Plantar faciitis is a repetitive microtrauma overload injury of the attachment of the plantar fascia at the inferior aspect of the valvaneus. Several aetiological factors have been implicated in the development of plantar faciitis, however the role of hamstring tightness has not previously been assessed.
Increasing the angle of flexion from 0–20° at the knee joint led to statistically significant increase in pressure in the forefoot phase by an average of 0.08K/cm2s (p, 0.05,t-test). An increase from 20 – 40° led to increased forefoot phase pressure of 0.15 kg/cm2s (p0.05, t-test). The percentage time spent in contact phase reduced from 30 to 26.5 to 16 with increasing flexion (P<
0.05). However there was an inverse increase in the time spent in the forefoot phase 51–58–69 with increasing degrees of flexion (P<
0.05). Thus the authors feel that an increase in hamstring tightness may induce prolonged fore foot loading.
Cement is still in common usage in primary and revision arthroplasty surgery. Infection rates in cemented arthroplasties ranges from 1–4% and poses a huge problem for the revision arthroplasty surgeon. Infection in septic implants is biofilm based and almost completely resistant to conventional anti-microbial therapy. Recent papers have questioned the efficacy of using gentamicin-loaded cement in arthroplasty as staphylococcus aureus biofilms will develop on same. The focus of this study was to investigate the efficacy of antibiotic loaded cement in preventing initial bacterial adhesion and subsequent development of a bacterial biofilm in vitro. Three cements Simplex unloaded, Simplex with erythromycin and Simplex with tobramycin were mixed in a conventional manner, ie vacuum hand mixing in sterile conditions and then injected into pre-moulded PTFE coated cylinder moulds yielding 8 cylinders in each group. The cement cylinders were then removed and exposed to a known pathogenic strain of staphylococcus aureus ATCC—29213-NCTC 12973 in solution 3x106 Colony forming units CFH/ml) for 15 minutes. The cylinders were then removed and cultured for 24 hours at 37°C in RPMI with Glutamine. Cylinders were then removed and subjected to rinsing in PBS to remove any non-adherent bacteria. Cylinders were then sonicated at 50 Hz in Ringer’s solution and adherent biofilms were serially log diluted and plated on Columbia blood agar. Colonies were counted manually. Control cylinders of unloaded cement showed 120,000 CFU/cm2 of adherent bacteria whereas loaded cement erythromycin and tobramycin showed 500 and 80 CFU/cm2 respectively (p<
.0005 Student t-test). This study shows that loaded cement does not prevent biofilm adhesion in its initial reversible stages whereas unloaded cement does not. This is important since most infected implants are infected at time of primary operation and cements anti-bacterial role beyond the first 48 hours remains questionable, when inflammatory encapsulation of the implant begins. We would therefore question the usage of unloaded cement in primary arthroplasty surgery.
While gentamycin, erythromycin, cefotaxime and vanomycin have a proven record as effective thermostatic antibiotics, newer antibiotics teicoplanin (although used in clinical practice) are as yet untested.
Heat alone did not affect the growth of the bacteria. None of the antibiotic impregnated cement batches had any effect on an established growth of Staph Aureus indicating the effect of antibiotic impregnated cement may be bacteriostatic rather than bacteriocidal. Teicoplanin is thermosable and is effective in the short term at least at halting the growth of Staph Aureus. Addition of antibiotics to cement may change the biomechanical properties of the cement. It was noted that it took on average twice as long for the teicoplanin-impregnated cement to harden. Further investigations into this are ongoing.
The K wires were added to either the culture media alone or the culture media containing platinum and incubated at 37 degrees for 24 hours. The wires were then removed from the media and rinsed in PBS. Samples were subjected to sonication, to fragment biofilms thereby releasing the bacteria, which were then quantified by serial log dilution technique and manual counting. The presence of platinum reduced the adhesion of both Staph Aureus and Staph Epidermidis to stainless steel. This reduction was statistically significant using paired t-test (SPSS version 6.0). There was a significant reduction of adhesion with platinum in the Staph Aureus and titanium group while the reduction in the Staph Epidermidis and titanium group did not reach statistical significance.