Anatomical study of the medial plantar proper digital nerve using ultrasound.

PURPOSE: To determine whether ultrasound allows precise assessment of the course and relations of the medial plantar proper digital nerve (MPPDN). MATERIALS AND METHODS: This work was initially undertaken in six cadaveric specimens and followed by a high-resolution ultrasound study in 17 healthy adult volunteers (34 nerves) by two musculoskeletal radiologists in consensus. Location and course of the MPPDN and its relationship to adjacent anatomical structures were analysed. RESULTS: The MPPDN was consistently identified by ultrasound along its entire course. Mean cross-sectional area of the nerve was 0.8 mm2 (range 0.4-1.4). The MPPDN after it branches from the medial plantar nerve was located a mean of 22 mm (range 19-27) lateral to the medial border of the medial cuneiform. More distally, at the level of the first metatarsophalangeal joint, mean direct distances between the nerve and the first metatarsal head and the medial hallux sesamoid were respectively 3 mm (range 1-8) and 4 mm (range 2-9). CONCLUSION: The MPPDN can be depicted by ultrasonography. Useful bony landmarks for its detection could be defined. Precise mapping of its anatomical course may have important clinical applications. KEY POINTS: • The medial plantar proper digital nerve (MPPDN) rises from the medial plantar nerve to the medial side of the hallux. • Because of its particularly long course and superficial position, the MPPDN may be subject to trauma, resulting in a condition known as Joplin's neuroma. • The MPPDN can be clearly depicted by ultrasound along its entire course. Precise mapping of its anatomical course may have important clinical applications.

Pressure pain thresholds at the diabetic Charcot-foot: an exploratory study.

OBJECTIVE: Painless mechanical trauma is believed to induce neuroosteoarthropathy at the neuropathic foot in diabetes (diabetic Charcot-foot). To investigate pressure nociception at the diabetic foot, we measured the pain perception thresholds for deep pressure (DPPPT, using Algometer II®) and cutaneous pressure (CPPPT, using calibrated monofilaments). METHODS: In 24 diabetic patients with painless neuropathy (11 with a chronic, inactive Charcot-foot and a history of foot ulcer, and 13 control patients who never had an ulcer), and in 20 healthy subjects, CPPPT (at palmar and plantar digital skinfolds) and DPPPT (over musculus abductor pollicis, musculus hallucis longus, and over metacarpophalangeal and metatarsophalangeal joints) was measured. RESULTS: At the hands, DPPPT and CPPPT were similar in patients and healthy subjects. At the feet, CPPPT was above the upper safety limit of measurement (512 mN) in 2/20 healthy subjects, and in 11/11 Charcot patients compared to 6/13 neuropathic controls (p=0.005). At the feet, median DPPPT was similar in all groups. In Charcot patients only, DPPPT was higher over metatarsophalangeal joint than over m. hallucis longus (p=0.048). CONCLUSION: Perception thresholds for cutaneous pressure pain, but not for deep pressure pain, may be extremely elevated at the diabetic neuropathic foot, and particularly at the Charcot-foot.

Surgical approaches to the forefoot for common sports-related pathologies: a review of the literature and cadaveric dissection.

This article reviews the published literature regarding the surgical approaches to pathologies encountered within the forefoot, including arthroscopic and open techniques, and their treatment. We have demonstrated these surgical approaches with cadavers, to identify the key anatomical landmarks and safe zones for these surgical techniques, to prevent the complications associated with their treatment.

The outcome of Morton's neurectomy in the treatment of metatarsalgia.

Morton's neuroma is a common cause of metatarsalgia caused by intermetarsal digital nerve thickening. This study reviews the pathology, presentation, symptoms and signs, and patient satisfaction with surgical treatment. Seventy-eight patients (82 feet) were treated for Morton's metatarsalgia by excision of the interdigital nerve. The patients were followed-up for a mean of 4.6 years (range 0.8-8.1 years) and scored using the Foot Functional Index and the American Orthopedic Foot Ankle Society scoring system. In 74 patients the Foot Functional Index was more than 85 (maximum score 100). Seventy-one patients scored more than 90 on the American Orthopedic Foot Ankle Society scoring system with two patients scoring 100 (maximum score). Postoperatively, 82% reported excellent or good results, 10% had a fair result with restriction of activities or pain and 8% had no improvement at all after surgery while 71% had restrictions with footwear.

Anatomy of the plantarmedial hallucal nerve in relation to the medial approach of the first metatarsophalangeal joint.

BACKGROUND: The medial approach has been widely utilized for various pathologies of the first metatarsophalangeal joint. Injury to the plantarmedial hallucal nerve has been cautioned but never been reported. This study evaluated the proximity of the plantarmedial hallucal nerve to the midline and the vertical capsulotomy through the medial approach. MATERIALS AND METHODS: Nine fresh cadaver legs were dissected under loupe magnification after AP radiographs were obtained. The distances from the plantarmedial hallucal nerve to the midline and to the plantar extent of the vertical capsulotomy were measured. The nerves were documented for their course, branching, and integrity. RESULTS: The average hallux valgus angle was 10.3 +/- 3.8 degrees (Mean +/- SD). The distances from the nerve to the midline and to the plantar extent of the vertical capsulotomy averaged 10.6 +/- 3.2 mm and 2.4 +/- 1.6 mm. One specimen demonstrated a partial nerve transection. All the nerves were found underneath the crural fascia and covered by vertical fibers investing the plantar fat pad at the level of the metatarsophalangeal joint. They gave off an average of seven terminal branches toward the pulp and tip of the hallux. CONCLUSION: The plantarmedial hallucal nerve is at risk for injury with the vertical capsulotomy during a medial approach to the first metatarsophalangeal joint due to its proximity to the plantar extent of the vertical capsulotomy. CLINICAL RELEVANCE: Surgeons should be vigilant in doing the vertical capsulotomy of the first metatarsophalangeal joint especially if the plantarmedial hallucal nerve is not identified.

[Anatomic danger of percutaneous section of the inter-metatarsal ligament for the treatment of Morton's neuroma]. / Dangers anatomiques de la section percutanée du ligament inter-métatarsien dans le traitement du névrome de Morton.

Certain authors have proposed percutaneous neurolysis of Morton's neuroma. We conducted a human anatomy study to assess the reliability and the iatrogenic effect of percutaneous section of the ligament. Percutaneous section of the inter-metatarsal ligament was performed on 16 fresh cadaver specimens via a dorsal approach. The plantar dissection demonstrated that the section was not complete, without associated lesion, in only six cases. Analyzing these failures, we determined the necessary procedure for correct section.

The deep peroneal nerve in the foot and ankle: an anatomic study.

Injury to the deep peroneal nerve in the foot and ankle may result from trauma, repetitive mechanical irritation, or iatrogenic harm. The nerve is most susceptible to injury along its more distal anatomic course. Dissection of 17 cadaver specimens was undertaken to describe the course of the deep peroneal nerve and quantify its branch patterns. In the distal one third of the leg, the nerve was located superficial to the anterior tibial artery between the tibialis anterior and extensor hallucis longus muscles. Typically, the nerve crossed deep to the extensor hallucis longus tendon to enter the interval between the extensor hallucis longus and extensor digitorum longus at an average distance of 12.5 mm proximal to the ankle. A proximal bifurcation was usually present at an average distance of 12.4 mm distal to the mortise. The lateral terminal branch penetrated the deep surface of the extensor digitorum brevis to provide motor innervation. The medial terminal branch passed over the talonavicular joint capsule, and coursed an average of 2.9 mm lateral to the first tarsometatarsal joint. Within the forefoot, it passed deep to the extensor hallucis brevis tendon, bifurcated in the midmetatarsal region, and then arborized, supplying sensibility to the first toe interspace and the adjacent sides of the first and second toes.

[Morton metatarsalgia]. / Die Metatarsalgia Morton.

Four cases of Morton's metatarsalgia are presented. In all cases history and clinical findings were typical. The duration of the disease until the assessment of the final diagnosis with an average of three years was very long. Conservative treatment in all cases was unsuccessful, operative excision of the neuroma resulted in complete relief of pain.

Results of excision of the interdigital nerve in the treatment of Morton's metatarsalgia.

Thirty-one patients (thirty-two feet) had excision of the interdigital nerve as treatment of their Morton's metatarsalgia. A longitudinal dorsal incision was used in all cases. Twenty-five out of 32 cases had a macroscopically visible neuroma, and only two had no evidence of a neuroma on histological examination. All thirty-two patients were available for follow-up at an average of 44.7 months (range 14 to 71 months) postoperatively. Eighty-one per cent of the patients had a good or excellent result, 12.5% had a fair result, with residual pain and some restriction of activities, and 6.5% had no improvement after their operation. It is noteworthy that 19 patients (60%) benefitted from wearing adapted shoes or inner soles for a considerable time after the operation. Even at final follow-up, only 10 patients (30%) had no restrictions in the choice of their shoes.

Long-term follow-up of Morton's neuroma.

The long-term results of neurectomy are evaluated in 70 symptomatic Morton's neuromas in 53 patients with an average postoperative follow-up of 4.8 years, and a maximum of 8.6 years. The presentation, number, and location of neuromas in this series, in some instances, coincides with previous publications. Neurectomy, by means of a dorsal approach, provided 93% patient satisfaction at long-term follow-up.

Quantitation of motion perception in the digits: a psychophysical study in normal human subjects.

Threshold perception of motion of the digits was obtained in 14 normal subjects. The metacarpophalangeal joint of the index and the fifth finger of each hand and the metatarsophalangeal joint of the hallux of each foot were passively moved up and down with respect to a horizontal plane defined by the palmar or plantar surface. The motion was sinusoidal at frequencies of 0.5 and 5.0 Hz. A mpdified von Békésy paradigm similar to that used in audiometry was utilized to yield threshold levels of motion sensation. There was little difference in the thresholds obtained for the different joints. The difference between high- and low-frequency stimulation, however, was significant (p less than 0.001): the 0.5 Hz threshold was found to range from 0.8 to 1.0 degree, whereas the 5.0 Hz threshold varied from 0.4 to 0.6 degree. It is thought that motion sense is largely dependent on joint receptor contributions, but muscle and cutaneous receptors may also contribute to this proprioceptive sensation.

[Weil's metatarsal osteotomy in the treatment of metatarsalgia]. / Die Metatarsalosteotomie nach Weil zur Behandlung der Metatarsalgie.

The Weil distal shortening osteotomy of the lesser metatarsals has been used by the author since June 1992, particularly in the treatment of metatarsalgia. Its advantages are a direct approach to the metatarsophalangeal (MP) joint and the metatarsal head, providing not only correction of the deformity, but accurate control of the metatarsal shortening, primary healing and early functional recovery thanks to the strong fixation allowed by the twist-off screw. Its disadvantage is the limitation of MP articular range motion, which is temporary in most cases. The role of the Weil osteotomy in metatarsalgia is to bring the metatarsal head behind the callus and to provide an axial decompression resolving the hammer toe deformity or MP luxations that are increasing or resulting in metatarsalgia. In cases of metatarsalgia resulting from the first ray insufficiency, the Weil osteotomy is a fair, reliable and efficient procedure; it is also good in cases when the small metatarsal bones are too long. However, shortening the metatarsal bones has to be part of general forefoot therapeutic management. In isolated metatarsalgia, the indication may be slightly difficult, indicating a "slimming" resection. In contrast, both in important metatarsalgia, and generally in severe forefoot disorders, the Weil osteotomy, together with the scarf osteotomy, constitutes a real surgical improvement, opening a new means of articular conservative treatment of severe static disorders.

[Morton's Metatarsalgia--a case report]. / Metatarsalgia Mortona--opis przypadku.

The authors describe the case of a 51 years old woman with interdigital neuroma at a level of II and IV metatarsal heads--Morton's Metatarsalgia.

Morton's neuroma--pathogenesis and ultrastructure.

In an attempt to clarify the pathogenesis of Morton's neuroma, 106 documented cases were analyzed by multiple staining techniques and electron microscopy. The lesion was found to consist of a progressive fibrosis which enveloped and disrupted nerves and arteries. No evidence of a nerve proliferation nor of a specific inflammatory process was encountered. Based on these observations, it is concluded that repeated trauma in the connective tissue elements, including nerves and arteries in the interdigital clefts, lead to a reactive overgrowth of connective tissue (scarring) that disrupts the nerves and the arteries. Sclerosis of the arteries and the narrowing of their lumen contributes to ischemia and further nerve atrophy. The nerves and arteries caught in this reactive scar become more sensitive to pressure and cause characteristic pain.

[Reconstruction of the I carpo-metacarpal joint by transplantation of the II metatarsophalangeal joint on the neuro-vascular pedicle]. / Rekonstruktsiia I zapiastno-piastnogo sustava s ispol'zovaniem peresadki II pliusnefalangovogo sustava na sosudisto-nervnoi nozhke.

In the article are presented the results of treatment of a patient with the consequences of severe damage of hand. As the basic method of treatment there was used free microneurovascular autotransplantation of tissue complexes. The main attention was paid to the problem of reconstruction of the I carpometacarpal joint by transplantation of the II metatarsophalangeal articulation on the neurovascular pedicle. There was achieved a favourable anatomic and functional result. There are indicated the advantages of the given method in case of irreversible destruction of the I carpometacarpal joint.

Histological comparison of the third interdigital nerve in patients with Morton's metatarsalgia and control patients.

This study compares the histology of the plantar-digital nerve supplying the third web space in asymptomatic patients with those who have clinically diagnosed Morton's metatarsalgia. Despite several studies concentrating on the histological changes in the interdigital nerve, the relevance of these changes is a matter of contention while the exact pathological process responsible for the symptoms has not been determined. The histological findings in control patients were identical to Morton's patients with the exception of demyelination, which was more common in the Morton's group. This suggests that the characteristic nodule and fibrotic changes seen in the interdigital nerves of patients with Morton's neuroma cannot account for the symptoms and that the changes seen in the neurovascular bundle are degenerative in origin and are found in asymptomatic patients.