Are Ankylosing Spondylitis Patients at Risk for Poor Total Hip Replacement Outcomes?

Abstract

Hip involvement in Ankylosing Spondylitis is common and leads to physical and function restriction. Hip replacement surgery is a successful and effective treatment for end-stage hip involvement; however in Ankylosing Spondylitis patient’s prosthesis long-term survival is lesser than other causes of hip osteoarthritis. We report a case of 61-year old Ankylosing Spondylitis male patient with bilateral cementless hip replacement with 26-year and 25-year follow-up.

Keywords: Ankylosing spondylitis; Arthroplasty; Hip

Introduction

Ankylosing Spondylitis (AS) is the prototype of Axial Spondyloarthritis (SpA) and is a chronic inflammatory disease of unknown etiology that affects mainly active young men [1]. AS is characterized by inflammation of the sacroiliac joints, axial spine and peripheral joints. Peripheral involvement has been reported between 73% of the cases with hip being the most commonly affected joint (25- 50%) [2,3]. Hip joint and spine involvement affect patient’s ability to walk and leads to deterioration of their function and physical activity, increases the burden of the disease and its prognosis [4].

A specific treatment option in end-stage hip involvement in AS is the Total Hip Replacement Surgery (THR). The aims of THR are pain relief, increased range of motion, improved mobility and correction of posture. THR is a successful surgical procedure in advance hip osteoarthritis with long-term outcome studies demonstrating a 90% outcome survival at 15 to 20 years of follow-up [5]. However, THR survival in AS patients is lesser, being reported as 60-65% over 15 years in best series [6-8].

The authors report a case of an AS 61-year-old patient with a severe disease with several joint replacements (shoulders, hips and right knee) with a bilateral THR with 26 and 25-year follow-up.

Case Presentation

A history of low back and cervical inflammatory pain began 40 years ago with prolonged morning stiffness leading to AS diagnosis 10 years later. He was under treatment with various NSAIDs. There was a history of dactilitis, entesitis and peripheral arthritis, but there was not uveitis, psoriasis or bowel inflammatory disease and he was HLA-B27 negative. There was syndesmophites in lumbar X-ray and radiological grade III bilateral sacroiliitis. Other co-morbidities were obesity (body mass index of 38 Kg/m2), arterial hypertension and dyslipidemia.

Despite NSAID treatment the patient presented hip inflammatory pain with progressive limitation of hip range of motion and inflammatory shoulder pain. Due to the bilateral hip osteoarthritis, continuous hip pain and daily life limitations, a right and left cementless THR were performed 26 and 25 years ago respectively.

The bilateral THR were implanted using a standard posterior hip approach with the patient in lateral decubitus. THR was composed by an acetabular cup (RM^®classiccup) and by a cementless femoral stem with a proximal porous coating, which allowed bone ingrowth into the stem.

Secondary shoulder osteoarthritis led to bilateral shoulder total replacement 7 and 5 years ago. Two years ago a right cemented Total Knee Replacement (TKR) was performed due a knee secondary osteoarthritis.

Currently, he presented mechanical right knee pain and unglued knee prosthesis at X-ray and need a revision surgery, however the others prostheses are well concreted.

In the last clinical and radiological controls, at 25 and 26 years after the bilateral hip artroplasty, the patient was asymptomatic, the hip mobily were normal and the patient was very pleased with the functional results. Hip radiographic study showed a stable seating of the acetabular components, no signs of stress shielding of the proximal femur, no heterotopic ossification and no signs of osteolysis (Figure 1). However, there were faint signs of wear of the left polyethylene cup, evidenced by a superior displacement of the metallic femoral head from the center of the acetabular cup.

    

    

    Figure 1:  Hip radiograph made 26 years and 25 years after a cementless
bilateral hip arthroplasty in an ankylosing spondylitis patient. The components
of the hip prosthesis presented a solid fixation with no signs of osteolysis and
no pain. Signs of wear of the left polyethylene cup.