A Transposition Flap Reconstruction after Resection of a Soft-Tissue Sarcoma in the Buttock

Introduction: Large defects following resection in the gluteal region are challenging. Of note, there are a limited number of fairly morbid options for reconstruction. Case Report: A 65-year-old female presented with complaints of an enlarging mass in the left buttock over the past several months. A high-grade sarcoma was diagnosed based on a biopsy. The final diagnosis was an undifferentiated pleomorphic sarcoma based on the resected tumor. An 11-cm tumor with surrounding tissues, including the great gluteal muscle, was resected, which resulted in a 17-cm full thickness defect. The defect was reconstructed with a transposition flap elevated from the lateral thorax. A transposition flap can cover large buttock defects without sacrificing other muscles. Conclusion: Moreover, a transposition flap is esthetically acceptable because most of the operative scar is within the buttock area. A transposition flap reconstruction is one of the several options for large defects after soft-tissue sarcoma resection in the buttock

Thoracoabdominal flap reconstruction after resection of superficial soft-tissue sarcomas in the chest wall

The thoracoabdominal flap is a rotation flap, and is well known for reconstruction of defects following resections for breast cancer, but the flap is not well known for reconstructing defects following resections of soft-tissue sarcomas involving the chest wall. Here we present two patients with superficial chest wall sarcomas consisting of a dermatofibrosarcoma protuberans in a 42-year-old man and a recurrent myxofibrosarcoma in a 76-year-old man. The tumors were resected with the surrounding tissue. The defect was reconstructed with a thoracoabdominal flap elevated from the ipsilateral thorax (medially-based flap). Neither case developed necrosis of the flap or reduced shoulder range of motion. The chest wall presents few options for a donor vessel. The thoracoabdominal flap has an axial blood supply and does not require a microsurgical procedure. A thoracoabdominal flap is a suitable reconstruction option for a defect after the resection of a superficial soft-tissue sarcoma in the chest wall

Preserving the posterior cortex of the sternum during resection of a superficial anterior chest wall sarcoma

Following resection of a sternal tumor, respiratory dysfunction can occur and rigid reconstruction is necessary. An 82-year-old woman noted a mass in the anterior chest wall that was increasing in size. The tumor was located on the left aspect of the sternum at the level of the third rib. A radiation-induced malignant spindle cell tumor was diagnosed because of a history of irradiation for hilar lymph node carcinoma. The tumor was resected with the surrounding tissues of the second-to-fourth ribs and sternum. The posterior sternal cortex was preserved by cutting with a curved chisel under fluoroscopy. The chest wall defect was reconstructed with a 2-mm thick Gore-Tex® sheet and a local transpositional flap. Sternal resection with a chisel under fluoroscopy avoids damage to the internal thoracic artery. Preserving the posterior sternal cortex does not require rigid reconstruction. The procedure is minimally invasive

Multifidus muscle retracted and preserved in resection of malignant bone tumor in the sacral ala

Resection of malignant tumors in the posterior pelvis requires multidirectional approaches for the resection and the subsequent spine-pelvic fixation. The multifidus muscle can be scarified during the operation. This is a case report of a 44-year-old male with a secondary chondrosarcoma arising from an osteochondroma in the sacral ala. Recurrence occurred 11 months after the initial operation, and the resected tissue from the recurrence was diagnosed as a chondrosarcoma. In both operations, the multifidus muscle was elevated from its distal attachment to provide an adequate view of the tumor resection and insertion of spine-pelvic instrumentation. An adequate view by elevation of the multifidus muscle is useful for a safe operation. A preserved multifidus muscle covering the instrumentation may reduce the risk of infection. The elevation and preservation of the multifidus muscle is an easy and simple method that contributes to successful resection of a malignant tumor of the pelvis

Difference in Therapeutic Strategies for Joint‐Preserving Surgery for Non‐Traumatic Osteonecrosis of the Femoral Head between the United States and Japan: A Review of the Literature

For patients with non-traumatic osteonecrosis of the femoral head (ONFH), core decompression (CD) and bone grafts (BG) are mainly performed in the West, while osteotomy is found to be predominant in Japan. It is not well recognized how the surgical procedures for joint preservation in patients with ONFH are completely different between the United States and Japan. This paper identifies the contexts and the differences in treatment strategies for ONFH between the two countries. We compared the surgical trends of the two countries over three periods, 1997-2001, 2002-2006, and 2007-2011 (the US data for the third period was 2007-2008), based on a 2014 US paper and a 2013 national publication in Japan. We compared the details of surgery for non-traumatic ONFH under the same conditions in the two reports. For the period 1997-2001, the rates of surgeries for ONFH in the US were as follows: total hip arthroplasty (THA), 86%; CD, 10%; and osteotomy, 0.4%. In Japan, THA was 61%, osteotomy 38%, and CD 0%. For the recent period, 2007-2011 (US 2007-2008), the rate of THA was 91%, CD 6%, and osteotomy 0.1%, in the US, compared to a THA rate of 73%, CD 0%, and osteotomy 26% in Japan. The results for the interim period (2002-2006) were between the old and new data. The use of joint-preserving surgery for ONFH differs greatly between the US and Japan. The first-line joint-preserving surgery was CD in the US and osteotomy in Japan. Each procedure was rarely done in the other country. From about 2000 to 2010, the percentage of THA increased in both countries. The proportion of joint-preserving surgery (CD in the US and osteotomy in Japan) declined. The decrease in joint-preserving procedures may be largely attributed to improved long-term outcomes of THA due to technological advances. There is also a reluctance for young ONFH patients to undergo joint-preserving procedures, such as osteotomy, that require long-term hospitalization

Discrepancy in the Responsiveness to Hip Range of Motion Between Harris and Oxford Hip Scores

Background: The primary objectives of total hip arthroplasty (THA) include mobility improvement and pain relief; however, the correlation between hip range of motion (ROM) and function remains unclear. We aimed to explore how ROM affects hip functions after THA and compare the responsiveness of each component of the modified Harris Hip Score (mHHS) and Oxford Hip Score (OHS) to preoperative and postoperative ROM. Methods: This prospective observational study involved 120 patients who underwent unilateral THA. Univariate regression analyses were performed using the University of California Los Angeles activity score and mHHS and OHS to determine the effects of preoperative and postoperative flex ROM on clinical scores at 12 months. Multivariate regressions were performed to adjust for the confounding effects of patient factors: age, sex, body mass index, and diagnosis. Results: A larger preoperative flexion ROM was associated with a higher score in the mHHS socks component (standardized coefficient [SC] = 0.26, P = .0041) at 12 months; the effect on the OHS socks component was not significant (P = .34). A larger flexion ROM at 12 months was associated with higher scores in the mHHS support (SC = 0.21, P = .026), stairs (SC = 0.35, P = .0002), and socks (SC = 0.32, P = .0007) components but had no significant effect on any OHS component. The effects of ROM on University of California Los Angeles activity score were limited. Conclusions: A discrepancy was noted in the responsiveness to ROM between the two major measurement tools; this difference might be because mHHS and OHS are surgeon- and patient-administered questionnaires, respectively. This discrepancy also suggests that the patients have higher satisfaction than that assumed by the surgeons

High Subsidence Rate After Primary Total Hip Arthroplasty Using a Zweymüller-type Noncemented Implant With a Matte Surface

INTRODUCTION: The surface topography is one key factor that affects the initial fixation of prosthesis in total hip arthroplasty (THA). We aimed to evaluate the mid-term results of a Zweymüller-type noncemented femoral implant (Elance stem) that had a matte surface with a target average roughness of 1.0 to 2.5 μm. The prosthesis was subjected to alkali and heat treatments to enhance its bone-bonding property. METHODS: In this retrospective study, 30 THAs (27 patients) done using an Elance stem from September 2012 to October 2014 were evaluated clinically and radiographically for a mean follow-up of 6.3 ± 1.7 years after the index THA. RESULTS: Stem revision was indicated for six hips (20%). The survival rate with stem revision for any reason was 86.4% (95% confidence interval, 68.9%-94.8%) at 5 years. Stem subsidence >5 mm was noted in 17 hips (56.7%). The survival rate with stem subsidence >5 mm as the end point was 46.6% (95% confidence interval, 29.9%-64.2%) at 5 years. CONCLUSION: The Zweymüller-type noncemented stem with a low-roughness matte surface demonstrated a high subsidence rate, although the bone-bonding property was potentially enhanced by the alkali and heat treatments. Surgeons should be aware that an insufficient surface roughness could lead to poor mechanical fixation of the noncemented stem, even with an appropriate stem geometry and surface chemistry

Generation of monkey iPS cell-derived cartilage lacking MHC class I molecules on the cell surface

Multiple immune reactions when transplanting cartilage into monkeys. 京都大学プレスリリース. 2021-07-07.Due to the poor capacity for articular cartilage to regenerate, its damage tends to result in progressively degenerating conditions such as osteoarthritis. To repair the damage, the transplantation of allogeneic human induced pluripotent stem cell (iPSC)-derived cartilage is being considered. However, although allogeneic cartilage transplantation is effective, immunological reactions can occur. One hypothetical solution is to delete the expression of MHC class I molecules in order to reduce the immunological reactions. For this purpose, we deleted the β2 microglobulin (B2M) gene in a cynomolgus monkey (crab-eating monkey (Macaca fascicularis)) iPS cells (cyiPSCs) to obtain B2M⁻/⁻ cyiPSCs using the CRISPR/Cas9 system. Western blot analysis confirmed B2M⁻/⁻ cyiPSCs lacked B2M protein, which is necessary for MHC class I molecules to be transported to and expressed on the cell surface by forming multimers with B2M. Flow cytometry analysis revealed no B2M⁻/⁻ cyiPSCs expressed MHC class I molecules on their surface. The transplantation of B2M⁻/⁻ cyiPSCs in immunodeficient mice resulted in teratoma that contained cartilage, indicating that the lack of MHC class I molecules on the cell surface affects neither the pluripotency nor the chondrogenic differentiation capacity of cyiPSCs. By modifying the chondrogenic differentiation protocol for human iPSCs, we succeeded at differentiating B2M⁺/⁺ and B2M⁻/⁻ cyiPSCs toward chondrocytes followed by cartilage formation in vitro, as indicated by histological analysis showing that B2M⁺/⁺ and B2M⁻/⁻ cyiPSC-derived cartilage were positively stained with safranin O and expressed type II collagen. Flow cytometry analysis confirmed that MHC class I molecules were not expressed on the cell surface of B2M⁻/⁻ chondrocytes isolated from B2M⁻/⁻ cyiPSC-derived cartilage. An in vitro mixed lymphocyte reaction assay showed that neither B2M⁺/⁺ nor B2M⁻/⁻ cyiPSC-derived cartilage cells stimulated the proliferation of allogeneic peripheral blood mononuclear cells. On the other hand, osteochondral defects in monkey knee joints that received allogeneic transplantations of cyiPSC-derived cartilage showed an accumulation of leukocytes with more natural killer (NK) cells around B2M⁻/⁻ cyiPSC-derived cartilage than B2M⁺/⁺ cartilage, suggesting complex mechanisms in the immune reaction of allogeneic cartilage transplanted in osteochondral defects in vivo

Extracellular-to-intracellular water ratios are associated with functional disability levels in patients with knee osteoarthritis: results from the Nagahama Study.

INTRODUCTION/OBJECTIVES: To test the hypothesis that greater extracellular-to-intracellular water (ECW/ICW) ratios in lower-limb muscles are associated with worsened functional abilities in patients with knee osteoarthritis (OA). METHODS: We analyzed data from 787 participants (82.2% female; mean age, 69.6 ± 5.3 years) from the Nagahama Prospective Cohort who were ≥60 years old and had radiographically confirmed bilateral knee OA. The Knee Scoring System (KSS) was used to assess functional abilities. Lower-limb ECW/ICW ratios and skeletal mass index values were determined with multi-frequency bioelectrical impedance analysis (BIA). Multiple linear regression analysis was used to test for associations between ECW/ICW ratios and functional abilities. Subgroup analyses based on OA severities and symptomaticity were also conducted. RESULTS: Increased ECW/ICW ratios were associated with a 4.38-point decrease in the KSS function scores (95% confidence interval [CI], 3.15-5.62 points) after adjusting for covariates. This association varied according to the degree of knee symptoms, especially in individuals with radiologically mild OA. ECW/ICW ratios in individuals with asymptomatic mild OA were associated with a 2.14-point decrease in the KSS function score (95% CI, 0.32-3.96 points), whereas those in individuals with severe symptomatic mild OA were associated with a 6.16-point decrease (95% CI, 2.13-10.19 points). CONCLUSIONS: Our findings indicate that higher ECW/ICW ratios are associated with greater functional disability in patients with knee OA. Therefore, ECW/ICW ratio measurements with multi-frequency BIA can serve as valuable indicators for functional disability in patients with knee OA. Key Points • Higher extracellular-to-intracellular water (ECW/ICW) ratios are associated with greater functional disability levels in patients with knee osteoarthritis (OA). • ECW/ICW ratios are useful clinical signs as a biomarker for poor functional abilities in patients with knee OA