Reconstruction of Foot Postaxial Polydactyly Using the On-top Plasty: A Case Report

Polydactyly is a common congenital hand, foot, or both anomalies characterized by the presence of extra fingers. Postaxial polydactyly is the most common congenital malformation consisting of the lateral or fibular aspect of the foot. Extra finger excision in the treatment of foot polydactyly is considered the basic procedure in surgery. However, in some cases more complex surgeries should be preferred. In this study, the “on-top plasty” method with a minimally invasive approach is presented in a case of complex foot postaxial polydactyly.     

An Unusual Case of Postaxial Polydactyly of the Foot Treated by Metatarsal Transfer

Postaxial polydactyly is a relatively rare congenital deformity. We present a unique unusual fourth metatarsal type polydactyly in which the extra bone from the fourth metatarsal bone articulated with the most lateral ray proximal phalanx. We discuss the surgical management of this problem using a bone transfer from the extra metatarsal bone within the midfoot. This is the first reported case of fourth metatarsal-type polydactyly treated by bone transfer of the extra metatarsal bone and internal plate fixation to recover normal articulation. The normal orientation of the metatarsophalangeal joint, alignment, and cosmesis are important determinants when selecting the bone to be excised in cases of lateral ray foot polydactyly.     

Correction of Postaxial Metatarsal Polydactyly of the Foot by Percutaneous Ray Amputation and Osteotomy

Polydactyly of the foot is a congenital anomaly characterized by the appearance of all or part of 1 or more additional rays. The patient with this condition might complain of an abnormal cosmetic appearance or difficulty with footwear. A minimally invasive technique for correction of postaxial metatarsal polydactyly of the foot is presented in this techniques report.     

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.     

Tendon Insertion at the Base of the Proximal Phalanx of the Hallux: Surgical Implications

Hallux valgus, limitus, and rigidus are conditions affecting the first metatarsophalangeal joint that can be treated by arthroplasty. Excessive arthroplasty can compromise the insertion of the tendons at the base of the proximal phalanx of the hallux, leading to first metatarsophalangeal joint plantarflexion weakness, cock-up toe deformity, and altered forefoot loading. The present study investigated the anatomic length of insertion of the medial and lateral flexor hallucis brevis, extensor hallucis brevis, abductor hallucis, and adductor hallucis tendons into the base of the hallux proximal phalanx and the amount of bone that can be safely resected without compromising the insertional limits. A total of 43 specimens (22 right and 21 left) from 22 embalmed cadavers (11 male and 11 female) were dissected. The insertion lengths of the 5 tendons were measured, along with the dimensions of the hallux proximal phalanx. No statistically significant differences were found in any proximal phalanx measurements or tendon insertion lengths according to side (p > .05). Significant differences were found between the genders in most dimensions of the hallux proximal phalanx (p < .05). The medial insertion site, where the medial flexor brevis tendon and distal abductor hallucis muscle join, was longer than the lateral site (p < .001). To preserve the tendon’s insertion, hallux proximal phalanx resection should not exceed 3 mm. Resection of the tendons is ensured by removal of more than 7.88 mm and 9.37 mm in females and males, respectively. When performing hallux arthroplasty of the first metatarsophalangeal joint, we recommend calculating the length of the tendon insertions, instead of the length of the hallux proximal phalanx.     

Accurate Osteotomy for the Treatment of a Rare Case of Postaxial Polydactyly of the Foot That Originated From a Deformed Calcaneus Using a 3D-Printed Guiding Plate

Polydactyly is a common congenital deformity of the foot that can be categorized as preaxial, central, or postaxial. Current treatments involve resecting the supernumerary toe(s) and repairing the normal toe(s) and soft tissue. Here, we present the first published report describing a very rare case of polydactyly of the foot, in which the supernumerary toe originated from a deformed calcaneus, which formed an abnormal bony bump. Preoperatively, 3-dimensional (3D) computed tomography reconstruction images revealed the morphology of the deformed toe and calcaneus, and gait analysis showed an abnormal weightbearing zone in the left foot. The 3D printing technology and a specially designed 3D-printed guiding plate were used for osteotomy. Postoperatively, x-ray showed that the calcaneus had a normal shape and surface, whereas gait analysis showed that the left foot was uniformly loaded and the area of pain was eliminated. Our findings should raise awareness among clinicians that a 3D-printed guiding plate is useful in the treatment of such an unusual deformity.     

The Role of the Shortened Proximal Phalanx in the Setting of Brachymetatarsia

Brachymetatarsia is a condition in which a metatarsal bone does not grow out to full length. This is caused by premature physeal closure. The proximal phalanx associated with the shortened metatarsal helps achieve the natural parabola of the foot. A hypoplastic proximal phalanx is a common finding in patients with brachymetatarsia. The goal of this study was to determine the length of the proximal phalanx in the setting of brachymetatarsia, and how much the shortening is attributed to the clinically smaller toe. We performed a retrospective study to evaluate the length of the proximal phalanx in the shortened ray. After the metatarsal was brought out to the desired length of correction, the proximal phalanx was measured on radiographs. Ninety-seven feet with congenital brachymetatarsia were reviewed in a cohort of 66 patients who underwent surgical correction between January 2005 and February 2020 at a single institution. The group was comprised of 61 females and 5 males, with a mean age of 27.5 years. The average length of the proximal phalanx associated with the affected metatarsal was noted to be 18.9 ± 3.83 mm for males and 15.6 ± 4.02 mm for females. Our results indicate the shortened proximal phalanx is 5 mm shorter when compared to normal population and is a contributing factor to the shortened clinical appearance of the digit in brachymetatarsia. Treating surgeons should be aware of this to better educate patients on the influence of the digit on the overall shortening seen in cases of brachymetatarsia.     

The Effect of Hallux Valgus Surgery on the Transverse Plane Hallux Proximal Phalanx Position

The objective of this investigation was to evaluate the apparent movement of the hallux proximal phalanx in the transverse plane relative to the second metatarsal following hallux valgus surgery. Pre- and postoperative radiographs of a consecutive series of 45 feet undergoing hallux valgus surgery were analyzed. Significant improvements were observed in the first intermetatarsal angle (12.4 vs 7.5 degrees; p < .001), hallux valgus angle (24.3 vs 13.4 degrees; p < .001), tibial sesamoid position (4.6 vs 2.7; p < .001), and second metatarsal-hallux proximal phalanx angle (80.1 vs 84.6 degrees; p < .001). No difference was observed in the distance between the second metatarsal bisection and the medial aspect of the tibial sesamoid (31.7 vs 31.5 mm; p = .756) nor between the second metatarsal bisection and medial aspect of the hallux proximal phalanx base (34.6 vs 34.2 mm; p = .592). Significant differences were observed between the second metatarsal bisection and the central aspect of hallux proximal phalanx base (26.5 vs 23.9 mm; p < .001) and between the second metatarsal bisection and the lateral aspect of the hallux proximal phalanx base (19.3 vs 15.4 mm; p < .001). A statistically significant difference was observed in the change of distance between the second metatarsal bisection and the medial, central, and lateral aspects of the hallux proximal phalanx base (-0.4 vs -2.6 vs -3.9 mm; p = .002). These results indicate that the hallux proximal phalanx does not translocate in the transverse plane following hallux valgus surgery, but instead pivots about the medial aspect of the joint.     

Ankle Structures of Professional Soccer (Football) Players With Proximal Diaphyseal Stress Fractures of the Fifth Metatarsal

Despite a high incidence of proximal diaphyseal stress fractures of the fifth metatarsal (zone 3) in soccer (football) players, studies that examine risk factors of the fractures in professional soccer players are scarce; in particular, ankle structures have not yet been investigated. This study was designed to investigate ankle structures of professional soccer players with proximal diaphyseal stress fractures of the fifth metatarsal. We reviewed the ankle radiographs of 100 professional soccer players (stress fractures n = 15; controls n = 85) and measured the medial malleolar slip angle (MMSA), the ratio of the medial malleolar length to the width of the talar dome (MML:TD ratio), the ratio of the lateral malleolar length to the width of the TD (LML:TD ratio), and the ratio of the MML to the LML (MML:LML ratio). The MMSA (p < .01: 28.7° ± 5.8° versus 23.0° ± 4.9°) in the stress fractures was significantly wider and the MML:TD ratio (p = .08: 0.49 ± 0.08 versus 0.52 ± 0.07) had a trend to be smaller compared with the values of the controls. Logistic regression analysis revealed that a wider malleolar slip angle became a factor associated with stress fractures in professional soccer players (p < .01: odds ratio 1.27, 95% confidence interval 1.110 to 1.463). Receiver operating characteristic curve with MMSA for the stress fractures was depicted with an area under the curve of 0.778, and the suitable cut-off point was set at MMSA >27° with a positive likelihood ratio of 3.67 (95% confidence interval 2.173 to 6.188). Our study results show that a wide MMSA was associated with proximal diaphyseal stress fractures of the fifth metatarsal in professional soccer players.     

Dynamic CT in the Preoperative Evaluation of Patients With Gastric Cancer: Correlation With Surgical Findings and Pathology

Background: The use of diagnostic techniques in the preoperative staging of patients with gastric cancer must be better defined. To further clarify which technique is indicated, we applied a new modality of computed tomography (CT) scanning for patients with gastric cancer.Methods: Dynamic CT of the abdomen using water as oral contrast agent was performed in 30 patients with gastric adenocarcinoma. Patients without evidence of metastatic disease underwent exploratory laparotomy and intraoperative staging. Resectable patients had surgical excision and definitive pathologic staging.Results: Two patients (7%) had metastatic disease by CT and were considered inoperable. The remaining 28 underwent laparotomy. Of these, six (21%) were unresectable and 22 (79%) had surgical resection. Dynamic CT adequately suggested advanced stage disease in four (67%) of the 6 unresectable patients. Wall thickness in dynamic CT correlated with the risk of serosal involvement (P < .001). Both CT and surgery had an accuracy of 64% (P > .05) in predicting pathologic staging. CT overstaged only 4% of cases.Conclusions: Dynamic CT is a useful modality that can indicate inoperable disease, obviating the need for laparotomy in patients with gastric adenocarcinoma. CT can modify the surgical approach by suggesting unresectable or advanced disease. The low percentage of patients that are overstaged by CT, combined with its similar staging accuracy when compared with laparotomy, support its preoperative use in these patients.     

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.