A model for evaluating the biomechanics of rib fracture fixation.

INTRODUCTION: High rates of morbidity and mortality following flail chest rib fractures are well publicized. Standard of care has been supportive mechanical ventilation, but serious complications have been reported. Internal rib fixation has shown improvements in pulmonary function, clinical outcomes, and decreased mortality. The goal of this study was to provide a model defining the biomechanical benefits of internal rib fixation. METHODS: One human cadaver was prepared with an actuator providing anteroposterior forces to the thorax and rib motion sensors to define interfragmentary motion. Cadaveric model was validated using a prior study which defined costovertebral motion to create a protocol using similar technology and procedure. Ribs 4-6 were fixed with motion sensors anteriorly, laterally and posteriorly. Motion was recorded with ribs intact before osteotomizing each rib anteriorly and laterally. Flail chest motion was record with fractures subsequently plated and analyzed. Motion was recorded in the sagittal, coronal and transverse axes. FINDINGS: Compared to the intact rib model, the flail chest model demonstrated an 11.3 times increase in sagittal plane motion, which was reduced to 2.1 times the intact model with rib plating. Coronal and sagittal plane models also saw increases of 9.7 and 5.1 times, respectively, with regards to flail chest motion. Both were reduced to 1.2 times the intact model after rib plating. INTERPRETATION: This study allows quantification of altered ribcage biomechanics after flail chest injuries and suggests rib plating is useful in restoring biomechanics as well as contributing to improving pulmonary function and clinical outcomes.

Improved Outcomes Using a Fibular Strut in Proximal Humerus Fracture Fixation.

Proximal humerus fractures, although common, have high rates of failure after open reduction and internal fixation. The use of a fibular allograft has been explored as a means to decrease complications, particularly varus collapse and the need for revision surgery. The authors performed a retrospective review of 133 proximal humerus fractures managed surgically with locking plates (n=72) or locking plates with fibular allograft intramedullary struts (n=61). Demographic, intraoperative, and postoperative variables were collected and analyzed. The fibular allograft group was more likely to be older (P<.01), be female (P=.04), and have a history of osteoporosis (P=.01). No differences were noted in the proportions of 2-, 3-, or 4-part fractures between groups. Average follow-up was 28 weeks. Medial calcar length was longer in the locking plate only group (P=.04); however, this group demonstrated a decreased head shaft angle (P=.01) and a trend toward increased rates of varus collapse (P=.06). No significant differences were found regarding other radiographic complications, irrespective of fracture complexity. A notable decrease in fluoroscopy time was seen with strut use (P=.04), but operative time and blood loss were similar between groups. A significant decrease in revision surgery rate was found with use of an allograft strut (P=.05). Using a strut appears to preserve the radiographic head shaft angle and decrease the risk of fracture collapse in 2-, 3-, and 4-part fractures, without increasing surgical time or morbidity. Use of an intramedullary strut appears to reduce the need for revision surgery, particularly in 3- and 4-part fractures. [Orthopedics. 2020;43(5):262-268.].

Suture Anchor Repair of Quadriceps and Patellar Tendon Injuries.

Operative treatment of quadriceps and patellar tendon ruptures with transosseous bone tunnels remains the gold standard, but potential benefits exist with the use of suture anchor fixation for these injuries. Such benefits include stronger biomechanical fixation, reduced soft-tissue disruption, smaller incision, reduced postoperative pain, shorter operative time, lower knot burden, lack of prepatellar bursa scarring, and avoidance of some transosseous repair risks. In this investigation, we present the reproducible technique and outcomes of using suture anchors for repair of quadriceps and patellar tendon ruptures.

Difficulty of Total Hip Arthroplasty Following Open Reduction and Internal Fixation of Acetabular Fractures.

BACKGROUND: The incidence of posttraumatic arthrosis after acetabular fractures is significant, and patients frequently require secondary total hip arthroplasty. Conversion arthroplasty is more technically difficult, and there is higher risk than with routine primary total hip arthroplasty. The goal of this study was to identify the challenges and risks of secondary total hip arthroplasty compared to primary total hip arthroplasty. METHODS: We retrospectively identified 30 patients who underwent secondary total hip arthroplasty after open reduction and internal fixation of an acetabulum fracture and compared them with 20 patients who had undergone primary total hip arthroplasty for degenerative joint disease. RESULTS: Demographic data were similar between groups. Hardware removal was deemed necessary in 21 patients (70%). Allograft was needed for bone defects in 33% of secondary total hip arthroplasty cases, while no primary cases required grafting. Operative time (217.4 vs. 113.7 min, P < 0.01) and estimated blood loss (875.8 vs. 365 mL, P < 0.01) were significantly greater in the secondary arthroplasty group. Early postoperative complications were also higher in the secondary arthroplasty group. CONCLUSIONS: Total hip arthroplasty after acetabular fracture open reduction and internal fixation is a more complex procedure due to exposure difficulty, possible implant removal, management of bony deficits, and the potential use of cages and revision components. Experienced surgeons managing these complicated cases must take great care not only in ensuring appropriate technique but also in appropriate patient education regarding increased risk of major and minor complications. LEVEL OF EVIDENCE: Level III.