Surgical Treatment Of Degenerative Disc Disease Research Articles

The Role of Cervical Muscles Morphology in the Surgical Treatment of Degenerative Disc Disease: Clinical Correlations Based on Magnetic Resonance Imaging Studies.

Cervical spine musculature still remains a less studied component of the cervical spine anatomical compartments, although it plays a significant role in the mobility of the head and the preservation of cervical spine alignment. The goal of this study was to extract any significant information from the literature regarding the role of cervical spine muscles morphology in the outcome of surgically treated patients for degenerative disc disease (DDD) based on preoperative magnetic resonance imaging (MRI) studies. Eleven clinical case series were found, from which four were prospective and seven were retrospective. Six studies were concentrated on anterior approaches and five studies on posterior approaches in the cervical spine. In posterior approaches aiming at the preservation of muscles attachments and overall less surgical manipulations, results on cervical lordosis, axial pain and patient’s functionality were found superior to traditional laminectomies. The study of cross-sectional areas (CSAs) of deep paraspinal muscles in the cervical spine could add significant information for the spine surgeon such as the prediction of adjacent level disease (ALD), fusion failure, axial pain persistence, postoperative cervical alignment and patient’s postoperative functionality. It seems that MRI studies focusing on muscle layers of the cervical spine could add significant information for the spinal surgeon regarding the final surgical outcome in terms of pain and function expression. Larger multicenter clinical studies are a necessity in defining the role of the muscle component of the cervical spine in the surgical treatment of DDD.

Association of catechol- O-methyltransferase genetic variants with outcome in patients undergoing surgical treatment for lumbar degenerative disc disease

Background context Surgical treatment for lumbar degenerative disc disease (DDD) has been associated with highly variable results in terms of postoperative pain relief and functional improvement. Many experts believe that DDD should be considered a chronic pain disorder as opposed to a degenerative disease. Genetic variation of the catechol- O-methyltransferase ( COMT) gene has been associated with variation in human pain sensitivity and response to analgesics in previous studies. Purpose To determine whether genetic variation of COMT is associated with clinical outcome after surgical treatment for DDD. Study design Prospective genetic association study. Patient sample Sixty-nine patients undergoing surgical treatment for lumbar DDD. Diagnosis was based on documentation of chronic disabling low back pain (LBP) present for a minimum of 6 months and unresponsive to supervised nonoperative treatment, including activity modification, medication, physical therapy, and/or injection therapy. Plain radiographs and magnetic resonance imaging revealed intervertebral disc desiccation, tears, and/or collapse without focal herniation, nerve root compression, stenosis, spondylolisthesis, spondylolysis, or alternative diagnoses. Outcome measures Oswestry Disability Index (ODI) and visual analog score (VAS) for LBP. Methods Surgical treatment included 65 instrumented fusions and four disc arthroplasty procedures. All patients completed preoperative and 1-year postoperative ODI questionnaires. DNA was extracted from a sample of venous blood, and genotype analysis was performed for five common COMT single nucleotide polymorphisms (SNPs). Potential genetic association between these COMT SNPs and the primary outcome variable, 1-year change in ODI, was investigated using both single-marker and haplotype association analyses. Association with VAS scores for LBP was analyzed as a secondary outcome variable. Results Single-marker analysis revealed that the COMT SNP rs4633 was significantly associated with greater improvement in ODI score 1 year after surgery (p=.03), with individuals homozygous for the less common “T” allele demonstrating the largest improvement in ODI. Haplotype analysis of four COMT SNPs, rs6269, rs4633, rs4818, and rs4680, also identified a common haplotype “ATCA” (haplotype frequency of 39.3% in the study population) associated with greater improvement in ODI (p=.046). The greatest mean improvement in ODI was observed in patients homozygous for the “ATCA” COMT haplotype. A nonsignificant trend was observed between SNP rs4633 and greater improvement in VAS score for LBP. Conclusions This is the first study to report an association between surgical treatment success in DDD patients and genetic variation in the putative pain sensitivity gene COMT. These findings require replication in other DDD populations but suggest that genetic testing for pain-relevant genetic markers such as COMT may provide useful clinical information in terms of predicting outcome after surgery for patients diagnosed with DDD.