MRI T2 mapping assessment of T2 relaxation time in desmoid tumors as a quantitative imaging biomarker of tumor response: preliminary results

Objectives

Because size-based imaging criteria poorly capture biologic response in desmoid-type fibromatosis (DF), changes in MRI T2 signal intensity are frequently used as a response surrogate, but remain qualitative. We hypothesized that absolute quantification of DF T2 relaxation time derived from parametric T2 maps would be a feasible and effective imaging biomarker of disease activity.

Methods

This IRB-approved retrospective study included 11 patients with DF, managed by observation or systemic therapy, assessed by 3T MRI. Tumor maximum diameter, volume, and T2-weighted signal intensity were derived from manual tumor segmentations. Tumor:muscle T2 signal ratios were recorded. Two readers measured tumor T2 relaxation times using a commercial T2 scanning sequence, manual ROI delineation and commercial calculation software enabling estimation of reader reliability. Objective response rates based on RECIST1.1 and best responses were compared between size-based and signal-based parameters.

Results

Median patient age was 52.6 years; 8 subjects were female (73%). Nine patients with longitudinal assessments were followed for an average of 314 days. Median baseline tumor diameter was 7.2 cm (range 4.4 - 18.2 cm). Median baseline T2 was 65.1 ms (range 40.4 - 94.8 ms, n=11); median at last follow-up was 44.3 ms (-32% from baseline; range 29.3 - 94.7 ms, n=9). T2 relaxation times correlated with tumor:muscle T2 signal ratios, Spearman p=0.78 (p<0.001). T2 mapping showed high inter-reader reliability, ICC=0.84. The best response as a percentage change in T2 values was statistically significant (mean -17.9%, p=0.05, paired t-test) while change in diameter was not (mean -8.9%, p=0.12).

Conclusions

Analysis of T2 relaxation time maps of DF may offer a feasible quantitative biomarker for assessing the extent of response to treatment. This approach may have high inter-reader reliability.

Characterization of three washing/decellularization procedures for the production of bioactive human micronized neural tissue (hMINT)

BACKGROUND

We developed a novel, injectable and decellularized human peripheral nerve-based scaffold, named Micronized Human Neural Tissue (hMINT), designed to be used as a supportive matrix for stem cell transplantation in the context of spinal cord injury (SCI).

MATERIALS AND METHODS

Human donated sciatic nerves were micronized at liquid nitrogen temperature prior to decellularization using 3 different procedures of various harshness. hMINT were characterized in terms of particle size, DNA, sulfated glycosaminoglycans (sGAG) and growth factors content. To test the biocompatibility and bioactivity of the various preparations, we used a type of mesenchymal stromal cells (MSCs), termed MIAMI cells, which were placed in contact with hMINT to monitor cell attachment by confocal microscopy and gene expression by RT-qPCR in vitro.

RESULTS

The content of DNA, sGAG and growth factors left in the product after processing was highly dependent on the decellularization procedure used. We demonstrated that hMINT are biocompatible and promoted the attachment and long-term survival of MIAMI cells in vitro. Finally, combination with hMINT increased MIAMI cells mRNA expression of pro-survival and anti-inflammatory factors. Importantly, the strongest bioactivity on MIAMI cells was observed with the hMINT decellularized using the mildest decellularization procedure, therefore emphasizing the importance of achieving an adequate decellularization without losing the hMINT's bioactivity.

PERSPECTIVES AND CLINICAL SIGNIFICANCE

The capacity of hMINT/stem cells to facilitate protection of injured neural tissue, promote axon re-growth and improve functional recovery will be tested in an animal model of SCI and other neurodegenerative disorders in the future.

Discoidin Domain Receptor Tyrosine Kinase 1 (DDR1) Is a Novel Therapeutic Target in Liposarcoma: A Tissue Microarray Study

BACKGROUND

Liposarcoma is the most commonly diagnosed subtype of soft tissue sarcoma. As these tumors often arise near vital organs and neurovascular structures, complete resection can be challenging; consequently, recurrence rates are high. Additionally, available chemotherapeutic agents have shown limited benefit and substantial toxicities. There is, therefore, a clear and unmet need for novel therapeutics for liposarcoma. Discoidin domain receptor tyrosine kinase 1 (DDR1) is involved in adhesion, proliferation, differentiation, migration, and metastasis in several cancers. However, the expression and clinical importance of DDR1 in liposarcoma are unknown.

QUESTIONS/PURPOSES

The purposes of this study were to assess (1) the expression, (2) the association between DDR1 and survival, and (3) the functional roles of DDR1 in liposarcoma.

METHODS

The correlation between DDR1 expression in tumor tissues and clinicopathological features and survival was assessed via immunohistochemical staining of a liposarcoma tissue microarray. It contained 53 samples from 42 patients with liposarcoma and 11 patients with lipoma. The association between DDR1 and survival in liposarcoma was analyzed by Kaplan-Meier plots and log-rank tests. The DDR1 knockout liposarcoma cell lines were generated by CRISPR-Cas9 technology. The DDR1-specific and highly selective DDR1 inhibitor 7RH was applied to determine the impact of DDR1 expression on liposarcoma cell growth and proliferation. In addition, the effect of DDR1 inhibition on liposarcoma growth was further accessed in a three-dimensional cell culture model to mimic DDR1 effects in vivo.

RESULTS

The results demonstrate elevated expression of DDR1 in all liposarcoma subtypes relative to benign lipomas. Specifically, high DDR1 expression was seen in 55% (23 of 42) of liposarcomas and no benign lipomas. However, DDR1 expression was not found to be associated with poor survival in patients with liposarcoma. DDR1 knockout or treatment of 7RH showed decreased liposarcoma cell growth and proliferation.

CONCLUSION

DDR1 is aberrantly expressed in liposarcoma, and it contributes to several markers of oncogenesis in these tumors.

CLINICAL RELEVANCE

This work supports DDR1 as a promising therapeutic target in liposarcoma.

Surgical Site Infection in Patients Managed with an Endoprosthesis for the Treatment of Cancer: Evaluation of Patient, Disease, and Index Surgical Factors

BACKGROUND

Surgical site infection (SSI) after segmental endoprosthetic reconstruction in patients treated for oncologic conditions remains both a devastating and a common complication. The goal of the present study was to identify variables associated with the success or failure of treatment of early SSI following the treatment of a primary bone tumor with use of a segmental endoprosthesis.

METHODS

The present study used the Prophylactic Antibiotic Regimens in Tumor Surgery (PARITY) data set to identify patients who had been diagnosed with an SSI after undergoing endoprosthetic reconstruction of a lower extremity primary bone tumor. The primary outcome of interest in the present study was a dichotomous variable: the success or failure of infection treatment. We defined failure as the inability to eradicate the infection, which we considered as an outcome of amputation or limb retention with chronic antibiotic suppression (>90 days or ongoing therapy at the conclusion of the study). Multivariable models were created with covariates of interest for each of the following: surgery characteristics, cancer treatment-related characteristics, and tumor characteristics. Multivariable testing included variables selected on the basis of known associations with infection or results of the univariable tests.

RESULTS

Of the 96 patients who were diagnosed with an SSI, 27 (28%) had successful eradication of the infection and 69 had treatment failure. Baseline and index procedure variables showing significant association with SSI treatment outcome were moderate/large amounts of fascial excision ≥1 cm2) (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.001), use of local muscle/skin graft (OR,11.88 [95% CI, 1.83 to 245.83]; p = 0.031), and use of a deep Hemovac (OR, 0.24 [95% CI, 0.05 to 0.85]; p = 0.041). In the final multivariable model, excision of fascia during primary tumor resection was the only variable with a significant association with treatment outcome (OR, 10.21 [95% CI, 2.65 to 46.21]; p = 0.018).

CONCLUSIONS

The results of this secondary analysis of the PARITY trial data provide further insight into the patient-, disease-, and treatment-specific associations with SSI treatment outcomes, which may help to inform decision-making and management of SSI in patients who have undergone segmental bone reconstruction of the femur or tibia for oncologic indications.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Neoadjuvant Radiation Therapy with Interdigitated High-Dose LRT for Voluminous High-Grade Soft-Tissue Sarcoma

Purpose

To report a case of large extremity soft tissue sarcoma (2933 cc), safely treated with a novel approach of interdigitating high-dose LATTICE radiation therapy (LRT) with standard radiation therapy as a neoadjuvant treatment to surgery.

Patients and Methods

Four sessions of high-dose LRT were delivered in a weekly interval, interdigitated with standard radiation therapy. The LRT plan consisted of 15 high-dose vertices receiving a dose >12 Gy per session, with 2-3 Gy to the peripheral margin of the tumor. The patient underwent surgical excision 2 months after the new regimen of induction radiation therapy.

Results and Discussion

The patient tolerated the radiation therapy regimen well. The post-operative assessment revealed a negative surgical margin and over 95% necrosis of the total tumor volume. The post-surgical wound complication was mitigated by outpatient wound care. Interdigitating multiple sessions of high-dose LATTICE radiation treatments with standard neoadjuvant radiation therapy as a neoadjuvant therapy for soft tissue sarcoma was feasible and did not incur additional toxicity in this clinical case. A phase-I/II trial will be conducted to further evaluate the toxicity and efficacy of the new treatment strategy with the intent to increase the rate of pathologic necrosis, which has been shown to positively correlate with the overall survival.

Update on aneurysmal bone cyst: pathophysiology, histology, imaging and treatment

Aneurysmal bone cyst (ABC) is a benign but locally aggressive lesion that predominantly affects children and young adults. ABC, which accounts for approximately 70% of the cases, is now recognized to be a true neoplasm, whereas ABC-like changes associated to other bone neoplasms (also referred in the literature as secondary ABC) accounts for the remaining 30%. The solid variant of ABC is also considered a true neoplasm but is rare. ABC can involve any bone in the body, and although it has a metaphyseal preference, it can involve any part of a bone and soft tissues. As with any bone tumor, the initial evaluation of ABCs should be done with radiographs followed by magnetic resonance imaging or less frequently computed tomography for further characterization. The imaging appearance of ABC is variable; however, a lytic and expansile lesion with fluid-fluid levels is the most common presentation. The main differential diagnosis of an ABC in the pediatric population is unicameral bone cyst (UBC) and telangiectatic osteosarcoma, therefore a biopsy is recommended before treatment. The therapeutic options of ABC range from curettage with or without adjuncts such as phenol, liquid nitrogen, argon laser and bone grafting or bone substitutes to more recently employed alternatives such as image-guided sclerotherapy with various sclerosing agents and monoclonal antibodies (e.g., Denosumab).

Lateral lumbar interbody fusion using a cellular allogeneic bone matrix in the treatment of symptomatic degenerative lumbar disc disease and lumbar spinal instability

Background

Cellular allogeneic bone grafts are used as a biologic adjuvant in lumbar spinal fusions. The clinical use of a minimally invasive extreme lateral approach to the lumbar spine has been widely adopted; however, there are few clinical studies that have documented the clinical and radiographic outcomes associated with the use of cellular allografts as an adjunct to fusion in this advanced surgical approach.

Methods

A consecutive series of 67 patients (34 males and 33 females) with a mean age of 66.8 years (26-85 years) who underwent single- or multilevel lateral lumbar interbody fusion (LLIF) with supplemental posterior segmental spinal fixation using a cellular allogeneic bone matrix as the only bone graft material was retrospectively reviewed by a single surgeon. Patients' preoperative and 3- and 12-month postoperative data were studied. All patients were followed for a minimum of 12 months. Standardized clinical outcome measures-36-Item Short Form Surgery (SF-36), Oswestry Disability Index (ODI), and visual analog scale (VAS) back and leg pain scores-were used to evaluate the clinical outcomes. An average of 2.25 levels was treated per patient (151 total levels). Fusion status was assessed by dynamic radiographs and computed tomography (CT) scans. The statistical method used to identify the significance of the observed changes in clinical outcomes was the paired 2-sided t-tests. Significance was ascribed to P values <0.05.

Results

Fusion was achieved at 142 levels (142/151; 94%). Eight levels (8/151; 5.3%) showed partial fusions and one patient (single level) had no fusion. In the group of patients with fusions, the mean back and leg pain scores showed improvement from preoperative scores at both 3 and 12 months (P<0.001). Functional outcomes showed similar clinical success in both in SF-36 and ODI scores.

Conclusions

The use of a cellular allogeneic bone matrix provided osteoconductive and osteoinductive components for successful spine fusions and was associated with statistically significant improvement in SF-36, VAS, and ODI scores.

The articularis genu muscle and its relevance in oncological surgical margins

Aims

The aticularis genu (AG) is the least substantial and deepest muscle of the anterior compartment of the thigh and of uncertain significance. The aim of the study was to describe the anatomy of AG in cadaveric specimens, to characterize the relevance of AG in pathological distal femur specimens, and to correlate the anatomy and pathology with preoperative magnetic resonance imaging (MRI) of AG.

Methods

In 24 cadaveric specimens, AG was identified, photographed, measured, and dissected including neurovascular supply. In all, 35 resected distal femur specimens were examined. AG was photographed and measured and its utility as a surgical margin examined. Preoperative MRIs of these cases were retrospectively analyzed and assessed and its utility assessed as an anterior soft tissue margin in surgery. In all cadaveric specimens, AG was identified as a substantial structure, deep and separate to vastus itermedius (VI) and separated by a clear fascial plane with a discrete neurovascular supply. Mean length of AG was 16.1 cm ( ± 1.6 cm) origin anterior aspect distal third femur and insertion into suprapatellar bursa. In 32 of 35 pathological specimens, AG was identified (mean length 12.8 cm ( ± 0.6 cm)). Where AG was used as anterior cover in pathological specimens all surgical margins were clear of disease. Of these cases, preoperative MRI identified AG in 34 of 35 cases (mean length 8.8 cm ( ± 0.4 cm)).

Results

AG was best visualized with T1-weighted axial images providing sufficient cover in 25 cases confirmed by pathological findings.These results demonstrate AG as a discrete and substantial muscle of the anterior compartment of the thigh, deep to VI and useful in providing anterior soft tissue margin in distal femoral resection in bone tumours.

Conclusion

Preoperative assessment of cover by AG may be useful in predicting cases where AG can be dissected, sparing the remaining quadriceps muscle, and therefore function.

Cite this article: Bone Joint Open 2020;1-9:585–593.

Nonmechanical Revision Indications Portend Repeat Limb-Salvage Failure Following Total Femoral Replacement

BACKGROUND

There is scant evidence to guide decision-making for patients considering total femoral replacement (TFR). We aimed to identify the indication, patient, disease, and surgical technique-related factors associated with failure. We hypothesized that failure occurs more frequently in the setting of revision surgical procedures, with infection as the predominant failure mode.

METHODS

We performed a retrospective cohort study of patients receiving total femoral endoprostheses for oncological and revision arthroplasty indications; 166 patients met these criteria. Our primary independent variable of interest was TFR for a revision indication (arthroplasty or limb salvage); the primary outcome was failure. Analyses were performed for patient variables (age, sex, diagnosis group, indication), implant variables (model, decade, length, materials), and treatment variables. We analyzed TFR failures with respect to patient factors, operative technique, and time to failure. We conducted bivariate logistic regressions predicting failure and used a multivariate model containing variables showing bivariate associations with failure.

RESULTS

Forty-four patients (27%) had treatment failure. Failure occurred in 24 (23%) of 105 primary TFRs and in 20 (33%) of 61 revision TFRs; the difference was not significant (p = 0.134) in bivariate analysis but was significant (p = 0.044) in multivariate analysis. The mean age at the time of TFR was 37 years in the primary group and 51 years in the revision group (p = 0.0006). Of the patients who had mechanical failure, none had reoccurrence of their original failure mode, whereas all 8 patients from the nonmechanical cohort had reoccurrence of the original failure mode; this difference was significant (p = 0.0001).

CONCLUSIONS

TFR has a high failure rate and a propensity for deep infection, especially in the setting of revision indications and prior infection. All failed TFRs performed for revision indications for infection or local recurrence failed by reoccurrence of the original failure mode and resulted in amputation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Abstract A23: Identification of prevalent targets for the development of tailored sarcoma immunotherapies using a rapid clinic-to-bench immunoprofiling pipeline

Sarcomas are rare malignancies of mesenchymal origin for which current treatment options are very limited. Due to the vast heterogeneity of the various subtypes, the development of new targeted therapies requires a customized approach. Checkpoint blockade therapies are a promising alternative that still have not been systematically investigated for sarcoma patients. Thus, utilizing the infrastructure of the Cell Therapy Core Facility (CTC) at Nova Southeastern University (NSU), we developed a clinic-to-bench pipeline that enables the processing of fresh tumor material after surgical excision to generate primary sarcoma cell lines for biobanking and research purposes. Using this pipeline, we have extensively characterized mRNA, miRNA and cell surface expression profiles from more than 40 sarcoma cell lines to date, as well as validated their tumorigenicity by assessing expression of sarcoma/cancer associated genes such as Birc5, Birc2, Bcl2, Ewsr1-fli1, Syt/Ssx and Pcna. Moreover, we assessed the expression of immunomodulatory molecules that may suppress antitumor responses, such as PD-L1, PD-L2, OX40L and CD40L, using multicolor flow cytometry. Detailed characterization of the immune profile of 7 bone-related and 7 soft tissue sarcoma cell lines, assessed after 12 weeks of in vitro serial passaging, revealed a common signature in the cell surface expression of proliferative marker PCNA, and lymphocyte ligands CD112 and CD115. Moreover, immunoprofiling of the PCNA/CD112/CD155+ sarcoma cell lines (n=14) demonstrated persistent expression of PD-L2 in all cell lines and the potential applications of currently clinically approved anti-PD-1 checkpoint inhibitors for sarcoma treatment. Importantly, the conserved expression of these proteins enabled the distinction of sarcoma tumor cells from other cells in the fresh primary tumor mix directly after isolation. Thus, we next performed a comparative analysis of the immune profile of 6 freshly isolated sarcoma tumors and their respective cell lines. Comparison of the surface expression profiles of the generated cell lines and the corresponding primary tumor cells showed that the initial phenotype was preserved after more than 12 weeks of expansion and after cryopreservation. This proves that the generated cell lines are an accurate tool that can be used for the development of novel personalized immunotherapies. Most importantly, our results enabled the design of a translational research pipeline that allows the systematic characterization of the immune profile of understudied sarcomas for the first time in order to gain insight into which patients may directly benefit from available immunotherapies and which may be eligible to enroll in clinical trials assessing the efficacy of checkpoint inhibitors. In summary, the generated sarcoma biobank serves as a unique and highly representative primary resource that can be utilized to identify potential candidates for novel targeted and personalized immunotherapies for the treatment of sarcomas.

Citation Format: Anna-Maria Georgoudaki, Robin Krueger, Michelle Hartman, Tamara Chinn, Dustin Tran, Reneé Potens, Wendy Weston, H. Thomas Temple, Adil D. Duru. Identification of prevalent targets for the development of tailored sarcoma immunotherapies using a rapid clinic-to-bench immunoprofiling pipeline [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2018 Nov 27-30; Miami Beach, FL. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(4 Suppl):Abstract nr A23.

Allograft Reconstruction of the Knee-Methods and Outcomes

Although allograft usage has decreased over the past three decades in favor of segmental metal implants, they still have an important role in the reconstruction of large osteochondral defects following tumor resection. The decline of allografts in limb salvage is multifactorial and includes limited availability, technical difficulty, increased rates of infection and fracture, and unpredictable results. There are circumstances where allograft transplantation is useful around the knee resulting in improved function, bone and joint preservation, and acceptable long-term outcomes.

Transforaminal Lumbar Interbody Fusion With Viable Allograft: 75 Consecutive Cases at 12-Month Follow-up

Background

When conservative treatments fail to alleviate the discomfort of abnormal motion, spinal fusion has been shown to provide symptomatic treatment for spinal instability, stenosis, spondylolisthesis, and symptomatic degenerative disc disease. The trend and rates of fusion over the past few years have been dramatic in the United States. Accompanying that higher incidence has been the shifting from traditional open surgery to minimally invasive techniques to reduce scar tissue formation, extent of muscle stripping, and muscle retraction which all have been shown to adversely affect outcomes. Other reasons supporting the widespread transition to minimally invasive surgical (MIS) techniques include decreased postoperative pain, decreased intraoperative blood loss, shorter postoperative hospital stay, faster return to normal activity, and reduced reoperation rates. Spinal fusion procedures rely on a bony fusion substrate in addition to fixation hardware. While available grafting options include autogenous, allogeneic, and synthetic materials, recent interest in viable allograft material with living cells has drawn attention and attraction for incorporating a biologic basis for regenerative consideration. A recent viable allograft, complete with cellular and designated bone carrier (VIA Graft, Vivex Biomedical, Marietta, Georgia) has been developed. This study represents a retrospective review of a single-practice, single-surgeon evaluation of the product in 75 consecutive patients for fusion by computed tomography (CT) and radiographic evaluation at 12 months in conjunction with a MIS approach. Viable allograft was used to fill the peri-implant space, and central implant lumen was filled with a cancellous bone sponge soaked in perivertebral bone marrow. Posterolateral supplementation was attained with beta-tricalcium phosphate as a bulking agent.

Methods

A retrospective review identified patients treated for both primary and revision surgery who received VIA Graft cellular bone matrix material in minimally invasive interbody fusion (MIS-TLIF) with a minimum of 12-month follow up. The patient diagnoses included radiculopathy in all instances and varied collateral indications such as foraminal collapse, recurrent disc herniation, and spondylolisthesis to which pain and morbidity had been unresolved by conservative treatment. Adverse events including infection, revisions, and evidence of immune response were evaluated and patient comorbidities defined for the entire population of patients. Patient fusion status was assessed using thin slice CT by 2 independent radiologists separate from the surgeon. There were 75 consecutive adult patients with degenerative conditions of the lumbar spine who underwent MIS-TLIF surgery of which 40 (53%) were male and 35 (47%) were female. Mean age, height, and weight were 58 years, 170.18 cm (67 in), and 88.45 kg (195 lbs), respectively. The mean body mass index was 30. There were 16 patients (21%) who smoked and 12 (16%) with a history of diabetes. Independent blinded review of fusion was obtained by a board certified musculoskeletal radiologist and an experienced board certified orthopaedic surgeon to assess patient fusion status. Spinal segments were deemed fused if 12-month CT scans demonstrated evidence of bridging bone at the fusion site without observed motion on flexion-extension radiographs. Findings such as osteolysis around the implant or pedicle screws, extensive endplate cystic changes, or linear defects parallel to the endplates through intradiscal new bone formation were interpreted as signs of pseudarthrosis. Interobserver and intraobserver error and κ assessments were analyzed to assure agreement in the CT outcomes assessment where interpretation of κ were as follows: <0.00 = poor agreement, 0.00-0.20 = slight agreement, 0.21-0.40 = fair agreement, 0.41-0.60 = moderate agreement, 0.61-0.80 = substantial agreement, and 0.81-1.00 = almost perfect agreement. Differences were resolved by consensus amongst the observers.

Results

In total, 96% of the 75 patients with a total of 85 levels (96.5% of levels treated) achieved a fusion at 12 months. There were no perioperative or latent complications and no transfusions in all 75 patients.

Conclusions

In this population, 96% of the patients treated achieved the surgical objective in 96.5% of the levels treated.

Level of Evidence

IV.

Clinical Relevance

The high rate of fusion, the lack of secondary morbidity with autologous bone harvest, and the clinical success account for the benefits of viable allograft matrix for MIS-TLIF use.

Intravital endoscopic technology for real-time monitoring of inflammation caused in experimental periodontitis

We report a novel method for in situ imaging of microvascular permeability in inflamed gingival tissue, using state-of-the-art Cellvizio™ intravital endoscopic technology and a mouse model of ligature-induced periodontitis. The silk ligature was first placed at the upper left second molar. Seven days later, the ligature was removed, and the animals were intravenously injected with Evans blue. Evans blue dye, which selectively binds to blood albumin, was used to monitor the level of inflammation by monitoring vascular permeability in control non-diseased and ligature-induced experimental periodontitis tissue. More specifically, leakage of Evans blue-bound albumin from the micro-capillary to connective tissue indicates the state of inflammation occurring in the specific site. Evans blue leakage from blood vessels was imaged in situ by directly attaching the endoscope (mini Z tip) of the Cellvizio™ system to the gingival tissue without any surgical incision. Evans blue emission intensity was significantly elevated in gingiva of periodontitis lesions, but not control non-ligature placed gingiva, indicating that this technology can be used as a potential minimally invasive diagnostic tool to monitor the level of inflammation at the periodontal disease site.

The stability of the hip after the use of a proximal femoral endoprosthesis for oncological indications: analysis of variables relating to the patient and the surgical technique

AIMS

Instability of the hip is the most common mode of failure after reconstruction with a proximal femoral arthroplasty (PFA) using an endoprosthesis after excision of a tumour. Small studies report improved stability with capsular repair of the hip and other techniques, but these have not been investigated in a large series of patients. The aim of this study was to evaluate variables associated with the patient and the operation that affect post-operative stability. We hypothesised an association between capsular repair and stability.

PATIENTS AND METHODS

In a retrospective cohort study, we identified 527 adult patients who were treated with a PFA for tumours. Our data included demographics, the pathological diagnosis, the amount of resection of the abductor muscles, the techniques of reconstruction and the characteristics of the implant. We used regression analysis to compare patients with and without post-operative instability.

RESULTS

A total of 20 patients out of 527 (4%) had instability which presented at a mean of 35 days (3 to 131) post-operatively. Capsular repair was not associated with a reduced rate of instability. Bivariate analysis showed that a posterolateral surgical approach (odds ratio (OR) 0.11, 95% confidence interval (CI) 0.02 to 0.86) and the type of implant (p = 0.046) had a significant association with reduced instability; age > 60 years predicted instability (OR 3.17, 95% CI 1.00 to 9.98). Multivariate analysis showed age > 60 years (OR 5.09, 95% CI 1.23 to 21.07), female gender (OR 1.73, 95% CI 1.04 to 2.89), a malignant primary bone tumour (OR 2.04, 95% CI 1.06 to 3.95), and benign condition (OR 5.56, 95% CI 1.35 to 22.90), but not metastatic disease or soft-tissue tumours, predicted instability, while a posterolateral approach (OR 0.09, 95% CI 0.01 to 0.53) was protective against instability. No instability occurred when a synthetic graft was used in 70 patients.

CONCLUSION

Stability of the hip after PFA is influenced by variables associated with the patient, the pathology, the surgical technique and the implant. We did not find an association between capsular repair and improved stability. Extension of the tumour often dictates surgical technique; however, our results indicate that PFA using a posterolateral approach with a hemiarthroplasty and synthetic augment for soft-tissue repair confers the lowest risk of instability. Patients who are elderly, female, or with a primary benign or malignant bone tumour should be counselled about an increased risk of instability. Cite this article: Bone Joint J 2017;99-B:531-7.

LHRH receptor expression in sarcomas of bone and soft tissue

AIM

Luteinizing hormone releasing hormone (LHRH) is a neurohormone, secreted by the hypothalamus, which regulates the secretion of gonadotropins, luteinizing hormone (LH) and follicle stimulating hormone (FSH) from the pituitary. LHRH acts by binding to receptors located in the pituitary gland. These receptors (LHRH receptors) have also been found in the cytoplasm of many tumor cells that involve both the reproductive and non-reproductive organs. These receptors have been demonstrated in prostate and breast cancers, endometrial carcinomas, renal cell carcinoma, lymphoma, carcinoma of liver, pancreas and skin. So far, the expression of LHRH receptors on sarcomas (i.e. malignant tumors of mesenchymal origin) has not been studied, except for endometrial sarcomas. It has also been demonstrated that both LHRH agonists and antagonists can down-regulate these receptors and thus inhibit these tumor cells. Another major therapeutic implication is that these receptors can be targeted specifically by peptides conjugated to anti-cancer drugs. The purpose of this study was to determine if LHRH receptors are expressed in primary and/or metastatic sarcomas of human origin.

METHODS

We looked at LHRH receptor expression in 38 consecutive sarcoma specimens, using immunohistochemistry. The specimens were either from office biopsy or from resected tumor; these were confirmed as sarcomas by histopathological examination. The receptor staining characteristics and the staining intensity were also documented. The pattern of staining was classified either as "focal or diffuse staining of the cytoplasm" and the intensity of staining was graded on a scale from 1+ to 4+.

RESULTS

Positive receptor staining was seen in 25 of the 38 (66%) specimens. Twelve of the specimens stained diffusely and 13 had focally positive staining. Three tumors had 1+ staining, 10 had 2+ staining, six had 3+ staining, and six tumors had 4+ staining. The tumors included undifferentiated pleomorphic sarcoma, synovial sarcoma, osteosarcoma, myofibroblastic sarcoma, myxofibrosarcoma, liposarcoma, dermatofibrosarcoma protuberans, metastatic chondrosarcoma and chordoma.

CONCLUSION

Sarcomas express LHRH receptors with a varying incidence and degree. Our study suggests that those sarcomas that are LHRH receptor positive could potentially be treated with targeted chemotherapy.

Simulation of water content distributions in degenerated human intervertebral discs

The objective of this study was to investigate the spatial and temporal variations of water content in intervertebral discs during degeneration and repair processes. We hypothesized that the patterns of water content distribution in the discs are related to the intensity patterns observed in T2-weighted MRI images. Water content distributions in the mildly (e.g., 80% viable cells in the disc, 2.3% decrease in disc height) and moderately (e.g., 40% viable cells in the disc, 9.3% decrease in disc height) degenerated discs were predicted using a finite element model. The variation of water content in the degenerated discs treated with three biological therapies (i.e., increasing the cell density in the nucleus pulposus [Case I], increasing glycosaminoglycan synthesis rate in the nucleus pulposus [Case II], and decreasing glycosaminoglycan degradation rate in the nucleus pulposus [Case III]) were also predicted. It was found that two patterns of water content distributions, a horizontal region with lower water content at the mid-axial plane of nucleus pulposus and a spot with higher water content at the posterior region, were shown during the degeneration progress for the disc simulated in this study. These two patterns disappeared after treatment in Case I, but in Case II and Case III. The implication of these patterns for the horizontal gray band and high intensity zone in T2-weighted MRI images was discussed. This study provided new guidance to develop a novel method for diagnosing disc degeneration and assessing outcomes of biological therapies with MRI techniques. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:147-153, 2017.

Desmoid fibromatosis: MRI features of response to systemic therapy

OBJECTIVE

Imaging criteria for measuring the response of desmoid fibromatosis to systemic therapy are not well established. We evaluated a series of patients with desmoids who underwent systemic therapy to document magnetic resonance imaging (MRI) features associated with a positive clinical response.

MATERIALS AND METHODS

This Institutional Review Board-approved retrospective study included 23 patients (mean age 40.5) with 29 extra-abdominal tumors. Therapeutic regimens included cytotoxic chemotherapy (n = 19), targeted therapy (n = 3), and nonsteroid anti-inflammatory drugs (NSAIDS; n = 1). Clinical effects were categorized as progressive disease, stable, or partial response. Maximum tumor dimension (Dmax), approximate tumor volume (VTumor), and quantitative tumor T2 hyperintensity and contrast enhancement (relative to muscle) for pre- and post-treatment MRIs were compared.

RESULTS

Three lesions progressed, 5 lesions were stable, whereas 21 showed a clinical response. Dmax decreased more in responders (mean -11.0 %) than in stable/progressive lesions (mean -3.6 and 0 % respectively, p = 0.28, ANOVA); by Response Evaluation Criteria in Solid Tumors (RECIST 1.1) 27 out of 29 lesions were "stable," including the 3 progressive lesions. In responders, VTumor change averaged -29.4 %, but -19.2 % and +32.5 % in stable and progressive lesions respectively (p = 0.002, ANOVA); by 3D criteria 14 out of 29 lesions showed a partial response. T2 hyperintensity decreased by 50-54 % in partial response/stable disease, but only by 10 % in progressive lesions (p = 0.049, t test). Changes in contrast enhancement ranged from -23 % to 0 %, but were not statistically significant among response groups (p = 0.37). Change in T2 hyperintensity showed a positive correlation with volumetric change (r = 0.40).

CONCLUSION

Decreases in volume and T2 hyperintensity reflect the positive response of desmoid fibromatosis to systemic therapy; RECIST 1.1 criteria are not sensitive to clinically determined tumor response.

Effects of gamma irradiation on the biomechanical properties of peroneus tendons

Purpose

This study was designed to investigate the biomechanical properties of nonirradiated (NI) and irradiated (IR) peroneus tendons to determine if they would be suitable allografts, in regards to biomechanical properties, for anterior cruciate ligament reconstruction after a dose of 1.5–2.5 Mrad.

Methods

Seven pairs of peroneus longus (PL) and ten pairs of peroneus brevis (PB) tendons were procured from human cadavers. The diameter of each allograft was measured. The left side of each allograft was IR at 1.5–2.5 Mrad, whereas the right side was kept aseptic and NI. The allografts were thawed, kept wet with saline, and attached in a single-strand fashion to custom freeze grips using liquid nitrogen. A preload of 10 N was then applied and, after it had reached steady state, the allografts were pulled at 4 cm/sec. The parameters recorded were the displacement and force.

Results

The elongation at the peak load was 10.3±2.3 mm for the PB NI side and 13.5±3.3 mm for the PB IR side. The elongation at the peak load was 17.4±5.3 mm for the PL NI side and 16.3±2.0 mm for the PL IR side. For PL, the ultimate load was 2,091.6±148.7 N for NI and 2,122.8±380.0 N for IR. The ultimate load for the PB tendons was 1,485.7±209.3 N for NI and 1,318.4±296.9 N for the IR group. The ultimate stress calculations for PL were 90.3±11.3 MPa for NI and 94.8±21.0 MPa for IR. For the PB, the ultimate stress was 82.4±19.0 MPa for NI and 72.5±16.6 MPa for the IR group. The structural stiffness was 216.1±59.0 N/mm for the NI PL and 195.7±51.4 N/mm for the IR side. None of these measures were significantly different between the NI and IR groups. The structural stiffness was 232.1±45.7 N/mm for the NI PB and 161.9±74.0 N/mm for the IR side, and this was the only statistically significant difference found in this study (P=0.034).

Conclusion

Our statistical comparisons found no significant differences in terms of elongation, ultimate load, or ultimate stress between IR and NI PB and PL tendons. Only the PB structural stiffness was affected by irradiation. Thus, sterilizing allografts at 1.5–2.5 Mrad of gamma irradiation does not cause major alterations in the tendons’ biomechanical properties while still providing a suitable amount of sterilization for anterior cruciate ligament reconstruction.

Effect of cytostatic proline rich polypeptide-1 on tumor suppressors of inflammation pathway signaling in chondrosarcoma

Cytokines produced in the tumour microenvironment exert an important role in cancer pathogenesis and in the inhibition of disease progression. Cancer of the cartilage is termed metastatic chondrosarcoma; however, the signaling events resulting in mesenchymal cell transformation to sarcoma have yet to be fully elucidated. The present study aimed to characterize the cytokine expression profile in the human JJ012 chondrosarcoma cell line, as well as the effect of cytostatic proline-rich polypeptide-1 (PRP-1). Western blot experiments demonstrated that the levels of suppressor of cytokine signaling 3 (SOCS3) were upregulated in chondrocytes compared with chondrosarcoma cells. Addition of PRP-1 restored the expression of the tumor suppressors, SOCS3 and ten-eleven-translocation methylcytosine dioxygenase 1 and 2 (TET1/2), in a dose-responsive manner. It is known that methylation of histone H3K9 was eliminated from the promoters of the inflammation-associated genes. PRP-1 inhibited H3K9 demethylase activity with an IC₅₀ (concentration required to give half-maximal inhibition) value of 3.72 µg/ml in the chondrosarcoma cell line. Data obtained from ELISA experiments indicated that the expression of interleukin-6 (IL-6) in chondrosarcoma cells was 86-fold lower compared with that in C28 chondrocytes. In the present study, a 53-fold downregulation of IL-6 expression in co-culture of chondrosarcoma cells and C28 chondrocytes was identified as well. Downregulation of IL-6 expression has been documented in numerous other tumor types, although the reasons for this have not been fully established. In chondrosarcoma, IL-6 manifests itself as an anti-inflammatory agent and, possibly, as an anti-tumorigenic factor. To explore protein-DNA interactions leading to such differences, a gel-shift chemiluminescent assay was performed. Gel shifts were observed for chondrosarcoma and chondrocytes in the lanes that contained nuclear cell extract and oligo-IL-6 DNA. Notably, the DNA-protein complexes in C28 chondrocytes were markedly larger compared with those in chondrosarcoma cells. The mechanisms that underpin such differences, and characterization of the interacting proteins, remain to be fully elucidated.

Primary Intraosseous Malignant Peripheral Nerve Sheath Tumor of the Medial Cuneiform: A Case Report and Review of the Literature

Peripheral nerve sheath tumors (benign and malignant) usually arise in the soft tissues and are unusual in bone. Intraosseous peripheral nerve sheath tumors are usually benign and constitute approximately 0.2% of all bone tumors. Intraosseous malignant peripheral nerve sheath tumors (MPNSTs) are uncommon and usually result from secondary invasion. Only a few cases of primary intraosseous MPNSTs have been reported in published studies, and these were localized mostly in the mandible (approximately 50%) or maxilla, spine, and, occasionally, in the appendicular skeleton. To the best of our knowledge, we report the first case of primary intraosseous MPNST involving a midtarsal bone (medial cuneiform). The patient was a 62-year-old female who presented with pain and tenderness but without swelling. Imaging revealed nonspecific findings, and the preoperative computed tomography-guided biopsy findings were consistent with MPNST. The patient was treated with neoadjuvant radiotherapy, followed by wide local excision and allograft reconstruction. At the final follow-up examination (24 months), the graft had been incorporated without evidence of local recurrence or distant disease. The patient with primary intraosseous MPNST of the medial cuneiform described in the present report presented with nonspecific clinical and radiologic findings. Thus, a high index of suspicion and histopathologic examination, including immunohistochemistry, are necessary for an accurate diagnosis.

Simulation of biological therapies for degenerated intervertebral discs

The efficacy of biological therapies on intervertebral disc repair was quantitatively studied using a three-dimensional finite element model based on a cell-activity coupled multiphasic mixture theory. In this model, cell metabolism and matrix synthesis and degradation were considered. Three types of biological therapies-increasing the cell density (Case I), increasing the glycosaminoglycan (GAG) synthesis rate (Case II), and decreasing the GAG degradation rate (Case III)-to the nucleus pulposus (NP) of each of two degenerated discs [one mildly degenerated (e.g., 80% viable cells in the NP) and one severely degenerated (e.g., 30% viable cells in the NP)] were simulated. Degenerated discs without treatment were also simulated as a control. The cell number needed, nutrition level demanded, time required for the repair, and the long-term outcomes of these therapies were analyzed. For Case I, the repair process was predicted to be dependent on the cell density implanted and the nutrition level at disc boundaries. With sufficient nutrition supply, this method was predicted to be effective for treating both mildly and severely degenerated discs. For Case II, the therapy was predicted to be effective for repairing the mildly degenerated disc, but not for the severely degenerated disc. Similar results were predicted for Case III. No change in cell density for Cases II and III were predicted under normal nutrition level. This study provides a quantitative guide for choosing proper strategies of biological therapies for different degenerated discs.

Genome-wide mRNA and miRNA expression data analysis to screen for markers involved in sarcomagenesis in human chondrosarcoma cell lines

Genes and miRNAs involved in sarcomagenesis related pathways are unknown and therefore signaling events leading to mesenchymal cell transformation to sarcoma are poorly elucidated. Exiqon and Illumina microarray study on human chondrosarcoma JJ012 and chondrocytes C28 cell lines to compare and analyze the differentially expressed miRNAs and their gene targets was recently published in the Journal Tumor Biology in 2014. Here we describe in details the contents and quality controls for the miRNA and gene expression data associated with the study that is relevant to this dataset.

Epigenetic regulation of embryonic stem cell marker miR302C in human chondrosarcoma as determinant of antiproliferative activity of proline-rich polypeptide 1

Metastatic chondrosarcoma of mesenchymal origin is the second most common bone malignancy and does not respond either to chemotherapy or radiation; therefore, the search for new therapies is relevant and urgent. We described recently that tumor growth inhibiting cytostatic proline-rich polypeptide 1, (PRP-1) significantly upregulated tumor suppressor miRNAs, downregulated onco-miRNAs in human chondrosarcoma JJ012 cell line, compared to chondrocytes culture. In this study we hypothesized the existence and regulation of a functional marker in cancer stem cells, correlated to peptides antiproliferative activity. Experimental results indicated that among significantly downregulated miRNA after PRP-1treatment was miRNAs 302c^*. This miRNA is a part of the cluster miR302-367, which is stemness regulator in human embryonic stem cells and in certain tumors, but is not expressed in adult hMSCs and normal tissues. PRP-1 had strong inhibitory effect on viability of chondrosarcoma and multilineage induced multipotent adult cells (embryonic primitive cell type). Unlike chondrosarcoma, in glioblastoma, PRP-1 does not have any inhibitory activity on cell proliferation, because in glioblastoma miR-302-367 cluster plays an opposite role, its expression is sufficient to suppress the stemness inducing properties. The observed correlation between the antiproliferative activity of PRP-1 and its action on downregulation of miR302c explains the peptides opposite effects on the upregulation of proliferation of adult mesenchymal stem cells, and the inhibition of the proliferation of human bone giant-cell tumor stromal cells, reported earlier. PRP-1 substantially downregulated the miR302c targets, the stemness markers Nanog, c-Myc and polycomb protein Bmi-1. miR302c expression is induced by JMJD2-mediated H3K9me2 demethylase activity in its promoter region. JMJD2 was reported to be a positive regulator for Nanog. Our experimental results proved that PRP-1 strongly inhibited H3K9 activity comprised of a pool of JMJD1 and JMJD2. We conclude that inhibition of H3K9 activity by PRP-1 leads to downregulation of miR302c and its targets, defining the PRP-1 antiproliferative role.

Unplanned excision of soft-tissue sarcomas: current concepts for management and prognosis

➤ Biopsy, staging, preoperative imaging and planning, as well as surgical treatment of soft-tissue sarcomas, are best carried out in specialized sarcoma centers, with the support of a multidisciplinary tumor board.➤ Tumor bed excision is recommended after most unplanned excisions, with a goal of obtaining complete tumor removal with an appropriately wide margin of resection.➤ The surgical resection area tends to be more extensive during tumor bed excision than during primary resection because of the need to resect potential areas of contamination, resulting in the need for more reconstructive procedures (flaps and skin grafts) and wider radiation fields.➤ Unplanned excisions are associated with an increased rate of local recurrence related to residual disease and positive margins after tumor bed excision, a deep location, and certain histologic subtypes, such as malignant peripheral nerve sheath tumor, myxofibrosarcoma, and dermatofibrosarcoma protuberans.➤ While adjuvant radiation therapy has not been found to mitigate the risk of local recurrence in unplanned excisions, it is generally utilized in the treatment of unplanned excisions as it is in the treatment of primary soft-tissue sarcomas.➤ Given the surgical and oncologic sequelae of unplanned excisions, prevention through the diffusion of concepts by means of provider education on how to approach soft-tissue masses, which can be potential soft-tissue sarcomas, is the best strategy.

Locally aggressive fibrous dysplasia mimicking malignancy: a report of four cases and review of the literature

BACKGROUND

Fibrous dysplasia is a benign fibroosseous bone tumor that accounts for 5% to 10% of benign bone tumors. It can present as monostotic fibrous dysplasia (70% to 80%), polyostotic fibrous dysplasia (20% to 30%), McCune-Albright syndrome (2% to 3%), or Mazabraud's syndrome in rare cases. Bone lesions in fibrous dysplasia arise in the medullary canal and usually are confined to the bone. Cortical destruction and extension into soft tissue usually indicates malignant transformation or secondary aneurysmal bone cyst formation. Locally aggressive fibrous dysplasia with cortical destruction and extension into soft tissue in the absence of these two possibilities is extremely rare. It is important for the treating physician to distinguish this entity from more aggressive or malignant tumors to avoid overtreating the patient for a benign condition or inattention to a malignant tumor.

CASE DESCRIPTIONS

We report four unusual cases of fibrous dysplasia with an aggressive radiographic appearance. They occurred in the rib (1), ilium (2), and distal femur (1). Two patients had pain and two had swelling. Radiologically, all were associated with cortical destruction and an associated soft tissue mass, and initially they were interpreted as potentially malignant. Three patients underwent biopsy and one patient did not have a biopsy. Histopathologic analysis by an experienced bone pathologist confirmed fibrous dysplasia in all patients. Two patients were treated surgically; one patient with zoledronic acid and one patient currently is being followed by observation alone.

LITERATURE REVIEW

There are only a few reports in the literature that describe the locally aggressive variant of fibrous dysplasia that presents with pain and progressive swelling clinically and with cortical destruction and soft tissue extension on imaging which suggest malignancy. We could not find any article that describes the use of bisphosphonates in such lesions or the response to bisphosphonates clinically, on laboratory parameters or imaging. To our knowledge, this is the largest case report published regarding locally aggressive fibrous dysplasia arising outside the craniofacial skeleton.

CLINICAL RELEVANCE

The locally aggressive variant of fibrous dysplasia may be confused with a malignant tumor or malignant degeneration of fibrous dysplasia. It is important to properly evaluate these lesions to ensure that a proper diagnosis is made, especially with respect to a malignant versus benign mass.

Classification of failure of limb salvage after reconstructive surgery for bone tumours : a modified system Including biological and expandable reconstructions

Previous classification systems of failure of limb salvage focused primarily on endoprosthetic failures and lacked sufficient depth for the effective study of the causes of failure. In order to address these inadequacies, the International Society of Limb Salvage (ISOLS) formed a committee to recommend revisions of the previous systems. The purpose of this study was to report on their recommendations. The modifications were prepared using an earlier, evidence-based model with subclassification based on the existing medical literature. Subclassification for all five primary types of failure of limb salvage following endoprosthetic reconstruction were formulated and a complementary system was derived for the failure of biological reconstruction. An additional classification of failure in paediatric patients was also described. Limb salvage surgery presents a complex array of potential mechanisms of failure, and a complete and precise classification of types of failure is required. Earlier classification systems lacked specificity, and the evidence-based system outlined here is designed to correct these weaknesses and to provide a means of reporting failures of limb salvage in order to allow the interpretation of outcome following reconstructive surgery.

Restoration of desmosomal junction protein expression and inhibition of H3K9-specific histone demethylase activity by cytostatic proline-rich polypeptide-1 leads to suppression of tumorigenic potential in human chondrosarcoma cells

Disruption of cell-cell junctions and the concomitant loss of polarity, downregulation of tumor-suppressive adherens junctions and desmosomes represent hallmark phenotypes for several different cancer cells. Moreover, a variety of evidence supports the argument that these two common phenotypes of cancer cells directly contribute to tumorigenesis. In this study, we aimed to determine the status of intercellular junction proteins expression in JJ012 human malignant chondrosarcoma cells and investigate the effect of the antitumorigenic cytokine, proline-rich polypeptide-1 (PRP-1) on their expression. The cell junction pathway array data indicated downregulation of desmosomal proteins, such as desmoglein (1,428-fold), desmoplakin (620-fold) and plakoglobin (442-fold). The tight junction proteins claudin 11 and E-cadherin were also downregulated (399- and 52-fold, respectively). Among the upregulated proteins were the characteristic for tumors gap junction β-5 protein (connexin 31.1) and the pro-inflammatory pathway protein intercellular adhesion molecule (upregulated 129- and 43-fold, respectively). We demonstrated that PRP-1 restored the expression of the abovementioned downregulated in chondrosarcoma desmosomal proteins. PRP-1 inhibited H3K9-specific histone demethylase activity in chondrosarcoma cells in a dose-dependent manner (0.5 µg/ml PRP, 63%; 1 µg/ml PRP, 74%; and 10 µg/ml PRP, 91% inhibition). Members of the H3K9 family were shown to transcriptionally repress tumor suppressor genes and contribute to cancer progression. Our experimental data indicated that PRP-1 restores tumor suppressor desmosomal protein expression in JJ012 human chondrosarcoma cells and inhibits H3K9 demethylase activity, contributing to the suppression of tumorigenic potential in chondrosarcoma cells.

Five polyostotic conditions that general orthopedic surgeons should recognize (or should not miss)

General orthopedic surgeons frequently encounter patients with conditions affecting multiple bones. It is important to recognize common polyostotic diseases. This article describes five polyostotic conditions: Multipe Enchondromatosis (Ollier Disease and Maffucci syndrome), Multiple Hereditary Exostosis (Diaphyseal Aclasis), Fibrous Dysplasia (McCune-Albright syndrome and Mazabraud syndrome), Paget's Disease of bone (Osteitis Deformans), and Skeletal Metastases. This is a survey of the clinical, pathologic and radiographic features that assist in diagnosing these conditions. Also, an overview of the laboratory findings, treatment, follow-up, and prognosis is presented. Recognizing these diseases will aid in prompt and accurate diagnosis and appropriate referral and therapy.

Adult soft tissue sarcoma local recurrence after adjuvant treatment without resection of core needle biopsy tract

BACKGROUND

Core needle biopsies of sarcomas allow a diagnosis in a high percentage of patients with few complications. However, it is unclear whether the tract needs to be excised to prevent recurrences.

QUESTIONS/PURPOSES

We therefore determined the rates of recurrence and metastases in patients with Stage III extremity sarcomas, who underwent wide local resection without excision of the needle tract and also received adjuvant treatment.

METHODS

We retrospectively reviewed 59 adult patients with deep, larger than 5 cm, high-grade soft tissue sarcomas of the upper or lower extremity treated between January 1999 and April 2009. All the patients underwent a core needle biopsy. Resection was performed with wide margins. The biopsy tract was not resected during the definitive surgery. Fifty-seven patients (97%) received preoperative and/or postoperative radiation, whereas 49 patients (83%) received chemotherapy. Local recurrence and distant recurrence rates were determined. The minimum followup was 24 months (median, 56 months; range, 24-122 months).

RESULTS

The local recurrence rate was 9%. Fifteen patients (25%) developed metastasis after diagnosis. Seven of the 59 patients (12%) had microscopic positive margins at resection.

CONCLUSIONS

Our data demonstrate no increase in local recurrence rates or rates of metastatic disease compared with previously published studies when resection of the core biopsy tract was not performed.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Three cases of melorheostosis with foot and ankle involvement

Melorheostosis is a rare and poorly understood condition of bone and soft tissue with a wide range of clinical presentations. This condition is typically characterized by cortical hyperostosis and pain in the involved extremity, but can also be associated with soft-tissue masses and limb deformities that may be additional sources of disability for those affected by this disease. Characteristic radiographic findings can aid in establishing an accurate diagnosis and the condition should not be mistaken for more aggressive neoplasms. This chronic condition is typically managed nonoperatively, but more invasive measures may be necessary when nonoperative measures fail. In cases of surgical intervention, physicians and patients should be aware that this disease has a high recurrence rate. Although there are only a few reports of melorheostosis in the foot and ankle, it is important to be aware of the difficulties the condition may cause in this anatomical location. Melorheostosis can be a source of significant morbidity when the foot and ankle are involved, especially when complicated by symptomatic soft-tissue masses. In this article, we report 3 cases of melorheostosis in the foot and ankle with distinct presentations and variations in outcomes.

Treatment and survival of osseous renal cell carcinoma metastases

BACKGROUND

Renal cell carcinoma is the seventh leading cause of cancer deaths. Studies have shown patients with solitary osseous metastases have a better prognosis; however, methods of resection are not well defined. The purpose of this study was to review factors associated with survival and assess the impact of wide versus intralesional management on function and disease-specific outcomes in patients with renal cell carcinoma metastases.

METHODS

Sixty-nine patients with 86 osseous renal cell metastases were reviewed. Potential factors associated with survival were evaluated with Kaplan-Meier curves. ANOVA was performed to compare means between groups.

RESULTS

One year survival for the group was 77% and 32.5% at 5 years. The absence of metastatic disease at presentation, nephrectomy, and pre-operative status were associated with improved survival. There was a lower rate of local recurrence with wide resection (5%) versus intralesional procedures (27%).

CONCLUSIONS

Improved pre-operative status, nephrectomy, and metachronous lesions had better overall survival. Wide resection results in decreased local recurrence and revision surgeries. However, it did not reliably predict improved survival. Our recommendation is for individual evaluation of each patient with osseous renal cell carcinoma metastases. Wide excision may be used for resectable lesions to prevent local progression and subsequent surgeries.

Failure mode classification for tumor endoprostheses: retrospective review of five institutions and a literature review

BACKGROUND

Massive endoprostheses provide orthopaedic oncologists with many reconstructive options after tumor resection, although failure rates are high. Because the number of these procedures is limited, failure of these devices has not been studied or classified adequately. This investigation is a multicenter review of the use of segmental endoprostheses with a focus on the modes, frequency, and timing of failure.

METHODS

Retrospective reviews of the operative databases of five institutions identified 2174 skeletally mature patients who received a large endoprosthesis for tumor resection. Patients who had failure of the endoprosthesis were identified, and the etiology and timing of failure were noted. Similar failures were tabulated and classified on the basis of the risk of amputation and urgency of treatment. Statistical analysis was performed to identify dependent relationships among mode of failure, anatomic location, and failure timing. A literature review was performed, and similar analyses were done for these data.

RESULTS

Five hundred and thirty-four failures were identified. Five modes of failure were identified and classified: soft-tissue failures (Type 1), aseptic loosening (Type 2), structural failures (Type 3), infection (Type 4), and tumor progression (Type 5). The most common mode of failure in this series was infection; in the literature, it was aseptic loosening. Statistical dependence was found between anatomic location and mode of failure and between mode of failure and time to failure. Significant differences were found in the incidence of failure mode Types 1, 2, 3, and 4 when polyaxial and uniaxial joints were compared. Significant dependence was also found between failure mode and anatomic location in the literature data.

CONCLUSIONS

There are five primary modes of endoprosthetic failure, and their relative incidences are significantly different and dependent on anatomic location. Mode of failure and time to failure also show a significant dependence. Because of these relationships, cumulative reporting of segmental failures should be avoided because anatomy-specific trends will be missed. Endoprosthetic design improvements should address failure modes specific to the anatomic location.

Peripheral nerve sheath tumors of the foot and ankle

BACKGROUND

Peripheral nerve sheath tumors (PNSTs) are soft tissue neoplasms found in intimate association with a peripheral nerve. They are rarely seen in the foot and ankle where they have an innocuous appearance, but these tumors have the potential to become malignant. This study reports a large series of foot and ankle PNSTs surgically treated at a single institution.

MATERIALS AND METHODS

Retrospectively, all cases of PNSTs confirmed by biopsy and surgically treated from 1992 to 2008 were included in the study. Preoperative, perioperative and postoperative variables were collected. Foot and ankle tumors were compared with the overall group of PNSTs. Fisher's test and Student's t-test were implemented to address the significance of the findings (p ≤ 0.05).

RESULTS

From all PNSTs identified (n = 137), there were 14 (10.2%) foot and ankle. A painful mass was the most common presenting symptom. Schwannoma represented the most common histologic type. Two cases of malignant foot and ankle PNSTs were identified. Foot and ankle PNSTs were significantly smaller in size and showed fewer postoperative neurologic deficits than the overall group of PNSTs. No differences were found in terms of histologic type distribution, age at diagnosis, duration of symptoms and postoperative tumor recurrence, but there was a preponderance of females in this series of foot and ankle tumors.

CONCLUSION

PNSTs of the foot and ankle usually present as innocuous, slow-growing masses leading to misdiagnosis and suboptimal surgical treatment of a potentially malignant lesion. A comprehensive diagnostic evaluation, preoperative planning and meticulous surgical excision are required to prevent tumor recurrence and minimize the incidence of postoperative sequelae, thus improving postoperative functional outcomes.

Hip abductor moment arm--a mathematical analysis for proximal femoral replacement

Background

Patients undergoing proximal femoral replacement for tumor resection often have compromised hip abductor muscles resulting in a Trendelenberg limp and hip instability. Commercially available proximal femoral prostheses offer several designs with varying sites of attachment for the abductor muscles, however, no analyses of these configurations have been performed to determine which design provides the longest moment arm for the hip abductor muscles during normal function.

Methods

This study analyzed hip abductor moment arm through hip adduction and abduction with a trigonometric mathematical model to evaluate the effects of alterations in anatomy and proximal femoral prosthesis design. Prosthesis dimensions were taken from technical schematics that were obtained from the prosthesis manufacturers. Manufacturers who contributed schematics for this investigation were Stryker Orthopaedics and Biomet.

Results

Superior and lateral displacement of the greater trochanter increased the hip abductor mechanical advantage for single-leg stance and adduction and preserved moment arm in the setting of Trendelenberg gait. Hip joint medialization resulted in less variance of the abductor moment arm through coronal motion. The Stryker GMRS endoprosthesis provided the longest moment arm in single-leg stance.

Conclusions

Hip abductor moment arm varies substantially throughout the hip's range of motion in the coronal plane. Selection of a proximal femur endoprosthesis with an abductor muscle insertion that is located superiorly and laterally will optimize hip abductor moment arm in single-leg stance compared to one located inferiorly or medially.

A biomechanical comparison of fan-folded, single-looped fascia lata with other graft tissues as a suitable substitute for anterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to evaluate the initial biomechanical properties of a fan-folded, single-loop construct of fan-folded fascia lata allograft in comparison to other graft tissues currently being used for anterior cruciate ligament (ACL) reconstruction.

METHODS

Eighteen fascia lata specimens were harvested from 11 donors and fan folded through a proprietary process. Bone-patellar tendon-bone (BPTB), tibialis anterior, tibialis posterior, and peroneus longus tendons were harvested from 4 additional donors. All soft-tissue grafts were tested to failure in an MTS machine (MTS Systems, Eden Prairie, MN) in a single-looped fashion. BPTB grafts were similarly clamped in freeze grips. The ultimate load to failure and stiffness were calculated for each graft type tested.

RESULTS

The mean ultimate load to failure was 3,266 N and stiffness was 414 N/mm for the single-looped fascia lata grafts (n = 18). There was no significant difference for ultimate load to failure and stiffness between the fascia lata and tibialis anterior (3,012 N and 342 N/mm, respectively), tibialis posterior (3,666 N and 392 N/mm, respectively), and peroneus longus (3,050 N and 346 N/mm, respectively) tendons. The fascia lata grafts performed significantly better (P < .001) than BPTB (1,404 N and 224 N/mm, respectively).

CONCLUSIONS

A single-loop construct of fan-folded fascia lata allograft has, on biomechanical testing, initial ultimate tensile strength (3,266 N) and stiffness values equivalent to or better than several other graft tissues currently used in ACL reconstruction, including BPTB (1,403 N), tibialis anterior (3,012 N), tibialis posterior (3,666 N), and peroneus longus (3,050 N).

CLINICAL RELEVANCE

In the face of potential allograft tissue shortages and increasing constraints on health care expenditures, the use of fascia lata has the potential to be a readily available graft for ACL reconstruction that performs as well as other grafts and at a comparable or lower cost.

Office-based core needle biopsy of bone and soft tissue malignancies: an accurate alternative to open biopsy with infrequent complications

BACKGROUND

Biopsy is a critical step in the diagnosis of musculoskeletal malignancy. As an alternative to open biopsy, percutaneous core needle biopsy techniques have been developed. As many studies combine office-based, image-guided, and operative biopsies, the accuracy of office-based core needle biopsy is not well documented.

QUESTION/PURPOSES

We asked whether (1) office-based core needle biopsy for the diagnosis of malignant musculoskeletal neoplasms would have few complications and diagnostic and accuracy rates comparable to those cited in the literature for core needle biopsy, (2) diagnostic errors related to office-based core needle biopsy would result in surgical treatment errors, and (3) tissue core quantity and tumor type would affect accuracy.

PATIENTS AND METHODS

We retrospectively reviewed 234 patients with 252 core needle biopsies of malignant bone and soft tissue neoplasms at one institution between 1999 and 2007. Biopsy accuracy and errors were determined on the basis of histologic evaluation of prior or subsequent biopsies and/or resected specimens, when available. We eliminated 19 patients who had needle biopsies: three had the core needle biopsy completed in the operating room and 16 had insufficient documentation or followup, leaving 233 for study.

RESULTS

Of the 233 core needle biopsies, 212 (91%) were diagnostic and accurate for malignancy. Fourteen (6%) biopsies were nondiagnostic. Major errors, defined as a benign diagnosis in a malignant tumor, occurred in seven cases (3%). Minor errors, defined as errors in histopathologic diagnosis or grade, occurred in 24 biopsies (10%). All nondiagnostic and major core needle biopsy errors were identified and addressed with either a diagnostic open biopsy or definitive wide local excision, resulting in no surgical treatment errors. Accuracy was not influenced by core number; however, myxoid lesions showed a correlation with biopsy error. There were no biopsy-related complications.

CONCLUSIONS

Office-based core needle biopsy for diagnosis of malignant musculoskeletal neoplasms has high diagnostic and accuracy rates without associated complications.

LEVEL OF EVIDENCE

Level II, diagnostic study. See the Guidelines for Authors for a complete description of the level of evidence.

Giant cell tumor of the distal femur associated with complete tumor necrosis

Giant cell tumor is a benign tumor of bone with a predilection for juxta-articular locations. Although not malignant, giant cell tumor often exhibits unpredictable and locally aggressive behavior, and in rare cases can metastasize in the absence of histologic malignancy. Partial tumor necrosis has been infrequently reported within typical giant cell tumor. A 17-year-old girl presented with a right distal femur giant cell tumor associated with complete tumor necrosis on histopathologic analysis. The etiology, prevalence, and implications of complete necrosis in previously untreated giant cell tumor of bone remain unclear, as there are no previously published reports. Despite the complete necrosis evident in our patient, she nonetheless presented with pain. There were no radiographic signs of the necrotic tumor space remodeling with new bone. The patient was treated with standard extended intralesional curetting through a generous cortical window permitting visualization of the entire lesion, and systematic high speed burring and thermal electrocautery ablation of the periphery, followed by micro particulate allogenic bone grafting. At short-term follow-up, she had healed well with no evidence of tumor recurrence. This article presents the first case, to our knowledge, of complete spontaneous tumor necrosis in a previously untreated bone giant cell tumor. Increased understanding of spontaneous tumor necrosis associated with giant cell tumor may help guided future targeted medical and surgical treatment modalities.