Impact of Individual Spinopelvic Anatomy on the Localization and Severity of Symptomatic Isthmic Spondylolisthesis

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVES

Isthmic spondylolisthesis (iSPL) occurs most commonly in L5/S1 and L4/5. This study investigates the association between spinopelvic anatomy and the pathogenesis of iSPL.

METHODS

Spinopelvic parameters as well as severity of slip grade were measured in sagittal spine radiographs of symptomatic patients with iSPL in segments L4/5 and L5/S1. Means were calculated and differences between both groups were analyzed. A correlation between the analyzed parameters and degree of slippage was performed.

RESULTS

We included 73 subjects in this study; 11 in L4/5 group and 62 in L5/S1 group. Pelvic anatomy significantly differed between L4/5 and L5/S1 iSPL (Pelvic Incidence (PI) 54.8° vs 66.3°, P value = .006; Pelvic Radius (PR) 124.4 mm vs 137.4 mm; P value = .005 and Sacral Table Angle (STA) 101.0° vs 92.2°, P value < .001). The relative degree of slippage was significantly higher in the L5/S1 group (L4/5 29.1% vs L5/S1 40.1%, P value .022). We also observed a significant correlation between pelvic anatomy and the severity of the slip in iSPL at the L5/S1 level.

CONCLUSIONS

Pelvic parameters PI and STA play an important role concerning the level of occurrence and severity of iSPL. Spinopelvic anatomy determines the pathogenesis of iSPL.

How does sagittal spinopelvic alignment of lumbar multisegmental spondylolysis differ from monosegmental spondylolysis?

OBJECTIVE

The aim of this study was to investigate sagittal alignment and compensatory mechanisms in patients with monosegmental spondylolysis (mono_lysis) and multisegmental spondylolysis (multi_lysis).

METHODS

A total of 453 adult patients treated for symptomatic low-grade spondylolytic spondylolisthesis were retrospectively studied at a single center. Patients were divided into 2 subgroups, the mono_lysis group and the multi_lysis group, based on the number of spondylolysis segments. A total of 158 asymptomatic healthy volunteers were enrolled in this study as the control group. Radiographic parameters measured on standing sagittal radiographs and the ratios of L4-S1 segmental lordosis (SL) to lumbar lordosis (L4-S1 SL/LL) and pelvic tilt to pelvic incidence (PT/PI) were compared between all experimental groups.

RESULTS

There were 51 patients (11.3%) with a diagnosis of multi_lysis in the spondylolysis group. When compared with the control group, the spondylolysis group exhibited larger PI (p < 0.001), PT (p < 0.001), LL (p < 0.001), and L4-S1 SL (p = 0.025) and a smaller L4-S1 SL/LL ratio (p < 0.001). When analyzing the specific spondylolysis subgroups, there were no significant differences in PI, but the multi_lysis group had a higher L5 incidence (p = 0.004), PT (p = 0.018), and PT/PI ratio (p = 0.039). The multi_lysis group also had a smaller L4-S1 SL/LL ratio (p = 0.012) and greater sagittal vertical axis (p < 0.001).

CONCLUSIONS

A high-PI spinopelvic pattern was involved in the development of spondylolytic spondylolisthesis, and a larger L5 incidence might be associated with the occurrence of consecutive multi_lysis. Unlike patients with mono_lysis, individuals with multi_lysis were characterized by an anterior trunk, insufficiency of L4-S1 SL, and pelvic retroversion.

Microendoscopic Surgery with an Ultrasonic Bone Curette for a Patient with Intraforaminal Stenosis of the Lumbar Spine Due to an Ossification Lesion: A Technical Case Report

Introduction:

We present a rare case with radiculopathy resulting from intraforaminal stenosis of the lumbar spine due to an ossification lesion. Microendoscopic surgery was chosen because of two strong advantages. One was the ease to reach the nerve foramen and ossification lesion and the other was the non-invasiveness at the posterior supporting structures of the spine. Moreover, an ultrasonic bone curette developed for microendoscopic spine surgery was applied. This is the first detailed case report of microendoscopic surgery using an ultrasonic bone curette for a patient with radiculopathy due to intraforaminal free ossification.

Case Report:

A 49-year-old woman born in Japan had complained of severe left leg pain for over 7 months in spite of conservative treatment including selective nerve root block. There was no lumbago, muscle weakness, or loss of sensation in her leg. Plain radiography revealed spondylolytic spondylolisthesis classified as Grade II at L4-L5, but there was no instability on dynamic assessment. Computed tomography (CT) showed a free ossification lesion in the foramen at L4-L5. Considering a diagnosis of left L4 radiculopathy due to the free ossification, ossification resection and nerve decompression were performed with posterior spinal microendoscopic surgery using an ultrasonic bone curette. A tubular retractor was introduced into the extraforaminal zone using Wiltse approach. After a part of the ossification lesion and the nerve root were exposed, an ultrasonic bone curette was applied to remove the ossification mass. After decompression, the nerve root was found to be relaxed. The surgical time was 83 min, and blood loss was 5 g. According to the Japanese Orthopedic Association scoring system, her score improved from 21/29 preoperatively to 29/29 postoperatively, and the full score was maintained at the final observation. Post-operative CT revealed the absence of an ossification lesion.

Conclusions:

For a rare case with radiculopathy resulting from intraforaminal stenosis of the lumbar spine due to an ossification lesion, microendoscopic surgery with an ultrasonic bone curette was very effective. The use of ultrasonic bone curette is easy and safe in microendoscopic surgery and it helps achieve less invasiveness and ideal decompression, without injuring the nerve root.

Adjacent disc and facet joint degeneration in young adults with low-grade spondylolytic spondylolisthesis: A magnetic resonance imaging study

BACKGROUND/PURPOSE

Premature adjacent-level degeneration has been attributed to vertebral fusion, but spondylolisthesis has not been reported as a pathological factor responsible for the degeneration of adjacent disc and facet joint. We hypothesized that the degeneration of disc and facet joints in the adjacent levels is correlated with spondylolisthesis.

METHODS

Magnetic resonance images of 35 symptomatic young adults (16-29 years old) with low-grade L5-S1 spondylolytic spondylolisthesis (Meyerding Grade 1 or 2) and 50 symptomatic young referents (20-29 years old) with L5-S1 disc herniation without spondylolisthesis were recruited to compare the differences between disc and facet-joint degenerations at the olisthetic and adjacent levels using the Mantel extension test.

RESULTS

There were statistically significant degenerative changes of the discs and facet joints at the olisthetic and adjacent levels of patients with spondylolytic spondylolisthesis compared with the reference group. There is a trend that the disc and facet joints degenerate the most at the olisthetic level and become less affected at adjacent levels away from the lesion of pars defect.

CONCLUSION

Low-grade spondylolytic spondylolisthesis was associated with significant degenerations of the disc and facet joints at olisthetic and adjacent levels in young adults.