Hyun Guy Kang

Computer-Assisted Sacral Tumor Resection: A Case Report

Resection of sacral tumors is one of the most difficult operations in orthopaedic oncology because complex anatomy and important internal organs in the pelvic area make it difficult to achieve wide surgical margins1. Wide resection of sacral tumors may lead to serious functional impairments due to injury to important internal organs and/or the lumbosacral nerve roots or through the disruption of load-bearing through the sacroiliac joint. Recent advances in diagnostic modalities facilitate better surgical planning and can help in the performance of surgeries as planned. Computer-assisted surgery has been used in orthopaedic operations such as cruciate ligament reconstruction, hip and knee arthroplasty, and pedicle screw placement. The main advantage of computer-assisted navigation over other imaging modalities is that intraoperative identification can increase the accuracy of surgical resection. We report a case of sacral chondrosarcoma in which computer-assisted surgery provided intraoperative real-time imaging, thereby allowing us to achieve adequate surgical margins while preserving the sacral nerve roots. Additionally, the tumor resection was carried out through a posterior approach only. The patient was informed that data concerning the case would be submitted for publication, and he consented. A fifty-two-year-old man was referred to us with a longer than five-month history of a dull pain in the lower back. There was no evidence of a neurologic deficit in the lumbosacral nerve roots. Systemic symptoms, such as fever or weight loss, were absent. Plain radiographs of the pelvis showed an osteolytic lesion at the right sacral ala. Magnetic resonance imaging revealed that the tumor was located in the right sacral ala, between the sacroiliac joint and the first and second sacral foramina (Fig. 1). Computed tomography revealed cortical destruction of the sacral side of the sacroiliac joint, but there was no evidence of involvement of the ilium. Further evaluation, including computed tomography …

MRI-guided Navigation Surgery with Temporary Implantable Bone Markers in Limb Salvage for Sarcoma

BackgroundTechnical errors during navigation-assisted bone tumor resection may occur by: (1) incorrect registration of images and corresponding anatomic points of bone sent to the navigation system; and (2) incorrect fusion of two or more images that have been transported to the navigation system.Questions/purposesWe investigated new methods of navigation surgery to minimize technical errors during the registration and image fusion processes and specifically asked whether a navigated cannula probe would reduce unnecessary soft tissue dissection, and allow percutaneous registration and implantation of a reference base tracker in the margin of bone to be resected.MethodsWe performed direct MRI-guided navigation surgery without image fusion on a patient with osteosarcoma using absorbable pins as temporary implanted bone markers that prevent artifacts on MR images.ResultsDirect MRI-guided navigation surgery was possible using bone markers. A navigated cannula probe allowed percutaneous registration and a navigated blade-shaped probe provided a real-time check on the narrow osteotomy gap. The surgical procedure was facilitated by implantation of a reference base tracker on the margin of bone to be resected.ConclusionsOur modified technique of MRI-guided navigation surgery for patients with a malignant bone tumor may reduce processing errors by increased accuracy and be helpful for joint preserving surgery.

Minimally invasive surgery of humeral metastasis using flexible nails and cement in high-risk patients with advanced cancer

This study was conducted to evaluate the preliminary outcome of palliative minimally invasive surgery for humeral metastasis in patients who have multiple advanced cancers with short life expectancy. Percutaneous Ender nailing and direct transcortical intramedullary cementing were performed on a total of 15 patients with metastatic disease of the humerus. The origins of the cancers were the lung (n=9), breast (n=3), colon (n=2) and liver (n=1). Each patient had multiple unresectable organic metastases and proved to be at high risk for anesthesia and bloody surgery. All procedures were performed under regional anesthesia and fluoroscopic guidance. The mean amount of intramedullary cement injection after Ender nailing was 13.4ml. The mean of the numeric rating scale (NRS) score for pain decreased from 9.6 points before surgery to 3.6 points after surgery (P<0.001). The mean of the Musculoskeletal Tumor Society (MSTS) functional score increased from 10.6 points before surgery to 19.9 points after surgery (P<0.001). Seven patients died within 7 months. There were no complications associated with cement leakage, fixation failure and surgical wound even in cases of early postoperative radiation or chemotherapy. Percutaneous flexible nailing along with intramedullary cementing could be a useful minimally invasive surgical method for the palliation of humeral metastasis in selective terminal cancer patients by providing immediate reliable fixation and effective pain relief.

Minimally invasive surgery for femoral neck fractures using bone cement infusible hollow-perforated screw in high-risk patients with advanced cancer

OBJECTIVE Pathologic or osteoporotic femoral neck fractures usually treated with joint replacement surgery rather than joint-preserving surgery because multiple screw fixation has a high risk for fixation failure and nonunion as well as the need for a postoperative protection period. However, joint-preserving surgery might be preferable in high-risk patients with short life expectancy due to advanced disease. Recently introduced hollow-perforated screws are devices for achieving percutaneous fixation by simultaneous injection to the weak bone area through its multiple side holes. We report our experience of surgical treatment of femoral neck fractures by controlled bone cement injection into the femoral head and neck through a modified hollow-perforated screw in patients with advanced cancer. METHODS We modified the hollow perforated screw with variable placing of screw-side holes as fracture patterns. Polymethylmethacrylate (PMMA) bone cement was injected through the screw holes to control its injection into the selective areas of the femoral head and neck while avoiding the fracture sites. One or two of these were fixed percutaneously in 12 patients who have Garden stage I or II femoral neck fractures in the advanced state of advanced cancer. Seven patients had pathologic fracture by metastatic cancer, but 5 had osteoporotic fractures. RESULTS Eleven patients died a mean of 4.1 months after surgery and 1 patient lived with ability to walk for 48 months. Sixteen modified hollow perforated-screws and 16 standard cannulated screws were used for fixation. The mean volume of cement injection was 13.8 ml. The complication developed in 4 patients: cement leakage to the hip joint in 2 patients, subtrochanteric fracture in 1 patient (5 months after surgery) and fixation failure in 1 patients (2 months after surgery). Nine patients could walk with or without a walking aid, and all others also could return to the prefracture-ambulation state with effective pain relief on the third postoperative day. CONCLUSION This current surgical method could be useful in patients with short life expectancy because of quick pain relief, early return to ambulation, simple operative procedures and short hospital stay. The modified hollow perforated screw which has a diversity of side hole locations for the regulation of bone cement injection into the planned area seems useful for selective femoral neck fractures.

Soft Tissue Reconstruction of the Foot Using the Distally Based Island Pedicle Flap after Resection of Malignant Melanoma

Background We report on our experience with using a distally based island flap for soft tissue reconstruction of the foot in limb salvage surgery for malignant melanoma patients. Methods A distally based sural flap was used for 10 cases for the hindfoot reconstruction, and a lateral supramalleolar flap was used for 3 cases for the lateral arch reconstruction of the mid- and forefoot after wide excision of malignant melanomas. Results The length of the flap varied from 7.5 cm to 12 cm (mean, 9.6 cm) and the width varied from 6.5 cm to 12 cm (mean, 8.8 cm). Superficial necrosis developed in four flaps, but this was successfully treated by debridement and suture or a skin graft. All thirteen flaps survived completely and they provided good contour, stable and durable coverage for normal weight bearing. Conclusions The distally based sural flap is considered to be useful for reconstructing the hindfoot, and the lateral supramalleolar flap is good for reconstructing the lateral archs of the mid- and forefoot after resection of malignant melanoma of the foot.

Distinct Clinical Characteristics of Unplanned Excision in Synovial Sarcoma

Background We aimed to describe the clinical characteristics and outcomes of unplanned excisions of synovial sarcomas. Methods In total, 90 patients with synovial sarcomas in the extremities were retrospectively reviewed. Patients were divided into unplanned excision (n = 38) and planned excision (n = 52) groups. The average follow-up period was 6 years. The clinicopathological characteristics and oncologic outcomes were compared. Results The unplanned excision group showed longer duration of symptoms before diagnosis (p = 0.023), smaller lesion dimensions (p = 0.001), superficial location (p = 0.049), and predilection in the upper extremities (p = 0.037). Synovial sarcomas were most commonly misdiagnosed as neurogenic tumors (56%) in the upper extremities or as cystic masses (47%) in the lower extremities. Oncological outcomes, including disease-specific survival, metastasis-free survival, or local recurrence were not significantly different between the 2 groups (p = 0.159, p = 0.444, and p = 0.335, respectively). Repeated unplanned excision (p = 0.012) and delayed re-excision (p = 0.038) were significant risk factors for local recurrence in the unplanned excision group. Conclusions Synovial sarcomas treated with unplanned excision had distinct characteristics. These findings are important for developing diagnostic and therapeutic strategies for synovial sarcoma.

Bone tumor resection guide using three-dimensional printing for limb salvage surgery: PARK et al.

The three‐dimensional (3D)‐printed bone tumor resection guide can be personalized for a specific patient and utilized for bone tumor surgery. It is noninvasive, eidetic, and easy to use. We aimed to categorize the use of the 3D‐printed guide and establish in vivo accuracy data.