The effects of anti-resorptive therapies and estrogen withdrawal in adult scoliosis measured by sub-segmental vertebral BMD analysis

Impact of mastectomy for breast cancer on spinal curvature: Considerations when treating patients with scoliosis

OBJECTIVE

Mastectomy has been shown to influence body posture in women; however, there are limited data outlining changes in spine curvature after mastectomy in patients with scoliosis. We sought to quantify changes in spine curvature after mastectomy for breast cancer.

METHODS

We conducted a retrospective review of 62 patients with scoliosis who underwent mastectomy for breast cancer at a single institution between 1995 and 2018. Preoperative and postoperative radiographs were used to measure Cobb angles to assess lateral spinal curvature. Changes in Cobb angle were compared using paired two-tailed t-tests. The relationship between mass of breast removed and changes in Cobb angle was modeled using a linear regression.

RESULTS

The median follow-up after mastectomy was 7.9 years (range 0.9-21.5). Median age was 62 years (range 30-85). Of 62 patients, 10 (16%) expressed that their back pain became worse after mastectomy. Nineteen patients had evaluable radiographs before and after mastectomy. In these patients, the average change in Cobb angle was 4.7° (range -0.2-12.2). Cobb angle significantly increased after mastectomy (P < .0001). Although not statistically significant, average Cobb angle was greater for patients who underwent unilateral compared to bilateral mastectomy (P = .09). Mass of breast removed significantly correlated with the difference in Cobb angle for patients who underwent unilateral mastectomy (P = .0006), but not for bilateral mastectomy (P = .55).

CONCLUSIONS

In this understudied patient population, mastectomy significantly increased the change in spine curvature. Further care should be taken to assess patient-reported pain and quality of life in patients with spine morbidity who undergo mastectomy for breast cancer.

Repeating Measurement of Bone Mineral Density when Monitoring with Dual-energy X-ray Absorptiometry: 2019 ISCD Official Position

Bone mineral density (BMD) can be measured at multiple skeletal sites using various technologies to aid clinical decision-making in bone and mineral disorders. BMD by dual-energy X-ray absorptiometry (DXA) has a critical role in predicting risk of fracture, diagnosis of osteoporosis, and monitoring patients. In clinical practice, DXA remains the most available and best validated tool for monitoring patients. A quality baseline DXA scan is essential for comparison with all subsequent scans. Monitoring patients with serial measurements requires technical expertise and knowledge of the least significant change in order to determine when follow-up scans should be repeated. Prior ISCD Official Positions have clarified how and when repeat DXA is useful as well as the interpretation of results. The 2019 ISCD Official Positions considered new evidence and clarifies if and when BMD should be repeated. There is good evidence showing that repeat BMD measurement can identify people who experience bone loss, which is an independent predictor of fracture risk. There is good evidence showing that the reduction in spine and hip fractures with osteoporosis medication is proportional to the change in BMD with treatment. There is evidence that measuring BMD is useful following discontinuation of osteoporosis treatment. There is less documentation addressing the effectiveness of monitoring BMD to improve medication adherence, whether monitoring of BMD reduces the risk of fracture, or effectively discriminates patients who should and should not recommence treatment following an interruption of medication. Further research is needed in all of these areas.

Does hormone replacement therapy prevent lateral rotatory spondylolisthesis in postmenopausal women?

PURPOSE

Degenerative scoliosis usually begins at menopause and lateral rotatory olisthesis (LRO) might be a triggering factor in the onset of degenerative scoliosis in postmenopausal women. We set out to evaluate the influence of hormone replacement therapy (HRT) on degenerative scoliosis and on LRO.

METHODS

A cross-sectional study was conducted in 146 postmenopausal women: 75 women had received HRT for more than 1 year (HRT > 1) and 71 women had never received HRT or less than 1 year (HRT < 1). Scoliotic curve, LRO, sacral slope, lordosis, kyphosis were measured. The excess risk of LRO associated with age, BMI, isometric strength of brachial biceps, bone mineral density, lean mass and HRT was evaluated using a multiple logistic regression model.

RESULTS

No difference was found in sacral slope, lumbar lordosis or thoracic kyphosis between both groups or in the presence of scoliosis. The prevalence of LRO was significantly lower in HRT >1 than HRT <1 (8 vs. 30%) while the risk was dependent on age, HRT and their interaction. LRO increased with age only in HRT <1 (11% when aged ≤66 years vs. 39% when aged >66 years, p = 0.013), whereas the prevalence of LRO remained stable in HRT >1.

CONCLUSIONS

LRO was significantly lower in women who received HRT. The excess risk of LRO was dependent on both age and HRT status. These findings suggest that HRT might prevent the onset of LRO, and therefore might contribute to the prevention of low back pain.