Do Antibiotic Intramedullary Dowels Assist in Eradicating Infection in Two-Stage Resection for Septic Total Knee Arthroplasty?

BACKGROUND: Evidence suggests approximately 40% of intramedullary (IM) canals are culture positive at resection for infected knee arthroplasty. While commonly utilized, no clinical data on the efficacy of antibiotic-eluding IM dowels exist. We quantified treatment success with and without the use of antibiotic-eluding IM dowels in two-stage treatment of periprosthetic knee infection using static and articulating antibiotic cement spacers. METHODS: 109 consecutive patients who underwent two-stage treatment for periprosthetic knee infection were reviewed. Treatment failure, defined as repeat resection before reimplantation or recurrent infection within 6 months of reimplantation, was evaluated based on spacer type and use of IM dowels, accounting for infection type and systemic host and local extremity grade. RESULTS: After exclusions for confounds, articulating spacers without IM dowels were used in 49 (57.7%) cases, articulating spacers with IM dowels in 14 cases (16.5%), and static spacers with IM dowels in 22 (25.9%) cases. Treatment success regardless of infection classification was 85.7% for articulating spacers with IM dowels, 89.8% for articulating spacers without IM dowels, and 68.2% for static spacers with IM dowels (P = .074). In chronically infected poor hosts with compromised extremities, treatment success remained highest in patients with articulating spacers with (90.9%) or without (92.9%) IM dowels compared with static spacers with IM dowels (68.4%) (P = .061). CONCLUSION: Findings suggest that the use of IM dowels did not enhance infection eradication above and beyond that observed for articulating spacers alone, including in the worst cases involving chronically infected poor hosts with compromised extremities.

Modern retrograde intramedullary nails versus periarticular locked plates for supracondylar femur fractures after total knee arthroplasty.

This study purpose is to analyze outcomes of modern intramedullary (IM) nails with a locked distal screw versus periarticular locking plates for peri-prosthetic supracondylar femur fractures in TKA. Ninety-five consecutive fractures in 91 patients were retrospectively reviewed. Fixation included 29 knees with a retrograde IM nail and 66 periarticular locked plates. Six patients died and 4 were lost to follow-up. There were 2 (9%) nonunions in the IM nail group and 12 non-unions/delayed-unions (19%) in the locked plate group (P = 0.34). A mean of 5.0 distal screws was used in locked plates versus 3.8 distal screws in the IM nails (P < 0.001). Despite a greater quantity of screws in the distal fragment, the failure rate of locked plating was twice that of IM nail fixation.

Evaluation of limb alignment, component positioning, and function in primary total knee arthroplasty using a pinless navigation technique compared with conventional methods.

The purpose of this study was to examine component positioning, limb alignment, and the early functional range of motion of a pinless image-free computer-assisted navigation system, and compare it to conventional intramedullary component alignment methods. A total of 72 patients underwent cemented total knee arthroplasty. The pinless navigation group consisted of 40 knees in 39 patients, while the conventional group comprised 33 knees in 33 patients. Preoperative and postoperative radiographs were evaluated for coronal and sagittal alignment. Functional assessment was evaluated by early postoperative range of motion. There was no statistical significance when examining individual component alignment or early functional range of motion. When evaluating ability to achieve overall anatomic tibiofemoral alignment within a range of 4 to 7 degrees valgus, the conventional group was able to accomplish this 39% of the time, whereas the pinless navigation group succeeded in 65% of cases (p < 0.03). The tourniquet time was mean 59.5 minutes (range: 48 to 77 minutes) for the conventional group, compared with mean 71.9 minutes (range: 54 to 97 minutes) for the navigation group (p < 0.0001, 95% CI). The pinless navigation technique improved coronal anatomic alignment without complications that have been cited with use of femoral or tibial reference tracker pins or intramedullary alignment guides.