Prophylactic Intrawound Antibiotics Significantly Reduce the Risk of Deep Infections in Fracture Fixation: Subgroup Meta-analyses of the Type of Fracture, Antibiotics, and Organism.

OBJECTIVES: To analyze the efficacy of subgroups of various intrawound local antibiotics in reducing the rate of fracture-related infections. DATA SOURCES AND STUDY SELECTION: PubMed, MEDLINE via Ovid, Web of Science, Cochrane database, and Science Direct were searched for articles in English on July 5, 2022, and December 15, 2022. STUDY SELECTION: All clinical studies comparing the incidence of fracture-related infection between the administration of prophylactic systemic and topical antibiotics in fracture repair were analyzed. DATA EXTRACTION: Cochrane collaboration's assessment tool and the methodological bias and the methodological index for nonrandomized studies were used to detect bias and evaluate the quality of included studies, respectively. DATA SYNTHESIS: RevMan 5.3 software (Nordic Cochrane Centre, Denmark) was used to conduct the meta-analyses and generate forest plots. CONCLUSIONS: From 1990 to 2021, 13 studies included 5309 patients. Nonstratified meta-analysis showed that intrawound administration of antibiotics significantly decreased the overall incidence of infection in both open and closed fractures, regardless of the severity of open fracture and antibiotics class [OR = 0.58, ( P = 0.007)] [OR = 0.33, ( P < 0.00001)], respectively. The stratified analysis revealed that prophylactic intrawound antibiotics significantly lowered infection rate in open fracture patients with Gustilo-Anderson type I (OR = 0.13, P = 0.004), type II (OR = 0.29, P = 0.0002), type III (OR = 0.21, P < 0.00001), when either tobramycin PMMA beads (OR = 0.29, P < 0.00001) or vancomycin powder (OR = 0.51, P = 0.03) was applied. This study demonstrates prophylactic administration of intrawound antibiotics significantly decreases the overall incidence of infection in all subgroups of surgically fixated fractures but does not affect the patient's length of hospital stay. LEVEL OF EVIDENCE: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.

Fixation of Transverse Acetabular Fractures With Precontoured Plates Alone Causes Fracture Malreduction: A Biomechanical Assessment.

BACKGROUND: Precontoured quadrilateral surface buttress (PQSB) plates have grown in popularity for acetabular fracture fixation. However, our experience has pushed us to hypothesize that their use as sole means of fixation may cause fracture malreduction. A biomechanical model was created to investigate this theory. METHODS: A transverse acetabular fracture was created and reduced anatomically in 18 synthetic hemipelvises. The reduced hemipelvises were fixated using 3 different techniques. Group A fixation included anterior and posterior column screws plus a suprapectineal pelvic reconstruction plate; group B models were fixed using a PQSB plate only; and group C models were fixed with an anterior column screw and a PQSB plate. Acetabular tracking points were placed before final fixation and used to quantify any postfixation displacement. One-way analysis of variance and Tukey HSD testing were used to determine the significant difference (P < 0.05). RESULTS: Models in group B had significant fracture displacement after final fixation when compared with group A and group C models. The average amount of displacement at the anterior column and within the acetabulum was 1.37 mm (95% CI, 1.08-1.65) in group B constructs compared with 0.32 mm (95% CI, 0.22-0.42) and 0.26 mm (95% CI, 0.15-0.38) in groups A and C constructs, respectively. There were no significant differences in displacement after final fixation between group A and group C models. CONCLUSIONS: PQSB plates for acetabular fractures cause malreduction when applied in isolation in this biomechanical model. If a PQSB plate is chosen for fixation, we suggest the use of a columnar lag screw at minimum to hold reduction before plate application.

Precontoured Quadrilateral Surface Acetabular Plate Fixation Demonstrates Increased Stability When Compared With Pelvic Reconstruction Plates: A Biomechanical Study.

OBJECTIVE: To compare the stability of 3 fixation strategies for a transverse acetabular fracture: a reconstruction plate with anterior and posterior column screws (group A); an infrapectineal precontoured quadrilateral surface buttress (iPQSB) plate alone (group B); and an anterior column lag-screw and iPQSB plate (group C). METHODS: A transverse acetabular fracture was created in 18 synthetic hemipelvises. Six were fixed by each of the 3 methods described. Specimens underwent cyclic axial compressive loading to 1700N for 42,000 cycles while anterior and posterior column displacements were measured, followed 4800N for 50 cycles. Displacement and stiffness data were analyzed with analysis of variance and Tukey HSD. A Cox proportional hazards regression model was used to determine survival rate. P values < 0.05 were considered significant. RESULTS: Group C had significantly less posterior column displacement (0.16 ± 0.06 mm) compared with group B (0.38 ± 0.37 mm, P < 0.0001) and group A (0.38 ± 0.37 mm, P < 0.0001). In addition, group A had significantly more anterior column displacement (0.28 ± 0.11 mm) than group B (0.22 ± 0.14 mm, P = 0.0310) and group C (0.18 ± 0.09 mm, P = 0.0001). Group C was 10.5% stiffer than group A (P = 0.0037). Group B had a 7.27x greater rate of failure than group C (95% confidence interval, 1.6-33.2). DISCUSSION AND CONCLUSION: Under anatomical loading, iPQSB plates with anterior column lag-screw fixation demonstrate increased stability in a synthetic bone transverse acetabular fracture model. Based on our data, we support additional evaluation of early weight-bearing after transverse acetabular fracture fixation in patients with healthy bone when an anterior column screw-iPQSB plate construct is used.

A New Fastener With Improved Bone-To-Implant Interface Shows Superior Torque Stripping Resistance Compared With the Standard Buttress Screw.

OBJECTIVE: The conventional AO buttress screw used for fracture fixation relies on a historic buttress thread design, which is prone to stripping at the bone-implant interface. We hypothesized that a new Bone-Screw-Fastener with an innovative interlocking thread design demonstrates increased resistance to torque stripping forces compared with the buttress screw, without compromising pullout strength. METHODS: A biomechanical model was established in 6 matched pairs of adult human cadaveric tibiae to test torque resistance between the 3.5 mm Bone-Screw-Fastener and the 3.5 mm cortical AO buttress screw until failure. Uniaxial pullout testing of both screw types was performed as an internal control experiment. RESULTS: The 3.5 mm Bone-Screw-Fastener had a significantly increased resistance to torque failure compared with the standard 3.5 mm AO buttress screw (P = 0.0145). In contrast to the buttress screws, none of the Bone-Screw-Fasteners stripped from the bone but rather failed at the screwdriver-implant interface in terms of a metal-on-metal failure. The internal control experiments revealed no significant difference in axial pullout strength between the 2 implants (P = 0.47). CONCLUSIONS: These data demonstrate the superiority of the new Bone-Screw-Fastener over the conventional AO buttress screw regarding protection from torque stripping forces. In addition, the new thread design that interlocks to the bone does not sacrifice axial pullout resistance conveyed by the buttress screw. Future controlled trials will have to validate the in vivo relevance of these findings in a clinical setting.

Introducing the "Bone-Screw-Fastener" for improved screw fixation in orthopedic surgery: a revolutionary paradigm shift?

BACKGROUND: Conventional screws used for fracture fixation in orthopedic surgery continue to rely on the historic buttress thread design. While buttress screws generally provide solid resistance against unidirectional axial loading forces, their design suffers from several limitations, as the buttress thread does not adequately resist multiaxial forces. Furthermore, the buttress screw is prone to stripping at the bone-screw interface and can cause microfracturing of the surrounding bone due to its thread design. Standard buttress screws are therefore at risk of adverse postoperative outcomes secondary to failure of bone fixation. A new patented Bone-Screw-Fastener was recently designed that is based on an interlocking thread technology. This new fastener provides distributive forces from the threads onto the bone and therefore resists loads in multiple directions. The underlying concept is represented by a "female thread" bone cutting technology designed to maximize bone volume, preserve bone architecture, and create a circumferential interlocking interface between the implant and bone that protects the thread from stripping and from failing to multiaxial forces. PRESENTATION OF THE HYPOTHESIS: We hypothesize that the new Bone-Screw-Fastener overcomes the classic shortcomings of conventional orthopedic screws with buttress threads by ease of insertion, improved bone preservation, increased resistance to off-axis multidirectional loading forces and to stripping of the threads. These advanced biomechanical and biological properties can potentially mitigate the classic limitations of conventional buttress screws by providing better resistance to implant failure under physiological loads, preserving bone biology, and thus potentially improving patient outcomes in the future. TESTING THE HYPOTHESIS: The presumed superiority of the new fastener will require testing and validation in well-designed prospective multicenter randomized controlled trials (RCTs), using the conventional buttress screw as control. IMPLICATIONS OF THE HYPOTHESIS: Once validated in multicenter RCTs, the new Bone-Screw-Fastener may drive a change in paradigm with regard to its innovative biomechanical principles and biologic bone preservation for surgical applications requiring screw fixation.