Are outpatient three- and four-level anterior cervical discectomies and fusion safe?

BACKGROUND CONTEXTThe safety of outpatient one- and two-level anterior cervical discectomy and fusion (ACDF) has been validated in a number of recent studies. However, recent advancements in anesthetic and surgical technique have rendered procedures previously only performed in an inpatient setting, such as three- and four-level ACDF, potentially amenable to outpatient management.PURPOSEThe present study aimed to investigate the safety of outpatient three- and four-level ACDF.STUDY DESIGNRetrospective cohort studyPATIENT SAMPLEThe National Surgical Quality Improvement Program – a large, prospectively-collected registry – was queried to identify patients undergoing three- and four-level ACDF in an inpatient and outpatient setting.OUTCOME MEASURESThe rates of total complications, perioperative blood transfusion, and unplanned hospital readmission in three- and four-level ACDF by inpatient or outpatient surgery status.METHODSBaseline patient characteristics and 30-day outcomes were tabulated and compared by inpatient or outpatient status using bivariate analysis. A multivariate analysis was also employed to adjust for differences in baseline patient characteristics when comparing outcomes, and was also used to identify independent predictors of complications and readmissions in patients undergoing three- and four-level ACDF.RESULTSIn total 3,441 patients underwent three- or four-level ACDF, with 2,718 (79.0%) procedures occurring inpatient and 723 (21.0%) outpatient. Of patients undergoing outpatient ACDF, 596 patients (82.4%) underwent a three-level and 127 patients (17.6%) underwent four-level procedures. There was an increase in the utilization of outpatient procedures, increasing from 7.0% to 32.9% between 2011 and 2018. Patients undergoing outpatient surgery were younger, white, more likely to have three-level fusions (vs four-level), had a lower American Society of Anesthesiologists (ASA) classification, and were less likely to have a history of diabetes mellitus or dependent functional status. Among the inpatient and outpatient cohorts, there was no significant difference in the rates of total complications (4.49% vs 2.49%) or unplanned readmissions (4.96% vs 3.72%). Increasing age, operative duration, and ASA classification were independent predictors of complications and readmissions, however, inpatient or outpatient surgery status and number of levels fused was not.CONCLUSIONSThis present study represents one of the largest cohorts of patients undergoing outpatient three- and four-level ACDF. Outpatient multilevel ACDF is performed in younger and healthier patients, with three-level procedures more commonly the four-level. There was no observed increased rates of total complications or readmissions in patients undergoing outpatient relative to inpatient surgery, however, we did identify increased age, operative duration, and ASA classification as independent predictors of these complications. Patient selection for outpatient procedures is of the highest importance, and future studies developing reproducible selection criteria are warranted.     

Sagittal subtalar and talocrural joint assessment between barefoot and shod walking: A fluoroscopic study

BackgroundWhile wearing shoes is common in daily activities, most foot kinematic models report results on barefoot conditions. It is difficult to describe foot position inside shoes. This study used fluoroscopic images to determine talocrural and subtalar motion.Research QuestionWhat are the differences in sagittal talocrual and subtalar kinematics between walking barefoot and while wearing athletic walking shoes?MethodsThirteen male subjects (mean age 22.9 ± 2.9 years, mean weight 77.2 ± 6.9 kg, mean height 178.2 ± 3.7 cm) screened for normal gait were tested. A fluoroscopy unit was used to collect images during stance. Sagittal motion of the talocrural and subtalar joints of the right foot were analyzed barefoot and in an athletic walking shoe.ResultsShod talocrural position at heel strike was 6.0° of dorsiflexion and shod peak talocrural plantarflexion was 4.2°. Barefoot talocrural plantarflexion at heel strike was 4.2° and barefoot peak talocrural plantarflexion was 10.9°. Shod subtalar position at heel strike was 2.6° of plantarflexion and peak subtalar dorsiflexion was 1.5°. The barefoot subtalar joint at heel strike was in 0.4° dorsiflexion and barefoot peak subtalar dorsiflexion was 3.5°. As the result of wearing shoes, average walking speed and stride length increased and average cadence decreased. Comparing barefoot to shod walking there was a statistical significance in talocrural dorsiflexion and at heel strike and peak talocrural dorsiflexion, subtalar plantarflexion at heel strike and peak subtalar dorsiflexion, walking speed, stride length, and cadence.SignificanceThis work demonstrates the ability to directly measure talocrural and subtalar kinematics of shod walking using fluoroscopy. Future work using this methodology can be used to increase understanding of hindfoot kinematics during a variety of non-barefoot activities.     

Role of substance P in the cardiovascular system

This article provides an overview of the structure and function of substance P signalling system and its involvement in the cardiovascular regulation. Substance P is an undecapeptide originating from TAC1 gen and belonging to the tachykinin family. The biological actions of substance P are mainly mediated through neurokinin receptor 1 since substance P is the ligand with the highest affinity to neurokinin receptor 1. Substance P is widely distributed within the central and peripheral nervous systems as well as in the cardiovascular system. Substance P is involved in the regulation of heart frequency, blood pressure and in the stretching of vessels. Substance P plays an important role in ischemia and reperfusion and cardiovascular response to stress. Additionally, it has been also implicated in angiogenesis, pain transmission and inflammation. The substance P/neurokinin receptor 1 receptor system is involved in the molecular bases of many human pathological processes. Antagonists of neurokinin receptor 1 receptor could provide clinical solutions for a variety of diseases. Neurokinin receptor 1 antagonists are already used in the prevention of chemotherapy induced nausea and vomiting.     

Allogeneic mesenchymal precursor cells treatment for chronic low back pain associated with degenerative disc disease: a prospective randomized,placebo-controlled 36-month study of safety and efficacy

BACKGROUND CONTEXT PURPOSEEvaluate the safety and efficacy of a single intradiscal injection of STRO-3+ adult allogeneic mesenchymal precursor cells (MPCs) combined with hyaluronic acid (HA) in subjects with chronic low back pain (CLBP) associated with degenerative disc disease (DDD) through 36-month follow-up.STUDY DESIGN/SETTINGA multicenter, randomized, controlled study conducted at 13 clinical sites (12 in the United States and 1 in Australia).SUBJECT SAMPLEA total of 100 subjects with chronic low back pain associated with moderate DDD (modified Pfirrmann score of 3–6) at one level from L1 to S1 for at least 6 months and failing 3 months of conservative treatment, including physical therapy were randomized in a 3:3:2:2 ratio to receive 6 million MPCs with HA, 18 million MPCs with HA, HA vehicle control, or saline control (placebo) treatment.OUTCOME MEASURESSubjects were clinically and radiographically evaluated at 1, 3, 6, 12, 24, and 36 months postinjection. Subject-reported outcomes including adverse events, LBP on a Visual Analog Scale (VAS), Oswestry Disability Index (ODI), SF-36 and Work Productivity and Activity Index were collected.METHODSClinical and radiographic measures were collected at each visit. All randomized subjects were included in the safety assessments and analyzed based on the treatment received. Safety assessments included assessments of AEs, physical and radiographic examinations and laboratory testing. Efficacy assessments evaluated changes in VAS, ODI, and modified Pfirrmann (MP) scores between all active and control groups, respectively. Assessments included least squares mean (Mean), LS mean change from baseline (Mean Change) and responder analyses in order to assess the clinical significance of observed changes from baseline. The population for efficacy assessments was adjusted for the confounding effects of post-treatment interventions (PTIs). This study was conducted under an FDA Investigational New Drug application sponsored and funded by Mesoblast.RESULTSThere were significant differences between the control and MPC groups for improvement in VAS and ODI. The PTI-corrected VAS and ODI Means and Mean Change analyses; the proportion of subjects with VAS ≥30% and ≥50% improvement from baseline; absolute VAS score ≤20; and ODI reduction ≥10 and ≥15 points from baseline showed MPC therapy superior to controls at various time points through 36 months. Additionally, the proportion of subjects achieving the minimally important change and clinically significant change composite endpoints for the MPC groups was also superior compared with controls at various time points from baseline to 36 months. There were no significant differences in change in MP score from baseline across the groups. There were also no statistically significant differences in change in modified MP score at the level above or below the level treated between study arms. Both the procedure and treatment were well tolerated and there were no clinical symptoms of immune reaction to allogeneic MPCs. There was a low rate of Treatment Emergent Adverse Events (TEAEs) and Serious Adverse Events, and the rates of these events in the MPC groups were not significantly different from the control groups. One TEAE of severe back pain was possibly related to study agent and one TEAE of implantation site infection was considered to be related to the study procedure.CONCLUSIONSResults provide evidence that intradiscal injection of MPCs could be a safe, effective, durable, and minimally invasive therapy for subjects who have CLBP associated with moderate DDD.     

Tibia and radius bone geometry and volumetric density in obese compared to non-obese adolescents

Childhood obesity is associated with biologic and behavioral characteristics that may impact bone mineral density (BMD) and structure. The objective was to determine the association between obesity and bone outcomes, independent of sexual and skeletal maturity, muscle area and strength, physical activity, calcium intake, biomarkers of inflammation, and vitamin D status. Tibia and radius peripheral quantitative CT scans were obtained in 91 obese (BMI > 97th percentile) and 51 non-obese adolescents (BMI > 5th and < 85th percentiles). Results were converted to sex- and race-specific Z-scores relative to age. Cortical structure, muscle area and muscle strength (by dynamometry) Z-scores were further adjusted for bone length. Obese participants had greater height Z-scores (p < 0.001), and advanced skeletal maturity (p < 0.0001), compared with non-obese participants. Tibia cortical section modulus and calf muscle area Z-scores were greater in obese participants (1.07 and 1.63, respectively, both p < 0.0001). Tibia and radius trabecular and cortical volumetric BMD did not differ significantly between groups. Calf muscle area and strength Z-scores, advanced skeletal maturity, and physical activity (by accelerometry) were positively associated with tibia cortical section modulus Z-scores (all p < 0.01). Adjustment for muscle area Z-score attenuated differences in tibia section modulus Z-scores between obese and non-obese participants from 1.07 to 0.28. After multivariate adjustment for greater calf muscle area and strength Z-scores, advanced maturity, and less moderate to vigorous physical activity, tibia section modulus Z-scores were 0.32 (95% CI − 0.18, 0.43, p = 0.06) greater in obese, vs. non-obese participants. Radius cortical section modulus Z-scores were 0.45 greater (p = 0.08) in obese vs. non-obese participants; this difference was attenuated to 0.14 with adjustment for advanced maturity. These findings suggest that greater tibia cortical section modulus in obese adolescents is attributable to advanced skeletal maturation and greater muscle area and strength, while less moderate to vigorous physical activities offset the positive effects of these covariates. The impact of obesity on cortical structure was greater at weight bearing sites.     

伴寰枢椎脱位颅底凹陷症患者后路减压失败的再手术治疗

目的:探讨伴有寰枢椎脱位的颅底凹陷症患者后路减压失败的再手术对策。方法 :2006年2月~2010年10月我院收治9例在外院接受后颅窝减压手术术后症状加重的伴寰枢椎脱位颅底凹陷症患者,入院时患者均有站立或行走不稳,肢体麻木、无力,JOA评分7~11分,平均7.8±2.1分,影像学检查显示枕骨大孔周围大部分骨质均被咬除,且均有明显的寰枢椎脱位,枢椎齿状突向上脱入枕骨内并压迫脑干和延髓,脑干脊髓角105°~138°,平均125°±11°。均采用经口前路齿状突复位、钢板内固定、植骨治疗。随访患者神经功能改善情况,术后3个月及末次随访时对患者进行JOA评分,计算脊髓神经功能改善率;在颈椎MRI片上测量脑干脊髓角,并与术前比较。结果:手术均顺利完成,未出现硬脊膜破裂、切口感染等并发症。随访10~26个月,平均14个月,9例患者神经功能均有不同程度的改善,术后3个月时JOA评分为13.7±1.8分,改善率为64.1%;脑干脊髓角改善至148°±15°。末次随访时JOA评分为14.4±2.1分,改善率为71.7%;脑干脊髓角维持良好。8例患者在术后6个月左右复查CT均显示植骨达到骨性融合;1例患者随访期间头部外伤致内固定松动,再次翻修,随访10个月植骨获得骨性融合。结论:后颅窝减压术不能解决寰枢椎脱位造成的脑干前方压迫问题,不适合治疗伴有寰枢椎脱位的颅底凹陷症,经口前路齿状突复位钢板内固定手术可以将寰枢椎脱位有效复位,恢复枕颈交界区域的有效椎管直径,纠正脑干脊髓角度,可以作为后颅窝减压失败后的补救手术。     

A novel approach for evaluating acceptable intra-operative correction of lower limb alignment in femoral and tibial malunion using the deviation angle of the normal contralateral knee

BackgroundA simple and appropriate approach for evaluating an acceptable alignment of bone around the knee during operation has not yet been reported.MethodsThirty-five men and 35 women presenting with nonunion or malunion of the unilateral femoral shaft were included in the first study. Using the standing scanograph, the contralateral normal lower extremity was measured to determine the normal deviation angle (DA) of the medial malleolus when the medial aspect of the knee was placed in the midline of the body. In the second study, the normal DA from individual patients was used as a reference to evaluate knee alignment during operation in 40 other patients presenting with distal femoral or proximal tibial nonunion or malunion. The clinical and knee functional outcomes of these 40 patients were investigated.ResultsThe average normal DA was 4.2° in men and 6.0° in women (p < 0.001). Thirty-four of the 40 patients presenting with disorders around the knee were followed up for an average of 3.6 years (range, 1.1–6.5 years). Thirty fractures healed with a union rate of 88% and an average union period of 4.2 months (range, 2.5–6.5 months). Ideal knee alignment was maintained in all 30 patients with fracture union. Satisfactory function of the knee was achieved in 28 patients (82%, p < 0.001).ConclusionsUsing a normal DA as a reference may be a feasible and effective technique for evaluating an acceptable alignment of bone around the knee during operation.Levels of evidenceLevel IV, Case series.     

Biomechanics of single-tunnel double-bundle anterior cruciate ligament reconstruction using fixation with a unique expandable interference screw

BackgroundSingle-tunnel double-bundle (STDB) anterior cruciate ligament (ACL) reconstruction can restore biomechanical function and anatomic structure, but existing methods of graft fixation are not adequate. The aims of this study are to examine knee biomechanics after STDB reconstruction using a unique expandable interference screw for fixation.MethodsThe biomechanical parameters of six pairs of human cadaveric knee specimens were measured with the ACL intact, after ACL removal, and after STDB reconstruction using the interference screw or single-tunnel single-bundle (STSB) reconstruction. Anterior tibial translation under 134 N anterior tibial load in a neutral position as well as in 15° and 30° internal and external knee rotation and the internal tibial rotation angle under the rotatory load (5 N · m internal tibial rotation) were measured.ResultsAnterior tibial translations at each degree of knee flexion in the STDB group were significantly less than in the STSB group (all, P < 0.05). The internal rotation angles in the STSB group at five flexion angles were significantly higher than in the ACL intact group, whereas there were significantly less than those of the ACL absent group (P < 0.05). Under rotatory loads in the neutral position, the tibial internal rotation angles of the STDB group were significantly lower than in the STSB group at all flexion angles (all, P < 0.05).ConclusionsSTDB ACL reconstruction with the expandable interference screw provides better anteroposterior and rotational stability than STSB reconstruction.Clinical relevanceThe technique provides the advantages of double-bundle reconstruction using a single-tunnel technique.