Strength of femoral neck fracture fixation: Comparison of six techniques in cadavers

Stability of femoral neck osteosynthesis: Comparison of fixation methods in cadavers

“…To avoid this problem, a paired comparison (Engesaeter et al 1984) or preloading with each femur as its own control (Swiontkowsky et al 1987) has been used. Use of intact bone, as in the present study, simulates the clinical stress distribution best, In previous studies, we have shown that the bone density between right and left femora varies insignificantly (Husby et al 1987). When using hipcompression screws with or without lag screws, we did not apply more compression over the osteotomy site than necessary for a good bone-tobone contact; compression of osteoporotic bone may be hannful as shown both experimentally by Frandsen and Madsen 1983 and clinically by Linde et al 1986.…”

“…A number of authors have reported (van Audekercke et al 1979, Engessteret al 1984, Swiontkowski et al 1987, Husby et al 1987) that the bending strength of the osteosynthesis in femoral neck fracture does not increase with the use of sliding screws even with a supplementary lag screw, or by using more than three screws (van Audekercke et al 1979). However, increasing the number of screws from 2 to 3 and increasing the screw diameter, thus increasing the total amount of metal in the femoral head, may be deleterious to the femoral head vitality (Stremquist et al 1983, Linde et al 1986).…”

Biomechanical comparison using finite element analysis of different screw configurations in the fixation of femoral neck fractures

“…Comparison of different configurations of the screws used for stabilization of femoral neck fracture has been studied in biomechanics (Baitner et al, 1999;Holmes et al, 1993;Husby et al, 1987Husby et al, , 1989Selvan et al, 2004). Reviewing the literature, it is reported in studies that the ideal configuration of screws is two screws for proximal and one for distal in inverted triangle configuration (Kyle, 2009;Ly and Swiontkowski, 2009;Melvin and Happenstall, 2009;Schmidt et al, 2005).…”

The Value of Washers in Cannulated Screw Fixation of Femoral Neck Fractures

“…On the basis of a review of the literature, we hypothesized that the following variables might be associated with fixation failure: age, 31 gender, 31 fracture type (displaced/undisplaced), 20,33,34,38 fracture comminution, 33,38 total number of screws, [7][8][9]22 number of screws with a short thread (16 mm) versus number of screws with a long thread (32 mm), absence of a washer, screw configuration (triangle, inverted triangle, or vertical alignment), 9,10,14,23,24 reduction quality 9-12,15-21 (Garden's Alignment Index), distance of the most inferior screw to the inferior neck, 9,25,26 screw alignment (parallel, convergent, divergent on anteroposterior and lateral radiographs), [9][10][11][12][13][14] mean angle of screw entry (relative to the lateral cortex of the shaft), and distance of the most inferior screw to the lesser trochanter. In addition, we recorded the sum of the distances of the tip of each screw and the apex of the femoral head on anteroposterior and lateral radiographs (tip-apex distance [TAD] sum) analogous to the tip-apex distance of Baumgaertner et al as a predictor of failure for placement of dynamic condylar screws.…”

“…5 Options for internal fixation have included a variety of implants, 7,8 but most recent reports and textbooks cite parallel multiple screws as the surgical technique of choice. 9 -14 Current recommendations for the insertion of cannulated screws include the following guidelines: adequate reduction, 9 -12,15-21 anterior capsulotomy, 10 use of three 22 cannulated screws, [7][8][9]22 parallel alignment of screws, 9 -14 an inverted triangular screw pattern, 9,10,14,23,24 and placement of the most inferior screw close to the inferior cortex. 9,25,26 The rationale for these guidelines is based primarily on anatomic data, 27,28 biomechanical data, 22,29,30 and clinical case series.…”