Forefoot inflammation in recent-onset ACPA-positive and ACPA-negative RA: clinically similar, but different in underlying inflamed tissues.

OBJECTIVES: Although joint swelling is traditionally interpreted as synovitis, recent imaging studies showed that there is also inflammation of tenosynovium and intermetatarsal bursae in the forefoot. We aimed to increase our understanding of differences and similarities regarding forefoot involvement between ACPA-positive and ACPA-negative rheumatoid arthritis (RA) at diagnosis. Therefore, we (1) compared metatarsophalangeal (MTP) joint counts, walking disabilities and inflamed tissues between ACPA groups and (2) studied associations of joint swelling/tenderness and walking disabilities with underlying inflamed tissues within ACPA groups. METHODS: 171 ACPA-positive and 203 ACPA-negative consecutively diagnosed patients with RA had a physical joint examination (swollen joint count-66/tender joint count-68), filled a Health Assessment Questionnaire including the domain walking and underwent MRI of the MTP joints at diagnosis. Synovitis, tenosynovitis, osteitis and intermetatarsal bursitis (IMB) were assessed. Findings in age-matched healthy controls were applied to define abnormalities on MRI. RESULTS: While ACPA-negative RA patients had more swollen joints (mean SJC 8 vs 6 in ACPA-positives, p=0.003), the number of swollen MTP joints was similar (mean 1 in both groups); walking disabilities were also equally common (49% vs 53%). In contrast, inflamed tissues were all more prevalent in ACPA-positive compared with ACPA-negative RA. Within ACPA-positive RA, IMB was associated independently with MTP-joint swelling (OR 2.6, 95% CI 1.4 to 5.0) and tenderness (OR 3.0, 95% CI 1.8 to 5.0). While in ACPA-negatives, synovitis was associated independently with MTP-joint swelling (OR 2.8, 95% CI 1.4 to 5.8) and tenderness (OR 2.5, 95% CI 1.3 to 4.8). Tenosynovitis contributed most to walking disabilities. CONCLUSIONS: Although the forefoot of ACPA-positives and ACPA-negatives share clinical similarities at diagnosis, there are differences in underlying inflamed tissues. This reinforces that ACPA-positive and ACPA-negative RA are different entities.

A rare mass with atypical localization: Heterotopic ossification associated with flexor hallucis longus.

Heterotopic ossification (HO), characterized by the formation of ectopic bone, is a benign mass observed in soft tissues. Depending on its location, it can cause symptoms beyond compression, such as mechanical blockage when associated with joints, leading to limitations in joint movements. In the majority of cases, involvement of the hip and elbow joints is common, while HO can sometimes be observed in atypical locations. Trauma, head injury, and spinal cord injuries are well-recognized risk factors for HO development. However, on rare occasions, in non-traumatic cases are identified without any known risk factors. Herein, we present a rare non-traumatic HO case associated with the flexor hallucis longus (FHL) tendon in a 58-year-old female patient. She complained of pain under the first toe of her right foot while wearing shoes for a year, and a mass was detected on the plantar surface of the foot along with limitation of movement in the first metatarsophalangeal joint. Further examinations revealed that the identified mass was a mature HO lesion. Surgical treatment was performed, and during one-year follow-up, the pain subsided, and joint movements returned to normal, resulting in a satisfactory outcome. In conclusion, although many cases of HO are associated with traumatic injuries, it can sometimes be idiopathic, as in our case, and rarely it is accompanied tendon such as FHL in the foot.

Development of an Ultrasound Imaging Atlas for Grading Osteoarthritis in the First Metatarsophalangeal Joint.

OBJECTIVE: Ultrasound (US) imaging may play a fundamental role in the earlier detection and assessment of first metatarsophalangeal joint (MTPJ) osteoarthritis (OA) because of its ability to depict tissue-specific morphologic changes before the point of irreversible structural damage. However, the role of US in supporting the diagnosis of OA in foot joints has not been clearly defined. The aims of this study were to develop a semiquantitative US atlas (the AUT ultrasound imaging [AUTUSI] atlas) to grade the degree of osteoarthritic change in the first MTPJ and to evaluate the intraexaminer and interexaminer reproducibility of using the atlas. METHODS: US images were obtained from 57 participants (30 participants with radiographically confirmed first MTPJ OA). The AUTUSI atlas supports the examination of grading joint effusion, synovial hypertrophy, synovitis, osteophytes, joint space narrowing, and cartilage thickness. Six examiners used the atlas to independently grade 24 US images across 2 sessions. Intraexaminer and interexaminer reproducibility were determined using percentage agreement and Gwet's AC2. RESULTS: Observations using the AUTUSI atlas demonstrated almost perfect-to-perfect interexaminer agreement (percentage agreement ranged from 96% to 100%, and Gwet's AC2 values ranged from 0.81 to 1.00) and moderate-to-perfect intraexaminer agreement (percentage agreement ranged from 67% to 100%, and Gwet's AC2 values ranged from 0.54 to 1.00). CONCLUSION: The AUTUSI atlas demonstrated excellent intraexaminer and interexaminer reproducibility for evaluating first MTPJ joint effusion, synovial hypertrophy, synovitis, joint space narrowing, osteophytes, and cartilage thickness. The AUTUSI atlas affords an opportunity to detect prognostic markers of OA earlier in the disease cascade and has the potential to advance understanding of the pathologic process of first MTPJ OA.

Cross-sectional study of the prevalence of hyperextension of the first metatarsophalangeal joint and its relationship to onycholysis in women with hallux valgus.

BACKGROUND: Hallux Valgus (HV) deformity is associated with misalignment in the sagittal plane that affects the first toe. However, the repercussions of the first toe hyperextension in HV have been scarcely considered. The purpose of this study was to provide evidence of the association between first-toe hyperextension and the risk of first toenail onycholysis in HV. METHODS: A total of 248 HV from 129 females were included. The extension of 1st MTP joint was measured while the patient was in the neutral position of the hallux using a two-branch goniometer. The classification of the HV severity stage was determined by the Manchester visual scale, and the height of the first toe in the standing position was measured using a digital meter. An interview and clinical examination were performed to collect information on the presence of onycholysis of the first toe. RESULTS: Of the 248 HV studied, 100 (40.3%) had onycholysis. A neutral extension > 30 degrees was noted in 110 (44.3%) HV. The incidence of onycholysis was higher in HV type C than in type B (p = 0.044). The probability of suffering onycholysis in the right foot was 2.3 times greater when the neutral position was higher than 30 degrees (OR = 2.3; p = 0.004). However, this was not observed in the left foot (p = 0.171). Onycholysis was more frequent in HV with more than 2 cm height of the first toe (p < 0.001). For both feet, the probability of suffering onycholysis was greater for each unit increase in hallux height (right foot OR = 9.0402, p = 0.005; left foot OR = 7.6633, p = 0.010). CONCLUSIONS: The incidence of onycholysis appears to be significantly associated with HV showing more than 30º extension, and more than 2 cm height of the first toe. Height and hyperextension of the first toe together with first toenail pathology should be mandatory in the evaluation of HV.

Particulate synovitis granuloma complication following a first metatarsophalangeal joint silastic implant.

This case presents a known complication of particulate synovitis granuloma associated with a first metatarsophalangeal joint silastic implant. However, the degree of soft tissue granuloma enlargement is quite unique in size and its proliferative effect-invading the medulla cavity and infiltrating the outer cortex of bone. This case study aims to demonstrate its clinical presentation, imaging investigations, surgical excision and histopathology findings. The learning points emphasised within this manuscript draw attention to the procedure selection for a silastic implant, as well as its proposed mode of action and various potential associated complications. Surgery was based on careful analysis of overall function, prior surgery conducted and patient expectations to achieve a shared decision-making process.

High-resolution 3T magnetic resonance imaging and histological analysis of capsuloligamentous complex of the first metatarsophalangeal joint.

BACKGROUND: There are discrepancies in the understanding of the structure of the capsuloligamentous complex of the first metatarsophalangeal joint (MTPJ); this study aims to investigate the differences with previous anatomical reports of high-resolution 3T magnetic resonance imaging (MRI) and histological analysis in illustrating the structure of the capsuloligamentous complex of the first MTPJ. METHODS: Nine fresh frozen cadaveric feet specimens (from two women and three men; aged 32 to 58 years) were used in this study. All specimens underwent MR examination with T1-weighted imaging and T2-weighted spectral attenuated inversion recovery in three planes. Subsequently, all cadaveric feet specimens were sliced into 2-mm-thick sections. The MRI features of the capsuloligamentous complex of the first MTPJ were analyzed in these specimens. Hematoxylin-eosin and Masson's trichrome staining methods were used to explore the histologic features of the capsuloligamentous complex of the first MTPJ. RESULTS: Different from most previous studies, our results showed that the plantar plate could be divided into four portions including the central portion of the plantar plate, the intersesamoid, the sesamoid phalangeal and the metatarsosesamoid ligaments. The normal central portion of the plantar plate could be clearly visualized in the sagittal and coronal plane MR images. The intersesamoid ligament is a continuation of the central portion of the plantar plate on the sagittal plane on the gross specimen, the MR imaging, and the histological examination. On the coronal plane of the gross specimen and MR imaging, the sesamoid phalangeal ligaments and the central portion of the plantar plate can be seen as separate ligaments, but they appeared interwoven with the same continuous collagenous fibers on the histological analysis. CONCLUSION: High-resolution 3T MRI allows accurate demonstration of the different anatomical details of the capsuloligamentous complex of the first MTPJ from previous anatomical reports. The histological analysis provides further understanding of the structures of the capsuloligamentous complex of the first MTPJ from previous studies.

High Prevalence of Degenerative Changes at the Metatarsal Head Sesamoid Articulation Found During Hallux Valgus Correction Surgery.

Background. Despite the absence of complications and a restoration of normal hallux alignment, some patients have suboptimal outcomes from hallux valgus correction surgery. One risk factor for persistent pain may be the presence of arthritic changes at the metatarsal head articulation with the sesamoids, an area not easily assessed with standard radiographs unless dedicated sesamoid views are obtained. In this study, we prospectively evaluated the metatarsal head for degenerative changes during hallux valgus correction surgery and identified preoperative risk factors associated with these changes. Methods. We prospectively evaluated 200 feet in 196 patients who underwent hallux valgus surgery intraoperatively for the pattern and severity of arthritic changes at the metatarsal head. Mann-Whitney U testing was implemented to compare differences in arthritic scores between preoperative deformity groups. The Spearman correlation test was used to determine the association between age and preoperative deformity with the severity of degenerative changes. Results. More than half of all feet assessed had severe arthritic changes at the plantar medial aspect of the metatarsal head and 40% of feet at the plantar lateral aspect. Age and intermetatarsal angle were found to be positively correlated with arthritis in this area. Conclusion. Our prospective study has demonstrated the high prevalence of arthritic changes at the metatarsal head sesamoid articulation and the positive influence of age and severity of deformity on metatarsal head arthritic changes seen during hallux valgus correction surgery. Furthermore, these arthritic changes were found to have no significant influence on preoperative functional and pain levels.Levels of Evidence: Level IV: Case series.

Hemorrhagic Synovitis of the First Metatarsophalangeal Joint: A Case Report.

CASE: A 69-year-old woman presented with a painful mass at her first metatarsophalangeal joint. Further evaluation was concerning for a neoplastic process, leading to surgical intervention. Pathological examination demonstrated hemosiderotic synovitis, and hematologic evaluation led to a new diagnosis of von Willebrand disease. CONCLUSION: Hemorrhagic synovitis, involving mostly larger joints, has been well described. However, a literature search demonstrates no cases of this in the foot or toes. Presentation of hemarthroses and underlying coagulopathies can be subtle and must be considered in patients presenting with soft-tissue masses or pseudotumors, despite having no previous diagnosis.

An experimentally induced osteoarthritis model in horses performed on both metacarpophalangeal and metatarsophalangeal joints: Technical, clinical, imaging, biochemical, macroscopic and microscopic characterization.

Osteoarthritis is a common cause of pain and economic loss in both humans and horses. The horse is recognized as a suitable model for human osteoarthritis, because the thickness, structure, and mechanical properties of equine articular cartilage are highly comparable to those of humans. Although a number of equine experimental osteoarthritis models have been described in the literature, these cases generally involve the induction of osteoarthritis in just one joint of each animal. This approach necessitates the involvement of large numbers of horses to obtain reliable data and thus limits the use of this animal model, for both economic and ethical reasons. This study adapts an established equine model of post-traumatic osteoarthritis to induce osteoarthritis-associated lesions in all 4 fetlock joints of the same horse in order to reduce the number of animals involved and avoid individual variability, thus obtaining a more reliable method to evaluate treatment efficacy in future studies. The objectives are to assess the feasibility of the procedure, evaluate variability of the lesions according to interindividual and operated-limb position and describe the spontaneous evolution of osteoarthritis-associated pathological changes over a twelve-week period. The procedure was well tolerated by all 8 experimental horses and successfully induced mild osteoarthritis-associated changes in the four fetlock joints of each horse. Observations were carried out using clinical, radiographic, ultrasonographic, and magnetic resonance imaging methods as well as biochemical analyses of synovial fluid and postmortem microscopic and macroscopic evaluations of the joints. No significant differences were found in the progression of osteoarthritis-associated changes between horses or between the different limbs, with the exception of higher synovial effusion in hind fetlocks compared to front fetlocks and higher radiographic scores for left fetlocks compared to the right. This model thus appears to be a reliable means to evaluate the efficacy of new treatments in horses, and may be of interest for translational studies in human medicine.

The relation between physical joint examination and MRI-depicted inflammation of metatarsophalangeal joints in early arthritis.

BACKGROUND: The relationship between physical joint examination (PE) and MRI-detected inflammation in early inflammatory arthritis has mostly been studied in the hands. Physical examination of MTP joints is considered difficult, and for these joints, this relationship is unknown. Therefore, we studied the concordance of PE with MRI inflammation in MTP joints. Metacarpophalangeal (MCP) joints were included for comparison. METHODS: One thousand seven hundred fifty-nine MTP(2-5) and 1750 MCP(2-5) joints of 441 consecutive patients with early arthritis underwent PE (for joint swelling) and MRI, all evaluated by two assessors. MRI was scored for synovitis, tenosynovitis, and osteitis (summed MRI inflammation). Synovial intermetatarsal bursae may enlarge upon inflammation and become palpable and were therefore also assessed. Analyses (frequencies, GEE) were performed on joint level. RESULTS: PE and MRI were concordant in 79% of MTP joints. Of 1606 non-swollen MTP joints, 83% showed no MRI inflammation and 17% showed subclinical MRI inflammation. Of 153 swollen MTP joints, 48% had MRI inflammation and 52% (79 MTP joints) did not. Of these 79 swollen MTP joints without MRI inflammation, 31 showed intermetatarsal bursitis and 48 joints had none of these MRI abnormalities (this concerned 31% of swollen MTP joints). MTP swelling was statistically independently associated with tenosynovitis (OR 2.21, 95% CI 1.1-4.3) and intermetatarsal bursitis (OR 2.91, 95% CI 1.8-4.8). MTP joints showed subclinical inflammation less often than MCP joints (17% vs. 34%, P < 0.001). Swollen MTP joints showed MRI inflammation less often than swollen MCP joints (48% vs. 88%, P < 0.001). CONCLUSIONS: The absence of swelling of MTP joints in early arthritis is mostly accompanied by the absence of MRI-detected inflammation. Swollen MTP joints are, in addition to synovitis, also explained by tenosynovitis and intermetatarsal bursitis and partly unexplained by MRI. Their clinical relevance must be determined in longitudinal studies.

Histopathological Evaluation of Mechanoreceptors in the Metatarsophalangeal Joint Capsule in Hallux Valgus.

To date, we could find no study concerning the relationship between mechanoreceptors in the joint capsule of the first metatarsophalangeal joint and hallux valgus deformity. We aimed to investigate the presence of mechanoreceptors in samples obtained from the first metatarsophalangeal joint capsules of patients with hallux valgus deformity to improve our understanding of the clinical and histopathological features of the disease. Samples were taken from the first metatarsophalangeal joint capsules of 13 fresh-frozen cadavers with normal anatomy (controls) and 29 patients undergoing surgery for hallux valgus (cases). For light microscopy, excised specimens were fixed in 10% formaldehyde and processed for routine histopathological investigation. All samples were dehydrated in a series of ethanol, cleared in xylene, and embedded in paraffin. Orientation of collagen fibers was determined on Masson's trichrome-stained sections, and mechanoreceptors were evaluated on S-100-immunostained sections. In the sections stained with Masson's trichrome, the orientation of collagen fibers was regular in the control group. However, coarse and disoriented collagen bundles were observed in the hallux valgus cases (P ≤ .05). S-100 immunostaining was positive in the sections of both the cases and controls. Finally, free nerve endings were more abundant in the samples obtained from the capsules of hallux valgus cases than from the control group (P ≤ .05). An increase in the number of free nerve endings within the capsules of the first metatarsophalangeal joints in feet with hallux valgus deformity might have a role in the development of clinically relevant joint pain and instability.

Ultrasonography supplements clinical exam to improve early rheumatoid arthritis disease activity monitoring in metatarsophalangeal joints.

INTRODUCTION: Compared with clinical examination (CE), ultrasonography (US) provides additional and more accurate assessment of inflammation and visualization of structural damage. To better understand the effectiveness of US in metatarsophalangeal joints (MTPJs), we compared disease activity in MTPJs 2-5 assessed by CE and US, with magnetic resonance imaging (MRI) as reference standard. METHOD: Treatment-naïve adult patients with early RA (ACR criteria, disease duration < 2 years) were consecutively recruited. MTPJs 2-5 were assessed for swelling and tenderness, and imaged by US (Esaote MyLab70). The most symptomatic foot was imaged by peripheral MRI (1.0 Tesla). US was semiquantitatively graded for synovial thickening (ST) and power Doppler (PD) (0-3), and erosions (yes/no). MRI was semiquantitatively graded for bone marrow edema (BME), synovitis, and erosions (OMERACT). Kappa agreement, sensitivity, specificity, and predictive values were analyzed using cut-offs at ST ≥ 2, PD ≥ 1, and MRI synovitis and BME at both ≥ 1 and ≥ 2. RESULTS: This study included 39 patients (85% female, mean (SD) age = 51.6 (10.3)). Using MRI synovitis and BME grade ≥ 2 as the reference, PD had superior sensitivity (82%) and kappa agreement (k = 0.43) than swollen joint count (55%, k = 0.20), but similar high specificity (88%, 83%). ST and PD were often observed in clinically asymptomatic MTPJs. US detected very few MRI erosions, but several observed erosions corresponded to grade ≥ 2 MRI erosions. CONCLUSION: Clinical swelling and PD are highly specific for active inflammation in the MTPJs. US supplemented CE by allowing observation of subclinical inflammation and structural damage. Key Points • Ultrasonography detected many subclinical synovial inflammations in metatarsophalangeal joints (MTPJs), many confirmed by MRI • Ultrasonography may best be used clinically to supplement clinical examination by assessing non-swollen joints • Ultrasonography provided quick method of visualizing bone erosions that were grade ≥ 2 on MRI.

Ultrasonographic Features of Lower-Limb Joints in Gout: Which Joints and Clinical Characteristics Would Provide More Information for Diagnosis?

OBJECTIVE: This observational cross-sectional study evaluated the distribution of ultrasound (US) features of lower-limb joints and the risk factors of tophus in gout patients. METHODS: We examined 588 joints including the bilateral knee, ankle, and first metatarsophalangeal (MTP) joints in 98 gout patients by US between March to August in 2017. The distribution of double-contour (DC), tophus, aggregates, synovitis, effusion and erosion in different joint, course, and age groups were investigated by Cochran Q and χ test. The risk factors of tophus were analyzed using logistic regression method. RESULTS: Double-contour was most commonly observed in the knee (p = 0.005). Tophus, aggregates, synovitis, and erosion were mostly detected in the first MTP (p < 0.001, p = 0.01, p = 0.001, p < 0.001, respectively). The prevalence rates of DC, tophus, and erosion in patients with a longer course were significantly higher (p = 0.029, p = 0.002, p < 0.001, respectively). Older patients had more detectable tophus and erosion than younger patients (p = 0.028, p = 0.021). Patients of older age (odds ratio [OR], 3.83; 95% confidence interval [CI], 1.27-11.48), with frequent attacks (OR, 3.80; 95% CI, 1.10-13.15), and with longer course (OR, 6.52; 95% CI, 1.37-30.96) had higher risks of tophus. CONCLUSIONS: Most signs were detected by US in the first MTP, except that DC was most commonly observed in the knees. Patients of older age with frequent attacks and longer course may experience higher risks for tophus. Comprehensive assessment of the lower limbs, particularly the knee and first MTP, can significantly help diagnosis.

The shape of the first metatarsal head and its association with the presence of sesamoid-metatarsal joint osteoarthritis and the pronation angle.

BACKGROUND: The purpose of this study was to evaluate the associations of the shape of the first metatarsal head with (1) the presence of osteoarthritis in the sesamoid-metatarsal joint and (2) the pronation angle of the first metatarsal head on foot radiographs. METHODS: A total of 121 patients, with the mean age of 61 years, underwent weight-bearing dorsoplantar, lateral, and first metatarsal axial radiographs. The shape of the first metatarsal head's lateral edge was classified as either rounded, intermediate, or angular in shape in the dorsoplantar view. The presence of osteoarthritis in the sesamoid-metatarsal joint and the pronation angle of the first metatarsal head were assessed in the first metatarsal axial view. Other variables that could affect the first metatarsal shape, including the lateral first metatarsal inclination angle, were also assessed. Univariate and multivariate analyses were performed to determine the associations. RESULTS: The prevalence of sesamoid-metatarsal osteoarthritis was significantly higher (77%, 27%, and 29% for rounded, intermediate, and angular, respectively, P < .001), and the metatarsal pronation angle was significantly larger (14°, 8°, and 4° for rounded, intermediate, and angular, respectively, P < .001) in feet with a rounded metatarsal head. These associations were also significant in the multiple regression analysis. CONCLUSION: A rounded metatarsal head was associated with a higher prevalence of osteoarthritis within the sesamoid-metatarsal joint, as well as a larger first metatarsal head pronation angle. A negative round sign can be used as a simple indicator of an effective correction to the first metatarsal pronation angle during hallux valgus surgery. However, in feet with sesamoid-metatarsal osteoarthritis, surgeons will need to be cautious as overcorrection may occur.

A search to the target tissue in which RA-specific inflammation starts: a detailed MRI study to improve identification of RA-specific features in the phase of clinically suspect arthralgia.

OBJECTIVE: Based on a unique cohort of clinically suspect arthralgia (CSA) patients, we analysed which combinations of MRI features at onset were predictive for rheumatoid arthritis (RA) development. This was done to increase our comprehension of locations of RA onset and improve the predictive accuracy of MRI in CSA. METHODS: In the discovery cohort, 225 CSA patients were followed on clinical arthritis development. Contrast-enhanced 1.5 T MRIs were made of unilateral metacarpophalangeal (MCP) (2-5), wrist, and metatarsophalangeal (1-5) joints at baseline and scored for synovitis, tenosynovitis, and bone marrow edema. Severity, number, and combinations of locations (joint/tendon/bone) with subclinical inflammation were determined, with symptom-free controls of similar age category as reference. Cox regression was used for predictor selection. Predictive values were determined at 1 year follow-up. Results were validated in 209 CSA patients. RESULTS: In both cohorts, 15% developed arthritis < 1 year. The multivariable Cox model selected presence of MCP-extensor peritendinitis (HR 4.38 (2.07-9.25)) and the number of locations with subclinical inflammation (1-2 locations HR 2.54 (1.11-5.82); ≥ 3 locations HR 3.75 (1.49-9.48)) as predictors. Severity and combinations of inflammatory lesions were not selected. Based on these variables, five risk categories were defined: no subclinical inflammation, 1-2 locations, or ≥ 3 locations, with or without MCP-extensor peritendinitis. Positive predictive values (PPVs) ranged 5% (lowest category; NPV 95%) to 67% (highest category). Similar findings were obtained in the validation cohort; PPVs ranged 4% (lowest category; NPV 96%) to 63% (highest category). CONCLUSION: Tenosynovitis, particularly MCP-extensor peritendinitis, is among the first tissues affected by RA. Incorporating this feature and number of locations with subclinical inflammation improved prediction making with PPVs up to 63-67%.

Prevalence of feet and ankle arthritis and their impact on clinical indices in patients with rheumatoid arthritis: a cross-sectional study.

BACKGROUND: We aimed to evaluate the prevalence of foot and/or ankle arthritis (FAA) and its impact on clinical indices in patients with rheumatoid arthritis (RA). METHODS: This cross-sectional study used data from the Korean College of Rheumatology Biologics & Targeted therapy registry to observe clinical outcomes of patients undergoing biologics therapy and conventional therapy. FAA was defined as ≥1 tender or swollen joint in the ankle and/or 1st-5th metatarsophalangeal (MTP) joints. Disease Activity Score 28 (DAS28), Routine Assessment of Patient Index Data 3 (RAPID3), Simplified Disease Activity Index (SDAI), and Clinical Disease Activity Index (CDAI) were assessed. RESULTS: Among 2046 patients, 598 had FAA. The ankle joint was the most commonly involved joint in FAA (tender joint, 71.4%; swollen joint, 59.5%), followed by the third and second MTP joints. Patients with FAA showed higher DAS28, RAPID3, SDAI, and CDAI scores. FAA presence was significantly associated with non-remission as per DAS28-ESR (odds ratio, 3.4; 95% confidence interval, 2.0-5.8), DAS28-CRP (3.6, 2.4-5.3), SDAI (6.3, 2.8-14.6), CDAI (7.6, 2.4-24.3), and RAPID3 (5.6, 2.7-11.5) indices on adjusting for age, sex, disease duration, presence of rheumatoid factor, presence of anti-cyclic citrullinated peptide antibody, lung disease, use of methotrexate, and previous use of biological disease-modifying anti-rheumatic drugs. Patients with FAA were less likely to achieve remission of SDAI (n = 6, 1.0%) and CDAI (n = 3, 0.5%) than that of DAS28-ESR (n = 21, 3.5%), DAS28-CRP (n = 38, 6.4%), and RAPID3 (n = 12, 2.0%). CONCLUSIONS: FAA represents a severe disease activity and is an independent risk factor for non-remission in patients with RA.

Preliminary Experience With Polyvinyl Alcohol Hydrogel Implant for Pathology of the Second Metatarsal Head.

BACKGROUND: There is no consensus regarding which surgical technique is most beneficial for pathology of the second metatarsophalangeal joint. We report the use of polyvinyl alcohol hydrogel synthetic cartilage implant hemiarthroplasty for pathology of the second metatarsal head that has failed nonoperative treatment and present 5 cases with a minimum 15 months of follow-up. METHODS: The technique for synthetic cartilage hemiarthroplasty of the second metatarsal head is described. The postoperative protocol included weightbearing as tolerated for 2 weeks and moderate limitations in activities of daily living to respect wound healing, followed by physiotherapy for range of motion exercises. Charts for patients who underwent this procedure between 2015 and 2017 were retrospectively reviewed. Outcome measures collected postoperatively included a pain visual analog scale, Short-Form 36 (SF-36) Physical Component Summary (PCS) and Mental Component Summary (MCS) scores, and Foot and Ankle Ability Measure (FAAM) Sports and Activities of Daily Living (ADL) current level of function percentages. RESULTS: At 15 to 38 months of follow-up, patients reported little to no pain and good range of motion, with no complications. Mean outcome measure scores were 89 for FAAM ADL, 75 for FAAM Sports, 44.4 for SF-36 PCS, and 52.1 for SF-36 MCS. CONCLUSION: This preliminary study of synthetic cartilage hemiarthroplasty for treatment of joint-destructive conditions of the second metatarsal head demonstrated good outcomes and no complications in 5 cases at a mean 25 months of follow-up. Large prospective cohort studies are needed to prove the efficacy and safety of this new surgical technique for the treatment of pathology of the second metatarsal head. LEVEL OF EVIDENCE: Level IV, retrospective case series.