Bone marrow and recombinant human bone morphogenetic protein-2 in osseous repair

Bone marrow stem cells and recombinant human bone morphogenetic protein-2 each has the capacity to repair osseous defects. Recombinant human bone morphogenetic proteins require the presence of progenitor cells to function. It is hypothesized that a composite graft of recombinant human bone morphogenetic protein-2 and marrow would be synergistic and could result in superior grafting to autogenous bone graft. Syngeneic Lewis rats with a 5-mm critical sized femoral defect were grafted with recombinant human bone morphogenetic protein-2 and marrow, recombinant human bone morphogenetic protein-2, marrow, syngeneic cancellous bone graft, or carrier alone (control). Serial radiographs (3, 6, 9, 12 weeks) and torque testing (12 weeks) were performed. Bone formation and union were determined. The recombinant human bone morphogenetic protein-2 and marrow composite grafts achieved 100% union at 6 weeks. Recombinant human bone morphogenetic protein alone achieved 80% union by week 12. Both groups yielded a higher union rate and superior mechanical properties than did either syngeneic bone graft (38%) or marrow (47%) alone. The superior performance of recombinant human bone morphogenetic protein-2 combined with bone marrow in comparison with each component alone strongly supports a biologic synergism. This experimentation shows the clinical importance of establishing operative site proximity for the osteoinductive factors and responding progenitor cells.     

Critically Sized Osteo-Periosteal Femoral Defects: A Dog Model

A 21-mm defect was created in 1 femoral diaphysis each of 15 dogs. Periosteum as well as a cylinder of bone was removed, and the defect was stabilized with a bone plate. Twelve of the defects were filled with an equal volume of autogenous cancellous bone harvested from the ipsilateral ilium. Three defects were left untreated. Cranial to caudal radiographs were taken postoperatively and every 4 weeks for 16 weeks. The radiographs were evaluated for healing using two ordinal scales. At 16 weeks, the dogs were euthanized and the femurs harvested for biomechanical testing and histologic evaluation. Both operated and contralateral not operated femurs were mechanically tested to failure in torsion, and load at failure and stiffness were calculated. All dogs tolerated the procedure well, and were using the operated limb within 1 or 2 days postoperatively. There were no complications noted during the 16 weeks of the study. Unfilled defects did not heal and became atrophic nonunions. The defects filled with autogenous cancellous bone healed in a consistent pattern of consolidation, incorporation, and remodeling, with uniform increases of both ordinal scales used. The femoral cortex opposite the bone plate demonstrated most mature remodeling, evident both radiographically as well as histologically. Unoperated femurs failed at 13.61 3.88 N-m and grafted femurs failed at 2.96 1.3 N-m, which was 23% of the measurement of the unoperated femur. Relative stiffness of the unoperated femurs was 5974 4316 N-m2/radian, and grafted femurs had a relative stiffness of 642 561 N-m2/radian, which was 10.4% of the measurement of unoperated femur. This model proved to be a critically sized defect, which when left unfilled resulted in an atrophic nonunion, and when filled with cancellous bone resulted in a consistent healing pattern.     

Critically sized osteo-periosteal femoral defects: a dog model.

A 21-mm defect was created in 1 femoral diaphysis each of 15 dogs. Periosteum as well as a cylinder of bone was removed, and the defect was stabilized with a bone plate. Twelve of the defects were filled with an equal volume of autogenous cancellous bone harvested from the ipsilateral ilium. Three defects were left untreated. Cranial to caudal radiographs were taken postoperatively and every 4 weeks for 16 weeks. The radiographs were evaluated for healing using two ordinal scales. At 16 weeks, the dogs were euthanized and the femurs harvested for biomechanical testing and histologic evaluation. Both operated and contralateral not operated femurs were mechanically tested to failure in torsion, and load at failure and stiffness were calculated. All dogs tolerated the procedure well, and were using the operated limb within 1 or 2 days postoperatively. There were no complications noted during the 16 weeks of the study. Unfilled defects did not heal and became atrophic nonunions. The defects filled with autogenous cancellous bone healed in a consistent pattern of consolidation, incorporation, and remodeling, with uniform increases of both ordinal scales used. The femoral cortex opposite the bone plate demonstrated most mature remodeling, evident both radiographically as well as histologically. Unoperated femurs failed at 13.61 +/- 3.88 N-m and grafted femurs failed at 2.96 +/- 1.3 N-m, which was 23% of the measurement of the unoperated femur. Relative stiffness of the unoperated femurs was 5974 +/- 4316 N-m2/radian, and grafted femurs had a relative stiffness of 642 +/- 561 N-m2/radian, which was 10.4% of the measurement of unoperated femur. This model proved to be a critically sized defect, which when left unfilled resulted in an atrophic nonunion, and when filled with cancellous bone resulted in a consistent healing pattern.     

Bone matrix and marrow versus cancellous bone in rabbit radial defects

Implants of demineralized bone matrix induce new bone formation. In order to estimate the possible clinical usefulness of this phenomenon, autologous cancellous bone grafts were compared with composite grafts of bone matrix and marrow. Cancellous bone from the tuber ischii of the rabbit was transplanted to a preformed radial defect in the same animal. On the opposite side, a similar defect was filled with a mixture of either allogenous or autogenous bone-matrix particles and autogenous bone marrow. After 25 days, calcium 45 was injected intravenously. Three days later the animals were killed. Standardized segments of the rabbit's forearms, containing the middle of the defect, were cut out, ashed, and analyzed for 45Ca activity. No side difference in 45Ca deposition was found. The callus ash weight of the allogenous matrix-transplanted side was approximately 60% of that of the cancellous bone side. This side difference of ash weights corresponds to the estimated initial mineral content of the cancellous graft. Nontransplanted defects had very low ash weight and 45Ca activity. Thus, in the rabbit, composite grafts of bone matrix and marrow produce a bone yield comparable to that of cancellous bone.     

A radiographical and biomechanical study of demineralized bone matrix implanted into a bone defect of rat femurs with and without bone marrow

Repair of large bone defects represents a challenge to orthopedic surgery since autogenous graft is not available in large amounts. Demineralized bone matrix (DBM) which contains bone morphogenic protein, a potent osteoinductive glycoprotein, and collagen, an osteoconductive matrix, may be an effective substitute for these graft materials. Bone marrow which contains osteoprogenitor cells could potentiate the osteoinductive and osteoconductive properties of demineralized bone matrix. This study tested the ability of demineralized bone matrix with and without bone marrow to bridge large segmental defects, and evaluated the results both radiographically and biomechanically as compared to autogenous (isogeneic) cancellous bone graft. Demineralized bone-matrix segments implanted into a plated femoral segmental defect in rats resulted in firm union in most animals. Bone marrow significantly enhanced bone formation of demineralized bone-matrix implants at an early stage but with time, differences between bone marrow-augmented and bone marrow-deprived demineralized bone implants were no longer demonstrable radiographically and biomechanically. Newly formed bone had about 50% of the strength of the contralateral control bones. Femurs implanted with cancellous bone isografts had similar evidence of absolute union rate, radiographic and mechanical properties as DBM-implanted femurs.     

Vordere Spondylodesen an der unteren Halswirbelsäule

Physical alterations in cervical fusions endanger healing. Experimentally we determined less stability loss in fixations using cancellous bone grafts than in those using tricortical grafts. Four hundred eighty-five Patients underwent anterior cervical fusion, for a total of 700 Segments. Patients were divided into four groups: (1) nonlocked H plate with autogenous cancellous bone, (2) nonlocked H plate with autogenous tricortical graft, (3) locked cervical plate with tricortical graft, and (4) stand-alone cage with cancellous bone. Evaluations included X-ray and random CT scan examinations. Our results suggest that anterior cervical fusions using nonlocked H screw plate systems with pure autogenous cancellous bone grafts provide the fastest (6 weeks) and most secure bone healing (P=0.00001), whereas fixations using nonlocked or locked screw plate systems and tricortical autograft require prolonged healing and develop nonunions more frequently. Complete consolidation was achieved using stand-alone cages filled with pure autogenous cancellous bone, but bony healing was delayed due to the cage. Rate of nonunions were: groups 1 and 4 0%, and groups 2 and 3 4.5% and 21%, respectively.     

New-bone formation by osteogenic protein-1 and autogenic bone marrow in a critical tibial defect model in sheep

AIM: Osteogenic Protein-1 (OP-1) is known to be a very potent osteoinductive growth factor. However, experimental studies using critical-size defect models in the weight-bearing lower extremity show non-uniform results. Therefore, we studied the osteoinductivity of OP-1 in a tibial worst-case defect model in sheep. Potential improvement of OP-1 induced new bone formation using a composite graft with autogenous bone marrow was to be investigated. METHOD: In 19 sheep a 5 cm segmental defect of the tibial diaphysis was treated by intramedullary nailing and filled with the following implants: 5 mg OP-1 + inactivated demineralized bone matrix (group 1; n = 6); 5 mg OP-1 + inactivated demineralized bone matrix + 5 ml autogenous bone marrow (group 2; n = 5); autogenous cancellous bone (group 3; n = 4), or inactivated demineralized bone matrix + 5 ml autogenous bone marrow (group 4; n = 4). RESULTS: In total, 3 out of 10 defect sites treated with OP-1 were completely bridged radiographically by 12 weeks. Initially, x-rays showed accelerated new bone formation by use of the composite grafts containing OP-1 and autogenous bone marrow. However, 12 weeks post surgery 3D-CT-volumetry could not detect significant differences of new bone formation within the defect sites treated by OP-1 with or without bone marrow, while new bone formation by autogenous cancellous bone was better than by OP-1. CONCLUSION: In our worst case defect model, the osteoinductive potential of OP-1 is initially accelerated but 12 weeks post surgery not increased when combined with autogenous bone marrow transplantation. So far, critical segmental bone defects of the weight-bearing lower extremity can not be bridged regularly in our model by use of OP-1. Therefore, for the treatment of such critical defects with rotational instability the examined application device of OP-1 can not yet be recommended.     

Bone matrix and marrow versus cancellous bone in rabbit radial defects

Summary Implants of demineralized bone matrix induce new bone formation. In order to estimate the possible clinical usefulness of this phenomenon, autologous cancellous bone grafts were compared with composite grafts of bone matrix and marrow. Cancellous bone from the tuber ischii of the rabbit was transplanted to a preformed radial defect in the same animal. On the opposite side, a similar defect was filled with a mixture of either allogenous or autogenous bone-matrix particles and autogenous bone marrow. After 25 days, calcium 45 was injected intravenously. Three days later the animals were killed. Standardized segments of the rabbit's forearms, containing the middle of the defect, were cut out, ashed, and analyzed for ⁴⁵Ca activity. No side difference in ⁴⁵Ca deposition was found. The callus ash weight of the allogenous matrix-transplanted side was approximately 60% of that of the cancellous bone side. This side difference of ash weights corresponds to the estimated initial mineral content of the cancellous graft. Nontransplanted defects had very low ash weight and ⁴⁵Ca activity. Thus, in the rabbit, composite grafts of bone matrix and marrow produce a bone yield comparable to that of cancellous bone.     

Porous ceramics as bone graft substitutes in long bone defects: A biomechanical,histological, and radiographic analysis

Three porous ceramic bone graft materials were compared with regard to their ability to heal a 2.5 cm defect created surgically in a bilateral canine radius model. The ceramic materials were analyzed at 12 and 24 weeks after surgery and included tricalcium phosphate, hydroxyapatite, and collagen hydroxyapatite, which contained a mixture of 35% tricalcium phosphate and 65% hydroxyapatite with added collagen. Each material was evaluated alone and with added bone marrow aspirate. All the implants were compared with a graft of autogenous cancellous bone in the contralateral radius. Biomechanical testing and radiographic evauation revealed that the addition of bone marrow aspirate was essential for tricalcium phosphate and hydroxyapatite to achieve results comparable with those of cancellous bone. Collagen hydroxyapatite performed well without the addition of bone marrow, although the addition of marrow did have a positive effect. Further qualitative radiographic and histological analysis demonstrated that tricalcium phosphate was the only ceramic that showed any sign of degradation at 24 weeks. This observed degradation proved to be an important factor in evaluating radiographs because the radiodensity of collagen hydroxyapatite and hydroxyapatite interfered with the determination of radiographic union. At 24 weeks, tricalcium phosphate with bone marrow was the material that performed most like cancellous bone. In this study, the biomechanical and radiographic parameters of tricalcium phosphate with bone marrow were roughly comparable with those of cancellous bone at 12 and 24 weeks. Tricalcium phosphate was the only implant that showed significant evidence of degradation at 24 weeks by both histological and radiographic evaluations, and this degradation took place only after a degree of mechanical competence necessary for weight-bearing was achieved.     

Bone morphogenetic protein augmentation grafting of resistant femoral nonunions. A preliminary report

Twelve patients with intractable nonunions of the femoral diaphyseal or metaphyseal-diaphyseal shaft were successfully treated by a combination of internal fixation and implants of human bone morphogenetic protein (h-BMP). There was an average of 4.3 surgical procedures per patient attempting union prior to h-BMP implantation. Union was obtained in 11 of 12 patients and in one patient with a repeat stabilization and implantation of h-BMP. Four patients received autogeneic cancellous bone graft and four patients received allogeneic bone grafts. The BMP implant was prepared in the form of an aggregate of h-BMP and bone matrix water-insoluble noncollagenous proteins (h-BMP/iNCP). Fifty to 100 mg of h-BMP/iNCP was either implanted in the fracture gap in ultra thin gelatin capsules, or incorporated in a strip of polylactic/polyglycolic acid copolymer (PLA/PGA) and placed as an onlay across the fracture gap. The average time to union was 4.7 months. Further clinical investigations are planned as a series of matched cases with and without BMP augmentation in order to distinguish h-BMP effects from new or improved methods of fracture fixation combined with autogeneic cancellous bone grafts.     

Percutaneous autologous bone marrow transplantation for nonunion of the femur.

Percutaneous bone marrow injections were performed on 7 nonunions of the femur. There were 6 hypervascular nonunions and one avascular nonunion. Two nonunions presented with active infections. One other patient had a history of infection which had subsided. One nonunion received the injection twice. After the site of nonunion was curetted and the bone surface was scored, 150 ml of bone marrow aspirated from the iliac bone was injected. Complete union occurred in 4 patients within 9 months; all of them were uninfected hypervascular nonunions following intramedullary nail fixation. One nonunion with a bone defect united partially leaving a 1 x 1 cm defect. The two infected femoral nonunions failed to unite. The results show that percutaneous autologous bone marrow injection for femoral nonunions can be considered for uninfected hypervascular nonunions following intramedullary nail fixation. In these cases stimulation of healing processes of fracture leading to consolidation can be expected from bone marrow injection. However, femoral nonunion with an active infection and loss of fixation is considered to be a contraindication for this technique.     

椎间盘镜下异体松质骨复合自体红骨髓植骨治疗骨不连及骨缺损

目的探讨椎间盘镜下异体松质骨复合自体红骨髓植骨治疗四肢长骨干骨不连及骨缺损的临床疗效。方法2003年9月～2006年9月,选择25例创伤后骨不连、骨缺损患者,其中胫骨9例,股骨13例,肱骨3例。骨不连、骨缺损引起须植骨长度1～6 cm,平均2.7 cm,均在椎间盘镜下行瘢痕清除,然后在骨缺损部位植入异体松质骨,再于髂骨取自体红骨髓15～20 ml注入植骨处。结果25例随访12～36个月,平均25个月,切口均一期愈合,无一例发生神经血管损伤症状。除2例术后内固定失败外,余23例骨不连、骨缺损均获骨性愈合,植骨生长良好,骨愈合时间4～9个月,平均5.1月,无感染及再出现骨不连。结论椎间盘镜下异体松质骨复合自体红骨髓植骨治疗骨不连和骨缺损,无须自体髂骨取骨,局部创伤小,血运破坏小,并发症少,骨愈合率高,是一种微创有效的治疗方法。     

Evaluation of bovine-derived bone protein with a natural coral carrier as a bone-graft substitute in a canine segmental defect model

The efficacy of a bone-graft substitute (bovine-derived bone protein in a carrier of natural coral) in the healing of a segmental defect of a weight-bearing long bone was evaluated. Twenty dogs, divided into two groups, underwent bilateral radial osteotomies with creation of a 2.5 cm defect. On one side of each dog, the defect was filled with autogenous cancellous bone graft. Contralateral defects received, in a blinded randomized fashion, cylindrical implants consisting of natural coral (calcium carbonate) or calcium carbonate enhanced with a standard dose of bovine-derived bone protein (3.0 mg/implant; 0.68 mg bone protein/cm³). The limbs were stabilized with external fixators, and all animals underwent monthly radiographs. They were killed at 12 (group 1) or 24 (group 2) weeks, and regenerated bone was Studied by biomechanical testing and histology. Radiographic union developed in all 20 radii with autogenous cancellous bone grafts and in all 10 of the radii with the composite implants. None of the radii with implants of calcium carbonate alone showed radiographic evidence of union. This represented a statistically significant difference between implant types. In addition, calcium carbonate implants both with and without bone protein demonstrated radiographic evidence of near total resorption of the radiodense carrier by 12 weeks. This resorption facilitated radiographic evaluation of healing. Mean values for. biomechanical parameters of radii with the composite implants exceeded those for the contralateral controls at 12 and 24 weeks; the difference was statistically significant at 12 weeks. Histology revealed scant residual calcium carbonate carrier at either time in the defects with calcium carbonate implants; however, a moderate amount was present in defects with the composite implants. In these specimens, the residual carrier was completely surrounded by newly formed bone that may have insulated the calcium carbonate from further degradation. The present study used a carrier of granular calcium carbonate reconstituted with bovine type-I collagen to deliver an osteoinductive protein to the defect site. This carrier is of nonhuman origin (eliminating the risk of disease transmission or antigenicity) and resorbs rapidly. In this model, bovine-derived bone protein in a natural coral carrier performed consistently better than the gold standard autogenous cancellous bone graft in terms of the amount of bone formation and strength of the healed defect. This may have implications for removal of hardware or resumption of weight-bearing in certain clinical situations. These data also indicate that coralline calcium carbonate alone. represents a poor option as a bone-graft substitute in this critical-sized segmental defect model.     

Autogenous cultured bone graft--bone reconstruction using tissue engineering approach.

Maniatopoulos et al. reported the formation of calcified bone-like tissue when rat bone marrow cells were cultured in the presence of dexamethasone and beta-glycerophosphate. We have succeeded to construct the in vitro cultured bone on the porous framework of hydroxyapatite ceramics (HA). After 2 weeks of the culture, the construct showed the existence of mineralized collagen fibers on the surface of HA determined by Scanning Electron Microscopy. The construct also demonstrated high alkaline phosphatase (ALP) activity together with noticeable level of osteocalcin. The results indicate that the construct consisted of thin layer of bone matrix covered hydroxyapatite surface and abundant bone forming active osteoblasts. After the in vivo implantation of the construct, volume of the matrix increased and obvious bone tissue was detected by ordinal microscopy even one-week after implantation and its high osteogenic activity was maintained for a long term (one year). The in vivo bone is biologically active tissue evidenced by Northern blot analysis of the implanted construct which showed ALP and osteocalcin mRNA expression comparable to those of normal cancellous bone. These results demonstrate that the in vitro fabricated cultured bone/HA construct can possess new bone forming capability in in vivo situations. We have also succeeded to fabricate the construct using aged human marrow cells and the construct showed thick lamellar bone formation after the in vivo implantation. Based on these findings, we propose alternative approach for bone reconstruction surgery using the autogenous cultured bone/HA construct. Importantly, we can fabricate the implantable autogenous bone tissue derived from patient's marrow cells and the cells can be obtained by needle aspiration without damaging the patient's normal tissue.     

The effect of histocompatibility matching on canine frozen bone allografts

The value of histocompatibility matching in frozen bone allografts was studied in a canine cancellous ulnar segmental-replacement model. Frozen bone that was exchanged across strong and weak transplantation barriers was evaluated histologically and radiographically at thirteen and twenty-six weeks after grafting. Histological grading criteria quantified the type of union at each end of the graft and the degree of remodeling of the marrow, spongiosa, and compacta. Radiographic grading criteria included the presence of union at each end of the graft and the degree of remodeling of the graft segment. In vitro studies for serum antibody and cell-mediated immunity were carried out by isotopic cytotoxicity methods at seven intervals during the twenty-six-week study period. Histologically, the strong-barrier allografts had fewer osseous unions and less reorganization of spongiosa and marrow when compared with autograft controls at both thirteen and twenty-six weeks. Radiographically, the strong-barrier allografts at thirteen weeks had fewer unions and marked resorption of grafts material when compared with autograft controls. There were no differences between weak transplantation-barrier grafts and control autografts radiographically or histologically at thirteen and twenty-six weeks after grafting. Frozen bone allografts did not elicit detectable serum antibody or lymphocytes that were cytotoxic for donor cells.     

Medial femoral condyle vascularized bone grafts for scaphoid nonunions

Free vascularized bone grafts from the medial femoral condyle provide both structural support and blood supply to promote union in the difficult subset of scaphoid nonunions complicated by humpback deformity and proximal pole avascular necrosis. These nonunions have not consistently achieved union when treated with grafts which fail to restore scaphoid geometry or vascularity. The rationale, indications, contraindications, technique and results of bone grafting scaphoid nonunions with grafts harvested from the medial femoral condyle are presented.     

Indications and outcomes of augmentation plating with decortication and autogenous bone grafting for femoral shaft nonunions

Introduction

Though augmentation plating (AP) with decortication and bone grafting (BG) reportedly has excellent outcomes for femoral shaft nonunions, there are no established indications of AP with decortication and BG. The purpose of this study was to evaluate the results of AP with decortication and autogenous BG for femoral shaft nonunions, focussing on the indications of AP with decortication and BG.

Methods

Thirty-nine patients treated with AP combined with decortication and BG for femoral shaft nonunions after femoral nail failure between November 1996 and October 2010 were retrospectively reviewed. Indications of AP with decortication and BG at the time of surgery and outcomes (bony union) were evaluated.

Results

The mean follow-up duration was 24.8 months (range 12–81 months). Thirty-eight (97%) of 39 femoral shaft nonunions achieved bony union. One incompliant patient showed screw breakage, which was healed uneventfully with subsequent cast application. The mean time to union was 6.1 months (range 3–16 months). Primary indications at the time of surgery were nonisthmal femoral nonunions in 17 patients, isthmal nonunions in 10 patients (cortical bone defect in five and widened canal in five), failed exchange nail in seven patients, nonunions with malrotation in two patients and difficult removal in three patients.

Conclusions

AP with decortication and autogenous BG is a good option for nonisthmal femoral shaft nonunions, such as supra-isthmal and infra-isthmal nonunions. In addition, this option is useful for selected cases of isthmal femoral shaft nonunions in which failure of exchange nailing is expected due to lack of a tight fit between the new larger nail and femoral cortices.     

Stability of fused versus nonfused THA femoral impaction grafts.

Impaction grafting for THA involves compacting morselized cancellous bone (MCB) into a cavitary defect to build up bone stock. Ideally, the MCB subsequently remodels into a new contiguous cancellous lattice. A recent laboratory model of MCB fusion allows simulating an impaction graft construct in this ideal eventual clinical state. The purpose of the present study was to determine the relative stability of femoral impaction graft constructs in which the MCB has fused versus that for MCB in the freshly impacted nonfused condition. Cemented femoral impaction graft constructs were created in composite femurs. For fused constructs, the MCB was mixed with an amine epoxy that causes the MCB to set up into a contiguous structure biomechanically comparable to intact cancellous bone in compression. The constructs were loaded with 500,000 physiologic gait cycles. Three-dimensional motion was measured between the femur and the stem. The fused femoral impaction grafts were much more stable than the nonfused grafts at the proximal stem location, but MCB fusion had only a modest effect on distal stem stability. These results indicate that most of the opportunity to reduce femoral stem micromotion and migration lies proximal, and that steps to enhance impaction graft remodeling and fusion are most effectively focused proximally.     

Reconstruction of osseous defects with freeze-dried allogeneic and autogenous bone: Clinical and histologic assessment

Freeze-dried allogeneic bone combined with autogenous particulate cancellous bone and marrow was used for reconstruction in 56 patients. With the exception of 3 patients who had infection postoperatively, the patients had complete acceptance of the composite graft system. Histologic examination at 2, 3, 12, 18, and 24 months demonstrated early incorporation, revascularization, resorption of the freeze-dried component, and formation of a bone ossicle that continued to remodel and form mature lamellar bone. This study suggests that freeze-dried allogeneic bone can serve as a latticework along which osteocompetent cells can proliferate, that composite grafts are readily accepted and will form a satisfactory and predictable bone ossicle over a considerable defect, and that freeze-dried allogeneic bone induces the host mesenchymal cells to differentiate into mature osteoblasts and aids in the formation of a long-lasting functional bone graft.     

更换髓内钉与保留髓内钉附加钢板治疗髓内钉固定后股骨肥大性骨不连

 目的 探讨更换髓内钉与保留髓内钉附加钢板治疗髓内钉固定后股骨肥大性骨不连的手术适应证。方法 1998年 4月至 2009年 6月收治髓内钉固定后股骨肥大性骨不连患者 20例,11例更换髓内钉,9例保留髓内钉附加钢板固定。两组患者性别、年龄、合并伤、骨折部位、骨折类型的差异无统计学意义。通过术后 1、2、3、4、6、12个月及以后每年 1次影像学和临床功能随访,观察骨痂生长情况和患肢功能。结果两组随访时间、手术时间、术中出血量、术后引流血量、住院时间、影像学愈合时间、临床愈合时间和美国矫形外科医师学会下肢功能评分均无统计学差异。更换髓内钉组住院费用多于保留髓内钉附加钢板组(t'=16.4,P=0.013)。更换髓内钉组 4例未获得骨性愈合,其中 2例为股骨下 1/3骨折,1例为狭部 B型骨折,1例为 32-A3型骨折。再次手术,其中 3例采用髂骨植骨保留髓内钉附加钢板固定,1例行动力化。保留髓内钉附加钢板组全部获得骨性愈合。两组愈合率的差异有统计学意义(χ²= 6.01,P=0.008)。结论 更换髓内钉只适用于股骨狭部肥大性骨不连。对干骺端骨不连、伴有大蝶形游离骨块、骨缺损及更换髓内钉失败病例可采用保留髓内钉附加钢板固定。