Guojing Chen

Irregular osteotomy in limb salvage for juxta-articular osteosarcoma under computer-assisted navigation

Joint‐preserving limb salvage surgery has been expected to have good functional outcomes. However, it is still a unsolved problem to perform a joint preserving resection for patients with juxta‐articular osteosarcoma invading epiphyseal line. We determined whether irregular osteotomy under image‐guided navigation make joint‐saving resection possible for juxta‐articular osteosarcoma while adhering oncological principles.

Limb salvage surgery for calcaneal malignancy

Advances in oncologic treatment modalities and wide resection have made limb salvage procedures in calcaneal malignancy increasingly possible. However, reconstructions of the calcaneal remain a major surgical challenge because of the rarity and specific anatomy of this condition.

Clinical evaluation of β-TCP in the treatment of lacunar bone defects: A prospective, randomized controlled study

The aim of this study was to investigate the potential wide application of beta tricalcium phosphate (β-TCP) only for bone defects as compared to allograft. 95 patients with a solitary bone cyst were randomly assigned to the treatment. A new radiographic scoring system was employed to calculate the biodegradation of bone graft and to evaluate the influence of multiple factors. At an average of 28.43 months after surgery, a radiographic semi-quantitative analysis revealed that the degradation rates of β-TCP and the allograft were comparable (p>0.05). Age, complication, packing methods and granule diameters have a significant influence on β-TCP degradation. The loose packing method and 3-5mm granule size should be employed in clinical practice. A histological analysis of biopsy showed that β-TCP supported the growth of fibrous tissue, vascular tissue, as well as bone tissue into the implants. The results proved that single β-TCP is an advantageous alternative to allografts for lacunar bone defect repair and would well guide the design and clinical application of the β-TCP.

A preliminary study on investigating the attachment of soft tissue onto micro-arc oxidized titanium alloy implants

Intraosseous transcutaneous amputation prostheses (ITAP) rely on the integrity of the soft tissue-implant interface as a barrier to exogenous agents, and in the prevention of avulsion and marsupilization. This experimental work aimed at the in vivo evaluation of soft tissue attachment to Ti alloy (Ti6Al4V) transcutaneous custom-made screws treated by a micro-arc oxidation (MAO) method. Prior to implantation, the surface of the MAO treated implants was analyzed by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and x-ray diffraction (XRD). The experimental model comprised implantation of 16 transcutaneous screws (two groups: MAO and machined (control); total eight implants/group) in the medial aspect of the left tibia of eight female goats. The animals were euthanized at eight weeks and the samples harvested and processed for histological and histomorphometrical analysis of soft tissue attachment to the implant surface. Significant higher soft tissue attachment was observed in the MAO-modified group compared to the control. The in vivo data indicated that MAO-modified Ti alloy could be a useful biomaterial for tissue engineering and benefit applications where bone-anchored transcutaneous implants are used.

The Use of Massive Allograft with Intramedullary Fibular Graft for Intercalary Reconstruction after Resection of Tibial Malignancy

Reconstruction after intercalary excision of tibia malignancy is challenging. The combined use of a vascularized fibular flap and allograft can provide a reliable reconstructive option. Eight patients underwent reconstruction with an allograft and vascularized fibula following tibia malignancy resection. Patients were examined clinically and radiographically. The average age of patients was 16.5 years. The mean follow-up time was 38.4 months. Contralateral free fibula flap was used in three patients and ipsilateral pedicle fibula in five. The average length of defect was 11.8 cm and of fibula flap was 15.9 cm. Primary union was achieved in seven patients. The average time for bone union was 5.8 months at fibula-tibia junction and 14.1 months at allograft-tibia junction. Five patients had 10 complications. The Musculoskeletal Tumor Society average score was 90.8% at final follow-up. Intramedullary fibular flap in combination with massive allografts provide an excellent option for reconstruction of large bony defects after tibial malignancy extirpation. Ipsilateral pedicle fibula transportation had the advantages of short operation time and avoidance of donor site complications compared with the contralateral free fibula transfer.

Precise resection and biological reconstruction under navigation guidance for young patients with juxta-articular bone sarcoma in lower extremity: preliminary report.

Background: It is a challenge to perform a joint-preserving resection for young patients with juxta-articular bone sarcomas. We determined whether osteotomy under image-guided navigation make joint-saving resection possible for juxta-articular lesions while adhering oncological principles. Methods: Between June 2008 and July 2010, joint-preserving limb salvage surgeries were performed on 9 patients with juxta-articular bone sarcomas under navigation guidance. Computed tomography/magnetic resonance imaging fusion images were used for real-time navigation. Eight lesions located around the knee and 1 in hip. Six tumors extend to and 3 beyond the epiphyseal line. Planned osteotomy under image-guided navigation was employed for achieving clear surgical margin while maximizing host tissue preservation. All tumors were en bloc removed and intercalary defect were reconstructed by combination of allograft with vascularized fibula graft. All specimens were examined for resection margin. Patients were followed up for an average of 25.2 months for evaluating of functional and oncology outcomes. Results: Entire joint were preserved in 6 patients and part of joint were saved in another 3 patients. The mean registration error for navigation was 0.40 mm (range, 0.31 to 0.62 mm). Clear surgical margin was obtained in all specimens. The average closest distance between the osteotomy line and tumor edge was 9.6 mm (range, 6 to 14 mm). Entire joint cartilage was preserved in 6 patients and portion of joint were saved in 3 patients (2 in proximal tibia, 1 in distal femur). No patient experienced local recurrence. Two patients developed lung metastasis. One died of disease and the other underwent metastasectomy and had no evidence of disease at the most recent follow-up. All reconstruction was in situ with the Musculoskeletal Tumor Society average score of 26.7 at final follow-up. Conclusions: With careful patient selection, image navigation–assisted surgery made it possible to resect the bone exactly as planned in length and orientation in the magnetic resonance imaging image, yielding a clear margin and preserving the entire or part of the articular cartilage in joint-sparing limb salvage procedures for treating skeletally immature patients with juxta-articular bone sarcomas. Level of Evidence: Level IV—therapeutic study.

Composite biological reconstruction following total calcanectomy of primary calcaneal tumors

Advances in oncologic treatment modalities and wide resection have made limb salvage procedures in calcaneal malignancy or aggressive benign tumor increasingly possible. However, reconstructions of the calcaneus remain a major surgical challenge because of the rarity and specific anatomy of this condition.

Precise resection and biological reconstruction for patients with bone sarcomas in the proximal humerus.

BACKGROUND It is a challenge to perform a joint-preserving resection for patients with bone sarcomas in the proximal humerus. We determined whether osteotomy under navigation guidance made joint-saving resection possible for juxtaarticular humeral sarcomas while adhering to oncological principles. METHOD Between January 2008 and July 2010, joint-preserving surgeries were performed on six patients with proximal humeral sarcomas under navigation guidance. Five tumors extended to, and one extended beyond, the epiphyseal line. Planned osteotomy under image-guided navigation was employed to achieve a clear surgical margin while preserving the humeral head and rotator cuff. All tumors were removed en bloc and intercalary defects were reconstructed by a combination of allograft and vascularized fibula graft. All specimens were examined for resection margin. Patients were followed up for an average of 19.1 months. RESULTS The entire glenohumeral joint was preserved in five patients and part of the humeral head was saved in one patient. Clear surgical margin was obtained in all specimens. The minimum closest distance between the osteotomy line and tumor edge was 7 mm. No patient experienced local recurrence. One patient developed lung metastasis and was alive with disease. The mean Musculoskeletal Tumor Society (MSTS) 93 score was 92.1%. All reconstruction was in situ at final follow-up. CONCLUSION With careful patient selection, image navigation-assisted surgery made it possible to excise the bone exactly as seen in orientation in magnetic resonance imaging (MRI) image, yielding a clear margin and preserving all or part of the humeral head in limb salvage procedures for patients with juxtaarticular bone sarcomas in proximal humerus. LEVEL OF EVIDENCE Therapeutic study; Level IV.

Giant cell tumor of axial vertebra: surgical experience of five cases and a review of the literature

BackgroundDue to the complex anatomy of the upper cervical spinal column region and the variable aggressiveness of giant cell tumors (GCTs), there exists no standard treatment for GCTs of axial vertebra. To the best of our knowledge, there are only a few case reports in the literature and no large sum numbers of clinical trials about the treatment of, or research into, axial vertebra GCTs.MethodsBetween 2009 and 2013, five patients pathologically diagnosed with axial vertebra GCTs were treated at our hospital. We performed intralesional excision and odontoid process reconstructive surgery to preserve the odontoid process, followed with adjuvant radiation therapy after surgery.ResultsFor those with an intact bone shell, part of the β-TCP (beta tricalcium phosphate) artificial bone could be seen clearly after surgery and became blurred three months after surgery, as seen on a radiograph. One year later, the part of β-TCP artificial bone was fused as a block. Subsequently, autogenous bone regenerated successfully and artificial bone degraded thoroughly. For those with a defective cortical bone, partial fusion of the odontoid process, autograft ilium and third vertebra body could be seen three months after surgery, and complete fusion was seen nine months later. The odontoid process was preserved successfully, and the upper cervical spine was reconstructed effectively, without implant failure or infection.ConclusionsIn this study, the odontoid process and function of upper cervical vertebra was preserved successfully through lesion curettage, combined with reconstruction with bone grafting, and adjuvant radiation therapy after surgery. During the follow-up periods, no recurrence or complications was observed.

What are the Oncologic and Functional Outcomes After Joint Salvage Resections for Juxtaarticular Osteosarcoma About the Knee

BackgroundJoint salvage surgery for patients with juxtaarticular osteosarcoma remains challenging, especially when the tumor invades the epiphysis. Because patients are surviving longer with current chemotherapy regimens, it is advantageous to retain native joints if possible, especially in young patients. However, the results using joint-preserving tumor resections in this context have not been well characterized.Questions/purposes(1) What are the functional outcomes after limb salvage surgery at a minimum of 3 years? (2) What are the oncologic outcomes? (3) Is joint salvage surgery for epiphyseal tumors associated with an increased risk of local recurrence compared with metaphyseal tumors not invading the epiphysis? (4) What are the complications associated with joint salvage surgery?MethodsBetween 2004 and 2013, we treated 117 patients with juxtaarticular osteosarcoma; of those, 43 (38%) were treated with joint salvage surgery, and 41 (95%) of the 43 patients are included in our study. The other two (5%) were lost to followup before 3 years (mean, 4.4 years; range, 3–11 years,). During the period in question, we generally performed joint salvage surgery in these patients when they had a favorable response to chemotherapy, did not have a pathologic fracture or extrusion of the tumor into the joint, and did not have a whole-epiphyseal osteolytic lesion, a large mass, or obvious neurovascular involvement. This report is a followup of an earlier study; the current study includes an additional nine patients, and additional followup of a mean of 19 months for the patients included in the earlier report. We ascertained overall survival and survival free from local recurrence which was estimated using the Kaplan-Meier method, functional status of the limb which was evaluated using the Musculoskeletal Tumor Society (MSTS)-93 scoring system, and recorded reconstructive complications including infection, fracture, skin necrosis, and nonunion. We compared oncologic and functional outcomes between patients with (n = 28) and without tumor extension to epiphysis (n =13). We also compared oncologic and functional outcomes among patients with different adjuvant treatments including microwave ablation (n = 11), cryoablation (n = 12), and navigation-assisted osteotomy (n = 5). Complications were tallied using records from our institutional database.ResultsThe overall Kaplan-Mayer survival rate was 82% (95% CI, 104–128 months) at 5 years. The overall Kaplan-Meier survivorship from local recurrence was 91% at 5 years (95% CI, 115–133 months). Three patients had a local recurrence, but none had local recurrence in or close to the remaining epiphysis. The MSTS scores ranged from 22 to 30 points, with a median of 28. There were no differences in survival rate, local recurrence, or MSTS scores between patients with a tumor that did not invade the epiphysis and those in whom the tumor did invade the epiphysis. There were differences in MSTS scores among patients with epiphyseal tumor extension in which different adjuvant techniques, including microwave ablation, cryoablation, and navigation-assisted osteotomy, were used. Additional surgical procedures were recorded for 10 patients (24%). Osteonecrosis of the residual epiphysis was detected 13 patients (31%).ConclusionsOur findings suggest it is possible to salvage joints in selected patients with juxtaarticular osteosarcoma around the knee. The patients who have a favorable response to chemotherapy are the best candidates for this approach. Future studies might explore the role of adjuvant techniques of microwave ablation and cryoablation, particularly when the tumor invades the epiphysis, and whether resections can be facilitated with navigation.Level of EvidenceLevel IV, therapeutic study.