Quantitative assessment of plantar pressure patterns in relation to foot deformities in people with hereditary motor and sensory neuropathies.

BACKGROUND: Hereditary motor and sensory neuropathies (HMSN), also known as Charcot-Marie-Tooth disease, are characterized by affected peripheral nerves. This often results in foot deformities that can be classified into four categories: (1) plantar flexed first metatarsal, neutral hindfoot, (2) plantar flexed first metatarsal, correctable hindfoot varus, (3) plantar flexed first metatarsal, uncorrectable hindfoot varus, and (4) hindfoot valgus. To improve management and for the evaluation of surgical interventions, a quantitative evaluation of foot function is required. The first aim of this study was to provide insight into plantar pressure of people with HMSN in relation to foot deformities. The second aim was to propose a quantitative outcome measure for the evaluation of surgical interventions based on plantar pressure. METHODS: In this historic cohort study, plantar pressure measurements of 52 people with HMSN and 586 healthy controls were evaluated. In addition to the evaluation of complete plantar pressure patterns, root mean square deviations (RMSD) of plantar pressure patterns from the mean plantar pressure pattern of healthy controls were calculated as a measure of abnormality. Furthermore, center of pressure trajectories were calculated to investigate temporal characteristics. Additionally, plantar pressure ratios of the lateral foot, toes, first metatarsal head, second/third metatarsal heads, fifth metatarsal head, and midfoot were calculated to measure overloading of foot areas. RESULTS: Larger RMSD values were found for all foot deformity categories compared to healthy controls (p < 0.001). Evaluation of the complete plantar pressure patterns revealed differences in plantar pressure between people with HMSN and healthy controls underneath the rearfoot, lateral foot, and second/third metatarsal heads. Center of pressure trajectories differed between people with HMSN and healthy controls in the medio-lateral and anterior-posterior direction. The plantar pressure ratios, and especially the fifth metatarsal head pressure ratio, differed between healthy controls and people with HMSN (p < 0.05) and between the four foot deformity categories (p < 0.05). CONCLUSIONS: Spatially and temporally distinct plantar pressure patterns were found for the four foot deformity categories in people with HMSN. We suggest to consider the RMSD in combination with the fifth metatarsal head pressure ratio as outcome measures for the evaluation of surgical interventions in people with HMSN.

Management of gait impairments in people with Charcot-Marie-Tooth disease: A treatment algorithm.

Gait impairments in people with Charcot Marie Tooths disease are the combined result of ankle-foot deformities, muscle weakness, and somatosensory impairments. People with Charcot-Marie-Tooth disease often experience pain and difficulties when walking, especially barefoot. They also trip and fall frequently and have a lower than normal gait speed and distance. Because these gait impairments and related complaints are disabling, clinical management aimed at improving gait is important. Management involves both conservative and surgical treatment options, each with limited scientific evidence. However, a treatment algorithm that describes both conservative and surgical treatment options is currently lacking. This study sets out a step-wise treatment algorithm, based on evidence, if available, and otherwise reflecting practice-based experience. The treatment algorithm will be of value in daily clinical practice, and will serve as a template for future research.

The effect of lengthening the gastrocnemius muscle in chronic therapy resistant plantar fasciitis.

BACKGROUND: The aetiology of chronic therapy resistant plantar fasciitis (CTRPF) is multifactorial with more focus in recent times on the gastroc-soleus complex. This study evaluates the effect of lengthening the gastrocnemius muscle in CTRPF. METHODS: All patients with CRTPF complaints for at least one year underwent the same standard conservative treatment prior to surgery. 32 patients failed this treatment and underwent gastrocnemius recession. Silfverskiöld test, questionnaires and plantar pressure measurements were obtained at 5 visits. RESULTS: One year follow up showed a significantly increase in dorsiflexion of the ankle (16 degrees), a decrease in VAS; 78 (SD: 19) to 20 (SD: 24) and significant improved functional scores. Plantar pressure measurements showed an increase of pressure under the medial proximal part of the midfoot and the 1 st metatarsal and a decrease under the hallux. CONCLUSIONS: A gastrocnemius recession results in a significant gain in dorsiflexion, altered loading of the foot and good clinical outcome in patients with CTRPF. LEVEL OF EVIDENCE: Level 2.

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.

INTRODUCTION: This 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). METHODS: Prospective 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 12months 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). RESULTS: Claw 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. DISCUSSION: These 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.

Tarsal fusion for pes equinovarus deformity improves gait capacity in chronic stroke patients.

BACKGROUND: Gait impairments are common and disabling in chronic stroke patients. Pes equinovarus deformity is one of the primary motor deficits underlying reduced gait capacity after stroke. It predisposes to stance-phase instability and subsequent ankle sprain or falls. This instability is most pronounced when walking barefoot. Tarsal fusion is a recommended treatment option for varus deformity, but scientific evidence is sparse. We therefore evaluated whether a tarsal fusion improved barefoot walking capacity in chronic stroke patients with pes equinovarus deformity. METHODS: Ten patients with a pes equinovarus deformity secondary to supratentorial stroke underwent surgical correction involving a tarsal fusion of one or more joints. Instrumented gait analysis was performed pre- and postoperatively using a repeated-measures design. Primary outcome measure was gait speed. RESULTS: Walking speed significantly improved by 32% after surgery (0.38 m/s ± 0.20 to 0.50 m/s ± 0.17, p = 0.007). Significant improvement was also observed when looking at cadence (p = 0.028), stride length (p = 0.016), and paretic step length (p = 0.005). Step length on the nonparetic side did not change. Peak ankle moment increased significantly on the nonparetic side (p = 0.021), but not on the paretic side (p = 0.580). In addition, functional ambulation scores increased significantly (p = 0.008), as did satisfaction with gait performance (p = 0.017). CONCLUSIONS: Tarsal fusion for equinovarus deformity in chronic stroke patients improves gait capacity, and the degree of improvement is of clinical relevance. Our results suggest that the improved gait capacity may be related to better prepositioning and loading of the paretic foot, leading to larger paretic step length and nonparetic ankle kinetics.

Long-term results after triple arthrodesis: Influence of alignment on ankle osteoarthritis and clinical outcome.

BACKGROUND: Pain, deformity and instability are the main reasons for fusion of the tarsal joints, a triple arthrodesis. The short and midterm results show that mobility, function and satisfaction increase postoperatively. However, osteoarthritis (OA) of the adjacent ankle joint is described as a long-term complication. Alignment of the foot could be an influencing factor. The aim of this study was to examine whether malalignment after triple arthrodesis leads to a higher grade of OA at long-term follow-up. METHODS: Between 1991 and 2002, 81 patients underwent a triple arthrodesis. Preoperatively, postoperatively, 3, 7.5 and 15 years after surgery, dorsoplantar (DP) and lateral X-rays were taken and used to evaluate the degree of OA and the geometry of the foot. The degree of OA was estimated using the Kellgren and Lawrence score. The geometry of the foot was assessed using Meary's angle; a Meary's angle exceeding 15° in DP and/or greater than -5 to 5° from the lateral view was defined as malalignment. In addition to the radiological evaluation, clinical scores (FFI and AOFAS) were recorded. RESULTS: Thirty-five patients (40 feet) were available for analysis 15 years after surgery. In 19 cases there was an increase in ankle OA following the operation. Eight feet showed malalignment on the lateral view and 28 on the DP view. There was no difference in both an increase of ankle OA or clinical outcome between correct aligned feet and feet classified as malaligned. Thirty-three patients with 38 treated feet stated that they would decide to undergo the treatment again. Two patients would not want to undergo the same surgery again. The patients were satisfied with the result of surgery, clinical scores improved after surgery and remained stable in the long-term. CONCLUSIONS: Triple arthrodesis is a salvage procedure in patients with a painful and deformed hindfoot and results in a clinically beneficial outcome, even 15 years after surgery. The present study did not show that malalignment after triple arthrodesis results in a higher grade of OA of the ankle joint in the long-term. The cause of the aggravation of OA is still not fully understood and needs further research. Nevertheless, clinical results are satisfying 15 years postoperatively.

Resection or preservation of the metatarsal heads in rheumatoid forefoot surgery? A randomised clinical trial.

BACKGROUND: Despite impressive results of the pharmacological management of rheumatoid arthritis, still certain patients suffer from rheumatoid forefoot problems. Surgical treatment of these forefoot deformities can be an option. In literature no high-quality studies on this topic can be found. The goal of present study is to compare the results of a metatarsal head (MTH) resecting technique with a MTH preserving technique in the operative treatment of severe rheumatoid forefoot deformity. METHODS: Patients suffering from well-defined rheumatoid forefoot deformity were prospectively enrolled in three institutions. This non-blinded study had a randomised clinical design and eligible patients were randomly assigned to undergo either resection of preservation of the MTH. The primary outcome measure consisted of the AOFAS score. Secondary outcome measures were: the FFI, the VAS for pain and the SF-36. RESULTS: Twenty-three patients (10 in MTH preservation group) were included and analysed. After one year follow-up no significant differences in AOFAS score and additional outcome factors were found. A total of 10 complications in 23 patients were reported. CONCLUSIONS: This randomised clinical study did not show significant clinical difference between a MTH resecting and a preserving procedure in patients suffering from rheumatoid forefoot deformity. Both procedures resulted in considerable improvement of pain and activity scores.

Asymmetries in Gait and Balance Control After Ankle Arthrodesis.

Previous gait analysis studies of patients with an ankle arthrodesis have reported increased motion in the adjacent joints. However, of similar importance are the forces that act on the ipsi- and contralateral joints and the effect of ankle arthrodesis with regard to balance control. The purpose of the present study was to determine the joint moments and the amount of asymmetrical loading of the ankle and joints adjacent to the ankle in patients after successful ankle arthrodesis. Therefore, 8 patients with a painless ankle fusion were included and assessed using 4 functional tests: preferred and fast speed walking, a sit-to-stand test, and a balance test. The ground reaction force and ankle joint moment were smaller in the fused ankle. During the balance on foam test, the velocity of the center of pressure was significantly larger on the contralateral extremity. In conclusion, ankle arthrodesis leads to small asymmetries in joint moments during gait, indicating greater loading of the contralateral ankle. In addition, the unaffected leg compensates for the operated leg in balance control. Because of the small alterations, overuse of the contralateral ankle is not expected after ankle arthrodesis.

Management of Gait Impairments in Chronic Unilateral Upper Motor Neuron Lesions: A Review.

Importance: Gait impairments are common in patients with chronic supratentorial upper motor neuron lesions and are a source of disability. Clinical management aimed at improving the gait pattern in these patients is generally perceived as a challenging task because many possible abnormalities may interact. Moreover, a multitude of treatment options exist, ranging from assistive devices and muscle stretching to pharmacologic and surgical interventions, but evidence is inconclusive for most approaches and clear treatment guidelines are lacking. Observations: Gait deviations in adults with a chronic supratentorial upper motor neuron lesion can approximately be reduced to the following 3 groups of primary deficits: (1) imbalance of muscle strength, length, and activity around the ankle and tarsal joints leading to pes equinovarus or pes equinus; (2) calf muscle weakness; and (3) overactivity of proximal leg muscles. Conclusions and Relevance: A stepwise treatment algorithm emphasizes medical-technical interventions, which are based on evidence when available and otherwise reflect practice-based experience.

Diagnostics in tarsal fusion: The theory and practise in The Netherlands.

BACKGROUND: This study compares the preferences of Dutch orthopaedic surgeons for different diagnostic modalities in performing tarsal fusions versus consensus, evidence or expert opinion reported in the literature. METHODS: A literature search of Medline was performed to obtain evidence-based information on various diagnostic tools. In addition, 89 registered Dutch foot and ankle surgeons were sent a questionnaire concerning the diagnostic modalities use in tarsal fusion. RESULTS: Fifty-eight (65%) questionnaires were returned. The experienced surgeons measured outcomes significantly more often than other surgeons. Diagnostic injections were often used, although scant evidence exists in the literature. Postoperative diagnostics mainly consist of X-ray examination, although there is consensus in the literature that computed tomography is more accurate. CONCLUSIONS: The study revealed some surprising discrepancies concerning the use of diagnostic imaging in tarsal fusion. More clinical research is needed to identify the most effective diagnostic imaging modalities so as to encourage their wider adoption.

Sports Participation, Functional Outcome, and Complications After Ankle Arthrodesis: Midterm Follow-up.

BACKGROUND: Ankle arthrodesis provides satisfactory functional outcome based on basic daily activities, but information regarding more demanding tasks is limited. Also, studies reporting longer term survival and complication rates are sparse and concern small study populations. This study reports functional outcome with more focus on demanding tasks and sports and reports the mid- to long-term union and complication rates in a large study population. METHODS: Between 2005 and 2010, an ankle arthrodesis was performed on 185 ankles. Clinical results were retrospectively assessed with the Foot Function Index (FFI), visual analog scale (VAS) for pain, and the Foot and Ankle Ability Measure (FAAM). Information regarding sports pre- and postoperatively was obtained through a questionnaire. In addition, postoperative complications, reoperations, and failures (defined as nonunion of the ankle arthrodesis) were determined. Mean follow-up time was 8 years. RESULTS: FFI scores significantly improved, the FAAM ADL score was 70%, and the mean VAS for pain at the ankle/hindfoot at follow-up was 20. Sports participation slightly diminished from 79.5% prior to the onset of disabling complaints to 68.9% postoperatively. Of the patients, 73.1% were able to hike with a median hiking time of 40 minutes (range, 2-600 minutes). Kneeling could be performed on average 10 minutes (range, 2-60 minutes) in 39.8% and jumping down from steps by 23.5% of the patients. A small selection of patients was able to sprint (14%), and 16.8% of the patients were able to run a median distance of 60 meters (range, 3-1000 meters). Failure occurred in 9.2% and other postoperative complications were present in 21.6%, requiring reoperation in 8.6% of the cases. CONCLUSION: Ankle arthrodesis led to satisfactory functional outcome and pain reduction. Most patients remained active in sports, but a transition to less demanding sporting activities was seen. The complication and failure rates were similar with previous literature, and the incidence of nonrevision secondary surgery was relatively low. LEVEL OF EVIDENCE: Level III, retrospective comparative study.

Does osteoarthritis of the ankle joint progress after triple arthrodesis? A midterm prospective outcome study.

BACKGROUND: Debate exists regarding the effect of triple fusion on the development of osteoarthritis (OA) of the ankle joint. The midterm outcome after triple arthrodesis and the prevalence of OA following triple arthrodesis are reported in this study. The role of alignment in the development of OA was investigated. METHODS: Seventy five patients (87 feet) were evaluated in 2003 and of these, 48 patients (55 feet) were available for second evaluation in 2008. X-rays of the ankles and feet were made prior to surgery, in 2003 and in 2008, and the level of osteoarthritis (OA) was graded with the Kellgren and Lawrence score. Of all postoperative X-rays, the AP and lateral talo first metatarsal angle X-rays were compared. Also, standardized digital photos were made to assess the geometry/alignment. The Foot Function Index (FFI) and the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot score were completed. In order to investigate the role of the underlying alignment on the aggravation of ankle osteoarthritis, patients were divided into a 'varus' and a 'valgus' group based on the indication for surgery. RESULTS: The outcome scores (AOFAS and FFI) after triple arthrodesis remained stable in the present 7.5-year follow-up study. An important increase of OA of the ankle was not established, 58% of the patients showed no aggravation, 31% one-grade and 2% two-grade increase of OA. A trend was found (P=.063) towards aggravation of OA of the ankle in patients of the varus group with the highest medial arches (persistent cavovarus deformity). CONCLUSION: This study reports minor, not statistically significant, changes of the ankle joint following triple arthrodesis after 7.5 years. Clinical outcome remained stable in time. Clinical relevance It seems that triple arthrodesis as such does not lead to major osteoarthritis of the ankle, given that adequate alignment of the hindfoot is achieved. LEVEL OF EVIDENCE: Level II, retrospective study.

Long-term Functional and Radiographic Outcome of a Mobile Bearing Ankle Prosthesis.

BACKGROUND: Total ankle arthroplasty is an accepted alternative to arthrodesis of the ankle. However, complication and failure rates remain high. Long-term results of the Scandinavian Total Ankle Replacement (STAR) are limited, with variable complication and failure rates observed. This prospective study presents the long-term survivorship and postoperative complications of the STAR prosthesis. METHODS: Between May 1999 and June 2008, 134 primary total ankle arthroplasties were performed using the STAR prosthesis in 124 patients. The survivorship, postoperative complications, and reoperations were recorded, with a minimum follow-up period of 7.5 years. Clinical results were assessed using the Foot Function Index and the Kofoed score. The presence of component migration, cysts, and radiolucency surrounding the prosthesis components, heterotopic ossification, and progression of osteoarthritis in adjacent joints were determined. RESULTS: The cumulative survival was 78% after the 10-year follow-up period. An ankle arthrodesis was performed in 20 ankles (14.9%) that failed. Fourteen polyethylene insert fractures occurred (10.4%). Other complications occurred in 29 ankles (21.6%), requiring secondary procedures in 21 ankles (15.7%). Nevertheless, the postoperative clinical results improved significantly. Osteolytic cysts were observed in 61 ankles (59.8%) and the surface area of these cysts increased during follow-up, without any association with the prosthesis alignment or clinical outcome. Heterotopic ossification at the medial malleolus was present in 58 cases (56.8%) and at the posterior tibia in 73 cases (71.6%), with no effect on clinical outcome. Osteoarthritis of the subtalar and talonavicular joint developed in 9 (8.8%) and 11 cases (10.8%), respectively. CONCLUSION: The long-term clinical outcomes for the STAR were found to be satisfactory. Although these results are consistent with previous studies, the survival and complication rates are disappointing compared to knee and hip arthroplasty. Higher rates of successful outcomes following ankle arthroplasty are important, and these results highlight the need for further research to clarify the origin and significance of the reported complications. LEVEL OF EVIDENCE: Level II, prospective comparative study.

Short term results of the Mobility Total Ankle System: Clinical and radiographic outcome.

BACKGROUND: Ankle arthroplasty is increasingly used to reduce pain and improve or maintain joint mobility in end-stage ankle arthritis. The aim of this study was to assess the clinical and radiographic short term results of the Mobility prosthesis. METHODS: Complications, secondary operations, failures and the survival rate were retrospectively examined in 67 primary Mobility total ankle arthroplasties. Prosthesis alignment was measured and patient reported outcomes were assessed with the use of questionnaires. RESULTS: There were two intraoperative and 13 postoperative complications, requiring seven reoperations. Failure occurred in three cases, with a survival of 95% after 61 months. Clinical scores improved after surgery and alignment was correct in 93% of the tibial and 93% of the talar components. CONCLUSION: Despite few intraoperative complications and satisfactory clinical and radiological outcome, the incidence of postoperative complications, reoperations and failure indicate the importance of further development and research in the field of ankle arthroplasty.

Lesser Toe PIP Joint Resection Versus PIP Joint Fusion: A Randomized Clinical Trial.

BACKGROUND: It is unclear whether proximal interphalangeal joint (PIPJ) resection or fusion leads to superior clinical outcome in patients undergoing hammertoe surgery. The purpose of this study was to prospectively evaluate a series of patients undergoing this surgery. METHODS: Patients with one or more toes with rigid PIP flexion deformity were prospectively enrolled. These patients were randomly assigned to undergo either PIPJ resection or PIPJ fusion. In addition to the PIPJ procedure, a metatarsophalangeal joint (MTPJ) release was performed if deemed necessary. Follow-up was up to 1 year postoperatively. Twenty-six patients (39 toes) were included in the PIPJ resection group and 29 (50 toes) in the PIPJ fusion group. RESULTS: Thirty-four underwent an MTPJ release. No significant difference in foot outcome scores (American Orthopaedic Foot & Ankle Society scale, the Foot Function Index, and visual analog scale pain) could be detected after 1-year follow-up. A statistically significant difference was found regarding the toe alignment in the sagittal plane in favor of PIPJ fusion. CONCLUSIONS: Our randomized controlled study did not show any clinical outcome difference between PIPJ fusion and PIPJ resection. Both procedures resulted in good to excellent outcome in pain and activity scores. LEVEL OF EVIDENCE: Level II, lesser quality RCT or prospective comparative study.

Comparison of the short-term results of the first and last 50 Scandinavian total ankle replacements: assessment of the learning curve in a consecutive series.

BACKGROUND: Total ankle replacement (TAR) is presently considered to be an acceptable alternative to ankle fusion for patients with debilitating conditions of the ankle. The placing of a total ankle prosthesis is a technically demanding procedure. We hypothesized that the challenging conditions could cause a longer learning curve (>30 cases), and therefore the short-term results of the first and the last 50 cases in a consecutive series of 134 cases were compared. METHODS: The first and last consecutive 50 cases by a single surgeon in a series of 134 Scandinavian Total Ankle Replacements (STAR; Waldemar Link, Hamburg, Germany), inserted between May 1999 and May 2008, were evaluated. Operation characteristics, clinical outcome (Foot Function Index [FFI], Kofoed score), complications, and the component alignment on X-rays were assessed. The outcome measures for both groups were compared using independent Student t tests, chi-square tests, and nonparametric alternatives (P < .05). RESULTS: Surgery time decreased from a median of 125 (83-160) to 100 (65-170) minutes (P < .001), and fewer perioperative complications were observed (12 vs 4, P = .04). The sagittal alignment of the tibial component was closer to normal in the last series (P < .001). The clinical outcome did not differ between the 2 series (median FFI: 32 [0-74] vs 25 [0-75], Kofoed score: median 71 [21-96] vs 80.5 [23-100]). The major underlying pathology did change from rheumatoid arthritis (60%) to osteoarthritis (44%; P = .002). No differences in type and number of complications were reported. CONCLUSION: The surgery time did decrease, there were fewer perioperative fractures, and the tibial component orientation improved, suggesting the presence of a learning curve. Operative experience and a shift in major underlying pathology did not influence clinical outcome. In view of this learning curve we suggest more restrictive patient selection for at least the first 50 TARs. LEVEL OF EVIDENCE: Level III, comparative series.

Rheumatoid forefoot deformity: pathophysiology, evaluation and operative treatment options.

Despite recent advances in pharmacological management of rheumatoid arthritis, forefoot deformity, with its symptoms, remains a common problem, often requiring operative treatment. Typical deformities in these patients comprise hallux valgus and deformity of the lesser metatarsophalangeal (MTP) joints and toes. With regard to the lesser rays the standard operative procedure, advocated for the disabling forefoot pain in these patients, remains metatarsal head resection. It should be considered that with increasing success of pharmacological treatment the degree of forefoot deformity in these patients is becoming less and that resection of the lesser MTP joints is becoming more and more superfluous. This supports a trend towards metatarsal head-preserving surgery. The optimal treatment of the hallux deformity remains unclear. Fusion of the first MTP joint is, generally, recommended. This article will discuss the current surgical options in rheumatoid forefoot pathology.

Flat feet, happy feet? Comparison of the dynamic plantar pressure distribution and static medial foot geometry between Malawian and Dutch adults.

In contrast to western countries, foot complaints are rare in Africa. This is remarkable, as many African adults walk many hours each day, often barefoot or with worn-out shoes. The reason why Africans can withstand such loading without developing foot complaints might be related to the way the foot is loaded. Therefore, static foot geometry and dynamic plantar pressure distribution of 77 adults from Malawi were compared to 77 adults from the Netherlands. None of the subjects had a history of foot complaints. The plantar pressure pattern as well as the Arch Index (AI) and the trajectory of the center of pressure during the stance phase were calculated and compared between both groups. Standardized pictures were taken from the feet to assess the height of the Medial Longitudinal Arch (MLA). We found that Malawian adults: (1) loaded the midfoot for a longer and the forefoot for a shorter period during roll off, (2) had significantly lower plantar pressures under the heel and a part of the forefoot, and (3) had a larger AI and a lower MLA compared to the Dutch. These findings demonstrate that differences in static foot geometry, foot loading, and roll off technique exist between the two groups. The advantage of the foot loading pattern as shown by the Malawian group is that the plantar pressure is distributed more equally over the foot. This might prevent foot complaints.

A clinical classification system for rheumatoid forefoot deformity.

BACKGROUND AND PURPOSE: In the present study a classification system for the rheumatoid forefoot is reported with its intra- and interobserver reliability and clinical relevance. The classification is based on the sequence of anatomical changes resulting from the loss of integrity of the MTP joints, loss of motion and changes regarding the quality and position of the plantar soft tissues. It is hypothesized that with progression of the amount of deformity of the MTP joint(s), patients have more pain and functional loss. PATIENTS AND METHODS: In total 94 patients were included in the study following precise inclusion criteria. The forefeet of the patients were classified according to the introduced classification system by two observers in order to determine the intra- and interobserver reliability. The relation of the suggested classification between pain, function scores, and plantar foot pressure measurements was examined. RESULTS AND CONCLUSION: According to the Cohen's kappa and the ICC, the intra- and inter-observer reliability were high. Despite the large variation between subjects in a certain grade, a clear trend was found between increase in classification and VAS for pain, FFI difficulty with activities, and plantar peak pressure under the metatarsals. The suggested classification is of clinical relevance and can be used to develop therapeutical algorithms and to test interventions.