Dropping of instrument by scrub team during hip and knee arthroplasty - Does patient's size matters?

Medical literature suggest that Hip and Knee replacement surgery takes far more time to conduct in overweight and obese patients than in general population. Reasons for increase in operating time in obese patient are difficult positioning, more bleeding from fatty tissue and difficult retraction. One very interesting and to our knowledge never reported cause of increased operating time in obese patients undergoing hip and knee arthroplasty is accidental dropping of instruments onto the floor by operating team. We looked into the relationship between patient's size and dropping of instruments during hip and knee arthroplasty.A prospective cohort study was done were we included twenty five patients with BMI <30 and 25 patients with BMI ≥30 undergoing hip and knee arthroplasty.Instruments were dropped in 31 out of a total of 50 operations giving a dropping rate of 62%, out of these 19 were in patients with BMI >30 and 12 were in patients with BMI <30, inferential analysis gave a p value of 0.04997 which is statistically significant.Operative time in obese patients may be indirectly affected by time take to replace dropped instruments. We recommend that there should be a backup of instruments in centres where obese patients are undergoing arthroplasty.