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Improvement of trochanteric bone quality in an osteoporosis model after short-term treatment with parathyroid hormone: a new mechanical test for trochanteric region of rat femur.

Tezval M, Stuermer EK, Sehmisch S, Rack T, Stary A, Stebener M, Konietschke F, Stuermer KM - Osteoporos Int (2009)

Bottom Line: We investigated the short-term effects of parathyroid hormone (PTH) and estrogen (E) on the strength of the rat trochanteric region in a new mechanical test.Animals of the PTH group demonstrated a significantly improved trabecular bone structure and area (75.67%) in comparison to the E (61.04%) and C (57.18%) groups.Our results show that the short-term antiosteoporotic effects of PTH are in the trochanteric region of ovariectomized rat superior to E.

View Article: PubMed Central - PubMed

Affiliation: Department of Trauma and Reconstructive Surgery, Georg-August-University of Goettingen, Goettingen, Germany. mtezval@med.uni-goettingen.de

ABSTRACT

Unlabelled: We have examined the changes induced in the trochanteric region of femur of ovariectomized rat after administration of estradiol and parathyroid hormone. We have developed a reproducible biomechanical test and produced trochanteric fractures to evaluate stiffness and strength of this region in addition to histomorphometry.

Introduction: We investigated the short-term effects of parathyroid hormone (PTH) and estrogen (E) on the strength of the rat trochanteric region in a new mechanical test.

Methods: Forty-four 3-month-old female Sprague-Dawley rats were ovariectomized and 8 weeks later treated with soy-free diet (C), daily applications of orally supplied E (0.5 mg/kg food) or subcutaneously injected PTH (0.014 mg/kg), for 5 weeks, and an additional untreated group was added as sham-operated. The femurs were examined for biomechanical and histomorphometric changes.

Results: Our new mechanical test was validated in a right-left comparison. The PTH treatment induced significantly superior biomechanical results (F (max) = 225.3 N, stiffness = 314.9 N/mm) compared to E (F (max) = 182.9 N, stiffness = 237.2 N/mm), C (F (max) = 166.03 N, stiffness = 235.56 N/mm), and sham (F (max) = 192.1 N, stiffness = 267.2 N/mm). Animals of the PTH group demonstrated a significantly improved trabecular bone structure and area (75.67%) in comparison to the E (61.04%) and C (57.18%) groups.

Conclusion: Our new biomechanical test is valid and produces trochanteric fracture. Our results show that the short-term antiosteoporotic effects of PTH are in the trochanteric region of ovariectomized rat superior to E.

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Related in: MedlinePlus

A radiograph of femoral cross section, 11 mm distal from femoral head, to measure bone diameter (B.Dm = ab) and marrow diameter (Ma.Dm = cd). The dorso-ventral line (ab) cuts the horizontal medio-lateral line in the middle of marrow (the histomorphometry software finds this point) and builds a vertical angle (90°). We used the dorso-lateral line for measuring of B.Dm and Ma.Dm because we could observe on this axis the minimal anatomical norm-variations in subtrochanteric region of rat femur. This region is reliable and easy to evaluate
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Fig2: A radiograph of femoral cross section, 11 mm distal from femoral head, to measure bone diameter (B.Dm = ab) and marrow diameter (Ma.Dm = cd). The dorso-ventral line (ab) cuts the horizontal medio-lateral line in the middle of marrow (the histomorphometry software finds this point) and builds a vertical angle (90°). We used the dorso-lateral line for measuring of B.Dm and Ma.Dm because we could observe on this axis the minimal anatomical norm-variations in subtrochanteric region of rat femur. This region is reliable and easy to evaluate

Mentions: It is known that minimal changes in cortical surface occur first a long time after OVX. The Ct.Wi between all of the rat groups shows often a large standard deviation within each group, and the real changes in this region remain difficult to measure. In our study, we measured the ratio between bone diameter and marrow diameter (B.Dm and Ma.Dm according to Parfitt et al. [16]) in the cross sections, 11 mm distal of femoral head in the subtrochanteric region (Fig. 2). We measured at first the B.Dm of the cross sections in a ventro-dorsal direction (in the middle of section) and in a second step on the same line the Ma.Dm. This provides the possibility to avoid many instrumental and operator-dependent errors and it is easy to perform. The B.Dm/Ma.Dm ratio helps us to compare the changes in the cortex of subtrochanteric region of rat femur between all groups.Fig. 2


Improvement of trochanteric bone quality in an osteoporosis model after short-term treatment with parathyroid hormone: a new mechanical test for trochanteric region of rat femur.

Tezval M, Stuermer EK, Sehmisch S, Rack T, Stary A, Stebener M, Konietschke F, Stuermer KM - Osteoporos Int (2009)

A radiograph of femoral cross section, 11 mm distal from femoral head, to measure bone diameter (B.Dm = ab) and marrow diameter (Ma.Dm = cd). The dorso-ventral line (ab) cuts the horizontal medio-lateral line in the middle of marrow (the histomorphometry software finds this point) and builds a vertical angle (90°). We used the dorso-lateral line for measuring of B.Dm and Ma.Dm because we could observe on this axis the minimal anatomical norm-variations in subtrochanteric region of rat femur. This region is reliable and easy to evaluate
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2801842&req=5

Fig2: A radiograph of femoral cross section, 11 mm distal from femoral head, to measure bone diameter (B.Dm = ab) and marrow diameter (Ma.Dm = cd). The dorso-ventral line (ab) cuts the horizontal medio-lateral line in the middle of marrow (the histomorphometry software finds this point) and builds a vertical angle (90°). We used the dorso-lateral line for measuring of B.Dm and Ma.Dm because we could observe on this axis the minimal anatomical norm-variations in subtrochanteric region of rat femur. This region is reliable and easy to evaluate
Mentions: It is known that minimal changes in cortical surface occur first a long time after OVX. The Ct.Wi between all of the rat groups shows often a large standard deviation within each group, and the real changes in this region remain difficult to measure. In our study, we measured the ratio between bone diameter and marrow diameter (B.Dm and Ma.Dm according to Parfitt et al. [16]) in the cross sections, 11 mm distal of femoral head in the subtrochanteric region (Fig. 2). We measured at first the B.Dm of the cross sections in a ventro-dorsal direction (in the middle of section) and in a second step on the same line the Ma.Dm. This provides the possibility to avoid many instrumental and operator-dependent errors and it is easy to perform. The B.Dm/Ma.Dm ratio helps us to compare the changes in the cortex of subtrochanteric region of rat femur between all groups.Fig. 2

Bottom Line: We investigated the short-term effects of parathyroid hormone (PTH) and estrogen (E) on the strength of the rat trochanteric region in a new mechanical test.Animals of the PTH group demonstrated a significantly improved trabecular bone structure and area (75.67%) in comparison to the E (61.04%) and C (57.18%) groups.Our results show that the short-term antiosteoporotic effects of PTH are in the trochanteric region of ovariectomized rat superior to E.

View Article: PubMed Central - PubMed

Affiliation: Department of Trauma and Reconstructive Surgery, Georg-August-University of Goettingen, Goettingen, Germany. mtezval@med.uni-goettingen.de

ABSTRACT

Unlabelled: We have examined the changes induced in the trochanteric region of femur of ovariectomized rat after administration of estradiol and parathyroid hormone. We have developed a reproducible biomechanical test and produced trochanteric fractures to evaluate stiffness and strength of this region in addition to histomorphometry.

Introduction: We investigated the short-term effects of parathyroid hormone (PTH) and estrogen (E) on the strength of the rat trochanteric region in a new mechanical test.

Methods: Forty-four 3-month-old female Sprague-Dawley rats were ovariectomized and 8 weeks later treated with soy-free diet (C), daily applications of orally supplied E (0.5 mg/kg food) or subcutaneously injected PTH (0.014 mg/kg), for 5 weeks, and an additional untreated group was added as sham-operated. The femurs were examined for biomechanical and histomorphometric changes.

Results: Our new mechanical test was validated in a right-left comparison. The PTH treatment induced significantly superior biomechanical results (F (max) = 225.3 N, stiffness = 314.9 N/mm) compared to E (F (max) = 182.9 N, stiffness = 237.2 N/mm), C (F (max) = 166.03 N, stiffness = 235.56 N/mm), and sham (F (max) = 192.1 N, stiffness = 267.2 N/mm). Animals of the PTH group demonstrated a significantly improved trabecular bone structure and area (75.67%) in comparison to the E (61.04%) and C (57.18%) groups.

Conclusion: Our new biomechanical test is valid and produces trochanteric fracture. Our results show that the short-term antiosteoporotic effects of PTH are in the trochanteric region of ovariectomized rat superior to E.

Show MeSH
Related in: MedlinePlus