Polydactyly of the foot. Literature review and case presentations

Polydactyly is a fairly common congenital condition of the foot and is characterized literally by supernumerary toes (digit or metatarsal). The frequency of polydactyly varies widely among populations. It may be an isolated condition or part of a congenital syndrome. Polydactyly is generally classified into three major groups: medial ray (preaxial), central ray and lateral ray (postaxial). The duplication may appear at the distal and middle phalanges or at the whole digit and metatarsal. The complexity of the deformity ranges from a simple soft-tissue problem to a completely developed accessory ray. Careful clinical and radiographic evaluation should be made prior to treatment to achieve good functional and cosmetic results. Most cases are treated during childhood before walking age. Adult cases are more rare, and surgical management of the deformity is still debated. Nevertheless, surgery can be performed at any age as in our series with good results.     

Metatarsale- und Zehenfrakturen

The metatarsal bones and the toes are important elements of the plantar arch and are subject to heavy stresses acting both statically and dynamically-functionally. In the case of injuries, the diagnosis can mostly be made with no room for doubt on the basis of clinical exploration and X-ray examinations. Associated lesions and complications need careful attention; full rehabilitation later is only possible if correct anatomical reconstruction allowing stable weightbearing is achieved. The first and fifth metatarsals must be stabilized very precisely in the case of dislocated and/or open fractures. When the second to fourth metatarsal bones are affected internal splinting with K-wires is mostly preferable, while fractures of the base of the fifth metatarsal are best fixed with screws or tension bands. Nondislocated fractures can be treated conservatively. Dislocated or unstable fractures of the great toe, especially those involving the joints, must be accurately treated operatively. Immobilisation by means of a plaster shoe or splint is adequate for the other toes. Toes two to five can generally be successfully treated by taping. The unique character of every injury means that a tailored therapy plan based on well-tried principles is needed in each case.     

An Eight-toed Foot: A Rare Pedal Polydactyly

Polydactyly is a fairly common congenital condition of the foot and is characterized literally by supernumerary toes (digit or metatarsal). The frequency of polydactyly varies widely among populations. It may be an isolated condition or part of a congenital syndrome. Eight-toed polydactyly is a distinctly rare congenital foot anomaly. In this report, an 18-month-old child with pre-axial 8-toed right foot had been treated with excision of the excess rays with muscular, tendentious, and ligamentous reconstructions. The patient had presented a good postoperative result. Through monthly follow-up visits for 1 year, the parents expressed excellent cosmesis, shoe fit, and walking function.     

Design criteria for rigid rocker shoes

In this study nine different rigid rocker shoe designs were tested in 17 symptom-free male subjects and compared with the control condition of a flexible, non-rockered extra-depth shoe with the same flat insole. Effects of both rocker height and axis location were explored. Peak pressure was reduced at most forefoot locations by rocker shoes, but increased in the midfoot and heel. Axis location was found to have an important effect, particularly on hallux pressures. On average the best axis location for reducing metatarsal head (MTH) pressure was in the region of 55-60% of shoe length, while for the toes it was 65%. There was a mean trend towards optimal reduction of pressure in one of the rocker shoe conditions at each anatomical location, but the axis position for this optimal placement was variable across subjects and anatomical locations. While most configurations of the rocker shoes were superior to the control shoe, no single configuration was optimal for all subjects at all sites or even for all subjects at the same site. Therefore, some form of plantar pressure measurement in conjunction with gait training to ensure correct use of the rocker shoes would appear to be essential if the pressure reducing effect of the rigid rocker bottom shoe is to be optimized.     

Polydactyly of the foot

Fifty-six patients with 72 duplicated toes were analysed. Postaxial duplication accounted for 79%, and the most common anatomical pattern was duplication of the proximal phalanx with a wide metatarsal head. Forty-two patients with 55 duplications were clinically and radiographically evaluated at long-term follow-up (mean 22.5 years). Results were satisfactory in 91% of the patients. Poor results were often associated with preaxial polydactyly because of persistent hallux varus. Surgical treatment is usually straightforward but must be individualized, and some anatomical and surgical details should be considered to obtain a better result.     

Forefoot reconstruction: Effectiveness of Stainsby operation in treating disclocated lesser toes

BackgroundDeformity of the forefoot is a common disabling problem especially in chronic rheumatoid arthritis. The most common deformities are hallux valgus and dorsally dislocated clawed lesser toes.ObjectiveThis paper assesses results of forefoot reconstruction with emphasis on the effectiveness of Stainsby's procedure in treating severely clawed lesser toes with irreducible dislocation at the metatarsophalangeal joint. The purpose of this procedure is to remove the deforming forces causing depression of the metatarsal head, and restore the dorsally displaced plantar plate of the MTP joint and the related part of the plantar fat pad to their correct position beneath the metatarsal head.MethodSeventy-four patients were operated on between 1998 and 2003. Sixty-nine patients (94 feet) were available for review at an average of 32 months (range 10–67) post surgery. American Orthopaedic Foot and Ankle Scores (AOFAS) were measured and footprints were obtained. Patients were asked about overall satisfaction and whether they would recommend the operation to a family member.ResultsEighty-nine of the 94 feet (95%) had severe or moderate pain preoperatively under the dislocated metatarsal head; only 19 (20%) had significant pain at review. Tender plantar callosities were reduced from 76 feet preoperatively (81%) to 31 feet (33%) at review, these were mainly under un-operated metatarsal heads. Footprints showed a normal loading under 63% of operated metatarsal heads. AOFAS scores were increased from a mean of 19 preoperatively to 52 at review. Residual valgus of the big toe of more than 25° persisted in 33 feet (35%). Corrective osteotomy of 44 first metatarsals resulted in significant residual valgus in 16 feet (36%).ConclusionsStainsby operation was effective in relieving pain and skin callosities from under dislocated lesser metatarsal heads, and in reducing shoe problems, but the osteotomy performed by the authors was unreliable in correcting valgus of the big toe.     

Metatarsalgia

Metatarsalgia is a complex entity requiring specific diagnoses and appropriate management, which may include shoe modifications and inserts. Metatarsalgia, pain in the metatarsal head areas, has a variety of specific causes, including mechanical, neurogenic, vascular, and inflammatory conditions. Many problems may be treated successfully with shoe modifications and inserts. Surgical intervention may be appropriate in advanced and recalcitrant cases.     

A rare shortening of the first metatarsus of the foot and its treatment with distraction arthrodesis

Multiple toes may develop on the medial or lateral side of the forefoot or in its middle. This may involve duplication of only the distal phalanx or the whole hallux including the metatarsal. In a duplicated big toe, the phalanx to be maintained, because short muscles of the leg are attached to it, is usually localized medially. A rare case of dysplasia of the first metatarsus, following a resection indicated in childhood for a hallux triples, is described in a 20-year-old girl. In order to remove hallux insufficiency and an overloading of the middle metatarsals, the authors decided to carry out a one-stage prolongation of the first metatarsal, using an autologous tricorticcal graft collected from the pelvis and a dynamic compression plate. No surgical treatment of the middle metatarsals was indicated because a disproportionate, short foot would result. Both the subjective and objective status of the patient at 6 months after the operation showed that the non-standard prolongation procedure was correctly indicated and allowed for physiological loading of the foot and restoration of normal walking.     

Anatomy of the forefoot, normal and pathologic.

The metatarsophalangeal joints divide the forefoot as a lever for the push-off into two segments. The proximal segment is used for the first antigravitational phase, and the distal is added when the foot has gained speed. The ligaments of the ball of the foot are tied to the distal segment and are in their function dependent on free mobility of this segment. Thus, for the kinematics of the foot, for the stability of the arches, and for the ability of the skin to withstand shear forces, it is important to select a shoe that does not compress the toes, restrict their movements unnecessarily or expose the metatarsal heads to uneven pressure.     

An unusual and nonclassified central polydactyly of the foot

Central-type, 8-toed polydactyly is a distinctly rare congenital foot anomaly. In this report, a new subtype of the metatarsal type of the central ray polydactyly of the foot is presented. This includes a triplication, one of which is Y-shaped of the second metatarsal and 8 toes. In the literature, polydactyly of the foot has been usually operated during childhood after walking age. We performed the surgery at 6 months of age. After ray amputation of the extra toes, we reapproximated the muscle pieces that remained on the original first and second metatarsals and repaired the transverse metatarsal ligament. Despite the early surgery, we did not encounter any problems intraoperatively and postoperatively.     

Comparison of plantar pressure distribution in CAD–CAM and prefabricated foot orthoses in patients with flexible flatfeet

BackgroundsThe effect of foot orthoses on plantar pressure distribution has been proven by researchers but there are some controversies about advantages of custom-made foot orthoses to less expensive prefabricated foot orthoses.MethodsNineteen flatfeet adults between 18 and 45 participated in this study. CAD–CAM foot orthoses were made for these patients according to their foot scan. Prefabricated foot orthoses were prepared according to their foot size. Plantar pressure, force and contact area were measured using pedar^®-x in-shoe system wearing shoe alone, wearing CAD–CAM foot orthoses and wearing prefabricated foot orthoses. Repeated measures ANOVA model with post-hoc, Bonferroni comparison were used to test differences.ResultsCAD–CAM and prefabricated foot orthoses both decreased pressure and force under 2nd, 3–5 metatarsal and heel regions comparing to shoe alone condition. CAD–CAM foot orthosis increased pressure under lateral toe region in comparison to shoe alone and prefabricated foot orthosis. Both foot orthoses increased pressure and contact area in medial midfoot region comparing to shoe alone condition. Increased forces were seen at hallux and lateral toes by prefabricated foot orthoses in comparison with CAD–CAM foot orthoses and control condition, respectively.ConclusionAccording to the results, both foot orthoses could decrease the pressure under heel and metatarsal area. It seems that the special design of CAD–CAM foot orthoses could not make great differences in plantar pressure distribution in this sample. Further research is required to determine whether these results are associated with different scan systems or design software.     

Stability of Lisfranc joints in ballet pointe position

BACKGROUND: Ballerinas develop stress fractures at the second metatarsal base associated with dancing en pointe. The purpose of this study was to evaluate the relative importance of the pointe shoe and the tarsometatarsal ligaments in Lisfranc joint stability en pointe. METHODS: Eleven cadaver feet were dressed with pointe shoes, loaded in foot flat with ligaments intact, and loaded en pointe before and after sequential sectioning of the dorsal, interosseous, and plantar ligaments between the first and second metatarsals and cuneiforms. Relative motion between the first and second metatarsals and cuneiforms was determined radiographically. RESULTS: No significant displacement of the Lisfranc joints occurred when the shod foot with intact ligaments was loaded in the foot flat or en pointe positions. Serial sectioning of the ligaments from dorsal to plantar in the shod foot en pointe demonstrated no change in alignment after the dorsal and interosseous ligaments were cut, but a significant change in alignment between the second metatarsal and second cuneiform was noted after the plantar ligament was cut (p < 0.0001). Removal of the pointe shoe after cutting the ligaments and applying a minimal (1 to 2 kg) load resulted in complete subluxation and diastasis through the first-second intermetatarsal and intercuneiform region. Replacing the shoe improved alignment en pointe with similar loading. CONCLUSIONS: Both the pointe shoe and Lisfranc ligaments are important for Lisfranc region stability in feet en pointe. The plantar ligaments are major stabilizers of the Lisfranc region in the loaded, shod foot en pointe. Selection of a pointe shoe with adequate support may limit susceptibility to stress fracture of the second metatarsal base in ballerinas.     

第2跖背动脉逆行筋膜岛状皮瓣修复足趾软组织缺损

目的 介绍应用第2跖背动脉逆行筋膜岛状皮瓣修复足趾软组织缺损的手术方法.方法 2005年5月至2008年9月,对5例患者应用第2跖背动脉逆行筋膜岛状皮瓣修复足趾软组织缺损.皮瓣切取面积为2 cm×3 cm～5 cm×6 cm.结果 5例皮瓣全部成活,术后1～2个月恢复正常行走.随访5～7个月趾外形饱满,皮瓣质地良好,感觉基本恢复.结论 以第2跖背动脉为血管蒂的逆行筋膜岛状皮瓣具有血供可靠,切取方便,质地优良等优点,是修复足趾软组织缺损的较好方法.     

Six first metatarsal shaft osteotomies: mechanical and immobilization comparisons

Because malunion (usually with dorsal elevation of the first metatarsal) has been reported after the treatment of severe hallux valgus deformities by proximal osteotomies, the current study was designed to compare the sagittal stability of six different metatarsal shaft osteotomies: the proximal crescentic, proximal chevron, Mau, Scarf, Ludloff, and biplanar closing wedge osteotomies. A plate was used in the biplanar closing wedge osteotomy; all others used screws for fixation. Ten fresh-frozen, human anatomic lower extremity specimens were used for each osteotomy. Failure loads were measured as units of force (newtons) and converted to pressure (kilopascals). Then the F-Scan system, which uses a thin insole to measure plantar pressure, was used to evaluate the pressure under the first metatarsal of seven volunteers using four types of shoes. According to the results, in patients with normal bone stock who are compliant, any of the four shoe types tested may be used after a Ludloff, Scarf, biplanar wedge (plantar screw fixation), or Mau osteotomy, but the wedge-based shoe should be used after a proximal crescentic or chevron osteotomy or for patients with severe osteopenic bone.     

Corns—Their etiology and treatment

A corn is produced by a shoe which causes friction and pressure on the skin of a toe at a point where a bony prominence underlies the skin. This pressure may be direct or it may be transferred to bony prominences between the toes. Palpation of the corn will reveal the prominence.Conservative methods of treatment are presented. If these fail, operative cure of the clavus is described.     

Shoe adaptation after amputation of the II - V phalangeal bones of the foot

In The Netherlands, about 50% of all amputations of the lower limb are toes and forefoot amputations. Traumata of toes and mid-foot are rare. Preservation of the foot is the primary goal for treatment. Crush injuries of the foot may be associated with prolonged morbidity. This case study presents an insole solution for the solitary first phalangeal bone after amputation of the phalangeal bones II - V. The normal adaptation for forefoot amputations is stiffening of the sole of the shoe and a rocker bar to improve the toe off phase with load reduction of the forefoot. Because the patient had to do excessive stair climbing during work another solution was chosen. As a foot orthosis, a metal soleplate was made in order to have free movement during loading and toe-off during walking. The soleplate gives safety and provides self-adjusting properties after toe off. This enables the shoe technician to make a shoe without a rocker bar or an extra stiff insole. The 0.5 mm custom-made spring-steel plate is also used as a protective in industrial safety shoes. To improve shoe adaptation more research and case reports have to be published in order to inform doctors and shoe technicians about everyday solutions to partial foot amputations.     

The influence of second toe and metatarsal length on stress fractures at the base of the second metatarsal in classical dancers

BACKGROUND: Stress fractures at the base of the second metatarsal frequently occur in female classical dancers. There is a strong belief that a foot shape in which the first metatarsal or toe is shorter than the second metatarsal or toe increases the risk of this injury in dancers. However, there is a lack of empirical evidence to support this theory. The objective of this study was to examine the influence of the relative length difference between the first and second metatarsals and first and second toes on the frequency of stress fractures at the base of the second metatarsal in elite, female classical dancers. METHODS: Both feet of 50 elite female classical dancers were measured for length differences between the first and second toes and first and second metatarsals. Retrospective analysis of dancers' medical histories revealed 17 feet with stress injury and 83 without. The mean of the difference between the metatarsal and toe length for the stress-injury group was compared to that of the control group. RESULTS: No difference between the groups was identified for first and second toe length difference (p = 0.865) and the relative difference between the ends of the first two metatarsals (p = 0.815). CONCLUSIONS: Dancers who had a stress injury at the base of the second metatarsal displayed similar variances in the two independent variables as dancers who had not had such an injury.     

Metatarsalgia: distal metatarsal osteotomies

Metatarsalgia is a common pathologic entity. It refers to pain at the MTP joints. Pain in the foot unrelated to the MTP joints (such as Morton’s neuroma) must be distinguished from those disorders, which lead to abnormal pressure distribution, reactive calluses, and pain. Initial treatment options for metatarsalgia include modifications of shoe wear, metatarsal pads, and custom-made orthoses. If conservative treatment fails, operative reconstructive procedures in terms of metatarsal osteotomies should be considered. Lesser metatarsal osteotomy is an effective and well-accepted method for the management of metatarsalgia. The main purpose of these osteotomies is to decrease prominence of the symptomatic metatarsal head. The distal metatarsal oblique osteotomy (Weil osteotomy) with its modification represents the best evaluated distal metatarsal osteotomy in terms of outcome studies and biomechanical analysis. The role of the Weil osteotomy in metatarsalgia owing to a subluxed or dislocated MTP joint is to bring the metatarsal head proximal to the callus and to provide axial decompression of the toe to correct the deformity contributing to metatarsalgia.     

Rheumatoid forefoot reconstruction. A long-term follow-up study

BACKGROUNDS: The purpose of the present study was to assess the results of reconstruction of the rheumatoid forefoot with arthrodesis of the metatarsophalangeal joint of the great toe, resection arthroplasty of the metatarsal heads of the lesser toes, and open repair of hammer-toe deformity (arthrodesis of the proximal interphalangeal joint) of the lesser toes when this deformity was present. METHODS: A retrospective study of forty-three consecutive patients (fifty-eight feet) with severe rheumatoid forefoot deformities was performed. Six patients (six feet) died before the most recent follow-up, and five patients (five feet) were excluded because a subtotal procedure had been performed. No patient was lost to follow-up. Thus, the study included thirty-two patients (forty-seven feet) in whom reconstruction of a rheumatoid forefoot had been performed by the author. RESULTS: All first metatarsophalangeal joints had successfully fused at an average of seventy-four months (range, thirty-seven to 108 months) postoperatively. The average postoperative hallux valgus angle was 20 degrees and the average postoperative angle subtended by the axes of the proximal phalanx and the metatarsal of the second ray (the MTP-2 angle) was 14 degrees, demonstrating that a stable first ray protected the lateral rays from later subluxation. One hundred and thirty-two (70 percent) of the 188 lesser metatarsophalangeal joints were dislocated preoperatively, compared with thirteen (7 percent) postoperatively. The result of the procedure (as rated subjectively by the patient) was excellent for twenty-three feet, good for twenty-two, and fair for two. There were no poor results. The average postoperative score according to the system of the American Orthopaedic Foot and Ankle Society was 69 points. Postoperative pain was rated as absent in eighteen feet, mild in twenty-five, moderate in four, and severe in none. Fifteen feet were not associated with any functional limitations, twenty-eight were associated with limitation of recreational activities, and four were associated with limitation of daily activities. At the time of the most recent follow-up, no special shoe requirements were reported. Fourteen feet (30 percent) had a reoperation for the removal of hardware from the first metatarsophalangeal joint, a procedure on the interphalangeal joint of the great toe, or additional procedures on the lesser toes or lesser metatarsophalangeal joints. CONCLUSIONS: In the present study, arthrodesis of the first metatarsophalangeal joint, resection arthroplasty of the lesser metatarsal heads, and repair of fixed hammer-toe deformities with intramedullary Kirschnerwire fixation resulted in a stable repair with a high percentage of successful results at an average of six years after the procedures.     

Contributions of active and passive toe flexion to forefoot loading.

Toe flexion during terminal stance has an active component contributed by the muscles that flex the toes and a passive component contributed by the plantar fascia. This study examined the relative importance of these two mechanisms in maintaining proper force sharing between the toes and forefoot. Thirteen nonpaired cadaver feet were tested in a dynamic gait stimulator, which reproduces the kinematics and kinetics of the foot, ankle, and tibia by applying physiologic muscle forces and proximal tibial kinematics. The distribution of plantar pressure beneath the foot was measured at the terminal stance phase of gait under normal extrinsic muscle activity with an intact plantar fascia, in the absence of extrinsic toe flexor activity (no flexor hallucis longus or flexor digitorum longus) with an intact plantar fascia, and after complete fasciotomy with normal extrinsic toe flexor activity. In the absence of the toe flexor muscles or after plantar fasciotomy the contact area decreased beneath the toes and contact force shifted from the toes to the metatarsal heads. In addition, pressure distribution beneath the metatarsal heads after fasciotomy shifted laterally and posteriorly, indicating that the plantar fascia enables more efficient force transmission through the high gear axis during locomotion. The plantar fascia enables the toes to provide plantar-directed force and bear high loads during push-off.