Bone tumor reconstruction with the Ilizarov method

Distraction Osteogenesis Reconstruction Following Resection of Bone Sarcomas: Surgical, Functional, and Oncological Outcomes from a Prospective Trial Analysis

BACKGROUND

While sustainable long-term function has been established for biological reconstruction with distraction osteogenesis (DO) following osseous resections, there is a paucity of published data informing surgeons and patients on important milestones in the reconstructive process. The objectives of this study were to determine when to expect complete bone healing and full weight-bearing as well as to quantify the influence of chemotherapy on the osseous regeneration process.

METHODS

Prospectively, pathological and clinical data were collected for 30 consecutive patients who underwent primary or secondary DO-based reconstruction following osseous resection from 2018 to 2021. Serial radiographs indicated the times to cortex formation and full union. An unpaired t test was used to compare the time required for full bone remodeling of segments transported with and without concurrent chemotherapy.

RESULTS

The average resection length was 13.6 cm (range, 4 to 22 cm). Patients underwent an average of 6.1 procedures (range, 1 to 14 procedures). Half (50%) of all procedures were planned, while half were unplanned procedures. All patients achieved full, independent weight-bearing at a median of 12 months (interquartile range [IQR], 9 to 16 months). For the 34 segments transported concurrently with chemotherapy, the mean bone healing index (BHI) was 2.3 ± 0.7, and the mean BHI was 1.2 ± 0.4 for the 25 segments without chemotherapy at any point during their transport (p < 0.0001).

CONCLUSIONS

All 30 patients achieved full bone healing and independent weight-bearing at a median of 1 year postoperatively and continued to show functional improvement afterward. Surgeons and patients can expect bone healing to be nearly twice as fast for segments transported after completion of systemic chemotherapy compared with segments transported concurrently with adjuvant chemotherapy.

LEVEL OF EVIDENCE

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

Is it possible to achieve multiplanar correction of complex deformities around the knee in children and adolescents using a monolateral external fixator?

PURPOSE

To present the technique of correction of multiplanar deformities around the knee in children and adolescents using the monolateral external fixator. Also, to evaluate the results of the technique regarding radiological correction, time to union, and possible complications.

METHODS

A total of 29 patients (47 limbs) were prospectively included in the study (14 males and 15 females). Their median age was 13 years (range, 7-17). All patients had at least a 2-plane deformity around the knee which was corrected using a monolateral external fixator. The primary outcome measure was deformity correction (correction of mechanical axis deviation (MAD) in both the coronal and sagittal planes with correction of rotational deformities). The secondary outcome measures included bony union, radiographic, and functional results (assessed by using the Association for the Study and Application of the Method of Ilizarov (ASAMI) score).

RESULTS

The median pre-operative MAD improved from 6.3 to 0.4 cm post-operatively. According to the ASAMI scoring system, the radiographic scoring was excellent in all cases (100%), and the functional scoring was excellent in 22 cases (89.7%) and good in three cases (10.3%).

CONCLUSION

The simple monolateral fixator can be an effective tool for multiplanar correction of complex deformities around the knee without limb length discrepancy.

Our Experience With Extracorporeal Irradiation and Reimplantation of the Irradiated Bone for the Reconstruction of Bone Defects Following Tumor Resection

BACKGROUND

With tremendous improvement in the survival of patients with malignant bone tumors, there is a greater emphasis on the functional outcome and durability of reconstruction following tumor resection. Tumor resection and extracorporeal irradiation (ECI) followed by reimplantation of the irradiated bone in malignant bone tumors is drawing popularity across various centers. In this study, we aim to put forward our experience with ECI, the outcomes achieved, and the complications faced by us.

METHODS

This is a prospective study conducted in patients with malignant and locally aggressive bone tumors who underwent ECI at our center. A total number of 20 patients were selected for the study and followed up for a mean duration of 32.5 months (maximum duration: 58 months, minimum duration: eight months). Orthopedic outcome was measured using the Enneking score. We assessed for local recurrence, functional outcome, union, and complications during the follow-up.

RESULTS

During the course of follow up, local recurrence was seen in two patients. The mean MSTS score of the remaining patients was found to be 23.6. Complications seen included limb length discrepancy, surgical site infection, and graft lysis.

CONCLUSION

Tumor resection and ECI is an effective procedure for biological reconstruction which gives satisfactory functional outcomes. In spite of certain complications, patients expressed satisfaction with the overall outcome of the procedure.

Radiographic findings involved in knee osteoarthritis progression are associated with pain symptom frequency and baseline disease severity: a population-level analysis using deep learning

PURPOSE

To (1) develop a deep-learning (DL) algorithm capable of producing limb-length and knee-alignment measurements, and (2) determine the association between limb-length discrepancy (LLD), coronal-plane alignment, osteoarthritis (OA) severity, and patient-reported knee pain.

METHODS

A multicenter, prospective patient cohort from the Osteoarthritis Initiative between 2004 and 2015 with full-limb standing radiographs at 12 month follow-up was included. A convolutional neural network was developed to automate measurements of the hip-knee-ankle (HKA) angle, femur, and tibia lengths, and LLD. At 12 month follow-up, patients reported their frequency of knee pain since enrollment and current level of knee pain.

RESULTS

A total of 1011 patients (2022 knees, 52.3% female) with an average age of 61.2 ± 9.0 years were included. The algorithm performed 12,312 measurements in 5.4 h. ICC values of HKA and LLD ranged between 0.87 and 1.00 when compared against trained radiologist measurements. Knees producing pain most days of the month were significantly more varus (mean HKA:- 3.9° ± 2.8°) or valgus (mean HKA:2.8° ± 2.3°) compared to knees that did not produce any pain (p < 0.05). In varus knees, those producing pain on most days were part of the shorter limb compared to nonpainful knees (p < 0.05). Baseline Kellgren-Lawrence grade was significantly associated with HKA magnitude, LLD, and pain frequency at 12 month follow-up (p < 0.05 all).

CONCLUSION

A higher frequency of knee pain was associated with more severe coronal plane deformity, with valgus deviation being one degree less than varus on average, suggesting that the knee tolerates less valgus deformation before symptoms become more consistent. Knee pain frequency was also associated with greater LLD and baseline KL grade, suggesting an association between radiographically apparent joint degeneration and pain frequency.

LEVEL OF EVIDENCE

IV case series.

Femoral Discrepancy After Childhood Bone Sarcoma Surgery Can Be Treated With Magnetic Intramedullary Nails

This study aims to determine whether femoral lengthening with a magnetic motorized intramedullary nail (PRECICE; NuVasive) is safe and effective in patients with discrepancy due to limb salvage performed for bone sarcomas before skeletal maturity. Six patients (male, 4; female, 2) with a mean age of 9.3 years (range, 4.8-12.8 years) at the time of index limb salvage surgery were retrospectively analyzed. Four patients had undergone biological reconstruction with liquid-nitrogen recycled frozen autograft shell and inlaid vascular fibula combination and 2 had undergone nonbiological reconstruction with distal femur modular tumor endoprosthesis. The mean age at PRECICE operation was 16.1 years (range, 13.4-20.1 years). The mean prelengthening femoral discrepancy was measured as 60 mm (range, 39-80 mm). Lengthening was achieved in 5 of these 6 patients. Although the PRECICE nail was successfully implanted in the sixth patient, lengthening could never be performed owing to failure to overcome the chronic diaphyseal nonunion first, as intended with compressive use of the nail. For the other 5 patients, in whom lengthening was performed, the mean lengthening was 45 mm (range, 35-52 mm), the mean ratio of achieved to planned lengthening was 93% (range, 74%-100%), and the mean bone-healing index was 41 days per cm (range, 24-69 days per cm). Mean Musculoskeletal Tumor Society score improved from 25.6 to 27.2 after lengthening. No major complications occurred. The outcomes of this study demonstrate that the PRECICE implant can safely and effectively correct femoral length discrepancy caused by limb salvage performed for osteosarcoma before skeletal maturity. [Orthopedics. 2023;46(1):27-34.].

Joint-preservation surgery for bone sarcoma in adolescents and young adults

Bone sarcoma often occurs in childhood, as well as in adolescents and young adults (AYAs). AYAs differ from pediatric patients in that their bone is skeletally mature and the physis has almost disappeared with the completion of growth. Although AYAs spend less time outside, they often participate in sports activities, as well as driving, working, and raising a family, which are natural activities in daily living. Multidisciplinary approaches involving imaging, multi-agent chemotherapy, surgical procedures, and careful postoperative care has facilitated an increase in limb-sparing surgery for bone sarcoma. In addition, recent advances in imaging modalities and surgical techniques enables joint-preservation surgery, preserving the adjacent epiphysis, for selected patients following the careful assessment of the tumor margins and precise tumor excision. An advantage of this type of surgery is that it retains the native function of the adjacent joint, which differs from joint-prosthesis replacement, and provides excellent limb function. Various reconstruction procedures are available for joint-preserving surgery, including allograft, vascularized fibula graft, distraction osteogenesis, and tumor-devitalized autografts. However, procedure-related complications may occur, including non-union, infection, fracture, and implant failure, and surgeons should fully understand the advantages and disadvantages of these procedures. The longevity of the normal limb function for natural activities and the curative treatment without debilitation from late toxicities should be considered as a treatment goal for AYA patients. This review discusses the concept of joint-preservation surgery, types of reconstruction procedures associated with joint-preservation surgery, and current treatment outcomes.

A composite, off-the-shelf osteoinductive material for large, vascularized bone flap prefabrication

We previously described an immortalized, genetically-engineered human Mesenchymal stromal cell line to generate BMP2-enriched Chondrogenic Matrices (MB-CM), which after devitalization and storage could efficiently induce ectopic bone tissue by endochondral ossification. In order to increase the efficiency of MB-CM utilization towards engineering scaled-up bone structures, here we hypothesized that MB-CM can retain osteoinductive properties when combined with an osteoconductive material. We first tested different volumetric ratios of MB-CM:SmartBone® (as clinically used, osteoconductive reference material) and assessed the bone formation capacity of the resulting composites following ectopic mouse implantation. After 8 weeks, as little as 25% of MB-CM was sufficient to induce bone formation and fusion across SmartBone® granules, generating large interconnected bony structures. The same composite percentage was then further assessed in a scaled-up model, namely within an axially-vascularized, confined, ectopically prefabricated flap (0.8 cm³) in rats. The material efficiently induced the formation of new bone (31% of the cross-sectional area after 8 weeks), including bone marrow and vascular elements, throughout the flap volume. Our findings outline a strategy for efficient use of MB-CM as part of a composite material, thereby reducing the amount required to fill large spaces and enabling utilization in critically sized grafts, to address challenging clinical scenarios in bone reconstruction. STATEMENT OF SIGNIFICANCE: Most bone repair strategies rely either on osteconductive properties of ceramics and devitalized bone, or osteoinductive properties of growth factors and extracellular matrices (ECM). Here we designed a composite material made of a clinically accepted osteoconductive material and an off-the-shelf tissue engineered human cartilage ECM with strong osteoinductive properties. We showed that low amount of osteoinductive ECM potentiated host cells recruitment to form large vascularized bone structures in two different animal models, one being a challenging prefabricated bone-flap model targeting challenging clinical bone repair. Overall, this study highlights the use of a promising human off-the-shelf material for accelerated healing towards clinical applications.

Osteofibrous dysplasia and adamantinoma: A summary of diagnostic challenges and surgical techniques

Osteofibrous dysplasia is an indolent benign fibro-osseous tumor, while adamantinoma is a locally aggressive biphasic malignancy with epithelial and fibro-osseous components. Predominantly arising in the tibial diaphysis of children and young adults, both tumors are resistant to chemotherapy and radiation. Wide surgical resection is regarded as the mainstay of therapy for adamantinoma, and limb-salvage reconstructive procedures can achieve good functional outcomes, albeit with non-negligible rates of complications. This review discusses emerging advances in the pathogenesis, histogenesis, and diagnosis of these entities and presents advantages and limitations of the most common surgical techniques used for their management.

Limb Length Discrepancy and Angular Deformity due to Benign Bone Tumors and Tumor-like Lesions

Benign bone tumors and tumor-like lesions are frequently diagnosed in children and adolescents. The immature skeleton is at risk for growth disturbances and deformity because of the effects of the lesions on normal bone architecture and the physis. The development, manifestation, and severity of the limb length inequality and deformity differs between the various bone pathologies. Distraction osteogenesis, osteotomy, and guided growth are key tools in the treatment of limb inequality and deformity using a combination of external and internal fixation devices.

[Plate-assisted segmental bone transport with a lengthening nail and a plate : A new technique for treatment of tibial and femoral bone defects]

BACKGROUND

Distraction osteogenesis represents an effective procedure for treatment of bone defects from various causes (e.g. trauma, malignancy, congenital and infection). In the past the available procedures were practically exclusively external.

PRINCIPLES

In the plate-assisted segmental bone transport (PABST) procedure a commercially available motorized intramedullary lengthening nail is used for segment transport. The transport segment is transported along a bone plate, which is responsible for maintaining the position of the proximal and distal main fragments.

SURGICAL TECHNIQUE

In staged sequences, a plate spanning the defect is placed. A lengthening nail is inserted in an antegrade or retrograde direction and a vascularized transport segment is created with an osteotomy. Bone transport is initiated at 1.0 mm a day. The transport segment is pulled or pushed into place, depending on the location of the bone void. In due time, a docking procedure is performed and full weight bearing is allowed. Supplementary lengthening can be initiated at docking or in a separate procedure. In smaller defects the gap is closed immediately over the plate and the bone is lengthened by the nail in the opposite end of the defect.

CONCLUSION

The presented method is a valuable addition to the armamentarium for treatment of bone defects. The main advantages are the avoidance of external fixation (fixation wires, Schanz screws) and the creation of physiological bone substitute. Vital soft tissues are essential for a good outcome. With appropriate management (systematic debridement, local and systemic administration of antibiotics and free soft tissue flaps), this method can be a solution to even complex reconstructive problems.

Plate-assisted Bone Segment Transport With Motorized Lengthening Nails and Locking Plates: A Technique to Treat Femoral and Tibial Bone Defects

This article describes a new bone transport technique for femoral and tibial bone defects using lengthening nails combined with locking plates. We term it plate-assisted bone segment transport (PABST).

Bone reconstruction after malignant tumour resection using a motorized lengthening intramedullary nail in adolescents: preliminary results

PURPOSE

Bone reconstruction after malignant tumour of the lower limbs is a challenge. Our aim was to investigate the results of bone lengthening and transport using the Fitbone motorized lengthening nail.

METHODS

Eight patients were included. Two patients had had a tumour involving soft tissue only without bone resection. In six patients, the initial bone defect was 15.5 cm (8 to 24). The first step of reconstruction had consisted of temporary fixation and a cement spacer. The second step had consisted of bone grafting in five patients. One patient was managed with bone transport. Eventually, five patients had a limb-length discrepancy (LLD) managed with bone lengthening only. Two patients had a LLD and a nonunion managed with bone transport and lengthening. Mean age at bone lengthening was 15.2 years (11 to 19). Mean follow-up was 30.5 months (10 to 48).

RESULTS

In all, 11 nails were implanted in eight patients (eight femurs, three tibias). Mean length gain per procedure was 54.5 mm (30 to 80). Mean healing index was 48.4 days per cm (22.6 to 85.7). The complication rate was 18%. In two cases we observed a loose locking screw, which was revised. In all cases the lengthening involved the short bone (femur or tibia). Mean Musculoskeletal Tumor Society (MSTS) score improved from 52.7 (16.6 to 73.3) to 79.9 (63.3 to 96.6).

CONCLUSIONS

Bone reconstruction using a motorized intramedullary nail stands as a safe and reliable alternative after malignant tumour. It allows biological reconstruction with satisfactory clinical and radiological outcome and low complication rate.

LEVEL OF EVIDENCE

III.

Correction of complex lower limb angular deformities with or without length discrepancy in children using the TL-HEX hexapod system: comparison of clinical and radiographical results

The aim of this study was to compare clinical and radiographical results for treatment of lower limb multiaxial deformities±limb length discrepancy (LLD) of at least 2 cm with the Truelok hexapod fixator system (TL-HEX). All consecutive cases of lower limb multiaxial deformities were included. Patients were divided in two groups: group 1, lower limb angular deformity+LLD less than 2 cm, and group 2, lower limb angular deformity+LLD of at least 2 cm. Only patients with age younger than or equal to 20 years and follow-up of 6 months after removal of the external fixator were included. A total of 27 (six femur and 39 tibia treated) and 20 patients (12 femur and 19 tibia) were enrolled in groups 1 and 2, respectively. Complete correction of the deformity was achieved in 90 and 96% of the patients in groups 1 and 2, respectively. There were no differences in terms of external fixator, maturation, and distraction indexes between the two groups and between different anatomical sites. Good to excellent functional results (ASAMI score) were obtained in 93% of patients in group 1 and 75% in group 2 (P=0.01). Complication rate was similar between the two groups (7.4 vs. 10%, respectively). Average follow-up after removal of the external fixator was 25.6 (range: 7.0-54.0) months. The TL-HEX external fixator system allows a predictable correction of complex lower limb deformities regardless of the presence of LLD. Although complication rate is similar between the two groups, lower functional outcomes can be expected in patients with significant preoperative LLD.

[Application of proximal tibial hemiprosthesis replacement and second-stage revision for proximal tibial osteosarcoma in three children]

Objective

To investigate the feasibility and effectiveness of proximal tibial hemiprosthesis replacement in the first stage and prosthesis revision in the second stage in reducing the risk of length discrepancy of limbs in children with proximal tibial osteosarcoma.

Methods

Between 2009 and 2013, 3 children with conventional osteosarcoma at the proximal tibia (stage ⅡB) were treated. There were 2 boys and 1 girl. They were 12, 13, and 13 years old, respectively. After 4 courses of preoperative chemotherapy, the proximal tumor segmental resection and proximal tibial hemiprosthesis replacement were performed. Then the patients underwent prosthetic revision in the second stage when they were 20, 17, and 17 years old, respectively.

Results

All patients successfully completed two stages of operations. The length discrepancy of lower limb after the second stage operation were 19, 7, and 21 mm, respectively. Three patients were followed up 13, 3, and 27 months after the second stage operation, and the lower extremities functions were satisfactory. The Musculoskeletal Tumor Society (MSTS) score was 26, 27, and 25, respectively.

Conclusion

The proximal tibial hemiprosthesis replacement in the first stage combined with prosthesis revision in the second stage for treating the proximal tibia osteosarcoma in children can keep the distal femur growth ability, reduce the length discreapancy of lower limb, and obtain satisfactory stability and good function.

Bone transport using the Ilizarov method for osteosarcoma patients with tumor resection and neoadjuvant chemotherapy

Background

Studies on the applications of bone transport using the Ilizarov method for osteosarcoma (OS) patients with surgical resection and neoadjuvant chemotherapy are rare.

Methods

A retrospective analysis was conducted in 10 patients with limb OS receiving limb-salvage treatment by Ilizarov method from 2007 to 2012 in our hospital. The general information, treatment outcomes and follow-up data of the patients were collected.

Results

The mean length of the transported fragment and the mean transport distance of the affected limb were both 14 cm. The mean time in the external fixator was 34.2 ± 11.2 months (16-47 months) and the mean external fixation index (EFI) was 75 days/cm. The mean follow-up time was 68.6 ± 26.6 months (37-103 months). Seven patients underwent additional operations to treat the postoperative complications, and the mean number of operation was 1.7 times. Only one patient underwent amputation due to tumor relapse and all patients survived without tumor. The limb-salvage rate was 90%. At the time of external fixator removal, the ASAMI-bone score was good in 66.7% of patients and the ASAMI-function score was fair in 66.7% of cases. The mean MSTS score was 18.6 ± 3.2 (n = 9). At 10 months after fixator removal, both the ASAMI-bone score and ASAMI-function score were both excellent in 80% and good in 20% cases, and the mean MSTS score was further improved to 27.2 ± 1.11 (n = 5).

Conclusion

Bone transport using the Ilizarov method can achieve good therapeutic effectiveness in the limb-salvage treatment for OS patients with neoadjuvant chemotherapy as long as the complications can be timely recognized and well managed.

Advances in limb salvage treatment of osteosarcoma

Osteosarcoma is the most common primary malignant bone tumor; its standard treatment includes neoadjuvant chemotherapy combined with surgery. Neoadjuvant chemotherapy has significantly improved the 5-year survival and limb salvage rates in osteosarcoma since the 1870s. The survival rate of patients with limb salvage was not inferior to that of amputees, and therefore, limb salvage has become the main surgical option for patients with osteosarcoma. The 5-year survival rate for osteosarcoma has plateaued. However, new advances in limb salvage therapy in osteosarcoma, including adjuvant chemotherapy, ablation techniques, bone transport techniques, and computer navigation techniques, are now available. This report summarizes the recent advances in limb salvage therapy for osteosarcoma over the past decade.

Distraction osteogenesis reconstruction of large segmental bone defects after primary tumor resection: pitfalls and benefits

Successful cure is achieved in almost 70% of patients with primary bone sarcomas with currently available therapies. Some soft tissue sarcomas require wide bone resection in order to achieve appropriate margins for cure of disease, and patients undergoing these procedures need durable reconstruction. Biological reconstruction has been shown to provide patients with superior long-term results over other alternatives. Distraction osteogenesis is well studied in the correction of deformities as well as in addressing some congenital musculoskeletal pathologies. The use of this technique in tumor settings has been avoided by many surgeons for a multitude of concerns, including infection risk, potential tumor activation, and uncertainty regarding the effect of systemic therapy on the callus regenerate. We review the use of this reconstruction technique using cases from our institutional experience to illustrate its incorporation into the successful management of orthopedic oncology patients. Distraction osteogenesis is an effective method for reconstructing even large bony defects and is safe in the setting of systemic therapy. This technique has the potential to address some of the common problems associated with orthopedic oncology resection, such as infection and leg length discrepancy.

Nutlin-3 treatment spares cisplatin-induced inhibition of bone healing while maintaining osteosarcoma toxicity

The majority of Osteosarcoma (OS) patients are treated with a combination of chemotherapy, resection, and limb salvage protocols. These protocols include distraction osteogenesis (DO), which is characterized by direct new bone formation. Cisplatin (CDP) is extensively used for OS chemotherapy and recent studies, using a mouse DO model, have demonstrated that CDP has profound negative effects on bone repair. Recent oncological therapeutic strategies are based on the use of standard cytotoxic drugs plus an assortment of biologic agents. Here we demonstrate that the previously reported CDP-associated inhibition of bone repair can be modulated by the administration of a small molecule p53 inducer (nutlin-3). The effects of nutlin-3 on CDP osteotoxicity were studied using both pre- and post-operative treatment models. In both cases the addition of nutlin-3, bracketing CDP exposure, demonstrated robust and significant bone sparing activity (p < 0.01-0.001). In addition the combination of nutlin-3 and CDP induced equivalent OS tumor killing in a xenograft model. Collectively, these results demonstrate that the induction of p53 peri-operatively protects bone healing from the toxic effects of CDP, while maintaining OS toxicity. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1716-1724, 2016.

The vascularised fibular graft for limb salvage after bone tumour surgery

Vascularised fibular grafts (VFGs ) are a valuable surgical technique in limb salvage after resection of a tumour. The primary objective of this multicentre study was to assess the risk factors for failure and complications for using a VFG after resection of a tumour.

The study involved 74 consecutive patients (45 men and 29 women with mean age of 23 years (1 to 64) from four tertiary centres for orthopaedic oncology who underwent reconstruction using a VFG after resection of a tumour between 1996 and 2011. There were 52 primary and 22 secondary reconstructions. The mean follow-up was 77 months (10 to 195).

In all, 69 patients (93%) had successful limb salvage; all of these united and 65 (88%) showed hypertrophy of the graft. The mean time to union differed between those involving the upper (28 weeks; 12 to 96) and lower limbs (44 weeks; 12 to 250). Fracture occurred in 11 (15%), and nonunion in 14 (19%) patients.

In 35 patients (47%) at least one complication arose, with a greater proportion in lower limb reconstructions, non-bridging osteosynthesis, and in children. These complications resulted in revision surgery in 26 patients (35%).

VFG is a successful and durable technique for reconstruction of a defect in bone after resection of a tumour, but is accompanied by a significant risk of complications, that often require revision surgery. Union was not markedly influenced by the need for chemo- or radiotherapy, but should not be expected during chemotherapy. Therefore, restricted weight-bearing within this period is advocated.

Cite this article: Bone Joint J 2015;97-B:853–61.

Distraction osteogenesis and arthrodesis as a new surgical option for chondrosarcoma in the distal tibia

Recent advances in the management of bone tumors have led to a significant increase in the survival rates of patients with malignant bone tumors. Thus, limb salvage surgery has gained importance for preserving limb function in the management of bone tumors. However, surgery presents unique difficulties in terms of the biomechanics and obtaining a soft-tissue cover, such as when the ankle is involved in the primary malignant bone tumor. We report a case of chondrosarcoma of the distal tibia treated with wide en bloc resection arthrodesis and reconstruction of the defect using distraction osteogenesis, which offers an effective alternative protocol for limb salvage. The patient has remained disease free for 3 years since the initial surgery and can maintain normal limb athletic function.

Reconstruction of intercalary bone defects following bone tumor resection with segmental bone transport using an Ilizarov circular external fixator

AIM

The purpose of this retrospective study was to report the long-term follow-up results of the reconstruction of bony defects with Ilizarov distraction osteogenesis using the bone transport method following en bloc resection of bone tumors.

MATERIALS AND METHODS

En bloc resection was performed in 13 patients with bone tumors between October 1991 and December 2010 in our clinic. The mean age of the patients was 19.46 years (range 7-42 years) at the time of surgery. Histological diagnosis was osteosarcoma in seven cases, Ewing's sarcoma in three cases, giant cell tumor in one case, osteoblastoma in one case and fibrous dysplasia in one case. In all cases either the femur or tibia was involved.

RESULTS

The average follow-up period was 157.23 months (range 32-288 months), and the bone defect after resection was 14.61 cm ± (9-24 cm). The mean Musculoskeletal Tumor Society score of the patients was 89.46 (83-96) at the final follow-up. The mean Knee Society Scale scores of patients in whom reconstruction was performed around the knee joint were 74.3 (51-84). The mean foot and ankle disability index of patients with a tumor around the ankle joint was 81 (73-95). Quality of life of the patients according to the SF-36 and BQUILI indexes was scored as 104 (88-150) and 4 (0-13), respectively.

CONCLUSION

From the long-term follow-up results, reconstruction with distraction osteogenesis seems to be an efficient method in patients with long life expectancies. However, a long external fixation time is a disadvantage of this technique. Problems in patient compliance and possible complications such as nonunion should be managed promptly.

Cisplatin inhibits bone healing during distraction osteogenesis

Osteosarcoma (OS) is the most common malignant bone tumor affecting children and adolescents. Many patients are treated with a combination of chemotherapy, resection, and limb salvage protocols. Surgical reconstructions after tumor resection include structural allografts, non-cemented endoprostheses, and distraction osteogenesis (DO), which require direct bone formation. Although cisplatin (CDP) is extensively used for OS chemotherapy, the effects on bone regeneration are not well studied. The effects of CDP on direct bone formation in DO were compared using two dosing regimens and both C57BL/6 (B6) and tumor necrosis factor receptor 1 knockout (TNFR1KO) mice, as CDP toxicity is associated with elevated TNF levels. Detailed evaluation of the five-dose CDP regimen (2 mg/kg/day), demonstrated significant decreases in new bone formation in the DO gaps of CDP treated versus vehicle treated mice (p < 0.001). Further, no significant inhibitory effects from the five-dose CDP regimen were observed in TNFR1KO mice. The two-dose regimen significantly inhibited new bone formation in B6 mice. These results demonstrate that CDP has profound short term negative effects on the process of bone repair in DO. These data provide the mechanistic basis for modeling peri-operative chemotherapy doses and schedules and may provide new opportunities to identify molecules that spare normal cells from the inhibitory effects of CDP.