A Diagnosis of Vitamin D Deficiency Is Associated With Increased Rates of Primary Patellar Instability and Need for Recurrent Surgical Stabilization

BACKGROUND

Vitamin D has been proven experimentally to affect musculoskeletal health. The purpose of this study was to identify the relationship between vitamin D deficiency and patellar instability.

HYPOTHESIS

Vitamin D deficiency is associated with an increased risk of experiencing primary patellar instability and recurrent patellar dislocation after primary surgical stabilization.

STUDY DESIGN

Retrospective comparative study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A 1:1 matched retrospective study of 328,011 patients diagnosed with vitamin D deficiency was performed using the PearlDiver database. Incidence of primary patellar instability was calculated according to sex and age. Rates of primary patellar instability and surgical stabilization for recurrent dislocation were calculated with sex- and age-specific stratifications. Multivariable logistic regression was used to compare the rates of primary injury and recurrent stabilization while controlling for demographics and medical comorbidities.

RESULTS

A total of 656,022 patients were analyzed. The overall 1-year incidence rate of patellar instability in patients with vitamin D deficiency was 82.6 per 100,000 person-years (95% CI, 73.2-92.9), compared with 48.5 (95% CI, 41.4-56.5) in the matched control. Women were significantly more likely to experience primary patellar instability within 1 (adjusted odds ratio [aOR] = 1.45; 95% CI, 1.12-1.88) and 2 years (aOR, 1.31; 95% CI, 1.07-1.59) of hypovitaminosis D diagnosis. Patients aged 10 to 25 years with hypovitaminosis D were at greater risk of requiring recurrent patellar stabilization for both men (aOR, 2.48; 95% CI, 1.06-5.80) and women (aOR, 1.77; 95% CI, 1.04-3.02).

CONCLUSION

Patients diagnosed with vitamin D deficiency experienced higher rates of primary patellar instability and have greater risk of requiring recurrent surgical stabilization for subsequent dislocations.

CLINICAL RELEVANCE

These results suggest that monitoring and proactively treating vitamin D deficiency in the physically active patient may lower the risk of suffering primary patellar instability or recurrence after surgical stabilization.

The effect of concurrent cervical spine degenerative disease on the outcome of rotator cuff repair: a national database study

BACKGROUND

Cervical spine degenerative disease (CSD) can cause shoulder pain, potentially confounding the management of patients with rotator cuff tears. This study aimed to investigate the relationships between CSD and rotator cuff repair (RCR).

METHODS

A national administrative database (PearlDiver) was used to study 4 patient cohorts: (1) RCR only (RCRo), (2) RCR with concurrent CSD (RCRC), (3) RCR after a cervical spine procedure (RCRA), and (4) RCR before a cervical spine procedure (RCRB). The outcomes of RCR were compared using multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index, as well as preoperative opioid utilization in the analysis of opioid use.

RESULTS

Between 2010 and 2021, a total of 889,977 patients underwent RCR. Of these patients, 784,230 (88%) underwent RCRo whereas 105,747 (12%) underwent RCRC, of whom 21,585 (2.4%) underwent cervical spine procedures (RCRA in 9670 [1.1%] and RCRB in 11,915 [1.3%]). At 2 years after RCR, compared with RCRo patients, RCRC patients had an increased risk of surgical-site infection (adjusted odds ratio [aOR] = 1.25, P = .0004), deep vein thrombosis (aOR = 1.17, P = .0002), respiratory complications (aOR = 1.19, P = .0164), and ipsilateral shoulder reoperations (débridement [aOR = 1.66, P < .0001], manipulation under anesthesia or arthroscopic lysis of adhesions [aOR = 1.23, P < .0001], distal clavicle excision [aOR = 1.78, P < .0001], subacromial decompression [aOR = 1.72, P < .0001], biceps tenodesis [aOR = 1.76, P < .0001], incision and drainage [aOR = 1.34, P = .0020], synovectomy [aOR = 1.48, P = .0136], conversion to shoulder arthroplasty [aOR = 1.62, P < .0001], revision RCR [aOR = 1.77, P < .0001], and subsequent contralateral RCR [aOR = 1.71, P < .0001]). At 2 years, compared with RCRC patients who did not undergo cervical spine procedures, RCRC patients who underwent cervical spine procedures had an increased risk of incision and drainage (aOR = 1.50, P = .0255), conversion to arthroplasty (aOR = 1.40, P < .0001), and revision RCR (aOR = 1.11, P = .0374), as well as a lower risk of contralateral RCR (aOR = 0.89, P = .0469). The sequence of cervical spine procedures did not affect the risk of shoulder reoperations. At 1 year, the risk of opioid use after RCR was less for RCRA patients compared with RCRB patients (aOR = 1.71 [95% confidence interval, 1.61-1.80; P < .0001] vs. aOR = 2.01 [95% confidence interval, 1.92-2.12; P < .0001]).

CONCLUSION

Concurrent CSD has significant detrimental effects on RCR outcomes. Patients with concurrent CSD undergoing cervical spine procedures have a greater risk of ipsilateral shoulder reoperations but a decreased risk of contralateral RCR. The risk of prolonged opioid use was lower if RCR followed a cervical spine procedure. Concurrent CSD must be considered and possibly treated to optimize the outcomes of RCR.

Impact of Self-Reported Loss of Balance and Gait Disturbance on Outcomes following Adult Spinal Deformity Surgery

Background: The objective of this study was to evaluate if imbalance influences complication rates, radiological outcomes, and patient-reported outcomes (PROMs) following adult spinal deformity (ASD) surgery. Methods: ASD patients with baseline and 2-year radiographic and PROMs were included. Patients were grouped according to whether they answered yes or no to a recent history of pre-operative loss of balance. The groups were propensity-matched by age, pelvic incidence-lumbar lordosis (PI-LL), and surgical invasiveness score. Results: In total, 212 patients were examined (106 in each group). Patients with gait imbalance had worse baseline PROM measures, including Oswestry disability index (45.2 vs. 36.6), SF-36 mental component score (44 vs. 51.8), and SF-36 physical component score (p < 0.001 for all). After 2 years, patients with gait imbalance had less pelvic tilt correction (-1.2 vs. -3.6°, p = 0.039) for a comparable PI-LL correction (-11.9 vs. -15.1°, p = 0.144). Gait imbalance patients had higher rates of radiographic proximal junctional kyphosis (PJK) (26.4% vs. 14.2%) and implant-related complications (47.2% vs. 34.0%). After controlling for age, baseline sagittal parameters, PI-LL correction, and comorbidities, patients with imbalance had 2.2-times-increased odds of PJK after 2 years. Conclusions: Patients with a self-reported loss of balance/unsteady gait have significantly worse PROMs and higher risk of PJK.

Decreased Prevalence of New-Onset Adhesive Capsulitis in Patients Prescribed Angiotensin Receptor Blockers

BACKGROUND

Angiotensin receptor blockers (ARBs) are commonly prescribed antihypertensive agents that have well-known antifibrotic properties. The purpose of this study was to examine the association between ARB use and the rates of new-onset adhesive capsulitis as well as adhesive capsulitis requiring operative treatment.

METHODS

Using a large national insurance database, a randomly generated cohort of patients with at least 3 continuous months of ARB use between January 2010 and December of 2019 (n=1,000,000) was compared to a separate randomly generated cohort without ARB use (n=3,000,000) . Rates of newly diagnosed adhesive capsulitis and associated manipulation under anesthesia and/or arthroscopic capsulotomy were calculated over a one- and two-year period following the completion of at least 3 continuous months of ARB therapy. Rates were compared using multivariable logistic regression to control for demographics and comorbidities. Both unadjusted and adjusted odds ratios (aOR) and 95% confidence intervals (CI) were calculated and reported for each comparison. Statistical significance was set at P<0.05.

RESULTS

The mean age in the ARBs cohort was 61.8 years (SD = 10.0), while in the control cohort, it was 54.8 years (SD = 12.3) (p < 0.001). The ARBs cohort had significantly lower rates of newly diagnosed adhesive capsulitis compared to the control cohort at both one year (0.15% vs. 0.55%, p < 0.001) and two years (0.3% vs. 0.78%, p < 0.001). Similar findings were observed for the arthroscopic capsular release/MUA cohort associated with adhesive capsulitis. After adjusting for confounding factors, the lower rates of adhesive capsulitis and arthroscopic capsular release/MUA associated with adhesive capsulitis in the ARBs cohort remained statistically significant (p < 0.001).

CONCLUSION

Patients prescribed ARBs experienced a decrease rate of newly diagnosed adhesive capsulitis, as well as adhesive capsulitis requiring surgical intervention when compared to a control cohort. These findings suggest a potential protective effect of ARBs against the development of adhesive capsulitis. Further investigations are warranted to elucidate the underlying mechanisms and establish a causal relationship.

Preoperative Resilience and Improvement in Patient-Reported Outcomes After Lumbar Spinal Fusion

BACKGROUND

It is incompletely understood how preoperative resilience affects 1-year postoperative outcomes after lumbar spinal fusion.

METHODS

Patients undergoing open lumbar spinal fusion at a single-center institution were identified between November 2019 and September 2022. Preoperative resilience was assessed using the Brief Resilience Scale. Demographic data at baseline including age, gender, comorbidities, and body mass index (BMI) were extracted. Patient-reported outcome measures including Oswestry Disability Index, PROMIS (Patient-Reported Outcomes Measurement Information System) Global Physical Health, PROMIS Global Mental Health (GMH), and EuroQol5 scores were collected before the surgery and at 3 months and 1 year postoperatively. Bivariate correlation was conducted between Brief Resilience Scale scores and outcome measures at 3 months and 1 year postoperatively.

RESULTS

Ninety-three patients had baseline and 1 year outcome data. Compared with patients with high resilience, patients in the low-resilience group had a higher percentage of females (69.4% vs. 43.9%; P = 0.02), a higher BMI (32.7 vs. 30.1; P = 0.03), and lower preoperative Global Physical Health (35.8 vs. 38.9; P = 0.045), GMH (42.2 vs. 49.2; P < 0.001), and EuroQol scores (0.56 vs. 0.61; P = 0.01). At 3 months postoperatively, resilience was moderately correlated with GMH (r = 0.39) and EuroQol (r = 0.32). Similarly, at 1 year postoperatively, resilience was moderately correlated with GMH (r = 0.33) and EuroQol (r = 0.34). Comparable results were seen in multivariable regression analysis controlling for age, gender, number of levels fused, BMI, Charlson Comorbidity Index, procedure, anxiety/depression, and complications.

CONCLUSIONS

Low preoperative resilience can negatively affect patient-reported outcomes 1 year after lumbar spinal fusion. Resiliency is a potentially modifiable risk factor, and surgeons should consider targeted interventions for at-risk patient groups.

Same-Day Versus Staged Spinal Fusion: A Meta-analysis of Clinical Outcomes

STUDY DESIGN

Meta-Analysis.

OBJECTIVE

This meta-analysis aims to compare same-day versus staged spine surgery, assessing their effects on patient care and healthcare system efficiency.

BACKGROUND

In spinal surgery, the debate between whether same-day and staged surgeries are better for patients continues, as the decision may impact patient related outcomes, healthcare resources and overall costs. While some surgeons advocate for staged surgeries citing reduced risks of complications, others proclaim same-day surgeries may minimize costs and length of hospital stays.

METHODS

PubMed, Cochrane and Google Scholar (Pages 1-20) were searched up until February 2024. The studied outcomes were operative room (OR) time, estimated blood loss (EBL), length of hospital stay (LOS), overall complications, venous thromboembolism (VTE), death, reoperations and non-home discharge.

RESULTS

Sixteen retrospective studies were included in this meta-analysis, representing a total of 2346 patients of which 644 underwent staged spinal fusion surgeries and 1702 same-day surgeries. No statistically significant difference was observed in EBL between staged and same-day surgery groups. However, the staged group exhibited a statistically significant longer OR time (P= 0.05) and LOS (P=0.004). A higher rate of overall complications (P=0.002) and VTE (P=0.0008) was significantly associated with the staged group. No significant differences were found in the rates of death, reoperations, and non-home discharge between the two groups.

CONCLUSION

Both staged and same-day spinal fusion surgeries showed comparable rates of death, reoperations and non-home discharges for patients undergoing spinal surgeries. However, given the increased OR time, LOS and complications associated with staged spinal surgeries, this study supports same-day surgeries when possible to minimize the burden on healthcare resources and enhance efficiency.

Predictors of pelvic tilt normalization: a multicenter study on the impact of regional and lower-extremity compensation on pelvic alignment after complex adult spinal deformity surgery

OBJECTIVE

The objective was to determine the degree of regional decompensation to pelvic tilt (PT) normalization after complex adult spinal deformity (ASD) surgery.

METHODS

Operative ASD patients with 1 year of PT measurements were included. Patients with normalized PT at baseline were excluded. Predicted PT was compared to actual PT, tested for change from baseline, and then compared against age-adjusted, Scoliosis Research Society-Schwab, and global alignment and proportion (GAP) scores. Lower-extremity (LE) parameters included the cranial-hip-sacrum angle, cranial-knee-sacrum angle, and cranial-ankle-sacrum angle. LE compensation was set as the 1-year upper tertile compared with intraoperative baseline. Univariate analyses were used to compare normalized and nonnormalized data against alignment outcomes. Multivariable logistic regression analyses were used to develop a model consisting of significant predictors for normalization related to regional compensation.

RESULTS

In total, 156 patients met the inclusion criteria (mean ± SD age 64.6 ± 9.1 years, BMI 27.9 ± 5.6 kg/m2, Charlson Comorbidity Index 1.9 ± 1.6). Patients with normalized PT were more likely to have overcorrected pelvic incidence minus lumbar lordosis and sagittal vertical axis at 6 weeks (p < 0.05). GAP score at 6 weeks was greater for patients with nonnormalized PT (0.6 vs 1.3, p = 0.08). At baseline, 58.5% of patients had compensation in the thoracic and cervical regions. Postoperatively, compensation was maintained by 42% with no change after matching in age-adjusted or GAP score. The patients with nonnormalized PT had increased rates of thoracic and cervical compensation (p < 0.05). Compensation in thoracic kyphosis differed between patients with normalized PT at 6 weeks and those with normalized PT at 1 year (69% vs 35%, p < 0.05). Those who compensated had increased rates of implant complications by 1 year (OR [95% CI] 2.08 [1.32-6.56], p < 0.05). Cervical compensation was maintained at 6 weeks and 1 year (56% vs 43%, p = 0.12), with no difference in implant complications (OR 1.31 [95% CI -2.34 to 1.03], p = 0.09). For the lower extremities at baseline, 61% were compensating. Matching age-adjusted alignment did not eliminate compensation at any joint (all p > 0.05). Patients with nonnormalized PT had higher rates of LE compensation across joints (all p < 0.01). Overall, patients with normalized PT at 1 year had the greatest odds of resolving LE compensation (OR 9.6, p < 0.001). Patients with normalized PT at 1 year had lower rates of implant failure (8.9% vs 19.5%, p < 0.05), rod breakage (1.3% vs 13.8%, p < 0.05), and pseudarthrosis (0% vs 4.6%, p < 0.05) compared with patients with nonnormalized PT. The complication rate was significantly lower for patients with normalized PT at 1 year (56.7% vs 66.1%, p = 0.02), despite comparable health-related quality of life scores.

CONCLUSIONS

Patients with PT normalization had greater rates of resolution in thoracic and LE compensation, leading to lower rates of complications by 1 year. Thus, consideration of both the lower extremities and thoracic regions in surgical planning is vital to preventing adverse outcomes and maintaining pelvic alignment.

Shoulder Adhesive Capsulitis Prior to Total Knee Arthroplasty is Associated With Increased Rates of Postoperative Stiffness Requiring Manipulation Under Anesthesia and Arthroscopic Lysis of Adhesions

BACKGROUND

Arthrofibrosis following total knee arthroplasty (TKA) and adhesive capsulitis (AC) of the shoulder develop via a similar pathologic process. The purpose of this study was to examine the relationship between these two conditions.

METHODS

This was a retrospective cohort study using a large nationwide claims database. Patients who had a history of shoulder AC prior to TKA were compared to TKA patients who did not have AC history comparing rates of postoperative stiffness, manipulation under anesthesia (MUA), arthroscopic lysis of adhesions (LOAs), and revision arthroplasty at postoperative timepoints (3 months, 6 months, 1 year, and 2 years).

RESULTS

Within 3 months, 6 months, 1 year, and 2 years of their TKAs, patients who had a history of AC prior to TKA were significantly more likely to experience stiffness (OR [odds ratio] = 1.29, 1.28, 1.32, and 1.36, respectively) and LOAs (OR = 6.78, 3.65, 2.99, and 2.81, respectively). They also showed increased risk of MUA within 6 months, 1 year, and 2 years (OR = 1.15, 1.15, and 1.16, respectively) of their TKAs. Patients having a preoperative diagnosis of AC did not have an increased risk of undergoing revision surgery 1 year or 2 years after their TKAs (P > .05).

CONCLUSIONS

Patients diagnosed with AC prior to TKA experience higher rates of postoperative stiffness, resulting in additional interventions such as MUA and LOAs. These findings identify a particularly high-risk patient population that may benefit from additional interventions prior to and following TKA.

LEVEL OF EVIDENCE

This is a level III prognostic study.

Postoperative Angiotensin Receptor Blocker Use is Associated With Decreased Rates of Manipulation Under Anesthesia, Arthroscopic Lysis of Adhesions, and Prosthesis-Related Complications in Patients Undergoing Total Knee Arthroplasty

BACKGROUND

The cellular mechanisms underlying excess scar tissue formation in arthrofibrosis following total knee arthroplasty (TKA) are well-described. Angiotensin receptor blockers (ARB), particularly losartan, is a commonly prescribed antihypertensive with demonstrated antifibrotic properties. This retrospective study aimed to assess the rates of 1- and 2-year postoperative complications in patients who filled prescriptions for ARBs during the 90 days after TKA.

METHODS

Patients undergoing primary TKA were selected from a large national insurance database, and the impact of ARB use after TKA on complications was assessed. Of the 1,299,106 patients who underwent TKA, 82,065 had filled at least a 90-day prescription of losartan, valsartan, or olmesartan immediately following their TKA. The rates of manipulation under anesthesia (MUA), arthroscopic lysis of adhesions (LOA), aseptic loosening, periprosthetic fracture, and revision at 1 and 2 years following TKA were analyzed using multivariable logistic regressions to control for various comorbidities.

RESULTS

ARB use was associated with decreased rates of MUA (odds ratio [OR] = 0.94, 95% confidence interval (CI), 0.90 to 0.99), arthroscopy/LOA (OR = 0.86, 95% CI, 0.77 to 0.95), aseptic loosening (OR = 0.71, 95% CI, 0.61 to 0.83), periprosthetic fracture (OR = 0.58, 95% CI, 0.46 to 0.71), and revision (OR = 0.79, 95% CI, 0.74 to 0.85) 2 years after TKA.

CONCLUSIONS

ARB use throughout the 90 days after TKA is associated with a decreased risk of MUA, arthroscopy/LOA, aseptic loosening, periprosthetic fracture, and revision, demonstrating the potential protective abilities of ARBs. Prospective studies evaluating the use of ARBs in patients at risk for postoperative stiffness would be beneficial to further elucidate this association.

A guide to selecting upper thoracic versus lower thoracic uppermost instrumented vertebra in adult spinal deformity correction

PURPOSE

Operative treatment of adult spinal deformity (ASD) has been shown to improve patient health-related quality of life (HRQOL). Selection of the uppermost instrumented vertebra (UIV) in either the upper thoracic (UT) or lower thoracic (LT) spine is a pivotal decision with effects on operative and postoperative outcomes. This review overviews the multifaceted decision-making process for UIV selection in ASD correction.

METHODS

PubMed was queried for articles using the keywords "uppermost instrumented vertebra", "upper thoracic", "lower thoracic", and "adult spinal deformity".

RESULTS

Optimization of UIV selection may lead to superior deformity correction, better patient-reported outcomes, and lower risk of proximal junctional kyphosis (PJK) and failure (PJF). Patient alignment characteristics, including preoperative thoracic kyphosis, coronal deformity, and the magnitude of sagittal correction influence surgical decision-making when selecting a UIV, while comorbidities such as poor body mass index, osteoporosis, and neuromuscular pathology should also be taken in to account. Additionally, surgeon experience and resources available to the hospital may also play a role in this decision. Currently, it is incompletely understood whether postoperative HRQOLs, functional and radiographic outcomes, and complications after surgery differ between selection of the UIV in either the UT or LT spine.

CONCLUSION

The correct selection of the UIV in surgical planning is a challenging task, which requires attention to preoperative alignment, patient comorbidities, clinical characteristics, available resources, and surgeon-specific factors such as experience.

Comparison of multilevel low-grade techniques versus three-column osteotomies in adult spinal deformity surgery: does harmonious correction matter?

OBJECTIVE

Recent debate has arisen between whether to use a three-column osteotomy (3CO) or multilevel low-grade (MLG) techniques to treat severe sagittal malalignment in adult spinal deformity (ASD) surgery. The goal of this study was to compare the outcomes of 3CO and MLG techniques performed in corrective surgeries for ASD.

METHODS

ASD patients who had a baseline PI-LL > 30° and 2-year follow-up data were included. Patients underwent either 3CO or MLG (thoracolumbar posterior column osteotomies at ≥ 3 levels or anterior lumbar interbody fusion at ≥ 3 levels with no 3CO). The segmental utility ratio was used to assess relative segmental correction (segmental correction divided by overall correction in lordosis divided by the number of thoracolumbar interventions [interbody fusion, thoracolumbar posterior column osteotomies, and 3CO]). The paired t-test was used to assess lordotic distribution by differences in lordosis between adjacent lumbar disc spaces (e.g., L1-2 to L2-3). Multivariate analysis, controlling for age, sex, BMI, osteoporosis, baseline pelvic incidence, and T1 pelvic angle, was used to evaluate the complication rates and radiographic and patient-reported outcomes between the groups.

RESULTS

A total of 93 patients were included, 53% of whom underwent MLG and 47% of whom underwent 3CO. The MLG group had a lower BMI (p < 0.05). MLG patients received fewer previous fusions than 3CO patients (31% vs 80%, p < 0.001). MLG patients had 24% less blood loss but a 22% longer operative time (565 vs 419 minutes, p = 0.008). Using adjusted analysis, the 3CO group had greater segmental and relative correction at each level (segmental utility ratio mean 69% for 3CO vs 23% for MLG, p < 0.001). However, the 3CO group had lordotic differences between two adjacent lumbar disc pairs (range -0.5° to 9.0°, p = 0.009), while MLG was more harmonious (range 2.2°-6.5°, p > 0.4). MLG patients were more likely to undergo realignment to age-adjusted standards (OR 5.6, 95% CI 1.2-46.4; p = 0.033). MLG patients were less likely to develop neurological complications or undergo reoperation (OR 0.4, 95% CI 0.1-0.9; p = 0.041). Adjusted analysis revealed that MLG patients more often met a substantial clinical benefit in the Oswestry Disability Index score (OR 5.3, 95% CI 1.1-26.8; p = 0.043).

CONCLUSIONS

MLG techniques showed better utility in lumbar distribution and age-adjusted global correction while minimizing neurological complications and reoperation rates by 2 years postoperatively. In selected instances, these techniques may offer the spine deformity surgeon a safer alternative when correcting severe adult spinal deformity.

Functional Alignment Within the Fusion in Adult Spinal Deformity (ASD) Improves Outcomes and Minimizes Mechanical Failures

STUDY DESIGN

Retrospective review of an adult deformity database.

OBJECTIVE

To identify pelvic incidence (PI) and age-appropriate physical function alignment targets using a component angle of T1-pelvic angle within the fusion to define correction and their relationship to proximal junctional kyphosis (PJK) and clinical outcomes.

SUMMARY OF BACKGROUND DATA

In preoperative planning, a patient's PI is often utilized to determine the alignment target. In a trend toward more patient-specific planning, age-specific alignment has been shown to reduce the risk of mechanical failures. PI and age have not been analyzed with respect to defining a functional alignment.

METHODS

A database of patients with operative adult spinal deformity was analyzed. Patients fused to the pelvis and upper-instrumented vertebrae above T11 were included. Alignment within the fusion correlated with clinical outcomes and PI. Short form 36-Physical Component Score (SF36-PCS) normative data and PI were used to compute functional alignment for each patient. Overcorrected, under-corrected, and functionally corrected groups were determined using T10-pelvic angle (T10PA).

RESULTS

In all, 1052 patients met the inclusion criteria. T10PA correlated with SF36-PCS and PI (R=0.601). At six weeks, 40.7% were functionally corrected, 39.4% were overcorrected, and 20.9% were under-corrected. The PJK incidence rate was 13.6%. Overcorrected patients had the highest PJK rate (18.1%) compared with functionally (11.3%) and under-corrected (9.5%) patients ( P <0.05). Overcorrected patients had a trend toward more PJK revisions. All groups improved in HRQL; however, under-corrected patients had the worst 1-year SF36-PCS offset relative to normative patients of equivalent age (-8.1) versus functional (-6.1) and overcorrected (-4.5), P <0.05.

CONCLUSIONS

T10PA was used to determine functional alignment, an alignment based on PI and age-appropriate physical function. Correcting patients to functional alignment produced improvements in clinical outcomes, with the lowest rates of PJK. This patient-specific approach to spinal alignment provides adult spinal deformity correction targets that can be used intraoperatively.

Factors Associated with the Maintenance of Cost-Effectiveness at 5 Years in Adult Spinal Deformity Corrective Surgery

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

To evaluate factors associated with the long-term durability of cost-effectiveness (CE) in ASD patients.

BACKGROUND

A substantial increase in costs associated with the surgical treatment for adult spinal deformity (ASD) has given precedence to scrutinize the value and utility it provides.

METHODS

We included 327 operative ASD patients with 5-year (5 Y) follow-up. Published methods were used to determine costs based on CMS.gov definitions and were based on the average DRG reimbursement rates. Utility was calculated using quality-adjusted life-years (QALY) utilizing the Oswestry Disability Index (ODI) converted to Short-Form Six-Dimension (SF-6D), with a 3% discount applied for its decline with life expectancy. The CE threshold of $150,000 was used for primary analysis.

RESULTS

Major and minor complication rates were 11% and 47% respectively, with 26% undergoing reoperation by 5 Y. The mean cost associated with surgery was $91,095±$47,003, with a utility gain of 0.091±0.086 at 1Y, QALY gained at 2 Y of 0.171±0.183, and at 5 Y of 0.42±0.43. The cost per QALY at 2 Y was $414,885, which decreased to $142,058 at 5 Y.With the threshold of $150,000 for CE, 19% met CE at 2 Y and 56% at 5 Y. In those in which revision was avoided, 87% met cumulative CE till life expectancy. Controlling analysis depicted higher baseline CCI and pelvic tilt (PT) to be the strongest predictors for not maintaining durable CE to 5 Y (CCI OR: 1.821 [1.159-2.862], P=0.009) (PT OR: 1.079 [1.007-1.155], P=0.030).

CONCLUSIONS

Most patients achieved cost-effectiveness after four years postoperatively, with 56% meeting at five years postoperatively. When revision was avoided, 87% of patients met cumulative cost-effectiveness till life expectancy. Mechanical complications were predictive of failure to achieve cost-effectiveness at 2 Y, while comorbidity burden and medical complications were at 5 Y.

Stronger association of objective physical metrics with baseline patient-reported outcome measures than preoperative standing sagittal parameters for adult spinal deformity patients

OBJECTIVE

Sagittal alignment measured on standing radiography remains a fundamental component of surgical planning for adult spinal deformity (ASD). However, the relationship between classic sagittal alignment parameters and objective metrics, such as walking time (WT) and grip strength (GS), remains unknown. The objective of this work was to determine if ASD patients with worse baseline sagittal malalignment have worse objective physical metrics and if those metrics have a stronger relationship to patient-reported outcome metrics (PROMs) than standing alignment.

METHODS

The authors conducted a retrospective review of a multicenter ASD cohort. ASD patients underwent baseline testing with the timed up-and-go 6-m walk test (seconds) and for GS (pounds). Baseline PROMs were surveyed, including Oswestry Disability Index (ODI), Patient-Reported Outcomes Measurement Information System (PROMIS), Scoliosis Research Society (SRS)-22r, and Veterans RAND 12 (VR-12) scores. Standard spinopelvic measurements were obtained (sagittal vertical axis [SVA], pelvic tilt [PT], and mismatch between pelvic incidence and lumbar lordosis [PI-LL], and SRS-Schwab ASD classification). Univariate and multivariable linear regression modeling was performed to interrogate associations between objective physical metrics, sagittal parameters, and PROMs.

RESULTS

In total, 494 patients were included, with mean ± SD age 61 ± 14 years, and 68% were female. Average WT was 11.2 ± 6.1 seconds and average GS was 56.6 ± 24.9 lbs. With increasing PT, PI-LL, and SVA quartiles, WT significantly increased (p < 0.05). SRS-Schwab type N patients demonstrated a significantly longer average WT (12.5 ± 6.2 seconds), and type T patients had a significantly shorter WT time (7.9 ± 2.7 seconds, p = 0.03). With increasing PT quartiles, GS significantly decreased (p < 0.05). SRS-Schwab type T patients had a significantly higher average GS (68.8 ± 27.8 lbs), and type L patients had a significantly lower average GS (51.6 ± 20.4 lbs, p = 0.03). In the frailty-adjusted multivariable linear regression analyses, WT was more strongly associated with PROMs than sagittal parameters. GS was more strongly associated with ODI and PROMIS Physical Function scores.

CONCLUSIONS

The authors observed that increasing baseline sagittal malalignment is associated with slower WT, and possibly weaker GS, in ASD patients. WT has a stronger relationship to PROMs than standing alignment parameters. Objective physical metrics likely offer added value to standard spinopelvic measurements in ASD evaluation and surgical planning.

Analysis of tranexamic acid usage in adult spinal deformity patients with relative contraindications: does it increase the risk of complications?

OBJECTIVE

Complex spinal deformity surgeries may involve significant blood loss. The use of antifibrinolytic agents such as tranexamic acid (TXA) has been proven to reduce perioperative blood loss. However, for patients with a history of thromboembolic events, there is concern of increased risk when TXA is used during these surgeries. This study aimed to assess whether TXA use in patients undergoing complex spinal deformity correction surgeries increases the risk of thromboembolic complications based on preexisting thromboembolic risk factors.

METHODS

Data were analyzed for adult patients who received TXA during surgical correction for spinal deformity at 21 North American centers between August 2018 and October 2022. Patients with preexisting thromboembolic events and other risk factors (history of deep venous thrombosis [DVT], pulmonary embolism [PE], myocardial infarction [MI], stroke, peripheral vascular disease, or cancer) were identified. Thromboembolic complication rates were assessed during the postoperative 90 days. Univariate and multivariate analyses were performed to assess thromboembolic outcomes in high-risk and low-risk patients who received intravenous TXA.

RESULTS

Among 411 consecutive patients who underwent complex spinal deformity surgery and received TXA intraoperatively, 130 (31.6%) were considered high-risk patients. There was no significant difference in thromboembolic complications between patients with and those without preexisting thromboembolic risk factors in univariate analysis (high-risk group vs low-risk group: 8.5% vs 2.8%, p = 0.45). Specifically, there were no significant differences between groups regarding the 90-day postoperative rates of DVT (high-risk group vs low-risk group: 1.5% vs 1.4%, p = 0.98), PE (2.3% vs 1.8%, p = 0.71), acute MI (1.5% vs 0%, p = 0.19), or stroke (0.8% vs 1.1%, p > 0.99). On multivariate analysis, high-risk status was not a significant independent predictor for any of the thromboembolic complications.

CONCLUSIONS

Administration of intravenous TXA during the correction procedure did not change rates of thromboembolic events, acute MI, or stroke in this cohort of adult spinal deformity surgery patients.

Sagittal Alignment in the Degenerative Lumbar Spine: Surgical Planning

➤ Sagittal alignment of the spine has gained attention in the field of spinal deformity surgery for decades. However, emerging data support the importance of restoring segmental lumbar lordosis and lumbar spinal shape according to the pelvic morphology when surgically addressing degenerative lumbar pathologies such as degenerative disc disease and spondylolisthesis.➤ The distribution of caudal lordosis (L4-S1) and cranial lordosis (L1-L4) as a percentage of global lordosis varies by pelvic incidence (PI), with cephalad lordosis increasing its contribution to total lordosis as PI increases.➤ Spinal fusion may lead to iatrogenic deformity if performed without attention to lordosis magnitude and location in the lumbar spine.➤ A solid foundation of knowledge with regard to optimal spinal sagittal alignment is beneficial when performing lumbar spinal surgery, and thoughtful planning and execution of lumbar fusions with a focus on alignment may improve patient outcomes.

Significant Association between a Diagnosis of Hypovitaminosis D and Rotator Cuff Tear, Independent of Age and Sex: A Retrospective Database Study

PURPOSE

As high rates of vitamin D deficiency have been demonstrated in orthopedic patient cohorts, this study aimed to characterize the association between a diagnosis of hypovitaminosis D and primary rotator cuff tear (RCT), primary rotator cuff repair (RCR), and postoperative complications in different sex and age cohorts.

METHODS

In this retrospective cohort study using PearlDiver, a nationwide administrative claims database, records for all patients aged 30 to 89 yr who received a diagnosis of hypovitaminosis D between January 1, 2011, and October 31, 2018, were queried. Rates of primary RCT, primary RCR, and postoperative complications including subsequent surgery were calculated within sex- and age-specific cohorts and compared with matched control cohorts using multivariable logistic regression.

RESULTS

Among the 336,320 patients included in the hypovitaminosis D cohort, these patients were significantly more likely to experience an RCT (odds ratio (OR), 2.70; 95% confidence interval (CI), 2.55-2.85) as well as a full-thickness RCT (OR, 2.36; 95% CI, 2.17-2.56) specifically within 2 yr of their diagnosis. Women with hypovitaminosis D were more likely to undergo surgery to address their full-thickness tears (OR, 1.37; 95% CI, 1.09-1.74). There was no difference in the rates of revision RCR or irrigation and debridement. However, women with hypovitaminosis D were significantly more likely to undergo manipulation under anesthesia (OR, 1.16; 95% CI, 1.03-1.31).

CONCLUSIONS

Patients diagnosed with hypovitaminosis D were significantly more likely to suffer from a primary RCT and to undergo manipulation under anesthesia within a year of their RCR. Although many risk factors for RCT are unmodifiable, vitamin D deficiency is a readily modifiable risk factor with several treatment regimens demonstrating positive effects on musculoskeletal health.

The Case for Operative Efficiency in Adult Spinal Deformity Surgery: Impact of Operative Time on Complications, Length of Stay, Alignment, Fusion Rates, and Patient-Reported Outcomes

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To analyze the impact of operative room (OR) time in adult spinal deformity (ASD) surgery on patient outcomes.

BACKGROUND

It is currently unknown if OR time in ASD patients matched for deformity severity and surgical invasiveness is associated with patient outcomes.

MATERIALS AND METHODS

ASD patients with baseline and two-year postoperative radiographic and patient-reported outcome measures (PROM) data, undergoing a posterior-only approach for long fusion (>L1-Ilium) were included. Patients were grouped into short OR time (<40th percentile: <359 min) and long OR time (>60th percentile: >421 min). Groups were matched by age, baseline deformity severity, and surgical invasiveness. Demographics, radiographic, PROM data, fusion rate, and complications were compared between groups at baseline and two years follow-up.

RESULTS

In total, 270 patients were included for analysis: the mean OR time was 286 minutes in the short OR group versus 510 minutes in the long OR group ( P <0.001). Age, gender, percent of revision cases, surgical invasiveness, pelvic incidence minus lumbar lordosis, sagittal vertical axis, and pelvic tilt were comparable between groups ( P >0.05). Short OR had a slightly lower body mass index than the short OR group ( P <0.001) and decompression was more prevalent in the long OR time ( P =0.042). Patients in the long group had greater hospital length of stay ( P =0.02); blood loss ( P <0.001); proportion requiring intensive care unit ( P =0.003); higher minor complication rate ( P =0.001); with no significant differences for major complications or revision procedures ( P >0.5). Both groups had comparable radiographic fusion rates ( P =0.152) and achieved improvement in sagittal alignment measures, Oswestry disability index, and Short Form-36 ( P <0.001).

CONCLUSION

Shorter OR time for ASD correction is associated with a lower minor complication rate, a lower estimated blood loss, fewer intensive care unit admissions, and a shorter hospital length of stay without sacrificing alignment correction or PROMs. Maximizing operative efficiency by minimizing OR time in ASD surgery has the potential to benefit patients, surgeons, and hospital systems.

Burst fracture treatment caudal to long posterior spinal fusion for adolescent idiopathic scoliosis utilizing temporary lumbo-pelvic fixation with restoration of lumbar mobility after instrumentation removal

Background

Thoracolumbar burst fractures are common traumatic spinal fractures. The goals of treatment include stabilization, prevention of neurologic compromise or deformity, and preservation of mobility. The aim of this case report is to describe the occurrence and treatment of an L4 burst fracture caudal to long posterior fusion for adolescent idiopathic scoliosis (AIS).

Case report

A 15-year-old girl patient underwent posterior spinal fusion from T3-L3. The patient tolerated the procedure well and there were no complications. Seven years postoperatively, the patient reported to the emergency department with lumbar pain after fall from height. A burst fracture at L4 was diagnosed and temporary posterior instrumentation to the pelvis was performed. One-year postinjury, the hardware was removed with fixation replaced only into the fractured segment. Flexion/extension radiographs revealed restored motion.

Conclusions

Treatment of fractures adjacent to fusion constructs may be challenging. This case demonstrates that avoiding fusion may lead to satisfactory outcomes and restoration of mobility after instrumentation removal.

Risk of Dysphagia and Dysphonia in Patients With Prior Thyroidectomy Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study using PearlDiver database.

OBJECTIVES

To evaluate the effect of prior thyroidectomy on complications of Anterior Cervical Discectomy and Fusion (ACDF) surgery.

METHODS

PearlDiver was used to identify patients without prior dysphagia or dysphonia undergoing ACDF between the years 2010-2020Q1. Patients with and without prior thyroidectomy were matched by levels of fusion, alcohol use, and gastroesophageal reflux disease in a 1:5 ratio. Postoperative outcomes were assessed for each cohort with multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index.

RESULTS

Between 2010 and 2019, matched cohorts of 792 ACDF patients with prior thyroidectomy and 3960 ACDF only patients were included in the study. Of patients with previous thyroidectomy undergoing ACDF, 16.3% experienced dysphagia at 1-year compared with 10.6% for patients undergoing ACDF only (aOR=1.39, P=.004). Patients with previous thyroidectomy also had higher odds of dysphonia at 1-year following ACDF, as compared to patients with ACDF alone (2.7% vs 1.2%, aOR=1.74, P= .048). Patients undergoing ACDF with prior thyroidectomy did not have increased risk of revision at 1 year (aOR=1.10, P=.698), 2 years (aOR=1.16, P=.457), or 5 years (aOR=1.20, P=.255) following surgery. There were no differences in postoperative opioid utilization rates at 1 month (aOR=2.07, P=.138), 3 months (aOR=2.45, P=.095), 6 months (aOR=1.34, P=.520), and 12 months (aOR=1.69, P=.202). Prior thyroidectomy was not associated with reintubation following ACDF (P=.995).

CONCLUSIONS

Patients with prior thyroidectomy undergoing ACDF surgery experience increased odds of dysphagia and dysphonia at 1-year follow-up compared to those without prior thyroidectomy.

Management of Thoracolumbar Vertebral Fractures and Dislocations in Patients with Ankylosing Conditions of the Spine

Ankylosing spondylitis (AS) and diffuse idiopathic skeletal hyperostosis (DISH) are bone-forming spinal conditions which inherently increase spine rigidity and place patients at a higher risk for thoracolumbar fractures. Due to the long lever-arm associated with their pathology, these fractures are frequently unstable and may significantly displace leading to catastrophic neurologic consequences. Operative and non-operative management are considerations in these fractures. However conservative measures including immobilization and bracing are typically reserved for non-displaced or incomplete fractures, or in patients for whom surgery poses a high risk. Thus, first line treatment is often surgery which has historically been an open posterior spinal fusion. Recent techniques such as minimally invasive surgery (MIS) and robotic surgery have shown promising lower complication rates as compared to open techniques, however these methods need to be further validated.

Management of traumatic spinal cord injury: A current concepts review of contemporary and future treatment

Spinal Cord Injury (SCI) is a condition leading to inflammation, edema, and dysfunction of the spinal cord, most commonly due to trauma, tumor, infection, or vascular disturbance. Symptoms include sensory and motor loss starting at the level of injury; the extent of damage depends on injury severity as detailed in the ASIA score. In the acute setting, maintaining mean arterial pressure (MAP) higher than 85 mmHg for up to 7 days following injury is preferred; although caution must be exercised when using vasopressors such as phenylephrine due to serious side effects such as pulmonary edema and death. Decompression surgery (DS) may theoretically relieve edema and reduce intraspinal pressure, although timing of surgery remains a matter of debate. Methylprednisolone (MP) is currently used due to its ability to reduce inflammation but more recent studies question its clinical benefits, especially with inconsistency in recommending it nationally and internationally. The choice of MP is further complicated by conflicting evidence for optimal timing to initiate treatment, and by the reported observation that higher doses are correlated with increased risk of complications. Thyrotropin-releasing hormone may be beneficial in less severe injuries. Finally, this review discusses many options currently being researched and have shown promising pre-clinical results.

Anterior cervical discectomy and fusion versus cervical disc arthroplasty: an epidemiological review of 433,660 surgical patients from 2011 to 2021

BACKGROUND CONTEXT

Anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) are commonly performed operations to address cervical radiculopathy and myelopathy. Trends in utilization and revision surgery rates warrant investigation.

PURPOSE

To explore the epidemiology, postoperative complications, and reoperation rates of ACDF and CDA DESIGN: Retrospective cohort study.

PATIENT SAMPLE

A total of 433,660 patients who underwent ACDF or CDA between 2011 and 2021 were included in this study.

OUTCOME MEASURES

The following data were observed for all cases: patient demographics, complications, and revisions.

METHODS

The PearlDiver database was queried to identify patients who underwent ACDF and CDA between 2011 and 2021. Epidemiological analyses were performed to examine trends in cervical procedure utilization by age group and year. After matching by age, sex, Charlson Comorbidity Index (CCI), levels of operation, and reason for surgery, the early postoperative (2-week), short-term (2-year), and long-term (5-year) complications of both cervical procedures were examined.

RESULTS

In total, 404,195 ACDF and 29,465 CDA patients were included. ACDF utilization rose by 25.25% between 2011 and 2014 while CDA utilization rose by 654.24% between 2011-2019 followed by relative plateauing in both procedures. Mann-Kendall trend test confirmed a significant but small rise in ACDF and large rise in CDA procedures from 2011 to 2021 (p<.001). After matching, ACDF and CDA had an overall complication rate of 12.20% and 8.77%, respectively, with the most common complications being subsequent anterior revision (4.96% and 3.35%) and dysphagia (3.70% and 2.98%). The ACDF cohort, especially multilevel ACDF patients, generally had more complications and higher revision rates than the CDA cohort (p<.05).

CONCLUSIONS

While ACDF utilization has plateaued since 2014, CDA rates have risen by a staggering 654.24% over the past decade. ACDF and CDA complication and revision rates were relatively low in comparison to previously published values, with significantly lower rates in CDA. Although a lack of radiographic data in this study limits its power to recommend either procedure for individual patients with cervical radiculopathy or myelopathy, CDA may be associated with minor improvement in the complication and revision profile.

Impact of Hip and Knee Osteoarthritis on Full Body Sagittal Alignment and Compensation for Sagittal Spinal Deformity

STUDY DESIGN

Retrospective review of prospectively collected data.

OBJECTIVE

To investigate the effect of lower extremity osteoarthritis on sagittal alignment and compensatory mechanisms in adult spinal deformity (ASD).

BACKGROUND

Spine, hip, and knee pathologies often overlap in ASD patients. Limited data exists on how lower extremity osteoarthritis impacts sagittal alignment and compensatory mechanisms in ASD.

METHODS

527 pre-operative ASD patients with full body radiographs were included. Patients were grouped by Kellgren-Lawrence grade of bilateral hips and knees and stratified by quartile of T1-Pelvic Angle (T1PA) severity into low-, mid-, high-, and severe-T1PA. Full body alignment and compensation were compared across quartiles. Regression analysis examined the incremental impact of hip and knee osteoarthritis severity on compensation.

RESULTS

The mean T1PA for low-, mid-, high-, and severe-T1PA groups was 7.3°, 19.5°, 27.8°, 41.6°, respectively. Mid-T1PA patients with severe hip osteoarthritis had an increased sagittal vertical axis and global sagittal alignment (P<0.001). Increasing hip osteoarthritis severity resulted in decreased pelvic tilt (P=0.001) and sacrofemoral angle (P<0.001), but increased knee flexion (P=0.012). Regression analysis revealed with increasing T1PA, pelvic tilt correlated inversely with hip osteoarthritis and positively with knee osteoarthritis (r2=0.812). Hip osteoarthritis decreased compensation via sacrofemoral angle (β-coefficient=-0.206). Knee and hip osteoarthritis contributed to greater knee flexion (β-coefficients=0.215, 0.101; respectively). For pelvic shift, only hip osteoarthritis significantly contributed to the model (β-coefficient=0.100).

CONCLUSIONS

For the same magnitude of spinal deformity, increased hip osteoarthritis severity was associated with worse truncal and full body alignment with posterior translation of the pelvis. Patients with severe hip and knee osteoarthritis exhibited decreased hip extension and pelvic tilt, but increased knee flexion. This examines sagittal alignment and compensation in ASD patients with hip and knee arthritis and may help delineate whether hip and knee flexion is due to spinal deformity compensation or lower extremity osteoarthritis.

Are insufficient corrections a major factor in distal junctional kyphosis? A simulated analysis of cervical deformity correction using in-construct measurements

OBJECTIVE

The present study utilized recently developed in-construct measurements in simulations of cervical deformity surgery in order to assess undercorrection and predict distal junctional kyphosis (DJK).

METHODS

A retrospective review of a database of operative cervical deformity patients was analyzed for severe DJK and mild DJK. C2-lower instrumented vertebra (LIV) sagittal angle (SA) was measured postoperatively, and the correction was simulated in the preoperative radiograph in order to match the C2-LIV by using the planning software. Linear regression analysis that used C2 pelvic angle (CPA) and pelvic tilt (PT) determined the simulated PT that matched the virtual CPA. Linear regression analysis was used to determine the C2-T1 SA, C2-T4 SA, and C2-T10 SA that corresponded to DJK of 20° and cervical sagittal vertical axis (cSVA) of 40 mm.

RESULTS

Sixty-nine cervical deformity patients were included. Severe and mild DJK occurred in 11 (16%) and 22 (32%) patients, respectively; 3 (4%) required DJK revision. Simulated corrections demonstrated that severe and mild DJK patients had worse alignment compared to non-DJK patients in terms of cSVA (42.5 mm vs 33.0 mm vs 23.4 mm, p < 0.001) and C2-LIV SVA (68.9 mm vs 57.3 mm vs 36.8 mm, p < 0.001). Linear regression revealed the relationships between in-construct measures (C2-T1 SA, C2-T4 SA, and C2-T10 SA), cSVA, and change in DJK (all R > 0.57, p < 0.001). A cSVA of 40 mm corresponded to C2-T4 SA of 10.4° and C2-T10 SA of 28.0°. A DJK angle change of 10° corresponded to C2-T4 SA of 5.8° and C2-T10 SA of 20.1°.

CONCLUSIONS

Simulated cervical deformity corrections demonstrated that severe DJK patients have insufficient corrections compared to patients without DJK. In-construct measures assess sagittal alignment within the fusion separate from DJK and subjacent compensation. They can be useful as intraoperative tools to gauge the adequacy of cervical deformity correction.

Machine learning clustering of adult spinal deformity patients identifies four prognostic phenotypes: a multicenter prospective cohort analysis with single surgeon external validation

BACKGROUND CONTEXT

Among adult spinal deformity (ASD) patients, heterogeneity in patient pathology, surgical expectations, baseline impairments, and frailty complicates comparisons in clinical outcomes and research. This study aims to qualitatively segment ASD patients using machine learning-based clustering on a large, multicenter, prospectively gathered ASD cohort.

PURPOSE

To qualitatively segment adult spinal deformity patients using machine learning-based clustering on a large, multicenter, prospectively gathered cohort.

STUDY DESIGN/SETTING

Machine learning algorithm using patients from a prospective multicenter study and a validation cohort from a retrospective single center, single surgeon cohort with complete 2-year follow up.

PATIENT SAMPLE

About 805 ASD patients; 563 patients from a prospective multicenter study and 242 from a single center to be used as a validation cohort.

OUTCOME MEASURES

To validate and extend the Ames-ISSG/ESSG classification using machine learning-based clustering analysis on a large, complex, multicenter, prospectively gathered ASD cohort.

METHODS

We analyzed a training cohort of 563 ASD patients from a prospective multicenter study and a validation cohort of 242 ASD patients from a retrospective single center/surgeon cohort with complete two-year patient-reported outcomes (PROs) and clinical/radiographic follow-up. Using k-means clustering, a machine learning algorithm, we clustered patients based on baseline PROs, Edmonton frailty, age, surgical history, and overall health. Baseline differences in clusters identified using the training cohort were assessed using Chi-Squared and ANOVA with pairwise comparisons. To evaluate the classification system's ability to discern postoperative trajectories, a second machine learning algorithm assigned the single-center/surgeon patients to the same 4 clusters, and we compared the clusters' two-year PROs and clinical outcomes.

RESULTS

K-means clustering revealed four distinct phenotypes from the multicenter training cohort based on age, frailty, and mental health: Old/Frail/Content (OFC, 27.7%), Old/Frail/Distressed (OFD, 33.2%), Old/Resilient/Content (ORC, 27.2%), and Young/Resilient/Content (YRC, 11.9%). OFC and OFD clusters had the highest frailty scores (OFC: 3.76, OFD: 4.72) and a higher proportion of patients with prior thoracolumbar fusion (OFC: 47.4%, OFD: 49.2%). ORC and YRC clusters exhibited lower frailty scores and fewest patients with prior thoracolumbar procedures (ORC: 2.10, 36.6%; YRC: 0.84, 19.4%). OFC had 69.9% of patients with global sagittal deformity and the highest T1PA (29.0), while YRC had 70.2% exhibiting coronal deformity, the highest mean coronal Cobb Angle (54.0), and the lowest T1PA (11.9). OFD and ORC had similar alignment phenotypes with intermediate values for Coronal Cobb Angle (OFD: 33.7; ORC: 40.0) and T1PA (OFD: 24.9; ORC: 24.6) between OFC (worst sagittal alignment) and YRC (worst coronal alignment). In the single surgeon validation cohort, the OFC cluster experienced the greatest increase in SRS Function scores (1.34 points, 95%CI 1.01-1.67) compared to OFD (0.5 points, 95%CI 0.245-0.755), ORC (0.7 points, 95%CI 0.415-0.985), and YRC (0.24 points, 95%CI -0.024-0.504) clusters. OFD cluster patients improved the least over 2 years. Multivariable Cox regression analysis demonstrated that the OFD cohort had significantly worse reoperation outcomes compared to other clusters (HR: 3.303, 95%CI: 1.085-8.390).

CONCLUSION

Machine-learning clustering found four different ASD patient qualitative phenotypes, defined by their age, frailty, physical functioning, and mental health upon presentation, which primarily determines their ability to improve their PROs following surgery. This reaffirms that these qualitative measures must be assessed in addition to the radiographic variables when counseling ASD patients regarding their expected surgical outcomes.

Sacroplasty for Sacral Insufficiency Fractures: Narrative Literature Review on Patient Selection, Technical Approaches, and Outcomes

Sacral insufficiency fractures commonly affect elderly women with osteoporosis and can cause debilitating lower back pain. First line management is often with conservative measures such as early mobilization, multimodal pain management, and osteoporosis management. If non-operative management fails, sacroplasty is a minimally invasive intervention that may be pursued. Candidates for sacroplasty are patients with persistent pain, inability to tolerate immobilization, or patients with low bone mineral density. Before undergoing sacroplasty, patients' bone health should be optimized with pharmacotherapy. Anabolic agents prior to or in conjunction with sacroplasty have been shown to improve patient outcomes. Sacroplasty can be safely performed through a number of techniques: short-axis, long-axis, coaxial, transiliac, interpedicular, and balloon-assisted. The procedure has been demonstrated to rapidly and durably reduce pain and improve mobility, with little risk of complications. This article aims to provide a narrative literature review of sacroplasty including, patient selection and optimization, the various technical approaches, and short and long-term outcomes.

Assessing the Accuracy and Reliability of AI-Generated Responses to Patient Questions Regarding Spine Surgery

BACKGROUND

In today's digital age, patients increasingly rely on online search engines for medical information. The integration of large language models such as GPT-4 into search engines such as Bing raises concerns over the potential transmission of misinformation when patients search for information online regarding spine surgery.

METHODS

SearchResponse.io, a database that archives People Also Ask (PAA) data from Google, was utilized to determine the most popular patient questions regarding 4 specific spine surgery topics: anterior cervical discectomy and fusion, lumbar fusion, laminectomy, and spinal deformity. Bing's responses to these questions, along with the cited sources, were recorded for analysis. Two fellowship-trained spine surgeons assessed the accuracy of the answers on a 6-point scale and the completeness of the answers on a 3-point scale. Inaccurate answers were re-queried 2 weeks later. Cited sources were categorized and evaluated against Journal of the American Medical Association (JAMA) benchmark criteria. Interrater reliability was measured with use of the kappa statistic. A linear regression analysis was utilized to explore the relationship between answer accuracy and the type of source, number of sources, and mean JAMA benchmark score.

RESULTS

Bing's responses to 71 PAA questions were analyzed. The average completeness score was 2.03 (standard deviation [SD], 0.36), and the average accuracy score was 4.49 (SD, 1.10). Among the question topics, spinal deformity had the lowest mean completeness score. Re-querying the questions that initially had answers with low accuracy scores resulted in responses with improved accuracy. Among the cited sources, commercial sources were the most prevalent. The JAMA benchmark score across all sources averaged 2.63. Government sources had the highest mean benchmark score (3.30), whereas social media had the lowest (1.75).

CONCLUSIONS

Bing's answers were generally accurate and adequately complete, with incorrect responses rectified upon re-querying. The plurality of information was sourced from commercial websites. The type of source, number of sources, and mean JAMA benchmark score were not significantly correlated with answer accuracy. These findings underscore the importance of ongoing evaluation and improvement of large language models to ensure reliable and informative results for patients seeking information regarding spine surgery online amid the integration of these models in the search experience.

Persistent Lower Extremity Compensation for Sagittal Imbalance After Surgical Correction of Complex Adult Spinal Deformity: A Radiographic Analysis of Early Impact

BACKGROUND AND OBJECTIVES

Achieving spinopelvic realignment during adult spinal deformity (ASD) surgery does not always produce ideal outcomes. Little is known whether compensation in lower extremities (LEs) plays a role in this disassociation. The objective is to analyze lower extremity compensation after complex ASD surgery, its effect on outcomes, and whether correction can alleviate these mechanisms.

METHODS

We included patients with complex ASD with 6-week data. LE parameters were as follows: sacrofemoral angle, knee flexion angle, and ankle flexion angle. Each parameter was ranked, and upper tertile was deemed compensation. Patients compensating and not compensating postoperatively were propensity score matched for body mass index, frailty, and T1 pelvic angle. Linear regression assessed correlation between LE parameters and baseline deformity, demographics, and surgical details. Multivariate analysis controlling for baseline deformity and history of total knee/hip arthroplasty evaluated outcomes.

RESULTS

Two hundred and ten patients (age: 61.3 ± 14.1 years, body mass index: 27.4 ± 5.8 kg/m2, Charlson Comorbidity Index: 1.1 ± 1.6, 72% female, 22% previous total joint arthroplasty, 24% osteoporosis, levels fused: 13.1 ± 3.8) were included. At baseline, 59% were compensating in LE: 32% at hips, 39% knees, and 36% ankles. After correction, 61% were compensating at least one joint. Patients undercorrected postoperatively were less likely to relieve LE compensation (odds ratio: 0.2, P = .037). Patients compensating in LE were more often undercorrected in age-adjusted pelvic tilt, pelvic incidence, lumbar lordosis, and T1 pelvic angle and disproportioned in Global Alignment and Proportion (P < .05). Patients matched in sagittal age-adjusted score at 6 weeks but compensating in LE were more likely to develop proximal junctional kyphosis (odds ratio: 4.1, P = .009) and proximal junctional failure (8% vs 0%, P = .035) than those sagittal age-adjusted score-matched and not compensating in LE.

CONCLUSION

Perioperative lower extremity compensation was a product of undercorrecting complex ASD. Even in age-adjusted realignment, compensation was associated with global undercorrection and junctional failure. Consideration of lower extremities during planning is vital to avoid adverse outcomes in perioperative course after complex ASD surgery.

Medicaid Expansion Is Associated With Increases in Medicaid-Funded Total Joint Arthroplasty

BACKGROUND

Existing literature presents competing views concerning the impact of Medicaid expansion on total joint arthroplasty (TJA) utilizations. While some reports demonstrate that expansion does not increase Medicaid acceptance by surgeons, others show increases in Medicaid-funded TJA via limited analyses. We conducted a nationwide, multi-insurance, econometric study to determine if Medicaid-funded and all-funding-source total hip arthroplasty (THA) or total knee arthroplasty (TKA) utilizations increased following expansion.

METHODS

This study examined 999,015 THA and 2,099,975 TKA from 2010 to 2017 using a commercially available national payer database. Difference-in-differences analyses, econometric regression methods used to assess the impact of policy change, were used to examine the impact of Medicaid expansion on TJA utilizations, and event analyses were used to confirm the parallel trends assumption, which helps to ensure that the estimated effect is not a result of existing differences in trends between treatment and nontreatment groups.

RESULTS

Event analyses confirmed parallel trends in the pre-expansion period. Difference-in-differences analyses found a persistent increase in Medicaid-funded THA (40.4%, P = .001, confidence interval [CI]: 12.7, 62.1%), but not THA from all funding sources (4.6%, P = .128, CI: -1.3, 10.8%). Medicaid-funded TKA (35.8%, P < .001, CI: 17.4, 68.0%) increased, but not TKA from all funding sources (3.4%, P = .321, CI: -3.1, 10.1%).

CONCLUSION

While the number of Medicaid-funded TJAs increased, expansion had no significant effect when examining all funding sources. This suggests that Medicaid expansion primarily affected source of TJA funding, not overall volume. Further research is needed to examine state-specific predictors of response to Medicaid expansion.

Patient-specific Cervical Deformity Corrections With Consideration of Associated Risk: Establishment of Risk Benefit Thresholds for Invasiveness Based on Deformity and Frailty Severity

STUDY DESIGN/SETTING

This was a retrospective cohort study.

BACKGROUND

Little is known of the intersection between surgical invasiveness, cervical deformity (CD) severity, and frailty.

OBJECTIVE

The aim of this study was to investigate the outcomes of CD surgery by invasiveness, frailty status, and baseline magnitude of deformity.

METHODS

This study included CD patients with 1-year follow-up. Patients stratified in high deformity if severe in the following criteria: T1 slope minus cervical lordosis, McGregor's slope, C2-C7, C2-T3, and C2 slope. Frailty scores categorized patients into not frail and frail. Patients are categorized by frailty and deformity (not frail/low deformity; not frail/high deformity; frail/low deformity; frail/high deformity). Logistic regression assessed increasing invasiveness and outcomes [distal junctional failure (DJF), reoperation]. Within frailty/deformity groups, decision tree analysis assessed thresholds for an invasiveness cutoff above which experiencing a reoperation, DJF or not achieving Good Clinical Outcome was more likely.

RESULTS

A total of 115 patients were included. Frailty/deformity groups: 27% not frail/low deformity, 27% not frail/high deformity, 23.5% frail/low deformity, and 22.5% frail/high deformity. Logistic regression analysis found increasing invasiveness and occurrence of DJF [odds ratio (OR): 1.03, 95% CI: 1.01-1.05, P =0.002], and invasiveness increased with deformity severity ( P <0.05). Not frail/low deformity patients more often met Optimal Outcome with an invasiveness index <63 (OR: 27.2, 95% CI: 2.7-272.8, P =0.005). An invasiveness index <54 for the frail/low deformity group led to a higher likelihood of meeting the Optimal Outcome (OR: 9.6, 95% CI: 1.5-62.2, P =0.018). For the frail/high deformity group, patients with a score <63 had a higher likelihood of achieving Optimal Outcome (OR: 4.8, 95% CI: 1.1-25.8, P =0.033). There was no significant cutoff of invasiveness for the not frail/high deformity group.

CONCLUSIONS

Our study correlated increased invasiveness in CD surgery to the risk of DJF, reoperation, and poor clinical success. The thresholds derived for deformity severity and frailty may enable surgeons to individualize the invasiveness of their procedures during surgical planning to account for the heightened risk of adverse events and minimize unfavorable outcomes.

Variability in expenses related to spine oncology care: comparison of payer-negotiated rates at National Cancer Institute-Designated Cancer Centers

BACKGROUND

As of 2021, the Centers for Medicare and Medicaid Services (CMS) requires all hospitals to publish their commercially negotiated prices. To our knowledge, price variation of spine oncology diagnosis and treatments has not been previously investigated.

PURPOSE

The aim of this study is to characterize the availability and variation of prices for spinal oncology services among National Cancer Institute-Designated Cancer Centers (NCI-DCC).

STUDY DESIGN

Cross-sectional analysis.

METHODS

Cancer centers were identified; those that did not provide patient care or participate in Medicare's Inpatient Prospective System were excluded. A cross-sectional analysis was conducted to gather commercially negotiated prices by searching online for "[center name] price transparency OR machine-readable file OR chargemaster." Data obtained was queried using 44 current procedural terminology (CPT) codes for imaging, procedures, and surgeries relevant to spine oncology. Comparison of prices was achieved by normalizing the median price for each service at each center to the estimated 2022 Medicare reimbursement for the center's Medicare Administrator Contractor. The ratios between the lowest and highest median commercial negotiated price within a center and across all centers were defined as "within-center ratio" and "across-center ratio" respectively.

RESULTS

In total, 49 centers disclosed commercial payer-negotiated rates. Mean rate (±SD) for cervical corpectomy was $9,134 (±$10,034), thoracic laminectomy for neoplasm excision was $5,382 (±$5502), superficial bone biopsy was $1,853 (±$1,717), and single-photon emission computerized tomography (SPECT) was $813 (±$232). Within-center ratios ranged from 5.0 (SPECT scan) to 17.8 (radiofrequency bone ablation). Across-center ratios (for codes with > 10 centers reporting) ranged from 9.0 (corpectomy, thoracic, lateral extra-cavitary) to 418.7 (anterior approach cervical corpectomy).

CONCLUSIONS

Price transparency for spinal oncology remains elusive despite recent CMS regulatory oversight, with marked heterogeneity in the quality of published rates complicating patients' ability to "shop" for care. Additionally, there continues to be significant variation in commercial rates for spine oncology diagnosis and treatment.

CLINICAL SIGNIFICANCE

Despite regulation by CMS, prices for spinal oncology services are not uniformly available to patients and vary between NCI-DCC. The findings of this manuscript present potential barriers for patients to compare and obtain affordable care.

Lumbar Lordosis Redistribution and Segmental Correction in Adult Spinal Deformity (ASD): Does it Matter?

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVE

Evaluate the impact of correcting to normative segmental lordosis values on post-operative outcomes.

BACKGROUND

Restoring lumbar lordosis magnitude is crucial in adult spinal deformity surgery, but the optimal location and segmental distribution remains unclear.

METHODS

Patients were grouped based on offset to normative segmental lordosis values, extracted from recent publications. Matched patients were within 10% of the cohort's mean offset, less than or over 10% were under- and over-corrected. Surgical technique, PROMs, and surgical complications were compared across groups at baseline and 2-year.

RESULTS

510 patients with an average age of 64.6, mean CCI 2.08, and average follow-up of 25 months. L4-5 was least likely to be matched (19.1%), while L4-S1 was the most likely (24.3%). More patients were overcorrected at proximal levels (T10-L2; Undercorrected, U: 32.2% vs. Matched, M: 21.7% vs. Overcorrected, O: 46.1%) and undercorrected at distal levels (L4-S1: U: 39.0% vs. M: 24.3% vs. O: 36.8%). Postoperative ODI was comparable across correction groups at all spinal levels except at L4-S1 and T10-L2/L4-S1, where overcorrected patients and matched were better than undercorrected (U: 32.1 vs. M: 25.4 vs. O: 26.5, P=0.005; U: 36.2 vs. M: 24.2 vs. O: 26.8, P=0.001; respectively). Patients overcorrected at T10-L2 experienced higher rates of proximal junctional failure (PJF) (U: 16.0% vs. M: 15.6% vs. O: 32.8%, P<0.001) and had greater posterior inclination of the upper instrumented vertebra (UIV) (U: -9.2±9.4° vs. M: -9.6±9.1° vs. O: -12.2±10.0°, P<0.001), whereas undercorrection at these levels led to higher rates of revision for implant failure (U: 14.2% vs. M: 7.3% vs. O: 6.4%, P=0.025).

CONCLUSIONS

Patients undergoing fusion for adult spinal deformity suffer higher rates of PJF with overcorrection and increased rates of implant failure with undercorrection based on normative segmental lordosis.

LEVEL OF EVIDENCE

IV.

Cannabis use Disorder and Complications After Anterior Cervical Diskectomy and Fusion

OBJECTIVE

The aim of this study, a retrospective database analysis, was to assess the impact of baseline cannabis use disorder (CUD) on perioperative complication outcomes in patients undergoing primary 1- to 2-level anterior cervical diskectomy and fusion (ACDF) surgery.

METHODS

The PearlDiver Database was queried from January 2010 to December 2021 for patients who underwent primary 1- to 2-level ACDF surgery for degenerative spine disease. Patients with CUD diagnosis 6 months before the index ACDF surgery (i.e., CUD) were propensity matched with patients without CUD (i.e., control in a ratio of 1:1, employing age, gender, and Charlson Comorbidity Index as matching covariates). Univariate and multivariable analysis models with adjustment of confounding variables were used to evaluate the risk of CUD on perioperative complications between the propensity-matched cohorts.

RESULTS

The 1:1 matched cohort included 838 patients in each group. Following multivariate analysis, CUD was demonstrated to be associated with an increased incidence of hospital readmission at 90 days (odds ratio [OR] = 2.64, 95% confidence interval: [1.19 to 6.78], [P = 0.027]) and revision surgery at 1 year postoperative (OR = 3.36, 95% confidence interval: [1.17 to 14.18], [P = 0.049]). CUD was additionally associated with reduced risk of overall medical complications at both 6 months and 1 year postoperative (OR = 0.55, [P = 0.021], and OR = 0.54, [P = 0.015], respectively).

CONCLUSIONS

These findings indicate that isolated baseline CUD is associated with an increased risk of hospital readmission at 90 days postoperative and cervical spine reoperation at 1 year after primary 1- to 2-level ACDF surgery with a decrease in overall medical complications, cardiac arrhythmias, and acute renal failure.

Efficacy of Varying Surgical Approaches on Achieving Optimal Alignment in Adult Spinal Deformity Surgery

BACKGROUND

The Roussouly, SRS-Schwab, and Global Alignment and Proportion (GAP) classifications define alignment by spinal shape and deformity severity. The efficacy of different surgical approaches and techniques to successfully achieve these goals is not well understood.

PURPOSE

Identify the impact of surgical approach and/or technique on meeting complex realignment goals in adult spinal deformity (ASD) corrective surgery.

STUDY DESIGN/SETTING

Retrospective study.

MATERIALS AND METHODS

Included patients with ASD fused to pelvis with 2-year data. Patients were categorized by: (1) Roussouly: matching current and theoretical spinal shapes, (2) improving in SRS-Schwab modifiers (0, +, ++), and (3) improving GAP proportionality by 2 years. Analysis of covariance and multivariable logistic regression analyses controlling for age, levels fused, baseline deformity, and 3-column osteotomy usage compared the effect of different surgical approaches, interbody, and osteotomy use on meeting realignment goals.

RESULTS

A total of 693 patients with ASD were included. By surgical approach, 65.7% were posterior-only and 34.3% underwent anterior-posterior approach with 76% receiving an osteotomy (21.8% 3-column osteotomy). By 2 years, 34% matched Roussouly, 58% improved in GAP, 45% in SRS-Schwab pelvic tilt (PT), 62% sagittal vertical axis, and 70% pelvic incidence-lumbar lordosis. Combined approaches were most effective for improvement in PT [odds ratio (OR): 1.7 (1.1-2.5)] and GAP [OR: 2.2 (1.5-3.2)]. Specifically, anterior lumbar interbody fusion (ALIF) below L3 demonstrated higher rates of improvement versus TLIFs in Roussouly [OR: 1.7 (1.1-2.5)] and GAP [OR: 1.9 (1.3-2.7)]. Patients undergoing pedicle subtraction osteotomy at L3 or L4 were more likely to improve in PT [OR: 2.0 (1.0-5.2)] and pelvic incidence-lumbar lordosis [OR: 3.8 (1.4-9.8)]. Clinically, patients undergoing the combined approach demonstrated higher rates of meeting SCB in Oswestry Disability Index by 2 years while minimizing rates of proximal junctional failure, most often with an ALIF at L5-S1 [Oswestry Disability Index-SCB: OR: 1.4 (1.1-2.0); proximal junctional failure: OR: 0.4 (0.2-0.8)].

CONCLUSIONS

Among patients undergoing ASD realignment, optimal lumbar shape and proportion can be achieved more often with a combined approach. Although TLIFs, incorporating a 3-column osteotomy, at L3 and L4 can restore lordosis and normalize pelvic compensation, ALIFs at L5-S1 were most likely to achieve complex realignment goals with an added clinical benefit and mitigation of junctional failure.

Utilization of Antibiotic Bone Cement in Spine Surgery: Pearls, Techniques, and Case Review

Vertebral osteomyelitis (VO) encompasses a spectrum of spinal infections ranging from isolated mild vertebral osteomyelitis to severe diffuse infection with associated epidural abscess and fracture. Although patients can often be treated with an initial course of intravenous antibiotics, surgery is sometimes required in patients with sepsis, spinal instability, neurological compromise, or failed medical treatment. Antibiotic bone cement (ABC) has been widely used in orthopedic extremity surgery for more than 150 years, both for prophylaxis and treatment of bacterial infection. However, relatively little literature exists regarding its utilization in spine surgery. This article describes ABC utilization in orthopedic surgery and explains the technique of ABC utilization in spine surgery. Surgeons can choose from multiple premixed ABCs with variable viscosities, setting times, and antibiotics or can mix in antibiotics to bone cements themselves. ABC can be used to fill large defects in the vertebral body or disc space or in some cases to coat instrumentation. Surgeons should be wary of complications such as ABC extravasation as well as an increased difficulty with revision. With a thorough understanding of the properties of the cement and the methods of delivery, ABC is a powerful adjunct in the treatment of spinal infections.

Cost Benefit of Implementation of Risk Stratification Models for Adult Spinal Deformity Surgery

STUDY DESIGN/SETTING

Retrospective cohort study.

OBJECTIVE

Assess the extent to which defined risk factors of adverse events are drivers of cost-utility in spinal deformity (ASD) surgery.

METHODS

ASD patients with 2-year (2Y) data were included. Tertiles were used to define high degrees of frailty, sagittal deformity, blood loss, and surgical time. Cost was calculated using the Pearl Diver registry and cost-utility at 2Y was compared between cohorts based on the number of risk factors present. Statistically significant differences in cost-utility by number of baseline risk factors were determined using ANOVA, followed by a generalized linear model, adjusting for clinical site and surgeon, to assess the effects of increasing risk score on overall cost-utility.

RESULTS

By 2 years, 31% experienced a major complication and 23% underwent reoperation. Patients with ≤2 risk factors had significantly less major complications. Patients with 2 risk factors improved the most from baseline to 2Y in ODI. Average cost increased by $8234 per risk factor (R2 = .981). Cost-per-QALY at 2Y increased by $122,650 per risk factor (R2 = .794). Adjusted generalized linear model demonstrated a significant trend between increasing risk score and increasing cost-utility (r2 = .408, P < .001).

CONCLUSIONS

The number of defined patient-specific and surgical risk factors, especially those with greater than two, were associated with increased index surgical costs and diminished cost-utility. Efforts to optimize patient physiology and minimize surgical risk would likely reduce healthcare expenditures and improve the overall cost-utility profile for ASD interventions.Level of evidence: III.

Young Age and Concomitant or Prior Bony Realignment Procedures are Associated with Decreased Risk of Failure of Osteochondral Allograft Transplantation in the Knee: A Nationwide Database Study

OBJECTIVE

Osteochondral allograft (OCA) transplantation is a restorative surgical option for large, full-thickness chondral or osteochondral defects in the knee. Variability in outcomes reporting has led to a broad range of graft survival rates. Using rate of salvage surgery following OCA as a failure metric, the purpose of this study was to analyze the incidence and risk factors for failure in a nationwide cohort.

DESIGN

The M151Ortho PearlDiver database was queried for patients aged 20 to 59 who underwent primary OCA between 2010 and 2020. Patients with prior cartilage procedures or arthroplasty were excluded. Kaplan-Meier survival analysis was performed to characterize cumulative rate of salvage surgery, defined as any patient subsequently undergoing revision OCA, autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), unicompartmental knee arthroplasty (UKA), or total knee arthroplasty (TKA). Multivariable logistic regression was used to determine the effect of several variables on odds of salvage surgery.

RESULTS

Around 6,391 patients met inclusion criteria. Cumulative 5-year salvage rate was 1.71%, with 68.8% in the first 2 years. Age 20 to 29 and concomitant or prior bony realignment procedures were associated with significantly decreased rate of salvage surgery (age-adjusted odds ratio [aOR] = 0.49, 95% confidence interval [CI], 0.24-0.99, P = 0.046; realignment-aOR = 0.24, 95% CI, 0.04-0.75, P = 0.046).

CONCLUSIONS

In the largest OCA cohort studied to date, less than 2% of patients required salvage surgery. Young age and bony realignment were protective. These findings suggest that OCA in the knee is a durable cartilage-restoration procedure, especially in young patients with corrected alignment.

Chronic obstructive pulmonary disease is an independent risk factor for increased opioid use in total hip arthroplasty: A retrospective PearlDiver study

Background

Total hip arthroplasty (THA) has become an incredibly common procedure due to its' predictability and high success rate. The success of surgery is related to strict indications and careful optimization of medical comorbidities to decrease risk and improve outcomes. Chronic obstructive pulmonary disease (COPD) has been associated with increased medical and surgical complications. A regulatory focus on opioid utilization does not usually consider COPD as a risk factor, but limited research exists on the impact of COPD on outcomes and risks after THA.

Methods

Retrospective all-inclusive database analysis of Medicare patients who had undergone THA between 2007 and 2017 included in the PearlDiver Database were studied. Postoperative opioid usage was examined at 1-, 3-, 6-, and 12 months, along with surgical infection, implant complications, and revisions. Post-operative complications within 30 days, either medical or implant related, were identified. Controlling for comorbidities, age, and sex, odds ratios were calculated using multivariable logistic regression with a significant α value of 0.05.

Results

COPD patients had significantly higher rates of opioid usage postoperatively. COPD patients also had an increased rate of readmissions, medical/implant complications, and revision surgeries.

Discussion

This is the only study raising concern regarding opioid use in COPD patients after total hip arthroplasty, which may be critical considering the associated respiratory depression further exacerbating the COPD. Considering the evidence of poor outcomes associated with COPD in arthroplasty, appropriately screening for COPD and counseling or planning for post-operative pain control and complications is paramount.

Spinal Cord Stimulators and Intrathecal Pain Pump Removal Versus Retention During Posterior Lumbar Fusion: A Matched Cohort Analysis

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine risks associated with posterior lumbar arthrodesis after spinal cord stimulator (SCS) and intrathecal pain pump (IPP) insertion.

SUMMARY OF BACKGROUND DATA

SCS and IPPs aid in the management of chronic back and radicular pain. Little is known regarding the risks of subsequent fusion with these devices in place.

METHODS

The PearlDiver Mariner database was queried for spinal fusion between 2010 and 2020. Study groups were created for indwelling SCS or IPP and matched to a separate cohort without SCS or IPP. Subgroups were created for those who had their device removed and those who retained their device at the time of surgery. Complications up to 2 years postoperatively were reviewed and confounding variables were controlled using multivariable logistic regression.

RESULTS

Four thousand five hundred three patients had an indwelling SCS/IPP and underwent posterior lumbar fusion. Compared with patients without history of an SCS/IPP, patients undergoing a lumbar fusion with an SCS/IPP which was removed or retained had higher rates of revision surgery at 1 year [7.3% vs. 5.0%, odds ratio (OR) =1.48, P <0.001] and 2 year (10.8% vs. 7.0%, OR =1.59, P <0.001). For all time intervals, there were higher odds of instrumentation failure (2 y: OR =1.65, P <0.001), and pulmonary complications (2 y: OR =1.18, P <0.001). At 2 years, there were higher odds of surgical site complications (OR 1.15, P =0.02) and urinary complications (OR=1.07, P =0.04). There were no differences in complications up to 2 years postoperatively in patients with an SCS/IPP who had their devices retained or removed ( P >0.05).

CONCLUSIONS

Patients with a history of spinal cord stimulators and intrathecal pain pumps are at increased risk of mechanical complications and revision fusion compared with patients without these devices. Patients with an SCS or IPP have similar rates of complications during lumbar fusion whether the device is removed or retained.

Delayed cerebrospinal fluid (CSF) leak following anterior cervical discectomy and fusion surgery

Background

An uncommon complication of anterior cervical discectomy and fusion (ACDF) is dura tear, which may be further complicated by cerebral spinal fluid (CSF) leak. Dural tears with CSF leak can lead to catastrophic neurologic outcomes and should be recognized early.

Case Description

This case report describes a 43-year-old female patient with history of Ehlers-Danlos syndrome who presented 1-year post-ACDF with positional headaches and lightheadedness. Imaging revealed ACDF plate subsidence and CSF leak with inferior displacement of the cerebellar tonsils.

Outcome

The patient underwent a revision procedure with removal of index screws and CSF repair using epidural blood patch, fat graft, and Tisseel. The original bicortical screws were replaced with shorter larger diameter unicortical screws. Post-operative imaging at 2 and 6 weeks confirmed resolution of CSF leak.

Conclusions

Healthcare professionals and patients undergoing spinal surgery should be aware of late presentation CSF leaks which can represent gradual decline in neurological function. Surgical candidates at risk to develop CSF leaks should be counseled about possible complications in preoperative planning.

Clinical outcomes and proximal junctional failure in adult spinal deformity patients corrected to normative alignment versus functional alignment

OBJECTIVE

The objective of this study was to explore the rate of proximal junctional failure (PJF) and functional outcomes of normative alignment goals compared with alignment targets based on age-appropriate physical function.

METHODS

Baseline relationships between age, pelvic incidence (PI), and a component of the T1 pelvic angle (TPA) within the fusion were analyzed in adult spinal deformity (ASD) patients and compared with those of asymptomatic patients. Linear regression modeling was used to determine alignment based on PI and age in asymptomatic patients (normative alignment), and in ASD patients, alignment corresponding to age-appropriate functional status (functional alignment). A cohort of 288 ASD patients was split into two groups based on whether the patient was closer to their normative or functional alignment goal at their 6-week postoperative radiographic follow-up. The rates of proximal junctional kyphosis (PJK) and PJF were determined for each cohort.

RESULTS

In the 288 ASD patients included in this pre- to postoperative analysis, there was no difference in baseline alignment or health-related quality of life (HRQOL) between the normative alignment and functional alignment groups. At 6 weeks, patients with normative alignment had a smaller TPA (4.45° vs 14.1°) and PI minus lumbar lordosis (-7.24° vs 7.4°) (both p < 0.0001) and higher PJK (40% vs 27.2%, p = 0.03) and PJF (17% vs 6.8%, p = 0.008) rates than patients with functional alignment.

CONCLUSIONS

Correction in ASD patients to normative alignment resulted in higher rates of PJK and PJF without improvements in HRQOL. Correction in ASD patients to functional alignment that mirrors the physical function of their age-matched asymptomatic peers is recommended.

A Diagnosis of Vitamin D Deficiency Is Associated With Increased Rates of Anterior Cruciate Ligament Tears and Reconstruction Failure

PURPOSE

To characterize the association between a diagnosis of hypovitaminosis D and primary anterior cruciate ligament (ACL) tear, primary anterior cruciate ligament reconstruction (ACLR), and revision ACLR in different sex and age cohorts.

METHODS

In this retrospective cohort study of the PearlDiver claims database, records were queried between January 1, 2011, and October 31, 2018 for all patients aged 10 to 59 years who received a diagnosis of hypovitaminosis D. Rates of primary ACL tears, primary reconstruction, and revision reconstruction were calculated for sex- and age-specific cohorts and compared with a control of patients without a diagnosis of hypovitaminosis D. Incidence rates for primary ACL injuries were calculated, and multivariable logistic regression was used to compare rates of ACL injury, primary reconstruction, and revision reconstruction while controlling for age, sex, Charlson Comorbidity Index, and several other comorbidities.

RESULTS

Among the 328,011 patients (mean age 41.9 ± 12.6 years, 65.8% female) included in both the hypovitaminosis D and control cohorts, the incidence of ACL tears was 115.2 per 100,000 person-years (95% confidence interval [CI] 107.2-123.7) compared with 61.0 (95% CI 55.2-67.2) in the demographic- and comorbidity-matched control cohort. The study cohort was significantly more likely to suffer an ACL tear over a 1- (aOR 1.67, 95% CI 1.41-1.99, P < .001) and 2-year (aOR 1.81, 95% CI 1.59-2.06, P < .001) period. This trend remained for both male patients at the 1- (aOR 1.66, 95% CI 1.29-2.14, P < .001) and 2-year (aOR 1.68, 95% CI 1.37-2.06, P < .001) mark and female patients at the 1- (aOR 1.69, 95% CI 1.33-2.14, P < .001) and 2-year (aOR 1.80, 95% CI 1.51-2.14, P < .001) mark. Finally, patients with vitamin D deficiency had a significantly increased likelihood of undergoing a revision ACLR within 2 years of a primary reconstruction (aOR 1.28, 95% CI 1.05-1.55, P = .012).

CONCLUSIONS

This study reports an association between patients previously diagnosed with hypovitaminosis D and significantly increased rates of both index ACL tears (81% increase within 2 years of diagnosis) and revision ACLR (28% within 2 years). These results identify a population with increased odds of injury and provide valuable knowledge as we expand our understanding of the relationship between vitamin D and musculoskeletal health.

LEVEL OF EVIDENCE

Level III, retrospective database study.

The impact of baseline cervical malalignment on the development of proximal junctional kyphosis following surgical correction of thoracolumbar adult spinal deformity

OBJECTIVE

The objective of this study was to identify the effect of baseline cervical deformity (CD) on proximal junctional kyphosis (PJK) and proximal junctional failure (PJF) in patients with adult spinal deformity (ASD).

METHODS

This study was a retrospective analysis of a prospectively collected, multicenter database comprising ASD patients enrolled at 13 participating centers from 2009 to 2018. Included were ASD patients aged > 18 years with concurrent CD (C2-7 kyphosis < -15°, T1S minus cervical lordosis > 35°, C2-7 sagittal vertical axis > 4 cm, chin-brow vertical angle > 25°, McGregor's slope > 20°, or C2-T1 kyphosis > 15° across any three vertebrae) who underwent surgery. Patients were grouped according to four deformity classification schemes: Ames and Passias CD modifiers, sagittal morphotypes as described by Kim et al., and the head versus trunk balance system proposed by Mizutani et al. Mean comparison tests and multivariable binary logistic regression analyses were performed to assess the impact of these deformity classifications on PJK and PJF rates up to 3 years following surgery.

RESULTS

A total of 712 patients with concurrent ASD and CD met the inclusion criteria (mean age 61.7 years, 71% female, mean BMI 28.2 kg/m2, and mean Charlson Comorbidity Index 1.90) and underwent surgery (mean number of levels fused 10.1, mean estimated blood loss 1542 mL, and mean operative time 365 minutes; 70% underwent osteotomy). By approach, 59% of the patients underwent a posterior-only approach and 41% underwent a combined approach. Overall, 277 patients (39.1%) had PJK by 1 year postoperatively, and an additional 189 patients (26.7%) developed PJK by 3 years postoperatively. Overall, 65 patients (9.2%) had PJF by 3 years postoperatively. Patients classified as having a cervicothoracic deformity morphotype had higher rates of early PJK than flat neck deformity and cervicothoracic deformity patients (p = 0.020). Compared with the head-balanced patients, trunk-balanced patients had higher rates of PJK and PJF (both p < 0.05). Examining Ames modifier severity showed that patients with moderate and severe deformity by the horizontal gaze modifier had higher rates of PJK (p < 0.001).

CONCLUSIONS

In patients with concurrent cervical and thoracolumbar deformities undergoing isolated thoracolumbar correction, the use of CD classifications allows for preoperative assessment of the potential for PJK and PJF that may aid in determining the correction of extending fusion levels.

How much are patients willing to pay for spine surgery? An evaluation of attitudes toward out-of-pocket expenses and cost-reducing measures

BACKGROUND CONTEXT

With rising healthcare expenditures in the United States, patients and providers are searching to maintain quality while reducing costs.

PURPOSE

The aim of this study was to investigate patient willingness to pay for anterior cervical discectomy and fusion (ACDF), degenerative lumbar spinal fusions (LF), and adult spine deformity (ASD) surgery.

STUDY DESIGN/SETTING

A survey was developed and distributed to anonymous respondents through Amazon Mechanical Turk (MTurk).

METHODS

The survey introduced 3 procedures: ACDF, LF, and ASD surgery. Respondents were asked sequentially if they would pay at each increasing price option. Respondents were then presented with various cost-saving methods and asked to select the options that made them most uncomfortable, even if those would save them out-of-pocket costs.

RESULTS

In total, 979 of 1,172 total responses (84%) were retained for analysis. The average age was 36.2 years and 44% of participants reported a household income of $50,000 to 100,000. A total of 63% used Medicare and 13% used Medicaid. A total of 40% stated they had high levels of financial stress. A total of 30.1% of participants were willing to undergo an ACDF, 30.3% were willing to undergo a LF, and 29.6% were willing to undergo ASD surgery for the cost of $3,000 (p=.98). Regression demonstrated that for ACDF surgery, a $100 increase in price resulted in a 2.1% decrease in willingness to pay. This is comparable to degenerative LF surgery (1.8% decrease), and ASD surgery (2%). When asked which cost-saving measures participants were least comfortable with for ACDF surgery, 60% stated "Use of the older generation implants/devices" (LF: 51%, ASD: 60%,), 61% stated "Having the surgery performed at a community hospital instead of at a major academic center" (LF: 49%, ASD: 56%), and 55% stated "Administration of anesthesia by a nurse anesthetist" (LF: 48.01%, ASD: 55%). Conversely, 36% of ACDF patients were uncomfortable with a "Video/telephone postoperative visit" to cut costs (LF: 51%, ASD: 39%).

CONCLUSIONS

Patients are unwilling to contribute larger copays for adult spinal deformity correction than for ACDF and degenerative lumbar spine surgery, despite significantly higher procedural costs and case complexity/invasiveness. Patients were most uncomfortable forfeiting newer generation implants, receiving the operation at a community rather than an academic center, and receiving care by physician extenders. Conversely, patients were more willing to convert postoperative visits to telehealth and forgo neuromonitoring, indicating a potentially poor understanding of which cost-saving measures may be implemented without increasing the risk of complications.

Reduction of adolescent grade IV L5-S1 spondylolisthesis with anterior joystick manipulation during a combined anterior and posterior surgical approach: A case report

Background

High-grade isthmic spondylolisthesis poses a clinical challenge in the pediatric and adolescent population. Current surgical management using posterior-based approaches may lead to incomplete reduction and restoration of listhesis, disc height, and lordosis. Combined anterior and posterior approach addresses these issues but has been infrequently reported, mainly in the treatment of low-grade isthmic spondylolisthesis. Neither offers good disc space visualization and control of spinal alignment during reduction.

Case Description

A healthy 17-year-old female presented with 9 months of progressively worsening lower back pain radiating down the left lower extremity and 3 inches of height loss. Diagnosis of grade IV L5-S1 spondylolisthesis was made using plain radiographs, CT, and MRI. Management with combined anterior and posterior fusion, involving the manual manipulation of segments using an anterior pedicle screw joystick, was pursued.

Outcome

Satisfactory alignment, solid arthrodesis, no complications, and improved patient reported outcomes.

Conclusions

Combined anterior and posterior fusion with anterior joystick manipulation allowed for full reduction of grade IV spondylolisthesis and restoration of disc/foraminal height and L5-S1 segmental lordosis without neurological complication. Although less commonly performed in children and adolescents, this surgical approach can assist in restoring optimal alignment in isthmic spondylolisthesis.

Alterations in Magnitude and Shape of Thoracic Kyphosis Following Surgical Correction for Adult Spinal Deformity

STUDY DESIGN

Retrospective review of prospective multicenter data.

OBJECTIVES

This study aimed to investigate the shape of TK before and after fusion in ASD patients treated with long fusion.

METHODS

ASD patients undergoing posterior spinal fusions including at least T5 to L1 without prior fusion extending to the thoracic spine were included. Patients were categorized based on the preoperative T1-T12 kyphosis into: Hypo-TK (if < 30°), Normal-TK, and Hyper-TK (if > 70°). Regional kyphosis at T10-L1 (Distal), T5-T10 (Middle), and T1-T5 (Proximal) and their relative contributions to total kyphosis were compared between groups, and the pre-to postoperative changes were investigated using paired t test.

RESULTS

In total, 329 patients were included in this analysis (mean age: 57 ± 16 years, 79.6% female). Preoperative T1-T12 TK for the entire cohort was 40.9 ± 2° (32% Hypo-TK, 11% Hyper-TK, 57% Normal-TK). The Hypo-TK group had the smallest distal TK (5.9 vs 17.1 & 26.0), and middle TK (8.0 vs 25.3 & 45.4), but the percentage of contribution to total kyphosis was not significantly different (Distal: 24.1% vs 34.1% vs 32.8%; Middle: 46.6% vs 53.9% vs 56.8%, all P > .1). Postoperatively, T1-12 TK increased significantly (40.9 ± 2.0° vs 57.8 ± 17.6°). Each group had a decrease in distal kyphosis (Hypo-TK 2.6 ± 10.4°; Normal-TK 8.9 ± 11.5°; Hyper-TK 14.9 ± 12°, all P < .05). The middle kyphosis significantly decreased for Hyper-TK (11.8 ± 12.4) and increased for both Normal-TK and Hypo-TK (3.8 ± 11° and 14.2 ± 11°). Proximal TK increased significantly for all groups by 14-18°. Deterioration from Normal-TK to Hyper-TK postoperatively was associated with lower rate of patient satisfaction (59.6% vs 77.3%, P = .032).

CONCLUSIONS

Posterior spinal fusion for ASD alters the magnitude and shape of thoracic kyphosis. While 60% of patients had a normal TK at baseline, 30% of those patients developed iatrogenic hyperkyphosis postoperatively. Patients with baseline hypokyphosis were more likely to be corrected to normal TK than hyperkyphotic patients. Future research should investigate TK restoration in ASD and its impact on clinical outcomes and complications.

Testosterone replacement therapy is associated with increased odds of Achilles tendon injury and subsequent surgery: a matched retrospective analysis

BACKGROUND

Prescription of testosterone replacement therapy (TRT) has increased in the United States in recent years, and though anabolic steroids have been associated with tendon rupture, there is a paucity of literature evaluating the risk of Achilles tendon injury with TRT. This study aims to evaluate the associative relationship between consistent TRT, Achilles tendon injury, and subsequent surgery.

METHODS

This is a one-to-one matched retrospective cohort study utilizing the PearlDiver database. Records were queried for patients aged 35-75 who were prescribed at least 3 consecutive months of TRT between January 1, 2010 and December 31, 2019. Achilles tendon injuries and subsequent surgeries were identified using ICD-9, ICD-10, and CPT billing codes. Multivariable logistic regression was used to compare odds of Achilles tendon injury, Achilles tendon surgery, and revision surgery, with a p-value < 0.05 representing statistical significance.

RESULTS

A sample of 423,278 patients who filled a TRT prescription for a minimum of 3 consecutive months was analyzed. The 2-year incidence of Achilles tendon injury was 377.8 (95% CI, 364.8-391.0) per 100,000 person-years in the TRT cohort, compared to 245.8 (95% CI, 235.4-256.6) in the control (p < 0.001). The adjusted analysis demonstrated TRT to be associated with a significantly increased likelihood of being diagnosed with Achilles tendon injury (aOR = 1.24, 95% CI, 1.15-1.33, p < 0.001). Of those diagnosed with Achilles tendon injury, 287/3,198 (9.0%) of the TRT cohort subsequently underwent surgery for their injury, compared to 134/2,081 (6.4%) in the control cohort (aOR = 1.54, 95% CI, 1.19-1.99, p < 0.001).

CONCLUSIONS

There is a significant association between Achilles tendon injury and prescription TRT, with a concomitantly increased rate of undergoing surgical management. These results provide insight into the risk profile of TRT and further research into the science of tendon pathology in the setting of TRT is an area of continued interest.

Are we improving in the optimization of surgery for high-risk adult cervical spine deformity patients over time?

OBJECTIVE

The aim of this study was to investigate whether surgery for high-risk patients is being optimized over time and if poor outcomes are being minimized.

METHODS

Patients who underwent surgery for cervical deformity (CD) and were ≥ 18 years with baseline and 2-year data were stratified by year of surgery from 2013 to 2018. The cohort was divided into two groups based on when the surgery was performed. Patients in the early cohort underwent surgery between 2013 and 2015 and those in the recent cohort underwent surgery between 2016 and 2018. High-risk patients met at least 2 of the following criteria: 1) baseline C2-7 Cobb angle > 15°, mismatch between T1 slope and cervical lordosis ≥ 35°, C2-7 sagittal vertical axis > 4 cm, or chin-brow vertical angle > 25°; 2) age ≥ 70 years; 3) severe baseline frailty (Miller index); 4) Charlson Comorbidity Index (CCI) ≥ 1 SD above the mean; 5) three-column osteotomy as treatment; and 6) fusion > 10 levels or > 7 levels for elderly patients. The mean comparison analysis assessed differences between groups. Stepwise multivariable linear regression described associations between increasing year of surgery and complications.

RESULTS

Eighty-two CD patients met high-risk criteria (mean age 62.11 ± 10.87 years, 63.7% female, mean BMI 29.70 ± 8.16 kg/m2, and mean CCI 1.07 ± 1.45). The proportion of high-risk patients increased with time, with 41.8% of patients in the early cohort classified as high risk compared with 47.6% of patients in the recent cohort (p > 0.05). Recent high-risk patients were more likely to be female (p = 0.008), have a lower BMI (p = 0.038), and have a higher baseline CCI (p = 0.013). Surgically, high-risk patients in the recent cohort were more likely to undergo low-grade osteotomy (p = 0.003). By postoperative complications, recent high-risk patients were less likely to experience any postoperative adverse events overall (p = 0.020) or complications such as dysphagia (p = 0.045) at 2 years. Regression analysis revealed increasing year of surgery to be correlated with decreasing minor complication rates (p = 0.030), as well as lowered rates of distal junctional kyphosis by 2 years (p = 0.048).

CONCLUSIONS

Over time, high-risk CD patients have an increase in frequency and comorbidity rates but have demonstrated improved postoperative outcomes. These findings suggest that spine surgeons have improved over time in optimizing selection and reducing potential adverse events in high-risk patients.