Lateral Forefoot Pressure Research Articles

Lateral Column Pressures Following Combined Subtalar/Talonavicular Fusion with and without Calcaneocuboid Fusion

Category: Hindfoot; Other Introduction/Purpose: There are few comparative studies between the traditional triple arthrodesis and the commonly performed modified procedure in which the calcaneocuboid joint is spared. Earlier investigations proposed that stiffening the lateral column of the hindfoot can increase lateral plantar pressures, potentially precipitating lateral column pain. We used a cadaver model to quantify the potential for reduced lateral column overload achieved by sparing the calcaneocuboid joint in a cadaveric model of triple arthrodesis simulating standing on both a neutral and sloping surface. Methods: Nine fresh-frozen, thawed cadaver legs were tested in 2 positions of the loaded surface: neutral and 10 degrees of eversion. Tendon loading and axial pressure was applied according to standard cadaveric models. Medial and lateral forefoot pressures were recorded using a pressure-sensitive plate (F-scan). The data were normalized as a percentage of the native state. Results: In neutral loading, the mean contact pressures under the fifth metatarsal head increased dramatically compared to the native state in both the standard (76.3%, p<.005) and calcaneocuboid-sparing (103.5%, p<.007) procedures. Pressure was reduced underneath the first metatarsal head medially in both standard (-52.8%, p< 0.017) and calcaneocuboid-sparing (-57.2%, p< 0.008). Loading on an everted surface yielded larger overall pressures laterally, but the further increases compared to the native state following both standard (39.0%, p < 0.04) and calcaneocuboid-sparing (57.9%, p< 0.03) procedures were smaller than in the neutrally loaded foot. No statistically significant difference was observed between the arthrodesis groups when loaded either on a neutral or sloped surface. Conclusion: In our cadaveric model, both traditional triple arthrodesis and the calcaneocuboid-sparing procedure resulted in significant elevation of lateral forefoot plantar pressures compared to the native state, but there was no identifiable protective effect from sparing the calcaneocuboid joint even in the provocative condition of loading on a sloping surface. Clinical Relevance: While other factors may guide the choice to spare the calcaneocuboid joint when performing hindfoot fusion, there is no evidence that preserving its motion significantly reduces the risk of lateral column overload.

The Effect of First Metatarsal Shortening and Sagittal Displacement on Forefoot Pressure in Minimally Invasive Hallux Valgus Correction.

Minimally invasive (MIS) treatment of hallux valgus (HV) deformity is increasing in popularity. A 2-mm diameter burr is used to create a distal first metatarsal osteotomy prior to capital fragment translation and fixation. The metatarsal will shorten by the burr's diameter (2 mm). Plantar or dorsal capital fragment displacement may also cause load transference and possibly transfer metatarsalgia. The purpose of this study is to examine the effect of MIS HV on forefoot loading mechanics with respect to metatarsal shortening and sagittal plane displacement. Four lower-limb cadaveric specimens were studied. A pedobarography pressure-sensing mat was used to record forefoot plantar pressure in a controlled weight-bearing stance position. Control and postosteotomy measurements were obtained with the capital fragment fixated in 3 possible positions: 0 mm, 5 mm dorsal, and 5 mm plantar displacement. Pedobarography data yielded pressure data within measurable graphical depictions. Raw mean contact pressure measurements were taken under the first and fourth metatarsal heads to establish medial and lateral forefoot loading pressure ratios. An a priori power analysis was performed based on previous peer-reviewed pedobarographic data, and our study was adequately powered. Around 40 measurements were recorded, and ratios of medial-to-lateral forefoot loading were constructed. Medial forefoot pressure control versus 0 mm displacement, and control versus dorsal displacement were not found to be statistically significant (p = 0.525, p = 0.55, respectively). Medial pressure significantly increased when comparing control versus plantar displacement (P = .006). Lateral pressure significantly increased with dorsal displacement of the osteotomy (P = .013). Our study found that MIS HV correction did not cause an increase in lateral forefoot pressure loading when sagittal plane displacements were controlled. Plantar displacement increased medial loading, and dorsal displacement increased lateral loading. It may be valuable for surgeons to consider metatarsal head position postosteotomy, as a decrease in medial loading and subsequent increase in lateral loading may lead to lateral forefoot pain and transfer metatarsalgia. IV.

The Effect of First Metatarsal Shortening and Sagittal Displacement on Forefoot Pressure in MIS Hallux Valgus Correction

Introduction/Purpose: Minimally invasive surgical (MIS) treatment of hallux valgus (HV) deformity is increasing in popularity. A 2mm-diameter burr is used to create a distal first metatarsal osteotomy prior to capital fragment translation and fixation. The metatarsal will shorten by the burr’s diameter (2mm). Plantar or dorsal capital fragment displacement may also cause load transference and possibly transfer metatarsalgia. In this study, we examine the effect of MIS HV on forefoot loading mechanics with respect to metatarsal shortening and sagittal plane displacement. Methods: Four lower-limb cadaveric specimens were studied. A pedobarography pressure-sensing mat was used to record forefoot plantar pressure in a controlled weightbearing stance position.10 Control and post-osteotomy measurements were obtained with the capital fragment fixated in 3 possible positions: 0mm, 5mm dorsal, and 5mm plantar displacement. Pedobarography data yielded pressure data within measurable graphical depictions. Raw mean contact pressure measurements were taken under the first and fifth metatarsal heads to establish medial and lateral forefoot loading pressure ratios. A priori power analysis was performed based on previous peer-reviewed pedobarographic data and our study was adequately powered. Results: 40 measurements were recorded and ratios of medial-to-lateral forefoot loading were constructed. Medial forefoot pressure change control versus 0mm displacement, and control versus dorsal displacement was not found to be statistically significant (p=0.525, p=0.55 respectively). Significant medial pressure increase was identified comparing control versus plantar displacement (p=0.006). Lateral pressure increased significantly with dorsal displacement of the osteotomy (p=0.013). Conclusion: MIS hallux valgus correction does not appear to cause increase in lateral forefoot pressure loading when sagittal plane displacements are controlled. Plantar displacement increases medial loading, and dorsal displacement increases lateral loading. The clinician must consider metatarsal head position post-osteotomy, as decrease in medial loading and subsequent increase in lateral loading may lead to lateral forefoot pain and transfer metatarsalgia.

Effect of Hind- and Fore-Foot Eversion on Positional and Rotational Displacement of the Knee in Standing Posture.

We investigated the effects of hindfoot and forefoot eversion on the knee's positional and rotational displacement, plantar pressure, and foot discomfort in a standing posture, beyond the traditional focus on external knee adduction moments (EKAM) in lateral wedge insoles. Twenty-six healthy participants underwent hindfoot eversion from 0 to 10 degrees in 2-degree increments, and forefoot eversion from 0 degrees to the hindfoot eversion angle in 2-degree increments in a standing posture. At each eversion angle, the knee's medial displacement, EKAM's moment arm decrease, plantar pressure changes, and foot discomfort were obtained and compared across varying angles. Both hindfoot-only and entire-foot eversion led to significant medial knee displacement and the EKAM's moment arm decrease, with more pronounced effects in entire-foot eversion. At each hindfoot eversion angle, increasing forefoot eversion resulted in significant medial knee displacement and EKAM's moment arm decrease. Lower leg rotations were not significantly affected in hindfoot-only eversion but displayed significant medial tilting and internal rotation in entire-foot eversion at specific combinations. Varying eversion angles significantly influenced the forefoot pressure, with heel pressure remaining unaffected. Notably, the lateral forefoot pressure increased significantly as the forefoot eversion angle increased, particularly at higher hindfoot eversion angles. Foot discomfort increased significantly with higher eversion angles, particularly in entire-foot eversion, and also increased significantly as the forefoot eversion angle increased at higher hindfoot eversion angles. Insole configurations incorporating 6-10 degrees of hindfoot eversion and 40-60% forefoot eversion of the hindfoot angle may offer optimized biomechanical support for knee osteoarthritis patients.

Foot shape and plantar pressure relationships in shod and barefoot populations.

This study presents population-based multivariate regression models for predicting foot plantar pressure from easily measured foot metrics in both shod and barefoot populations for running and walking tasks. Both shod and barefoot models were trained on 50 participants and predicted plantar pressure from anthropometric measurements using a 'leave-one-out' validation with R2 values of 0.72-0.78 across walking and running in both populations. When the model was blindly tested on 16 new data sets, the model performed just as well with R2 values of 0.76-0.79 across both populations. Walking and running peak plantar pressure were predicted with similar levels of accuracy in both populations. It was revealed that forefoot plantar pressure was more sensitive to the hallux-toe distance in barefoot people with shod participants showing little response to this foot characteristic. Lateral forefoot plantar pressure was sensitive to the arch index in both shod and barefoot participants but only for walking. During running, the arch index was not a useful determinant of lateral forefoot pressure. Hence, habitually barefoot people who adopt minimalist footwear should consider additional support in the medial forefoot and walking footwear should include forefoot support stratified by arch index (foot type), but running footwear is challenging due to the variability in strike patterns.

Effect of different fusion types on kinematics of midfoot lateral column: a comparative biomechanical study.

This study aimed to compare the biomechanical outcomes of the isolated 4th or 5th tarsometatarsal (TMT) joint arthrodesis with the whole lateral TMT joints arthrodesis. Ten cadaveric lower legs underwent isolated 4th TMT joint arthrodesis, 5th TMT joint arthrodesis, and whole lateral TMT joints arthrodesis in sequence. Texson F-scan and K-scanTM joint sensor were used to test the medial and lateral plantar pressure and the pressure of calcaneocuboid joint. Compared with the intact foot, the lateral forefoot pressure increased significantly (P<0.05) after 4th TMT joint fusion. The medial forefoot pressure was significantly lower in the 5th TMT joint fusion than that in the intact foot (P<0.05) and the 4th TMT joint fusion (P<0.05), but higher than that in the whole lateral TMT joints fusion (P<0.05). On the contrary, the lateral forefoot pressure was significantly higher in the 5th TMT joint fusion than that in the intact foot and the 4th TMT joint fusion, but lower than that in the whole lateral TMT joints fusion (P<0.05). The medial forefoot pressure was the lowest (P<0.05) and lateral forefoot pressure was the highest (P<0.05) in the whole lateral TMT joints fusion. The calcaneocuboid joint pressure increased respectively with the intact foot being the lowest, followed by the isolated 4th TMT joint arthrodesis, the isolated 5th TMT joint arthrodesis, and the whole lateral TMT joints arthrodesis (P<0.05). The isolated 4th or 5th TMT joint arthrodesis has less impact on the pressure of forefoot and adjacent joints than the whole lateral TMT joints arthrodesis. The isolated 4th TMT joint arthrodesis has the lowest influence on the pressure of forefoot and adjacent joints.

Examination of the effects of coordination and balance problems on gait in ataxic multiple sclerosis patients.

Objectives:To investigate the effects of coordination and balance problems on gait and plantar pressure distribution in multiple sclerosis patients.Methods:This was an observational, cross-sectional study. It was conducted at Necmettin Erbakan University between March and December 2017. Twenty-four individuals with coordination problems, 36 individuals with balance problems and 32 healthy individuals were included in the study. The EDSS, Functional Reach Test, Dynamic Gait Index, baropodometry and stabilometry evaluations were performed.Results:There were significant differences between the groups (velocity p = 0.000, cadence p = 0.000, step width p = 0.018, step length p = 0.000, foot angle p = 0.000). Multiple comparisons demonstrated that the velocities and cadences of the coordination group were lower, while their step widths were found to be higher, compared to the balance group (p = 0.012, p = 0.004, p = 0.017, respectively). In static plantar pressure distribution, lateral forefoot pressure, lateral hindfoot pressure and medial hindfoot pressure were significantly different between the groups (p = 0.002, p = 0.000, respectively) Multiple comparisons showed that the pressure on the lateral part of the hindfoot in the coordination group was found to be significantly higher compared to the balance group (p = 0.002). According to the dynamic plantar pressure distribution, lateral forefoot, medial forefoot, lateral hindfoot and medial hindfoot pressures were significantly different between the groups (p < 0.05).Conclusion:Coordination and balance problems affect gait and plantar pressure distribution. The identification of these changes will help physiotherapists determine specific therapeutic targets.

Biomechanical Analysis of Cuboid Osteotomy Lateral Column Lengthening for StageⅡB Adult- acquired Flatfoot Deformity

Category: Basic Sciences/Biologics Introduction/Purpose: To investigate the effect of cuboid osteotomy lateral column lengthening (LCL) for the correction of stage? B adult-acquired flatfoot deformity in cadaver. Methods: Six cadaver specimens were compressively loaded to 350 N. Flatfoot models were established and each was evaluated radiographically and pedobarographically in the following conditions: (1) intact foot, (2) flatfoot, (3) cuboid osteotomy LCL (2, 3, 4, and 5 mm). Results: Compared with the flatfoot model, the 2-,3-,4-, and 5-mm LCLs showed significant correction of talonavicular coverage on anteroposterior radiographs and talus-first metatarsal angle on both anteroposterior and lateral radiographs. As the graft increased in size incrementally, lateral forefoot pressure increased consistently, and medial pressure decreased significantly except for the 2-mm LCL. Compared with the intact foot, the above angles of the LCLs showed no significant difference except for the 2- mm LCL. In terms of forefoot pressure, medial pressure of the 2-mm LCL and lateral pressure of the 3-, 4- and 5-mm LCLs showed statistical differences, but lateral pressure of the 3-mm LCL was not much more than the intact foot as compared to the 4- and 5-mm LCLs, which was still less than medial pressure. Conclusion: Cuboid osteotomy LCL procedure avoids damage to subtalar joint and has a good effect on correction of stage? B adult-acquired flatfoot deformity with a 3 mm lengthening in cadavers.

Osteoarthritis of Lateral Lisfranc Joint After Lateral Column Lengthening in Flatfoot

Category: Lesser Toes Introduction/Purpose: Lateral column lengthening (LCL) procedure is commonly optional treatment as one of reconstruction surgery for the adult acquired flatfoot deformity (AAFD) due to posterior tibial tendon insufficiency in stage II. However, it had been confirmed that lateral forefoot pressures increase after LCL in previous studies. We may occasionally encounter some cases who have pain in the lateral aspect of the foot associated with osteoarthritis of Lisfranc joint after the surgery (Fig.). In this study, we retrospectively assessed lateral Lisfranc arthritis as postoperative complications after LCL. Methods: 17 feet in 15 patients who underwent operation including LCL for AAFD due to posterior tibial tendon insufficiency in stage II (two patients male and 13 were female). The mean age at the time of surgery was 64.2 years (52-80). All cases had LCL by calcaneocuboid distraction arthrodesis. The amounts of LCL achieved were 12.7 mm on average (8.0-15.0). The average duration of follow-up after the surgery was 21.8 months (4-97). We divided the subjects up into two groups: (1) pain group (n=7), were experiencing pain in the plantar-lateral aspect of the foot and/or tenderness at fourth and/or fifth tarsometatarsal (TMT) joint postoperatively; and (2) no-pain group (n=10), did not have that pain nor tenderness until the latest follow-up. Two groups were compared in age, body mass index (BMI), the American Orthopaedic Foot and Ankle Society (AOFAS) score, the amounts of LCL and several parameters on the radiograph. Results: In the pain group, all cases had osteoarthritic changes of the lateral Lisfranc joint (41.2%) on radiographs (grade II or more on the Kellgren-Lawrence grading scale). In overall subjects, 11 feet (65%) were revealed lateral Lisfranc arthritis. There were no significant differences in age, BMI, AOFAS scale, the LCL amounts between both groups. The medial column height was lower than lateral preoperatively, it became higher postoperatively by the reconstruction. In the pain group, the postoperative differences between medial and lateral tend to be greater than in no-pain group (P = 0.17). Patients with pain had significantly lower postoperative first talometatarsal angle (p &lt; 0.05). However, no significant differences were found in terms of the other radiographic parameters such as calcaneal pitch angle, talonavicular coverage angle and hindfoot alignment by Cobey’s view. Conclusion: This study indicated a high possibility of Lisfranc arthritis in patients who have pain of the lateral aspect of the foot after LCL. We suggest that this osteoarthritic change is one of the causes of such pain, and attribute the arthritis to increased lateral column pressures by excess calcaneocuboid distraction. As a preventive measure had reported previously, we may have to keep LCL within less than 10 mm, and may have to add the stabilization of medial column such as the first TMT fusion or Cotton osteotomy.

Lower activity levels are related to higher plantar pressures in overweight children.

This study aimed to establish whether the peak plantar pressures generated by overweight and obese school-age children during walking were associated with their objectively measured physical activity. Physical activity levels of a subset of 73 overweight/obese children from a randomized controlled trial (mean ± SD: age, 8.3 ± 1.1 yr; 47 girls; body mass index z-score, 2.7 ± 0.7) were objectively measured using accelerometers. Plantar pressure distributions were also quantified as the participants walked over a pressure platform. Pearson product moment correlation coefficients were calculated to determine the strength of the relations between the peak plantar pressures generated during walking and the physical activity levels for overweight/obese children. Peak pressures generated beneath the forefoot during walking were inversely correlated with time spent in different intensity levels of physical activity. Moderate-intensity (r = -0.321, P = 0.007), vigorous-intensity (r = -0.326, P = 0.006), and moderate- to vigorous-intensity (r = -0.342, P = 0.004) physical activity were significantly correlated with middle forefoot pressure and with lateral forefoot pressure (r = -0.248, P = 0.040; r = -0.264, P = 0.028; r = -0.267, P = 0.027, respectively). Lateral midfoot (r = -0.244, P = 0.044) and second toe (r = 0.227, P = 0.021) pressure were also significantly correlated with vigorous-intensity activity. Those children who generated higher pressures beneath their forefoot and midfoot during walking had lower levels of physical activity. Further research is required to determine the long-term effects of excessive body mass on participation in physical activity and whether the walking plantar pressure patterns associated with reduced physical activity are related to foot pain or discomfort.

Salient features of the Maasai foot: analysis of 1,096 Maasai subjects.

BackgroundThe Maasai are the most widely known African ethnic group located in Kenya and northern Tanzania. Most spend their days either barefoot or in their traditional shoes made of car tires. Although they walk long distances of up to sixty kilometers a day, they do not suffer from any foot ailments. Little is known about their foot structure and gait. The goal of this investigation was to characterize various aspects of Maasai foot in standing and walking.MethodsFoot length, calf circumference, hindfoot alignment, step length, cadence, and walking velocity were obtained from 1,096 adult Maasai people (545 males and 551 females; mean age, 40.28 ± 14.69 years; age range, 16 to 65 years). All included subjects were from rural areas, where the primary terrain was sandy soil, who spend most of their lifetime barefoot, walking. They all denied any medical history or previous symptoms related to foot problems. A trained clinician scanned all feet for deformities. Static (standing) and dynamic (walking) Harris mat footprints were taken to determine the distribution of forefoot pressure patterns during walking.ResultsThe average foot length was 250.14 ± 18.12 mm (range, 210 to 295 mm) and calf circumference was 32.50 ± 3.22 cm (range, 25 to 41 cm). The mean hindfoot alignment was 6.21° ± 1.55° of valgus. Sixty-four subjects (5.84%) had bilateral flat-shaped feet with a low medial longitudinal arch that exactly matched the broad pattern of their static footprints. Step length, cadence, and walking velocity were 426.45 ± 88.73 cm (range, 200 to 690 cm), 94.35 steps/min (range, 72 to 111 steps/min), and 40.16 ± 8.36 m/min (range, 18.20 to 63.36 m/min), respectively. A total of 83.39% subjects showed unilateral or bilateral deformities of multiple toes regardless of age. The most frequent deformity was clawing (98.79%) of which the highest incidence occurred with the fifth toe (93.23%). Dynamic footprints showed even pressure patterns throughout the forefoot (64.87%), followed by lateral forefoot pressure concentration patterns (21.81%).ConclusionsOur study shows the distinct parameters that provide more insight into the Maasai foot.

Lateral and Medial Plantar Pressures after Split versus Whole Anterior Tibialis Tendon Transfer

If whole and split transfer of the anterior tibialis tendon (SPLATT) do not differ in balancing the forefoot, whole tendon transfer would provide a simpler alternative as part of treatment of an equinovarus deformity. We hypothesized that no significant differences in percent plantar lateral forefoot pressures would be observed between split and whole tendon transfer. We used a spastic model to test the hypothesis that overcorrection would not occur with whole tendon transfer. In ten specimens from five lower extremity matched pairs, a SPLATT was anchored to the cuboid. After loading, simulated whole tendon transfer to the lateral cuneiform was done. Normal loading was Achilles, 250 N, tibialis anterior, 200 N, peroneals/tibialis posterior, 142 N; and spastic loading was Achilles, 500 N, tibialis anterior, 400 N, peroneals/tibialis posterior, 142 N. Pressure data were collected for both normal and spastic conditions. Percent of forefoot pressure was calculated for the lateral and medial sector. Percent lateral pressure was slightly lower after whole tendon transfer (normal, p < 0.01; spastic, p < 0.01). This difference was not clinically important. Medial pressure did not differ in the spastic versus the normal model after split or whole tendon transfer. Whole and split anterior tibialis tendon transfer both resulted in a balanced forefoot. Neither whole tendon nor split tendon transfer resulted in overcorrection in a simulated spastic model. Whole tendon transfer may be an effective and simpler alternative to SPLATT for unloading the lateral forefoot in both a normal and a spastic foot.

New insights into stance phase foot biomechanics using pedobarographic statistical parametric mapping

There is disagreement in the literature regarding the peak plantar pressure correlates of walking speed. Some studies report generalized increased pressures across the entire plantar surface [1] while others report decreases in lateral forefoot pressures and infer a medial shift in load with increased walking speeds [2]. The purposes of this study were: (a) To use statistical parametric mapping (SPM), a high resolution statistical technique, to clarify the pressure correlates of walking speed and (b) To corroborate SPM results with those of a traditional ten-region subsampling technique.

Plantar Pressure Analysis in Cadaver Feet After Bony Procedures Commonly Used in the Treatment of Stage II Posterior Tibial Tendon Insufficiency

Bony procedures play an essential role in the operative treatment of stage II posterior tibial tendon insufficiency and often substantially alter the loading characteristics of the foot. Eight matched pairs of cadaver lower extremities were axially loaded onto a TekScan HR Mat. (TekScan, Inc., South Boston, MA) After intact testing, each specimen had a lateral column lengthening (either a calcaneocuboid distraction arthrodesis [CCDA] or Evans procedure), a medializing calcaneal osteotomy (MCO), and a plantarflexion (Cotton) osteotomy of the medial cuneiform. The measured plantar pressures were divided into three forefoot regions, two midfoot regions, and two hindfoot regions. For each region, average pressure, peak pressure, and contact area data were collected. Despite the fact that both lateral column lengthening procedures resulted in increased lateral forefoot pressures, no significant differences were noted between the CCDA and the Evans procedure. The addition of a MCO did not significantly alter the plantar pressures measured after the lateral column lengthening alone. Although the Cotton osteotomy resulted in increased average pressures within the medial forefoot, a compensatory significant decrease in lateral forefoot pressures was not observed. The present study demonstrated increased lateral forefoot pressures after a combined lateral column lengthening and MCO and does not support the idea that a Cotton osteotomy significantly reduces loading of the lateral forefoot. The incidence of lateral forefoot pain and fifth metatarsal stress fractures subsequent to either lateral column lengthening procedure may not significantly decline after a Cotton osteotomy.

Calcaneocuboid Distraction Arthrodesis and First Metatarsocuneiform Arthrodesis for Correction of Acquired Flatfoot Deformity in a Cadaver Model

Lateral column lengthening has been associated with residual forefoot supination and symptomatic lateral overload in treatment of acquired flatfoot. A medial column procedure may be useful to redistribute load to the medial column. We evaluated radiographic and pressure changes in a severe flatfoot model with lateral column lengthening and investigated the effect of an added first metatarsocuneiform arthrodesis. Ten cadaver specimens were loaded in simulated double-legged stance, and radiographic and pressure data were collected for all tested states. Calcaneocuboid arthrodesis was done with a 10-mm foam wedge. Residual forefoot varus was corrected through the first metatarsocuneiform joint. Differences in the mean lateral talar-first metatarsal angle, talonavicular angle, talocalcaneal angle, and calcaneal pitch were significant between the intact foot and the flatfoot. After calcaneocuboid distraction arthrodesis and tendon transfer, the lateral talar-first metatarsal angle, talonavicular angle, and calcaneal pitch were significantly different from the flatfoot. After added first metatarsocuneiform arthrodesis, the talonavicular angle was not significantly different from the intact foot. Lateral forefoot pressure increased in the flatfoot after lateral column lengthening but was not significantly different from the intact foot after first metarsocuneiform arthrodesis was added. Adding first metatarsocuneiform arthrodesis to calcaneocuboid distraction arthrodesis for treatment of flatfoot deformity provided improvement in radiographic and pedobarographic parameters of a severe model of stage II posterior tibial tendon dysfunction.

Lateral Column Calcaneal Lengthening, Flexor Digitorum Longus Transfer, and Opening Wedge Medial Cuneiform Osteotomy for Flexible Flatfoot: A Biomechanical Study

Lengthening of the lateral column is commonly used for reconstruction of the adult and pediatric flatfoot, but can result in supination of the foot and symptomatic lateral column overload. The addition of a medial cuneiform osteotomy has been used to redistribute forces to the medial column. The combined use of a lateral column lengthening and medial cuneiform osteotomy in a reproducible cadaver flatfoot model was evaluated. Twelve cadaver specimens were physiologically loaded and each was evaluated radiographically and pedobarographically in the following conditions: 1) intact, 2) severe flatfoot, 3) lateral column lengthening with simulated flexor digitorum longus transfer, and 4) lateral column lengthening and flexor digitorum longus (FDL) transfer with added medial cuneiform osteotomy. The lateral column lengthening was performed with a 10-mm foam bone wedge through the anterior process of the calcaneus, and the medial cuneiform osteotomy was performed with a dorsally placed 6-mm wedge. Lateral column lengthening with simulated FDL transfer on a severe flatfoot model resulted in a significant change as compared with the flatfoot deformity in three measurements: in lateral talus-first metatarsal angle (-17 to -7 degrees; p<0.001), talonavicular angle (46 to 24 degrees; p<0.001), and medial cuneiform height (16 to 20 mm; p<0.001). Lateral forefoot pressure increased from 24.6 to 33.9 kPa (p<0.001) after these corrections as compared with the flatfoot. Adding a medial cuneiform osteotomy decreased the lateral talar-first metatarsal angle from -7 to -4 degrees, decreased the talonavicular coverage angle from 24 to 20 degrees, and increased the medial cuneiform height from 20 to 25 mm. After added medial cuneiform osteotomy, lateral pressure was significantly different from that of the flatfoot (p=0.01) and was not significantly different from that of the intact foot (p=0.14). Medial forefoot pressure was overcorrected as compared with the intact foot with added medial cuneiform osteotomy. Lateral column lengthening increased lateral forefoot pressures in a severe flatfoot model. An added medial cuneiform osteotomy provided increased deformity correction and decreased pressure under the lateral forefoot.

The Effects of a Medializing Calcaneal Osteotomy With and Without Superior Translation On Achilles Tendon Elongation and Plantar Foot Pressures

The medial calcaneal osteotomy (MCO) is a frequently used corrective procedure for posterior tibial tendon (PTT) insufficiency; however, patients often complain of lateral foot pain postoperatively. Published findings have documented the usefulness of MCO in off-loading the plantar surface of the first and second metatarsal heads but with a concomitant increase in peak pressure over the lateral forefoot and heel. Achilles tendon elongation revealed a trend toward shortening of the ventromedial aspect of the tendon. It was then hypothesized that translating the osteotomized posterior aspect of the calcaneus medially and superiorly would reduce lateral forefoot pressure and decrease the amount of lengthening of the Achilles tendon while continuing to relieve medial forefoot pressure. Twenty-eight fresh-frozen cadaver legs were axially loaded on a load-frame device to 100 lbs to assess the effects of a 1-cm MCO in conjunction with either 0.5-cm or 1-cm superior translation on plantar foot pressures and Achilles tendon elongation. The 0.5-cm superior translation resulted in a greater off-loading of the first and second metatarsals than the MCO alone with a trend toward decreased pressures in the lateral forefoot. The 1-cm superior translation continued to unload the first and second metatarsals; however, lateral forefoot and midfoot pressures were increased. Achilles tendon lengthening remained unchanged in the cadaver foot model. Our findings suggest that the addition of a 0.5-cm superior translation to the traditional 1-cm MCO should allow some degree of off-loading of the medial forefoot without increasing lateral forefoot or heel pressures.