The denervated first dorsal interosseous muscle flap: a case report

Innervation and vascular supply of the first dorsal interosseous muscle and palmar interosseous muscle of the index: An anatomic descriptive study

INTRODUCTION

The first dorsal interosseous muscle (FDI) and palmar interosseous muscle of the index (P2I) are essential for the strength and mobility of the index finger. This study aims to describe the course of the deep branch of the ulnar nerve (DBUN) and the blood supply to these muscles.

MATERIAL AND METHODS

An anatomical cadaver study was carried out with 14 upper limbs from fresh, non-embalmed cadavers. All limbs were filled with an equal amount, based on weight, of colored silicone and diluent that was combined and catalyzed with 5% curing agent. The location of the DBUN's termination was specified relative the carpometacarpal joint. Every artery supplying either muscle was identified and documented.

RESULTS

The DBUN had a slightly convex path, distal to the hook of the hamate and penetrated the FDI muscle at an average 41% of the second metacarpal length. An average of 1.3 branches to the P2I and 2.6 branches to the FDI were found. Four artery pedicles coming from the deep palmar arch supply the FDI with an average of one consistent and exclusive pedicle to the FDI and three pedicles heading to the P2I. According to the classification of Mathes and Nahai, the FDI has a type 2 blood supply and the P2I has a type 3 blood supply.

CONCLUSION

In-depth knowledge of the vascular network supplying the FDI and P2I muscles and the course of the DBUN is essential when the DBUN is damaged or when dissecting these muscles for index pollicization.

Vascular basis of intrinsic muscle flaps in the hand

BACKGROUND

Intrinsic hand muscles can occasionally be used as pedicled flaps for wound coverage or functioning transfer in hand trauma. The purpose of this study was to define the vascular supply of the individual intrinsic muscles of the hand for potential use of these muscles as muscle flaps.

METHODS

In part A, 10 fresh cadavers were injected using a lead oxide-gelatin injection technique. The intrinsic muscles were meticulously dissected, removed, and radiographed. The number, type, and diameter of the vascular pedicles of each muscle and their distribution within the muscle were analyzed. The area of the vascular territory supplied by each source vessel was calculated. In part B, 10 embalmed cadavers were injected with red latex and a similar dissection protocol was followed.

RESULTS

The 18 hand muscles each received an average of 3 +/- 1 vascular pedicles. The average diameter was 0.8 +/- 0.2 mm; the length and width of the area supplied by each pedicle was 2.2 +/- 0.4 cm and 1.0 +/- 0.2 cm, respectively. The vascular territories of the majority of hand muscles were aligned longitudinally along their long axes. Nine intrinsic hand muscles have been identified that can potentially be used as a muscle flap or musculocutaneous or musculo-osseous flap.

CONCLUSIONS

The size and course of the vascular pedicles to the hand muscles are variable. This anatomical study provides an improved understanding of the vascular supply of the intrinsic muscles of the hand and provides further information to assist in the design of intrinsic hand muscle transfer.

Use of dorsal ulnar neurocutaneous island flap in the treatment of chronic postburn palmar contractures

In the present study, the authors evaluated efficiency of the "dorsal ulnar neurocutaneous island flap" in the coverage of palmar defects resulting from radical release of selected chronic postburn contractures. Eight white male hands with palmar contracture were treated with this flap between November 2001 and December 2003. The mean follow-up period was 11.6 months. The flap, which was planned on the ulnar aspect of the forearm and the hand, is transferred to the palmar defect. The subcutaneous pedicle of the flap was skin-grafted to avoid tension. All operations were successful. Distal flap necrosis that healed by secondary intention was observed in one of the eight flaps. Seventy-five degrees was the maximum improvement in metacarpophalangeal (MP) joint extension achieved in the little finger. Grasp function of the hand dramatically improved and the bulk of the flap did not interfere with grasping. No recurrent palmar contracture was observed. The authors concluded that the dorsoulnar neurocutaneous island flap can be used effectively in the treatment of postburn palmar contractures. The safety of the flap can be enhanced by grafting the intervening skin between the pivot point of the flap and the palmar defect.

Vascular anatomy of the metacarpal bones and the interosseous muscles

The utilization of the metacarpal bones and interosseous muscles in the reconstruction of the hand should be based on the vascular anatomy of the metacarpal bones and the interosseous muscles. The authors studied the vascular anatomy of the metacarpal bones and the interosseous muscles to design a split metacarpal musculoosseous flap. Eighteen cadaveric hands from 9 cadavers were included in the study. The dorsal metacarpal arteries arise from the arch and course along the metacarpal bones closer to the ulnar borders of the bones supplying their periosteum through the muscular branches. Despite the indistinct pattern of muscular supply and anastomotic branches to the palmar surface, in all hands the arteries extend constantly along the metacarpal bone closer to the ulnar border. For defects or any pathology of the carpal bones, the metacarpal bones could be split at the ulnar border distally and a split metacarpal musculoosseous flap (based proximally depending on the dorsal metacarpal artery) could be performed (or based distally along with a distal intermetacarpal anastomosis).

The neurocutaneous flap based on the dorsal branches of the ulnar artery and nerve: a new flap for extensive reconstruction of the hand

Soft-tissue repair in the hand often requires skin flaps due to exposure of bone, tendons, nerves, and arteries. However, alternatives for flap surgery are very limited, especially in dealing with palmar hand reconstruction. In the present report, the dorsal branch of the ulnar nerve and its accompanying artery were studied anatomically, and a neurocutaneous flap distally based on these structures was developed. The flap was raised on the medial aspect of the hand and distal half of the forearm, and its rotation point was located dorsally near the metacarpalphalangeal joints. The clinical use of this flap for the repair of skin defects in the hand is reported. All the clinical flaps survived completely, including a 3.5 x 13-cm large flap. Donor site morbidity was minimal. This flap represents a new alternative in hand reconstruction.

Revisitation of the vascular anatomy of the lumbrical and interosseous muscles

Functional outcome after transmetacarpal replantations and revascularizations is discouragingly poor and often associated with a high incidence of intrinsic-related complications. In order to explore the hypothesis that intrinsic muscle ischemia may play a significant role, we revisited the vascular anatomy of the lumbrical and interosseous muscles. Six fresh-frozen cadaver hands were injected with latex-barium sulfate, and dissections were performed focusing on the contributions of the deep and superficial palmar arches and their branches to the intrinsic muscle vasculature. We found that the lumbrical muscles are supplied from both their volar and dorsal surfaces by both the superficial and deep palmar arches in both axial and segmental fashions. The dorsal and volar interossei receive their major blood supply from the deep arch and metacarpal arteries without any distinct pattern of axial or segmental vessels. These minute vessels cannot be repaired and are not reconstituted even with arch reconstruction. Moreover, with injuries distal to the arch, dissection of the digital arteries further disrupts this blood supply. These anatomic findings may have significant implications in clinical replantation and revascularization.

Local muscle flaps of the second and third interosseus space for the treatment of osteomyelitis in the central metacarpal region

Both experimental and clinical studies showed that muscle flap transposition is a reliable tool in treating chronic infections of the bone. The major advantage of local muscle flaps is the treatment with well perfused autogenous tissue without using any implants. The primary closure of the operation site and the cure of infection within four weeks allow a short immobilisation time. Nevertheless, the loss of muscle function with a possible functional and aesthetic defect in the donor site has to be accepted. The first dorsal interosseus muscle and the abductor digiti minimi muscle have been used successfully for the treatment of metacarpal osteomyelitis. Osteomyelitis in the central metacarpal bones cannot be treated with these techniques, because of their limited range. We present the muscles of the second and third interosseus space for local pedicled muscle flap transfer. The arterial network in this interosseus spaces and the vascularisation of the dorsal and palmar interosseus muscles allow to harvest muscle flaps with either proximal or distal pedicle. The loss of interosseus muscles in the second and third interosseus space is tolerable from a functional and esthetic point of view. Operative techniques are shown for the elevation of dorsal and palmar interosseus muscle flaps. Two cases of osteomyelitis in the central metacarpal bones, which were treated successfully with the new local interosseus muscle flaps, are reported.

The first dorsal interosseous muscle: an anatomic study

The anatomy of the first dorsal interosseous muscle, with particular reference to its vascular and nerve supply, was studied in ten fresh cadaveric hands. A constant dorsal and palmar blood supply is identified from four major branches of the radial artery and deep palmar arch. The ulnar nerve innervates the muscle in a pattern that parallels the palmar blood supply. This information provides a basis for the use of the muscle as a local transposition flap.