Customized 3-dimensional-printed Vertebral Implants for Spinal Reconstruction After Tumor Resection: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: To examine the outcomes of customized 3-dimensional (3D) printed implants for spinal reconstruction after tumor resection. SUMMARY OF BACKGROUND DATA: Various techniques exist for spinal reconstruction after tumor resection. Currently, there is no consensus regarding the utility of customized 3D-printed implants for spinal reconstruction after tumor resection. MATERIALS AND METHODS: A systematic review was registered with PROSPERO and performed according to "Preferred Reporting Items for Systematic Reviews and Meta-analyses" guidelines. All level I-V evidence studies reporting the use of 3D-printed implants for spinal reconstruction after tumor resection were included. RESULTS: Eleven studies (65 patients; mean age, 40.9 ± 18.1 y) were included. Eleven patients (16.9%) underwent intralesional resections with positive margins and 54 patients (83.1%) underwent en bloc spondylectomy with negative margins. All patients underwent vertebral reconstruction with 3D-printed titanium implants. Tumor involvement was in the cervical spine in 21 patients (32.3%), thoracic spine in 29 patients (44.6%), thoracolumbar junction in 2 patients (3.1%), and lumbar spine in 13 patients (20.0%). Ten studies with 62 patients reported perioperative outcomes radiologic/oncologic status at final follow-up. At the mean final follow-up of 18.5 ± 9.8 months, 47 patients (75.8%) had no evidence of disease, 9 patients (14.5%) were alive with recurrence, and 6 patients (9.7%) had died of disease. One patient who underwent C3-C5 en bloc spondylectomy had an asymptomatic subsidence of 2.7 mm at the final follow-up. Twenty patients that underwent thoracic and/or lumbar reconstruction had a mean subsidence of 3.8 ± 4.7 mm at the final follow-up; however, only 1 patient had a symptomatic subsidence that required revision surgery. Eleven patients (17.7%) had one or more major complications. CONCLUSION: There is some evidence to suggest that using customized 3D-printed titanium or titanium alloy implants is an effective technique for spinal reconstruction after tumor resection. There is a high incidence of asymptomatic subsidence and major complications that are similar to other methods of reconstruction. LEVEL OF EVIDENCE: Level V, systematic review of level I-V studies.

Pelvic Fixation With a Quad-Rod Technique Using S2 Alar Iliac and Medialized Entry Iliac Screws for Long Fusion Constructs.

PURPOSE: Patients with adult spinal deformity (ASD) may have risk factors for nonunion and subsequent instrumentation failure. This study reviews a novel surgical technique for a quad-rod construct to the pelvis using both S2 alar iliac (S2AI) screw fixation and medialized entry iliac screw fixation as described through three separate cases and a review of the literature. METHODS: This technique facilitates alignment of the construct and rod insertion into the tulip heads. The medialized iliac screw technique also avoids the potential soft-tissue complications of the conventional iliac screw bolt given that it is deeper and has more soft-tissue coverage. RESULTS: Three cases performed by the most senior author (V.A.) in which this novel technique was used are presented in this report along with clinical and radiographic images to educate the reader on appropriate execution of this technique. A review of the existing literature regarding pelvic fixation techniques for ASD was also done. CONCLUSION: Quad-rod augmentation of long thoracolumbar spinal constructs with two independent SI anchoring points is potentially an effective technique to increase lumbar sacral construct rigidity, thereby promoting fusion rates and decreasing revision rates. The described technique provides spine surgeons with an additional tool in their armamentarium to treat patients with complex ASD.

Postoperative Rehabilitation to Improve Outcomes After Cervical Spine Fusion for Degenerative Cervical Spondylosis: A Systematic Review.

Postoperative rehabilitation has recently been identified as a high-priority research topic for improving surgical outcomes for degenerative cervical spondylosis (DCS). However, there remains no consensus on specific rehabilitation strategies. Thus, the objective of this study was to evaluate the effectiveness of postoperative rehabilitation strategies for short-term and long-term outcomes after cervical spine fusion for DCS. A systematic review was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines using the PubMed, Scopus, and Ovid Medline databases. All level I-IV therapeutic studies in the English language investigating the outcomes of postoperative rehabilitation strategies after cervical spine fusion for DCS were included. Nine studies with 895 patients with DCS (747 anterior-only fusion, 55 patients with posterior-only fusion, 93 patients with physiotherapy alone) were included in this analysis, with 446 (49.8%) patients receiving physiotherapy alone or standard postoperative therapy and 449 (50.2%) patients receiving standard postoperative therapy with additional intervention or augmentation. These interventions included pulsed electromagnetic field (PEMF) stimulation, telephone-supported home exercise program (HEP), early cervical spine stabilizer training, structured postoperative therapy, and a postoperative cervical collar. One level II study demonstrated that PEMF led to increased fusion rates at six months postoperatively compared to standard therapy alone, one level II study demonstrated that postoperative cervical therapy in addition to standard therapy was better than standard therapy alone in the improvement of neck pain intensity, one level IV study demonstrated home exercise therapy led to an improvement in neck pain, arm pain, and disability, and six level II studies reported no difference in clinical outcome measures between augmented or targeted therapy and standard postoperative therapy for DCS. In conclusion, there is moderate evidence to suggest that there is no significant difference in clinical and surgical outcomes between standard postoperative therapy and augmented or targeted postoperative therapy for cervical fusion in the setting of cervical spondylosis. However, there is some evidence to support that certain therapeutic modalities, such as PEMF stimulation, may lead to improved fusion rates, clinical outcomes, and patient satisfaction when compared to standard postoperative therapy protocols. There is no evidence to support a difference in effectiveness with different types of postoperative rehabilitation strategies between anterior and posterior fusions for DCS.

Obesity and perioperative adverse events in patients undergoing complex revision surgery for the thoracolumbar spine.

BACKGROUND: There are no previous studies that evaluate the effect of obesity on patients undergoing complex revision thoracolumbar spine surgery. The primary objective was to determine the relationship between obesity and perioperative adverse events (AEs) with patients undergoing complex revision thoracolumbar spine surgery while controlling for psoas muscle index (PMI) as a confounding variable. The secondary objective was to determine the relationship between obesity and 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, and post-operative length of stay (LOS). METHODS: Between May 2016 and February 2020, a retrospective analysis of individuals undergoing complex revision surgery of the thoracolumbar spine was performed at a single institution. Obesity was defined as BMI ≥ 30.0 kg/m2. PMI < 500 mm2/m2 for males and < 412 mm2/m2 for females were used to define low muscle mass. A Spine Surgical Invasiveness Index (SSII) > 10 was used to define complex revision surgery. A multivariable logistic regression model was used to ascertain the effects of low muscle mass, obesity, age, and gender on the likelihood of the occurrence of any AE. RESULTS: A total of 114 consecutive patients were included in the study. Fifty-four patients were in the obese cohort and 60 patients in the non-obese cohort. There was not a significant difference in perioperative outcomes of both the obese and non-obese patients. There were 22 obese patients (40.7%) and 33 non-obese patients (55.0%) that experienced any AE (p = 0.130). Multivariable analysis demonstrated that individuals with low muscle mass had a significantly higher likelihood for an AE than individuals with normal or high muscle mass (OR: 7.53, 95% CI: 3.05-18.60). Obesity did not have a significant effect in predicting AEs. CONCLUSIONS: Obesity is not associated with perioperative AEs, 30-day readmission rates, 30-day re-operation rates, rate of discharge to a facility, or post-operative length of stay (LOS) among patients undergoing complex revision thoracolumbar spine surgery. LEVEL OF EVIDENCE: III.

S2 alar-iliac screw versus traditional iliac screw for spinopelvic fixation: a systematic review of comparative biomechanical studies.

PURPOSE: To review and compare biomechanical properties between S2 alar-iliac (S2AI) screws and traditional iliac screws for spinopelvic fixation. METHODS: A systematic review was performed according to PRISMA guidelines. All clinical, cadaveric, and finite-element model (FEM) studies that compared the biomechanical properties between S2AI screws and traditional iliac screws were included. Study methodological quality for cadaveric studies were analyzed using the Quality Appraisal for Cadaveric Studies (QUACS) scale. RESULTS: Eight studies (4 cadaveric, 4 FEM) analyzing 58 S2AI screws and 48 traditional iliac screws were included. According to QUACS, the overall methodological quality was "moderate to good" for all four cadaveric studies. All four cadaveric studies found no difference in biomechanical stiffness, screw toggle, rod strain, and/or load-to-failure between the S2AI screws and traditional iliac screws for spinopelvic fixation. All four FEM studies found that S2AI screws were associated with lower implant stresses compared to traditional iliac screws. CONCLUSIONS: There is moderate biomechanical evidence to suggest that there is no significant difference in stability and stiffness between S2AI screws and traditional iliac screws for spinopelvic fixation. However, there is some evidence to support that the placement of S2AI screws may have lower implant stresses on the overall lumbosacral instrumentation compared to traditional iliac screws.

Instrumented Versus Noninstrumented Spinal Fusion for Degenerative Lumbar Spondylolisthesis: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: This systematic review compares radiographic and clinical outcomes between instrumented and noninstrumented posterolateral lumbar spine fusions for the treatment of degenerative lumbar spondylolisthesis. SUMMARY OF BACKGROUND DATA: The optimal method of fusion for instability from degenerative lumbar spondylolisthesis remains to be an area of debate amongst spine surgeons. There are no prior comprehensive systematic review of comparative studies that compares outcomes between instrumented and noninstrumented posterolateral spine fusions for the treatment of degenerative lumbar spondylolisthesis. MATERIALS AND METHODS: A systematic review was registered with PROSPERO and performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines using the PubMed, SCOPUS, and Ovid MEDLINE databases. All level I-III comparative studies published in the English language investigating the clinical outcomes between instrumented and noninstrumented posterolateral spine fusions for the treatment of degenerative lumbar spondylolisthesis were included. RESULTS: Seven studies (672 patients, 274 noninstrumented, 398 instrumented) were analyzed. One randomized study was level I evidence, 2 randomized studies were level II, and 4 nonrandomized studies were level III. Mean follow-up ranged from 1.4 to 5.9 years. Instrumented patients had a higher rate of solid fusion (87.6% vs. 77.1%, P=0.023) and a lower rate of definitive pseudarthrosis (5.3% vs. 19.9%, P<0.001). However, there was no difference in overall functional improvement at final follow-up between the 2 treatment groups (75.0% vs. 81.7%, P=0.258). In addition, there was no difference in reoperation or complication rates. CONCLUSIONS: For the treatment of degenerative lumbar spondylolisthesis, there are significantly higher rates of fusion among patients undergoing instrumented posterolateral fusion compared with noninstrumented posterolateral fusion. However, there is no difference in overall functional improvement, pain-related outcome scores, reoperation rates, or complication rates between the 2 treatment groups. LEVEL OF EVIDENCE: Level III-systematic review of level I-III studies.

Necrotizing Fasciitis Due to Prevotella denticola Infection in an Intravenous Drug User.

Intravenous drug users (IVDUs) have an increased risk for various types of local and systemic infections including necrotizing fasciitis (NF), which is a life-threatening bacterial soft tissue infection that requires a prompt diagnosis and treatment. Prevotella denticola is a part of the Prevotella species, which are obligate anaerobic, Gram-negative rods related to Bacteroides genus and often implicated in periodontal and dental disease, but have been associated with soft tissue infections and other systemic complications such as cerebral abscess and endocarditis. This case reports a 30-year-old female IVDU who presented with necrotizing fasciitis of the right anterior thigh with associated right knee septic arthritis due to Prevotella denticola. The patient was treated with emergent irrigation and radical debridement along with IV antibiotic treatment for eight weeks. A review of literature was performed regarding necrotizing fasciitis caused by Prevotella species. Necrotizing fasciitis caused by Prevotella species is rare; however, there must be a high index of suspicion among IVDUs to allow for a prompt diagnosis and treatment.

Anterior versus posterior spinal fusion for Lenke type 5 adolescent idiopathic scoliosis: a systematic review and meta-analysis of comparative studies.

PURPOSE: To review and compare clinical and radiologic outcomes between anterior spinal fusion (ASF) and posterior spinal fusion (PSF) for the treatment of Lenke type 5 adolescent idiopathic scoliosis (AIS). METHODS: A systematic review was performed according to Preferred reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. All level I-III evidence studies investigating the clinical and radiologic outcomes of ASF and PSF for the treatment of Lenke type 5 AIS were included. RESULTS: Nine studies (285 ASF patients, 298 PSF patients) were included. ASF was associated with a significantly lower number of levels fused compared with PSF (p < 0.01) with similar immediate and long-term coronal deformity correction (p = 0.16; p = 0.12, respectively). PSF achieved a better correction of thoracic hypokyphosis in one study and lumbar hypolordosis in three studies. PSF was associated with a significant shorter length of stay (LOS) compared with ASF (p < 0.01). One long-term study demonstrated a significantly higher rate of proximal junctional kyphosis (PJK) with PSF compared with ASF. There were no significant differences in major complication or re-operation rates. CONCLUSION: For the treatment of Lenke type 5 AIS, there is moderate evidence to suggest that ASF requires a lower number of instrumented levels to achieve similar immediate and long-term coronal deformity correction compared with PSF. There is some evidence to suggest that PSF may achieve better thoracic and lumbar sagittal deformity correction compared with ASF. There is some evidence to suggest a higher incidence of PJK at long-term follow-up with PSF compared with ASF. ASF is associated with a longer post-operative LOS compared with PSF.

Duloxetine for the Treatment of Chronic Low Back Pain: A Systematic Review of Randomized Placebo-Controlled Trials.

This systematic review determines the efficacy and safety of duloxetine for chronic low back pain (CLBP). We queried the PubMed, SCOPUS, and Ovid MEDLINE databases. All level I and II randomized controlled studies published in the English language investigating the efficacy of duloxetine for chronic low back pain were included. Five studies (832 duloxetine-treated patients, 667 placebo-treated patients, and 41 duloxetine and placebo crossover analysis patients) were analyzed. One study was level I evidence and four studies were level II evidence. All five studies reported statistically significant improvements in more than one back-pain-specific clinical outcome score with duloxetine versus placebo. Four studies found that duloxetine 60 mg daily leads to one or more statistically significant improvements versus placebo in Brief Pain Inventory Severity (BPI-S) scores. All five studies found no significant difference in serious adverse events (AEs) between the duloxetine and placebo groups. One study found a higher rate of total AEs among the duloxetine 120 mg group versus the placebo group; however, the same study did not find a significant difference in total AEs among duloxetine 20 mg and 60 mg groups versus placebo. Duloxetine is a safe and effective first-line option for the treatment of CLBP. Current studies demonstrate that 60 mg taken once daily has the highest efficacy for reducing pain and disability while minimizing minor adverse effects. Further randomized controlled trials with long-term follow-up are necessary to determine its long-term effects.

Platelet-Rich Plasma Versus Corticosteroid Injection for Lumbar Spondylosis and Sacroiliac Arthropathy: A Systematic Review of Comparative Studies.

This systematic review compares clinical outcomes between platelet-rich plasma (PRP) and corticosteroid injections for the treatment of lumbar spondylosis and sacroiliac arthropathy. A systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO) and performed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using the Pubmed, SCOPUS, and Ovid MEDLINE databases. All level I-III evidence comparative studies published in the English language investigating the clinical outcomes between PRP and corticosteroid injections for the treatment of lumbar spondylosis and sacroiliac arthropathy were included. Five studies (242 patients, 114 PRP, 128 corticosteroid) were analyzed. One randomized study was level I evidence, two randomized studies were level II, and two non-randomized studies were level III. Final follow-up ranged from six weeks to six months. Four studies found that both PRP and corticosteroid treatment led to a statistically significant reduction in the visual analog scale (VAS). One found that only the PRP group led to a statistically significant reduction in VAS. Three studies found more significant improvements in one or more clinical outcome scores among PRP patients as compared with corticosteroid patients at the three- to six-month follow-up. Two studies found no difference in outcome score improvements between the two groups at six- to 12-week follow-up. There were no reports of major complications. There were no significant differences in minor complication rates between the two groups. In conclusion, both PRP and corticosteroid injections are safe and effective options for the treatment of lumbar spondylosis and sacroiliac arthropathy. There is some evidence that PRP injection is a more effective option at long-term follow-up compared with corticosteroid injection. Further randomized controlled trials with longer-term follow-up are necessary to compare its long-term efficacy.

The relationship between maximum tolerance and motor activation during transcutaneous spinal stimulation is unaffected by the carrier frequency or vibration.

Transcutaneous spinal stimulation (TSS) is a useful tool to modulate spinal sensorimotor circuits and has emerged as a potential treatment for motor disorders in neurologically impaired populations. One major limitation of TSS is the discomfort associated with high levels of stimulation during the experimental procedure. The objective of this study was to examine if the discomfort caused by TSS can be alleviated using different stimulation paradigms in a neurologically intact population. Tolerance to TSS delivered using conventional biphasic balanced rectangular pulses was compared to two alternative stimulation paradigms: a 5 kHz carrier frequency and biphasic balanced rectangular pulses combined with vibrotactile stimulation. In ten healthy participants, tolerance to TSS was examined using both single-pulse (0.2 Hz) and continuous (30 Hz) stimulation protocols. In both the single-pulse and continuous stimulation protocols, participants tolerated significantly higher levels of stimulation with the carrier frequency paradigm compared to the other stimulation paradigms. However, when the maximum tolerable stimulation intensity of each stimulation paradigm was normalized to the intensity required to evoke a lower limb muscle response, there were no statistical differences between the stimulation paradigms. Our results suggest that, when considering the intensity of stimulation required to obtain spinally evoked motor potentials, neither alternative stimulation paradigm is more effective at reducing discomfort than the conventional, unmodulated pulse configuration.