The loading protocol commenced with an initial nondestructive quasi-static ramp from 20 N preload to 200 N at a rate of 18 N/s, followed by progressively increasing cyclic loading in axial compression with a physiological profile of each cycle at a rate of 2 Hz [ 17]. Keeping the valley load at a constant level of 20 N, the peak load, starting at 200 N, was monotonically increased cycle by cycle at a rate of 0.05 N/cycle until the test stop criterion of 10 mm actuator displacement had been fulfilled with respect to its position at the beginning of the loading protocol, which was found adequate to provoke catastrophic failure of the specimens [ 18, 19]. Data acquisition and analysis Gardner MJ, Kendoff D, Ostermeier S, Citak M, Hüfner T, Krettek C, Nork SE (2007) Sacroiliac joint compression using an anterior pelvic compressor: a mechanical study in synthetic bone. J Orthop Trauma 21:435–441 A biomechanical cadaver study comparing the stability of two 3.5 mm fully threaded screws vs. one 7.3 mm partial threaded screw treating SPRF also presented comparable results [ 15]. On the contrary, as seen in surgical fixations of ankle fractures, partially threaded screws have been proven to reduce the initial screw stiffness as well as yield load, compared to fully threaded screws [ 24]. Giesen et al 6 reported their experience with 31 consecutive extra-articular unstable fractures of the proximal or middle phalanges. An intra-articular technique was used in 17 fractures of the proximal phalanx and five fractures of the middle phalanx. A trans-articular technique was adopted in seven fractures of the proximal phalanx and two fractures of the middle phalanx. All fractures healed clinically and radiographically between 28 and 43 days after surgery. At the last follow-up, a mean total active motion (TAM) of 222° (range, 90–295°) was noted. The average extension deficit for the PIP joint was 8° (range, 0–20°). van Zwienen CMA, van den Bosch EW, Snijders CJ, Kleinrensink GJ, van Vugt AB. Biomechanical comparison of sacroiliac screw techniques for unstable pelvic ring fractures. J Orthop Trauma. 2004;18(9):589–95.

Screws are often manufactured as self-threading, which means the thread cuts into the material when the screw is turned. This creates an internal thread that allows the fastening material to be pulled together and prevents it from being pulled out. Use a strong drill bit, maybe even a carbide or diamond-tipped one, and simply destroy the screw. Keep drilling at it and shaving away the pieces until there is nothing left. Of course, this is not the ideal solution, but if all else fails, it’s going to be your last resort. How to Remove a Headless Screw from WoodA complete instruments set are available for Headless Compression Screws. Instruments can be modified according to the customer’s requirement with minimum quantity required. All these instruments can be used several times. 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. The guide wire, .062″, for the 4.7 Screw can be positioned at the base of the fifth metatarsal under fluoroscopic guidance. A small incision is made at the base of the fifth metatarsal at the intersection of the peroneus brevis and tertius tendons. Care is made to identify and protect the sural nerve branches which run over the peroneal tendons. If necessary, fibers of the lateral aponeurosis and peroneus brevis tendon are separated and retracted away from the styloid process of the base of the fifth metatarsal. A mini Hohman Retractor is placed on the plantar In recent years, I have noted a shift towards headless screw usage in multiple foot and ankle applications. In my observation, headless screws boast a low-profile design with the ability to bury the screw below the bone’s cortical surface leading to decreased soft tissue adhesion and irritation. But, are we getting the best screw for those perks? Schmalzried TP, Grogan TJ, Neumeier PA, Dorey FJ. Metal removal in a pediatric population: benign procedure or necessary evil? J Pediatr Orthop. 1991;11(1):72–6.

In general, the length of the thread is either full or partial. Therefore, full thread and partial screw threads are also available. #7 Tip Sagi H, Ordway N, DiPasquale T. Biomechanical analysis of fixation for vertically unstable sacroiliac dislocations with iliosacral screws and symphyseal plating. J Orthop Trauma. 2004;18(3):138–43. Teo AQA, Yik JH, Keat SNJ, Murphy DP, O’Neill GK. Accuracy of sacroiliac screw placement with and without intraoperative navigation and clinical application of the sacral dysmorphism score. Injury. 2018;49(7):1302–6.Douglas Appel, DPM, FACFAS is a dual board-certified Foot and Ankle surgeon in private practice in Wilmington, Delaware.

Fowler JR, Ilyas AM. Headless compression screw fixation of scaphoid fractures. Hand Clin. 2010;26(3):351–61. Group FT: Stabilization of the posterior pelvis ring with two 7.3 mm fully threaded cannulated SI screws and washers, 90 mm in length for S1 and 65 mm in length for S2.According to the AO surgery references, either a fully threaded 3.5 mm/4.5 mm cortical screw, or a 6.5/ 7.3 mm cancellous screw without a washer are recommended for SPRF fixation [ 14]. A washer does not appear to be an option for the starting point at the pubic tubercle due to the steep and small bearing surface. Due to the proximity to the skin with little overlying muscle tissue, a washer would likely interfere due to its protruding angle. Yet, a washer, presented as an integral component of a screw, has been described as advantageous [ 20]. It is a standard component of cannulated 6.5 mm or 7.3 mm cancellous iliosacral screw placements of the posterior pelvic ring [ 21]. Hence, the anatomy-limited absence of the washer may explain the high number of implant failures reported in the literature. The CCHS has threads of different pitch on either end with an unthreaded central part/shaft and is headless. It acts as a countersink, allowing the different threads at each end to draw the fracture fragments together and therefore create compression. This combines the advantages of the screws in group RST and group RSV. The partially threaded screws allow fracture compression, while the fully threaded screws potentially provide more stability due to their proximal thread anchorage. Additionally, it rests flush with the proximal cortex and thus provides less surface for potential irritation. By using the CCHS, both advantages are combined within one screw.