Induction of Lumbar Disc Degeneration in Rabbits Through a Transabdominal Approach.

Lower back pain is an extremely common medical issue in populations worldwide. One of the main contributors to lower back pain is intervertebral disc (IVD) degeneration. An ideal animal model of IVD degeneration is essential to study the pathophysiology of lower back pain and investigate potential therapeutic strategies. Rabbit models are reliable, economical, and easily established animal models. The retroperitoneal approach has been widely used to induce IVD degeneration in rabbit models. However, there are reported complications associated with this technique, such as the avulsion of segmental arteries and nerve root injury. In this paper, we aim to show a surgical protocol using needle puncture to establish rabbit lumbar disc degeneration via a transabdominal approach. Consequently, radiological checks and histological analyses indicated that lumbar disc degeneration was successfully established in rabbits. This surgical protocol presents the precise location of target discs and high reproducibility of IVD degeneration models with fewer complications.

Anterior Cervical Hybrid Decompression and Fusion Surgery to Treat Multilevel Cervical Spondylotic Myelopathy.

Cervical spondylotic myelopathy (CSM) is a common disease resulting from intervertebral disc herniation, ossification of the posterior longitudinal ligament, and other pathological changes that cause spinal cord compression. CSM progresses insidiously with mild upper-limb numbness, which patients tend to ignore. As the condition worsens, the patients may experience a limp, limited fine motor activity, and eventually, a loss of daily activity. Conservative treatments, such as physical therapy and medication, are frequently ineffective for CSM. Once surgery is deemed to be required, decompression surgery is the best option. So far, both anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) have been commonly used to treat CSM. In addition, a type of hybrid procedure that combines ACDF with ACCF has been used to treat some CSM cases and achieved satisfying results. Thus, this study aims to introduce this hybrid surgical technique and advocate for it based on its patient success.

The role of biomechanical factors in models of intervertebral disc degeneration across multiple length scales.

Low back pain is the leading cause of disability, producing a substantial socio-economic burden on healthcare systems worldwide. Intervertebral disc (IVD) degeneration is a primary cause of lower back pain, and while regenerative therapies aimed at full functional recovery of the disc have been developed in recent years, no commercially available, approved devices or therapies for the regeneration of the IVD currently exist. In the development of these new approaches, numerous models for mechanical stimulation and preclinical assessment, including in vitro cell studies using microfluidics, ex vivo organ studies coupled with bioreactors and mechanical testing rigs, and in vivo testing in a variety of large and small animals, have emerged. These approaches have provided different capabilities, certainly improving the preclinical evaluation of these regenerative therapies, but challenges within the research environment, and compromises relating to non-representative mechanical stimulation and unrealistic test conditions, remain to be resolved. In this review, insights into the ideal characteristics of a disc model for the testing of IVD regenerative approaches are first assessed. Key learnings from in vivo, ex vivo, and in vitro IVD models under mechanical loading stimulation to date are presented alongside the merits and limitations of each model based on the physiological resemblance to the human IVD environment (biological and mechanical) as well as the possible feedback and output measurements for each approach. When moving from simplified in vitro models to ex vivo and in vivo approaches, the complexity increases resulting in less controllable models but providing a better representation of the physiological environment. Although cost, time, and ethical constraints are dependent on each approach, they escalate with the model complexity. These constraints are discussed and weighted as part of the characteristics of each model.

Spinal Shortening Surgery for Lumbosacral Nerve Bowstring Disease: A Surgical Technique.

Lumbosacral nerve bowstring disease (LNBD) is a syndrome of neurological symptoms caused by differences in the development speed of lumbosacral bone tissue and nerve tissue, which result in a longitudinal stretch of the slow-growing nerve tissue. LNBD is usually caused by congenital factors and accompanied by other lumbosacral diseases, such as lumbar spinal stenosis, lumbar spondylolisthesis, and iatrogenic factors. The main symptoms of LNBD are lower extremity neurological symptoms and fecal dysfunction. The conservative treatment of LNBD includes rest, functional exercise, and drug therapy, but it usually fails to achieve satisfactory clinical results. Few studies have reported on the surgical treatment of LNBD. In this study, we used posterior lumbar interbody fusion (PLIF) to shorten the spine (0.6-0.8mm/segment). This reduced the axial tension of the lumbosacral nerves and relieved the patient's neurological symptoms. We report on the case of a 45 year old male patient whose main symptoms were left lower extremity pain, decreased muscle strength, and hypoesthesia. The above symptoms were significantly relieved 6 months after surgery.

Incidence and risk factors of lumbar plexus injury in patients undergoing oblique lumbar interbody fusion surgery.

PURPOSE: To investigate the incidence and risk factors of lumbar plexus injury (LPI) after oblique lumbar interbody fusion (OLIF) surgery. METHODS: A total of 110 patients who underwent OLIF surgery between January 2017 and January 2021 were retrospectively reviewed. Patients were divided into two groups: the group with LPI (LPI group) and the group without LPI (non-LPI group). The baseline demographic data, surgical variables and radiographic parameters were compared and analyzed between these two groups. RESULTS: Among all participants, 13 (8.5%) had LPI-related symptoms postoperatively (short-term), and 6 (5.5%) did not fully recover after one year (long-term). Statistically, there were no significant differences in the baseline demographic data, surgery duration, intraoperative blood loss, preoperative diagnosis, surgical procedures used and incision length. Compared with the non-LPI group, patients in the LPI group had a narrower OLIF channel space. In LPI group, the anterior edge of left psoas major muscle overpasses the anterior edge of surgical intervertebral disk (IVD) on axial MRI. Logistic regression analysis revealed that narrow OLIF channel space and the anterior edge of left psoas major muscle overpassing the anterior edge of surgical IVD on axial MRI were independently associated with both short-term and long-term LPI. CONCLUSION: Narrow OLIF channel space and the anterior edge of left psoas major muscle overpassing the anterior edge of surgical IVD are significant risk factors of OLIF surgery-related LPI. Surgeons should use preoperative imaging to adequately assess these risk factors to reduce the occurrence of LPI.

Treatment of three-level cervical spondylotic myelopathy using ACDF or a combination of ACDF and ACCF.

Objectives: This study aims to compare the outcomes between two anterior decompression and fusion techniques to treat multilevel cervical spondylotic myelopathy (MCSM). Methods: After the screening for eligibility, a total of 66 patients were admitted to this study. These participants underwent anterior surgeries due to MCSM in our hospital between June 2016 and July 2018. All participants underwent either the anterior cervical discectomy and fusion (ACDF) surgery (ACDF group) or the combination of ACDF and anterior cervical corpectomy and fusion (ACCF), which was the anterior cervical hybrid decompression and fusion (ACHDF) surgery group. All the patients were followed up ≥18 months, the average latest followed up time was 23.64 (±2.69) months. The length of hospitalization, operation time, blood loss, visual analog scale (VAS), Japanese Orthopaedic Association (JOA) score, improvement rate, Hounsfield units (HU) of C3-C7, cobb angle, and anterior column height of fusion levels pre and post operation were analyzed. Results: There were no statistical differences between the ACDF and ACHDF groups regarding the length of hospitalization, operation time, blood loss, HU of C3-C7, VAS, JOA score, improvement rate, cobb angle, and anterior column height in fusion levels in pre-operation and 3 months after operation (all P > 0.05). However, compared with the ACHDF group, the ACDF group achieved significantly better improvement in the anterior column height of fusion levels in the final 18-29 months post-operatively (P < 0.05). Conclusions: Both approaches of ACDF alone and a combination of ACDF and ACCF can achieve satisfactory outcomes in the treatment of MCSM, but ACDF has better outcomes in maintaining anterior column height of fusion levels.

Correlation Analysis between Tamoxifen and Lumbar Intervertebral Disc Degeneration: A Retrospective Case-Control Study.

Objectives: To investigate the correlation between tamoxifen (TAM) and lumbar intervertebral disc (IVD) degeneration (IVDD). Methods: The patients who visited the department of spine surgery from January 2015 to December 2020 were retrospectively reviewed. Those with a history of breast cancer surgery were identified and their data were collected. These data included patients' age, body mass index (BMI), menstrual history, postoperative history, drug treatment plan, and imaging data. The participants were divided into the TAM group and the non-TAM group. Lumbar IVDD was assessed by lumbar lordosis (LL), vertebral CT density, lumbar disc height index (DHI), Modic changes, and modified Pfirrmann grading score. SPSS 20 was used for statistical analysis. Results: A total of 75 patients were included in this study, 46 patients in the TAM group and 29 patients in the non-TAM group. No significant differences were present in age, BMI, postoperative history, LL, and vertebral CT density between the two groups. The DHI of L1/2 and L2/3 in the TAM group was lower compared to the non-TAM group (P=0.038 and P=0.034, respectively), while comparisons regarding the DHI of L3/4, L4/5, and L5/S1, and the average DHI between TAM and non-TAM groups were not significant. The modified Pfirrmann grading scores of the L1/2 and L2/3 IVDs in the TAM group were higher than those in the non-TAM group (P=0.004 and P=0.025, respectively). Comparisons of L3/4, L4/5, and L5/S1 between the two groups were not significant. The comparisons regarding the occurrence of Modic changes did not show a significant difference between the TAM and non-TAM groups. Conclusions: This study indicates that there might be some positive correlation between TAM use and lumbar IVDD. In particular, the degeneration of L1/2 and L2/3 has shown a correlation with TAM use.

The treatment effect of posterior lumbar fusion surgery on patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis.

Purpose: The purpose of this study is to investigate the clinical effect of posterior lumbar fusion surgery on patients who suffer from lumbar disc herniation concurrent with peroneal nerve paralysis. Methods: The patients suffering from peroneal nerve paralysis and undergoing posterior lumbar fusion surgery between January 2012 and December 2019 were retrospectively reviewed. The data of the identified patients were then collected and processed. All patients were followed up post-operatively after discharge from the hospital. The data was analyzed in terms of Oswestry disability index (ODI), visual analogue scale (VAS) score, and relative lower-limb muscle strength. Results: A total of 87 patients (52 males and 35 females) aged 54 ± 11 years met the inclusion criteria for this study. These patients stayed in hospital for 16 ± 6 days and were followed up for 81 ± 24 months. Data analysis showed that muscle strength of the tibialis anterior and extensor digitorum significantly recovered at the last follow-up with a grade of 3 (median), compared to grade 0 at admission (p < 0.001). Furthermore, the median VAS score decreased to 1 at the last follow-up from 6 at admission (p < 0.001), and the ODI greatly improved with 10% (median) at the last follow-up, while it was 58% at admission (p < 0.001). The ODI improvement rate was 60% on average at the last follow-up. Multivariate regression analysis regarding the ODI and muscle strength improvement rates showed that advanced age was a risk factor for postoperative recovery. Conclusions: Most of the patients suffering from lumbar disc herniation concurrent with peroneal nerve paralysis can improve after undergoing posterior lumbar fusion surgery, but few can reach full recovery. Advanced age might be a risk factor that affects the prognosis of these patients after surgery.