Does addition of gentamicin for antibiotic prophylaxis in total knee arthroplasty reduce the rate of periprosthetic joint infection?

BACKGROUND: First-generation cephalosporins are used as antibiotic prophylaxis in total joint arthroplasty patients. However, this regimen does not address Gram-negative bacteria causing periprosthetic joint infection (PJI). Previous studies have suggested that the addition of an aminoglycoside as antibiotic prophylaxis in THA reduces surgical site infection (SSI), and less is known on its effect in TKA. This study aimed to investigate if the addition of a single-dose gentamicin, administered pre-operatively, is associated with lower rates of infection in TKA patients. PATIENTS AND METHODS: This is a retrospective study of patients who underwent primary TKA as treatment for osteoarthritis between January 2011 and April 2021, with a minimum 1-year follow-up. The mean age was 69.9 (± 9.8), the mean BMI was 29.7 (± 5.5), and most patients had American Society of Anaesthesiology (ASA) score of 2-3 (92.9%). Patients were stratified based on the peri-operative antibiotic prophylaxis they received: cefazolin with addition of gentamicin (case group) or cefazolin (control group). Our primary study endpoints were rates of PJI and SSI, which were compared between groups using the chi-square test. Statistical significance was set as p < 0.05. RESULTS: The final study population consisted of 1590 patients, 1008 (63.4%) in the control group and 582 (36.6%) patients in the case group. The total infection rate for patients that received gentamicin dropped by 34%; however, this finding did not reach statistical significance (1.3% (control) vs. 0.86% (case), p = 0.43). The same drop was seen after subdivision of infections to PJI (0.5% vs. 0.34%, 32% drop, p = 0.66) and SSI (0.8% vs. 0.52%, 35% drop, p = 0.52). CONCLUSIONS: A single dose of gentamicin administered pre-operatively to a standard antibiotic prophylaxis was not associated with a statistically significant lower rate of PJI. Although the difference in infection rate did not reach statistical significance, the current study noted a drop in the rate of infection by 1/3 in the gentamicin cohort. Further investigation to evaluate the potential benefit of adding gentamicin to a peri-operative antibiotic regimen is warranted.

The walls of the femoral neck as an auxiliary tool for femoral stem positioning.

BACKGROUND: Femoral anteversion is a major contributor to functionality of the hip joint and is implicated in many joint pathologies. Accurate determination of component version intraoperatively is a technically challenging process that relies on the visual estimation of the surgeon. The following study aimed to examine whether the walls of the femoral neck can be used as appropriate landmarks to ensure appropriate femoral prosthesis version intraoperatively. METHODS: We conducted a retrospective study based on 32 patients (64 hips) admitted to our centre between July and September 2020 who had undergone a CT scan of their lower limbs. Through radiological imaging analysis, the following measurements were performed bilaterally for each patient: anterior wall version, posterior wall version, and mid-neck femoral version. Anterior and posterior wall version were compared and evaluated relative to mid-neck version, which represented the true version value. RESULTS: Mean anterior wall anteversion was 20° (95% CI, 17.6-22.8°) and mean posterior wall anteversion was -12° (95% CI, -15 to -9.7°). The anterior walls of the femoral neck had a constant of -7 and a coefficient of 0.9 (95% CI, -9.8 to -4.2; p < 0.0001; R2 0.77).The posterior walls of the femoral neck had a constant of 20 and a coefficient of 0.7 (95% CI, 17.8-22.5; p < 0.0001; R2 0.60). CONCLUSIONS: Surgeons can accurately obtain femoral anteversion by subtracting 7° from the angle taken between the anterior wall and the posterior femoral condyles or by adding 20° to the angle taken between the posterior wall and the posterior femoral condyles.

Intraoperative three-dimensional navigation for surgical treatment of osteoid osteoma in the foot and ankle - A series of 14 cases.

BACKGROUND: The surgical treatment for osteoid osteoma (OO) in the foot and ankle is challenging. It is difficult to locate the lesion and the anatomy is crowded by sensitive structures. The purpose of this study was to describe the outcomes of navigated mini open-intralesional curettage (NMIC) or navigated minimally invasive radiofrequency ablation (NMRFA) in treating these lesions. METHODS: All patients who underwent surgery for OO in the foot and ankle between 2015 and 2020 were included. O-arm navigation was used in All procedures. The choice of NMIC versus NMRFA was made by the surgeon according to the location of the lesion and its proximity to sensitive anatomic structures. RESULTS: Fourteen patients were included. Ten were operated by NMRFA and 4 by NMIC. All patients' symptoms related to OO resolved following a single procedure. Average AOFAS score increased by 18.7 (P < .001). Three patients had the following complications: pathologic fracture, superficial infection and transient deep peroneal nerve sensory loss. CONCLUSION: Navigated surgical treatment of OO in the foot and ankle is accurate, efficient and safe.