Ilkyu Han

Joint-preserving limb salvage surgery under navigation guidance.

Recently, the navigation system has been introduced to orthopedic oncology. It can apply MRI and/or CT images to intraoperative visualization. We performed navigation‐assisted limb salvage surgeries on patients with a malignant bone tumor of the metaphysis of the long bone or the iliac bone while preserving the adjacent joint.

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 …

Outcome after Surgical Treatment of Pelvic Sarcomas

Background We present here the oncological and functional outcomes of limb salvage with or without reconstruction for primary sarcomas in the pelvic bone. Methods Forty-four patients who underwent pelvic resection for primary sarcomas involving the pelvis were reviewed. The average follow-up period was 39 months (range, 0 to 146 months). Chondrosarcoma (n = 17) and osteosarcoma (n = 10) were the most common diagnoses. Various clinicopathologic factors were analyzed in relation to the oncological outcomes of overall survival and local recurrence. The Musculoskeletal Tumor Society functional scores and complications were compared according to the tumor location, pelvic continuity and the type of resection. Results The overall 5-year survival rate was 40%. Metastasis at the time of diagnosis, the surgical margin and the histologic grade were the independent prognostic factors for survival. The surgical margin was an independent prognostic factor for local recurrence. An ischiopubic location of the tumor, restoration of pelvic continuity and hip joint reconstruction with total hip replacement arthroplasty were related with higher functional scores. Complications occurred in 50% of the patients and the complications varied according to the tumor location with infection being the most common complication. Conclusions Achieving an adequate surgical margin is necessary for improving the oncological outcome of pelvic sarcomas. Restoration of the pelvic continuity and the hip joint improves the functional outcome. However, complications are common and so careful selection of the reconstruction method is needed.

Simultaneous Bilateral MIS-TKA Results in Faster Functional Recovery

AbstractSimultaneous bilateral TKAs subject patients to more arduous and painful functional recovery and increased risk of hemodynamic complications than staged bilateral TKAs. Minimally invasive TKA (MIS-TKA) reportedly results in more rapid return of function by limiting the amount of soft tissue disruption. We asked whether bilateral MIS-TKA had advantages over conventional TKA with respect to faster functional recovery. We prospectively randomized 30 patients into an MIS group (mini-medial parapatellar approach, 15 patients) and a conventional group (conventional medial parapatellar approach, 15 patients). We recorded range of motion and the time required to regain the ability to walk without assistance. Functional recovery in the MIS group was faster in rehabilitation milestones of walking without assistance and gain in range of motion. Minimally invasive TKA may benefit patients undergoing simultaneous bilateral procedures with faster functional recovery. Level of Evidence: Level II, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Broken Bioabsorbable Femoral Cross-Pin After Anterior Cruciate Ligament Reconstruction With Hamstring Tendon Graft A Case Report

Hamstring tendon grafts have increasingly been used for ACL reconstruction, with comparable results reported to those of bone–patellar tendon grafts. In ACL reconstruction using hamstring tendon grafts, fixation of the grafts has been regarded as one of the weak points. Recently, a variety of fixation devices have been developed and widely used with satisfactory results. Cross-pin femoral fixation is a new strategy of fixation that transversely places the pin through the femoral tunnel. Several products using bioabsorbable femoral crosspins, such as the RigidFix system (Mitek Products, Norwood, Mass), Cross-screw system (Stryker, Kalamazoo, Mich), and Transfix-II system (Arthrex, Naples, Fla) have been developed. The RigidFix system uses 2 parallel bioabsorbable pins that pierce the strands of the graft perpendicularly in the femoral tunnel. Biomechanical studies have shown that the biomechanical properties of the RigidFix are better than or comparable to those of interference screws. Although Clark et al mentioned 3 cases of pin migration in a stainless steel cross-pin system, to our knowledge, no cases of complications involving the bioabsorbable cross-pin system have been reported. We present a case in which 1 of the 2 bioabsorbable pins used for femoral fixation broke and migrated into the joint cavity 1 year postoperatively, after the graft had been incorporated at the femoral site. The patient was unable to return to preinjury level of activity until the broken pin was removed. The patient was informed that information regarding his case would be submitted for publication.

Hedgehog and Notch Signaling Regulate Self-Renewal of Undifferentiated Pleomorphic Sarcomas

Like many solid tumors, sarcomas are heterogeneous and include a small fraction of the so-called side population (SP) cells with stem-like tumor-initiating potential. Here, we report that SP cells from a soft tissue tumor of enigmatic origin termed undifferentiated pleomorphic sarcoma (also known as malignant fibrous histiocytoma or MFH sarcoma) display activation of both the Hedgehog and Notch pathways. Blockade to these pathways in murine xenograft models, this human cancer decreased the proportion of SP cells present and suppressed tumor self-renewal, as illustrated by the striking inability of xenograft tumors subjected to pathway blockade to be serially transplanted to new hosts. In contrast, conventional chemotherapies increased the proportion of SP cells present in tumor xenografts and did not affect their ability to be serially transplanted. SP cells from these tumors displayed an unexpectedly high proliferation rate which was selectively inhibited by Hedgehog and Notch blockade compared with conventional chemotherapies. Together, our findings deepen the concept that Hedgehog and Notch signaling are fundamental drivers of tumor self-renewal, acting in a small population of tumor-initiating cells present in tumors. Furthermore, our results suggest not only novel treatment strategies for deadly recurrent unresectable forms of this soft tumor subtype, but also potential insights into its etiology which has been historically controversial.

Correlation of the condition of the patellar articular cartilage and patellofemoral symptoms and function in osteoarthritic patients undergoing total knee arthroplasty

We sought to determine the degree of correlation between the condition of the patellar articular cartilage and patellofemoral symptoms and function in osteoarthritic patients undergoing total knee arthroplasty. The depth of the osteoarthritic lesion, as graded by the Outerbridge classification and its size and location were assessed to determine the condition of the patellar cartilage in 80 consecutive osteoarthritic knees undergoing total knee arthroplasty. The association between the condition of the cartilage and patellofemoral symptoms and function was investigated by correlation analysis. The depth and size of the lesion had a significant but weak correlation with anterior knee pain (r = -0.300 and -0.289; p = 0.007 and 0.009, respectively), whereas location had no significant association (p > 0.05). None had a significant association with patellofemoral functional parameters (chair-rising, stair-climbing, and quadriceps power) (p > 0.05). Our study indicates that patellofemoral symptoms and function are not completely determined by the condition of the cartilage. Caution should be taken when the symptoms and functional limitations are attributed to a lesion in the patellofemoral joint in making a decision regarding patellar resurfacing in total knee arthroplasty.

The use of pasteurized autologous grafts for periacetabular reconstruction.

Reconstruction after periacetabular resection is a challenge. We asked whether the use of pasteurized autologous grafts would provide satisfactory results regarding patient survival, local recurrence, and metastasis, and graft union and functional outcome. We retrospectively reviewed 11 patients having such grafts with a minimum followup of 12 months (mean, 40 months; range, 12-116 months). All patients underwent periacetabular (Type II) resection of malignant periacetabular tumors. The resected bone was treated in saline at 65°C for 30 minutes and reimplanted into the host bone with internal fixation. Total hip arthroplasty was performed in all patients. Local recurrence occurred in two of nine patients with primary sarcoma. Ten grafts survived at the last followup. Union of the resected bone with the host bone was achieved in eight of the 11 patients at an average of 12 months. The overall functional rating was 61% according to the Musculoskeletal Tumor Society System, with better results in the patients with primary tumors. Graft fracture (one patient) and infection (one patient) were the major complications. Our data suggest the use of pasteurization may be a reasonable option for reconstruction after resection of malignant periacetabular tumors.Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Expression of Macrophage Migration Inhibitory Factor Relates to Survival in High-grade Osteosarcoma

AbstractMacrophage migration inhibitory factor (MIF), a proinflammatory cytokine, is implicated in many aspects of tumor progression, including cell proliferation, invasion, and angiogenesis. We asked if MIF expression predicts survival and if it is associated with angiogenesis and cell invasion in osteosarcoma. We performed immunohistochemistry for MIF expression in prechemotherapy biopsy specimens of 58 patients with osteosarcoma. To investigate the role of MIF in angiogenesis, microvessel density was measured and compared with MIF expression. We also treated osteosarcoma cell lines (U2-OS and MG63) with MIF and measured vascular endothelial growth factor, a potent proangiogenic factor, by enzyme-linked immunosorbent assay. To study the role of MIF in cell invasion, Boyden chamber assay was performed after knockdown of MIF by short interfering RNA. MIF independently predicted overall survival and metastasis-free survival. MIF expression correlated with microvessel density and induced a dose-dependent increase in vascular endothelial growth factor. Knockdown of MIF by short interfering RNA resulted in decreased cell invasion. These results suggest MIF could serve as a prognostic marker and a potential therapeutic target for osteosarcoma. Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Association between radiological findings and symptoms at the patellofemoral joint in advanced knee osteoarthritis.

We investigated the association between the radiological findings and the symptoms arising from the patellofemoral joint in advanced osteoarthritis (OA) of the knee. Four radiological features, joint space narrowing, osteophyte formation, translation of the patella and focal attrition were assessed in 151 consecutive osteoarthritic knees in 107 patients undergoing total knee replacement. The symptoms which were assessed included anterior knee pain which was scored, the ability to rise from a chair and climb stairs, and quadriceps weakness. Among the radiological features, only patellar translation and obliteration of the joint space had a statistically significant association with anterior knee pain (odds ratio (OR) 4.85; 95% confidence interval (CI) 1.83 to 12.88 and OR 11.23; 95% CI 2.44 to 51.62) respectively. Patellar translation had a statistically significant association with difficulty in rising from a chair (OR 9.06; 95% CI 1.75 to 45.11). Other radiological features, including osteophytes, joint space narrowing, and focal attrition had no significant association. Our study indicates that the radiological findings of patellar translation and significant loss of cartilage are predictive of patellofemoral symptoms and functional limitation in advanced OA of the knee.