Imaging Considerations in Differentiating Plantar Plate Pathology and Webspace Neuroma.

Myriad pathologies affect the lesser toes. In this article, the focus is on the challenging radiological differential diagnosis of plantar plate (PP) degeneration and tear versus webspace neuroma. It is now understood that PP tear and even degeneration without tear is most accompanied by reactive pericapsular soft tissue thickening (pseudoneuroma), which contributes to neuritic symptoms that are often indistinguishable from webspace neuroma. In this article, the authors will review the differing clinical presentations and radiographic, sonographic, and MRI findings of these entities and the different acquired toe deformities that occur in PP dysfunction with pseudoneuroma, versus webspace neuroma.

Morphologic Changes in Postaxial Polydactyly of the Foot: A Standardized Quantitative Analysis Using the Watanabe-Fujita Classification.

BACKGROUND: Postaxial polydactyly of the foot is one of the most common congenital abnormalities. A wide forefoot, short toe, and lateral joint deviation are associated with aesthetic and functional outcomes. This study used the Watanabe-Fujita classification to characterize the preoperative and postoperative skeletal morphology of postaxial polydactyly of the foot. METHODS: This retrospective study included 42 patients (51 feet) with postaxial polydactyly treated at age 1 year. Radiographs taken at ages 0 and 3 to 4 years were used for morphologic analysis. The length of the reconstructed toe, the distance between the fourth and fifth metatarsals, and joint deviation angles were measured. The length measures were standardized using the length of the third metatarsal. Morphologic characteristics were compared based on the Watanabe-Fujita classification at ages 0 and 3 to 4 years. Long-term outcomes were also evaluated in patients followed up for longer than 6 years. RESULTS: The fifth-ray proximal phalangeal subtype had the shortest toe length both at ages 0 and 3 to 4 years. Proximal phalangeal joint lateral deviation improved postoperatively in 78% of patients with the fifth-ray middle phalangeal subtype, regardless of reconstruction type. There was no significant change in proximal phalangeal joint deviation between ages 3 to 4 years and 7 years or older. A residual metatarsal was associated with lateral metatarsophalangeal joint deviation and a wide intermetatarsal distance, and required revision surgery. CONCLUSIONS: Morphologic changes of postaxial polydactyly of the foot were successfully characterized using the Watanabe-Fujita classification. This classification could be useful for planning surgical strategies and anticipating morphologic outcomes. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Comparison of hamate versus second or third toe osteochondral graft using magnetic resonance imaging for reconstruction of proximal interphalangeal fracture-dislocations.

Hemi-hamate arthroplasty is a method used to reconstruct complex fracture-dislocations of the proximal interphalangeal joint of the fingers. Other graft sites, including the toe second and third phalanges, have been proposed as alternatives to hemi-hamate arthroplasty due to variable clinical outcomes and anatomy. Through a prospective magnetic resonance imaging (MRI)-based study in asymptomatic individuals, we aimed to characterize the anatomy of the proximal interphalangeal joint and compare this with the hamate, second and third toes to determine the closest anatomical match using pre-determined measurements. Our results show that the second and third toes have greater anatomical similarity to the proximal interphalangeal joint of the fingers compared to the hamate. High-resolution MRI is a reliable method of characterizing the anatomy of these structures and could be a useful clinical tool in determining reconstructive options in the management of this challenging injury.Level of evidence: II.

From second webspace syndrome to second cross over toe: Clinical and radiological findings following Weil osteotomy with no soft tissue procedure.

BACKGROUND: The second webspace syndrome (SWS) refers to the progressive divergence between 2nd and 3rd toes associated with pain at the second intermetatarsal space that can be confused with Morton's neuroma and treated as such without considering the underlying deformity. There is yet no consensus regarding the best treatment, from isolated soft tissue or bony procedures or a combination of both. The objective of this study was to describe the clinical characteristics of the disease, as well as to evaluate the radiological outcomes of patients with SWS treated with open Weil's osteotomy or distal metatarsal minimal invasive osteotomy (DMMO) of the second metatarsal, with main emphasis on medialization of the head in the anteroposterior plane in either procedure. METHODS: A retrospective study of all patients with SWS treated with Weil's medializing osteotomy (open and percutaneous) associated or not with other forefoot procedures, treated between 2012 and 2019, was performed. Radiological variables such as metatarsal-phalangeal angle (MTPA), percentage of metatarsal uncoverage of M2 with respect to its phalanx, intermetatarsal angle (M1, M2 and M3), length of second metatarsal and intermetatarsal distance M2 - M3 were measured and compared before and after surgery. RESULTS: Twenty-six patients were included, with a mean follow-up of 26 months. All patients presented divergence between the 2nd and 3rd toes, 75 % associated pain at the level of the second intermetatarsal space and two patients presented neuropathic symptoms. After surgery (nineteen open and seven DMMO), all patients rated their results as good or excellent, and the two patients with neuropathic symptoms had improvement in their symptoms. Regarding the radiological results, the percentage of subluxation of the second MTP decreased in a large percentage of the operated patients (from 43.3 % to 3.9 %) with statistical significance as well as the length of M2, IM angle between M1 - M2, IM distance between M2-M3 and the percentage of uncoverage of the second MTP (p < 0.001). CONCLUSION: Medial translation associated with open Weil osteotomy or DMMO seems to correct the muscle-ligament imbalance of the second metatarsophalangeal joint and restore normal radiographic measurements, especially in the coronal and sagittal plane, without the need for soft tissue procedures, as well as the resolution of associated neuropathic symptoms in some patients. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Comparative Radiographic Analysis of the Width of the Lesser Digit Proximal Phalangeal Heads.

BACKGROUND: Digital deformities represent a common presenting abnormality and target for surgical intervention in podiatric medicine and surgery. The objective of this investigation was to compare the radiographic width of the heads of the lesser digit proximal phalanges. METHODS: One hundred fifty consecutive feet with a diagnosis of digital deformity and performance of weightbearing radiographs were analyzed. The maximum width of the heads of the lesser digit proximal phalanges were recorded from the radiographs using computerized digital software. RESULTS: The mean ± standard deviation of the head of the second digit proximal phalanx was 9.74 ± 0.87 mm (range, 7.94-11.78 mm); the head of the third digit proximal phalanx, 9.00 ± 0.91 mm (range,7.27-10.94 mm); the head of the fourth digit proximal phalanx, 8.49 ± 1.01 mm (range, 5.57-10.73 mm); and the head of the fifth digit proximal phalanx, 8.67 ± 0.89 mm (range, 6.50-11.75 mm). The width of the head of the proximal phalanx decreased from the second digit to the third digit (P < .001), decreased from the third digit to the fourth digit (P < .001), and then increased from the fourth digit to the fifth digit (P = .032). CONCLUSIONS: The results of this investigation provide evidence in support of an anatomical and structural contribution to digital deformities. The width of the heads of the lesser digit proximal phalanges decreased from the second to the third to the fourth toes, and then subsequently increased with the fifth proximal phalangeal head.

Quantitative Evaluation and Midterm Progress of Reconstructed Toe Thickness in Lateral Ray Polydactyly of the Foot.

In lateral ray polydactyly, the reconstructed toe often tends to become thicker, but no standard evaluation criteria for this thickness are available. 57 patients (68 toes) with Hirai-Togashi classification type II, III, or IV whom we were able to follow-up for more than 6 months after the operation were underwent measurement of the "Reconstructed toe width to Third toe width ratio." In addition, 16 patients who could be followed up for 3 years through the mid-term course were evaluated for mid-term progress. At 6 months after surgery, the mean R/T ratio was 1.246. In patients who could be followed up for 3 years after surgery, the mean R/T ratios at 6 months after surgery and at 3 years were significantly decreased. This result suggests that the thickness of the reconstructed toe may become relatively thin in the long term.

Examination of Postoperative Outcomes Using Morphological and X-Ray Classifications and Selection of the Toe to Be Excised in Postaxial Polydactyly of the Foot.

The treatment of postaxial polydactyly requires excision of the medial fifth or lateral sixth toe, and separation of the adjacent fourth/fifth toes if the adjacent toes exhibit skin syndactyly. Morphological changes in the retained toes and reoperation are common problems after such surgery. This study examined the effects of preoperative classifications and selecting the medial fifth or lateral sixth toe for excision on the postoperative outcomes of surgery for postaxial polydactyly. From April 2006 to March 2019, surgery for postaxial polydactyly was performed on 55 feet in 49 patients. The patients' mean age at surgery was 28.8 months. Postoperative esthetic and bone alignment scores, the reoperation rate, and postoperative dysfunction were examined. The postoperative esthetic and bone alignment evaluations were performed by examining postoperative photograph and X-ray images using original scoring systems. The surgical procedure was chosen by the surgeon-in-charge during a preoperative conference after considering the toe growth and bone alignment. In the postoperative esthetic evaluation, excising the lateral sixth toe produced significantly better outcomes than excising the medial fifth toe. The morphological classification also indicated that excising the lateral sixth toe produced better outcomes, as it resulted in the bifurcated toes being clearly independent. Interestingly, the postoperative X-ray-based bone alignment score was not correlated with the esthetic score. The reoperation rate tended to be high after medial fifth toe excision. There were no postoperative functional complications. Lateral sixth toe excision for postaxial polydactyly of the foot produces good postoperative esthetic outcomes.

Using 320-detector row computed tomography angiography to investigate the arterial anatomy of the toe flaps on living humans.

PURPOSE: Using 320-detector row computed tomography angiography (320-CTA) to investigate the arterial supply for the toe flaps, namely the anatomical characteristics of the dorsalis pedis artery (DPA), the first dorsal metatarsal artery (FDMA), and the arteries of the first toe web space (AsFTWS). METHODS: This was a prospective study on CTA of 72 intact feet of 36 Vietnamese adults who had sequelae of thumb or metacarpal hand amputation, from June 2017 to December 2019, then preoperative CTA images were compared with surgical findings on 31 feet of 29 patients. RESULTS: 320-CTA was able to investigate the DPA, FDMA, and AsFTWS in 100% of cases. DPA was absent in 6.9% of cases. The average diameters at its origin and termination were 3.22 and 2.56 mm, respectively. For FDMA, the rates of Gilbert type I, II, and III were 52.8%, 18.1%, and 29.2%; the average diameters at its origin and termination were 1.98 and 1.67 mm, respectively. At the first toe web space, FDMA was dominant in 54.2% of cases; the first plantar metatarsal artery (FPMA) was dominant in 29.2% of cases; both arteries were equally dominant in 16.6%. The average diameter at the origin of the lateral plantar digital artery of the great toe was 1.48 mm, of the medial plantar digital artery of the second toe was 1.21 mm. Preoperative CTA images resembled the surgical findings in all cases. The survival rate of toe flaps was 100%. CONCLUSION: The 320-CTA provided proper preoperative images in two and three dimensions, and helped surgeons to establish a preoperative surgical plan, thus increasing the success rate of toe transfer surgery.

Surgical Procedures Based on the Arthrographic Findings of the Fifth MTP Joint With Proximal Phalanx Duplication in Postaxial Polydactyly of the Foot.

Radiographic findings in several atypical cases of postaxial polydactyly of the foot do not provide sufficient information to assess the cartilaginous structures or duplicated digit connections at the MTP joint. The purpose of this study was to demonstrate the surgical procedures using arthrography for the cartilaginous structures of the MTP joint in postaxial polydactyly of the foot. We performed arthrography in 7 feet of 7 patients with postaxial polydactyly of the foot in which duplication of the proximal phalanx was observed at the fifth MTP joint on the basis of radiographic evaluation. The average age at surgery was 13.5 months and average duration of postsurgical follow-up was 36 months. Individual surgical procedures were confirmed or modified during the operation by reference to the arthrographic findings. Radiographic and arthrographic findings were assessed in relation to the findings from direct observation of the cartilaginous structures at surgery. Postoperative malalignment, functional disturbance and pain in the reconstructed toe were evaluated. The arthrographic findings provided different forms of cartilaginous structures that could be categorized in 4 types, and reflected the cartilaginous connection visualized at surgery that could not be detected on radiographs in each case. No cases revealed any deformities, functional disturbance, or pain in the reconstructed toe after surgery. The parents' evaluation in each case was "very satisfied" or "satisfied." The arthrographic findings provided additional information regarding variations in the cartilaginous structures of the fifth MTP joint and for determining individual surgical procedure for postaxial polydactyly of the foot.

BCOR-CCNB3 Sarcoma with Prominent Rhabdoid Cells Mimicking Rhabdomyoblasts: Expanding the Morphologic spectrum of BCOR-CCNB3 Sarcoma.

BCOR-CCNB3 sarcoma (BCS) is a rare recently defined undifferentiated sarcoma that predominantly affects children and young adults. The diagnosis of this tumor is difficult due to the highly variable morphology and nonspecific immunophenotype. Emerging data suggest that patients with BCS show response to Ewing sarcoma-based treatment regimen, thus correct diagnosis is of clinical relevance. In this study, we report a case of BCS arising from the big toe of a 15-year-old male patient. The tumor had a prominent population of rhabdoid cells with bright eosinophilic cytoplasm mimicking rhabdomyosarcoma. The tumor cells were focally positive for desmin and myogenin, and negative for CD99. Next-generation sequencing showed the presence of BCOR-CCNB3 gene fusion. BCS with prominent rhabdoid cells has not been described before. This study further expands the morphologic spectrum of BCS.

Impact of intertendinous connections between the flexor digitorum brevis and longus on percutaneous tenotomy for the treatment of claw toes: an anatomic and ultrasound study.

PURPOSE: Selective percutaneous tenotomy of the flexor digitorum longus (FDL) is a treatment for claw toes that gives astonishingly good functional results despite tendon sacrifice. However, the involution of the FDL tendon stump after tenotomy is unknown. The aim of our study was to assess the involution of the tendon stump after selective percutaneous tenotomy of the FDL. METHODS: The study included two parts. In the clinical part, an ultrasound analysis of 15 FDL tenotomies in 7 patients was carried out 3 months post-surgery. In the anatomic part, the feet of 10 bodies donated to science were dissected and examined anatomically. RESULTS: The proximal stump of the FDL was located near the base of the proximal phalanx and moved synchronously with the flexor digitorum brevis (FDB).Separating the FDB and FDL revealed a large tissue connection between the plantar surface of the tendinous chiasm of the FDB and the dorsal part of the FDL. These connections had significant resistance ranging from 2 to 9 Newtons depending on the toe. Tenotomy of the FDL followed by proximal traction of it led to retraction of the stump up to the base of the proximal phalanx and transfer of its action to the FDB by tensioning the intertendinous structure. Histologically, these structures were mostly comprised of tendon connective tissue. Their vascular component was small. CONCLUSION: The presence of this intertendinous connection leads, in the case of isolated tenotomy of the FDL, to equivalent transfer of the latter to the FDB.

Closed Internal Degloving of the Toes: A Case Report.

Closed degloving injuries are uncommon, high-energy injuries that separate the bony structures from the soft tissue and frequently result in amputation. Because the epidermis is often intact, it is difficult to visualize the extent of the soft tissue damage. Although there is no gold standard of treatment for closed degloving injuries at present, previous cases have reported that neurovascular presentation is a key predictor of amputation Herein, we report a closed degloving injury involving the second through fifth phalanges of the left foot following a crushing injury with a forklift. Despite adequate capillary refill upon initial presentation, the patient ultimately underwent transmetatarsal amputation.

Minimally invasive correction for symptomatic, fixed curly toe deformity.

BACKGROUND: Curly toe deformity is a relatively common deformity that generally occurs at the 4th and 5th proximal and/or middle phalanges but rarely presents with symptoms. Although numerous open operative techniques have been introduced, there is no established treatment yet. We report the results of minimally invasive correction for symptomatic, fixed curly toe deformity. METHODS: Between 2016 and 2018, 25 consecutive percutaneous dorsolateral closing wedge-shaped osteotomies with Shannon burrs at the proximal and/or middle phalanx were performed. We assessed the postoperative clinical and radiological changes at a mean of 22.51 months of follow-up. RESULTS: The locations of osteotomy were at the middle phalanx in 10 cases, proximal phalanx in 13 cases, and both in one case. The mean amount of corrections of varus inclination and shortening were 16.54° and 2.24 mm, respectively. The Foot and Ankle Ability Measure Activities of Daily Living scores significantly improved from 59.09 preoperatively to 74.55 at the last follow-up. There was one case of pin site infection and one case of incision site numbness due to digital nerve injury. CONCLUSIONS: Minimally invasive dorsolateral closing wedge-shape osteotomy is a simple, safe, and effective correction for symptomatic, fixed curly toe deformity.

Missed Fracture Dislocation of the Fifth Toe in a Two-Year-Old Child: A Case Report.

Fracture dislocation injuries of the toes are rare among pediatric population. These injuries when acute are mostly treated conservatively and a good reduction must be ensured. We present the case of a 2-year-old girl who presented with missed chronic fracture dislocation of the proximal interphalangeal joint of the fifth toe, which was managed by open reduction and internal fixation and had a good outcome at over 1 year of follow up. We believe that this is the first case of this injury to be published in the peer-reviewed literature.

Common atrium/atrioventricular canal defect and postaxial polydactyly: A mild clinical subtype of Ellis-van Creveld syndrome caused by hypomorphic mutations in the EVC gene.

Clinical expression of Ellis-van Creveld syndrome (EvC) is variable and mild phenotypes have been described, including patients with mostly cardiac and limb involvement. Whether these cases are part of the EvC phenotypic spectrum or separate conditions is disputed. Herein, we describe a family with vertical transmission of atrioventricular canal defect (AVCD), common atrium, and postaxial polydactyly. Targeted sequencing of EVC, EVC2, WDR35, DYNC2LI1, and DYNC2H1 identified different compound heterozygosity in EVC genotypes in the two affected members, consisting of a nonsense (p.Arg622Ter) and a missense (p.Arg663Pro) variant in the father, and the same nonsense variant and a noncanonical splice-site in-frame change (c.1316-7A>G) in the daughter. Complementary DNA sequencing, immunoblot, and immunofluorescence experiments using patient-derived fibroblasts and Evc-/- mouse embryonic fibroblasts showed that p.Arg622Ter is a loss-of-function mutation, whereas p.Arg663Pro and the splice-site change c.1316-7A>G are hypomorphic variants resulting in proteins that retain, in part, the ability to complex with EVC2. Our molecular and functional data demonstrate that at least in some cases the condition characterized as "common atrium/AVCD with postaxial polydactyly" is a mild form of EvC due to hypomorphic EVC mutations, further supporting the occurrence of genotype-phenotype correlations in this syndrome.

Risk of necrosis in the adjacent toe after one-toe fillet flap in diabetic foot: Retrospective study of 107 cases over 5 years.

PURPOSE: Fillet flap is a "spare part" concept. This technique allows the defect to be covered without donor site morbidity. Over the past 5 years, there were 107 diabetic foot cases of one-toe fillet flap in our hospital. After the operation, in some patients, there was necrosis of the adjacent toe that required additional amputation. The aim of our study was to determine the cause of necrosis of the adjacent toe after fillet flap. METHODS: The patients were divided into two groups. One group had no necrosis of the adjacent toe (group A) after the operation, and the other group had necrosis of the adjacent toe that required additional amputation after the operation (group B). Then, to confirm the cause of the additional necrosis of the adjacent toe, χ2 tests, Fisher's tests, and logistic regression tests were performed. RESULTS: A total of 107 patients were included, and 48 patients needed additional amputation. The logistic regression test revealed that a fillet flap at the metatarsophalangeal joint (MTPJ), horizontal sutures, and a fillet flap at the second toe were significant risk factors for developing necrosis. CONCLUSIONS: If a fillet flap with a second toe, fillet flap on MTPJ level and horizontal closure after fillet flap is needed, the chance of developing necrosis of the adjacent toe and additional revisional surgery must be communicated preoperatively.

Intraosseous epidermoid cysts of adjacent digits in a dog.

BACKGROUND: Intraosseous epidermoid cyst (IEC) is a rare, non-neoplastic, pathology in animals and humans that most commonly affects the distal phalanx. In dogs, it is important to differentiate this lesion from malignant digital tumours causing bone lysis. In previous reports, IEC has been described to affect only a single digit at the time of diagnosis which is usually based on histopathology. This is the first case report to describe immunohistochemically confirmed IECs affecting simultaneously multiple digits. CASE PRESENTATION: A 4-and-a-half-year-old female spayed Great Dane was presented with a 2-month history of progressive swelling of the distal phalanx (PIII) of digits IV and V of the right pelvic limb. Eleven weeks prior to presentation, the dog had a low-grade cutaneous mast cell tumour completely excised from the craniolateral base of its left pinna. A history of trauma to 1 of the nails of the same pes 4 years prior to referral was also reported. Examination of the right pelvic limb identified firm non-painful swelling of PIII of digits IV and V, with concurrent deformation of the nails. Radiographs of the right pes obtained by the primary veterinarian identified an expansile lesion of PIII of digits IV and V. Computed tomography identified large expansile lesions of PIII of digits IV and V, with associated cortical thinning and soft tissue swelling. Neoplasia was considered the most likely radiographic diagnosis. Histopathology of Jamshidi bone biopsies was consistent with intraosseous epidermoid cyst, which was confirmed with immunohistochemistry. Amputation of PIII of digits IV and V at the level of mid-PII was performed as definitive treatment. No recurrence of the lesion occurred during the 10-month follow-up period. CONCLUSIONS: Intraosseous epidermoid cysts should be included in the differential diagnosis for expansile lesions affecting the canine digit. It is important to differentiate them from other digital lesions, with bone involvement, such as malignant digital tumours, which often require more extensive surgery for definitive treatment. The case herein highlights that this lesion can affect simultaneously multiple digits. Definitive diagnosis can be achieved by identification of keratin-producing epithelial cells on histopathology and confirmed by pancytokeratin labelling.

Maternal mosaicism underlies the inheritance of a rare germline AKT3 variant which is responsible for megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome in two Roma half-siblings.

Megalencephaly-polymicrogyria-polydactyly-hydrocephalus (MPPH) syndrome is a developmental brain disorder characterized by an enlarged brain size with bilateral perisylvian polymicrogyria and a variable degree of ventriculomegaly. MPPH syndrome is associated with oromotor dysfunction, epilepsy, intellectual disability and postaxial hexadactyly. The molecular diagnosis of this disorder is established by the identification of a pathogenic variant in either AKT3, CCND2 or PIK3R2. Previously reported AKT3 variants are associated with various brain abnormalities and may lead to megalencephaly. MPPH syndrome is usually due to germline pathogenic AKT3 variants. Somatic mosaic pathogenic variants associated with hemimegalencephaly, which is similar to MPPH, have also been observed. A Hungarian Roma family with two half-siblings, which present with intellectual disability, dysmorphic features, epilepsy, brain malformations, and megalencephaly was studied. Whole exome sequencing (WES) analysis was performed. WES analysis revealed a heterozygous c.1393C > T p.(Arg465Trp) pathogenic missense AKT3 variant in both affected half-siblings. The variant was verified via Sanger sequencing and was not present in the DNA sample from the healthy mother, which was derived from peripheral blood, suggesting maternal germline mosaicism. In conclusion, this is the first report in which maternal germline mosaicism of a rare pathogenic AKT3 variant leads to autosomal dominantly inherited MPPH syndrome.