Is there still a role for osteoarticular allograft reconstruction in musculoskeletal tumour surgery? a long-term follow-up study of 38 patients and systematic review of the literature

Malawer type I/V proximal humerus reconstruction after tumor resection: a systematic review

BACKGROUND

Several reconstruction methods exist for Malawer type I/V proximal humerus reconstruction after bone tumor resection; however, no consensus has been reached regarding the preferred methods.

METHODS

We conducted a literature search on various types of proximal humerus oncologic reconstruction methods. We collected data on postoperative functional outcomes assessed based on Musculoskeletal Tumor Society (MSTS) scores, 5-year reconstruction survival rates, and complications. We calculated each reconstruction's weighted mean based on the sample size and standard errors. Complications were categorized based on the Henderson classification. Based on these integrated data, our primary objective is to propose an optimal strategy for proximal humerus reconstruction after bone tumor resection.

RESULTS

We examined various reconstruction techniques, including modular prosthesis (752 patients in 21 articles), osteoarticular allograft (142 patients in 6 articles), allograft prosthesis composites (APCs) (236 patients in 12 articles), reverse shoulder total arthroplasty (141 patients in 10 articles), composite reverse shoulder total arthroplasty (33 patients in 4 articles), claviculo-pro-humero (CPH) technique (51 patients in 6 articles), and cement spacer (207 patients in 4 articles). Weighted mean MSTS scores were: modular prosthesis (73.8%), osteoarticular allograft (74.4%), APCs (79.2%), reverse shoulder total arthroplasty (77.0%), composite reverse shoulder total arthroplasty (76.1%), CPH technique (75.1%), and cement spacer (69.1%). Weighted 5-year reconstruction survival rates were modular prosthesis (85.4%), osteoarticular allograft (67.6%), APCs (85.2%), reverse shoulder total arthroplasty (84.1%), and cement spacer (88.0%). Reconstruction survival data was unavailable for composite reverse shoulder total arthroplasty and CPH technique. Major complications included shoulder joint instability: modular prosthesis (26.2%), osteoarticular allograft (41.5%), APCs (33.9%), reverse shoulder total arthroplasty (17%), composite reverse shoulder total arthroplasty (6.1%), CPH technique (2.0%), and cement spacer (8.7%). Aseptic loosening of the prosthesis occurred: modular prosthesis (3.9%) and reverse shoulder total arthroplasty (5.7%). Allograft fracture was observed in 54.9% of patients with osteoarticular allograft.

CONCLUSION

The complication profiles differed among reconstruction methods. Weighted mean MSTS scores exceeded 70% in all methods except cement spacer, and the 5-year reconstruction survival rate surpassed 80% for all methods except osteoarticular allograft. Proximal humerus reconstruction after bone tumor resection should consider potential complications and patients' individual factors.

Clinical Perspectives on Surgical Reconstruction of Eccentric Tumors at the Distal Femur with Unicondylar Resection

The distal femur is one of the most common sites for primary bone tumors. As the tumor progresses and bone destruction worsens, it can severely affect knee function and even pose a threat to life. In cases where only one condyle is affected and requires resection, preserving the healthy contralateral condyle can substantially enhance the biomechanics of the knee. Furthermore, preserving bone stock may enable future salvage procedures in the event of initial surgery failure, be it from fractures or osteoarthritis. Distal femoral unicondyle resection can offer better functional outcomes in select cases. However, it is essential to prioritize oncological safety with adequate margins over short-term knee function. Currently, the primary methods for reconstruction after the excision of a unicondylar tumor include allograft transplantation (bi- or uni-condylar) and prosthetic or allograft-prosthesis composite replacement (APC). However, there is currently some controversy regarding the optimal surgical reconstruction method, and a consensus within the academic community has yet to be reached. Moreover, due to the rarity of bone tumors, extensive clinical data from a single center is limited. Current studies are mainly retrospective and single-center, lacking sufficient cases and follow-up duration. This article reviews surgical reconstruction after solitary condylar excision in distal femoral tumors. It summarizes, compares, and analyzes mainstream reconstruction methods, exploring their technical details and clinical outcomes to highlight their potential in bone oncology.

Complications and functional outcomes after reconstruction of the proximal humerus with allograft-prosthetic composite: a systematic review of the literature

BACKGROUND

Allograft prosthetic composite (APC) reconstruction is performed after resection of proximal humerus tumors or failure of arthroplasty implants. There is limited literature on the postoperative outcomes of this technique. We sought to assess implant survival, failure rates, and postoperative functional outcomes after APC reconstruction of the proximal humerus.

METHODS

A systematic review of the PubMed and Embase databases was conducted. The study was registered on PROSPERO (ID: 448,663). The Strengthening of the Reporting of Observational Studies in Epidemiology checklist was used for quality assessment. Implant failure was determined using the Henderson classification for biological reconstruction. Functional outcome was primarily assessed using the Musculoskeletal Tumor Society score at last follow-up.

RESULTS

Twenty-five studies with a total of 488 patients were included. Mean follow-up in reporting studies ranged from 2.5 to 10 years. Five-year revision-free survival for implants ranged from 41% to 92%. Overall implant failure rate ranged from 9% to 54%, and reoperation rate ranged from 0% to 55%. Graft host nonunion (type 2) was the most common mode of failure, with rates ranging from 0% to 75%. The mean Musculoskeletal Tumor Society scores at last follow-up ranged from 57% to 90% across studies. A trend towards better functional outcomes was seen in patients having an APC with a reverse total shoulder arthroplasty (rTSA) compared with those with hemiarthroplasty.

CONCLUSIONS

APCs show promise in proximal shoulder reconstruction, with heterogeneous functional outcomes that are noninferior to other reconstruction techniques. Graft host nonunion is a common mode of failure and remains a concern in this type of prosthesis. Future studies should compare rTSA-APCs and rTSA endoprostheses while controlling for potential confounders.

Proximal Humerus Reconstruction for Bone Sarcomas: A Critical Analysis

» The proximal humerus is a common location for primary bone tumors, and the goal of surgical care is to obtain a negative margin resection and subsequent reconstruction of the proximal humerus to allow for shoulder function.» The current evidence supports the use of reverse total shoulder arthroplasty over hemiarthroplasty when reconstructing the proximal humerus after resection of a bone sarcoma if the axillary nerve can be preserved.» There is a lack of high-quality data comparing allograft prosthetic composite (APC) with endoprosthetic reconstruction of the proximal humerus.» Reverse APC should be performed using an allograft with donor rotator cuff to allow for soft-tissue repair of the donor and host rotator cuff, leading to improvements in shoulder motion compared with an endoprosthesis.

Biological Prosthesis (Hollow 3D-Printed Titanium Custom-Made Prosthesis and Bone Graft) for Humeral Reconstruction in Pediatric Oncologic Patients: Surgical Indications and Results

This study presents the mid-term outcomes of a novel "biological prosthesis" for pediatric humerus reconstruction after major bone tumor removal. This approach involves a hollow 3D-printed titanium custom-made prosthesis combined with bone grafting. The primary aim was to preserve and revitalize the unaffected autologous proximal or distal humeral stump. Between 2017 and 2021, we treated five pediatric patients (mean age 11.2 years; range 7-17) with humeral bone sarcomas. A one-stage surgical procedure involved tumor resection and implanting a hollow 3D-printed custom-made prosthesis. In two cases, we preserved the proximal humerus; in two, the distal part; and in one, both. Graft materials included homologous bone chips in three cases and free vascularized fibular grafts in two cases. All patients were clinically and radiographically assessed after a mean follow-up of 32.2 months (range of 14-68). No significant complications were observed, and no implant revisions were needed. Osseointegration was evident in all cases within eight months post-surgery; vascular support for the remaining autologous stump was demonstrated in all cases. Our hollow 3D-printed custom-made prosthesis and bone grafting offer the potential for partial or complete articular surface preservation. This approach encourages revascularization of the epiphysis, leading to satisfactory outcomes in humerus reconstruction within the pediatric population.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Salvage of a Fractured Proximal Ulnar Osteoarticular Allograft Using a Medial Femoral Condyle Free Flap: A Case Report

CASE

We present the case of a 47-year-old paraplegic woman who underwent resection of an intermediate-grade chondrosarcoma in the proximal ulna, which was initially reconstructed with an osteoarticular allograft. However, after more than 25 years without complications, she sustained an intra-articular fracture of the allograft, which was then successfully treated using a vascularized medial femoral condyle (MFC) flap and anterolateral thigh flap. The patient has subsequently recovered her baseline elbow function, has no pain, and can use her wheelchair without restrictions.

CONCLUSION

Free MFC flaps are viable options to salvage osteoarticular allografts that are affected by intra-articular fractures.

Surgical Fixation Method in Lower Extremity Intercalary Allograft Reconstruction After Oncologic Resection: A Comparison of Plates and Nails

INTRODUCTION

Fixation in intercalary allograft reconstruction includes plates and intramedullary nails. The purpose of this study was to examine rates of nonunion, fracture, the overall need for revision surgery, and allograft survival based on the surgical fixation method in lower extremity intercalary allografts.

METHODS

A retrospective chart review was performed on 51 patients with intercalary allograft reconstruction in the lower extremity. Fixation methods compared were intramedullary fixation with nails (IMN) and extramedullary fixation with plates (EMP). Complications compared were nonunion, fracture, and wound complications. The alpha was set at 0.05 for statistical analysis.

RESULTS

Nonunion incidence at all allograft-to-native bone junction sites was 21% (IMN) and 25% (EMP) (P = 0.8). Fracture incidence was 24% (IMN) and 32% (EMP) (P = 0.75). Median fracture-free allograft survival was 7.9 years (IMN) and 3.2 years (EMP) (P = 0.04). Infection was seen in 18% (IMN) and 12% (EMP) (P = 0.7). The overall need for revision surgery was 59% (IMN) and 71% (EMP) (P = 0.53). Allograft survival at the final follow-up was 82% (IMN) and 65% (EMP) (P = 0.33). When the EMP group was subdivided into single plate (SP) and multiple plate (MP) groups and compared with the IMN groups, fracture rates were 24% (IMN), 8% (SP), and 48% (MP) (P = 0.04). Rates of revision surgery were 59% (IMN), 46% (SP), and 86% (MP) (P = 0.04). Allograft survival at the final follow-up was 88% (IMN), 92% (SP), and 52% (MP) (P = 0.05).

DISCUSSION

Median fracture-free allograft survival was notably longer for the IMN group than the EMP group; otherwise, there were no notable differences between the intramedullary and extramedullary groups. When the EMP group was subdivided into the SP and MP groups, patients with MPs had higher rates of fracture, higher rates of revision surgery, and lower overall allograft survival.

LEVEL OF EVIDENCE

III, Therapeutic Study, Retrospective Comparative Study.

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.

The effect of surgical revascularization on the mechanical properties of cryopreserved bone allograft in a porcine tibia model

Cryopreserved bone allografts(CBA) are susceptible to infection, nonunion, and late stress fracture. Although surgical revascularization by intramedullary implantation of an arteriovenous bundle (AV bundle) generates a neoangiogenic blood supply, there is potential for vascular ingrowth-mediated bone resorption to weaken the graft. For this reason, we have evaluated changes in CBA mechanical properties of structural tibial allografts with and without surgically induced angiogenesis. Cryopreserved tibia bone allografts were transplanted to reconstruct a 3.5 cm segmental tibial defect in 16 Yucatan mini pigs. Surgical revascularization was performed in half by implantation of a cranial tibial AV bundle, (revascularization group). A control group of identical size had a ligated AV bundle implanted, (ligated group). At 20 weeks micro-computed tomography (CT) measured bone mineral density (BMD) as well as bone union. Reference point indentation (RPI) compared cortex material properties, and axial compression determined the allotransplant compressive modulus. Seven of eight tibiae in the angiogenesis group were healed at both junction points at 20 weeks. Only four of eight tibiae healed in the ligated control group. There was no significant difference between the revascularization and ligated control groups in BMD and axial compression test. Similarly, RPI parameters were statistically equal. In paired comparisons with contralateral tibias, however, some RPI values were significantly worse in the ligated control group tibiae. This study demonstrates no adverse effect of surgical angiogenesis on cryopreserved structural bone allograft biomechanical properties in a large animal orthotopic segmental tibial defect model. These data suggest the potential value of surgical angiogenesis in clinical limb-sparing reconstructive surgery.

Functional Outcome Following Proximal Tibial Osteosarcoma Resection and Reconstruction by Modular Endoprosthesis

PURPOSE

The proximal tibia is a common location for osteosarcoma. Modular endoprosthesis is a popular reconstructive option, yet it has been associated with many complications. Our study aimed to evaluate the functional outcome and complications of proximal tibial osteosarcoma patients treated by limb salvage using modular endoprosthesis.

METHODS

A retrospective study of a prospective database was performed during the period between January 2000 and July 2017. Fifty-five patients with proximal tibial osteosarcoma underwent resection and modular endoprosthetic reconstruction. The functional outcome was evaluated using the Musculoskeletal tumor society scoring system and knee range of motion. Postoperative complications were classified according to Henderson classification; Type 1 (soft tissue failure), Type 2 (aseptic loosening), Type 3 (structural failure), Type 4 (infection) and Type 5 (local tumor progression).

RESULTS

The mean follow-up period was 71.69 ± 49.76 months. The mean musculoskeletal tumor society score was 26.5 ± 2.22; the mean range of motion was 72.63 ± 25.07, and the mean extension lag was 15.09 ± 15.38. Type 1, type 2, type 3, type 4, and type 5 complications occurred in 7.3%, 14.5%, 21.8%, 23.6%, and 5.5%, respectively. Chest metastasis developed in 10 patients (18.2%). The estimated 5-year and 10-year survival rates for the treated patients were 83.6% and 79.9%.

CONCLUSIONS

Proximal tibial osteosarcoma reconstruction with a modular endoprosthesis is a reliable treatment option for retaining limb function. Most complications are manageable.

Giant Cell Tumor of the Distal Radius: A Review

Giant cell tumor of the distal radius presents a significant challenge in management due to high risk of recurrence and potential loss of function. Shared decision-making guides management, particularly for more advanced lesions. Intralesional curettage can optimize wrist function but at the cost of a higher recurrence risk. Wide resection decreases local recurrence but has higher complication rates regardless of reconstruction method. No functional difference exists between motion-preserving procedures and arthrodesis; therefore, patients should be clearly informed of the risks and benefits of each treatment option.

Three-dimensional printed customized uncemented unipolar prosthesis combined with ligament reconstruction for tumorous defect of the distal femur in children

BACKGROUND

Hemiarthroplasty following tumor resection of the distal femur in children provides a chance to preserve the proximal tibial physis for limb elongation. Based on three-dimensional (3D) printing technology, the uncemented unipolar prosthesis with joint stability reinforced structures (JSRSs) was custom-designed for our cases. This study aimed to describe the design and assess the short-term outcomes of this refined prosthetic hemiarthroplasty.

METHODS

Seven patients (four females and three males) received 3D-printed customized uncemented unipolar prosthesis for hemiarthroplasty after removal of the distal femur, from September 2019 to October 2020 at our Orthopedics department. The limb function, growth of the preserved proximal tibial physis, joint stability, and limb length discrepancy (LLD) were assessed. Complications were recorded.

RESULTS

Six patients survived with no evidence of metastasis or local recurrence at the last follow-up, and one patient died of lung metastasis at 19 months postoperatively. Follow-up ranged from 19 to 32 months, with an average of 26 months. Elongation of the tibia was observed in all cases. At the last follow-up, four patients exhibited equal growth length compared with the healthy contralateral tibia. LLD ranged from 0.8 to 1.6 cm with a mean of 1.3 cm. The average knee range of motion was 95.3° of flexion and 4.5° of extension. All patients achieved satisfactory postoperative limb function with a mean MSTS score of 25.8. The results of the drawer, Lachman, and pivot shift tests were negative in all patients. During follow-up, painless joint space narrowing was observed in two patients. The screw for ligament fixation loosened in one of the seven patients at 17 months postoperatively. No subluxation of the joint, angular deformity, or breakage of the implant was detected in the remaining patients.

CONCLUSIONS

3D-printed customized uncemented unipolar prosthesis with JSRS would be a good choice for reconstructing tumorous defect in the distal femur in children.

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 < 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<0.001) and residual proximal femur length were observed (p<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.

Hemiarthroplasty of Pedicle-Frozen Proximal Tibia for Primary Malignant Bone Tumours

The proximal tibia is one of the most common locations for primary malignant bone tumours and is usually seen in a population that has not attained skeletal maturity. Most of the surgical techniques for resection and reconstruction of the proximal tibia in children involves sacrificing the distal femoral epiphysis, which leads to a significant limb length discrepancy. Hemiarthroplasty is a relatively lesser known technique for knee joint reconstruction that preserves one of the epiphyses around the knee joint. Pedicle freezing is a sterilization technique used to treat malignant bone tumours, without performing an osteotomy of the diaphysis, thereby preventing non-union which is the most common complication of biological reconstruction techniques. We describe the surgical technique of hemiarthroplasty of the pedicle-frozen proximal tibia for malignant bone tumours of the proximal tibia. This is a novel, safe and effective reconstructive method in children, resulting in reduced limb length discrepancy and excellent functional outcomes.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-022-00658-9.

Case Report: Reconstruction of Medialis Malleolus (1/4 of the Ankle Joint) After Resection of Distal Tibia Tumor With an Uncemented Three-Dimensional-Printed Prosthesis

Introduction

Few patients presented with a distal tibial tumor that only invaded a small area of bone in the medial malleolus. There have been no previous cases in which only the medial or lateral malleolus was removed and reconstruction was complete. This article describes our attempt to reconstruct the medial malleolus (1/4 of the ankle joint) after resection of a distal tibial tumor with an uncemented three-dimensional (3D)-printed prosthesis.

Case Description

A 39-year-old man presented with a lump in the right medial malleolus, and biopsy results suggested fibrosarcoma. To preserve the patient's normal bone and function, we only removed the medial malleolus and reconstructed the ankle joint using a personalized 3D-printed prosthesis. The patient had no complications other than necrosis of the skin flap that covered the wound. The patient recovered well after undergoing an additional skin flap transfer. Follow-up at 7 months and again at 3 years after surgery showed good ankle function and stability, with no pain or complications.

Conclusion

The 3D-printed partial ankle prosthesis had a good matching degree, strength, and osseointegration ability, but also had a few complications. The patient achieved satisfactory ankle function and stability. However, a longer follow-up period is needed, and more research is required to confirm the efficacy of the prosthesis.

Structural Allograft and Induced Membrane Technique for Treatment of 10-cm Segmental Femoral Bone Defect: A Case Report

CASE

A modified induced membrane technique for the treatment of a posttraumatic 10-cm infected segmental femoral defect is reported. The first stage involved debridement and insertion of an antibiotic cement spacer and 2 Ender nails. Reconstruction was performed with a 14-cm structural bone allograft, inverted and telescoped into both ends of the remaining host femur, and stabilized with an interlocking nail. Progressive weight-bearing was allowed at 3 weeks with full weight-bearing achieved at 6 months.

CONCLUSION

The use of a telescoped structural allograft and intramedullary nailing as the second stage of the Masquelet induced membrane technique facilitated postoperative rehabilitation, increased surface contact between host and graft bone, and improved integration.

Distal Tibial Reconstruction in the Management of Primary Bone Tumors in Children and Adolescents

BACKGROUND

Distal tibial primary bone tumors are rare, and options for limb salvage surgery are limited and challenging. Importantly, local control has shown to be crucial and necessary for cure, and radical surgery is one of the most important components of therapy for some bone sarcomas. We investigated the feasibility and functional and oncological outcomes of distal tibial reconstruction using endoprosthesis in children with malignant bone tumors.

METHODS

Fourteen patients (median age 13.6 years) with primary bone tumors (4 Ewing sarcoma [ES], 10 osteosarcoma) of the distal tibiae were treated during 2013-2019. All patients had reconstruction using a modular (13 patients) or expandable custom-made titanium bone replacement system (1 patient). All patients received chemotherapy before and after surgery.

RESULTS

Twelve patients (85.7%) are alive with a median follow-up 20 months from diagnosis. Five-year estimates of event-free survival and overall survival were 60.6% and 76.4%, respectively. Three patients had postoperative complications requiring second surgery. Maximum dorsiflexion and plantar flexion of the foot were 20 degrees (range 0-20 degrees) and 20 degrees (range 5-20 degrees), respectively.

CONCLUSION

For select distal tibial sarcomas, after neoadjuvant chemotherapy pretreatment and radical resection, reconstruction using an endoprosthesis as a radical surgery provides an option was associated with a low rate of short-term local complications and relatively good early function.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

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.

Strategies for large bone defect reconstruction after trauma, infections or tumour excision: a comprehensive review of the literature

Large bone defects resulting from musculoskeletal tumours, infections, or trauma are often unable to heal spontaneously. The challenge for surgeons is to avoid amputation, and provide the best functional outcomes. Allograft, vascularized fibular or iliac graft, hybrid graft, extracorporeal devitalized autograft, distraction osteogenesis, induced-membrane technique, and segmental prostheses are the most common surgical strategies to manage large bone defects. Given its optimal osteogenesis, osteoinduction, osteoconduction, and histocompatibility properties, along with the lower the risk of immunological rejection, autologous graft represents the most common used strategy for reconstruction of bone defects. However, the choice of the best surgical technique is still debated, and no consensus has been reached. The present study investigated the current reconstructive strategies for large bone defect after trauma, infections, or tumour excision, discussed advantages and disadvantages of each technique, debated available techniques and materials, and evaluated complications and new perspectives.

Assessment of the Viability and Union Feature of Diaphysis Reconstruction Using Pasteurized Tumor Bone and Intramedullary Free Fibular After Tumor Resection

BACKGROUND

Reconstruction using pasteurized tumor bone (PTM) and intramedullary-placed vascularized free fibular (VFG) has the combined advantages of mechanical strength and biological activity. The aims of this study were to investigate scintigraphic viability and radiographic union patterns of composite grafts after surgery, union rates, functional outcomes, and complication rates.

METHODS

Seventeen patients underwent intercalary composite reconstruction using PTM and VFG (12 male, 2 female, mean age: 10.9 y). Retrospective evaluation of radiography and bone scintigraphy was performed. The most common diagnosis was osteosarcoma (12/14, 85.7%). All radiography and bone scintigraphy was reviewed for bone healing and tracer uptake semiquantitatively using the ratio of the reconstructed portion to the contralateral side. Complications and oncological and functional outcomes were recorded.

RESULTS

At a mean follow-up of 33.1 months, primary union was achieved in all 28 host-graft junctions in all 14 patients. The respective mean times to proximal and distal junction bone union were 6.9 and 6.5 months. Metaphyseal junctions healed faster than diaphysis junctions (5.2 vs. 8.0 mo, P=0.02). Free fibular was integrated with surrounding bone after a mean of 10.1 months. The mean tracer uptake ratio was 1.1 after a mean of 4.8 months postoperatively. Half patients (50%) had higher uptake on bone scan than contralateral side. There was no significant correlation between uptake value and bone healing time. Five complications occurred in 4 patients (28.6%), and 1 patient (7.1%) contracted an infection. No fractures or breakages were observed. The mean Musculoskeletal Tumor Society 93 score was 87.6%.

CONCLUSIONS

Reconstruction using PTM combined with VFG is associated with good short-term biological activity as indicated by bone scintigraphy, a high union rate, and an acceptable complication rate. The technique is a useful reconstruction option for large segmental bone defects after tumor resection in lower extremities.

LEVEL OF EVIDENCE

Level IV-therapeutic study.

Clinical outcomes of frozen autograft reconstruction for the treatment of primary bone sarcoma in adolescents and young adults

Age affects the clinical outcomes of cancer treatment, including those for bone sarcoma. Successful reconstruction using frozen autograft after excision of bone sarcoma has been reported; however, little is known about the clinical outcomes of frozen autograft reconstruction according to age. The purpose was to evaluate the clinical outcomes of the frozen autograft reconstruction focusing on skeletally mature adolescents and young adults (AYAs) that was 15 to 39 years of age. A total of 37 AYA patients with primary bone sarcoma on the appendicular skeleton were enrolled in this study. The mean follow-up period was 89 months. The graft survival (GS), overall survival (OS), recurrence-free survival (RFS), complications and the function were retrospectively evaluated using medical records. The 10-year GS, OS, and RFS rates were 76%, 84%, and 79%, respectively. Bone union was achieved with a rate of 94% within 1 year after surgery, and nonunion (n = 1) and fracture (n = 2) were infrequently observed. Graft removal was performed in 7 cases, and the most common reason for the removal was infection (n = 5). The Musculoskeletal Tumor Society score was excellent in 23 cases of the available 29 cases. Frozen autograft reconstruction for AYAs showed excellent clinical outcomes, although the long-term follow-up is required.

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.

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.

Megaprosthesis Versus Allograft Prosthesis Composite for the Management of Massive Skeletal Defects: A Meta-Analysis of Comparative Studies

PURPOSE OF REVIEW

Megaprosthesis and Allograft Prosthesis Composite (APC) are the established treatment modalities for massive skeletal defects. There are a handful of studies comparing the use of megaprosthesis and APC in the management of substantial bone loss and it has always been a topic of debate regarding the superiority of one modality over the other. Therefore, we aim to compare the functional outcome and implant survivorship of each modality including complications, revision rates, amputation rate and mortality.

RECENT FINDINGS

The Allograft Prosthesis Composite (APC) constitutes a skeletal allograft implanted with a revision type prosthesis in it. The biological environment provided by the allograft allows attachment of the muscles and tendons imparting better stability and function. However, the literature is not kind enough with APC due to associated risk of infection, disease transmission and nonunion at the graft-host junction. The megaprosthesis (MP) on the other hand is a nonbiologic modality with better survivorship but subservient functional outcome. Infection has been a major issue in both the modalities. Advancement in metallurgy using silver coated megaprosthesis also failed to provide strong evidence in preventing infection. The functional outcome is better with APC in both the upper and lower limbs. However, the survivorship is better with megaprosthesis, especially in the upper limb when revision rates were compared between the two modalities. Deep infection and mechanical complications were significantly higher in the APC group. There was no significant difference between the two groups in terms of amputation rate, mortality, and local recurrence.

LEVEL OF EVIDENCE (CEBM)

2a.

Proximal Humerus Reconstruction after Tumor Resection: An Overview of Surgical Management

Proximal humerus is one of the anatomical sites that are most frequently involved by bone and soft tissue malignant tumors. Alone or in association with adjuvant treatments, surgery represents the main therapeutic option to treat and eradicate these diseases. Once the first-line option, in the last decades, amputation lost its role as treatment of choice for the large majority of cases in favor of the modern limb sparing surgery that promises to preserve anatomy and-as much as possible-upper limb functionality. Currently, the main approaches used to replace proximal humerus after a wide resection in oncologic surgery can be summarized in biological reconstructions (allografts and autografts), prosthetic reconstructions (anatomic endoprostheses, total reverse shoulder prostheses), and graft-prosthetic composite reconstructions. The purpose of this overview is to present nowadays surgical options for proximal humerus reconstruction in oncological patients, with their respective advantages and disadvantages.

Osteoarticular allograft reconstruction after distal radius tumor resection: Reoperation and patient reported outcomes

BACKGROUND

The aims of this study are to evaluate the rate of wrist joint preservation, allograft retention, factors associated with reoperation and to report the patient reported outcomes after osteoarticular allograft reconstruction of the distal radius.

METHODS

Retrospective chart review identified 33 patients who underwent distal radius resection followed by osteoarticular allograft reconstruction, including 27 giant cell tumors and 6 primary malignancies. Ten patients with a preserved wrist joint completed the QuickDASH, PROMIS-CA physical function, and Toronto extremity salvage score (TESS) at a median of 13 years postoperatively.

RESULTS

The allograft retention rate was 89%, and an allograft fracture predisposed to conversion to wrist arthrodesis. The reoperation rate was 55% and 36% underwent wrist arthrodesis at a median of 4.2 years following index surgery. The use of locking plate fixation was associated with lower reoperation and allograft fracture rates. Patients reported a median QuickDASH of 10.2 (range: 0-52.3), a mean PROMIS physical function of 57.8 (range: 38.9-64.5) and the median TESS was 95.5 (range: 67.0-98.4).

CONCLUSION

Osteoarticular allograft reconstruction results in acceptable long-term patient reported outcomes, despite a high revision rate. Allograft fixation with locking plates seems to reduce the number of reoperations and allograft fractures, along with reduction in wrist arthrodesis rates.

Long-term results of uncemented allograft prosthesis composite reconstruction for the tumor in proximal femur: a minimum follow-up of sixty-five months

BACKGROUND

Uncemented allograft prosthesis composite (APC) has been applied for tumorous bone defect reconstruction in the proximal femur. However, the long-term results are rarely reported. This study aimed to evaluate long-term outcomes of uncemented APC.

METHODS

Eighteen patients who received uncemented APC reconstruction in the proximal femur after tumor resections were retrospectively reviewed.

RESULTS

The average resection length was 110 mm (80-154) and the average follow-up was 106.7 months (65-141). Bone union achieved in all patients with an average duration of 7.6 months (5-10). The average HHS, MSTS score and gluteus medius strength at one-year follow-up were 88.0 (80-94), 25.2 (22-28) and 4 (3-5), respectively. While at the last follow-up, the HHS, MSTS score and gluteus medius strength were 83.0 (48-100), 24.0 (10-30) and 4 (2-5), respectively. Five intraoperative fractures were fixed with cerclage wires. Two postoperative periprosthetic and prosthetic fractures received a revision. Three local recurrent patients received a secondary surgery. One of these three lung metastatic patients underwent lung metastatic tumor resection. Another two patients were diagnosed with both bone and lung metastases, only one of them underwent amputation. Two greater trochanteric fractures received no treatment. There were10 severe, 3 moderate and 5 mild allograft resorptions without treatment.

CONCLUSION

Uncemented APC is a reliable reconstruction for neoplastic bone defect of the proximal femur, especially for the young patient who expected long-life expectancy and good function. Though allograft resorption and trochanteric fracture are the common complications, they seem no effect on the function.

Optimal configuration of a dual locking plate for femoral allograft or recycled autograft bone fixation: A finite element and biomechanical analysis

BACKGROUND

Allografts and recycled bone autograft are commonly used for biological reconstruction. The dual locking plates fixation method has been advocated for increasing allograft stability and preventing fixation failure; however, the biomechanical properties of the various configurations of dual locking plates have not been extensively studied.

METHODS

In a finite element (FE) analysis, we developed 6 patterns of different dual locking plate configurations for fixation of the mid shaft of the femur. The maximum strains were recorded for each of the 6 models then axial, bending and torsion stiffness were calculated. The FE analysis was validated the results with mechanical testing (axial compression, bending, and torsional stiffness) on a cadaveric femur.

FINDINGS

The highest axial compression (715.41 N/mm) and lateral bending (2981.24 N/mm) was found in Model 4 (with two 10-hole locking plates placed at the medial and lateral side), while the highest torsional stiffness (193.59 N·mm /mm) was found in Model 3 (with 8- and 10-hole locking plates placed at the posterior and lateral side). Excellent agreement was found between the finite element analysis and biomechanical testing (r² = 0.98).

INTERPRETATION

The dual locking plate configuration with medial and lateral, 10-hole locking plates provided the most rigid and strongest fixation of the femur; both in terms of axial compression and lateral bending stiffness.

Different reconstructive techniques for tumours of the distal tibia

AIMS

The aim of this study was to report the results of three forms of reconstruction for patients with a ditsl tibial bone tumour: an intercalary resection and reconstruction, an osteoarticular reconstruction, and arthrodesis of the ankle.

METHODS

A total of 73 patients with a median age of 19 years (interquartile range (IQR) 14 to 36) were included in this retrospective, multicentre study.

RESULTS

Reconstructions included intercalary resection in 17 patients, osteoarticular reconstruction in 11, and ankle arthrodesis in 45. The median follow-up was 77 months (IQR 35 to 130). Local recurrence occurred in eight patients after a median of 14 months (IQR 9 to 36), without a correlation with adequacy of margins or reconstructive technique. Major complications included fracture of the graft in ten patients, nonunion of the proximal osteotomy in seven, and infection in five. In the osteoarticular group, three of 11 patients developed radiological evidence of severe osteoarthritis, but only one was symptomatic and required conversion to ankle arthrodesis. Functional evaluation showed higher values of the Musculoskeletal Tumour Society (MSTS) and American Orthopaedic Foot and Ankle Society (AOFAS) scores in the intercalary group compared with the others.

CONCLUSION

Preservation of the epiphysis in patients with a distal tibial bone tumour is a safe and effective form of limb-sparing treatment. It requires rigorous preoperative planning after accurate analysis of the imaging. When joint-sparing resection is not indicated, ankle arthrodesis, either isolated tibiotalar or combined tibiotalar and subtalar arthrodesis, should be preferred over osteoarticular reconstruction. Cite this article: Bone Joint J 2020;102-B(11):1567-1573.

Does Osteoarticular Allograft Reconstruction Achieve Long-term Survivorship after En Bloc Resection of Grade 3 Giant Cell Tumor of Bone?

BACKGROUND

En bloc resection of benign tumors is only indicated in aggressive lesions with substantial destruction of the affected bone. Few reports have evaluated the long-term outcome of Grade 3 giant cell tumor of bone (GCTB; defined as severe bone destruction and soft tissue extension) treated with en bloc resection and reconstruction with a massive allograft. We recently reported that patients with benign tumors achieved better allograft reconstruction survivorship compared with those treated for a malignant bone tumor. In light of that finding, we wondered whether osteoarticular allografts would be a viable long-term alternative for Grade 3 GCTB, which could be important in some countries because of greater availability and lower costs compared with endoprostheses.

QUESTIONS/PURPOSES

We analyzed a group of patients with Grade 3 GCTBs treated with en bloc resection and osteoarticular allograft reconstruction in terms of (1) survivorship free from allograft removal at 10 years; (2) survivorship free from reoperation for any reason at 10 years, (3) functional results as measured by the Musculoskeletal Tumor Society (MSTS) score, (4) assessment of arthrosis at the knee.

METHODS

We retrospectively analyzed all patients with a Grade 3 GCTB treated between 1980 and 2007. Only patients treated with en bloc resection and reconstruction with massive osteoarticular allografts were included in the analysis. The indication for osteoarticular reconstruction during that time included severe bone destruction with intraarticular compromise of the tumor, intraarticular fracture because of tumor growth, the presence of inadequate remaining subchondral bone to resist normal loading (for the distal femur or proximal tibia), and the preservation of a soft-tissue component (ligaments or meniscus) for articular stability. During the period, 75 patients were treated with en bloc resection. Patients treated with intralesional curettage (n = 7), reconstruction with an endoprosthesis (n = 2), intercalary arthrodesis (n = 13), or unicondylar reconstruction (n = 14) were excluded. Of the original 75 treated with en bloc resection, 52% (39) were treated with osteoarticular allograft reconstruction, and no patient was lost to follow-up before 2 years or had substantial missing data. However, of the 39 patients, another 21% (8) have not been seen in the last 5 years, but these were included here because they reached the 10-year minimum surveillance period before being lost. Twenty-three of those 39 patients were previously reported by our group and 16 new patients (treated between 1980-1985) were included in this series (eight distal radius, six distal femur, two proximal tibias), extending the follow-up period and including more patients for analysis. The median (range) follow-up duration was 26 years (10 to 34). We assessed survivorship using a Kaplan-Meier analysis, we drew MSTS scores retrospectively from patients´ medical records, and we graded arthrosis using the Ahlbäck scale for the knee (which was by far the most common joint involved, n = 31, and so it was the joint we assessed for the presence of arthrosis).

RESULTS

The survivorship free from allograft removal was 85% at 10 years (95% CI 74 to 96). The allograft survivorship free from reoperation for any reason at 10 years was 72% (95% CI 59 to 87). The median (range) MSTS score was 28 points (19 to 30). The grade of arthrosis in the knee at last follow-up was analyzed in 20 patients and classified in nine as Ahlbäck Type 4, in six as Type 3, in three as Type 2 and in two as Type 5.

CONCLUSIONS

Osteoarticular allograft reconstruction after a Grade 3 GCTB en bloc resection showed excellent long-term survivorship. We believe these results compare favorably with other studies on endoprosthetic reconstruction and head-to-head studies of these approaches should be performed; these would need to be multicenter trials. In the meantime, in locations where endoprostheses are unavailable or too expensive, we believe our results support the use of osteoarticular allografts.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Wrist Arthrodesis and Osteoarticular Reconstruction in Giant Cell Tumor of the Distal Radius

PURPOSE

The aim of this multi-institutional retrospective study was to compare osteoarticular graft reconstruction (OA) and wrist arthrodesis (WA) after distal radius resection for giant cell tumor.

MATERIAL AND METHODS

Sixty-seven patients affected by giant cell tumor of the distal radius underwent resection and reconstruction with OA (47 patients) or WA (20 patients). The mean age was 40 years (range, 13-74 years). Grafts included fresh-frozen allograft or nonvascularized fibular autograft. Complications requiring surgical revision were recorded. Clinical outcome was assessed with the Musculoskeletal Tumour Society Score (MSTS) and Disabilities of the Arm, Shoulder, and Hand (DASH) score.

RESULTS

Fifteen patients developed a local recurrence after a median of 12 months (range, 6-137 months). Sixteen patients required revision surgery for complications. Of these, 10 were graft-related complications (7 in the OA group and 3 in the WA group). Among OA, 2 patients with painful instabilities and 4 with severe arthritis required conversion into WA after a mean of 26 months (range, 13-38 months) At a median follow-up of 105 months (range, 12-395 months), similar functional outcome (MSTS and DASH score) was observed between OA and WA.

CONCLUSIONS

Our results did not show any advantage of OA or WA over the other technique. A patient-by-patient decision should be taken both regarding the type of reconstruction (OA or WA) and the type of graft (allograft or autograft). The reconstructive choice should also consider the patient's functional expectations.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Clinical course of grafted cartilage in osteoarticular frozen autografts for reconstruction after resection of malignant bone and soft-tissue tumor involving an epiphysis

•

Frozen autograft of tumour-bearing bone using liquid nitrogen as a recycling autograft has various advantages.

•

This paper is the first report focusing on the fate of grafted cartilage in recycled autograft after bone tumour excision.

•

We found hemicondylar frozen autograft is promising reconstruction method.

There are several options for biological reconstruction after bone tumor resection. If the tumor invades an epiphysis, the reconstruction is far more complicated because there is no option to restore large joint cartilage using currently available medical techniques. Frozen autograft with liquid nitrogen has been used as recycled autologous bone graft and the purpose of the present study was to assess the outcome of grafted cartilage in osteoarticular frozen autografts used in the treatment of patients with bone and soft-tissue sarcoma. We have treated 27 patients with cases of bone tumor resection involving an epiphysis where frozen autografts were used for reconstruction. If the tumor was located in a limited part of the epiphysis, partial resection of the epiphysis was performed to preserve the healthy part of the cartilage in 4 cases. The survival of grafted frozen cartilage was assessed by X-ray imaging. The end point was defined as grade IV of the Kellgren and Lawrence osteoarthritis grading system and was recorded using the Kaplan–Meier method. In case of removal of grafted bone after the surgery, pathological findings were assessed by hematoxylin and eosin staining of sections of resected cartilage in available cases to observe the fate of grafted cartilage over time. The postoperative mean follow-up period was 94.0 months. Grade IV osteoarthritis occurred in 12 patients. All patients in the partial epiphyseal freezing group survived compared with only 1 patient in the total epiphyseal freezing group who had survived to the final follow up (p < 0.01). Resected specimens with grafted cartilage were examined histologically. A sample excised after 14 months had dead cartilage with empty lacunae and the surface of the cartilage had reactive fibrous tissue. Grafted cartilage of frozen osteoarticular autografts was worn out over time. However, intraepiphyseal resection preserving partial healthy cartilage resulted in excellent survival. This technique requires careful planning of the surgery but might be an alternative to megaprosthesis.

Bone defect reconstruction with autologous bone inactivated with liquid nitrogen after resection of primary limb malignant tumors: An observational study

Surgical treatment of malignant bone tumors comprises tumor resection and reconstruction. The most commonly used reconstruction method is prosthesis replacement, which achieves good early function, but has a high long-term incidence of complications. Another reconstruction option is autologous bone replantation, which has the advantages of anatomical matching and no need for large bone bank support. Few studies have evaluated reconstruction with liquid nitrogen-inactivated autogenous bone.The present study aimed to evaluate the oncological results, bone healing results, complications, and indications of reconstruction with liquid nitrogen-inactivated autogenous bone grafts.The study population comprised 21 consecutive patients. The tumor site was the tibia in 9 cases, femur in 8, and humerus in 4. There were 37 osteotomy ends in total. After freezing and rewarming, the medullary cavity of the autogenous bone was filled with antibiotic bone cement. Seventeen patients received bilateral plate fixation, 2 received intramedullary nail and distal plate fixation, and 2 received single plate fixation.The average follow-up was 31 ± 6 months. Eighteen patients survived without tumors, and the 3-year survival rate was 80.4%. All cases had adequate surgical margins, but recurrence developed in 1 patient. Metastasis occurred in 3 patients, who all died of metastasis. Intraoperative inactivated bone fracture occurred in 1 patient, and screw breakage was found in 1 patient. Nonunion occurred at 1 humeral diaphysis osteotomy site, and 1 patient was lost to follow-up; the average healing time of the other 35 ends was 13 ± 6 months, and the bone healing rate was 97.2%. The average bone healing times in the metaphysis and diaphysis were 9 ± 3 months and 15 ± 6 months (P = .003). The average bone healing times in the upper and lower limbs were 16.6 ± 7.4 months and 12.3 ± 5.8 months (P = .020). The average Muscle and Skeletal Tumor Society score was 28 ± 3 (21-30) in the 18 survivors.Liquid nitrogen-inactivated autologous bone replantation for primary malignant limb tumor was safe and effective, as shown by the relatively low complication rate, high bone healing rate, and satisfactory postoperative function. This is a reliable biological reconstruction method for malignant bone tumors with specific site and bone destruction characteristics.

Intercalary Allograft to Reconstruct Large-Segment Diaphysis Defects After Resection of Lower Extremity Malignant Bone Tumor

Aim

To evaluate the clinical effect of intercalary allograft transplantation and reconstruction in the treatment of diaphyseal defect after resection of lower extremity malignant bone tumor.

Methods

Clinical data of 17 patients diagnosed with malignant lower-limb bone tumors and having undergone segmental allograft reconstruction with a mean follow-up of 49.8 (26–78) months were included. Segmental allografts of average 17-cm length preserved by deep-freezing were used and fixed using intramedullary nail, double plate, and intramedullary nail and plate combination in 2, 5, and 10 patients, respectively. Host–donor junctions were perfectly and roughly matched in 5 and 12 patients, respectively. Allograft union, local recurrence, and complications were assessed using clinical and radiological tests. Allograft union was evaluated using the International Society of Limb Salvage (ISOLS) scoring system. The functional prognosis was evaluated using the Musculoskeletal Tumour Society (MSTS) scoring system.

Results

Intercalary allograft reconstruction of femoral shaft, tibial shaft, and distal tibia with ankle arthrodesis was performed in eight, four, and five patients, respectively. Two patients had local recurrence and underwent amputation; one died of metastasis. Host–donor junctions in two patients showed nonunion; 12 patients achieved bone union. The average union time was 12.1 months. No allograft fracture or infection occurred. Union rates were 100% and 88.2% at metaphyseal and diaphyseal junctions, respectively. Healing time differed significantly between the precisely and roughly matched groups (p<0.01). The incidence of nonunion was higher after intramedullary nailing than after the other two methods (p<0.05). The mean MSTS score was 24.2 (14–29) at the end of follow-up.

Conclusion

Intercalary allograft transplantation is an effective strategy for diaphyseal defect following post-tumor resection in the lower extremity. Good bone healing after allograft reconstruction is achieved with stable internal fixation and perfectly matched host–donor interfaces.

Clinical Outcomes of Osteoarticular Extracorporeal Irradiated Autograft for Malignant Bone Tumor

Methods

We retrospectively reviewed 33 patients who underwent osteoarticular ECIA after bone tumor resection from 1988 to 2014. We investigated complications, radiographic changes by the International Society of Limb Salvage graft evaluation criteria, and functional outcomes according to the Musculoskeletal Tumor Society scoring system.

Results

Fifteen patients were reoperated upon due to infection (n = 9), protruding fixation implant (n = 4), or fracture of the grafted bone (n = 2). The average radiographic evaluation score was 66.4%, and the median functional score was 23 (77%). The radiographic score for the proximal humerus or proximal tibia was lower than that for the other locations. The functional score was not different among the autograft sites but was related to the radiographic score.

Conclusion

Although osteoarticular ECIA is one of the reasonable surgical options for patients with tumors for which reliable prostheses are not available, we do not recommend osteoarticular ECIA as a routine procedure because of high complication rate.

Do Massive Allograft Reconstructions for Tumors of the Femur and Tibia Survive 10 or More Years after Implantation?

BACKGROUND

Massive bone allografts have been used for limb salvage in patients undergoing bone tumor resections as an alternative to endoprostheses. Although several studies on massive allograft reconstructions for bone tumors reported that most complications occur in the first 3 years after surgery, there are no long-term reports on complications to substantiate this contention. We believe such information is important so that surgeons and patients can make more informed decisions when choosing a reconstructive method after tumor resection.

QUESTIONS/PURPOSES

(1) What is the survival of allografts free from removal, amputation, or joint replacement in patients treated for bone tumors in the lower limb with a minimum of 10 years of followup? (2) What complications occur after 10 or more years of followup? (3) Are there factors associated with allograft survival, such as age, sex, the affected bone, reconstruction type (intercalary or osteoarticular allograft), tumor type (malignant or benign), failure type, and chemotherapy use?

METHODS

We retrospectively analyzed the records of 398 patients treated in one center with benign or malignant bone tumors in the femur or tibia between 1986 and 2007. During the period in question, our general indications for using allografts (354 patients) included patients with benign or low-grade sarcomas and patients with high-grade sarcomas with clinical and imaging response to neoadjuvant chemotherapy. Other approaches such as endoprostheses (44 patients) were indicated if the patient received radiotherapy, in patients with high-grade sarcomas without clinical and imaging response to neoadjuvant chemotherapy, or with neurovascular tumor involvement. We excluded from the analysis 53 patients treated with allograft-prosthetic composites, 46 with hemicondylar osteoarticular allografts, and 57 with intercalary hemicylindrical allografts. The study was thus performed in 198 patients treated with segmental massive allografts in the long bones of the lower extremity (132 femurs and 66 tibias) after resection of a primary bone tumor, including 120 patients treated with osteoarticular and 78 with segmental intercalary allografts. A total of 32 (16%) of the 198 patients died before 10 years, and graft status was known in all of those patients; these patients were included (mean followup, 192 months; range, 1-370 months). All remaining 166 patients who were not known to have died before 10 years were accounted for at least 10 years after the allograft procedure (mean, 222 months; range, 120-370 months). No patient was lost to followup. The mean age was 22 years (range, 2-55 years); 105 patients were male (53%) and 93 were female. The predominant diagnoses were osteosarcoma (n = 125, 63%), giant cell tumor of bone (n = 27, 14%), and Ewing's sarcoma (n = 19, 10%). In all, 146 patients (74%) underwent chemotherapy. Selected variables were analyzed using multivariate logistic regression analyses to identify risk factors of allograft removal, joint replacement, or amputation. We performed competitive risk analysis with allograft removal, joint replacement, or amputation as the endpoint at 5, 10, and 20 years. Patient function was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 scoring system.

RESULTS

The risk of allograft removal, joint replacement, or amputation was 36% at 5 years (95% CI, 30-43), 40% at 10 years (95% CI, 33-47), and 44% at 20 years (95% CI, 37-51). Fractures occurred in 15% (29 patients), infection in 14% (27 patients), nonunion in 12% (23 patients) and tumor recurrence in 7% (13 patients). Thirty-two patients died of disease before 10 years; nine of these patients had a second surgery before death, eight had an amputation, and one underwent graft removal. Of the 166 patients who were still alive 10 years after the allograft procedure, 36 underwent allograft removal, six patients underwent joint replacement, and four had an amputation; however, after 10 years, six more allografts were removed (four due to fractures, one due to infection, and one due to instability), and another patient was amputated due to a second malignancy. After controlling for potentially confounding variables including death, we found that the risk of allograft removal, joint replacement, or amputation in osteoarticular tibial grafts (58% [95% CI, 43-73] at 5, 10, and 20 years) was higher than that of osteoarticular femur allografts (29% [95% CI, 18-39] at 5 years, 30% [95% CI, 19-40] at 10 years, 37% [95% CI, 25-48] at 20 years; p = 0.010) and tibia intercalary allografts (26% [95% CI, 7-45] at 5, 10 and 20 years; p = 0.020). Fractures occurred more frequently in the femur (18% [95% CI, 11-25]) than in the tibia (5% [95% CI, 0-10]; p < 0.010), and infections occurred more frequently in the tibia (24% [95% CI, 14-35]) than in the femur (4% [95% CI, 0-8]; p < 0.001). With the number of patients we had, we found no difference in the proportion of local recurrence in the tibia (12% [95% CI, 4-20]) compared with the femur (5% [95% CI, 1-9]; p < 0.053).

CONCLUSIONS

Infections were the most common complications associated with allograft removal in the first 2 to 3 years after reconstruction and were more frequently associated with tibial allograft removal. Fractures were more commonly associated with graft removal with longer term followup and were more frequently associated with femoral allograft removal. Although we cannot directly compare our results with other types of reconstructions, we believe that allografts still have a role in the reconstruction of patients with a benign or low-grade bone tumor. Future studies in femoral allograft with longer followup should be performed to analyze factors that may explain why some grafts fail, such as the percent of the length of the bone resected, type and number of plates and screws used and type of fixation (rods versus plates). There was a higher incidence of graft removal in patients with proximal tibia osteoarticular allografts, which has led us to use this type of reconstruction only in pediatric patients over the last 15 years.

LEVEL OF EVIDENCE

Level III, therapeutic study.

The functional outcomes and complications of different reconstruction methods for Giant cell tumor of the distal radius: comparison of Osteoarticular allograft and three-dimensional-printed prosthesis

Background

En bloc excision has been increasingly used for the management of giant cell tumors (GCTs) in the distal radius. An osteoarticular allograft has been used extensively for decades, and custom-made prosthesis reconstruction has been more recently applied. We aimed to compare the clinical outcomes of the two procedures.

Methods

We retrospectively analyzed 30 patients with Campanacci III or recurrent GCTs of the distal radius for follow-up at a mean of 33.2 months. In total, 15 underwent osteoarticular allograft reconstruction (allograft group) and 15 received cementless three-dimensional (3D)-printed prosthesis reconstruction (prosthesis group) between March 18, 2013, and May 20, 2018. All patients underwent by clinical and radiological examinations, including pre- and postoperative active range of motion (ROM) of the wrist, VAS score, grip strength, degenerative change of wrist, Mayo wrist score and Musculoskeletal Tumor Society (MSTS) score. Complications were evaluated using the Henderson classification.

Results

Both groups showed significantly increased ROM, grip strength, Mayo score and MSTS score postoperatively. Furthermore, the extension, flexion, MSTS, and Mayo score were significantly higher in the prosthesis group. There was no significant difference in grip strength and VAS between the groups. In allograft group, one patient had a late infection one had resorption of allograft without allograft bone fracture. and four had wrist subluxation. All patients had degenerative changes (mean 9 months). In the prosthesis group, three patients developed wrist subluxation, three had separation of the distal radioulnar joint, and none of the patients developed wrist degeneration.

Conclusions

Our study compared the objective functional outcomes and complications of two reconstructive methods for Campanacci III or recurrent GCT in the distal radius. 3D-printed prosthesis replacement can partially preserve wrist function better than allograft reconstruction in the short-term. During the design of 3D-printed prosthesis, preoperative morphological assessment of the affected proximal row carpal is helpful to control postoperative dislocation. After allograft reconstruction, wrist degeneration, which has been demonstrated in all patients, severely influence their wrist function. Therefore, compared to allograft reconstruction, 3D-printed prosthesis reconstruction has irreplaceable advantages at early-stage application, especially in wrist function, however, further studied with a larger number of cases and longer follow-up.

Extendable Endoprostheses in Skeletally Immature Patients: A Study of 124 Children Surviving More Than 10 Years After Resection of Bone Sarcomas

BACKGROUND

Extendable endoprostheses are used to reconstruct segmental defects following resection of bone sarcomas in skeletally immature patients. However, there remains a paucity of studies with regard to long-term outcomes.

METHODS

We retrospectively reviewed 124 skeletally immature children who underwent an extendable endoprosthetic replacement and survived more than 10 years after the surgical procedures. Anatomical sites included the distal part of the femur (n = 66), the proximal part of the femur (n = 13), the proximal part of the tibia (n = 29), and the proximal part of the humerus (n = 16). Complications and implant survival were classified according to the modified Henderson criteria.

RESULTS

The mean follow-up was 24 years (range, 10 to 36 years). The mean age at the time of the extendable endoprosthetic replacement was 9 years (range, 2 to 16 years). All patients had reached skeletal maturity at the last follow-up. The 10-year endoprosthetic failure-free survival rate was 28%. A total of 243 complications occurred in 90% of patients; these complications were most frequently related to soft-tissue problems (27% of complications). The incidence of and cumulative survival with respect to each failure mode varied between anatomical sites. Soft-tissue failures occurred most frequently in the proximal part of the femur (77%; p = 0.003), and the distal part of the femur was the most frequent site of aseptic loosening (52%; p = 0.014) and structural failure (55%; p = 0.001). Excluding lengthening procedures, 105 patients (85%) underwent an additional surgical procedure, with a mean of 2.7 surgical procedures per patient (range, 0 to 7 surgical procedures per patient). The mean limb-length discrepancy at the final follow-up was 1 cm (range, 0 to 9 cm). Limb salvage was achieved in 113 patients (91%). The mean Musculoskeletal Tumor Society functional score (the percentage of a total score of 30 points) was 82% (range, 40% to 100%) in 115 patients with available data at the last follow-up.

CONCLUSIONS

Extendable endoprostheses are associated with a high complication rate and a need for additional surgical procedures over time. Despite this, successful limb salvage with reasonable function and small limb-length discrepancy is achievable in the long term. Our study provides benchmark data for individual anatomical sites for further improvements of outcomes.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Preoperative surgical risk stratification in osteosarcoma based on the proximity to the major vessels

Aims

The aim of this study was to determine the risk of local recurrence and survival in patients with osteosarcoma based on the proximity of the tumour to the major vessels.

Patients and Methods

A total of 226 patients with high-grade non-metastatic osteosarcoma in the limbs were investigated. Median age at diagnosis was 15 years (4 to 67) with the ratio of male to female patients being 1.5:1. The most common site of the tumour was the femur (n = 103) followed by tibia (n = 66). The vascular proximity was categorized based on the preoperative MRI after neoadjuvant chemotherapy into four types: type 1 > 5 mm; type 2 ≤ 5 mm, > 0 mm; type 3 attached; type 4 surrounded.

Results

Limb salvage rate based on the proximity type was 92%, 88%, 51%, and 0% for types 1 to 4, respectively, and the overall survival at five years was 82%, 77%, 57%, and 67%, respectively (p < 0.001). Local recurrence rate in patients with limb-salvage surgery was 7%, 8%, and 22% for the types 1 to 3, respectively (p = 0.041), and local recurrence at the perivascular area was observed in 1% and 4% for type 2 and 3, respectively. The mean microscopic margin to the major vessels was 6.9 mm, 3.0 mm, and 1.4 mm for types 1 to 3, respectively. In type 3, local recurrence-free survival with limb salvage was significantly poorer compared with amputation (p = 0.025), while the latter offered no overall survival benefit. In this group of patients, factors such as good response to chemotherapy or limited vascular attachment to less than half circumference or longitudinal 10 mm reduced the risk of local recurrence.

Conclusion

The proximity of osteosarcoma to major blood vessels is a poor prognostic factor for local control and survival. Amputation offers better local control for tumours attached to the blood vessels but does not improve survival. Limb salvage surgery offers similar local control if the tumour attachment to blood vessels is limited. Cite this article: Bone Joint J 2019;101-B:1024–1031.

Proximal Tibial Reconstruction After Tumor Resection: A Systematic Review of the Literature

BACKGROUND

The proximal part of the tibia is a common location for primary bone tumors, and many options for reconstruction exist following resection. This anatomic location has a notoriously high complication rate, and each available reconstruction method is associated with unique risks and benefits. The most commonly utilized implants are metallic endoprostheses, osteoarticular allografts, and allograft-prosthesis composites. There is a current lack of data comparing the outcomes of these reconstructive techniques in the literature.

METHODS

A systematic review of peer-reviewed observational studies evaluating outcomes after proximal tibial reconstruction was conducted, including both aggregate and pooled data sets and utilizing a Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) review for quality assessment. Henderson complications, amputation rates, implant survival, and functional outcomes were evaluated.

RESULTS

A total of 1,643 patients were identified from 29 studies, including 1,402 patients who underwent reconstruction with metallic endoprostheses, 183 patients who underwent reconstruction with osteoarticular allografts, and 58 patients who underwent with reconstruction with allograft-prosthesis composites. The mean follow-up times were 83.5 months (range, 37.3 to 176 months) for the metallic endoprosthesis group, 109.4 months (range, 49 to 234 months) for the osteoarticular allograft group, and 88.8 months (range, 49 to 128 months) for the allograft-prosthesis composite reconstruction group. The mean patient age per study ranged from 13.5 to 50 years. Patients with metallic endoprostheses had the lowest rates of Henderson Type-1 complications (5.1%; p < 0.001), Type-3 complications (10.3%; p < 0.001), and Type-5 complications (5.8%; p < 0.001), whereas, on aggregate data analysis, patients with an osteoarticular allograft had the lowest rates of Type-2 complications (2.1%; p < 0.001) and patients with an allograft-prosthesis composite had the lowest rates of Type-4 complications (10.2%; p < 0.001). The Musculoskeletal Tumor Society (MSTS) scores were highest in patients with an osteoarticular allograft (26.8 points; p < 0.001). Pooled data analysis showed that patients with a metallic endoprosthesis had the lowest rates of sustaining any Henderson complication (23.1%; p = 0.009) and the highest implant survival rates (92.3%), and patients with an osteoarticular allograft had the lowest implant survival rates at 10 years (60.5%; p = 0.014).

CONCLUSIONS

Osteoarticular allograft appears to lead to higher rates of Henderson complications and amputation rates when compared with metallic endoprostheses. However, functional outcomes may be higher in patients with osteoarticular allograft. Further work is needed using higher-powered randomized controlled trials to definitively determine the superiority of one reconstructive option over another. In the absence of such high-powered evidence, we encourage individual surgeons to choose reconstructive options based on personal experience and expertise.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Mid- to long-term results of allograft-prosthesis composite reconstruction after removal of a distal femoral malignant tumor are comparable to those of the proximal tibia

PURPOSE

To compare the outcomes of allograft-prosthesis composite for reconstruction after malignant tumors at the distal femur and proximal tibia.

METHODS

Case-control study of 24 patients with distal femur tumor and 21 with proximal tibia tumor. Union of the allograft-host interface was assessed by the International Society of Limb Salvage criteria, and complications according Henderson. Functional outcome was evaluated by the Musculoskeletal Tumor Society (MSTS) score, Western Ontario and McMaster Universities (WOMAC) score, and pain by a visual analog scale.

RESULTS

The median follow-up in the femoral group was 11.4 (range 2.3-25.0) years, and 10.1 (range 2.2-25.0) in tibial group. Incorporation of the allograft was successful in more than 90% in both groups. Tumor location was not significant predictor for allograft failure in multivariate analysis. Aseptic prosthesis loosening occurred in two patients in either group, and another patient in the tibial group had a breakage of the tibial insert. Excluding local recurrences and amputations, the prosthesis survival at 10 years was 94.1% in the femoral group, and 83.3% in the tibial group (n.s.). For the patients with preserved limb, the median MSTS score was 23.6 in the femoral group and 22.8 in tibial group (n.s.). Likewise, there were no significant differences in median WOMAC score (n.s.) or VAS pain (n.s.).

CONCLUSIONS

Allograft-prosthesis composite is an effective procedure for distal femur tumors related to the graft, prosthesis survival, and functional outcomes. The results are comparable to those for proximal tibial tumors.

LEVEL OF EVIDENCE

Therapeutic study, Level III.

Limb salvage surgery with joint preservation for malignant humeral bone tumors: operative procedures and clinical application

BACKGROUND

However, the application of limb salvage with joint preservation is controversial. The purpose of this study is to propose a selection strategy of joint-sparing operative procedures for humeral malignancies based on tumor origin, site and bone strength.

METHODS

The medical data of 28 patients with humeral malignancies treated at our institute from January 2010 to December 2016 were analyzed retrospectively. The patients had a median age of 51 years (range, 8-82 years). Bone strength scoring system was utilized to evaluated bone strength of the tumor. Four joint-sparing surgical methods were performed on selected patients. Evaluation of limb function was based on the Musculoskeletal Tumor Society scoring system. Two-sample t-test was used to compare patient group data such as bone strength score and postoperative Musculoskeletal Tumor Society score.

RESULTS

The mean follow-up period for the 7 patients with primary malignancies was 45 months (range, 15-66 months). One patient died due to recurrence and lung metastasis, while the remaining 6 patients (6/7, 85.7%) survived without recurrence. For the 21 patients with metastases, 5 survived with tumors, with an average survival time of 25.8 months (range, 9-48 months). The rest died from progression of the primary tumors. The mean bone strength score for the biological reconstruction group and non-biological reconstruction group was respectively 9.7 ± 1.3 and 12.9 ± 1.2. A significant difference between the 2 groups (p < 0.05) was found. Mean postoperative Musculoskeletal Tumor Society score was respectively 27.2 ± 1.8 and 26.1 ± 1.7 for the 2 groups. There was no significant difference between the 2 groups (p > 0.05). Non-oncological complications included fracture (1), aseptic loosening (1) and radial nerve injury (1).

CONCLUSIONS

Alcohol devitalized autograft replantation is applicable for diaphyseal humeral primary malignancies, with a good response to chemotherapy and a low bone strength score (≤10). In situ microwave ablation is suitable for diaphyseal and (or) metaphyseal low-grade malignant bone tumors or metastases with a low bone strength score (≤10). Intercalary prosthetic reconstruction is preferred for diaphyseal metastases with a high bone strength score (> 10).

3D bioprinted hydrogel model incorporating β-tricalcium phosphate for calcified cartilage tissue engineering

One promising strategy to reconstruct osteochondral defects relies on 3D bioprinted three-zonal structures comprised of hyaline cartilage, calcified cartilage, and subchondral bone. So far, several studies have pursued the regeneration of either hyaline cartilage or bone in vitro while-despite its key role in the osteochondral region-only few of them have targeted the calcified layer. In this work, we present a 3D biomimetic hydrogel scaffold containing β-tricalcium phosphate (TCP) for engineering calcified cartilage through a co-axial needle system implemented in extrusion-based bioprinting process. After a thorough bioink optimization, we showed that 0.5% w/v TCP is the optimal concentration forming stable scaffolds with high shape fidelity and endowed with biological properties relevant for the development of calcified cartilage. In particular, we investigate the effect induced by ceramic nano-particles over the differentiation capacity of bioprinted bone marrow-derived human mesenchymal stem cells in hydrogel scaffolds cultured up to 21 d in chondrogenic media. To confirm the potential of the presented approach to generate a functional in vitro model of calcified cartilage tissue, we evaluated quantitatively gene expression of relevant chondrogenic (COL1, COL2, COL10A1, ACAN) and osteogenic (ALPL, BGLAP) gene markers by means of RT-qPCR and qualitatively by means of fluorescence immunocytochemistry.