Spinal alignment shift between supine and prone CT imaging occurs frequently and regardless of the anatomic region, risk factors, or pathology

Computer-assisted spine surgery based on preoperative CT imaging may be hampered by sagittal alignment shifts due to an intraoperative switch from supine to prone. In the present study, we systematically analyzed the occurrence and pattern of sagittal spinal alignment shift between corresponding preoperative (supine) and intraoperative (prone) CT imaging in patients that underwent navigated posterior instrumentation between 2014 and 2017. Sagittal alignment across the levels of instrumentation was determined according to the C2 fracture gap (C2-F) and C2 translation (C2-T) in odontoid type 2 fractures, next to the modified Cobb angle (CA), plumbline (PL), and translation (T) in subaxial pathologies. One-hundred and twenty-one patients (C1/C2: n = 17; C3-S1: n = 104) with degenerative (39/121; 32%), oncologic (35/121; 29%), traumatic (34/121; 28%), or infectious (13/121; 11%) pathologies were identified. In the subaxial spine, significant shift occurred in 104/104 (100%) cases (CA: *p = .044; T: *p = .021) compared to only 10/17 (59%) cases that exhibited shift at the C1/C2 level (C2-F: **p = .002; C2-T: *p 5 segments (" increment PL > 5 segments": 4.5 +/- 1.8 mm; " increment PL <= 5 segments": 2 +/- 0.6 mm; *p = .013) or in revision surgery with pre-existing instrumentation (" increment PL presence": 5 +/- 2.6 mm; " increment PL absence": 2.4 +/- 0.7 mm; **p = .007). Interestingly, typical morphological instability risk factors did not influence the degree of shift. In conclusion, intraoperative spinal alignment shift due to a change in patient position should be considered as a cause for inaccuracy during computer-assisted spine surgery and when correcting spinal alignment according to parameters that were planned in other patient positions

Video-assisted thoracoscopic surgery using mobile computed tomography: New method for locating of small lung nodules

BACKGROUND: The O-arm is an intraoperative imaging device that can provide computed tomography images. Surgery for small lung tumors was performed based on intraoperative computed tomography images obtained using the O-arm. This study evaluated the usefulness of the O-arm in thoracic surgery. METHODS: From July 2013 to November 2013, 10 patients with small lung nodules or ground glass nodules underwent video-assisted thoracoscopic surgery using the O-arm. A needle was placed on the visceral pleura near the nodules. After the lung was re-expanded, intraoperative computed tomography was performed using the O-arm. Then, the positional relationship between the needle marking and the tumor was recognized based on the intraoperative computed tomography images, and lung resection was performed. RESULTS: In 9 patients, the tumor could be seen on intraoperative computed tomography images using the O-arm. In 1 patient with a ground glass nodule, the lesion could not be seen, but its location could be inferred by comparison between preoperative and intraoperative computed tomography images. In only 1 patient with a ground glass nodule, a pathological complete resection was not performed. There were no complications related to the use of the O-arm. CONCLUSIONS: The O-arm may be an additional tool to facilitate intraoperative localization and surgical resection of non-palpable lung lesions

The Accuracy of Patient-Specific Spinal Drill Guides Is Non-Inferior to Computer-Assisted Surgery:The Results of a Split-Spine Randomized Controlled Trial

In recent years, patient-specific spinal drill guides (3DPGs) have gained widespread popularity. Several studies have shown that the accuracy of screw insertion with these guides is superior to that obtained using the freehand insertion technique, but there are no studies that make a comparison with computer-assisted surgery (CAS). The aim of this study was to determine whether the accuracy of insertion of spinal screws using 3DPGs is non-inferior to insertion via CAS. A randomized controlled split-spine study was performed in which 3DPG and CAS were randomly assigned to the left or right sides of the spines of patients undergoing fixation surgery. The 3D measured accuracy of screw insertion was the primary study outcome parameter. Sixty screws inserted in 10 patients who completed the study protocol were used for the non-inferiority analysis. The non-inferiority of 3DPG was demonstrated for entry-point accuracy, as the upper margin of the 95% CI (−1.01 mm–0.49 mm) for the difference between the means did not cross the predetermined non-inferiority margin of 1 mm (p < 0.05). We also demonstrated non-inferiority of 3D angular accuracy (p < 0.05), with a 95% CI for the true difference of −2.30◦–1.35◦, not crossing the predetermined non-inferiority margin of 3◦ (p < 0.05). The results of this randomized controlled trial (RCT) showed that 3DPGs provide a non-inferior alternative to CAS in terms of screw insertion accuracy and have considerable potential as a navigational technique in spinal fixation

Factors affecting accuracy and fusion rate in lumbosacral fusion surgery - a preclinical and clinical study

Lumbosacral fusion surgery is indicated in symptomatic degenerative lumbosacral disorder, when the origin of pain is demonstrated to lie within the restricted number of functional spinal units and when the pain is refractory to the conservative treatment, to eliminate painful motion of the spinal units. Inaccurate placement of pedicle screws may cause neurological symptoms, and result in early hardware failure and return of spinal instability symptoms. All spinal instrumentation eventually fails without solid bony fusion, and the presence of symptomatic bony non-union at least a year after fusion surgery is defined as pseudoarthrosis. Bioactive glasses (BAGs) are synthetic, biocompatible, osteoconductive and osteostimulative materials with angiogenic and antibacterial properties, able to bond to bone. In a study of 147 patients and 837 pedicle screws placed due to degenerative lumbosacral spine disorder, 14.3 % breached the pedicle. New neurological symptoms corresponding to the breach were observed in 25.9 % of patients with pedicle breach, and 89.2 % of the symptomatic breaches were either medially or inferiorly. A preclinical controlled study of novel BAG S53P4 putty showed good biocompatibility, slightly higher intramedullary ossification of putty group compared to the control group, and that the binder agent did not disturb formation of new bone in vivo. The interbody fusion rate was 95.8 % with BAG S53P4 putty as bone graft expander with autograft in clinical lumbosacral interbody fusion, indicating at least as good interbody fusion results as the presently used materials. One early operative subsidence remaining unchanged over the study period was observed with putty.Lannerangan luudutusleikkausten tarkkuuteen ja luutumiseen vaikuttavat tekijät Lannerangan luudutusleikkaus voidaan tehdä oireisessa lannerangan rappeumasairaudessa, kun kivun syyn on osoitettu sijaitsevan rajallisessa määrässä selkärangan toiminnallisia yksikköjä ja kun kipu ei vähene leikkauksettomilla hoidoilla. Leikkauksella voidaan poistaa kipua tuottava selkärangan toiminnallisten yksikköjen liike. Epätarkka pedikkeliruuvien asettaminen voi aiheuttaa neurologisia oireita ja johtaa nopeaan kiinnitysosien irtoamiseen ja rangan epätukevuusoireiden palaamiseen. Suuri osa selkärangan kiinnityslaitteista irtoaa lopulta, jollei luutumista kiinnitettyjen kohtien välillä tapahdu. Vuoden kuluttua luudutusleikkauksesta oireista luutumatonta kiinnityskohtaa nimitetään pseudoartroosiksi. Bioaktiiviset lasit ovat synteettisiä, bioyhteensopivia, osteokonduktiivisia ja osteostimulatiivisia materiaaleja, joilla on angiogeenisiä ja antibakteerisia ominaisuuksia, ja ne voivat sitoutua suoraan luuhun. 147 potilaalle lannerangan rappeumasairauden vuoksi asetetut 837 pedikkeliruuvia käsittävän tutkimuksen mukaan 14.3 % ruuveista rikkoi luisen pedikkelin seinämän. 25.9 %:lla potilaista, joilla ruuvi läpäisi pedikkelin seinämän, ilmeni uusia neurologisia oireita, ja 89.2 %:lla oireisista potilaista pedikkeliruuvi läpäisi pedikkelin seinämän mediaalisesti tai inferiorisesti. Prekliinisessä kontrolloidussa tutkimuksessa uudenlainen bioaktiivisesta lasista valmistettu S53P4 luunkorviketahna todettiin bioyhteensopivaksi, ja sen avulla saavutettiin hieman vertailuryhmää parempi luutuminen luuydinontelossa. Tahnan sidosaineen ei eläinkokeessa todettu häiritsevän luun muodostumista. Kliinisessä tutkimuksessa saavutettiin 95.8 %:n luutuminen käytettäessä S53P4 biolasitahnaa yhdessä oman luun kanssa lannerangan nikamasolmujen välisessä luudutuksessa. Siten yhdessä oman luun kanssa käytettäessä S53P4 biolasitahnalla saadaan aikaan vähintään yhtä hyvä nikamasolmujen välinen luutuminen kuin nykyisin käytettävillä synteettisillä luunkorvikkeilla. Tutkimuksessa todettiin yksi leikkauksen yhteydessä tapahtunut nikamasolmujen välisen implantin päätelevyyn painuminen, jonka suuruus ei muuttunut seurantakuvantamisissa

Precision and safety of Multilevel Cervical Transpedicular Screw Fixation with 3D Patient-Specific Guides; A Cadaveric Study

The aim is to design a patient-specific instrument (PSI) for multilevel cervical pedicle screw placement from C2 to C7, as well as verifying reliability and reproducibility. Computed tomography (CT) scans were obtained from 7 cadaveric cervical spines. Using Mimics software, semiautomatic segmentation was performed for each cervical spine, designing a 3D cervical spine bone model in order to plan transpedicular screw fixation. A PSI was designed according to the previously cited with two cannulated chimneys to guide the drill. The guides were 3D printed and surgeries performed at the laboratory. Postoperative scans were obtained to study screw placement. Sixty-eight transpedicular screws were available for study. 61.8% of all screws were within the pedicle or partially breached <4 mm. No differences were observed between cervical levels. None of these screws had neurovascular injury. Of the 27 screws with a grade 3 (screw outside the pedicle; 39.7%), only 2 had perforation of the transverse foramen and none of them would have caused a neural injury. In conclusion, multilevel PSI for cervical pedicle screw is a promising technology that despite showing improvements regarding free-hand technique requires further studies to improve the positioning of the PSI and their accuracy

Medial Pedicle Pivot Point Using Preoperative Computed Tomography Morphometric Measurements for Cervical Pedicle Screw Insertion: A Novel Technique and Case Series

This study describes a new and safe freehand cervical pedicle screw insertion technique using preoperative computed tomography (CT) morphometric measurements as a guide and a medial pedicle pivot point (MPPP) during the procedure. This study included 271 pedicles at 216 cervical spine levels (mean: 4.75 pedicles per patient). A pedicle diameter (PD) ≥ 3.5 mm was the cut-off for pedicle screw fixation. The presence and grade of perforation were detected using postoperative CT scans, where perforations were graded as follows: 0, no perforation; 1, perforation 1.75 mm. The surgical technique involved the use of an MPPP, which was the point at which the lines representing the depth of the lateral mass and total length of the pedicle intersected, deep in the lateral mass. The overall success rate was 96.3% (261/271, Grade 0 or 1 perforations). In total, 54 perforations occurred, among which 44 (81.5%) were Grade 1 and 10 (18.5%) were Grade 2. The most common perforation direction was medial (39/54, 72.2%). The freehand technique for cervical pedicle screw fixation using the MPPP may allow for a safe and accurate procedure in patients with a PD ≥3.5 mm.ope

3D Innovations in Personalized Surgery

Current practice involves the use of 3D surgical planning and patient-specific solutions in multiple surgical areas of expertise. Patient-specific solutions have been endorsed for several years in numerous publications due to their associated benefits around accuracy, safety, and predictability of surgical outcome. The basis of 3D surgical planning is the use of high-quality medical images (e.g., CT, MRI, or PET-scans). The translation from 3D digital planning toward surgical applications was developed hand in hand with a rise in 3D printing applications of multiple biocompatible materials. These technical aspects of medical care require engineers’ or technical physicians’ expertise for optimal safe and effective implementation in daily clinical routines.The aim and scope of this Special Issue is high-tech solutions in personalized surgery, based on 3D technology and, more specifically, bone-related surgery. Full-papers or highly innovative technical notes or (systematic) reviews that relate to innovative personalized surgery are invited. This can include optimization of imaging for 3D VSP, optimization of 3D VSP workflow and its translation toward the surgical procedure, or optimization of personalized implants or devices in relation to bone surgery