We present a prospective, randomised, single-centre, multi-surgeon, controlled trial comparing minimally invasive (MIS) and standard approach total knee arthroplasty (TKA).

86 patients undergoing 92 total knee replacements were recruited. 46 operations were randomised to the MIS treatment arm, 46 to the standard control arm. Data collected included postoperative blood loss, length of stay and complications. Patients underwent surgery via a quadriceps sparing or standard medial parapatella approach. All operations were performed using MIS instruments and an identical postoperative care pathway.

The MIS group had a significantly shorter length of stay (1.4 days, p=0.004) and fewer complications (p=0.003). Demographics, operative time blood loss and radiographic alignment were comparable between the groups. There were no deaths, pulmonary emboli or surgical site infections. 1 patient developed DVT and 1 required revision for pain and failure to regain flexion within 9 months of surgery, both in the control group. Nine percent of MIS patients versus 35% controls suffered a complication delaying discharge, of which 2% and 17% related to surgical site problems respectively.

MIS resulted in a shorter admission and fewer complications, whilst achieving satisfactory component alignment. We discuss the potential economic implications.

Aim: To determine the effects of the different types of headgear on bacterial shedding in laminar flow theatres.

Material and Methods: Sham experiments were carried out using standard theatre clothing, sterile gowns and face masks with visors. Three experimental groups were utilised; no headgear (control), surgeons hoods or fabric balaclavas (known colloquially as “chicken hats”). The sham experiments consisted of two surgeons, scrubbed and gowned, both wearing the same headgear, talking and moving hands for 30 minutes over a sterile mock operating field. 5 bacterial plates were placed on the sterile sheets to capture shed bacteria. An additional 5 plates were placed above head height in the laminar flow enclosure. An air sampler was positioned within the laminar flow and set off for the middle 5 mins of the experiment. Plates were then incubated for 48hrs at 37oC and the number of colony forming units at head and waist height as well as in the air sampler were counted. Each experiment was repeated 5 times.

Results: The bacterial shedding rate at waist height was 0.2 CFUs/plate (314 CFUs/m2/hr) for the control experiment, 0 CFUs/plate (0 CFUs/m2/hr) for the surgeons hoods and 0.08 CFUs/plate (126 CFUs/m2/hr) for the fabric balaclavas.

Conclusion: These experiments show very low bacterial shedding rates with standard clothing and headgear in laminar flow theatres. Although these results demonstrate worse bacterial shedding with fabric balaclavas (which contradicts conventional thinking), the low rate of shedding rates means the results are not statistically significant. It therefore raises the question as to whether we should be using the more expensive fabric balaclavas without proven benefit, and the possibility of increased bacterial shedding.

We performed MRI on 13 infants after operative reduction for developmental dysplasia of the hip (DDH). Using an axial gradient-echo sequence, MRI accurately depicted the acetabular anatomy and confirmed adequate reduction in 12 patients. The one patient with redislocation after surgery was correctly identified. MRI can be carried out quickly, inexpensively and without risk of radiation and is the investigation of choice to confirm adequate reduction in DDH.