Back to Authors

Yen, Chun-Po

https://orcid.org/0000-0002-6229-4740

Mayo Clinic

University of Virginia

Citations 5

Comparing those Most Satisfied Versus Least Satisfied Following Surgery for Cervical Spondylotic Myelopathy
Chan, Andrew K., Park, Christine , Shaffrey, Christopher I., Gottfried, Oren N., Than, Khoi D., Ef, Bisson, Williamson, Theresa , Bydon, Mohamad, Asher, Anthony L. , Coric, Domagoj , Potts, Eric A., Foley, Kevin T., Wang, Michael Y., Fu, Kai-Ming, Virk, Michael S. , Knightly, John J. , Meyer, Scott, Park, Paul, Upadhyaya, Cheerag, Yen, Chun-Po, Uribe, Juan S., Tumialán, Luis M., Turner, Jay, Chou, Dean, Haid, Regis W., Mummaneni, Praveen V., Chan, Andrew K. , Shaffrey, Christopher I. , Than, Khoi D. , Bisson, Erica F. , Bydon, Mohamad , Potts, Eric A. , Foley, Kevin T. , Wang, Michael Y. , Fu, Kai-Ming, Meyer, Scott, Yen, Chun-Po , Uribe, Juan S. , Tumialán, Luis M. , Turner, Jay D. , Chou, Dean , Mummaneni, Praveen V.

Spine | July 3, 2026 | Volume: 51 | Issue: 15 | Pages: 1093-1100

10.1097/brs.0000000000005402 Get It

Study Design. Post hoc analysis of prospectively-collected data. Objective. To identify factors predicting the most (and least) satisfaction following surgery for cervical spondylotic myelopathy (CSM). Summary of Background Data. Patient satisfaction affects long-term outcomes after surgery but the preoperative factors that influence postoperative satisfaction have not been well studied in patients with CSM. Methods. We conducted a post hoc analysis of prospectively-collected data from the Quality Outcomes Database (QOD) CSM registry cohort. Baseline and surgical characteristics were compared for patients with CSM reporting the most [North American Spine Society Satisfaction Score (NASS) 1] and least (NASS 4) satisfaction 24 months postoperatively. A multivariable logistic regression model was constructed using backward stepwise elimination to determine significant predictors of most versus least satisfaction. Twenty-four-month patient-reported outcomes (PROs) were compared. Results. Overall, 1141 patients were prospectively enrolled with 948 (83.1%) reaching 24-month follow-up. Of these, 699 met prespecified inclusion criteria: 610 (87.3%) were most satisfied and 89 (12.7%) were least satisfied. Though there were mean improvements in all 24-month PROs for the most satisfied cohort ( P <0.001), there were no significant improvements in 24-month PROs for the least satisfied cohort ( P >0.05). Using multivariable logistic regression modeling, a preoperative symptom of upper extremity weakness (OR=2.5, P =0.003), subjective myelopathy (OR=2.0, P =0.04), absence of numbness complaints (OR=2.2, P =0.003), symptom duration under 12 months (OR=1.6, P =0.047), Caucasian race (OR=2.3, P =0.001), participation in activities outside of the home (OR=2.0, P =0.04), anterior approach (OR=2.3, P <0.001), and higher baseline quality of life (OR=4.0, P =0.01) were predictive of the most satisfaction. Conclusion. Compared with the least satisfied, those most satisfied following surgery for CSM more often had a preoperative symptom of arm weakness, subjective myelopathy, the absence of numbness complaints, symptom duration under 12 months, higher baseline quality of life, and participation in activities outside of the home. Compared with a posterior approach, an anterior approach was associated with the most satisfaction. Taken together, early surgical treatment--before myelopathic symptoms significantly impact one's quality of life--may be considered to optimize patient satisfaction following CSM surgery.
In Reply: Are There Differences in 2-Year Outcomes Between 2-Level Anterior Cervical Diskectomy and Fusion Versus Single-Level Anterior Cervical Corpectomy and Fusion to Treat Cervical Myelopathy? A Quality Outcomes Database Study
Berlin, Connor , Mummaneni, Praveen V., Chan, Andrew K. , Chou, Dean , Fu, Kai-Ming, Bydon, Mohamad , Bisson, Erica F. , Shaffrey, Christopher I. , Gottfried, Oren N., Asher, Anthony L. , Coric, Domagoj , Potts, Eric A. , Foley, Kevin T. , Wang, Michael Y. , Virk, Michael S. , Knightly, John J. , Meyer, Scott A., Upadhyaya, Cheerag D., Tumialán, Luis M. , Turner, Jay D. , Uribe, Juan S. , Haid, Regis W., Yen, Chun-Po , Shaffrey, Mark E., Ibrahim, Sufyan , Mummaneni, Praveen V. , Park, Paul

Neurosurgery | October 14, 2025 | Volume: 97 | Issue: 6 | Pages: e177-e178

10.1227/neu.0000000000003811 Get It

Defining cervical spondylotic myelopathy surgical endotypes using comorbidity clustering: a Quality Outcomes Database cervical spondylotic myelopathy study
Howell, Harrison, Mummaneni, Praveen V., Chou, Dean , Bydon, Mohamad , Bisson, Erica F. , Shaffrey, Christopher I., Gottfried, Oren N., Asher, Anthony L. , Coric, Domagoj , Potts, Eric A. , Foley, Kevin T. , Wang, Michael Y. , Fu, Kai-Ming, Virk, Michael S. , Knightly, John J. , Meyer, Scott A., Upadhyaya, Cheerag D., Yen, Chun-Po , Uribe, Juan S. , Tumialán, Luis M. , Turner, Jay D. , Haid, Regis W., Chan, Andrew K. , Howell, Harrison J. , Howell, Harrison , Yang, Eunice, Mummaneni, Praveen V. , Shaffrey, Christopher I. , Park, Paul , Uribe, Juan S.

Neurosurgical Focus | July 1, 2025 | Volume: 59 | Issue: 1 | Pages: E4

10.3171/2025.4.focus25207 Get It

OBJECTIVE Coexisting medical conditions are increasingly prevalent in surgical populations. The impact of multiple comorbidities on patient-reported outcomes (PROs) and endotypes of frequently co-occurring conditions for cervical spondylotic myelopathy (CSM) remain unclear. This study explores whether CSM patients with multimorbidity have worse baseline and postoperative PROs and less functional improvement after surgery compared to those with few or no comorbidities. The authors also investigated whether distinct comorbidity endotypes exist among CSM surgical patients and whether they influence postoperative outcomes. METHODS The prospective Quality Outcomes Database (QOD) was used to assess patients undergoing surgery for CSM. Multimorbidity was defined as ≥ 2 chronic conditions, including diabetes, coronary artery disease, peripheral vascular disease, arthritis, chronic renal disease, chronic obstructive pulmonary disease, Parkinson’s disease, multiple sclerosis, depression, and anxiety. Baseline characteristics and 24-month PROs were assessed across multiple-comorbidity status, including modified Japanese Orthopaedic Association (mJOA), Neck Disability Index (NDI), visual analog scale for neck and arm pain, EQ-5D, and patient satisfaction scores. Clusters were identified from the full cohort using k-medoids, revealing subgroups with similar comorbidity endotypes. RESULTS The final cohort included 1141 CSM patients (83.1% reaching 24-month follow-up), with 761 (66.7%) having 0 or 1 comorbidity and 380 (33.3%) ≥ 2 comorbidities. The multimorbidity cohort was older (mean age 62.6 ± 11.2 vs 59.5 ± 12.0 years, p < 0.001), more likely to be female (52.9% vs 44.7%, p = 0.011), and had a higher BMI (mean 31.1 ± 6.7 vs 29.7 ± 6.2 kg/m 2 , p < 0.001). Multimorbidity patients exhibited worse mJOA, NDI, and EQ-5D scores at baseline and 24 months (p < 0.05). On multivariable analysis, the total number of comorbidities was not significantly associated with any PRO measures. Four comorbidity clusters were identified: low burden, arthritis, diabetes, and high burden. On one-way ANOVA, the baseline mJOA score was significantly different across clusters (p = 0.003). At 24 months, the mJOA score was significantly lower in the diabetes and high-burden endotypes. Twenty-four-month score change and minimal clinically important difference (MCID) achievement of all PROs remained similar across clusters (p > 0.05). CONCLUSIONS While patients with multimorbidity have worse baseline and postoperative PROs, they achieve similar functional and pain-related improvements following CSM surgery. Similarly, the comorbidity endotypes identified in this QOD cohort suggest that certain patterns of coexisting chronic conditions, such as overlapping diabetes and arthritis, are associated with different levels of disability but may not diminish the effectiveness of surgical intervention.
Are There Differences in 2-Year Outcomes Between Two-Level Anterior Cervical Diskectomy and Fusion Versus Single-Level Anterior Cervical Corpectomy and Fusion to Treat Cervical Myelopathy? A Quality Outcomes Database Study
Berlin, Connor , Mummaneni, Praveen V., Chan, Andrew K. , Chou, Dean , Fu, Kai-Ming, Bydon, Mohamad , Bisson, Erica F. , Shaffrey, Christopher I. , Gottfried, Oren N., Asher, Anthony L. , Coric, Domagoj , Potts, Eric A. , Foley, Kevin T. , Wang, Michael Y. , Virk, Michael S. , Knightly, John J. , Meyer, Scott A., Upadhyaya, Cheerag D., Tumialán, Luis M. , Turner, Jay D. , Uribe, Juan S. , Haid, Regis W., Yen, Chun-Po , Shaffrey, Mark E., Shaffrey, Mark E , Ibrahim, Sufyan , Mummaneni, Praveen V. , Park, Paul

Neurosurgery | May 19, 2025 | Volume: 97 | Issue: 5 | Pages: 1091-1099

10.1227/neu.0000000000003518 Get It

BACKGROUND AND OBJECTIVES: There has been limited assessment between anterior cervical diskectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) on patient-reported outcome measures (PROMs) in the treatment of cervical spondylotic myelopathy. We sought to compare PROMs from two-level ACDF with single-level ACCF procedures. We evaluate these results in the context of minimum clinically important difference (MCID) thresholds, which have not been performed previously. METHODS: This retrospective analysis of prospectively collected data from the Quality Outcomes Database Spine Collaborative Research Study Group compared two-level ACDF and single-level ACCF at 3-, 12-, and 24 months postoperatively. PROMs included arm pain Numeric Rating Scale, neck pain Numeric Rating Scale, Neck Disability Index, and North American Spine Society Patient Satisfaction Index. Multivariate logistic regression was used to determine differences in perioperative outcomes, as well as the impact of two-level ACDF vs one-level ACCF on PROMs. MCID thresholds were based off previously established limits. RESULTS: Three hundred and thirty patients were included (236 ACDF, 94 ACCF), and the follow-up rate was 82% at 2 years. There was a significantly higher baseline age, American Society of Anesthesiologists grade, proportion of diabetes, osteoarthritis, ambulation dependence, and myelopathy severity in the ACCF cohort. On multivariable analysis, the ACCF group had greater average length of stay and estimated blood loss. There were no significant differences between reoperation rates or nonroutine discharge. There were similar rates of MCID achievement for PROMs at all time points. CONCLUSION: This study suggests that both ACDF and ACCF procedures for cervical spondylotic myelopathy are able to achieve similar, clinically meaningful improvements in PROMs by 2 years. Patients undergoing single-level ACCF have more estimated blood loss and longer length of stay, as well as worse baseline myelopathy. Both procedures have efficacious, durable outcomes. It is reasonable that other factors, such as radiographic characteristics and patient symptoms, may influence patient selection for ACDF vs ACCF.
Novel method of iliac accessory rods for rod fracture prevention in adult deformity surgery: a case series of 82 patients with outcomes and complications
Berlin, Connor , Ben‐Israel, David , Park, Brian J. , Yen, Chun-Po , Shaffrey, Mark E., Sardi, José , Ibrahim, Sufyan , Smith, Justin S.

Journal of Neurosurgery: Spine | July 26, 2024 | Volume: 43 | Issue: 4 | Pages: 424-432

10.3171/2024.5.spine24208 Get It

OBJECTIVE Primary rod fracture after surgery for adult spinal deformity (ASD) is a leading cause of revision, with recent prospective multicenter fracture rates reported at 11%–14% by 2 years. Consequently, the addition of supplemental rods has been explored to reduce fractures. Here the authors describe their experience with a novel iliac accessory rod technique in which each accessory rod anchors to an independent iliac bolt caudally via lateral connector, and attaches to the primary rod rostrally via side-to-side connector. METHODS This retrospective, single-center case series included patients who underwent thoracolumbar/lumbar fusion for ASD between March 2019 and August 2023. Data on baseline demographics, radiographic parameters, surgical characteristics, complications, rod fracture, and revision rates were collected. Paired, 2-tailed t-tests were used to compare pre- and postoperative radiographic outcomes. Rod fracture rates were compared to prior investigations via chi-square goodness of fit testing. The technique for iliac accessory rod placement is described. RESULTS The study consisted of 82 patients (mean age 66 years, 51% female, 26% with prior fusion) with a median follow-up of 2 years (IQR 28–104 weeks). A total of 50 patients (61%) had ≥ 2-year follow-up. Each surgery involved an average of 4 posterior column osteotomies and 8 segments. Iliac accessory rods were cobalt chromium and were placed bilaterally in 87% of constructs. Postoperative alignment improved significantly in the following parameters: maximum coronal Cobb angle, fractional curve, sagittal vertical axis, lumbar lordosis, thoracic kyphosis, and pelvic incidence to lumbar lordosis mismatch (p < 0.001 for all comparisons). Of 50 patients with ≥ 2-year follow-up, rod fracture occurred in 1 (2.0%), which was incidentally found and required no intervention. The present rod fracture rate was significantly lower than the authors’ historically reported institutional rate of 21% for traditional dual-rod constructs, and the 11%–14% reported in recent prospective multicenter studies that used traditional and supplemental rod constructs (p < 0.05 for all comparisons). Reoperation occurred in 12 patients (14.6%); 7 (8.5%) for proximal junctional kyphosis and 5 (6.1%) for wound complication. CONCLUSIONS Here the authors describe their experience with a novel iliac accessory rod technique to prevent rod fracture in patients undergoing surgery for ASD. The 2-year rod fracture rate (2.0%) in this study is significantly lower than the authors’ historical dual-rod fracture rate, and other prospective multicenter investigations. Future studies with longer follow-up are needed to determine the durability of this technique.