Liquid nitrogen-treated recycled autograft for reconstruction of a large tibial defect following wide resection of adamantinoma: a case report

Abstract

Introduction and importance:

Adamantinoma is a rare, low-grade malignant bone tumor with a predilection for the tibial diaphysis. Wide resection is the standard treatment, but reconstruction of large segmental tibial defects remains technically challenging. Liquid nitrogen-treated recycled autografts offer biological reconstruction, though experience with adamantinoma is extremely limited.

Case presentation:

A 36-year-old male presented with a 6-month history of progressive left tibial pain and swelling. Imaging revealed a 20-cm expansile osteolytic mid-diaphyseal lesion, confirmed histologically as adamantinoma. He underwent wide resection of a 25-cm tibial segment with liquid nitrogen devitalization (20-minute freezing at −196°C, 15-minute thawing, and 15-minute washing), followed by reimplantation with combined intramedullary nail and plate fixation, bone cement augmentation, autologous iliac crest grafting, and gastrocnemius flap coverage.

Clinical discussion:

Only two prior cases of LN2-treated recycled autograft for adamantinoma have been reported. This case demonstrates consistent outcomes and highlights the role of combined fixation, cement augmentation, and vascularized soft tissue coverage in achieving union over a 25-cm defect.

Conclusion:

Liquid nitrogen-treated recycled autograft with rigid fixation, cement augmentation, and vascularized soft tissue coverage achieves satisfactory oncological and functional outcomes in tibial adamantinoma. Lifelong surveillance remains mandatory.

Introduction and importance

Adamantinoma is a rare, low-grade malignant epithelial bone tumor with an annual incidence of 0.1–0.3 per million, constituting less than 0.5% of primary skeletal neoplasms^[1^]. This tumor exhibits a striking predilection for the tibial diaphysis (85–90% of cases), with peak incidence in the second and third decades and a slight male predominance^[2,3^]. Epidemiological data from national bone tumor registries confirm this rarity, with fewer than 30 cases per year reported in large population-based series^[4,5^]. Despite its low-grade histology, adamantinoma demonstrates unpredictable biological behavior, with local recurrence rates of 15–30% following inadequate resection and pulmonary metastasis in 15–20% of cases. Metastatic events may occur decades after primary treatment, and lifelong surveillance is therefore mandatory^[3,6^].

HIGHLIGHTS

• Adamantinoma is rare; liquid nitrogen-recycled autograft experience remains extremely limited.

• Wide resection of a 25-cm tibial segment with LN2 devitalization achieved complete union at 15 months.

• Combined nail, dual-plate fixation, and cement augmentation ensured immediate mechanical stability.

• Gastrocnemius flap and iliac crest graft provided biological augmentation for graft incorporation.

• Musculoskeletal Tumour Society score: 28/30 (93.3%) with no recurrence or complications at the 36-month follow-up.

Wide en bloc resection with ≥2-cm margins remains the cornerstone of treatment, as adamantinoma resists chemotherapy and radiotherapy^[7^]. Reconstruction of large tibial defects presents formidable challenges. Endoprostheses provide immediate stability but are associated with high costs, infection rates of 10–15%, and limited longevity (10-year survival of 65–75%)^[8^]. Massive allografts carry risks of disease transmission, immunological complications, and high fracture rates (15–20%)^[9^]. Vascularized fibular bone grafting (VFBG) requires technical expertise and prolonged hypertrophy before full weight-bearing^[10^].

Recycled autografts, wherein resected tumor-bearing bone is devitalized extracorporeally and reimplanted, offer biological reconstruction that circumvents these limitations. Liquid nitrogen (LN2) cryotherapy at −196°C induces complete tumor cell necrosis while preserving structural integrity, bone morphogenetic proteins, and mechanical strength^[11^]. Long-term follow-up studies report 5-year graft survival exceeding 80% with this technique^[12^]. However, experience specifically with LN2-treated autografts for adamantinoma remains extremely limited. This case contributes to this nascent evidence base and demonstrates technical feasibility with favorable short-term outcomes.

Case presentation

A 36-year-old male presented in January 2023 with a 6-month history of progressive left tibial pain and swelling. Physical examination revealed a firm, fixed, 5 cm × 4 cm anterolateral mid-tibial mass without overlying skin changes; neurovascular status was intact.(Fig. 1) Imaging demonstrated an expansile osteolytic lesion of the mid-tibial diaphysis with cortical destruction limited to a 6-cm anteromedial segment, where tumor had breached the cortex and extended into the adjacent soft tissues (Fig. 2). Open incisional biopsy revealed epithelial cell nests within an osteofibrous stroma; immunohistochemistry was positive for cytokeratin (AE1/AE3), epithelial membrane antigen, and p63, confirming classic adamantinoma. Staging was Enneking IIB with no evidence of distant metastasis. The patient provided written informed consent for surgery and for the publication of this case report.

Figure 1.

Preoperative clinical photographs of the left leg showing a firm, fixed swelling over the anterolateral mid-tibial region with the incisional biopsy scar.

Figure 2.

Preoperative imaging of the left tibial adamantinoma. (A) Anteroposterior and lateral radiographs demonstrating a multifocal expansile mixed lytic-sclerotic mid-diaphyseal lesion with a “soap-bubble” appearance and anterior cortical breach. (B, C) MRI showing a heterogeneous intermediate signal on T1-weighted sequences and a hyperintense signal on T2/STIR sequences, with a 21-cm intramedullary extent from 10 cm distal to the tibial tuberosity to 5 cm proximal to the ankle joint.

The patient underwent wide en bloc resection via a longitudinal anterolateral incision incorporating the biopsy scar. Under fluoroscopic guidance, proximal and distal osteotomy sites were marked 2 cm beyond tumor margins, confirmed intraoperatively by frozen section. A 25-cm tibial segment was resected.

The resected specimen was prepared prior to cryotherapy: all soft tissue and periosteum were stripped, the medullary canal was reamed, gross tumor was curetted, and multiple 2-mm drill holes were created through the cortex to facilitate nitrogen penetration. The specimen was submerged in liquid nitrogen (−196°C) for 20 minutes, thawed at room temperature (22°C) for 15 minutes, and immersed in distilled water for 15 minutes prior to reimplantation^[11^].

Reconstruction was achieved with an intramedullary nail, providing primary stability. One-third tubular plates and screws were applied at each osteotomy junction to augment rotational fixation. The mid-diaphyseal cortical defect resulting from tumor curettage was filled with bone cement to restore structural continuity. Autologous iliac crest bone graft was applied as an onlay at both junctions to promote osseous healing. A medial gastrocnemius muscle flap was transposed to envelop the recycled autograft, providing vascular soft tissue coverage, followed by split-thickness skin grafting (Fig. 3). Two closed-suction drains were placed at closure. Estimated blood loss was 400 mL, and total operative time was 6 hours.

Figure 3.

Intraoperative photographs. (A) Resected tumor-bearing tibial segment following wide resection. (B) Specimen following liquid nitrogen treatment. (C) Reconstruction with recycled bone graft, fixation with an intramedullary nail, and two one-third tubular plates. (D) Medial gastrocnemius muscle flap transposed to provide vascularized soft tissue coverage.

The postoperative course was uncomplicated, and the patient was discharged on postoperative day 10. A structured weight-bearing protocol was implemented: non-weight-bearing for the first 6 weeks, progressive touch-down weight-bearing (10–20% body weight) from weeks 6 to 12, partial weight-bearing from weeks 12 to 24, and full weight-bearing from month 6 onwards, following radiographic confirmation of bridging callus.

Serial radiographs demonstrated progressive graft incorporation. Early callus formation was evident at the proximal junction at 10 weeks. At 6 months, bridging callus was present across three of four cortices at the proximal junction. Complete osseous union at both junctions was confirmed at 15 months, and mature bone incorporation without resorption was achieved at 36 months (Fig. 4).

Figure 4.

Postoperative radiographic follow-up. (A) Immediate postoperative anteroposterior and lateral radiographs demonstrating graft position and fixation construct, with cement augmentation visible at the mid-diaphysis. (B) Anteroposterior and lateral radiographs at 15 months showing complete osseous union at both osteotomy junctions (red arrow indicates bridging callus at the proximal junction). (C) Anteroposterior and lateral radiographs at 36 months demonstrating mature bone incorporation.

At the 36-month follow-up, the Musculoskeletal Tumour Society (MSTS) score was 28/30 (93.3%). No complications, local recurrence, or distant metastasis were recorded (Fig. 5). The patient, an office worker, returned to sedentary occupational duties 3 months postoperatively and reported high satisfaction with the functional outcome. This case report has been presented in line with the SCARE 2025 Criteria^[13^].

Figure 5.

Clinical photographs at 36-month follow-up demonstrating functional outcome of the left leg.

Clinical discussion

Reconstruction of a 25-cm intercalary tibial defect in a young patient requires a strategy that balances immediate mechanical stability with long-term biological incorporation. Endoprosthetic replacement was considered less suitable given the patient’s age and the intercalary defect location; a massive allograft was unavailable at our institution; and VFBG was precluded by the absence of microsurgical expertise. The LN2-treated recycled autograft was selected for its anatomical conformity and preservation of osteoconductive properties. Published experience with LN2-treated recycled autograft for adamantinoma comprises only two prior cases. Gede et al reported one distal tibial case achieving an MSTS score of 75% at 3 years without recurrence^[14^]. Cheng et al reported a tibial shaft case in an 8-year-old female with union at 4 months, MSTS 29/30, and no recurrence at 64 months^[15^]. Although defect size has been associated with prolonged union time in LN2-treated autograft reconstruction, successful union has been consistently achieved in defects up to 25.9 cm at mean intervals of 8–9 months^[16,17^]. These findings support the feasibility of this technique for large intercalary defects, in line with contemporary series that increasingly favor intercalary over osteoarticular reconstruction given superior long-term graft survival^[12^].

Nonunion, graft fracture, and infection are the most frequently reported complications of LN2-treated recycled autograft reconstruction^[12,16^]. In intercalary reconstruction, two osteotomy junctions must achieve biological union across a devitalized segment, making these risks more significant. Reported complication rates in intercalary LN2-treated autograft reconstruction include nonunion in up to 38.5%, graft fracture in 23.1%^[12^], and an overall complication rate of 27.3% in larger series^[16^]. In the present case, several technical measures were employed to address these risks.

The osteotomy configuration near the proximal and distal thirds of the resected segment presented a mechanically challenging construct in which intramedullary nailing alone would provide insufficient rotational stability. One-third tubular plates were applied at each junction to augment fixation while minimizing soft tissue irritation. This combined fixation strategy is supported by Morinaga et al, who demonstrated that intramedullary nail fixation alone was significantly associated with nonunion in frozen autograft reconstruction, whereas plate fixation, particularly with multiple plates, achieved more reliable union^[18^].

Although frozen autografts from highly osteolytic tumors carry an increased risk of mechanical failure, cortical destruction in this case was limited to a 6-cm anteromedial segment, with the remaining circumferential cortex substantially preserved, justifying autograft recycling. Gross preparation of the autograft was performed through the zone of cortical breach, which provided direct access for medullary curettage. This resulted in a residual defect on the graft requiring structural management. Bone cement was selected to address this defect for its simplicity and ability to immediately restore structural continuity, permitting early weight-bearing. Although VFBG offers superior biological augmentation for such defects^[10^], it was not feasible in this case, as discussed above. Regarding the use of cement, its placement within the medullary canal inevitably impedes endosteal revascularization. In retrospect, cement application should be limited to cortical defects only, preserving medullary continuity to facilitate biological incorporation; this is a technical refinement we recommend for future cases.

The 25-cm segment length and devitalization-related loss of osteogenic capacity necessitated biological supplementation. An autologous iliac crest bone graft was applied as an onlay at both junctions to provide an osteogenic stimulus, while the medial gastrocnemius muscle flap ensured vascularized coverage, which is critical in the subcutaneous tibial region where the native soft tissue envelope is limited.

The favorable outcome in this young patient with predominantly preserved cortical integrity suggests that careful case selection, including assessment of cortical status, soft tissue condition, and available surgical expertise, is important when considering this technique.

This case has several limitations. First, the 36-month follow-up period is insufficient to assess long-term oncological outcomes. Adamantinoma is known to metastasize decades after primary treatment, and the current disease-free interval should not be interpreted as evidence of oncological cure. Surveillance beyond 5–10 years remains essential. Second, as a single case, no conclusions regarding superiority over alternative reconstructions can be drawn. Additionally, patient-reported outcome measures beyond the MSTS score were not obtained.

Conclusion

Adamantinoma is a rare, low-grade malignant bone tumor with a predilection for the tibial diaphysis. Wide resection remains the cornerstone of treatment, and reconstruction of large tibial defects presents a formidable surgical challenge. This case demonstrates that LN2-treated recycled autograft, combined with rigid fixation, cement augmentation, autologous bone grafting, and vascularized soft tissue coverage, achieves satisfactory oncological and functional outcomes. Lifelong surveillance remains mandatory, and further evidence is needed to establish this technique specifically for adamantinoma.

Ethical approval

This report was conducted in accordance with the World Medical Association’s Declaration of Helsinki.

Consent

Written informed consent was obtained from the patient for the publication of this case report and accompanying images. A copy of the written consent is available for review by the editor-in-chief upon request.

Sources of funding

This report did not receive any specific grant from any funding agency.

Author contributions

N.N.V.: Assisting with the surgery, writing the literature review, and reviewing the manuscript. H.D.P.: Conceptualizing the plan for surgery and performing the surgery. P.N.H.: Preparing for and assisting with the surgery. D.P.B.V.: Preparing for and assisting with the surgery.

Conflicts of interest disclosure

The authors declare no conflicts of interest in this work.

Research registration unique identifying number (UIN)

Not required.

Guarantor

Hung Do Phuoc.

Provenance and peer review

Not commissioned; externally peer-reviewed.

Data availability statement

All data are contained within the manuscript.

Assistance with the study

None.

AI declaration

Artificial intelligence (Claude, Anthropic) was used to assist with language editing and manuscript preparation. All clinical content, data interpretation, and conclusions were generated solely by the authors, who take full responsibility for the accuracy and integrity of the work.