Arthrofibrosis is a major obstacle to restoring joint function after trauma. The objective of this study was to evaluate montelukast, forskolin, and triamcinolone as possible means of prophylaxis against the formation of arthrofibrosis. Forty-eight rats underwent surgical knee trauma with post-operative immobilization in full flexion. The treatment groups were: control (CTL), oral montelukast (3.75 mg/kg/day) (MLK), intra-articular forskolin injections (0.6 mg/kg) (FSK), and intra-articular triamcinolone injections (0.68 mg/kg) (STR). Rats were sacrificed after 14 days and femorotibial contracture angles were measured with the posterior capsule intact and with the posterior capsule cut. A 0.015Nm extension moment was applied to the knee. All treatment groups had significant reductions in contracture angle compared to the control. Mean contractures with the posterior capsule intact were 32˚(CTL), 20˚(MLK), 22˚(FSK), and 7˚(STR). Contractures with the posterior capsule cut were 28˚(CTL), 19˚(MLK), 20˚(FSK), and 5˚(STR). The STR group was significantly better than FSK and MLK. Triamcinolone injections provided dramatic reductions in stiffness. Both forskolin and montelukast provided significant, though lesser, reductions in stiffness. While the triamcinolone contracture angles were significantly better, the novel treatments of forskolin and montelukast provided encouraging results and should be studied further. ß

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Background Postoperative acromial stress fracture is a troublesome postoperative complication after reverse shoulder arthroplasty. Our study aims to utilize routinely performed preoperative computed tomography scans to identify differences in the material properties of the acromion in patients who did and did not develop a postoperative acromial stress fracture. Methods Treatment records and computed tomography scans for 99 reverse shoulder arthroplasties were collected. Scans were calibrated using a phantom and transferred for post-processing where the acromion, full scapula, and humeral head were isolated. The final segmented model was used to assess acromial volume and volumetric bone mineral density for each region of interest. Results There was no association between age and volumetric bone mineral density in any region of interest (all R2 ≤ 0.048, all p > 0.082). Patients who developed an acromial stress fracture were not significantly different from those who did not in terms of age, acromial volume, or acromial volumetric bone mineral density (all p > 0.559). Patients with known osteoporosis or osteopenia had slightly lower volumetric bone mineral density, but the differences were not significant (all p ≥ 0.072). Conclusion Postoperative acromial fractures following reverse shoulder arthroplasty cannot be predicted by computed tomography-derived volumetric bone mineral density or volume. These mechanical characteristics also do not predictably decrease with age or osteoporosis diagnosis.

A step-economical synthesis of clinprost is reported that concludes with 3 different transition metal-catalyzed reactions: Pd-catalyzed decarboxylation with allylic rearrangement, Rh-catalyzed diene-ene [2+2+1] reaction, and Ru-catalyzed cross-metathesis reaction. The complexity bestowed to the molecule from these reactions converts a readily accessible ester to clinprost without using protecting groups in only 9 total steps.

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