Operative treatment of deep burns of the scalp and skull.

Traditional surgical treatment of deep burns of the scalp and skull involve the excision of necrotic bone and soft tissues with trephanation of the bone to permit granulation tissue formation and subsequent grafting. This approach prolongs wound time, adds additional trauma and, even after initial healing, necessitates secondary soft tissue and bone reconstruction. The treatment described here is an alternate and more aggressive one involving early excision of necrotic soft tissue without bone resection followed by immediate coverage with well-vascularized axial flaps from adjacent intact scalp. This method provides an optimal environment for healing and regeneration of areas of destruction to the skull. This surgical method was used in the treatment of 22 patients with deep burns of the scalp with satisfactory clinical results. Bone regeneration was confirmed by roentgenological investigations.     

Treatment of severe electrical burn of the skull

From Jan. 1970 to Feb. 1989, 10 cases of severe electrical burns of the skull were treated. There were necroses of the full skull bone layer and skin in 4 cases and necroses of the skull skin and external skull bone layer in 6 cases. Cure in 8 cases and death in 2 cases. The authors consider that in the early-stage protecting and reserving the skull intact is important. Repairing wound with full-circulatory skin flap or myocutaneous flap is a reasonable selection. In the later-stage, the wound may be repaired with skin graft on the granulating wound after removing the necrotic bone.     

Preservation of devitalized calvarium following high-voltage electrical injury: case reports

Three victims of electrical injury with necrosis of a portion of the skull had excision of overlying necrotic soft tissue soon after injury with immediate coverage of the devitalized bone with soft-tissue flaps. In two instances, the flap was from adjacent scalp; in the other a free myocutaneous flap was used. All wounds healed without sequestration of bone. Necrosis of the calvarium was substantiated by evidence of nonperfusion on a radionucleotide bone scan. In each instance, a followup bone scan showed evidence of regeneration of bone. This experience supports an earlier observation which suggested that devitalized but intact calvarium following electrical injury does not need to be removed and is the perfect in situ bone graft.     

Healing of burns of the skull: a histological study

A histological study of burns of the calvarium is reported with reference to depth of necrosis, pyogenic infection and, especially, repair processes. It is based on 14 specimens from 9 subjects—biopsies in 6 cases and necropsy specimens in the 3 others. They ranged from 6 days to 12 months after the accident, most being between 4 and 15 weeks. Necrosis in some extended through the full thickness of the skull (full-thickness necrosis), but deep parts had remained viable in others (partial-thickness necrosis). Necrosis seems largely ischaemic in origin, through heat destruction of the epicranial blood supply. Pyogenic infection of necrotic bone was common, invading through the outer table, and was usually clinically silent. It could be restricted to the outer table or extend deep into the diploë, and certain specimens showed gross histological infection of the whole thickness of the skull. One was a sequestrum.Repair seems slow in onset and is prolonged. The earliest evidence of healing was in a specimen at 4 weeks after burning. Healing proceeded from viable soft tissue within the calvarial plate after partial-thickness necrosis and from the dural membrane after both partial-thickness and full-thickness necrosis. In the former mode, fibrovascular proliferation and invasion within diploëic spaces is associated with appositional seams of new bone on old trabeculae, but much new spongy bone had also formed in the diploë in one case. Osteoclastic resorption was common. Healing from the dura is manifest as fibrovascular invasion of the diploë via Volkmann's canals and sometimes also by new bone deposition on the surface of the inner table. Healing from the periphery into the necrotic centre was studied in one case and was very limited. The question of progressive creeping substitution of necrotic bone by new bone is discussed with reference to possible final replacement by a new calvarial plate. For this, early skin closure of the burn is likely to be required to prevent or reduce pyogenic bone infection.     

The use of artificial dermis for reconstruction of full thickness scalp burn involving the calvaria

The incidence of extensive full thickness scalp burn involving the calvaria is rare and can be very difficult to reconstruct, as the application of local or free tissue transfer is limited. Although wound closure can be achieved with bone debridement and immediate or delayed split-thickness autografting, the result may be problematic due to unstable skin graft surface. The use of artificial dermis that may provide stable thick coverage in the treatment scalp and skull burn has rarely been reported in literature. We encountered two patients who suffered from severe head burns involving the calvarium. Following debridement including the necrotic bone, the artificial dermis (Integra) was used for immediate wound coverage which was 15 cmx10 cm in one case and 5 cmx6 cm in another. Three weeks later, ultra-thin skin grafting was placed on the neodermis. Compared to split-thickness skin graft, this technique provides a thicker coverage for wound closure. Neither skin breakdown nor ulceration was noted in the 1-year follow-up. This paper reports the successful use of artificial dermis for reconstruction of severe scalp burn with calvarial bone involvement.     

Burns of the skull with underlying intracranial meningioma.

A 68-year-old white-skinned male fell head first into a fireplace while having a seizure. Extensive burns of the skull were sustained requiring removal of the necrotic bone. The patient had an underlying meningioma. Healing of the skull was obtained using a latissimus dorsi flap. After the scalp was completely healed, the meningioma was successfully resected with significant improvement in the patient's mental function.     

面颈部电烧伤骨外露头皮瓣移植后再回植

目的　探讨面颈部电烧伤骨外露用头皮瓣移植后再回植的临床疗效。　方法　采用早期扩创 ,保留坏死骨质 ,用邻近的带血管头皮瓣移植覆盖创面 ,电性坏死骨质在血循环良好的皮瓣覆盖下 ,为周边及基底健康骨质生长起到支架作用 ,3～ 6个月后将头皮瓣回植原位 ,保留颅骨表面的软组织 ,以利再移植的中厚皮成活。　结果　 8例面颈部高压电烧伤患者应用头皮瓣共 10个 ,最大面积为 2 4cm× 10cm ,全部成活 ,未出现感染坏死 ,创面一次性封闭。　结论　面颈部电烧伤骨外露头皮瓣移植后再回植的方法可缩短创面愈合时间 ,外形较好 ,效果满意     

Osteoblastic skull metastasis of lung cancer

A case of osteoblastic skull metastasis of lung cancer is reported. A 56-year-old female patient was admitted to our hospital with complaints of headache and tumor of the right parietal bone. A plain skull X-ray showed hyperostotic feature of the right parietal bone. CT scan displayed that right parietal bone became thick and osteoblastic. Soft tissue was shown in the hyperostotic bone under MRI. An external carotid angiogram showed that the skull tumor was fed by the middle meningeal artery. The skull tumor and 2 solid intracerebral tumors were extirpated. Histological examination revealed adenocarcinoma in the skull and intracerebral lesions. The present case indicates that osteoblastic stimulating factor may be secreted by lung cancer.     

可塑形组织工程骨修复兔颅骨缺损的组织学及力学研究

目的探讨用藻酸钙凝胶、成骨细胞和骨粉复合构建可塑形组织工程骨修复兔颅骨缺损后,体内成骨的组织学及生物力学特征。方法28只日本大耳白兔,随机分为A组(16只)、B组(8只)和C组(4只)。制备兔颅骨左右两侧直径1cm的骨膜-颅骨全层缺损,左侧用藻酸钙凝胶-成骨细胞-骨粉填补修复为A1组(n=16);右侧用藻酸钙凝胶-骨粉填补修复为A2组(n=16);B组骨缺损不作处理,为空白对照组(n=16);C组为正常组。术后6周和12周时,行大体观察及组织学观察;12周时行生物力学测试。结果术后6、12周时,A1组:颅骨缺损基本被硬组织所修复,镜下见材料已大部分被骨组织替代,成骨面积为40.92%±19.36%;A2组:材料部分被骨组织替代,成骨面积为18.51%±6.01%;B组:颅骨缺损边缘可见硬组织形成,镜下见修复组织以致密纤维组织为主,成骨面积为12.72%±9.46%。术后12周,生物力学测试修复组织能耐受的最大压力载荷,A1组37.33±2.95N;A2组30.59±4.65N;B组29.5±2.05N;C组41.55±2.52N;A1组明显大于A2组和B组(P<0.05)。最大载荷时应变位移,A1组1.05±0.20mm;A2组1.35±0.44mm;B组1.57±0.31mm;C组0.95±0.17mm;A1组小于B组(P<0.05)。载荷/应变比值,A1组35.82±6.48N/mm;A2组24.95±12.40N/mm;B组19.90±5.47N/mm;C组47.57±11.22N/mm;A1组大于B组(P<     

Rapid publication. TGF-beta 1 induces bone closure of skull defects.

Transforming growth factor beta 1 (TGF-beta 1) is a multifunctional regulatory protein. It is capable of inducing site-specific healing responses by increasing collagen synthesis and deposition as well as remodeling at sites of soft tissue repair. Large bony defects in the skull heal by fibrous connective tissue and never form bone unless osteoinductive bony fragments or powders are placed in the defect. We have found, however, that the single application of human recombinant TGF-beta 1 in a simple 3% methylcellulose gel to skull defects induced a dose-dependent increase in intramembranous bone formation. Complete bony bridging of defects occurred within 28 days after treatment with 2 micrograms TGF-beta 1. Sites treated with vehicle alone did not heal with bone formation but rather contained dense fibrous connective tissue between the defect margins.     

Evaluation of blood flow within the subchondral bone of the femoral head: use of the laser speckle method at surgery for osteonecrosis.

The laser speckle method is a new form of tissue flowmetry that can analyze the interference pattern that appears when tissue is illuminated with a laser beam. During surgery for 100 cases of osteonecrosis of the femoral head, we measured the blood flow within the subchondral bone using this method. We compared the flow maps (two-dimensional distribution of the microcirculation) obtained this way with the necrotic area estimated by the preoperative magnetic resonance images and with the collapse seen during surgery. The laser speckle method was able to distinguish between the ischemic areas and the normal areas in 92 femoral heads, including five hips for which neither the magnetic resonance images nor the collapse observed during surgery demonstrated a distinct margin surrounding the necrotic area. We concluded that the laser speckle method is useful for defining the margin around a necrotic area.     

Bone regeneration at rabbit skull defects treated with transforming growth factor-beta1 incorporated into hydrogels with different levels of biodegradability

OBJECT: Skull bone regeneration induced by transforming growth factor-beta1 (TGFbeta1)-containing gelatin hydrogels (TGFbeta1-hydrogels) was investigated using a rabbit skull defect model. Different strengths of TGFbeta1 were examined and compared: different TGFbeta1 doses in gelatin hydrogels with a fixed water content, different water contents in gelatin hydrogels with a fixed TGFbeta1 dose, and TGFbeta1 in solution form. In addition, regenerated skull bone was observed over long time periods after treatment. METHODS: Soft x-ray, dual energy x-ray absorptometry, and histological studies were performed to assess the time course of bone regeneration at a 6-mm-diameter skull defect in rabbits after treatment with TGFbeta1-hydrogels or other agents. The influence of TGFbeta1 dose and hydrogel water content on skull bone regeneration by TGFbeta1-hydrogels was evaluated. Gelatin hydrogels with a water content of 95 wt% that incorporated at least 0.1 microg of TGFbeta1 induced significant bone regeneration at the rabbit skull defect site 6 weeks after treatment, whereas TGFbeta1 in solution form was ineffective, regardless of dose. The in vivo degradability of the hydrogels, which varied according to water content, played an important role in skull bone regeneration induced by TGFbeta1 -hydrogels. In our hydrogel system, TGFbeta1 is released from hydrogels as a result of hydrogel degradation. When the hydrogel degrades too quickly, it does not retain TGFbeta1 or prevent ingrowth of soft tissues at the skull defect site and does not induce bone regeneration at the skull defect. It is likely that hydrogel that degrades too slowly physically impedes formation of new bone at the skull defect. Following treatment with 0.1-microg TGFbeta1-hydrogel (95 wt%), newly formed bone remained at the defect site without being resorbed 6 and 12 months later. The histological structure of the newly formed bone was similar to that of normal skull bone. Overgrowth of regenerated bone and tissue reaction were not observed after treatment with TGFbeta1 -hydrogels. CONCLUSIONS: A TGFbeta1-hydrogel with appropriate biodegradability will function not only as a release matrix for the TGFbeta1, but also as a space provider for bone regeneration. The TGFbeta1-hydrogel is a promising surgical tool for skull defect repair and skull base reconstruction.     

Implantation With New Three‐Dimensional Porous Titanium Web for Treatment of Parietal Bone Defect in Rabbit

Titanium net (meshes) with excellent mechanical properties can promote bone compatibility and has been used as a repairing material for bone defects in clinical settings. In the present study, using spiral computed tomography (CT) and histomorphlogical techniques, we investigated the effect of a novel kind of titanium web with a three‐dimensional (3D) porous structure on bone formation in rabbit skull (os parietal) defect. The images from the spiral CT scan demonstrate that the titanium web is completely fused with the surrounding bone tissue, even at the first month after implantation. The histomorphological findings show that different cells and tissues, including osseous tissue, connective tissue, and adipose cells, can easily grow into the 3D scaffold meshes of the titanium web, even in the center of the web and combine together as a whole body, suggesting that the titanium web possesses a very good biocompatibility, which is beneficial to the growth of bone tissue and promotes healing of the defected rabbit skull.     

Reconstruction of Skull Base and Fronto-orbital Defects following Tumor Resection.

Reconstruction of the anterior skull base and fronto-orbital framework following extensive tumor resection is both challenging and controversial. Dural defects are covered with multiple sheets of fascia lata that provide sufficient support and avoid herniation. Plating along the skull base is contraindicated. After resection of orbital walls, grafting is necessary if the periosteum or parts of the periorbital tissue had to be removed, to avoid enophthalmus or strabism. Free bone grafts exposed to the sinonasal or pharyngeal cavity are vulnerable to infection or necrosis: therefore, covering the grafts with vascularized tissue, such as the Bichat fat-pad or pedicled temporalis flaps, should reduce these complications. Alloplastic materials are indispensable in cranial defects, whereas microsurgical free tissue transfer is indicated in cases of orbital exenteration and skin defects. The authors review their experience and follow-up of 122 skull base reconstructions following extensive subcranial tumor resection. Most significant complications were pneumocranium in 4.9%, CSF leaks in 3.2%, and partial bone resorption in 8.1%.     

Infantile chronic subdural hematoma with local protrusion of the skull in a case of osteogenesis imperfecta

Osteogenesis imperfecta with infantile chronic subdural hematoma is extremely rare and has not been previously described in the literature. Our patient was a baby girl suffering from osteogenesis imperfecta tarda (Type I) who had an acute subdural hematoma at birth and who developed a progressive chronic subdural hematoma with local protrusion of the overlying skull. She was treated surgically with a good result. This rare complication is due to weakness of an insufficiently calcified skull, which is peculiar to this disorder of bone and connective tissue development.     

Anatomy of head injury

The scalp has an extremely rich blood and nerve supply. It comprises five layers – skin, connective tissue, aponeurosis, loose areolar tissue and periosteum. The blood vessels lie within the tough fibrous septa of the connective tissue layer and cannot retract when divided – hence the copious bleeding from a scalp laceration. The loose areolar tissue beneath the aponeurosis is the plane in which the scalp is avulsed in trauma and in which the surgeon mobilizes a scalp flap. The periosteum adheres to the suture lines of the skull and a haematoma in this plane outlines the affected skull bone (cephalohaematoma).     

Heparan-like molecules induce the repair of skull defects

Heparin-binding growth factors (HBGFs) are known to stimulate bone repair when applied to bone lesions. Nevertheless, successful treatments are obtained with high protein doses since HBGFs are rapidly degraded in situ by multiple proteolytic activities associated with the inflammatory period of tissue healing. Like heparin or heparan sulfates, heparan-like molecules, named carboxymethyl-benzylamide-sulfonated dextrans (CMDBS), are known to potentiate fibroblast growth factor activities by stabilizing them against pH, thermal or proteolytic denaturations, and by enhancing their binding with cell surface receptors. We have postulated that CMDBS stimulate in vivo bone healing by interacting with endogenous HBGFs, spontaneously released in the wounded site. The effect of CMDBS on bone repair was studied in a skull defect model in rats by computer-assisted radiomorphometry and histomorphometry. Single application of CMDBS in a collagen vehicle to skull defects induced a dose-dependent increase in bone defect closure and new bone formation after 35 days. Complete bony bridging occurred in defects treated with 3 μg CMDBS, whereas bone formation was not observed in vehicle-treated defects which contained only dense fibrous connective tissue between the defect margins. These results indicate that heparan-like molecules, such as CMDBS, are able to induce bone regeneration of skull defects. This action is possibly mediated by potentiation of endogenous growth factor activities and/or by neutralization of proteolytic activities.     

Osteogenesis in cranial defects and diffusion chambers: Comparison in rabbits of bone matrix, marrow, and collagen implants

In rabbits, we compared calcification and bone formation by bone marrow, acid-demineralized bone matrix and glutaraldehyde-cross-linked Type I collagen implanted in intramuscular diffusion chambers or in trephine skull defects. The rabbits were killed 4 weeks postimplantation and calcification and osteogenesis were evaluated radiographically and histologically, and by calcium and alkaline phosphatase assays. Bone marrow produced bone and fibrous tissue within the chambers and had high alkaline phosphatase levels. Bone matrix in chambers with intact filters failed to induce bone formation within and outside the chambers, while glutaraldehyde-cross-linked collagen produced only scant calcific deposits following implantation in either diffusion chambers or skull defects. Central areas of skull defects implanted with bone marrow were partially repaired with new bone and had high calcium and alkaline phosphatase levels, but not as high as defects implanted with demineralized bone matrix.     

Material reaction to suture anchor

The authors present a case of material reaction to suture anchor, which is rarely reported. Leukocyte rate, leukocyte differential, multiple cultures, and gram stain test could not prove infection. A second surgery for exploration of the shoulder joint was performed to reconstruct the rotator cuff without using anchors, and the rotator cuff tear healed after the second surgery. During the second surgery, the bone surrounding the anchors was found to be eroded and substituted with necrotic tissue. The anchors protruded outside the bone. The pathological examination of the necrotic tissue showed multinucleated giant cells of foreign body type, some of which had engulfed minute splinters of particulate foreign material. Either metal- or suture-induced bioreaction is suspected in this case.     

Osteogenesis in cranial defects and diffusion chambers: Comparison in rabbits of bone matrix,marrow, and collagen implants

In rabbits, we compared calcification and bone formation by bone marrow, acid-demineralized bone matrix and glutaraldehyde-cross-linked Type I collagen implanted in intramuscular diffusion chambers or in trephine skull defects. The rabbits were killed 4 weeks postimplantation and calcification and osteogenesis were evaluated radiographically and histologically, and by calcium and alkaline phosphatase assays. Bone marrow produced bone and fibrous tissue within the chambers and had high alkaline phosphatase levels. Bone matrix in chambers with intact filters failed to induce bone formation within and outside the chambers, while glutaraldehyde-cross-linked collagen produced only scant calcific deposits following implantation in either diffusion chambers or skull defects. Central areas of skull defects implanted with bone marrow were partially repaired with new bone and had high calcium and alkaline phosphatase levels, but not as high as defects implanted with demineralized bone matrix.