Foot pressures during gait: a comparison of techniques for reducing pressure points

PURPOSE: Various methods have been used to redistribute plantar surface foot pressure in patients with foot ulcers. This study was conducted to determine the effectiveness of four modalities (fracture walker, fracture walker with insert, and open and closed toe total contact casts) in reducing plantar foot pressure. METHODS: Ten healthy, normal volunteer subjects had an F-scan sensor (ultra thin shoe insert pressure monitor) placed under the right foot. They then ambulated on a flat surface, maintaining their normal gait. Dynamic plantar pressures were averaged over 10 steps at four different sites (plantar surface of great toe, first metatarsal head, base of fifth metatarsal, and plantar heel). All subjects repeated this sequence under five different testing conditions (barefoot, with a fracture walker, fracture walker with arch support insert, open and closed toe total contact cast). Each subject's barefoot pressures were then compared with the pressures during the different modalities. RESULTS: All four treatment modalities significantly reduced (p < 0.05) plantar pressure at the first metatarsal head (no method was superior). The fracture walker, fracture walker with insert, and open toe total contact cast significantly reduced pressure at the heel. Pressures at the base of the fifth metatarsal and great toe were not significantly reduced with any treatment form. CONCLUSION: The fracture walker, with and without arch support, and total contact cast can effectively reduce plantar pressure at the heel and first metatarsal head.     

Biomechanical consequences of adding plantar fascia release to metatarsal osteotomies: Changes in forefoot plantar pressures

Destruction of the normal metatarsal arch by a long metatarsal is often a cause for metatarsalgia. When surgery is warranted, distal oblique, or proximal dorsiflexion osteotomies of the long metatarsal bones are commonly used. The plantar fascia has anatomical connection to all metatarsal heads. There is controversial scientific evidence on the effect of plantar fascia release on forefoot biomechanics. In this cadaveric biomechanical study, we hypothesized that plantar fascia release would augment the plantar metatarsal pressure decreasing effects of two common second metatarsal osteotomy techniques. Six matched pairs of foot and ankle specimens were mounted on a pressure mat loading platform. Two randomly assigned surgery groups, which had received either distal oblique, or proximal dorsiflexion osteotomy of the second metatarsal, were evaluated before and after plantar fasciectomy. Specimens were loaded up to a ground reaction force of 400 N at varying Achilles tendon forces. Average pressures, peak pressures, and contact areas were analyzed. Supporting our hypothesis, average pressures under the second metatarsal during 600 N Achilles load were decreased by plantar fascia release following proximal osteotomy (p < 0.05). However contrary to our hypothesis, peak pressures under the second metatarsal were significantly increased by plantar fascia release following modified distal osteotomy, under multiple Achilles loading conditions (p < 0.05). Plantar fasciotomy should not be added to distal metatarsal osteotomy in the treatment of metatarsalgia. If proximal dorsiflexion osteotomy would be preferred, plantar fasciotomy should be approached cautiously not to disturb the forefoot biomechanics. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:800–804, 2017.

     

Treatment of metatarsalgia based on claw toe deformity through soft tissue release of the metatarsophalangeal joint and resection of the proximal interphalangeal joint: Evaluation based on foot kinematics and plantar pressure distribution

IntroductionThis study investigated the effect of operative claw toe correction with release of the metatarsophalangeal (MTP) joint, repositioning of the plantar fat pad and resection of the proximal interphalangeal joint on foot kinematics, plantar pressure distribution and Foot Function Index (FFI).MethodsProspective experimental study with pretest-posttest design. The plantar pressure, 3D foot kinematics and the FFI of 15 patients with symptomatic claw toes were measured three months before and 12 months after surgery. Mean pressure, peak pressure and pressure time integral per sensor and various foot angles were calculated for the pre- and posttest and compared to a control group (N = 15).ResultsClaw toe patients have increased pressure under the distal part of the metatarsal head and less pressure under the proximal part of the metatarsal heads compared to healthy controls. After surgery, there was a redistribution of pressure, resulting in a significant decrease of pressure under the distal part and an increase under the proximal part of the metatarsal head, providing a more equal plantar pressure distribution. Except for some small areas under the forefoot, heel and toes, there were no significant differences in pressure distribution between the operated feet and controls. Small, but significant differences between the pre- and postoperative condition were found for the lateral arch angle, calcaneus/malleolus supination and tibio-talar flexion. The score on the FFI improved statistically significant.DiscussionThese findings imply that the present operative procedure results in a more equal distribution of the plantar pressure under the forefoot and decrease of pain and offers successful treatment of metatarsalgia based on claw toe deformity.     

两种第二趾切取游离移植对供足足底应力影响的生物力学研究

目的 探讨第2足趾切取游离移植对供足足底应力的影响.方法 取6具正常成人新鲜尸体足标本,根据不同状态分3组:完整组(A组)、第2趾截除(保留跖骨头)组(B组)及带部分跖骨的第2趾截除(跖骨远l/3处)组(C组).应用电子万能试验机以2 mm/min的速度从胫骨远端施加轴向压载,加载载荷分别为0、600、1200 N.通过F-Scan足底压力测量系统检测足底应力变化,并对数据进行统计学分析.结果 足底应力随轴向压载的增加而增大.A组(足母)指及5个跖骨头的峰值压强以第2跖骨头最大,600 N垂直载荷时为(37.33±7.34)kPa,1200 N垂直载荷时为(112.33±10.33)kPa.同一载荷下,A组与B组的(足母)指及5个跖骨头的峰值压强差异均无统计学意义(P>0.05).同一载荷下,A组、B组分别与C组比较,(足母)指及5个跖骨头的峰值压强差异均有统计学意义(P<0.05).结论 第2跖骨的完整对足底应力正常分布及维持足弓具有重要意义.保留跖骨头的第2趾切取对供足足底应力分布影响较小,带部分跖骨的第2趾切取可导致供足足底应力的异常分配.     

The relationship of the position of the metatarsal heads and peak plantar pressure

We test the premise that peak plantar pressure is located directly under the bony prominences in the forefoot region. The right foot of standing volunteers was examined in three different postures by a CT-scanner. The plantar pressure distribution was simultaneously recorded. The position of the metatarsal heads and the sesamoids could be related to the corresponding local peak plantar pressures. The metatarsal heads 1, 4, and 5 had a significantly different position than the local peak plantar pressures. The average difference in distance between the position of the metatarsal heads and the peak plantar pressure showed a significant correlation: on the medial side the head was located more distally to the local peak plantar pressure, on the lateral side more proximally. The findings suggest that normal plantar soft tissue is able to deflect a load. The observations might improve insight into the function of the normal forefoot and might direct further research on the pathological forefoot and on the design of footwear.     

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.     

Second metatarsal osteotomies for metatarsalgia: A robotic cadaveric study of the effect of osteotomy plane and metatarsal shortening on plantar pressure

Symptom relief of recalcitrant metatarsalgia can be achieved through surgical shortening of the affected metatarsal, thus decreasing plantar pressure. Theoretically an oblique metatarsal osteotomy can be oriented distal to proximal (DP) or proximal to distal (PD). We characterized the relationship between the amount of second metatarsal shortening, osteotomy plane, and plantar pressure. We hypothesized that the PD osteotomy is more effective in reducing metatarsal peak pressure and pressure time integral. We performed eight DP and eight PD second metatarsal osteotomies on eight pairs of cadaveric feet. A custom designed robotic gait simulator (RGS) generated dynamic in vitro simulations of gait. Second metatarsals were incrementally shortened, with three trials for each length. We calculated regression lines for peak pressure and pressure time integral vs. metatarsal shortening. Shortening the second metatarsal using either osteotomy significantly affected the metatarsal peak pressure and pressure time integral (first and third metatarsal increased, p < 0.01 and <0.05; second metatarsal decreased, p < 0.01). Changes in peak pressure (p = 0.0019) and pressure time integral (p = 0.0046) were more sensitive to second metatarsal shortening with the PD osteotomy than the DP osteotomy. The PD osteotomy plane reduces plantar pressure more effectively than the DP osteotomy plane. Published 2013 by Wiley Periodicals, Inc. on behalf of the Orthopaedic Research Society. J Orthop Res 32:385–393, 2014.     

Rotational Flap Closure of First and Fifth Metatarsal Head Plantar Ulcers: Adjunctive Procedure When Performing First or Fifth Ray Amputation

Partial ray amputation is a common treatment of diabetes-related neuropathic ulcers located beneath the metatarsal heads. The standard incision for partial first or fifth ray amputation involves a tennis racket incision, with the proximal arm made mid-line along the respective medial or lateral side of the metatarsal head and neck, creating equal dorsal and plantar flaps. This incision works well when the ulcer is located within the excised soft tissue distal to the incision or when the plantar ulcer is superficial and will heal secondarily once the underlying bone has been removed. This standard first or fifth ray amputation incision does not, however, allow excision and closure of plantar ulcers located beneath the first or fifth metatarsal head. Two cases are presented to demonstrate our surgical protocol for partial first or fifth ray amputation using a local rotational flap to cover plantar metatarsal head ulcers. These cases highlight our patient selection criteria, staging protocol when cellulitis or abscess is present, rotational flap design, surgical technique pearls, and the typical postoperative healing progress.     

Plantar fat pad atrophy: a cause of metatarsalgia?

The aim of this prospective study was to evaluate if atrophy of the plantar fat pad in splay-foot deformities was a major cause of metatarsalgia. A sonographic method of measuring the thickness of the plantar fat pad under the second and third metatarsal heads was developed. The method was tested on 25 volunteers and the intraobserver reliability was calculated to be 97.1% for the second metatarsal and 96.7% for the third metatarsal. Sonographic measurement of the plantar fat pad was then performed on 100 symptomatic feet Pain frequency and pain intensity were determined by using a verbal rating scale (VRS) and a visual analog scale (VAS). The intermetatarsal angle 1/2 was measured and then compared to the thickness of the fat pad for each patient. A correlation between the increase of the intermetatarsal angle and the decrease of the fat pad thickness could not be demonstrated (r = 0.041). The frequency of metatarsalgia did not correlate with a decrease of the thickness of the plantar fat pad under the second metatarsal head (t statistic: 1.978; Durbin-Watson test: 1.999; p value = .0507) and the third metatarsal head (t statistic: 3.199; Durbin-Watson test: 1.962; p value = .0019). The pain intensity showed a similar lack of correlation with the thickness of the plantar fat pad under the second metatarsal head (t statistic: 1.828; Durbin-Watson test: 2.365; p value = .0706) and the third metatarsal head (t statistic: 1.846; Durbin-Watson test: 2.371; p value = .0678). This study shows that a splay-foot deformity is not associated with a decrease of the thickness of the plantar fat pad. Furthermore, alterations of the thickness of the plantar fat pad are not relevant to the intensity and frequency of metatarsalgia.     

A simple method for repositioning metatarsal fractures]

Because of small direct contact to the fracture fragments reduction of metatarsal fractures can be achieved only indirectly by applying traction to the toes. In this article a method for simple direct manipulation of the distal main fragment of metatarsal fractures is described: A K-wire is drilled in dorsi plantar direction across the head of the fractured metatarsal and mounted on a traction bow. In this manner the distal fracture fragment can be moved in all directions and placed exactly onto the proximal fragment. All 8 patients with multiple metatarsal fractures could be treated by closed reduction and percutaneous pinning. The described method allows simple and precise reduction of metatarsal fractures, reduced x-ray exposure of the surgeon's hand by short operation times, and manipulation for fracture reduction outside the x-ray beam.     

Blood supply to the first metatarsal head and vessels at risk with a chevron osteotomy

BACKGROUND: Chevron osteotomy, a commonly performed procedure for the treatment of hallux valgus, results in osteonecrosis of the first metatarsal head in 0% to 20% of cases. The aim of this study was to map out the arrangement of the vascular supply to the first metatarsal head and its relationship to the limbs of the chevron osteotomy. METHODS: Ten cadaveric lower limbs were injected with an India ink-latex mixture, and the feet were dissected to assess the blood supply to the first metatarsal head. The dissection was carried out by tracing the branches of the dorsalis pedis and posterior tibial vessels. A distal chevron osteotomy was mapped, with the limbs of the osteotomy set at an angle of 60 degrees from the geometric center of the first metatarsal head. The relationship of the limbs of the osteotomy to the blood vessels was recorded. RESULTS: The first metatarsal head was found to be supplied by branches from the first dorsal metatarsal, first plantar metatarsal, and medial plantar arteries. The first dorsal metatarsal artery was the dominant vessel among the three arteries in eight specimens. All of the vessels formed a plexus at the plantar-lateral aspect of the metatarsal neck, just proximal to the capsular attachment, with a varying number of branches from the plexus then entering the metatarsal head. The plantar limb of the proposed chevron cuts exited through this plexus of vessels in all specimens. Contrary to the widely held view, only minor vascular branches could be found entering the dorsal aspect of the neck. CONCLUSIONS: The identification of the plantar-lateral corner of the metatarsal neck as the major site of vascular ingress into the first metatarsal head suggests that constructing the chevron osteotomy with a long plantar limb exiting well proximal to the capsular attachment may decrease the postoperative prevalence of osteonecrosis of the first metatarsal head.     

Plantar pressure and load in cadaver feet after a Weil or chevron osteotomy

BACKGROUND: Since metatarsal osteotomy was first used to treat metatarsalgia in the early twentieth century, many techniques have been described to accomplish the basic aim of reduction of load transmission through the operated metatarsal and reduction of localized high pressure on the plantar surface of the metatarsal. Our study examined two popular distal metatarsal neck osteotomies used for the relief of central metatarsalgia and the biomechanical changes that result from their use in a cadaver forefoot model. METHODS: After applying 445 N (100 lbs) of axially directed force, we measured plantar pressure using the TekScan HR Mat (TekScan, Inc., South Boston, MA) in twelve paired, thawed, fresh-frozen intact cadaver legs, then after either a Weil or chevron osteotomy of the second metatarsal and finally after the addition of the same osteotomy of the third metatarsal. RESULTS: Load in the forefoot was not significantly affected by the Weil osteotomy. A significant increase in load was produced in the first metatarsal region, and significant decreases in load were produced beneath the operated metatarsal heads after the chevron osteotomy. Average pressure in the contact area of the forefoot showed similar trends; however, load and pressure changes occurred independently, owing to the changes in contact area produced by the osteotomies. No significant changes were observed in the nonoperated metatarsal regions. CONCLUSIONS: In this model, the chevron osteotomy more effectively reduced load and plantar pressure in the operated metatarsal regions; however, increases in load and pressure were observed in the first metatarsal region. The increase in pressure without a change in load in region 3 (third metatarsal) after a Weil osteotomy of the third metatarsal was attributed to the creation of a plantar prominence. This study did not show a reduction in load transmission as a result of the Weil osteotomy, which contradicts the proposed mechanism of clinical benefit. An intact first ray likely prevents transfer of load or pressure to adjacent lesser metatarsals with chevron osteotomy.     

第1跖跗关节骨折脱位不同内固定方式对前足足底压力变化的影响

目的 :测量第1跖跗关节骨折脱位3种内固定对前足足底压力的变化,为选择内固定提供实验参考。方法:取8具新鲜足标本,制成第1跖跗关节骨折脱位模型,依次进行3.5 mm全螺纹皮质骨螺钉,1/4管形钢板及加压骑缝钉固定。经加载600 N后,通过F-scan足底压力分析系统,测量前足足底压力的变化。结果:第1跖跗关节骨折脱位后,第1跖骨头下的峰值压力将减小,而第2跖骨头下的峰值压力将增大,差异具有统计学意义(P<0.05)。对第1跖跗关节分别采用螺钉、钢板进行固定后,第1、2跖骨头下的峰值压力都将趋于正常状态,而进行骑缝钉固定后,虽然第1、2跖骨头下的峰值压力都有所恢复,但仍与正常状态比较,差异有统计学意义(P<0.05)。结论 :当第1跖跗关节骨折脱位后,邻近跖骨头可能存在着"负荷转移"的调节机制以代偿部分足底压力;当第1跖跗关节骨折脱位采用螺钉和钢板内固定治疗后,前足足底压力都可恢复至正常状态,而若采用骑缝钉固定,则前足足底压力仍难以恢复至正常状态。     

The effect of pre-fabricated insole on plantar pressure distribution in patients with rheumatoid arthritis

BackgroundFoot deformities result in pain and changes in plantar pressure distribution in rheumatoid arthritis (RA) patients. Medical insoles are commonly prescribed for declining pain and modifying foot pressure distribution in these patients. The purpose of this study was to evaluate the effect of a pre-fabricated insole with metatarsal pad and medial longitudinal arch support on plantar pressure distribution in rheumatoid arthritis patients.MethodsFifteen females with RA participated in this study. All patients received a pair of pre-fabricated insoles that were individually modified using metatarsal pads and medial longitudinal arch supports. Mean peak pressure (kPa), maximum force (N), and contact area (cm²) were calculated for the heel, midfoot, metatarsophalangeal joint, and toe regions using the Pedar-X system immediately and after a month follow-up.FindingsIn the heel and metatarsophalangeal joint regions, maximum pressure and force showed a significant reduction in the follow-up assessment (p < 0.05). The comparison showed a significant increase in maximum pressure and force in the midfoot when participants walked with insole compared to without insole condition (p < 0.001).InterpretationUsing a pre-fabricated insole with an individually modified metatarsal pad and medial longitudinal arch support could alter rheumatoid arthritis patients’ plantar pressures after one month of follow-up. This type of insole is simple and inexpensive and showed a significant effect on decreasing pressures under the metatarsal heads.     

Two modifications of the Weil osteotomy: analysis on sawbone models

Second metatarsal osteotomies (30 degrees angle to shaft) were performed in 40 sawbones with: 1. head shifted proximally 5 mm; 2. head shifted proximally 10 mm; 3. 5-mm slice resected and head shifted proximally 5 mm; or 4. 5-mm dorsally based wedge resected and head shifted proximally 5 mm. Bone slice resection resulted in shortening (16.4+/-1.7 mm) and mild plantar displacement of the head (3.5+/-0.8 mm). Bone wedge excision resulted in moderate shortening (7.8+/-0.9 mm) and essentially no plantar displacement of the head (0.8+/-1.4 mm).     

Plantar pressure distribution in hallux valgus feet after a first metatarsal proximal crescentic osteotomy with a lesser metatarsal proximal shortening osteotomy

BackgroundPlantar pressure distribution after the first metatarsal proximal crescentic osteotomy (FMPCO) with lesser metatarsal proximal shortening osteotomy (LMPSO) for hallux valgus with metatarsalgia has not been previously described.MethodsThe pre- (Pre) and postoperative (Post) groups comprised of 18 patients who underwent unilateral FMPCO with LMPSO; fifteen healthy volunteers constituted the control (C) group. For each of the 10 regions, peak pressure (Peak-P), maximum force (Max-F), contact time (Con-T), contact area (Con-A), and force-time integral (FTI) were measured.ResultsThe mean Peak-P of the second metatarsal head was significantly lower in the Post group than the Pre group. The mean Peak-P, Max-F, Con-T, and FTI were not significantly different between the Post and C groups. The mean Con-A was significantly lower in the Post group than the C group.ConclusionFMPCO with LMPSO may improve the plantar pressure of the central forefoot comparable to healthy subjects.     

Closed Transverse Pinning for Reduction and Fixation of Metatarsal Neck Fractures: Surgical Technique

Most metatarsal neck fractures can be successfully treated non-operatively in a cast boot. Displaced metatarsal neck fractures tend to be less stable and have a propensity for the distal fragment to angulate, secondary to the strong flexor tendons, which often forces the distal fracture fragment in a plantar direction and leads to relative metatarsal shortening. Most literature is focussed on antegrade fixation of metatarsal neck fractures using pre-bent K wires or thin elastic nails. Apart from the technical challenges, this technique is limited when bones are osteoporotic as the pre-bent distal end of the K-wire may penetrate the plantar cortex of the proximal metatarsal and prevent the wire from entering the medullary canal of the metatarsal and advancing to the fracture site. Furthermore, when the medullary canal is narrow especially in Asian patients, it may be difficult to pass a bent K-wire through the isthmus of the metatarsal shaft. We describe an innovative technique of closed transverse wiring of the metatarsal head necks that has a distinct advantage in Asian population with osteoporotic bones. With percutaneous manipulation using digital pressure, closed reduction of fracture fragments of the most displaced fracture is done under fluoroscopic guidance to achieve a satisfactory alignment followed by closed transverse wiring of the metatarsal heads. With this procedure, adjacent fractures remain stable within an acceptable range because of intermetatarsal ligaments connected to the adjacent intact head. Our technique has a relatively short operating time and allows for early motion of the metatarso-phalangeal joint. This is especially useful for those with osteoporosis, narrow canal, soft tissue compromise, intra-operative failure of ante-grade pinning and in scenarios of limited surgical equipment/expertise.     

Iatrogenic fracture gapping during fixation of Jones fractures: Anatomic and mechanical considerations in a cadaveric model

BackgroundSurgical fixation of Jones fractures is often recommended to facilitate recovery and achieve union. Iatrogenic fracture displacement during intramedullary screw fixation is a commonly encountered technical issue. This may be related to fracture location in relation to the surrounding ligamentous attachments, namely the robust intermetatarsal ligaments found at the proximal articulation of the 4th and 5th metatarsals. This study examines the relationship between fracture line and its location in regards to the surrounding ligamentous structures and its effect on Jones fracture displacement, reduction and fixation in a cadaveric model.MethodsEighteen fresh-frozen cadaveric feet were dissected with preservation of all ligamentous attachments. Given the similar anatomic distal extent of the dorsal and plantar intermetatarsal ligaments on the 5th metatarsal, measurements were obtained detailing the anatomic position of the dorsal intermetatarsal ligament (DIL) only. The specimens were divided into two groups with modelled fractures created at the 4th & 5th metatarsal articulation proximal to the distal extent of the DIL (Group 1) or just distal to the DIL (Group 2). Fractures were fixed in standard fashion with serial fluoroscopic images obtained to study fracture gapping and rotation.ResultsThere was approximately 5 mm of fracture gapping created iatrogenically during tapping with no statistically significant differences between Group 1 and Group 2 (4.53 mm versus 5.25 mm, p = 0.5430). The distal aspect of the DIL was anatomically located 2.77 mm (Range 1.58 mm–4.46 mm) distal to the 4th & 5th metatarsal articulation.ConclusionsConsiderable iatrogenic fracture gapping occurs during intramedullary screw fixation of Jones fractures in a cadaveric model regardless of fracture location in relation to the intermetatarsal ligamentous attachments. Specific techniques may be required to maintain anatomic alignment during tapping and screw fixation to prevent iatrogenic displacement.Level of evidenceV, Expert Opinion.     

Effects of wearing foot orthosis with medial arch support on the fifth metatarsal loading and ankle inversion angle in selected basketball tasks

STUDY DESIGN: Preintervention and post-intervention, repeated-measures experimental design. OBJECTIVES: The objective was to investigate the effects of foot orthoses with medial arch support on ankle inversion angle and plantar forces and pressures on the fifth metatarsal during landing for a basketball lay-up and during the stance phase of a shuttle run. BACKGROUND: Proximal fractures of the fifth metatarsal, specifically the Jones fracture, are common in sports. Wearing foot orthoses with medial arch support could increase the ankle inversion angle and the plantar forces and pressure on the fifth metatarsal that may increase the risk for fifth metatarsal fracture, METHODS AND MEASURES: Three-dimensional (3-D) videographic, force plate, and in-shoe plantar force and pressure data were collected during landing after a basketball lay-up and during the stance phase of a shuttle run with and without foot orthoses with medial arch support for 14 male subjects. Two-way ANOVAs with repeated measures were performed to compare ankle inversion angle, maximum forces, and pressure on the fifth metatarsal head and base between conditions and between tasks. RESULTS: The maximum ankle inversion angle and maximum plantar force and pressure on the base of the fifth metatarsal during both tasks as well as the maximum plantar force and pressure on the head of the fifth metatarsal during the stance of the shuttle run were significantly increased (P< or =026) when wearing foot orthoses. No significant differences were found in the maximum vertical ground reaction forces between foot orthotic conditions. CONCLUSION: Generic use of off-the-shelf foot orthoses with medial arch support causes increased plantar forces and pressures on the fifth metatarsal and may increase the risk for proximal fracture of the fifth metatarsal. Future studies are needed to investigate this risk, acknowledging that the differences noted in our study were small in magnitude and the foot type was not measured.     

Distances from the deep plantar arch to the lesser metatarsals at risk during osteotomy: a fresh cadaveric study

Background

The deep plantar arch is formed by anastomosis of the lateral and deep plantar arteries. Osteotomy of the lesser metatarsals is often used to treat metatarsalgia and forefoot deformity. Although it is known that some blood vessels supplying the lesser metatarsals are prone to damage during osteotomy, there is little information on the distances between the deep plantar arch and the three lesser metatarsals. The aims of this study were to identify the distances between the deep plantar arch and the lesser metatarsals and to determine how osteotomy could damage the arch.

Methods

Enhanced computed tomography scans of 20 fresh cadaveric feet (male, n?=?10; female, n?=?10; mean age 78.6 years at the time of death) were assessed. The specimens were injected with barium via the external iliac artery, and the distance from the deep plantar arch to each lesser metatarsal was measured on axial and sagittal images.

Results

The shortest distances from the deep plantar arch to the second, third, and fourth metatarsals in the axial plane were 0.5, 2.2, and 2.8 mm, respectively. The shortest distances from the distal epiphysis to a line passing through the deep plantar arch perpendicular to the longitudinal axis of the lesser metatarsal in the sagittal plane were 47.0, 45.7, and 46.4 mm, respectively, and those from the tarsometatarsal joint were 23.0, 21.0, and 18.6 mm. The deep plantar arch ran at the level of the middle third, within the proximal portion of this third in 11/20 (55.0%), 7/20 (35.0%), and 5/16 (31.2%) specimens, respectively, and at the level of the proximal third in 9/20 (45.0%), 13/20 (65.0%), and 11/16 (68.8%).

Conclusions

Overpenetration into the medial and plantar aspect of the second metatarsal or the proximal and plantar aspect of the fourth metatarsal during shaft or proximal osteotomy could easily damage the deep plantar arch. Shaft or proximal osteotomy approximately 45–47 mm proximal to the distal epiphysis or 18–23 mm distal to the tarsometatarsal joint on the plantar aspect could interrupt blood flow in the deep plantar arch.