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BackgroundChest wall malignant tumor (including primary and metastatic lesions) is rare, representing less than 5% of all thoracic malignancies. Local control of chest wall malignancies requires wide resection with tumor-free margins. These requirements increase the risk of thoracic cavity failure and subsequent pulmonary failure. The restoration strategy for chest wall defects comprises chest wall reconstruction and soft-tissue coverage. Various reconstruction methods have been used, but both evidence and guidelines for chest wall reconstruction remain lacking. The purposes of this study were to collate our institutional experience, evaluate the outcomes of full-thickness chest wall resection and reconstruction for patients with chest wall malignant tumor, and identify problems in current practice for chest wall reconstruction with a focus on local control, complications, pulmonary function and scoliosis.MethodsParticipants comprised 30 patients with full-thickness chest wall malignant tumor who underwent chest wall resection and reconstruction between 1997 and 2021 in Mie University Hospital. All patients underwent chest wall resection of primary, recurrent or metastatic malignant tumors. A retrospective review was conducted for 32 operations.ResultsRecurrence was observed after 5 operations. Total 5-year recurrence-free survival (RFS) rate was 79.3%. Diameter ≥5 cm was significantly associated with poor RFS. The postoperative complication rate was 18.8%. Flail chest was observed with resection of ≥3 ribs in anterior and lateral resections or with sternum resection without polyethylene methylmethacrylate reconstruction. Postoperative EFV1.0% did not show any significant decrease. Postoperative %VC decreased significantly with resection of ≥4 ribs or an area of >70 cm2. Postoperative scoliosis was observed in 8 of 28 patients. Posterior resection was associated with a high prevalence of scoliosis (88.9%).ConclusionWith chest wall reconstruction, risks of pulmonary impairment, flail chest and scoliosis were significantly increased. New strategies including indications for rigid reconstruction are needed to improve the outcomes of chest wall reconstruction.

Osteoarthritis (OA) is a degenerative disorder that is characterized by articular cartilage destruction. The level of tenascin-C (TNC), an extracellular matrix protein, is increased in synovial fluid (SF) from OA patients, and TNC concentration in SF correlates with the severity of OA in the knee. Tenascin-X (TNX), another member of the tenascin family, has been identified as a causative protein of classical-like Ehlers-Danlos syndrome (clEDS). In this study, we investigated the correlation between TNX concentration and the degree of cartilage denaturation in OA patients. TNX concentrations in SF from patients with meniscus tears and from OA patients were lower than those of control sera. However, significant difference in TNX concentration in SF was not observed between patients with meniscus tears and OA patients. Furthermore, a significant correlation was not found between TNX concentration in SF and severity of OA in the knees of patients. These results suggest that TNX might not be as useful as TNC as a biomarker.

Tomoki Nakamura, Kunihiro Asanuma, Tomohito Hagi, Akihiro Sudo Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, Tsu, JapanCorrespondence: Tomoki Nakamura Department of Orthopaedic SurgeryMie University Graduate School of Medicine, Tsu, Mie, JapanTel +81-592315022Fax +81-592315211Email tomoki66@clin.medic.mie-u.ac.jpIntroduction: The median survival time of patients with advanced soft tissue sarcoma (STS) is typically < 12 months. Since 2012, physicians were able to administer second- and/or third-line treatment easily in Japan, following the approval of new drugs, namely, pazopanib, eribulin, and trabectedin. We investigated the real-life experience of adults with advanced STS who received systemic therapy after the approval of the aforementioned new drugs.Patients and Methods: We retrospectively evaluated 34 patients (median age: 66 years) with primary STS arising at the extremities/trunk or unresectable local and/or metastatic STS between 2012 and 2019. We evaluated the tumor response and patient survival after initial systemic treatment.Results: As first-line treatment, doxorubicin and ifosfamide and other drugs were administered to 7 and 27 patients, respectively. Of 31 patients with an evaluable tumor response, partial response was observed in 2 (6.5%) patients, and 16 (52%) patients showed stable disease at 8 weeks. The 1- and 2-year survival rates were 51.4% and 28.4%, respectively. The median overall survival (OS) time was 12.6 months. Tumor response to first-line therapy was related to patient prognosis.Conclusion: New drugs may be beneficial for patients with advanced STS. When patients cannot receive anthracycline-based chemotherapy because of a high risk of side effects, we believe that the aforementioned drugs may be administered as the first-line treatment.Keywords: soft tissue sarcoma, eribulin, pazopanib, trabectedin, efficacy, overall survival

Introduction Synovial chondromatosis is a rare metaplastic disorder of the synovial membrane. Primary synovial chondromatosis of the shoulder joint is a rare localization and extra-articular localization around the shoulder is much less common. Case Report We report a rare case of a 13-year-old boy with primary synovial chondromatosis of the subscapular bursa. Computed tomography and magnetic resonance imaging showed that multiple cartilaginous loose bodies were found in the subscapular bursa and the glenohumeral joint. Arthroscopic removal of loose bodies and synovectomy of the subscapular bursa was performed through sublabral foramen. Conclusion Pre-operative investigation for the precise location of the lesions was important for the planning the operative procedure. Arthroscopic removal of loose bodies and synovectomy was useful treatment options for synovial chondromatosis of the subscapular bursa.

Supplementary Material 1

Background: Systemic chemotherapy for advanced disease is another therapeutic option in the management of metastases in soft tissue sarcoma (STS). Doxorubicin either alone or in combination with ifosfamide has been used as first-line chemotherapy. Furthermore, in the past decade, new drugs have been shown to be effective in the treatment of advanced STS after the failure of first-line anthracycline-based chemotherapy: trabectedin, pazopanib and eribulin. However, the appropriate usage of these agents has not been established.Methods: We summarized clinical trials of trabectedin focusing on the efficacy and toxicity of trabectedin in the treatment of STS.Results: Trabectedin can be administered safely and effectively to the patients with advanced STS at second line setting or later. Although trabectedin may be effective as first-line treatment in selected patients, anthracycline-based chemotherapy should be recommended because no regimen in addition to trabectedin has proved to be unequivocally superior to doxorubicin as the first-line treatment for locally advanced or metastatic STS. Nucleotide excision repair (NER) and homologous recombination (HRe) repair may be of particular importance as efficacy of trabectedin.Conclusion: Trabectedin has shown a favorable toxicity profile and is an alternative therapeutic option in patients with advanced STS.

Background: Treatment of metastatic bone tumors is challenging due to the morbidity associated with patients with metastasis. The present case report described a patient with successful treatment of bone metastasis using cryoablation with plate and cementation to prevent fracture for bone metastasis of leiomyosarcoma in the mid-shaft of the femur. Case report: The metastatic tumor was located at intramedullary lesion of the femur. At first, cryoablation was performed under local anesthesia. After one week after cryoablation, curettage and fixation with plate and cementation were performed to prevent fracture. Tumor cells were not observed in the histopathological findings of the curettage tissue. Four years after cryoablation, there was no recurrence and the patient could walk without any support. Conclusion: We suggest that a tumor with limited cancellous bone and of a small size may undergo cryoablation. The prevention of fracture after cryoablation should be considered.

With improving prognosis for recipients of liver transplantation, the necessity of medical care for musculoskeletal disorders, including spinal diseases, of these patients is also increasing. Only a few reports are available on cases of spine surgery following liver transplantation. Furthermore, a case of lateral access surgery following liver transplantation has not thus far been reported. The purpose of this study is to present the first two cases of patients treated with lateral access spine surgery following liver transplantation. Case 1. A 49-year-old female had received living donor liver transplantation (LT) for acute-on-chronic liver failure (ACLF) ten years prior to spine surgery. The patient underwent two levels of lateral lumbar interbody fusion (LLIF) followed by posterior lumbar interbody fusion (PLIF) for degenerative lumbar disease. Although neurological symptoms in the lower extremity improved, a liver disorder resulting from acetaminophen-induced hepatotoxicity occurred at an early stage following spine surgery. Case 2. A 66-year-old female had received living donor liver transplantation for hepatocellular carcinoma (HCC) six years prior to spine surgery. She underwent posterior instrumentation surgery followed by a T12 corpectomy using a wide-foot print expandable cage for T12 vertebral collapse. Following surgery, her weakened muscle strength in the lower extremities was significantly improved. Lateral access spine surgery for lumbar and thoracolumbar lesions can be successfully performed for patients following liver transplantation. However, careful follow-up should be performed for complications related to the function of the liver graft following spine surgery.

Introduction. In cases of bone deficiency or osteoporosis, and especially in revision cases, there were only two options for treatment until the impaction bone graft procedure was proposed. These were cemented or cementless femoral prosthesis. In the early 1990s, the use of impaction bone graft with a cemented mantle had gained popularity and had proven to be clinically effective. In Germany, a cementless impaction bone graft procedure using Corail® (DePuy Synthes) stems was devised, and functional scores were similar to conventional cemented Impaction bone grafts. Case presentation. A 48-year-old man presented with femur loosening of a reamed bipolar arthroplasty performed in 1990. The patient was treated with a cementless impaction bone graft using a Corail® (DePuy Synthes) stem in the femur in revision THA surgery, and the calcar was reconstructed by allograft. Results. At five years, the calcar allograft united with the host bone, and the femoral component showed no subsidence. Conclusion. Calcar reconstruction with a strut allograft, aimed at preventing sinking of the stem was key in this operation. Surgical indication for femoral cementless impaction bone graft should be for loosened femoral prosthesis in a type II Paprosky classification, where only the cortical bone of the isthmus is partially affected, cortical thinning does not exist, and it is mechanically strong enough for the allograft tip impaction. The procedure was safely feasible through the direct anterior approach.

Objectives/Interrogation: Trigger finger (TF) is a common hand problem and sometimes leads to positional contracture of proximal interphalangeal (PIP) joint after treatments, especially it is mostly in middle finger (MF), however this has not been proven scientifically. Though several studies reported[for full text, please go to the a.m. URL], 14th Triennial Congress of the International Federation of Societies for Surgery of the Hand (IFSSH), 11th Triennial Congress of the International Federation of Societies for Hand Therapy (IFSHT), 11th Triennial Congress of the International Federation of Societies for Hand Therapy (IFSHT)

Objective: Kaarela's procedure is the simple method for osteoarthritis of thumb carpometacarpal joints (CMC-OA), while is not able to prevent longitudinal instability. Furthermore, there were few studies that compared with the clinical outcomes of the homogenous interposition arthroplasty between[for full text, please go to the a.m. URL], 14th Triennial Congress of the International Federation of Societies for Surgery of the Hand (IFSSH), 11th Triennial Congress of the International Federation of Societies for Hand Therapy (IFSHT), 11th Triennial Congress of the International Federation of Societies for Hand Therapy (IFSHT)

Kouji Kita,1 Tomoki Nakamura,1 Takashi Yamanaka,2 Keisuke Yoshida,1 Tomohito Hagi,1 Kunihiro Asanuma,1 Atsuhiro Nakatsuka,2 Akihiro Sudo11Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, Tsu, Japan; 2Department of Radiology, Mie University Graduate School of Medicine, Tsu, JapanBackground: Treatment of metastatic bone tumors is challenging due to the morbidity associated with patients with metastasis. The present case report described a patient with successful treatment of bone metastasis using cryoablation with plate and cementation to prevent fracture for bone metastasis of leiomyosarcoma in the mid-shaft of the femur.Case report: The metastatic tumor was located at intramedullary lesion of the femur. At first, cryoablation was performed under local anesthesia. After one week after cryoablation, curettage and fixation with plate and cementation were performed to prevent fracture. Tumor cells were not observed in the histopathological findings of the curettage tissue. Four years after cryoablation, there was no recurrence and the patient could walk without any support.Conclusion: We suggest that a tumor with limited cancellous bone and of a small size may undergo cryoablation. The prevention of fracture after cryoablation should be considered.Keywords: leiomyosarcoma, bone metastasis, cryoablation &nbsp

Koji Akeda,1 Junichi Yamada,1 Erikka T Linn,2 Akihiro Sudo,1 Koichi Masuda2 1Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, Tsu City, Mie 514-8507, Japan; 2Department of Orthopaedic Surgery, University of California, San Diego, La Jolla, CA 92093-0863, USA Abstract: Low back pain (LBP) is now regarded as the first cause of disability worldwide and should be a priority for future research on prevention and therapy. Intervertebral disc (IVD) degeneration is an important pathogenesis of LBP. Platelet-rich plasma (PRP) is an autologous blood concentrate that contains a natural concentration of autologous growth factors and cytokines and is currently widely used in the clinical setting for tissue regeneration and repair. PRP has great potential to stimulate cell proliferation and metabolic activity of IVD cells in vitro. Several animal studies have shown that the injection of PRP into degenerated IVDs is effective in restoring structural changes (IVD height) and improving the matrix integrity of degenerated IVDs as evaluated by magnetic resonance imaging (MRI) and histology. The results of this basic research have shown the great possibility that PRP has significant biological effects for tissue repair to counteract IVD degeneration. Clinical studies for evaluating the effects of the injection of PRP into degenerated IVDs for patients with discogenic LBP have been reviewed. Although there was only one double-blind randomized controlled trial, all the studies reported that PRP was safe and effective in reducing back pain. While the clinical evidence of tissue repair of IVDs by PRP treatment is currently lacking, there is a great possibility that the application of PRP has the potential to lead to a feasible intradiscal therapy for the treatment of degenerative disc diseases. Further large-scale studies may be required to confirm the clinical evidence of PRP for the treatment of discogenic LBP. Keywords: intervertebral disc, intervertebral disc degeneration, platelet-rich plasma, PRP, low back pain

Spontaneous osteonecrosis of the tarsal navicular, called the Mueller-Weiss syndrome, is an uncommon disease. Patients who are resistant to conservative treatment require operative treatment. However, there is no established operative treatment. Two cases of spontaneous osteonecrosis of the tarsal navicular with double (talonavicular and naviculocuneiform joints) arthrodeses with different locking plates are presented. Removal of necrotic areas from the tarsal navicular and replacement with autologous bone graft procured from the iliac crest followed by arthrodesis using a locking plate were performed. Case 1 was fixed with an LCP Distal Radius Plate (SYNTHES) and 6 2.4 mm locking screws. Case 2 was fixed with a Cervical Spine Locking Plate Variable Angle (SYNTHES) and 4 4.0 mm locking screws. Case 2 achieved solid fusion of the talonavicular-cuneiform joints, but case 1 resulted in nonunion of the talonavicular joint. This difference in internal fixation strength might have caused the difference in the results. Performance of double arthrodeses from the medial aspect using a locking plate is a reasonable operative procedure to treat spontaneous osteonecrosis of the tarsal navicular. Strong primary fixation using a thick plate with large-thread screws was important to obtain joint fusions.

Low back pain (LBP) is now regarded as the first cause of disability worldwide and should be a priority for future research on prevention and therapy. Intervertebral disc (IVD) degeneration is an important pathogenesis of LBP. Platelet-rich plasma (PRP) is an autologous blood concentrate that contains a natural concentration of autologous growth factors and cytokines and is currently widely used in the clinical setting for tissue regeneration and repair. PRP has great potential to stimulate cell proliferation and metabolic activity of IVD cells in vitro. Several animal studies have shown that the injection of PRP into degenerated IVDs is effective in restoring structural changes (IVD height) and improving the matrix integrity of degenerated IVDs as evaluated by magnetic resonance imaging (MRI) and histology. The results of this basic research have shown the great possibility that PRP has significant biological effects for tissue repair to counteract IVD degeneration. Clinical studies for evaluating the effects of the injection of PRP into degenerated IVDs for patients with discogenic LBP have been reviewed. Although there was only one double-blind randomized controlled trial, all the studies reported that PRP was safe and effective in reducing back pain. While the clinical evidence of tissue repair of IVDs by PRP treatment is currently lacking, there is a great possibility that the application of PRP has the potential to lead to a feasible intradiscal therapy for the treatment of degenerative disc diseases. Further large-scale studies may be required to confirm the clinical evidence of PRP for the treatment of discogenic LBP.

There is no consensus on an optimal treatment after daily teriparatide (TPTD). We performed a prospective, randomized, open‐label, 12‐month trial to investigate the efficacy of follow‐up treatment after daily TPTD treatment for Japanese patients. Three‐hundred patients were enrolled in this study. Patients received oral bisphosphonate (BP) including alendronate (ALN; 35 mg/week) and minodoronate (MINO; 50 mg/month), or subcutaneous denosumab (60 mg/6 month). The primary efficacy measure was bone mineral density (BMD) responses in the lumbar spine (LS) and femoral neck (FN). Lumbar spine BMD increased by 1.3 ± 5.1% in the ALN subgroups, 0.5 ± 4.6% in the MINO subgroups, and 4.3 ± 3.5% in the denosumab subgroups. Femoral neck BMD increased by 0.7 ± 4.6% in the ALN subgroups, 0.2 ± 4.6% in the MINO subgroups, and 1.4 ± 3.4% in the denosumab subgroups. Lumbar spine BMD increases were significantly greater in the denosumab subgroup than the BP subgroups. There were no significant differences in FN BMD increases among the three subgroups. Lumbar spine BMD increases were significantly greater in the denosumab subgroup than the BP subgroups, whereas FN BMD increases were not significant. Denosumab treatment was more effective in increasing BMD and therefore has the potential benefit of fracture prevention. Further research is warranted to determine the optimal treatment after daily TPTD. © 2018 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

Idiopathic osteonecrosis of the femoral head (IONFH) is an ischemic disorder that causes bone necrosis of the femoral head, resulting in hip joint dysfunction. IONFH is a polygenic disease and steroid and alcohol have already known to increase its risk; however, the mechanism of IONFH remains to be elucidated. We performed a genome-wide association study using ~60, 000 subjects and found two novel loci on chromosome 20q12 and 12q24. Big data analyses identified LINC01370 as a candidate susceptibility gene in the 20q12 locus. Stratified analysis by IONFH risk factors suggested that the 12q24 locus was associated with IONFH through drinking capacity. Our findings would shed new light on pathophysiology of IONFH.

Data for 14 patients. Abbreviations: M, male; F, female; ND, not documented; SNHL, sensorineural hearing loss; POD, postoperative day. (PPTX 52 kb)

Among stress fractures associated with sports activities, patellar stress fracture is rare. Regarding patella stress fractures, so far only distal transverse or lateral longitudinal fractures have been reported, but there are no reports of transverse fractures occurring in the proximal patella. We describe an extremely rare case of transverse stress fracture of proximal patella in a 9-year-old athlete. A 9-year old boy, who participated in sports (sprints and Kendo) presented with left knee pain without any external injury. In plain radiographs, a fracture line was observed in the proximal 1/3 of the left patella, and a patella stress fracture was diagnosed. For treatment, because 7 months of conservative therapy showed no improvement, internal fixation was carried out using Acutrak screws, and bone union was thus achieved. Three months after the operation, he was able to return to his previous level of athletic sports activity. Regarding the mechanism of onset, it is believed that the causes are longitudinal traction force and patellofemoral contact pressure. On the other hand, the contact region of the patella with the femur changes with the flexion angle of the knee. In the current case, the fracture occurred at a site where the patella was in contact with the femur at a flexion angle of >90°, so it is believed that it occurred as a clinical condition from being subjected to repeated longitudinal traction force and patellofemoral contact pressure at a flexion angle of >90°, during the sports activities of sprints and Kendo. The nonunion of the transverse stress fracture of his proximal patella was successfully treated with internal fixation using Acutrak screws.

Tomoki Nakamura, Akihiko Matsumine, Akihiro Sudo Department of Orthopaedic Surgery, Mie University Graduate School of Medicine, Mie, Japan Abstract: Soft tissue sarcomas (STSs) are a group of rare tumors accounting for less than 1% of all adult malignant tumors, a heterogeneous group of more than 50 histological subtypes. Five percent to 30% of STS patients experience local recurrence and 10%–38% present with clinically detectable metastases. Doxorubicin either alone or in combination with ifosfamide has been used as first-line chemotherapy for advanced disease. After failure of first-line chemotherapy, high-dose ifosfamide, gemcitabine + docetaxel, and dacarbazine may be applicable, although high-level evidence is lacking. Trabectedin is a synthetic, marine-derived alkylating agent derived from the Caribbean tunicate, Ecteinascidia turbinata. Several clinical trials have shown that trabectedin has a favorable toxicity profile and is an alternative therapeutic option in adult patients with advanced STS who have not responded to treatment with doxorubicin and ifosfamide. Several clinical trials also recommend the 24-hour intravenous infusion every 3weeks regimen. The most frequently reported grade 3/4 adverse events were neutropenia and elevated serum levels of AST/ALT. Steroid pretreatment is an effective way of reducing the extent of hepatotoxicity, and steroids are now given routinely before trabectedin administration. Further studies are ongoing to evaluate the efficacy and safety of combination therapy of trabectedin with other agents. Keywords: trabectedin, soft tissue sarcoma, efficacy, safety

We describe entrapment of the common peroneal nerve by a suture after surgical repair of the distal biceps femoris tendon. Complete rupture of the distal biceps femoris tendon of a 16-year-old male athlete was surgically repaired. Postoperative common peroneal nerve palsy was evident, but conservative treatment did not cause any neurological improvement. Reexploration revealed that the common peroneal nerve was entrapped by the surgical suture. Complete removal of the suture and external neurolysis significantly improved the palsy. The common peroneal nerve is prone to damage as a result of its close proximity to the biceps femoris tendon and it should be identified during surgical repair of a ruptured distal biceps femoris tendon.

A 25-year-old man with a pronation-external rotation type of fracture was surgically treated using a fibular plate. Five years later, he underwent resection of bone hyperplasia because of the ankle pain and limitation of range of motion. Thereafter, the left ankle became intermittently painful, which persisted for about one year. He presented at the age of 43 with persistent ankle pain. Physical and image analysis findings indicated a diagnosis of posttraumatic posterior tibial tendinitis, which we surgically treated using tendoscopy. Endoscopic findings showed tenosynovitis and fibrillation on the tendon surface. We cleaned and removed the synovium surrounding the tendon and deepened the posterior tibial tendon groove to allow sufficient space for the posterior tibial tendon. Full weight-bearing ambulation was permitted one day after surgery and he returned to his occupation in the construction industry six weeks after surgery. The medial aspect of the ankle was free of pain and symptoms at a review two years after surgery. Although tendoscopic surgery for stage 1 posterior tibial tendon dysfunction has been reported, tendoscopic surgery to treat posttraumatic posterior tibial tendinitis has not. Our experience with this patient showed that tendoscopic surgery is useful not only for stage 1 posterior tibial dysfunction, but also for posttraumatic posterior tibial tendinitis.

We report an extremely rare case of double-layered lateral meniscus accompanied by meniscocapsular separation. The upper accessory meniscus was connected with the posterior horn and middle segment of the lower normal meniscus and was more mobile than the lower normal meniscus. A meniscocapsular separation was evident at the overlapping middle segment. Clinical symptoms were significantly improved by the resection of the upper accessory meniscus and the repair of the meniscocapsular separation. Careful arthroscopic analysis of other associated pathologies together with this rare abnormality was needed to achieve clinical improvement.

We presented a very rare case of adult Fielding type I atlantoaxial rotatory fixation (AARF). We performed awake manual reduction of the dislocation without need for anesthesia, achieving excellent outcomes, and no previous reports have described awake reduction without the need for anesthesia. AARF in this case was attributed to excessive extension and rotation forces applied to the cervical spine. For the management of adult Fielding type I AARF, early diagnosis and early reduction may lead to excellent outcomes.

As a matter of fact, the in vivo oxidative degradation of highly cross-linked polyethylene (HXLPE) still remains one of the limiting factors that affect the long term survivorship of joint replacements. Recent studies clearly pointed out that also the new generation of highly cross-linked and remelted polyethylene components in total hip and knee replacement underwent unexpected oxidation after 5–10 years of implantation. The standard methodology to investigate the oxidation of polyethylene (PE) relies on the use of infrared spectroscopy, which, if from one hand is a reliable technique for the detection of oxidized species containing carbonyl group, on the other hand it is not capable of discriminating the fraction of carboxyl acids that is responsible for chain scission and subsequent deterioration of the mechanical properties of the polymer. In the present study we validate a new protocol based on Raman spectroscopy, which is suitable on assessing the structural degradation of polyethylene induced by oxidation. Following in vitro accelerated aging experiments, the oxidation index ( OI ) of different commercially available HXLPEs, as calculated by infrared spectroscopy according to ASTM standard, has been univocally correlated to the most severe variation of crystalline phase ( α c ), as calculated by Raman spectroscopy. In each material, locations with equal values of OI showed different degree of recrystallization induced by chain scission, confirming that infrared spectroscopy might overestimate the effective mechanical degradation of the polymer. In addition, as compared to the standards based on infrared spectroscopy, this new method of assessing oxidation enables to investigate the degradation occurring on the original surface of HXLPE components, due to the nondestructive nature of Raman spectroscopy and its high spatial resolution. Statement of Significance In the present study we validate a new protocol based on Raman spectroscopy, which is suitable on assessing the structural degradation of polyethylene induced by oxidation. In fact, the standard methodology to investigate the oxidation in polyethylene relies on the use of infrared spectroscopy, which is capable of detecting the presence of oxidized species containing carbonyl group, the main products of oxidation in polyolefins. If from one hand this technique enables quantitative analysis of oxidation, on the other hand it is not capable of discriminating the fraction of species with carbonyl groups responsible for the chain scission. In fact, esters, ketones and carboxyl acids are products of oxidation with carbonyl groups commonly formed on polyethylene at the end of the oxidative cascade initiated by the presence of free radicals, but only the latter are responsible for the chain scission and the subsequent deterioration of the mechanical properties. The oxidation index as obtained according to the ASTM standards is not univocally correlated to a certain degree of mechanical deterioration, but, in simple words, two retrievals with the same amount of carbonyl groups might have had different degradation of the mechanical properties. Recrystallization is a direct consequence of the reduction of molecular weight that occurs after chain scission. Raman spectroscopy (RS) is a viable non-destructive method to assess the fraction of crystalline phase in polyethylene and, due to its high spatial resolution, is perfectly suitable to analyze the microstructural modification at the mesoscopic scale, where the effects of oxidation manifest themselves. The aim of the present paper is twofold: i) to compare the microstructural modifications caused by in vitro oxidation on 5 different types of polyethylene currently available on the market of joint replacements; ii) to establish a protocol based on the comparative analysis of IR and RS results to obtain a phenomenological correlation capable to judge the mechanical deterioration of the material induced by the oxidative degradation.

Although limb salvage surgery involving wide resection and limb reconstruction for musculoskeletal sarcomas is well established for low risk of local tumor recurrence, limb function is unsatisfactory for many patients because of the disability in active athletics such as running, jumping, throwing, swimming etc. To avoid poor limb function caused by surgery, it is important to preserve normal nerves, vessels, bones, joints and muscles adjacent to tumor as possible as we can, supported by effective adjuvant therapy to inhibit local tumor recurrence. To develop minimally-invasive limb salvage surgery with minimal damage of normal tissues and low risk of local recurrence, we have recently established a new limb salvage modality of acridine orange (AO) therapy (AOT) based on photodynamic surgery (PDS), photodynamic therapy (PDT) and radiodynamic therapy (RDT) using AO in patients with high-grade malignant musculoskeletal sarcoma. Clinical outcomes of the study showed that: 1) low risk of local recurrence which is almost the same as that with conventional wide resection, and 2) superior limb function to that by wide resection. In this chapter, we present mechanisms of cytocidal effects of AOT based on experimental research and clinical outcome of AOT applied to musculoskeletal sarcoma patients. © 2012 by Nova Science Publishers, Inc. All Rights Reserved.