Survival and failure modes of the Compress® spindle and expandable distal femur endoprosthesis among pediatric patients: A multi-institutional study.

BACKGROUND: Expandable endoprostheses can be used to equalize limb length for pediatric patients requiring reconstruction following large bony oncologic resections. Outcomes of the Compress® Compliant Pre-Stress (CPS) spindle paired with an Orthopedic Salvage System expandable distal femur endoprosthesis have not been reported. METHODS: We conducted a multi-institutional retrospective study of pediatric patients with distal femoral bone sarcomas reconstructed with the above endoprostheses. Statistical analysis utilized Kaplan-Meier survival technique and competing risk analysis. RESULTS: Thirty-six patients were included from five institutions. Spindle survivorship was 86.3% (95% confidence interval [CI], 67.7-93.5) at 10 years. Two patients had a failure of osseointegration (5.7%), both within 12 months. Twenty-two (59%) patients had 70 lengthening procedures, with mean expansions of 3.2 cm (range: 1-9) over 3.4 surgeries. The expandable mechanism failed in eight patients with a cumulative incidence of 16.1% (95% CI, 5.6-31.5) at 5 years. Twenty-nine patients sustained International Society of Limb Salvage failures requiring 63 unplanned surgeries. Periprosthetic joint infection occurred in six patients (16.7%). Limb preservation rate was 91% at 10 years. CONCLUSIONS: There is a high rate of osseointegration of the Compress® spindle among pediatric patients when coupled with an expandable implant. However, there is a high rate of expansion mechanism failure and prosthetic joint infections requiring revision surgery. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Factors Associated with Osteoid Osteoma Recurrence after CT-Guided Radiofrequency Ablation.

PURPOSE: To identify clinical and imaging variables associated with symptomatic recurrence of osteoid osteomas (OOs) treated with computerized tomography (CT)-guided radiofrequency (RF) ablation. MATERIALS AND METHODS: Seventy-one patients treated with the use of CT-guided RF ablation for OO at a single institution from July 2005 to May 2018 were included in this retrospective cohort analysis. Clinical data, including patient age, sex, race, and clinical outcomes, were collected from institutional electronic health records and telephone follow-up. Imaging variables regarding tumor characteristics were gathered from imaging reports and a blinded review of preprocedural images by an experienced musculoskeletal radiologist. Logistic regression, Cox proportional hazards, and Kaplan-Meier analyses were used to identify variables that are significantly associated with symptomatic recurrence, which was defined as pain occurring > 2 weeks after RF ablation. RESULTS: Ten patients (14.1%) experienced symptomatic recurrence at a median of 21.5 months after RF ablation. Univariable logistic regression classified young age (≤ 13 years), female sex, maximum tumor length, and "eccentricity index" (EI) ≥ 3 as predictive variables significantly associated with symptomatic recurrence. Multivariable logistic regression identified female sex and EI ≥ 3 to be significant predictors for symptomatic recurrence. A multivariable proportional hazards Cox regression of time to recurrence revealed EI ≥ 3 to be the only significant predictor of symptomatic recurrence. CONCLUSIONS: Female patients with OOs with an EI ≥ 3 have a greater risk of symptomatic recurrence following RF ablation. The EI is a useful tool to identify OOs with elongated 3-dimensional morphology, which may warrant more extensive ablation.

Soft Tissue Sarcoma, Version 2.2018, NCCN Clinical Practice Guidelines in Oncology.

Soft tissue sarcomas (STS) are rare solid tumors of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Guidelines for STS provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as intra-abdominal/retroperitoneal STS, gastrointestinal stromal tumors, desmoid tumors, and rhabdomyosarcoma. This portion of the NCCN Guidelines discusses general principles for the diagnosis, staging, and treatment of STS of the extremities, superficial trunk, or head and neck; outlines treatment recommendations by disease stage; and reviews the evidence to support the guidelines recommendations.

NCCN Guidelines Insights: Bone Cancer, Version 2.2017.

The NCCN Guidelines for Bone Cancer provide interdisciplinary recommendations for treating chordoma, chondrosarcoma, giant cell tumor of bone, Ewing sarcoma, and osteosarcoma. These NCCN Guidelines Insights summarize the NCCN Bone Cancer Panel's guideline recommendations for treating Ewing sarcoma. The data underlying these treatment recommendations are also discussed.

Soft Tissue Sarcoma, Version 2.2016, NCCN Clinical Practice Guidelines in Oncology.

Soft tissue sarcomas (STS) are rare solid tumors of mesenchymal cell origin that display a heterogenous mix of clinical and pathologic characteristics. STS can develop from fat, muscle, nerves, blood vessels, and other connective tissues. The evaluation and treatment of patients with STS requires a multidisciplinary team with demonstrated expertise in the management of these tumors. The complete NCCN Guidelines for Soft Tissue Sarcoma (available at NCCN.org) provide recommendations for the diagnosis, evaluation, and treatment of extremity/superficial trunk/head and neck STS, as well as intra-abdominal/retroperitoneal STS, gastrointestinal stromal tumor, desmoid tumors, and rhabdomyosarcoma. This manuscript discusses guiding principles for the diagnosis and staging of STS and evidence for treatment modalities that include surgery, radiation, chemoradiation, chemotherapy, and targeted therapy.

How Often Does Spindle Failure Occur in Compressive Osseointegration Endoprostheses for Oncologic Reconstruction?

BACKGROUND: Compressive osseointegration is a promising modality for limb salvage in distal femoral oncologic tumors. However, few studies have explored short-term survival rates in a large patient cohort of distal femur compressive endoprostheses or highlighted the risk factors for spindle failures. QUESTIONS/PURPOSES: We asked: (1) What is the frequency of compressive osseointegration spindle failure in distal femoral reconstructions? (2) What are the characteristics of rotational failure cases with distal femur compressive osseointegration endoprostheses? (3) What are the risk factors for mechanical and rotational failure of distal femur compressive osseointegration implantation? (4) What are other modalities of failure or causes of revision surgery, which affect patients undergoing distal femur compressive osseointegration implantation for oncologic reconstruction? METHODS: Between 1996 and 2013, 127 distal femoral reconstructions with the Compress(®) prosthesis were performed in 121 patients. During that time, 116 Compress(®) prostheses were implanted for aggressive primary tumors of the distal femur and/or failure of previous oncologic reconstruction. This approach represented approximately 91% of the distal femoral reconstructions performed during that time. Of the patients with prostheses implanted, four patients (four of 116, 3%) had died, and 37 (37 of 116, 32%) were lost to followup before 24 months. The median followup was 84 months (range, 24-198 months), and 71 patients (66% of all patients) were seen within the last 3 years. A retrospective chart review was performed to determine failure modality as defined by radiographs, clinical history, and intraoperative findings. Risk factors including age, sex, BMI, resection length, and perioperative chemotherapy were analyzed to determine effect on spindle and rotational failure rates. Survival analysis was determined using the Kaplan-Meier estimator. Differences in survival between groups were analyzed using the log rank test. Risk factors were determined using Cox proportional hazard modeling. RESULTS: Spindle survival at 5 and 10 years was 91% (95% CI, 82%-95%). Survival rates from rotational failure at 5 and 10 years were 92% (95% CI, 83%-96%); the majority of failures occurred within the first 2 years postoperatively and were the result of a twisting mechanism of injury. With the numbers available, none of the potential risk factors examined were associated with mechanical failure. The 5-year and 10-year all-cause revision-free survival rates were 57% (95% CI, 44%-67%) and 50% (95% CI, 36%-61%), respectively. CONCLUSIONS: Distal femur compressive osseointegration is a viable method for endoprosthetic reconstruction. Rotational failure is rare with the majority occurring early. No variables were found to correlate with increased risk of mechanical failure. More research is needed to evaluate methods of preventing mechanical and rotational failures in addition to other common causes of revision such as infection in these massive endoprosthetic reconstructions. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Gastrointestinal stromal tumors, version 2.2014.

Gastrointestinal stromal tumors (GIST) are the most common soft tissue sarcoma of the gastrointestinal tract, resulting most commonly from KIT or platelet-derived growth factor receptor α (PDGFRα)-activating mutations. These NCCN Guideline Insights highlight the important updates to the NCCN Guidelines for Soft Tissue Sarcoma specific to the management of patients with GIST experiencing disease progression while on imatinib and/or sunitinib.

Soft tissue sarcoma, version 2.2014.

These NCCN Guidelines Insights highlight the important updates to the NCCN Guidelines for Soft Tissue Sarcoma (STS) specific to the role of radiation therapy in the management of patients with retroperitoneal/intra-abdominal STS. The guidelines have also included recommendations for genetic testing and counseling for patients with a clinical and/or family history of genetic cancer syndromes associated with a predisposition for the development of STS.

Bone cancer.

Primary bone cancers are extremely rare neoplasms, accounting for fewer than 0.2% of all cancers. The evaluation and treatment of patients with bone cancers requires a multidisciplinary team of physicians, including musculoskeletal, medical, and radiation oncologists, and surgeons and radiologists with demonstrated expertise in the management of these tumors. Long-term surveillance and follow-up are necessary for the management of treatment late effects related to surgery, radiation therapy, and chemotherapy. These guidelines discuss the management of chordoma, giant cell tumor of the bone, and osteosarcoma.

Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures.

The Prevention of Orthopaedic Implant Infection in Patients Undergoing Dental Procedures evidence-based clinical practice guideline was codeveloped by the American Academy of Orthopaedic Surgeons (AAOS) and the American Dental Association. This guideline replaces the previous AAOS Information Statement, "Antibiotic Prophylaxis in Bacteremia in Patients With Joint Replacement," published in 2009. Based on the best current evidence and a systematic review of published studies, three recommendations have been created to guide clinical practice in the prevention of orthopaedic implant infections in patients undergoing dental procedures. The first recommendation is graded as Limited; this recommendation proposes that the practitioner consider changing the long-standing practice of routinely prescribing prophylactic antibiotic for patients with orthopaedic implants who undergo dental procedures. The second, graded as Inconclusive, addresses the use of oral topical antimicrobials in the prevention of periprosthetic joint infections. The third recommendation, a Consensus statement, addresses the maintenance of good oral hygiene.

Regulators of skeletal development: a cluster analysis of 206 bone tumors reveals diagnostically useful markers.

The molecules Indian hedgehog (IHH), SP7 (also known as osterix), sex-determining region Y-box 9 (SOX9), runt-related transcription factor 2 (RUNX2) and TWIST1 regulate the normal differentiation of osteo- and chondrogenic cells from precursors during skeletal development and remodeling. The aberrant function of the same molecules has been implicated in the pathogenesis of bone tumors. Preliminary studies suggest that antibodies against these molecules have practical, diagnostic or prognostic utility in tumors. However, a comprehensive analysis of the expression of these molecules in a large, diverse set of bone tumors has yet to be reported. The goals of this study were to compare the immunohistochemical profiles of IHH, SP7, SOX9, RUNX2 and TWIST1 among bone tumors and to determine the optimum panel for diagnostic utility. Tissue microarrays prepared from 206 undecalcified tumors (71 osteosarcomas, 26 osteoblastomas/osteoid osteomas, 50 giant cell tumors, 5 chondromyxoid fibromas and 54 chondroblastomas) were stained with antibodies to IHH, SP7, SOX9, RUNX2 and TWIST1. The stains were scored for intensity (0-3+) and distribution. The results were analyzed by cluster analysis. Optimum antibody panels for diagnostic sensitivity and specificity were calculated. Analysis revealed six main clusters that corresponded well to tumor types and suggested a close relationship between the stromal cells of giant cell tumor and the osteoblasts of osteosarcoma. The expression profile of chondromyxoid fibroma and chondroblastoma also suggested related differentiation. The distribution of osteoblastomas and osteoid osteomas was more heterogeneous. RUNX2, SOX9 and TWIST1 represented the most sensitive and specific immunohistochemical panel to distinguish among these diagnoses with the limitation that no result could discriminate between chondroblastoma and chondromyxoid fibroma. IHH and SP7 did not yield additional utility.

Soft tissue sarcoma, version 2.2012: featured updates to the NCCN guidelines.

The major changes to the 2012 and 2011 NCCN Guidelines for Soft Tissue Sarcoma pertain to the management of patients with gastrointestinal stromal tumors (GISTs) and desmoid tumors (aggressive fibromatosis). Postoperative imatinib following complete resection for primary GIST with no preoperative imatinib is now included as a category 1 recommendation for patients with intermediate or high risk of recurrence. The panel also reaffirmed the recommendation for preoperative use of imatinib in patients with GISTs that are resectable with negative margins but associated with significant surgical morbidity. Observation was included as an option for patients with resectable desmoid tumors that are small and asymptomatic, not causing morbidity, pain, or functional limitation. Sorafenib is included as an option for systemic therapy for patients with desmoid tumors.

Aseptic failure: how does the Compress(®) implant compare to cemented stems?

BACKGROUND: Failure of endoprosthetic reconstruction with conventional stems due to aseptic loosening remains a challenge for maintenance of limb integrity and function. The Compress(®) implant (Biomet Inc, Warsaw, IN, USA) attempts to avoid aseptic failure by means of a unique technologic innovation. Though the existing literature suggests survivorship of Compress(®) and stemmed implants is similar in the short term, studies are limited by population size and followup duration. QUESTIONS/PURPOSES: We therefore compared (1) the rate of aseptic failure between Compress(®) and cemented intramedullary stems and (2) evaluated the overall intermediate-term implant survivorship. METHODS: We reviewed 26 patients with Compress(®) implants and 26 matched patients with cemented intramedullary stems. The patients were operated on over a 3-year period. Analysis focused on factors related to implant survival, including age, sex, diagnosis, infection, aseptic loosening, local recurrence, and fracture. Minimum followup was 0.32 years (average, 6.2 years; range, 0.32-9.2 years). RESULTS: Aseptic failure occurred in one (3.8%) patient with a Compress(®) implant and three (11.5%) patients with cemented intramedullary stems. The 5-year implant survival rate was 83.5% in the Compress(®) group and 66.6% in the cemented intramedullary stem group. CONCLUSIONS: The Compress(®) implant continues to be a reliable option for distal femoral limb salvage surgery. Data regarding aseptic failure is encouraging, with equivalent survivorship against cemented endoprosthetic replacement at intermediate-term followup. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

CT-guided biopsy of bone and soft-tissue lesions: role of on-site immediate cytologic evaluation.

PURPOSE: To assess the impact of on-site immediate cytologic assessment (ICA) on the diagnostic success rate of computed tomography (CT)-guided percutaneous needle biopsy (PNB) of musculoskeletal lesions and the long-term outcome in inconclusive PNB findings. MATERIALS AND METHODS: A total of 299 CT-guided PNBs of musculoskeletal lesions performed between January 1997 and December 2009 were retrospectively reviewed. The lesions were categorized by their morphology, location, and size, and by biopsy type. The diagnostic success rates, impact of ICA, and outcome in inconclusive PNBs were studied, with final histopathologic findings and/or clinical follow-up as a reference. RESULTS: The overall diagnostic success rate of PNBs was 72.9% (218 of 299). The success rate increased with larger lesions (> 2 cm to 4 cm; P = .009). Biopsies performed with ICA had a higher success rate (77.0% vs 63.3%; P = .015). PNBs had inconclusive results in 109 of 299 cases (36.5%). In 66 of these, repeat open biopsy or clinical follow-up demonstrated 19 malignant/aggressive lesions (28.8%) and 47 benign/nonaggressive lesions (71.2%). CONCLUSIONS: CT-guided PNB had a satisfactory success rate, which significantly increased when performed with ICA. Inconclusive results in PNB were most frequently associated with benign findings during further workup.

Epithelioid sarcoma expresses epidermal growth factor receptor but gene amplification and kinase domain mutations are rare.

Epithelioid sarcoma is a rare, malignant, soft tissue neoplasm that can be classified into proximal, distal and fibroma-like subtypes. Regardless of subtype, epithelioid sarcoma often shows morphologic and immunophenotypic evidence of epithelial differentiation. Current therapeutic strategies include surgical resection, amputation, radiation or chemotherapy, although the overall prognosis remains poor. The epidermal growth factor receptor (EGFR) is a novel therapeutic target in carcinomas. In some carcinomas, EGFR kinase domain mutations or gene amplification may correlate with response to specific inhibitors. EGFR expression has been reported in some sarcoma types, but expression, amplification and mutations have not been studied in epithelioid sarcoma. We evaluated 15 cases of epithelioid sarcoma from 14 patients for EGFR expression using immunohistochemistry, EGFR copy number aberration using fluorescence in situ hybridization and screened for mutations in the tyrosine kinase domain of the EGFR gene using direct sequencing. In all, 14 of the 15 epithelioid sarcomas (93%) showed expression of EGFR by immunohistochemistry. A majority of the cases (n=11, 73%) showed strong (2+ to 3+) and homogeneous (>75% of cells) membrane staining. No amplification or polysomy of the EGFR gene or mutations of the tyrosine kinase domain of EGFR (exons 18-21) were detected. These results imply that although EGFR is expressed in most epithelioid sarcomas regardless of subtype, gene amplification and activating mutations in the tyrosine kinase domain appear to be rare or absent. Thus, the benefit of targeted therapy against EGFR in patients with epithelioid sarcoma remains to be determined.

Osteoid osteoma of the femur in a 7-month-old infant treated with radiofrequency ablation.

Osteoid osteoma occurs most commonly in children, adolescents, and young adults between the ages of 5 and 30 years. In the preschool age group, it is quite uncommon, accounting for only 3-8% of all osteoid osteoma cases. We report a case of osteoid osteoma in a 7-month-old infant, who presented with decreased use of the right lower extremity due to pain. Magnetic resonance imaging (MRI) showed an atypical appearance. A biopsy of the lesion, with histopathological examination, confirmed the diagnosis of osteoid osteoma. Radiofrequency ablation (RFA) of the nidus under computed tomography (CT) guidance was performed. The patient developed a recurrence after 3 months, which was treated with a second RFA. On subsequent follow-up, the infant did not show signs of pain after 1 month. In summary, this case report shows that osteoid osteoma can present in early infancy and can be successfully treated with RFA at this age, however, recurrence after the procedure can occur and close follow-up is recommended.

Secondary aneurysmal bone cysts and associated primary lesions: imaging features of 49 cases.

PURPOSE: To describe the imaging, anatomic, and clinical features of a series of secondary aneurysmal bone cysts (ABC) and to ascertain their most commonly associated primary bone lesions. METHODS: Forty-nine cases of histopathologically proven secondary ABCs were retrospectively reviewed. Demographic data and clinical history were obtained. Radiographic, computed tomographic, magnetic resonance, and nuclear medicine imaging were analyzed. Lesion location, imaging characteristics, and associated primary lesions were documented. Linear regression analysis and Chi-squared testing was performed for statistical analysis. RESULTS: Twenty-four males and 25 females were included, with an age range of 8-79 years (mean 29.7 + - 4.5 years). Eleven types of primary bone lesion were identified, with giant-cell tumor (n = 17, 35%), chondroblastoma (n = 11, 22%), fibrous dysplasia (n = 6, 12%), osteoblastoma (n = 4, 8%) and osteosarcoma (n = 4, 8%) being the most frequent. The lesions involved chiefly the long bone epiphyses (n = 25, 51%). Secondary ABC imaging findings and locations most closely approximated those of their primary counterparts, although fluid-fluid levels were seen at a higher frequency than previously reported in primary chondroblastoma (9/11, 82%), fibrous dysplasia (2/6, 33%), osteoblastoma (4/4, 100%), osteosarcoma (3/4, 75%), and chondromyxoid fibroma (1/2, 50%). CONCLUSION: The most common primary lesions associated with secondary ABC were giant cell tumor and chondroblastoma, located in the long bone epiphyses. The majority of the secondary ABCs demonstrate predominant imaging characteristics typical of the primary bone lesions, but with a higher presence of fluid-fluid levels.

Similarity in genetic alterations between paired well-differentiated and dedifferentiated components of dedifferentiated liposarcoma.

Liposarcoma represents a unique model insofar as some well-differentiated liposarcomas progress to non-lipogenic, so-called 'dedifferentiated,' forms. The well-differentiated and dedifferentiated family of liposarcomas demonstrates amplification of the chromosome subregion 12q13-q15 with resultant amplification of the MDM2 and CDK4 genes. However, the specific genetic changes that distinguish between well-differentiated and dedifferentiated liposarcomas are less well understood. To study the genetic changes in dedifferentiated liposarcomas, paired well-differentiated and dedifferentiated components of 29 tumors were analyzed separately by array-based comparative genomic hybridization. A bacterial artificial chromosome array at approximately 1-Mb resolution was used. The genetic changes were compared with clinical presentation, grade of the dedifferentiated component and overexpression of MDM2 and CDK4. Most tumors (n=21, 72%) were retroperitoneal, with both components present at initial diagnosis (n=25, 86%). Eight tumors (28%) were classified as low-grade dedifferentiation. In four cases (14%), a well-differentiated liposarcoma preceded the presentation of the dedifferentiated tumor by 1-5 years. 12q13-q15 was amplified in all tumors. Using unsupervised hierarchical clustering of copy-number changes, all but two tumors showed close similarities between well-differentiated and dedifferentiated components, and segregated as pairs. Dedifferentiated components had more total amplifications (P=0.008) and a trend for gain at 19q13.2, but no genetic changes were significant in distinguishing between the two components. High-level amplifications of 1p21-32 (n=7, 24%), 1q21-23 (n=9, 31%), 6q23-24 (n=6, 21%) and 12q24 (n=3, 10%) were common, but none significantly correlated with differentiation. Presentation and grade correlated with the frequency of changes at a number of genetic loci (P<0.001), whereas CDK4 immunostaining showed negative correlation with 12q13.13 amplification. The genotypic similarity, at the limit of the array's resolution, between components implies that most genetic changes precede phenotypic 'progression,' early in tumorigenesis. The relationship between genetic changes and presentation or grade may reflect differences in factors that control genomic instability or the background genotype of the tumor.

Compressive osseointegration of tibial implants in primary cancer reconstruction.

UNLABELLED: Compressive osseointegration technology, which provides immediate, mechanically compliant endoprosthetic fixation, has been adapted for massive proximal tibial reconstructions in an attempt to avoid aseptic failure encountered with conventional stems. A retrospective review of 16 patients with resected tumors was undertaken to determine whether compressive osseointegration can provide durable anchorage of tibial implants. Medical records, radiographs, and clinical examinations were reviewed to assess surgical, local disease control, and prosthetic outcomes. The average age was 18 years (range, 12-42 years). Diagnoses included osteosarcoma (12), Ewing sarcoma (two), chondrosarcoma (one), and undifferentiated sarcoma (one). Minimum followup was 2 years (mean, 4.5 years; range, 2-10.3 years); no patient was lost to followup. There were no local recurrences. Four patients developed metastatic disease; one patient died of his primary tumor, and another died from a chemotherapy-related malignancy. Complications included one early deep infection that ultimately resulted in prosthetic loosening and the need for an above-knee amputation. There were two late deep infections; prosthetic retention was achieved with débridement and antibiotics. One patient developed aseptic loosening and underwent revision; the other 15 implants provided stable osseointegration at last followup. Compressive osseointegration technology can thus achieve acceptable short-term endoprosthetic fixation results and may reduce the risk of aseptic loosening reported with conventional tibial stems. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Compress periprosthetic fractures: interface stability and ease of revision.

UNLABELLED: Periprosthetic fractures after massive endoprosthetic reconstructions pose a reconstructive challenge and jeopardize limb preservation. Compressive osseointegration technology offers the promise of relative ease of prosthetic revision, since fixation is achieved by means of a short intramedullary device. We retrospectively reviewed the charts of 221 patients who had Compress((R)) devices implanted in two centers between December, 1996 and December, 2008. The mean followup was 50 months (range, 1-123 months). Six patients (2.7%) sustained periprosthetic fractures and eight (3.6%) had nonperiprosthetic ipsilateral limb fractures occurring from 4 to 79 months postoperatively. All periprosthetic fractures occurred in patients with distal femoral implants (6/154, 3.9%). Surgery was performed in all six patients with periprosthetic femur fractures and for one with a nonperiprosthetic patellar fracture. The osseointegrated interface was radiographically stable in all 14 cases. All six patients with periprosthetic fracture underwent limb salvage procedures. Five patients had prosthetic revision; one patient who had internal fixation of the fracture ultimately underwent amputation for persistent infection. Periprosthetic fractures involving Compress((R)) fixation occur infrequently and most can be treated successfully with further surgery. When implant revision is needed, the bone preserved by virtue of using a shorter intramedullary Compress((R)) device as compared to conventional stems, allows for less complex surgery, making limb preservation more likely. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.