a suspected acromioclavicular joint (ACJ) separation. Which of the following is the most appropriate radiographic view to evaluate the ACJ? a. Stryker notch view. b. Serendipity view. c. Zanca view. d. Supraspinatus outlet view. e. Garth view. # Cambridge University Press 2012. 25
