Vascular and neural anatomy of the thenar area of the hand: its surgical applications

Free flap from the flexor aspect of the wrist for resurfacing defects of the hand and fingers

The distal portion of the flexor aspect of the forearm has been used as the donor site of full-thickness skin grafts, venous skin grafts, and Chinese forearm flaps. This article describes the use of a free flap harvested from the flexor aspect of the wrist and based on the superficial palmar branch of the radial artery to repair skin defects of the hand and fingers. The advantages of this flap are as follows: (1) the operative field is the same; (2) the radial artery is preserved; (3) it is thin, pliable, and hairless and thus can supply a gliding surface for tendons beneath it; (4) when it involves a palmaris longus tendon and/or the palmar cutaneous branch of the median nerve, it can be used as a vascularized tendon or nerve graft; and (5) in view of the flow-through type of the pedicle of the flap, the digital artery can be reconstructed simultaneously. However, it should be noted that a hypesthesia in the proximal central carpal area remains when the palmar cutaneous branch of the median nerve is harvested as a vascularized nerve graft. The scar of the donor site should be left in the distal wrist crease. If it is not lying in the distal wrist crease, it may suggest that the patient has tried to commit suicide.

Wrist arthroscopy through a volar radial portal

PURPOSE

To quantitatively describe the neurovascular relationships of a volar radial wrist arthroscopy portal and to evaluate whether volar wrist arthroscopy identified additional pathology of the dorsal capsular structures and the palmar region of the scapholunate interosseous ligament that was not seen through the dorsal portals.

TYPE OF STUDY

This study was an anatomic study and retrospective chart review.

METHODS

Cadaver dissections established the neurovascular anatomy of the volar radial portal. Measurements were taken from the portal to the radial artery and its superficial palmar branch; the superficial radial nerve, the median nerve, and its palmar cutaneous branch; and the pronator quadratus. A dorsal capsulotomy was performed to assess the ligamentous interval. A chart review of 30 patients in whom a volar radial portal was used was performed. Intraoperative pathology identified through volar wrist arthroscopy that was not visible through a dorsal portal was recorded. Postoperative neurovascular complications were noted.

RESULTS

There was a greater than 3 mm safe zone surrounding the portal that was free of any neurovascular structures. There were no complications from the use of the portal. Additional pathology that was not visible from a dorsal portal was identified in 10 cases. This included 1 case of hypertrophic synovitis of the dorsal capsule, 1 patient with an avulsion of the radioscapholunate ligament, 1 patient with a tear restricted to the palmar region of the scapholunate interosseous ligament, and 7 patients with tears of the dorsal radiocarpal ligament.

CONCLUSIONS

This study provides a safe, standardized approach to the volar radial aspects of the radiocarpal and midcarpal joints. Volar wrist arthroscopy identified additional pathology of the palmar scapholunate interosseous ligament and dorsal capsular structures in 30% of the patients. The volar radial portal should be considered for inclusion in the arthroscopic examination of any patient with radial-sided wrist pain.

Anatomy of the ulnar artery as it relates to the transverse carpal ligament

The anatomic relationship between the ulnar artery and transverse carpal ligament (TCL) as an aid in planning for minimally invasive carpal tunnel surgery was investigated. The anatomic course of the ulnar artery and its branches toward the TCL and the location of the median nerve were determined in 24 fresh cadaver hands perfused with a silicone compound. The ulnar artery coursed from 7 mm ulnar to 2 mm radial to the hook of hamate. The average distance between the superficial palmar arch and the distal margin of the TCL was 12 mm as measured along the flexor tendon of the ring finger. The location of the median nerve extended an average of 11 mm radial to the hook of hamate. A small arterial branch (average diameter, 0.7 mm) from the ulnar artery ran transversely just over the TCL in 6 of the 24 specimens. This branch was consistently located within 15 mm proximal to the TCL distal margin. These and other microscopic observations indicated that transecting the ligament at approximately 5 mm radial to the radial margin of the hook of hamate may minimize postoperative bleeding and avoid iatrogenic vascular and neural injury.

Unusual anatomic variation of palmar sensory branches of the ulnar nerve: a case report

Variant sensory branches of the ulnar nerve were encountered during a routine dissection of the palmar aspects of a cadaver hand. The variant branches were distributed to the ulnar half of the index, ulnar half of the middle, and radial half of the ring fingers. The communicating branch between the superficial ulnar branch and the third common digital branch of the median nerve was absent. Distribution of the median nerve sensory branches was normal. The clinical significance of this variation is discussed.