Palmar Cutaneous Nerve Research Articles

The Architecture of the Fibrous Complex between the Palmar Aponeurosis and the Flexor Retinaculum

Summary. During cadaver dissections of 34 adult human hands (fixed in formaldehyd solution), we examined a fibrous complex at the distal end of the flexor retinaculum. This fibrous complex was first mentioned by Legueu and Juvara (1892). It is located always ulno-dorsally to the attachment of the palmaris longus tendon into the palmar aponeurosis. Measurements of this special connective tissue show a mean length of 18.6 mm, a mean height of 4.3 mm and a mean width of 3.1 mm.Also, we looked for the fibrous complex in six adult plastinated transverse sections and in 12 fetal hands where it occurred in a constant way. We also found a very close topographic relationship between these oblique criss-crossed fibers and the palmar cutaneous branch of the median nerve. This nerve regularly gives some ulnar branches to the fibrous complex. The clinical relevance of the fibrous complex is discussed in relationship to a carpal tunnel syndrome. The described transverse fibers of the connective tissue complex are in danger as well as the ulnar branches of the palmar cutaneous nerve when releasing the flexor retinaculum during operation.

The Relationship between the Palmaris Longus Tendon and the Palmar Cutaneous Branch of the Median Nerve

The palmaris longus tendon is an idea donor for tendon grafts for plastic surgery. Ethnological variations may affect surgical procedures. In this study, we evaluated the relationship of the palmaris longus (PL) tendon to the palmar cutaneous nerve of median nerve (PCN) in the Chinese adult. We measured the a) distance between the PCN radially to palmaris longus, b) distance between the ulnarward PCN to palmaris longus, c) distance between the origin of PCN to the distal wrist crease and, d) distance between the proximal tendon part of PL to distal wrist crease. A total of 60 cadavers with 120 PCNs and 109 PLs were examined in three consecutive years. 106 cases (88.3%) of the PCNs originated from radial side of the median nerve and the mean distance was 1.4 cm. 14cases (11.7%) of the PCNs originated ulnarward and the mean distance was 0.3 cm. The mean distance of origin of the PCN to the distal wrist crease was 3.2 cm and the mean distance of the proximal tendon part of PL to the distal wrist creast was 13.1 cm. Therefore, we suggest that transverse incision be made 4cm from the distal wrist crease in palmaris longus tendon graft.

Anatomical study of the pre-retinacular fat pad of the wrist: application to a new surgical approach to the carpal tunnel

Decompression of the median nerve in the carpal tunnel by section of the flexor retinaculum is the generally accepted treatment for carpal tunnel syndrome and is usually effective in relieving the symptoms. Following postoperative observations we proposed the hypothesis that incisional pain following open carpal tunnel release could be partly explained by injury to the fat pad situated between the palmar carpal ligament and the flexor retinaculum. We performed an anatomical study on 20 fresh adult latex injected upper limbs. The sus-retinacularis fat pad is a real anatomical structure, clearly delineated and located inside a defined fibrous space with its own innervation from the ulnar nerve. It lies in the path of the normal carpal tunnel approach. Although most postoperative scar tenderness is attributed to neuroma formation because of injury to transverse branches of the palmar cutaneous nerves, we nevertheless consider that injury to the preretinacular fat pad also plays a part. We propose a modified approach to the carpal tunnel. This is a safe and simple method which respects the integrity of the sus-retinacularis fat pad so as to minimise the extent of scar tenderness.

Identification and preservation of palmar cutaneous nerves during open carpal tunnel release

We looked for crossing cutaneous nerve branches during standard open carpal tunnel release and attempted to preserve them. Open carpal tunnel release was performed on 34 hands in 29 patients. Crossing cutaneous nerves were identified in 47% of hands and successfully preserved in each case. No patient experienced postoperative pillar pain or scar hypersensitivity.

The detailed anatomy of the palmar cutaneous nerves and its clinical implications

The forearms and hands of 40 fresh-frozen cadavers were dissected under the microscope to study the palmar cutaneous branch of the median nerve (PCBm) and the palmar cutaneous branch of the ulnar nerve (PCBu). Branches of the PCBm innervating the scaphoid were typically found, but in no specimen did we find a 'typical' cutaneous branch of the ulnar nerve. According to our findings, standard incisions for open carpal tunnel release carry a significant risk of damaging branches of the PCBm or PCBu. The chance of injury to these sensory nerves can be minimized by using a short incision in the proximal palm or a twin incision approach, which we describe. Because the PCBm is closely associated with the ulnar side of the flexor carpi radialis (FCR) sheath, this sheath should be opened on the radial side during harvest of the FCR tendon for transfer. When transferring the palmaris longus tendon, it should be cut proximal to the distal wrist crease to avoid possible damage to the PCBm.

Anatomical Findings and Preservation of Transverse Sensory Branches of the Palmar Cutaneous Nerve during Carpal Tunnel Decompression

Of the possible complications following carpal tunnel release, one of the most distressing to the patient is a painful surgical scar. In this clinical study, 89 hands were examined at the time of surgery in order to identify the precise location, number and size of transverse sensory branches of the median palmar cutaneous nerve (PCN) and to preserve these during the procedure. Without the aid of operating microscope or loupes, a longitudinal interthenar incision was made, followed by careful splitting dissection of the subcutaneous fat. Transverse branches of the PCN, arising from the median nerve, were found in 85.4% of hands. Both median and ulnar nerve branches were found in 3.4% of hands, only ulnar nerve branches were found in 1.12% of hands and no branches were identified in 13.5% of hands. Multiple branches were found in 32.6% of cases. On average, these branches crossed the palm 1.5 cm from the distal wrist crease and were preserved 95% of the time without the use of operating microscope or loupes. Preservation of these small sensory nerves may prevent neuroma formation and, thereby, reduce the incidence of painful scars following carpal tunnel release.

Anatomical classification of sites of compression of the palmar cutaneous branch of the median nerve

The anatomical course of the palmar cutaneous nerve was studied in ten cadavers and classified into six zones or sites. The literature on entrapment neuropathy of the palmar cutaneous nerve was then reviewed and the cases were classified according to the anatomical site of compression.

Anatomical findings and preservation of transverse sensory branches of the palmar cutaneous nerve during carpal tunnel decompression

Of the possible complications following carpal tunnel release, one of the most distressing to the patient is a painful surgical scar. In this clinical study, 89 hands were examined at the time of s...

Compression neuropathy of the palmar cutaneous branch of the median nerve by the antebrachial fascia

An isolated compression neuropathy of the palmar cutaneous branch of the median nerve is described in a woman who presented with a small tender mass over the anterior aspect of her distal forearm and complete numbness over the thenar eminence. Surgical exploration revealed thickening of the palmar cutaneous nerve as it passed upwards through the antebrachial fascia on the ulnar aspect of the flexor carpi radialis tendon. Neurolysis of two separate fascicles of the palmar cutaneous branch of the median nerve and excision of a window of antebrachial fascia resulted in complete return of sensation over the thenar eminence.

Are the palmar cutaneous nerves safe during standard carpal tunnel release?

An incision in the axis of the ring finger is thought to be the safest for carpal tunnel release based on cadaveric studies that suggest that the palmar cutaneous nerves do not cross into this area. Despite the use of this incision, persistent postoperative scar tenderness has been reported in up to 36% of patients following standard carpal tunnel release. For this reason, an investigation was undertaken to determine the presence of palmar cutaneous nerves in this incision. Random biopsies of transversely oriented fibrous bands in the subcutaneous tissue were taken during 15 open carpal tunnel releases. In every patient, at least one biopsy was positive for peripheral nerve tissue. These findings, combined with previous cadaveric studies, suggest that a "safe" palmar incision that will avoid injury to palmar cutaneous nerves does not exist. Carpal tunnel release techniques that avoid a palmar incision may lessen postoperative morbidity by avoiding injury to these small cutaneous nerves.

Ganglion-related compression neuropathy of the palmar cutaneous branch of the median nerve: A report of two cases

Entrapment or compression of the palmar cutaneous nerve is rare. Five reported cases in the English literature have been identified; one caused by atypical palmaris longus muscle,’ one by fascia of the flexor digitorum superficialis,* and three by ganglions.‘.4 Of the compression neuropathies caused by ganglions, one case was relieved of symptoms after surgical treatment. Of the previously reported cases caused by ganglions, all three were clinically apparent and presented as a discrete mass in the forearm, just proximal to the wrist flexion crease. Two additional cases related to ganglions in which the ganglion was not discretely palpable prior to surgical exploration are reported.

Injury to the deep motor branch of the ulnar nerve during carpal tunnel release

Complications following carpal tunnel release have been reported to occur in 12-20%’ of cases and are numerous and varied. Neurologic complications that have been reported usually involve the palmar cutaneous or motor branch of the median nerve.’ Ulnar nerve injury during carpal tunnel release has been reported rarely. The only cases reported include cases of injury to the main ulnar palmar cutaneous nerve,* the ramus communicans3 (a normal sensory communication between the ulnar and median nerve in the palm), and a partial ulnar nerve injury in Guyon’s cana1.4 We have encountered three cases of injury to the deep motor branch of the ulnar nerve just distal to the hook of the hamate in the midpalmar space. All injuries occurred during routine carpal tunnel release performed by experienced orthopaedic surgeons and were not appreciated intraoperatively. Case Reports

Entrapment neuropathy of the palmar cutaneous nerve within its tunnel

A case of isolated entrapment of the palmar cutaneous branch of the median nerve is presented. At operation, a ganglion compressing the nerve within its tunnel was found. Symptoms were relieved with no recurrence at 2 years after decompression and excision of the ganglion.

Pseudo-anterior interosseous nerve syndrome: A case report

and patients with increased anesthetic risk can be treated safely. No local anesthetic is present at the incision site; this allows a more anatomic dissection without distorted tissues. The patient maintains use of the fingers and hand and can be released promptly from the day surgery area. The effects of the anesthetic last 6 to 8 hours, providing postoperative pain relief. A tourniquet can be placed on the distal forearm for the short time required for performance of the procedure. If desired, the tourniquet may be deflated without loss of anesthesia. The anesthetic can be administered in a preoperating room to expedite turnover time between operations. The potential for variation in nerve distribution to the palm must be remembered.’ This is the reason the anesthetic agent is placed above the fascia, allowing for more proximal branching of the median palmar cutaneous nerve as well as lateral and medial antebrachial cutaneous nerve distributions. The palmar cutaneous branch of the ulnar nerve is also anesthetized with this technique. If, for some reason, the block fails, the local anesthetic agent can still be injected at the incision site, since the amount of anesthetic used is far below the toxic level in adults. The most common area of persistent sensation is the thenar crease; an additional 5 ml of anesthetic may be injected subcutaneously in the palmar wrist crease near the flexor carpi radialis tendon to anesthetize this region. The risk of intravascular injection is remote. Only the ulnar artery is within the injection fields, and only a small amount of anesthetic is injected near the artery. As always, the surgeon who performs the block should be familiar with the pharmacology and side effects of local anesthetics, as well as possible complications and their treatment. This technique has also been used for other hand procedures, including palmar tenolysis, with excellent results.

Palmar cutaneous branch of the median nerve

The palmar cutaneous branch of the median nerve was dissected in 25 fresh cadavers. The origin from the median nerve, the course, termination, and variability of the palmar cutaneous nerve are described in relation to two reference lines. In no case did a branch of the palmar cutaneous nerve extend ulnar to the axial line of the ring finger. The planning of incisions around the palmar aspect of the palm and wrist should be based on this anatomical knowledge.

Anatomie des nerfs articulaires du poignet: Application à la technique de dénervation

The knowledge of the anatomy of the wrist articular nerves is at the base of the denervation technique. After a dissection of 12 adult wrists, we specify the situation and the relation of these nerves at the level where they are accessible to a surgical approach. The 10 articular branches of Wilhelm are described successively. The posterior interosseous is the most voluminous and most constant. Some branches need a specific surgical approach: anterior and posterior interosseous nerve, lateral cutaneous nerve, articular branch of the first web. Other nerves are cut blindly after skin undermining (perforating branches from cutaneous nerves). Some branches appear inaccessible to a cautious surgery because they are closely tight to other motor branches (deep branches of the cubital nerve). Finally some branches described by Wilhelm were not found in our dissections: branches of the median palmar cutaneous nerve, and direct branch of the cubital nerve.

Palmar cutaneous branch of the ulnar nerve

With recent attention being placed on the median palmar cutaneous nerve, a surgical approach, ulnar to the axis of the ring finger ray, has been advocated for median nerve decompression at the wrist. Painful hypothenar neuromas have developed in two patients with this type of incision. After dissecting 21 cadaver forearms and hands, three classic and two variants of the ulnar palmar cutaneous nerve were identified and found to emerge in the subcutaneous tissue ulnar to the ring finger ray. The terminal branches supplied the hypothenar skin and extended radially to the ring finger ray axis. Because of these anatomic findings, we recommend an incision in line with the ring finger ray axis in an attempt to avoid injury to both ulnar and median palmar cutaneous nerves.

The significance of the palmar cutaneous nerve at the wrist.

The Significance of the Palmar Cutaneous Nerve at the Wrist Robert Carroll;David Green; Clinical Orthopaedics and Related Research

Restoration of Sensory Function in Severe Degloving Injuries of the Hand

Degloving injuries of the hand characteristically result in avulsion of a skins flap which is often irreparably damaged and will require replacement by a free or pedicle graft. Such a graft on the distal volar surface of the digits gives poor sensory quality for useful manual dexterity, but may be corrected by local-tissue shift or a sensory island pedicle when the disability is sufficiently great. However, in the severe degloving injury there may not be sufficient normal digital skin for such restorative techniques. A technique for transposing a flap of palmar skin onto the volar surface of the dominant injured digit is illustrated by two clinical examples. Details of the anatomy of the palmar cutaneous nerves are described in relation to the design of palmar sensory skin pedicles. Quality of sensation in the transposed tissue is evaluated.