Ultrastructural changes in paravertebral muscles associated with degenerative spondylolisthesis

Histochemical and histological changes of paraspinal muscles in patients with thoracic and lumbar spine fractures treated with open and minimally invasive stabilisation

BACKGROUND

Histological and histochemical analyses of muscle samples were used to determine the intensity of paraspinal muscle injury during open (OPEN) and minimally invasive (MIS) procedures due to spinal trauma.

OBJECTIVE

A randomised prospective study design was chosen. According to our hypothesis, OPEN procedures will lead to more intensive microscopic changes than MIS.

METHODS

Muscle samples were collected during the primary surgery - fracture surgery (FRS) from the left and during material extraction (EXS) from the right side. Complete samples were acquired from 17 OPEN and 18 MIS subjects. We compared them histochemically and histologically; muscle fibre typing and statistical analysis were performed.

RESULTS

We statistically confirmed that the increase in fibrosis in the OPEN EXS sample was significantly higher than in the MIS EXS sample, with p< 0.05 (p= 0.000322453). Fibre types in MIS did not differ almost at all in both samples; the changes were statistically insignificant.In OPEN samples, the number of type I fibres differed significantly. In EXS, it was significantly lower (46.23%) than in FRS (60.63%), at a statistically significant level, p< 0.05 (p= 0.0234375000) especially with the increase of the type IIA fibres, less in IIB fibres.

CONCLUSIONS

These microscopic findings provide a statistically significant confirmation that OPEN procedures in spinal fracture lead, in most cases, to significant changes in the structure of the corset muscle at the fracture site and surgical access point than MIS procedures.

Histological characterization and biochemical analysis of paraspinal muscles in neuromuscularly healthy subjects

INTRODUCTION

There are no generally accepted histopathological reference values in paraspinal skeletal muscle biopsies.

METHODS

We examined multifidii muscle biopsies from 20 neuromuscularly healthy subjects using routine histological stains and biochemical analyses of respiratory chain enzymes.

RESULTS

Staining showed incomplete myopathic features, such as increased variability in fiber size, type 1 hypertrophy, rounded fiber shape, endomysial fibrosis, and replacement by adipose tissue. Acid phosphatase reaction was positive in up to 35% of the selected muscle fibers. Mitochondrial changes were obvious but revealed no selective age dependence. Reduced complex I, cytochrome c oxidase (COX), and citrate synthase (CS) could be observed.

CONCLUSIONS

Because the increased variability in morphological details can easily be misinterpreted as myopathic changes, analysis of paraspinal muscles should take into consideration that incomplete myopathic features and reduced oxidative enzyme activities for complex I, COX, and CS are normal variations at this location.

Mitochondrial DNA deletions and depletion within paraspinal muscles

Aims

Although mitochondrial abnormalities have been reported within paraspinal muscles in patients with axial weakness and neuromuscular disease as well as with ageing, the basis of respiratory deficiency in paraspinal muscles is not known. This study aimed to determine the extent and basis of respiratory deficiency in paraspinal muscles from cases undergoing surgery for degenerative spinal disease and post mortem cases without a history of spinal disease, where age-related histopathological changes were previously reported.

Methods

Cervical and lumbar paraspinal muscles were obtained peri-operatively from 13 patients and from six post mortem control cases (age range 18–82 years) without a neurological disease. Sequential COX/SDH (mitochondrial respiratory chain complex IV/complex II) histochemistry was performed to identify respiratory-deficient muscle fibres (lacking complex IV with intact complex II activity). Real-time polymerase chain reaction, long-range polymerase chain reaction and sequencing were used to identify and characterize mitochondrial DNA (mtDNA) deletions and determine mtDNA copy number status. Mitochondrial respiratory chain complex subunits were detected by immunohistochemistry.

Results

The density of respiratory-deficient fibres increased with age. On average, 3.96% of fibres in paraspinal muscles were respiratory-deficient (range 0–10.26). Respiratory deficiency in 36.8% of paraspinal muscle fibres was due to clonally expanded mtDNA deletions. MtDNA depletion accounted for further 13.5% of respiratory deficiency. The profile of immunohistochemically detected subunits of complexes was similar in respiratory-deficient fibres with and without mtDNA deletions or mtDNA depletion.

Conclusions

Paraspinal muscles appeared to be particularly susceptible to age-related mitochondrial respiratory chain defects. Clonally expanded mtDNA deletions and focal mtDNA depletion may contribute towards the development of age-related postural abnormalities.

Motion characteristics of the vertebral segments with lumbar degenerative spondylolisthesis in elderly patients

OBJECTIVE

Although some studies have reported on the kinematics of the lumbar segments with degenerative spondylolisthesis (DS), few data have been reported on the in vivo 6 degree-of-freedom kinematics of different anatomical structures of the diseased levels under physiological loading conditions. This research is to study the in vivo motion characteristics of the lumbar vertebral segments with L4 DS during weight-bearing activities.

METHODS

Nine asymptomatic volunteers (mean age 54.4) and 9 patients with L4 DS (mean age 73.4) were included. Vertebral kinematics was obtained using a combined MRI/CT and dual fluoroscopic imaging technique. During functional postures (supine, standing upright, flexion, and extension), disc heights, vertebral motion patterns and instability were compared between the two groups.

RESULTS

Although anterior disc heights were smaller in the DS group than in the normal group, the differences were only significant at standing upright. Posterior disc heights were significantly smaller in DS group than in the normal group under all postures. Different vertebral motion patterns were observed in the DS group, especially in the left-right and cranial-caudal directions during flexion and extension of the body. However, the range of motions of the both groups were much less than the reported criteria of lumbar spinal instability.

CONCLUSION

The study showed that lumbar vertebra with DS has disordered motion patterns. DS did not necessary result in vertebral instability. A restabilization process may have occurred and surgical treatment should be planned accordingly.

Factors affecting clinical outcomes in treating patients with grade 1 degenerative spondylolisthesis using interspinous soft stabilization with a tension band system: a minimum 5-year follow-up

STUDY DESIGN

Retrospective clinical study.

OBJECTIVE

To explore the factors influencing the clinical outcomes and motion-preserving stabilization after interspinous soft stabilization (ISS) with a tension band system for grade 1 degenerative spondylolisthesis (DS).

SUMMARY OF BACKGROUND DATA

Despite increasing recognition of the benefits of dynamic stabilization systems for treating lumbar degenerative disorders, the factors affecting the clinical and radiological outcomes of these systems have rarely been identified.

METHODS

Sixty-five patients (mean age, 60.3 years) who underwent ISS with a tension band system between 2002 and 2004 were analyzed. The mean follow-up period was 72.5 months. The patients were divided according to the postsurgical clinical improvements into the optimal (n = 44) and suboptimal groups (n = 21), and the radiological intergroup differences were analyzed. Multiple linear regression analysis was performed to determine the impact of the radiological factors on the clinical outcomes.

RESULTS

Significant intergroup differences were observed on the follow-up clinical examination. Radiologically, total lumbar lordosis (TLL) and segmental lumbar lordosis (SLL) were significantly improved only in the optimal group, resulting in significant intergroup differences in TLL (P = 0.023), SLL (P = 0.001), and the L1 tilt (P = 0.002). All these measures were closely associated with postoperative segmental lumbar lordosis, which also was the most influential radiological variable for the clinical parameters.

CONCLUSION

In the patients with grade 1 DS, the back pain relief and functional improvement following ISS were affected by the improvements in the sagittal spinal alignment through the achievement of segmental lumbar lordosis. ISS can be an alternative treatment to fusion surgery for grade 1 DS in patients who do not require fixation or reduction.