Adjacent segment disease following anterior cervical fusion and the presence of surgery for lumbar disc herniation and surgery at the musculoskeletal joints: are they related?

Does Focal Kyphotic Deformity at Non-responsible Levels Affect the Outcomes of Anterior Cervical Decompression and Fusion?

OBJECTIVE

Focal cervical kyphotic deformity (FCK) without neurologic compression is not uncommon in patients with cervical spondylotic myelopathy (CSM) who underwent anterior cervical decompression and fusion (ACDF) surgery. It remains unclear whether FCK at non-responsible levels needs to be treated simultaneously. This study aims to investigate whether FCK at non-responsible levels is the prognostic factor for CSM and elucidate the surgical indication for FCK.

METHODS

Patients with CSM who underwent ACDF between January 2016 and April 2021 were included. Patients were divided into two groups according to the presence of FCK and two classifications according to global cervical sagittal alignment. Clinical outcomes were compared using Japanese Orthopaedic Association (JOA) scores and recovery rate (RR) of neurologic function. Univariate and multivariate analysis based on RR assessed the relationship between various possible prognostic factors and clinical outcomes. The receiver operating characteristic curve (ROC) was used to determine the optimal cutoff value of the focal Cobb angle to predict poor clinical outcomes.

RESULTS

A total of 94 patients were included, 41 with FCK and 53 without. Overall, the RR of neurologic function was significantly lower in the FCK than in the non-FCK group. Further analysis showed that the RR difference between the two groups was only observed in hypo-lordosis classification (kyphotic and sigmoid alignment), but not in the lordosis classification. Multivariate analysis showed that the preoperative focal Cobb angle in the FCK level (OR = 0.42; 95% CI = 0.18-0.97) was independently associated with clinical outcomes in the hypo-lordosis classification. The optimal cutoff point of the preoperative focal kyphotic Cobb angle was calculated at 4.05°.

CONCLUSION

For CSM with hypo-lordosis, FCK was a risk factor for poor postoperative outcomes. Surgeons may consider treating the FCK simultaneously if the focal kyphotic Cobb angle of FCK is greater than 4.05° and is accompanied by cervical global kyphotic or sigmoid deformity.

Prevalence and Risk Factors for Cervical Adjacent Segment Disease and Analysis of the Clinical Effect of Revision Surgery: A Minimum of 5 Years' Follow-Up

STUDY DESIGN

A retrospective study was performed.

OBJECTIVE

To investigate the prevalence and risk factors for adjacent segment disease (ASD) after anterior cervical discectomy and fusion (ACDF) and the clinical efficacy of revision surgery.

METHOD

A total of 219 patients treated with ACDF were analyzed retrospectively. Demographic characteristics, including age, sex, body mass index (BMI) and bone mineral density (BMD), and radiographic measurements, including C2-C7 cervical sagittal vertical axis (cSVA), T1 slope (T1S), thoracic inlet angle (TIA) and C2-C7 Cobb angle, were analyzed. Modified Japanese Orthopaedic Association (mJOA) score and visual analog scale (VAS) score were used to evaluate patient function. Parameters were analyzed with Student's t test, and potential risk factors for ASD were further analyzed with multivariate logistic regression analysis.

RESULTS

The incidence of ASD after ACDF surgeries was 21%. The severity of osteoporosis, BMI and C2-C7 cSVA were significantly higher in the ASD group than in the NASD group (P < .05). The preoperative and postoperative TIAs were lower in the ASD group (P < .05). Multivariate logistic regression analysis showed that a high BMI, severe osteoporosis and a high C2-C7 cSVA were risk factors for ASD after ACDF (P < .05). The postoperative TIA and postoperative T1S were also correlated with ASD (P < .05).

CONCLUSION

Patients with a high BMI, severe osteoporosis, and a large C2-C7 cSVA after ACDF have a higher risk of ASD, while a large T1S and TIA may be protective factors. In addition, revision surgery can restore cervical spine balance in patients with ASD and promote better clinical outcomes.

Long-term follow-up MRI shows no hastening of adjacent segment degeneration following cervical disc arthroplasty

Cervical disc arthroplasty is an established procedure, but studies with data on long-term clinical outcome, reoperation for symptomatic adjacent segment degeneration (sASD), and degenerative changes based on MRI findings are rare. Thus, a file review was performed and patients with complete documentation of neurological status at preoperative, postoperative, 12 month, 3–4 years follow-up including surgical reports for reoperation with a minimum follow-up of 9 years were included. Final follow-up assessment included a physical examination, assessment of pain levels, Odoms criteria, Neck disability index. The degeneration of each cervical segment at preoperative and at final follow-up was assessed using an MRI. Forty-six out of 68 included patients participated, the mean follow-up was 11 (range 9–15) years, at which 71.7% of patients were free of arm pain, 52.2% of patients were free of neck pain, 63% of patients had no sensory dysfunction, and full motor strength was noted in 95.6% of patients. The clinical success rate was 76.1%, the mean NDI was 12%. Overall repeated procedure rate was 17%, the reoperation rate for sASD was 9%, and removal of CDA was performed in 4%. MRI showed progressive degeneration but no significant changes of SDI from preoperative to final follow-up.

Smoking and degenerative spinal disease: A systematic review

Smoking is a major cause of morbidity and mortality worldwide and is responsible for the death of more than 8 million people per year globally. Through a systematic literature review, we aim to review the harmful effects of tobacco smoking on degenerative spinal diseases (DSD). DSD is a debilitating disease and there is a need to identify if smoking can be an attributable contender for the occurrence of this disease, as it can open up avenues for therapeutic options. Sources such as PubMed and Embase were used to review literature, maintaining tobacco smoking and spinal diseases as inclusion factors, excluding any article that did not explore this relationship. Risk of bias was assessed using analysis of results, sample size and methods and limitations. Upon review of the literature, tobacco smoking was found to be a major risk factor for the occurrence of DSDs, particularly lumbar spinal diseases. Smokers also experienced a greater need for surgery and greater postoperative wound healing complications, increased pain perception, delay in recovery and decreased satisfaction after receiving surgery. These effects were noted along the entire spine. Many mechanisms of action have been identified in the literature that provide plausible pictures of how smoking leads to spinal degeneration, exploring possible primary targets which can open up opportunities to develop potential therapeutic agents. More studies on cervical and thoracic spinal degeneration would be beneficial in identifying the effect of nicotine on these spinal levels. Some limitations included insufficient sample size, inconclusive evidence and lack of sufficient repeat studies. However, there appears to be a sufficient amount of research on smoking directly contributing to lumbar spinal pathology.

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Smoking is a risk factor for the occurence of degenerative spinal disease (DSD).

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There are numerous pathological mechanisms attributed to spinal pathology by smoking.

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Smoking appears to be a significant risk factor for lumbar DSDs, with smoke studies also suggesting its role in cervical DSDs.

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There is insufficient research on the effect of smoking on the thoracic spine.

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Smoking leads to worse outcomes and potential complications post-surgery, as well as increased pain perception and poorer subjective response post-surgery.

Reoperations after fusion surgeries for degenerative spinal diseases depending on cervical and lumbar regions: a national database study

BACKGROUND

Reoperation is one of the key factors affecting postoperative clinical outcomes. The reoperation rates of cervical surgeries might be different from those of lumbar surgeries due to the anatomical and biomechanical differences. However, there has been no study to compare the reoperation rate between them. The purpose is to compare reoperation rates after fusion surgeries for degenerative spinal diseases depending on the anatomic region of cervical and lumbar spines.

METHOD

We used the Korean Health Insurance Review & Assessment Service national database. Subjects were included if they had any of the primary procedures of fusion combined with the procedure of decompression procedures under the diagnosis of degenerative diseases (n = 42,060). We assigned the patients into two groups based on anatomical regions: cervical and lumbar fusion group (n = 11,784 vs 30,276). The primary endpoint of reoperation was the repeat of any aforementioned fusion procedures. Age, gender, presence of diabetes, associated comorbidities, and hospital types were considered potential confounding factors.

RESULTS

The reoperation rate was higher in the patients who underwent lumbar fusion surgery than in the patients who underwent cervical fusion surgery during the entire follow up period (p = 0.0275). A similar pattern was found during the late period (p = 0.0468). However, in the early period, there was no difference in reoperation rates between the two groups. Associated comorbidities and hospital type were noted to be risk factors for reoperation.

CONCLUSIONS

The incidence of reoperation was higher in the patients who underwent lumbar fusion surgery than those who underwent cervical fusion surgery for degenerative spinal diseases.