Intercalary allograft reconstructions following resection of primary bone tumors: a nationwide multicenter study

Failure Modes in Orthopedic Oncologic Reconstructive Surgery: A Review of Imaging Findings and Failure Rates

Limb salvage surgeries utilizing endoprostheses and allografts are performed for a variety of oncologic conditions. These reconstructions can fail and require revision for many reasons, which are outlined and classified into mechanical failures (soft tissue failures, aseptic loosening, structural failure), non-mechanical failures (infection, tumor progression), and pediatric failures (physeal arrest, growth dysplasia). Distinct radiologic and clinical findings define specific failure subtypes but are sparsely illustrated in the radiology literature. Specifically, an understanding of the organizational structure of the failure modes can direct radiologists' search for post-reconstruction complications, enhance an appreciation of their prognostic significance, and facilitate research by standardizing the language and conceptual framework around outcomes. The purpose of this review is to highlight the key radiologic findings and imaging studies of each failure mode in orthopedic oncologic reconstructive surgery in the context of risk factors, failure rates, prognosis and survival statistics, and clinical decision-making regarding chemotherapy, radiation, and revision surgery.

An algorithm for surgical treatment of children with bone sarcomas of the extremities

INTRODUCTION

Limb salvage surgery in children following bone sarcoma resection is a challenging problem because of the small size of the bones, the lack of appropriate size-matched implants, and the risk of limb-length discrepancy once skeletal growth is complete, secondary to the loss of the epiphyseal plate. Although several reconstruction options are available in children with bone sarcomas, such as vascularized fibula, massive bone allograft, extracorporeal devitalized autograft, endoprosthesis, and allograft-prosthesis composite, a consensus has not been reached on the best reconstruction method. The purpose of the present study is to propose an algorithm for reconstruction after resection of bone sarcomas in children.

METHODS

In this review, we analyzed reports on limb reconstruction in children following treatment for bone sarcoma, to provide a comprehensive overview of the different reconstruction options in children with bone sarcomas, the outcomes, and the risks and benefits of the different surgical approaches.

RESULTS

Despite a high risk of complications and the necessity for limb-lengthening procedures, prosthetic or biological reconstructions seem to achieve good functional outcomes in children with bone sarcoma. The use of massive bone graft seems to be recommended for intercalary reconstructions, with a free vascularized fibular graft for long defects, while for osteoarticular reconstruction a modular or expandable prosthesis or an allograft-prosthesis composite seems to have good results. For reconstruction of the proximal humerus, modular prosthesis or allograft-prosthesis composite are more commonly used than expandable prosthesis since there are fewer functional constraints related to possible limb-length discrepancy on the upper limb compared to the lower limb.

DISCUSSION

We discuss the advantages and limitations of the different available surgical options for bone reconstruction following tumor resection in children and propose an algorithm of potential surgical treatments for children with bone sarcomas of the extremities.

In vitro evaluation of bone cell response to novel 3D-printable nanocomposite biomaterials for bone reconstruction

Critically-sized segmental bone defects represent significant challenges requiring grafts for reconstruction. 3D-printed synthetic bone grafts are viable alternatives to structural allografts if engineered to provide appropriate mechanical performance and osteoblast/osteoclast cell responses. Novel 3D-printable nanocomposites containing acrylated epoxidized soybean oil (AESO) or methacrylated AESO (mAESO), polyethylene glycol diacrylate, and nanohydroxyapatite (nHA) were produced using masked stereolithography. The effects of volume fraction of nHA and methacrylation of AESO on interactions of differentiated MC3T3-E1 osteoblast (dMC3T3-OB) and differentiated RAW264.7 osteoclast cells with 3D-printed nanocomposites were evaluated in vitro and compared with a control biomaterial, hydroxyapatite (HA). Higher nHA content and methacrylation significantly improved the mechanical properties. All nanocomposites supported dMC3T3-OB cells' adhesion and proliferation. Higher amounts of nHA enhanced cell adhesion and proliferation. mAESO in the nanocomposites resulted in greater adhesion, proliferation, and activity at day 7 compared with AESO nanocomposites. Excellent osteoclast-like cells survival, defined actin rings, and large multinucleated cells were only observed on the high nHA fraction (30%) mAESO nanocomposite and the HA control. Thus, mAESO-based nanocomposites containing higher amounts of nHA have better interactions with osteoblast-like and osteoclast-like cells, comparable with HA controls, making them a potential future alternative graft material for bone defect repair.

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.

Parallel Reconstruction of Vascularized Fibula Autograft for Treatment of Complications after Resection of Malignant Tumor from the Thigh

SUMMARY

The authors herein introduce a modification of parallel reconstruction with a vascularized fibula autograft (VFA) for cases of femur allograft complications. Conventional parallel reconstruction, in which the fibula with its vascular pedicle is placed on the medial side of the femur and allogeneic bone, may be an effective means to solve the allograft complications. However, the limited contact area between the fibula and femur/allogeneic bone can affect the bone healing ability. Furthermore, the rigid internal fixation method for the VFA may cause stress shielding and result in bone resorption. The authors propose the use of modified parallel reconstruction of the VFA with fibula expansion and titanium cable fixation for patients with allograft-host junction nonunion, allogeneic bone fracture, and femoral shaft fracture after surgical removal of a malignant tumor from the thigh. The modified parallel reconstruction has been performed on 5 patients (2 patients underwent fibular expansion). All 5 patients with 7 nonunions of the allograft-host junction or fracture were followed up for 33.2 months. The length of fibular graft was 10 to 20 cm, with an average of 15.0 cm. The union rate of allograft-host junction and fracture was 100% (7 of 7), and the union time was 15.9 months. This modified parallel reconstruction technique can achieve satisfactory union in treatment of the above complications.

3D-printed modular prostheses for reconstruction of intercalary bone defects after joint-sparing limb salvage surgery for femoral diaphyseal tumours

Aims

The aim of this study was to investigate the safety and efficacy of 3D-printed modular prostheses in patients who underwent joint-sparing limb salvage surgery (JSLSS) for malignant femoral diaphyseal bone tumours.

Methods

We retrospectively reviewed 17 patients (13 males and four females) with femoral diaphyseal tumours who underwent JSLSS in our hospital.

Results

In all, 17 patients with locally aggressive bone tumours (Enneking stage IIB) located in the femoral shaft underwent JSLSS and reconstruction with 3D-printed modular prostheses between January 2020 and June 2022. The median surgical time was 153 minutes (interquartile range (IQR) 117 to 248), and the median estimated blood loss was 200ml (IQR 125 to 400). Osteosarcoma was the most common pathological type (n = 12; 70.6%). The mean osteotomy length was 197.53 mm (SD 12.34), and the median follow-up was 25 months (IQR 19 to 38). Two patients experienced local recurrence and three developed distant metastases. Postoperative complications included wound infection in one patient and screw loosening in another, both of which were treated successfully with revision surgery. The median Musculoskeletal Tumor Society score at the final follow-up was 28 (IQR 27 to 28).

Conclusion

The 3D-printed modular prosthesis is a reliable and feasible reconstruction option for patients with malignant femoral diaphyseal tumours. It helps to improve the limb salvage rate, restore limb function, and achieve better short-term effectiveness.

Hip Preservation and Capanna Reconstruction for Pediatric Proximal Femur Ewing Sarcoma: A Report of 2 Cases

CASE

This is a first report describing preservation of the femoral head by transcervical resection of proximal femoral Ewing sarcoma in 2 pediatric patients. A unique Capanna reconstruction supported joint salvage. At 1 year, Pediatric Outcomes Data Collection Instrument and Pediatric Toronto Extremity Salvage Score outcomes were excellent. Surveillance magnetic resonance imaging was without evidence of recurrence or impaired perfusion to the femoral head.

CONCLUSION

We demonstrate the feasibility of hip joint preservation and maintenance of femoral head viability after transcervical resection of pediatric proximal femur bone sarcomas while preserving the medial circumflex femoral artery. This technique may be a preferred option over joint sacrifice and endoprosthetic replacement in young patients when tumor margins permit.

Modular intercalary prosthetic reconstruction for malignant and metastatic tumours of the proximal femur

To illustrate the surgical technique and explore clinical outcomes of the reconstruction for the malignant and metastatic bone tumour of proximal femur with metallic modular intercalary prosthesis. Sixteen patients who underwent modular intercalary prosthetic reconstruction after tumour resection were included from April 2012 and October 2020. Prosthesis and screws parameters, resected bone length and residual bone length, clinical outcomes and survivorship were analyzed. All patients were followed up for an average of 19 months (range 1-74). In our series, 12 patients died of the progression of the primary disease at the final follow-up. The cumulative survivorship since the treatment of proximal femoral metastasis was 78.6% (11 patients) at 6 months and 38.5% (5 patients) at 1 year. The mean MSTS score was 22.25 ± 4.55 among all patients. There were no cases of loosening or breakage of the prostheses, plates or screws, despite the various measurements of prostheses and residual bones. Modular intercalary prosthetic reconstruction was an effective method for malignant tumour of the proximal femur, including the advantages of providing early pain relief, quickly restoring postoperative function, required a short operation time, and preserving the adjacent joints.

What Are the Complications, Function, and Survival of Tumor-devitalized Autografts Used in Patients With Limb-sparing Surgery for Bone and Soft Tissue Tumors? A Japanese Musculoskeletal Oncology Group Multi-institutional Study

BACKGROUND

Tumor-devitalized autografts treated with deep freezing, pasteurization, and irradiation are biological reconstruction methods after tumor excision for aggressive or malignant bone or soft tissue tumors that involve a major long bone. Tumor-devitalized autografts do not require a bone bank, they carry no risk of viral or bacterial disease transmission, they are associated with a smaller immunologic response, and they have a better shape and size match to the site in which they are implanted. However, they are associated with disadvantages as well; it is not possible to assess margins and tumor necrosis, the devitalized bone is not normal and has limited healing potential, and the biomechanical strength is decreased owing to processing and tumor-related bone loss. Because this technique is not used in many countries, there are few reports on the results of this procedure such as complications, graft survival, and limb function.

QUESTIONS/PURPOSES

(1) What was the rate of complications such as fracture, nonunion, infection, or recurrence in a tumor-devitalized autograft treated with deep freezing, pasteurization, and irradiation, and what factors were associated with the complication? (2) What were the 5-year and 10-year grafted bone survival (free from graft bone removal) of the three methods used to devitalize a tumor-containing autograft, and what factors were associated with grafted bone survival? (3) What was the proportion of patients with union of the tumor-devitalized autograft and what factors were associated with union of the graft-host bone junction? (4) What was the limb function after the tumor-devitalized autograft, and what factors were related to favorable limb function?

METHODS

This was a retrospective, multicenter, observational study that included data from 26 tertiary sarcoma centers affiliated with the Japanese Musculoskeletal Oncology Group. From January 1993 to December 2018, 494 patients with benign or malignant tumors of the long bones were treated with tumor-devitalized autografts (using deep freezing, pasteurization, or irradiation techniques). Patients who were treated with intercalary or composite (an osteoarticular autograft with a total joint arthroplasty) tumor-devitalized autografts and followed for at least 2 years were considered eligible for inclusion. Accordingly, 7% (37 of 494) of the patients were excluded because they died within 2 years; in 19% (96), an osteoarticular graft was used, and another 10% (51) were lost to follow-up or had incomplete datasets. We did not collect information on those who died or were lost to follow-up. Considering this, 63% of the patients (310 of 494) were included in the analysis. The median follow-up was 92 months (range 24 to 348 months), the median age was 27 years (range 4 to 84), and 48% (148 of 310) were female; freezing was performed for 47% (147) of patients, pasteurization for 29% (89), and irradiation for 24% (74). The primary endpoints of this study were the cumulative incidence rate of complications and the cumulative survival of grafted bone, assessed by the Kaplan-Meier method. We used the classification of complications and graft failures proposed by the International Society of Limb Salvage. Factors relating to complications and grafted autograft removal were analyzed. The secondary endpoints were the proportion of bony union and better limb function, evaluated by the Musculoskeletal Tumor Society score. Factors relating to bony union and limb function were also analyzed. Data were investigated in each center by a record review and transferred to Kanazawa University.

RESULTS

The cumulative incidence rate of any complication was 42% at 5 years and 51% at 10 years. The most frequent complications were nonunion in 36 patients and infection in 34 patients. Long resection (≥ 15 cm) was associated with an increased risk of any complication based on the multivariate analyses (RR 1.8 [95% CI 1.3 to 2.5]; p < 0.01). There was no difference in the rate of complications among the three devitalizing methods. The cumulative graft survival rates were 87% at 5 years and 81% at 10 years. After controlling for potential confounding variables including sex, resection length, reconstruction type, procedure type, and chemotherapy, we found that long resection (≥ 15 cm) and composite reconstruction were associated with an increased risk of grafted autograft removal (RR 2.5 [95% CI 1.4 to 4.5]; p < 0.01 and RR 2.3 [95% CI 1.3 to 4.1]; p < 0.01). The pedicle freezing procedure showed better graft survival than the extracorporeal devitalizing procedures (94% versus 85% in 5 years; RR 3.1 [95% CI 1.1 to 9.0]; p = 0.03). No difference was observed in graft survival among the three devitalizing methods. Further, 78% (156 of 200 patients) of patients in the intercalary group and 87% (39 of 45 patients) of those in the composite group achieved primary union within 2 years. Male sex and the use of nonvascularized grafts were associated with an increased risk of nonunion (RR 2.8 [95% CI 1.3 to 6.1]; p < 0.01 and 0.28 [95% CI 0.1 to 1.0]; p = 0.04, respectively) in the intercalary group after controlling for confounding variables, including sex, site, chemotherapy, resection length, graft type, operation time, and fixation type. The median Musculoskeletal Tumor Society score was 83% (range 12% to 100%). After controlling for confounding variables including age, site, resection length, event occurrence, and graft removal, age younger than 40 years (RR 2.0 [95% CI 1.1 to 3.7]; p = 0.03), tibia (RR 6.9 [95% CI 2.7 to 17.5]; p < 0.01), femur (RR 4.8 [95% CI 1.9 to 11.7]; p < 0.01), no event (RR 2.2 [95% CI 1.1 to 4.5]; p = 0.03), and no graft removal (RR 2.9 [95% CI 1.2 to 7.3]; p = 0.03) were associated with an increased limb function. The composite graft was associated with decreased limb function (RR 0.4 [95% CI 0.2 to 0.7]; p < 0.01).

CONCLUSION

This multicenter study revealed that frozen, irradiated, and pasteurized tumor-bearing autografts had similar rates of complications and graft survival and all resulted in similar limb function. The recurrence rate was 10%; however, no tumor recurred with the devitalized autograft. The pedicle freezing procedure reduces the osteotomy site, which may contribute to better graft survival. Furthermore, tumor-devitalized autografts had reasonable survival and favorable limb function, which are comparable to findings reported for bone allografts. Overall, tumor-devitalized autografts are a useful option for biological reconstruction and are suitable for osteoblastic tumors or osteolytic tumors without severe loss of mechanical bone strength. Tumor-devitalized autografts could be considered when obtaining allografts is difficult and when a patient is unwilling to have a tumor prosthesis and allograft for various reasons such as cost or socioreligious reasons.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Are Vascularized Fibula Autografts a Long-lasting Reconstruction After Intercalary Resection of the Humerus for Primary Bone Tumors?

BACKGROUND

A vascularized fibula graft (VFG) is the vascular autograft most frequently used to restore large segmental long bone defects, particularly in the upper limb. Because the use of a vascularized fibula involves an operation in an uninvolved extremity with potential morbidity, it is important to document that this type of reconstruction is successful in restoring function to the humerus. However, the long-term results of VFG after intercalary resection of the humeral diaphysis for bone tumors are still unknown.

QUESTIONS/PURPOSES

(1) What was the complication rate of reconstruction? (2) What was the functional result after surgical treatment, as assessed by the Musculoskeletal Tumor Society (MSTS) score, the American Shoulder and Elbow Society (ASES) score, and Constant score? (3) What was the survivorship of these grafts free from revision and graft removal at 5, 10, and 15 years?

METHODS

Between 1987 and 2021, 127 patients were treated at our institution with en bloc resection for a primary malignant or an aggressive benign bone tumor of the humerus; we excluded patients treated with extra-articular resection or amputation. Of those, 14% (18 of 127) were treated with intercalary resection of the humeral diaphysis for primary bone tumors and reconstruction with VFG, with or without a bulk allograft, and were analyzed in this retrospective study. Generally, our indications for reconstruction with VFG are intercalary resection of the humerus for primary malignant or aggressive benign bone tumors in patients with long life expectancy and high functional demands, in whom adequate bone stock of the proximal and distal epiphysis can be preserved. In 13 patients, VFG was used alone, whereas in five patients, a massive allograft was used. Our policy was to use VFG combined with a massive allograft in patients undergoing juxta-articular joint-sparing resections in which proximal osteotomy was performed close to the anatomic neck of the humerus to obtain more stable fixation and better tendinous reattachment of the rotator cuff and deltoid. All 18 patients who were treated with a VFG were available for follow-up at a minimum of 2 years (median follow-up 176 months, range 26 to 275 months), and although three have not been seen in the past 5 years and are not known to have died, they had 172, 163, and 236 months of follow-up, and were included. The median age at surgery was 25 years (range 2 to 63 years), the median humeral resection length was 15 cm (range 8 to 21 cm), and the median fibular length was 16 cm (range 12 to 23 cm). Complications and functional scores were ascertained by chart review that was performed by an individual not involved in patient care. Functional results were assessed with the MSTS score (range 0 to 30), the ASES score (range 0 to 100), and the Constant score (range 0% to 100%). Survivorship was estimated using a Kaplan-Meier survivorship estimator, which was suitable because there were few deaths in this series.

RESULTS

Seven patients underwent a revision procedure (one radial nerve transient palsy because of screw impingement, four nonunions in three patients with one humeral head avascular necrosis, treatment for screw-related pain in one patient, and two VFG fractures), and one patient underwent VFG removal. Donor site complications were observed in four patients (one ankle valgus deformity and three claw toes-the first toe in two patients and the other toes in the third). At the final clinical control, at a median follow-up of 176 months (range 26 to 275 months), the median MSTS score was 30 of 30 (range 28 to 30), the median ASES score was 98.3 (range 93 to 100), and the median Constant score was 93.5% (range 79% to 100%). Revision-free survival was 71% (95% CI 53% to 96%) at 5 years and 57% (95% CI 37% to 88%) at 10 and 15 years; VFG removal-free survival was 94% (95% CI 83% to 100%) at 5, 10, and 15 years.

CONCLUSION

VFG appears to be an effective reconstructive option after humeral intercalary resection for primary bone tumors. These are complex procedures and should be performed by an experienced team of surgeons who recognize that complications may occur frequently in the first years after the procedure. The frequency of mechanical complications observed in the first 5 years postoperatively may be lessened by using long spanning-plate fixation, and if successful, this reconstruction provides a long-term, durable reconstruction with excellent functional results.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Biological reconstruction of bone defect after resection of malignant bone tumor by allograft: a single-center retrospective cohort study

BACKGROUND

Allograft reconstruction following the resection of malignant bone tumors is associated with high rates of complications and failures. This study aimed to evaluate the efficacy and current problems of allograft reconstruction techniques to optimize treatment strategies at our center.

MATERIALS AND METHODS

Thirty-eight cases (16 men and 22 women), who were diagnosed with malignant bone tumors and had undergone allograft reconstruction, were recruited. Allograft was fixed by intramedullary nail, single steel plate, double plate, and intramedullary nail combined plate in 2, 4, 17, and 15 cases, respectively. Allograft union, local recurrence, and complications were assessed with clinical and radiological tests. Tumor grade was assessed using the Enneking staging of malignant bone tumors. Functional prognosis was evaluated by the Musculoskeletal Tumor Society (MSTS) scoring system.

RESULTS

Intercalary and osteoarticular reconstructions were performed in 32 and 6 cases, respectively. Six patients underwent reoperation related to allograft complications, four patients had local recurrence, and three patients with allograft fracture underwent allograft removal. A total of eight host-donor junctions showed nonunion, including seven cases (18.4%) in diaphysis and one case (3.1%) in metaphysis (p < 0.01). Host rejection and secondary osteoarthritis occurred in nine and two cases, respectively. No deep infection and internal fixation device fracture occurred. The overall allograft survival rate was 81.6%. Postoperative MSTS score of patients with allograft survival was 26.8 ± 2.9, indicating a significant improvement as compared to their preoperative function.

CONCLUSIONS

Allograft represents an excellent choice for intercalary bone defects after malignant bone tumor resection. Robust internal fixation protection across the whole length of the allograft is an important prerequisite for the survival of the allograft, while multidimensional osteotomy, intramedullary cement reinforcement, and pedicled muscle flap transfer can effectively improve the survival rate and healing rate of the allograft.

Effect of bone cement augmentation with different configurations of the dual locking plate for femoral allograft fixation: finite element analysis and biomechanical study

AIMS

Implant failure in allograft reconstruction is one of the most common problems after treating a large bone defect for a primary bone tumor. The study aimed to investigate the effect of bone cement augmentation with different configurations of dual locking plates used for femoral allograft fixation.

METHODS

Four finite element (FE) models of the femur with a 1-mm bone gap were developed at the midshaft with different configurations of the 10-hole fixation dual locking plate (LP) with and without intramedullary bone cement augmentation. Model 1 was the dual LP at the lateral and medial aspect of the femur. Model 2 was Model 1 with bone cement augmentation. Model 3 was the dual LP at the anterior and lateral aspect of the femur. Finally, Model 4 was Model 3 with bone cement augmentation. All models were tested for stiffness under axial compression as well as torsional, lateral-medial, and anterior-posterior bending. In addition, the FE analyses were validated using biomechanical testing on a cadaveric femur.

RESULTS

Model 2 had the greatest axial compression stiffness, followed by Models 1, 4, and 3. Bone cement augmentation in Models 2 and 4 had 3.5% and 2.4% greater axial stiffness than the non-augmentation Models 1 and 3, respectively. In the bone cement augmentation models, Model 2 had 11.9% greater axial compression stiffness than Model 4.

CONCLUSION

The effect of bone cement augmentation increases construct stiffness less than the effect of the dual LP configuration. A dual lateral-medial LP with bone cement augmentation provides the strongest fixation of the femur in terms of axial compression and lateral bending stiffness.

A classification system of joint-salvage tumor resection in osteosarcoma of the knee: A retrospective cohort study

BACKGROUND

Joint-preserving surgery is possible for patients with juxta-articular osteosarcoma of the knee, even when the tumor invades the epiphysis. Oncologic and functional outcomes may vary due to the extent of tumor invasion, the amount of epiphysis preservation, and reconstruction methods. We aimed to introduce a novel classification facilitating clinical evaluation of different surgical treatments.

METHODS

We identified 52 patients with osteosarcoma of the knee undergoing joint-preserving tumor resection and intercalary reconstruction. We classified procedures into two types and six subtypes based on the tumor location and adjuvant treatment employed. Oncologic outcomes, limb function and complications were compared among different types.

RESULTS

None of the patients had a local recurrence in the preserved epiphysis apart from three (5.7 %) who had local recurrence in soft tissue. Overall survival rate of the patients was 82.7 % at 5 and 10 years. There was no difference in survival rate (P = 0.909), local recurrence (P = 0.642) between type I (tumor not invading epiphysis) and type II (tumor invading epiphysis). In addition to one skin necrosis in the 3D-printed prosthesis reconstruction and one infection in Capanna reconstruction, all complications necessitating additional surgery occurred in allograft. The Musculoskeletal Tumor Society (MSTS) scores ranged from 21 to 30 with a median of 26. There were differences in the MSTS scores among six subgroups (P = 0.015), with the highest in type Ia and the lowest in type IIc. The less of the viable epiphysis retained, the worse the knee function was at long-term follow up.

CONCLUSIONS

The suggested classification can guide surgical strategy and is convenient for comparison of the functional results.

Mechanical strain induces ex vivo expansion of periosteum

Segmental bone defects present complex clinical challenges. Nonunion, malunion, and infection are common sequalae of autogenous bone grafts, allografts, and synthetic bone implants due to poor incorporation with the patient's bone. The current project explores the osteogenic properties of periosteum to facilitate graft incorporation. As tissue area is a natural limitation of autografting, mechanical strain was implemented to expand the periosteum. Freshly harvested, porcine periosteum was strained at 5 and 10% per day for 10 days with non-strained and free-floating samples serving as controls. Total tissue size, viability and histologic examination revealed that strain increased area to a maximum of 1.6-fold in the 10% daily strain. No change in tissue anatomy or viability via MTT or Ki67 staining and quantification was observed among groups. The osteogenic potential of the mechanical expanded periosteum was then examined in vivo. Human cancellous allografts were wrapped with 10% per day strained, fresh, free-floating, or no porcine periosteum and implanted subcutaneously into female, athymic mice. Tissue was collected at 8- and 16-weeks. Gene expression analysis revealed a significant increase in alkaline phosphatase and osteocalcin in the fresh periosteum group at 8-weeks post implantation compared to all other groups. Values among all groups were similar at week 16. Additionally, histological assessment with H&E and Masson-Goldner Trichrome staining showed that all periosteal groups outperformed the non-periosteal allograft, with fresh periosteum demonstrating the highest levels of new tissue mineralization at the periosteum-bone interface. Overall, mechanical expansion of the periosteum can provide increased area for segmental healing via autograft strategies, though further studies are needed to explore culture methodology to optimize osteogenic potential.

Customized three dimensional printed prosthesis as a novel intercalary reconstruction for resection of extremity bone tumours: a retrospective cohort study

AIMS

The 3D-printed prosthesis (3DP) is a novel treatment for massive bone defect reconstruction after tumor resection. This study was aiming to explore the clinical efficacy of customized 3DP for intercalary reconstruction by comparing the clinical outcomes after implanting customized 3DP or conventional allograft in limb salvage surgery.

METHODS

A total of 28 patients with extremity bone tumors who underwent customized 3DP or conventional allograft reconstruction between 2011 and 2018 at our institution were analyzed retrospectively. Among them, 14 cases received customized 3DP reconstruction (3DP group), and 14 cases received conventional allograft reconstruction (control group). Demographics, surgical outcomes, radiographical assessments, limb functions, and post-operative complications between these two groups were collected to evaluate clinical outcomes.

RESULTS

No significant difference was observed in the demographics, mean intra-operative blood loss, MOSI scores, and MSTS scores between the two groups. Patients in 3DP group had a shorter operative time (157.9 vs 199.6 min, p = 0.03) and lesser number of fluoroscopy (4.1 vs 8.1, p < 0.001) compared to control group. The mean time to osseointegration at bone-implant interfaces in 3DP group was significantly earlier than that in control group (6.1 vs 12.2 months, p < 0.001). Moreover, the 3DP group had a significantly lower post-operative complication rate than the control group (7% vs 50%, p = 0.03).

CONCLUSIONS

The customized 3DP might provide a promising strategy for intercalary reconstruction in limb salvage surgery with more precise reconstruction, higher surgical efficiency, and comparable satisfactory clinical outcomes.

Complications of patients with bone tumors treated with carbon-fiber plates: an international multicenter study

Carbon-fiber (CF) plates are a promising alternative to metal plates. However, reported experience in orthopaedic oncology remains limited. The aim of this study was to identify complications of patients with bone tumors treated with CF plates. Between February 2015 and May 2021, 13 centers retrospectively registered patients with bone tumors that were reconstructed using CF plates. Complications were identified, and timing and etiology of complications were noted. Similar complications were tabulated and classified based on mechanical, non-mechanical and paediatric complications. Mechanical complications included: (1) aseptic loosening or graft-host non-union, and (2) structural complications. Non-mechanical complications included: (3) soft tissue complications, (4) infection and (5) tumor progression. Specific paediatric complications included (6) growth arrest resulting in longitudinal or angular deformity. Ninety-six patients were included with a median follow-up time of 35 months. In total, 22 (23%) patients had complications. Mechanical complications included: 1 (1%) aseptic loosening, 2 (2%) non-unions, and 7 (7%) structural complications. Non-mechanical complications included 1 (1%) soft tissue complication, 4 (4%) infections and 5 (5%) tumor progressions. Paediatric complications occurred in 2 (2%) patients. This study suggests CF plates are safe to use in demanding reconstructions after bone tumor resections, presenting a seemingly low complication profile.

Factors Influencing Nonunion and Fracture Following Biological Intercalary Reconstruction for Lower-Extremity Bone Tumors: A Systematic Review and Pooled Analysis

OBJECTIVES

To determine nonunion rate, fracture rate, and their risk factors following biological intercalary reconstruction for lower extremity bone tumors.

METHODS

A systematic review and pooled analysis were conducted. PubMed, Embase, and Wiley Cochrane Library were searched from inception up to June 01, 2020. Studies concerning biological intercalary reconstruction after resection of lower extremity bone tumors were included. Overall nonunion and fracture rates were calculated. For studies reporting patient outcomes individually with precise graft characteristics and fixation methods, the individual data were extracted. Patients with demographical and clinical characteristics, including age, sex, tumor location, graft characteristics, and fixation method, were pooled for a multivariate analysis. For each factor of interest, odds ratio (OR), 95% confidence interval (95% CI), and p-value from logistic regression were reported.

RESULTS

A total of 2776 articles were identified from the initial literature search and 76 studies (2052 patients) were included. Sixty-nine studies were case series and seven were comparative studies. The overall nonunion rate was 19% (382/2052; range: 0%-53%), and the overall fracture rate was 17% (344/2052; range: 0%-75%). Thirty of the 76 studies (362 patients) reported patients' characteristics individually and were thus included in the pooled multivariate analysis. Intramedullary nail fixation was associated with a significantly higher nonunion rate compared to plate fixation (OR = 2.2, 95% CI: 1.23-4.10, p = 0.009). Reconstruction with a vascularized fibula graft had a statistically non-significant lower nonunion rate than reconstruction without the graft (OR = 0.6, 95% CI: 0.34-1.07, p = 0.086). Devitalized autografts had a lower fracture risk than allografts (OR = 0.3, 95% CI: 0.14-0.64, p = 0.002), and males tended to have higher fracture risk than females (OR = 2.1, 95% CI: 1.00-4.44, p = 0.049).

CONCLUSIONS

Reconstruction with intramedullary nail fixation is related to an elevated risk of nonunion. Allografts and males have a higher fracture risk than devitalized autografts and females, respectively. Further high-quality comparative analyses with large sample sizes and adequate follow-up duration are needed to validate these findings.

Performance of Biocomposite Materials Reinforced by Hydroxyapatite and Seashell Nanoparticles for Bone Replacement

Bone defects and disorders include trauma, osteonecrosis, osteoporosis, bone tumours, arthritis rheumatoid, osteosarcoma, and iatrogenic injury. Obtaining a composite material with characteristics that mimic what bones in the human body have is a vital target for the purpose of replacing or repairing damaged bones. The key objective of this study was to develop a composite having mechanical and biological properties that resemble to a large extent native bone features. Highly biocompatible epoxy resin was reinforced by various weight fractions of seashell nanoparticles. The morphologies of the pristine bioepoxy, seashell-bioepoxy, and hydroxyapatite-bioepoxy composites were observed by scanning electron microscopy. Moreover, the mechanical properties were examined by the means of tension and Izod impact tests. Besides, the influence of seashell and hydroxyapatite nanoparticles on the bioepoxy chemical structure and thermal properties was also evaluated using Fourier transform infrared spectroscopy and differential scanning calorimetry technique, respectively. The tensile strength, modulus of elasticity, and impact strength of the seashell nanoparticle-reinforced bioepoxy were revealed to be higher than those of the unmodified bioepoxy and were significantly depended on the filler content. When the mass fraction of the reinforcement was 7 wt%, the improvement in the tensile strength, modulus of elasticity, and impact strength was around 46.7%, 37%, and 57%, respectively, compared to that of blank bioepoxy. In addition, these properties were higher for the composites loaded with seashell nanoparticles than those filled with commercially available hydroxyapatite nanoparticles. An enhancement in glass transition temperature for the bioepoxy after modification with both of these nanofillers was also achieved. All these features make these kinds of composites a promising option that could be used in the orthopaedic field. Furthermore, the use of seashell nanoparticles may reduce the cost of the resulted composite and alleviate the negative consequences of large quantity by-product waste seashells on the environment.

Hip-preserving reconstruction using a customized cemented femoral endoprosthesis with a curved stem in patients with short proximal femur segments: Mid-term follow-up outcomes

Background

Short metaphyseal segments that remain following extensive distal femoral tumor resection can be challenging to manage, as the residual short segments may not be sufficient to accept an intramedullary cemented stem of standard length. The present study was developed to detail preliminary findings and experiences associated with an intra-neck curved stem (INCS) reconstructive approach, with a particular focus on mechanical stability.

Method

From March 2013 to August 2016, 11 total patients underwent reconstructive procedures using a customized cemented femoral endoprosthesis (CCFE) with an INCS. Measurements of femoral neck-shaft angle values were made before and after this procedure. Radiological outcomes associated with this treatment strategy over an average 63-month follow-up period were additionally assessed. Functionality was assessed based upon Musculoskeletal Tumor Society (MSTS) scores, while a visual analog scale (VAS) was used to rate pre- and postoperative pain, and any complications were noted.

Results

Relative to the preoperative design, no significant differences in femoral neck–shaft angle were observed after this reconstructive procedure (p = 0.410). Postoperatively, the tip of the stem was primarily positioned within the middle third of the femoral head in both lateral and posterior-anterior radiographic, supporting the accuracy of INCS positioning. The average MSTS score for these patients was 25 (range: 21–28), and VAS scores were significantly reduced after surgery (p &lt; 0.0001). One patient exhibited local disease recurrence and ultimately succumbed to lung metastases, while two patients exhibited aseptic loosening. None of the treated patients exhibited complications such as infections, periprosthetic fractures, or prosthetic fractures as of most recent follow-up.

Conclusion

CCFE with an INCS represents a viable approach to massive femoral diaphyseal defect with short proximal femur repair, as patients can achieve good functional outcomes and early weight-bearing with proper individualized rehabilitative interventions, all while exhibiting low rates of procedure-related complications.

A comparison of cemented and cementless intra-neck curved stem use during hip-preserving reconstruction following massive femoral malignant tumor removal

Background

Patients who undergo massive femoral malignant tumor (MFMT) resection often exhibit shortened femoral metaphyseal juxta-articular segments. The use of a customized femoral endoprosthesis (CFE) with an intra-neck curved stem (INCS) has emerged as a viable reconstructive surgical strategy for these individuals. Relative to a cemented INCS, it remains unclear as to whether cementless INCS use is associated with improvements in functionality or reconstructive longevity. As such, the present study was conducted to compare functional outcomes, endoprosthetic survival, and endoprosthesis-related complication rates in patients undergoing cemented and cementless INCS implantation.

Methods

A total of 24 patients undergoing lower limb salvage and reconstructive surgical procedures utilizing cemented or cementless INCS endoprostheses were retrospectively included. Patient-functional outcomes, endoprosthetic survival, and complication rates were compared as a function of age; diagnosis; the length of femoral resection; residual proximal femur length; Musculoskeletal Tumor Society (MSTS) scores; visual analog scale (VAS) scores; and the rates of implant breakage, periprosthetic infections, periprosthetic fractures, and aseptic loosening.

Results

The mean follow-up was 56 months. Significant differences in the length of femoral resection (p&lt;0.001) and residual proximal femur length were observed (p&lt;0.001) between the cemented and cementless INCS groups. There were no differences in overall patient survival and aseptic loosening-associated endoprosthesis survival in the cemented and cementless groups. None of the included patients experienced periprosthetic fractures, infections, or implant breakage. Average respective MSTS and VAS scores did not differ between groups.

Conclusion

For patients undergoing treatment for MFMTs, the use of a CFE with an INCS has emerged as a viable approach to hip-preserving reconstructive surgery. With appropriately designed individualized rehabilitative programs, good functional outcomes can be achieved for these endoprostheses, which are associated with low complication rates. Moreover, the selection between cemented or cementless INCS in the clinic should be made based on patient-specific factors, with cementless INCS implementation being preferable in younger patients with good-quality bone, the potential for long-term survival, and the osteotomy site near the lesser trochanter, whereas cemented INCS use should be favored for individuals who are older, have a shorter life expectancy, or have poor bone quality.

Allograft versus autograft for reconstruction after resection of primary bone tumors: a comparative study of long-term clinical outcomes and risk factors for failure of reconstruction

There have been no studies comparing the outcomes of nonvascularized autograft (NA) and allograft after resection of primary bone tumors. This study compares the clinical, functional outcomes of NA and allograft reconstruction and analyzes the risk factors for failure after these procedures. A retrospective study of patients with primary bone tumors of the extremities who underwent NA (n = 50) and allograft reconstruction (n = 47). The minimum follow up time was 24 months. The mean time to union for the NA and allograft group was 9.8 ± 2.9 months and 11.5 ± 2.8 months, respectively (p = 0.002). Reconstruction failure in the NA and allograft group was 19 (38%) and 26 (55.3%), respectively. Nonunion (30%) was the most common complication found in the NA group, while structural failure (29.8%) was the most common in the allograft group. There was no significant difference in functional outcome in terms of the mean Musculoskeletal Tumor Society score between the NA and allograft groups (23.5 ± 2.8 and 23.9 ± 2.1, respectively, p = 0.42). Age, sex, tumor location, graft length, method of reconstruction did not significantly influence failure of reconstruction. Chemotherapy was the only significant risk factor affecting outcomes (HR = 3.49, 95% CI = 1.59–7.63, p = 0.002). In the subgroup analysis, the use of chemotherapy affected graft-host nonunion (p < 0.001) and structural failure in both the NA and allograft groups (p = 0.02). Both NA and allograft reconstruction methods provide acceptable clinical and functional outcomes. Chemotherapy is a risk factor for failure of both reconstructions, particularly graft-host nonunion and structural failure.

Rotationplasty after failed limb salvage: an alternative to amputation

PURPOSE

Limb salvage procedures for musculoskeletal tumors have inherent complications. Though most complications can be managed with retention of the reconstructions, occasionally salvaging these reconstructions is not possible. We evaluated the outcomes of patients undergoing rotationplasty after multiple failed revisions of limb salvage surgery and document the success rate of this "salvage" technique and the subsequent functional outcome of these patients.

METHOD

Between January 1, 1999, and December 31, 2018, 14 patients (12 male and 2 female) with a median age of 24 years (11-51 years) underwent rotationplasty after multiple failed revisions of limb salvage surgery. Indication for rotationplasty was infection (10 patients), failed megaprosthesis (2 patients), unstable biological reconstruction (1 patient) and local recurrence (1 patient). The mean number of surgeries done before the patient underwent rotationplasty was 5 (range 2-7).

RESULTS

One patient developed a vascular complication (venous congestion) immediately after rotationplasty and underwent an early amputation. The remaining 13 patients had no surgical complications. Mean Musculo Skeletal Tumor Society score in 13 evaluable patients was 26 (23-30).

CONCLUSION

Our study demonstrates the utility of rotationplasty as a "salvage" procedure after multiple failed lower limb salvage surgeries. It offers good success rates, low rates of complications and good functional outcomes in carefully selected cases.

Intercalary allograft reconstruction following femoral tumour resection: mid- and long-term results and benefits of adding a vascularised fibula autograft

Purpose

Bone healing in femoral reconstructions using intercalary allografts can be compromised in a tumour context. There is also a high revision rate for non-union, infection, and fractures in this context. The advantages and disadvantages of an associated vascularised fibula graft (VFG) are still a matter of debate.

Methods

In a multicentre study, we retrospectively analysed 46 allograft reconstructions, operated on between 1984 and 2017, of which 18 were associated with a VFG (VFG+) and 28 without (VFG−), with a minimum follow-up of 2 years. We determined the cumulative probability of bone union as well as the mid- and long-term revision risks for both categories by Kaplan-Meier survival analysis and a multivariate Cox model. We also compared the MSTS scores.

Results

Significant differences in favour of VFG+ reconstruction were observed in the survival analyses for the probability of bone union (log-rank, p = 0.017) and in mid- and long-term revisions (log-rank, p = 0.032). No significant difference was observed for the MSTS, with a mean MSTS of 27.6 in our overall cohort (p = 0.060). The multivariate Cox model confirmed that VFG+ was the main positive factor for bone union, and it identified irradiated allografts as a major risk factor for the occurrence of mid- and long-term revisions.

Conclusion

Bone union was achieved earlier in both survival and Cox model analyses for the VFG+ group. It also reduced the mid- and long-term revision risk, except when an irradiated allograft was used. In case of a tumour, we thus recommend using VFG+ from a fresh-frozen allograft, as it appears to be a more reliable long-term option.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-022-02650-x.

The High-cycle Fatigue Life of Cortical Bone Allografts Is Radiation Sterilization Dose-dependent: An In Vitro Study

BACKGROUND

Structural cortical bone allografts are a reasonable treatment option for patients with large cortical bone defects caused by trauma, tumors, or complications of arthroplasty. Although structural cortical bone allografts provide the benefit of an osteoconductive material, they are susceptible to fatigue failure (fracture) and carry a risk of disease transmission. Radiation-sterilization at the recommended dose of 25 kGy decreases the risk of disease transmission. However, previous studies demonstrated that radiation sterilization at this dose can negatively impact the high cycle-fatigue life of cortical bone. Although the effects of higher doses of radiation on cortical bone allografts are well described, the effects of lower doses of radiation on a high-cycle fatigue life of cortical bone are poorly understood.

QUESTIONS/PURPOSES

(1) Does the cycle-fatigue life of human cortical allograft bone vary with gamma radiation dose levels of 0 (control), 10 kGy, 17.5 kGy, and 25 kGy? (2) What differences in Raman spectral biomarkers are observed following varying doses of gamma radiation exposure?

METHODS

The high-cycle fatigue behavior of human cortical bone specimens was examined at different radiation sterilization doses under physiologic stress levels (35 MPa) and in a 37° C phosphate-buffered saline bath using a custom-designed rotating-bending fatigue device. Six human femora from three donors were obtained for this study (two male, 63 and 61 years old, respectively, and one female, 48 years old). Test specimens were allocated among four treatment groups (0 kGy [control], 10 kGy, 17.5 kGy, and 25 kGy) based on donor and anatomic location of harvest site (both length and cross-sectional quadrant of femoral diaphysis) to ensure equal variation (n = 13 per group). Specimens underwent high-cycle fatigue testing to failure. The number of cycles to failure was recorded. Raman spectroscopy (a noninvasive vibrational spectroscopy used to qualitatively assess bone quality) was used to detect whether any changes in Raman spectral biomarkers occurred after varying doses of gamma radiation exposure.

RESULTS

There was a decrease in the log-transformed mean high-cycle fatigue life in specimens irradiated at 25 kGy (5.39 ± 0.32) compared with all other groups (0 kGy: 6.20 ± 0.50; 10k Gy: 6.35 ± 0.79; 17.5 kGy: 6.01 ± 0.53; p = 0.001). Specimens irradiated at 25 kGy were also more likely to exhibit a more brittle fracture surface pattern than specimens with more ductile fracture surface patterns irradiated at 0 kGy, 10 kGy, and 17.5 kGy (p = 0.04). The Raman biomarker for the ratio of the relative amount of disordered collagen to ordered collagen showed a decrease at the 10 kGy radiation level from 1.522 ± 0.025 preirradiation to 1.489 ± 0.024 postirradiation (p = 0.01); no other detectable changes in Raman biomarkers were observed.

CONCLUSION

The high-cycle fatigue life of cortical bone undergoes a nonlinear, dose-dependent decrease with an increase in gamma radiation sterilization in a clinically relevant dose range (0-25 kGy). Importantly, a notable drop-off in the high-cycle fatigue life of cortical bone appeared to occur between 17.5 kGy and 25 kGy, correlating to a sixfold decrease in mean cycles to failure. We speculate that the decrease in the Raman biomarker for disordered collagen at 10 kGy with no loss in high-cycle fatigue life may be caused by an increased amount of nonenzymatic crosslinking of the collagen backbone relative to collagen chain-scission (whereas the benefits of crosslinking may be outweighed by excess scission of the collagen backbone at higher radiation doses), but future studies will need to ascertain whether this in fact is the case.

CLINICAL RELEVANCE

Radiation sterilization at the industry standard of 25 kGy has a substantial negative impact on the high-cycle fatigue life of cortical bone. Given these findings, it is possible to provide a meaningful increase in the high-cycle fatigue life and improve the overall functional lifetime of cortical bone allografts by lowering the radiation-sterilization dose below 25 kGy. Future work on radiation-sterilization methods at these clinically relevant doses is warranted to aid in preserving the high cycle fatigue life of cortical bone allografts while maintaining sterility.

Hip-Preserved Reconstruction Using a Customized Cementless Intercalary Endoprosthesis With an Intra-Neck Curved Stem in Patients With an Ultrashort Proximal Femur: Midterm Follow-Up Outcomes

Background: Hemiarthroplasty is widely used for proximal femoral reconstruction after tumor resection. However, complications of hemiarthroplasty include infection, hip dislocation, and acetabular wear. This study aimed to: (1) evaluate the reliability and validity of a customized cementless intercalary endoprosthesis (CCIE) with an intra-neck curved stem (INCS) to reconstruct femoral diaphyseal defects with an ultrashort proximal femur (UPF); (2) assess the lower extremity function after reconstruction with this endoprosthesis; and (3) identify the postoperative complications associated with the use of this endoprosthesis.

Methods: Between October 2015 and May 2019, 13 patients underwent reconstruction with a CCIE with an INCS. The distance from the center of the femoral head to the midline of the body and the apex of the acetabulum was measured preoperatively. Additionally, the distance from the tip of the INCS to the midline of the body and the apex of the acetabulum was measured postoperatively. The femoral neck–shaft angle was also measured pre- and postoperatively. After an average follow-up duration of 46 months, the radiological outcomes of the CCIE with an INCS were analyzed. Function was evaluated with the Musculoskeletal Tumor Society (MSTS) score. Pain was measured using a paper visual analog scale (VAS) pre- and postoperatively, and complications were recorded.

Results: Compared with our preoperative design, we found no significant difference in the postoperative distance from the tip of the INCS to the body midline (p = 0.187) and the apex of the acetabulum (p = 0.159), or in the postoperative femoral neck–shaft angle (p = 0.793). Thus, the INCS positions were deemed accurate. The average MSTS score was 26 (range: 24–28), and the VAS score was significantly decreased postoperatively compared with preoperatively (p < 0.0001). No patients developed aseptic loosening, infection, periprosthetic fracture, or prosthetic fracture as of the last follow-up.

Conclusion: The CCIE with an INCS was a valid and reliable method for reconstructing femoral diaphyseal defects with a UPF following malignant tumor resection. Postoperative lower extremity function was acceptable, with an appropriate individualized rehabilitation program, and the incidence of complications was low.

The clinical outcome of hemicortical resection in extremity malignant bone tumors

INTRODUCTION

Hemicortical resection is challenging when a huge fungating tumor is covering the osteotomy site. We report the clinical outcome of hemicortical resection and reconstruction for primary bone tumors, especially with high-grade histology and extensive circumferential involvement.

MATERIALS AND METHODS

We retrospectively reviewed 44 patients (males, n = 18; females, n = 26) who underwent hemicortical resection from 2005 to 2014.

RESULTS

The median follow-up period was 46.0 (23-178) months. Disease-specific, local recurrence-free, and metastasis-free survival rates of patients in the malignant group at 5 years were 96.6%, 84.5%, and 93.6%, respectively. Among 42 patients, there were local recurrences (n = 6), metastasis (n = 2), and death (n = 1). Surgical margin was an independent prognostic factor for local recurrence (hazard ratio = 5.7; p = 0.038). The recycled autograft and strut allograft groups did not show statistical difference in bone union. Failure rate was 31.8% and local recurrence was the most frequent, followed by infection.

CONCLUSION

Hemicortical resection can be a feasible option for extremity malignant bone tumors. Regarding reconstruction, there were no difference between autograft and allograft in bone union rate. Surgical margin was an independent prognostic factor for local recurrence.

Intercalary reconstruction of long bones by massive allograft: Comparison of construct stability ensured by three different host-graft junctions and two types of fixations in a synthetic femur model

An intercalary segmental allograft is an option for limb salvage in bone tumours. Stable and congruent intercalary reconstructions are a prerequisite for achieving host-graft union. However, a too rigid fixation could increase the risk of late complications correlated with negative bone remodelling. This study compared the reconstruction stiffness achieved by three different host-graft junctions, namely, end-to-end, modified step-cut, and taper. A low-stiffness bone plate was used as the fixation method, except for the taper junction where a low-stiffness intramedullary nail was also used to investigate the effects of different types of fixation on construct stiffness. Composite femora were tested under four loading conditions to determine coronal and sagittal bending stiffness, as well as torsional stiffness in opposite directions. Stiffness values were expressed as a percentage of intact host bone stiffness (%IBS). While a reduction of coronal bending stiffness was found with taper junctions (76%IBS) compared with the high values ensured by end-to-end (96%IBS) and modified step-cut junctions (92%IBS), taper junctions significantly increased stiffness under sagittal bending and torsion in intra- and extra-direction: end-to-end 29%IBS, 7%IBS, 7%IBS, modified step-cut 38%IBS, 20%IBS, 21%IBS, and taper junction 52%IBS, 55%IBS, 56%IBS, respectively. Construct stiffness with taper junctions was decreased by 11-41%IBS by replacing the bone plate with an intramedullary nail. Taper junctions can be an alternative to achieve intercalary reconstructions with more homogeneous and, in three out of four loading conditions, significantly higher construct stability without increasing bone plate stiffness. The risk of instability under high torsional loads increases when taper junctions are associated with a low-stiffness intramedullary nail.

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.

Lower Limb Reconstruction Using Tibial Strut Autograft after Resection of Primary Malignant Bone Tumors in Skeletally Immature Patients

Background

Reconstruction of large bone defects in skeletally immature patients remains a surgical challenge. We report the long-term clinical outcomes of a novel surgical technique for lower limb reconstruction using the tibia as a strut autograft following resection of primary malignant bone tumors in skeletally immature patients.

Methods

We retrospectively reviewed the medical records of six patients diagnosed with lower limb primary bone sarcoma. All patients underwent tumor resection and reconstruction using tibial strut autograft. The radiological and clinical outcomes including complications at the recipient and donor sites were assessed.

Results

The mean age at presentation was ten years (range 6-15 years). Two cases had osteosarcoma and four had Ewing sarcoma. The mean length of the resected tumor and tibial autografts were 20.83 and 19.33 cm respectively. Union at both ends was achieved in five grafts while one graft achieved union only at the distal end. The mean time for union of the proximal and distal junctions was 4 and 8.8 months respectively. The mean follow-up period was 8.4 years (range 14 months-20 years). One patient developed a foot drop, and three patients underwent subsequent joint arthrodesis (2 knees and 1 ankle). The mean musculoskeletal tumor society functional score was 80.8%. Two patients had clinically significant leg-length discrepancy that needs further lengthening procedure. Four patients survived with no evidence of disease and two patients died due to their primary oncologic disease. All donor sites regenerated, with the earliest signs of new bone formation at (2-4) weeks post-operatively.

Conclusion

Reconstruction using non-vascularized‎ tibia strut autograft after resection of primary malignant lower limb bone tumors can be a viable alternative method for reconstructing large bone defects in the immature skeleton.

Osteosarcoma: An Evolving Understanding of a Complex Disease

Osteosarcoma is the most common primary bone sarcoma and affects both children and adults. The cornerstone of treatment for patients with localized and oligometastatic disease remains neoadjuvant chemotherapy, surgical resection of all sites of disease, followed by adjuvant chemotherapy. This approach is associated with up to an 80% 5-year survival. However, survival of patients with metastatic disease remains poor, and overall, osteosarcoma remains a challenging disease to treat. Advances in the understanding of molecular drivers of the disease, identification of poor prognostic factors, development of risk-stratified treatment protocols, successful completion of large collaborative trials, and surgical advances have laid the ground work for progress. Advances in computer navigation, implant design, and surgical techniques have allowed surgeons to improve patients' physical functional without sacrificing oncologic outcomes. Future goals include identifying effective risk stratification algorithms which minimize patient toxicity while maximizing oncologic outcomes and continuing to improve the durability, function, and patient acceptance of oncologic reconstructions.

Risk factors and outcomes for failure of biological reconstruction after resection of primary malignant bone tumors in the extremities

Biological reconstruction is widely used to reconstruct bone defects after resection of bone tumors in the extremities. This study aimed to identify risk factors for failure and to compare outcomes of the allograft, nonvascularized autograft, and recycled frozen autograft reconstruction after resection of primary malignant bone tumors in the extremities. A retrospective study was performed at a single center between January 1994 and December 2017. Ninety patients with primary malignant bone tumors of the extremities were treated with tumor resection and reconstruction using one of three bone graft methods: nonvascularized autograft (n = 27), allograft (n = 34), and recycled frozen autograft (n = 29). The median time for follow-up was 59.2 months (range 24-240.6 months). Overall failure of biological reconstruction occurred in 53 of 90 patients (58.9%). The allograft group had the highest complication rates (n = 21, 61.8%), followed by the recycled frozen autograft (n = 17, 58.6%) and nonvascularized autograft (n = 15, 55. 6%) groups. There was no statistically significant difference among these three groups (p = 0.89). The mean MSTS score was 22.6 ± 3.4 in the nonvascularized autograft group, 23.4 ± 2.6 in the allograft group, and 24.1 ± 3.3 in the recycled frozen autograft group. There was no significant difference among the groups (p = 0.24). After bivariate and multivariable analyses, patient age, sex, tumor location, graft length, methods, and type of reconstruction had no effects on the failure of biological reconstruction. Biological reconstruction using allograft, nonvascularized autograft, and recycled frozen autograft provide favorable functional outcomes despite high complication rates. This comparative study found no significant difference in functional outcomes or complication rates among the different types of reconstruction.

Gene therapy for bone healing: lessons learned and new approaches

Although gene therapy has its conceptual origins in the treatment of Mendelian disorders, it has potential applications in regenerative medicine, including bone healing. Research into the use of gene therapy for bone healing began in the 1990s. Prior to this period, the highly osteogenic proteins bone morphogenetic protein (BMP)-2 and -7 were cloned, produced in their recombinant forms and approved for clinical use. Despite their promising osteogenic properties, the clinical usefulness of recombinant BMPs is hindered by delivery problems that necessitate their application in vastly supraphysiological amounts. This generates adverse side effects, some of them severe, and raises costs; moreover, the clinical efficacy of the recombinant proteins is modest. Gene delivery offers a potential strategy for overcoming these limitations. Our research has focused on delivering a cDNA encoding human BMP-2, because the recombinant protein is Food and Drug Administration approved and there is a large body of data on its effects in people with broken bones. However, there is also a sizeable literature describing experimental results obtained with other transgenes that may directly or indirectly promote bone formation. Data from experiments in small animal models confirm that intralesional delivery of BMP-2 cDNA is able to heal defects efficiently and safely while generating transient, local BMP-2 concentrations 2-3 log orders less than those needed by recombinant BMP-2. The next challenge is to translate this information into a clinically expedient technology for bone healing. Our present research focuses on the use of genetically modified, allografted cells and chemically modified messenger RNA.

Technique and results after immediate orthotopic replantation of extracorporeally irradiated tumor bone autografts with and without fibular augmentation in extremity tumors

Background

Reconstruction of the skeletal defects resulting from the resection of bone tumors remains a considerable challenge and one of the possibilities is the orthotopic replantation of the irradiated bone autograft. One technical option with this technique is the addition of a vital autologous fibular graft, with or without microvascular anastomosis. The aim of our study was to evaluate the clinical results of the treatment of our patient cohort with a specific view to the role of fibular augmentation.

Methods

Twenty-one patients with 22 reconstructions were included. In all cases, the bone tumor was resected with wide margins and in 21 of them irradiated with 300 Gy. In the first case, thermal sterilization in an autoclave was used. The autograft was orthotopically replanted and stabilized with plates and screws. Fifteen patients underwent an additional fibular augmentation, 8 of which received microvascular anastomoses or, alternatively, a locally pedicled fibular interposition.

Results

the most common diagnosis was a Ewing sarcoma (8 cases) and the most common location was the femur (12 cases). The mean follow-up time was 70 months (16–154 months). For our statistical analysis, the one case with autoclave sterilization and 3 patients with tumors in small bones were excluded. During follow-up of 18 cases, 55.6% of patients underwent an average of 1.56 revision surgeries. Complete bony integration of the irradiated autografts was achieved in 88.9% of cases after 13.6 months on average. In those cases with successful reintegration, the autograft was shorter (n.s.). Microvascular anastomosis in vascularized fibular strut grafts did not significantly influence the rate of pseudarthrosis.

Conclusions

the replantation of extracorporeally irradiated bone autografts is an established method for the reconstruction of bone defects after tumor resection. Our rate of complications is comparable to those of other studies and with other methods of bone reconstruction (e.g. prosthesis). In our opinion, this method is especially well suited for younger patients with extraarticular bone tumors that allow for joint preservation. However, these patients should be ready to accept longer treatment periods.

Lower limb reconstruction for malignant bone tumours in children

Malignant bone tumours of the lower limb represent the majority of cases in both osteosarcoma and Ewing sarcoma in the growth period. Surgical treatment represents a key element of treatment. Different localizations and age groups require a differentiated surgical approach. Life and limb salvage are first on the list of treatment goals, followed by functional and cosmetic considerations. This review article delivers and discusses current surgical treatment strategies and outcomes for lower limb malignant bone tumours in children.

Biology and technology in the surgical treatment of malignant bone tumours in children and adolescents, with a special note on the very young

PURPOSE

The main challenge in reconstruction after malignant bone tumour resection in young children remains how and when growth-plates can be preserved and which options remain if impossible.

METHODS

We describe different strategies to assure best possible long-term function for young children undergoing resection of malignant bone tumours.

RESULTS

Different resources are available to treat children with malignant bones tumours: a) preoperative planning simulates scenarios for tumour resection and limb reconstruction, facilitating decision-making for surgical and reconstructive techniques in individual patients; b) allograft reconstruction offers bone-stock preservation for future needs. Most allografts are intact at long-term follow-up, but limb-length inequalities and corrective/revision surgery are common in young patients; c) free vascularized fibula can be used as stand-alone reconstruction, vascularized augmentation of structural allograft or devitalized autograft. Longitudinal growth and joint remodelling potential can be preserved, if transferred with vascularized proximal physis; d) epiphysiolysis before resection with continuous physeal distraction provides safe resection margins and maintains growth-plate and epiphysis; e) 3D printing may facilitate joint salvage by reconstruction with patient-specific instruments. Very short stems can be created for fixation in (epi-)metaphysis, preserving native joints; f) growing endoprosthesis can provide for remaining growth after resection of epi-metaphyseal tumours. At ten-year follow-up, limb survival was 89%, but multiple surgeries are often required; g) rotationplasty and amputation should be considered if limb salvage is impossible and/or would result in decreased function and quality of life.

CONCLUSION

Several biological and technological reconstruction options must be merged and used to yield best outcomes when treating young children with malignant bone tumours.

LEVEL OF EVIDENCE

Level V Expert opinion.

Cryoablation-aided joint retention surgery for epiphysis involvement in osteosarcoma compared with endoprosthetic replacement

AIMS

We have previously reported cryoablation-assisted joint-sparing surgery for osteosarcoma with epiphyseal involvement. However, it is not clear whether this is a comparable alternative to conventional joint arthroplasty in terms of oncological and functional outcomes.

METHODS

A total of 22 patients who had localized osteosarcoma with epiphyseal involvement around the knee and underwent limb salvage surgery were allocated to joint preservation (JP) group and joint arthroplasty (JA) group. Subjects were followed with radiographs, Musculoskeletal Tumor Society (MSTS) score, and clinical evaluations at one, three, and five years postoperatively.

RESULTS

Patients in both groups (ten in JP and 12 in JA) did not differ in local recurrence (p ≥ 0.999) and occurrence of metastases (p ≥ 0.999). Overall survival was similar in both groups (p = 0.858). Patients in the JP group had less range of motion (ROM) of the knee (p < 0.001) and lower MSTS scores (p = 0.010) compared with those of the JA group only at one year postoperatively. There was no difference between groups either at three years for ROM (p = 0.185) and MSTS score (p = 0.678) or at five years for ROM (p = 0.687) and MSTS score (p = 0.536), postoperatively. Patients in the JA group tended to have more complications (p = 0.074). Survival of primary reconstruction in the JP group was better than that of the JA group (p = 0.030).

CONCLUSION

Cryoablation-aided joint-sparing surgery offers native joint preservation with comparable functional recovery and more durable reconstruction without jeopardizing oncological outcomes compared with conventional limb salvage surgery. Cite this article: Bone Joint J 2021;103-B(8):1421-1427.

Is the Capanna Technique a Reliable Method for Revision Surgery after Failure of Previous Limb-Salvage Surgery?

BACKGROUND

Reconstruction of a massive bone defect caused by previous failed limb-salvage surgery in patients with bone sarcoma is challenging. Many procedures have been used, but they all have their inherent disadvantages. The Capanna technique has demonstrated good functional outcomes and a low incidence of complications in primary reconstructive surgery of massive bone defect. However, few studies have focused on its usage in revision surgery after failed primary limb-salvage surgery.

METHODS

Between June 2011 and January 2017, 13 patients underwent revision surgery with the Capanna technique for reconstruction of a secondary segmental bone defect caused by a previous failed surgical procedure. The demographics, operating procedures, graft union, functional outcomes, oncologic outcomes, and postoperative complications of each patient were recorded.

RESULTS

The current study investigated 13 patients. The rate of limb salvage was 100 %. Bone union was achieved for all patients during a mean time of 8.54 ± 2.15 months (range 4-11 months) at the fibula-host bone junction and 14.92 ± 2.33 months (range 12-21 months) at the allograft-host bone junction. The postoperative complications included wound healing issues and internal fixation loosening. Allograft fracture, nonunion, and infection were not observed. All the patients achieved good functional outcomes, with a Musculoskeletal Tumor Society (MSTS) score of 0.86 ± 0.03 at the latest follow-up visit.

CONCLUSIONS

The Capanna technique is a reliable alternative method for revision reconstruction of a segmental bone defect caused by a previous failed surgical procedure.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Resection arthrodesis and osteoarticular allografts reconstruction after resection of primary bone tumors around the knee: Long-term clinical outcomes and prognostic factors for failure of biological reconstruction

AIM

The biological reconstruction of the knee with osteoarticular allografts and resection arthrodesis have been reported but there has not yet been a direct comparison between both these procedures. This study aimed to identify the prognostic factors that influence failure of biological reconstruction and compared the results between both procedures.

METHODS

Between 1994 and 2017, we performed 92 limb-sparing procedures using resection arthrodesis (n = 53) and osteoarticular allograft reconstruction (n = 39) for the management of primary bone tumors around the knee. The minimum follow-up time was 2 years in both groups.

RESULTS

The failure rate of reconstruction in the osteoarticular allograft and resection arthrodesis group was 48.7% and 39.6%, respectively (p = 0.75). The mean MSTS score in the osteoarticular allograft and resection arthrodesis group was 23.7 and 21.8, respectively (p = 0.01). The significant risk factor for failure after biological reconstruction was the administration of chemotherapy (p = 0.001; HR = 3.39; 95% CI, 1.60-7.17).

CONCLUSION

Patients who underwent osteoarticular allograft had a better functional outcome than those who underwent resection arthrodesis reconstruction, but clinical outcomes between the groups were comparable. Chemotherapy is a significant adverse prognostic factor for failure of biological reconstruction.

Combining a Vascular Bundle and 3D Printed Scaffold with BMP-2 Improves Bone Repair and Angiogenesis

Vascularization is currently considered the biggest challenge in bone tissue engineering due to necrosis in the center of large scaffolds. We established a new expendable vascular bundle model to vascularize a three-dimensional printed channeled scaffold with and without bone morphogenetic protein-2 (BMP-2) for improved healing of large segmental bone defects. Bone formation and angiogenesis in an 8 mm critical-sized bone defect in the rat femur were significantly promoted by inserting a bundle consisting of the superficial epigastric artery and vein into the central channel of a large porous polycaprolactone scaffold. Vessels were observed sprouting from the vascular bundle inserted in the central tunnel. Although the regenerated bone volume in the group receiving the scaffold and vascular bundle was similar to that of the healthy femur, the rate of union of the group was not satisfactory (25% at 8 weeks). BMP-2 delivery was found to promote not only bone formation but also angiogenesis in the critical-sized bone defects. Both insertion of the vascular bundle alone and BMP-2 loading alone induced comparable levels of angiogenesis and when used in combination, significantly greater vascular volume was observed. These findings suggest a promising new modality of treatment in large bone defects. Level of Evidence: Therapeutic level I.

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?

BACKGROUND

Massive 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/PURPOSES

In 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?

METHODS

Between 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.

RESULTS

The 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).

CONCLUSION

We 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.

Intercalary reconstruction following resection of diaphyseal bone tumors: A systematic review

INTRODUCTION

The options for the reconstruction of diaphyseal defects following the resection of bone tumors include biological or prosthetic implants. The purpose of our study was to evaluate different types of intercalary reconstruction techniques, including massive bone allograft, extracorporeal devitalized autograft, vascularized free fibula, and modular prosthesis.

METHODS

We performed a systematic review of articles using the terms diaphyseal bone tumor and intercalary reconstruction. All the studies reporting the non-oncological complications such as infection, nonunion and fracture of the intercalary reconstructions were included. We excluded articles published before 2000 or did not involve humans in the study. Case reports, reviews, technique notes and opinion articles were also excluded based on the abstracts. Thirty-three articles included in this review were then studied to evaluate failure rates, complications and functional outcome of different surgical intercalary reconstruction techniques.

RESULTS

Nonunion rates of allograft ranged 6%-43%, while aseptic loosening rates of modular prosthesis ranged 0%-33%. Nonunion rates of allograft alone and allograft with a vascularized fibula graft ranged 6%-43% and 0%-33%, respectively. Fracture rates of allograft alone and allograft with a vascularized fibula graft ranged 7%-45% and 0%-44%, respectively. Infection rates of allograft alone and allograft with a vascularized fibula graft ranged 0%-28% and 0%-17%, respectively. All of the allograft (range: 67%-92%), extracorporeal devitalized autograft including irradiation (87%), autoclaving (70%), pasteurization (88%), low-heat (90%) or freezing with liquid nitrogen (90%), and modular prosthesis (range: 77%-93%) had similar Musculoskeletal Tumor Society functional scores. Addition of a vascularized fibula graft to allograft did not affect functional outcome [allograft with a vascularized fibula graft (range: 86%-94%) vs. allograft alone (range: 67%-92%)].

CONCLUSION

Aseptic loosening rates of modular prosthesis seem to be less than nonunion rates of allograft. Adding a vascularized fibula graft to allograft seems to increase bone union rate and reduce the risk of fractures and infections, though a vascularized fibula graft needs longer surgical time and has the disadvantage of donor site morbidity. These various intercalary reconstruction techniques with or without a vascularized fibula autograft had similar functional outcome.

Concave-convex Reaming of Intercalary Allograft: 1-year Clinical Outcomes

Complication rates associated with intercalary allograft reconstruction may be reduced by maximizing tenants of allograft reconstruction. Intercalary allograft reconstruction using a hemispherical reaming technique for graft-host interface may increase surface contact areas, provide intimate contact between surfaces, and equally distribute pressure subsequently decreasing risk of nonunion. The purpose of these case reports was to present short-term results for limb salvage using this novel technique for two young, active duty military members who returned to full-impact activity.

Avoiding Limb-Length Discrepancy with Reconstruction of a Massive Tibial Defect Using a Bone Allograft and a Minimally Invasive Lengthening System in a Pediatric Patient: A Case Report

CASE

A 7-year-old boy was found to have Ewing sarcoma of the left tibia. The sarcoma was resected, and the defect was reconstructed using a humeral head allograft and intramedullary limb-lengthening nail.

CONCLUSIONS

Limb-salvage reconstruction in children can be complicated by the sacrifice of epiphyseal plates and limb-length discrepancies and thus requires techniques tailored to each case.

Synthetic Polymeric Materials for Bone Replacement

Some treatment options available to repair bone defects are the use of autogenous and allogeneic bone grafts. The drawback of the first one is the donor site’s limitation and the need for a second operation on the same patient. In the allograft method, the problems are associated with transmitted diseases and high susceptibility to rejection. As an alternative to biological grafts, polymers can be used in bone repair. Some polymers used in the orthopedic field are poly(methyl methacrylate), poly(ether-ether-ketone), and ultra-high molecular weight polyethylene (UHMWPE). UHMWPE has drawn much attention since it combines low friction coefficient and high wear and impact resistance. However, UHMWPE is a bioinert material, which means that it does not interact with the bone tissue. UHMWPE composites and nanocomposites with hydroxyapatite (HA) are widely studied in the literature to mitigate these issues. HA is the main component of the inorganic phase in the natural bone, and the addition of this bioactive filler to the polymeric matrix aims to mimic bone composition. This brief review discusses some polymers used in orthopedic applications, focusing on the UHMWPE/HA composites as a potential bone substitute.

Therapy-Related Imaging Findings in Patients with Sarcoma

Knowledge of imaging findings related to therapy administered to patients with sarcoma is pivotal in selecting appropriate care for these patients. Imaging studies are performed as surveillance in asymptomatic patients or because symptoms, including anxiety, develop. In addition to detection of recurrent disease and assessment of response to therapy, diagnosis of conditions related to therapy that may or may not need treatment has a marked positive impact on quality of life. The purpose of this review is to assist radiologists, nuclear physicians, and others clinicians involved in the diagnosis and treatment of these patients in recognizing imaging findings related to therapy and not to activity of the previously treated sarcoma. Imaging findings are time dependent and often specific in relation to therapy given.

[Musculoskeletal tumour surgery for adolescent and young-adult population: Collaboration between adult and pediatric surgeons is necessary]

Orthopaedic surgery I has a key role on the medical pathway of adolescent and young-adult (AYA) patients with musculo-skeletal tumor from diagnosis, tumor resection, musculo-skeletal immediate or delayed reconstruction, to dealing with late complications and sequelae following reconstruction during childhood. Administrative authorizations, organization by health authorities as well as training courses are quite different for adult and pediatric surgery. However, surgery for musculo-skeletal tumors in AYA patients have neither adult nor pediatric specifities; resection-reconstruction rules and technics are the same for adult or pediatric patients, with nevertheless lower complication rate and more biologic reconstructions for the youngest, and more prosthetic reconstructions for the oldest. Late complications after bone and soft-tissue reconstructions in childhood and musculo-skeletal deformation after surgery and/or radiotherapy in childhood need the vision from "adult" orthopaedic teams for long and very long term success of the surgical project with a good knowledge of pediatric technics previously used. Thus, formal shared time and transition care are necessary between pediatric and adult surgical teams to prepare long-term follow-up of these childhood cancer survivors. Participation to the same specialized Multi-Disciplinary Board, scientific society gathering adult and pediatric surgeons, clinical trials with no age-limitation might help to erase barriers and to ease collaboration between adult and pediatric ortho-oncologic teams.

Adding a Fibular Strut Allograft to Intramedullary Nail and Cancellous Autograft During Stage II of the Masquelet Technique for Segmental Femur Defects: A Technique Tip

Reconstruction of segmental diaphyseal bone defects has been a major challenge in limb salvage surgery. Staged reconstruction as first described by Masquelet is a common strategy to deal with this problem in limb salvage surgery. One consequence of this technique is a time period of prolonged limited weightbearing while the segmental defect heals. The purpose of this study was to describe an adjunctive technique for stage II of the Masquelet procedure and retrospectively analyze the outcome and weight bearing progression of 3 patients who sustained femur fractures with significant bone loss and underwent this technique. A retrospective chart review was performed. The patients (2 males, 1 female with an average age of 36.6 years) all sustained segmental femur fractures which resulted in significant bone loss. Induced membrane technique with adjunct use of a fibular strut allograft was performed after initial stabilization and PMMA spacer placement. All three patients went on to union and full weight bearing after being treated by the described technique. All the patients were allowed toe-touch weight bearing immediately after surgery and all progressed to weight bearing as tolerated at an average of 3.6 months. Using a fibular strut allograft as an adjunct to the induced membrane technique serves as a biologic and mechanical scaffold and may allow earlier weightbearing.

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

AIMS

We report a series of patients treated with intercalary bone graft (IBG) of the tibia diaphysis (TD) after resection of primary bone tumors. The purpose of this study was to evaluate the mid- and long-term survival of TD IBG reconstruction in children and adults, characterizing patterns of success and failure.

METHODS

A total of 35 patients were included in this retrospective study. Median age was 22 years (range, 8-57). This series included 19 patients (54.3%) treated with homologous bone graft alone and 16 patients (45.7%) treated combining intercalary allograft with fibular autograft. Complications were recorded according to Henderson classification.

RESULTS

Median follow-up was 36 months (range, 1-165). Local recurrence occurred in 2 patients (5.7%) after 12 and 60 months, respectively. Major complications included graft fracture (9 cases), non-union (5 cases) and infection (4 cases). Other complications were axial deformity (2 cases), superficial infection (2 cases), compartmental syndrome (1 case).

CONCLUSION

Intercalary bone grafts of TD have been recommended as a reliable solution with long-term success rates and good functional outcome in more than 80% of patients. However, approximately half of the patients may require further surgeries to treat major complications (deep infection, delayed or non-union and graft fracture). Additional vascularized fibula graft may ameliorate final result.