SEARCH

SEARCH BY CITATION

Keywords:

  • fracture;
  • kyphoplasty;
  • osteoporosis;
  • pregnancy

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Reports
  5. Discussion
  6. Disclosure
  7. References

The syndrome of pregnancy-associated osteoporosis (PAO) is a rare disorder which occurs either in late pregnancy or early post-partum period leading to fragility fracture(s), most commonly in the vertebral bodies. We presented two cases with PAO who had compression fractures at multiple levels involving five vertebrae in one case and 10 vertebrae in the other. Their spinal bone mineral density values were below −2.5 standard deviations. Anti-osteoporotic treatments with nasal calcitonin 400 IU/day, vitamin D 300.000 IU single dose, calcium 1000 mg/day, vitamin D 880 IU/day were initiated. In one case, kyphoplasty was performed by a spinal surgeon. In addition to a thoracolumbosacral orthosis, a rehabilitation program including muscle strengthening, range of motion, relaxation and weight-bearing exercises was started for both cases. These cases emphasize that all pregnant women with complaints of back/lumbar pain should be carefully evaluated.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Reports
  5. Discussion
  6. Disclosure
  7. References

Osteoporosis is defined as a progressive systemic skeletal disease characterized by low bone mass and micro-architectural deterioration of bone tissue, leading to enhanced bone fragility and consequent increase in fracture risk.[1] Although it has been well studied and documented in postmenopausal women, it has received little attention in young women, particularly in pregnancy, due to the lower incidence of the disorder and limited information to explain its etiology. Nordin and Roper[2] were the first to suggest the syndrome of pregnancy-associated osteoporosis (PAO) which is characterized by the occurrence of fragility fracture(s), most commonly involving the vertebral bodies, and which occur either in late pregnancy or early post-partum period. Because it presents with back pain, it is often incorrectly considered a common symptom because the back pain is put down to ligamentous laxity induced by hormones of pregnancy.[3] Although there is no agreed definition of PAO, each patient with back pain during pregnancy should undergo a detailed examination to rule out an underlying osteoporotic fracture. In this paper, we report two cases with vertebral fractures in multiple levels due to pregnancy-induced osteoporosis.

Case Reports

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Reports
  5. Discussion
  6. Disclosure
  7. References

Case 1

A 22-year-old uniparous housewife presented to our outpatient clinic at the ninth month post-partum with the complaint of back pain persisting since late pregnancy. History revealed that the pain had begun during the late stages of pregnancy, approximately 1 month before delivery with no change in severity of pain until labor. The severity of pain increased 1 week following delivery and it was stated that the pain increased with movement and decreased with rest. Due to pain, the patient had difficulty in performing daily activities and in nursing her baby. There was no history of alcohol use, smoking or any disease. Physical examination revealed tenderness to palpation in the lower thoracic and lumbar vertebrae and restriction in spinal movements. The dorsolumbar radiograms showed loss of height in the corpuses of the lower dorsal vertebrae. No significant characteristics were seen in the routine biochemical analyses. The 24-h urine analysis results were as follows: Ca was decreased (74 mg), while serum P, thyroid function test (TFT), parathyroid hormone (PTH), adrenocorticotropic hormone (ACTH), cortisol and 25-OH-vitamin D were normal. Deoxypyridinoline (17 nmol/L) and osteocalcin (33.9 ng/mL) were increased. By dual-energy X-ray absorptiometry (DXA), T scores were a lumbar total of −3.6 and femur total of −2.7. Loss of height was determined in the T 6, 8, 9, 10 and 11 the vertebrae corpuses in the thoracolumbar magnetic resonance imaging (MRI) (Fig. 1). The patient was diagnosed with osteoporosis due to pregnancy and treatment with nasal calcitonin 200 IU/day, calcium 1000 mg/day and vitamin D 880 IU/day was initiated. Analgesics were used for pain. Lactation was stopped and an oral contraceptive was begun upon consultation with the Department of Gynaecology and Obstetrics for contraception. In addition, a thoracolumbosacral orthosis (TLSO) was prescribed. A rehabilitation program including muscle strengthening, range of motion and relaxation exercises as well as weight-bearing exercises was started. After 3 months, although the complaint of pain decreased significantly, the patient still experienced some pain. Tenderness to palpation in the lower thoracic and lumbar regions persisted. At the sixth month, she did not have any complaint about back pain. During the follow-up, evaluations at the first year revealed that biochemical values and the 24-h urine analysis were normal as shown in Table 1. DXA was measured as a lumbar total of −2.6 and femur total of −2.2 (Table 1). Treatment with the same doses of calcitonin, calcium and vitamin D was maintained.

figure

Figure 1. First case's thoracolumbar magnetic resonance imaging.

Download figure to PowerPoint

Table 1. Patients' biochemical findings
 Case 1Case 2
At baseline1st yearAt baseline1st year
  1. DPD, deoxypyridinoline; PTH, parathyroid hormone.

Bone metabolism    
Osteocalcin (3.1–13.7 ng/mL)33.95.6412.53.2
DPD (2.3–7.4 W nM/mM)17.06.277.53.3
Mineral metabolism    
Serum    
Calcium (8.2–10.4 mg/dL)8.99.39.18.8
Phosphate (2.3–4.5 mg/dL)3.33.83.43.4
24-h urine    
Calcium (100–300 mg)74121135147
Phosphate (400–1300 mg)435861398785
PTH (12–72 pg/mL)24262217
25-OH-vitamin D (50–300 nmol/L)396852127

Case 2

A 34-year-old female patient presented with severe back pain in the first month after her first delivery. History revealed that back pain began in the sixth to seventh months of pregnancy, which increased with movement and decreased with rest. No risk factors such as smoking and use of alcohol were present. Physical examination revealed tenderness to palpation in the lower thoracic and lumbar vertebrae. Extension of the lumbar region was painful and back pain increased on standing. The findings of other examinations were found to be normal with no neurological deficits. No abnormal finding was encountered in the routine biochemical examination, apart from mild elevation in alkaline phosphatase (ALP). Serum 25-OH-vitamin D, PTH, osteocalcin and TFT were normal. Serum ALP was 127 (normal range, 35–104). Ca and P were normal in the 24-h urine analysis. DXA lumbar total T score was −3.6, femur total T score –1.5. The 2-D radiograms of the dorsolumbar vertebrae showed osteoporotic loss of height at multiple levels in the middle and lower dorsal regions. Lumbar MRI revealed compression fractures at multiple levels including T8 L5 with a total of 10 vertebrae (Fig. 2). The patient was diagnosed with osteoporosis due to pregnancy and treatment with nasal calcitonin 400 IU/day, vitamin D 300.000 IU single dose, calcium 1000 mg/day, vitamin D 880 IU/day was initiated; additional analgesics were used and lactation was stopped. In order to decrease pain, kyphoplasty was performed for T11, T12, L1, L2 and L4 vertebrae (Fig. 3). Her back pain significantly decreased within a few days after the operation. In addition to analgesic medications, a TLSO was applied. At 6 weeks following operation, strengthening extension exercises for the back and abdominal muscles and weight-bearing exercises were started. At the following visits, she did not have any complaint of back pain. At the first year, biochemical values were normal (Table 1) and lumbar T score was increased. Treatment with the same doses of calcitonin, calcium and vitamin D was maintained.

figure

Figure 2. Second case's thoracolumbar magnetic resonance imaging.

Download figure to PowerPoint

figure

Figure 3. Second case's thoracolumbar radiography after kyphoplasty.

Download figure to PowerPoint

Discussion

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Reports
  5. Discussion
  6. Disclosure
  7. References

In this report, two cases of PAO syndrome have been presented. In one case, back pain started during the last month of pregnancy and continued till the ninth month post-partum during which she presented to our clinic. In the other patient, pain developed during the second trimester, in other words, during the sixth to seventh months of pregnancy. In both cases, fractures at multiple levels were seen on radiographies and MRI, involving five vertebrae in one case and 10 vertebrae in the other.

In a report presented by O'Sullivan et al.,[4] vertebral fractures at multiple levels were observed in 10 of 11 cases after a mean of 1 month following delivery. In nine of these cases, other underlying risk factors such as low bodyweight, smoking, family history of osteoporosis/fracture and deficiency of vitamin D were determined. However, no risk factors were found in our cases, apart from pregnancy and lactation. Furthermore, the number of fractures at multiple levels varied between two and five in the trial of O'Sullivan et al.,[4] but in one of our cases, the fractures were found in 10 vertebrae. Similarly, in a case presentation of Ofluoglu and Ofluoglu,[5] it was reported that loss of height was observed in eight vertebrae and this patient was regarded as the first case in the published work with the highest number of fractures. Considering our second case, it may be stated that PAO may cause fractures at multiple localizations such as more than eight levels of the vertebrae.

Despite the fact that the etiopathogenesis of PAO has not been fully described, it was suggested that certain underlying factors may be responsible in the development of PAO. One of these factors is heredity, and during trials, development of PAO was more frequently observed in individuals with a positive family history.[6] On the other hand, absence of a positive family history in either of our cases indicates that other factors play a role in the development of osteoporosis.

Another factor which is held responsible for PAO is the changes seen in bone and calcium metabolism during pregnancy and lactation.[7] Indeed, the bone turnover significantly increases during pregnancy, especially in the third trimester; approximately 20–30 g of calcium is transferred to the baby and the mother's skeleton is under considerable risk in terms of demineralization.[8] In spite of the fact that a number of adaptive mechanisms like increased intestinal absorption of dietary calcium, increased renal reabsorption, and additionally, mobilization of calcium from maternal skeleton develop against calcium deficiency in the mother, calcium supplementation is essential in preventing osteoporosis. The fact that supplementation of calcium and vitamin D was missing in both of our cases indicates that changes in calcium and vitamin D metabolism in pregnancy may be responsible for the etiopathogenesis of PAO. The same reason was suggested in the case with eight vertebral fractures.[5] Authors indicate that negative calcium balance is a critical etiological factor in cases with no calcium supplementation.

Nevertheless, it is well known that PAO may develop in patients in whom calcium and vitamin D supplementation are provided during pregnancy and lactation; therefore, the above-mentioned etiological factors are not sufficient in explaining the etiopathogenesis of PAO. Further large scale trials are needed in this regard.

The clinical manifestation of PAO is severe back/lumbar pain, as it was in our cases. Unfortunately, this symptom is frequently encountered during pregnancy due to physiological reasons; hence, PAO cases are frequently missed. Indeed, a late presentation, such as 9 months after delivery in our first case, is due to this cause. Hence, it is not clear whether vertebral fractures developed during pregnancy or during lactation.

Treatment of PAO is not different from the classical treatment of osteoporosis. In various trials, antiresorptive agents such as biphosphonates and calcitonin are usually the first-line therapeutic options.[4, 5, 9-11] Among the nine cases who used biphosphonates in the trial conducted by O'Sullivan et al.,[4] spinal bone mineral density increased by 17% at the first year and by 23% at the second year. On the other hand, biphosphonates have a long-term retention rate in bone and some of them were found to cross the placenta. Animal studies showed that biphosphonates administrated during pregnancy can decrease bone length in fetuses.[12, 13] Although they do not seem to affect skeletal growth in fetuses in humans, we used nasal calcitonin, concurrently with calcium and vitamin D in both of our cases. In previous studies, it has been showed that salmon calcitonin nasal spray at a dose of 200 IU/day can reduce the risk of vertebral osteoporotic fractures by 33%.[14, 15] There is also evidence to show that calcitonin diminishes bone pain in osteoporotic vertebral fractures, which may have clinical utility in the cases with multiple fractures.[15]

The treatment of PAO demands a combination of options, including not only therapeutic interventions, but also physiotherapy and exercises. In the acute phase following vertebral fracture, performing isometric contractions of paraspinal muscles can help to decrease post-fracture pain and edema.[16] Ongoing chronic pain may be caused by vertebral fractures or may result from postural deformities, such as hyperkyphotic changes in the spine with inappropriate stretching of ligaments. Exercises to improve muscle strength need to focus on the back extensors. The exercises of back extensors may decrease kyphosis, lead to better dynamic static posturing, reduce pain and subsequently increase mobility and improve the patient's quality of life.[16-18] For this reason, we commenced a rehabilitation program including muscle strengthening, range of motion and relaxation exercises as well as weight-bearing exercises in both cases.

One of the other treatment options is kyphoplasty, which is usually used in acute fractures for pain relief.[11] In the first case that was diagnosed as PAO and treated with kyphoplasty for three vertebral fractures, the authors reported that this intervention was very efficient for relief.[11] Actually, kyphoplasty can be discussed in the management of our case. However, considering previous data, it is difficult to determine which patients with osteoporotic vertebral fractures would benefit most from kyphoplasty.[19] Our case reported good pain relief within a few days after the operation; for this reason, it can be stated that kyphoplasty was an effective procedure for the management of her pain.

In conclusion, we described two cases with multiple vertebral fractures due to PAO. This disorder is a rare but serious problem leading to considerable morbidity in the form of pain and disability. The majority of patients present with multiple vertebral fractures like our cases. Nevertheless, it is usually unnoticed since musculoskeletal complaints – particularly back pain – are very common in pregnancy. These cases emphasized that all pregnant women with complaints of back/lumbar pain should be carefully evaluated.

Disclosure

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Reports
  5. Discussion
  6. Disclosure
  7. References

None of the authors have relationship with companies.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Case Reports
  5. Discussion
  6. Disclosure
  7. References
  • 1
    Kanis JA, Melton LJ 3rd, Christiansen C, Johnston CC, Khaltaev N. The diagnosis of osteoporosis. J Bone Miner Res 1994; 9: 11371141.
  • 2
    Nordin BEC, Roper A. Post pregnancy osteoporosis: A syndrome? Lancet 1955; 1: 431434.
  • 3
    Khovidhunkit W, Epstein S. Osteoporosis in pregnancy. Osteoporos Int 1996; 6: 345354.
  • 4
    O'Sullivan SM, Grey AB, Singh R, Reid IR. Biphosphonates in pregnancy and lactation-associated osteoporosis. Osteoporos Int 2006; 17: 10081012.
  • 5
    Ofluoglu O, Ofluoglu D. A case report: Pregnancy- induced severe osteoporosis with eight vertebral fractures. Rheumatol Int 2008; 29: 197201.
  • 6
    Dunne F, Walters B, Marshall T, Heath DA. Pregnancy associated osteoporosis. Clin Endocrinol 1993; 39: 487490.
  • 7
    Holmberg-Marttila D, Sievanen H, Tuimala R. Changes in bone mineral density during pregnancy and postpartum: Prospective data on five women. Osteoporos Int 1999; 10: 4146.
  • 8
    Uemura H, Yasui T, Kiyokawa M et al. Serum osteoprotegerin/osteoclastogenesis-inhibitory factor during pregnancy and lactation and the relationship with calcium-regulating hormones and bone turnover markers. J Endocrinol 2002; 174: 353359.
  • 9
    Foster SA, Foley KA, Meadows ES et al. Characteristics of patients initiating teriparatide for the treatment of osteoporosis. Osteoporos Int 2008; 19: 373377.
  • 10
    Hellmeyer L, Kuhnert M, Ziller V, Schmidt S, Hadji P. The use i.v bisphosphonate in pregnancy-associated osteoporosis–case study. Exp Clin Endocrinol Diabetes 2007; 115: 139142.
  • 11
    Bayram S, Ozturk C, Sivrioglu K, Aydinli U, Kucukoglu S. Kyphoplasty for pregnancy-associated osteoporotic vertebral fractures. Joint Bone Spine 2006; 73: 564566.
  • 12
    Patlas N, Colomb G, Yaffe P, Pinto T, Breuer E, Ornoy A. Transplacental effects of bisphosphonates on fetal skeletal ossification and mineralization in rats. Teratology 1999; 60: 6873.
  • 13
    Lin JH, Duggan DE, Chen IWU, Ellsworth RL. Physiological disposition of alendronate, a potent anti-osteolytic bisphosphonate, in laboratory animals. Drug Metab Dispos 1991; 19: 926932.
  • 14
    Chesnut CH 3rd, Silverman S, Andriano K et al. A randomized trial of nasal spray salmon calcitonin in postmenopausal women with established osteoporosis: The prevent recurrence of osteoporotic fractures study. PROOF Study Group. Am J Med 2000; 109: 267276.
  • 15
    Muñoz-Torres M, Alonso G, Raya MP. Calcitonin therapy in osteoporosis. Treat Endocrinol 2004; 3: 117132.
  • 16
    Francis RM, Aspray TJ, Hide G, Sutcliffe AM, Wilkinson P. Back pain in osteoporotic vertebral fractures. Osteoporos Int 2007; 19: 895903.
  • 17
    Bennell KL, Matthews B, Greig A et al. Effects of an exercise and manual therapy program on physical impairments, function and quality-of-life in people with osteoporotic vertebral fracture: A randomised, single-blind controlled pilot trial. BMC Musculoskelet Disord 2010; 11: 36.
  • 18
    Dusdal K, Grundmanis J, Luttin K et al. Effects of therapeutic exercise for persons with osteoporotic vertebral fractures: A systematic review. Osteoporos Int 2011; 22: 755769.
  • 19
    Boonen S, Wahl DA, Nauroy L et al. CSA Fracture Working Group of International Osteoporosis Foundation. Balloon kyphoplasty and vertebroplasty in the management of vertebral compression fractures. Osteoporos Int 2011; 22: 29152934.