BACKGROUND: Femoral head osteotomy in cases of fractures or degenerative diseases is as a routine surgical procedure. Less duration of the healing period and the creation of minimal fibrous tissue and its replacement with bone tissue can be effective in return to health. OBJECTIVES: The aim of this study was to evaluate the histopathological changes following administration of platelet-rich plasma at the site of  removed femoral head in rabbits. METHODS: Twenty male New Zealand white rabbits were distributed into two groups including: control (underwent femoral head osteotomy, FHO) and treatment (underwent FHO and planting the platelet-rich plasma on surgical site FHO₊ PRP). In both groups after general anesthesia, femoral head was removed using standard method. In group 2, pre-prepared auto log PRP was used at the site of surgery. After eight weeks all animals were euthanised, femur and its  surrounding healing tissues were cut 2cm  far from the head of femur and removed. Slides were prepared from each sample  through serial sectioning and were stained with H&E and Mason Trichrome. Qualitative changes such as granulation tissues, cartilage and bone formation and their organization and timeliness, thickness of collagen fibers and cellular changes were compared. To quantify the changes, whole surface of the Mason Trichrom stained samples underwent scan with ×50 magnifications and then area of different new formation tissues was measured. Average occupancy levels of each tissue, their ratio to whole surface of sample and to each other in two groups were calculated and compared. RESULTS: In PRP treated group ratio of cartilage tissue to granulation tissue and formation of bone to granulation tissue is significantly more than these parameters in control group. Results indicate faster healing on the damaged area in group 2. Also in group 2, cartilage and bone tissues formation in the healing process was more orderly. CONCLUSIONS: PRP could accelerate healing of bone tissue that is cut at the head of the rabbit’s femur. So it seems that the use of PRP as a treatment protocol in these cases could be suggested.

The effects of intra-articular administration of methylprednisolone acetate (MPA) on the healing of full-thickness osteochondral defects and on normal cartilage were evaluated in 8 horses. In group-1 horses (n = 4), a 1-cm-diameter, full-thickness defect was created bilaterally in the articular cartilage on the dorsal distal surface of the radial carpal bone. Cartilage defects were not created in group-2 horses (n = 4). One middle carpal joint was randomly selected in each horse (groups 1 and 2), and treated with an intra-articular injection of 100 mg Of MPA, once a week for 4 treatments. Injections began 1 week after surgery in group-1 horses. The contralateral middle carpal joint received intra-articular injections of an equivalent volume of 0.9% sodium chloride solution (SCS), and served as a control. Horses were evaluated for 16 weeks, then were euthanatized, and the middle carpal joints were examined and photographed. Synovial and articular cartilage specimens were obtained for histologic and histochemical evaluation. Gross morphometric evaluation of the healing defects in group-1 horses revealed that 48.6% of the defect in control joints and 0% of the defect in MPA-treated joints was resurfaced with a smooth, white tissue, histologically confirmed as fibrocartilage. This replacement tissue was a firmly attached fibrocartilage in control joints and a thin fibrous tissue in MPA-treated joints. The articular cartilage in joints treated with MPA had morphologic changes, including chondrocyte cluster formation, loss of palisading architecture, and cellular necrosis in both groups of horses. Histochemical (safranin-0) staining intensity was reduced significantly (P < 0.05) in all layers of articular cartilage in MPA-treated joints in groups 1 and 2. In the replacement tissue, intense safranin-O staining was found only in the chondrocyte clusters deep in the tissue of control joints, confirming fibrocartilage repair. Intra-articular administration of MPA in this dosing regimen thus induced degenerative changes in normal articular cartilage and resulted in histomorphologic changes in the repair of full-thickness articular osteochondral defects in horses.

Arthrotomies of middle carpal joints were done on 13 horses, and a 1-cm partial thickness, round defect was made on the radial facet of both third carpal bones. In one joint, 1-mm diameter 1-cm deep holes were drilled within the defect, and one joint was used as a control. Horses were assigned to 2 groups--group 1 (n = 6 horses), 5 drill holes; group 2 (n = 7 horses), 11 drill holes. At 1 and 3 weeks after surgery, differences between joints in synovial fluid total protein values, WBC counts, or results of mucin precipitate tests were not significant (P = 0.005). Physically and radiographically, horses were the same during the 12 initial weeks they were housed in stalls and the 9 weeks they were kept in paddocks. Twenty-one weeks after surgery, horses were euthanatized. Joints with drill holes had a significantly greater area (P less than 0.05) of healthy fibrocartilage new tissue: group 1--33 to 68% new tissue, compared with 0 to 23% new tissue in controls; and group 2--22 to 64% new tissue, compared with 0 to 37% new tissue in controls. Differences between healing of defects with drill holes in groups 1 and 2 were not significant. Thickness of new tissue over drill holes was 33 to 61% of thickness of cartilage adjacent to the defect, and thickness of tissue between drill holes was 11 to 43% (group 1) and 8 to 79% (group 2) of the thickness of cartilage adjacent to the defect. In all defects with drill holes, new tissue in the form of fibrocartilage was detected deep in drill holes, whereas fibrous tissue was observed superficially and adjacent to drill holes.

In this study, the effects of three different ozonated oils (Sesame, Nigella sativa and Hypericum perforatum) on wound closure rate, healing process and possible complications were examined macroscopically and microscopically. Twenty-one adult Wistar albino female rats were used in the study. Subjects were divided into three groups, early wound healing, (7 days), medium wound healing, (14 days) and late wound healing (21 days). Four full-thickness skin wounds of equal size (10 mm in diameter) were formed on the back regions of all rats. This region was chosen for preventing self-inflicted injuries and reducing external irritation. The wound was left open during the healing process. While the first wound (control) received no treatment in the second wound, ozonated Sesame oil, in the third wound ozonated Nigella sativa oil and in the fourth wound ozonated Hypericum perforatum oil were used. No group obtained parenteral drug administration. First, second and third main groups were euthanized on days 7, 14 and 21, respectively. The wound healing was assessed macroscopically daily. Wound sizes of individual rats were measured with a caliper and digitally photographed every day from the day of injury. After euthanasia, all wound sites of the subjects were evaluated histopathologically.There were no significant differences in wound healing between treatments in the first day 7. On they 14, it was found that the healing was better in the group applied Nigella sativa and Sesame oils (p≤0.05). On day 21 wound healing was completed in all subjects with a resultant of better outcome in Nigella sativa oil treatment compared with others (p≤0.01).In this study the best wound healing outcome was achieved with Nigella sativa oil and Sesame oil where three different minced oils were used.

The objective of the present study was to evaluate the ability of Chitosan to promote induced tibial fracture healing in a rat model. The study was conducted on 14 albino rats divided into two equal groups (seven rats in each group). The first group was considered as a control group. The second group was injected Chitosan solution 0.1 mg/kg into the fracture gap. The progress of healing in each group was evaluated by clinical, radiography, ultrasonography and pathological examinations. The healing process was observed to be superior in the Chitosan group compared to the control one. Chitosan was found to promote healing of injured bone and is suggested to be used in cases of complicated or delayed bone fracture.

A 20-year-old gelding suffering from 10 months of relapsing squamous cell carcinoma (SCC) on the penile sheath wastreated with a natural remedy as surgical intervention was not successful. A daily application of herbal ointment healed theulcer within 21 days. No relapse of ulcer was observed 3 months post heal.

Bilateral osteochondral defects (10 mm2 X 3 mm deep) were created on the distal articular surface of the radial carpal bone of ten, 2- to 3-year-old horses. One defect of each horse was repaired, using a sternal cartilage autograft (treated), and the other was left untreated (control). The horses were exercised on a high-speed treadmill at incrementally increased speed and duration over the course of 12 months. Horses were evaluated arthroscopically at 6 to 7 weeks, and clinical examinations were conducted weekly at exercise. Twelve months after surgery, carpuses of each horse were radiographed and clinically examined prior to euthanasia. A gross pathologic evaluation of each joint was conducted, and samples were collected for histologic, histochemical, histomorphometric, and biochemical evaluation. Radiographically, the grafted joints had more extensive evidence of arthropathy, and clinically, 8 of the 10 horses were more lame in the grafted limb. On the basis of histomorphometry, the repair tissue of the grafted defects contained a greater median percentage of hyaline cartilage (45%) than that of control defects 4.5%), and the control defects contained a greater percentage of fibrocartilage (82%) than did grafted defects (28.5%). A greater median percentage of repair tissue stained with safranin-O in the grafted defects (24.5%) than in the control defects (3.5%). On gross pathologic and histologic evaluation, repair tissue of the control defects had better continuity and was more firmly attached to the subchondral bone than was repair tissue of the grafted defects. Repair tissue of the grafted defects had extensive fissure and flap formation. Histologically, subchondral bone reactivity and fibroplasia was extensive in grafted joints. Repair tissue of grafted defects had a greater percentage of type II collagen (mean sem, 83.5 +/- 2.95%) than did controls (mean, 79.4 3.87%) that was not statistically significant. Hexosamine content was significantly higher (P < 0.05) in repair tissue of the grafted defect (mean, 28.9 +/- 3.00 mg/g of dry weight) vs control (mean, 20.6 +/- 1.85 mg/g of dry weight). On the basis of this experimental model, sternal cartilage autografts cannot be recommended at this time for repair of osteochondral defects in athletic horses.

After removal of 1 metatarsal pad and formation of a granulation tissue bed, free segmental 6- X 8-mm grafts from digital pads were sutured into recessed same-size recipient sites in the granulation tissue. In 5 dogs, the grafted area had been denervated by excision of a segment of the tibial nerve at the level of the tarsus. The grafted area was not denervated in the remaining 5 dogs. In both groups of dogs, the grafts placed around the periphery of the wound healed, blocked ingrowth of delicate epithelium from the surrounding skin, and provided a tough keratinized epithelium that covered the wound's center. As healing progressed, the grafts coalesced as the wounds contracted. Weight bearing resulted in graft expansion to provide functional weight-bearing tissue. Dogs of the denervated group had clinical and histologic evidence of collateral sensory reinnervation of the denervated area. However, with the exception of 1 dog, results of sensory nerve action potential tests indicated that reinnervation may not have been by way of regeneration across the excisional gap in the nerve. Evaluation of reinnervation of the tibial autonomous zone in 2 additional dogs revealed clinical evidence that collateral reinnervation began between 19 and 28 days after nerve excision and progressed proximad to distad. Results of sensory nerve action potential tests indicated that reinnervation may not have been via regeneration across the excision site. Results of fluorescent tracer studies did not have positive findings regarding the route of collateral reinnervation. Segmental paw pad grafts can be used effectively to provide weight-bearing tissue on a dog's limb. With local nerve damage on the distal portion of the limb, collateral innervation can grow into the area to reinnervate tissues, including pad grafts.

Hexosamine concentration, DNA concentration, and [35S]sulfate incorporation for articular cartilage obtained from various sites in the metacarpophalangeal and carpal joints of horses were measured. The same measurements were made on the repair tissue filling full-thickness articular defects in the intermediate carpal bone and on cartilage surrounding partial-thickness defects 6 weeks after the defects were created arthroscopically. Cellularity (measured as DNA concentration), proteoglycan content (measured as hexosamine concentration), and proteoglycan synthesis (measured as [35S]sulfate incorporation) varied according to the site sampled. Cartilage from the transverse ridge of the head of the third metacarpal bone and the radial facet of the third carpal bone had the lowest hexosamine concentration, whereas rate of proteoglycan synthesis was lowest in cartilage from the transverse ridge of the head of the third metacarpal bone and the distal articular surface of the radial carpal bone. Repair tissue filling a full-thickness cartilage defect at 6 weeks was highly cellular. It was low in proteoglycan content, but was actively synthesizing these macromolecules. In contrast, the cartilage surrounding a partial-thickness defect was unchanged 6 weeks after the original defect was made.