To observe the regional anatomy of the lumbar artery (LA) associated with the extrapedicular approach applied during percutaneous vertebroplasty (PVP) and percutaneous kyphoplasty (PKP), we collected 78 samples of abdominal computed tomography angiography imaging data. We measured the nearest distance from the center of the vertebral body puncture point to the LA (distance VBPP-LA, D VBPP-LA ). According to the D VBPP-LA , four zones, Zone I, Zone II, Zone III and Zone IV, were identified. LAs that passed through these zones were called Type I, Type II, Type III and Type IV LAs, respectively. A portion of the lumbar vertebrae had an intersegmental branch that originated from the upper segmental LA and extended longitudinally across the lateral wall of the pedicle; it was called Type V LA. Compared with the D VBPP-LA in L1, L2, L3 and L4, the overall difference and between-group differences were significant ( P < 0.05). In L1, L2, L3, L4 and L5, there were 8, 4, 4, 0 and 1 Type I LAs, respectively. There were no Type V LAs in L1 and L2, but there were 2, 16 and 26 Type V LAs in L3, L4 and L5, respectively. In L1-L5, the numbers of Type I LA plus Type V LA were 8, 4, 6, 16 and 27, and the presence ratios were 5.1%, 2.6%, 5.6%, 10.3% and 17.3%, respectively. In L4 and L5, the male presence ratios of Type I LA plus Type V LA were 7.1% and 10.7%, respectively, and the female presence ratios were 13.9% and 25.0%, respectively. Thus, extrapedicular PVP (PKP) in lumbar vertebrae had a risk of LA injury and was not suggested for use in L4 and L5, especially in female patients.

Aim. This report introduces extrapedicular infiltration anesthesia as an improved method of local anesthesia for unipedicular percutaneous vertebroplasty or percutaneous kyphoplasty. Method. From March 2015 to March 2016, 44 patients (11 males and 33 females) with osteoporotic vertebral compression fractures with a mean age of 71.4 ± 8.8 years (range: 60 to 89) received percutaneous vertebroplasty or percutaneous kyphoplasty. 24 patients were managed with conventional local infiltration anesthesia (CLIA) and 20 patients with both CLIA and extrapedicular infiltration anesthesia (EPIA). Patients evaluated intraoperative pain by means of the visual analogue score and were monitored during the procedure for additional sedative analgesia needs and for adverse nerve root effects. Results. VAS of CLIA + EPIA and CLIA group was 2.5 ± 0.7 and 4.3 ± 1.0, respectively, and there was significant difference (P = 0.001). In CLIA group, 1 patient required additional sedative analgesia, but in CLIA + EPIA group, no patients required that. In the two groups, no adverse nerve root effects were noted. Summary. Extrapedicular infiltration anesthesia provided good local anesthetic effects without significant complications. This method deserves further consideration for use in unipedicular percutaneous vertebroplasty and percutaneous kyphoplasty.

Background At present, bicortical pedicle screws (BPSs) are not used clinically because they carry the potential risk of damaging the prevertebral great vessels (PGVs). The authors observed the anatomical relationship between the PGVs and simulated BPSs at different transverse screw angles (TSAs), exploring the insertion method of the BPS. Methods Computed tomography angiography (CTA) images from 65 adults were collected. A total of 4–5 TSAs of the BPSs were simulated on the left and right sides of L1-L5 (L1-L3: 0°, 5°, 10°, 15°; L4-L5: 0°, 5°, 10°, 15°, 20°). There were three types of distances from the anterior vertebral cortex (AVC) to the PGVs (D AVC-PGV ); D AVC-PGV < 0.50 cm , D AVC-PGV ≥ 0.50 cm , and D AVC-PGV↑ ; these distances represented close, distant, and noncontact PGV, respectively. Results The ratio of every type of PGV was calculated, and the appropriate TSA of the BPS was recommended. In L1, the recommended left TSA of the BPS was 0°, and the ratio of the close PGV was 7.69%, while the recommended right TSA was 0°-10°, and the ratio of the close PGV was 1.54–4.62%. In L2, the recommended left TSA of the BPS was 0° and the ratio of the close PGV was 1.54%, while the recommended right TSA was 0°-15° and the ratio of the close PGV was 3.08–9.23%. In L3, the recommended left TSA was 0°-5°, and the ratio of the close PGV was 1.54–4.62%. In L4, the recommended left TSA was 0°, and the ratio of the close PGV was 4.62%. BPS use was not recommended on the right side of either L3 or L4 or on the either side of L5. Conclusions From the anatomical perspective of the PGVs, BPSs were not suitable for insertion into every lumbar vertebra. Furthermore, the recommended methods for inserting BPSs were different in L1-L4.

Anterior lumbar interbody fusion (ALIF) followed by posterior pedicle screw fixation (PSF) in a second procedure is mostly used to implement lumbar spine fusion. ALIF followed by anterior lumbar screw-plate has a lot of advantages, but its biomechanical stability requires confirmation. This study evaluated the biomechanical stability of a novel anterior lumbar locked screw-plate (ALLSP) by comparison with posterior lumbar PSF. Twelve fresh human cadaveric lumbar specimens (L4-L5) were assigned to four groups: ALIF+PSF group, ALIF+ALLSP (both fixed) group, ALIF group and an untreated control (both non-fixed) group. The first three groups received implantation of a rectangular titanium cage. Tests under axial compression, flexion, extension, lateral bending, or rotation showed that the fixed groups had significantly stronger stability than the non-fixed groups (P=0.000 for all). The ALIF+ALLSP group had significantly greater axial stiffness under applied axial compression and significantly less angular displacement under rotational forces than the ALIF+PSF group. The angular displacement of the ALIF+ALLSP group was less under flexion than that of the ALIF+PSF, and the angular displacement under lateral bending and extension was greater, but these differences were not statistically significant. In summary, the ALLSP conforms to the anterior lumbar spine and has good biomechanical stability. It is a reliable choice for enhancing the stability of ALIF.

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