Metatarsophalangeal Dorsiflexion Research Articles

High-Heel Wearing Does Not Change The Forefoot Alignment In Non-Frequent Users Without Hallux Valgus: 3D Weight-Bearing Scan Study

Category: Lesser Toes; Midfoot/Forefoot Introduction/Purpose: Women wearing high heels for 20 years without Hallux valgus angle alterations make it debatable that causes Hallux valgus deformation. A recent systematic review determined that 4.13 ± 0.34 cm of heel height would improve foot weight-bearing . Wearing high heels would realign the foot, causing an inversion of the foot, which locked the navicular-cuneiform and cuneo-metatarsal joints rather than primarily rotate the metatarsophalangeal joint. Nowadays, weight-bearing scans could favor understanding the alignment mechanism involved in the foot and ankle with different shoe heights. Therefore, we aimed to determine the acute foot alignment in non-frequent HH users without Hallux valgus during stand posture. Here, we hypothesize that high heels studied by weight-bearing scans shows radiology changes linked to hindfoot alignment rather than primary forefoot rotation. Methods: This comparative cross-sectional study, participants were randomly submitted to a tridimensional weight-bearing CT. Foot alignment for barefoot and wearing custom high heels of 3, 6, and 9 cm. Forty-one feet from twenty-one participants (11 males and 10 females, aged 30.8 ± 8.9 years, and Body Mass Index 25.5 ± 2.0 m kg-2) were submitted to a tridimensional weight- bearing scan in barefoot and wearing high heels of 3, 6, and 9 cm. The inclusion criteria were: Aged between 20 and 50 years, and no regular wearing of heels.Participants were instructed to bear weight in their regular standing upright posture, dispensing the body weight uniformly between the lower limbs with the feet set at shoulder width. Declination talar, forefoot arch, foot ankle offset, 1st, 2nd, and 3rd metatarsophalangeal dorsiflexion, and metatarsal rotation and sesamoid rotation angles were compared with repeated measurement analysis and multiple comparisons as well as the raters intraclass coefficient. Results: When height increases, the declination talar angle decrease (p < 0.001), the foot ankle offset decreases (p < 0.001), the 1st, 2nd, and 3rd dorsiflexion angle increases (p < 0.001), and metatarsal rotation angle (p=0.696) and sesamoid rotation angles (p=0.649) did not change. The forefoot arch for 6 cm was higher than 3 cm (p < 0.001) and then 9 cm (p=0.001), and the forefoot arch for 9 cm was higher than 3 cm (p=0.049). Conclusion: The main finding was that increased forefoot arch, lower ankle offset, no metatarsal rotation angle, and no sesamoid rotation angle strongly suggest an acute primary hindfoot alignment adaptation mechanism rather than forefoot rotation with increase of heel heigth. The most critical mechanism combines the activation of the windlass mechanism together with a stiffer alignment of Hindfoot. Our interpretation here is supported by the lower FAO, and increased forefoot arch and metatarsophalangeal joints, giving insight into pathology foot deformation like Hallux valgus. Thus, our findings suggest that it is debatable that wearing high heels can trigger forefoot deformity,

Neuropathic Pain Associated With First Metatarsophalangeal Joint Osteoarthritis: Frequency and Associated Factors.

To determine whether neuropathic pain is a feature of first metatarsophalangeal (MTP) joint osteoarthritis (OA). A total of 98 participants (mean ± SD age 57.4 ± 10.3 years) with symptomatic radiographic first MTP joint OA completed the PainDETECT questionnaire (PD-Q), which has 9 questions regarding the intensity and quality of pain. The likelihood of neuropathic pain was determined using established PD-Q cutoff points. Participants with unlikely neuropathic pain were then compared to those with possible/likely neuropathic pain in relation to age, sex, general health (Short Form 12 [SF-12] health survey), psychological well-being (Depression, Anxiety and Stress Scale), pain characteristics (self-efficacy, duration, and severity), foot health (Foot Health Status Questionnaire [FHSQ]), first MTP dorsiflexion range of motion, and radiographic severity. Effect sizes (Cohen's d coefficient) were also calculated. A total of 30 (31%) participants had possible/likely neuropathic pain (19 possible [19.4%], 11 likely [11.2%]). The most common neuropathic symptoms were sensitivity to pressure (56%), sudden pain attacks/electric shocks (36%) and burning (24%). Compared to those with unlikely neuropathic pain, those with possible/likely neuropathic pain were significantly older (d=0.59, P=0.010), had worse SF-12 physical scores (d=1.10, P < 0.001), pain self-efficacy scores (d=0.98, P < 0.001), FHSQ pain scores (d=0.98, P < 0.001), and FHSQ function scores (d=0.82, P < 0.001), and had higher pain severity at rest (d=1.01, P < 0.001). A significant proportion of individuals with first MTP joint OA report symptoms suggestive of neuropathic pain, which may partly explain the suboptimal responses to commonly used treatments for this condition. Screening for neuropathic pain may be useful in the selection of targeted interventions and may improve clinical outcomes.

The Role of the Plantar Fascia, Flexor Hallucis Longus, and Fiberosseous Tunnel in Functional Hallux Rigidus

Category: Midfoot/Forefoot Introduction/Purpose: Functional hallux rigidus is characterized by limited first metatarsophalangeal (MTP) dorsiflexion during weight bearing conditions, but normal motion when the metatarsal is allowed to plantarflex. This phenomenon alters the mechanics of the foot, potentially leading to lateral column overloading and dynamic cavovarus. Furthermore, it is suspected that the abnormal forces across the first MTP alters its biomechanics, leading to cartilage destruction and eventual structural hallux rigidus. The purpose of this study is to assess the role of the flexor hallucis longus (FHL) and plantar fascia in functional hallux rigidus and to determine the best surgical treatment. Methods: Six cadaveric lower limbs disarticulated at the hip were analyzed. The feet were positioned manually in the same manner that would be used in a clinical exam of patients. The examiner's thumb was used to stabilize the first metatarsal head and prevent plantarflexion to simulate the closed-chain kinetics of weight bearing. The same hand was used to hold the ankle neutrally aligned to the leg. The other hand was used to maximally dorsiflex the great toe. X-ray was used to obtain images of the feet. The plantar fascia was transected with a Z cut, shortened approximately 5 mm, then repaired. The fiberosseous tunnel was released. The FHL was transected with a Z cut then shortened approximately 5 mm. Great toe dorsiflexion was assessed and X-rays taken after each of the manipulations. Range of motion of the first MTP was measured on Xrays and analyzed using Student's T-test. Results: Average passive dorsiflexion of the first MTP is 29.8° (range 17-46°) prior to manipulation. Shortening the plantar fascia and FHL did not decrease the MTP dorsiflexion significantly beyond baseline (P = 0.08, 0.09 respectively). Transecting the plantar fascia increased the dorsiflexion by 14° (standard deviation (SD) 9.5) and transecting the FHL increased dorsiflexion by 13.7° (SD 4.0). Dorsiflexion increased significantly beyond baseline with both these methods (P = 0.02 and P &lt; 0.001 respectively), but the difference between the two methods was not significant (P = 0.93). Releasing the fiberosseous tunnel alone increased the dorsiflexion 8.8° (SD 5.7). Increased dorsiflexion beyond baseline was significant (P = 0.03). The increase in dorsiflexion with fiberosseous tunnel release was not significantly different than transecting the plantar fascia or the FHL (P = 0.40 and 0.42 respectively). Conclusion: By definition, functional hallux rigidus is diagnosed when first MTP dorsiflexion cannot reach 60°. Its prevalence may be more widespread than previously identified. Both the FHL and plantar fascia are implicated in functional hallux rigidus, as transection of either improves the dorsiflexion of the great toe. However, accessing the plantar fascia comes with significant risks and complete transection of the FHL is not feasible. As an alternative, releasing the fiberosseous tunnel is a simple, minimally morbid procedure that can also significantly improve functional hallux rigidus to a similar degree.

The relationship between foot and ankle joint flexibility measures and barefoot plantar pressures in healthy older adults: a cross-sectional study

BackgroundRestriction in foot and ankle joint range of motion, such as an ankle equinus, has been associated with increased plantar pressure and its complications. However, previous research is limited by its scope of measures and study populations. The aim of this study was to investigate the relationship between foot and ankle joint range of motion on barefoot plantar pressures during walking in healthy older adults.MethodsThis cross-sectional study recruited 49 older adults. Participants underwent measures of foot (first metatarsophalangeal dorsiflexion range of motion, and navicular drop and drift) and ankle joint range of motion, foot posture, body mass index, and plantar pressure during barefoot walking. Spearman Rank Order Correlations were used to explore the relationship between foot and ankle measures, body mass index, and plantar pressure, with significant correlations explored in a hierarchical regression analysis. A Mann-Whitney U test was performed to compare plantar pressure values between those with and without ankle equinus per region of the foot.ResultsMean (SD) age and BMI were 72.4 years (5.2) and 29.8 kg/m2 (5.9) respectively. A total of 32 of the 49 participants (65%) identified as female sex. Mean (SD) ankle joint range of motion was 32.7 (6.4) degrees with 17/49 (34.7%) participants classified as having an ankle equinus (defined as < 30 degrees of ankle joint dorsiflexion range of motion). We found that an ankle equinus predicted a statistically significant amount of peak forefoot plantar pressure (p = 0.03). Participants with an ankle equinus displayed significantly higher forefoot peak pressure 677.8 kPa (589.9 to 810.4) compared to those with no equinus 565.58 kPa (447.3 to 651.2), p = 0.02. A statistically significant correlation was found between body mass index and midfoot peak pressure (p < 0.01) and pressure-time integral (p < 0.01). No other significant correlations were found.ConclusionClinicians should consider screening for an ankle equinus and body mass index as a simple way to identify which healthy older adults may be at risk of pressure-related complications in the mid- and forefoot.

Adjacent Joint Restriction Differentially Influences Intra- and Inter-rater Reliability and Agreement of Goniometric Measurements.

BackgroundReliability and agreement of goniometric measurements can be altered by variations in measurement technique such as restricting adjacent joints to influence bi-articular muscles. It is unknown if the influence of adjacent joint restriction is consistent across different range of motion (ROM) tests, as this has yet to be assessed within a single study. Additionally, between-study comparisons are challenged by differences between methodology, participants and raters, obscuring the development of a conceptual understanding of the extent to which adjacent joint restriction can influence goniometric ROM measurements.PurposeTo quantify intra- and inter-rater reliability and levels of agreement of goniometric measurements across five ROM tests, with and without adjacent joint restriction.Study DesignDescriptive reliability studyMethodsThree trained and experienced raters made two measurements of bilateral ankle dorsiflexion, first metatarsophalangeal dorsiflexion, hip extension, hip flexion, and shoulder flexion, with and without adjacent joint restriction. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), along with participant, measurement/rater and random error variance were estimated.ResultsEleven females (age 21.4 ±2.3 years) and 19 males (age 22.1 ±2.8 years) participated. Adjacent joint restriction did not influence the reliability and agreement in a consistent way across the five ROM tests. Changes in the inter-rater reliability and agreement were more pronounced compared to the intra-rater reliability and agreement. Assessing variance components (participant, measurement/rater and random error variance) that are used to calculate the ICC and SEM, improved interpretation of ICC and SEM scores.ConclusionThe effects of adjacent joint restriction on reliability and agreement of goniometric measurements depend on the ROM test and should be considered when comparing measurements between multiple raters. Reporting variance components that are used to calculate the ICC and SEM can improve interpretation and may improve between-study comparisons, towards developing a conceptual framework to guide goniometric measurement technique.Level of Evidence3b

The interaction effects of rocker angle and apex location in rocker shoe design on foot biomechanics and Achilles tendon loading

The influences of rocker shoes on foot biomechanics were controversial because the interaction between two design factors—rocker angle and apex location, was usually omitted. This study investigated the interaction effects of rocker angle and apex location on plantar foot pressure, metatarsophalangeal/ankle angle, and Achilles tendon force during walking. Ten participants performed walking trials under six rocker shoe conditions: 2 rocker angles (mild and severe) ​× ​3 apex locations (distal, standard, and proximal), wherein the plantar foot pressure was measured and the movement data were processed by musculoskeletal modeling to report joint angle and Achilles tendon force. A two-way ANOVA repeated measures was used for statistics. Significant interaction effects were reported in examinations of forefoot pressure, midfoot pressure, and metatarsophalangeal dorsiflexion. The standard apex significantly reduced peak forefoot and midfoot pressures (p ​= ​0.008–0.034, Hedges'g ​= ​0.75–0.84), which was further decreased by a severe rocker angle (p ​= ​0.006, Hedges'g ​= ​0.51–0.81). Moving the apex proximally reduced Achilles tendon forces (p ​< ​0.001, Hedges' g ​= ​0.80) and facilitated both metatarsophalangeal dorsiflexion and ankle plantarflexion during push-off (p ​= ​0.003–0.006, Hedges' g ​= ​0.03–0.82). Rocker angle seemed to have fewer effects on ankle joint angle and Achilles tendon force. We concluded that apex location was likely the dominant design factor of the rocker sole in influencing foot biomechanics, yet its interactions with rocker angle should be considered. The configuration of the two features could be varied to possess different therapeutic merits and adapt to specific application purposes.

The Adelaide Experience: Short Term Results with the Use of Cartiva Implant

Category:Midfoot/ForefootIntroduction/Purpose:Hallux rigidus is the most common arthritic condition of the foot. There are only few surgical options that does not require fusing the 1st MTPJ thus allowing motion in the joint. A new first metatarsophalangeal (MTP) joint hemiarthroplasty with a polyvinyl alcohol (PVA) hydrogel implant (Cartiva) has demonstrated pain relief and functional outcomes equivalent to first MTP arthrodesis at 2 and 5 years postoperation in few studies done in North America. We would like to present the Adelaide short term result with the use of this implant.Methods:40 Patients who underwent first PVA hydrogel MTP hemiarthroplasty in Adelaide by two senior foot and ankle surgeons (C.B and P.S) and by two international foot and ankle fellow (G.G and J.P) between 2017 and 2019 were included in this study. The follow up period was 24 months postoperation. Patients underwent physical examination and radiographic evaluation and completed a pain VAS, the Short-Form-36 (SF-36), and the Foot and Ankle Ability Measure (FAAM) sports subscale and activities of daily living (ADL) subscale. At the time of this study, 40 patients had reached 2 year follow-up.Results:There were no lost to follow up, leaving 40 patients with mean age 63.4 (range, 40.1-79.9) years. Mean follow-up was 24 months (range, 6-30 months). Postoperative active MTP natural joint dorsiflexion and peak MTP dorsiflexion were mean 18.2 (range, 10.0- 30.0) and 29.7 (range, 10.0-45.0) degrees, respectively. Pain VAS, SF-36, FAAM ADL, and FAAM Sports scores demonstrated clinically and statistically significant improvements. Radiographically, no patient demonstrated changes in implant position, implant loosening or subsidence, or implant wear. One implant was removed because of persistent pain 7 months post surgery and was converted to fusion 3 months after the removal of the Cartiva implant.Conclusion:Short term results for the use of Cartiva implant in Adelaide show that functional outcomes improved significantly, pain was reduced significantly, and the implant demonstrated excellent survivorship. Our results are similar for those described in the North American literature

Longitudinal bending stiffness does not affect running economy in Nike Vaporfly Shoes

PurposeThis study aimed to determine the independent effect of the curved carbon-fiber plate in the Nike Vaporfly 4% shoe on running economy and running biomechanics. MethodsFifteen healthy male runners completed a metabolic protocol and a biomechanics protocol. In both protocols participants wore 2 different shoes, an intact Nike Vaporfly 4% (VFintact) and a cut Nike Vaporfly 4% (VFcut). The VFcut had 6 medio-lateral cuts through the carbon-fiber plate in the forefoot to reduce the effectiveness of the plate. In the metabolic protocol, participants ran at 14 km/h for 5 min, twice with each shoe, on a force-measuring treadmill while we measured metabolic rate. In the biomechanics protocol, participants ran across a runway with embedded force plates at 14 km/h. We calculated running economy, kinetics, and lower limb joint mechanics. ResultsRunning economy did not significantly differ between shoe conditions (on average, 0.55% ± 1.77% (mean ± SD)) worse in the VFcut compared to the VFintact; 95% confidence interval (–1.44% to 0.40%). Biomechanical differences were only found in the metatarsophalangeal (MTP) joint with increased MTP dorsiflexion angle, angular velocity, and negative power in the VFcut. Contact time was 1% longer in the VFintact. ConclusionCutting the carbon-fiber plate and reducing the longitudinal bending stiffness did not have a significant effect on the energy savings in the Nike Vaporfly 4%. This suggests that the plate's stiffening effect on the MTP joint plays a limited role in the reported energy savings, and instead savings are likely from a combination and interaction of the foam, geometry, and plate.

Clinical and radiological outcomes after arthrodesis of the first metatarsophalangeal joint.

The main aim of this study was to investigate the correlation between radiographic findings and clinical outcomes following the first metatarsophalangeal (MTP) joint arthrodesis. In a comparative retrospective study, on 46 patients (48ft), the correlation between post-operative radiographic findings including hallux valgus angle (HVA) and first MTP dorsiflexion angle (MTPDA) and clinical outcomes including VAS pain, modified AOFAS hallux score, and FFI questionnaire were evaluated. Moreover, clinical outcomes were compared between cases with pre-operative diagnosis of first MTP inflammatory arthritis, hallux valgus, hallux varus, and grade 3 and 4 of hallux rigidus. The effect of first MTP arthrodesis on Meary's angle and intermetatarsal angle (IMA) were found out. The mean age of the patients was 56.3 ± 9.1 (range, 29-69) years, including 42 (91.3%) females and 4 (8.7%) males. We had fusion rate of 97.9%, one asymptomatic nonunion case (2.1%). Totally, mean scores of modified AOFAS hallux score, FFI percentage, and VAS pain were 88.9 ± 12.6, 9.4 ± 16.5, and 1.23 ± 2.24, respectively. Hallux varus was associated with the most favourable outcomes; whereas, patients with first MTP arthritis got the worst outcome. Regression analysis test between clinical outcomes and HVA > 15° and first MTPDA >15° showed correlation coefficient of almost zero. No statistically significant differences were found between the clinical outcomes of grade 3 and 4 of hallux rigidus (p value of modified AOFAS hallux score, FFI percentage, and VAS pain: 0.879, 0.906, and 0.298, respectively). Mean of HVA and IMA reduction in 15 hallux valgus underwent first MTP fusion were 34.4° and 8.4°, respectively. Meary's angle increased about 4° with statistically significant difference (p value 0.001). Patients with first MTP fusion > 15° in coronal and transverse plans could have acceptable clinical outcomes. The clinical outcome of first MTP arthrodesis for grade 3 hallux rigidus is comparable with grade 4. First MTP fusion would have positive effect on IMA and Meary's angle.

Evaluation of Outcomes Following Lesser Toe Metatarsophalangeal Interpositional Arthroplasty with Semitendinosus Allograft with Description of the Anchovy Technique

Category: Lesser Toes Introduction/Purpose: Lesser toe metatarsal head degeneration and collapse can cause significant pain and disability. If conservative measures fail, there is not a clear surgical solution, particularly in the setting of bone loss. A wide variety of causes of lesser metatarsophalangeal (MTP) joint degeneration exist, including Freiberg’s disease, failure of previous surgery, and primary osteoarthritis. Previous studies have evaluated joint preserving osteotomies; however, they do not offer a solution for complete head collapse. Isolated metatarsal head excision is associated with poor outcomes. The purpose of our study was to evaluate clinical outcomes and review radiologic finding after lesser toe MTP interpositional arthroplasty with semitendinosus allograft and to describe the technique. To our knowledge, this technique and its outcomes have not been described for the lesser toes. Methods: We retrospectively reviewed a consecutive series of patients treated by three foot and ankle trained surgeons at one institution from 2007-2017. We identified sixteen patients who underwent allograft interpostional arthroplasty for the second or third MTP joint. We performed a retrospective chart review to obtain demographics, diagnosis, range of motion, and concomitant procedures. A phone survey was created to evaluate satisfaction, pain, and likelihood to repeat the surgery. Foot and Ankle Ability Measure (FAAM) scores were reviewed. Preoperative and postoperative radiographs were reviewed for preservation of metatarsal lengths and cascade. The procedure was performed through a dorsal midline approach to the MTP joint. Osteophytes were removed and a cannulated reamer created a concavity in the metatarsal head. A semitendinosus allograft was then rolled and sutured into a ball, which was approximately 1.5 cm in diameter. The allograft was secured to the medullary canal with a suture anchor. Results: Fourteen patients underwent 2nd MTP interposition, and two patients underwent 3 rd MTP interposition arthroplasty. The average age of the patients were 51.3 years (median 53.4, range 24-61), and the average follow up was 3.4 years. Seven patients had multiple procedures. The diagnoses included six primary osteoarthritis, four Freiberg’s disease, two failed prior surgery. Preoperative FAAM showed the patients were able to complete 73% of activities of daily living and 63% of sport specific activities. Average MTP dorsiflexion was 27 and 30 degrees before and after surgery, respectively. Radiographically, preoperative metatarsal length ranged from 9.36 - 12.63 cm. Postoperatively, the metatarsal length added to the space filled by the allograft ranged from 9.65 cm - 11.77 cm. Conclusion: Interpositional arthroplasty of the lesser MTP joints with a rolled semitendinosus allograft, secured with a suture anchor, provides a unique solution to a difficult problem. This procedure allows the surgeon to fill a bony void and replace collapsed metatarsal head. This study shows patient reported outcomes based on phone survey and FAAM scores, where pain caused significant limitations before surgery. This study also showed preservation of range of motion after surgery. Radiographic review suggests that length of the affected metatarsal can be maintained, bone voids can be filled, and the cascade of the metatarsals can be preserved.

Joint Preservation of the 1st MTP

Category: Midfoot/Forefoot Introduction/Purpose: Focal damage to articular cartilage and the supporting subchondral plate, commonly referred to as an osteochondral defect (OCD), can be a cause of joint pain and subsequent decreased range of motion. There are few studies specifically describing these lesions in the first metatarsophalangeal (MTP) joint, where they are traditionally grouped into hallux rigidus. There exists an opportunity for early detection and intervention with the intent to prevent deterioration and improve patient outcomes. One contemporary treatment concept is to implant particulated juvenile cartilage allograft to restore articular cartilage. The aim of our study was to review the clinical results of patients that had undergone this procedure for first metatarsal head OCDs. Methods: After IRB approval, a retrospective review of a consecutive case series was studied utilizing the records of three foot and ankle surgeons. Inclusion criteria included all adult patients who were a minimum of one year post surgery and consented to participate. Patient demographics and preoperative visual analog scale (VAS) pain level were recorded from a standardized intake sheet. From the operative note, the OCD size and location was recorded, as well as any concomitant procedures. At a minimum follow up of one year, we obtained objective measurements of arthritis grade and subjective considerations of pain and function, including VAS pain level, Foot Function Index (FFI) questionnaire, the American Orthopaedic Foot and Ankle Society (AOFAS) Hallux Metatarsophalangeal-Interphalangeal scale, and an overall patient satisfaction score. Results: Nine patients met inclusion criteria, 4 males and 5 females. The average age was 41 years old (±11.77, range 21-65). The mean preoperative VAS pain score was 57.50 (±18.32, range 30-80). Four OCDs were located centrally on the first metatarsal head. The average OCD size intraoperatively was 30 mm2 (range 16-49). The average time since surgery was 3.26 years (±1.21, range 1.41-5.62). Average first MTP dorsiflexion was 41.78 degrees (±20.70, range 6-70). The average postoperative hallux rigidus classification was grade 2 (range 1-3). The mean VAS pain score improved to 5.22 (±8.44, range 0-20). The average AOFAS score was 88 (±15.91, range 52-100). The average FFI score was 8.04 (±12.60, range 0-30.6). All but one patient were satisfied or very satisfied with their results. Conclusion: At an average of 3.26 years postoperatively, patients had improved pain, did not show significant progression of their first MTP joint degeneration, and were satisfied with their results. Patients reported very little, if any, limitations in their activity level. We believe that articular damage of the first MTP should be viewed in the same way as OCD lesions in larger joints with emphasis on early detection and treatment to avoid the progression to arthritis. Particulated juvenile cartilage allograft is a valuable tool for surgeons to use in treating focal articular defects of the first metatarsal head.

Age-related plantar centre of pressure trajectory changes during barefoot walking

Plantar centre of pressure (COP) variables during gait have been used to predict risk of injury, or consequences thereof. The aim of this study was to determine the effect of age on the COP trajectory during barefoot gait at a self-selected speed. 287 participants (aged 18–80year, 163 women) walked barefoot at self-selected speed across a Footscan® force platform, completing five trials for each side. COP trajectories were extracted and trajectory-level canonical correlation analysis was used to test their correlation with age. Post hoc linear regressions were performed on the medio-lateral (COPx) and anterior-posterior (COPy) components. The test statistic trajectory exceeded the critical threshold for the left (p=0.001) and right foot (p=0.003). Post hoc analyses showed positive correlation between age and COPx in late stance, placed more laterally with increasing age, while no significant correlation was found for COPy. While no significant correlations were observed for the test statistic trajectory during heel strike and mid-stance, post hoc analysis indicated that the COPx component was placed more laterally at heel strike for the left foot with increasing age (p=0.016). The findings suggest that older individuals tend to push-off with less metatarso-phalangeal dorsiflexion. These results do not necessarily imply that ageing itself causes the observed correlation. Further evidence is needed to determine whether the laterally placed COP during roll-off may be a useful factor for determining risk for falling in the older population, or as a risk for future injuries or overuse disorders.

Midterm Outcomes of Polyvinyl Alcohol Hydrogel Hemiarthroplasty of the First Metatarsophalangeal Joint in Advanced Hallux Rigidus.

Hallux rigidus is the most common arthritic condition of the foot. A randomized clinical trial of first metatarsophalangeal (MTP) joint hemiarthroplasty with a polyvinyl alcohol (PVA) hydrogel implant (Cartiva) demonstrated pain relief and functional outcomes equivalent to first MTP arthrodesis at 2 years postoperation, with no cases of implant fragmentation, wear, or bone loss. We prospectively determined 5-year outcomes of first MTP hemiarthroplasty with the PVA hydrogel implant. Patients who underwent first PVA hydrogel MTP hemiarthroplasty in the previously reported trial were evaluated at 5 years postoperatively. Patients underwent physical examination and radiographic evaluation and completed a pain VAS, the Short-Form-36 (SF-36), and the Foot and Ankle Ability Measure (FAAM) sports subscale and activities of daily living (ADL) subscale. At the time of this study, 29 patients had reached 5 years' follow-up. Two were lost to follow-up, leaving 27 patients with mean age 56.1 (range, 40.1-71.9) years. Mean follow-up was 5.4 (range, 4.9-6.4) years. Postoperative active MTP natural joint dorsiflexion and peak MTP dorsiflexion were mean 18.2 (range, 10.0-30.0) and 29.7 (range, 10.0-45.0) degrees, respectively. Pain VAS, SF-36 PCS, FAAM ADL, and FAAM Sports scores demonstrated clinically and statistically significant improvements. Radiographically, no patient demonstrated changes in implant position, implant loosening or subsidence, or implant wear. One implant was removed because of persistent pain and converted to fusion 2 years postoperation. Five years following first MTP hemiarthroplasty with a PVA hydrogel implant, functional outcomes improved significantly, pain was reduced significantly, and the implant demonstrated excellent survivorship. Level IV, prospective case series.

Mid-term functional outcome of a total arthroplasty of the first metatarsophalangeal joint

BackgroundArthroplasty of the first metatarsophalangeal joint is an alternative treatment option for end-stage hallux rigidus to the current gold standard of arthrodesis. The aim of this study was to investigate the mid-term functional outcome of an anatomically shaped prosthesis for the first metatarsophalangeal joint using pedobarography. MethodsTen patients (12 affected feet; age at surgery: 62.1 (SD: 7.2) years) were investigated preoperatively and 52 (SD: 3) months postoperatively using pedobarography (EMED, novel GmbH, Munich, Germany). Two patients were excluded at follow-up because their prosthesis was converted to an arthrodesis. Peak force and plantar pressure under the five metatarsal heads and the hallux were analyzed and correlated with the clinical outcome (pain, American Orthopaedic Foot and Ankle Society forefoot score and radiographic maximum first metatarsophalangeal dorsiflexion). Differences between pre- and postoperative data were analyzed using paired t-tests (alpha=0.05). FindingsPostoperatively, forefoot peak forces under the fourth (+40.9%; P=0.018) and fifth metatarsal (+54.9%; P=0.037) and plantar pressures under the fifth metatarsal (+38.7%; P=0.027) increased significantly, while peak plantar pressures and forces under the hindfoot, medial forefoot and hallux did not change. While maximum passive dorsiflexion was not significantly greater at the 4-year follow-up compared to preoperatively, overall greater passive dorsiflexion was associated with higher first metatarsal peak pressure. InterpretationDespite of patients reporting less pain, the functional results indicate an altered and potentially non-physiological postoperative gait pattern with a lateralization of the load during walking, especially in patients with limited passive dorsiflexion.

Accurate Measurement of First Metatarsophalangeal Range of Motion in Patients with Hallux Rigidus

Category: Midfoot/Forefoot Introduction/Purpose: The reliability of range of motion (ROM) measurements has not been established for the hallux metatarsophalangeal (MTP) joint in patients with hallux rigidus. The aim of the present study was to prospectively assess the clinical versus radiographic difference in ROM of the arthritic hallux MTP joint. Methods: One-hundred consecutive patients who presented with any grade of hallux rigidus were included in this prospective study to determine the hallux MTP dorsiflexion. Clinical range of motion using a goniometer and radiographic range of motion on dynamic xrays was recorded. Inter and intra-rater reliability were calculated. Results: The mean difference between clinical and radiographic dorsiflexion was 13°. This difference was statistically significant. For all measurements clinical dorsiflexion was equal or less than radiographically-measured dorsiflexion. The difference was significantly greater in patients with a clinical dorsiflexion of less than 30° than in patients with 30° or more. Radiographic measurement of hallux dorsiflexion had an excellent intra- and inter-observer reliability. Conclusion: This study describes a reliable, reproducible, and straightforward method of measuring hallux MTP ROM that eliminates the “human” component of measuring clinical ROM and all the variables that are encountered when making said measurement.

Dorsal wedge phalangeal osteotomy for grade II-III hallux rigidus in active adult patients.

The purpose of this study was to evaluate prospectively the results of the dorsal wedge phalangeal osteotomy for treating moderate hallux rigidus. The prospective study included 42 consecutive feet in 40 active patients, with an average age of 55.1 (range, 41-65) years. Clinical evaluation included American Orthopaedic Foot and Ankle Society (AOFAS) score, pain visual analog scale, range of motion, and subjective patient satisfaction. Radiographic evaluation was performed, including linear and angular measurements. The average follow-up was 2.7 (range, 2-3.8) years. The preoperative and postoperative mean AOFAS scores were 51.7 and 88.8, respectively (P = .001), and for pain VAS were 7.6 and 1.9, respectively (P = .001). Good and excellent results at final follow-up were seen in 34 feet. All patients returned to their previous activities. Satisfaction with surgery was good or excellent in 39 patients. The average passive metatarsophalangeal (MTP) dorsiflexion improved from 20.3 to 55.7 degrees (P = .001). The average MTP joint space improved from 2.2 to 2.3 degrees (P = .001). The radiographic measurements were unchanged, except anatomic angles related to phalangeal dorsiflexion. The average width of the bone wedge was 3.5 (range, 2.2-5.0) mm, and significant correlation was found with final AOFAS score (P = .006) and pain VAS (P = .001). There were 2 revisions for screw irritation. Phalangeal osteotomy was a reliable and reproducible treatment for moderate hallux rigidus in active patients, with substantial improvement in AOFAS score and MTP dorsiflexion and decreased pain. Level IV, prospective case series.

Effect of Turf Toe on Foot Contact Pressures in Professional American Football Players

The relationship between turf toe and plantar foot pressures has not been extensively studied. Two hypotheses were tested in a cohort of professional American football players: first, that a history of turf toe is associated with increased peak hallucal and first metatarsophalangeal (MTP) plantar pressures; second, that decreased range of motion (ROM) of the first MTP correlates with increased peak hallucal and first MTP plantar pressures. Forty-four athletes from one National Football League (NFL) team were screened for a history of turf toe during preseason training. Dorsal passive MTP ROM and dynamic plantar pressures were measured in both feet of each player. Anatomical masking was used to assess peak pressure at the first MTP and hallux. First MTP dorsiflexion was significantly lower in halluces with a history of turf toe (40.6 +/- 15.1 degrees versus 48.4 +/- 12.8 degrees, p = 0.04). Peak hallucal pressures were higher in athletes with turf toe (535 +/- 288 kPa versus 414 +/- 202 kPa, p = 0.05) even after normalizing for athlete body mass index (p = 0.0003). Peak MTP pressure was not significantly different between the two groups tested. First MTP dorsiflexion did not correlate with peak hallucal or first MTP pressures. This study showed that turf toe is associated with decreased MTP motion. In addition, increased peak hallucal pressures were found. Further study is warranted to determine whether these pressures correlate with the severity of symptoms or progression of turf toe to first MTP arthritis.

Effect of Turf Toe on Foot Contact Pressures in Professional American Football Players

The relationship between turf toe and plantar foot pressures has not been extensively studied. Two hypotheses were tested in a cohort of professional American football players: first, that a history of turf toe is associated with increased peak hallucal and first metatarsophalangeal (MTP) plantar pressures; second, that decreased range of motion (ROM) of the first MTP correlates with increased peak hallucal and first MTP plantar pressures.Forty-four athletes from one National Football League (NFL) team were screened for a history of turf toe during preseason training. Dorsal passive MTP ROM and dynamic plantar pressures were measured in both feet of each player. Anatomical masking was used to assess peak pressure at the first MTP and hallux.First MTP dorsiflexion was significantly lower in halluces with a history of turf toe (40.6 +/- 15.1 degrees versus 48.4 +/- 12.8 degrees, p = 0.04). Peak hallucal pressures were higher in athletes with turf toe (535 +/- 288 kPa versus 414 +/- 202 kPa, p = 0.05) even after normalizing for athlete body mass index (p = 0.0003). Peak MTP pressure was not significantly different between the two groups tested. First MTP dorsiflexion did not correlate with peak hallucal or first MTP pressures.This study showed that turf toe is associated with decreased MTP motion. In addition, increased peak hallucal pressures were found. Further study is warranted to determine whether these pressures correlate with the severity of symptoms or progression of turf toe to first MTP arthritis.

An Anatomical Study of Morton's Interdigital Neuroma: The Relationship Between the Occurring Site and the Deep Transverse Metatarsal Ligament (DTML)

Using clinical and cadaver studies, we examined the relationship between the location of Morton interdigital neuromas and the surrounding structures, including the deep transverse metatarsal ligament (DTML), which has been suspected as a major causative factor in neuroma formation. Seventeen fresh-frozen cadavers were evaluated to determine the relationship between the location of Morton interdigital neuromas and the DTML at two phases of the gait cycle with 60 degrees of metatarsophalangeal dorsiflexion and with 15 degrees of ankle dorsiflexion. We measured the distance from the bifurcation of the common digital nerve in the foot to the anterior margin of the DTML and also measured the length of the DTML itself. Clinically, we checked the location of the Morton interdigital neuroma and its length during surgery in 32 feet. In the second and third webspace, the mean distance from the bifurcation of the common digital nerve of the foot to the anterior margin of the DTML was 16.7 mm, 15.1 mm in the mid-stance position, and 15.9 mm and 14.6 mm in the heel-off position. The length of the second and third DTML averaged 12.8 mm and 10.6 mm. Clinically, all of the cases of Morton interdigital neuroma started at the bifurcation area of the common digital nerve, and the mean neuroma length was 7.5 mm (6 to 11). Morton interdigital neuromas were located more distally than the DTML in both the mid-stance and the heel-off stage during walking. The main lesion was located between the metatarsal head and the metatarsophalangeal joint and more distal than the DTML, questioning previous studies suggesting that the DTML is the major causative factor in development of Morton interdigital neuroma.

The Influence of Foot Position on Stretching of the Plantar Fascia

A recent study found nonweightbearing stretching exercises specific to the plantar fascia to be superior to the standard program of weightbearing Achilles tendon-stretching exercises in patients with chronic plantar fasciitis. The present study used a cadaver model to demonstrate the influence of foot and ankle position on stretching of the plantar fascia. Twelve fresh-frozen lower-leg specimens were tested in 15 different configurations representing various combinations of ankle and metatarsophalangeal (MTP) joint dorsiflexion, midtarsal transverse plane abduction and adduction, and forefoot varus and valgus. Measurements were recorded by a differential variable reluctance transducer (DVRT) implanted into the medial band of the plantar fascia, and primary measurement was a percent deformation of the plantar fascia (stretch) with respect to a reference position (90 degrees ankle dorsiflexion, 0 degrees midtarsal and forefoot orientation, and 0 degrees MTP dorsiflexion). Ankle and MTP joint dorsiflexion produced a significant increase (14.91%) in stretch compared to the position of either ankle dorsiflexion alone (9.31% increase, p < 0.001) or MTP dorsiflexion alone (7.33% increase, p < 0.01). There was no significant increase in stretch with positions of abduction or varus (2.49%, p = 0.27 and 0.55%, p = 0.79). This study provides a mechanical explanation for enhanced outcomes in recent clinical trials using plantar fascia tissue-specific stretching exercises and lends support to the use of ankle and MTP joint dorsiflexion when employing stretching protocols for nonoperative treatment in patients with chronic proximal plantar fasciitis.