Purpose

Traditionally, an inpatient hospital stay has been required for joint replacement surgery. The three primary drivers of cost for joint replacement have been implant cost, other hospital charges and postoperative rehabilitation costs. The three primary reasons that have made hospitalization necessary are pain control, blood loss / transfusion, and monitoring patients with comorbidities. Advances in surgical technique, implants, comprehensive blood management, and multimodal pain management have allowed a marked reduction in the hospital stay required and have eliminated the need for extensive formal rehabilitation. The purpose of this study is to evaluate if hip resurfacing can be performed safely and cost-effectively as an outpatient procedure.

Staphylococcus aureus is the bacterial pathogen which is responsible for approximately 80% of all cases of human osteomyelitis. It can invade and remain within osteoblasts. The fate of intracellular Staph. aureus after the death of the osteoblast has not been documented.

We exposed human osteoblasts to Staph. aureus. After infection, the osteoblasts were either lysed with Triton X-100 or trypsinised. The bacteria released from both the trypsinised and lysed osteoblasts were cultured and counted. Colonies of the recovered bacteria were then introduced to additional cultures of human osteoblasts.

The number of intracellular Staph. aureus recovered from the two techniques was equivalent. Staph. aureus recovered from time zero and 24 hours after infection, followed by lysis/trypsinisation, were capable of invading a second culture of human osteoblasts.

Our findings indicate that dead or dying osteoblasts are capable of releasing viable Staph. aureus and that Staph. aureus released from dying or dead osteoblasts is capable of reinfecting human osteoblasts in culture.