Predicting Factors for Requiring Routine Postoperative Blood Analysis in Primary Hip and Knee Arthroplasty: A Prospective Study.

Background Minimising unnecessary expenditure is essential to cope with high demands on the health sector. A set of full blood count, electrolyte, creatinine and urea tests cost £12 in the National Health Service (NHS). Identifying selected patients requiring postoperative blood tests following primary knee and hip arthroplasty will avoid unnecessary tests and help to reduce expenditure.  The aim of our study is to propose criteria for requesting postoperative blood tests that are safe and do not miss patients. Materials and methods We prospectively evaluated 126 patients (72 in the total knee replacement (TKR) group and 54 in the total hip replacement (THR) group) who underwent either an elective primary THR or a TKR. The mean patient age was 71 years. Patient demographics as well as in-patient events throughout each patient's hospital stay were recorded. Hospital readmissions were also monitored for up to 90 days postoperatively.  Statistical analysis was performed using SPSS Statistics software (IBM Corp., Armonk, NY) with paired t-tests / Wilcox and mixed measures analysis of variance. Binary logistic regression was used to identify predictors of patients requiring a postoperative blood test. Results Analysis of our data identified the following as risk factors for requiring postoperative full blood count tests, including pre-operative Hb of ≤ 110 g/L, cardiac disease, clinical features of anaemia postoperatively and intraoperative blood loss of > 500 mL. The additional risk factors identified for requiring postoperative electrolyte and urea tests are deranged pre-operative electrolytes and clinical signs or symptoms of electrolyte/renal disturbance such as anuria. No patient was readmitted within 90 days of discharge. Conclusion Overall, applying the criteria we have devised would have saved 74 blood tests in the cohort of 126 patients. This provides an odds ratio of 14.0 (95% confidence interval: 1.77-110, p=0.012) of an abnormal result in the patients that would have been tested, compared to those that would not have been tested.

Reconstruction of irreparable rotator cuff tears with an acellular dermal matrix in elderly patients without joint arthritis.

Background: Reverse shoulder arthroplasty is the mainstay of treatment for symptomatic irreparable rotator cuff tears in elderly patients without arthritis. However, this treatment incurs significant costs and is a major surgical undertaking. This study explores an alternative that involves the reconstruction of irreparable rotator cuff tears using an acellular dermal matrix in elderly patients without established joint arthritis. Methods: We prospectively evaluated the reconstruction of massive irreparable rotator cuff tears in 21 patients aged 68 years and over without radiographic glenohumeral joint osteoarthritis in whom conservative management had failed. A human dermal acellular matrix graft was used as a bridging graft for reconstruction. Pain scores, Oxford Shoulder Scores and ranges of movement were all assessed preoperatively and postoperatively. The mean follow-up period was 5.8 years (range 2.6 to 8.9 years). Results: Statistically significant (p < 0.05) improvements were observed in Oxford Shoulder Scores (mean preoperative score, 21; mean postoperative score, 46), pain scores (mean preoperative score, 6; mean postoperative score, 0) and ranges of movement. Patients also reported a high satisfaction rate with the procedure. Discussion: Human tissue matrix allografts could serve as a suitable option for the treatment of elderly patients with massive irreparable rotator cuff tears without arthritis.

Ultrasound-guided regional anaesthesia in foot and ankle surgery.

The use of regional anaesthesia in foot and ankle surgery is becoming well recognised, particularly in patients who prefer to stay awake during the procedure and for better post-operative analgesia. Its use is ideal for patients with multiple co-morbidities, in whom general anaesthesia (GA) otherwise would could be challenging. The procedures performed with landmark/anatomical guidance alone carry a relatively higher risk of complications, risk of inadvertant injection into the intarvascualr space leadinf to local anaesthetic toxicity, the majority of which complications are caused by incorrect placement of the needle. Hence, ultrasound guidance is frequently used to minimise those risks. Although various regional anaesthetic techniques for foot and ankle surgery have been described, their comprehensive review is lacking. This manuscript aims to fulfil this void. The focus will be on the peripheral methods of regional anaesthesia including the plexus and single nerve blocks. Various techniques with their benefits and potential complications will be discussed. In addition, the evidence on the efficacy of an ultrasound-guided approach as well as its cost implications will be explored. There are significant considerations in deciding whether to implement this technique in routine clinical practice and this review aims to summarise the available literature to establish the evidence base behind it.

How well does synovial fluid gram staining correlate with cultures in native joint infections?

To evaluate the sensitivity and specificity of Gram staining of synovial fluid aspirated from native joints suspected to be infected, we reviewed results of synovial fluid Gram stain and cultures. The sensitivity and specificity of the synovial Gram stain were then calculated. From the 1067 consecutive synovial fluid samples evaluated, 830 samples fulfilled the set criteria. From these 830 synovial fluid samples, organisms were detected by culture technique in only 100 samples; most of which were Gram-positive bacteria (78%). The other 22% comprised Gram-negative bacteria, Fungi and a mixture of growth. Of these, concomitant Gram stain test revealed sensitivity and specificity of 17.0% and 99.7% respectively. Our study demonstrates that the Gram stain technique has low sensitivity in detecting organisms in presumed native joint infections. Our findings demonstrate that the Gram stain test is an unreliable investigation in diagnosing native joint infections.

The role of microbial biofilms in prosthetic joint infections.

Prosthetic joint infection (PJI) still remains a significant problem. In line with the forecasted rise in joint replacement procedures, the number of cases of PJI is also anticipated to rise. The formation of biofilm by causative pathogens is central to the occurrence and the recalcitrance of PJI. The subject of microbial biofilms is receiving increasing attention, probably as a result of the wide acknowledgement of the ubiquity of biofilms in the natural, industrial, and clinical contexts, as well as the notorious difficulty in eradicating them. In this review, we discuss the pertinent issues surrounding PJI and the challenges posed by biofilms regarding diagnosis and treatment. In addition, we discuss novel strategies of prevention and treatment of biofilm-related PJI.

Characterisation of in vivo release of gentamicin from polymethyl methacrylate cement using a novel method.

PURPOSE: The purpose of this study was to investigate the in vivo elution kinetics of gentamicin from bone cement by assessing antibiotic levels in the urine. METHODS: Urinary samples of 35 patients who had undergone primary total hip arthroplasty were collected post-operatively. Gentamicin concentrations were analysed using the fluorescence polarisation immunoassay technique. RESULTS: The mean duration of urinary gentamicin release in all cases was 43 days (range 13-95). There was still detectable gentamicin at the final collection in 20% (7/35) of cases, and in these cases, the mean gentamicin release was 71 days. CONCLUSIONS: From the assessment of urinary gentamicin, we were able to demonstrate the biphasic gentamicin elution from bone cement. In addition, there were detectable concentrations of the antibiotic from the urinary samples for prolonged periods of up to two to six months. Our study indicates that the assessment of urinary antibiotics can offer a non-invasive method of monitoring the in vivo release kinetics of antibiotics from bone cement.

The posterior transpedicular approach for circumferential decompression and instrumented stabilization with titanium cage vertebrectomy reconstruction for spinal tumors: consecutive case series of 50 patients.

STUDY DESIGN: A retrospective case series. OBJECTIVE: To demonstrate the feasibility, safety, and results of the posterior transpedicular approach for circumferential decompression and instrumented reconstruction of thoracolumbar spinal tumors. SUMMARY OF BACKGROUND DATA: Patients presenting with spinal tumor disease requiring 3-column instrumented stabilization are typically treated with a combined anterior and posterior surgical approach. However, circumferential decompression and instrumented stabilization may also be achieved through a single-stage, midline posterior transpedicular approach. METHODS: Fifty consecutive patients (27 women and 23 men) underwent surgery between 2003 and 2010 at a single institution by the senior author. Mean age was 55.9 years (range, 25-79 yr).Single or multilevel, contiguous subtotal vertebrectomy was performed ranging from T1 to L4 (38 thoracic and 12 lumbar). Three-column spinal stabilization was achieved using posterior pedicle screw fixation and vertebral body reconstruction, with a titanium cage introduced through the posterior transpedicular route. The mean follow-up period was 17 months (range, 1-54 mo). RESULTS: The mean operating time was 4.2 hours. The mean estimated blood loss for a subgroup of 9 patients with hypervascular tumor pathology was 3933 mL (range, 2700-5800 mL). The mean blood loss in the remaining 41 patients was 1262 mL (range, 250-2500 mL).Postoperative neurological status was maintained or improved in all patients. Mean postoperative stay was 7.7 days (range, 3-12 d). At last review, 14 patients were alive, with a mean survival of 36 months (range, 13-71 mo). The mean survival for the 36 patients who died was 19 months (range, 2 weeks to 54 mo). CONCLUSION: This is the largest reported series of patients with spinal tumor disease undergoing circumferential decompression and 3-column instrumented stabilization through the posterior transpedicular approach.This surgical approach provides sufficient access for safe and effective circumferential decompression and stabilization, with reduced complications compared with costotransversectomy or combined anterior transcavitary and posterior approaches.

Does improved instrumentation result in better component alignment in total knee arthroplasty?

Accurate component alignment and joint line reproduction in total knee replacement (TKR) is crucial for successful clinical outcome. Advances in instrumentation and better understanding of the biomechanics can help to achieve better three dimensional alignments of TKR components and joint line restoration. We compared the accuracy of component alignment and joint line restoration with the use of 2 different TKR instrumentation kits (an older Gobot and a newer Xcelerate). Retrospective study of 150 consecutive patients undergoing primary TKR had their pre and post-operative x-rays reviewed. Seventy-five patients (group A) had their TKR using the older instrumentation kit (Gobot) and 75 (group B) had the newer version (Xcelerate). The positioning of the prosthesis components were assessed using the American Knee society radiographic evaluation method and the joint line position using the Figgie's method. The results from the two groups were statistically compared. There was a significantly greater elevation of the joint line position in TKRs done with the Gobot instrumentation (mean 4.49 mm vs. 2.71 mm in group B, P=0.03), and significant differences in the mean tibial component angle cTCA (group A 88.6°, group B 90.1°, P=0.04) and the mean Q angle (group A 6.28° valgus, group B 8.45° valgus, P=0.04). Use of the newer Xcelerate instrumentation was associated with better restoration of joint line position, however the femoral component flexion and posterior slope of the tibial component ere found to be above the desired level. Hence the overall differences between the two groups were found to be small.

Spontaneous regression of a third ventricle colloid cyst.

We present a case of a third ventricle colloid cyst in a 65-year-old patient who was managed conservatively with neuroimaging surveillance. To our surprise, the cyst underwent spontaneous regression 19 months after initial diagnosis. To our knowledge there has only been one similar case previously reported in Glasgow, United Kingdom in 2008.