spondyloarthritis ( spa ) is a group of rheumatic diseases characterized by inflammatory back 
 pain , peripheral oligoarthritis , enthesitis , and/or extraarticular manifestations1 . ankylosing spondylitis ( as ) and psoriatic 
 arthritis ( psa ) are the most frequently seen spa subtypes in rheumatology units2,3,4 .
foot involvement in spa is not uncommon and 
 enthesitis , erosive changes , or ankylosis are the main symptoms5 , 6 .
this involvement 
 may affect foot functions negatively , similar to rheumatoid arthritis ( ra)7 . in rheumatology units , the functional 
 states of patients with spa are usually evaluated using bath ankylosing spondylitis 
 functional index ( basfi ) or other similar scales globally .
however , these assessments may 
 underestimate the foot - related functional limitations in these patients .
the foot and ankle outcome score ( faos ) is a scale measuring the foot - related functional 
 limitations in the disorders affecting the foot7,8,9,10 .
it consists of 5 subscales : pain , 
 symptoms , activities of daily living ( adl ) , function in sport and recreation ( sport - rec ) , 
 and foot and ankle - related quality of life ( qol ) .
the turkish version of faos is a valid and 
 reliable instrument to assess foot and ankle related problems11 .
the aim of this study was to assess specifically the functional limitations caused by foot 
 involvement in patients with spa .
patients with as and psa aged 1870  years , with foot pain for more than 4 weeks who 
 underwent anteroposterior ( ap ) and lateral ( l ) feet radiography were included into the 
 study .
they met the modified new york criteria for as and moll - wright criteria for psa12 , 13 .
patients who had 
 flatfoot , previous foot surgery , or any other foot disorder unrelated to spa , and who had a 
 systemic disease such as diabetes or hyperthyroidism were excluded .
ethical approval for 
 this study was obtained from the ethical committee of the university where the study was 
 conducted .
the clinical findings of foot 
 involvement were assessed by observing for swelling , redness , or tenderness . to obtain a 
 numerical value , a 
( cfs ) was calculated by giving 1 point for 
 every finding on one foot [ swelling : 1 point , redness : 1 point , tenderness : 1 point ; the 
 maximum cfs score was 6 for the two feet ] .
the radiologic involvement of the foot was 
 evaluated by the spondyloarthropathy tarsal radiographic index ( spa - tri ) , which is a valid 
 and reliable radiologic index developed specifically for the assessment of foot involvement 
 in spa , and is suitable for use with two or more x - ray projections .
it has five points ; 0 : 
 normal , 1 : osteopenia or suspicious findings , 2 : definite joint space narrowing , bony 
 erosions , periosteal whiskering , enthesophytes , 3 : paraarticular enthesophytes / incomplete 
 bridging , 4 : bony ankylosis / joint space fusion or complete bridging .
the maximum spa - tri 
 score for the two feet ( total spa - tri score ) is 5614 .
foot x - ray images were evaluated by a radiologist who had no 
 information about the clinical status of subjects .
talonavicular , calcaneocuboid , 
 intercuneiform , cuneonavicular , and subtalar joints , and the calcaneal attachments of the 
 achilles tendon and plantar fascia ( 7 places ) were assessed using the spa - tri .
the foot - related functional status of patients was determined by the turkish version of the 
 faos .
faos is 
 calculated by a specific equation , and  100  indicates no problems while  0  indicates 
 extreme problems8 .
since the pain 
 assessment was achieved in detail by faos , no other pain assessment scale was needed .
c - reactive protein ( crp ) and erythrocyte sedimentation rate ( esr ) were used as serum 
 markers for disease activity .
thirty patients with spa ( 14 as , 16 psa ) with a mean age of 49  years ( range 2670  years ) 
 completed the study .
the mean faos subscale scores were as follows : pain=58.70  21.75 , 
 symptoms=64.88  26.05 , adl=66.27  22.56 , sport - rec=44.33  26.42 , and qol=42.08  24.99 . 

pain subscale scores correlated positively with adl , sport - rec , and qol subscale scores . 

symptoms subscale score also positively correlated with adl , sport - rec , and qol subscale 
 scores ( table 1table 1.positive correlation between pain and symptoms subscale scores with other faos 
 subscale scoresadl sport - rec qolsymptomsr0.749 * 0.693 * 0.552*painr0.875 * 0.872 * 0.629*faos : the foot and ankle outcome score , adl : function in daily living , sport - rec : 
 functions in sport and recreation , qol : quality of life .
pain and symptoms subscale scores positively correlated with each other ( r : 
 0.679 , p<0.001 ) .
faos : the foot and ankle outcome score , adl : function in daily living , sport - rec : 
 functions in sport and recreation , qol : quality of life .
this value demonstrated that although patients had foot pain , 
 they did not have prominent physical examination findings .
the mean crp and esr were 1.1 
 ( 0.18.5 )  mg / dl and 32 ( 7100 )  mm / h , respectively , showing low disease activity .
there were 
 no relationships between faos subscale scores and cfs or serum markers ( crp/ esr ) .
the mean spa - tri score was 7.7 ( 024 ) and no correlation was found between faos subscale 
 scores and radiologic score .
foot disorders may affect mobility and life quality significantly . as frequently involves 
 the foot ; the achilles tendon is the second most common site of enthesitis after the 
 chondro - sternal junction , and the ankle is the second most common site for peripheral joint 
 disease after the knee6 . the involvement 
 of the ankle and small joints of the foot is also frequent in psa15 .
these effects of as or psa on the foot may lead to 
 functional limitations . the functional states and quality of life of patients with spa are 
 usually evaluated using questionnaires such as basfi , health assessment questionnaire for 
 spondyloarthropathies ( haq - s ) , ankylosing spondylitis quality of life questionnaire ( asqol ) , 
 or psa - specific quality of life questionnaire ( psaqol)16,17,18,19 .
however , these 
 questionnaires evaluate the functional activities in a global manner without considering the 
 specific cause of the limitation . therefore , the functional cost of foot involvement can not 
 be assessed clearly with these indices leading to underestimation .
faos is a 42-item questionnaire developed for the assessment of functional limitations 
 after ankle ligament reconstruction , but it was also used in other disorders affecting the 
 foot such as hallux valgus and rheumatoid arthritis7,8,9 .
it has 5 subscales ; pain , symptoms , adl , sport - rec , and qol .
pain 
 subscale include 9 questions evaluating the frequency and severity of pain in certain 
 situations such as walking on flat surface or at night while in bed .
symptoms subscale has 7 
 questions assessing the stiffness , swelling , and movement properties of the foot / ankle .
the 
 adl and sport - rec subscales evaluate the degree of difficulty experienced due to foot / ankle 
 disorders in functional activities .
the fifth subscale , qol , focuses on the awareness of the 
 foot / ankle problem8 , 11 .
pain and symptoms subscale scores significantly and positively 
 correlated with each other and with adl , sport - rec , and qol subscale scores . pain and 
 symptoms such as stiffness or range of motion loss ,
plain radiography is a routinely used imaging technique in the evaluation of radiologic 
 involvement in rheumatic diseases .
spa - tri is the radiologic index developed specifically 
 for the assessment of foot involvement in spa . in this study
the mean spa - tri score was 7 , a very low score 
 when compared with the maximum score of 56 .
it could be speculated that although patients 
 had symptoms , radiography did not show the involvement clearly , and therefore , no 
 statistically significant results were obtained .
the magnetic resonance imaging technique is 
 quite successful in demonstrating very early changes at the feet even in patients with 
 asymptomatic as and psa20 , 21 .
therefore , this should be the preferred technique for 
 future studies . in this study ,
the relationships between the faos subscale scores and cfs and serum markers 
 were also assessed .
the 
 foot is composed of small joints and their examination is relatively difficult than that of 
 the large joints .
the inflammatory changes producing pain in these small joints may not 
 always lead to swelling , redness , or tenderness .
these reasons may explain the lack of a 
 relationship between cfs and faos subscale scores
. in our study , crp and esr values were 
 distributed in a wide range ( 0.18.5  mg / dl and 7100  mm / h , respectively ) showing that foot 
 involvement may not be directly affected from the disease activity .
this hypothesis remains 
 to be clarified with studies having a larger sample size . in conclusion , rheumatic pain ,
resulting from the inflammatory changes in the joints and 
 related structures , is a very important clinical problem disturbing the mood , sleep , and 
 quality of life of patients22,23,24 .
it is the most 
 common presenting symptom of rheumatic diseases of the foot and may precede clinical and 
 radiologic findings25 .
this study 
 demonstrated that foot pain in patients with spa might result in significant foot - related 
 functional limitation .
therefore , foot involvement and its functional results should be 
 evaluated separately regardless of the global functional state and disease activity of the 
 patient . to improve pain and function physical therapy modalities or orthosis
more studies about the foot involvement at the early and late 
 stages of the disease are needed and the possible treatment approaches must be 
 investigated .
 [ purpose ] spondyloarthritis is a major inflammatory disease followed - up in the 
 rheumatology clinics , foot involvement in spodyloarthritis is common . 
 the functional 
 states of patients with spondyloarthritis are usually evaluated globally . 
 the aim of this 
 study was to assess the foot involvement - related functional limitations in patients with 
 spondyloarthritis . 
 [ subjects and methods ] patients with ankylosing spondylitis and 
 psoriatic arthritis with foot pain more than 4 weeks who underwent anteroposterior and 
 lateral feet radiography were enrolled into the study . 
 a  clinical findings score  was 
 calculated by assigning 1 point for every finding of swelling , redness , and tenderness . 
 
 c - reactive protein and erythrocyte sedimentation rate were used as serum markers for 
 disease activity . 
 foot radiograms were evaluated using the spondyloarthropathy tarsal 
 radiographic index and the foot - related functional state of patients was determined by the 
 turkish version of the foot and ankle outcome score . [ results ] 
 there were no relationships 
 between foot and ankle outcome score subscales and clinical findings score , serum markers , 
 or radiologic score . 
 pain and symptoms subscale scores were result positively correlated 
 with activity of daily living , sport and recreation , and quality of life subscale scores . 
 
 [ conclusion ] pain and symptoms are the main determinants of foot - related functional 
 limitations in spondyloarthritis . 
INTRODUCTION
SUBJECTS AND METHODS
RESULTS
DISCUSSION