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Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study)
Beni-Suef University Journal of Basic and Applied Sciences xxx (2017) xxx–xxx
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Beni-Suef University Journal of Basic and Applied Sciences journal homepage: www.elsevier.com/locate/bjbas
Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study) M.Z. Fathy a, G.H. Ragab a, M.M. Seif a, S.M. Gadallah b, Salah Deeb c, Nesreen M. Safwat c,⇑ a
Surgery, Anesthesiology and Radiology Dept., Faculty of Veterinary Medicine, Beni-Suef Univ., Beni Suef 62511, Egypt Surgery, Anesthesiology and Radiology Dept., Faculty of Veterinary Medicine, Sadat City Univ., Egypt c Pathology Dept, Faculty of Veterinary Medicine, Beni-Suef Univ., 62511, Egypt b
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Article history: Received 10 June 2017 Received in revised form 23 August 2017 Accepted 8 September 2017 Available online xxxx Keywords: Ilium Canine Experimental study Histopathology
a b s t r a c t The pelvic region has a great importance as it is the connecting ring between the hind limbs and the trunk as well as having special shape. The present study was conducted on 15 adult, mongrel male dogs aged 2– 3 years and weighted 15–20 kg. Iliac shaft fracture was induced experimentally, and the fractured ilium was fixed by Dynamic Compatable Plate (DCP). Fracture healing was evaluated clinically, radiologically and histopahologically. The animals were partially-weight bearing on the limb of operated side 4th day post-operatively and they were full-weight bearing within 17th days post-operatively. The gait was varied from occasional lameness to full function at the 21–28th post-operatively. The results of this study was conducted along 16 weeks confirmed that the internal fixation for fractured ilium using a bone plate and screws had a good fixation and healing and all animals returned to normal gait within short time. Ó 2017 Beni-Suef University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction The pelvic fractures are serious injuries associated with mortality rate ranged from 10% to 50% depending on the severity of the fracture itself, bleeding, as well as presence of soft tissue injuries or absence (Demetriades et al., 2002; Baylis and Norris, 2004). Pelvic fractures represent 22–25% of all fractures recorded among canine population (Piermattei et al., 2006). Iliac fracture is the most common fracture type represented by 46% of all pelvic bones fractures (Betts, 2003; De Camp, 2005 and Prassinos et al., 2007). Recent trend for iliac fracture treatment aimed to achieve an anatomical reduction, short hospital stay, fastest healing and enable the animal return to normal function (Aron, 1998; Shahar, 2000; and Hirvensalo et al., 2007). The objective of this study is to achieve an evaluation for experimentally surgically induced iliac shaft fracture in canine model through clinical, radiological and histopathological investigations 2. Materials and methods
Beni – Suef and Sadat City Universities. It was carried out on 15 adult male apparently healthy mongrel dogs weighting 15–20 kg and aged 2–3 years. Food and water were withheld for a period of 8–12 h before the operation. A prophylactic course of cefotaxime sodium (CefotaxÒ, EPICO, A. R. E) at dose of 4.5 mg/kg body weight was received intravenously prior to the operation. All animals were given pre-operative, subcutaneously injected anthelmintics for external and internal parasites (Iver-mectin super) 2.5 mg/kg body weight. All dogs were pre-medicated with I.V injection of a mixture of atropine sulfate 0.05 mg/kg. (Atropine sulfateÒ 1 mg/ml Med. Co., A. R. E) and diazepam 1 mg/kg. (NeurilÒ 0.5% sol. Memphis Co. for pharm. & chem. Ind. Cairo A.R.E). Anaesthesia was induced immediately through I.V injection of a mixture of Ketamin 10 mg/kg (KetamarÒ 5% sol. Amoun Co. A.R.E) and Xylazine 1 mg/ kg (Xyla-JectÒ 2% ADWIA Co., A.R.E.). The anesthetic depth was maintained with 25 mg/kg b.wt 2.5% thiopental sodium (ThiopentalÒ EPICO, A.R.E.) administrated intravenously if needed and all operated animals were controlled in lateral recumbence (Schmidt-Oechtering and Alef, 1995; Torad, 2000).
2.1. Experimental animal 2.2. Induction of iliac shaft fracture The present work was done at Surgery, anesthesiology, radiology and Pathology departments, faculty of veterinary medicine, ⇑ Corresponding author. E-mail address: [email protected] (N.M. Safwat).
The pelvic region was prepared for aseptic surgery. The prepared area was extends from midline of the sacrum dorsally to an area of the stifle joint distally and from the last rib cranially to the base of the tail caudally. Induction of iliac shaft fracture by
http://dx.doi.org/10.1016/j.bjbas.2017.09.001 2314-8535/Ó 2017 Beni-Suef University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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a lateral approach was performed according to (Piermattei and Johnson, 2004), the skin incision was began from the iliac crest cranially and extended caudally over the greater trochanter of the femur (Fig. 1-1). The incision is continued through the subcutaneous fat and blunt dissection to the gluteal fascia between superficial gluteal muscle and the tensor fascia lata to expose the aponeurosis of middle gluteal muscle. The middle gluteal muscle was retracted dorsally with superficial gluteal muscle while the tensor fasciae lata retracted distally (Fig. 1-2). The deep gluteal muscle was elevated by sharp dissection to expose the lateral surface of the iliac wing and shaft. By using bone hummer and bone chisel, the iliac shaft was completely transverse fractured (Fig. 13). Stabilization of iliac shaft fracture according to (Brinker et al., 2006) following reduction of the fracture ends. A Dynamic Compression Plate (DCP) of six holes and of sufficient length were selected of a minimum of three screws cranially and a minimum 2 screws of 3.5 mm Ø caudally (Fig. 2-1). The plate is contoured by using plate bender to the lateral concave surface of the ilium (Fig. 2-2 and -3). The surgical field was flushed several times by normal saline then irrigation by gentamycin 10%. The surgical wound closed using simple continuous suture pattern and polyglactin 910 (VicrylÒ) No. 0 (Fig. 2-4) for muscles. The continuous interlocked suture pattern was used for skin by silk No. 1 (Fig. 2-5).
2.3. Post-operative care All operated dogs were confined to individual cages along the study. All Dogs were given course of antibiotic (CefotaxÒ) 1 g every 24 h for five days. The skin sutures were removed 10 days postoperatively. 2.3.1. Post-operative Follow up 2.3.1.1. Clinical evaluation. All dogs were subjected to clinical examination daily for the first week and weekly along of the study; include wound drainage, weight bearing capacity, and return to full limb function. 2.3.1.2. Radiographic evaluation. Serial radiographs of the operated pelvis were performed two, four, eight and 16 weeks. Radiographs were evaluated for stability of fixation device, alignment and fracture gap (healing pattern). Radiographs were taken with a standard 30 40 cm F.F.D, at 50–60 kVp and 15–20 mAs in Ventro-dorsal projection. 2.3.1.3. Histopathological evaluation. It was performed for monitoring the different pathological changes that occurred during the healing process of experimentally induced fractured areas.
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Fig. 1. (1) Showing S/C fat (A). (2) Tensor fascia lata (A), Middle gluteal muscle (B) and superficial gluteal muscle (C). (3) Induced iliac shaft fracture (yellow arrow).(For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
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Fig. 2. (1) Selection of suitable plate (2) Using of bone drill. (3) Bone plate after fixation by bone screws (4) The surgical wound closed using simple continuous suture pattern (5) The continuous interlocked suture pattern for skin.
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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M.Z. Fathy et al. / Beni-Suef Univ. J. Basic Appl. Sci. xxx (2017) xxx–xxx
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Fig. 3. (1) Showing the harvested operated fractured iliac shafts (2) Bone samples freed from any surrounding tissues (3) The sagittally sectioned bone samples.
3.1.1.2. After four weeks. Increase in radiographic density at fracture gap (Fig. 5-2).
The operated fractured iliac shafts were harvested at time intervals of one week, two weeks, four weeks, eight weeks and 16 weeks from euthanized dogs Fig. 3-1, the collected bone samples were freed from any surrounding tissues Fig. 3-2, the bone samples were sagittally bisected and examined grossly for periosteal, endosteal reactivity and nature of callus then sawed into small slabs approximately 5 mm thickness Fig. 3-3. The specimens were then fixed in 10% neutral buffered formalin for 48 h. After fixation, bone slabs were decalcified using a buffer solution of 17% EDTA disodium solution (Ethylenediamine tetraAcetic acid disodium salt B.P.93Ò: El Nasr pharmaceutical chemical, Egypt) for one month during which the specimens weekly inspected for signs of complete decalcification (Shibata et al., 2000). After complete decalcification, the specimens were washed in running tap water for 24 h, then dehydrated in ascending grades of ethyl alcohol (70%, 80%, 90% and 96%) (Absolute I, Absolute II and Absolute III), cleared in xylene (xylene I, xylene II and xylene III) and embedded in soft paraffin (paraffin I, paraffin II and paraffin III) then blocked in hard paraffin wax, sectioned 5–7 m and stained with routinely Hematoxylin and Eosin according to (Bancroft and Marilyn, 2008).
3.1.1.3. After eight weeks. The fracture gap is partially disappeared (Fig. 5-3). 3.1.1.4. After 16 weeks. The fracture gap was completely disappeared. (Fig. 5-4). 3.2. Histopathological evaluation of iliac fractures healing process The fundamental bone fracture healing process or repair possess take placed through four overlapping stages: inflammation, soft callus formation, hard callus formation, and final remodeling stage. Our results showed that the initial event occurred at one week post-operation with presence of remnant structures of hematoma which constituted by the presence of many numbers of erythrocytes embedded in remnant fibrin network with disruption of the blood supply in the fracture gap could also be detected between bone ends. Necrotic bony fragments in the fracture gap due to the induced fracture trauma Fig. 6-1. At the 2nd week post operation, there was a prominent feature of inflammatory response represented by presence of many lymphocytes, some neutrophils and macrophages filling the fracture gap as well as appearance of newly formed blood capillaries Fig. 6-2 and -3. At the 4th week post operation, the findings showed an early immature interlacing reticular fibers bridging the fracture gap, the bone ends gradually become enveloped in a fusiform mass of callus containing increasing numbers of blood capillaries Fig. 6-4 and -5. The reticular fibers begin to be differentiated into a fibroblasts which maturated into a more supportive collagen fibrous connective tissue which characterized by spindle shaped nuclei and prominent collagen fibers type II,III which laied down between two fracture edges as initial hard callus formation Fig. 6-4 and -5. At the 8th week post operation, there was a relatively little cartilaginous substance originated from the external callus above
3. Results 3.1. Clinical evaluation All dogs were partially-weight bearing on the operated limb by the second day post-operative (P.o) (Fig. 4-1), these animals were able to stand by the end of the first week P.o (Fig. 4-2), and the animals started to walk within two weeks P.o (Fig. 4-3), finally all dogs return to the full limb function by the end of the 8th weeks (Fig. 4-4). There was no either clinical evidence of infection or adverse reaction. 3.1.1. Sequential radiographic assessment of iliac fracture 3.1.1.1. After two weeks. The radiographs revealed adequate metal implant stability, alignment was good and the fracture gap is appear (low radiodensity) (Fig. 5-1)
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Fig. 4. (1) Showing dog after two days (P.o) (2) Dog after one week (P.o) (3) Dog after two weeks (P.o) (4) Dog after eight weeks (P.o).
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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Fig. 5. (1) Radiographic picture after two weeks (P.o) (2) Radiographic picture after four weeks (P.o) (3) Radiographic picture after eight weeks (P.o) (4) Radiographic picture after 16 weeks (P.o).
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Fig. 6. (1): One week post operation; showing numerous erythrocytes in the fracture gap (FG), and necrotic bone debris (two head black arrow) (H&E; Bar = 200 mm). (2): Two weeks post operation; showing different types of leucocytes in the fracture gap (FG) (H&E; Bar = 100 mm). (3): A higher magnification of the previous picture to show the different leucocytic types; lymphocytes, neutrophils and macrophages (H&E; Bar = 50 mm). (4): Four weeks post operation; showing reticular fibers having blood capillaries (two head yellow arrow) in the fracture gap (FG), adjacent to the newly formed osteoid tissue (one head yellow arrow) (H&E; Bar = 200 mm). (5): A higher magnification of the previous figure to show the reticular fibers which became differentiated into a more supportive collagen fibers invaded by blood capillaries (H&E; Bar = 100 mm). (6): 8 weeks post operation; Showing the beginning of formation of persisting cartilage from the external callus (one head four yellow arrows) (H&E; Bar = 200 mm). (7): 8 weeks post operation; showing the fracture gap filled with cartilaginous tissue (H&E; Bar = 200 mm). (8): A higher magnification of the previous figure to show the beginning of formation of a osteoid tissue adjacent to the newly formed cartilage; osteoid bone tissue (A), osteoblasts (B), and cartilaginous tissue or chondrocytes (C) (H&E; Bar = 50 mm). (9): 16 weeks post operation; showing the beginning of remodeling stage, adjacent normal osteoid tissue (two head black arrow), and presence of newly formed haversian system (one head yellow arrow) (H&E; Bar = 200 mm).
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
M.Z. Fathy et al. / Beni-Suef Univ. J. Basic Appl. Sci. xxx (2017) xxx–xxx
with a vascular invasion of this cartilage below Fig. 6-6. this cartilaginous tissue filled the whole fracture gap Fig. 6-7 and -8. At 16th week post operation, cartilage which was highly vascularized filled the fractured gap. Haversian remodeling began with the formation of resorption cavities that penetrate longitudinally the necrotic fragment ends and approach the newly formed tissue within the fracture gap Fig. 6-9.
4. Discussion Orthopedic surgeons were using the metal plates and screws to stabilize the fractures and occur healing to the fracture gap without any deformity in the bone. Fibroblast is considered as the most prominent cell in fracture healing process which able to produce collagen in the region of the fracture and this mass of collagenous material called a callus which stabilizes the fracture The ilium may be approached either dorsally (Chaffee, 1977) or laterally (Hohn and Janes, 1966). The lateral approach utilizes an incision between the fascia lata muscle and the middle gluteal muscle. The middle gluteal muscle can be elevated from its cranial-most origin on the ilial wing. This finding is in agreement with (Hohn and Janes, 1966). Lateral plating of ilium fractures, plates should therefore be positioned along the ventral border of the ilial wing, where the bone is slightly thicker. Cranially located screws can also be inserted across the sacroiliac joint into the sacral wing to enhance fixation stability this finding in agreement with (Roush and Manley, 1992; Hamilton et al., 2006). On the other hand, the high incidence of screw loosening is likely to be due to suboptimal screw holding power in the thin cortices of the ilium, especially the iliac wing and a recent study showed that screw loosening and subsequent incidence and degree of pelvic canal collapse are less common when the plate is applied along the dorsal rim of the ilium (Breshears et al., 2004). There is no complication appeared after internal fixation of iliac shaft fractures in dogs by lateral bone plate and screws. This finding disagrees with that reported by (Neil, 2011) who stated that complications following internal fixation of iliac shaft fractures in dogs have been described. A recent study reviewing lateral iliac body plating in a small series of cases highlighted complications such as postoperative loss of reduction of the fracture with medial divergence of the hemi pelvis and resultant loss of pelvic canal diameter (100% of cases), and screw loosening. Plate fixation is well suited for iliac shaft fractures (Denny, 1978). Postoperative care should include normal weight bearing with less total activity. This is accomplished best by keeping the dog on a leash for 2– 4 weeks postoperatively. This result is correlated with the recorded by (Denny and Butterworth, 2006). Prognosis following plate fixation of iliac shaft fractures is excellent (Brown and Biggart, 1975; Denny and Butterworth, 2006) Plate fixation also gives a much shorter recovery period, average of 2–3 weeks, compared with an average recovery period of 8– 12 weeks in conservatively managed cases. This result is correlated with the recorded by (Denny, 1978). Radiography was repeated in all cases there was no evidence of implant breakage, loosening or migration. Following the repeat radiographs the pets underwent a progressive return to full activity within 8–12 weeks. This finding is in agreement with that reported by (Denny and Butterworth, 2006). Bone healing is usually seen in 6–12 weeks. Animals should experience an excellent return to function. Generally, plates are not removed after bone healing unless there are problems with the implant (Fitch, 2004).
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Iliac fractures are generally stabilized by open reduction and application of appropriately contoured plates and screws (Breshears et al., 2004). There is no muscular atrophy to gluteal muscle, this result is not in agreement with that recorded by (Brown and Biggart, 1975; Denny, 1978, Remedios and Fries, 1993; Breshears et al., 2004; Fitch, 2004) stated that complications such as post-surgical muscular atrophy can occur following plate and screw stabilization of iliac fractures and osteotomies. While iliac fractures stabilized by plating generally heal without any complications (Denny, 1978), failures are often ascribed to inappropriate implant selection or application (Roush and Manley, 1992). All of the implants that were used in the study were applied according to the recommended technique and without any complications (Kock, 2005; Piermattei et al., 2006). In the current study, 2.7 mm rather than 3.5 mm dynamic compression plates were employed based on previous recommendations (Kock, 2005; Henry, 1985). The larger central section of a 3.5 mm plate would have allowed greater distance between the osteotomy and the adjacent caudal screw where these 2.7 mm constructs failed, but the application of 3.5 mm plates would not have allowed screws to be placed equidistant from the osteotomy due to the larger central section. The prognosis for all flat bone fractures of the pelvis is excellent. Nonunion is rare and return to good function following surgery is usual if alignment is good. Piermattei et al. (2006) and Richard Meeson and Sandra Corr (2011) stated that ilial fractures are most commonly repaired using a lateral plate and screws. However, other fixation methods have been reported Bone plate repair is the most common and successful means of surgical iliac management. Bone is a highly specialized connective tissue providing mechanical support and protecting organ systems from traumatic injury, in spite of their apparent inertia, bones are dynamic organs undergoing constant remodeling throughout life. Unlike most other tissues, bone is capable of repair by regeneration rather than scar formation and the successful repair of a fracture can return the bone both to its original shape and strength (Jubb et al., 2016). The process of fracture repair follows a consistent pattern, but can be modified by methods of stabilization and by interfering factors, such as infection or an underlying bone disease (Jubb et al., 2016). In this study the experimentally induced bone fracture was a aseptic simple iliac shaft fracture, where the fracture repair one week postoperatively constituted of prominent hemorrhagic areas containing many numbers of erythrocytes embedded inside fibrin network that is to say a hematoma formation which agreed with Kalfas (2001) who stated that a hematoma develops within the fracture site during the first few hours. Moreover the presence of some necrotic bony debris in fracture gap was due to the trauma by which the fracture was induced. As a consequent process two weeks post operation the fracture gap was filled by massive numbers of leucocytes mainly lymphocytes which considered the inflammatory stage of fracture healing process possess just after hematoma formation such cells act as chemotactic factor to other cell types at the site of the fracture such results coincide with that of Kalfas (2001) who stated that the inflammatory cells (macrophages, monocytes, lymphocytes, and poly morph nuclear cells) and fibroblasts infiltrate the bone under prostaglandin mediation resulting in the formation of granulation tissue and ingrowth of vascular tissue for nutrient and oxygen supply. Additionally an acute inflammatory response is triggered by mediators released from the hematoma and the necrotic tissues which responsible for the presence of leucocytes in the fracture gap as neutrophils, macrophages and lymphocytes which secrete
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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cytokines and growth factors that attract multipotential mesenchymal stem cells to the site from the periosteum, bone marrow, and potentially other sites as beginning of soft callus formation (Jubb et al., 2016). Our results revealed that the inflammatory response occurs, as a subsequent stage in which angiogenesis develops and granulation tissue appeared prominently at four weeks post operation as beginning of hard callus formation. Callus formation is composed of randomly arranged collagen bundles and irregularly shaped vascular spaces lined with osteoblasts (Bolander, 1992). During the repairing stage, fibroblasts begin to lay down a stroma that helps support vascular ingrowth. As vascular ingrowth progresses, a collagen matrix is laid down while osteoid is secreted and subsequently mineralized which leads to the formation of a hardcallus around the repair site (Buckwalter et al., 1996). In subsequent stages, cartilage begins to be form at 8 weeks post operatively. Cartilage calcification (endochondral ossification), removal of cartilage and bone formation and ultimately bone remodeling occurs. Finally, the original structure and strength of the bone are restored over months to years (Jubb et al., 2016). Fracture healing is completed during the remodeling stage in which the healed boneis restored to its original shape, structure, and mechanical strength; Remodeling of the bone occurs slowly over months to years and is facilitated by mechanical stress placed on the bone. As the fracture site is exposed to an axial loading force, bone is generally laid down where it is needed and resorbed from where it is not needed. Adequate strength is typically achieved in 3–6 months (Kalfas, 2001). In conclusion, surgical repair of pelvic fractures is of great interest, surgically and pathologically, it requires anatomic reduction, application of stable implants based on knowledge of pelvic biomechanics and early ambulation, facilitate such knowledge athletic recovery. Improvement in our understanding of pelvic fracture biomechanics and patho-morphologic has improved the available repair techniques and prognosis. Conflict of interest None declared. Acknowledgements The authors are grateful to owners of private farms and faculty of veterinary medicine, Beni-Suef University.
References Aron, D.N., 1998. Practical techniques for fractures. In: Bojrab M.J. (Ed.), Current Techniques in Small Animal Surgery, 4th Ed., Philadelphia, pp. 934–941. Bancroft, J.D., Marilyn, G., 2008. Theory and practice of histological techquines, 6th Ed., North Hollywood, CA, USA. Baylis, T.B., Norris, B.L., 2004. Pelvic fractures and the general surgeon. Curr. Surg. 61, 30–35. Betts, C.W., 2003. Pelvic Fractures. In: Slatter, D. (Ed.), Textbook of Small Animal Surgery. 2nd Ed. W.B. Saunders Co., Philadelphia, pp. 1769–1786.
Bolander, M.E., 1992. Regulation of fracture repair by growth factors. Proc. Soc. Exp. Biol. Med. 200 (2), 165–170. Breshears, L.A., Fitch, R.B., Wallace, L.J., et al., 2004. The radiographic evaluation of repaired canine ilial fractures (69 cases). Vet. Comp. Orthop. Traumatol. 17, 64– 72. Brinker, W.O., Piermattei, D.L., Flo, G.L., 2006. Fractures of the pelvis. In: Handbook of Small Animal Orthopaedics and Fracture Repair. 4th ed. WB Saunders, Philadelphia, pp. 443–460. Brown, G.S., Biggart, J.E., 1975. Plate fixation of iliac shaft fractures in the dog. J. Am. Vet. Med. Assoc. 167, 472–479. Buckwalter, J.A., et al., 1996. Healing of the musculoskeletal tissues, in Rockwood and Green’s Fractures in Adults Lippincott-Raven, Philadelphia, pp. 261–304. Chaffee, V.W., 1977. Dorsolateral approach to the canine pelvis. Vet. Med. [Small Anim Pract] 72, 1319. DeCamp, C., 2005. Fractures of the ilium. In: Johnson, A.L., Houlton, J.E.F., Vannini, R. (Eds.), AO Principles of Fracture Management in the Dog and Cat Stuttgart. Thieme AO publishing, Germany, p. 171. Demetriades, D., Karaiskakis, M., Toutouzas, K., 2002. Pelvic fractures: epidemiology and predictors of associated abdominal injuries and outcomes. J. Am. Coll. Surg. 195, 1–10. Denny, R.H., Butterworth, J.S., 2006. A Guide to Canine and Feline Orthopaedic Surgery. Blackwell Printed and bound by Replika Press Pvt Ltd, India. Denny, H.R., 1978. Pelvic fractures in the dog: a review of 123 cases. J. Small Anim. Pract. 19, 151–155. Fitch, R.B., 2004. Incorporating Ventral Fixation Into Ilial Fracture Repairs. ACVS Surgical Summit meeting, Denver CO. Hamilton, M.H., et al., 2006. A review of feline ilial fractures repaired by lateral plating and the use of a dorsal plate as an alternative method of repair, Proceedings of the ECVS meeting, Seville, Spain, pp. 314–317. Henry, W.B., 1985. A method of bone plating for repairing iliac and acetabular fractures. Comp. Cont. Ed. Prac. Vet. 7, 924–940. Hohn, R.B., Janes, J.M., 1966. Lateral approach to the canine ilium. J. Am. Anim. Hosp. Assoc. 2, 111. Jubb, K.V.F., Kennedy, P.C., Palmer, N., 2016. Pathology of domestic animals. Saunders, Elsevier, Pheladelphia. Kalfas, I.H., 2001. Principles of bone healing. Neurosurg Focus 10 (4). Article 1, Department of Neurosurgery, Section of Spinal Surgery, Cleveland Clinic Foundation, Cleveland, Ohio. Kock, D., 2005. Screws and plates. In: Johnson, A.L., Houlton, J.E.F., Vannini, R. (Eds.), AO Principles of Fracture Management in the Dog and Cat. AO publishing, Clavadelerstrasse, Switzerland. Neil, J.B., 2011. Composite fixation of comminuted ilial wing fractures in cats: three cases. J. Feline Med. Surg. 13, 376–438. Piermattei, D.L., Johnson, K.A., 2004. An Atlas of Surgical Approaches to the Bones and Joints of the Dog and the Cat. WB Saunders, Philadelphia. Piermattei, D.L., Flo, G.L., DeCamp, C.E., 2006. Fractures of the Pelvis. In: Handbook of Small Animal Orthopaedics and Fracture Treatment. 4th ed. Saunders Elsevier, St Louis, Missouri, pp. 433–460. Prassinos, N.N., Adamama-, K.K., Gouletsou, P.G., Rallis, T.S., 2007. Symphyseal distraction-osteotomy using a novel spacer of spirally fashioned orthopaedic wire for the management of obstipation. J. Feline Med. Surg. 9, 23–28. Remedios, A., Fries, C., 1993. Implant complications in 20 triple pelvic osteotomies. Vet. Comp. Orthop. Traumatol. 1993 (6), 202–207. Meeson, Richard, Corr, Sandra, 2011. Management of pelvic trauma neurological damage, urinary tractdisruption and pelvic fractures. Clinical review. JFMS Clin. Pract. 2011 (13), 347–361. Roush, J.K., Manley, P.A., 1992. Mini plate failure after repair of ilial and acetabular fractures in 9 small dogs and 1 cat. J. Am. Anim. Hosp. Assoc. 28, 112–118. Schmidt-Oechtering, Alef, 1995. neue aspekte der veterinaranasthesia und intensivertherapie. Blackwell wissenschafts-Verlag, Berlin. Shahar, R., 2000. Relative stiffness and stress of type I and type II external fixators: Acrylic versus stainless-steel connecting bars-a theoretical approach. Vet. Surg. 29, 59–69. Shibata, Y., Fujita, S., Takahashi, H., Yamaguchi, A., Koji, T., 2000. Assessment of decalcifying protocols for detection of specific RNA by non-radioactive site hybridization in calcified tissue. Histochem. Cell Biol. 113, 153–159. Torad, F.M., 2000. Evaluation of some anaesthestic techniques in pet animal under local circumstances. M.V.Sc, surgery, anaesthesiology and radiology. Fac. Vet. Med. Cairo Univ.
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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Beni-Suef University Journal of Basic and Applied Sciences journal homepage: www.elsevier.com/locate/bjbas
Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study) M.Z. Fathy a, G.H. Ragab a, M.M. Seif a, S.M. Gadallah b, Salah Deeb c, Nesreen M. Safwat c,⇑ a
Surgery, Anesthesiology and Radiology Dept., Faculty of Veterinary Medicine, Beni-Suef Univ., Beni Suef 62511, Egypt Surgery, Anesthesiology and Radiology Dept., Faculty of Veterinary Medicine, Sadat City Univ., Egypt c Pathology Dept, Faculty of Veterinary Medicine, Beni-Suef Univ., 62511, Egypt b
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Article history: Received 10 June 2017 Received in revised form 23 August 2017 Accepted 8 September 2017 Available online xxxx Keywords: Ilium Canine Experimental study Histopathology
a b s t r a c t The pelvic region has a great importance as it is the connecting ring between the hind limbs and the trunk as well as having special shape. The present study was conducted on 15 adult, mongrel male dogs aged 2– 3 years and weighted 15–20 kg. Iliac shaft fracture was induced experimentally, and the fractured ilium was fixed by Dynamic Compatable Plate (DCP). Fracture healing was evaluated clinically, radiologically and histopahologically. The animals were partially-weight bearing on the limb of operated side 4th day post-operatively and they were full-weight bearing within 17th days post-operatively. The gait was varied from occasional lameness to full function at the 21–28th post-operatively. The results of this study was conducted along 16 weeks confirmed that the internal fixation for fractured ilium using a bone plate and screws had a good fixation and healing and all animals returned to normal gait within short time. Ó 2017 Beni-Suef University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
1. Introduction The pelvic fractures are serious injuries associated with mortality rate ranged from 10% to 50% depending on the severity of the fracture itself, bleeding, as well as presence of soft tissue injuries or absence (Demetriades et al., 2002; Baylis and Norris, 2004). Pelvic fractures represent 22–25% of all fractures recorded among canine population (Piermattei et al., 2006). Iliac fracture is the most common fracture type represented by 46% of all pelvic bones fractures (Betts, 2003; De Camp, 2005 and Prassinos et al., 2007). Recent trend for iliac fracture treatment aimed to achieve an anatomical reduction, short hospital stay, fastest healing and enable the animal return to normal function (Aron, 1998; Shahar, 2000; and Hirvensalo et al., 2007). The objective of this study is to achieve an evaluation for experimentally surgically induced iliac shaft fracture in canine model through clinical, radiological and histopathological investigations 2. Materials and methods
Beni – Suef and Sadat City Universities. It was carried out on 15 adult male apparently healthy mongrel dogs weighting 15–20 kg and aged 2–3 years. Food and water were withheld for a period of 8–12 h before the operation. A prophylactic course of cefotaxime sodium (CefotaxÒ, EPICO, A. R. E) at dose of 4.5 mg/kg body weight was received intravenously prior to the operation. All animals were given pre-operative, subcutaneously injected anthelmintics for external and internal parasites (Iver-mectin super) 2.5 mg/kg body weight. All dogs were pre-medicated with I.V injection of a mixture of atropine sulfate 0.05 mg/kg. (Atropine sulfateÒ 1 mg/ml Med. Co., A. R. E) and diazepam 1 mg/kg. (NeurilÒ 0.5% sol. Memphis Co. for pharm. & chem. Ind. Cairo A.R.E). Anaesthesia was induced immediately through I.V injection of a mixture of Ketamin 10 mg/kg (KetamarÒ 5% sol. Amoun Co. A.R.E) and Xylazine 1 mg/ kg (Xyla-JectÒ 2% ADWIA Co., A.R.E.). The anesthetic depth was maintained with 25 mg/kg b.wt 2.5% thiopental sodium (ThiopentalÒ EPICO, A.R.E.) administrated intravenously if needed and all operated animals were controlled in lateral recumbence (Schmidt-Oechtering and Alef, 1995; Torad, 2000).
2.1. Experimental animal 2.2. Induction of iliac shaft fracture The present work was done at Surgery, anesthesiology, radiology and Pathology departments, faculty of veterinary medicine, ⇑ Corresponding author. E-mail address: [email protected] (N.M. Safwat).
The pelvic region was prepared for aseptic surgery. The prepared area was extends from midline of the sacrum dorsally to an area of the stifle joint distally and from the last rib cranially to the base of the tail caudally. Induction of iliac shaft fracture by
http://dx.doi.org/10.1016/j.bjbas.2017.09.001 2314-8535/Ó 2017 Beni-Suef University. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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a lateral approach was performed according to (Piermattei and Johnson, 2004), the skin incision was began from the iliac crest cranially and extended caudally over the greater trochanter of the femur (Fig. 1-1). The incision is continued through the subcutaneous fat and blunt dissection to the gluteal fascia between superficial gluteal muscle and the tensor fascia lata to expose the aponeurosis of middle gluteal muscle. The middle gluteal muscle was retracted dorsally with superficial gluteal muscle while the tensor fasciae lata retracted distally (Fig. 1-2). The deep gluteal muscle was elevated by sharp dissection to expose the lateral surface of the iliac wing and shaft. By using bone hummer and bone chisel, the iliac shaft was completely transverse fractured (Fig. 13). Stabilization of iliac shaft fracture according to (Brinker et al., 2006) following reduction of the fracture ends. A Dynamic Compression Plate (DCP) of six holes and of sufficient length were selected of a minimum of three screws cranially and a minimum 2 screws of 3.5 mm Ø caudally (Fig. 2-1). The plate is contoured by using plate bender to the lateral concave surface of the ilium (Fig. 2-2 and -3). The surgical field was flushed several times by normal saline then irrigation by gentamycin 10%. The surgical wound closed using simple continuous suture pattern and polyglactin 910 (VicrylÒ) No. 0 (Fig. 2-4) for muscles. The continuous interlocked suture pattern was used for skin by silk No. 1 (Fig. 2-5).
2.3. Post-operative care All operated dogs were confined to individual cages along the study. All Dogs were given course of antibiotic (CefotaxÒ) 1 g every 24 h for five days. The skin sutures were removed 10 days postoperatively. 2.3.1. Post-operative Follow up 2.3.1.1. Clinical evaluation. All dogs were subjected to clinical examination daily for the first week and weekly along of the study; include wound drainage, weight bearing capacity, and return to full limb function. 2.3.1.2. Radiographic evaluation. Serial radiographs of the operated pelvis were performed two, four, eight and 16 weeks. Radiographs were evaluated for stability of fixation device, alignment and fracture gap (healing pattern). Radiographs were taken with a standard 30 40 cm F.F.D, at 50–60 kVp and 15–20 mAs in Ventro-dorsal projection. 2.3.1.3. Histopathological evaluation. It was performed for monitoring the different pathological changes that occurred during the healing process of experimentally induced fractured areas.
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Fig. 1. (1) Showing S/C fat (A). (2) Tensor fascia lata (A), Middle gluteal muscle (B) and superficial gluteal muscle (C). (3) Induced iliac shaft fracture (yellow arrow).(For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)
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Fig. 2. (1) Selection of suitable plate (2) Using of bone drill. (3) Bone plate after fixation by bone screws (4) The surgical wound closed using simple continuous suture pattern (5) The continuous interlocked suture pattern for skin.
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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Fig. 3. (1) Showing the harvested operated fractured iliac shafts (2) Bone samples freed from any surrounding tissues (3) The sagittally sectioned bone samples.
3.1.1.2. After four weeks. Increase in radiographic density at fracture gap (Fig. 5-2).
The operated fractured iliac shafts were harvested at time intervals of one week, two weeks, four weeks, eight weeks and 16 weeks from euthanized dogs Fig. 3-1, the collected bone samples were freed from any surrounding tissues Fig. 3-2, the bone samples were sagittally bisected and examined grossly for periosteal, endosteal reactivity and nature of callus then sawed into small slabs approximately 5 mm thickness Fig. 3-3. The specimens were then fixed in 10% neutral buffered formalin for 48 h. After fixation, bone slabs were decalcified using a buffer solution of 17% EDTA disodium solution (Ethylenediamine tetraAcetic acid disodium salt B.P.93Ò: El Nasr pharmaceutical chemical, Egypt) for one month during which the specimens weekly inspected for signs of complete decalcification (Shibata et al., 2000). After complete decalcification, the specimens were washed in running tap water for 24 h, then dehydrated in ascending grades of ethyl alcohol (70%, 80%, 90% and 96%) (Absolute I, Absolute II and Absolute III), cleared in xylene (xylene I, xylene II and xylene III) and embedded in soft paraffin (paraffin I, paraffin II and paraffin III) then blocked in hard paraffin wax, sectioned 5–7 m and stained with routinely Hematoxylin and Eosin according to (Bancroft and Marilyn, 2008).
3.1.1.3. After eight weeks. The fracture gap is partially disappeared (Fig. 5-3). 3.1.1.4. After 16 weeks. The fracture gap was completely disappeared. (Fig. 5-4). 3.2. Histopathological evaluation of iliac fractures healing process The fundamental bone fracture healing process or repair possess take placed through four overlapping stages: inflammation, soft callus formation, hard callus formation, and final remodeling stage. Our results showed that the initial event occurred at one week post-operation with presence of remnant structures of hematoma which constituted by the presence of many numbers of erythrocytes embedded in remnant fibrin network with disruption of the blood supply in the fracture gap could also be detected between bone ends. Necrotic bony fragments in the fracture gap due to the induced fracture trauma Fig. 6-1. At the 2nd week post operation, there was a prominent feature of inflammatory response represented by presence of many lymphocytes, some neutrophils and macrophages filling the fracture gap as well as appearance of newly formed blood capillaries Fig. 6-2 and -3. At the 4th week post operation, the findings showed an early immature interlacing reticular fibers bridging the fracture gap, the bone ends gradually become enveloped in a fusiform mass of callus containing increasing numbers of blood capillaries Fig. 6-4 and -5. The reticular fibers begin to be differentiated into a fibroblasts which maturated into a more supportive collagen fibrous connective tissue which characterized by spindle shaped nuclei and prominent collagen fibers type II,III which laied down between two fracture edges as initial hard callus formation Fig. 6-4 and -5. At the 8th week post operation, there was a relatively little cartilaginous substance originated from the external callus above
3. Results 3.1. Clinical evaluation All dogs were partially-weight bearing on the operated limb by the second day post-operative (P.o) (Fig. 4-1), these animals were able to stand by the end of the first week P.o (Fig. 4-2), and the animals started to walk within two weeks P.o (Fig. 4-3), finally all dogs return to the full limb function by the end of the 8th weeks (Fig. 4-4). There was no either clinical evidence of infection or adverse reaction. 3.1.1. Sequential radiographic assessment of iliac fracture 3.1.1.1. After two weeks. The radiographs revealed adequate metal implant stability, alignment was good and the fracture gap is appear (low radiodensity) (Fig. 5-1)
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Fig. 4. (1) Showing dog after two days (P.o) (2) Dog after one week (P.o) (3) Dog after two weeks (P.o) (4) Dog after eight weeks (P.o).
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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Fig. 5. (1) Radiographic picture after two weeks (P.o) (2) Radiographic picture after four weeks (P.o) (3) Radiographic picture after eight weeks (P.o) (4) Radiographic picture after 16 weeks (P.o).
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Fig. 6. (1): One week post operation; showing numerous erythrocytes in the fracture gap (FG), and necrotic bone debris (two head black arrow) (H&E; Bar = 200 mm). (2): Two weeks post operation; showing different types of leucocytes in the fracture gap (FG) (H&E; Bar = 100 mm). (3): A higher magnification of the previous picture to show the different leucocytic types; lymphocytes, neutrophils and macrophages (H&E; Bar = 50 mm). (4): Four weeks post operation; showing reticular fibers having blood capillaries (two head yellow arrow) in the fracture gap (FG), adjacent to the newly formed osteoid tissue (one head yellow arrow) (H&E; Bar = 200 mm). (5): A higher magnification of the previous figure to show the reticular fibers which became differentiated into a more supportive collagen fibers invaded by blood capillaries (H&E; Bar = 100 mm). (6): 8 weeks post operation; Showing the beginning of formation of persisting cartilage from the external callus (one head four yellow arrows) (H&E; Bar = 200 mm). (7): 8 weeks post operation; showing the fracture gap filled with cartilaginous tissue (H&E; Bar = 200 mm). (8): A higher magnification of the previous figure to show the beginning of formation of a osteoid tissue adjacent to the newly formed cartilage; osteoid bone tissue (A), osteoblasts (B), and cartilaginous tissue or chondrocytes (C) (H&E; Bar = 50 mm). (9): 16 weeks post operation; showing the beginning of remodeling stage, adjacent normal osteoid tissue (two head black arrow), and presence of newly formed haversian system (one head yellow arrow) (H&E; Bar = 200 mm).
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
M.Z. Fathy et al. / Beni-Suef Univ. J. Basic Appl. Sci. xxx (2017) xxx–xxx
with a vascular invasion of this cartilage below Fig. 6-6. this cartilaginous tissue filled the whole fracture gap Fig. 6-7 and -8. At 16th week post operation, cartilage which was highly vascularized filled the fractured gap. Haversian remodeling began with the formation of resorption cavities that penetrate longitudinally the necrotic fragment ends and approach the newly formed tissue within the fracture gap Fig. 6-9.
4. Discussion Orthopedic surgeons were using the metal plates and screws to stabilize the fractures and occur healing to the fracture gap without any deformity in the bone. Fibroblast is considered as the most prominent cell in fracture healing process which able to produce collagen in the region of the fracture and this mass of collagenous material called a callus which stabilizes the fracture The ilium may be approached either dorsally (Chaffee, 1977) or laterally (Hohn and Janes, 1966). The lateral approach utilizes an incision between the fascia lata muscle and the middle gluteal muscle. The middle gluteal muscle can be elevated from its cranial-most origin on the ilial wing. This finding is in agreement with (Hohn and Janes, 1966). Lateral plating of ilium fractures, plates should therefore be positioned along the ventral border of the ilial wing, where the bone is slightly thicker. Cranially located screws can also be inserted across the sacroiliac joint into the sacral wing to enhance fixation stability this finding in agreement with (Roush and Manley, 1992; Hamilton et al., 2006). On the other hand, the high incidence of screw loosening is likely to be due to suboptimal screw holding power in the thin cortices of the ilium, especially the iliac wing and a recent study showed that screw loosening and subsequent incidence and degree of pelvic canal collapse are less common when the plate is applied along the dorsal rim of the ilium (Breshears et al., 2004). There is no complication appeared after internal fixation of iliac shaft fractures in dogs by lateral bone plate and screws. This finding disagrees with that reported by (Neil, 2011) who stated that complications following internal fixation of iliac shaft fractures in dogs have been described. A recent study reviewing lateral iliac body plating in a small series of cases highlighted complications such as postoperative loss of reduction of the fracture with medial divergence of the hemi pelvis and resultant loss of pelvic canal diameter (100% of cases), and screw loosening. Plate fixation is well suited for iliac shaft fractures (Denny, 1978). Postoperative care should include normal weight bearing with less total activity. This is accomplished best by keeping the dog on a leash for 2– 4 weeks postoperatively. This result is correlated with the recorded by (Denny and Butterworth, 2006). Prognosis following plate fixation of iliac shaft fractures is excellent (Brown and Biggart, 1975; Denny and Butterworth, 2006) Plate fixation also gives a much shorter recovery period, average of 2–3 weeks, compared with an average recovery period of 8– 12 weeks in conservatively managed cases. This result is correlated with the recorded by (Denny, 1978). Radiography was repeated in all cases there was no evidence of implant breakage, loosening or migration. Following the repeat radiographs the pets underwent a progressive return to full activity within 8–12 weeks. This finding is in agreement with that reported by (Denny and Butterworth, 2006). Bone healing is usually seen in 6–12 weeks. Animals should experience an excellent return to function. Generally, plates are not removed after bone healing unless there are problems with the implant (Fitch, 2004).
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Iliac fractures are generally stabilized by open reduction and application of appropriately contoured plates and screws (Breshears et al., 2004). There is no muscular atrophy to gluteal muscle, this result is not in agreement with that recorded by (Brown and Biggart, 1975; Denny, 1978, Remedios and Fries, 1993; Breshears et al., 2004; Fitch, 2004) stated that complications such as post-surgical muscular atrophy can occur following plate and screw stabilization of iliac fractures and osteotomies. While iliac fractures stabilized by plating generally heal without any complications (Denny, 1978), failures are often ascribed to inappropriate implant selection or application (Roush and Manley, 1992). All of the implants that were used in the study were applied according to the recommended technique and without any complications (Kock, 2005; Piermattei et al., 2006). In the current study, 2.7 mm rather than 3.5 mm dynamic compression plates were employed based on previous recommendations (Kock, 2005; Henry, 1985). The larger central section of a 3.5 mm plate would have allowed greater distance between the osteotomy and the adjacent caudal screw where these 2.7 mm constructs failed, but the application of 3.5 mm plates would not have allowed screws to be placed equidistant from the osteotomy due to the larger central section. The prognosis for all flat bone fractures of the pelvis is excellent. Nonunion is rare and return to good function following surgery is usual if alignment is good. Piermattei et al. (2006) and Richard Meeson and Sandra Corr (2011) stated that ilial fractures are most commonly repaired using a lateral plate and screws. However, other fixation methods have been reported Bone plate repair is the most common and successful means of surgical iliac management. Bone is a highly specialized connective tissue providing mechanical support and protecting organ systems from traumatic injury, in spite of their apparent inertia, bones are dynamic organs undergoing constant remodeling throughout life. Unlike most other tissues, bone is capable of repair by regeneration rather than scar formation and the successful repair of a fracture can return the bone both to its original shape and strength (Jubb et al., 2016). The process of fracture repair follows a consistent pattern, but can be modified by methods of stabilization and by interfering factors, such as infection or an underlying bone disease (Jubb et al., 2016). In this study the experimentally induced bone fracture was a aseptic simple iliac shaft fracture, where the fracture repair one week postoperatively constituted of prominent hemorrhagic areas containing many numbers of erythrocytes embedded inside fibrin network that is to say a hematoma formation which agreed with Kalfas (2001) who stated that a hematoma develops within the fracture site during the first few hours. Moreover the presence of some necrotic bony debris in fracture gap was due to the trauma by which the fracture was induced. As a consequent process two weeks post operation the fracture gap was filled by massive numbers of leucocytes mainly lymphocytes which considered the inflammatory stage of fracture healing process possess just after hematoma formation such cells act as chemotactic factor to other cell types at the site of the fracture such results coincide with that of Kalfas (2001) who stated that the inflammatory cells (macrophages, monocytes, lymphocytes, and poly morph nuclear cells) and fibroblasts infiltrate the bone under prostaglandin mediation resulting in the formation of granulation tissue and ingrowth of vascular tissue for nutrient and oxygen supply. Additionally an acute inflammatory response is triggered by mediators released from the hematoma and the necrotic tissues which responsible for the presence of leucocytes in the fracture gap as neutrophils, macrophages and lymphocytes which secrete
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001
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cytokines and growth factors that attract multipotential mesenchymal stem cells to the site from the periosteum, bone marrow, and potentially other sites as beginning of soft callus formation (Jubb et al., 2016). Our results revealed that the inflammatory response occurs, as a subsequent stage in which angiogenesis develops and granulation tissue appeared prominently at four weeks post operation as beginning of hard callus formation. Callus formation is composed of randomly arranged collagen bundles and irregularly shaped vascular spaces lined with osteoblasts (Bolander, 1992). During the repairing stage, fibroblasts begin to lay down a stroma that helps support vascular ingrowth. As vascular ingrowth progresses, a collagen matrix is laid down while osteoid is secreted and subsequently mineralized which leads to the formation of a hardcallus around the repair site (Buckwalter et al., 1996). In subsequent stages, cartilage begins to be form at 8 weeks post operatively. Cartilage calcification (endochondral ossification), removal of cartilage and bone formation and ultimately bone remodeling occurs. Finally, the original structure and strength of the bone are restored over months to years (Jubb et al., 2016). Fracture healing is completed during the remodeling stage in which the healed boneis restored to its original shape, structure, and mechanical strength; Remodeling of the bone occurs slowly over months to years and is facilitated by mechanical stress placed on the bone. As the fracture site is exposed to an axial loading force, bone is generally laid down where it is needed and resorbed from where it is not needed. Adequate strength is typically achieved in 3–6 months (Kalfas, 2001). In conclusion, surgical repair of pelvic fractures is of great interest, surgically and pathologically, it requires anatomic reduction, application of stable implants based on knowledge of pelvic biomechanics and early ambulation, facilitate such knowledge athletic recovery. Improvement in our understanding of pelvic fracture biomechanics and patho-morphologic has improved the available repair techniques and prognosis. Conflict of interest None declared. Acknowledgements The authors are grateful to owners of private farms and faculty of veterinary medicine, Beni-Suef University.
References Aron, D.N., 1998. Practical techniques for fractures. In: Bojrab M.J. (Ed.), Current Techniques in Small Animal Surgery, 4th Ed., Philadelphia, pp. 934–941. Bancroft, J.D., Marilyn, G., 2008. Theory and practice of histological techquines, 6th Ed., North Hollywood, CA, USA. Baylis, T.B., Norris, B.L., 2004. Pelvic fractures and the general surgeon. Curr. Surg. 61, 30–35. Betts, C.W., 2003. Pelvic Fractures. In: Slatter, D. (Ed.), Textbook of Small Animal Surgery. 2nd Ed. W.B. Saunders Co., Philadelphia, pp. 1769–1786.
Bolander, M.E., 1992. Regulation of fracture repair by growth factors. Proc. Soc. Exp. Biol. Med. 200 (2), 165–170. Breshears, L.A., Fitch, R.B., Wallace, L.J., et al., 2004. The radiographic evaluation of repaired canine ilial fractures (69 cases). Vet. Comp. Orthop. Traumatol. 17, 64– 72. Brinker, W.O., Piermattei, D.L., Flo, G.L., 2006. Fractures of the pelvis. In: Handbook of Small Animal Orthopaedics and Fracture Repair. 4th ed. WB Saunders, Philadelphia, pp. 443–460. Brown, G.S., Biggart, J.E., 1975. Plate fixation of iliac shaft fractures in the dog. J. Am. Vet. Med. Assoc. 167, 472–479. Buckwalter, J.A., et al., 1996. Healing of the musculoskeletal tissues, in Rockwood and Green’s Fractures in Adults Lippincott-Raven, Philadelphia, pp. 261–304. Chaffee, V.W., 1977. Dorsolateral approach to the canine pelvis. Vet. Med. [Small Anim Pract] 72, 1319. DeCamp, C., 2005. Fractures of the ilium. In: Johnson, A.L., Houlton, J.E.F., Vannini, R. (Eds.), AO Principles of Fracture Management in the Dog and Cat Stuttgart. Thieme AO publishing, Germany, p. 171. Demetriades, D., Karaiskakis, M., Toutouzas, K., 2002. Pelvic fractures: epidemiology and predictors of associated abdominal injuries and outcomes. J. Am. Coll. Surg. 195, 1–10. Denny, R.H., Butterworth, J.S., 2006. A Guide to Canine and Feline Orthopaedic Surgery. Blackwell Printed and bound by Replika Press Pvt Ltd, India. Denny, H.R., 1978. Pelvic fractures in the dog: a review of 123 cases. J. Small Anim. Pract. 19, 151–155. Fitch, R.B., 2004. Incorporating Ventral Fixation Into Ilial Fracture Repairs. ACVS Surgical Summit meeting, Denver CO. Hamilton, M.H., et al., 2006. A review of feline ilial fractures repaired by lateral plating and the use of a dorsal plate as an alternative method of repair, Proceedings of the ECVS meeting, Seville, Spain, pp. 314–317. Henry, W.B., 1985. A method of bone plating for repairing iliac and acetabular fractures. Comp. Cont. Ed. Prac. Vet. 7, 924–940. Hohn, R.B., Janes, J.M., 1966. Lateral approach to the canine ilium. J. Am. Anim. Hosp. Assoc. 2, 111. Jubb, K.V.F., Kennedy, P.C., Palmer, N., 2016. Pathology of domestic animals. Saunders, Elsevier, Pheladelphia. Kalfas, I.H., 2001. Principles of bone healing. Neurosurg Focus 10 (4). Article 1, Department of Neurosurgery, Section of Spinal Surgery, Cleveland Clinic Foundation, Cleveland, Ohio. Kock, D., 2005. Screws and plates. In: Johnson, A.L., Houlton, J.E.F., Vannini, R. (Eds.), AO Principles of Fracture Management in the Dog and Cat. AO publishing, Clavadelerstrasse, Switzerland. Neil, J.B., 2011. Composite fixation of comminuted ilial wing fractures in cats: three cases. J. Feline Med. Surg. 13, 376–438. Piermattei, D.L., Johnson, K.A., 2004. An Atlas of Surgical Approaches to the Bones and Joints of the Dog and the Cat. WB Saunders, Philadelphia. Piermattei, D.L., Flo, G.L., DeCamp, C.E., 2006. Fractures of the Pelvis. In: Handbook of Small Animal Orthopaedics and Fracture Treatment. 4th ed. Saunders Elsevier, St Louis, Missouri, pp. 433–460. Prassinos, N.N., Adamama-, K.K., Gouletsou, P.G., Rallis, T.S., 2007. Symphyseal distraction-osteotomy using a novel spacer of spirally fashioned orthopaedic wire for the management of obstipation. J. Feline Med. Surg. 9, 23–28. Remedios, A., Fries, C., 1993. Implant complications in 20 triple pelvic osteotomies. Vet. Comp. Orthop. Traumatol. 1993 (6), 202–207. Meeson, Richard, Corr, Sandra, 2011. Management of pelvic trauma neurological damage, urinary tractdisruption and pelvic fractures. Clinical review. JFMS Clin. Pract. 2011 (13), 347–361. Roush, J.K., Manley, P.A., 1992. Mini plate failure after repair of ilial and acetabular fractures in 9 small dogs and 1 cat. J. Am. Anim. Hosp. Assoc. 28, 112–118. Schmidt-Oechtering, Alef, 1995. neue aspekte der veterinaranasthesia und intensivertherapie. Blackwell wissenschafts-Verlag, Berlin. Shahar, R., 2000. Relative stiffness and stress of type I and type II external fixators: Acrylic versus stainless-steel connecting bars-a theoretical approach. Vet. Surg. 29, 59–69. Shibata, Y., Fujita, S., Takahashi, H., Yamaguchi, A., Koji, T., 2000. Assessment of decalcifying protocols for detection of specific RNA by non-radioactive site hybridization in calcified tissue. Histochem. Cell Biol. 113, 153–159. Torad, F.M., 2000. Evaluation of some anaesthestic techniques in pet animal under local circumstances. M.V.Sc, surgery, anaesthesiology and radiology. Fac. Vet. Med. Cairo Univ.
Please cite this article in press as: Fathy, M.Z., et al. Clinico-radiographic and histopathologic evaluation of iliac shaft fracture in dogs (an experimental study). Beni-Suef Univ. J. Basic Appl. Sci. (2017), http://dx.doi.org/10.1016/j.bjbas.2017.09.001