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Objective To evaluate the initial outcomes of a composite cage with integral fixation using the Redmond titanium (Ti)/polyetheretherketone (PEEK) anterior cervical discectomy and fusion (ACDF) device. Methods Data from 50 consecutive patients were prospectively collected from a single senior surgeon cohort. All cages were between 5 and 8 mm in height, and were packed with supercritical CO2 sterilized allograft. Patients were followed up for a minimum of 6 months, and implant complications were assessed. Results From the original cohort, three were unavailable for follow-up. Forty-seven patients with a total of 58 operative levels were observed for a mean of 7.9 months. A fusion rate of 96% was achieved. Good to excellent outcomes were seen in 92% of patients. There were no cases of implant Ti/PEEK delamination or implant failure, with excellent early fusion rates using supercritical CO2 allograft. Conclusions The present study demonstrates the development of a composite ACDF cage design that is a safe and effective treatment option with the potential for early osseointegration and interbody fusion. Supercritical CO2 sterilized allograft was an effective graft material supporting fusion.

OBJECTIVE The role of bacterial infection in the causation of disc degeneration and its consequences is controversial. The current evidence is limited to underpowered studies, with the majority of such studies having only an internal contaminant arm, and only one study having a control arm with a non-degenerate disc population. The Degenerate-disc Infection Study with Contaminant Control (DISC) study includes a control arm and an internal contaminant control to resolve these shortcomings. METHODS The study is designed as a case-control study: cases are patients undergoing surgery for degenerated disc pathology and controls are patients undergoing surgery for non-degenerate pathology, such as trauma, scoliosis or tumor cases. RESULTS This study is part of a multi-centric trial involving six spine centers with 15 spine surgeons contributing. The DISC study methodology, rationale and controversies are presented here. The predominant issue is how to interpret contamination. We present our algorithm for the DISC study to address this. For disc samples that are positive concurrently with positive paraspinal tissue sample, the result will be interpreted as contamination. For positive disc samples with a negative paraspinal tissue culture result, the interpretation of this result will be infection. If cultures for both disc sample and paraspinal tissue sample are negative, then the result is interpreted as non-infected. If the disc culture is negative but paraspinal tissue culture is positive, then it is treated as a contaminant. CONCLUSIONS Future large-scale studies are required with a good control arm, a contamination arm, and histopathological correlations.

Objective Unilateral hemilaminectomy (UHIL), an alternative surgical approach to intradural lesions, involves a unilateral approach to meningeal opening that provides an adequate window for tumor extraction while leaving most of the vertebral structures intact. The techniques and results of a modified hemilaminectomy technique with spinal endoscopy is discussed and limited unilateral hemilaminectomy for intradural tumors (UHIT) evaluated prospectively. Methods Relevant clinical variables, operative reports, histological findings, pre- and post-operative imaging, and follow-up data for 11 consecutive patients (five males, six females; mean age 63.36 ± 20.69 years) who underwent modified hemilaminectomy over a 3 year time period were analyzed. Contrast-enhanced MRI was used to demonstrate the side, size and location of the suspected tumor or intradural lesion and CT to evaluate the bone anatomy. Post-operative MRI and CT allowed evaluation of anatomy following resection. Results Lesions included meningiomas (n = 2), neuromas (n = 3), and metastases, cysts or gliomas (n = 6). Pre-operative indications in order of incidence included cord compression, claudication, lower back pain, radiculopathy, paraplegia, weakness, incontinence, and generalized neuro-deterioration. There were no major complications, and no spinal deformity or instability at final follow up (mean, 13 months; range, 3–36 months). Conclusion Our data suggest that there is a place for the UHIT approach. This minimally invasive approach is useful for resecting all intradural tumors. UHIL is a useful minimally invasive technique for resecting intradural spinal tumors with maximal preservation of musculoligamentous attachments and posterior bony elements and should be considered an improvement on currently employed techniques.

Objective The present retrospective study was performed to assess the anatomical features of the pedicle in isthmic spondylolisthesis and to correlate this with degree of slip. Methods Twenty-six patients with isthmic spondylolytic spondylolisthesis were studied. Relevant patient variables, length, width, height of the L5 pedicle, and the product of height and angle between pedicle and vertebral midline were measured. The length of the posterior compartment of the pedicle was calculated as the product of the pedicle length and angle. Results With measurements comparable to those reported in previous publications, the L5 pedicle was found to be longer, and the height and width of the body shorter, than published values for patients without spondylolysis. The difference between the length of the posterior compartment of the pedicle and height of body is significantly proportional to the degree of slip and may reflect an adaptive response for stabilizing the vertebral body with posterior elements. Conclusions The pedicle anatomy was found to be altered in patients with L5S1 spondylolytic spondylolisthesis. These anatomical changes have implications for surgeons performing fusion operations in terms of length of screw, landmarks used and entry approach.

OBJECTIVE: The role of bacterial infection in the causation of disc degeneration and its consequences is controversial. The current evidence is limited to underpowered studies, with the majority of such studies having only an internal contaminant arm, and only one study having a control arm with a non‐degenerate disc population. The Degenerate‐disc Infection Study with Contaminant Control (DISC) study includes a control arm and an internal contaminant control to resolve these shortcomings. METHODS: The study is designed as a case‐control study: cases are patients undergoing surgery for degenerated disc pathology and controls are patients undergoing surgery for non‐degenerate pathology, such as trauma, scoliosis or tumor cases. RESULTS: This study is part of a multi‐centric trial involving six spine centers with 15 spine surgeons contributing. The DISC study methodology, rationale and controversies are presented here. The predominant issue is how to interpret contamination. We present our algorithm for the DISC study to address this. For disc samples that are positive concurrently with positive paraspinal tissue sample, the result will be interpreted as contamination. For positive disc samples with a negative paraspinal tissue culture result, the interpretation of this result will be infection. If cultures for both disc sample and paraspinal tissue sample are negative, then the result is interpreted as non‐infected. If the disc culture is negative but paraspinal tissue culture is positive, then it is treated as a contaminant. CONCLUSIONS: Future large‐scale studies are required with a good control arm, a contamination arm, and histopathological correlations.

Objective Surgical treatment of spinal metastasis is generally a palliative procedure. Although minimally invasive surgical (MIS) techniques are supposedly less morbid than open techniques, there is a lack of stratification of MIS techniques based on anticipated longevity. A simple stratification into three percutaneous surgical techniques based on modified Tokuhashi score is here proposed. Methods Patients recommended for spinal surgery for metastatic spinal disease between 2009 and 2012 and operated on by the senior author (RJM) were retrospectively reviewed. One of three MIS techniques was offered based on estimated survival using a modified Tokuhashi score. Technique #1 is suitable for patients with predicted short longevity ( 12 months). In these patients, the primary goal of surgery is a wide local or marginal resection of tumor, decompression of the neurological elements and a robust stabilization construct. They are suitable for an open 360°decompression, vertebral body reconstruction and a multilevel stabilization. Results The study included eight patients with a mean age of 59 years (range, 36–72 years). Mean modified Tokuhashi score was 10 (range, 7–13) with three patients in the short term, two in the medium term and three in the long term survival category. Mean blood loss was 700 mL (range, 100–1200 mL), mean operating time 280 min (range, 120–360 min) and length of stay in the hospital was on average 13 days (range, 3–30 days). Conclusion The authors present three minimally invasive technique options for the management of spinal metastatic disease corresponding to three clinical prognostic categories. In this small series, MIS techniques resulted in speedy recovery, minimal morbidity and no mortality.

Because degenerative spondylolithesis is prevalent in the elderly with associated osteoporosis, the rate of failure of pedicle screws is high; this leads to pseudoarthrosis and potentially requires reoperation. The burden of recurrent symptoms and reoperation is sufficiently significant to warrant prevention. We here describe a hybrid technique that involves a combination of a unilateral approach to bilateral decompression via a midline incision, transforaminal lumbar interbody fusion (TLIF), contralateral facet fusion, and percutaneously placed pedicle screws without compromising operative time and visualization. This approach is familiar to spine surgeons, adheres to the basic principles of minimally invasive spine surgery technique, minimizes dural and neural injury because of the unilateral TLIF approach, and provides a superior fusion construct because of facet fusion. In this procedure, patients with degenerative spondylolisthesis or scoliosis with moderate-severe canal/foraminal stenosis undergo a midline unilateral TLIF and contralateral facet fusion with closure of the midline incision. Percutaneous pedicle screws are inserted under stereotactic guidance with reduction of the deformity using a pedicle screws construct. Rods are inserted percutaneously to link the pedicle screws. Image intensification is used to confirmed satisfactory screw placement and reduction of the spondylolisthesis.

The procedure of anterior lumbar interbody fusion (ALIF) is commonly performed on patients suffering from pain and/or neurological symptoms associated with disorders of the lumbar spine caused by disc degeneration and trauma. Surgery is indicated when prolonged conservative management proves ineffective. Because an important objective of the ALIF procedure is solid arthrodesis of the degenerative spinal segment, bone graft selection is critical. Iliac crest bone grafts (ICBG) remain the “gold standard” for achieving lumbar fusion. However, patient dissatisfaction stemming from donor site morbidity, lengthier operating times and finite supply of ICBG has prompted a search for better alternatives. Here presented is a literature review evaluating available bone graft options assessed within the clinical setting. These options include autografts, allograft-based, synthetic and cell-based technologies. The emphasis is on the contentious use of recombinant human bone morphogenetic proteins, which is in widespread use and has demonstrated both significant osteogenic potential and risk of complications.

The authors describe a hybrid technique that involves a combination of open decompression and posterior lumbar interbody fusion (PLIF) and percutaneously inserted pedicle screws. This technique allows performance of PLIF and decompression via a midline incision and approach without compromising operative time and visualization. Furthermore, compared to standard open decompression, this approach reduces post-operative wound pain because the small midline incision significantly reduces muscle trauma by obviating the need to dissect the paraspinal muscles off the facet joint complex and by avoiding posterolateral fusion, thus requiring limited lateral muscle dissection off the transverse processes. A series of patients with Grade I-II spondylolisthesis at L4-5 and moderate-severe canal/foraminal stenosis underwent midline PLIF at L4-5, with closure of the midline incision. Percutaneous pedicle screws were inserted, thereby minimizing local muscle trauma, reduction of the spondylolisthesis being performed by using a pedicle screw construct. Rods were inserted percutaneously to link the L4 and L5 pedicle screws. Image intensification was used to confirmed satisfactory screw placement and reduction of spondylolisthesis. The results of a prospective study comparing a standard open decompression and fusion technique for spondylolisthesis versus the minimally invasive hybrid technique are discussed. The minimally invasive technique resulted in shorter hospital stay, earlier mobilization and reduced postoperative narcotic usage. The long-term clinical outcomes were equivalent in the two groups.

OBJECTIVE: Unilateral hemilaminectomy (UHIL), an alternative surgical approach to intradural lesions, involves a unilateral approach to meningeal opening that provides an adequate window for tumor extraction while leaving most of the vertebral structures intact. The techniques and results of a modified hemilaminectomy technique with spinal endoscopy is discussed and limited unilateral hemilaminectomy for intradural tumors (UHIT) evaluated prospectively. METHODS: Relevant clinical variables, operative reports, histological findings, pre‐ and post‐operative imaging, and follow‐up data for 11 consecutive patients (five males, six females; mean age 63.36 ± 20.69 years) who underwent modified hemilaminectomy over a 3 year time period were analyzed. Contrast‐enhanced MRI was used to demonstrate the side, size and location of the suspected tumor or intradural lesion and CT to evaluate the bone anatomy. Post‐operative MRI and CT allowed evaluation of anatomy following resection. RESULTS: Lesions included meningiomas (n = 2), neuromas (n = 3), and metastases, cysts or gliomas (n = 6). Pre‐operative indications in order of incidence included cord compression, claudication, lower back pain, radiculopathy, paraplegia, weakness, incontinence, and generalized neuro‐deterioration. There were no major complications, and no spinal deformity or instability at final follow up (mean, 13 months; range, 3–36 months). CONCLUSION: Our data suggest that there is a place for the UHIT approach. This minimally invasive approach is useful for resecting all intradural tumors. UHIL is a useful minimally invasive technique for resecting intradural spinal tumors with maximal preservation of musculoligamentous attachments and posterior bony elements and should be considered an improvement on currently employed techniques.

Because degenerative spondylolithesis is prevalent in the elderly with associated osteoporosis, the rate of failure of pedicle screws is high; this leads to pseudoarthrosis and potentially requires reoperation. The burden of recurrent symptoms and reoperation is sufficiently significant to warrant prevention. We here describe a hybrid technique that involves a combination of a unilateral approach to bilateral decompression via a midline incision, transforaminal lumbar interbody fusion (TLIF), contralateral facet fusion, and percutaneously placed pedicle screws without compromising operative time and visualization. This approach is familiar to spine surgeons, adheres to the basic principles of minimally invasive spine surgery technique, minimizes dural and neural injury because of the unilateral TLIF approach, and provides a superior fusion construct because of facet fusion. In this procedure, patients with degenerative spondylolisthesis or scoliosis with moderate‐severe canal/foraminal stenosis undergo a midline unilateral TLIF and contralateral facet fusion with closure of the midline incision. Percutaneous pedicle screws are inserted under stereotactic guidance with reduction of the deformity using a pedicle screws construct. Rods are inserted percutaneously to link the pedicle screws. Image intensification is used to confirmed satisfactory screw placement and reduction of the spondylolisthesis.

Anterior lumbar interbody fusion (ALIF) has become a widely recognized surgical technique for degenerative pathology of the lumbar spine. Spinal fusion has evolved dramatically ever since the first successful internal fixation by Hadra in 1891 who used a posterior approach to wire adjacent cervical vertebrae in the treatment of fracture‐dislocation. Advancements were made to reduce morbidity including bone grafting substitutes, metallic hardware instrumentation and improved surgical technique. The controversy regarding which surgical approach is best for treating various pathologies of the lumbar spine still exists. Despite being an established treatment modality, current indications of ALIF are yet to be clearly defined in the literature. This article discusses the current literature on indications on ALIF surgery.

The procedure of anterior lumbar interbody fusion (ALIF) is commonly performed on patients suffering from pain and/or neurological symptoms associated with disorders of the lumbar spine caused by disc degeneration and trauma. Surgery is indicated when prolonged conservative management proves ineffective. Because an important objective of the ALIF procedure is solid arthrodesis of the degenerative spinal segment, bone graft selection is critical. Iliac crest bone grafts (ICBG) remain the “gold standard” for achieving lumbar fusion. However, patient dissatisfaction stemming from donor site morbidity, lengthier operating times and finite supply of ICBG has prompted a search for better alternatives. Here presented is a literature review evaluating available bone graft options assessed within the clinical setting. These options include autografts, allograft‐based, synthetic and cell‐based technologies. The emphasis is on the contentious use of recombinant human bone morphogenetic proteins, which is in widespread use and has demonstrated both significant osteogenic potential and risk of complications.

The authors describe a hybrid technique that involves a combination of open decompression and posterior lumbar interbody fusion (PLIF) and percutaneously inserted pedicle screws. This technique allows performance of PLIF and decompression via a midline incision and approach without compromising operative time and visualization. Furthermore, compared to standard open decompression, this approach reduces post‐operative wound pain because the small midline incision significantly reduces muscle trauma by obviating the need to dissect the paraspinal muscles off the facet joint complex and by avoiding posterolateral fusion, thus requiring limited lateral muscle dissection off the transverse processes. A series of patients with Grade I‐II spondylolisthesis at L(4–5) and moderate–severe canal/foraminal stenosis underwent midline PLIF at L(4–5), with closure of the midline incision. Percutaneous pedicle screws were inserted, thereby minimizing local muscle trauma, reduction of the spondylolisthesis being performed by using a pedicle screw construct. Rods were inserted percutaneously to link the L(4) and L(5) pedicle screws. Image intensification was used to confirmed satisfactory screw placement and reduction of spondylolisthesis. The results of a prospective study comparing a standard open decompression and fusion technique for spondylolisthesis versus the minimally invasive hybrid technique are discussed. The minimally invasive technique resulted in shorter hospital stay, earlier mobilization and reduced postoperative narcotic usage. The long‐term clinical outcomes were equivalent in the two groups.