TY  - JOUR
A1  - Schanda, Jakob
A1  - Keibl, Claudia
A1  - Heimel, Patrick
A1  - Monforte, Xavier
A1  - Feichtinger, Xaver
A1  - Teuschl, Andreas
A1  - Baierl, Andreas
A1  - Muschitz, Christian
A1  - Redl, Heinz
A1  - Fialka, Christian
A1  - Mittermayr, Rainer
T1  - Zoledronic Acid Substantially Improves Bone Microarchitecture and Biomechanical Properties After Rotator Cuff Repair in a Rodent Chronic Defect Model
JF  - Am J Sports Med
N2  - Background: Bone mineral density at the humeral head is reduced in patients with chronic rotator cuff tears. Bone loss in the humeral head is associated with repair failure after rotator cuff reconstruction. Bisphosphonates (eg, zoledronic acid) increase bone mineral density.

Hypothesis: Zoledronic acid improves bone mineral density of the humeral head and biomechanical properties of the enthesis after reconstruction of chronic rotator cuff tears in rats.

Study design: Controlled laboratory study.

Methods: A total of 32 male Sprague-Dawley rats underwent unilateral (left) supraspinatus tenotomy with delayed transosseous rotator cuff reconstruction after 3 weeks. All rats were sacrificed 8 weeks after rotator cuff repair. Animals were randomly assigned to 1 of 2 groups. At 1 day after rotator cuff reconstruction, the intervention group was treated with a single subcutaneous dose of zoledronic acid at 100 µg/kg bodyweight, and the control group received 1 mL of subcutaneous saline solution. In 12 animals of each group, micro-computed tomography scans of both shoulders were performed as well as biomechanical testing of the supraspinatus enthesis of both sides. In 4 animals of each group, histological analyses were conducted.

Results: In the intervention group, bone volume fraction (bone volume/total volume [BV/TV]) of the operated side was higher at the lateral humeral head (P = .005) and the medial humeral head (P = .010) compared with the control group. Trabecular number on the operated side was higher at the lateral humeral head (P = .004) and the medial humeral head (P = .001) in the intervention group. Maximum load to failure rates on the operated side were higher in the intervention group (P < .001). Cortical thickness positively correlated with higher maximum load to failure rates in the intervention group (r = 0.69; P = .026). Histological assessment revealed increased bone formation in the intervention group.

Conclusion: Single-dose therapy of zoledronic acid provided an improvement of bone microarchitecture at the humeral head as well as an increase of maximum load to failure rates after transosseous reconstruction of chronic rotator cuff lesions in rats.

Clinical relevance: Zoledronic acid improves bone microarchitecture as well as biomechanical properties after reconstruction of chronic rotator cuff tears in rodents. These results need to be verified in clinical investigations.
KW  - Tissue Engineering
KW  - Rotator Cuff Tears
Y1  - 
VL  - 2020 Jul
IS  - 48 (9)
SP  - 2151
EP  - 2160
ER  - 
TY  - JOUR
A1  - Feichtinger, Xaver
A1  - Monforte, Xavier
A1  - Keibl, Claudia
A1  - Hercher, David
A1  - Schanda, Jakob
A1  - Teuschl, Andreas
A1  - Muschitz, Christian
A1  - Redl, Heinz
A1  - Fialka, Christian
A1  - Mittermayr, Rainer
T1  - Substantial Biomechanical Improvement by Extracorporeal Shockwave Therapy After Surgical Repair of Rodent Chronic Rotator Cuff Tears.
JF  - American Journal of Sports Medicine
KW  - Shockwave Therapy
KW  - Tissue Engineering
KW  - Regeneration
KW  - Surgery
Y1  - 
ER  - 
TY  - JOUR
A1  - Feichtinger, Xaver
A1  - Heimel, Patrick
A1  - Tangl, Stefan
A1  - Keibl, Claudia
A1  - Nürnberger, Sylvia
A1  - Schanda, Jakob Emanuel
A1  - Hercher, David
A1  - Kocijan, Roland
A1  - Redl, Heinz
A1  - Grillari, Johannes
A1  - Fialka, Christian
A1  - Mittermayr, Rainer
T1  - Improved biomechanics in experimental chronic rotator cuff repair after shockwaves is not reflected by bone microarchitecture
JF  - PLoS One
KW  - chronic rotator cuff repair
KW  - bone microarchitecture
Y1  - 
U6  - http://dx.doi.org/10.1371/journal.pone.0262294
VL  - 17
IS  - 1
ER  -