Low interobserver and intraobserver reliability using the Matta radiographic system for intraoperative assessment of reduction following acetabular ORIF.

INTRODUCTION: The system described by Matta for rating acetabular fracture quality of reduction following ORIF has been used extensively throughout the literature. However, the reliability of this system remains to be validated. We sought to determine the interobserver and intraobserver reliability of this system when used by fellowship-trained pelvic and acetabular surgeons to evaluate intraoperative fluoroscopy. METHODS: This is a retrospective evaluation of a prospectively collected acetabular fracture database at an academic level I trauma center. The quality of reduction of all acetabular fractures treated with open reduction internal fixation (ORIF) between May 2013 and December 2015 was assessed using three standard intraoperative fluoroscopic views (anteroposterior and two 45˚ oblique Judets). Displacement of ≤1 mm was considered to be an anatomic reduction, 2-3 mm imperfect, and >3 mm poor according to the system described by Matta. A total of 107 acetabular fractures treated with ORIF with complete intraoperative fluoroscopic images during that time period were available for review. Acetabular fracture reductions were reviewed by the operative surgeon at the time of surgery and subsequently reviewed by two fellowship-trained pelvic and acetabular surgeons. All reduction assessments were performed in a blinded fashion. The primary outcome measure was interobserver reliability for assessing reduction quality. This was evaluated using a weighted kappa (κw) statistic between each evaluator and the operative surgeon and a generalized kappa (κg) for all 3 surgeons. After a 6-week "washout interval," the surgeons reviewed the images again and intraobserver agreement was calculated using a weighted kappa statistic. RESULTS: Interobserver reliability based on the initial assessment was low (κg = 0.09); however, did slightly improve with the second assessment to fair (κg = 0.24). Intraobserver reliability ranged from slight (κw = 0.20) to moderate (κw = 0.53) among the surgeons. DISCUSSION: Low interobserver and intraobserver reliability was found when quality of reduction was assessed with intraoperative fluoroscopic images by the operative and two other pelvic and acetabular surgeons using the Matta system. Given the importance of an anatomic reduction on functional and radiographic outcomes, an accurate and reliable system for assessing intraoperative quality of reduction is essential.

Factors Predictive of Blocking Screw Placement in Retrograde Nailing of Distal Femur Fractures.

OBJECTIVES: (1) Identify factors that predict blocking screw placement in the treatment of a distal femur fracture with retrograde nail fixation and (2) determine whether acceptable alignment and stability were achieved in fractures that received blocking screws. DESIGN: Retrospective Comparative Study. SETTING: Level I Trauma Center. PATIENTS/PARTICIPANTS: Between 2011 and 2017, we identified 84 patients with distal third femur fractures treated with a retrograde femoral nail. Data were analyzed according to those who did (BLOCK, n = 30) and did not (NO BLOCK, n = 54) receive blocking screws. Patients in both groups were treated by orthopaedic trauma surgeons; postoperative weight-bearing radiographs were obtained of every patient. INTERVENTION: Fixation using a retrograde femoral nail with or without blocking screws. Blocking screws were placed at the discretion of the treating surgeon to reduce malaligned fractures or improve stability. MAIN OUTCOME MEASUREMENTS: (1) Demographics, radiographic apparent bone gap (RABG), space available for the nail (SAFN), and distal segment length [as a ratio of bicondylar width (BCW)]; and (2) post-operative alignment and stability (change in alignment over time). RESULTS: Patients treated with blocking screws had a higher body mass index (BMI) (BLOCK: 29.0, NO BLOCK 25.7, P = 0.03). In addition, the BLOCK group had larger RABGs (BLOCK: 8.2 mm, NO BLOCK: 3.6 mm, P = 0.02), more SAFN (BLOCK: 51.4 mm, NO BLOCK: 39.8 mm, P = 0.02), and shorter distal segments (BLOCK: 1.7 × BCW, NO BLOCK: 2.0 × BCW, P = 0.01). In a multivariable logistic regression, the combination of these factors was significantly predictive of blocking screw placement with a large effect size (R = 0.36, P < 0.01). A distal segment length ≤ ×2 BCW was 77% sensitive for blocking screw placement, and a BMI ≥25 kg/m was 70% sensitive. Negative predictive values for blocking screw placement were distal segment length > ×2 BCW (79%), BMI <25 kg/m (77%), RABG <4 mm (76%), and SAFN <50 mm (71%). Patients that received blocking screws had acceptable postoperative alignment and stability, similar to fractures that did not receive blocking screws (P > 0.05). CONCLUSIONS: This retrospective study of distal femur fractures treated with retrograde nails identified several factors that can be used to predict when blocking screw placement may be useful for increasing stability and maintaining alignment in distal third femur fractures treated with retrograde IM nails. Patients treated with blocking screws had a higher BMI, greater cortical bone loss, more SAFN, and shorter distal segments. There was no difference in postoperative alignment or stability between the 2 groups. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The "Well-Cap" Technique: Screw Insertion for Pelvic Nutrient Foramen Hemostasis.

Several approaches to the pelvis and acetabulum involve subperiosteal dissection of the iliacus from the internal iliac fossa.Typically bleeding is encountered from the nutrient foramen located near the sacroiliac joint. Bone wax and electrocautery have traditionally been used to achieve hemostasis from this foramen but produce inconsistent results.The authors of this technical tip describe a novel technique of inserting a cortical screw directly into the foramen tocontrol osseous hemorrhage.This technique has been consistently effective at achieving hemostasis in cases of refractory bleeding and has produced no complications. (Journal of Surgical Orthopaedic Advances 27(3):246-250, 2018).

Use of the Reamer-Irrigator-Aspirator for bone graft harvest: a mechanical comparison of three starting points in cadaveric femurs.

OBJECTIVES: The mechanical behavior of cadaveric femurs after intramedullary reaming using the Reamer-Irrigator-Aspirator (RIA) for autogenous bone graft harvest has not been fully described. We hypothesized that reamed femurs, regardless of starting point, would adequately withstand cyclic loading simulating postoperative single-leg stance. METHODS: Twenty-one cadaveric pairs were randomly assigned to one of three groups based on starting point: Group 1 (trochanteric), Group 2 (piriformis fossa), and Group 3 (retrograde). Each femur underwent dual-energy x-ray absorptiometry scanning and radiographs. Each test femur was reamed to 15 mm using the RIA with the contralateral femur serving as the control. The specimens were loaded to 1400 N of axial compression with 2 degrees simultaneous torsion for 10,000 cycles. If the femur survived cyclic loading, it was then loaded to failure in axial compression. Comparisons regarding survival of cyclic loading were made using Fisher exact test. RESULTS: No differences were seen between groups regarding age, sex, and T-score. The mean T-score for the femurs was -2.531 +/- 1.372. Overall, 18 of 21 (86%) test femurs and 20 of 21 (95%) control femurs withstood cyclic loading (P = 0.606). Statistical significance was not reached for the three pairwise comparisons between test groups. The femurs failed in patterns consistent with simple pertrochanteric, basicervical, midcervical, or subcapital fractures. CONCLUSIONS: Intramedullary reaming for bone graft harvest using the RIA without subsequent intramedullary stabilization did not significantly degrade the mechanical behavior of cadaveric femurs in simulated single-leg stance regardless of reamer starting point. It appears safe to allow single-leg stance weightbearing on a reamed, unstabilized femur after bone graft harvesting using the RIA.

Tetracycline labeling as a measure of humeral head viability after 3- or 4-part proximal humerus fracture.

HYPOTHESIS: Specifically located humeral head biopsies from three-part proximal humerus fractures taken at the time of hemiarthroplasty will show greater tetracycline labeling under fluorescent microscopy than those biopsies taken from four-part fractures. Additionally, biopsies from younger patients would show greater fluorescence than older patients. MATERIAL AND METHODS: Nineteen consecutive adult patients (range 43-83 years) underwent hemiarthroplasty as definitive treatment for 20 displaced three- and four-part proximal humerus fractures after having received 500 mg of tetracycline hydrochloride orally every six hours for the immediate five preoperative days. Humeral head biopsies were taken from four pre-determined locations intraoperatively. The biopsies were prepared and analyzed with fluorescent microscopy. RESULTS: All specimens in each biopsy location demonstrated fluorescence. There was no difference between the mean rank gray values for the four biopsy locations (p = 0.78 with the Friedman test). There was no difference between the mean rank gray values for the four biopsy locations when analyzed according to three-part vs four-part fracture (p > 0.05 with the Mann-Whitney test). There was an inverse relationship between age and fluorescence for the anterosuperior biopsy location (p = 0.033 with Spearman correlation). DISCUSSION: Vascular supply is preserved in displaced three- and four-part proximal humerus fractures. With intact vascularity to the humeral head, head-preserving techniques utilizing stable, site-specific fixation and minimal dissection should be considered in the treatment of displaced three- and four-part proximal humerus fractures. CONCLUSION: Vascular supply is preserved in displaced three- and four-part proximal humerus fractures, especially in younger patients in the anterosuperior aspect of the humeral head. LEVEL OF EVIDENCE: Basic Science Study.

Bladder incarceration following anterior external fixation of a traumatic pubic symphysis diastasis treated with immediate open reduction and internal fixation.

Anterior pelvic ring disruptions are often associated with injuries to the genitourinary structures with the potential for considerable resultant morbidity. Herniation of the bladder into the symphyseal region after injury with subsequent entrapment upon reduction of the symphyseal diastasis has seldom been reported in the literature. We report such a case involving bladder herniation and subsequent entrapment after attempted closed reduction with anterior pelvic external fixation immediately treated with open reduction and internal fixation along with a review of the literature.