What Are the Challenges and Complications of Sterilizing Autografts with Liquid Nitrogen for Malignant Bone Tumors? A Preliminary Report

Frozen inactivated autograft replantation for bone and soft tissue sarcomas

Background

The frozen inactivation of autologous tumor bones using liquid nitrogen is an important surgical method for limb salvage in patients with sarcoma. At present, there are few research reports related to frozen inactivated autograft replantation.

Methods

In this study, we retrospectively collected the clinical data of patients with bone and soft tissue sarcoma treated with liquid nitrogen-frozen inactivated tumor bone replantation, and analyzed the safety and efficacy of this surgical method. The healing status of the frozen inactivated autografts was evaluated using the International Society of Limb Salvage (ISOLS) scoring system. Functional status of patients was assessed using the Musculoskeletal Tumor Society (MSTS) scale.

Results

This study included 43 patients. The average length of the bone defect after tumor resection is 16.9 cm (range 6.3-35.3 cm). Patients with autograft not including the knee joint surface had significantly better healing outcomes (ISOLS scores) (80.6% ± 15% vs 28.2% ± 4.9%, P<0.001) and limb function (MSTS score) (87% ± 11.6% vs 27.2% ± 4.4%, P<0.001) than patients with autografts including the knee joint surface. The healing time of the end of inactivated autografts near the metaphyseal was significantly shorter than that of the end far away from the metaphyseal (9.8 ± 6.3 months vs 14.9 ± 6.3 months, P=0.0149). One patient had local recurrence, one had an autograft infection, five (all of whom had an autograft including the knee joint surface) had joint deformities, and seven had bone non-union.

Conclusion

Frozen inactivated autologous tumor bone replantation is safe and results in good bone healing. But this method is not suitable for patients with autograft involving the knee joint surface.

Does A Single Osteotomy Technique for Frozen Autograft (Pedicled Freezing) in Patients With Malignant Bone Tumors of the Long Bones Achieve Union and Local Tumor Control?

BACKGROUND

Biological reconstruction by replanting the resected tumor-bearing segment is preferred by some surgeons when caring for a patient with a bone sarcoma. Frozen autografts are advantageous because they are cost-effective, provide an excellent fit, permit the maintenance of osteoinductive and osteoconductive properties, and are not associated with transmission of viral disease. The pedicle frozen autograft technique, in which only one osteotomy is made for the freezing procedure, keeping the affected segment in continuity with the host bone and soft tissue instead of two osteotomies, maintains the affected segment with the host bone and soft tissue. This could restore blood flow more rapidly in a frozen autograft than in a free-frozen autograft with two osteotomies.

QUESTIONS/PURPOSES

(1) In what proportion of patients was union achieved by 6 months using this technique of frozen autografting? (2) What complications were observed in a small series using this approach? (3) What was the function of these patients as determined by Musculoskeletal Tumor Society (MSTS) score? (4) What proportion of patients experienced local recurrence?

METHODS

Between 2014 and 2017, we treated 87 patients for primary sarcomas of the femur, tibia, or humerus. Of those, we considered patients who could undergo intercalary resection and showed a good response to neoadjuvant chemotherapy as potentially eligible for this technique. Based on these criteria, 49% (43 patients) were eligible; a further 9% (eight) were excluded because of inadequate bone quality (defined as cortical thickness less than 50% by CT assessment). We retrospectively studied 32 patients who were treated with a single metaphyseal osteotomy, the so-called pedicle freezing technique, which uses liquid nitrogen. There were 20 men and 12 women. The median age was 18 years (range 13 to 48 years). The median follow-up duration was 55 months (range 48 to 63 months). Patients were assessed clinically and radiologically regarding union (defined in this study as bony bridging of three of four cortices by 6 months), the proportion of patients experiencing local recurrence, the occurrence of nononcologic complications, and MSTS scores.

RESULTS

Three percent (one of 32) of the patients had nonunion (no union by 9 months). The median MSTS score was 90%, with no evidence of metastases at the final follow-up interval. Nine percent (three of 32) of our patients died. The local recurrence rate was 3.1% (one of 32 patients). The mean restricted disease-free survival time at 60 months (5 years) was 58 months (95% CI 55 to 62 months). Twenty-five percent of patients (eight of 32) experienced nononcologic complications. This included superficial skin burns (two patients), superficial wound infection (two patients), deep venous thrombosis (one patient), transient nerve palsy (two patients), and permanent nerve palsy (one patient).

CONCLUSION

This treatment was reasonably successful in patients with sarcomas of the femur, tibia, and humerus who could undergo an intercalary resection, and this treatment did not involve the epiphysis and upper metaphysis. It avoids a second osteotomy site as in prior reports of freezing techniques, and union was achieved in all but one patient. There were few complications or local recurrences, and the patients' function was shown to be good. This technique cannot be used in all long-bone sarcomas, but we believe this is a reasonable alternative treatment for patients who show a good response to neoadjuvant chemotherapy, those in whom intercalary resection is feasible while retaining at least 2 cm of the subchondral area, and in those who have adequate bone stock to withstand the freezing process. Experienced surgeons who are well trained on the recycling technique in specialized centers are crucial to perform the technique. Further study is necessary to see how this technique compares with other reconstruction options.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Complications and Outcome of Bone Sarcoma Patients with Limb Salvage using Liquid Nitrogen-treated Bone for Reconstruction

Introduction

The recommended treatment method for bone sarcoma is wide local excision and reconstruction to preserve limb function. Established methods of reconstruction are mega prosthesis or biological reconstruction. This study aimed to determine the complications and functional outcomes associated with limb salvage surgery using liquid nitrogen-treated bone.

Materials and Methods

We retrospectively observed the short-term outcome of limb salvage surgeries where liquid nitrogen bone was used for reconstruction. A total of 15 patients underwent reconstruction with liquid nitrogen auto graft from January 2018 to December 2020. We used the free freezing method of liquid nitrogen treatment after wide local excision of sarcoma. We observed short-term outcomes after liquid nitrogen-treated bone reconstruction in limb salvage surgery. Survival of the auto grafts was recorded using the Kaplan-Meier method with a 95% confidence interval.

Results

The mean follow-up was 19.83 ± 4.5 months. The mean musculoskeletal tumor society score was 62.4 ± 7.9%, while the average Toronto extremity score was 59.6 ± 5.7%. Three patients died during the study duration due to visceral metastasis. Skin necrosis and wound breakdown were major complications in 9 (60%) patients. Deep infection was observed in 4 (26.7%). Similarly, 4 (26.7%) patients had non-union at either the proximal or distal osteotomy site, while the average time of bone union in the rest of the patients was 6.3 ± 1.7 months. A total of 6 (40%) patients underwent reoperation after liquid nitrogen treatment, either due to infection or non-union at the osteotomy site. Recurrence was observed in 3 (20%) of patients.

Conclusion

We observed a high complication rate with liquid nitrogen-treated autograft reconstruction. Vascularized fibula with liquid nitrogen-treated autograft or endoprosthesis should be encouraged.

Biomimetic Hydrogels as the Inductive Endochondral Ossification Template for Promoting Bone Regeneration

Repairing critical size bone defects (CSBD) is a major clinical challenge and requires effective intervention by biomaterial scaffolds. Inspired by the fact that the cartilaginous template-based endochondral ossification (ECO) process is crucial to bone healing and development, developing biomimetic biomaterials to promote ECO is recognized as a promising approach for repairing CSBD. With the unique highly hydrated 3D polymeric network, hydrogels can be designed to closely emulate the physiochemical properties of cartilage matrix to facilitate ECO. In this review, the various preparation methods of hydrogels possessing the specific physiochemical properties required for promoting ECO are introduced. The materiobiological impacts of the physicochemical properties of hydrogels, such as mechanical properties, topographical structures and chemical compositions on ECO, and the associated molecular mechanisms related to the BMP, Wnt, TGF-β, HIF-1α, FGF, and RhoA signaling pathways are further summarized. This review provides a detailed coverage on the materiobiological insights required for the design and preparation of hydrogel-based biomaterials to facilitate bone regeneration.

RESECTION OF ANKLE TUMOR LESION AND RECONSTRUCTION WITH THE USE OF ALLOGRAFT

Reconstruction of the distal third of the tibia due to resection of a malignant tumor has some hindering factors, such as a thin subcutaneous layer, neurovascular bundles that cross compartments, prolonged operative duration, specific orthopedic material, and a trained multidisciplinary team. Allografting with material from tissue banks is part of this orthopaedic arsenal.

OBJECTIVE

To describe the protocol used at Instituto Nacional de Traumatologia e Ortopedia Jamil Haddad.

METHODS

Series of six cases subjected to resection with oncologic margins, allograft reconstruction, and use of a retrograde ankle nail as limb-salvage surgery. Three of the six patients were women, the lesions were on average 9.3 cm long, and the average operative duration was 3.25 hours.

RESULTS

The main short-term complication (≤ 30 days) was peroneal nerve palsy, while the main long-term complication (> 30 days) was surgical site infection (two cases). Consolidation of the two foci occurred in three patients, and two patients developed asymptomatic pseudoarthrosis of the proximal focus with consolidation of the distal focus.

CONCLUSION

Despite the complications, the proposed surgery gives patients the chance to preserve their limb in the face of immediate radical surgery. Level of Evidence IV, Case Series.

Comparison of the Results of Patients Treated With Limb-Sparing Treatment Options in Malignant Bone Tumors: Sharing the Experience of Twelve Bicentric Patients

OBJECTIVES

Extremity-sparing surgery should be the main objective if a functional extremity is to be obtained in cases of malignant bone tumors. After extensive resection, numerous techniques have been described to reconstruct bone defects. This study aimed to compare the outcomes of patients who underwent external radiation therapy and liquid nitrogen biological reconstruction at two different facilities.

METHODS

The study included 12 patients who received biological reconstruction therapy for bone sarcoma and had at least two years of follow-up. Demographic data, pathological diagnosis, presence of systemic metastasis, and recurrence during follow-up were among the information logged. Patients who used liquid nitrogen were placed in group 1, and those who underwent external irradiation were placed in group 2. After being contacted for their final follow-up appointments, the outcomes were compared by recording the Musculoskeletal Tumor Society Score (MSTSS).

RESULTS

For participants with a mean age of 10.75±3.6 (5-17), the follow-up period was 30.2±16.3 months in total. In contrast to the patients in group 1, who experienced union on average after 7.5±1.2 months, those in group 2 experienced union after 7.6±1.1 months. Patients in group 1 had an MSTSS of 75.5±11.8%, while those in group 2 had a score of 77±4.4. There was no discernible difference between the two groups' union times (p>0.05). There was no statistically significant difference between the two groups' MSTSS (p>0.05).

CONCLUSION

After tumor resection, extracorporeal radiation therapy and the application of liquid nitrogen are still useful treatment options and neither of them is superior to the other.

Do Liquid Nitrogen-treated Tumor-bearing Nerve Grafts Have the Capacity to Regenerate, and Do They Pose a Risk of Local Recurrence? A Study in Rats

BACKGROUND

Under most circumstances, the resection of soft tissue sarcomas of the extremities can be limb-sparing, function-preserving oncologic resections with adequate margins. However, en bloc resection may require resection of the major peripheral nerves, causing poor function in the extremities. Although liquid nitrogen treatment has been used to sterilize malignant bone tumors, its use in the preparation of nerve grafts has, to our knowledge, not been reported. Hence, this study aimed to investigate the tumor recurrence and function after peripheral nerve reconstruction using liquid nitrogen-treated tumor-bearing nerves in a rat model.

QUESTIONS/PURPOSES

(1) Do liquid nitrogen-treated frozen autografts have regeneration capabilities? (2) Do liquid nitrogen-treated tumor-bearing nerves cause any local recurrences in vivo in a rat model?

METHODS

Experiment 1: Twelve-week-old female Wistar rats, each weighing 250 g to 300 g, were used. A 10-mm-long section of the right sciatic nerve was excised; the prepared nerve grafts were bridge-grafted through end-to-end suturing. The rats were grouped as follows: an autograft group, which underwent placement of a resected sciatic nerve after it was sutured in the reverse orientation, and a frozen autograft group, which underwent bridging of the nerve gap using a frozen autograft. The autograft was frozen in liquid nitrogen, thawed at room temperature, and then thawed in distilled water before application. The third group was a resection group in which the nerve gap was not reconstructed. Twenty-four rats were included in each group, and six rats per group were evaluated at 4, 12, 24, and 48 weeks postoperatively. To assess nerve regeneration after reconstruction using the frozen nerve graft in the nontumor rat model, we evaluated the sciatic functional index, tibialis anterior muscle wet weight ratio, electrophysiologic parameters (amplitude and latency), muscle fiber size (determined with Masson trichrome staining), lower limb muscle volume, and immunohistochemical findings (though neurofilament staining and S100 protein produced solely and uniformly by Schwann cells associated with axons). Lower limb muscle volume was calculated via CT before surgery (0 weeks) and at 4, 8, 12, 16, 20, 24, 32, 40, and 48 weeks after surgery. Experiment 2: Ten-week-old female nude rats (F344/NJcl-rnu/rnu rats), each weighing 100 g to 150 g, were injected with HT1080 (human fibrosarcoma) cells near the bilateral sciatic nerves. Two weeks after injection, the tumor grew to a 10-mm-diameter mass involving the sciatic nerves. Subsequently, the tumor was resected with the sciatic nerves, and tumor-bearing sciatic nerves were obtained. After liquid nitrogen treatment, the frozen tumor-bearing nerve graft was trimmed to a 5-mm-long tissue and implanted into another F344/NJcl-rnu/rnu rat, in which a 5-mm-long section of the sciatic nerve was resected to create a nerve gap. Experiment 2 was performed with 12 rats; six rats were evaluated at 24 and 48 weeks postoperatively. To assess nerve regeneration and tumor recurrence after nerve reconstruction using frozen tumor-bearing nerve grafts obtained from the nude rat with human fibrosarcoma involving the sciatic nerve, the sciatic nerve's function and histologic findings were evaluated in the same way as in Experiment 1.

RESULTS

Experiment 1: The lower limb muscle volume decreased once at 4 weeks in the autograft and frozen autograft groups and gradually increased thereafter. The tibialis anterior muscle wet weight ratio, sciatic functional index, muscle fiber size, and electrophysiologic evaluation showed higher nerve regeneration potential in the autograft and frozen autograft groups than in the resection group. The median S100-positive areas (interquartile range [IQR]) in the autograft group were larger than those in the frozen autograft group at 12 weeks (0.83 [IQR 0.78 to 0.88] versus 0.57 [IQR 0.53 to 0.61], difference of medians 0.26; p = 0.04) and at 48 weeks (0.86 [IQR 0.83 to 0.99] versus 0.74 [IQR 0.69 to 0.81], difference of median 0.12; p = 0.03). Experiment 2: Lower limb muscle volume decreased at 4 weeks and gradually increased thereafter. The median muscle fiber size increased from 0.89 (IQR 0.75 to 0.90) at 24 weeks to 1.20 (IQR 1.08 to 1.34) at 48 weeks (difference of median 0.31; p< 0.01). The median amplitude increased from 0.60 (IQR 0.56 to 0.67) at 24 weeks to 0.81 (IQR 0.76 to 0.90) at 48 weeks (difference of median 0.21; p < 0.01). Despite tumor involvement and freezing treatment, tumor-bearing frozen grafts demonstrated nerve regeneration activity, with no local recurrence observed at 48 weeks postoperatively in nude rats.

CONCLUSION

Tumor-bearing frozen nerve grafts demonstrated nerve regeneration activity, and there was no tumor recurrence in rats in vivo.

CLINICAL RELEVANCE

A frozen nerve autograft has a similar regenerative potential to that of a nerve autograft. Although the findings in a rat model do not guarantee efficacy in humans, if they are substantiated by large-animal models, clinical trials will be needed to evaluate the efficacy of tumor-bearing frozen nerve grafts in humans.

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.

Engineering Multifunctional Hydrogel With Osteogenic Capacity for Critical-Size Segmental Bone Defect Repair

Treating critical-size segmental bone defects is an arduous challenge in clinical work. Preparation of bone graft substitutes with notable osteoinductive properties is a feasible strategy for critical-size bone defects. Herein, a biocompatible hydrogel was designed by dynamic supramolecular assembly of polyvinyl alcohol (PVA), sodium tetraborate (Na2B4O7), and tetraethyl orthosilicate (TEOS). The characteristics of the supramolecular hydrogel were evaluated by rheological analysis, swelling ratio, degradation experiments, and scanning electron microscopy (SEM). In in vitro experiments, this TEOS-hydrogel had self-healing property, low swelling rate, degradability, good biocompatibility, and induced osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by upregulating the expression of Runx-2, Col-1, OCN, and osteopontin (OPN). In segmental bone defect rabbit models, the TEOS-containing hydrogel accelerated bone regeneration, thus restoring the continuity of bone and recanalization of the medullary cavity. The abovementioned results demonstrated that this TEOS-hydrogel has the potential to realize bone healing in critical-size segmental bone defects.

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

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