Tissue-engineered augmentation of a rotator cuff tendon using a reconstituted collagen scaffold: a histological evaluation in sheep.

To determine if an absorbable collagen scaffold of high porosity would allow rapid tissue in-growth and permit the functional maturation and alignment of tendon-like tissue, scaffolds were sutured to the superficial surface of the infraspinatus tendons of adult sheep. Histology demonstrated complete ingrowth with fibrovascular tissue by 6 weeks and by 12 weeks the scaffold had induced the formation of a layer of dense, regularly-oriented collagenous tissue which significantly increased the thickness of the native tendon. This new tissue was well-integrated into the host tissues at both the bone interface and along the length of the tendon.

Evaluation of effects of sciatic and femoral nerve blocks in sheep undergoing stifle surgery.

The authors evaluated the effects of locally anesthetizing the sciatic and femoral nerves in sheep undergoing stifle (femorotibial) surgery (16 sheep received nerve blocks; 16 sheep underwent a nerve localization procedure but received no nerve blocks). Heart rate, mean arterial blood pressure and end-tidal isoflurane were recorded every 5 min while sheep were anesthetized. At some of the observed time points, the mean heart rate in the sheep that had received no nerve blocks was significantly higher than in the sheep that had received the nerve blocks.

Histocompatibility of photocrosslinked polyanhydrides: a novel in situ forming orthopaedic biomaterial.

Cell-polymer interactions in subcutaneous and bony tissue were examined for a novel class of in situ forming and surface eroding polyanhydride networks. Specifically, photopolymerized disks of several polyanhydride compositions were implanted subcutaneously in rats, and the tissue was analyzed for an inflammatory response. The compositions elicited varied histological responses, ranging from highly active cell layers to moderate fibrous capsules, depending on the degrading polymer composition.