a 91-year - old gentleman presented with incidental finding of left neck of femur fracture on a routine radiograph . a quick review of the patient notes revealed a fall , with a lengthy hospital admission , approximately 1 year previously . despite his initial inability to weight - bear and protracted slow progress with physiotherapy no further imaging of the hip was obtained beyond an initial , negative pelvic radiograph .
doctors must be bold in questioning a radiograph that does not fit with the clinical picture .
clinical suspicion of neck of femur fracture in the face of a negative radiograph necessitates further imaging to obtain a definitive answer .
the more experienced doctor knows that some cases are not clear - cut , as between 2% and 10% are occult on conventional radiography [ 1 - 4 ] . in cases , where there is clinical suspicion of a neck of femur fracture , but imaging has been negative or equivocal , further imaging ( e.g. magnetic resonance imaging / computed tomography ) is required .
hip fractures , like everything else , can be missed and this can have serious implications for patients . a delay of over 48 h from admission to surgery doubles the risk of death within 1 year postoperatively .
following a routine radiograph performed by his general practitioner a 91-year - old gentleman was referred to accident and emergency with an incidental finding of fractured left neck of femur ( fig .
1 ) . his general practitioner had requested a pelvic radiograph to further investigate the cause of this gentleman s left knee pain . despite no falls within the previous year
the radiograph demonstrated the well - corticated edges of an old fracture , and the patient was able to mobilize using his frame .
routine pelvic radiograph of a 91-year - old man requested by his general practitioner to further investigate the cause for his left knee pain
old , left sided , displaced , intracapsular had as neck of femur fracture with well - corticated edges .
review of past incidents to find a cause for this neck of femur fracture quickly illuminated a possible event .
approximately 1 year prior , the patient had been admitted to hospital following a mechanical fall at home , after which he was unable to weight - bear .
clinical examination had demonstrated none of the salient features of a neck of femur fracture or had initial radiographs of the pelvis exposed a fracture ( fig .
radiographs of the knee demonstrated no abnormality , yet the gentleman was unable to walk and was admitted .
lateral radiograph of the left hip from the same 91-year - old gentleman taken 1 year previously , following a fall .
anteroposterior radiograph of the left hip from the same 91-year - old gentleman taken 1 year previously , following a fall .
degenerative changes of the left hip joint are demonstrated although no obvious fracture is evident .
magnetic resonance imaging of his left knee was requested to exclude the possibility of soft tissue injury , which demonstrated a tear of the medial meniscus . felt to be the cause of his delayed progress ,
further physiotherapy was encouraged and eventually this gentleman managed to mobilize independently with a frame .
hip fractures are often simple to diagnose clinically and radiologically , with initial imaging sensitivity estimated as 90 - 98% [ 1 - 4 ] .
approximately 75,000 femoral necks are fractured in the uk per annum   and this is projected to rise further . if initial radiographs alone are used to exclude a neck of femur fracture then this poses the alarming possibility that up to 7,500 ( of the known ) neck of femur fractures could have been missed .
delays in diagnosis increase the risk of avascular necrosis , arthroplasty , nonunion , thromboembolic events , and mortality [ 9 , 10 ] .
this case and figures above demonstrates the need for clinicians to have a high index of suspicion when evaluating elderly patients following a fall .
if there is clinical suspicion of a neck of femur fracture , then a negative radiograph is not enough and further imaging is required ; magnetic resonance imaging - or computed tomography , if unavailable or contraindicated .
the sheer prevalence of neck of femur fractures , combined with the knowledge that up to 10% are occult on radiograph [ 1 , 2 , 3 , 4 ] necessitates clinicians to have a high index of suspicion of occult neck of femur fractures in elderly patients following a fall .
although occult fractures are well documented in the literature , hilton s law , as well as referred pain from the joint above or below , are reasons for the threshold for further imaging modalities to be lowered .
the aim of this case report is to raise awareness , to encourage doctors to be bold in questioning a radiograph that does not fit with the clinical picture and to increase requests for further imaging to obtain a definitive answer ; the numbers and guidelines   are on your side . to encourage clinicians to question a radiograph that does not fit with the clinical findings of a neck of femur fracture and consider further imaging to obtain a more definitive picture
 introduction : on rare occasions , hip fractures can be missed . 
 approximately 75,000 neck of femur fractures occur in the united kingdom per annum . 
 up to 10% of hip fractures are occult on plain radiograph . 
 this case demonstrates a usual presentation of an  
 incidental  neck of femur fracture , which had been missed 1 year prior.case report : a 91-year - old gentleman presented with incidental finding of left neck of femur fracture on a routine radiograph . a quick review of the patient notes revealed a fall , with a lengthy hospital admission , approximately 1 year previously . despite his initial inability to weight - bear and protracted slow progress with physiotherapy 
 no further imaging of the hip was obtained beyond an initial , negative pelvic radiograph.conclusion:doctors must be bold in questioning a radiograph that does not fit with the clinical picture 
 . clinical suspicion of neck of femur fracture in the face of a negative radiograph necessitates further imaging to obtain a definitive answer . 