Matthew Dicaprio - Academia.edu (original) (raw)

Papers by Matthew Dicaprio

The Journal of Arthroplasty

JBJS Case Connector

Case: We describe a case of biopsy-proven blastomycosis in a patient residing in Upstate New York... more Case: We describe a case of biopsy-proven blastomycosis in a patient residing in Upstate New York with osseous and skin lesions and no pulmonary or constitutional symptoms. The patient had a rapid resolution of symptoms after the initiation of antifungal treatment, followed by curettage and cementation of her distal femoral lesion. Conclusions: Orthopaedic surgeons should be aware of the presence of blastomycosis in nonendemic areas, especially since bone involvement may be the predominant manifestation. Tissue should be submitted for both histologic and microbiologic analysis. Antifungal therapy and surgical management if needed can result in a good outcome.

Annals of Joint, 2021

More than 17 million Americans living today have a history of cancer and an additional 1.8 millio... more More than 17 million Americans living today have a history of cancer and an additional 1.8 million new cancer cases are expected to be diagnosed in 2020 (3,4). By January 1, 2030, it is estimated that the population of people with a history of cancer will increase to more than 22.1 million (Figure 1) (4). As patients with cancer live longer, the incidence of metastatic bone disease (MBD) is also increasing, however accurate figures are not readily available for how many of these patients will develop skeletal metastases. The management of patients with MBD is complex and requires the utilization of various resources. Here, we review the epidemiology of MBD and the profound effects it has on patients, caregivers, society and the economy. We present the following article in accordance with the Narrative Review checking checklist

Instructional course lectures, 2019

Management of a painful metastatic acetabular lesion is complex and requires the assessment of tu... more Management of a painful metastatic acetabular lesion is complex and requires the assessment of tumor size and location, remaining integrity of the acetabulum, analgesic requirements, ability to use postoperative radiation, and projected patient survival. Patients presenting with suspected periacetabular metastasis frequently have groin pain aggravated by weight bearing. After a complete physical examination, advanced imaging and a complete laboratory workup should be performed to assess the extent of local and systemic disease. If a patient has a previously identified metastatic lesion, it is beneficial to communicate with the patient's medical oncologist to gather information on responses to chemotherapeutic agents, hormonal agents, and radiation therapy. Management may be nonsurgical, interventional, or surgical. Despite the limited life expectancy of patients with periacetabular metastasis, when performed in the appropriate setting, reconstruction by using anti-protrusio cage...

Clinical Orthopaedics & Related Research, 2021

Abstract Background Metformin, an oral drug used to treat patients with diabetes, has been associ... more Abstract Background Metformin, an oral drug used to treat patients with diabetes, has been associated with prolonged survival in patients with various visceral carcinomas. Although the exact mechanisms are unknown, preclinical translational studies demonstrate that metformin may impair tumor cellular metabolism, alter matrix turnover, and suppress oncogenic signaling pathways. Currently used chemotherapeutic agents have not been very successful in the adjuvant setting or for treating patients with metastatic sarcomas. We wanted to know whether metformin might be associated with improved survival in patients with a soft tissue sarcoma. Questions/purposes In patients treated for a soft tissue sarcoma, we asked: (1) Is there an association between metformin use and longer survival? (2) How does this association differ, if at all, among patients with and without the diagnosis of diabetes? Methods The Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database was used to identify patients with a diagnosis of soft tissue sarcoma from 2007 to 2016. Concomitant medication use was identified using National Drug Codes using the Medicare Part D event files. This database was chosen because of the large number of captured sarcoma patients, availability of tumor characteristics, and longitudinal linkage of Medicare data. A total of 14,650 patients were screened for inclusion. Patients with multiple malignancies, diagnosis at autopsy, or discrepant linkage to the Medicare database were excluded. Overall, 4606 patients were eligible for the study: 598 patients taking metformin and 4008 patients not taking metformin. A hazard of mortality (hazard ratio) was analyzed comparing patients taking metformin with those patient groups not taking metformin and expressed in terms of a 95% confidence interval. Cox regression analysis was used to control for patient-specific, disease-specific, and treatment-specific covariates. Results Having adjusted for disease-, treatment-, and patient-specific characteristics, patients taking metformin experienced prolonged survival compared with all patients not taking metformin (HR 0.76 [95% CI 0.66 to 0.87]). Associated prolonged survival was also seen when patients taking metformin were compared with those patients not on metformin irrespective of a diabetes diagnosis (HR 0.79 [95% CI 0.66 to 0.94] compared with patients with a diagnosis of diabetes and HR 0.77 [95% CI 0.67 to 0.89] compared with patients who did not have a diagnosis of diabetes). Conclusion Without suggesting causation, we found that even after controlling for confounding variables such as Charlson comorbidity index, tumor grade, size, stage, and surgical/radiation treatment modalities, there was an association between metformin use and increased survival in patients with soft tissue sarcoma. When considered separately, this association persisted in patients not on metformin with and without a diabetes diagnosis. Although metformin is not normally prescribed to patients who do not have a diabetes diagnosis, these data support further study, and if these findings are substantiated, it might lead to the performance of multicenter, prospective clinical trials about the use of metformin as an adjuvant therapy for the treatment of soft tissue sarcoma in patients with and without a preexisting diabetes diagnosis. Level of Evidence Level III, therapeutic study.

JBJS Reviews, 2021

» A small yet growing subset of total joint arthroplasty (TJA) candidates are diagnosed with the ... more » A small yet growing subset of total joint arthroplasty (TJA) candidates are diagnosed with the hepatitis C virus (HCV), which is a known risk factor for periprosthetic joint infections. Given the poor outcomes associated with TJA infection, we recommend that candidates with HCV receive treatment prior to elective TJA. » Interferon and ribavirin have historically been the standard treatment regimen for the management of HCV; however, adverse events and an inconsistent viral response have limited the efficacy of these therapies. The advent of direct-acting antivirals has resolved many of the issues associated with interferon and ribavirin regimens. » Despite the success of direct-acting antivirals, there are still barriers to seeking treatment for TJA candidates with HCV. Many patients are faced with financial burdens, as insurance coverage of direct-acting antiviral therapies is inconsistent and varies by the patient's state of residence and specific treatment regimen. » TJA candidates with HCV present health-care providers with a unique set of challenges, often encompassing economic, psychosocial, and complex medical concerns. Multidisciplinary care teams can be beneficial when caring for and optimizing this patient cohort. » Management of HCV prior to elective TJA is associated with higher up-front costs but ultimately reduces long-term patient morbidity as well as associated direct and indirect health-care expenditures.

The Journal of Bone & Joint Surgery, 2004

Background: Orthopaedic residency programs lack gender and race diversity. This study examines th... more Background: Orthopaedic residency programs lack gender and race diversity. This study examines the hypothesis that exposure to a required course in musculoskeletal medicine in medical school is associated with a higher rate of application to orthopaedic surgery residency programs by underrepresented groups. Methods: All 122 medical schools in the United States were surveyed in 2001 to determine whether they required dedicated course work in musculoskeletal medicine, defined as a preclinical module or clinical clerkship in orthopaedic surgery, rheumatology, or physiatry. Data from the Electronic Residency Application Service were obtained for the class of 2002. From these two sources, the rate of applications from students to orthopaedic surgery residency programs was calculated as a function of exposure to a required course in musculoskeletal medicine. Subgroup analysis was further carried out for women and for African Americans, Latinos, and Native Americans.

Journal of the American Academy of Orthopaedic Surgeons, 2014

Langerhans cell histiocytosis is a rare group of disorders without a well-understood etiology. Kn... more Langerhans cell histiocytosis is a rare group of disorders without a well-understood etiology. Known formerly as histiocytosis X, the disease has a wide spectrum of clinical presentations, including eosinophilic granuloma (solitary bone lesion), diabetes insipidus, and exophthalmos. It is also known by several eponyms, including Hand-Schüller-Christian disease when it manifests as a triad of cranial bone lesions and Letterer-Siwe disease when it is found in infantile patients with severely disseminated disease. Children aged 5 to 15 years are most commonly affected. Many of these patients initially present to orthopaedic surgeons, and misdiagnosis is frequent. To accurately diagnosis and treat these patients, the orthopaedic surgeon must be familiar with the clinical manifestations and pathophysiology of the disease as well as the treatment guidelines and outcomes for Langerhans cell histiocytosis.

Techniques in Orthopaedics, 2007

Hepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. Percutaneous rad... more Hepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. Percutaneous radiofrequency ablation (RFA) for HCC was introduced in Japan in 1999. It has been established as a major local treatment method worldwide including in Japan. On comparing outcomes between resection and RFA, they were comparable when cases were limited to those with 3 or fewer tumors of size 3 cm or smaller in many reports, based on which RFA has become the main treatment for small HCCs. RFA was introduced into our system at Toho University Medical Center Omori Hospital in 1999, and we treat nearly 200 HCC cases annually with RFA. Although individual medical facilities use their own methods of RFA, we would like to share our experience of RFA treatment protocols. Contents

Orthopaedic Nursing, 1984

Comparing cost and outcome between teaching and non-teaching hospitals for orthopaedic procedures... more Comparing cost and outcome between teaching and non-teaching hospitals for orthopaedic procedures. Poster No. 227.

Clinical Orthopaedics and Related Research, 2005

Each author certifies that he has no commercial associations (eg, consultancies, stock ownership,... more Each author certifies that he has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Each author certifies that his institution has approved the reporting of this case report, that all investigations were conducted in conformity with ethical principles of research, and that informed consent was obtained.

Introduction: Metastatic bone cancer occurs in the long bones of the body in 2/3 of all breast an... more Introduction: Metastatic bone cancer occurs in the long bones of the body in 2/3 of all breast and lung cancer patients and in 1/3 of all thyroid and kidney patients. Current treatments are highly invasive often resulting in amputation or in partial removal of the joint via megaprosthesis. Less invasive limb salvage procedures can be attempted using an allograft to treat the segmental bone defect; however allografts are structurally weak, may lead to disease transfer and/or rejection of the foreign tissue, and have slow incorporation rates with native tissue, often leading to failure. Additive manufacturing (aka 3D Printing) can be used to fabricate porous, titanium alloy implants to treat the segmental bone defect; however, geometric and mechanical differences between the implant's design and what is actually fabricated are not entirely clear. In other words, implants can be designed using computer-aided design (CAD) software with material properties that are predicted using finite element analyses (FEA), but what is actually being fabricated by the 3D printer? In this study, a porous, titanium alloy (Ti-6Al-4V) implant was developed to treat a segmental bone defect in the mid-diaphysis of a cancerous femur. Mechanical properties were optimized using finite element analysis so that the effective elastic modulus was equivalent to cortical bone and stresses were below the endurance limit of Ti-6Al-4V during physiologic loading. The implant was then fabricated using direct metal laser sintering (DMLS) and the geometric and mechanical properties were experimentally tested to validate the computational model. Methods: Implant Design: Computed tomography (CT) scans were taken of a patient containing a middiaphyseal lesion in the left femur. CT data were brought into medical imaging software (Materialise, Leuven, Belgium) and segmentation was applied to isolate bony tissue. A "virtual surgery" was conducted to remove the diseased tissue including appropriate proximal and distal margins. The femur, including the 15cm segmental bone defect, was then brought into CAD (SolidWorks, Waltham, MA, USA) and a patient-specific implant was designed to fit the defect. Pore Optimization: Finite element analyses (SolidWorks Simulation, Waltham, MA, USA) was used to assess the effects of pore shape, pore orientation, and overall porosity on a Ti-6Al-4V implant under physiologic load magnitudes. In all studies, titanium alloy (Ti-6Al-4V) properties were applied to the implant, the distal portion of the implant was fixed in plane, and an axial force of 1500N was applied. Peak stresses and the effective elastic moduli were measured for three different pore shapes (circular, square, and triangular) of equal cross-sectional area and pore quantity, as well as three different pore orientations: axial only, transverse only, and combined axial and transverse in 3 orthogonal directions. Overall stress distributions were also characterized. Pore density was increased until the modulus of the implant reached that of cortical bone (10-21 GPa). Experimental Validation: Based on the optimized computational design, an implant was fabricated using Direct Metal Laser Sintering (Figure 1). Mass and bulk volume measurements of the fabricated implant were taken and compared to the predicted values from the computational model. Scanning electron microscopy (SEM) was used to characterize the pore diameters in the transverse

Trials

Background Limb salvage with endoprosthetic reconstruction is the current standard practice for t... more Background Limb salvage with endoprosthetic reconstruction is the current standard practice for the surgical management of lower extremity bone tumors in skeletally mature patients and typically includes tumor resection followed by the functional limb reconstruction with modular metallic and polyethylene endoprosthetic implants. However, owing to the complexity and length of these procedures, as well as the immunocompromised nature of patients treated with chemotherapy, the risk of surgical site infection (SSI) is high. The primary research objective of the Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial is to assess whether a 5-day regimen of post-operative antibiotics decreases the risk of SSI at 1 year post-operatively compared to a 1-day regimen. This article describes the statistical analysis plan for the PARITY trial. Methods/design The PARITY trial is an ongoing multi-center, blinded parallel two-arm randomized controlled trial (RCT) of 600 participants who h...

JAAOS: Global Research and Reviews

Journal of the American Academy of Orthopaedic Surgeons

The Journal of Arthroplasty

Techniques in Orthopaedics

The Journal of Arthroplasty

JBJS Case Connector

Case: We describe a case of biopsy-proven blastomycosis in a patient residing in Upstate New York... more Case: We describe a case of biopsy-proven blastomycosis in a patient residing in Upstate New York with osseous and skin lesions and no pulmonary or constitutional symptoms. The patient had a rapid resolution of symptoms after the initiation of antifungal treatment, followed by curettage and cementation of her distal femoral lesion. Conclusions: Orthopaedic surgeons should be aware of the presence of blastomycosis in nonendemic areas, especially since bone involvement may be the predominant manifestation. Tissue should be submitted for both histologic and microbiologic analysis. Antifungal therapy and surgical management if needed can result in a good outcome.

Annals of Joint, 2021

More than 17 million Americans living today have a history of cancer and an additional 1.8 millio... more More than 17 million Americans living today have a history of cancer and an additional 1.8 million new cancer cases are expected to be diagnosed in 2020 (3,4). By January 1, 2030, it is estimated that the population of people with a history of cancer will increase to more than 22.1 million (Figure 1) (4). As patients with cancer live longer, the incidence of metastatic bone disease (MBD) is also increasing, however accurate figures are not readily available for how many of these patients will develop skeletal metastases. The management of patients with MBD is complex and requires the utilization of various resources. Here, we review the epidemiology of MBD and the profound effects it has on patients, caregivers, society and the economy. We present the following article in accordance with the Narrative Review checking checklist

Instructional course lectures, 2019

Management of a painful metastatic acetabular lesion is complex and requires the assessment of tu... more Management of a painful metastatic acetabular lesion is complex and requires the assessment of tumor size and location, remaining integrity of the acetabulum, analgesic requirements, ability to use postoperative radiation, and projected patient survival. Patients presenting with suspected periacetabular metastasis frequently have groin pain aggravated by weight bearing. After a complete physical examination, advanced imaging and a complete laboratory workup should be performed to assess the extent of local and systemic disease. If a patient has a previously identified metastatic lesion, it is beneficial to communicate with the patient's medical oncologist to gather information on responses to chemotherapeutic agents, hormonal agents, and radiation therapy. Management may be nonsurgical, interventional, or surgical. Despite the limited life expectancy of patients with periacetabular metastasis, when performed in the appropriate setting, reconstruction by using anti-protrusio cage...

Clinical Orthopaedics & Related Research, 2021

Abstract Background Metformin, an oral drug used to treat patients with diabetes, has been associ... more Abstract Background Metformin, an oral drug used to treat patients with diabetes, has been associated with prolonged survival in patients with various visceral carcinomas. Although the exact mechanisms are unknown, preclinical translational studies demonstrate that metformin may impair tumor cellular metabolism, alter matrix turnover, and suppress oncogenic signaling pathways. Currently used chemotherapeutic agents have not been very successful in the adjuvant setting or for treating patients with metastatic sarcomas. We wanted to know whether metformin might be associated with improved survival in patients with a soft tissue sarcoma. Questions/purposes In patients treated for a soft tissue sarcoma, we asked: (1) Is there an association between metformin use and longer survival? (2) How does this association differ, if at all, among patients with and without the diagnosis of diabetes? Methods The Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database was used to identify patients with a diagnosis of soft tissue sarcoma from 2007 to 2016. Concomitant medication use was identified using National Drug Codes using the Medicare Part D event files. This database was chosen because of the large number of captured sarcoma patients, availability of tumor characteristics, and longitudinal linkage of Medicare data. A total of 14,650 patients were screened for inclusion. Patients with multiple malignancies, diagnosis at autopsy, or discrepant linkage to the Medicare database were excluded. Overall, 4606 patients were eligible for the study: 598 patients taking metformin and 4008 patients not taking metformin. A hazard of mortality (hazard ratio) was analyzed comparing patients taking metformin with those patient groups not taking metformin and expressed in terms of a 95% confidence interval. Cox regression analysis was used to control for patient-specific, disease-specific, and treatment-specific covariates. Results Having adjusted for disease-, treatment-, and patient-specific characteristics, patients taking metformin experienced prolonged survival compared with all patients not taking metformin (HR 0.76 [95% CI 0.66 to 0.87]). Associated prolonged survival was also seen when patients taking metformin were compared with those patients not on metformin irrespective of a diabetes diagnosis (HR 0.79 [95% CI 0.66 to 0.94] compared with patients with a diagnosis of diabetes and HR 0.77 [95% CI 0.67 to 0.89] compared with patients who did not have a diagnosis of diabetes). Conclusion Without suggesting causation, we found that even after controlling for confounding variables such as Charlson comorbidity index, tumor grade, size, stage, and surgical/radiation treatment modalities, there was an association between metformin use and increased survival in patients with soft tissue sarcoma. When considered separately, this association persisted in patients not on metformin with and without a diabetes diagnosis. Although metformin is not normally prescribed to patients who do not have a diabetes diagnosis, these data support further study, and if these findings are substantiated, it might lead to the performance of multicenter, prospective clinical trials about the use of metformin as an adjuvant therapy for the treatment of soft tissue sarcoma in patients with and without a preexisting diabetes diagnosis. Level of Evidence Level III, therapeutic study.

JBJS Reviews, 2021

» A small yet growing subset of total joint arthroplasty (TJA) candidates are diagnosed with the ... more » A small yet growing subset of total joint arthroplasty (TJA) candidates are diagnosed with the hepatitis C virus (HCV), which is a known risk factor for periprosthetic joint infections. Given the poor outcomes associated with TJA infection, we recommend that candidates with HCV receive treatment prior to elective TJA. » Interferon and ribavirin have historically been the standard treatment regimen for the management of HCV; however, adverse events and an inconsistent viral response have limited the efficacy of these therapies. The advent of direct-acting antivirals has resolved many of the issues associated with interferon and ribavirin regimens. » Despite the success of direct-acting antivirals, there are still barriers to seeking treatment for TJA candidates with HCV. Many patients are faced with financial burdens, as insurance coverage of direct-acting antiviral therapies is inconsistent and varies by the patient's state of residence and specific treatment regimen. » TJA candidates with HCV present health-care providers with a unique set of challenges, often encompassing economic, psychosocial, and complex medical concerns. Multidisciplinary care teams can be beneficial when caring for and optimizing this patient cohort. » Management of HCV prior to elective TJA is associated with higher up-front costs but ultimately reduces long-term patient morbidity as well as associated direct and indirect health-care expenditures.

The Journal of Bone & Joint Surgery, 2004

Background: Orthopaedic residency programs lack gender and race diversity. This study examines th... more Background: Orthopaedic residency programs lack gender and race diversity. This study examines the hypothesis that exposure to a required course in musculoskeletal medicine in medical school is associated with a higher rate of application to orthopaedic surgery residency programs by underrepresented groups. Methods: All 122 medical schools in the United States were surveyed in 2001 to determine whether they required dedicated course work in musculoskeletal medicine, defined as a preclinical module or clinical clerkship in orthopaedic surgery, rheumatology, or physiatry. Data from the Electronic Residency Application Service were obtained for the class of 2002. From these two sources, the rate of applications from students to orthopaedic surgery residency programs was calculated as a function of exposure to a required course in musculoskeletal medicine. Subgroup analysis was further carried out for women and for African Americans, Latinos, and Native Americans.

Journal of the American Academy of Orthopaedic Surgeons, 2014

Langerhans cell histiocytosis is a rare group of disorders without a well-understood etiology. Kn... more Langerhans cell histiocytosis is a rare group of disorders without a well-understood etiology. Known formerly as histiocytosis X, the disease has a wide spectrum of clinical presentations, including eosinophilic granuloma (solitary bone lesion), diabetes insipidus, and exophthalmos. It is also known by several eponyms, including Hand-Schüller-Christian disease when it manifests as a triad of cranial bone lesions and Letterer-Siwe disease when it is found in infantile patients with severely disseminated disease. Children aged 5 to 15 years are most commonly affected. Many of these patients initially present to orthopaedic surgeons, and misdiagnosis is frequent. To accurately diagnosis and treat these patients, the orthopaedic surgeon must be familiar with the clinical manifestations and pathophysiology of the disease as well as the treatment guidelines and outcomes for Langerhans cell histiocytosis.

Techniques in Orthopaedics, 2007

Hepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. Percutaneous rad... more Hepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. Percutaneous radiofrequency ablation (RFA) for HCC was introduced in Japan in 1999. It has been established as a major local treatment method worldwide including in Japan. On comparing outcomes between resection and RFA, they were comparable when cases were limited to those with 3 or fewer tumors of size 3 cm or smaller in many reports, based on which RFA has become the main treatment for small HCCs. RFA was introduced into our system at Toho University Medical Center Omori Hospital in 1999, and we treat nearly 200 HCC cases annually with RFA. Although individual medical facilities use their own methods of RFA, we would like to share our experience of RFA treatment protocols. Contents

Orthopaedic Nursing, 1984

Comparing cost and outcome between teaching and non-teaching hospitals for orthopaedic procedures... more Comparing cost and outcome between teaching and non-teaching hospitals for orthopaedic procedures. Poster No. 227.

Clinical Orthopaedics and Related Research, 2005

Each author certifies that he has no commercial associations (eg, consultancies, stock ownership,... more Each author certifies that he has no commercial associations (eg, consultancies, stock ownership, equity interest, patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article. Each author certifies that his institution has approved the reporting of this case report, that all investigations were conducted in conformity with ethical principles of research, and that informed consent was obtained.

Introduction: Metastatic bone cancer occurs in the long bones of the body in 2/3 of all breast an... more Introduction: Metastatic bone cancer occurs in the long bones of the body in 2/3 of all breast and lung cancer patients and in 1/3 of all thyroid and kidney patients. Current treatments are highly invasive often resulting in amputation or in partial removal of the joint via megaprosthesis. Less invasive limb salvage procedures can be attempted using an allograft to treat the segmental bone defect; however allografts are structurally weak, may lead to disease transfer and/or rejection of the foreign tissue, and have slow incorporation rates with native tissue, often leading to failure. Additive manufacturing (aka 3D Printing) can be used to fabricate porous, titanium alloy implants to treat the segmental bone defect; however, geometric and mechanical differences between the implant's design and what is actually fabricated are not entirely clear. In other words, implants can be designed using computer-aided design (CAD) software with material properties that are predicted using finite element analyses (FEA), but what is actually being fabricated by the 3D printer? In this study, a porous, titanium alloy (Ti-6Al-4V) implant was developed to treat a segmental bone defect in the mid-diaphysis of a cancerous femur. Mechanical properties were optimized using finite element analysis so that the effective elastic modulus was equivalent to cortical bone and stresses were below the endurance limit of Ti-6Al-4V during physiologic loading. The implant was then fabricated using direct metal laser sintering (DMLS) and the geometric and mechanical properties were experimentally tested to validate the computational model. Methods: Implant Design: Computed tomography (CT) scans were taken of a patient containing a middiaphyseal lesion in the left femur. CT data were brought into medical imaging software (Materialise, Leuven, Belgium) and segmentation was applied to isolate bony tissue. A "virtual surgery" was conducted to remove the diseased tissue including appropriate proximal and distal margins. The femur, including the 15cm segmental bone defect, was then brought into CAD (SolidWorks, Waltham, MA, USA) and a patient-specific implant was designed to fit the defect. Pore Optimization: Finite element analyses (SolidWorks Simulation, Waltham, MA, USA) was used to assess the effects of pore shape, pore orientation, and overall porosity on a Ti-6Al-4V implant under physiologic load magnitudes. In all studies, titanium alloy (Ti-6Al-4V) properties were applied to the implant, the distal portion of the implant was fixed in plane, and an axial force of 1500N was applied. Peak stresses and the effective elastic moduli were measured for three different pore shapes (circular, square, and triangular) of equal cross-sectional area and pore quantity, as well as three different pore orientations: axial only, transverse only, and combined axial and transverse in 3 orthogonal directions. Overall stress distributions were also characterized. Pore density was increased until the modulus of the implant reached that of cortical bone (10-21 GPa). Experimental Validation: Based on the optimized computational design, an implant was fabricated using Direct Metal Laser Sintering (Figure 1). Mass and bulk volume measurements of the fabricated implant were taken and compared to the predicted values from the computational model. Scanning electron microscopy (SEM) was used to characterize the pore diameters in the transverse

Trials

Background Limb salvage with endoprosthetic reconstruction is the current standard practice for t... more Background Limb salvage with endoprosthetic reconstruction is the current standard practice for the surgical management of lower extremity bone tumors in skeletally mature patients and typically includes tumor resection followed by the functional limb reconstruction with modular metallic and polyethylene endoprosthetic implants. However, owing to the complexity and length of these procedures, as well as the immunocompromised nature of patients treated with chemotherapy, the risk of surgical site infection (SSI) is high. The primary research objective of the Prophylactic Antibiotic Regimens In Tumor Surgery (PARITY) trial is to assess whether a 5-day regimen of post-operative antibiotics decreases the risk of SSI at 1 year post-operatively compared to a 1-day regimen. This article describes the statistical analysis plan for the PARITY trial. Methods/design The PARITY trial is an ongoing multi-center, blinded parallel two-arm randomized controlled trial (RCT) of 600 participants who h...

JAAOS: Global Research and Reviews

Journal of the American Academy of Orthopaedic Surgeons

The Journal of Arthroplasty

Techniques in Orthopaedics