Treatment of 10-mm-Deep or Greater Uncontained Tibial Bone Defects in Primary Total Knee Reconstruction without Metal Augmentation: Autologous Oblique Structural Peg Bone and Cancellous Chip Bone Grafting

BackgroudIn this study, we report satisfactory clinical and radiological outcomes after autologous oblique structural peg bone and cancellous chip bone grafting without metal augmentation, including the use of a metal wedge, block, or additional stem, for patients with ≥ 10-mm-deep uncontained medial proximal tibial bone defects in primary total knee replacement.MethodsThe study group included 40 patients with primary total knee replacement with ≥ 10-mm-deep uncontained tibial bone defects who underwent autologous oblique structural peg bone and cancellous chip bone grafting and were followed-up for at least 1 year. Tibial cutting was performed up to a depth of 10 mm from the articular surface of the lateral tibial condyle, after which the height and area of the remaining bone defect in the medial condyle were measured. The bone defect was treated by making a peg bone and chip bone using excised segments of the tibia and femur. In all cases, the standard tibial stem and full cemented fixation techniques were used without metal augmentation. Preoperative and final follow-up radiologic changes and clinical measures were compared, and prosthesis loosening and bone union were checked radiologically at final follow-up.ResultsThe mean depth of the bone defects was 10.9 mm, and the mean percentage of the area occupied by bone defects in the axial plane was 18.4%. The mean mechanical femorotibial angle was corrected from 19.5° varus preoperatively to 0.2° varus postoperatively (p < 0.002). There was no prosthesis loosening, and all cases showed bone union at the 1-year postoperative follow-up.ConclusionsEven in patients with uncontained tibial bone defects ≥ 10-mm deep in primary total knee replacement, if the defect occupies less than 30% of the cut surface, autologous oblique structural peg bone and cancellous chip bone grafting can be used to achieve satisfactory outcomes with a standard tibial stem and no metal augmentation.     

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.     

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.     

The missing effect of human recombinant Bone Morphogenetic Proteins BMP-2 and BMP-7 in surgical treatment of aseptic forearm nonunion

IntroductionIn this cohort study, the surgical revision concept of open compression plating and autologous bone grafting with and without additional application of BMP for treatment of aseptic ulna and/or radius shaft nonunion was evaluated. The purpose was to evaluate the clinical and radiological outcome, and to determine any difference in osseous healing, range of time between revision surgery and bone healing, and postoperative complications between the cohort groups.Patients and methodsBetween 01/2005 and 03/2015, a prospective, randomised, controlled cohort study was performed in a Level I Trauma Centre. Forty-nine patients were treated with the diagnosis of aseptic diaphyseal ulnar and/or radial shaft nonunion using compression plating and autologous bone grafting. Additional biological augmentation using BMP-2 or BMP-7 was performed in 24 patients. Clinical and radiological follow-up was performed six weeks, three and six months after revision surgery in accordance to the system by Anderson.ResultsThe study group consisted of 38 men and 11 women with a median age of 44 years (range 19–77). Twenty-four out of 49 patients obtained compression plating either with autologous iliac crest bone grafting (11/24 patients) or cancellous bone grafting (13/24 patients) and additional application of BMP-2 (4/24 patients) or BMP-7 (20/24 patients). The remaining 25 patients did not receive any additional application of BMP, but autologous bone grafting. The median follow-up was 15 months (range 6–54 months). Forty-six out of 49 nonunion healed within 12 months after revision surgery with a median time to union of six months. The clinical outcome, as assessed using the system by Anderson, as well as osseous healing, duration of time interval between revision surgery and bone healing, and postoperative complications did not demonstrate significant differences between the cohort groups.DiscussionAtrophic/oligotrophic forearm nonunion healed irrespective of additional application of BMP combined with autologous bone grafting. For successful treatment, radical resection of fibrous nonunion tissue and internal compression plate fixation is required with the aim of achieving high degree of rigid stability. Also, correction of angular deformities, restoration of length, and precise axial alignment of the distal radio-ulnar joint are mandatory prerequisites to successfully achieve bone healing.     

Screw pullout strength: a biomechanical comparison of large-fragment and small-fragment fixation in the tibial plateau

OBJECTIVES: To compare the pullout strengths of 6.5-millimeter diameter partially threaded cancellous screws and 4.5-millimeter diameter fully-threaded cortical screws versus 3.5-millimeter diameter cortical screws in the proximal tibia. DESIGN: Three screws were inserted in the lateral tibial plateau of each leg of fifteen paired cadaveric tibias. In one tibia, large-fragment fixation was used, consisting of a unicortical 6.5-millimeter screw in the subchondral bone, and bicortical 4.5-millimeter screws in the metadiaphyseal and diaphyseal bone. In the contralateral tibia, small-fragment fixation consisting of three 3.5-millimeter screws was used, placing the screws in the same positions as described above. MAIN OUTCOME MEASUREMENTS: A materials-testing machine was used to determine axial pullout strengths of each screw. The mean pullout strengths of large-fragment and small-fragment screws in each position were compared. RESULTS: No significant difference in pullout strengths was found between the large-fragment and small-fragment screws in subchondral and metadiaphyseal bone. A statistically significant difference was found between pullout strengths of large-fragment and small-fragment screws in diaphyseal bone. CONCLUSIONS: In human proximal tibial bone, the data from this study do not suggest that the pullout strength of 3.5-millimeter screws differs from that of 6.5-millimeter screws in subchondral bone, or that the pullout strength of 3.5-millimeter screws differs from that of 4.5-millimeter screws in metadiaphyseal bone. However, the pullout strength of 3.5-millimeter screws is significantly less than that of 4.5-millimeter screws in diaphyseal bone. The authors of the present study believe this supports the use of small-fragment fixation in the treatment of tibial plateau fractures.     

同种异体骨移植在骨肿瘤手术中的应用

目的：探讨同种异体骨移植在骨肿瘤手术中应用的范围、效果以及排异反应等问题.方法：1983年10月～2003年3月在骨肿瘤手术中使用异体骨移植120例。其中肿瘤刮除、异体松质骨移植102例；肿瘤刮除、异体大块皮质骨和松质骨移植12例；肿瘤段切除、异体股骨干移植2例；肿瘤段切除、异体半关节移植3例；肿瘤切除、大块异体骶骨移植l例：结果：120例中只有2例出现较轻的排异反应，表现为手术后切口渗出较多，3个月后停止渗出，切口愈合.其余病例均一期愈合.结论：同种异体骨在骨肿瘤手术中应用范围，一、效果好、很少出现排异反应,在骨缺损填充物中占有重要位置.     

Does the Addition of a Vascularized Fibula Improve the Results of a Massive Bone Allograft Alone for Intercalary Femur Reconstruction of Malignant Bone Tumors in Children?

BackgroundMassive bone allograft with or without a vascularized fibula is a potentially useful approach for femoral intercalary reconstruction after resection of bone sarcomas in children. However, inadequate data exist regarding whether it is preferable to use a massive bone allograft alone or a massive bone allograft combined with a vascularized free fibula for intercalary reconstructions of the femur after intercalary femur resections in children. Because the addition of a vascularized fibula adds to the time and complexity of the procedure, understanding more about whether it reduces complications and improves the function of patients who undergo these resections and reconstructions would be valuable for patients and treating physicians.Questions/purposesIn an analysis of children with bone sarcomas of the femur who underwent an intercalary resection and reconstruction with massive bone allograft with or without a vascularized free fibula, we asked: (1) What was the difference in the surgical time of these two different surgical techniques? (2) What are the complications and number of reoperations associated with each procedure? (3) What were the Musculoskeletal Tumor Society scores after these reconstructions? (4) What was the survival rate of these two different reconstructions?MethodsBetween 1994 and 2016, we treated 285 patients younger than 16 years with a diagnosis of osteosarcoma or Ewing sarcoma of the femur. In all, 179 underwent resection and reconstruction of the distal femur and 36 patients underwent resection and reconstruction of the proximal femur. Additionally, in 70 patients with diaphyseal tumors, we performed total femur reconstruction in four patients, amputation in five, and a rotationplasty in one. The remaining 60 patients with diaphyseal tumors underwent intercalary resection and reconstruction with massive bone allograft with or without vascularized free fibula. The decision to use a massive bone allograft with or without a vascularized free fibula was probably influenced by tumor size, with the indication to use the vascularized free fibula in longer reconstructions. Twenty-seven patients underwent a femur reconstruction with massive bone allograft and vascularized free fibula, and 33 patients received massive bone allograft alone. In the group with massive bone allograft and vascularized fibula, two patients were excluded because they did not have the minimum data for the analysis. In the group with massive bone allograft alone, 12 patients were excluded: one patient was lost to follow-up before 2 years, five patients died before 2 years of follow-up, and six patients did not have the minimum data for the analysis. We analyzed the remaining 46 children with sarcoma of the femur treated with intercalary resection and biological reconstruction. Twenty-five patients underwent femur reconstruction with a massive bone allograft and vascularized free fibula, and 21 patients had reconstruction with a massive bone allograft alone. In the group of children treated with massive bone allograft and vascularized free fibula, there were 17 boys and eight girls, with a mean ± SD age of 11 ± 3 years. The diagnosis was osteosarcoma in 14 patients and Ewing sarcoma in 11. The mean length of resection was 18 ± 5 cm. The mean follow-up was 117 ± 61 months. In the group of children treated with massive bone allograft alone, there were 13 boys and eight girls, with a mean ± SD age of 12 ± 2 years. The diagnosis was osteosarcoma in 17 patients and Ewing sarcoma in four. The mean length of resection was 15 ± 4 cm. The mean follow-up was 130 ± 56 months. Some patients finished clinical and radiological checks as the follow-up exceeded 10 years. In the group with massive bone allograft and vascularized free fibula, four patients had a follow-up of 10, 12, 13, and 18 years, respectively, while in the group with massive bone allograft alone, five patients had a follow-up of 10 years, one patient had a follow-up of 11 years, and another had 13 years of follow-up. In general, there were no important differences between the groups in terms of age (mean difference 0.88 [95% CI -0.6 to 2.3]; p = 0.26), gender (p = 0.66), diagnosis (p = 0.11), and follow up (mean difference 12.9 [95% CI-22.7 to 48.62]; p = 0.46). There was a difference between groups regarding the length of the resection, which was greater in patients treated with a massive bone allograft and vascularized free fibula (18 ± 5 cm) than in those treated with a massive bone allograft alone (15 ± 4 cm) (mean difference -3.09 [95% CI -5.7 to -0.4]; p = 0.02). Complications related to the procedure like infection, neurovascular compromise, and graft-related complication, such as fracture and nonunion of massive bone allograft or vascularized free fibula and implant breakage, were analyzed by chart review of these patients by an orthopaedic surgeon with experience in musculoskeletal oncology. Survival of the reconstructions that had no graft or implant replacement was the endpoint. The Kaplan-Meier test was performed for a survival analysis of the reconstruction. A p value less than 0.05 was considered significant.ResultsThe surgery was longer in patients treated with a massive bone allograft and vascularized free fibula than in patients treated with a massive bone allograft alone (10 ± 0.09 and 4 ± 0.77 hours, respectively; mean difference -6.8 [95% CI -7.1 to -6.4]; p = 0.001). Twelve of 25 patients treated with massive bone allograft and vascularized free fibula had one or more complication: allograft fracture (seven), nonunion (four), and infection (four). Twelve of 21 patients treated with massive bone allograft alone had the following complications: allograft fracture (five), nonunion (six), and infection (one). The mean functional results were 26 ± 4 in patients with a massive bone allograft and vascularized free fibula and 27 ± 2 in patients with a massive bone allograft alone (mean difference 0.75 [95% CI -10.6 to 2.57]; p = 0.39). With the numbers we had, we could not detect a difference in survival of the reconstruction between patients with a massive bone allograft and free vascularized fibula and those with a massive bone allograft alone (84% [95% CI 75% to 93%] and 87% [95% CI 80% to 94%], respectively; p = 0.89).ConclusionWe found no difference in the survival of reconstructions between patients treated with a massive bone allograft and vascularized free fibula and patients who underwent reconstruction with a massive bone allograft alone. Based on this experience, our belief is that we should reconstruct these femoral intercalary defects with an allograft alone and use a vascularized fibula to salvage the allograft only if a fracture or nonunion occurs. This approach would have resulted in about half of the patients we treated not undergoing the more invasive, difficult, and risky vascularized procedure.Level of Evidence Level III, therapeutic study.     

Osteoperiosteal Decortication and Autogenous Cancellous Bone Graft Combined with Bridge Plating for Non-hypertrophic Diaphyseal Nonunion

BackgroudThe aim of this study was to evaluate results of osteoperiosteal decortication and autogenous cancellous bone graft combined with a bridge plating technique in atrophic and oligotrophic femoral and tibial diaphyseal nonunion.MethodsWe retrospectively reviewed 31 patients with atrophic or oligotrophic femoral and tibial diaphyseal nonunion treated with osteoperiosteal decortication and autogenous cancellous bone graft between January 2008 and December 2018. Patients with hypertrophic nonunion, infected nonunion, and nonunion treated with autogenous cancellous bone graft alone were excluded. The nonunion site was exposed by using the Judet technique of osteoperiosteal decortication. Nonunion with a lack of stability was stabilized with a new plate using a bridge plating technique or augmented by supplemental fixation with a plate. Nonunion with malalignment was stabilized with a new plate after deformity correction. Autogenous cancellous bone graft was harvested from the posterior iliac crest and placed within the area of decortication. A basic demographic survey was conducted, and the type of existing implants, mechanical stability of the implants, the type of implants used for stabilization, the operation time, the time to bone union, and postoperative complications were investigated.ResultsThe average follow-up period was 33.3 months (range, 8–108 months). The operation time was 207 minutes (range, 100–351 minutes). All but 1 nonunion (96.7%) were healed at an average of 4.2 months (range, 3–8 months). In 1 patient, bone union failed due to implant loosening with absorbed bone graft, and solid union was achieved by an additional surgery for stable fixation with a new plate, osteoperiosteal decortication, and autogenous cancellous bone graft. There were no other major complications such as neurovascular injuries, infection, loss of fixation, and malunion.ConclusionsOsteoperiosteal decortication and autogenous cancellous bone graft combined with stable fixation by bridge plating showed reliable outcomes in atrophic and oligotrophic diaphyseal nonunion. This treatment modality can be effective for treating atrophic and oligotrophic diaphyseal nonunion because it is very helpful stimulating bone union.     

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。     

Bone impregnated hip screw in femoral neck fracture: Clinicoradiological results

Background:

Femoral neck fractures are treated either by internal fixation or arthroplasty. Usually, cannulated cancellous screws are used for osteosynthesis of fracture neck of femur. The bone impregnated hip screw (BIHS) is an alternative implant, where osteosyntehsis is required in femoral neck fracture.

Materials and Methods:

The BIHS is a hollow screw with thread diameter 8.3 mm, shank diameter 6.5 mm and wall thickness 2.2 mm and holes in the shaft of the screw with diameter 2 mm, placed in a staggered fashion. Biomechanical and animal experimental studies were done. Clinical study was done in two phases: Phase 1 in a group of volunteers, only with BIHS was used in a pilot study and phase 2 comparative study was done in a group with AO cannulated screws and the other group treated with BIHS.

Results:

In the phase 1 study, out of 15 patients, only one patient had delayed union. In phase 2, there were 78 patients, 44 patients in BIHS showed early union, compared to the rest 34 cases of AO cannulated screws Out of 44 patients with BIHS, 41 patients had an excellent outcome, 2 had nonunions and one implant breakage was noted.

Conclusions:

Bone impregnated hip screw has shown to provide early solid union since it incorporates the biomechanical principles and also increases the osteogenic potential and hence, found superior to conventional cannulated cancellous screw.     

Progressive femoral cortical and cancellous bone density loss after uncemented tapered-design stem fixation

Background Aseptic implant loosening and periprosthetic bone loss are major problems after total hip arthroplasty (THA). We present an in vivo method of computed tomography (CT) assisted osteodensitometry after THA that differentiates between cortical and cancellous bone density (BD) and area around the femoral component.

Method Cortical and cancellous periprosthetic femoral BD (mg CaHA/mL), area (mm²) and contact area between the prothesis and cortical bone were determined prospectively in 31 patients 10 days, 1 year, and 6 years after uncemented THA (mean age at implantation: 55 years) using CT-osteodensitometry.

Results 6 years postoperatively, cancellous BD had decreased by as much as 41% and cortical BD by up to 27% at the metaphyseal portion of the femur; this decrease was progressive between the 1-year and 6-year examinations. Mild cortical hypertrophy was observed along the entire length of the diaphysis. No statistically significant changes in cortical BD were observed along the diaphysis of the stem.

Interpretation Periprosthetic CT-assisted osteodensitometry has the technical ability to discriminate between cortical and cancellous bone structures with respect to strain-adapted remodeling. Continuous loss of cortical and cancellous BD at the femoral metaphysis, a homeostatic cortical strain configuration, and mild cortical hypertrophy along the diaphysis suggest a diaphyseal fixation of the implanted stem. CT-assisted osteodensitometry has the potential to become an effective instrument for quality control in THA by means of in vivo determination of periprosthetic BD, which may be a causal factor in implant loosening after THA.     

Drilled Hole Defects in Mouse Femur as Models of Intramembranous Cortical and Cancellous Bone Regeneration

In order to identify pertinent models of cortical and cancellous bone regeneration, we compared the kinetics and patterns of bone healing in mouse femur using two defect protocols. The first protocol consisted of a 0.9-mm-diameter through-and-through cortical hole drilled in the mid-diaphysis. The second protocol was a 0.9-mm-diameter, 1-mm-deep perforation in the distal epimetaphyseal region, which destroyed part of the growth plate and cancellous bone. Bone healing was analyzed by ex vivo micro-computerized X-ray tomography and histology. In the diaphysis, the cortical gap was bridged with woven bone within 2 weeks. This newly formed bone was rapidly remodeled into compact cortical bone, which showed characteristic parameters of intact cortex 4 weeks after surgery. In the epimetaphysis, bone formation was initiated at the deepest region of the defect and spread slowly toward the cortical gap. In this position, newly formed bone quickly adopted the characteristics of trabecular bone, whereas a thin compact wall was formed at its external border, which reached the density of intact cortical bone but failed to bridge the cortical gap even 13 weeks after surgery. This comparative study indicates that the diaphyseal defect is a model of cortical bone healing and that the epimetaphyseal defect is a model of cancellous bone repair. These models enable experimental genetics studies to investigate the cellular and molecular mechanisms of spontaneous cortical and cancellous bone repair and may be useful for pharmacological studies.     

The Effect of Delayed Internal Fixation on Fracture Healing: An Experimental Study

Background and purpose The most frequently used bones for mechanical testing of orthopedic and trauma devices are fresh frozen cadaveric bones, embalmed cadaveric bones, and artificial composite bones. Even today, the comparability of these different bone types has not been established.

Methods We tested fresh frozen and embalmed cadaveric femora that were similar concerning age, sex, bone mineral density, and stiffness. Artificial composite femora were used as a reference group. Testing parameters were pullout forces of cortex and cancellous screws, maximum load until failure, and type of fracture generated.

Results Stiffness and type of fracture generated (Pauwels III) were similar for all 3 bone types (fresh frozen: 969 N/mm, 95% confidence interval (CI): 897–1,039; embalmed: 999 N/mm, CI: 875–1,121; composite: 946 N/mm, CI: 852–1,040). Furthermore, no significant differences were found between fresh frozen and embalmed femora concerning pullout forces of cancellous screws (fresh frozen: 654 N, CI: 471–836; embalmed: 595 N, CI: 365–823) and cortex screws (fresh frozen: 1,152 N, CI: 894–1,408; embalmed: 1,461 N, CI: 880–2,042), and axial load until failure (fresh frozen: 3,427 N, CI: 2,564–4290; embalmed: 3,603 N, CI: 2,898–4,306). The reference group showed statistically significantly different results for pullout forces of cancellous screws (2,344 N, CI: 2,068–2,620) and cortex screws (5,536 N, CI: 5,203–5,867) and for the axial load until failure (> 7,952 N).

Interpretation Embalmed femur bones and fresh frozen bones had similar characteristics by mechanical testing. Thus, we suggest that embalmed human cadaveric bone is a good and safe option for mechanical testing of orthopedic and trauma devices.     

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.     

Bone grafting of cryosurgically treated bone defects: experiments in goats

It is hypothesized that cryosurgically treated bone defects are inappropriate host sites for cancellous bone grafting. The influence of autologous cancellous bone grafting on the healing of cryosurgically treated gap defects of long bones was investigated. A unilateral in vivo experiment was done to study bone strength and graft incorporation in the goat. The lining of a cylindrical defect of the femoral diaphysis was treated with a closed liquid nitrogen cryoprobe in 62 goats. Thirty-one animals received an impacted, morselized, cancellous bone graft harvested from the sternum. The other 31 animals served as controls. At 0, 4, 7, 10, 13, 16, and 26 weeks animals were euthanized and the femurs were evaluated for torsional strength, computed tomography, and histologic assessment. Specimens with a bone graft showed no significant increase in torsional strength with time compared to the controls. In all goats euthanized at 10 weeks or later, the graft was resorbed. The amount of bone apposition at the site of the cryosurgical lesion and the time at which the defect was bridged were similar in both groups. Autologous cancellous bone grafting does not accelerate healing of cryosurgically treated, stable, diaphyseal defects in the goat.     

Bone substitution in revision hip replacement

The aim of this retrospective study was to report the preliminary results of femoral peri-prosthetic bone defect reconstruction with a synthetic bone substitute. Twenty-one revisions of the femoral component in 20 patients were evaluated. The mean age at operation was 65.7 years (range, 30 to 79 years). Preoperative femoral deficiencies were rated grade II in 7 cases and grade III in 14 cases according to the SOFCOT classification. None was rated grade IV. Femoral revision was indicated for loosening in 18 hips (including 8 septic cases), femoral osteolysis (1 hip), persistent pain (1 hip) and recurrent dislocation (1 hip). Once the loose prosthesis had been removed, calcium phosphate ceramic (CPC) granules (14 cases) or ceramic granules + cancellous allograft (5 cases) or autograft (2) were firmly impacted in the femoral canal. The stem was standard and always cemented using modern cementing technique. At a mean follow-up of 36 months (range, 14 to 76 months), 90% of the hips were rated good or very good according to the Merle d'Aubigné score. Two diaphyseal femoral fractures occurred and later united. Two hips required re-revision (aseptic loosening; septic recurrence). The absence of radiological osteolysis in 17 cases suggested direct bonding between ceramic granules and bone. Stem subsidence occurred in two cases and was limited (5 and 8 mm). Femoral bone reconstruction using impacted CPC or CPC in conjunction with bone graft in revision hip replacement commonly provided restoration of the bone stock in the short to mid-term. Further long-term studies will be necessary to support this conclusion.     

Ⅰ期开放松质骨植骨治疗感染性骨缺损

目的：探讨Ⅰ期开放松质骨植骨治疗感染性骨缺损的可行性,总结提高治疗成功率的因素。方法：12例感染性骨缺损患者,男8例,女4例;年龄22～68岁,平均42岁。其中跟骨骨缺损7例,胫骨4例,股骨1例。采用患处换药,刮除失活的软组织及骨组织,清创后Ⅰ期行自体松质骨植骨,伤口开放,术后创面爬满肉芽后行游离植皮治疗。结果：术后移植骨质表面覆盖肉芽组织时间平均24.1d,创面完全闭合时间平均30.3d,所有患者经过8～30个月（平均18个月）随访,所有骨缺损处经植骨后均骨性愈合,未发现感染复发者。结论：Ⅰ期开放植骨术是治疗感染性骨缺损简单可行的方法,术前刮除失活组织,术中彻底清除肉芽组织、充分植入松质骨及术后严格无菌换药是手术成功的关键。     

Induced membranes secrete growth factors including vascular and osteoinductive factors and could stimulate bone regeneration.

Based on a new concept, a procedure combining induced membranes and cancellous autografts allows the reconstruction of wide diaphyseal defects. In the first stage of this procedure, a cement spacer is inserted into the defect; the spacer is responsible for the formation of a pseudo-synovial membrane. In the second stage, the defect is reconstructed two months later by an autologous cancellous bone graft. The aim of this study was to evaluate the histological and biochemical characteristics of these membranes induced in rabbits. Histological studies carried out two, four, six, and eight weeks following implantation revealed a rich vascularization. Qualitative and quantitative immunochemistry showed production of growth factors (VEGF, TGFbeta1) and osteoinductive factors (BMP-2). Maximum BMP-2 production was obtained four weeks after the implantation, and, at this time, induced membranes favored human bone marrow stromal cell differentiation to the osteoblastic lineage. Should these results be confirmed in humans, bone reconstruction could be carried out earlier than previously thought and in better conditions than expected, the membrane playing the role of an in situ delivery system for growth and osteoinductive factors.     

Evaluation of osteosynthesis with dual fibular bone grafting for neglected femoral neck fractures

BackgroundFemoral neck fractures in young adults is an unsolved problem and neglected femoral neck fractures presents more challenge to the orthopaedics surgeon if femoral head salvage is attempted. We reviewed the operative results of neglected femoral neck fractures in young adults with fixation with dual fibular bone grafting Purpose of study was evaluation of epidemiological, clinical, functional, rehabilitative outcome and complications in such patients.MethodsTwentyeight patients in age group 18–50 years were operated having fracture neck femur by dual fibular bone grafting in the Department of Orthopaedics, S.N. Medical College, Agra in (May 2005–February 2008) and divided into two groups. Group A: comprised of 8 patients treated by dual fibular bone grafting alone and Group B: comprised of 18 patients treated by dual fibular bone grafting with single cancellous hip screw.ResultsAll the patients of the present series were having neglected intracapsular fracture, neck femur which were treated by dual fibular bone grafting with or without cancellous hip screw fixation. Majority of the patients had good to fair result according to Larson method with average time of union 16 weeks. All patients had useful range of movement at hip. Satisfactory union was achieved in all patients except two.ConclusionDouble bone grafting is a simple and cost effective modality of treatment for late femoral neck fracture with good results. It is a stable and biological method of fixation with preservation of natural femoral head with fewer complications.     

Plate Fixation for Atypical Fractures of the Femoral Diaphysis

BackgroundPlate fixation for atypical femoral fractures has shown high failure rates compared to intramedullary nail fixation. The aim of this study was to evaluate the radiological results of patients treated with a plate and screws for atypical fractures of the femoral diaphysis.MethodsThis study was conducted retrospectively on 16 patients who had undergone internal fixation using plates for treatment of atypical femoral complete fractures from 2007 to 2015. Nine patients were treated with lag screws and short plates while 7 patients were treated with position screws and long plates, which covered the whole femur. Radiologic evaluation was performed on all patients. Complications were also evaluated.ResultsBone union was achieved in all patients and the average bone union time was 17.7 weeks (range, 14–28 weeks). There was no correlation between the preoperative use of a bisphosphonate, plate length, postoperative teriparatide use, and the time to bone union. Regarding complications, 2 cases of complete fractures and 1 impending fracture occurred at the end of short plates.ConclusionsSatisfactory results were obtained with use of plates for patients with atypical femoral complete diaphyseal fractures, in whom intramedullary nails could not be applied due to severe bowing. In particular, it seemed advantageous compared with intramedullary nail fixation in that it could maintain the leg length through anatomical reduction and prevent iatrogenic fracture.