We evaluated the clinical, radiographic, and functional outcome of uncemented total hip arthroplasty (THA) following vascularized fibular grafting for avascular necrosis (AVN) of the femoral head. A group of twenty-two patients who had been converted from a vascularized fibular graft to THA was compared to a similar group of twenty-two patients who had received a THA with no prior graft. The graft group was found to have worse outcomes than the control group as measured by SF-36, and WOMAC scores, as well as a hip score.

These results show that vascularized fibular grafting complicates future THA.

The Purpose of this study was to evaluate the clinical, radiographic, and functional outcome of uncemented total hip arthroplasty (THA) following vascularized fibular grafting for avascular necrosis (AVN) of the femoral head. These results indicate that functional and clinical outcome following post-graft THA is worse than outcome following THA performed as a primary intervention.

Judicious use of the vascularized fibular graft procedure is critical in order to minimize the number of graft failures and avoid the negative outcomes associated with THA after failed vascularized fibular grafting.

Twenty-six hips in twenty-two patients who had a THA following a failed vascularized fibular graft were compared to a group of twenty-three hips in twenty-two age and sex-matched patients who had received a THA with no prior graft (combined mean age: 39.0 yrs). Primary outcome measures included the SF-36 (patient-based general health assessment – total score and physical sub-component) and WOMAC (patient-based arthritis specific score) scores at matched follow up times (mean: 6.2years, range: two to fourteen years). An objective hip score was also used, as were several radiographic variables. The post-graft group had lower SF-36 final scores (p< 0.006), lower SF-36: physical function scores (p< 0.001), and lower WOMAC scores (p< 0.045) than the control group. Post-graft THA was complicated by longer operative time (p< 0.025) and greater subsidence of the femoral prosthesis (p< 0.004) compared to controls. Additionally, the post-graft group had worse hip score values (p< 0.05) than controls.

Vascularized fibular grafting is a commonly used procedure to cure or delay progression of AVN in the hip. Currently this procedure is used for young (< 40 years) patients with hip AVN who are in an early, pre-collapse stage of the disease. Although the efficacy of vascularized fibular grafting has been proven, up to 29% of grafts fail at five years and need to be converted to THA (Urbaniak et al., 1995). This study shows that THA after failed vascularized fibular grafting has a worse outcome than THA as a primary intervention. Therefore judicious use of the graft procedure is critical in order to minimize the number of graft failures and avoid the negative outcomes associated with it.

Introduction: Biomaterial implants in the human body constitute passive surfaces that are prone to bacterial adhesion as the on-set of biomaterials-associated infection. Antibiotic treatment of infected biomaterial implants is little successful clinically, because the biofilm-mode of growth protects the adhering organisms. Percutaneous implants, such as bone screws used in orthopedics or dental implants, constitute a special class of implants with infection rates exceeding the infection rate of deep body implants by far. Especially fixation frames, used in orthopedic surgery for the treatment of complicated fractures, inevitably become infected during the course of a treatment.

The aim of this study is to determine whether it is possible to stimulate bacterial detachment from surgical stainless steel and decrease the viability of the remaining adhering bacteria using block currents. Method: Bacteria were allowed to adhere from a flowing suspension of high ionic strength in a parallel plate flow chamber, after which the suspension was replaced by a bacterium free solution with 10 mM potassium phosphate buffer. Block currents of 15, 60 and 100 ìA with different frequencies (0.1 to 2 Hz) and duty cycles (5 to 50%) were applied to induce bacterial detachment.

Results: Initial detachment rate increased with increasing frequency and duty cycle, namely from 0 to 3700 cm⁻²s⁻¹. The total detachment percentage for block currents of 100 ìA with 25% to 50% duty cycle and frequencies as of 0.5 Hz are similar for all conditions. The detachment percentage in this range amounts on average 76%, whereas DC currents around 100 ìA have an average of 60%, which was found to be significant lower (p=0.03).

The killing capacity of these current series can be up to two log scales depending on the current.

Conclusion: Current induced detachment of Staphylococcus epidermidis from surgical stainless steel seems very effective, especially for a 100 ìA, 50% duty cycle and 2 Hz block current. The viability of the remaining adhering bacteria decreased with 2 log scales. Clinically this could mean another way of preventing and curing pin tract infection.