New Evidence for Structural Integration across the Cartilage-Vertebral Endplate Junction and its Relation to Herniation

Publication date: Available online 31 August 2018

Source: The Spine Journal

Author(s): Nurul Haiza Sapiee, Ashvin Thambyah, Peter A. Robertson, Neil D. Broom

Abstract

BACKGROUND CONTEXT

Both cartilaginous and bony material present in herniated tissue suggests that failure can involve both cartilaginous and vertebral-endplates. How structural integration is achieved across the junction between these two distinct tissue regions via its fibril and mineral components is clearly relevant to the modes of endplate failure that occur.

PURPOSE

To understand how structural integration is achieved across the cartilage-vertebral endplate junction.

STUDY DESIGN

A micro- and fibril-level structural analysis of the cartilage-vertebral endplate region was carried out using healthy, mature ovine motion segments.

METHODS

Oblique vertebra-annulus-vertebra samples were prepared such that alternate layers of lamellar fibers extended from vertebra to vertebra. The endplate region of each sample was then decalcified in a targeted manner before being loaded in tension along the fiber direction to achieve incomplete rupture within the region of the endplate. The failure regions were then analyzed with differential interference contrast microscopy and scanning electron microscopy.

RESULTS

Microstructural analysis revealed that failure within the endplate region was not confined to the cement line alone. Instead, rupture continued into the underlying vertebral endplate with bony material still attached to the now unanchored annular bundles. Ultrastructural analysis of the partially ruptured regions of the cement line revealed clear evidence of blending/interweaving relationships between the fibrils of the annular bundles, the calcified cartilage and the bone with no one pattern of association appearing dominant. These findings suggest that fibril-based structural cohesion exists across the cement line at the site of annular insertion, with strengthening via a mechanism somewhat analogous to steel-reinforced concrete. The fibrils are brought into a close intermingling association with interfibril forces mediated via the mineral component.

CONCLUSIONS

This study provides clear evidence of structural connectivity across the cartilaginous-vertebral endplate junction by the intermingling of their fibrillar components and mediated by the mineral phase. This is consistent with the clinical observation that in some disc herniations bony material can be still attached to the extruded soft tissue.

https://ift.tt/2wDtdab

Incidental Durotomy in Degenerative Lumbar Spine Surgery – A register study of 64,431 operations

Publication date: Available online 30 August 2018

Source: The Spine Journal

Author(s): Fredrik Strömqvist, Freyr Gauti Sigmundsson, Björn Strömqvist, Bo Jönsson, Magnus K. Karlsson

Abstract

Background

Incidental durotomy (ID) is one of the most common intraoperative complications seen in spine surgery. Conflicting evidence has been presented regarding whether or not outcomes are affected by the presence of an ID.

Purpose

To evaluate whether outcomes following degenerative spine surgery are affected by ID and the incidence of ID with different diagnoses and different surgical procedures.

Material

By using SweSpine, the national Swedish Spine Surgery Register, preoperative, surgical and postoperative 1 year follow up data were obtained for 64,431 surgeries. All patients were surgically treated due to spinal stenosis (LSS) without or with concomitant degenerative spondylolisthesis (DS) or lumbar disc herniation (LDH) between 2000-2015. Gender, age, smoking habits, walking distance, consumption of analgesics, back and leg pain (VAS), quality of life (EQ5D, SF-36) and disability (ODI) were recorded.

Results

Overall, incidence of ID during the study period was 5.0%. For the LDH, LSS, and DS subgroups it was 2.8%, 6.5%, and 6.5%, respectively. Laminectomy was associated with higher incidence of ID than discectomy (p<0.001). ID was more common in all three subgroups if the patient had previously been subjected to spine surgery and with increasing age of the patients (p<0.001). LDH patients with an ID reported a higher degree of residual leg pain, inferior mental quality of life (SF-36 MCS) and higher disability (ODI) than LDH patients without ID (all p<0.001) one-year after surgery. LSS patients with an ID reported inferior SF-36 MCS (p<0.001) and DS patients with an ID had inferior SF-36 MCS and higher ODI compared to patients with the same diagnosis but without an ID (p<0.001). However, these numerical differences are well below references for MCID, for all 3 subgroups. ID was associated with a higher frequency of patients being dissatisfied with the surgical outcome at one year follow up. In patients who did not improve in back-and leg pain following surgery (delta-value), ID was less common than in patients reporting improved back- and legpain from before as compared to following surgery.

Conclusions

The overall occurrence of ID in the present study was 5%, with higher figures in LSS and DS and lower figures in LDH. Higher age of the patient and previous surgery was associated with higher frequencies of ID. The outcome at one year following surgery was not affected to a clinically relevant extent when an ID. However, ID was associated with a higher degree of patient dissatisfaction and a longer hospital length of stay.

https://ift.tt/2CaRiLT

Clinical effect of early bisphosphonate treatment for pyogenic vertebral osteomyelitis with osteoporosis: An analysis by the Cox proportional hazard model

Publication date: Available online 30 August 2018

Source: The Spine Journal

Author(s): Jihye Kim, Seung Bo Jang, Seok Woo Kim, Jae-Keun Oh, Tae-Hwan Kim

Abstract

Background Context

Patients with pyogenic vertebral osteomyelitis (PVO) are expected to have an increased risk of bone loss. Therefore, early bisphosphonate therapy would be clinically effective for PVO patients with osteoporosis.

Purpose

To investigate the effect of bisphosphonate on clinical outcomes of PVO patients with osteoporosis. Study Design/Setting: A retrospective comparative study.

Patient Sample

PVO patients with osteoporosis Outcome measures: Four events of interest for Cox proportional hazard model included surgical treatment, recurrence of infection, subsequent fracture of adjacent vertebral bodies, and death.

Methods

PVO patients were divided into three groups: group A (initiation of bisphosphonate within 6 weeks after PVO diagnosis), group B (initiation of bisphosphonate between 6 weeks and 3 months after PVO diagnosis), and group C (no treatment for osteoporosis). Cox proportional hazard model was used for the four events of interest.

Results

A total of 360 PVO patients with osteoporosis were investigated for the four events of interest. Group A had significantly lower hazard ratios for undergoing later (>6 weeks after diagnosis) surgery than group C (p=0.014) despite similar occurrences of overall surgery. A significant difference was also observed in the occurrence of subsequent fractures at adjacent vertebral bodies (p=0.001 for model 1 and p=0.002 for model 2). Groups A and B had significantly lower hazard ratios for subsequent fracture than group C. No significant differences were observed in the hazard ratios of recurrence and death among the three groups.

Conclusions

Early bisphosphonate treatment in PVO patients with osteoporosis was associated with a significantly lower occurrence of subsequent vertebral fracture at adjacent vertebral bodies and lower occurrence of subsequent surgery.

https://ift.tt/2MKTChc

Robotic-assisted pedicle screw placement fails to reduce overall postoperative complications in fusion surgery

Publication date: Available online 29 August 2018

Source: The Spine Journal

Author(s): Alexander M. Lieber, Gregory J. Kirchner, Yehuda E. Kerbel, Amrit S. Khalsa

Abstract

BACKGROUND CONTEXT

Surgeons have increasingly adopted robotic-assisted lumbar spinal fusion due to indications that robotic-assisted surgery can reduce pedicle screw misplacement. However, the impact of robotic-assisted spinal fusion on patient outcomes is less clear.

PURPOSE

This study aimed to compare rates of perioperative complications between robotic-assisted and conventional lumbar spinal fusion.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

A total of 520 patients undergoing lumbar fusion were analyzed. The average ages of patients in the robotic-assisted versus conventional groups were 60.33 and 60.31, respectively (p=.987). Patients with a diagnosis of fracture, traumatic spinal cord injury, spina bifida, neoplasia, or infection were excluded.

OUTCOME MEASURES

This study compared the rates perioperative major and minor complications for elective lumbar fusion between each cohort.

METHODS

This study screened hospital discharges in the United States from 2010 to 2014 using the National Inpatient Sample and the Nationwide Inpatient Sample (NIS). The International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) procedure codes were used to identify 209,073 patients who underwent conventional lumbar fusion (ICD 81.04-8) and 279 patients who underwent robotic-assisted lumbar fusion (ICD 81.04-8 and ICD 17.41, 17.49). Major and minor complications were identified using ICD-9-CM diagnosis codes. The robotic-assisted and conventional fusion groups were statistically matched on age, year, sex, indication, race, hospital type, and comorbidities. Univariate and multivariate logistic regression were used to compare risks of major and minor complications.

RESULTS

We matched 257 (92.11%) robotic-assisted patients with an equal number of patients undergoing conventional lumbar fusion. Minor complications occurred in 16.73% of cases in the conventional group and 31.91% of cases in the robotic-assisted group (p<.001). Major complications occurred in 6.61% of the conventional cases compared to 8.17% of robotic-assisted cases (p=.533). For robotic-assisted fusion, multivariate analysis revealed that there was no difference in the likelihood of major complications (OR=0.834, 95% CI=0.214–3.251) or minor complications (OR = 1.450, 95% CI=0.653–3.220).

CONCLUSIONS

In a statistically matched cohort, patients who underwent robotic-assisted lumbar fusion had similar rates of major and minor complications compared to patients who underwent conventional lumbar fusion.

https://ift.tt/2CbuBqS

Alterations in 90-day morbidity, mortality, and readmission rates following spine surgery in Medicare Accountable Care Organizations (2009–2014)

Publication date: Available online 27 August 2018

Source: The Spine Journal

Author(s): Andrew J. Schoenfeld, Daniel J. Sturgeon, Justin A. Blucher, Adil H. Haider, James D. Kang

Abstract

BACKGROUND CONTEXT

The impact of Accountable Care Organizations (ACOs) on healthcare quality and outcomes, including morbidity, mortality, and readmissions, has not been substantially investigated, especially following spine surgery.

PURPOSE

To evaluate the impact of ACO formation on postoperative outcomes in the 90-day period following spine surgery.

STUDY DESIGN

Retrospective review of national Medicare claims data (2009–2014).

PATIENT SAMPLE

Patients who underwent one of four lumbar spine surgical procedures in an ACO or non-ACO.

OUTCOME MEASURES

The development of in-hospital mortality, complications or hospital readmission within 90 days of the surgical procedure.

METHODS

The primary outcome measures included postsurgical complications and readmissions at 90 days following surgery. In-hospital mortality and 30-day outcomes were considered secondarily. The primary predictor variable consisted of ACO enrollment designation. Multivariable logistic regression analysis was utilized to adjust for confounders and determine the independent effect of ACO enrollment on postsurgical outcomes. The multivariable model included a propensity score adjustment that accounted for factors associated with the preferential enrollment of patients in ACOs, namely, sociodemographic characteristics, medical co-morbidities, hospital teaching status, bed size, and location.

RESULTS

In all, there were 344,813 patients identified for inclusion in this analysis with 97% (n = 332,890) treated in non-ACOs and 3% (n = 11,923) in an ACO. Although modest changes were apparent across both ACOs and non-ACOs over the time-period studied, improvements were slightly more dramatic in non-ACOs leading to statistically significant differences in both 90-day complications and readmissions. Specifically, in the period 2012–2014, ACOs demonstrated an 18% increase in the odds of 90-day complications and a 14% elevation in the odds of 90-day readmissions when compared to non-ACOs. There was no difference in hospital mortality between ACOs and non-ACOs.

CONCLUSIONS

Our study of Medicare data from 2009 to 2014 failed to demonstrate superior reductions in postoperative morbidity, mortality, and readmissions for beneficiaries treated in ACOs as compared to non-ACOs. These results indicate that meaningful changes in postoperative outcomes should not be anticipated based on organizational participation in ACOs at present.

https://ift.tt/2PVcKqK

Minimum clinically important difference of the health-related quality of life scales in adult spinal deformity calculated by latent class analysis: is it appropriate to use the same values for surgical and nonsurgical patients?

Publication date: Available online 27 August 2018

Source: The Spine Journal

Author(s): Selcen Yuksel, Selim Ayhan, Vugar Nabiyev, Montse Domingo-Sabat, Alba Vila-Casademunt, Ibrahim Obeid, Francisco Sanchez Perez-Grueso, Emre Acaroglu, European Spine Study Group (ESSG)

Abstract

BACKGROUND CONTEXT

Health-related quality of life (HRQOL) parameters have been shown to be reliable and valid in patients with adult spinal deformity (ASD). Minimum clinically important difference (MCID) has become increasingly important to clinicians in evaluating patients with a threshold of improvement that is clinically relevant.

PURPOSE

To calculate MCID and minimum detectable change (MDC) values of total scores of the Core Outcome Measures Index (COMI), Oswestry Disability Index (ODI), Physical Component Summary (PCS), Mental Component Summary (MCS) of the Short Form 36 (SF-36), and Scoliosis Research Society 22R (SRS-22R) in surgically and nonsurgically treated ASD patients who have completed an anchor question at pretreatment and 1-year follow-up.

STUDY DESIGN/SETTING

Prospective cohort.

PATIENT SAMPLE

Surgical and nonsurgical patients from a multicenter ASD database.

OUTCOME MEASURES

Self-reported HRQOL measures (COMI, ODI, SF-36, SRS-22R, and anchor question).

METHODS

A total of 185 surgical and 86 nonsurgical patients from a multicenter ASD database who completed pretreatment and 1-year follow-up HRQOL scales and the anchor question at the first year follow-up were included. The anchor question was used to determine MCID for each HRQOL measure. MCIDs were calculated by an anchor-based method using latent class analysis (LCA) and MDCs by a distribution-based method.

RESULTS

All differences between means of baseline and first year postoperative total score measures for all scales demonstrated statistically significant improvements in the overall population as well as the surgically treated patients but not in the nonsurgical group. The calculated MDC and MCID values of HRQOL parameters in the entire study population were 1.34 and 2.62 for COMI, 10.65 and 14.31 for ODI, 6.09 and 7.33 for SF-36 PCS, 6.14 and 4.37 for SF-36 MCS, and 0.42 and 0.71 for SRS-22R. The calculated MCID values for surgical and non-surgical treatment groups were 2.76 versus 1.20 for COMI, 14.96 versus 2.45 for ODI, 7.83 versus 2.15 for SF-36 PCS, 5.14 versus 2.03 for SF-36 MCS, and 0.94 versus 0.11 for SRS-22R; the MDC values for surgical and nonsurgical treatment groups were 1.22 versus 1.51 for COMI, 10.27 versus 9.45 for ODI, 5.16 versus 6.77 for SF-36 PCS, 6.05 versus 5.67 for SF-36 MCS, and 0.38 versus 0.43 for SRS-22R.

CONCLUSIONS

This study has demonstrated that MCID calculations for the HRQOL scales in ASD using LCA yield values comparable to other studies that had used different methodologies. The most important finding was the significantly different MCIDs for COMI, ODI, SF-36 PCS and SRS-22 in the surgically and nonsurgically treated cohorts. This finding suggests that a universal MCID value, inherent to a specific HRQOL for an entire cohort of ASD may not exist. Use of different MCIDs for surgical and nonsurgical patients may be warranted.

https://ift.tt/2wDkWTR

European evidence-based guidelines on pancreatic cystic neoplasms

Evidence-based guidelines on the management of pancreatic cystic neoplasms (PCN) are lacking. The guideline discussed in this podcast is a joint initiative of the European Study Group on Cystic Tumours of the Pancreas, United European Gastroenterology, European Pancreatic Club, European-African Hepato-Pancreato-Biliary Association, European Digestive Surgery, and the European Society of Gastrointestinal Endoscopy.

Listen to the discussion between the Education Editor of Gut, Mairi McLean, and Marco del Chiaro, from The European Study Group on Cystic Tumours of the Pancreas. And read the details of the guidelines on the Gut website: https://ift.tt/2wAPS7a.

https://ift.tt/2MIbmdd