Background

Correct positioning of the femoral component in resurfacing hip arthroplasty (RHA) is an important factor in successful long-term outcomes. The purpose of computer-assisted navigation (CAS) in resurfacing is to insert the femoral neck guide wire with greater accuracy and to help size the femoral component, thus reducing the risk of notching at the head and neck junction. Several recent studies reported satisfactory precision and accuracy of CAS. However, there is little evidence that CAS is useful in the presence of anatomical deformities of the proximal femur, which is frequently observed in young patients with secondary degenerative joint disease.

Introduction

The precise indications for tibial component metal backing and modularity remain controversial in routine primary total knee arthroplasty. This is particularly true in elderly patients where the perceived benefits of metal backing such as load redistribution and the reduction of polyethylene strain may be clinically less relevant. The cost implications for choosing a metal-backed design over an all-polyethylene design may exceed USD500 per primary knee arthroplasty case.

Introduction: The incidence of degenerative scoliosis in the lumbar spine is not known. In the ageing population deformity may coexist or cause stenosis. MRI gives limited information on this important parameter and is often the only investigation used pre-operatively in the treatment of stenosis. The aim of this study was to highlight the incidence of coronal abnormalities of the lumbar spine dependent on age in a large population of patients requiring abdominal and KUB radiographs at our institution.

Method: We reviewed all abdominal and KUB radiographs performed in our hospital in the first ten months from the introduction of our digital PACS system. 2276 radiographs were analysed for the incidence of degenerative lumbar scoliosis and lateral vertebral slips in patients who are ≥ 20 years old, in ten-year age ranges. Evidence of osteoarthritis of the spine was also documented. Radiographs were included if the inferior border of T12 to the superior border of S1 was visualised and no previous spinal surgery was evident (metal work/laminectomy).

Results: 2233 (98%) radiographs were analysed. 48% of patients were female. The youngest patient was 20 and the oldest 101 years. The incidence of degenerative lumbar scoliosis, lateral listhesis and osteoarthritis increased with age.

In all age groups curves were more frequent and had greater average Cobb angles in female patients except in the 30–39 year olds–where the males equalled females in frequency and had the greatest Cobb angles.

Conclusions: Degenerative lumbar scoliosis starts to appear in the third decade of life and increases in frequency every decade thereafter, affecting almost a third of patients in the ninth decade. It is more common in female patients and has a greater magnitude. Deformity may be even greater on standing views and is important to recognise in all patients that are undergoing lumbar spinal decompressive surgery. A failure to do so may lead to inferior results or the need for further surgery.