Distal Interphalangeal Joint Osteoarthritis Research Articles

Sustained increase of pinch strength after traction treatment for symptomatic distal interphalangeal joint osteoarthritis

BackgroundSymptomatic distal interphalangeal joint osteoarthritis is a common joint disease that causes hand disability and reduces quality of life. There are few conservative treatment options for this condition. The purpose of this study was to investigate the effect of traction treatment on symptomatic distal interphalangeal joint osteoarthritis. MethodsThis prospective, longitudinal study involved multiple time-series observations and within-subject controls. The most painful distal interphalangeal joints in patients with hand osteoarthritis were treated by daily, 15-min joint traction at home using a finger trap orthosis. The corresponding contralateral digits were used as within-subject controls. The primary outcome measure was two-point pinch strength, and the secondary outcome measures were radiographic findings and treatment adherence. Longitudinal and pairwise comparison analyses of the treated and control digits examined improvements in two-point pinch strength at months 1, 3, and 6 from baseline. The durability of treatment effects after treatment discontinuation was investigated at month 12. ResultsEighteen treated digits and 18 corresponding control digits were eligible for analysis. There was a significant increase in two-point pinch strength after 1-month traction, and this increase was maintained until month 6 despite the absence of radiographic changes. Compared to controls, significant improvement in two-point pinch strength relative to baseline was seen at every observation time point, with a moderate to large effect size. There was no time–treatment interaction. Treatment adherence was high. At months 3 and 6, around 60–80 % of digits were voluntarily treated. Pinch strength was comparable between months 6 and 12, with greater improvement than in the control group. ConclusionJoint traction treatment can improve pinch strength in symptomatic distal interphalangeal joint osteoarthritis. Larger, randomized studies on traction treatment and the effect on hand function are warranted.

Investigation of MicroRNA Biomarkers in Equine Distal Interphalangeal Joint Osteoarthritis.

Osteoarthritis of the equine distal interphalangeal joint is a common cause of lameness. MicroRNAs from biofluids are promising biomarkers and therapeutic candidates. Synovial fluid samples from horses with mild and severe equine distal interphalangeal joint osteoarthritis were submitted for small RNA sequencing. The results demonstrated that miR-92a was downregulated in equine synovial fluid from horses with severe osteoarthritis and there was a significant increase in COMP, COL1A2, RUNX2 and SOX9 following miR-92a mimic treatment of equine chondrocytes in monolayer culture. This is the first equine study to evaluate the role of miR-92a in osteoarthritic chondrocytes in vitro.

Computed tomographic guidance for internal fixation of type II distal phalangeal fractures in 51 horses.

Type II distal phalanx (P3) fractures are a well-described cause of lameness in horses. Reports on outcome following internal fixation of type II P3 fractures are lacking, and with little emphasis on complications. To describe a technique for internal fixation of type II P3 fractures, and evaluate whether specific variables influenced post-operative complications or a horse's ability to return to work. Retrospective case series. Medical records of 51 horses with CT-guided internal fixation of type II P3 fractures were reviewed. Outcome data were acquired from race records and telephone interviews. Associations between independent variables and outcome were analysed using multivariable logistic regression. Eighty-six per cent (95% CI 74%-94%; n=44) successfully returned to work. Implant infection (n=15) and distal interphalangeal joint osteoarthritis (n=9) were the most common complications, with the latter reducing the likelihood of success (OR=0.09, 95% CI 0.01-0.7, P=.02). Implant infection increased the time to return to work (HR=0.5, 95% CI 0.2-0.9, P=.03). The odds of delayed infection decreased by filling the hoof defect with acrylic hoof adhesive rather than poly(methyl methacrylate) and deeply countersinking the screw head (OR=0.08, 95% CI 0.02-0.38, P=.001); the individual effect of each treatment is unknown. Radiographic healing was not associated with likelihood of success. Study limitations included variation in follow-up methods, lack of control population for comparison and lack of randomisation of treatment protocols. Internal fixation of type II P3 fractures is an effective treatment that allows horses to return to athletic use, with similar improved success rates as those reported for conservative management. Infection rates were reduced by deeply countersinking the screw head and filling the hoof defect with an acrylic that mimics hoof wall flexibility and provides a secure seal. Recommencement of training should be based on clinical rather than strictly radiographic findings.

Contrast Enhanced Computed Tomography Findings in 105 Horse Distal Extremities

The poor soft tissue conspicuity of CT can be improved by using intra-arterial CT Angiography (CTA), and intra-articular and intra-bursal contrast enhanced CT (CTAR). This retrospective study describes a combination protocol of CT and CTA of the horse's foot, and CTAR of the distal interphalangeal joint and navicular bursa. It is hypothesized this would provide a comprehensive overview of the range and severity of distal limb pathology. Radiology reports of all horses admitted for distal limb CT over a 5 year period were reviewed. All horses with a complete four stage CT examination and radiology report with lameness isolated to the foot were included. Twenty seven imaging findings using a four grade semiquantitative severity scoring system contributing towards six main diagnostic categories were described. One hundred and five examinations on 56 horses revealed a diagnosis of navicular bone disease in 64%, deep digital flexor tendinopathy in 43%, distal interphalangeal osteoarthritis in 35%, navicular bursitis in 31%, distal interphalangeal collateral ligament desmopathy in 26%, and hoof capsule and distal phalanx pathology in 10%. Only 25% of the navicular bone disease cases were considered clinically significant. The majority of deep digital flexor tendon lesions (77%) and distal interphalangeal joint osteoarthritis (51%) were considered significant. Approximately one third of navicular bursa (37%) and collateral ligament (33%) abnormalities were considered significant. Navicular bursa abnormalities were associated with navicular bone and deep digital flexor tendon lesions. The findings support the hypothesis and the use of this protocol for evaluation of foot lameness.

CLINICAL CONDITIONS FOUND RADIOGRAPHICALLY IN THE FRONT FEET OF RETICULATED GIRAFFE (GIRAFFA CAMELOPARDALIS RETICULATA) IN A SINGLE ZOO.

Front foot radiographs from 22 giraffe (Giraffa camelopardalis reticulata) at one zoo were analyzed to better understand causes of lameness in this giraffe population. The herd had a history of front hoof overgrowth and intermittent lameness. Radiographic findings included distal interphalangeal joint osteoarthritis (OA), distal phalangeal bone (P3) osteitis, P3 fractures, P3 rotation, and sesamoid bone cysts. OA of the distal interphalangeal joint occurred in at least one front foot of 73% (16/22 giraffe) of the herd, and all giraffe had OA by 7 yr of age. Pedal osteitis was present in at least one front foot in 86% (19/22) of the giraffe, starting in animals as young as 1 yr old. P3 fractures were present in 36% (8/22) of the herd. These fractures were near the site of the deep digital flexor attachment and were diagnosed in giraffe as young as 10 yr old. The presence of severe osteitis was associated with the presence of P3 fractures. This study is unique in that a large herd was trained to participate in voluntary front foot radiographs so multiple causes of foot disease could be diagnosed antemortem and without anesthesia. Although the underlying causes of these lesions are likely multifactorial and currently unknown to us, the high prevalence of foot disease in relatively young animals warrants further investigation across zoos. In this study, OA, osteitis, and P3 fractures were common radiographic findings among giraffe that were limping. Subsequent monitoring and management changes suggest that proactive management of foot health can decrease morbidity and mortality in zoo giraffe.

Brief Report: Influence of Disease Activity in Rheumatoid Arthritis on Radiographic Progression of Concomitant Interphalangeal Joint Osteoarthritis.

Distal interphalangeal (DIP) joints are commonly considered to be unaffected by rheumatoid arthritis (RA). Despite synovitis and bone marrow edema being associated with radiographic progression in hand osteoarthritis (OA) and hand RA, radiographic courses differ substantially. This study was undertaken to analyze incidence and progression of radiographically evident DIP joint OA in RA patients, in relation to RA activity and patient characteristics. In sequential radiographs of 1,988 RA patients in the Swiss Clinical Quality Management in Rheumatic Diseases registry, we evaluated and scored 15,904 DIP joints. Scoring was based on the presence of central erosions and subchondral sclerosis and on the severity of osteophytes and joint space narrowing, according to the modified Kellgren/Lawrence (K/L) grade. The presence of DIP joint OA was defined as ≥1 joint with a K/L grade of ≥2, and progression was defined as an increase in a summed K/L grade. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated. The median follow-up time was 4.5 years (interquartile range 3.1-7.0), and the mean ± SD age was 56.1 ± 11.1 years. DIP joint OA was present in 60% of patients at baseline. Higher mean age (OR 1.09 [95% CI 1.08-1.10]), female sex (OR 1.37 [95% CI 1.08-1.74]), and higher mean body mass index (OR 1.03 [95% CI 1.00-1.06]) were associated with the presence of DIP joint OA, but neither the presence of anti-citrullinated protein antibodies (ACPAs) (OR 0.72 [95% CI 0.50-1.03]) nor the presence of rheumatoid factor (OR 1.01 [95% CI 0.74-1.38]) were associated with it. Disease Activity Score using the erythrocyte sedimentation rate and metacarpophalangeal (MCP) joint erosions were not associated with DIP joint OA progression. RA disease duration had no relevant effect size associated with DIP joint OA progression (OR 0.97 [95% CI 0.96-0.99]). Known risk factors for DIP joint OA were replicated in patients with RA. The observation that RA activity, the presence of ACPA, and MCP joint erosions were not associated with the prevalence or progression of DIP joint OA indicates that there are distinct roles of inflammation in the pathogenesis of RA and DIP joint OA.

Review of Acute Traumatic Closed Mallet Finger Injuries in Adults.

In adults, mallet finger is a traumatic zone I lesion of the extensor tendon with either tendon rupture or bony avulsion at the base of the distal phalanx. High-energy mechanisms of injury generally occur in young men, whereas lower energy mechanisms are observed in elderly women. The mechanism of injury is an axial load applied to a straight digit tip, which is then followed by passive extreme distal interphalangeal joint (DIPJ) hyperextension or hyperflexion. Mallet finger is diagnosed clinically, but an X-ray should always be performed. Tubiana's classification takes into account the size of the bony articular fragment and DIPJ subluxation. We propose to stage subluxated fractures as stage III if the subluxation is reducible with a splint and as stage IV if not. Left untreated, mallet finger becomes chronic and leads to a swan-neck deformity and DIPJ osteoarthritis. The goal of treatment is to restore active DIPJ extension. The results of a six- to eight-week conservative course of treatment with a DIPJ splint in slight hyperextension for tendon lesions or straight for bony avulsions depends on patient compliance. Surgical treatments vary in terms of the approach, the reduction technique, and the means of fixation. The risks involved are stiffness, septic arthritis, and osteoarthritis. Given the lack of consensus regarding indications for treatment, we propose to treat all cases of mallet finger with a dorsal glued splint except for stage IV mallet finger, which we treat with extra-articular pinning.

Concentrations of cytokines, matrix metalloproteinases, and tissue inhibitors of matrix metalloproteinases in autologous conditioned serum from horses with distal interphalangeal joint osteoarthritis

Concentrations of cytokines, matrix metalloproteinases, and tissue inhibitors of matrix metalloproteinases in autologous conditioned serum from horses with distal interphalangeal joint osteoarthritis

Magnetic resonance protocols in equine lameness examination, used sequences, and interpretation

Magnetic resonance is a great diagnostic tool in equine lameness examination. Its value is most significantly visible in evaluating distal extremities. Problems with podotrochlear apparatus, laminitis or distal interphalangeal joint osteoarthritis are the most common disorders diagnosed in equine patients. Without using magnetic resonance it was impossible to clearly assess which structures are involved in each of these diseases. One of the most important things in MRI is the choice of sequence. Most commonly used are T1 GE, T2 FSE, STIR and T2* GE, in sagittal, transverse and dorsal planes. To make a reliable diagnosis it is important to compare findings in all these sequences.

PATHOMORPHOLOGICAL FINDINGS OF WHITE LINE DISEASE WITH DIGITAL AND INNER ORGAN INFECTIONS IN CULLING DAIRY COWS

The aim of this study was to investigate pathomorph ological findings of white line disease in culling lame cows, with special reference to the lesions and the ir distribution. The most prominent pathomorphologic findings of the claw with white line disease includ ed extensor process entheseophyte (75.0%), flexor t uberisity entheseophyte (37.5%) and abaxial margin bone absorption (68.7%). Six out of the total of WLD3 cases h ad osteolysis of flexor tuberisity (66.7%). In WLD3 ca ses, three out of the total of 9 cases showed septi c osteoarthritis in distal inter-phalangeal joint (33 .3%). Ankylosis was observed only in one case between P3 bone and distal sesamoid bone. One of case with WLD2 showed severe bone sequestration of P3 bone. Laminitis may have affected virtually this case at some previous time. Routine trimming and scoring of locomotion seems to provide suitable parameters for early diagnosis and prevention of premature culling in dairy cows.

Denervation of the Distal Interphalangeal Joint

Distal interphalangeal joint osteoarthritis is one of the most common conditions hand surgeons have to deal with. When daily manual activities are impaired by symptoms, surgical treatment is indicated. Usually, this is carried out by means of arthrodesis, being joint replacement another option. In this study, a technique for distal interphalangeal joint denervation is presented as a treatment for painful degenerative or posttraumatic osteoarthritis. Potential complications and contraindications are also discussed.

Treatment with TNF-α inhibitor infliximab might reduce hand osteoarthritis in patients with rheumatoid arthritis

To investigate the association between systemic and local inflammation and incident and progressive radiographic secondary osteoarthritis (OA) in interphalangeal joints (IPJs) over 3 years in rheumatoid arthritis (RA) patients and the effect of tumor necrosis factor alpha (TNF-α) inhibitor infliximab on secondary OA in IPJs. In the present observational longitudinal study baseline and 3-year hand X-rays of 416 recent-onset RA patients were scored for osteophytes and erosions in IPJs, blinded for time, using Osteoarthritis Research Society International atlas and Sharp-van der Heijde score. The associations between inflammatory factors and incident and progressive secondary OA in distal IPJs (DIPJs) and proximal IPJs (PIPJs) and the effect of infliximab compared to disease-modifying anti-rheumatic drug treatment on secondary OA were analyzed by multivariable regression and generalised estimating equations analyses. Sixty-seven percent of the patients were female with, at baseline, a mean age of 54 years and OA present in DIPJs and PIPJs in 37% and 13%. Three years later, new secondary OA in DIPJs and PIPJs was seen in 11% and 10%, and progressive secondary OA in 36% and 35%. High erythrocyte sedimentation rate over 3 years and progressive erosive damage were risk factors for incident secondary OA in DIPJs, but not in PIPJs. At joint level, progression of erosions was associated with both incident and progressive secondary OA, only in DIPJs. Infliximab treatment was associated with lower incident secondary OA in PIPJs [relative risk 0.5 (95% confidence interval 0.2, 1.0)], independent of decrease in inflammation. Incident and progressive secondary OA in DIPJs over 3 years was associated with high inflammatory activity in RA. Infliximab treatment reduced incident secondary OA in PIPJs independent of decrease in inflammation, suggesting that anti-TNF-α therapy might be effective against secondary hand OA via other pathways than suppression of inflammation. Further studies in populations of primary hand OA are necessary to determine the role of anti-TNF-α in treatment of primary hand OA.

Natural history of radiographic features of hand osteoarthritis over 10 years

To evaluate the natural history of radiographic hand osteoarthritis (OA) over 10 years. We assessed 118 subjects (30 women) twice (X-ray A and B) with mean (SD) follow-up time of 9.6 (0.4) years. Subjects were of mean (SD) age 52 (10) years at X-ray A and had undergone prior knee meniscectomy. Radiographs of the distal interphalangeal (DIP) and proximal interphalangeal (PIP) joints, and the first interphalangeal (IP1) and first carpometacarpal (CMC1) joints of both hands were read for joint space narrowing (JSN) and osteophytes according to the OARSI atlas. Radiographic progression was evaluated both at joint and subject level. At the time of X-ray A, we found radiographic OA (approximating Kellgren and Lawrence grade 2 or worse) in at least one hand joint in 42 (36%) subjects, and in 62 (53%) at X-ray B (P<0.001). At X-ray A, 21 subjects (18%) were classified as having primary hand OA vs 35 (30%) at X-ray B (P<0.001). Increase in JSN and osteophyte grade occurred most frequently in the DIP joints. OA at X-ray B was most frequently found in subjects' CMC1 (29%), DIP (14-27%), and IP1 joints (19%). Fifty-nine percent of subjects progressed radiographically (increase in total radiographic score by at least 2). However, the progression of the radiographic changes was mostly minor. In subjects with prior meniscectomy, CMC1, DIP, and IP1 joint OA is common. However, further hand OA progression over 10 years, as detected by plain radiography, is relatively modest. More sensitive imaging techniques may be preferable for clinical trials to evaluate structural hand OA progression.

Allelic variants of IL1R1gene associate with severe hand osteoarthritis

BackgroundIn search for genes predisposing to osteoarthritis (OA), several genome wide scans have provided evidence for linkage on 2q. In this study we targeted a 470 kb region on 2q11.2 presenting the locus with most evidence for linkage to severe OA of distal interphalangeal joints (DIP) in our genome wide scan families.MethodsWe genotyped 32 single nucleotide polymorphisms (SNPs) in this 470 kb region comprising six genes belonging to the interleukin 1 superfamily and monitored for association with individual SNPs and SNP haplotypes among severe familial hand OA cases (material extended from our previous linkage study; n = 134), unrelated end-stage bilateral primary knee OA cases (n = 113), and population based controls (n = 436).ResultsFour SNPs in the IL1R1 gene, mapping to a 125 kb LD block, provided evidence for association with hand OA in family-based and case-control analysis, the strongest association being with SNP rs2287047 (p-value = 0.0009).ConclusionsThis study demonstrates an association between severe hand OA and IL1R1 gene. This gene represents a highly relevant biological candidate since it encodes protein that is a known modulator of inflammatory processes associated with joint destruction and resides within a locus providing consistent evidence for linkage to hand OA. As the observed association did not fully explain the linkage obtained in the previous study, it is plausible that also other variants in this genome region predispose to hand OA.

Association Between Interleukin 1 Gene Cluster Polymorphisms and Bilateral Distal Interphalangeal Osteoarthritis

To examine the association of the interleukin 1 gene (IL1) cluster polymorphisms and their haplotypes with bilateral distal interphalangeal joint osteoarthritis (DIP OA). Radiographs of both hands of 295 dentists and 248 teachers were examined and classified for the presence of OA using reference images. Bilateral DIP OA was defined by the presence of radiographic findings of grade 2 or more in at least 1 symmetrical pair of the DIP joints. We genotyped 10 single-nucleotide polymorphisms (SNP) in the IL1R1, IL1RL2, IL1A, IL1B, and IL1RN genes using polymerase chain reaction-based methods. Haplotypes were statistically reconstructed using the PHASE program. The association between the genotypes/diplotypes and bilateral DIP OA was examined with logistic regression analysis. Two IL1B SNP (rs1143634 and rs1143633) were associated with bilateral DIP OA. The carriers of the IL1B rs1143634 minor allele had an increased OA risk [odds ratio (OR) 1.6; 95% confidence interval (CI) 1.08-2.26] compared to the noncarriers. The association was stronger in the dentists. The distribution of the IL1B rs1143633 genotype fit a recessive mode of inheritance (OR 3.03, 95% CI 1.35-6.83, p = 0.006). Two IL1B-IL1RN extended haplotype alleles (211-1 and 121-1) were associated with bilateral DIP OA. An interaction between the IL1B rs1143634 and the IL1R1-IL1RL2 and IL1B-IL1RN extended haplotypes and occupation (increased risk of OA among dentists only) was observed. Our results provide further evidence for the role of IL1 gene cluster polymorphisms in the etiology of OA and suggest that some of these may predispose DIP joints to the effects of mechanical overload.

Two subtypes of radiographic osteoarthritis in the distal interphalangeal joint of the hand

BackgroundThe etiology and pathogenesis of hand osteoarthritis (OA) are not completely clarified, and several factors may cooperate in a multifactorial fashion in its development. The purpose of this study was to clarify the effects of the dominant hand that contribute to the development of distal interphalangeal (DIP) joint OA using epidemiological analyses. MethodsA total of 518 subjects (156 men, 362 women) in a rural community were analyzed. Their mean age was 63.8 years for men and 60.7 years for women. Anteroposterior (AP) standing radiographs of bilateral knees, lateral views of the lumbar spine, and AP views of bilateral hands were obtained. Furthermore, a survey of their life patterns was conducted using self-administered questionnaires. Radiographic osteoarthritis was defined as Kellgren and Lawrence grade 2 or higher. Hand OA was limited to Heberden’s nodes. Generalized OA (GOA) was defined as bilateral knee OA plus lumbar spine OA. ResultsGOA was observed in 13.0% of the subjects. The incidence of DIP joint OA was significantly higher in the GOA group than that in the non-GOA group. In the GOA group, the incidence of right-hand DIP joint OA in right-handed and left-handed subjects was 37.5% and 40.0%, respectively, without a significant difference. In the non-GOA group, however, the incidence of right-hand DIP joint OA in right-handed and left-handed subjects was 16.4% and 3.2%, respectively, with a significant difference. With a multiple logistic regression model, the P value of the handedness was marginal (0.060), but a clear tendency of increase in the odds ratio (7.129) was observed in the dominant hand for the non-GOA group. In contrast, there was no effect of the handed-ness on right-hand DIP joint OA in the GOA group. ConclusionsThere are two subtypes of hand DIP joint OA in terms of the etiology. One is environmental, and the other is genetic.

A high‐resolution magnetic resonance imaging study of distal interphalangeal joint arthropathy in psoriatic arthritis and osteoarthritis: Are they the same?

Distal interphalangeal (DIP) joint arthropathy is characteristic of both psoriatic arthritis (PsA) and osteoarthritis (OA), but the microanatomic basis for DIP joint localization is poorly understood. This study used high-resolution magnetic resonance imaging (MRI) to investigate the basis for hand disease localization in both conditions. Twenty patients matched for disease duration (10 with DIP joint PsA and 10 with DIP joint OA) and 10 normal control subjects were scanned with a 1.5T MRI scanner utilizing a high-resolution 23-mm diameter surface coil with displayed pixel dimensions of 80-100 mum. Images were obtained precontrast and postcontrast, and all joint structures, including ligaments, tendons, and entheses, were evaluated by 2 independent assessors. PsA could be distinguished from OA on the basis of more severe inflammation in the collateral ligaments and the extensor tendons and more severe changes at the corresponding DIP joint entheseal insertions. A much greater degree of extracapsular enhancement, with diffuse involvement of the nailbed and diffuse bone edema without cartilage damage, was also typical of PsA. Compared with the normal controls, the OA cohort exhibited prominent ligament and entheseal changes, but with much less contrast enhancement than in PsA and less bone involvement at the insertions. These findings suggest prominent inflammatory changes in ligament, tendon, enthesis, and adjacent bone in the DIP joint disease of PsA patients. Involvement of the same structures is common in the DIP joints of OA patients, but inflammatory changes are much less marked. These findings are potentially important for a better understanding of arthritis in humans.

The prevalence of symptomatic knee and distal interphalangeal joint osteoarthritis in the urban population of Antalya, Turkey

The aim of this cross-sectional study was to estimate the prevalence and risk factors of symptomatic knee and distal interphalangeal (DIP) joint osteoarthritis (OA) in the elderly (> or =50 years of age) urban population of Antalya, Turkey. According to the 1997 national census, Antalya's population was 508,840. By random cluster sampling, 655 individuals aged 50 years or more were interviewed face-to-face and subjected to structured interviews regarding knee pain, worsening pain on exertion, and the gelling phenomenon. They were also asked about performing namaz (a fundamental act of worship in Islam performed five times a day), smoking, type of residence, type of toilet, work style, and duration of walking per day. They were also questioned about swelling in DIP joints. In the case of suspicion of knee OA, the individuals were invited to the hospital for further evaluation by physical examination and direct roentgenogram. The diagnosis of knee OA was based on clinical or clinical and radiographic findings. The prevalence of symptomatic knee OA was determined as 14.8% in the population aged 50 years or over. Advanced age, female sex, namaz, and type of residence were found to be associated with knee OA. The rate of symptomatic knee OA was significantly lower in smokers and those walking more than 2 h per day. Female sex was also strongly associated with OA DIP joints. OA of DIP joints was found significantly associated with symptomatic knee OA. The latter is a major health problem in the elderly population, especially in about one fourth of women aged 50 years or over. These data suggest that advanced age, female sex, and type of residence are risk factors.

Genomewide Scan for Hand Osteoarthritis: A Novel Mutation in Matrilin-3

Osteoarthritis (OA) is the most common human joint disease, characterized by loss and/or remodeling of joint synovium, cartilage, and bone. Here, we describe a genomewide linkage analysis of patients with idiopathic hand OA who were carefully phenotyped for involvement of either or both the distal interphalangeal (DIP) joints and the first carpometacarpal (CMC1) joints. The best linkage peaks were on chromosomes 4q and 3p and on the short arm of chromosome 2. Genomewide significance was reached for a locus on chromosome 2 for patients with affected CMC1 joints (LOD = 4.97); this locus was also significant for patients with OA in both CMC1 and DIP joints (LOD = 4.44). The peak LOD score at this locus coincides with a gene, MATN3, encoding the noncollagenous cartilage extracellular matrix protein, matrilin-3. Subsequent screening of the genomic sequence revealed a missense mutation, of a conserved amino acid codon, changing threonine to methionine in the epidermal growth factor-like domain in matrilin-3. The missense mutation cosegregates with hand OA in several families. The mutation frequency is slightly more than 2% in patients with hand OA in the Icelandic population and has a relative risk of 2.1.

The embryology of the domestic animals—Developmental mechanisms and malformations

The poor soft tissue conspicuity of CT can be improved by using intra-arterial CT Angiography (CTA), and intra-articular and intra-bursal contrast enhanced CT (CTAR). This retrospective study describes a combination protocol of CT and CTA of the horse's foot, and CTAR of the distal interphalangeal joint and navicular bursa. It is hypothesized this would provide a comprehensive overview of the range and severity of distal limb pathology. Radiology reports of all horses admitted for distal limb CT over a 5 year period were reviewed. All horses with a complete four stage CT examination and radiology report with lameness isolated to the foot were included. Twenty seven imaging findings using a four grade semiquantitative severity scoring system contributing towards six main diagnostic categories were described. One hundred and five examinations on 56 horses revealed a diagnosis of navicular bone disease in 64%, deep digital flexor tendinopathy in 43%, distal interphalangeal osteoarthritis in 35%, navicular bursitis in 31%, distal interphalangeal collateral ligament desmopathy in 26%, and hoof capsule and distal phalanx pathology in 10%. Only 25% of the navicular bone disease cases were considered clinically significant. The majority of deep digital flexor tendon lesions (77%) and distal interphalangeal joint osteoarthritis (51%) were considered significant. Approximately one third of navicular bursa (37%) and collateral ligament (33%) abnormalities were considered significant. Navicular bursa abnormalities were associated with navicular bone and deep digital flexor tendon lesions. The findings support the hypothesis and the use of this protocol for evaluation of foot lameness.