Posterior instrumentation through the pedicle is a common surgery. Understanding the morphometry of the pedicle and the anatomy of adjacent neural structures should help decrease the risk of postoperative complications. T1-L5 segments from 15 sets of human vertebrae were separated into individual vertebrae and the morphometric characteristics of the thoracic and lumbar spine and the safe zone of the pedicle were analyzed. T11-L5 segments from six human cadavers were dissected. Measurements were taken from the pedicle to the dura and nerve roots superiorly, inferiorly, medially, and laterally, and the transverse angles of the nerve roots were measured. Pedicles were widest in L5 and narrowest in T4 in the transverse plane, and widest in T11 or T12 and narrowest in T1 in the sagittal plane. In individual pedicle, the ranges of the safe zone width and height were 3.4-7.7 and 8.6-13.7 mm, respectively, in T1-T10; and 7.2-17.8 and 13.9-16.7 mm, respectively, in T11-L5. The transverse angle of the pedicle decreases progressively from T1 to T12, then increase from L1 to L5.In sagittal angle, the largest angle localized at T2 and the smallest at L5. The mean distances from pedicles to adjacent neural structures were greater superiorly and laterally than inferiorly and medially. The lateral distance between nerve root and the pedicle ranged from 2.4 to 9.6 mm in lumbar spine. This study provides potential safe zones for the application of through-pedicle procedures to help decrease the risk of postoperative complications.
Delayed treatment and postoperative varus alignment were major factors contributing to AVNFH in our series. Early treatment and anatomical fixation of displaced SFFN are essential for diminishing the risk of AVNFH development.
Eighteen symptomatic advanced-stage osteochondritis dissecans (OCD) of the talus (Berndt and Harty stages III 7 and IV 11) in 17 patients were treated with multiple autogenous osteochondral cylindrical grafts. The mean time of follow-up was 36 months (range, 25-49). The average age at surgery was 22.7 years (range, 19-34). The mean size of defect of OCD was 13.6 mm x 7.2 mm. Two or three osteochondral grafts (6 or 7 mm in diameter and 15-20 mm in length) were harvested from the superomedial margin of the ipsilateral knee. A partial osteotomy of the medial malleolus or osteotomy of the distal lateral tibia was performed for all cases. Being evaluated by the Freiburg ankle score, 16 of 18 ankles (88.8%) had excellent and two (11.8%) had good results. "Second-look" arthroscopy of 16 ankles revealed consistency of the osteochondral grafts and congruity between grafts and native cartilage in 14 (87.5%), and a softening or fissuring of the osteochondral graft in two. Our results showed that this procedure provided an effective treatment for a symptomatic advanced-stage OCD of the talus.
We aimed to establish an animal model to investigate primary osteoarthritis of the lumbar facet joints after collagenase injection in rats and its effects on chondrocyte apoptosis. We hypothesized that osteoarthritic-like changes would be induced by collagenase injection and that apoptosis of chondrocytes would increase. Collagenase (1, 10, or 50 U) or saline (control) was injected into the lumbar facet joints. The histology and histochemistry of cartilage, synovium, and subchondral bone were examined at 1, 3, and 6 weeks after surgery. Apoptotic cells induced by 1 U of collagenase were quantified using the terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay. Degeneration of the cartilage and changes to the synovium and subchondral bone were dependent on both the doses of collagenase and the time after surgery. There were significantly more apoptotic chondrocytes in collagenase-treated joints than in control (P < 0.001 at 1 and 3 weeks and P < 0.05 at 6 weeks). Thus, lumbar facet joints subjected to collagenase developed osteoarthritic-like changes that could be quantified and compared. This model provides a useful tool for further study on the effects of compounds that have the potential to inhibit enzyme-associated damage to cartilage.
This method provides single-stage posterior decompression, correction, and stabilization on as definitive management for post traumatic kyphosis of the thoracolumbar and lumbar spine.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.