Lateral lumbar interbody fusion in adult spine deformity - A review of literature.

INTRODUCTION: Surgery for adult spine deformity presents a challenging issue for spinal surgeons with high morbidity rates reported in the literature. The minimally invasive lateral approach aims at reducing these complications while maintaining similar outcomes as associated with open spinal surgeries. The aim of this paper is to review the literature on the use of lateral lumbar interbody fusion in the cases of adult spinal deformity. METHODS: A literature review was done using the healthcare database Advanced Research on NICE and NHS website using Medline. Search terms were "XLIF" or "LLIF" or "DLIF" or "lateral lumbar interbody fusion" or "minimal invasive lateral fusion" and "adult spinal deformity" or "spinal deformity". RESULTS: A total of 417 studies were considered for the review and 44 studies were shortlisted after going through the selection criteria. The data of 1722 patients and 4057 fusion levels were analysed for this review. The mean age of the patients was 65.18 years with L4/5 being the most common level fused in this review. We found significant improvement in the radiological parameters (lordosis, scoliosis, and disk height) in the pooled data. Transient neurological symptoms and cage subsidence were the two most common complications reported. CONCLUSION: LLIF is a safe and effective approach in managing adult spinal deformity with low morbidity and acceptable complication rates. It can be used alone for lower grades of deformity and as an adjuvant procedure to decrease the magnitude of open surgeries in high-grade deformities.

A systematic review of MIS and open decompression surgery for spinal metastases in the last two decades.

OBJECTIVE: The primary intention of this review being to produce an updated systematic review of the literature on published outcomes of decompressive surgery for metastatic spinal disease including metastatic spinal cord compression, using techniques of MIS and open decompressive surgery. METHODS: The authors conducted database searches of OVID MEDLINE and EMBASE identifying those studies that reported clinical outcomes, surgical techniques used along with associated complications when decompressive surgery was employed for metastatic spinal tumors. Both retrospective and prospective studies were analysed. Articles were assessed to ensure the required inclusion criteria was met. Articles were then categorised and tabulated based on the following reported outcomes: predictors of survival, predictors of ambulation or motor function, surgical technique, neurological function, and miscellaneous outcomes. RESULTS: 2654 citations were retrieved from databases, of these 31 met the inclusion criteria. 5 studies were prospective, the remaining 26 were retrospective. Publication years ranged from 2000 to 2020. Study size ranged from 30 to 914 patients. The most common primary tumors identified were lungs, breast, prostate and renal cancers. One study ( Lo and Yang, 2017)13 reported that in those patients with motor deficit, survival was significantly improved when surgery was performed within 7 days of the development of motor deficit compared to situations when surgery was carried out 7 days after onset. This was the only study that showed that the timing of surgery plays a significant role w.r.t. survival following the onset of spinal cord compression symptoms. Four articles identified that a pre-operative intact motor function and or ambulatory status conferred a higher likelihood of a better post-operative outcome, not just in relation to survival but also in relation to post-operative ambulation as well as a greater tendency towards suitability for adjuvant treatment. Even for the same scoring system e.g. tokuhashi and its effectiveness in predicting survival, results from different studies varied in their outcome. The Karnofsky Performance Status (KPS) being the most commonly used tool to assess functional impairment, the Eastern Cooperative Oncology Group (ECOG) performance status being used in two studies. 23 studies identified an improvement in neurological function following surgery. The most common functional scale used to assess neurological outcome was the Frankel scale, 3 studies used the American Spinal Injury Association (ASIA) impairment scale for this purpose. Wound problems including infection and dehiscence appeared to be the most commonly reported surgical complication. (25 studies). The most commonly used surgical technique involved a posterior approach with decompression, with or without stabilisation. Less commonly employed techniques included percutaneous pedicle screw fixation associated with or without mini-decompression as well as anterior approaches involving corpectomy and instrumentation. 9 studies included in their data, the effect of radiation therapy in combination with surgery or as a comparison used as an alternative to surgery in spinal metastases. CONCLUSIONS: We provide a systematic literature review on the outcomes of decompressive surgery for spinal metastases. We analyse survival data, motor function, neurological function, as well as the techniques of surgery used. Where appropriate complications of surgery are also highlighted. It is the authors' intention to provide the reader with a reference text where this information is ready to hand, allowing for the consideration of means and methods to improve and optimise the standard of care in patients undergoing surgical intervention for metastatic spinal disease.

Current Treatment Options for Intervertebral Disc Pathologies.

The complex structure of the intervertebral disc within the spine is well suited to its mechanical function. However, it is also prone to degeneration, which is associated with various clinical symptoms and conditions, ranging from disc herniation to back pain to spinal stenosis. Most patients' conditions are managed conservatively but a small proportion progress to having surgery. This may be decompression (to remove tissue such as the disc, bone, or hypertrophic ligaments impinging on nerves) or fusion of the normally mobile intervertebral joint to immobilize it and so reduce pain. These used to involve fairly major surgical procedures, but in the past decade there has been much progress to make the surgery more refined and less invasive, for example using endoscopic approaches. Simultaneously, the research world has been studying and developing tissue engineering and cellular techniques for attempting to regenerate the intervertebral disc, whether simply the central nucleus pulposus or a complete intricate assembly to replicate the native structure of this and the surrounding annulus fibrosus, cartilage endplate, and bone. To date, none of the complex entities have been trialed, while cellular approaches are easier to utilize, have progressed to clinical trials, and may offer a better solution.

Is Osteogenic Differentiation of Human Nucleus Pulposus Cells a Possibility for Biological Spinal Fusion?

OBJECTIVE: The purpose of this study was to investigate whether a simple, biologically robust method for inducing calcification of degenerate intervertebral discs (IVD) could be developed to provide an alternative treatment for patients requiring spinal fusion. DESIGN: Nucleus pulposus (NP) cells isolated from 14 human IVDs were cultured in monolayer and exposed to osteogenic medium, 1,25-dihydroxyvitamin D3 (VitD3), parathyroid hormone (PTH), and bone morphogenic proteins (BMPs) 2/7 to determine if they could become osteogenic. Similarly explant cultures of IVDs from 11 patients were cultured in osteogenic media with and without prior exposure to VitD3 and BMP-2. Osteogenic differentiation was assessed by alkaline phosphatase activity and areas of calcification identified by alizarin red or von Kossa staining. Expression of osteogenic genes during monolayer culture was determined using polymerase chain reaction and explant tissues assessed for BMP inhibitors. Human bone marrow-derived mesenchymal stromal cells (MSCs) were used for comparison. RESULTS: Standard osteogenic media was optimum for promoting mineralization by human NP cells in monolayer. Some osteogenic differentiation was observed with 10 nM VitD3, but none following application of PTH or BMPs. Regions of calcification were detected in 2 of the eleven IVD tissue explants, one cultured in osteogenic media and one with the addition of VitD3 and BMP-2. CONCLUSIONS: Human NP cells can become osteogenic in monolayer and calcification of the extracellular matrix can also occur, although not consistently. Inhibitory factors within either the cells or the extracellular matrix may hinder osteogenesis, indicating that a robust biological fusion at this time requires further optimization.

Minimally invasive spinal surgery for the management of symptomatic spinal metastasis.

INTRODUCTION: Symptomatic metastatic spinal disease is on the increase. Minimally invasive spinal surgery has been associated with a lower complication profile when compared to traditional open methods; however there is paucity of literature evaluating the place of percutaneous pedicle screw fixation (PPSF) in the management of spinal metastases. The purpose of the study is to assess the efficacy of Minimally Invasive Spine Surgery (MISS) using PPSF with or without mini-decompression in the management of symptomatic spinal metastases. MATERIAL AND METHODS: This is a single institution prospective study of 51 consecutive patients with metastatic spinal disease treated with PPSF. Patients presenting with pathological compression fractures and mechanical instability had PPSF, and those with radiological and/or clinical metastatic spinal cord compression (MSCC) underwent an additional mini-decompression. Data collected included patient demographics, Karnofsky's performance status (KPS), pain scores and neurology. Other data included number and location of involved levels, number of instrumented levels, blood loss, accuracy of screw placement and complications. RESULTS: Of the 51 patients, 49 could be successfully treated with MISS (26 females and 23 males). 26 patients (55%) required a mini-decompression. 27 patients (55%) had improvement in KPS by at least 10 points (p < 0.0005). Only 2 patients (4%) had a worsening of KPS, due to other coexisting problems. Six of the 13 patients improved their neurology by one Frankel grade following surgery and 95% reported improvement in pain. Mean blood loss was 92mls for the fixation only group and 222mls for those requiring mini-decompression, with no other differences between these two surgical groups. Screw positioning was excellent in 91%, with 98% having uncompromised bony hold. Only two patients required revision surgery for aseptic loosening. CONCLUSION: MISS using PPSF is a safe and reproducible technique that maintains or improves functional outcome in the vast majority of patients presenting with spinal metastases.

Only walking matters-assessment following lumbar stenosis decompression.

PURPOSE: Multiple outcome measures exist to evaluate the outcomes of spinal decompression surgery; however, these tend to be complex and are difficult to express to the patient pre-operatively to accurately guide their expectations. We present outcomes, in terms of walking distance measurement, of a prospective single surgeon series of 76 consecutive patients with spinal stenosis. METHODS: 76 patients (mean age 68.8 years; 48-91 years) had decompression surgery using spinous process osteotomy. Accurate measurement of walking distance was used as an outcome measure, and factors that affect it were evaluated. Walking distance was measured pre-operatively, post-operatively and at 3 months follow-up using a measuring wheel. The minimum follow-up was 5 years. RESULTS: The mean distances walked were 78.1, 419.9 and 1285 m, respectively. Pre-operative disc height (p = 0.023) and male gender (p = 0.039) predicted a significant improvement in walking distance, while age (p = 0.23), ASA grade (p = 0.39) and the number of levels operated on (p = 0.89) did not significantly affect the increase in walking distance. 12 patients experienced post-operative complications (15.8%), and at last clinical follow-up (6.3 years, 5.1-6.9 years) 27 patients (35.5%) had residual leg symptoms and 8 had undergone further revision procedures (10.5%). CONCLUSION: This study demonstrates that walking distance is an accurate and accessible method of determining surgical outcomes.

The outcome of decompression alone for lumbar spinal stenosis with degenerative spondylolisthesis.

PURPOSE: Lumbar spinal stenosis in the presence of degenerative spondylolisthesis is generally treated by means of surgery. The role of lumbar decompression without fusion is not clear. Therefore, the aim of this study was to assess whether patients who undergo decompression alone have a favourable outcome without the need for a subsequent fusion. METHODS: This is a prospective cohort study with single blinding of 83 consecutive patients with lumbar stenosis and degenerative spondylolisthesis treated by decompression, without fusion, using a spinous process osteotomy. Blinded observers collected pre- and post-operative Oswestry Disability Index (ODI), EuroQol Five Dimensions (EQ-5D), and visual analogue scale (VAS) for back and leg pain scores prospectively. Failures for this study were those patients who required a subsequent lumbar fusion procedure at the decompressed levels. Statistical analysis was performed using paired t test and Mann-Whitney test. RESULTS: There were 36 males and 47 females with a mean age of 66 years (range 35-82). The mean follow-up was 36 months (range 19-48 months). The mean pre-operative ODI, EQ-5D, and VAS scores were 52 [standard deviation (SD) 18], 0.25 (SD 0.30), and 61 (SD 22), respectively. All mean scores improved post-operatively to 38 (SD 23), 0.54 (SD 0.34) and 36 (SD 27), respectively. There was a statistically significant improvement in all scores (p ≤ 0.0001). Nine patients (11 %) required a subsequent fusion procedure and five patients (6 %) required revision decompression surgery alone. CONCLUSION: Our study's results show that a lumbar decompression procedure without arthrodesis in a consecutive cohort of patients with lumbar spinal stenosis with degenerative spondylolisthesis had a significant post-operative improvement in ODI, EQ-5D, and VAS. The rate of post-operative instability and subsequent fusion is not high. Only one in 10 patients in this group ended up needing a subsequent fusion at a mean follow-up of 36 months, indicating that fusion is not always necessary in these patients.

Mesenchymal stromal cells derived from whole human umbilical cord exhibit similar properties to those derived from Wharton's jelly and bone marrow.

Mesenchymal stromal cells (MSC) can be isolated from several regions of human umbilical cords, including Wharton's jelly (WJ), artery, vein or cord lining. These MSC appear to be immune privileged and are promising candidates for cell therapy. However, isolating MSC from WJ, artery, vein or cord lining requires time-consuming tissue dissection. MSC can be obtained easily via briefly digesting complete segments of the umbilical cord, likely containing heterogenous or mixed populations of MSC (MC-MSC). MC-MSC are generally less well characterized than WJ-MSC, but nevertheless represent a potentially valuable population of MSC. This study aimed to further characterize MC-MSC in comparison to WJ-MSC and also the better-characterized bone marrow-derived MSC (BM-MSC). MC-MSC proliferated faster, with significantly faster doubling times reaching passage one 8.8 days sooner and surviving longer in culture than WJ-MSC. All MSC retained the safety aspect of reducing telomere length with increasing passage number. MSC were also assessed for their ability to suppress T-cell proliferation and for the production of key markers of pluripotency, embryonic stem cells, tolerogenicity (CD40, CD80, CD86 and HLA-DR) and immunomodulation (indoleamine 2,3-dioxygenase [IDO] and HLA-G). The MC-MSC population displayed all of the positive attributes of WJ-MSC and BM-MSC, but they were more efficient to obtain and underwent more population doublings than from WJ, suggesting that MC-MSC are promising candidates for allogeneic cell therapy in regenerative medicine.

Temporal Analyses of the Response of Intervertebral Disc Cells and Mesenchymal Stem Cells to Nutrient Deprivation.

Much emphasis has been placed recently on the repair of degenerate discs using implanted cells, such as disc cells or bone marrow derived mesenchymal stem cells (MSCs). This study examines the temporal response of bovine and human nucleus pulposus (NP) cells and MSCs cultured in monolayer following exposure to altered levels of glucose (0, 3.15, and 4.5 g/L) and foetal bovine serum (0, 10, and 20%) using an automated time-lapse imaging system. NP cells were also exposed to the cell death inducers, hydrogen peroxide and staurosporine, in comparison to serum starvation. We have demonstrated that human NP cells show an initial "shock" response to reduced nutrition (glucose). However, as time progresses, NP cells supplemented with serum recover with minimal evidence of cell death. Human NP cells show no evidence of proliferation in response to nutrient supplementation, whereas MSCs showed greater response to increased nutrition. When specifically inducing NP cell death with hydrogen peroxide and staurosporine, as expected, the cell number declined. These results support the concept that implanted NP cells or MSCs may be capable of survival in the nutrient-poor environment of the degenerate human disc, which has important clinical implications for the development of IVD cell therapies.

Incidence of numerical variants and transitional lumbosacral vertebrae on whole-spine MRI.

OBJECTIVES: This study sets out to prospectively investigate the incidence of transitional vertebrae and numerical variants of the spine. MATERIALS AND METHODS: Over a period of 28 months, MRIs of the whole spine were prospectively evaluated for the presence of transitional lumbosacral vertebrae and numerical variants of the spine. RESULTS: MRI of the whole spine was evaluated in 420 patients, comprising 211 female and 209 male subjects. Two patients had more complex anomalies. Lumbosacral transitional vertebrae were seen in 12 patients: eight sacralised L5 (3 male, 5 female) and four lumbarised S1 (3 male, 1 female). The incidence of transitional vertebrae was approximately 3.3. % (14/418). Thirty-two (7.7 %) of 418 patients had numerical variants of mobile vertebrae of the spine without transitional vertebrae. The number of mobile vertebrae was increased by one in 18 patients (12 male, 6 female), and the number was decreased by one in 14 patients (4 male, 10 female). CONCLUSIONS: Numerical variants of the spine are common, and were found to be almost 2.5 times as frequent as transitional lumbosacral vertebrae in the study population. Only whole-spine imaging can identify numerical variants and the anatomical nature of transitional vertebrae. The tendency is toward an increased number of mobile vertebrae in men and a decreased number in women. Main messages • Numerical variants of the spine are more common than transitional vertebrae. • Spinal numerical variants can be reliably identified only with whole-spine imaging. • Increased numbers of vertebrae are more common in men than women. • Transitional lumbosacral vertebrae occurred in about 3.3 % of the study population. • The incidence of numerical variants of the spine was about 7.7 %.

Viability, growth kinetics and stem cell markers of single and clustered cells in human intervertebral discs: implications for regenerative therapies.

PURPOSE: There is much interest in the development of a cellular therapy for the repair or regeneration of degenerate intervertebral discs (IVDs) utilising autologous cells, with some trials already underway. Clusters of cells are commonly found in degenerate IVDs and are formed via cell proliferation, possibly as a repair response. We investigated whether these clusters may be more suitable as a source of cells for biological repair than the single cells in the IVD. METHODS: Discs were obtained at surgery from 95 patients and used to assess the cell viability, growth kinetics and stem or progenitor cell markers in both the single and clustered cell populations. RESULTS: Sixty-nine percent (±15) of cells in disc tissue were viable. The clustered cell population consistently proliferated more slowly in monolayer than single cells, although this difference was only significant at P0-1 and P3-4. Both populations exhibited progenitor or notochordal cell markers [chondroitin sulphate epitopes (3B3(-), 7D4, 4C3 and 6C3), Notch-1, cytokeratin 8 and 19] via immunohistochemical examination; stem cell markers assessed with flow cytometry (CD73, 90 and 105 positivity) were similar to those seen on bone marrow-derived mesenchymal stem cells. CONCLUSIONS: These results confirm those of previous studies indicating that progenitor or stem cells reside in adult human intervertebral discs. However, although the cell clusters have arisen via proliferation, there appear to be no greater incidence of these progenitor cells within clusters compared to single cells. Rather, since they proliferate more slowly in vitro than the single cell population, it may be beneficial to avoid the use of clustered cells when sourcing autologous cells for regenerative therapies.

Isolation and characterisation of mesenchymal stem cells from different regions of the human umbilical cord.

Umbilical cords as a source of stem cells are of increasing interest for cell therapies as they present little ethical consideration and are reported to contain immune privileged cells which may be suitable for allogeneic based therapies. Mesenchymal stem cells (MSCs) sourced from several different cord regions, including artery, vein, cord lining, and Wharton's jelly, are described in the literature. However, no one study has yet isolated and characterised MSCs from all regions of the same cord to determine the most suitable cells for cell based therapeutics.

Does walking change the Romberg sign?

The Romberg sign helps demonstrate loss of postural control as a result of severely compromised proprioception. There is still no standard approach to applying the Romberg test in clinical neurology and the criteria for and interpretation of an abnormal result continue to be debated. The value of this sign and its adaptation when walking was evaluated. Detailed clinical examination of 50 consecutive patients of cervical myelopathy was performed prospectively. For the walking Romberg sign, patients were asked to walk 5 m with their eyes open. This was repeated with their eyes closed. Swaying, feeling of instability or inability to complete the walk with eyes closed was interpreted as a positive walking Romberg sign. This test was compared to common clinical signs to evaluate its relevance. Whilst the Hoffman's reflex (79%) was the most prevalent sign seen, the walking Romberg sign was actually present in 74.5% of the cases. The traditional Romberg test was positive in 17 cases and 16 of these had the walking Romberg positive as well. Another 21 patients had a positive walking Romberg test. Though not statistically significant, the mean 30 m walking times were slower in patients with traditional Romberg test than in those with positive walking Romberg test and fastest in those with neither of these tests positive. The combination of either Hoffman's reflex and/or walking Romberg was positive in 96% of patients. The walking Romberg sign is more useful than the traditional Romberg test as it shows evidence of a proprioceptive gait deficit in significantly more patients with cervical myelopathy than is found on conventional neurological examination. The combination of Hoffman's reflex and walking Romberg sign has a potential as useful screening tests to detect clinically significant cervical myelopathy.

Coccygectomy for coccydynia: case series and review of literature.

STUDY DESIGN: This is a case series in which case notes review and telephone interview update were used to assess the outcome following coccygectomy. OBJECTIVE: To correlate the clinical results of coccygectomy with histology and discography of the sacrococcygeal and intercoccygeal segments. SUMMARY OF BACKGROUND DATA: Clinicians regard chronic disabling pain in the sacrococcygeal region with much dismay because of the reputed unpredictability of the treatment outcome. METHODS: A total of 38 patients had coccygectomy for intractable coccydynia, and 31 were available for follow-up. The excised specimen with intact sacrococcygeal joint was sent for histologic examination in 22 patients. There were 6 patients investigated using sacrococcygeal and intercoccygeal discography. RESULTS: Mean postoperative follow-up was 6.75 years (range 2-16). There were 16 patients who benefited highly from the surgery, and 6 benefited to some extent, giving an overall beneficial result of 71%. Of all specimens, 86.3% had histologic changes of degeneration. Moderate-to-severe degenerate changes in sacrococcygeal and intercoccygeal joints on histology were found in 54.5% of patients. Of these patients, 83.3% did well with surgery. Only 57.1% of those patients with mild changes did well. There were 2 patients who had positive discography, and both did well with surgery. Three patients had negative diskographies, and 2 of them had a poor result, and 1 had only some relief. CONCLUSIONS: It is possible that degenerate changes in sacrococcygeal discs and/or intercoccygeal discs are associated with pain. Surgical results are better in those with a severe degree of degenerative change. Coccygectomy remains a successful treatment for a majority of severely disabled patients with coccydynia.

Isolated, closed rupture of the common femoral artery resulting from blunt trauma.

We present a case of a 13-year-old child with an isolated, closed rupture of the common femoral artery and no associated bony injury sustained as a result of blunt trauma. Though few isolated cases of femoral artery injury secondary to blunt trauma have been reported in the literature, most of them were the result of a bony/penetrating injury. The probable mechanism of injury is discussed.

Pedicle morphology of the lower thoracic, lumbar, and S1 vertebrae: an Indian perspective.

STUDY DESIGN: Analysis of morphometric data obtained from computed tomography scans in relation to the lower thoracic, lumbar, and S1 pedicle in patients from the Indian subcontinent. OBJECTIVES: To record the surgically relevant parameters of transverse pedicle isthmus width, transverse pedicle angle, and depth to anterior cortex along the midline axis and the pedicle axis and to compare the results with those of similar studies in literature. SUMMARY OF BACKGROUND DATA: Most studies reported are for white populations. Considerable differences are documented in the few reports in Oriental populations compared with Western populations. To the authors' knowledge, no similar study has been published for patients from the Indian subcontinent. METHODS: Computed tomography scans of the lower thoracic and lumbosacral spine of patients from the Indian subcontinent were reviewed. We selected and analyzed 86 vertebrae in 31 patients. Parameters recorded were transverse pedicle isthmus width, transverse pedicle angle, and depth to anterior cortex along the midline axis and the pedicle axis. RESULTS: The mean transverse pedicle isthmus width was least at the T9 level (5.02 mm). Of the pedicles at T9, 46.15% had a diameter of less than 5 mm, followed by T10 (12.5%), T11 (11.11%), and L1 (11.11%). Of the pedicles at T9, 76.92% had a diameter of less than 6 mm, followed by T11 (33.33%), L1 (33.33%), T10 (25%), T12 (25%), L2 (20%), and L3 (5.56%). The mean transverse pedicle angle faced laterally at T11 (-2.97 degrees ) and T12 (-3.00 degrees ), being least at T12. The depth to the anterior cortex was more along the pedicle axis at all levels except T11 and T12, consistent with the laterally facing pedicles at these levels. CONCLUSIONS: Significant differences exist between the pedicles of Indian and white populations. It is suggested that preoperative computed tomography scans of the patients must be evaluated to choose the appropriately sized implant and avoid inadvertent complications. Preparation of the pedicle intraoperatively should take into account the orientation of the transverse pedicle angle.