Assessment of the effectiveness of weight-adjusted antibiotic administration, for reduced duration, in surgical prophylaxis of primary hip and knee arthroplasty.

BACKGROUND: Prophylactic antibiotics have significantly led to a reduction in the risk of post-operative surgical site infections (SSI) in orthopaedic surgery. The aim of using antibiotics for this purpose is to achieve serum and tissue drug levels that exceed, for the duration of the operation, the minimum inhibitory concentration of the likely organisms that are encountered. Prophylactic antibiotics reduce the rate of SSIs in lower limb arthroplasty from between 4% and 8% to between 1% and 3%. Controversy, however, still surrounds the optimal frequency and dosing of antibiotic administration. AIM: To evaluate the impact of introduction of a weight-adjusted antibiotic prophylaxis regime, combined with a reduction in the duration of administration of post-operative antibiotics on SSI incidence during the 2 years following primary elective total hip and knee arthroplasty. METHODS: Following ethical approval, patients undergoing primary total hip arthroplasty (THA)/total knee arthroplasty (TKA) with the old regime (OR) of a preoperative dose [cefazolin 2 g intravenously (IV)], and two subsequent doses (2 h and 8 h), were compared to those after a change to a new regime (NR) of a weight-adjusted preoperative dose (cefazolin 2 g IV for patients < 120 kg; cefazolin 3g IV for patients > 120 kg) and a post-operative dose at 2 h. The primary outcome in both groups was SSI rates during the 2 years post-operatively. RESULTS: A total of n = 1273 operations (THA n = 534, TKA n = 739) were performed in n = 1264 patients. There was no statistically significant difference in the rate of deep (OR 0.74% (5/675) vs NR 0.50% (3/598); fishers exact test P = 0.72), nor superficial SSIs (OR 2.07% (14/675) vs NR 1.50% (9/598); chi-squared test P = 0.44) at 2 years post-operatively. With propensity score weighting and an interrupted time series analysis, there was also no difference in SSI rates between both groups [RR 0.88 (95%CI 0.61 to 1.30) P = 0.46]. CONCLUSION: A weight-adjusted regime, with a reduction in number of post-operative doses had no adverse impact on SSI incidence in this population.

Acute versus delayed total hip arthroplasty after acetabular fracture fixation: a systematic review and meta-analysis.

BACKGROUND: Post-traumatic osteoarthritis (PTOA) is a disabling complication of open reduction and internal fixation (ORIF) for acetabular fractures. There is a trend towards acute total hip arthroplasty (THA), 'fix-and-replace', in patients considered to have a poor prognosis and likelihood of PTOA. Controversy remains between early fix-and-replace, versus delayed THA as required after initial ORIF. This systematic review included studies comparing functional and clinical outcomes between acute versus delayed THA after displaced acetabular fractures. METHODS: Comprehensive searches following the PRISMA guideline were performed on six databases for articles in English published anytime up to 29 March 2021. Two authors screened articles and discrepancies were resolved by consensus. Patient demographics, fracture classification, functional and clinical outcomes were compiled and analysed. RESULTS: The search yielded 2770 unique studies, of which five retrospective studies were identified with a total of 255 patients. Of them, 138 (54.1%) were treated with acute and 117 (45.9%) treated with delayed THA. Delayed THA group represented a younger cohort compared to the acute group (mean age, 64.3 vs 73.3). The mean follow-up time for the acute and delayed group was 23 and 50 months, respectively. There was no difference in functional outcomes between the two study groups. Complication and mortality rates were comparable. Delayed THA had a higher revision rate compared to the acute group (17.1 vs 4.3%; p = 0.002). CONCLUSION: Fix-and-replace had functional outcomes and complication rates similar to ORIF and delayed THA, but lower revision rates. Although the quality of studies was mixed, sufficient equipoise now exists to justify randomised studies in this area. PROSPERO registration: CRD42021235730.

Adjustable loop ACL suspension devices demonstrate less reliability in terms of reproducibility and irreversible displacement.

PURPOSE: The aim of this study was to perform a comprehensive biomechanical examination of frequently applied femoral cortical suspension devices, comparing the properties of both fixed and adjustable fixation mechanisms. It was hypothesized that adjustable loop devices demonstrate less consistent fixation properties with increased variability compared to fixed loop devices. METHODS: Nine frequently applied fixation button types were tested, six adjustable and three rigid loop devices. Six samples of each device type were purchased. Each device was installed in a servo-hydraulic mechanical testing machine, running a 2000 cycle loading protocol at force increments between 50 and 500 N. Irreversible displacement in mm was measured for all of the tested samples of each implant. Ultimately, maximum load to failure was applied and measured in Nm. An irreversible displacement of 3 mm was considered failure of the implant. RESULTS: Three of the six adjustable devices (GraftMax™, TightRope® ToggleLoc™) demonstrated a median displacement above the threshold of clinical failure before completion of the cycles. All adjustable loop devices showed a wide intragroup variation in terms of irreversible displacement, compared to fixed-loop devices. Fixed-loop devices provided consistent reproducible results with narrow ranges and significantly lower irreversible displacement (p < 0.05), the maximum being 1.4 mm. All devices withstood an ultimate force of more than 500 N. CONCLUSION: Adjustable loop devices still show biomechanical inferiority and demonstrate heterogeneity of fixation properties with wide- and less-reproducible displacement ranges resultant to the mechanism of adjustment, denoting less reliability. However, three adjustable devices (RIGIDLOOP™ Adjustable, Ultrabutton ◊, ProCinch™) demonstrate fixation capacities within the margins of clinical acceptance. RIGIDLOOP™ Adjustable provides the most comparable fixation properties to fixed loop devices.