Utility of LEF1 to differentiate desmoid fibromatosis from its histologic mimics

Diagnosis of desmoid-type fibromatosis (DF) may be challenging on biopsy due to morphologic overlap with reactive fibrosis (scar) and other uniform spindle cell neoplasms. Evaluation of nuclear β-catenin, a surrogate of Wnt pathway activation, is often difficult in DF due to weak nuclear expression and high background membranous/cytoplasmic staining. Lymphoid enhancer-factor 1 (LEF1) is a recently characterized effector partner of β-catenin which activates the transcription of target genes. We investigated the performance of LEF1 and β-catenin immunohistochemistry in a retrospective series of 156 soft tissue tumors, including 35 DF, 3 superficial fibromatosis, and 121 histologic mimics (19 soft tissue perineurioma, 8 colorectal perineurioma, 4 intraneural perineurioma, 26 scars, 23 nodular fasciitis, 6 low-grade fibromyxoid sarcomas, 6 angioleiomyomas, 5 neurofibromas, 5 dermatofibrosarcoma protuberans, 3 low-grade myofibroblastic sarcomas, 3 synovial sarcomas, 3 inflammatory myofibroblastic tumors, 2 schwannomas, and 1 each of Gardner-associated fibroma, radiation-associated spindle cell sarcoma, sclerotic fibroma, dermatofibroma, and glomus tumor). LEF1 expression was not only seen in 33/35 (94%) of DF but also observed in 19/23 (82%) nodular fasciitis, 7/19 (37%) soft tissue perineurioma, 2/3 (66%) synovial sarcoma, and 6/26 (23%) scar, as well as in 1 radiation-associated spindle cell sarcoma. The sensitivity and specificity of LEF1 IHC for diagnosis of DF were 94% and 70%, respectively. By comparison, β-catenin offered similar sensitivity, 94%, but 88% specificity. Positivity for LEF1 and β-catenin in combination showed sensitivity of 89%, lower than the sensitivity of β-catenin alone (94%); however, the combination of both LEF1 and β-catenin improved specificity (96%) compared to the specificity of β-catenin alone (88%). Although LEF1 has imperfect specificity in isolation, this stain has diagnostic utility when used in combination with β-catenin.

Multivariate evaluation of prognostic markers in synovial sarcoma

AIMS

Synovial sarcoma (SS) is an aggressive neoplasm but with varied clinical outcomes despite standard treatment protocols. Several clinicopathological features and immunohistochemical stains have been proposed as prognostic markers in SS. The aim of this study was to evaluate SS from a single institution for prognostically relevant clinicopathological and immunohistochemical factors.

METHODS

We identified a single-institution cohort of SS with follow-up. Clinical and pathological factors examined included age, sex, tumour location, AJCC (American Joint Committee on Cancer) stage, tumour size, grade and status of surgical margins. Immunohistochemical staining for p16, p53, RB1, MYC, PTEN (phosphatase and tensin homologue), β-catenin, MDM2 and Ki67 proliferative index was performed on tissue microarray. Cox proportional hazard model was used for multivariate assessment of overall survival (OS) and disease-free survival (DFS).

RESULTS

133 patients with SS met the inclusion criteria for our cohort, with 100 having complete dataset for all study covariates. On Cox regression multivariate analysis, location (axial vs extremity, p<0.001), AJCC stage (p<0.001), p16 expression (≥75%, p=0.021) were significantly associated with worse OS, whereas PTEN intensity (score 2, p<0.001) and p53 expression (null/≥75%, p=0.013) were correlated with improved OS. For DFS analysis, location (axial vs extremity, p=0.030), tumour size (≥5 cm, p=0.009) and MYC expression (≥33%, p=0.013) were associated with inferior outcome. Only PTEN intensity (score 2, p<0.001) correlated with improved DFS.

CONCLUSIONS

In reviewing numerous clinicopathological and immunohistochemical markers, this study shows that location, AJCC stage, p16, p53 and PTEN expression were prognostically significant in multivariate analysis for OS in a uniformly treated SS cohort. Location, tumour size, MYC and PTEN expression were significantly associated with DFS.

Fluorescence lifetime of injected indocyanine green as a universal marker of solid tumours in patients

The surgical resection of solid tumours can be enhanced by fluorescence-guided imaging. However, variable tumour uptake and incomplete clearance of fluorescent dyes reduces the accuracy of distinguishing tumour from normal tissue via conventional fluorescence intensity-based imaging. Here we show that, after systemic injection of the near-infrared dye indocyanine green in patients with various types of solid tumour, the fluorescence lifetime (FLT) of tumour tissue is longer than the FLT of non-cancerous tissue. This tumour-specific shift in FLT can be used to distinguish tumours from normal tissue with an accuracy of over 97% across tumour types, and can be visualized at the cellular level using microscopy and in larger specimens through wide-field imaging. Unlike fluorescence intensity, which depends on imaging-system parameters, tissue depth and the amount of dye taken up by tumours, FLT is a photophysical property that is largely independent of these factors. FLT imaging with indocyanine green may improve the accuracy of cancer surgeries.

Titanium vs. carbon fiber-reinforced intramedullary nailing for humeral bone tumors

BACKGROUND

Multiple techniques have been described to treat humeral diaphyseal bone tumors requiring curettage or excision. Recent studies have suggested that carbon fiber-reinforced polyetheretherketone (CFR-PEEK) intramedullary nails (IMNs) may be preferable to titanium IMNs for patients with musculoskeletal tumors due to CFR-PEEK's high tensile strength, radiolucency, a modulus of elasticity closer to native bone, and improved postoperative surveillance/radiation dosing. In this study, we describe the rate of fixation failure for both CFR-PEEK and titanium humeral IMNs when used for humeral diaphyseal bone tumors requiring curettage or excision.

METHODS

This was a single-institution retrospective cohort study including 81 patients (27 CFR-PEEK and 54 titanium) treated for a humeral diaphyseal bone tumor using an IMN ± methylmethacrylate between January 2017 and December 2022. Primary outcome was revision surgery due to soft tissue complications, nonunions, structural complications such as periprosthetic fracture or IMN breakage, periprosthetic infection, tumor progression, and implant failure due to rejection or fatigue.

RESULTS

No failures were observed in either patients treated with titanium nails or patients treated with CFR-PEEK not requiring curettage. Fixation failure due to implant failure was observed in 2 cases-at 214 days and 469 days after surgery-where CFR-PEEK IMN was used for stabilization after a wide segmental resection for oncologic control with a cement spacer reconstruction. In both cases, the resection was larger than 6 cm, the remaining distal humerus was less than 5 cm, and failures occurred at the interface of the residual bone and spacer. Both patients were revised using a titanium distal posterolateral humeral plate fixed with screws and cables without any subsequent complications. One additional CFR-PEEK IMN required revision surgery after 744 days due to progression of the tumor and subsequent nonunion. One revision surgery was observed after 63 days for the titanium IMN because of nonunion and tumor progression.

CONCLUSIONS

Humeral diaphyseal bone tumors requiring large segmental resection with small residual bone and a large cement spacer may fail via tension due to bending forces at the distal portion. In this clinical scenario, the use of larger-diameter CFR-PEEK IMNs may be indicated when available. In the interim, use of intercalary allografts instead of cement spacers, additional fixation with a titanium plate distally, or the use of a titanium nail when using a cement spacer may be considered.

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.

What Are the Functional and Surgical Outcomes of Tibial Turnup-plasty for Salvage in Patients With Chronic Lower Extremity Infection?

BACKGROUND

Tibial turnup-plasty is a rarely performed surgical option for large bone defects of the distal or entire femur and can serve as an alternative to hip disarticulation or high above-knee amputation. It entails pedicled transport of the ipsilateral tibia with or without the proximal hindfoot for use as a vascularized autograft. It is rotated 180° in the coronal or sagittal plane to the remaining proximal femur or pelvis, augmenting the functional length of the thigh. Prior reports consist of small case series with heterogeneous surgical techniques. Patient-reported outcome measures after the procedure have not been reported, and ambulatory status after the procedure is also unknown.

QUESTIONS/PURPOSES

(1) What proportion of patients underwent reoperation after tibial turnup-plasty? (2) What is the ambulatory status and what proportion of patients used a prosthesis after tibial turnup-plasty? (3) What are the Patient-Reported Outcome Measurement Information System (PROMIS) Global-10 mental and physical function scores after tibial turnup-plasty?

METHODS

A retrospective analysis was performed of 11 patients who underwent tibial turnup-plasty between 2003 and 2021 by a single orthopaedic oncology division in collaboration with a reconstructive plastic surgery team. Nine patients were men, with a median age of 55 years (range 34 to 75 years). All had chronic infections after arthroplasty or oncologic reconstructions, with a median number of 13 surgeries before turnup-plasty. All were considered to have no other surgical options other than hip disarticulation or high transfemoral amputation. All patients who were offered this possibility accepted it. Data of interest included patient demographics and comorbidities, surgical history that led to limb compromise, medical and surgical perioperative complications, date of prosthesis fitting, and functional capacity at the most recent follow-up interval based on ambulatory status and PROMIS Global-10 mental and physical function scores. The statistical analysis was descriptive.

RESULTS

The median number of reoperations after turnup-plasty was one (range 0 to 11). Of the six patients who underwent at least one reoperation, indications for surgery included wound infection (four patients), nonunion of the osteosynthesis site (two), heterotopic ossification (one), tumor recurrence (one), and flap hypoperfusion treated with local tissue revision (one). One patient underwent conversion to external hemipelvectomy for tumor recurrence. Ten of the 11 patients were ambulatory at the final follow-up interval with standard above-knee amputation prostheses. Two ambulated unassisted, four used a single crutch or cane, and four used two crutches or a walker. Of the nine patients for whom scores were available, the median PROMIS Global-10 physical and mental health scores were 48 (range 30 to 68) and 53 (range 41 to 68), both within the standard deviation of the population mean of 50.

CONCLUSION

The tibial turnup-plasty is a complex surgical option for patients with large bone defects of the femur for whom there are no alternative surgeries capable of producing residual extremities with acceptable functional length. This should be viewed as a procedure of last resort to avoid a hip disarticulation or a high transfemoral amputation in patients who have typically undergone numerous prior operations. Although ambulation with a prosthesis within 1 year can be expected, almost all patients will require an assistive device to do so, and reoperations are frequent.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Orthopedic Surgery Fellowship Directors: Trends in Demographics, Education, Employment, and Institutional Familiarity

Background: Fellowship directors are assumed to be distinguished in orthopedics, but the traits and training that have enabled them to achieve their leadership positions have not been assessed. Purpose: We sought to identify common demographics, research output, and educational trends of fellowship directors in orthopedics, with an emphasis on racial, ethnic, and gender diversity. Methods: We conducted a literature review to identify published studies on fellowship directors in orthopedic surgery and found 4 cross-sectional studies of fellowship directors in spine, arthroplasty, pediatrics, and sports medicine subspecialties. Another 4 accredited orthopedic subspecialties and their fellowship directors were identified using the American College of Graduate Medical Education Public Accreditation Data System for 2020-2021 and national fellowship directories. Data endpoints included race/ethnicity, age, sex, residency and fellowship training institutions, year of fellowship completion, year of hire at current institution, year of fellowship directors appointment, and h-index. The demographics and educational backgrounds for listed fellowship directors were collected from curricula vitae (CVs). Results: Of the 537 fellowship directors identified among 8 orthopedic subspecialties, the average age was 52.9 ± 2.2 years, 5.6% (N = 30) were women, 79.1% (N = 406) were white, 12.5% (N = 64) were Asian American, 3.7% (N = 19) were African American, 2.9% (N = 15) were Middle Eastern, and 1.7% (N = 9) were Hispanic/Latino. Oncology 20% (N = 4) had the highest percentage of female fellowship directors; 37.6% (N = 202) of fellowship directors were at the same institution they trained at for residency or fellowship. Their average h-index was 18.6 ± 3.7. Conclusion: This study of fellowship directors in orthopedics found that they have a high research output and a high level of institutional familiarity. We identified a need for greater diversity in these leadership positions in both gender and race/ethnicity.

A novel core biopsy needle with shorter dead space for percutaneous image-guided musculoskeletal biopsies - how does it compare with an established core biopsy needle?

PURPOSE

To compare diagnostic yield and utility of a novel core biopsy needle (NCBN) with shortened tip dead space for percutaneous musculoskeletal biopsies with an established core biopsy needle (ECBN).

METHODS

This study was IRB approved and HIPAA compliant. All percutaneous biopsies using an NCBN performed between July 2020 and August 2021 were retrospectively reviewed. Data on patient demographics, biopsy technique, biopsy needle, and histopathology were collated.

RESULTS

Thirty-six patients were included in this study, 16 (44%) undergoing biopsy with both an NCBN and an ECBN, and 20 (56%) with an NCBN only. All 36 NCBN biopsies were 16 gauge. Fifteen (94%) of the ECBN biopsies were 14 gauge, and 1 (6%) was 16 gauge. Thirty-four (94%) of the NCBN and 15 (94%) of the ECBN biopsies were diagnostic. No adverse events were identified.

CONCLUSION

Both the NCBN and ECBN have high diagnostic rates. No adverse events were identified. NCBN could be considered for biopsy of lesions limited by anatomic location or near adjacent critical structures.

Fibrous and Fibro-Osseous Lesions of Bone

Fibrous and fibro-osseous tumors are some of the most common benign lesions involving bones. Although many of the histomorphologic features of these tumors overlap significantly, an interdisciplinary approach helps to consolidate the classification of these tumors. Herein, the clinical, radiologic, and pathologic features of lesions within these categories are described.

Oncological and Functional Outcomes in Joint-sparing Resections of the Proximal Femur for Malignant Primary Bone Tumors

BACKGROUND

Joint-sparing resections (JSR) of the proximal femur allow for preservation of the proximal femoral growth plate and native hip joint, but whether this offers fewer complications or better function and longevity of the reconstruction remains unknown. In this study, we compared the functional outcomes of pediatric patients with bone sarcomas undergoing JSR of the proximal femur with intercalary allograft (ICA) reconstruction to those undergoing proximal femoral resections (PFR) with allograft-prosthetic composite (APC) reconstructions.

METHODS

We retrospectively reviewed all patients undergoing JSR with ICA reconstruction and PFR with APC reconstructions between 1995 and 2013 at a tertiary pediatric referral center. Primary outcomes included major and minor complications and secondary outcomes included the need for a secondary procedure, presence of local or distant relapse, survival status, and the presence of pain and ambulatory status (limp, assistive device, highest level of function). We assessed differences in outcomes using the Fisher exact and Wilcoxon rank-sum tests.

RESULTS

Eight patients underwent a JSR and ICA reconstruction, while 7 patients underwent a PFR with APC reconstruction. Median patient follow-up was 60.4 months (interquartile range: 36.8 to 112.9) Patients undergoing JSR and ICA reconstruction were younger than patients undergoing PFR with APC reconstruction (7.7 vs. 11.7 y, P=0.043); however, we found no other statistically significant differences in patient demographics. There were no statistically significant differences in primary or secondary outcomes between the study groups; however, patients who underwent JSR with ICA had more major complications (62.5% vs. 42.9%, P=0.29) and a lower rate of minor complications (25% vs. 28.6%, P=0.22).

CONCLUSION

Treatment of proximal femoral bone sarcomas in pediatric and adolescent patients remains a challenging enterprise. JSR with ICA reconstruction in the proximal femur, when feasible, may provide a similar function and risk of intermediate-term major and minor complications when compared with PFR with APC reconstruction. Further long-term studies are required to determine the impact of the native femoral head retention with respect to revision rates.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Aneurysmal bone cyst with an unusual clinical presentation and a novel VDR-USP6 fusion

Aneurysmal bone cyst is a benign bone neoplasm that most commonly arises from the metaphyses of long bones in the first and second decades of life. Here, we describe a case of an aneurysmal bone cyst that occurred in the distal tibial diaphysis of a 72-year-old female that was concerning for malignancy on imaging, demonstrating cortical breakthrough and soft tissue extension. Histologically, the tumor showed the characteristic morphologic features of aneurysmal bone cyst. Fluorescence in situ hybridization was positive for USP6 rearrangement, and RNA sequencing revealed a USP6 gene fusion with VDR, a novel partner that encodes the vitamin D receptor and that has not been implicated previously in human neoplasia. This case highlights the diagnostic challenges presented by aneurysmal bone cyst in elderly adults, and it expands the genetic spectrum of USP6 rearrangements.

VAC temporization pending final margins after suprafascial myxofibrosarcoma excision to reduce the rate of local recurrence

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Background: The microinvasive nature of suprafascial myxofibrosarcoma complicates the accuracy of intraoperative margin assessment, and tumor bed resections after soft tissue reconstruction are unreliable. For the past 3 years we have temporized the excised tumor bed with a wound VAC, delaying soft tissue coverage until final negative margins were achieved. Here, we compare the oncologic/surgical outcomes of suprafascial myxofibrosarcomas managed with VAC temporization (VT) with single-stage excision/reconstruction (SS). Methods: We retrospectively studied suprafascial myxofibrosarcomas managed from 1/1/2000 to 1/1/2019 who received neoadjuvant or adjuvant radiation and had at least 2-years of oncologic follow-up at a tertiary referral cancer center. Our primary outcome was local recurrence. Comparisons were performed using Fisher’s Exact Test or Students t-test. A p-value < 0.05 was considered significant. Results: Fifty-three patients (18 VAC temporized, 35 single stage) were included. While VT patients were older (74.9 ± 10.2 vs. 63.9 ± 13.6, p = 0.003), treatment groups did not significantly differ with respect to comorbidity, tumor volume, stage and grade. VT patients had significantly fewer local recurrences (5.6% vs. 28.6% after SS, p = 0.048) and R1 resections that required an unplanned readmission for tumor bed re-excision (0% vs. 37.1% after SS, p = 0.002). VT required more total surgeries (2.8 ± 0.9 vs. 1.8 ± 0.9 for SS, p = 0.0002). Post-operative infectious and wound complications were equivalent (Table). Conclusions: Our VAC temporization strategy had a significantly lower LR than SS treatment. While high quality multi-institutional validation is required, VT may represent a paradigm shift in the management of myxofibrosarcoma.[Table: see text]

Outcomes of VAC temporization following the excision of microinvasive sarcomas pending negative formal pathologic margins

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Background: Microinvasive sarcomas can yield a high number of false negative intraoperative pathology margin analyses. Additional oncologic resection after soft tissue coverage is technically challenging and oncologically inaccurate. As a result the rate of local recurrence for these histologies can be 25% or higher. In select patients we have temporized the sarcoma tumor bed with a wound VAC pending final pathologic margins. If positive, the patient can return to the OR for a tumor bed excision. If negative, soft tissue coverage can proceed. Here we evaluate our outcomes using this approach. Methods: We retrospectively studied patients with primary sarcomas managed with a VAC temporizing approach from from 1/1/2003 to 12/1/2019 with a minimum of 2 years of oncologic follow-up. Patients with unplanned ("oopsie") excisions were also included. Our primary outcome was local recurrence. Data is presented as percentages or mean ± standard deviation where appropriate. Results: Sixty-three patients were included (Table). Mean age was 62.3 ± 22.3 (median 67.3) years, 23 (36.5%) were female, and mean age-adjusted charlson comorbidity index was 5.3 ± 1.9. Twenty-four (38.1%) had undergone “oopsie” excisions. R0 margins were achieved in 59 (93.7%) patients, while the other 4 were known R1 resections due to patient tolerance or anatomy. Five local recurrences (7.9%) were diagnosed 3.2 ± 1.5 years after surgery, of which 3 had known positive margins. Free flaps were needed in 17 (27.0%) patients. Metastatic disease was diagnosed in 8 (12.7%) patients, who all died of disease. Mean follow-up was 4.4 ± 2.9 years. Conclusions: VAC temporization results few local recurrences in patients with formally confirmed negative margins. This technique is particularly useful in the treatment of microinvasive disease or in the management of vulnerable hosts who may not be able to tolerate additional surgery in the future.[Table: see text]

Low-dose preoperative radiation, resection, and reduced-field postoperative radiation for soft tissue sarcomas

BACKGROUND AND OBJECTIVES

Radiotherapy (RT) enables conservative surgery for soft tissue sarcoma (STS). RT can be delivered either pre-operatively (PreRT) or postoperatively (PORT), yet in some patients, neither approach is fully satisfactory (e.g., urgent surgery or wound healing risk prevents PreRT, yet PORT alone cannot cover the entire surgical field). We hypothesized that, in such situations, low-dose PreRT (LD-PreRT) would decrease the risk of intraoperative tumor seeding and thus permit PORT to a reduced volume (covering the high-risk tumor bed but not all surgically manipulated tissues).

METHODS

We identified a single-institution retrospective cohort of 78 patients treated with LD-PreRT (10-30 Gy), resection, and PORT between 1980 and 2018.

RESULTS

At a median follow-up of 8.2 years, 8-year overall survival (OS) was 65.9%, disease-free survival (DFS) 50.5%, and local control (LC) 76.7%; in 45 patients with extremity/superficial trunk (E/ST) STS, 8-year LC was 80.9%. Both before and after propensity score adjustment, there were no differences in OS, DFS, or LC between this cohort and a separate cohort of 394 STS (221 E/ST-STS) patients treated with surgery and PORT alone.

CONCLUSIONS

In patients for whom neither PreRT nor PORT alone is optimal, LD-PreRT may prevent intraoperative tumor seeding and enable PORT to a reduced volume while preserving oncologic outcomes.

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.

Survivorship of Megaprostheses in Revision Hip and Knee Arthroplasty for Septic and Aseptic Indications: A Retrospective, Multicenter Study With Minimum 2-Year Follow-Up

Background

The use of megaprostheses in nononcologic patients has been associated with complication rates greater than 50%. In patients with prior periprosthetic joint infection (PJI) with subsequent two-stage reimplantation, this complication rate may be even higher. This study was to investigate the outcomes of megaprostheses in nononcologic patients undergoing revision hip/knee arthroplasty.

Methods

We retrospectively studied patients who underwent megaprosthesis replacements from 1999 to 2017 at 5 hospitals with minimum 24 months of follow-up. Patients were stratified based on history of prior PJI (septic vs aseptic) and location of the megaprosthesis (the hip or knee). Postoperative complications were classified as soft-tissue failure, aseptic loosening, structural failure, and infection.

Results

Of the 42 patients, 19 were in the septic cohort and 23 were in the aseptic cohort. The overall complication rate was 28.6%. Complication rates for the septic and aseptic cohorts were 32% and 26%, respectively (P = .74). By anatomic location, there were 2 of 13 (15%) and 10 of 29 (34%) complications in the hip and knee groups, respectively (P = .28). In the septic cohort, there were no (0%) complications in the hip group and 6 of 14 (43%) complications in the knee group (P = .13), all due to infection. In the aseptic cohort, there were 2 of 8 (25%) and 4 of 15 (27%) complications in the hip and knee groups, respectively (P = 1.0).

Conclusions

There is no difference in the postoperative complication rates between the septic or aseptic cohorts undergoing revision hip or knee megaprosthesis replacements. In patients with prior PJI, proximal femoral replacements have improved short-term survivorship compared with distal femoral or proximal tibial replacements.

Inter-rater Variability in the Interpretation of Pre and Post Contrast MRI for Pre-Surgical Evaluation of Osteosarcoma in Long Bones in Pediatric Patients and Young Adults

BACKGROUND AND OBJECTIVES

The value of gadolinium enhanced magnetic resonance imaging (MRI) sequences for extremity osteosarcoma resection planning is unverified. We evaluate the performance of intravenous gadolinium enhanced MRI for identification of neurovascular bundle involvement (NBI) and intraarticular extension (IAE) in patients with osteosarcoma.

METHODS

Two pediatric radiologists independently analyzed MRI examinations of patients with pathology proven extremity osteosarcoma for NBI and IAE. Initial evaluation utilized only non-contrast MRI images (PRE) and, after 2 weeks, subsequent evaluation included both the pre and post contrast images (POST). Cohen's Kappa and McNemar's test were calculated to assess agreement between PRE and POST image interpretations of NBI and IAE.

RESULTS

56 patients with 90 preoperative MRI examinations were analyzed. PRE and POST interpretations were rarely discordant; 4/90 cases for NBI (Kappa 0.91) and 2/90 cases for IAE (Kappa 0.95). McNemar's test did not show a difference between PRE and POST imaging (NBI p=0.62; IAE p=0.48).

CONCLUSION

No significant difference between PRE and POST image interpretation was found. A high level of agreement between PRE and POST image interpretation suggests that pre-contrast MRI may be sufficient for pre-surgical planning for pediatric patients with long bone osteosarcoma.

A Phase 1 Study of Nilotinib Plus Radiation in High-Risk Chordoma

PURPOSE

Chordomas are malignant tumors arising from remnant notochordal tissue. Despite improved local control with preoperative/postoperative radiation therapy (RT), progression-free survival and overall survival (OS) remain poor in patients with high-risk features. Chordoma has been identified to express and activate platelet-derived growth factor receptor signaling. We conducted a phase 1 trial to identify the maximum tolerated dose (MTD), safety, and feasibility of nilotinib with RT as either preoperative or definitive treatment for patients with high-risk chordoma.

METHODS AND MATERIALS

We recruited 23 patients with high-risk, nonmetastatic chordoma. High risk was defined as the presence of any of the following: local recurrence after surgery, previous intralesional resection, unplanned incomplete resection, unresectable or marginally resectable disease based on locally advanced stage, or declining surgery because of excessive morbidity. Patients were treated with nilotinib and concurrent RT to 50.4 Gy relative biological effectiveness (RBE) followed by surgery and postoperative RT to a cumulative dose up to 70.2 Gy RBE or definitively up to 77.4 Gy RBE without surgery. On completion of RT, patients were eligible to continue nilotinib until disease progression.

RESULTS

In patients receiving nilotinib 200 mg twice daily with RT, 3 dose-limiting toxicities (DLT) occurred in 5 patients. One DLT was seen among 6 patients receiving nilotinib 200 mg daily with RT. Therefore, 200 mg daily was declared the maximum tolerated dose. Eleven additional patients received nilotinib with RT at the maximum tolerated dose, and 1 additional DLT occurred. The objective best response rate was 6% (1 of 18 patients, 95% confidence interval [CI], 0.1%-27%). The median progression-free survival was 58.15 months (95% CI, 39.10-∞). The median OS was 61.5 months (43.1-∞), and the 2-year OS rate was 95%.

CONCLUSIONS

Nilotinib 200 mg/d with RT is safe and tolerated in patients with high-risk chordoma. Long-term follow-up is needed to understand whether nilotinib combined with RT, with or without surgery, adds greater improvement to progression-free survival or OS than with RT with or without surgery alone in patients with high-risk chordoma.

Targeting ABCB1 (MDR1) in multi-drug resistant osteosarcoma cells using the CRISPR-Cas9 system to reverse drug resistance

Background

Multi-drug resistance (MDR) remains a significant obstacle to successful chemotherapy treatment for osteosarcoma patients. One of the central causes of MDR is the overexpression of the membrane bound drug transporter protein P-glycoprotein (P-gp), which is the protein product of the MDR gene ABCB1. Though several methods have been reported to reverse MDR in vitro and in vivo when combined with anticancer drugs, they have yet to be proven useful in the clinical setting.

Results

The meta-analysis demonstrated that a high level of P-gp may predict poor survival in patients with osteosarcoma. The expression of P-gp can be efficiently blocked by the clustered regularly interspaced short palindromic repeats (CRISPR)-associated Cas9 system (CRISPR-Cas9). Inhibition of ABCB1 was associated with reversing drug resistance in osteosarcoma MDR cell lines (KHOSR2 and U-2OSR2) to doxorubicin.

Materials and Methods

We performed a meta-analysis to investigate the relationship between P-gp expression and survival in patients with osteosarcoma. Then we adopted the CRISPR-Cas9, a robust and highly efficient novel genome editing tool, to determine its effect on reversing drug resistance by targeting endogenous ABCB1 gene at the DNA level in osteosarcoma MDR cell lines.

Conclusion

These results suggest that the CRISPR-Cas9 system is a useful tool for the modification of ABCB1 gene, and may be useful in extending the long-term efficacy of chemotherapy by overcoming P-gp-mediated MDR in the clinical setting.

miR-15b modulates multidrug resistance in human osteosarcoma in vitro and in vivo

The development of multidrug resistance (MDR) in cancer cells to chemotherapy drugs continues to be a major clinical problem. MicroRNAs (miRNA, miR) play an important role in regulating tumour cell growth and survival; however, the role of miRs in the development of drug resistance in osteosarcoma cells is largely uncharacterized. We sought to identify and characterize human miRs that act as key regulators of MDR in osteosarcoma. We utilized a miR microarray to screen for differentially expressed miRs in osteosarcoma MDR cell lines. We determined the mechanisms of the deregulation of expression of miR-15b in osteosarcoma MDR cell lines, and its association with clinically obtained tumour samples was examined in tissue microarray (TMA). The significance of miR-15b in reversing drug resistance was evaluated in a mouse xenograft model of MDR osteosarcoma. We identified miR-15b as being significantly (P < 0.01) downregulated in KHOS_MR and U-2OS_MR cell lines as compared with their parental cell lines. We found that Wee1 is a target gene of miR-15b and observed that transfection with miR-15b inhibits Wee1 expression and partially reverses MDR in osteosarcoma cell lines. Systemic in vivo administration of miR-15b mimics sensitizes resistant cells to doxorubicin and induces cell death in MDR models of osteosarcoma. Clinically, reduced miR-15b expression was associated with poor patient survival. Osteosarcoma patients with low miR-15b expression levels had significantly shorter survival times than patients with high expression levels of miR-15b. These results collectively indicate that MDR in osteosarcoma is associated with downregulation of miR-15b, and miR-15b reconstitution can reverse chemotherapy resistance in osteosarcoma.

Non-neoplastic soft tissue masses that mimic sarcoma

Non-neoplastic soft tissue masses may mimic soft tissue sarcoma in a wide variety of clinical settings. Systematic and thorough review of patient history, physical examination, imaging, laboratory results, and biopsy will allow the clinician to differentiate between the two in most cases. We describe several common non-neoplastic entities that may mimic soft tissue sarcoma in case presentation format along with the characteristics that help distinguish them.

Immediate weight bearing after modified percutaneous Achilles tendon repair

BACKGROUND

Controversy exists regarding postoperative treatment of Achilles tendon repair. The purpose of this study was to evaluate the results of immediate weight bearing following modified percutaneous Achilles tendon repair using readily available materials.

METHODS

Fifty-two patients who were treated at a single center from 2000 to 2009 underwent percutaneous Achilles tendon repair by a single surgeon and were allowed immediate weight bearing. They were followed for on average of 2 years postoperatively and evaluated with functional and subjective outcomes.

RESULTS

The average American Orthopaedic Foot and Ankle Society ankle-hindfoot scale was 96 points (range, 81 to 100), with 95% confidence interval ranging from 89.1 to 102.9. Subjective evaluation demonstrated that 47 patients (90%) were able to return to a desired level of activity, with an overall complication rate of 11.5%.

CONCLUSION

Immediate weight bearing after percutaneous Achilles tendon repair had a low overall complication rate with good clinical and functional outcomes.

Elbow position affects distal radioulnar joint kinematics

PURPOSE

Previous in vivo and in vitro studies of forearm supination-pronation suggest that distal radioulnar joint kinematics may be affected by elbow flexion. The primary hypotheses tested by this study were that, in vivo, ulnar variance changes with elbow flexion and forearm rotation, and the arc of forearm rotation changes in relationship to elbow flexion.

METHODS

Changes in radioulnar kinematics during forearm supination-pronation and elbow flexion (0 degrees to 90 degrees ) were studied in 5 uninjured subjects using computed tomography, dual-orthogonal fluoroscopy, and 3-dimensional modeling. Analysis of variance and post-hoc testing was performed.

RESULTS

Proximal translation of the radius was greatest with the elbow flexed to 90 degrees with the arm in midpronation. With the arm in midpronation, the translation of the radius was significantly greater at 0 degrees versus 45 degrees of elbow flexion (0.82 +/- 0.59 mm vs 0.65 +/- 0.80 mm, F: 4.49, post hoc: 0.055; p = .05) and significantly smaller at 45 degrees versus 90 degrees of elbow flexion (0.65 +/- 0.80 mm vs 0.97 +/- 0.35 mm, F: 4.49, post hoc: 0.048; p = .05). Proximal translation of the radius in midpronation was significantly greater than when the forearm was in a supinated position when the elbow was at 0 degrees or 90 degrees flexion (F: 14.90, post hoc: <0.01; p < .01, F: 19.11, post hoc: <0.01, p < .01). The arc of forearm rotation was significantly decreased at 0 degrees compared with 90 degrees of elbow flexion (129.3 degrees +/- 22.2 degrees vs 152.8 degrees +/- 14.4 degrees , F: 3.29, post hoc: 0.79; p = .09). The center of rotation shifted volarly and ulnarly with increasing elbow extension.

CONCLUSIONS

Elbow position affects the kinematics of the distal radioulnar joint. The kinematics of the distal radioulnar joint are primarily affected by forearm rotation and secondarily by elbow flexion. These findings have clinical relevance to our understanding of ulnar impaction, and how elbow position affects the proximal-distal translation of the radius. These findings have implications for the treatment of ulna impaction, radiographic evaluation of the distal ulna, and future biomechanical studies.

Predictors of acute carpal tunnel syndrome associated with fracture of the distal radius

PURPOSE

A better understanding of the risk factors for acute carpal tunnel syndrome (CTS) associated with fracture of the distal radius might influence recommendations for prophylactic carpal tunnel release.

METHODS

Fifty patients who had release of an acute CTS in association with open reduction and internal fixation (ORIF) of a fracture of the distal radius were identified from orthopedic trauma databases at 2 institutions. Each patient was matched with a control patient (ORIF, but no acute CTS) of the same gender, similar age (+/-4 years), and similar injury mechanism.

RESULTS

The prevalence of acute CTS among patients with a surgically treated fracture of the distal radius was 5.4%. In univariate analysis, only fracture translation was a significant predictor of acute CTS, but ipsilateral upper extremity trauma and status as a multitrauma patient were nearly significant. The best multivariate model included fracture translation alone and accounted for 60% of the observed increase in risk. A subgroup analysis using receiver operating characteristics (ROC) identified a threshold of approximately 35% fracture translation associated with a significantly increased risk of acute CTS in women less than 48 years of age. No threshold was identified in the other 3 subgroups.

CONCLUSIONS

Fracture translation is the most important risk factor for acute CTS in patients who subsequently had ORIF of a fracture of the distal radius. On the basis of these data, prophylactic carpal tunnel release might be appropriate in women less than 48 years of age with greater than 35% fracture translation, but further investigation is needed to confirm that a true threshold exists.

Injection of dexamethasone versus placebo for lateral elbow pain: a prospective, double-blind, randomized clinical trial

PURPOSE

We tested the hypothesis that there is no difference in disability, pain, and grip strength 1 and 6 months after corticosteroid and lidocaine injection compared with lidocaine injection alone (placebo).

METHODS

Sixty-four patients were randomly assigned to dexamethasone (n = 31) or placebo (n = 33) injection. At enrollment, disability (Disabilities of the Arm, Shoulder, and Hand [DASH] questionnaire), pain on a visual analog scale, grip strength, depression (the Center for Epidemiologic Studies Depression Scale; CESD), and ineffective coping skills (the Pain Catastrophizing Scale; PCS) were comparable between treatment groups. At 1 and 6 months, DASH, pain, and grip strength measures were repeated. Univariate and multivariate analyses were used to determine predictors of disability. Analysis was by intention to treat.

RESULTS

One month after injection, DASH scores averaged 24 versus 27 points (dexamethasone vs placebo), pain 3.7 versus 4.3 cm, and grip strength 83% versus 87%. At 6 months, DASH scores averaged 18 versus 13 points, pain 2.4 versus 1.7 cm, and grip strength 98% versus 97%. CESD and PCS scores correlated with disability as measured by the DASH questionnaire. The best multivariate models included CESD at 1 month and PCS scores at 6 months and explained the majority of variability in DASH scores.

CONCLUSIONS

Corticosteroid injection did not affect the apparently self-limited course of lateral elbow pain. In secondary analyses in a subset of patients, perceived disability associated with lateral elbow pain correlated with depression and ineffective coping skills.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic I.

Stigmatization of repetitive hand use in newspaper reports of hand illness

Failure to provide a balanced evidence-based consideration of the role of activity in illness can stigmatize individuals and their activities. We assessed the prevalence of language that stigmatized repetitive hand use and those that use their hand repetitively in newspaper coverage of common hand illnesses. The LexisNexis Academic database was used to search five major US newspapers for articles containing keywords about common hand illnesses during a 3-year period. Article language was assessed for stigmatization of activities involving repetitive hand use as well as for stigmatization of patients who use their hand repetitively. One hundred and twenty-four articles on hand illnesses were identified. Of these, 65.3% of articles stigmatized activities involving repetitive hand use, including 96.6% of articles discussing overuse injury of the hand, 90% of articles discussing tendonitis or tenosynovitis, and 51.8% of articles discussing carpal tunnel syndrome. Patient stigmatization was documented in 30.6% of the newspaper articles. Stigmatizing statements were most commonly made by journalists (94.8%), followed by patients (3.1%), and physicians (2.1%). Language that stigmatizes repetitive hand use and patients who use their hand repetitively is prevalent among US newspaper articles. Both health professionals and journalists reporting health-related news should be more sensitive to the use of stigmatizing language and provide a more balanced, measured, and evidenced-based account of hand illnesses.

Computed tomography of suspected scaphoid fractures

PURPOSE

Computed tomography (CT) can be used to triage suspected scaphoid fractures. This study assessed intraobserver and interobserver reliability and positive and negative predictive values of CT for the diagnosis of a nondisplaced scaphoid fracture.

METHODS

Eight observers evaluated CT scans from 30 patients (13 with nondisplaced scaphoid fractures, 17 with no scaphoid fractures) for the presence or absence of a fracture. Five observers evaluated the scans a second time. Statistical analyses included intraobserver and interobserver reliability and diagnostic characteristics.

RESULTS

Computed tomography had substantial intraobserver and interobserver reliability for the diagnosis of a nondisplaced scaphoid fracture. The average sensitivity, specificity, and accuracy of CT for a nondisplaced scaphoid fracture were 89%, 91%, and 90% for the first round and 97%, 85%, and 88% for the second round of observations, respectively. Based on an estimated prevalence of 5% true fractures among patients with suspected scaphoid fractures, the average positive predictive value for the detection of radiographically occult scaphoid fractures with tomography of the wrist was 0.28. The average negative predictive value was 0.99.

CONCLUSIONS

Computed tomography should be used with caution for triage of nondisplaced scaphoid fractures because false-positive results occur, perhaps from misinterpretation of vascular foraminae or other normal lines in the scaphoid. Given the relative infrequency of true fractures among patients with suspected scaphoid fractures, CT is better for ruling out a fracture than for ruling one in.

The volar extension of the lunate facet of the distal radius: a quantitative anatomic study

PURPOSE

To describe quantitatively the protrusion of the volar part of the lunate facet of the distal radius articular surface anterior to the volar metaphyseal cortex, which is susceptible to fracture and can be difficult to control with plates and screws alone.

METHODS

Quantitative anatomic measurements of 48 3-dimensional computed tomography scans of the distal radius were analyzed to quantify the anatomy of the volar part of the lunate facet of the distal radius. The measurements were scaled to account for overall bone size. Male and female anatomies were compared.

RESULTS

The height and width of the volar extension of the lunate facet were 3 +/- 1 mm and 19 +/- 4 mm, respectively. The mean height of the lunate facet was 19 +/- 3 mm. An average of 16% of the lunate facet projects anterior to the flat volar surface of the distal radius. The thickness of the volar extension of the lunate facet averaged 5 +/- 1 mm. There were no statistically significant differences between men and women for any of the scaled measurements.

CONCLUSIONS

The observation that the volar lunate facet projects approximately 3 mm (or 16% of the dorsal-volar height of the lunate facet) anterior to the flat volar surface of the distal radius and is approximately 5 mm thick helps explain its relative vulnerability to injury and the difficulty encountered when trying to secure it with a plate and screws.