Cervicothoracic Versus Proximal Thoracic Lower Instrumented Vertebra Have Comparable Radiographic and Clinical Outcomes in Adult Cervical Deformity

Frail patients require Longer Fusions for Success following Adult Cervical Deformity Surgery

BACKGROUND

Adult cervical deformity (ACD) surgery is more frequently being performed in frail patients. Although surgical outcomes are largely successful, there remains significant risk of poor outcomes. The ideal length of fusion constructs in these patients remains debatable.

METHODS

Patients undergoing cervical fusion for ACD with lower instrumented vertebra (LIV) at T4-or-above, with clinical and radiographic data from baseline (BL) to 2 years (2Y) were stratified by CD-modified frailty index into not frail (NF), frail (F) and severely frail (SF) categories. Deformity was classified by Kim et al. criteria. Means comparisons tests were used to assess differences between both groups. Logistic regression analyses were used to analyze associations between frailty categories, lower instrumented vertebra (LIV) and outcomes.

RESULTS

286 patients (Age: 57.3 ± 10.9 years, BMI: 28.9 ± 6.4 kg/m2, CCI: 0.84 ± 1.26). 47% of patients were female. 32.2% of patients were NF, 50.3% F and 17.5% SF. By deformity, 66% were focal kyphosis (FK), 12% were flatneck, and 22% were cervicothoracic. Only FK type differed between NF and F/SF patients (39.2 vs 73.6%, p = 0.005). At baseline (BL), differences in age, BMI, CCI and deformity were not significant. F/SF patients had longer LOS (p = 0.018) and higher rates of distal junctional kyphosis/failure (DJK/F) at 2 years. Controlling for baseline disability, F and SF patients were more likely to experience poor outcomes at 2 years with C7 compared with more distal LIVs. The risk for poorer outcomes was not significant when comparing LIVs within the upper thoracic spine. Similar trends were seen performing sub-analyses specifically comparing F vs SF patients.

CONCLUSIONS

Frail patients are at risk for poor outcomes following ACD surgery due to their comorbidities. These patients appear to be at even greater risk for poor outcomes with a lower instrumented vertebra proximal to T1.

Optimizing Surgical Strategy for Cervical Spinal Deformity: Global Alignment and Surgical Targets

Cervical spinal deformity (CSD) is a complex condition characterized by abnormal curvature and cervical spine alignment. It can lead to a multitude of symptoms, including chronic pain, neurological deficits, and functional impairments, severely impacting an individual's health-related quality of life (HRQoL). Surgical intervention is often necessary to address the deformity and alleviate symptoms, but optimal surgical strategies remain a topic of ongoing research and debate. This narrative review aims to provide an in-depth overview of the surgical management of CSD, focusing on optimizing patient outcomes and enhancing readers' understanding of the complexities involved. We begin by discussing the importance of preoperative assessment, including comprehensive radiographic evaluation and careful consideration of the global spinal alignment. The relationship between the cervical spine and the reciprocal changes that occur are explored to guide surgeons in their decision-making process. Furthermore, we delve into the selection of fusion levels, emphasizing the significance of identifying the primary driver of deformity. We review the current literature on optimal alignment targets and strategies to optimize surgical planning. By providing a comprehensive analysis of the surgical management of CSD, this review aims to enhance the readers' knowledge and assist surgeons in making informed decisions when planning and executing surgical interventions. Understanding the intricacies of CSD correction and the latest advancements in the field can ultimately improve patient outcomes and enhance HRQoL for individuals suffering from this challenging condition.

Evolution of polyetheretherketone (PEEK) and titanium interbody devices for spinal procedures: a comprehensive review of the literature

INTRODUCTION

Interbody fusion is commonly utilized for arthrodesis and stability among patients undergoing spine surgery. Over the last few decades, interbody device materials, such as titanium and polyetheretherketone (PEEK), have been replacing traditional autografts and allografts for interbody fusion. As such, with the exponential growth of bioengineering, a large variety cage surface technologies exist. Different combinations of cage component materials and surface modifications have been created to optimize interbody constructs for surgical use. This review aims to provide a comprehensive overview of common surface technologies, their performance in the clinical setting, and recent modifications and material combinations.

MATERIALS AND METHODS

We performed a comprehensive review of the literature on titanium and PEEK as medical devices between 1964 and 2021. We searched five major databases, resulting in 4974 records. Articles were screened for inclusion manually by two independent reviewers, resulting in 237 articles included for review.

CONCLUSION

Interbody devices have rapidly evolved over the last few decades. Biomaterial and biomechanical modifications have allowed for continued design optimization. While titanium has a high osseointegrative capacity, it also has a high elastic modulus and is radio-opaque. PEEK, on the other hand, has a lower elastic modulus and is radiolucent, though PEEK has poor osseointegrative capacity. Surface modifications, material development advancements, and hybrid material devices have been utilized in search of an optimal spinal implant which maximizes the advantages and minimizes the disadvantages of each interbody material.