Menopause and the intervertebral disc

Epidemiology of non-trauma orthopedic conditions among inpatients admitted at a tertiary teaching and referral hospital in Kenya: A chart review

Non-traumatic orthopedic conditions are pathological conditions involving musculoskeletal system that includes muscles, tendons, bone and joints and associated with frequent medical and surgical care and high treatment costs. There is paucity of information on the pattern of non-traumatic orthopedic conditions in low and middle income countries. The purpose of this study was to determine the epidemiology of non-traumatic orthopedic conditions among inpatients at the Kenyatta National Hospital in Kenya. This was a cross-sectional study with a sample of 175 charts reviewed. Approximately, 70.3% of the inpatients were aged between 25 to 64 years of age with the mean age of 39.97 years (STD 18.78). Ever married tended to be older 53.5 (95% CI: 46.8-60.2) years than other marital statuses. Approximately, 60.6% were males, 38.9% had comorbidities and 49.1% were casuals or unemployed. All inpatients were Kenyans with Nairobi County comprising 52.6% of all inpatients. Approximately, 77.7% were self-referrals. The commonest non-trauma orthopaedic conditions were infection and non-union (35.4%) and spinal degenerative diseases (20.60%) and the least was limb deformities (1.70%). Compared to females, males were 3.703 (p<0.001) times more likely to have infection and non-union. Patients with primary, secondary and tertiary education were 88.2% (p<0.001), 75.6% (p<0.001) and 68.1% (p = 0.016) less likely to have infection and non-union compared to those with no or preschool education. Widows were 8.500 (p = 0.028) times more likely to have spinal degenerative disease than married. Males were 70.8% (p = 0.031) less likely to have osteoarthritis than females. Inpatients with secondary education were 5.250 (p = 0.040) times more likely to have osteoarthritis than those with no or preschool education. In conclusion, majority of inpatients were young and middle aged adults. Infection and non-union and spinal degenerative diseases were the most common non-trauma orthopedic conditions. While males and those with low education were more likely to have infection and non-union, married were more likely to have spinal degenerative disease. Osteoarthritis was more likely among female admissions.

Effect of hormone replacement therapy on intervertebral disc height

OBJECTIVE

Intervertebral discs act as shock absorbers, thereby helping to reduce the risk of vertebral body fractures. Previous studies have shown that estrogen loss following menopause is associated with disc height reduction whereas treatment with hormone replacement therapy (HRT) helps to maintain disc height. This study reports the effect of HRT on disc height from a post hoc analysis of a prospective randomized clinical trial of the effect of HRT on bone density.

METHODS

A total of 355 healthy postmenopausal women aged (mean ± standard deviation) 55.4 ± 4.8 years were randomized to HRT with oral 1 mg or 2 mg estradiol plus dydrogesterone or placebo. Dual-energy X-ray absorptiometry measurements (Lunar DPX) were obtained at baseline and following 2 years of treatment. Intervertebral disc height was measured in discs between T12 and L3 using the bone densitometer ruler.

RESULTS

Compared with baseline, treatment with HRT resulted in a significant increase in total disc height with 1 mg estradiol (0.16 ± 0.65 cm, p = 0.015) and with 2 mg estradiol (0.21 ± 0.86 cm, p = 0.006) whilst there was no significant increase with placebo (0.13 ± 0.65 cm, p = 0.096). Between-group differences were not statistically significant.

CONCLUSIONS

These results are consistent with previous findings of a beneficial effect of estrogen on discs. This may be in part responsible for the anti-fracture efficacy of HRT on vertebral fractures.

An update on animal models of intervertebral disc degeneration and low back pain: Exploring the potential of artificial intelligence to improve research analysis and development of prospective therapeutics

Animal models have been invaluable in the identification of molecular events occurring in and contributing to intervertebral disc (IVD) degeneration and important therapeutic targets have been identified. Some outstanding animal models (murine, ovine, chondrodystrophoid canine) have been identified with their own strengths and weaknesses. The llama/alpaca, horse and kangaroo have emerged as new large species for IVD studies, and only time will tell if they will surpass the utility of existing models. The complexity of IVD degeneration poses difficulties in the selection of the most appropriate molecular target of many potential candidates, to focus on in the formulation of strategies to effect disc repair and regeneration. It may well be that many therapeutic objectives should be targeted simultaneously to effect a favorable outcome in human IVD degeneration. Use of animal models in isolation will not allow resolution of this complex issue and a paradigm shift and adoption of new methodologies is required to provide the next step forward in the determination of an effective repairative strategy for the IVD. AI has improved the accuracy and assessment of spinal imaging supporting clinical diagnostics and research efforts to better understand IVD degeneration and its treatment. Implementation of AI in the evaluation of histology data has improved the usefulness of a popular murine IVD model and could also be used in an ovine histopathological grading scheme that has been used to quantify degenerative IVD changes and stem cell mediated regeneration. These models are also attractive candidates for the evaluation of novel anti-oxidant compounds that counter inflammatory conditions in degenerate IVDs and promote IVD regeneration. Some of these compounds also have pain-relieving properties. AI has facilitated development of facial recognition pain assessment in animal IVD models offering the possibility of correlating the potential pain alleviating properties of some of these compounds with IVD regeneration.

Intervertebral disc degeneration and how it leads to low back pain

The purpose of this review was to evaluate data generated by animal models of intervertebral disc (IVD) degeneration published in the last decade and show how this has made invaluable contributions to the identification of molecular events occurring in and contributing to pain generation. IVD degeneration and associated spinal pain is a complex multifactorial process, its complexity poses difficulties in the selection of the most appropriate therapeutic target to focus on of many potential candidates in the formulation of strategies to alleviate pain perception and to effect disc repair and regeneration and the prevention of associated neuropathic and nociceptive pain. Nerve ingrowth and increased numbers of nociceptors and mechanoreceptors in the degenerate IVD are mechanically stimulated in the biomechanically incompetent abnormally loaded degenerate IVD leading to increased generation of low back pain. Maintenance of a healthy IVD is, thus, an important preventative measure that warrants further investigation to preclude the generation of low back pain. Recent studies with growth and differentiation factor 6 in IVD puncture and multi-level IVD degeneration models and a rat xenograft radiculopathy pain model have shown it has considerable potential in the prevention of further deterioration in degenerate IVDs, has regenerative properties that promote recovery of normal IVD architectural functional organization and inhibits the generation of inflammatory mediators that lead to disc degeneration and the generation of low back pain. Human clinical trials are warranted and eagerly anticipated with this compound to assess its efficacy in the treatment of IVD degeneration and the prevention of the generation of low back pain.