Li C (2014) Clinical comparative analysis on unstable pelvic fractures in the treatment with percutaneous sacroiliac screws and sacroiliac joint anterior plate fixation. Eur Rev Med Pharmacol Sci 18:2704–2708 del Piñal F, Moraleda E, Rúas JS, de Piero GH, Cerezal L. Minimally invasive fixation of fractures of the phalanges and metacarpals with intramedullary cannulated headless compression screws. J Hand Surg. 2015;40(4):692–700. Burgess AR, Eastridge BJ, Young JW, Ellison TS, Ellison PS Jr, Poka A, et al. Pelvic ring disruptions: effective classification system and treatment protocols. J Trauma Acute Care. 1990;30(7):848–56. Oberst M, Konrad G, Herget GW, El Tayeh A, Suedkamp NP. Novel endoscopic sacroiliac screw removal technique: reduction of intraoperative radiation exposure. Arch Orthop Traum Su. 2014;134(11):1557–60. Throughout my research, I often found recommendations for prefixation clamping when using headless screws. 1 Another study I reviewed was one by Lange and colleagues, utilizing 4.0-mm ASIF cancellous screws and Herbert screws in a cancellous bone model using lumbar vertebrae of calves. This study found that “the pullout strength of the 4.0 mm ASIF screw was 98.4 N. The single and double Herbert screw produced pullout forces of 56.5 N and 129.2 N, respectively. Compressive force generated by the 4.0 mm ASIF screw was 74.5 N and 9.4 N for the Herbert screw. Adding a second Herbert screw increased the compressive load to 27.2 N.” 1,3

intensifier. By gently levering on the trapezium this maneuver brings the distal pole of the scaphoid more radial and thus ultimately facilitates screw insertion. The entry point should be approximately 1/3 the way across the scaphoid from the tuberosity in the A/P plane and central in the lateral plane. 2. Guide Wire Insertion A recent study with similarly used specimens concluded that fully threaded 7.3 mm screws could withstand significantly higher axial loads to failure than partially threaded 7.3 mm screws [ 40]. However, the created constructs were not intended to be representative of the SI joint. When these findings are compared with the results from our study, it becomes clear that the SI joint is biomechanically of particular importance and plays a significant part in the surgical treatment strategy. The ideal surgical technique for SI or transiliac–transsacral screw fixation remains controversial due to the diversity of posterior pelvis fracture morphologies and considerable forces transmitted through the SI joint [ 10, 41, 42]. Supplementary studies in this field of interest are therefore beneficial for a better understanding of this complex topic. The current study was able to present a possible alternative implant for pelvis surgery, which indicates partly superior and partly comparable stability compared to the standard treatment. In addition, all implants described in this investigation can be inserted minimally invasively since percutaneous SI screw fixation is known for reduced blood loss and shorter surgery times [ 43, 44].Gardner MJ, Kendoff D, Ostermeier S, Citak M, Hüfner T, Krettek C, et al. Sacroiliac joint compression using an anterior pelvic compressor: a mechanical study in synthetic bone. J Orthop Trauma. 2007;21(7):435–41. Keep in mind that if you need to chip or drill away at the wood to get to the screw, you might cause so much damage that the wood will be unusable

Group RSV: SPRF stabilization using 7.3 mm full threaded cannulated screws, length 90 mm (DePuy Synthes, Zuchwil, Switzerland, Fig. 2B)Appropriate screw length and width should be measured on pre-operative imaging. First, a closed reduction is performed. To better reach the head of the metacarpal, the metacarpophalangeal (MCP) joint is flexed to 90°. A 3.0 mm longitudinal incision is made over the MCP joint. A guidewire is inserted along the metacarpal axis under fluoroscopy. The entry point should be on the dorsal part of the metacarpal head for optimal positioning of the screw inside the intramedullary canal. Some authors 5 suggest using a blunt K-wire to avoid cortical penetration. We use headless cannulated compression screws (SpeedTip CCS, Medartis, Basel, Switzerland) and normally insert 3.0 mm screws for the metacarpals.

Berber O, Amis AA, Day AC. Biomechanical testing of a concept of posterior pelvic reconstruction in rotationally and vertically unstable fractures. J Bone Joint Surg Br Vol. 2011;93B(2):237–44.

Lin CC, Lin KP, Huang CC, et al. Partially threaded headless screw may benefit adequate interfragmentary compression and reduced driving torque for small bone fixation. J Orthop Surg (Hong Kong). 2018;26(1):2309499018760130. The aim of this biomechanical study was to assess the stability of cannulated compression headless screws used for fixation of SPRF. Advances on this topic have the potential to reduce the reported high number of implant failures in the literature, while supporting minimally invasive procedures and possibly providing a new implant with greater stability. Outcome measures of the investigated relative interfragmentary movements lead to the following three primary concluding statements.