Aims

We compared the risks of re-revision and mortality between two-stage revision surgery and single-stage revision surgery among patients with infected primary knee arthroplasty.

Purpose

The outcome following isolated liner exchange for revision knee arthroplasty, while an attractive option for its simplicity, has a mixed outcome reported in the literature. We report our experience in patients who had a minimum of two years follow-up.

Resurfacing hip arthroplasty is a successful option for the treatment of the young and active patient with hip arthritis. However, it is complicated by femoral neck fracture and avascular necrosis, which result from devascularisation during surgery. Devascularisation maybe caused by thermal necrosis. Thermal necrosis of bone has been shown to occur in temperatures of 47°C and above. We investigated the temperatures generated during femoral head preparation to see if the temperatures reached were great enough to induce osteonecrosis.

Method: Eight patients with osteoarthritis underwent standard resurfacing hip arthroplasty through the posterior approach. From the first over-drilling of the femoral heads until the prosthesis was cemented in place the temperatures generated at the bone surface were recorded using an infra-red thermal imaging camera. Images were captured every 4 seconds as the operation was performed with no interference to the surgeon

Results: The maximum temperatures generated occurred during sleeve reaming at 88.4°C. Seven patients had a temperature recorded greater than 47°C. Removing the femoral caput with an oscillating saw had the highest mean temperature 62.2°C, followed by sleeve reaming (mean 48.7°C). Female patients had the lowest temperature rises and patients receiving the larger femoral prosthesis the greatest temperatures at the bone surface.

Conclusions: Heat generated during femoral head preparation exceeded 47°C in all but one case. Osteonecrosis secondary to thermal insult is likely to occur during femoral head preparation. Strategies need to be devised to decrease the temperatures generated during femoral head preparation.

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 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.

We reviewed all abdominal radiographs performed in our hospital over ten months. 2276 radiographs were analysed for degenerative lumbar scoliosis and lateral vertebral slips in patients who are ≥ 20 years old. 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).

2233 (98%) radiographs were analysed. 48% of patients were female. The incidence of degenerative lumbar scoliosis, lateral listhesis and osteoarthritis increased with age. Degenerative scoliosis was present in 1.6% of 30–39 year olds increasing every decade to 29.7% of patients 90 years or older. 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 males equalled females.

Degenerative lumbar scoliosis starts to appear in the third decade of life increasing 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.

Introduction: Resurfacing hip arthroplasty is a successful option for the treatment of the young and active patient with hip arthritis. However, it is complicated by femoral neck fracture and avascular necrosis, which may result from devascularisation during surgery. Devascularisation maybe caused by thermal necrosis. Thermal necrosis of bone has been shown to occur in temperatures of 47°C and above. We investigated the temperatures generated during femoral head preparation to see if the temperatures reached were great enough to induce osteonecrosis.

Method: Eight patients with osteoarthritis underwent standard resurfacing hip arthroplasty through the posterior approach. From the first over-drilling of the femoral heads until the prosthesis was cemented in place the temperatures generated at the bone surface were recorded using an infra-red thermal imaging camera. Images were captured every 4 seconds as the operation was performed with no interference to the surgeon

Results: The maximum temperatures generated occurred during sleeve reaming at 88.4°C. Seven patients had a temperature recorded greater than 47°C. Removing the femoral caput with an oscillating saw had the highest mean temperature 62.2°C, followed by sleeve reaming (mean 48.7°C). Female patients had the lowest temperature rises and patients receiving the larger femoral prosthesis the greatest temperatures at the bone surface.

Conclusions: Heat generated during femoral head preparation exceeded 47°C in all but one case. Osteonecrosis secondary to thermal insult is likely to occur during femoral head preparation. Strategies need to be devised to decrease the temperatures generated during femoral head preparation.

Introduction: Arthroplasty is the most effective management of displaced intracapsular femoral neck fracture. Hemiarthroplasty (HEMI) is associated with acetabular erosion and loosening in mobile active patients and total hip arthroplasty (THA) with instability.

We sought to establish whether HEMI or THA gave better results in independent mobile patients with displaced femoral neck fracture.

Method: Eighty-one patients were randomised into two groups. One arm received a modular HEMI, the second a THA using the same femoral stem. Patients were followed for a mean of three years after surgery.

Results: After HEMI, eight patients died, two were revised to THA and there is intention to revise three. One patient had a Peri-prosthetic fracture. Mean walking distance was 1.08 miles and Oxford Hip Score (OHS) 22.5. Twenty patients (64.5% of survivors) had radiological evidence of acetabular erosion.

After THA, three patients died, three dislocated, one required revision. Mean walking distance was 2.23 miles and OHS was 18.8. There was no radiological evidence of polyethylene wear

Patients with THAs after three years walked further (p=0.039) and had a lower OHS (p=0.033).

Discussion: HEMI is associated with a higher actual and potential revision rate than THA because of acetabular erosion, higher OHS after three years and shorter walking distances.

THA is a preferable option to HEMI in independent mobile elderly patients with displaced intracapsular femoral neck fracture.