The most frequent cause of failure after total
hip replacement in all reported arthroplasty registries is peri-prosthetic
osteolysis. Osteolysis is an active biological process initiated
in response to wear debris. The eventual response to this process
is the activation of macrophages and loss of bone. Activation of macrophages initiates a complex biological cascade
resulting in the final common pathway of an increase in osteolytic
activity. The biological initiators, mechanisms for and regulation
of this process are beginning to be understood. This article explores current
concepts in the causes of, and underlying biological mechanism resulting
in peri-prosthetic osteolysis, reviewing the current basic science
and clinical literature surrounding the topic.
Classification of osteoarthritis of the hip is fraught with difficulty Although different patterns of disease are recognised, there is no accepted classification or grading system. We aim to develop a classification system that reflects both the radiological changes, and the local disease process within the joint. After ethical permission and consent tissue was taken from 20 patients undergoing primary hip replacement surgery. Intra-operative tissue samples were taken from each patient and the steady state gene expression of several cytokines (TNF-α, IL1-β, IFN-γ, IL-6, RANKL and OPG) measured quantitatively using Taqman RT-PCR. Relative expression was calculated for each sample using standard curves and normalised to 18S expression. The technique was consistent with high correlations for repeated measures from the same tissue type (κ=0.99) and from different tissue types in the same joint (κ=0.92). Intra-observer (κ=0.93) and inter-observer (κ=0.89) reliability for the technique were also found to be high. Preoperative radiographs were scored by two independent observers and joint space narrowing, cysts, osteophytes and sclerosis noted in each of the DeLee-Charnley zones on the femoral and acetabular side. Based on these scores patients were then classified to either lytic or sclerotic type and subclassified into either hypertrophic or atrophic. Subgroup analysis of cytokine expression by radiographic type was performed. There were statically significant differences in expression of macrophage stimulating cytokines (IL-1γ and OPG) in the lytic group as compared to the sclerotic group (p<
0.05). Conversely, the sclerotic group expressed significantly higher levels of IL-6. Individuals with atrophic subtype demonstrated significantly higher levels of IL-1β and IL-6, but lower levels of IFN-γ Our results demonstrate greatly differing patterns of disease within osteoarthritic hip joints. These changes are reflected in radiographic appearances of osteoarthritis. Our proposed classification system can be used grade and classify osteoarthritis in a manner that reflects the disease process.
The recent NICE guidelines on management of osteoarthritis outline weight loss as first line treatment in degenerative joint disease in the obese. There is little data surrounding the effects of obesity on the outcomes in spinal surgical interventions. Intervertebral discectomy is one treatment for prolapse of a lumbar vertebral disc. We aim to investigate the effect of obesity on outcomes for discectomy. Demographic details including age, sex, weight and BMI were recording with a pre-operative Oswestry Disability Index (ODI). The fat thickness was measured at L5/S1 using calibrated MRI scans. Outcome measures included complications, length of surgery and change in ODI at 1 year following surgery. Obesity was defined as a body mass index of over 30. The units Serial patients undergoing discectomy were recruited into the study. Patients with bony decompression, instrumentation, revision surgery or multilevel disease were excluded. Fifty patients with a single level uncomplicated disc prolapse were entered into the study. Sixteen patients had a BMI over 30 and so were obese, whilst 34 had a BMI of less than 30. The mean pre-operative ODI was 46.5 in the obese group and 52 in the normal group this difference was not significant (p>
0.05). The mean post operative ODI was statistically improved in the high BMI group at 28 (18.5 point improvement) and 25.2 (29.1 point improvement) in the normal group. The ODI improvement was significantly better in the low BMI group (p=0.036). There was no significant difference in operative time (p=0.24). Only a single patient had a complication (dural leak), so no valid comparison could be made. The outcomes of spinal surgery in the obese are mixed. We found no increase in the complication rate or intra-operative time associated with an increased BMI. However, the improvement in ODI was significantly better in the normal BMI group.
Four hundred and twelve patients were included in the study. The mean Harris, VAS and HSS were significantly different between the failed and well fixed groups. However there was no statistically significant difference between the mean Oxford and MDA scores. ROC analysis demonstrated the Harris (0.97), VAS (0.98) and HSS (0.77) score to have good prediction of outcome.
Radiographic analysis was undertaken using Harris’, Hodgkinson’s and Amstutz’s criteria, evaluation of component position, neck narrowing and migration using diagnostic PACS workstations with standardised scaled images.
Component position was satisfactory in 93% of cases. Radiographic analysis showed no cups, or stems were definitely loose. Radiolucent lines were present in 8/100 acetabular and 3/100 femoral components, osteolytic lesions were seen in three acetabular components. Mean neck narrowing was 9mm. No patients show any radiographic evidence of avascular necrosis. Conclusion This independent series shows the results of the Birmingham hip resurfacing are reproducible and comparable to those reported in the originating centre. The Birmingham hip resurfacing gives excellent clinical results, and there is no early evidence of radiographic failure. The high rate of neck narrowing gives us cause for concern and we would recommend regular radiographic follow up.
The rate and mode of early failure in 463 Birmingham hip resurfacings in a two-centre, multisurgeon series were examined. Of the 463 patients two have died and three were lost to follow-up. The mean radiological and clinical follow-up was for 43 months (6 to 90). We have revised 13 resurfacings (2.8%) including seven for pain, three for fracture, two for dislocation and another for sepsis. Of these, nine had macroscopic and histological evidence of metallosis. The survival at five years was 95.8% (95% confidence interval (CI) 94.1 to 96.8) for revision for all causes and 96.9% (95% CI 95.5 to 98.3) for metallosis. The rate of metallosis related revision was 3.1% at five years. Risk factors for metallosis were female gender, a small femoral component, a high abduction angle and obesity. We do not advocate the use of the Birmingham Hip resurfacing procedure in patients with these risk factors.
We report the follow-up at 12 years of the use of the Elite Plus total hip replacement (THR). We have previously reported the results at a mean of 6.4 years. Of the 217 patients (234 THRs), 83 had died and nine had been lost to follow-up. The patients were reviewed radiologically and clinically using the Oxford hip score. Of the 234 THRs, 19 (8.1%) had required a revision by the final follow-up in all but one for aseptic loosening. Survivorship analysis for revision showed a survival of 93.9% (95% confidence interval (CI) 89.2 to 96.5) at ten years, and of 88.0% (95% CI 81.8 to 92.3) at 12 years. At the final follow-up survival analysis showed that 37% (95% CI 37.3 to 44.7) of the prostheses had either failed radiologically or had been revised. Patients with a radiologically loose femoral component had a significantly poorer Oxford hip score than those with a well-fixed component (p = 0.03). Radiological loosening at 6.4 years was predictive of failure at 12 years. Medium-term radiographs and clinical scores should be included in the surveillance of THR to give an early indication of the performance of specific implants.
Carpal Tunnel Syndrome is the most common entrapment neuropathy encountered in clinical practice. Previous studies have suggested that the disease has a higher prevalence in the elderly(Stevens JC etal, Neurology 1988;) and that this sub group also tends to have a higher prevalence of severe CTS.(Seror P, Ann Hand Surg 1991; Bland etal, J Neurol Neurosurg Psychiatry). Surgical decompression of the median nerve is the treatment of choice with a reported success rate of between 53 and 97 %.(Katz et al, J Hand Surg 1998). There has been some controversy regarding the effectiveness of surgery in elderly patients. The aim of our study was to evaluate the results of carpal tunnel release in patients over the age of 75 years at the time of surgery. A literature search revealed few studies carried out in elderly patients–Weber etal-(mean age 75 years), Porter etal (mean age 59.8 years) and Leit et al (mean age 79 years). The average age of our patient group (80.4 years) is the highest reported in literature so far. We posted questionnaires to all patients who were over 75 years at the time of their surgery. There were a total of 49 patients (65 hands) operated over the last 10 years who belonged to this age group. We used the Brigham And Women’s Hospital Questionnaire devised by Levine et al. (1993). In addition, we added some questions to assess patient satisfaction with the procedure. 65% of the patients were females. The average age was 80.4 years. The completed questionnaires were used to calculate the Pre and Post operative scores. The mean pre operative score was found to be 3.18, which improved post operatively to 1.8. (Scale of 1 to 5, with 1 being the best and 5 the worst). Importantly, although all symptoms improved, some such as pain and numbness showed a much greater improvement than grasping power. On the Visual Analogue Scale, pain scores improved from 6.4 to 2.3 post surgery. 82 % of patients had no scar tenderness, 12 % had mild to moderate tenderness, while 6 % reported severe scar tenderness. Overall 79% of patients showed improvement, 15 % felt that the surgery had made no difference, while 6% reported worsening of their symptoms after surgery. Our study showed that 8 out of 10 elderly patients will improve after carpal tunnel release, though all symptoms are unlikely to improve. The symptom least likely to improve is weakness of the hand. The results of this study are important to counsel this sub group of elderly patients, so that they may take an informed decision on whether to proceed with the surgery.