Intercalary bone graft of the tibia: case series and review of the literature

Graft Infections in Biologic Reconstructions in the Oncologic Setting: A Systematic Review of the Literature

Background: Biologic graft infection (BGI) is one of the main complications in graft reconstructions. However, very little evidence exists regarding the epidemiology of BGI, as most of the data come from sparse reports. Moreover, most of the series did not detail the treatment and outcome of graft infections. The aim of this systematic review of the literature is to provide a comprehensive data collection on BGI after oncologic resections. Methods: Three different databases (PubMed, Scopus, and Web of Science) were searched for relevant articles, and further references were obtained by cross-referencing. Results: 139 studies met the inclusion criteria. A total of 9824 grafts were retrieved. Among these, 684 (6.9%) were in the humerus, 365 (3.7%) in the pelvis, 2041 (20.7%) in the femur and 1660 (16.8%) in the tibia. Most grafts were osteoarticular (2481, 26.7%) and intercalary 2112 (22.7%) allografts. In 461 (5.0%), vascularized fibula grafts (VFGs) were used in combination with recycled autografts. Recycled grafts were reported in 1573 (16.9%) of the cases, and allograft-prosthetic composites in 1673 (18.0%). The pelvis and the tibia had the highest incidence of BGI (20.4% and 11.0%, respectively). The most reported first treatment was debridement and implant retention (DAIR) in 187 (42.8%) cases and two-stage revision with graft removal in 152 (34.8%). Very little data are reported on the final outcome specified by site or type of graft. Conclusions: This systematic review of the literature confirms a high incidence of infections in biologic reconstructions after resections of primary bone tumors. Despite DAIR being a viable attempt, in most cases, a two-stage approach with graft removal and reconstruction with endoprosthesis presented the highest chance to overcome infection, guaranteeing a reconstruction. We emphasize the need for future multicentric studies to focus on the management of infections after biological reconstructions in bone sarcomas.

Impact of NaOH based perfusion-decellularization protocol on mechanical resistance of structural bone allografts

INTRODUCTION

To mitigate the post-operative complication rates associated with massive bone allografts, tissue engineering techniques have been employed to decellularize entire bones through perfusion with a sequence of solvents. Mechanical assessment was performed in order to compare conventional massive bone allografts and perfusion/decellularized massive bone allografts.

MATERIAL AND METHODS

Ten porcine femurs were included. Five were decellularized by perfusion. The remaining 5 were left untreated as the "control" group. Biomechanical testing was conducted on each bone, encompassing five different assessments: screw pull-out, 3-points bending, torsion, compression and Vickers indentation.

RESULTS

Under the experimental conditions of this study, all five destructive tested variables (maximum force until screw pull-out, maximum elongation until screw pull-out, energy to pull out the screw, fracture resistance in flexion and maximum constrain of compression) were statistically significantly superior in the control group. All seven nondestructive variables (Young's modulus in flexion, Young's modulus in shear stress, Young's modulus in compression, Elastic conventional limit in compression, lengthening to rupture in compression, resilience in compression and Vickers Hardness) showed no significant difference.

DISCUSSION

Descriptive statistical results suggest a tendency for the biomechanical characteristics of decellularized bone to decrease compared with the control group. However, statistical inferences demonstrated a slight significant superiority of the control group with destructive mechanical stresses. Nondestructive mechanical tests (within the elastic phase of Young's modulus) were not significantly different.

Vascular study of decellularized porcine long bones: Characterization of a tissue engineering model

INTRODUCTION

Massive bone allografts enable the reconstruction of critical bone defects in numerous conditions (e.g. tumoral, infection or trauma). Unfortunately, their biological integration remains insufficient and the reconstruction may suffer from several postoperative complications. Perfusion-decellularization emerges as a tissue engineering potential solution to enhance osseointegration. Therefore, an intrinsic vascular study of this novel tissue engineering tool becomes essential to understand its efficacy and applicability.

MATERIAL AND METHODS

32 porcine long bones (humeri and femurs) were used to assess the quality of their vascular network prior and after undergoing a perfusion-decellularization protocol. 12 paired bones were used to assess the vascular matrix prior (N = 6) and after our protocol (N = 6) by immunohistochemistry. Collagen IV, Von Willebrand factor and CD31 were targeted then quantified. The medullary macroscopic vascular network was evaluated with 12 bones: 6 were decellularized and the other 6 were, as control, not treated. All 12 underwent a contrast-agent injection through the nutrient artery prior an angio CT-scan acquisition. The images were processed and the length of medullary vessels filled with contrast agent were measured on angiographic cT images obtained in control and decellularized bones by 4 independent observers to evaluate the vascular network preservation. The microscopic cortical vascular network was evaluated on 8 bones: 4 control and 4 decellularized. After injection of gelatinous fluorochrome mixture (calcein green), non-decalcified fluoroscopic microscopy was performed in order to assess the perfusion quality of cortical vascular lacunae.

RESULTS

The continuity of the microscopic vascular network was assessed with Collagen IV immunohistochemistry (p-value = 0.805) while the decellularization quality was observed through CD31 and Von Willebrand factor immunohistochemistry (p-values <0.001). The macroscopic vascular network was severely impaired after perfusion-decellularization; nutrient arteries were still patent but the amount of medullary vascular channels measured was significantly higher in the control group compared to the decellularized group (p-value <0.001). On average, the observers show good agreement on these results, except in the decellularized group where more inter-observer discrepancies were observed. The microscopic vascular network was observed with green fluoroscopic signal in almost every canals and lacunae of the bone cortices, in three different bone locations (proximal metaphysis, diaphysis and distal metaphysis).

CONCLUSION

Despite the aggressiveness of the decellularization protocol on medullary vessels, total porcine long bones decellularized by perfusion retain an acellular cortical microvascular network. By injection through the intact nutrient arteries, this latter vascular network can still be used as a total bone infusion access for bone tissue engineering in order to enhance massive bone allografts prior implantation.

Limb salvage surgery reconstructive techniques following long-bone lower limb oncological resection: a systematic review and meta-analysis

BACKGROUND

Limb salvage surgery (LSS) is now considered the gold standard surgical treatment for lower limb bone sarcomas. However, there is a paucity of literature comparing the various LSS reconstructive options. The aim of this systematic review and meta-analysis was to compare functional outcomes and complications of LSS reconstructive techniques.

METHODS

The primary aim of the meta-analysis was to determine functional outcomes from the pooled data utilizing the Musculoskeletal Tumour Society score (MSTS). Comparisons could then made for this outcome between biological and prosthetic, vascularised and non-vascularised, and prosthetic and composite reconstructions. The secondary aim was to compare complication outcomes of each reconstruction. Standardized mean difference (Cohen's d) and odds ratios were estimated using a random effects model.

RESULTS

Fourteen studies with a total of 785 patients were included. We found structural failure was 75% less likely to occur in prosthetic reconstruction compared to biological (OR = 0.24; 95% CI: 0.07-0.79; P = 0.02). We did not find any evidence of difference in function (MSTS score) between vascularised verses non-vascularised reconstructions (Cohen's d = -1.14; 95% CI = -3.06 to 0.78; I2  = 87%). Other analyses comparing complications found no difference between the reconstructive groups.

CONCLUSION

The study found no correlation between functional outcomes and the type of LSS reconstruction. Structural failure was more likely to occur in biological when compared with prosthetic reconstruction. There was no correlation between the incidence of other complications and the type of LSS technique. This suggests a role for improved approaches to reconstruction methods including bioprinting and bioresorbable devices.

Intercalary frozen autografts for reconstruction of bone defects following meta-/diaphyseal tumor resection at the extremities

Background

For patients with malignant limb tumors, salvage surgery can be achieved using endoprosthesis or biological reconstructions like allograft or autograft. In carefully selected patients, resected bone can be recycled after sterilization using methods like autoclaving, irradiation, pasteurization or freezing with liquid nitrogen. We evaluated the clinical outcome and complications of malignant limb tumors treated with intercalary resection and frozen autograft reconstruction.

Methods

We reviewed 33 patients whose malignant bone tumors were treated by wide resection and reconstruction with recycling liquid nitrogen-treated autografts between 2006 and 2017. Limb function, bone union at the osteotomy site and complications were evaluated. Functional outcome was assessed using the Musculoskeletal Tumor Society (MSTS) scoring system.

Results

The cohort comprised 16 males and 17 females, with a mean age of 35.4 years (14–76 years). The most common tumor was osteosarcoma (7 cases). Tumors were located in the humerus (5), ulna (1), femur (10) and tibia (17). The mean follow-up was 49.9 months (range 12–127 months). Of the 33 patients, 16 remained disease-free, and 3 were alive with disease. The mean size of the defect after tumor resection was 11.6 cm (range 6–25 cm). Bone union was achieved in 32 patients, with a mean union time of 8.8 months (range 4–18 months). Complications included 1 graft nonunion, 2 infections (1 superficial, 1 deep infection), 1 leg length discrepancy, 2 graft fractures and 3 local recurrences. The mean MSTS score was 87.2% (range 70–100%).

Conclusion

Liquid nitrogen-treated tumor-bearing autograft is an effective option for biological reconstruction after meta-/diaphyseal tumor resection of long bones. This method has excellent clinical outcomes and is especially recommended for patients with no severe osteolytic bone tumors.

How the Choice of Osteosynthesis Affects the Complication Rate of Intercalary Allograft Reconstruction? A Systematic Review and Meta-analysis

BACKGROUND

There is no clear consensus on the optimal type of fixation in intercalary allograft reconstruction. In this study, we aimed to compare the rate of most common complications following the plate and nail fixation of the intercalary allograft.

MATERIALS AND METHODS

We searched PubMed, EMBASE, Web of Science, Scopus, and Cochrane Library. Studies in which the complication rate of the single bridging plate and intramedullary nail fixation was extractable were included. Studies that used extra procedures such as cementation and fibular vascular graft augmentation were excluded. The primary outcome was the fixation-specific rate of nonunion. Secondary outcomes were the fixation-specific rate of fracture, infection, and local recurrence.

RESULTS

In total, 13 studies with 431 reconstructions (352 reconstructions in the plate group and 79 reconstructions in the intramedullary nailing group) were included in this study. In the plate fixation, the rate of nonunion, fracture, infection and local recurrence was 12%, 11%, 11%, and 3%, respectively. In the intramedullary nail fixation, the rate of nonunion, fracture, infection, and local recurrence was 37%, 5%, 4%, and 0%, respectively. The rate of nonunion was significantly higher in the intramedullary nail group (OR = 6.34; 95% CI 2.98-13.49, P < 0.001). The rate of fracture, infection, and local recurrence was not significantly different between the two fixation methods.

CONCLUSIONS

Intramedullary nail is associated with a significantly higher rate of nonunion. Since the rate of other complications was not significantly different between the two osteosynthesis types, plate fixation could be considered as a better type of fixation.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00563-7.