3D Augmented Reality-Based Surgical Navigation and Intervention
Terry M. Peters, Cristian A. Linte, Ziv Yaniv, Jacqueline Williams in Mixed and Augmented Reality in Medicine, 2018
In spine surgery, pedicle screw placement can provide strong fixation to the spine, which prevents injury when the back stretches, bends, or rotates excessively. However, a screw that is improperly placed can result in neurologic and vascular complications. To assist accurate placement, a navigation system is used. However, the surgical target as well as surgical instruments, such as pedicle screws, may be hidden in other structures during surgery. To solve these problems, research on a 3D IV AR system complemented with ultrasound-assisted registration has been proposed for pedicle screw placement, as shown in Figure 17.8 (Ma et al. 2017). Ultrasound (US) is used to perform registration between the preoperative medical image and patient to avoid the effect of extracting anatomical landmarks on the surface and reduce radiation exposure. The registration method is based on least-squares fitting of these two 3D point sets of anatomical landmarks from US images and preoperative images. A 3.0-mm Kirschner wire (K-wire), instead of a pedicle screw, is calibrated to acquire its orientation and tip location prior to use. An agar phantom experiment was performed to verify the feasibility of the system. Eight K-wires were successfully placed after US-assisted registration. The mean targeting and angle errors were 3.35 mm and 2.74°, respectively. Experiments demonstrate that the proposed system has acceptable targeting accuracy and repeated radiation exposure is reduced for both the patient and the surgeon.
Instruments and Implants in Hand Surgery
J. Terrence Jose Jerome in Clinical Examination of the Hand, 2022
Kirschner wire set: In 1909 Martin Kirschner introduced a smooth pin which is now as Kirschner or K wires. K wires are available in varying sizes ranging from 0.9 to 15 mm in diameter (0.035, 0.045, 0.062 inches) (Figure 15.28A), mainly used to fix the bone fragments together. Wires are also of varying lengths which may vary in the end construct. K wire could be a trocar tip, threaded tip or a diamond cut tip. The trocar tip is better suited for penetrating the cortical bone and later able to be braced against the endosteal surface of bone cortex or applicable to lodging in cancellous bone. Some may have one spatulated end without a point. Threaded wires are also available which are referred to as screw tips. These wires are driven into the bone through the skin using a K wire driver. One of the advantages of K wires is the ease of atraumatic percutaneous insertion leading to less damage to soft tissue and tendons. Percutaneous fixation achieves stable fixation after adequate reduction and allows early mobilization thereby avoiding stiffness. Once driven, the wires are bent externally using a wire bender to avoid injury to surrounding structures. This also prevents proximal migration which is considered as one of the complications. Pin tract infection can be prevented by avoiding repeated drilling and optimal pin tract dressing. Burying the wire inside the skin can also be employed and at times requires a secondary procedure to remove them.
Paediatric and adolescent foot disorders
Maneesh Bhatia in Essentials of Foot and Ankle Surgery, 2021
Postoperatively, plaster is applied with the foot in a neutral position to stretch the peroneal tendons and the ankle in slight dorsiflexion to maintain hindfoot equinus correction. The plaster and the Kirschner wire are removed at 5–6 weeks postoperatively and a bar brace is provided to be worn full time for 2 months and then at bedtime time for 2 years. The boots are set to point in a straight position, rather than external rotation in the Ponseti clubfoot method. Ankle-foot orthoses (AFOs), with moulding under the medial arch, are fitted to provide more support when the child begins to stand or walk. This minimally invasive technique helps to avoid complications of extensive surgery and is more likely to result in a relatively more flexible and less painful foot. Recurrence is still a concern, mainly with in patients with underlying comorbidities, but happens at a much lower rate.
Femoral and pelvic osteotomies for severe hip displacement in nonambulatory children with cerebral palsy: a prospective population-based study of 31 patients with 7 years’ follow-up
Published in Acta Orthopaedica, 2019
The surgical procedures were done with the patient in the supine position, and an image intensifier was used. Femoral varus osteotomy was performed through a longitudinal lateral approach. A transverse femoral osteotomy just above the lesser trochanter was performed with an oscillating saw. The osteotomy was a combination of varization, derotation, and shortening. One Kirschner wire drilled transversely into the femur proximal to the osteotomy and one distal to the osteotomy were used as guide wires for derotation. A neck–shaft angle of 110–120° and derotation of about 30° were aimed at. In 24 osteotomies a second transverse osteotomy distal to the first was performed, and a wedge of bone was removed, aiming for a femoral shortening of 1–2 cm. The osteotomy was fixed with a 110° pediatric locked compression plate (LCP; Synthes, Switzerland) (Rutz and Brunner 2010) in 30 osteotomies (Figure 1) and a 90° AO blade plate in 2. In the remaining 7 osteotomies a straight plate with 2 screws in each fragment was used, after the plate had been bent according to the planned varization.
Pelnac® Artificial Dermis Assisted by VSD for Treatment of Complex Wound with Bone/Tendon Exposed at the Foot and Ankle, A Prospective Study
Published in Journal of Investigative Surgery, 2020
Zhenmu Lv, Qiusheng Wang, Rui Jia, Wenyuan Ding, Yong Shen
For every patient, 2 separate operations were performed. The first procedure involved thorough debridement of necrotic tissues, meticulous hemostasis, and then immediate coverage of VSD at continuous negative pressure suction. For bone exposure in adult case, a rongeur forcep was used to remove the necrotic tissues and a kirschner wire was used to slightly drill into the exposed bone surface to induce punctate bleeding; in children case, the surgical knife blade was used for the slight bleeding. For cases with tendons exposed, the contaminated tissues around were cleared, with aponeuroses protected carefully. After adequate hemostasis was controlled, the artificial dermis Pelnac was trimmed to the appropriate size and shape to achieve a tension-free closure and interrupted 3-0 or 4-0 absorbable stitch was used to suture the artificial dermis to the surrounding skin. The overlying silicone layer was stabbed with No.11 scalpel blade to facilitate drainage of effusion. Immediate coverage with VSD was applied, for 2–3 weeks. Afterwards, VSD was removed and the wound surface was inspected. Based on the freshness of the wound bed, a second debridement and VSD coverage or artificial dermis coverage was performed.
Correction of 4th and 5th metacarpal synostosis in a skeletally mature hand using de-rotational osteotomies
Published in Case Reports in Plastic Surgery and Hand Surgery, 2022
Christopher D. Liao, Feras Yamin, Roger L. Simpson
Because of the variability in metacarpal synostoses, numerous treatment strategies have been proposed [3]. Our review demonstrated that the most frequently performed surgical approach involves dividing the bony synostosis and separating the metacarpals with an interpositional spacer (Table 2; Figure 5). Options for the spacer include iliac crest bone graft, silicone rubber, costal cartilage, and bone substitutes [3]. Less commonly, Kirschner-wire (K-wire) fixation, tendon transposition, and Hoffman lengtheners were utilized (Table 2; Figure 5). One report in 2005 described the use of two osteotomies: one oblique-transverse and another vertical osteotomy with the placement of two bone blocks [8]. In 1997, Kawabata et al. proposed a hemicallotasis of the radial cortex of the 5th metacarpal as an alternative lengthening strategy [9].
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