[Triple arthrodesis for correction of cavovarus deformity]

OBJECTIVE

The aim is to correct the underlying cavovarus deformity and to achieve a pain-free and stable hindfoot.

INDICATIONS

Rigid neurologic, posttraumatic, congenital, and idiopathic cavovarus deformities.

CONTRAINDICATIONS

General surgical or anesthesiological risks, infections, critical soft tissue conditions, neurovascular impairment of the lower extremity, noncompliance, patients with severely reduced bone quality, insulin-dependent diabetes mellitus, smoking.

SURGICAL TECHNIQUE

The talonavicular and subtalar joints are exposed using a single medial approach. Joint cartilage is carefully debrided. Hindfoot reposition with complete correction of cavovarus deformity in all three planes. Joints are stabilized using cannulated screws, followed by wound closure.

POSTOPERATIVE MANAGEMENT

A soft wound dressing is used. Thromboprophylaxis is recommended. Patient mobilization starts on postoperative day 1 using a stabilizing walking boot or cast for 6 weeks with 15 kg partial weight bearing. Clinical and radiographic follow-up 6 weeks postoperatively to assess osseous consolidation at the arthrodesis site. Following clinical and radiographic follow-up at 6 weeks, full weight bearing is gradually initiated.

RESULTS

Between January 2012 and July 2014, triple arthrodesis was performed in 11 patients with a mean age of 62 ± 14 years due to cavovarus deformity. The mean follow-up was 34 ± 8 months (range 24-48 months). In all patients, the cavovarus deformity was substantially corrected. Significant pain relief from 7.1 ± 2.2 (range 5-10) to 1.8 ± 1.5 (range 0-4) on the visual analogue scale was observed.

Comparison of the effects of forefoot joint-preserving arthroplasty and resection-replacement arthroplasty on walking plantar pressure distribution and patient-based outcomes in patients with rheumatoid arthritis

Purpose

The purpose of this retrospective study is to clarify the difference in plantar pressure distribution during walking and related patient-based outcomes between forefoot joint-preserving arthroplasty and resection-replacement arthroplasty in patients with rheumatoid arthritis (RA).

Methods

Four groups of patients were recruited. Group1 included 22 feet of 11 healthy controls (age 48.6 years), Group2 included 36 feet of 28 RA patients with deformed non-operated feet (age 64.8 years, Disease activity score assessing 28 joints with CRP [DAS28-CRP] 2.3), Group3 included 27 feet of 20 RA patients with metatarsal head resection-replacement arthroplasty (age 60.7 years, post-operative duration 5.6 years, DAS28-CRP 2.4), and Group4 included 34 feet of 29 RA patients with metatarsophalangeal (MTP) joint-preserving arthroplasty (age 64.6 years, post-operative duration 3.2 years, DAS28-CRP 2.3). Patients were cross-sectionally examined by F-SCAN II to evaluate walking plantar pressure, and the self-administered foot evaluation questionnaire (SAFE-Q). Twenty joint-preserving arthroplasty feet were longitudinally examined at both pre- and post-operation.

Results

In the 1^st MTP joint, Group4 showed higher pressure distribution (13.7%) than Group2 (8.0%) and Group3 (6.7%) (P<0.001). In the 2^nd-3^rd MTP joint, Group4 showed lower pressure distribution (9.0%) than Group2 (14.5%) (P<0.001) and Group3 (11.5%) (P<0.05). On longitudinal analysis, Group4 showed increased 1^st MTP joint pressure (8.5% vs. 14.7%; P<0.001) and decreased 2^nd-3^rd MTP joint pressure (15.2% vs. 10.7%; P<0.01) distribution. In the SAFE-Q subscale scores, Group4 showed higher scores than Group3 in pain and pain-related scores (84.1 vs. 71.7; P<0.01) and in shoe-related scores (62.5 vs. 43.1; P<0.01).

Conclusions

Joint-preserving arthroplasty resulted in higher 1^st MTP joint and lower 2^nd-3^rd MTP joint pressures than resection-replacement arthroplasty, which were associated with better patient-based outcomes.

Prominent midfoot involvement in children with enthesitis-related arthritis category of juvenile idiopathic arthritis

Foot involvement is common in juvenile idiopathic arthritis (JIA) but is often unrecognized and difficult to treat. This study was done to assess clinical and radiological involvement of the feet and its impact on function in Indian children with enthesitis-related arthritis (ERA). We enrolled consecutive children with ERA with disease duration of less than 5 years. All patients underwent clinical examination of the feet and filled the juvenile arthritis foot index (JAFI) questionnaire. Ultrasound (US) of foot joints and entheses and extremity magnetic resonance imaging (MRI) scan of one foot were done. Fifty-five patients (53 boys), with median 14 years and disease duration 1.9 years, were included. Thirty-seven of 46 were HLA-B27-positive. Mean juvenile spondyloarthritis disease activity (JSpADA) index and juvenile idiopathic arthritis disease activity scrore-10 (JADAS10) scores were 4 and 14.25. Forty-six had history of foot pain, 36 had foot involvement on examination (15 ankle, 8 subtalar, 24 midfoot, 10 forefoot, and 21 tendoachilles), and 7 had plantar fascia involvement. On US (N = 55), 16 had ankle involvement and 8 had subtalar involvement, and 19 patients had midfoot arthritis, 24 had tendoachilles enthesitis, and 11 had plantar fasciitis. On MRI (N = 50), 27 had midfoot involvement. Thirty-three had bone edema. Fourteen had midfoot enthesitis and 17 had tenosynovitis. Clinical and US had 82% concordance at the midfoot and 90% at the ankle. MRI had 74% concordance with examination and 72% with US at the midfoot. The median JAFI scores were as follows: total JAFI = 4 (0-11), impairment = 1, activity limitation = 2, and participation restriction = 1. JAFI total and individual domains correlated with JADAS10, JSpADAS, and childhood health assessment questionnaire (CHAQ) but not duration of foot disease. JAFI was higher in children with midfoot arthritis on US. Foot joints and entheses are involved in a substantial proportion of patients with ERA patients and the midfoot is commonly involved. Foot disease produces significant functional limitation.

Ultrasound of the osteoarthritic joint

Ultrasound (US) has acquired an increasing role in the assessment of joint and periarticular abnormalities in osteoarthritis (OA). It is able to image a large set of abnormalities in this disease which include both inflammatory and structural changes at different peripheral joint sites and it is helpful in guiding local procedures that can be easily and safely performed with optimal patient's tolerance. US is a feasible imaging modality that has become a bedside procedure in the rheumatology clinical practice, thus filling the gap between clinical and radiographic evaluations of patients with OA. The present review focuses and summarises the currently available data on the applications of US in OA.

A reduced 12-joint ultrasound examination predicts lack of X-ray progression better than clinical remission criteria in patients with rheumatoid arthritis

To study the predictive value of clinical remission definitions and ultrasound (US) examination on X-ray progression in rheumatoid arthritis (RA). This was an observational prospective multicenter 1-year follow-up cohort of RA patients with moderate disease activity (3.2 < DAS28 ≤ 5.1) who started anti-TNF therapy. DAS28ESR, DAS28CRP, SDAI, CDAI, and ACR/EULAR remission criteria were applied and reduced 12-joint US examination was performed at baseline and at 6 and 12 months. At baseline and month 12, radiographs of hands and feet were obtained in a subset of patients. A blind independent reader scored radiographs. X-ray progression was defined as Sharp van der Heijde change score >1 and no progression was defined as ≤0. 319 of 357 patients completed the study; patients had a mean (SD) age of 53.5 (13.1) years, with a disease duration of 7.5 (7.1) years. Laboratory, clinical, and US values significantly improved at month 6, except CRP, with additional improvement at month 12. Remission and low disease activity rates increased at follow-up. In the subset of 115 patients with radiological studies, clinical remission by any definition was not significantly associated with X-ray progression. Patients without PD signal at baseline and month 6 were a lower risk of X-ray progression than patients with PD signal, OR 0.197 (95% CI 0.046-0.861) and 0.134 (95% CI 0.047-0.378), respectively. Absence of PD signal, but not clinical remission predicts lack of X-ray progression. A feasible 12-joint US examination may add relevant information to RA remission criteria.

Biomechanical investigation of two plating systems for medial column fusion in foot

Background

Arthrodesis of the medial column (navicular, cuneiform I and metatarsal I) is performed for reasons such as Charcot arthropathy, arthritis, posttraumatic reconstruction or severe pes planus. However, the complication rate is still high and mainly resulting from inadequate fixation. Special plates, designed for medial column arthrodesis, seem to offer potential to reduce the complication rate. The aim of this study was to investigate biomechanically plantar and dorsomedial fusion of the medial column using two new plating systems.

Methods

Eight matched pairs of human cadaveric lower legs were randomized in two groups and medial column fusion was performed using either plantar or dorsomedial variable-angle locking compression plates. The specimens were biomechanically tested under cyclic progressively increasing axial loading with physiological profile of each cycle. In addition to the machine data, mediolateral x-rays were taken every 250 cycles and motion tracking was performed to determine movements at the arthrodesis site. Statistical analysis of the parameters of interest was performed at a level of significance p = 0.05.

Results

Displacement of the talo-navicular joint after 1000, 2000 and 4000 cycles was significantly lower for plantar plating (p≤0.039) while there was significantly less movement in the naviculo-cuneiform I joint for dorsal plating post these cycle numbers (p<0.001). Displacements in all three joints of the medial column, as well as angular and torsional deformations between the navicular and metatarsal I increased significantly for each plating technique between 1000, 2000 and 4000 cycles (p≤0.021). The two plating systems did not differ significantly with regard to stiffness and cycles to failure (p≥0.171).

Conclusion

From biomechanical point of view, although dorsomedial plating showed less movement than plantar plating in the current setup under dynamic loading, there was no significant difference between the two plating systems with regard to stiffness and cycles to failure. Both tested techniques for dorsomedial and plantar plating appear to be applicable for arthrodesis of the medial column of the foot and other considerations, such as access morbidity, associated deformities or surgeon's preference, may also guide the choice of plating pattern. Further clinical studies are necessary before definitive recommendations can be given.

Clinical Outcomes and Development of Symptomatic Osteoarthritis 2 to 24 Years After Surgical Treatment of Tarsometatarsal Joint Complex Injuries

BACKGROUND

Injuries to the tarsometatarsal (TMT) joint complex, or Lisfranc injuries, have been reported to result in osteoarthritis (OA) following surgical treatment. Good outcomes with respect to short and medium-term results have been reported. However, long-term results, specifically regarding clinical outcomes and the development of symptomatic OA, are limited. The objectives of this study were to assess clinical outcomes, the occurrence of symptomatic OA, and risk factors for OA at 2 to 24 years after a Lisfranc injury treated surgically with open reduction and internal fixation (ORIF) or with primary arthrodesis.

METHODS

This was a retrospective study involving 61 patients treated surgically at our institution between 1988 and 2009 for an injury to the TMT joint complex. Patients underwent either ORIF with transarticular screws or primary arthrodesis when joint comminution at the TMT level was such that ORIF was not possible. Functional outcomes were assessed according to the American Orthopaedic Foot & Ankle Society (AOFAS) score, the Foot Function Index (FFI), and a visual analog scale (VAS) for pain. Global health was evaluated with the Short Form (SF)-12 Health Survey physical component summary (PCS).

RESULTS

Sixty-one of the 128 patients were available for clinical evaluation, including the use of questionnaires, and radiographic assessment at a mean of 10.9 years postoperatively (range, 2.4 to 23.9 years). Mean scores were as follows: AOFAS score, 79.0; FFI, 16.9, and VAS for pain, 2.5. Radiographic evidence of OA was noted in 44 (72.1%) of the patients, and symptomatic OA, in 54.1%, the latter having worse outcomes. Risk factors for OA were nonanatomic reduction, fracture classification of Myerson type C, and a history of smoking.

CONCLUSIONS

Two to 24 years following surgical treatment to restore and maintain joint anatomy for Lisfranc injuries, we found satisfactory clinical outcome scores and a large number of patients who had returned to their previous level of functioning and employment, with little need for secondary procedures. However, there was a substantial occurrence of posttraumatic OA, as evident on radiographs, albeit the occurrence of symptomatic OA was lower.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

To what extent is foot pain related to biomechanical changes and ultrasound-detected abnormalities in rheumatoid arthritis?

OBJECTIVES

To investigate the presence of biomechanical abnormalities and ultrasound (US)-detected inflammation and damage in low disease or remission status rheumatoid arthritis (RA) patients with foot complaints.

METHODS

We recruited 136 subjects with foot complaints. Sixty-two were biologic disease-modifying antirheumatic drug-treated RA patients presenting Disease Activity Score-determined remission or low disease activity while the remaining 74 were gender matched controls without rheumatic or musculoskeletal disorders. Both groups underwent a comprehensive podiatric, biomechanical and B-mode and Doppler US assessment of the feet.

RESULTS

Most RA patients and controls were female (77.4% and 83.8%, respectively). There was no statistical difference in the proportion of obese subjects in either group (p=0.792). Inappropriate shoes were used by 50.0% of RA patients and 33.8% of controls (p=0.080). Talalgia, particularly heel pain, was more frequent in the control group, with associated talalgia and metatarsalgia being more prevalent in the RA group (p<0.05). The RA patient group was also more likely to present greater foot deformity, more limited joint movement and biomechanical abnormalities than the controls (p<0.05). US inflammatory and structural changes were significantly more frequent in RA patients than in controls (p<0.05). US structural involvement was significantly associated with limited joint mobility and pathologic biomechanical tests only in RA patients (p<0.05).

CONCLUSIONS

RA foot complaints seemed to be linked to US-detected RA involvement and biomechanical abnormalities. Podiatric and US assessments can be useful to help the clinician to optimise the management of RA patients in remission/low disease activity with foot complaints.

Investigations of Potential Phenotypes of Foot Osteoarthritis: Cross-Sectional Analysis From the Clinical Assessment Study of the Foot

OBJECTIVE

To investigate the existence of distinct foot osteoarthritis (OA) phenotypes based on pattern of joint involvement and comparative symptom and risk profiles.

METHODS

Participants ages ≥50 years reporting foot pain in the previous year were drawn from a population-based cohort. Radiographs were scored for OA in the first metatarsophalangeal (MTP) joint, first and second cuneometatarsal, navicular first cuneiform, and talonavicular joints according to a published atlas. Chi-square tests established clustering, and odds ratios (ORs) examined symmetry and pairwise associations of radiographic OA in the feet. Distinct underlying classes of foot OA were investigated by latent class analysis (LCA) and their association with symptoms and risk factors was assessed.

RESULTS

In 533 participants (mean age 64.9 years, 55.9% female) radiographic OA clustered across both feet (P < 0.001) and was highly symmetrical (adjusted OR 3.0, 95% confidence interval 2.1, 4.2). LCA identified 3 distinct classes of foot OA: no or minimal foot OA (64%), isolated first MTP joint OA (22%), and polyarticular foot OA (15%). After adjustment for age and sex, polyarticular foot OA was associated with nodal OA, increased body mass index, and more pain and functional limitation compared to the other classes.

CONCLUSION

Patterning of radiographic foot OA has provided insight into the existence of 2 forms of foot OA: isolated first MTP joint OA and polyarticular foot OA. The symptom and risk factor profiles in individuals with polyarticular foot OA indicate a possible distinctive phenotype of foot OA, but further research is needed to explore the characteristics of isolated first MTP joint and polyarticular foot OA.

Reconstructive Shelf Arthroplasty as a Salvage Procedure for Complex Fifth Tarsometatarsal Joint Complex Injuries: A Case Review and Discussion

High-energy cuboid fractures are rare injuries that are commonly associated with other midfoot trauma. With displacement, operative intervention is critical to restore articular congruity and the length of the lateral column. Failure to achieve this predisposes patients to posttraumatic arthritis and deformity, often necessitating secondary procedures. Although primary open reduction and internal fixation is the standard of care for these injuries, at times the traditional principles of fracture fixation cannot be applied to cuboid fractures. We describe the case of a 45-year-old woman who underwent a reconstructive shelf arthroplasty of the cuboid and fifth tarsometatarsal joint for a severe injury to the lateral column of the midfoot.

Clinical diagnosis of symptomatic midfoot osteoarthritis: cross-sectional findings from the Clinical Assessment Study of the Foot

OBJECTIVE

To derive a multivariable diagnostic model for symptomatic midfoot osteoarthritis (OA).

METHODS

Information on potential risk factors and clinical manifestations of symptomatic midfoot OA was collected using a health survey and standardised clinical examination of a population-based sample of 274 adults aged ≥50 years with midfoot pain. Following univariable analysis, random intercept multi-level logistic regression modelling that accounted for clustered data was used to identify the presence of midfoot OA independently scored on plain radiographs (dorso-plantar and lateral views), and defined as a score of ≥2 for osteophytes or joint space narrowing in at least one of four joints (first and second cuneometatarsal, navicular-first cuneiform and talonavicular joints). Model performance was summarised using the calibration slope and area under the curve (AUC). Internal validation and sensitivity analyses explored model over-fitting and certain assumptions.

RESULTS

Compared to persons with midfoot pain only, symptomatic midfoot OA was associated with measures of static foot posture and range-of-motion at subtalar and ankle joints. Arch Index was the only retained clinical variable in a model containing age, gender and body mass index. The final model was poorly calibrated (calibration slope, 0.64, 95% CI: 0.39, 0.89) and discrimination was fair-to-poor (AUC, 0.64, 95% CI: 0.58, 0.70). Final model sensitivity and specificity were 29.9% (95% CI: 22.7, 38.0) and 87.5% (95% CI: 82.9, 91.3), respectively. Bootstrapping revealed the model to be over-optimistic and performance was not improved using continuous predictors.

CONCLUSIONS

Brief clinical assessments provided only marginal information for identifying the presence of radiographic midfoot OA among community-dwelling persons with midfoot pain.

Diabetic Charcot neuroarthropathy: The diagnosis must be considered in all diabetic neuropathic patients presenting with a hot, swollen foot

The diagnosis of diabetic Charcot neuroarthropathy (CN) is challenging. This is especially true early in the disease process, when its classical presentation of an acutely inflamed foot may masquerade as other more common lower limb conditions. Prompt diagnosis and appropriate treatment reduces the risk of CN causing permanent incapacitating foot deformity or amputation. We report two cases in which the diagnosis was delayed, resulting in long-term sequelae. These cases highlight the importance of considering CN in patients with diabetic peripheral neuropathy, who present with a red, hot, and swollen foot.

Radiologic damage at baseline predicts patient-related outcomes 18 years after the initiation of methotrexate therapy in patients with severe rheumatoid arthritis

OBJECTIVES

We aimed to assess the association of the degree of radiologic damage at baseline with long-term patient-related outcomes (PRO) in patients with severe rheumatoid arthritis (RA).

METHODS

This prospective observational single-centre study (Ratingen, Germany) included all RA patients starting treatment with methotrexate (MTX) between 1980 and 1987. Standardised clinical evaluations and radiographs of hands and feet were obtained at baseline and during the following years. About 18 years later, patients were invited for a re-assessment. PRO were assessed in three dimensions according to the International Classification of Functioning and Disability (ICF). Statistical analyses comprised multivariable models using baseline values for radiologic damage of hands and feet, age, gender, disease duration, rheumatoid factor positivity, measures of disease activity, and response to MTX as covariates.

RESULTS

At baseline, the mean disease duration was 8.5 years. The disease was active with a mean number of swollen joints of 18 (out of 32) and a mean erythrocyte sedimentation rate of 55 mm/hour. Radiologic damage was present in 95% of the patients. After 18 years, patient-related outcomes could be assessed in 78/271 patients (29%). Among chosen covariates, only the degree of baseline radiologic damage as measured by the Ratingen score was predictive of all long-term PRO (p<0.016).

CONCLUSIONS

In this cohort including patients with severe RA, baseline radiologic damage was a good long-term predictor of PRO related to all three ICF dimensions.

Radiographic scoring methods in psoriatic arthritis

Psoriatic arthritis (PsA) leads to structural damage that can be an important driver for disability and handicap associated with the disease. Serial radiographs, usually of hands and feet, facilitate follow-up documentation of development of these changes. Semi-quantitative scoring methods are designed to measure the degree of radiographically detectable joint damage, and of changes over time. Several radiographic scoring methods that had been developed originally for rheumatoid arthritis have been adopted for the use in PsA. Four different scoring methods used in PsA are presented with instructions on how to use them: modified Steinbrocker global scoring method; PsA scoring method based on Sharp method for RA; Sharp van der Heijde modified method; and PsA Ratingen score (PARS). Available data on the reliability, sensitivity to change, and use in clinical trials, of these four methods are presented.

Serological and Progression Differences of Joint Destruction in the Wrist and the Feet in Rheumatoid Arthritis - A Cross-Sectional Cohort Study

Objective

To investigate clinical and radiological differences between joint destruction in the wrist and the feet in patients with RA.

Methods

A cross-sectional clinical study was conducted in an RA cohort at a single institution. Clinical data included age, sex and duration of disease. Laboratory data included sero-positivity for anti-cyclic citrullinated peptide (CCP) antibody and RF. Radiological measurements included Larsen grades and the modified Sharp/van der Heijde method (SHS) for the hands/wrists and the feet. Statistical analyses were performed using the Kruskal—Wallis H-test, a dummy variable linear regression model and multivariate logistic regression analysis with 95% confidence interval and odds ratios.

Results

A total of 405 patients were enrolled, and 314 patients were analysed in this study. The duration of disease in the foot-dominant group was significantly less than that in the wrist-dominant group. When patients were subdivided by duration of disease, the Larsen grade of the feet was significantly higher than that of the wrist in the first quadrant subgroup, but this was reversed with increasing duration of disease. Anti-CCP status was a significant predictive factor for joint destruction in the wrist but not in the feet, while RF status was not predictive in either the wrist or the feet.

Conclusions

Joint destruction in the feet started earlier than in the wrist, but the latter progresses faster with increasing duration of disease. Anti-CCP status predicts joint destruction in the wrist better than in the feet.

Association of valine and leucine at HLA-DRB1 position 11 with radiographic progression in rheumatoid arthritis, independent of the shared epitope alleles but not independent of anti-citrullinated protein antibodies

OBJECTIVE

For decades it has been known that the HLA-DRB1 shared epitope (SE) alleles are associated with an increased risk of development and progression of rheumatoid arthritis (RA). Recently, the following variations in the peptide-binding grooves of HLA molecules that predispose to RA development have been identified: Val and Leu at HLA-DRB1 position 11, Asp at HLA-B position 9, and Phe at HLA-DPB1 position 9. This study was undertaken to investigate whether these variants are also associated with radiographic progression in RA, independent of SE and anti-citrullinated protein antibody (ACPA) status.

METHODS

A total of 4,911 radiograph sets from 1,878 RA patients included in the Leiden Early Arthritis Clinic (The Netherlands), Umeå (Sweden), Hospital Clinico San Carlos-Rheumatoid Arthritis (Spain), and National Data Bank for Rheumatic Diseases (US) cohorts were studied. HLA was imputed using single-nucleotide polymorphism data from an Immunochip, and the amino acids listed above were tested in relation to radiographic progression per cohort using an additive model. Results from the 4 cohorts were combined in inverse-variance weighted meta-analyses using a fixed-effects model. Analyses were conditioned on SE and ACPA status.

RESULTS

Val and Leu at HLA-DRB1 position 11 were associated with more radiographic progression (meta-analysis P = 5.11 × 10(-7)); this effect was independent of SE status (meta-analysis P = 0.022) but not independent of ACPA status. Phe at HLA-DPB1 position 9 was associated with more severe radiographic progression (meta-analysis P = 0.024), though not independent of SE status. Asp at HLA-B position 9 was not associated with radiographic progression.

CONCLUSION

Val and Leu at HLA-DRB1 position 11 conferred a risk of a higher rate of radiographic progression independent of SE status but not independent of ACPA status. These findings support the relevance of these amino acids at position 11.

Urate crystal deposition in asymptomatic hyperuricaemia and symptomatic gout: a dual energy CT study

BACKGROUND

The aim of this study was to compare the frequency and volume of dual energy CT (DECT) urate deposits in people with asymptomatic hyperuricaemia and symptomatic gout.

METHODS

We analysed DECT scans of the feet from asymptomatic individuals with serum urate ≥540 µmol/L (n=25) and those with crystal proven gout without clinically apparent tophi (n=33).

RESULTS

DECT urate deposits were observed in 6/25 (24%) participants with asymptomatic hyperuricaemia, 11/14 (79%) with early gout (predefined as disease duration ≤3 years) and 16/19 (84%) with late gout (p<0.001). DECT urate deposition was observed in both joints and tendons in the asymptomatic hyperuricaemia group, but significantly less frequently than in those with gout (p≤0.001 for both joint and tendon sites). The volume of urate deposition was also significantly lower in those with asymptomatic hyperuricaemia, compared with the early and the late gout groups (p<0.01 for both comparisons). Similar urate volumes were observed in the early and late gout groups.

CONCLUSIONS

Although subclinical urate deposition can occur in people with asymptomatic hyperuricaemia, these deposits occur more frequently and at higher volumes in those with symptomatic gout. These data suggest that a threshold of urate crystal volume may be required before symptomatic disease occurs.

The population prevalence of symptomatic radiographic foot osteoarthritis in community-dwelling older adults: cross-sectional findings from the clinical assessment study of the foot

OBJECTIVES

To estimate the population prevalence of symptomatic radiographic osteoarthritis (OA) affecting the 1st metatarsophalangeal joint (MTPJ), 1st and 2nd cuneometatarsal joints (CMJs), navicular first cuneiform joint (NCJ) and talonavicular joint (TNJ) in community-dwelling older adults.

METHODS

9334 adults aged ≥50 years registered with four general practices were mailed a health survey. Responders reporting foot pain within the last 12 months were invited to undergo weight-bearing dorso-plantar and lateral radiographs of both feet. OA at the 1st MTPJ, 1st and 2nd CMJs, NCJ and TNJ was graded using a validated atlas. Population prevalence estimates for symptomatic radiographic foot OA overall and for each joint were calculated using multiple imputation and weighted logistic regression modelling to account for missing data and non-response.

RESULTS

5109 health surveys were received (adjusted response 56%). Radiographs were obtained on 557 participants. Overall population prevalence of symptomatic radiographic OA was 16.7% (95% CI 15.3% to 18.0%), 1st MTPJ 7.8% (6.7% to 8.9%), 1st CMJ 3.9% (2.9% to 4.9%), 2nd CMJ 6.8% (5.7% to 7.8%), NCJ 5.2% (4.0% to 6.4%) and TNJ 5.8% (4.8% to 6.9%). With the exception of the 1st CMJ, prevalence was greater in females than males, increased with age and was higher in lower socioeconomic classes. Three-quarters of those with symptomatic radiographic OA reported disabling foot symptoms.

CONCLUSIONS

While cautious interpretation due to non-response is warranted, our study suggests that symptomatic radiographic foot OA affects one in six older adults and the majority report associated disability. Clinicians should consider OA as a possible cause of chronic foot pain in older people.

Imaging of the Lisfranc injury

Lisfranc ligament and joint injuries are relatively uncommon but can result from a variety of low- and high-impact trauma. Up to 20% of Lisfranc fracture-dislocations are misdiagnosed or missed during the initial evaluation. Timely and accurate diagnosis of the injury and early anatomical reduction and stabilization of the Lisfranc joint are crucial to avoid long-term sequelae and functional impairment. Magnetic resonance imaging (MRI) is a sensitive and specific imaging modality and should be considered in injuries with equivocal physical and radiographic findings. In this article, the mechanism and the classification of the Lisfranc joint and ligament injuries are outlined, and imaging findings of different modalities are discussed with the emphasis on MRI.

A genetic variant in the region of MMP-9 is associated with serum levels and progression of joint damage in rheumatoid arthritis

OBJECTIVES

The severity of joint destruction is highly variable between rheumatoid arthritis (RA) patients. The majority of its heritability is still unexplained. Several autoimmune diseases share genetic risk variants that may also influence disease progression. We aimed to identify genetic risk factors for the severity of joint damage in RA by studying genetic susceptibility loci of several autoimmune diseases.

METHODS

In phase 1, 3143 sets of x-rays of 646 Dutch RA patients taken over 7 years (Sharp van der Heijde (SHS) scored) were studied. Genotyping was done by Immunochip. Associations of single-nucleotide polymorphisms (SNPs) with minor allele frequency (MAF) >0.01 and joint destruction were analysed. In phase 2, 686 North American RA patients with 926 SHS-scored x-rays over 15 years of follow-up were evaluated. In both phases multiple testing corrections were done for the number of uncorrelated SNPs; the thresholds for significance were p<1.1×10(-6) and p<0.0036. Matrix metalloproteinase 9 (MMP-9) levels were measured with ELISA in baseline serum samples.

RESULTS

In phase 1, 109 SNPs associated significantly with joint destruction (p<1.1×10(-6)). Of these, 76 were located in the HLA region; the 33 non-HLA variants were studied in phase 2. Here two variants were associated with the severity of joint destruction: rs451066 on chromosome 14 (p=0.002, MAF=0.20) and rs11908352 on chromosome 20 (p=0.002, MAF=0.21). Rs11908352 is located near the gene encoding MMP-9. Serum levels of MMP-9 were significantly associated with the rs11908352 genotypes (p=0.007).

CONCLUSIONS

These data indicate that two loci that confer risk to other autoimmune diseases also affect the severity of joint destruction in RA. Rs11908352 may influence joint destruction via MMP-9 production.