Can Discharge Radiographs Predict Junctional Complications? A Decision Tree Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To determine if standing pre-discharge radiographs can predict the development of junctional complications.

MATERIALS AND METHODS

Adult spinal deformity patients who underwent fusion of the lumbar spine (≥5 levels, LIV pelvis) were included. All patients underwent full-length standing radiographs before hospital discharge. Outcomes of interest included 2-year radiographic PJK and proximal junctional failure (PJF). Patients were stratified into 3 exclusive groups: No PJK, PJK, and PJF. Chi-square automatic interaction detection (CHAID) decision tree analysis was utilized to identify pre-discharge proximal junctional angle (PJA) thresholds associated with increased risk of PJK or PJF.

RESULTS

The 117 study patients had a mean age 65.8 ± 8.5, BMI 27.2 ± 4.9, PI-LL 23.3 ± 17.4, TPA 27.2 ± 11.5. Sample was stratified into 64 (54.7%) No PJK, 39 (33.3%) PJK, 14 (12.0%) PJF. No differences were detected between cohorts in discharge alignment, preop-discharge change, or offset from age-adjusted alignment targets (P > .005). Decision tree analysis showed that the first branch point depended on the UIV, as most patients with an UT UIV did not develop PJK or PJF (no PJK, 67.4%). For patients with an LT UIV, a second branch point occurred based on the ΔPJA. 89.5% of LT patients with a ΔPJA < 4.3° were free of radiographic PJK and PJF. The third branch point occurred based on the PJA at discharge. Thus, the highest risk group was comprised of ΔPJA ≥4.3° and PJA > 15.5°, as 57.1% of developed PJF and 28.6% PJK.

CONCLUSION

Most patients with a lower thoracic UIV, preop-discharge ΔPJA ≥4.3°, and discharge PJA > 15.5° develop PJF.

Left-digit bias in surgical decision-making for lumbar spinal stenosis

BACKGROUND CONTEXT

Left-digit bias is a behavioral heuristic or cognitive "shortcut" in which the leftmost digit of a number, such as patient age, disproportionately influences surgical decisions.

PURPOSE

To determine if left-digit bias in patient age influences the decision to perform arthrodesis with instrumentation vs decompression in lumbar spinal stenosis (LSS).

DESIGN

Retrospective cohort.

PATIENT SAMPLE

Patients with an ICD-10 diagnosis of lumbar stenosis or spondylolisthesis identified in the 2017-2021 National Surgical Quality Improvement Program (NSQIP) database.

OUTCOME MEASURES

The primary outcome was the percent of patients who underwent arthrodesis with instrumentation (AwI). Matched age group comparisons without left-digit differences (ie, 76/77 vs 78/79, 80/81 vs 82/83, etc.) were performed to isolate the effect of the heuristic. Secondary outcomes including peri-operative events and complications were also compared within AwI and decompression cohorts.

METHODS

Using CPT codes, procedures were classified as either AwI or decompression. Patients were grouped into 6 cohorts based on 2-year age windows (74/75, 76/77, 78/79, 80/81, 82/83, 84/85). The cohorts were propensity matched with neighboring age groups based on the presence of spondylolisthesis, demographics, and comorbidities. The primary comparison was between those aged 78/79 vs 80/81.

RESULTS

After matching, the primary cohort consisted of two groups of 1,550 patients (aged 78/79 and 80/81). Patients aged 80/81 were less likely to undergo AwI than patients aged 78/79 (23.5% vs 27.2%, p=.021). AwI procedures occurred at similar rates between age groups with the same left digit. Within the decompression and AwI cohorts, there were no differences in secondary outcomes between patients aged 78/79 and 80/81.

CONCLUSIONS

LSS patients aged 80/81 are less likely to undergo AwI than patients aged 78/79, regardless of comorbidities. This was not seen when comparing patients with similar left digits in age. Until objective measures of physiologic capacity are established, left-digit bias may influence clinical decisions.

Pre-operative bone quality deficits and risk of complications following spine fusion surgery among postmenopausal women

Poor bone quality is a risk factor for complications after spinal fusion surgery. This study investigated pre-operative bone quality in postmenopausal women undergoing spine fusion and found that those with small bones, thinner cortices and surgeries involving more vertebral levels were at highest risk for complications.

PURPOSE

Spinal fusion is one of the most common surgeries performed worldwide. While skeletal complications are common, underlying skeletal deficits are often missed by pre-operative DXA due to artifact from spinal pathology. This prospective cohort study investigated pre-operative bone quality using high resolution peripheral CT (HRpQCT) and its relation to post-operative outcomes in postmenopausal women, a population that may be at particular risk for skeletal complications. We hypothesized that women with low volumetric BMD (vBMD) and abnormal microarchitecture would have higher rates of post-operative complications.

METHODS

Pre-operative imaging included areal BMD (aBMD) by DXA, cortical and trabecular vBMD and microarchitecture of the radius and tibia by high resolution peripheral CT. Intra-operative bone quality was subjectively graded based on resistance to pedicle screw insertion. Post-operative complications were assessed by radiographs and CTs.

RESULTS

Among 50 women enrolled (age 65 years), mean spine aBMD was normal and 35% had osteoporosis by DXA at any site. Low aBMD and vBMD were associated with "poor" subjective intra-operative quality. Skeletal complications occurred in 46% over a median follow-up of 15 months. In Cox proportional models, complications were associated with greater number of surgical levels (HR 1.19 95% CI 1.06-1.34), smaller tibia total area (HR 1.67 95% CI1.16-2.44) and lower tibial cortical thickness (HR 1.35 95% CI 1.05-1.75; model p < 0.01).

CONCLUSION

Women with smaller bones, thinner cortices and procedures involving a greater number of vertebrae were at highest risk for post-operative complications, providing insights into surgical and skeletal risk factors for complications in this population.

Revision-Free Loss of Sagittal Correction Greater Than Three Years After Adult Spinal Deformity Surgery: Who and Why?

STUDY DESIGN

Multicenter retrospective cohort study.

OBJECTIVE

To investigate risk factors for loss of correction within the instrumented lumbar spine after adult spinal deformity surgery.

SUMMARY OF BACKGROUND DATA

The sustainability of adult spinal deformity surgery remains a health care challenge. Malalignment is a major reason for revision surgery.

PATIENTS AND METHODS

A total of 321 patients who underwent fusion of the lumbar spine (≥5 levels, LIV pelvis) with a revision-free follow-up of ≥3 years were identified. Patients were stratified by a change in pelvic incidence-lumbar lordosis from 6 weeks to 3 years postoperative as "maintained" versus "loss" >5°. Those with instrumentation failure (broken rod, screw pullout, etc .) were excluded before comparisons. Demographics, surgical data, and radiographic alignment were compared. Repeated measure analysis of variance was performed to evaluate the maintenance of the correction for L1-L4 and L4-S1. Multivariate logistic regression was conducted to identify independent surgical predictors of correction loss.

RESULTS

The cohort had a mean age of 64 years, a mean Body Mass Index of 28 kg/m 2 , and 80% females. Eighty-two patients (25.5%) lost >5° of pelvic incidence-lumbar lordosis correction (mean loss 10±5°). After the exclusion of patients with instrumentation failure, 52 losses were compared with 222 maintained. Demographics, osteotomies, 3CO, interbody fusion, use of bone morphogenetic protein, rod material, rod diameter, and fusion length were not significantly different. L1-S1 screw orientation angle was 1.3 ± 4.1 from early postoperative to 3 years ( P = 0.031), but not appreciably different at L4-S1 (-0.1 ± 2.9 P = 0.97). Lack of a supplemental rod (odds ratio: 4.0, P = 0.005) and fusion length (odds ratio 2.2, P = 0.004) were associated with loss of correction.

CONCLUSIONS

Approximately, a quarter of revision-free patients lose an average of 10° of their 6-week correction by 3 years. Lordosis is lost proximally through the instrumentation ( i.e. tulip/shank angle shifts and/or rod bending). The use of supplemental rods and avoiding sagittal overcorrection may help mitigate this loss.

Bone Density Distribution in the Cervical Spine

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Given changes in bone density induced by degenerative disease, general measures of bone health (ie DEXA) are inadequate to evaluate bone density in surgical areas of interest. Regional differences in HU in the cervical spine may influence surgical strategies. The purposes of our study were to determine whether cervical Hounsfield units (HU) vary by level, examine their relationship with age, comorbidities, and alignment, and propose a technique to measure HU in the lateral masses.

METHODS

Two hundred twenty-four patients with degenerative spine pathology with a cervical computed tomography were included (2015-2019). Measurements were performed in each vertebral body (C2-T1; mid-axial, anterior-axial, posterior-axial, mid-coronal, and mid-sagittal) and 2 regions of the lateral masses (C3-C6; mid-cor, mid-sag). To evaluate reliability, 6 observers each measured 355 HU values, inter-relater reliability assessed with intraclass correlation coefficients Correlations of HU with age, BMI, comorbidities, and cervical alignment were evaluated.

RESULTS

Bone density differed by level, with the lowest HU scores in the lower cervical spine (C6-T1) (P < .001). No correlations were found between LM HU and age, BMI, CCI, or alignment (P > .05). Increased kyphosis was weakly correlated with VB HU, while age and CCI showed moderate correlations with VB HU at all levels (P<.001). ICC for HU measurements were good to excellent for the VBs, but poor to moderate for the LMs.

CONCLUSION

Bone is least dense in the lower cervical spine. HU scoring is not reliable in the lateral masses. We recommend that a level-specific approach to bone density is considered in surgical planning.

How Does Gravity Influence the Distribution of Lordosis in Patients With Sagittal Malalignment?

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Compare the supine vs standing radiographs of patients with adult spinal deformity against ideals defined by healthy standing alignment.

METHODS

56 patients with primary sagittal ASD (SRS-Schwab Type N) and 119 asymptomatic volunteers were included. Standing alignment of asymptomatic volunteers was used to calculate PI-based formulas for normative age-adjusted standing PI-LL, L4-S1, and L1-L4. These formulas were applied to the supine and standing alignment of ASD cohort. Analyses were repeated on a cohort of 25 patients with at least 5 degrees of lumbar flexibility (difference between supine and standing lordosis).

RESULTS

The asymptomatic cohort yielded the following PI-based formulas: PI-LL = -38.3 + .41*PI + .21*Age, L4-S1 = 45.3-.18*Age, L1-L4 = -3 + .48*PI). PI-LL improved with supine positioning (mean 8.9 ± 18.7°, P < .001), though not enough to correct to age-matched norms (mean offset 12.2 ± 16.9°). Compared with mean normative alignment at L1-L4 (22.1 ± 6.2°), L1-L4 was flatter on standing (7.2 ± 17.0°, P < .001) and supine imaging (8.5 ± 15.0°, P < .001). L4-S1 lordosis of subjects with L1-S1 flexibility >5° corrected on supine imaging (33.9 ± 11.1°, P = 1.000), but L1-L4 did not (23.0 ± 6.2° norm vs 2.2 ± 14.4° standing, P < .001; vs 7.3 ± 12.9° supine, P < .001).

CONCLUSIONS

When the effects of gravity are removed, the distal portion of the lumbar spine (i.e., below the apex of lordosis) corrects, suggesting that structural lumbar deformity is primarily proximal.

Robotic-Assisted Single-Position Prone Lateral Lumbar Interbody Fusion: Indications, Techniques, and Outcomes

Background

Lateral lumbar interbody fusion (LLIF) is a widely utilized minimally invasive surgical procedure for anterior fusion of the lumbar spine. However, posterior decompression or instrumentation often necessitates patient repositioning, which is associated with increased operative time and time under anesthesia1-3. The single-position prone transpsoas approach is a technique that allows surgeons to access both the anterior and posterior aspects of the spine, bypassing the need for intraoperative repositioning and therefore optimizing efficiency4. The use of robotic assistance allows for decreased radiation exposure and increased accuracy, both with placing instrumentation and navigating the lateral corridor.

Description

The patient is placed in the prone position, and pedicle screws are placed prior to interbody fusion. Pedicle screws are placed with robotic guidance. After posterior instrumentation, a skin incision for LLIF is made in the cephalocaudal direction, orthogonal to the disc space, with use of intraoperative (robotic) navigation. Fascia and abdominal muscles are incised to enter the retroperitoneal space. Under direct visualization, dilators are placed through the psoas muscle into the disc space, and an expandable retractor is placed and maintained with use of the robotic arm. Following a thorough discectomy, the disc space is sized with trial implants. The expandable cage is placed, and intraoperative fluoroscopy is utilized to verify good instrumentation positioning. Finally, posterior rods are placed percutaneously.

Alternatives

An alternative surgical approach is a traditional LLIF with the patient beginning in the lateral position, with intraoperative repositioning from the lateral to the prone position if circumferential fusion is warranted. Additional alternative surgical procedures include anterior or posterior lumbar interbody fusion techniques.

Rationale

LLIF is associated with reported advantages of decreased risks of vascular injury, visceral injury, dural tear, and perioperative infection5,6. The single-position prone transpsoas approach confers the added benefits of reduced operative time, anesthesia time, and surgical staffing requirements7. Other potential benefits of the prone lateral approach include improved lumbar lordosis correction, gravity-induced displacement of peritoneal contents, and ease of posterior decompression and instrumentation8-11. Additionally, the use of robotic assistance offers numerous benefits to minimally invasive techniques, including intraoperative navigation, instrumentation templating, a more streamlined workflow, and increased accuracy in placing instrumentation, while also providing a reduction in radiation exposure and operative time. In our experience, the table-mounted LLIF retractor has a tendency to drift toward the floor-i.e., anteriorly-when the patient is positioned prone, which may, in theory, increase the risk of iatrogenic bowel injury. The rigid robotic arm is much stiffer than the traditional retractor, thereby reducing this risk.

Expected Outcomes

Compared with traditional LLIF, with the patient in the lateral and then prone positions, the single-position prone LLIF has been shown to have several benefits. Guiroy et al. performed a systematic review comparing single and dual-position LLIF and found that the single-position surgical procedure was associated with significantly lower operative time (103.1 versus 306.6 minutes), estimated blood loss (97.3 versus 314.4 mL), and length of hospital stay (1.71 versus 4.08 days)17. Previous studies have reported improved control of segmental lordosis in the prone position, which may be advantageous for patients with sagittal imbalance18,19.

Important Tips

Adequate release of the deep fascial layers is critical for minimizing deflection of retractors and navigated instruments.The hip should be maximally extended to maximize lordosis, allowing for posterior translation of the femoral nerve and increasing the width of the lateral corridor.A bolster is placed against the rib cage to provide resistance to the laterally directed force when impacting the graft.The cranial and caudal limits of the approach are bounded by the ribcage and iliac crest; thus, surgery at the upper or lower lumbar levels may not be feasible for this approach. Preoperative radiographs should be evaluated to determine the feasibility of this approach at the intended levels.When operating at the L4-L5 disc space, posterior retraction places substantial tension on the femoral nerve. Thus, retractor time should be minimized as much as possible and limited to a maximum of approximately 20 minutes20-22.A depth of field (distance from the midline to the flank) of approximately 20 cm may be the limit for this approach with the current length of retractor blades19.In robotic-assisted surgical procedures, minor position shifts in surface landmarks, the robotic arm, or the patient may substantially impact the navigation software. It is critical for the patient and navigation components to remain fixed throughout the operation.In addition to somatosensory evoked potential and electromyographic monitoring, additional motor evoked potential neuromonitoring or monitoring of the saphenous nerve may be considered22.In the prone position, the tendency is for the retractor to migrate superficially and anteriorly. It is critical to be aware of this tendency and to maintain stable retractor positioning.

Acronyms and Abbreviations

LLIF = lateral lumbar interbody fusionMIS = minimally invasive surgeryPTP = prone transpsoasy.o. = years oldASIS = anterior superior iliac spinePSIS = posterior superior iliac spineALIF = anterior lumbar interbody fusionTLIF = transforaminal lumbar interbody fusionMEP = motor evoked potentialSSEP = somatosensory evoked potentialEMG = electromyographyCT = computed tomographyMRI = magnetic resonance imagingOR = operating roomPOD = postoperative dayIVC = inferior vena cavaA. = aortaPS. = psoas.

Single-position Minimally Invasive Surgery for Correction of Adult Spinal Deformity

Minimally invasive adult spinal deformity (MIS ASD) surgery may offer benefits over conventional techniques in select circumstances. The success of the procedure is based on proper patient selection, restoring adequate alignment, and optimizing fusion. In the past, MIS techniques were limited because of the need to reposition the patient-a source of increased surgical time and potentially patient risk. New developments now allow for single-position, MIS correction of adult deformity. Additional research will be needed to determine the ideal patient for minimally invasive adult spinal deformity surgery and whether prone or lateral single-position confers the best outcomes.

Is High-Dose Tranexamic Safe in Spine Surgery? A Systematic Review and Meta-Analysis

STUDY DESIGN

Literature review and meta-analysis.

OBJECTIVES

Single-center series may be underpowered to detect whether high-dose (HD) tranexamic acid (TXA) confers a higher risk of complications. We sought to determine the safety and efficacy of HD TXA as compared to low-dose (LD) or placebo.

METHODS

A systematic literature review was performed to find studies where spine surgery patients were given HD TXA (loading dose ≥30 mg/kg). Complication rates were pooled, and meta-analyses performed on outcomes of interest. Articles were evaluated for risk of bias and a strength of evidence assessment was given for each conclusion.

RESULTS

Twenty three studies (n = 2331) were included. The pooled medical complication rate was 3.2% in pediatric patients, 8.2% in adults. Using lower dose TXA or placebo as the reference, meta-analysis showed no difference in medical complications (n = 1,723, OR 1.22 [95% CI, .78 to 1.22]; P = .388; I2 = 0%) or thrombotic events (n = 1158 patients, OR 1.27 [95% CI, .71 to 2.63]; P = .528; I2 = 0%). Compared to LD, HD TXA was associated with less intraoperative blood loss (823 patients, WMD = -285 [95% CI, -564 to -5.90]; P = .0454; I2 = 86%), fewer perioperative transfusions (n = 505, OR .28 [95% CI, .082 to .96]; P = .043; I2 = 76%) and lower perioperative transfusion volumes (n = 434, WMD -227.7 mL [95% CI, -377.3 to -78.02]; P = .0029; I2 = 0%).

CONCLUSION

Compared to LD TXA or placebo, there is moderate evidence that HD is not associated with an increased risk of medical complications. Compared to LD, there is moderate evidence that HD reduces transfusion requirements. High-Dose TXA can be safely utilized in healthy patients undergoing major spine surgery.

Why Didn't You Walk Yesterday? Factors Associated With Slow Early Recovery After Adult Spinal Deformity Surgery

STUDY DESIGN

This is a retrospective case-control study.

OBJECTIVES

The objectives of this study are to identify (1) risk factors for delayed ambulation following adult spinal deformity (ASD) surgery and (2) complications associated with delayed ambulation.

METHODS

One-hundred and ninety-one patients with ASD who underwent posterior-only fusion (≥5 levels, LIV pelvis) were reviewed. Patients who ambulated with physical therapy (PT) on POD2 or later (LateAmb, n = 49) were propensity matched 1:1 to patients who ambulated on POD0-1 (NmlAmb, n = 49) based on the extent of fusion and surgical invasiveness score (ASD-S). Risk factors, as well as inpatient medical complications were compared. Logistic regressions were used to identify risk factors for late ambulation.

RESULTS

Of the patients who did not ambulate on POD0-1, 32% declined participation secondary to pain or dizziness/fatigue, while 68% were restricted from participation by PT/nursing due to fatigue, inability to follow commands, nausea/dizziness, pain, or hypotension. Logistic regression showed that intraoperative estimated blood loss (EBL) >2L (OR = 5.57 [1.51-20.55], P = .010) was independently associated with an increased risk of delayed ambulation, with a 1.25 times higher risk for every 250 mL increase in EBL (P = .014). Modified 5-Item Frailty Index (mFI-5) was also independently associated with delayed ambulation (OR = 2.53 [1.14-5.63], P = .023). LateAmb demonstrated a higher hospital LOS (8.4 ± 4.0 vs 6.2 ± 2.6, P < .001). The LateAmb group trended toward an increase in medical complications on POD3+ (14.3% vs 26.5%, P = .210).

CONCLUSIONS

EBL demonstrates a dose-response relationship with risk for delayed ambulation. Delayed ambulation increases LOS and may impact medical complications.

Telemedicine in Spine Surgery: Global Perspectives and Practices

STUDY DESIGN

Cross-sectional, anonymous, international survey.

OBJECTIVES

The COVID-19 pandemic has resulted in the rapid adoption of telemedicine in spine surgery. This study sought to determine the extent of adoption and global perspectives on telemedicine in spine surgery.

METHODS

All members of AO Spine International were emailed an anonymous survey covering the participant's experiences with and perceptions of telemedicine. Descriptive statistics were used to depict responses. Responses were compared among regions.

RESULTS

485 spine surgeons participated in the survey. Telemedicine usage rose from <10.0% to >39.0% of all visits. A majority of providers (60.5%) performed at least one telemedicine visit. The format of "telemedicine" varied widely by region: European (50.0%) and African (45.2%) surgeons were more likely to use phone calls, whereas North (66.7%) and South American (77.0%) surgeons more commonly used video (P < 0.001). North American providers used telemedicine the most during COVID-19 (>60.0% of all visits). 81.9% of all providers "agreed/strongly agreed" telemedicine was easy to use. Respondents tended to "agree" that imaging review, the initial appointment, and postoperative care could be performed using telemedicine. Almost all (95.4%) surgeons preferred at least one in-person visit prior to the day of surgery.

CONCLUSION

Our study noted significant geographical differences in the rate of telemedicine adoption and the platform of telemedicine utilized. The results suggest a significant increase in telemedicine utilization, particularly in North America. Spine surgeons found telemedicine feasible for imaging review, initial visits, and follow-up visits although the vast majority still preferred at least one in-person preoperative visit.

Optimizing the Definition of Proximal Junctional Kyphosis: A Sensitivity Analysis

STUDY DESIGN

Diagnostic binary threshold analysis.

OBJECTIVE

(1) Perform a sensitivity analysis demonstrating the test performance metrics for any combination of proximal junctional angle (PJA) magnitude and change; (2) Propose a new proximal junctional kyphosis (PJK) criteria.

SUMMARY OF BACKGROUND DATA

Previous definitions of PJK have been arbitrarily selected and then tested through retrospective case series, often showing little correlation with clinical outcomes.

MATERIALS AND METHODS

Surgically treated adult spinal deformity patients (≥4 levels fused) enrolled into a prospective, multicenter database were evaluated at a minimum 2-year follow-up for proximal junctional failure (PJF). Using PJF as the outcome of interest, test performance metrics including sensitivity, positive predictive value, and F1 metrics (harmonic mean of precision and recall) were calculated for all combinations of PJA magnitude and change using different combinations of perijunctional vertebrae. The combination with the highest F1 score was selected as the new PJK criteria. Performance metrics of previous PJK definitions and the new PJK definition were compared.

RESULTS

Of the total, 669 patients were reviewed. PJF rate was 10%. Overall, the highest F1 scores were achieved when the upper instrumented vertebrae -1 (UIV-1)/UIV+2 angle was measured. For lower thoracic cases, out of all the PJA and magnitude/change combinations tested, a UIV-1/UIV+2 magnitude of -28° and a change of -20° was associated with the highest F1 score. For upper thoracic cases, a UIV-1/UIV+2 magnitude of -30° and a change of -24° were associated with the highest F1 score. Using PJF as the outcome, patients meeting this new criterion (11.5%) at 6 weeks had the lowest survival rate (74.7%) at 2 years postoperative, compared with Glattes (84.4%) and Bridwell (77.4%).

CONCLUSIONS

Out of all possible PJA magnitude and change combinations, without stratifying by upper thoracic versus lower thoracic fusions, a magnitude of ≤-28° and a change of ≤-22° provide the best test performance metrics for predicting PJF.

Complications and Revisions After Spine Surgery in Patients With Skeletal Dysplasia: Have We Improved?

STUDY DESIGN

Retrospective case series.

OBJECTIVE

To report contemporary rates of complications and subsequent surgery after spinal surgery in patients with skeletal dysplasia.

METHODS

A case series of 25 consecutive patients who underwent spinal surgery between 2007 and 2017 were identified from a single institution's skeletal dysplasia registry. Patient demographics, medical history, surgical indication, complications, and subsequent surgeries (revisions, extension to adjacent levels, or for pathology at a non-contiguous level) were collected. Charlson comorbidity indices were calculated as a composite measure of overall health.

RESULTS

Achondroplasia was the most common skeletal dysplasia (76%) followed by spondyloepiphyseal dysplasia (20%); 1 patient had diastrophic dysplasia (4%). Average patient age was 53.2 ± 14.7 years and most patients were in excellent cardiovascular health (88% Charlson Comorbidity Index 0-4). Mean follow up after the index procedure was 57.4 ± 39.2 months (range). Indications for surgery were mostly for neurologic symptoms. The most commonly performed surgery was a multilevel thoracolumbar decompression without fusion (57%). Complications included durotomy (36%), neurologic complication (12%), and infection requiring irrigation and debridement (8%). Nine patients (36%) underwent a subsequent surgery. Three patients (12%) underwent a procedure at a non-contiguous anatomic zone, 3 (12%) underwent a revision of the previous surgery, and another 3 (12%) required extension of their previous decompression or fusion.

CONCLUSIONS

Surgical complication rates remain high after spine surgery in patients with skeletal dysplasia, likely attributable to inherent characteristics of the disease. Patients should be counseled on their risk for complication and subsequent surgery.

Catastrophic acute failure of pelvic fixation in adult spinal deformity requiring revision surgery: a multicenter review of incidence, failure mechanisms, and risk factors

OBJECTIVE

There are few prior reports of acute pelvic instrumentation failure in spinal deformity surgery. The objective of this study was to determine if a previously identified mechanism and rate of pelvic fixation failure were present across multiple institutions, and to determine risk factors for these types of failures.

METHODS

Thirteen academic medical centers performed a retrospective review of 18 months of consecutive adult spinal fusions extending 3 or more levels, which included new pelvic screws at the time of surgery. Acute pelvic fixation failure was defined as occurring within 6 months of the index surgery and requiring surgical revision.

RESULTS

Failure occurred in 37 (5%) of 779 cases and consisted of either slippage of the rods or displacement of the set screws from the screw tulip head (17 cases), screw shaft fracture (9 cases), screw loosening (9 cases), and/or resultant kyphotic fracture of the sacrum (6 cases). Revision strategies involved new pelvic fixation and/or multiple rod constructs. Six patients (16%) who underwent revision with fewer than 4 rods to the pelvis sustained a second acute failure, but no secondary failures occurred when at least 4 rods were used. In the univariate analysis, the magnitude of surgical correction was higher in the failure cohort (higher preoperative T1-pelvic angle [T1PA], presence of a 3-column osteotomy; p < 0.05). Uncorrected postoperative deformity increased failure risk (pelvic incidence-lumbar lordosis mismatch > 10°, higher postoperative T1PA; p < 0.05). Use of pelvic screws less than 8.5 mm in diameter also increased the likelihood of failure (p < 0.05). In the multivariate analysis, a larger preoperative global deformity as measured by T1PA was associated with failure, male patients were more likely to experience failure than female patients, and there was a strong association with implant manufacturer (p < 0.05). Anterior column support with an L5-S1 interbody fusion was protective against failure (p < 0.05).

CONCLUSIONS

Acute catastrophic failures involved large-magnitude surgical corrections and likely resulted from high mechanical strain on the pelvic instrumentation. Patients with large corrections may benefit from anterior structural support placed at the most caudal motion segment and multiple rods connecting to more than 2 pelvic fixation points. If failure occurs, salvage with a minimum of 4 rods and 4 pelvic fixation points can be successful.

Classification system for cervical spine deformity morphology: a validation study

OBJECTIVE

The objective of this study was to initially validate a recent morphological classification of cervical spine deformity pathology.

METHODS

The records of 10 patients for each of the 3 classification subgroups (flat neck, focal deformity, and cervicothoracic), as well as for 8 patients with coronal deformity only, were extracted from a prospective multicenter database of patients with cervical deformity (CD). A panel of 15 physicians of various training and professional levels (i.e., residents, fellows, and surgeons) categorized each patient into one of the 4 groups. The Fleiss kappa coefficient was utilized to evaluate intra- and interrater reliability. Accuracy, defined as properly selecting the main driver of deformity, was reported overall, by morphotype, and by reviewer experience.

RESULTS

The overall classification demonstrated a moderate to substantial agreement (round 1: interrater Fleiss kappa = 0.563, 95% CI 0.559-0.568; round 2: interrater Fleiss kappa = 0.612, 95% CI 0.606-0.619). Stratification by level of training demonstrated similar mean interrater coefficients (residents 0.547, fellows 0.600, surgeons 0.524). The mean intrarater score was 0.686 (range 0.531-0.823). A substantial agreement between rounds 1 and 2 was demonstrated in 81.8% of the raters, with a kappa score > 0.61. Stratification by level of training demonstrated similar mean intrarater coefficients (residents 0.715, fellows 0.640, surgeons 0.682). Of 570 possible questions, reviewers provided 419 correct answers (73.5%). When considering the true answer as being selected by at least one of the two main drivers of deformity, the overall accuracy increased to 86.0%.

CONCLUSIONS

This initial validation of a CD morphological classification system reiterates the importance of dynamic plain radiographs for the evaluation of patients with CD. The overall reliability of this CD morphological classification has been demonstrated. The overall accuracy of the classification system was not impacted by rater experience, demonstrating its simplicity.

Supine Imaging Is a Superior Predictor of Long-Term Alignment Following Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To investigate correlations between preoperative supine imaging and postoperative alignment.

METHODS

A retrospective review was conducted of a single-institution database of patients with adult spinal deformity (ASD). Patients were stratified by fusion location in the lumbar or thoracic spine. Outcomes of interest were postoperative lumbar lordosis (LL) and thoracic kyphosis (TK). Sagittal alignment parameters were compared and correlation analyses were performed. Multilinear stepwise regression was conducted to identify independent predictors of postoperative LL or TK. Regression analyses were repeated within the lumbar and thoracic fusion cohorts.

RESULTS

A total of 99 patients were included (mean age 63.2 years, 83.1% female, mean body mass index 27.3 kg/m²). Scoliosis Research Society classification demonstrated moderate to severe sagittal and/or coronal deformity (pelvic tile modifier, 18.2% ++; sagittal vertical axis, 27.3% ++, pelvic incidence minus lumbar lordosis mismatch, 29.3% ++, SRS type, 29.3% N type curve and 68.7% L or D type curve). A total of 73 patients (73.7%) underwent lumbar fusion and 50 (50.5%) underwent thoracic fusion. Correlation analyses demonstrated a significant association between pre- and postoperative LL and TK. Multilinear regression demonstrated that LL supine and pelvic incidence were significant predictors of postoperative LL (r² = 0.568, P < .001). LL supine, TK supine, and age were significant predictors of postoperative TK (r² = 0.490, P < .001).

CONCLUSION

Preoperative supine films are superior to standing in predicting postoperative alignment at 1-year follow-up. Anticipation of undesired alignment changes through supine imaging may be useful in mitigating the risk of iatrogenic malalignment.

Acute development of spinal lumbar synovial facet cyst within 1 week after lumbar decompression: illustrative case

BACKGROUND

Synovial facet cysts can sometimes develop in patients with lumbar spinal stenosis after decompressive laminectomy. The etiology of spinal lumbar synovial cysts is still unclear, but their formation is associated with underlying spinal instability, facet joint arthropathy, and degenerative spondylolisthesis.

OBSERVATIONS

A 61-year-old-male patient presented with neurogenic claudication due to lumbar spinal stenosis. Radiographic studies showed grade I spondylolisthesis and radiological predictors of delayed spinal instability. He underwent lumbar decompression and shortly thereafter developed spinal instability and recurrent symptoms, with formation of a new spinal lumbar synovial facet cyst. He required revisional decompression, cyst excision, and posterolateral spinal fusion for definitive treatment.

LESSONS

The literature reports postoperative spinal instability in up to one-third of patients with lumbar spinal stenosis and stable degenerative spondylolisthesis who undergo decompressive laminectomy. Close radiographic monitoring and early advanced imaging may be prudent in this patient population if they develop new postoperative neurological symptoms and show radiographic predictors of instability on preoperative imaging. Posterolateral spinal fusion with instrumentation should be considered in addition to lumbar decompression in this select group of patients who demonstrate radiographic predictors of delayed spinal instability if they are medically capable of tolerating a spinal fusion procedure.

Early Opioid Consumption Patterns After Anterior Cervical Spine Surgery

STUDY DESIGN

This is a prospective observational study.

OBJECTIVE

The aim was to record daily opioid use and pain levels after 1-level or 2-level anterior cervical discectomy and fusion (ACDF) or cervical disc arthroplasty (CDA).

SUMMARY OF BACKGROUND DATA

Data to inform opioid prescription guidelines following ACDF or CDA is lacking. Understanding postoperative opioid consumption behaviors is critical to provide appropriate postdischarge prescriptions.

METHODS

Patients undergoing 1-level or 2-level primary ACDF or CDA were consecutively enrolled at 2 participating institutions between March 2018 and March 2019. Patients with opioid dependence (defined as daily use ≥6 mo before surgery) were excluded. Starting postoperative day 1, daily opioid use and numeric pain rating scale pain levels were collected through a Health Insurance Portability and Accountability Act-compliant, automated text-messaging system. To facilitate clinical applications, opioid use was converted from oral morphine equivalents into "pills" (oxycodone 5 mg equivalents). After 6 weeks or upon patient-reported cessation of opioid use, final survey questions were asked. Refill data were verified from the state prescription registry. Risk factors for patients in top quartile of consumption were analyzed.

RESULTS

Of 57 patients, 48 completed the daily queries (84.2%). Mean age of the patient sample was 50.2±10.9 years. Thirty-two patients (66.7%) underwent ACDF and 16 CDA (33.3%); 64.6% one level; 35.4% two levels. Median postdischarge use was 6.7 pills (range: 0-160). Cumulative opioid use did not vary between the 1-level and 2-level groups (median pill consumption, 10 interquartile range: 1.3-31.3 vs. 4 interquartile range: 0-18, respectively, P=0.085). Thirteen patients (27.1%) did not use any opioids after discharge. Of those patients that took opioids after discharge, half ceased opioids by postoperative day 8. Preoperative intermittent opioid use was associated with the top quartile of opioid consumption (9.1% vs. 50%, P=0.006).

CONCLUSION

Given that most patients use few opioids, patients could be offered the option of a 12 oxycodone 5 mg (90 oral morphine equivalents) discharge prescription, accompanied by education on appropriate opioid use and disposal.

The Spine Physical Examination Using Telemedicine: Strategies and Best Practices

STUDY DESIGN

Technical note.

OBJECTIVES

To provide spine surgeons new to telemedicine with a structured physical examination technique based on manual motor testing principles.

METHODS

Expert experience describing a series of specific maneuvers for upper and lower extremity strength testing that can be performed using a telemedicine platform. In addition, we offer instruction on "setting up" for these visits and highlight special tests that can be used to diagnose specific cervical and lumbar spine conditions.

RESULTS

From our experiences in conducting telemedicine visits, we provide a means of testing and scoring upper and lower extremity strength for interpretation of weakness in the context of traditional manual motor testing. Also, we acknowledge the limitations of a remote examination and discuss maneuvers that cannot be performed remotely.

CONCLUSIONS

COVID-19 has drastically altered the delivery of care for patients with spine-related complaints. The need for social distancing has led to the widespread adoption of telemedicine. This technical note provides an urgently needed framework for the standardization of the remote physical exam. Validation of the exam as a diagnostic tool will be a crucial next step in studying the impact of telemedicine.

The impact of preoperative supine radiographs on surgical strategy in adult spinal deformity

OBJECTIVE

Preoperative planning for adult spinal deformity (ASD) surgery is essential to prepare the surgical team and consistently obtain postoperative alignment goals. Positional imaging may allow the surgeon to evaluate spinal flexibility and anticipate the need for more invasive techniques. The purpose of this study was to determine whether spine flexibility, defined by the change in alignment between supine and standing imaging, is associated with the need for an osteotomy in ASD surgery.

METHODS

A single-center, dual-surgeon retrospective analysis was performed of adult patients with ASD who underwent correction of a thoracolumbar deformity between 2014 and 2018 (pelvis to upper instrumented vertebra between L1 and T9). Patients were stratified into osteotomy (Ost) and no-osteotomy (NOst) cohorts according to whether an osteotomy was performed (Schwab grade 2 or higher). Demographic, surgical, and radiographic parameters were compared. The sagittal correction from intraoperative prone positioning alone (sagittal flexibility percentage [Sflex%]) was assessed by comparing the change in lumbar lordosis (LL) between preoperative supine to standing radiographs and preoperative to postoperative alignment.

RESULTS

Demographics and preoperative and postoperative sagittal alignment were similar between the Ost (n = 60, 65.9%) and NOst (n = 31, 34.1%) cohorts (p > 0.05). Of all Ost patients, 71.7% had a grade 2 osteotomy (mean 3 per patient), 21.7% had a grade 3 osteotomy, and 12.5% underwent both grade 3 and grade 2 osteotomies. Postoperatively, the NOst and Ost cohorts had similar pelvic incidence minus lumbar lordosis (PI-LL) mismatch (mean PI-LL 5.2° vs 1.2°; p = 0.205). Correction obtained through positioning (Sflex%) was significantly lower for in the osteotomy cohort (38.0% vs 76.3%, p = 0.004). A threshold of Sflex% < 70% predicted the need for osteotomy at a sensitivity of 78%, specificity of 56%, and positive predictive value of 77%.

CONCLUSIONS

The flexibility of the spine is quantitatively related to the use of an osteotomy. Prospective studies are needed to determine thresholds that may be used to standardize surgical decision-making in ASD surgery.

Early Failures After Lumbar Discectomy Surgery: An Analysis of 62 690 Patients

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine the rate of early failures (readmission or reoperation for new or recurrent pain/neurological symptoms) within 30 days after lumbar discectomy and identify associated risk factors.

METHODS

A retrospective cohort study was conducted of patients undergoing lumbar discectomy in the National Surgical Quality Improvement Program database between 2013 and 2017. Rates of readmission for new or recurrent symptoms or reoperation for revision discectomy or fusion within 30 days postoperatively were measured and correlated with risk factors.

RESULTS

In total 62 690 patients were identified; overall rate of readmission within 30 days was 3.3%, including 1.2% for pain or neurological symptoms. Populations at increased risk of readmission were those with 3 or more levels of treatment (2.0%, odds ratio [OR] 2.8%, P < .01), age >70 years (1.8%, OR 1.6, P < .01), class 3 obesity (1.5%, OR 1.4, P = .04), and female gender (1.4%, OR 1.2, P = .02). The overall rate of reoperation within 30 days was 2.2%, including 1.2% for revision decompression or lumbar fusion surgery. Populations at increased risk of reoperation were revision discectomies (1.4%, OR 1.7, P < .01) and females (1.1%, OR 1.4, P < 0.01). Extraforaminal discectomies were associated with lower rates of readmission (0.7%, OR 0.6, P = 0.02) and reoperation (0.4%, OR 0.4, P = .01).

CONCLUSIONS

Early failures after lumbar discectomy surgery are rare. However, certain subpopulations are associated with increased rates of early failure: obesity, multilevel surgery, females, and revision discectomies.

Prevalence of Cannabidiol Use in Patients With Spine Complaints: Results of an Anonymous Survey

BACKGROUND

Cannabidiol (CBD) is a cannabis derivative that has been popularized as a medicinal product with analgesic and anti-inflammatory effects. Given the anecdotal observations that several patients have reported use of CBD for spine-related pain, this study was designed to characterize CBD consumption patterns and perceived effects in patients with spine-related complaints.

METHODS

The study design was a cross-sectional survey. Over a 4-week period, an anonymous paper survey was administered to all patients presenting for evaluation by 1 of 9 spine surgeons at a single institution. Surveys were given upon registration for the office visit and collected by the office manager or nurse before evaluation by the surgeon. Patients were included regardless of surgical status (ie, preoperative, postoperative, or nonoperative) or region of pathology (lumbar, thoracic, or cervical). The survey consisted of multiple-choice questions on patient patterns of CBD use.

RESULTS

Out of 300 surveys, 214 (71%) were completed. CBD use for spine-related pain was reported by 54 (25.2%) patients. CBD was initially used for potential relief of back pain (66.7%), neck pain (37.0%), leg pain (35.2%), and/or arm pain (9.3%). Users also sought improvements in insomnia (25.9%) and mood (18.5%). Oil was the most popular formulation (64.8%). CBD was most often consumed 2-5 times (40.7%) or 6-10 times (31.5%) per week. The most common source of initial recommendation for CBD was friends or family (75.9%). Reported benefits were pain relief (46.3%), improved sleep (33.3%), and reduced anxiety (20.4%); however, 24.1% of patients reported no benefit from CBD use. The most reported side effect was fatigue (7.4%). Most users (63.0%) would recommend CBD to a friend for pain relief.

CONCLUSION

CBD is already used by many patients, and further high-quality research on this supplement is essential.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

CBD is a commonly used by spine patients as an off label treatment.

Factors Associated With Short Length of Stay After Long Fusions for Adult Spinal Deformity: Initial Steps Toward Developing an Enhanced Recovery Pathway

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

The identification of case types and institutional factors associated with reduced length of stay (LOS) is a key initial step to inform the creation of clinical care pathways that can assist hospitals to maximize the benefit of value-based payment models. The objective of this study was to identify preoperative, intraoperative, and postoperative factors associated with shorter than expected LOS after adult spinal deformity (ASD) surgery.

METHODS

A retrospective cohort study was performed of 82 patients with ASD who underwent ≥5 levels of fusion to the pelvis between 2013 and 2018. A LOS <6 days was determined as a basis for comparison, as 5.7 days was the "expected LOS" generated through Poisson regression modeling of the sample. Clinical, radiographic, surgical, and postoperative factors were compared between those staying ≥6 days (L group) and <6 days (S group). Logistic regression was used to identify factors associated with LOS <6 days.

RESULTS

A total of 35 patients were in group S (42.7%). Gender, age, body mass index, ASA (American Society of Anesthesiologists) class, and use of preoperative narcotics, revision surgery, day of admission, and surgical complications did not vary between the cohorts (P > .05). Mild-moderate preoperative sagittal deformity (sagittal Schwab modifiers 0 or +), lower estimated blood loss (<1200 mL), fewer levels fused (7 vs 10 levels), shorter operating room time, procedure end time before 15:00, and no intensive care unit stay, were associated with short LOS (P < .05). Only 1 major medical complication occurred in the short LOS group (P < .05).

CONCLUSIONS

This study identifies the ASD "case phenotype," intra-, and postoperative benchmarks associated with shorter LOS, providing targets for pathways designed to reduce LOS.

The utility of supine radiographs in the assessment of thoracic flexibility and risk of proximal junctional kyphosis

OBJECTIVE

Supine radiographs have successfully been used for preoperative planning of lumbar deformity corrections. However, they have not been used to assess thoracic flexibility, which has recently garnered attention as a potential contributor to proximal junctional kyphosis (PJK). The purpose of this study was to compare supine to standing radiographs to assess thoracic flexibility and to determine whether thoracic flexibility is associated with PJK.

METHODS

A retrospective study was conducted of a single-institution database of patients with adult spinal deformity (ASD). Sagittal alignment parameters were compared between standing and supine and between pre- and postoperative radiographs. Thoracic flexibility was determined as the change between preoperative standing thoracic kyphosis (TK) and preoperative supine TK, and these changes were measured over the overall thoracic spine and the fused portion of the thoracic spine (i.e., TK fused). A case-control analysis was performed to compare thoracic flexibility between patients with PJK and those without (no PJK). The cohort was also stratified into three groups based on thoracic flexibility: kyphotic change (increased TK), lordotic change (decreased TK), and no change. The PJK rate was compared between the cohorts.

RESULTS

A total of 101 patients (mean 63 years old, 82.2% female, mean BMI 27.4 kg/m2) were included. Preoperative Scoliosis Research Society-Schwab ASD classification showed moderate preoperative deformity (pelvic tilt 27.7% [score ++]; pelvic incidence-lumbar lordosis mismatch 44.6% [score ++]; sagittal vertical axis 42.6% [score ++]). Postoperatively, the average offset from age-adjusted alignment goals demonstrated slight overcorrection in the study sample (-8.5° ± 15.6° pelvic incidence-lumbar lordosis mismatch, -29.2 ± 53.1 mm sagittal vertical axis, -5.4 ± 10.8 pelvic tilt, and -7.6 ± 11.7 T1 pelvic angle). TK decreased between standing and supine radiographs and increased postoperatively (TK fused: -25.3° vs -19.6° vs -29.9°; all p < 0.001). The overall rate of radiographic PJK was 23.8%. Comparisons between PJK and no PJK demonstrated that offsets from age-adjusted alignment goals were similar (p > 0.05 for all). There was a significant difference in the PJK rate when stratified by thoracic flexibility cohorts (kyphotic: 0.0% vs no change: 18.4% vs lordotic: 35.0%; p = 0.049). Logistic regression revealed thoracic flexibility (p = 0.045) as the only independent correlate of PJK.

CONCLUSIONS

Half of patients with ASD experienced significant changes in TK during supine positioning, a quality that may influence surgical strategy. Increased thoracic flexibility is associated with PJK, possibly secondary to fusing the patient's spine in a flattened position intraoperatively.

Enhanced recovery pathway in adult patients undergoing thoracolumbar deformity surgery

BACKGROUND CONTEXT

Enhanced recovery (ERAS) pathways can help hospitals maximize the incentives of bundled payment models while maintaining high-quality patient care. A key component of an enhanced recovery pathway is the ability to predictably reduce inpatient length of stay, as this is a critical component of the cost equation.

PURPOSE

To determine the efficacy of an enhanced recovery pathway on reducing length of stay after thoracolumbar adult deformity surgery.

STUDY DESIGN

Single surgeon retrospective review of prospectively-collected data.

PATIENT SAMPLE

Forty adult deformity patients who underwent ≥5 levels of fusion to the pelvis (two to L5) with a single surgeon before and after implementation of an ERAS pathway.

METHODS

The pathway involved participation by anesthesiology, hospital medicine, and physical therapy, and was designed to achieve goals previously associated with decreased LOS (eg, EBL<1200 mL, procedure time <4.5 hours, avoidance of ICU postoperatively, and mobilization POD0-1). Patients were propensity-score matched 1:1 to a historical cohort (enhanced recovery [ER] and historical [H] cohorts), based on demographics, medical comorbidities, radiographic alignment parameters, and surgical factors. Outcomes were compared to determine the effect of the enhanced recovery pathway. Primary outcomes included LOS and 90-day complications and readmissions.

RESULTS

After matching, gender, BMI, ASA class, preoperative opioid dependence, day of surgery, sagittal alignment parameters, rate of revision surgery, three-column osteotomies, and interbody fusions were comparable between the cohorts (p>.05). In the ER cohort, there was reduced EBL (920±640 vs. 1437±555, p=.004) and no ER patient went to the ICU immediately following surgery, compared with 30% of H patients (p=.022). The ER cohort also had a greater number of patients ambulating by POD1 compared to the H cohort (100% vs. 55%, p=.010). ER patients had a shorter LOS (4.5±1.3 vs. 7.3±4.4 days, p=.010). A 90-day readmission and complications were comparable between the cohorts (p>.05).

CONCLUSIONS

The creation of an ERAS pathway for patients undergoing thoracolumbar adult deformity surgery reduced length of stay without negatively affecting short-term morbidity and complications. Given the specificity of this pathway to a single surgeon and hospital, the resources and staffing changes that were instrumental in creating the pathway may not be generalizable to other centers.

The relationship of global sagittal malalignment to fatty infiltration in the aging spine

PURPOSE

To investigate associations between muscle size, fat infiltration (FI), and global sagittal alignment in patients with adult spinal deformity (ASD).

METHODS

Retrospective cohort study was conducted on a single-institution database of ASD patients with preoperative radiographs and CTs. Following multiplanar reconstructions of CTs, images in the plane of each vertebra were generated. The posterior vertebral musculature (PVM) was contoured on axial images at three vertebral levels (T2, T10, L3). FI was calculated by comparing Hounsfield units within muscles to the normative values of fat. Correlation analyses were conducted between demographics, alignment, and muscle characteristics.

RESULTS

107 patients underwent preoperative spine CT (58yo, 79%F, BMI 27 kg/m²). Muscle data were available for 49 pts at T2, 39 pts at T10, and 81 pts at L3. Mean FI was T2 = 33% ± 18, T10 = 28% ± 19, L3_Erector = 39% ± 19, and L3_Psoas = 19% ± 9. FI correlated across levels (T2 vs. T10 r = 0.698; T10 vs L3_Erector r = 0.506; L3_Erector vs Psoas r = 0.419) and with demographics; older pts had greater fat percentages (r = 0.31-0.45) and BMIs (r = 0.24-0.51). Increased FI at T2, T10, and L3 was associated with increased pelvic retroversion (PT: r = 0.25-0.43), global deformity (TPA: r = 0.27-0.45), and anterior malalignment (SVA: r = 0.23-0.41). The degree of FI in the PVM increased with the severity of SRS-Schwab PT and SVA modifiers.

CONCLUSION

In ASD patients, global sagittal malalignment is related to FI of the PVM throughout the lumbar and thoracic spine, as identified through CT. Future research should investigate how FI relates to ASD pathogenesis.

The Use of Patient-Reported Outcomes Measurement Information System in Spine: A Systematic Review

BACKGROUND

The Patient-Reported Outcomes Measurement Information System (PROMIS) was developed to provide an easily administered patient-outcome questionnaire that was adaptable to a variety of medical and surgical subspecialties. Numerous authors have examined the effectiveness of PROMIS in various areas of spine surgery. Our goal was to systematically review PROMIS scores compared with legacy patient-reported outcomes measures (PROMs) in spinal surgery and spine pathology.

METHODS

A systematic search of the PubMed, EMBASE, and Cochrane databases using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines was performed, yielding 254 unique studies reporting on "PROMIS" in "spine." Each study was independently reviewed. A total of 16 studies were selected for inclusion.

RESULTS

The pooled sample size yielded a total of 4268 patients. In the cervical population, PROMIS physical function (PF; |r| = .47-.87, pain intensity (PIn; |r| = .61-.74), pain interference (PIf; |r| = .65-.88), and pain behavior (PB; |r| = .59-.74) correlated with the Neck Disability Index (NDI). PROMIS PF also strongly correlated with the modified Japanese Orthopaedic Association scale (mJOA; |r| = .61-.72). Among patients with lumbar pathology and adult spinal deformities, PROMIS PF (|r| = .53-.85), PIn (|r| = .73-.78), PIf (|r| = .59-.89), and PB (|r| = .58-.82) strongly correlated with the Oswestry Disability Index (ODI). PF (|r| = .51-.78), PIf (|r| = .60-.70), and anxiety (|r| = .73) also strongly correlated with the Scoliosis Research Society (SRS)-22 and SRS-30. When comparing measures of global health, PROMIS PF was strongly correlated with the Short Form (SF)-12 and SF-36 (|r| = .50-.85). On average, all PROMIS domains required less time to complete (49.6-56 seconds) than the ODI (176 seconds), NDI (190.3 seconds), SF-12 (214 seconds), and SF-36 physical function domains (99 seconds). The responsiveness of the PROMIS PF, PIf, and PB was comparable to that of legacy measures ODI, NDI, and SF-12.

CONCLUSIONS

The PROMIS PF, PIn, PIf, and PB demonstrated moderate to strong correlations with NDI, mJOA, ODI, SRS, and SF-12 measures in various populations of spine patients. All PROMIS domains had decreased time to completion and similar responsiveness compared with legacy measures.

LEVEL OF EVIDENCE

2.

CLINICAL RELEVANCE

These results highlight the potential of PROMIS as a valid and reliable tool to assess patient-reported outcomes in spinal surgery patients and support more widespread use of PROMIS in spine.

Early Catastrophic Failure of Cervical Disc Arthroplasty: A Case Report

CASE

A 47-year-old healthy man underwent cervical disc arthroplasty (CDA) for a C6 radiculopathy. Two-week radiographs showed a well-positioned implant. At the 6-week postoperative visit, the inferior portion of the implant had displaced ventrally, with C6 anterior vertebral body collapse. The next day, the implant was removed and converted to a C5/6 anterior cervical discectomy and fusion. Bone biopsy was unremarkable.

CONCLUSIONS

This is the first reported case of early catastrophic failure of a well-positioned CDA in a healthy patient with good bone quality. Possible contributing mechanisms include hypermobility and anterior bone loss, factors previously associated with CDA.

Provider confidence in the telemedicine spine evaluation: results from a global study

Purpose

To utilize data from a global spine surgeon survey to elucidate (1) overall confidence in the telemedicine evaluation and (2) determinants of provider confidence.

Methods

Members of AO Spine International were sent a survey encompassing participant’s experience with, perception of, and comparison of telemedicine to in-person visits. The survey was designed through a Delphi approach, with four rounds of question review by the multi-disciplinary authors. Data were stratified by provider age, experience, telemedicine platform, trust in telemedicine, and specialty.

Results

Four hundred and eighty-five surgeons participated in the survey. The global effort included respondents from Africa (19.9%), Asia Pacific (19.7%), Europe (24.3%), North America (9.4%), and South America (26.6%). Providers felt that physical exam-based tasks (e.g., provocative testing, assessing neurologic deficits/myelopathy, etc.) were inferior to in-person exams, while communication-based aspects (e.g., history taking, imaging review, etc.) were equivalent. Participants who performed greater than 50 visits were more likely to believe telemedicine was at least equivalent to in-person visits in the ability to make an accurate diagnosis (OR 2.37, 95% C.I. 1.03–5.43). Compared to in-person encounters, video (versus phone only) visits were associated with increased confidence in the ability of telemedicine to formulate and communicate a treatment plan (OR 3.88, 95% C.I. 1.71–8.84).

Conclusion

Spine surgeons are confident in the ability of telemedicine to communicate with patients, but are concerned about its capacity to accurately make physical exam-based diagnoses. Future research should concentrate on standardizing the remote examination and the development of appropriate use criteria in order to increase provider confidence in telemedicine technology.

Predictive Model for Selection of Upper Treated Vertebra Using a Machine Learning Approach

OBJECTIVE

To train and validate an algorithm mimicking decision making of experienced surgeons regarding upper instrumented vertebra (UIV) selection in surgical correction of thoracolumbar adult spinal deformity.

METHODS

A retrospective review was conducted of patients with adult spinal deformity who underwent fusion of at least the lumbar spine (UIV > L1 to pelvis) during 2013-2018. Demographic and radiographic data were collected. The sample was stratified into 3 groups: training (70%), validation (15%) and performance testing (15%). Using a deep learning algorithm, a neural network model was trained to select between upper thoracic (T1-T6) and lower thoracic (T7-T12) UIV. Parameters used in the deep learning algorithm included demographics, coronal and sagittal preoperative alignment, and postoperative pelvic incidence-lumbar lordosis mismatch.

RESULTS

The study included 143 patients (mean age 63.3 ± 10.6 years, 81.8% women) with moderate to severe deformity (maximum Cobb angle: 43° ± 22°; T1 pelvic angle: 27° ± 14°; pelvic incidence-lumbar lordosis mismatch: 22° ± 21°). Patients underwent a significant change in lumbar alignment (Δpelvic incidence-lumbar lordosis mismatch: 21° ± 16°, P < 0.001); 35.0% had UIV in the upper thoracic region, and 65.0% had UIV in the lower thoracic region. At 1 year, revision rate was 11.9%, and rate of radiographic proximal junctional kyphosis was 29.4%. Neural network comprised 8 inputs, 10 hidden neurons, and 1 output (upper thoracic or lower thoracic). After training, results demonstrated an accuracy of 81.0%, precision of 87.5%, and recall of 87.5% on testing.

CONCLUSIONS

An artificial neural network successfully mimicked 2 lead surgeons' decision making in the selection of UIV for adult spinal deformity correction. Future models integrating surgical outcomes should be developed.

Posterior Ligamentous Reinforcement of the Upper Instrumented Vertebrae +1 Does Not Decrease Proximal Junctional Kyphosis in Adult Spinal Deformity

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Violation of the posterior soft tissues is believed to contribute to the development of proximal junctional kyphosis (PJK). Biomechanical and clinical studies suggest that augmentation of the posterior ligamentous structures (PLS) may help prevent PJK. The purpose of this study was to evaluate the effect of PLS augmentation on the rate of PJK at 1 year.

METHODS

A retrospective single-surgeon cohort study was performed of 108 adult spinal deformity patients who underwent 5 level fusions to the pelvis. Patients were divided into 2 groups: PLS+ patients had reconstruction of the PLS between upper instrumented vertebrae +1 (UIV+1) and UIV-1 with a surgical nylon tape while PLS- patients did not. Demographics, surgical data, and sagittal alignment parameters were compared between the cohorts. The primary outcome of interest was the development of PJK at final follow-up. A subgroup propensity match and logistic regression model were utilized to control for differences in the cohorts.

RESULTS

A total of 108 patients met final criteria, 31 patients (28.7%) were PLS+. There were no differences with regard to preoperative or final sagittal alignment parameters, number of levels fused, rates of 3-column osteotomies, and body mass index (P > .05), though the PLS+ cohort was older and had larger initial sagittal corrections (P < .05). The rates of PJK for PLS+ (27.3%) and PLS- (28.6%) were similar (P = .827). After controlling for sagittal correction via propensity matching, PLS+ had no impact on PJK (29% vs 38.7%, P = .367). In our multivariate analysis, only increased sagittal malalignment and failure to restore sagittal balance were retained as significant predictors of PJK.

CONCLUSION

Even after controlling for extent of correction and preoperative sagittal alignment, PLS reinforcement at UIV+1 using a hand-tensioned nylon tape does not reduce the incidence of PJK at 1 year.

Outcomes of Revision Surgery for Pseudarthrosis After Anterior Cervical Fusion: Case Series and Systematic Review

STUDY DESIGN

Case series/systematic review.

OBJECTIVES

To report on patients undergoing posterior cervical fusion for symptomatic pseudarthrosis following anterior cervical discectomy and fusion (ACDF), and to assess outcomes reporting in the literature.

METHODS

Patients undergoing posterior instrumented fusion for pseudarthrosis after primary ACDF from 2013 to 2018 by a single surgeon were reviewed consecutively. Neck Disability Index (NDI) and visual analogue scale (VAS) arm/neck were recorded at preoperative, 6-month, and 1-year time points. A systematic review of the literature was performed, and outcomes reporting was recorded.

RESULTS

NDI scores were 54.4 (SD 19.1), 36.6 (SD 18.1), and 41.2 (SD 19.2) at preoperative, 6-month, and 1-year time points, respectively, with improvement from preoperatively to 6 months (P = .004). VAS neck scores were 8.1 (SD 1.3), 5.0 (SD 2.9), and 5.8 (SD 2.2) at preoperative, 6-month, and 1-year time points, respectively, with improvement from preoperatively to 6 months (P = .038). VAS arm scores were 5.1 (SD 4.1), 3.5 (SD 3.2), and 3.6 (SD 2.7) at preoperative, 6-month, and 1-year time points, respectively, with improvement although these did not reach statistical significance (P = .145). The most common subjective outcomes reported in the literature were general symptoms assessments (43%), ordinal scales (43%), and VAS neck (19%) scales, with the majority of studies (67%) documenting one measure.

CONCLUSIONS

Patient-reported outcomes demonstrate clinically meaningful improvement within the first 6 months after posterior fusion for pseudarthrosis. Studies demonstrate substantial variability and no standardization in outcomes reporting, limiting the ability to compare results across interventions and pathologies. Standardized reporting will enable comparisons to inform patients and physicians on the optimal approach to treat this difficult problem.

Opioid Consumption After Arthroscopic Meniscal Procedures and Anterior Cruciate Ligament Reconstruction

Background:

Procedure-specific opioid-prescribing guidelines have the potential to decrease the number of unused pills in the home without compromising patient satisfaction. However, there is a paucity of data on the minimum necessary quantity to prescribe for outpatient orthopaedic surgeries.

Purpose:

To prospectively record daily opioid use and pain levels after arthroscopic meniscal procedures and anterior cruciate ligament reconstruction (ACLR) at a single institution.

Study Design:

Case series; Level of evidence, 4.

Methods:

A total of 95 adult patients who underwent primary arthroscopic knee surgery (meniscectomy, repair, or ACLR) were enrolled. Patients with a history of opioid dependence were ineligible. Daily opioid consumption and Numeric Rating Scale pain scores were collected through an automated text-messaging platform starting on postoperative day 1 (POD1). At 6 weeks or at patient-reported cessation of opioid use, final survey questions were asked. Patients who failed to complete data collection were excluded. Opioid use was converted into “pills” (oxycodone 5-mg equivalents) to facilitate comparisons and clinical applications. Factors associated with high and low opioid use were compared.

Results:

Of the 95 patients enrolled, 71 (74.7%) were included in the final analysis. Of these, 40 (56.3%) underwent meniscal surgery and 31 (43.7%) underwent ACLR. After outpatient arthroscopic meniscectomy or repair, the total median postdischarge opioid use was 0.3 pills (oxycodone 5-mg equivalents), with 75% of patients consuming 3.3 or fewer pills (range, 0-19 pills). For ACLR, the median postdischarge consumption was 7 pills (75th percentile, 23.3 pills; range, 0-41 pills). Almost one-third of patients (32.3%) took no opioids after surgery (3 ACLR, 20 meniscus). All meniscus patients and 71% of ACLR patients ceased opioid consumption by postoperative day 7.

Conclusion:

Opioids may not be necessary in all patients, particularly after meniscal surgery and in comparison with ACLR. For patients requesting opioids for pain relief, reasonable prescription quantities are 5 oxycodone 5-mg pills after arthroscopic meniscal procedures and 20 5-mg pills after ACLR. Slowing the current opioid epidemic and preventing future crises is dependent on refining prescribing habits. Clinicians should strongly consider patient education regarding expected pain as well as pain management strategies.

Wide Variability in Patient-Reported Outcomes Measures After Fusion for Lumbar Spinal Stenosis: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

The purpose of this study is to review outcomes reporting methodology in studies evaluating fusion for lumbar spinal stenosis.

METHODS

A systematic review of PubMed and Embase databases was conducted from January 2007 to June 2017 for English language studies with minimum of 2 years postoperative follow-up reporting outcomes after fusion for lumbar spinal stenosis. Two reviewers assessed each study; those meeting inclusion criteria were examined for pertinent data. Outcome measures were categorized into relevant domains: pain/symptomatology, function/disability, and surgical satisfaction. Return to work reporting was also recorded.

RESULTS

Of 123 studies meeting inclusion criteria, 76% included posterior-only fusion, 32% included posterior/transforaminal interbody fusion, and 5% included anterior/lateral interbody fusion (non-mutually exclusive). There was significant variation in patient-reported outcomes (PROs) used-studies reported 31 unique PROs assessing at least one domain: 22 evaluating pain, 23 evaluating function, and 3 evaluating surgical satisfaction. Most commonly utilized PROs were the Oswestry Disability Index (73% of studies), Visual Analog Scale (55%), and 36-Item Short Form Survey (32%). The remaining 28 measures were used in 14% of studies or fewer. PROs specific to symptoms of lumbar spinal stenosis, such as the Zurich Claudication Questionnaire, were only used rarely (7/123 studies). Only 14% of studies reported on time to return to work.

CONCLUSIONS

The literature surrounding fusion in the setting of lumbar stenosis is characterized by substantial variability in outcomes reporting. Very few studies utilized measures specific to lumbar spinal stenosis. Efforts to standardize outcomes reporting would facilitate comparisons of surgical interventions.

The Current State of Minimally Invasive Approaches to Adult Spinal Deformity

PURPOSE OF REVIEW

Minimally invasive approaches to adult spinal deformity (ASD) surgery have seen a large increase in popularity over the last decade, largely because these techniques are viewed as a potential improvement to the lengthy recovery and high complication rates observed after traditional open surgery for this pathology. The purpose of this review is to present a summary of the latest minimally invasive techniques used in adult spinal deformity surgery, examine whether MIS surgery can accomplish the goals of ASD surgery, and investigate whether MIS surgery is safer than traditional approaches.

RECENT FINDINGS

While minimally invasive approaches have been able to achieve similar patient-reported outcomes as open approaches, they are associated with their own unique complications. Furthermore, they are limited in their ability to correct severe sagittal imbalance. Emerging techniques, such as anterior column realignment and mini-open posterior column osteotomy, have been developed to address these limitations. The minimally invasive spinal deformity surgery algorithm (MISDEF) can help guide surgeons on which approaches may be appropriate for a particular case. To maximize the benefits of a minimally invasive approach without compromising the goals of ASD surgery, surgeons must be selective in choosing which cases are amenable to an MIS approach. Leading experts continue to develop algorithms to guide surgical decision-making. As we learn to better define our indications, understand treatment goals, and refine our techniques, MIS approaches will likely play an even larger role in a comprehensive ASD treatment strategy.

An institutional intervention to modify opioid prescribing practices after lumbar spine surgery

OBJECTIVEPatients with lumbar spine pathology are at high risk for opioid misuse. Standardizing prescribing practices through an institutional intervention may reduce the overprescribing of opiates, leading to a decrease in the risk for opioid misuse and the number of pills available for diversion. Without quantitative data on the "minimum necessary quantity" of opioids appropriate for postdischarge prescriptions, the optimal method for changing existing prescribing practices is unknown. The purpose of this study was to determine whether mandatory provider education and prescribing guidelines could modify prescriber behavior and lead to a decreased amount of opioids prescribed at hospital discharge following lumbar spine surgery.METHODSQualified staff were required to attend a mandatory educational conference, and a consensus method among the spine service was used to publish qualitative prescribing guidelines. Prescription data for 2479 patients who had undergone lumbar spine surgery were captured and compared based on the timing of surgery. The preintervention group consisted of 1177 patients who had undergone spine surgery in the period before prescriber education and guidelines (March 1, 2016-November 1, 2016). The postintervention group consisted of 1302 patients who had undergone spine surgery after the dissemination of the guidelines (February 1, 2017-October 1, 2017). Surgeries were classified as decompression or fusion procedures. Patients who had undergone surgeries for infection and patients on long-acting opioids were excluded.RESULTSFor all lumbar spine surgeries (decompression and fusion), the mean amount of opioids prescribed at discharge was lower after the educational program and distribution of prescribing guidelines (629 ± 294 oral morphine equivalent [OME] preintervention vs 490 ± 245 OME postintervention, p < 0.001). The mean number of prescribed pills also decreased (81 ± 26 vs 66 ± 22, p < 0.001). Prescriptions for 81 or more tablets dropped from 65.5% to 25.5%. Tramadol was prescribed more frequently after prescriber education (9.9% vs 18.6%, p < 0.001). Refill rates within 6 weeks were higher after the institutional intervention (7.6% vs 12.4%, p < 0.07).CONCLUSIONSQualitative guidelines and prescriber education are effective in reducing the amount of opioids prescribed at discharge and encouraging the use of weaker opioids. Coupling provider education with prescribing guidelines is likely synergistic in achieving larger reductions. The sustainability of these changes is yet to be determined.

Fighting Back: Institutional Strategies to Combat the Opioid Epidemic: A Systematic Review

BACKGROUND

Current research on opioid use within orthopedic surgery has focused on efforts to identify patients at risk for chronic opioid use. Studies addressing prevention of opioid misuse related to orthopedic care are lacking. Evidence-based interventions to reduce the reliance on opioids for post-operative pain relief will be a key component of any comprehensive institutional opioid policy.

QUESTIONS/PURPOSES

The purpose of this systematic review was to evaluate institutional strategies that reduce opioid administration or consumption after orthopedic surgery.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist, a search was conducted of the PubMed database for English-language articles that analyzed interventions by physicians, nurses, pharmacists, physical therapists, or other hospital staff to reduce post-operative opioid use or narcotic prescription amounts after surgery. Studies that contained objective outcome measures (i.e., no expert opinion articles) were selected. Investigations on the effect of pharmacologic adjuvants, cryotherapy, or regional nerve blockades on opioid use were excluded.

RESULTS

The initial search yielded 6598 titles, of which 13 full-text articles were ultimately selected for inclusion in this systematic review. The review identified two major categories of interventions-patient-focused and provider-focused (e.g., physicians, nurses, physical therapists, pharmacists). Formal patient education programs were most effective in reducing opioid use. On the provider side, prescribing guidelines appear to decrease the overall number of pills prescribed, often without changes in patient satisfaction or requests for refills.

CONCLUSIONS

Researchers are just beginning to establish the most effective ways for institutions to reduce opioid use and promote responsible post-operative prescribing. Institutional prescribing guidelines, standardized bedside pain-management programs, and formal patient education curriculums are all evidence-based interventions that can achieve these goals. The available research also supports an interprofessional approach in any institutional opioid-reduction strategy.

Does Obesity Explain the Effect of the Metabolic Syndrome on Complications Following Elective Lumbar Fusion? A Propensity Score Matched Analysis

STUDY DESIGN

Propensity score matched retrospective cohort study.

OBJECTIVES

Obesity is a major confounder in determining the independent effect of metabolic syndrome (MetS) on complications after spinal surgery. The purpose of this study is to differentiate MetS from obesity as an independent influence on perioperative outcomes after elective lumbar spine fusion.

METHODS

One- to 3-level posterior spinal fusion cases were identified from the 2011-2014 American College of Surgeons' National Surgical Quality Improvement Program. To determine the effects of MetS outside of obesity itself, patients with MetS were first compared to a no-MetS cohort and then to an obese-only no-MetS cohort. Two propensity score matches based on demographics, comorbidities, surgical complexity, and diagnosis were used to match patients in 1:1 ratios and compare outcomes. Logistic regression with propensity score adjustment was further utilized as a secondary method of reducing selection bias.

RESULTS

Out of 18 605 patients that met criteria for inclusion, 1903 (10.2%) met our definition of MetS. Patients with MetS had a higher rate of wound complications (3.8% vs 2.7% obese no MetS, P = .045; vs 2.6% no MetS, P = .035), readmissions (7.4% vs 2.2% obese no MetS, P < .001; vs 4.6% no MetS, P < .001), and extended length of stay (29.1% vs 23.9% obese no MetS, P < .001; vs 23.5% no MetS, P < .001). Patients with MetS were more likely to experience a wound complication (odds ratio = 1.47, 95% confidence interval = 1.02-2.12) or readmission (odds ratio = 1.48, 95% confidence interval = 1.22-1.80).

CONCLUSIONS

Even after controlling for obesity, MetS is an independent risk factor for adverse short-term outcomes. These findings have various implications for preoperative risk stratification and reduction strategies.

The Effect of Smoking on Thirty-Day Postoperative Complications After Total Joint Arthroplasty: A Propensity Score-Matched Analysis

BACKGROUND

Total joint arthroplasty (TJA) is a highly successful treatment, but is burdensome to the national healthcare budget. National quality initiatives seek to reduce costly complications. Smoking's role in perioperative complication after TJA is less well known. This study aims to identify smoking's independent contribution to the risk of short-term complication after TJA.

METHODS

All patients undergoing primary TJA between 2011 and 2012 were selected from the American College of Surgeon's National Surgical Quality Improvement Program's database. Outcomes of interest included rates of readmission, reoperation, mortality, surgical complications, and medical complications. To eliminate confounders between smokers and nonsmokers, a propensity score was used to generate a 1:1 match between groups.

RESULTS

A total of 1251 smokers undergoing TJA met inclusion criteria. Smokers in the combined total hip and knee arthroplasty cohort had higher 30-day readmission (4.8% vs 3.2%, P = .041), were more likely to have a surgical complication (odds ratio 1.84, 95% confidence interval 1.21-2.80), and had a higher rate of deep surgical site infection (SSI) (1.1% vs 0.2%, P = .007). Analysis of total hip arthroplasty only revealed that smokers had higher rates of deep SSI (1.3% vs 0.2%, P = .038) and higher readmission rate (4.3% vs 2.2%, P = .034). Analysis of total knee arthroplasty only revealed greater surgical complications (2.8% vs 1.2%, P = .048) and superficial SSI (1.8% vs 0.2%, P = .002) in smokers.

CONCLUSION

Smoking in TJA is associated with higher rates of SSI, surgical complications, and readmission.

The Impact of Metabolic Syndrome on 30-Day Complications Following Total Joint Arthroplasty

BACKGROUND

The arthroplasty population increasingly presents with comorbid conditions linked to elevated risk of postsurgical complications. Current quality improvement initiatives require providers to more accurately assess and manage risk presurgically. In this investigation, we assess the effect of metabolic syndrome (MetS), as well as the effect of body mass index (BMI) within MetS, on the risk of complication following hip and knee arthroplasty.

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Program database for total hip or knee arthroplasty cases. Thirty-day rates of Centers for Medicare and Medicaid Services (CMS)-reportable complications, wound complications, and readmissions were compared between patients with and without a diagnosis of MetS using multivariate logistic regression. Arthroplasty cases with a diagnosis of MetS were further stratified according to World Health Organization BMI class, and the role of BMI within the context of MetS was assessed.

RESULTS

Of the 107,117 included patients, 11,030 (10.3%) had MetS. MetS was significantly associated with CMS complications (odds ratio [OR] = 1.415; 95% confidence interval [CI], 1.306-1.533; P < .001), wound complications (OR = 1.749; 95% CI, 1.482-2.064; P < .001), and readmission (OR = 1.451; 95% CI, 1.314-1.602; P < .001). When MetS was assessed by individual BMI class, the MetS + BMI >40 group was associated with significantly higher risk of CMS complications, wound complications, and readmission compared to the lower MetS BMI groups.

CONCLUSION

MetS is an independent risk factor for CMS-reportable complications, wound complications, and readmission following total joint arthroplasty. The risk attributable to MetS exists irrespective of obesity class and increases as BMI increases.

Is Outpatient Arthroplasty as Safe as Fast-Track Inpatient Arthroplasty? A Propensity Score Matched Analysis

BACKGROUND

In the emerging fiscal climate of value-based decision-making and shared risk and remuneration, outpatient total joint arthroplasty is attractive provided the incidence of costly complications is comparable to contemporary "fast-track" inpatient pathways.

METHODS

All patients undergoing total hip arthroplasty or total knee arthroplasty between 2011 and 2013 were selected from the American College of Surgeons-National Surgical Quality Improvement Program database. A propensity score was used to match 1476 fast-track (≤2 day length of stay) inpatients with 492 outpatients (3:1 ratio). Thirty-day complication, reoperation, and readmission rates were compared, both during and after hospitalization. Logistic regression was used to calculate propensity score adjusted odds ratios.

RESULTS

After matching, outpatients had higher rates of medical complication (anytime, 10.0% vs 6.7%, P = .018; post discharge, 6.3% vs 1.1%, P < .001). Most complications were bleeding requiring transfusion, which occurred at similar rates after surgery but at higher rates post discharge in outpatients (anytime, 7.5% outpatients vs 5.6% inpatients, P = .113; post discharge, 4.1% outpatients vs 0.1% inpatients, P < .001). There was no difference in readmission rate (2.4% outpatient vs 2.0% inpatient, P = .589).

CONCLUSION

Outpatients experience higher rates of post-discharge complications, which may countermand cost savings. Surgeons wishing to implement outpatient total joint arthroplasty clinical pathways must focus on preventing post-discharge medical complications to include blood management strategies.

Factors Affecting Readmission Rates Following Primary Total Hip Arthroplasty

BACKGROUND

Readmissions following total hip arthroplasty are a focus given the forthcoming financial penalties that hospitals in the United States may incur starting in 2015. The purpose of this study was to identify both preoperative comorbidities and postoperative conditions that increase the risk of readmission following total hip arthroplasty.

METHODS

Using the American College of Surgeons-National Surgical Quality Improvement Program data for 2011, a study population was identified using the Current Procedural Terminology code for primary total hip arthroplasty (27130). The sample was stratified into readmitted and non-readmitted cohorts. Demographic variables, preoperative comorbidities, laboratory values, operative characteristics, and surgical outcomes were compared between the groups using univariate and multivariate logistic regression models.

RESULTS

Of the 9441 patients, there were 345 readmissions (3.65%) within the first thirty days following surgery. Comorbidities that increased the risk for readmission were diabetes (p < 0.001), chronic obstructive pulmonary disease (p < 0.001), bleeding disorders (p < 0.001), preoperative blood transfusion (p = 0.035), corticosteroid use (p < 0.001), dyspnea (p = 0.001), previous cardiac surgery (p = 0.002), and hypertension (p < 0.001). A multivariate regression model was used to control for potential confounders. Having a body mass index of ≥40 kg/m² (odds ratio, 1.941 [95% confidence interval, 1.019 to 3.696]; p = 0.044) and using corticosteroids preoperatively (odds ratio, 2.928 [95% confidence interval, 1.731 to 4.953]; p < 0.001) were independently associated with a higher likelihood of readmission, and a high preoperative serum albumin (odds ratio, 0.688 [95% confidence interval, 0.477 to 0.992]; p = 0.045) was independently associated with a lower risk for readmission. Postoperative surgical site infection, pulmonary embolism, deep venous thrombosis, and sepsis (p < 0.001) were also independent risk factors for readmission.

CONCLUSIONS

The risk of readmission following total hip arthroplasty increases with growing preoperative comorbidity burden, and is specifically increased in patients with a body mass index of ≥40 kg/m², a history of corticosteroid use, and low preoperative serum albumin and in patients with postoperative surgical site infection, a thromboembolic event, and sepsis.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Heparin-induced thrombocytopenia

Abstract A summary of heparin-induced thrombocytopenia (HIT) is presented. HIT is an adverse drug reaction characterized by thrombocytopenia and a high risk for venous or arterial thrombosis. The frequency of HIT ranges from 1 to 5% of patients receiving heparin with exact frequencies ranging between specific agents. Interestingly, this immune-mediated syndrome is ironically associated with thrombosis, not bleeding, with thrombin formation playing a major role. It is caused by heparin-dependent, platelet-activating antibodies that identifies a self-protein, PF4, bound to heparin that results in an antibody formation. The resulting platelet activation is associated with increased thrombin generation. Typically, the platelet count fall begins 5-10 days after starting heparin, although a rapid platelet count fall can occur in a patient who has antibodies from recent heparin use. Typical causes of HIT as well as the best diagnostic studies and treatment are discussed in this review. HIT was reviewed using a pubmed™ search; google scholar™ using key words: "Heparin-induced thrombocytopenia"; "heparin", and "drug AND thrombocytopenia."

Synergistic interactions with a high intraoperative expander fill volume increase the risk for mastectomy flap necrosis

Purpose

Prosthetic-based breast reconstruction is performed with increasing frequency in the United States. Major mastectomy skin flap necrosis is a significant complication with outcomes ranging from poor aesthetic appearance to reconstructive failure. The present study aimed to explore the interactions between intraoperative fill and other risk factors on the incidence of flap necrosis in patients undergoing mastectomy with immediate expander/implant-based reconstruction.

Methods

A retrospective review of 966 consecutive patients (1,409 breasts) who underwent skin or nipple sparing mastectomy with immediate tissue expander reconstruction at a single institution was conducted. Age, body mass index, hypertension, smoking status, premastectomy and postmastectomy radiation, acellular dermal matrix use, and application of the tumescent mastectomy technique were analyzed as potential predictors of flap necrosis both independently and as synergistic variables with high intraoperative fill. The following three measures of interaction were calculated: relative excess risk due to interaction, attributable proportion of risk due to interaction, and synergy index (SI).

Results

Intraoperative tissue expander fill volume was high (≥66.7% of the maximum volume) in 40.9% (576 of 1,409 breasts) of cases. The unadjusted flap necrosis rate was greater in the high intraoperative fill cohort than in the low fill cohort (10.4% vs. 7.1%, p=0.027). Multivariate logistic regression did not identify high intraoperative fill volume as an independent risk factor for flap necrosis (odds ratio 1.442, 95% confidence interval 0.973-2.137, p=0.068). However, four risk factors were identified that interacted significantly with intraoperative fill volume, namely tumescence, age, hypertension, and obesity. The SI, or the departure from additive risks, was largest for tumescence (SI, 25.3), followed by hypertension (SI, 2.39), obesity (SI, 2.28), and age older than 50 years (SI, 1.17).

Conclusion

In the postmastectomy, hypovascular milieu, multiple risk factors decreasing flap perfusion interact with high intraoperative fill volume to cross a threshold and synergistically increase the risk of flap necrosis.

Intravenous pyridoxine-induced metabolic acidosis

STUDY OBJECTIVE

Pyridoxine hydrochloride, the antidote for isonicotinic acid hydrazide (INH)--induced seizures, is available in solution at a concentration of 100 mg/mL at a pH of less than 3. Pyridoxine is often infused rapidly in large doses for INH-induced seizures. Effects of pyridoxine infusion on base deficit in amounts given for INH poisoning have not been studied in human subjects. We hypothesized that this infusion would result in transient worsening of acidosis.

METHODS

We conducted a randomized, controlled crossover trial in human volunteers. Five healthy volunteers (mean age, 35 years; range, 29 to 43 years) were randomized to receive intravenous placebo (50 mL of normal saline solution) or 5 g of pyridoxine (50 mL) over 5 minutes. A peripheral intravenous catheter was established in each arm, and a heparinized venous blood sample was obtained for base deficit at baseline and 3, 6, 10, 20, and 30 minutes after infusion. After at least a 1-week washout period, the volunteers were assigned to the alternate arms of the experiments, thus acting as their own control subjects. Data were analyzed by using the 2-tailed paired t test, controlling for multiple comparisons.

RESULTS

No difference was noted between groups at baseline. A statistically significant increased base deficit was noted after the pyridoxine infusion versus control at 3 to 20 minutes but not at 30 minutes (P =.1). Maximal mean increase in base deficit (2.74 mEq/L) was noted at 3 minutes.

CONCLUSION

A transient increase in base deficit occurs after the infusion of 5 g of pyridoxine in normal volunteers.