Which parameters predict correction of the intermetatarsal angle after first metatarsophalangeal fusion?

Fusion of the first metatarsophalangeal joint (MTPJ) is a commonly performed surgical procedure. Although the effect of first MTPJ fusion on reduction of Intermetatarsal angle (IMA) is well described, contributing factors remain unclear. The aim of this study was to identity predictive parameters for IMA reduction. Fifty-one patients (68 feet) who underwent a first MTPJ fusion and had an IMA greater than fourteen degrees were assessed retrospectively. The average age was 68 (31.4-79.3) years. Sixteen demographic and radiographic variables were evaluated using a multivariate regression analysis for association with change in IMA after surgery. The mean preoperative IMA was 16.11 (range, 14.0-22.5) degrees with a mean reduction of 4.95 (range, 0-17) degrees after surgery. Multivariate regression analysis revealed three significant independent predictors of the change in IMA. Increased preoperative IMA (ß = .663, CI = .419, .908, P <.001), increased preoperative translation at base of MT1 (ß = .490, CI = 0.005, .974, P = 0.039), and less postoperative translation in the fusion (ß= -0.693, CI= -1.054, -.331, P= 0.002) significantly increased the amount of IMA reduction. Pre-operative IMA and translation at the base of the first metatarsal were positive predictors for correction of IMA after first MTPJ fusion. Translation at the level of the MTP I fusion was a negative predictor for the amount of IMA correction. Based on these findings, we recommend minimizing the lateral translation of the proximal phalanx relative to the metatarsal head to optimize IMA correction after MTPJ fusion.

Venous malformation as source of a tarsal tunnel syndrome: treat the source or the cause of the complaints? A case report.

Painful tarsal tunnel syndrome is a compression neuropathy with a variety of possible sources. As it presents a challenging differential diagnostic problem, it is often under-diagnosed. Among the intrinsic and extrinsic factors, varicose veins are the main source in case of a venous etiology. We report a case of a 39-year old male patient who presented with complaints of paresthesia and excessive pain of the right foot, especially the medial side. Further work up by ultrasonography, magnetic resonance imaging and electromyography revealed an extensive congenital venous malformation of the right lower limb with subsequent compression of the tibial nerve in the tarsal tunnel. We did not treat the source, but the cause by open tarsal tunnel release. Excellent result with immediate full relieve of the patients complaints was achieved.

Biomechanical markers and theoretical concepts related to haemophilic ankle and subtalar joint arthropathy: introducing the term 'haemophilic tarsal pan-arthropathy'.

BACKGROUND: Although regular factor replacement can reduce the incidence of joint bleeds and slow down the development of haemophilic arthropathy, the ankle joint remains particularly vulnerable even in children with haemophilia on primary or secondary prophylaxis and is now the primary joint affected. The heterogeneity in the pathoaetiology of haemophilic ankle arthropathy means that the functional consequences of early stage of ankle arthropathy are difficult to define as early morphological and structural changes can be observed in clinically asymptomatic ankles. In this context, understanding biomechanics of the normal and arthritic foot is complex and difficult to quantify unless considering the foot as multiple functional segments using more sophisticated assessment tools such as multisegment foot models. However, this understanding can undoubtedly aid in the analysis of an underlying clinical problem and provide a strategic basis for a more optimal management. AIMS: The purpose of this narrative review was firstly to revise information on the anatomy and biomechanics of the foot and ankle. Finally, related biomechanical markers of human motor performance, which are potentially implicated in the development of haemophilic ankle arthropathy, will be discussed based on published literature and expert opinion. MATERIALS AND METHODS: Searches in published literature were limited to the year 2000 onwards. RESULTS: Although the ankle (tibiotalar joint) is the most commonly affected joint, associated subtalar joint (SJT) involvement is often seen. This would therefore imply that an alternative phraseology might be better. DISCUSSION AND CONCLUSION: In this context, the authors propose the use of 'haemophilic tarsal pan-arthropathy' (HTPA) which encompasses both tibiotalar and subtalar joints.

Comparison of foot segmental mobility and coupling during gait between patients with diabetes mellitus with and without neuropathy and adults without diabetes.

BACKGROUND: Reduction in foot mobility has been identified as a key factor of altered foot biomechanics in individuals with diabetes mellitus. This study aimed at comparing in vivo segmental foot kinematics and coupling in patients with diabetes with and without neuropathy to control adults. METHODS: Foot mobility of 13 diabetic patients with neuropathy, 13 diabetic patients without neuropathy and 13 non-diabetic persons was measured using an integrated measurement set-up including a plantar pressure platform and 3D motion analysis system. In this age-, sex- and walking speed matched comparative study; differences in range of motion quantified with the Rizzoli multisegment foot model throughout different phases of the gait cycle were analysed using one-way repeated measures analysis of variance (ANOVA). Coupling was assessed with cross-correlation techniques. FINDINGS: Both cohorts with diabetes showed significantly lower motion values as compared to the control group. Transverse and sagittal plane motion was predominantly affected with often lower range of motion values found in the group with neuropathy compared to the diabetes group without neuropathy. Most significant changes were observed during propulsion (both diabetic groups) and swing phase (predominantly diabetic neuropathic group). A trend of lower cross-correlations between segments was observed in the cohorts with diabetes. INTERPRETATION: Our findings suggest an alteration in segmental kinematics and coupling during walking in diabetic patients with and without neuropathy. Future studies should integrate other biomechanical measurements as it is believed to provide additional insight into neural and mechanical deficits associated to the foot in diabetes.

Inter- and intra-observer reliability of masking in plantar pressure measurement analysis.

Plantar pressure measurement is an important tool in gait analysis. Manual placement of small masks (masking) is increasingly used to calculate plantar pressure characteristics. Little is known concerning the reliability of manual masking. The aim of this study was to determine the reliability of masking on 2D plantar pressure footprints, in a population with forefoot deformity (i.e. hallux valgus). Using a random repeated-measure design, four observers identified the third metatarsal head on a peak-pressure barefoot footprint, using a small mask. Subsequently, the location of all five metatarsal heads was identified, using the same size of masks and the same protocol. The 2D positional variation of the masks and the peak pressure (PP) and pressure time integral (PTI) values of each mask were calculated. For single-masking the lowest inter-observer reliability was found for the distal-proximal direction, causing a clear, adverse impact on the reliability of the pressure characteristics (PP and PTI). In the medial-lateral direction the inter-observer reliability could be scored as high. Intra-observer reliability was better and could be scored as high or good for both directions, with a correlated improved reliability of the pressure characteristics. Reliability of multi-masking showed a similar pattern, but overall values tended to be lower. Therefore, small sized masking in order to define pressure characteristics in the forefoot should be done with care.

Changes in contact area characteristics of the ankle after a cartilage biopsy at the postero-medial rim of the talar dome.

OBJECTIVE: Study the changes in local and generalized biomechanical characteristics of the ankle joint, associated with a well defined cartilage biopsy at the postero-medial rim of the talar dome, to evaluate its safety. METHODS: Ten cadaver ankles were (sub-) physiologically loaded pre- and post-biopsy; in neutral position, 10 degrees of plantar-flexion (PF) and 10 degrees of dorsi-flexion (DF). Fuji film was used as transducer. Qualitatively, the coverage of the biopsy by the tibial plafond, and changes in the shape of the footprint were analyzed. Quantitatively, the pressure profile plot, normalized-tibio-talar contact area and the centroid position of pressure were examined. Results were reported as a mean for all specimens, and as individual values for every single specimen as well. RESULTS: Mean results did not show significant changes, but those of some single specimens did. The majority of those changes were in PF. Some occurred in N, and besides two exceptions none occurred in DF. Two specimens did not show any change. One specimen showed an isolated quantitative change. Seven specimens showed both qualitative and quantitative changes. However, all changes were of low-magnitude and contact stresses did not show any rebound effect. CONCLUSIONS: Although biopsies at the postero-medial rim of the talar dome did not induce on average significant changes in quantitative contact characteristics, few specimens did show some alterations. Currently, the investigated biopsy site seems safe, but long term follow-up studies in patients are needed for confirmation.

Repeatability and contact stress gradient detection of sealed pressure-sensitive film when used in a physiological joint model.

Sealed pressure-sensitive film is frequently used to record contact characteristics in physiological joints. However, the effect on the pressure-recording characteristics of sealing the film when used in these circumstances has never been studied. This study compares the coefficient of variation, the standardized coefficient of variation, the tangent and secant contact stress gradients, and the actual pressures between unsealed and sealed Fuji film, in a simplified physiological joint model with a full-thickness surface defect. Unsealed film and sealed film were loaded through a range of nominal loads and the resulting stains were analysed by use of custom-made macros for the ImageJ image-processing program. The coefficient of variation did not exceed 5.7 per cent (sealed film), and the standardized coefficient of variation did not exceed 1.8 per cent (unsealed and sealed film). Contact stress gradients did not differ significantly. The recorded pressure at the level of surface defects was always about 0.2 MPa higher in the case of sealed film, and therefore predictable. It is concluded that sealing the film will not change the pressure-recording characteristics.

Anomalous origin of a lumbrical muscle as cause of a trigger finger.

We report a case of a trigger finger due to an anomalous origin of the fourth lumbrical muscle. Total excision of the involved muscle fibers gave complete relief of symptoms.

Revision of total hip arthroplasty using the R.M. isoelastic prosthesis.

A cemented revision of failed total hip arthroplasty is prone to early mechanical failure. Cementless revision seems to be much more promising. We present our 2 year follow-up of 19 cementless revisions using the R.M. isoelastic stem. During follow-up special attention focused on the restoration of bone stock on the femoral side of the arthroplasty. Bone stock deficiencies encountered during the operation were managed with grafts. Other complications to solve during the procedure were encountered frequently. The average follow-up was 58 months. Rating the results following Merle d'Aubigné and Postel showed very good or good result only in half of the cases, one case needed a revision. Nevertheless good restoration of bone stock was observed in nearly all cases. A greater number of patients should be followed for a longer period of time to establish the exact role of this prosthesis design.