intrapelvic migration of the acetabular cup along with proximal migration of the femoral stem is one of these entities . we report a case image of an elderly lady who presented 6 months after total hip arthroplasty to her general practitioner and gynaecologist complaining of a palpable hard pelvic mass as well as difficulty walking . ntrapelvic complications of total hip arthroplasty ( tha ) ire not well understood , and most are secondary to ntrapelvic migration of the acetabular component . ntrapelvic migration of the acetabular component after otal hip replacement , where there is severe acetabular lestruction making reconstruction very difficult as was the : ase with our patient , is a very rare entity . a 73-year - old female presented to her general practitioner vith a complaint of difficulty with walking , and an inability o weight bear on her right side . she also complained of elvic pain , and had noticed an abdominal mass centrally nd on her right side . there was no history of vaginal > leeding , discharge or a change in bowel habits . the general ractitioner suspected a possible gynaecological cause for er presentation , most likely fibroid uterus , and ubsequently referred her to a gynaecologist for further work up . she also had a history of five previous hip replacement operations for severe osteoarthritis of her hip joints , three on her right and two on her left side . for this she had undergone successful endovascular stenting of her right external iliac artery and was discharged home . having now suspected a non - gynaecological aetiolgy for her presentation , plain film radiographs were requested . supine pelvis and lateral hip radiographs ( fig.1a , b ) demonstrated superior migration of the femoral head component of the prosthesis into the right side of the pelvis as well as a dislocated acetabular component lying in the mid lower pelvis . on lateral view the dislocated acetabular component was situated in the region of the pouch of douglas with its screws directed inferiorly . supine pelvis ( a ) and lateral hip ( b ) radiographs demonstrate superior migration of the femoral head component of the prosthesis into the right side of the pelvis as well as a dislocated acetabular component lying in the mid lower pelvis . the patient was transferred to a teaching orthopaedic unit where she underwent emergency surgery for removal of the intrapelvic acetabular cup . it was postulated by the surgeons that her multiple revision surgeries and osteoporotic bone state predisposed her to protruso acetabuli prosthetica . her surgery involved a laparotomy with a transperitoneal approach . in view of the extensive destruction of the acetabular bone salvage this was done at a different institute and thus a follow up radiograph was not available . protrusio acetabuli prosthetica refers to failure of hip replacement surgery when there is intrapelvic migration of components . predisposition to protrusio acetabuli prosthetica includes : over - reaming , multiple pelvic perforations , osteopenia , infection , trauma , diseases of bone deficiency , overactivity , or formation of a hypertrophic membrane . in cases of osteoporosis and where acetabular rim support is inadequate the 2007 paper by stiehl reported 17 previous such cases and they described three additional cases . since then we could find 5 more articles in pubmed [ 6 - 10 ] . other complications reported include vascular injury , haematoma , nerve palsy , fistula from the hip to the intrapelvic viscera , compression of the bladder , ureters and vagina and clinical features of dyspareunia and gross haematuria . in our case patient had peculiar history of palpable abdominal mass with pelvic pain and symtoms of right hip . such high degree of migration of the femoral stem is uncommon especially with cemented stem that has not loosened from the medullary canal . another peculiarity of these cases is female preponderance   which might be because of higher incidence and severity of osteoporosis in post - menopausal females . a treatment trend for such complications was mostly girdlestone excision arthroplasty however recent reports do favor use of saddle prosthesis or other reconstructions . long term follow up will be needed to recommend for or against any treatment protocol . our patient presented with two masses without haematuria or vaginal bleeding . even though presentation was to a gynaecologist ( via a general practitioner ) , use of multiple imaging techniques allowed for early management and prevented further complications .
introduction : intrapelvic complications resulting from total hip arthroplasty are rare . 
 intrapelvic migration of the acetabular cup along with proximal migration of the femoral stem is one of these entities . despite being a rare entity 
 , there are serious complications.case report : we report a case image of an elderly lady who presented 6 months after total hip arthroplasty to her general practitioner and gynaecologist complaining of a palpable hard pelvic mass as well as difficulty walking . 
 this proved to be the result of protrusio acetabuli prosthetica . 
 this was reconstructed using saddle prosthesis.conclusion:protrusio acetabuli prosthetica can present as pelvic mass without any other associated symtoms . 
 although a rare complication , with noted morbidity , it might still be reconstructable .