The outcome following arthroscopic anterior cruciate (ACL) reconstruction is dependant on a combination of surgical and non-surgical factors. Technical error is the commonest cause for graft failure, with poor tunnel placement accounting for over 80% of those errors. A routine audit of femoral and tibial tunnel positions following single bundle hamstring arthroscopic ACL reconstruction identified apparent inconsistent positioning of the tibial tunnel in the sagittal plane. Intra-operative fluoroscopy was therefore introduced (when available) to verify tibial guide wire position prior to tunnel reaming. This paper reports a comparison of tibial interference screw position measured on post-operative radiographs with known tunnel position as shown on intra-operative fluoroscopic images in 20 patients undergoing routine primary ACL reconstruction between January and June 2009. Surgery took a mean of 5 minutes longer when intra-operative fluoroscopy was used. In 3/20 patients, fluoroscopy led to re-positioning of the tibial guide wire prior to tunnel reaming. The mean tibial tunnel position as indicated by the tunnel reamer was 41 +/− 2.7 % of the total plateau depth (range 37% to 47%). The mean position projected from the tibial screw on post operative radiographs was 46 +/− 9.2% (range 38% to 76%). A paired t-test showed a significant difference (p = 0.022) between true tunnel position and tibial screw position. 6/20 patients had post operative screw positions that were > 5% more posterior than the known position of the tibial tunnel. The position of the tunnel should be measured at its mid-point where this is evident. On most early radiographic images, the margins of the tunnel are not clear and therefore a line projected from the centre of the screw is used. This audit demonstrates the potential inaccuracy associated with this.
Thickness (mm)
Stiffness (Nm / Degree)
1
58 +/− 4
2
37 +/− 1
3
39 +/− 1
4
25 +/− 0.3
5
24 +/− 0.3
Guidelines from the National Institute of Clinical Excellence (NICE) recommend comparative clinical evaluation for prostheses without long-term follow-up data and set an initial ‘benchmark’ for performance at 3 years. Data collection for the CPS-Plus stem is on-going as part of a multi-centre prospective clinical trial. 227 patients have been recruited to the trial and 70 of these have reached 3 years follow-up.
The rate of deep infection following primary joint replacement has reduced to below 1%, but the cost remains high. The surgical team is the most important source of bacteria causing infection. All surgical gowns are susceptible to penetration by these organisms, which may then spread to the wound via the surgeon’s hands or contact with wet drapes without ever being airborne. There is insufficient clinical data on the penetration of bacteria through surgical gowns, in part due to the difficulty of There was a significant difference between the two gown types when tested in the axilla (p <
0. 05), the groin (p <
0. 05) and the peri-anal region (p <
0. 01), with the disposable gowns performing to a higher standard. Re-usable gowns demonstrated significant variation in penetrability. This is most likely to be due to the number of laundering and sterilisation cycles that they had undergone. Unless the continued satisfactory performance of multiple-use gowns can be guaranteed, they may be unsuitable for use in orthopaedic implant surgery.
Twelve patients undergoing total hip replacements were given 600mg linezolid as a 20min intravenous infusion along with conventional prophylaxis of 1gm cefamandole immediately before surgery. Routine total hip arthroplasty was performed and at timed intervals during surgery, samples of bone, fat, muscle and blood were collected for assay by HPLC analysis. Samples of haematoma fluid that formed around the operation site and further blood samples were also collected at timed intervals following the operation for assay. The penetration of linezolid into bone was rapid with mean levels of 9.1mg/L (95% CI: 7.7–10.6mg/L) achieved at 10min after the infusion, decreasing to 6.3mg/L (95% CI: 3.9–8.6mg/L) at 30min. Correcting for the simultaneous blood concentrations gave values for bone penetration of 51% at 10min, 60% at 20min and 47% at 30min. although the penetration of linezolid into fat was also rapid, mean levels and degree of penetration were approximately 60% of those seen in bone at 10min: 4.5mg/L (95%CI:3–6.1mg/L; penetration 27%) 20min: 5.2mg/L (95% CI:4–6.4mg/L; penetration 37%) and 30min:4.1mg/L (95% CI:3.3–4.8mg/L; penetration 31%). For muscle, the corresponding values were 10min: 10.4mg/L (95%CI:8.1–12.7mg/L; penetration 58%), 20min 13.4mg/L (95%:10.2–16.5mg/L; penetration 94%) and 30min 12mg/L (95% CI:9.2–14.8mg/L; penetration 93%). Mean concentration of linezolid in the haematoma around the operation site were 8.2mg/L at 6–8h and 5.6mg/L at 8–10h after the infusion and 7mg/L at 2–4h following a second 600mg infusion given 12h postoperatively. We conclude that linezolid exhibits rapid penetration in bone, fat and muscle of patients undergoing hip arthroplasty to achieve levels in excess of the MIC for sensitive organisms (MIC of <
_ 4mg/L); with therapeutic levels maintained in the drainage which surrounds the operation site for more than 16h. This pharmaco-kinetic profile is similar to those of agents currently used for the treatment of bone and associated soft tissue infections and suggests a role for linezolid in the management of such patients