Biological principles of adult degenerative scoliosis

The global aging population has led to an increase in geriatric diseases, including adult degenerative scoliosis (ADS). ADS is a spinal deformity affecting adults, particularly females. It is characterized by asymmetric intervertebral disc and facet joint degeneration, leading to spinal imbalance that can result in severe pain and neurological deficits, thus significantly reducing the quality of life. Despite improved management, molecular mechanisms driving ADS remain unclear. Current literature primarily comprises epidemiological and clinical studies. Here, we investigate the molecular mechanisms underlying ADS, with a focus on angiogenesis, inflammation, extracellular matrix remodeling, osteoporosis, sarcopenia, and biomechanical stress. We discuss current limitations and challenges in the field and highlight potential translational applications that may arise with a better understanding of these mechanisms.

Unfulfilled Expectations After Surgery for Adult Lumbar Scoliosis Compared with Other Degenerative Conditions

BACKGROUND

Patients' expectations influence their decisions to undergo surgery for scoliosis, and fulfillment of expectations is an important patient-centered outcome.

QUESTIONS/PURPOSES

In a 2-year cohort study, we compared the proportion of expectations fulfilled based on the number of vertebrae involved in surgery between adult lumbar scoliosis patients and controls with other degenerative conditions.

METHODS

Patients pre-operatively completed a valid lumbar surgery expectations survey addressing expected improvements for symptoms, function, and psychosocial well-being (scores from 0 to 100; higher score indicates more expectations). Two years post-operatively, the patients completed another survey, this one recording how much improvement they actually experienced; fulfillment was defined as a proportion (i.e., received improvement/expected improvement). The range was 0 (none fulfilled) to > 1 (expectations surpassed). We further analyzed data according to the number of vertebrae involved in the surgery.

RESULTS

We included 42 scoliosis patients and 134 controls with similar mean ages (66 vs 64 years, respectively) and pre-operative expectations survey scores (72 vs 70, respectively). When we stratified by < 3 or ≥ 3 vertebrae, we found that the proportion of expectations fulfilled differed for scoliosis patients but not for controls. In multivariable analysis, lower proportion of expectations fulfilled was associated with greater pre-operative expectations, less improvement in pre- to post-operative disability, and the composite interaction of scoliosis and number of vertebrae.

CONCLUSIONS

Compared with controls, scoliosis patients who required surgery to a greater number of vertebrae were more likely to have unfulfilled expectations 2 years post-operatively. Our findings support the importance of addressing expectations pre-operatively with all patients, especially those with scoliosis who require surgery to ≥ 3 vertebrae.

Adult idiopathic de novo lumbar scoliosis: Analysis of surgical treatment in 14 patients by "only fixation"

Objective:

The authors report their experience with 14 cases having adult idiopathic de novo lumbar scoliosis (AIDLS) and presenting with the predominant symptoms of claudication pain in the low back and legs. The patients were treated by only multisegmental stabilization, and the surgical procedure aimed for arthrodesis without any form of bone or soft-tissue decompression. The clinical outcome of this novel form of surgical treatment is presented.

Materials and Methods:

During the period of June 2014 to June 2019, 14 patients having AIDLS (degenerative scoliosis) were surgically treated. Apart from clinical and radiological guides, instability was diagnosed on the basis of direct physical observation of the status of articulation and by manual manipulation of bones of the region. The Camille transarticular facet screw fixation technique provided a quick, safe, and strong segmental spinal fixation. An additional inter-screw metal link plate provided intersegmental stability at selected levels. The Oswestry Disability index and visual analog scale were used to assess the patients before and after surgery and at follow-up. In addition, a personalized Patient Satisfaction Score was used to assess the outcome of surgery.

Results:

Clinical symptomatic recovery was observed in all patients in the immediate postoperative period. During the average follow-up period, 100% patients had varying degrees of symptomatic relief.

Conclusions:

Spinal instability is the nodal point of pathogenesis of spinal degeneration-related AIDLS. Only fixation of the involved spinal segments is necessary, and decompression by bone or soft-tissue resection is not necessary.

Effect of the lumbar scoliosis on the results of dual-energy X-ray absorptiometry

One of the most common causes of lumbar scoliosis in adults is the decreased bone mineral density (BMD). The scoliosis in the lumbar spine has a known effect over the dual-energy X-ray absorptiometry (DXA) scan results. The objective of this study is to assess the influence of the lumbar scoliosis on the results of the DXA scan of the lumbar spine. 1019 women aged ≥40 years underwent a DXA scan of the spine. Age, weight, height, total BMD, total Tscore of the lumbar spine were recorded. The angle of the lumbar scoliosis (Cobb’s angle) was measured from the DXA scan image using a DICOM software. The incidence of lumbar scoliosis in the current study accounts to 12.3%. Women with scoliosis showed significantly higher incidence of discrepancy in BMD T-scores between the adjacent vertebrae by more than 1 SD compared to women without scoliosis, (p=0.046). DXA results of subjects with scoliosis require more detailed evaluation of the T-scores of each vertebra to make a prompt decision about the final diagnosis.

Surgical correction of severe adult lumbar scoliosis (major curves ≥ 75°): retrospective analysis with minimum 2-year follow-up

OBJECTIVE

Prior reports have demonstrated the efficacy of surgical correction for adult lumbar scoliosis. Many of these reports focused on mild to moderate scoliosis. The authors' objective was to report their experience and to assess outcomes and complications after deformity correction for severe adult scoliosis.

METHODS

The authors retrospectively analyzed consecutive adult scoliosis patients with major thoracolumbar/lumbar (TL/L) curves ≥ 75° who underwent deformity correction at their institution. Those eligible with a minimum 2 years of follow-up were included. Demographic, surgical, coronal and sagittal plane radiographic measurements, and health-related quality of life (HRQL) scores were analyzed.

RESULTS

Among 26 potentially eligible patients, 22 (85%) had a minimum 2 years of follow-up (range 24-89 months) and were included in the study (mean age 57 ± 11 years; 91% women). The cohort comprised 16 (73%), 4 (18%), and 2 (9%) patients with adult idiopathic scoliosis, de novo degenerative scoliosis, and iatrogenic scoliosis, respectively. The surgical approach was posterior-only and multistage anterior-posterior in 18 (82%) and 4 (18%) patients, respectively. Three-column osteotomy was performed in 5 (23%) patients. Transforaminal and anterior lumbar interbody fusion were performed in 14 (64%) and 4 (18%) patients, respectively. All patients had sacropelvic fixation with uppermost instrumented vertebra in the lower thoracic spine (46% [10/22]) versus upper thoracic spine (55% [12/22]). The mean fusion length was 14 ± 3 levels. Preoperative major TL/L and lumbosacral fractional (L4-S1) curves were corrected from 83° ± 8° to 28° ± 13° (p < 0.001) and 34° ± 8° to 13° ± 6° (p < 0.001), respectively. Global coronal and sagittal balance significantly improved from 5 ± 4 cm to 1 ± 1 cm (p = 0.001) and 9 ± 8 cm to 2 ± 3 cm (p < 0.001), respectively. Pelvic tilt significantly improved from 33° ± 9° to 23° ± 10° (p < 0.001). Significant improvement in HRQL measures included the following: Scoliosis Research Society (SRS) pain score (p = 0.009), SRS appearance score (p = 0.004), and SF-12/SF-36 physical component summary (PCS) score (p = 0.026). Transient and persistent neurological deficits occurred in 8 (36%) and 2 (9%) patients, respectively. Rod fracture/pseudarthrosis occurred in 6 (27%) patients (supplemental rods were utilized more recently in 23%). Revisions were performed in 7 (32%) patients.

CONCLUSIONS

In this single-center surgical series for severe adult scoliosis (major curves ≥ 75°), a posterior-only or multistage anterior-posterior approach provided major curve correction of 66% and significant improvements in global coronal and sagittal spinopelvic alignment. Significant improvements were also demonstrated in HRQL measures (SRS pain, SRS appearance, and SF-12/SF-36 PCS). Complications and revisions were comparable to those of other reports involving less severe scoliosis. The results of this study warrant future prospective multicenter studies to further delineate outcomes and complication risks for severe adult scoliosis correction.

Decompression in Adult Lumbar Deformity Surgery Is Associated With Increased Perioperative Complications but Favorable Long-Term Outcomes

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To analyze the impact of performing a formal decompression in patients with adult lumbar scoliosis with symptomatic spinal stenosis on perioperative complications and long-term outcomes.

METHODS

Adult patients undergoing at least 5 levels of fusion to the sacrum with iliac fixation from 2002 to 2008 who had a minimum 5-year follow-up at one institution were studied. Patients who had 3-column osteotomy were excluded from the study. Perioperative complications and clinical outcomes (Scoliosis Research Society [SRS], Oswestry Disability Index [ODI], and Numerical Rating Scale [NRS] back/leg pain) were analyzed. Patients who underwent formal laminectomy/decompressions were compared with those who did not. Differences between the 2 groups were analyzed using Student's t test.

RESULTS

A total of 147 patients were included in the study (Decompression: n = 55 [37%], No decompression: n = 92 [63%]). Average fusion levels for the decompression and no decompression groups were 11 and 12 levels, respectively (P = .26). Mean improvements in SRS domains for decompression versus no decompression patients, respectively, were pain (1.1 vs 0.9, P = .3), function (0.7 vs 0.5, P = .09), self-image (1.1 vs 1.1, P = .9), and mental health (0.5 vs 0.4, P = .5). Furthermore, additional mean improvements were ODI (21 vs 21, P = .14), NRS-Back pain (3.0 vs 1.3, P = .16), and NRS-Leg pain (3.9 vs 0.5, P = .002). Complication rates between the decompression group and no decompression group differed in incidental durotomies (18.2% vs 0%) and cardiac-related (9.1% vs 1.1%).

CONCLUSIONS

Performing a formal decompression in adult lumbar scoliosis with symptomatic spinal stenosis is associated with increased perioperative complications but favorable long-term clinical outcomes.

Multilevel Contiguous Osteoporotic Lumbar Compression Fractures: The Relationship of Scoliosis to the Development of Cascading Fractures

Osteoporotic patients can present with either single or multiple fractures secondary to repeated falls and progressive osteoporosis. Multiple fractures often lead to additional spinal deformity and are a sign of more severe osteoporosis. In the thoracic spine, multiple fractures are associated with the development of gradual thoracic kyphosis but neurologic deficits are uncommon. In the lumbar spine, patients with multiple lumbar fractures have more constant lumbar pain, may have symptoms related to concurrent lumbar stenosis or degenerative scoliosis, and may present with radiculopathy, especially with fractures at L4 and L5. In a review of a series of patients with recurrent multiple lumbar fractures or 'cascading' fractures, it was found that all the patients were female, had severe osteoporosis, often untreated, had a previous history of multiple previous thoracic and lumbar fractures, and all had associated scoliotic spinal deformities ranging from 6^o to 50^o. It was found that if the curve progressed and the greater the degree of curvature, the more frequently subsequent multiple fractures developed, leading to recurrent acute episodes of pain. Forty percent also had additional sacral insufficiency fractures, an unusually high percentage. Biomechanically, the lumbar spine is both more mobile and supports a larger portion of the spinal load compared to the thoracic spine. The existence or worsening of a lumbar spinal deformity from degenerative lumbar scoliosis shifts the mechanical forces more to one side on already weakened osteoporotic lumbar vertebrae and sacrum, leading to an increased incidence of these fractures. Because of the chronic and uneven lower lumbar spinal load with severe vertebral osteoporosis in certain patients with repeat lumbar fractures and worsening degenerative lumbar scoliosis, there may be a rationale to add preventive vertebroplasty at adjacent vertebral endplates when treating acute recurrent lumbar fractures to decrease the incidence of recurrence in other vertebrae.