Wrist CASES 4

CASE                               27                               

Several years after sustaining an injury to his wrist, a firefighter presents to your clinic with chronic wrist pain. What does his x-ray (Fig. 3–20) reveal?

1. DISI

2. Carpal coalition

3. Ulnar translation

4. VISI

5. None of the above

 

 

Figure 3–20 (©) Sunil Thirkannad and Christine M. Kleinert.

 

Discussion

The correct answer is (C).

 

How much does the width of the lunate need to be off the radius for a diagnosis of ulnar translation to be made?

1. >30%

2. >50%

3. >25%

4. Is determined by the displacement of the scaphoid in the scaphoid fossa

5. None of the above

 

Discussion

The correct answer is (B).

 

Ulnar translation of the lunate serves as a relative contraindication for which

procedure?

1. Total wrist fusion

2. Total wrist arthroplasty

3. Four-corner fusion

4. Proximal row carpectomy

5. Fascia lata interposition arthroplasty

 

Discussion

The correct answer is (D). Ulnar translation of the lunate indicates weakness of the radio-scaphocapitate ligament. This serves as a relative contraindication for proximal row carpectomy as the risk of the capitate also translating ulnar wards is high, leading to an unstable wrist.

Which of the following surgical procedures is indicated in correcting ulnar translation of the carpus?

1. Radioscapholunate fusion

2. Radial styloidectomy

3. Arthroscopic debridement of the TFCC

4. Ulnar shortening

5. Scaphoid excision and four-corner fusion

 

Discussion

The correct answer is (A).

 

Objectives: Did you learn...?

 

Identify criteria of ulnar translation?

 

 

Identify contraindications of proximal row carpectomy? Surgically manage ulnar translation of the carpus?

 

CASE                               28                               

A young lady presents with chronic pain in her wrist which she describes as a deep boring type. An x-ray (Fig. 3–21) is shown. She denies any history of trauma in the past. What do you suspect?

1. Kienbock’s disease

2. Osteoid osteoma

3. Preiser’s disease

4. Osteopetrosis

5. Hyperparathyroidism

 

 

 

Figure 3–21 (©) Sunil Thirkannad and Christine M. Kleinert.

 

Discussion

The correct answer is (C).

 

What investigation would help confirm your diagnosis?

1. CT scan

2. Arthroscopy

3. Arthrogram

4. MRI with contrast

5. Angiogram

 

Discussion

The correct answer is (D).

Preiser’s disease is a spontaneous avascular necrosis of the scaphoid. MRI with gadolinium is the most sensitive modality to confirm this condition.

What is your preferred treatment for this condition?

1. Scaphoid excision and four-corner fusion

2. Botox injection

3. Daily application of nitroglycerine paste over the scaphoid

4. Proximal row carpectomy

5. Vascularized bone graft to the scaphoid

 

Discussion

The correct answer is (E).

 

Which pedicle is commonly used to revascularize the scaphoid?

1. 2–3 ICSRA

2. 1–2 ICSRA

3. 1st ECA

4. 2nd ECA

5. Dorsal carpal arch

 

Discussion

The correct answer is (B).

 

Objectives: Did you learn...?

 

Diagnose Preiser’s disease?

 

 

Identify signs and symptoms of Preiser’s disease? Operatively manage Preiser’s disease?

 

CASE                               29                               

A 19-year-old girl presents to you with a painful wrist. As part of your investigations, you ask for x-rays of the wrist. Your radio technician is inexperienced and unsure of how to obtain proper views. How would you position the patient to obtain a PA view?

1. Shoulder adducted, elbow flexed to 90 degrees with forearm pronated and hand placed flat on the film

2. Shoulder abducted to 90 degrees, elbow flexed to 90 degrees with forearm neutral and hand placed flat on the film

3. Shoulder adducted, elbow flexed to 90 degrees with forearm supinated and hand placed flat on the film

4. Shoulder abducted to 90 degrees, elbow flexed to 90 degrees with forearm supinated and hand placed flat on the film

5. Shoulder abducted to 90 degrees, elbow flexed to 90 degrees with forearm pronated and hand placed flat on the film

Discussion

The correct answer is (B).

 

How would you position your patient for a lateral view of the wrist?

1. Shoulder adducted, elbow flexed to 90 degrees with forearm neutral and ulnar border of hand placed on the film

2. Shoulder abducted to 90 degrees, elbow flexed to 90 degrees with forearm neutral and ulnar border of hand placed on the film

3. Shoulder adducted, elbow flexed to 90 degrees with forearm supinated and ulnar border of hand placed on the film

4. Shoulder abducted to 90 degrees, elbow flexed to 90 degrees with forearm supinated and ulnar border of hand placed on the film

5. Shoulder abducted to 90 degrees, elbow flexed to 90 degrees with forearm pronated and ulnar border of hand placed on the film

Discussion

The correct answer is (A).

 

Whose lines are used to determine proper intercarpal alignment within the proximal and distal carpal rows?

1. Shenton’s lines

2. Kleinert’s lines

3. Zaidemberg’s lines

4. Barton’s lines

5. Gilula’s lines

Discussion

The correct answer is (E). Gilula described three smooth lines drawn on a PA view. The first corresponds to the proximal articular surfaces of the scaphoid, lunate, and triquetrum. The second line is along the distal articular surfaces of the scaphoid, lunate, and triquetrum while the third line is along the proximal articular surfaces of the capitates and hamate.

How is the carpal height ratio determined on an x-ray of the wrist?

1. Ratio of the height of the lunate to the height of the capitate

2. Ratio of the height of the carpus to the height of the third metacarpal

3. Ratio of the height of the capitate to the height of the carpus

4. Both B and C

5. Ratio of the height of the lunate to the longitudinal axis of the scaphoid

 

Discussion

The correct answer is (D). The carpal height ratio is classically described as the ratio of the height of the carpus to the height of the third metacarpal. However, as most wrist x-rays do not include the entire third metacarpal, the ratio of the height of the capitate to the height of the carpus is accepted as an alternate method of assessing the carpal height ratio.

 

Objectives: Did you learn...?

 

 

How to properly position the upper extremity for a PA view of the wrist? Describe the significance of Gilula’s Lines?

 

How to determine the carpal height ratio on x-ray?

 

CASE                               30                               

You are invited by your medical school to speak to first year medical students about the anatomy of the wrist. One of the students asks you about the most likely role of the terminal branches of the posterior interosseous nerve. What is your response?

1. They carry cutaneous nerves to the dorsum of the wrist

2. They supply proprioceptive branches to the wrist joint

3. They carry motor nerves to the 3rd and 4th dorsal interossei

4. They carry sympathetic fibers to the dorsal carpal arch artery

5. They carry sudomotor nerves to the dorsum of the wrist

 

Discussion

The correct answer is (B). The posterior interosseous nerve ends in a pseudoganglion over the dorsum of the carpus. Small terminal branches pass from this to the wrist joint. The general consensus is that these fibers are mainly proprioceptive in nature and may also carry deep pain sensations. Resection of the posterior interosseous nerve over the wrist joint is often carried out as a remedy for intractable wrist pain.

Another student asks you to name the weak spot over the carpus that has been implicated in lunate and perilunate dislocations. What would you say?

1. Parona’s space

2. Midpalmar space

3. Poisuelli’s space

4. Poirier’s space

5. Carpal recess

 

Discussion

The correct answer is (D). The space of Poirier is a bare area over the volar aspect of the lunate that is not covered by any extrinsic or intrinsic carpal ligament. While controversy exists about the exact nomenclature of the ligaments that border this space, it is generally agreed that this is the weak spot through which volar luxations of the lunate occur.

Your old anatomy teacher tells you that he thinks there is a muscle that has a dual nerve supply in the hand but is unable to recollect its name. What would you say to him?

1. There is no muscle with a dual nerve supply in the hand

2. Flexor pollicis brevis

3. Second lumbrical

4. Palmaris brevis

5. Abductor digitorum minimus

Discussion

The correct answer is (B). The FPB has two bellies and receives supply from both the median nerve and deep branch of the ulnar nerve.

Finally, a bright, eager student asks you what the nerve of Henle is. What is your response?

1. It is a branch of the ulnar nerve that carries sympathetic fibers

2. It is an anomalous connection between the median and ulnar nerves in the wrist

3. It is a branch from the posterior interosseous nerve that provides proprioception to the carpus

4. It is an anomalous branch from the median nerve that can sometimes supply the palmaris brevis muscle

5. It is the nerve supplying the anomalous extensor digitorum manus brevis muscle

 

Discussion

The correct answer is (A).

 

Objectives: Did you learn...?

 

 

Discuss the role of the terminal branches of the posterior interosseous nerve? Identify the significance of Poirier’s space?

 

 

Identify the innervation of the FPB? Describe the nerve of Henle?