Orthopedic Teaching Cases 2023, Jan, 17 | 12:00 am

Hand CASE 42

CASE                               42                               

The patient is a 65-year-old, diabetic, male carpenter who presents with bilateral carpal tunnel syndrome. His primary symptoms are paresthesias in the median nerve distribution, although he also complains of clumsiness of his hands. On examination, he has weakness to palmar abduction in his thumbs bilaterally with a positive Durkan test. EMG demonstrates moderate bilateral carpal tunnel syndrome. After patient education and counseling, the patient is prepared to undergo carpal tunnel release.

Which of the following is a benefit of endoscopic carpal tunnel release compared to open release?

  1. More complete release of the transverse carpal ligament

  2. Lower complication rate

  3. Faster return of sensation in the median nerve distribution

  4. Faster return to work

  5. Better visualization of critical structures in the palm

 

Discussion

The correct answer is (D). There are many purported and actual benefits of both open and endoscopic carpal tunnel release, and there are proponents of both techniques. Advantages of the open technique may include better visualization of critical structures in the palm and less required equipment. Some studies have

demonstrated a faster return to work with endoscopic release compared with the open technique. In general, both techniques are comparable and can be used successfully in experienced hands.

What structures are at risk during the distal release of the transverse carpal ligament?

  1. The superficial palmar arch vessels

  2. The palmar cutaneous branch of the median nerve

  3. The recurrent motor branch of the median nerve

  4. A and B

  5. A and C

 

Discussion

The correct answer is (E). There are many structures at risk during the distal release of the transverse carpal ligament, including the superficial palmar arch, the recurrent motor branch of the median nerve, the flexor tendons, and the median nerve, among others. The palmar cutaneous branch of the median nerve arises from the radial side of the median nerve approximately 6cm proximal to the distal volar wrist crease and travels radially onto the thenar eminence. This nerve branch is at risk during proximal, not distal, division of the transverse carpal ligament.

This patient has diabetes. Which of the following is true about diabetic patients and the development of carpal tunnel syndrome?

  1. Patients with diabetes are more likely than nondiabetic patients to develop carpal tunnel syndrome

  2. Patients with diabetes are less likely than nondiabetic patients to develop carpal tunnel syndrome

  3. Patients with diabetes have the same incidence of carpal tunnel syndrome as nondiabetic patients

  4. Patients with diabetes have worse surgical outcomes than those without diabetes

  5. Patients with diabetes have better surgical outcomes than those without diabetes

 

Discussion

The correct answer is (A). There are many risk factors for the development of carpal tunnel syndrome, including prior wrist fracture, rheumatoid arthritis, hypothyroidism, and diabetes. Patients with diabetes, including those who do not require insulin, are more likely than nondiabetic patients to develop carpal tunnel

syndrome. Outcomes following carpal tunnel release, however, appear to be similar in both diabetic and nondiabetic patients.

 

Objectives: Did you learn...?

 

Describe the benefits of endoscopic vs open carpal tunnel release?

 

 

Identify the structures at risk during the release of the transverse carpal ligament? Identify the risk factors for carpal tunnel syndrome?

 

CASE                               43                               

The patient is a 52-year-old, right-hand-dominant male with a history of a nondisplaced right distal radius fracture treated with a short-arm cast for 6 weeks who presents with wrist pain and weakness. His fracture occurred 2 months prior to this presentation, and he initially did well and fully regained range of motion in his wrist and hand. Over the past 3 to 4 weeks, the patient has developed thumb and radial-sided wrist pain. On examination, the patient has crepitation with wrist flexion and wrist extension and has weakness with thumb extension at the MP joint and no appreciable extension at the IP joint.

What is the most specific part of the physical examination to confirm the diagnosis?

  1. Thumb flexion with the MP joint held in extension

  2. Thumb abduction strength

  3. Thumb retropulsion by extending thumb from a palm-down position

  4. Thumb extension at the MP joint

  5. Finkelstein test

 

Discussion

The correct answer is (C). The most specific test to isolate and evaluate the extensor pollicis longus tendon is to examine for thumb retropulsion by having the patient place his palm flat down on a table and asking him/her to extend the thumb. The EPL is the only muscle able to perform this function. Thumb flexion and adduction are performed by different muscles; thumb extension at the MP joint is performed primarily by the EPB.

What is the incidence of this complication following treatment for nondisplaced distal radius fractures?

  1. 0%

  2. 2% to 5%

  3. 7% to 10%

  4. 10% to 15%

  5. 15% to 20%

 

Discussion

The correct answer is (B). EPL rupture is an uncommon, but recognized complication of distal radius fractures, even those that are nondisplaced and treated without surgery. The incidence of this complication varies in different studies but probably occurs in 2% to 5% of patients. EPL rupture following ORIF of a distal radius fracture with a volar plate may be due to improper screw length, tendon ischemia, or attrition.

What is the most appropriate treatment for this problem?

  1. Observation only

  2. Urgent direct repair of the ruptured EPL tendon

  3. Urgent repair of the EPL tendon with palmaris longus tendon graft

  4. Nonurgent repair of the EPL tendon within 2 weeks

  5. Extensor indicis proprius tendon transfer

 

Discussion

The correct answer is (E). Rupture of the EPL tendon following distal radius fracture is rarely amenable to direct repair. The most commonly utilized and best option for this patient would be transfer of the EIP tendon to the EPL. The EIP is an extensor of the index finger, and is identified ulnar to the EDC tendon. This tendon transfer often provides satisfactory extension of the thumb IP joint without sacrificing additional function.

What is the location of the EPL tendon in the distal forearm?

  1. First dorsal extensor compartment

  2. Second dorsal extensor compartment

  3. Third dorsal extensor compartment

  4. Forth dorsal extensor compartment

  5. Fifth dorsal extensor compartment

 

Discussion

The correct answer is (C). The extensor pollicis longus is located in the third dorsal extensor compartment. The first compartment contains the APL and EPB, the second contains the ECRL and ECRB, the third the EPL, the fourth the EDC and EIP, the fifth the EDM, and the sixth the ECU.

 

Objectives: Did you learn...?

 

Evaluate maneuvers for the EPL?

 

 

Describe the incidence of EPL rupture after nondisplaced distal radius fracture? Describe the anatomy of the dorsal extensor compartments?

 

Treat EPL rupture?