Induced membrane technique for reconstruction to manage bone loss

Multiple surgeries are often required to manage segmental bone loss because of the complex mechanics and biology involved in reconstruction. These procedures can lead to prolonged recovery times, poor patient outcomes, and even delayed amputation. A two-stage technique uses induced biologic membranes with delayed placement of bone graft to manage this clinical challenge. In the first stage, a polymethyl methacrylate spacer is placed in the defect to produce a bioactive membrane, which appears to mature biochemically and physically 4 to 8 weeks after spacer placement. In the second, cancellous autograft is placed within this membrane and, via elution of several growth factors, the membrane appears to prevent graft resorption and promote revascularization and consolidation of new bone. Excellent clinical results have been reported, with successful reconstruction of segmental bone defects >20 cm.     

Reconstruction of the long bones by the induced membrane and spongy autograft

In the reported series of 35 cases bone reconstruction of large diaphyseal defects was performed in two stages. The first stage was the insertion into the defect of a cement spacer which was responsible for the formation of a pseudosynovial membrane. The second stage was the reconstruction of the defect by a huge fresh autologous cancellous bone graft. The membrane induced by the spacer prevents the resorption of the graft and favors its vascularity and its corticalisation. In weight bearing diaphyseal segments the normal walking was possible at 8.5 months on average. The length of the reconstructed defects was 4 to 25 cm.     

Thumb salvage after infected toe-to-hand vascularised transfer with induced membrane technique

The induced membrane technique of bone reconstruction described by A.C. Masquelet is a well-known and efficient procedure for the lower limbs but is rarely used in the hand. After debridement, the technique consists first in inducing a foreign body membrane by the implantation of a cement methyl methacrylate polymer spacer and then filling the defect by cancellous bone. We report a case of induced membrane to save an infected vascularized custom made toe-to-hand transfer. The second stage was done 3 months after the first. Bone healing was obtained 4 months later. No specific complication was observed. Induced membrane technique seems to be another possibility for bony defects of the hand besides vascularised or non-vascularised grafts. It is essential to apply the principles of the two stages of the procedure, first respecting the foreign body membrane and second stable fixation of the graft. In sepsis, this allows a second surgical debridement without compromising the graft. Masquelet technique, simple and reproducible, seems an effective salvage procedure for bone defects of the thumb.     

Case Report: Reconstruction of a 16-cm Diaphyseal Defect after Ewing’s Resection in a Child

Numerous options exist for intercalary segmental reconstruction after bone tumor resection. We present the extension of a recently developed surgical two-stage technique that involves insertion of a cement spacer, induction of a membrane, and reconstruction of the defect with cancellous and cortical bone autograft in a 12-year-old child. The boy was referred to our center for treatment of a right femoral diaphyseal Ewing’s sarcoma. The first stage involved resection of the tumor and reconstruction with a locked intramedullary nail and a polymethylmethacrylate cement spacer. Seven months after the initial procedure during which adjuvant chemotherapy was given, the second-stage procedure was performed. The cement was removed and cancellous and cortical bone autograft was grafted in the membrane created around the cement spacer. Touchdown weightbearing was allowed immediately, partial weightbearing was resumed 6 weeks after the operation, and full weightbearing was allowed 4 months later. Successive plain radiographs showed rapid integration of the autograft to the host bone with bone union and cortical reconstitution. The principle of the induced membrane reconstruction seems applicable to intercalary segmental reconstruction after bone tumor resection in children. Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. Each author certifies that his or her institution has approved the reporting of this case report, that all investigations were conducted in conformity with ethical principles of research, and that informed consent for participation in the study was obtained.     

Decalcified and undecalcified cancellous bone block implants do not heal diaphyseal defects in dogs

Summary In a previous study it has been shown that granulae of decalcified bone matrix do not induce bony healing of 8-week-old mid-diaphyseal defects in dogs. The aim of this study was to test whether osteoinduction combined with the osteoconductive mechanisms provided by the natural structure of cancellous bone blocks would yield better results. A 30-mm-long diaphyseal defect of the left ulna was created in eight adult mongrel dogs and the bone was stabilized with a plate. A Silastic spacer was inserted in the defect for 8 weeks, followed by implantation of frozen undecalcified or decalcified allogeneic cancellous bone blocks for 16 weeks. Healing was analyzed using morphologic methods. At 16 weeks after implantation all grafts had been resorbed. In the decalcified group one defect healed, while none in the other group did so. The implant material was bioassayed in nude rats for osteoinductivity, which was found to be low in decalcified matrix and not detectable in undecalcified bone. Conclusion: Allogeneic cancellous bone blocks, demineralized or not, have no osteoinductive capacity and no osteoconductive function that promotes healing of mid-diaphyseal bone defects in dogs.     

Pertes de substance osseuse à la main et au poignet traitées en urgence par technique de la membrane induite (technique de Masquelet)

A prospective study is reported concerning 11 cases of bone defect of the hand and wrist treated by the induced membrane technique. Ten men and one woman with an average age of 49 yrs (17–72) sustained a high-energy trauma with severe mutilation of digit and hand but with intact pulp. Eight cases of open finger fractures with composite loss of substance and three cases of bone and joint infection (thumb, wrist, fifth finger) were included. All cases were treated by the induced membrane technique which consists in stable fixation, flap if necessary, and in filling the bone defect by a cement methyl methacrylate polymere (PMMA) spacer. A secondary procedure at two months is needed where the cement is removed and the void is filled by cancellous bone. The key point of this induced membrane technique is to respect the foreign body membrane which formed around the cement spacer creating a biologic chamber. Bone union was evaluated prospectively by X-ray and CT scan by a surgeon not involved in the treatment. Failure was defined as non-union at one year, or uncontrolled sepsis at one month. Two cases failed to achieve bone union. No septic complications occurred and all septic cases were controlled. In nine cases, bone union was achieved within four months (three to 12). Evidence of osteoid formation was determined by a bone biopsy in one case. Masquelet first reported 35 cases of large tibial non-union defects treated by the induced membrane technique. The cement spacer promotes foreign body membrane induction constituting a biological chamber. Works on animal models reported by Pellissier and Viateau demonstrated membrane properties: secretion of growths factors (VEGF, TGF beta1, BMP2) and osteoinductive cellular activity. The induced membrane seems to mimic a neoperiosteum. This technique is useful in emergency or septic conditions where bone defects cannot be treated by shortening. It avoids microsurgery and is limited by availability of cancellous bone.     

Foot reconstruction with the "bi-Masquelet" procedure

A case of complex injury of the dorsal aspect of the foot is reported, the reconstruction of which combined two procedures described by A.C. Masquelet. The induced membrane and spongy autograft technique was used to reconstruct the metatarsal arch. The first stage was the insertion into the defect of a cement spacer which was responsible for the formation of a pseudosynovial membrane. The second stage was the reconstruction by a fresh autologous cancellous bone graft combined with hydroxyapatite. The membrane induced by the spacer prevents from the resorption of the graft and favors its vascularity and its corticalization. Soft tissue reconstruction was achieved by the mean of a supramalleolar island flap. Although bone healing occurred by the ninth month, the authors describe and discuss the possible mistakes when using this technique. Despite the many technical problems reported in this clinical case, bone reconstruction with the induced membrane and spongy autograft technique has proved to be easily handable and effective under adverse conditions.     

Muscle reconstruction in reconstructive surgery: soft tissue repair and long bone reconstruction

Background We report a series of reconstructions of long bone defects in 35 patients. Bone defects ranged from 5.0 to 25.0 cm.Method Reconstruction was performed in two stages. The first stage was the insertion into the defect of a cement spacer, which was responsible for the formation of a pseudosynovial membrane. A soft tissue repair employing a flap was done in the same operating time in 28 cases. The second stage was the reconstruction of the bone defect by a large, fresh, autologous cancellous bone graft.Results The membrane induced by the spacer prevents the resorption of the graft and favours its revascularisation and its corticalisation. Experimental study has also shown that the membrane plays the role of an "in situ growth-factors delivery system".Conclusion In weight-bearing diaphyseal segments normal walking was possible at 8.5 months on average.     

Experimental study on repair of the defect of the pars interarticularis in rat with bone morphogenetic protein and fibrin glue]

The possibility of repairing the defect of the pars interarticularis (pars defect) with Bone Morphogenetic Protein (BMP) and fibrin glue was studied. The pars defect established in the 5th lumbar vertebra of Wistar rat was treated with surgical implantation of a composite consisting of BMP, fibrin glue and autologous cancellous bone. At 3, 6, 9 and 12 weeks after implantation, the osteoinductive activity in the pars defect was observed histologically and compared with that of other composite implants such as BMP with fibrin glue, autologous cancellous bone alone and autologous cancellous bone with fibrin glue. Although perfect bone fusion was not obtained with any of the composites employed, a significant increase in bone formation was seen in a composite of BMP, fibrin glue and autologous cancellous bone (p less than 0.01) as compared with that seen in the others. Consequently, implantation of BMP and fibrin glue combined with some biomaterials which support osteo-induction of BMP and stabilize the pars defect might be successfully applied to repair the pars defect.     

Rekonstruktion segmentaler Knochendefekte

The relevance of autologous cancellous bone grafts (ACBG) for the treatment of segmental bone defects is not clearly defined. In the literature, 5?C6?cm is considered the maximum defect length that can be bridged. Longer defects carry an increased risk of graft necrosis and resorption. The major concerns of ACBG for segmental bone defects are the limited resources and the significant comorbidities of cancellous bone harvesting. The recently developed reamer?Caspirator?Cirrigator system has opened the opportunity to gain more cancellous bone with fewer comorbidities. In combination with the technique of induced membranes developed by Masquelet, where a well-vascularised membrane develops within 12 weeks around a polymethylmethacrylate spacer which is inserted into a segmental defect, being filled with cancellous bone, both restrictions of cancellous bone transplantation might be overcome. Systematic evaluations are necessary to more precisely define the indications for the different procedures at hand to treat segmental bone defects. It can be expected that ACBG will take an important place in the treatment of segmental bone defects beyond the currently accepted indication for defects of 5?C6?cm.     

Tubular Remodeling of Massive Cancellous Bone Graft in the Treatment of Long Bone Defects

Abstract Background: This case report describes the clinical and radiological result at the 4.5-year follow-up after an extensive reconstruction of the femoral diaphysis using autologous cancellous bone graft. The radiological study including axial tomography demonstrates secondary remodelling to form tubular diaphyseal bone. Methods: A patient with an existing hip fusion, who sustained a fracture of the proximal femur 12 years later, was treated by open internal fixation using a plate and screws. Infection followed which became chronic, causing bone resorption and necrosis and producing a septic non-union. Reconstruction in two stages was performed: open radical debridement which ended with a 14.5 cm diaphyseal defect of the femur, temporary alloplastic spacer interposition and secondary de-arthrodesis of the hip with massive autologous cancellous grafts into the induced foreign body membrane left by the spacer. Fixation was provided by a plate and screws. Results: The femur was free of infectious recurrence at 4.5 years. The patient walks without crutches with a shortened lower limb using a leg length compensation shoe and a painfree sine-sine hip arthroplasty. The former bone defect is fully remodelled into new cortical bone. X-ray and CT-scan demonstrate the tubular form of the reconstructed bone. Conclusion: This clinical case demonstrates the restoration of a medullar cavity after massive cancellous bone grafting of a diaphyseal defect of the femur. The question remains open as to whether the foreign body membrane has only a simple passive protective function against extraosseous bone resorbing factors or whether it functions actively by producing growth factors or other beneficial bone inducing factors.     

Does the use of antibiotic spacer disrupt induced membrane function?

Treatment of large segmental bone defects has been a challenging and long process for both physicians and patients. At present, the induced membrane technique is one of the reconstruction techniques commonly utilized in treating large segmental bone defects. It consists of a two-step procedure. In the first one, after bone debridement, the defect is filled with bone cement. The aim at this stage is to support and protect the defective area with cement. A membrane is formed around the area where cement was inserted 4-6 weeks after the first surgical stage. This membrane secretes vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), as shown in the earliest studies. In the second step, the bone cement is removed, and the defect is filled with cancellous bone autograft. In the first stage, antibiotics can be added to the applied bone cement, depending on the infection. Still, the histological and micromolecular effects of the added antibiotic on the membrane are unknown.This study investigates the molecular and histological effects of antibiotics addition into bone cement on the induced membrane.In this study, conducted on 27 male New Zealand rabbits, the 2 cm long defects of a bone were created in the rabbit femurs. Three groups were formed by placing antibiotic-free, gentamicin, and vancomycin-containing cement in the defect area.These groups were followed for six weeks, and the membrane formed at the end of 6 weeks was examined histologically. As a result of this study, it found that the membrane quality markers (Von Willebrand factor (vwf), Interleukin 6-8 (IL), Transforming growth factor beta (TGF-β), Vascular endothelial growth factor (VEGF) were significantly higher in the antibiotic-free bone cement group. Our study has shown that antibiotics added to the cement have negative effects on the membrane. Based on the results we obtained, it would be a better choice to use antibiotic-free cement in aseptic nonunions. However, more data is needed to understand the effects of these changes on the cement on the membrane.     

Tissue-engineered bone formation in vivo using a novel sintered polymeric microsphere matrix

We have evaluated in vivo a novel, polymer-based, matrix for tissue engineering of bone. A segmental defect of 15 mm was created in the ulna of New Zealand white rabbits to determine the regenerative properties of a porous polylactide-co-glycolide matrix alone and in combination with autogenous marrow and/or the osteoinductive protein, BMP-7. In this study four implant groups were used: 1) matrix alone; 2) matrix with autogenous marrow; 3) matrix with 20 microg of BMP-7; and 4) matrix with 20 microg of BMP-7 and autogenous marrow. The results showed that the degree of bone formation was dependent on the properties of the graft material. The osteoconductive sintered matrix structure showed significant formation of bone at the implant-bone interface. The addition of autogenous marrow increased the penetration of new bone further into the central area of the matrix and also increased the degree of revascularisation. The osteoinductive growth factor BMP-7 induced penetration of new bone throughout the entire structure of the implant. The most effective treatment was with the combination of marrow cells and osteoinductive BMP-7.     

Induced membrane technique for the reconstruction of bone defects in upper limb. A prospective single center study of nine cases

Introduction

Bone defect in the upper limb remain infrequent with few reported in the literature. Their reconstruction raises the problem of bone union of non weight-bearing segments as well as the function of adjacent joints. We report a monocentric continuous series of nine patients treated with the induced membrane technique (Masquelet technique).

Patients and methods

Nine patients with a mean age of 39.2 years (17–69) presented with a bone defect of the humerus (six cases) or one of two bones (three cases). Diaphyseal (six cases) or metaphyseal (three cases) defects were secondary to trauma in three patients, to non-union in four others and following tumors for the other two. The mean defect was 5.1 cm (2.5–9). Reconstruction was done by initial filling using a spacer in cement, followed by a cancellous bone graft within the induced membrane. BMP's growth factor was used in two cases.

Results

Bone union was achieved in eight out of nine cases with a follow-up of 23 months (8–52) after the first stage, and 17 months (6–49) following filling by the graft. One patient did not want the second stage done before one year. The failure was in a very non-compliant patient who had a bone substitute associated with aBMP. Two septic non-unions were cured. Shoulder and elbow functional outcomes were comparable to the controlateral side for humeral defects; pronosupination decreased by 17% for the cases of reconstruction of two bones.

Discussion

The technique of the induced membrane allows filling of a large bone defect, while avoiding vascularised bone autografts and their morbidity. It requires two procedures but can be used in emergency or after failure of other interventions. It is a reliable, and reproducible technique where the only limit is the cancellous bone stock. Following the series of Masquelet, Apard and Stafford in the lower limb, and the series of Flamans in the hand, this is the first report of reconstruction of defect in the upper limb using this technique.     

Quantitative assessment of scaffold and growth factor-mediated repair of critically sized bone defects.

An 8-mm rat segmental defect model was used to evaluate quantitatively the ability of longitudinally oriented poly(L-lactide-co-D,L-lactide) scaffolds with or without growth factors to promote bone healing. BMP-2 and TGF-beta3, combined with RGD-alginate hydrogel, were co-delivered to femoral defects within the polymer scaffolds at a dose previously shown to synergistically induce ectopic mineralization. A novel modular composite implant design was used to achieve reproducible stable fixation, provide a window for longitudinal in vivo micro-CT monitoring of 3D bone ingrowth, and allow torsional biomechanical testing of functional integration. Sequential micro-CT analysis showed that bone ingrowth increased significantly between 4 and 16 weeks for the scaffold-treated defects with or without growth factors, but no increase with time was observed in empty defect controls. Treatment with scaffold alone improved defect stability at 16 weeks compared to nontreatment, but did not achieve bone union or restoration of mechanical function. Augmentation of scaffolds with BMP-2 and TGF-beta3 significantly increased bone formation at both 4 and 16 weeks compared to nontreatment, but only produced bone bridging of the defect region in two of six cases. Histological evaluation indicated that bone formed first at the periphery of the scaffolds, followed by more limited mineral deposition within the scaffold interior, suggesting that the cells participating in the initial healing response were primarily derived from periosteum. This study introduces a challenging segmental defect model that facilitates quantitative evaluation of strategies to repair critically sized bone defects. Healing of the defect region was improved by implanting structural polymeric scaffolds infused with growth factors incorporated within RGD-alginate. However, functional integration of the constructs appeared limited by continued presence of slow-degrading scaffolds and suboptimal dose or delivery of osteoinductive signals.     

Strain imparted during impaction grafting may contribute to bony incorporation: an in vitro study of the release of bmp-7 from allograft

In order to investigate the osteoinductive properties of allograft used in impaction grafting and the effect of strain during impaction on these properties, we designed an in vitro experiment to measure strain-related release of bone morphogenetic protein-7 (BMP-7) from fresh-frozen femoral head allograft. A total of 40 10 mm cubes of cancellous bone were cut from ten samples of fresh-frozen femoral head. The marrow was removed from the cubes and the baseline concentrations of BMP-7 were measured. Specimens from each femoral head were allocated to four groups and subjected to different compressive strains with a material testing machine, after which BMP-7 activity was reassessed. It was present in all groups. There was a linear increase of 102.1 pg/g (95% confidence interval 68.6 to 135.6) BMP-7 for each 10% increase in strain. At 80% strain the mean concentration of BMP-7 released (830.3 pg/g bone) was approximately four times that released at 20% strain. Activity of BMP-7 in fresh-frozen allograft has not previously been demonstrated. This study shows that the freezing and storage of femoral heads allows some maintenance of biological activity, and that impaction grafting provides a source of osteoinductive bone for remodelling. We have shown that BMP-7 is released from fresh-frozen femoral head cancellous bone in proportion to the strain applied to the bone. This suggests that the impaction process itself may contribute to the biological process of remodelling and bony incorporation.     

A bioactive synthetic membrane improves bone healing in a preclinical nonunion model

ObjectivesHigh energy long bone fractures with critical bone loss are at risk for nonunion without strategic intervention. We hypothesize that a synthetic membrane implanted at a single stage improves bone healing in a preclinical nonunion model.MethodsUsing standard laboratory techniques, microspheres encapsulating bone morphogenic protein-2 (BMP2) or platelet derived growth factor (PDGF) were designed and coupled to a type 1 collagen sheet. Critical femoral defects were created in rats and stabilized by locked retrograde intramedullary nailing. The negative control group had an empty defect. The induced membrane group (positive control) had a polymethylmethacrylate spacer inserted into the defect for four weeks and replaced with a bare polycaprolactone/beta-tricalcium phosphate (PCL/β-TCP) scaffold at a second stage. For the experimental groups, a bioactive synthetic membrane embedded with BMP2, PDGF or both enveloped a PCL/β-TCP scaffold was implanted in a single stage. Serial radiographs were taken at 1, 4, 8, and 12 weeks postoperatively from the definitive procedure and evaluated by two blinded observers using a previously described scoring system to judge union as primary outcome.ResultsAll experimental groups demonstrated better union than the negative control (p = 0.01). The groups with BMP2 incorporated into the membrane demonstrated higher average union scores than the other groups (p = 0.01). The induced membrane group performed similarly to the PDGF group. Complete union was only demonstrated in groups with BMP2-eluting membranes.ConclusionsA synthetic membrane comprised of type 1 collagen embedded with controlled release BMP2 improved union of critical bone defects in a preclinical nonunion model.     

Relevance of osteoinductive biomaterials in critical-sized orthotopic defect.

Several publications have shown the phenomenon of osteoinduction by biomaterials to be real. However, whether the ability of a biomaterial to initiate bone formation in ectopic implantation sites improves the performance of such osteoinductive biomaterial in clinically relevant orthotopic sites remains unclear. No studies have been published in which osteoinductive potential of a biomaterial is directly related to its performance orthotopically. In this study, we compared osteoinductive and nonosteoinductive biphasic calcium-phosphate (BCP) ceramics ectopically and in a clinically relevant critical-sized orthotopic defect in goats. The two materials, BCP1150 and BCP1300, had similar chemical compositions, crystallinities, and macrostructures, but their microstructures differed significantly. BCP1150, sintered at a lower temperature, had a large amount of micropores, small average crystal size, and hence a high specific surface area. In contrast, BCP1300, with few micropores, had a significantly lower specific surface area as compared to BCP1150. Twelve-week intramuscular implantation in goats (n = 10) showed that bone was induced in all BCP1150 implants, while no signs of bone formation were found in any of the BCP1300 implants. After 12 weeks of implantation in a bilateral critical-sized iliac wing defect in the same goats, BCP1150 showed significantly more bone than BCP1300. In addition, the analysis of fluorochrome markers, which were administered to the animals 4, 6, and 8 weeks after implantation to follow the bone growth dynamics, showed an earlier start of bone formation in BCP1150 as compared to BCP1300. Significantly better performance of an osteoinductive ceramic in a critical-sized orthotopic defect in a large animal model in comparison to a nonosteoinductive ceramic suggests osteoinduction to be clinically relevant. Further improvement of material osteoinductive properties is thus a significant step forward in the search for alternatives for autologous bone graft.     

Influence of the induced membrane filled with syngeneic bone and regenerative cells on bone healing in a critical size defect model of the rat’s femur

IntroductionThe induced membrane technique for the treatment of large bone defects consists of a 2-stage procedure. In the first stage, a polymethylmethacrylate (PMMA) cement spacer is inserted into the bony defect of a rat’s femur and over a period of 2–4 weeks a membrane forms that encapsulates the defect/spacer. In a second operation the membrane is opened, the PMMA spacer is removed and the resulting cavity is filled with autologous bone.Since little effort has been made to replace the need for autologous bone this study was performed to elucidate the influence of different stem cells and the membrane itself on bone healing in a critical size femur defect model in rats.Especially the question should be addressed whether the use of stem cells seeded on a β-TCP scaffold is equivalent to syngeneic bone as defect filling in combination with the induced membrane technique.Materials and MethodsA total of 96 male Sprague-Dawley (SD) rats received a 10 mm critical size defect of the femur, which was stabilized by a plate osteosynthesis and filled with PMMA cement. In a second step the spacer was extracted and the defects were filled with syngeneic bone, β-TCP with MSC + EPC or BM-MNC. In order to elucidate the influence of the induced membrane on bone defect healing the induced membrane was removed in half of the operated femurs. The defect area was analysed 8 weeks later for bone formation (osteocalcin staining), bone mineral density (BMD) and bone strength (3-point bending test).ResultsNew bone formation, bone mineral density and bone stiffness increased significantly, if the membrane was kept. The transplantation of biologically active material (syngeneic bone, stem cells on b-TCP) into the bone defect mostly led to a further increase of bone healing. Syngeneic bone had the greatest impact on bone healing however defects treated with stem cells were oftentimes comparable.ConclusionFor the first time we demonstrated the effect of the induced membrane itself and different stem cells on critical size defect healing. This could be a promising approach to reduce the need for autologous bone transplantation with its’ limited availability and donor site morbidity.     

Immunohistochemical demonstration of growth factors at the tendon–bone interface in anterior cruciate ligament reconstruction using a rabbit model

Background The success of anterior cruciate ligament (ACL) reconstruction using tendon grafts depends on biological integration between the tendon and bone. Growth factors play a significant role in this integration process, but few studies have defined the regulating mechanisms of these growth factors during tendon–bone healing. The aim of the present study was to clarify the relationship between the histological changes and the expression of endogenous growth factors at the tendon–bone interface. Methods Using intra-articular tendon transfer in rabbits to stimulate ACL reconstruction, the presence of fibroblast growth factor-2 (FGF-2), vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP-2), and BMP-7 at the interface between the tendon and bone was evaluated immunohistochemically. Histological and immunohistochemical investigations were performed at 1, 3, 6, and 12 weeks after surgery. Results Fibrous integration of the tendon graft to the bone was observed immediately after tendon transfer and followed remodeling of the bone tunnel. Fibroblast and vascular growth factors were found in abundance at the tendon–bone interface in the first 3 weeks of graft incorporation, but were absent in the 12-week specimens. BMPs were found throughout the 12-week study period and were observed at high concentrations near the bone. Conclusions These results indicate that FGF-2 and VEGF contribute to fibrous integration between the tendon and bone during the early postoperative stage, and that BMP-2 and BMP-7 are specifically involved in bone remodeling leading to osseous integration. The early stages of tendon–bone healing might be important in controlling the integration process of the interface in ACL reconstruction surgery as seen in this rabbit model.