Anatomical Basis and Clinical Application of the First Metatarsal Proximal Perforator-Based Neurocutaneous Vascular Flap.

Forefoot defects caused by accidents are very common, but their reconstruction remains a substantial challenge for plastic surgeons. The purpose of this study is to determine the anatomical structure of the first metatarsal proximal perforator-based flap and to propose its clinical application. The study was divided into two parts: an anatomical study and a clinical application. Thirty preserved lower limbs injected with red latex were chosen for observation, and the following were recorded: the course and distribution of the medialis dorsalis pedis cutaneous nerve; the origin, course, branching and distribution of the first metatarsal proximal perforator; and the communication of the perforator and the dorsal medial vessels. Clinically, six cases of forefoot skin defects were reconstructed with the first metatarsal proximal perforator-based neurocutaneous vascular flap. The medialis dorsalis pedis cutaneous nerve mainly arose from the medial branch of the superficial peroneal nerve and proceeded forward for a distance of 2.5 ± 0.4 cm under the surface of the inferior extensor retinaculum; then, the nerve divided into the medial dorsal branch and the first and second dorsal metatarsal branches. The first metatarsal proximal perforator-based neurocutaneous vessels were multisegmented and multisourced, and the first branch was closely related to the operative procedure. In terms of the clinical application, all flaps of the six cases survived completely with good appearance, texture and elasticity. The first metatarsal proximal perforators present as constant. The first metatarsal proximal perforator-based neurocutaneous vascular flap may become a useful supplemental material for the reconstruction of forefoot defects. Clin. Anat., 33:653-660, 2020. © 2019 Wiley Periodicals, Inc.

Anatomical Basis of the Intermediate Dorsal Pedal Neurocutaneous Perforator Pedicled Propeller Flap: A Cadaveric Dissection.

Soft tissue defects of the forefoot represent a challenging surgical modality to reconstructive microsurgeons. This study describes the anatomical basis and design of the perforator-based intermediate dorsal pedal neurocutaneous vascular flap. Thirty fresh human lower limb specimens were injected with red latex and used for dissection of the dorsal vascular and neural anatomy of the foot. The direction and distribution of the intermediate dorsal cutaneous nerve and the vascular anatomy of the third dorsal artery of the plantar arch, along with the intermediate dorsal neurocutaneous nutrient vessels, were mapped. A simulated flap elevation procedure was performed on one fresh cadaver specimen. A clinical series of five cases is presented to demonstrate the feasibility of using the perforator-based intermediate dorsal pedal neurocutaneous vascular flap to reconstruct soft-tissue defects of the forefoot. The intermediate dorsal cutaneous nerve usually originates from the lateral branch of the superficial peroneal nerve. Crossing the surface of the cruciate ligament, it descends distally to the proximal part of the fourth intermetatarsal space and divides into the third and fourth dorsal metatarsal branches. The intermediate dorsal cutaneous neural nutrient vessels, which are multi-segmental and polyphyletic, offer innervation to the skin paddle of the flap elevated on the basis of the third dorsal perforator of the plantar arch. This perforator occupies a relatively constant position in the proximal part of the intermetatarsal space. It sends multiple tiny branches toward the intermediate dorsal cutaneous neural or paraneural nutrient vessel chain. In terms of clinical application, all flaps survived completely; one patient had partial loss of the skin graft. The design and anatomical basis of the intermediate dorsal pedal neurocutaneous vascular flap based on the third dorsal perforator of the plantar arch is a reliable reconstructive option for reconstructing small soft tissue defects in the forefoot. Clin. Anat. 31:1077-1084, 2018. © 2018 Wiley Periodicals, Inc.

Corticosteroid injection for Morton's neuroma with or without ultrasound guidance: a randomised controlled trial.

AIMS: The objective of this double-blind randomised controlled trial was to assess whether ultrasound guidance improved the efficacy of corticosteroid injections for Morton's neuroma (MN). PATIENTS AND METHODS: In all, 50 feet (40 patients) were recruited for this study but five feet were excluded due to the patients declining further participation. The mean age of the remaining 36 patients (45 feet) was 57.8 years (standard deviation (sd) 12.9) with a female preponderance (33F:12M). All patients were followed-up for 12 months. Treatment was randomised to an ultrasound guided (Group A) or non-ultrasound guided (Group B) injection of 40 mg triamcinolone acetonide and 2 ml 1% lignocaine, following ultrasound confirmation of the diagnosis. RESULTS: The mean visual analogue score for pain improved significantly in both groups (Group A - from 64 mm, sd 25 mm to 29 mm, sd 27; Group B - from 69 mm, sd 23 mm to 37 mm, sd 25) with no statistical difference between them at all time-points. The failure rate within 12 months of treatment was 11/23 (48%) and 12/22 (55%) in Groups A and B, respectively (p = 0.458). The improvement in Manchester Oxford Foot Questionnaire Index and patient satisfaction favoured Group A in the short-term (three months) that almost reached statistical significance (p = 0.059 and 0.066 respectively). However, this difference was not observed beyond three months. CONCLUSION: This study has shown that ultrasound guidance did not demonstrably improve the efficacy of corticosteroid injections in patients with MN. TAKE HOME MESSAGE: In the presence of a clear diagnosis of MN, a trained clinician who understands the forefoot anatomy may perform an injection without ultrasound guidance with good and safe results.

What factors predict the need for further intervention following corticosteroid injection of Morton's neuroma?

BACKGROUND: This study investigated factors that may predict the need for Morton's neuroma (MN) to undergo further treatment within 2 years of a single ultrasound-guided corticosteroid injection. METHODS: A retrospective study was undertaken over a three-year period. The data was stratified into two groups: Group A - did not receive further intervention and Group B - received further treatment. We investigated age, gender, neuroma size and presence of other forefoot pathology or ipsilateral neuromas. RESULTS: 54 patients (57 feet) were reviewed. 29 feet (51%) required further treatment within 2 years (11 repeat injections, 18 surgical excisions). Binary logistic regression showed that larger neuromas (p=0.011) and younger patients (p=0.007) predicted the need for further intervention but not gender (p=0.272). The distribution of concomitant forefoot pathology and ipsilateral neuromas were similar between the two groups. CONCLUSION: Size and age appear to be predictors for further treatment of MN within 2 years of corticosteroid injection.

An Algorithm for Forefoot Reconstruction With the Innervated Free Medial Plantar Flap.

BACKGROUND: Because of shearing forces, the forefoot is more prone to trophic ulcers than the heel. Reconstruction of trophic ulcers and other forefoot defects is a vexing challenge. We favor the innervated free medial plantar flap to replace like-with-like and confer protective sensation. We investigate the feasibility of this flap with the largest series to date and the first to describe ipsilateral flap transfer. METHODS: Between 2009 and 2013, 7 patients with forefoot defects were treated with innervated free medial plantar flaps. The average age of 4 men and 3 women was 35.1 years (range, 8-50 years). Indications were secondary reconstruction after trauma and coverage of oncologic defects. The mean defect was 5 × 7 cm (range, 4-6 cm × 6-10 cm). Four patients were treated with contralateral flaps and 3 with ipsilateral flaps using interposition vein graft. RESULTS: The mean flap size was 8.1 ± 1.6 cm × 5.9 ± 1.2 cm. There was no perioperative complication, venous congestion, or arterial insufficiency. Patients were followed clinically for 38.5 months (range, 6 months to 10 years). One patient died from complications of metastatic disease 7 months after plantar flap reconstruction. Two patients underwent sensory testing and gait analysis. The appearance was satisfactory, ambulation returned to normal, and there was protective sensation in every case. In 2 cases, hyperkeratotic tissue was excised in revision procedures. CONCLUSIONS: The innervated free medial plantar flap is an attractive and feasible option for coverage of medium-to-large defects of the plantar forefoot in the hands of a skilled microsurgeon. It has a place in our algorithmic approach to forefoot reconstruction.

Simple Neurectomy Versus Neurectomy With Intramuscular Implantation for Interdigital Neuroma: A Comparative Study.

BACKGROUND: Simple neurectomy is a standard treatment of interdigital nerve neuroma after failure of conservative treatment. Recently, neurectomy with intramuscular implantation of the proximal nerve stump has been proposed as a safe and effective alternative method providing significant pain improvement. However, there remains little evidence supporting one technique over the other. The purpose of this study was to compare functional outcomes and complications of simple neurectomy versus neurectomy with intramuscular implantation. METHODS: Retrospective chart review along with prospectively collected data of 99 consecutive patients (105 feet with 118 neuromas) who were diagnosed with interdigital neuroma of the foot and underwent simple neurectomy (66 patients / 72 feet / 78 neuromas) and neurectomy with intramuscular implantation of proximal nerve stump into intrinsic muscle of foot (33 patients / 33 feet / 40 neuromas) between 2000 and 2013. The minimum follow-up to be included in the study was 6 months for both techniques (mean = 44.6 months, range = 6 to 150 months for simple neurectomy; and mean = 19.3 months, range = 6 to 66 months for neurectomy with intramuscular implantation of proximal nerve stump into the intrinsic muscle). The primary outcomes were Foot Function Index (FFI); pain, disability, activity limitation, and total score, Short Form-36 (SF-36: physical and mental component scores); and visual analog scale (VAS). Secondary outcomes included operative time and complications. Pre- and postoperative SF-36, and FFI, and pain (VAS) scores were obtained and compared using a paired t test. An independent t test was used to assess the functional outcomes and operative time between the 2 groups, and a chi-square test was used to compare the complications between the 2 techniques. RESULTS: Both groups demonstrated significant improvement of postoperative functional outcomes (FFI, SF-36, and VAS; P < .001, all) compared to the preoperative period. Neurectomy with intramuscular implantation demonstrated significant improvement of pain compared to simple neurectomy as measured with VAS (P = .002); however, the operative time was significantly longer than the simple neurectomy technique (P = .001). The rest of the functional outcomes measured were comparable between the 2 techniques. Complications in both simple neurectomy and implantation techniques were persistent pain (11.5% vs. 2.5%, P = .07), revision rate (5.1% vs. 0.0%, P = .08), and painful scar (5.1% vs. 5.0%, P = .83), respectively, but it did not reach statistical significance (P > .05, all). CONCLUSION: Both simple neurectomy and neurectomy with intramuscular implantation demonstrated significant improvement in terms of functional outcomes as measured with the FFI, SF-36, and VAS in patients with interdigital neuroma. Although requiring a longer operative time, neurectomy with intramuscular implantation technique might offer superior pain relief with comparable complications to the simple neurectomy technique.

A systematic review of ultrasound-guided and non-ultrasound-guided therapeutic injections to treat Morton's neuroma.

BACKGROUND: Morton's neuroma is a frequently painful condition of the forefoot, causing patients to seek medical care to alleviate symptoms. A plethora of therapeutic options is available, some of which include injection therapies. Researchers have investigated injection therapy for Morton's neuroma, and latterly the evidence base has been augmented with methods that use diagnostic ultrasound as a vehicle to deliver the injectate under image guidance for additional accuracy. To date, there seems to be no consensus that ultrasound-guided injections provide better therapeutic outcomes than nonguided injections for the treatment of Morton's neuroma. METHODS: A systematic review was chosen because this method can undertake such a process. The review process identified 13 key papers using predetermined inclusion and exclusion criteria, which then underwent methodological quality assessment using a pretested Quality Index. A narrative synthesis of the review findings is presented in light of the heterogeneity of the data from the extraction process. RESULTS: This systematic review provides an argument that ultrasound guidance can produce better short- and long-term pain relief for corticosteroid injections, can reduce the need for additional procedures in a series of sclerosing alcohol injections, can reduce the surgical referral rate, and can add efficacy to a single injection. CONCLUSIONS: Ultrasound guidance should be considered for injection therapy in the management of Morton's neuroma.

Free sensate medial plantar flap for contralateral plantar forefoot reconstruction with flap reinnervation using end-to-side neurorrhaphy: a case report and literature review.

Reconstruction of weight-bearing plantar defects remains a challenge due to the unique characteristics of the plantar skin and thus the limited available options. The medial plantar flap, either pedicled or free, represents an ideal option, but its use as sensate flap for forefoot defects has been scarcely reported. We present a case of plantar forefoot reconstruction with a free sensate medial plantar flap, with end-to-side coaptation of the cutaneous sensory fascicles of the flap to the medial plantar nerve of the recipient. Last follow-up, at 2 years post-op, verified a very good functional and aesthetic outcome, indicating that the suggested approach may prove the treatment of choice in selected cases of plantar forefoot reconstruction.

Cooling reduces the cutaneous afferent firing response to vibratory stimuli in glabrous skin of the human foot sole.

Skin on the foot sole plays an important role in postural control. Cooling the skin of the foot is often used to induce anesthesia to determine the role of skin in motor and balance control. The effect of cooling on the four classes of mechanoreceptor in the skin is largely unknown, and thus the aim of the present study was to characterize the effects of cooling on individual skin receptors in the foot sole. Such insight will better isolate individual receptor contributions to balance control. Using microneurography, we recorded 39 single nerve afferents innervating mechanoreceptors in the skin of the foot sole in humans. Afferents were identified as fast-adapting (FA) or slowly adapting (SA) type I or II (FA I n = 16, FA II n = 7, SA I n = 6, SA II n = 11). Receptor response to vibration was compared before and after cooling of the receptive field (2-20 min). Overall, firing response was abolished in 30% of all receptors, and this was equally distributed across receptor type (P = 0.69). Longer cooling times were more likely to reduce firing response below 50% of baseline; however, some afferent responses were abolished with shorter cooling times (2-5 min). Skin temperature was not a reliable indicator of the level of receptor activation and often became uncoupled from receptor response levels, suggesting caution in the use of this parameter as an indicator of anesthesia. When cooled, receptors preferentially coded lower frequencies in response to vibration. In response to a sustained indentation, SA receptors responded more like FA receptors, primarily coding "on-off" events.

Ultrasound guided alcohol ablation of Morton's neuroma.

BACKGROUND: Morton's neuroma is a common cause of metatarsalgia. This study evaluated the efficacy of ultrasound guided alcohol injection as a treatment for this condition. METHOD: Data from 87 treatment courses were included in this study with a mean follow of 14.3 months. RESULTS: Technical success was 100%. One patient developed symptoms consistent with an allergic reaction to the injection and one patient declined further injection because of periprocedural pain. Partial or total treatment response was achieved in 66%, with 32% of patients having complete resolution of pain. The median visual analogue score (VAS) decreased from 8 pre-procedure to 4 post-procedure (p < 0.0001). Procedural success was greater in patients under 55 years old and in those with solitary neuromas. Seventeen patients (20%) went on to have surgery due to continuing pain. CONCLUSION: Ultrasound guided alcohol ablation for the treatment of Morton's neuroma was a safe procedure that significantly reduced pain and may offer an alternative therapy to surgery.

Patient's assessment of discomfort during ultrasound-guided injection of Morton's neuroma: selecting the optimal approach.

PURPOSE: Assess patient discomfort during two different methods of injection of Morton's neuroma. METHODS: Sixty-eight patients referred for ultrasound-guided injection of Morton's neuroma had punctures performed dorsal or plantar to the interdigital skin crease, with and without preliminary subcutaneous local anesthesia (LA). Patients rated discomfort during skin puncture (SP) and needle advancement (NA) using a visual analog scale. RESULTS: Average pain score was 4.4 ± 2.3 (1 SD) for the plantar approach and 2.9 ± 2.0 for the dorsal approach. This difference was statistically significant during SP (p < 0.01) and NA (p < 0.05). During the plantar approach with LA, mean pain score during SP was 4.4 (± 2.1) and 3.9 (± 2.8) during NA. This plantar approach without LA resulted in a pain score of 4.3 (± 2.6) and 3.8 (± 3.1), respectively. Mean pain scores for patients injected from the dorsal approach with LA during SP were 3.8 (± 2.7) and NA were 2.2 (± 2.0) and without LA were 2.6 (± 1.9) and 3.0 (± 2.1). There was no statistical significance in mean pain score difference during SP and NA, with and without LA for either the plantar (p > 0.05) or the dorsal (p > 0.05) approach. CONCLUSIONS: Injection of Morton's neuroma was better tolerated via a dorsal approach and use of preliminary LA did not confer any benefit.

Long-term results of neurectomy in the treatment of Morton's neuroma: more than 10 years' follow-up.

PURPOSE: The objective of this retrospective study was to evaluate the long-term follow-up results of neurectomy clinical outcomes and complications in the treatment of Morton's neuroma. MATERIALS AND METHODS: A total of 19 patients (19 different feet) were treated for Morton's neuroma by excision of the interdigital nerve at our institute between May 1997 and May 1999. Thirteen (13 feet) of them were followed up. The 13 patients were female and had an average age of 43 years (range 34-54 years) at the time of the operation. The patients were followed-up for a mean of 10.5 years (range 10.0-12.2 years) and scored using the American Orthopaedic Foot & Ankle Society (AOFAS) forefoot scoring system and Visual Analogue Scale (VAS) score. Subjective satisfaction was evaluated at the final follow-up. RESULTS: Eight patients scored more than 90 on the AOFAS forefoot scoring system. The VAS score was improved in all patients. The mean preoperative VAS score was 8.6 ± 0.8 cm (7-10) and the mean follow-up VAS score was 2.4 ± 1.8cm (0-6), which indicated no significant difference (P > .05). The final follow-up satisfaction results indicated that 4 patients were completely satisfied with the operation, 4 were satisfied with minor reservations, 5 were satisfied with major reservations, and no patient was unsatisfied. Neurectomy to treat Morton's neuroma had a good satisfaction rate (61%). Eleven of the patients complained of numbness on the plantar aspect of the foot adjacent to the interspace, and 2 of these 11 patients complained of disability induced by severe numbness. There was a complaint of residual pain by 1 patient. There were no skin problems on the operation lesions. CONCLUSION: The long-term results of neurectomy clinical outcomes in Morton's neuroma are slightly worse than the short- and mid-term results. LEVELS OF EVIDENCE: Therapeutic, Level IV, Retrospective case series.

Morton's neuroma.

Morton neuroma is a common source of forefoot pain. This condition is more correctly termed as interdigital nerve compression and is not a true neuroma. Although Morton neuroma is a common diagnosis, debate exists as to the best surgical and nonsurgical treatments. This article discusses the pathogenesis, diagnosis, nonsurgical and surgical management, and surgical complications of this common disorder.

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.

Effectiveness of ultrasound-guided corticosteroid injection in the treatment of Morton's neuroma.

BACKGROUND: The purpose of this study was to evaluate the efficacy of corticosteroid injection and determine the duration of symptom-free period after treatment with a single ultrasound-guided injection for a painful Morton's neuroma. MATERIALS AND METHODS: From May 2002 to November 2003, 35 consecutive patients (7 males, 28 females) (mean age, 54; age range, 29 to 77 years) underwent a single ultrasound guided corticosteroid injection. Thirty-nine injections were performed as 4 patients had bilateral Morton's neuromas. The injection of 1.0 cc Celestone Chronodose (5.7 mg/ml) with 0.5 cc of 1% lidocaine was performed into the symptomatic intermetatarsal web-space. The efficacy of the injection was determined by the Johnson grading scale, and modified lower extremity functional scale. RESULTS: On the Johnson scale, 15 of 39 (38%) neuromas showed complete satisfaction 9 months after treatment and 11 of 39 (28%) were satisfied with minor reservations. A total of 26 of 39 (66%) neuromas had a positive outcome 9 months after the injection. On the functional daily activity (FDA) scale, 20 of 39 (51%) neuromas showed no difficulty and 4 of 39 (10%) indicated minor difficulties, which was considered a positive outcome 9 months after injection. Complete pain relief was achieved in 11 of 39 (28%) neuromas 9 months after treatment. Twelve of 39 (31%) neuromas did not respond to conservative treatment and required surgery. The results of treatment suggested improvement in efficacy if injection was used early. The size of the lesion measured on ultrasound showed no correlation with pain relief after injection. CONCLUSION: A single corticosteroid injection can offer short-term pain relief in the conservative management of Morton's neuroma.

Innervation of three weight-bearing areas of the foot: an anatomic study and clinical implications.

The aim of this cadaver study is to improve our knowledge on the anatomy of the sensory fibres of the three weight-bearing areas of the plantar region. Previous studies mainly focused on the innervation of the heel but the innervation of the other two weight-bearing areas over the most medial and lateral metatarses have been neglected and are not well known. The study was carried out on 10 feet of five male cadavers. The tibial nerve was dissected down to the fat pads over the heel and the first and fifth metatarsal heads under the microscope. The distances of the branching point of the tibial nerve and origins of the medial and inferior calcaneal nerves to a line drawn from the centre of the medial malleolus to the centre of the calcaneous were all measured. The tibial nerve was divided into two branches called the lateral and medial plantar nerves 23.45 mm proximal to the predefined axis. The medial plantar nerve passed underneath the abductor hallucis muscle and gave two sensory branches to the fat pad over the first metatarsal head. The lateral plantar nerve coursed beneath the abductor hallucis and flexor digitorum brevis muscles and supplied innervation of the fat pad over the fifth metatarsal head. The sensory innervation of the heel was provided by medial calcaneal and inferior calcaneal nerves. The medial calcaneal nerve originated from the tibial nerve 41.89 mm proximal to the axis. It divided into two or three branches innervating the fat pad over the heel. The inferior calcaneal nerve originated from the lateral plantar nerve (70%) or the medial calcaneal nerve (30%) 10.66 mm proximal to the axis. This study describes the sensory fibres to the heel and the previously neglected weight-bearing areas over the first and fifth metatarses. Reconstruction of defects in these areas is very difficult so every attempt should be made to protect the sensory fibres during any surgical procedure.

Painful os intermetatarseum in athletes: report of four cases and review of the literature.

INTRODUCTION: A painful os intermetatarseum, which described the compression of the deep peroneal nerve by an os intermetatarseum, is a very rare condition. The authors reported four cases of painful os intermetatarseum in athletes and reviewed the present literature. CASE PRESENTATION: We present four cases of a painful os intermetatarseum in athletes, who complained of pain over the dorsum of their foot associated with paresthesias in the first web space. Surgical excision of the os intermetatarseum relieved the pain in all patients. All patients returned to previous sporting activities. CONCLUSION: We should consider a painful os intermetatarseum as being the cause of dorsal foot pain in athletes, and surgical excision of the os intermetatarseum is effective for these patients.

Intramuscular nerve distribution pattern of the oblique and transverse heads of the adductor hallucis muscles in the human foot.

To understand which layer of the intrinsic muscles of the foot the adductor hallucis muscle belongs to, it is essential to investigate the innervation patterns of this muscle. In the present study, we examined the innervation patterns of the adductor hallucis muscles in 17 feet of 15 Japanese cadavers. We investigated the intramuscular nerve supplies of the adductor hallucis muscles in six feet and performed nerve fiber analysis in three feet. The results indicate that: (i) the oblique head of the adductor hallucis muscle is divided into three compartments (i.e. lateral, dorsal and medial parts) or two compartments (i.e. dorsal and medial parts) based on its intramuscular nerve supplies, but we could not classify the transverse head into any parts; (ii) the communicating twig between the lateral and medial plantar nerves penetrated the oblique head of the adductor hallucis muscle in 13 of 17 feet (76.5%); (iii) the penetrating twig entered between the lateral and dorsal parts of the oblique head, passed between the lateral and medial parts of this muscle and then connected with the medial plantar nerve; and (iv) the majority of the nerve fibers of the penetrating twig derived from the lateral plantar nerve. The present study demonstrated that only the lateral part of the oblique head of the adductor hallucis muscle had a unique innervating pattern different from other parts of this muscle, suggesting that the lateral part of the oblique head has a different origin from other parts of this muscle.