Long-term follow-up of custom cross-pin fixation of 56 tumour endoprosthesis stems: a single-institution experience.

AIMS: Aseptic loosening is a major cause of failure in cemented endoprosthetic reconstructions. This paper presents the long-term outcomes of a custom-designed cross-pin fixation construct designed to minimize rotational stress and subsequent aseptic loosening in selected patients. The paper will also examine the long-term survivorship and modes of failure when using this technique. PATIENTS AND METHODS: A review of 658 consecutive, prospectively collected cemented endoprosthetic reconstructions for oncological diagnoses at a single centre between 1980 and 2017 was performed. A total of 51 patients were identified with 56 endoprosthetic implants with cross-pin fixation, 21 of which were implanted following primary resection of tumour. Locations included distal femoral (n = 36), proximal femoral (n = 7), intercalary (n = 6), proximal humeral (n = 3), proximal tibial (n = 3), and distal humeral (n = 1). RESULTS: The median follow-up was 132 months (interquartile range (IQR) 44 to 189). In all, 20 stems required revision: eight for infection, five for structural failure, five for aseptic loosening, and two for tumour progression. Mechanical survivorship at five, ten, and 15 years was 84%, 78%, and 78%, respectively. Mechanical failure rate varied by location, with no mechanical failures of proximal femoral constructs and distal femoral survivorship of 82%, 77%, and 77% at five, ten, and 15 years. The survivorship of primary constructs at five years was 74%, with no failure after 40 months, while the survivorship for revision constructs was 89%, 80%, and 80% at five, ten, and 15 years. CONCLUSION: The rate of mechanical survivorship in our series is similar to those reported for other methods of reconstruction for short diaphyseal segments, such as compressive osseointegration. The mechanical failure rate differed by location, while there was no substantial difference in long-term survival between primary and revision reconstructions. Overall, custom cross-pin fixation is a viable option for endoprosthetic reconstruction of short metaphyseal segments with an acceptable rate of mechanical failure. Cite this article: Bone Joint J 2019;101-B:724-731.

Management of metastatic humeral fractures: Variations according to orthopedic subspecialty, tumor characteristics.

HYPOTHESIS: This study assessed, if there was a difference in surgical decision making for metastatic humeral lesions based on; orthopaedic subspecialty, tumor characteristics. STUDY TYPE: Cross sectional survey study. MATERIALS AND METHODS: Twenty-four case scenarios were created by combining: tumor type, life expectancy, fracture type, and anatomical location. Participants were asked for every case: what treatment would you recommend? Participants were 78 (48%) orthopaedic oncologists and 83 (52%) orthopaedic surgeons that were not regularly involved in the treatment of bone tumors. RESULTS: There was a difference between orthopaedic oncologists and other subspecialty surgeons in recommendation for specific treatments: intramedullary nailing was less often recommended by orthopaedic oncologists (53%, 95%CI: 47-59) compared to other surgeons (62%, 95%CI: 57-67) (p=0.023); while endoprosthetic reconstruction (orthopaedic oncologists: 8.8% [95%CI: 6.6-11], other surgeons: 3.6%[95%CI: 2.3-4.8], p<0.001) and plate-screw fixation (orthopaedic oncologists: 19%[95%CI: 14-25], other surgeons: 9.5%[95%CI: 5.9-13], p=0.003) were more often recommended by orthopaedic oncologists. There was no difference in recommendation for nonoperative management. There were differences in recommendation for specific treatments based on tumor type, life expectancy, and anatomical location, but not fracture type. DISCUSSION: Subspecialty training and patient and tumor characteristics influence the decision for operative management and the decision for a specific implant in metastatic humeral fractures. LEVEL OF EVIDENCE: Level 3.

Quality of life after resection of a chordoma of the mobile spine.

AIMS: The aim of the study was to compare measures of the quality of life (QOL) after resection of a chordoma of the mobile spine with the national averages in the United States and to assess which factors influenced the QOL, symptoms of anxiety and depression, and coping with pain post-operatively in these patients. PATIENTS AND METHODS: A total of 48 consecutive patients who underwent resection of a primary or recurrent chordoma of the mobile spine between 2000 and 2015 were included. A total of 34 patients completed a survey at least 12 months post-operatively. The primary outcome was the EuroQol-5 Dimensions (EQ-5D-3L) questionnaire. Secondary outcomes were the Patient-Reported Outcome Measurement Information System (PROMIS) anxiety, depression and pain interference questionnaires. Data which were recorded included the indication for surgery, the region of the tumour, the number of levels resected, the status of the surgical margins, re-operations, complications, neurological deficit, length of stay in hospital and rate of re-admission. RESULTS: The median EQ-5D-3L score was 0.71 (interquartile range (IQR) 0.44 to 0.79) which is worse than the national average in the United States of 0.85 (p < 0.001). Anxiety (median: 55 (IQR 49 to 61), p = 0.031) and pain (median: 61 (IQR 56 to 68), p < 0.001) were also worse than the national average in the United States (50), while depression was not (median: 52 (IQR 38 to 57), p = 0.513). Patients who underwent a primary resection had better QOL and less anxiety, depression and pain compared with those who underwent resection for recurrent or residual disease. The one- and five-year probabilities were 0.96 and 0.74 for survival, 0.07 and 0.25 for tumour recurrence, and 0.02 and 0.16 for developing distant metastasis. A total of 25 local complications occurred in 20 patients (42%), and there were 50 systemic and other complications in 25 patients (52%) within 90 days. CONCLUSION: These patient reported outcomes and oncological and surgical outcomes can be used when counselling patients and to aid decision-making when planning surgery. Cite this article: Bone Joint J 2017;99-B:979-86.

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.

Best practices for the management of local-regional recurrent chordoma: a position paper by the Chordoma Global Consensus Group.

Chordomas are rare, malignant bone tumors of the skull-base and axial skeleton. Until recently, there was no consensus among experts regarding appropriate clinical management of chordoma, resulting in inconsistent care and suboptimal outcomes for many patients. To address this shortcoming, the European Society of Medical Oncology (ESMO) and the Chordoma Foundation, the global chordoma patient advocacy group, convened a multi-disciplinary group of chordoma specialists to define by consensus evidence-based best practices for the optimal approach to chordoma. In January 2015, the first recommendations of this group were published, covering the management of primary and metastatic chordomas. Additional evidence and further discussion were needed to develop recommendations about the management of local-regional failures. Thus, ESMO and CF convened a second consensus group meeting in November 2015 to address the treatment of locally relapsed chordoma. This meeting involved over 60 specialists from Europe, the United States and Japan with expertise in treatment of patients with chordoma. The consensus achieved during that meeting is the subject of the present publication and complements the recommendations of the first position paper.

What Factors are Associated With Quality Of Life, Pain Interference, Anxiety, and Depression in Patients With Metastatic Bone Disease?

BACKGROUND: It would be helpful for the decision-making process of patients with metastatic bone disease to understand which patients are at risk for worse quality of life (QOL), pain, anxiety, and depression. Normative data, and where these stand compared with general population scores, can be useful to compare and interpret results of similar patients or patient groups, but to our knowledge, there are no such robust data. QUESTIONS/PURPOSES: We wished (1) to assess what factors are independently associated with QOL, pain interference, anxiety, and depression in patients with metastatic bone disease, and (2) to compare these outcomes with general US population values. METHODS: Between November 2011 and February 2015, 859 patients with metastatic bone disease presented to our orthopaedic oncology clinic; 202 (24%) were included as they completed the EuroQOL-5 Dimension (EQ-5DTM), PROMIS® Pain Interference, PROMIS® Anxiety, and PROMIS® Depression questionnaires as part of a quality improvement program. We did not record reasons for not responding and found no differences between survey respondents and nonrespondents in terms of age (63 versus 64 years; p = 0.916), gender (51% men versus 47% men; p = 0.228), and race (91% white versus 88% white; p = 0.306), but survey responders were more likely to be married or living with a partner (72%, versus 62%; p = 0.001). We assessed risk factors for QOL, pain interference, anxiety, and depression using multivariable linear regression analysis. We used the one-sample signed rank test to assess whether scores differed from US population averages drawn from earlier large epidemiologic studies. RESULTS: Younger age (ß regression coefficient [ß], < 0.01; 95% CI, 0.00-0.01; p = 0.041), smoking (ß, -0.12; 95% CI, -0.22 to -0.01; p = 0.026), pathologic fracture (ß, -0.10; 95% CI, -0.18 to -0.02; p = 0.012), and being unemployed (ß, -0.09; 95% CI, -0.17 to -0.02; p = 0.017) were associated with worse QOL. Current smoking status was associated with more pain interference (ß, 6.0; 95% CI, 1.6-11; p = 0.008). Poor-prognosis cancers (ß, 3.8; 95% CI, 0.37-7.2; p = 0.030), and pathologic fracture (ß, 6.3; 95% CI, 2.5-7.2; p = 0.001) were associated with more anxiety. Being single (ß, 5.9; 95% CI, 0.83-11; p = 0.023), and pathologic fracture (ß, 4.4; 95% CI, 0.8-8.0; p = 0.017) were associated with depression. QOL scores (0.68 versus 0.85; p < 0.001), pain interference scores (65 versus 50; p < 0.001), and anxiety scores (53 versus 50; p = 0.011) were worse for patients with bone metastases compared with general US population values, whereas depression scores were comparable (48 versus 50; p = 0.171). CONCLUSIONS: Impending pathologic fractures should be treated promptly to prevent deterioration in QOL, anxiety, and depression. Our normative data can be used to compare and interpret results of similar patients or patient groups. Future studies could focus on specific cancers metastasizing to the bone, to further understand which patients are at risk for worse patient-reported outcomes. LEVEL OF EVIDENCE: Level III, prognostic study.

Functional and oncological outcome after surgical resection of the scapula and clavicle for primary chondrosarcoma.

PURPOSE: The scapula is a relatively common site for chondrosarcoma to develop in contrary to the clavicle, which is rarely affected by these tumors. The aim of this study is to determine the functional and oncological outcome for patients treated operatively for scapular or clavicular chondrosarcoma. METHODS: In this single-center retrospective study, we included a sample of 20 patients that received the diagnosis of a primary chondrosarcoma of the scapula or clavicle. Of the surviving patients, the functional function was assessed using the DASH and the PROMIS Physical Function-Upper Extremity. Patients were longitudinally tracked for their oncological outcome. RESULTS: All patients were followed for at least 2 years or until death. The mean age of the cohort was 47 years. Eighteen patients suffered from a chondrosarcoma of the scapula, and in 2 patients, the tumor was located in the clavicle. Metastasis, local recurrence and a higher tumor grade were all associated with a decreased overall survival. For the patients with a chondrosarcoma of the scapula, the average DASH score was 16 ± 16 and the mean PROMIS Physical Function-Upper Extremity score was 48 ± 10. Patients with both an intact rotator cuff and glenoid had a better physical function. CONCLUSIONS: Upper extremity function after (partial) scapulectomy varied depending on whether the glenoid was spared and whether a functioning shoulder abductor remained. When the resection spared these structures, then excellent functional outcomes were reported. Oncologic outcomes depended upon the grade of the tumor and whether local recurrence and metastases occurred.

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.

Prevention of multidrug resistance (MDR) in osteosarcoma by NSC23925.

BACKGROUND: The major limitation to the success of chemotherapy in osteosarcoma is the development of multidrug resistance (MDR). Preventing the emergence of MDR during chemotherapy treatment has been a high priority of clinical and investigational oncology, but it remains an elusive goal. The NSC23925 has recently been identified as a novel and potent MDR reversal agent. However, whether NSC23925 can prevent the development of MDR in cancer is unknown. Therefore, this study aims to evaluate the effects of NSC23925 on prevention of the development of MDR in osteosarcoma. METHODS: Human osteosarcoma cell lines U-2OS and Saos were exposed to increasing concentrations of paclitaxel alone or in combination with NSC23925 for 6 months. Cell sublines selected at different time points were evaluated for their drug sensitivity, drug transporter P-glycoprotein (Pgp) expression and activity. RESULTS: We observed that tumour cells selected with increasing concentrations of paclitaxel alone developed MDR with resistance to paclitaxel and other Pgp substrates, whereas cells cultured with paclitaxel-NSC23925 did not develop MDR and cells remained sensitive to chemotherapeutic agents. Paclitaxel-resistant cells showed high expression and activity of the Pgp, whereas paclitaxel-NSC23925-treated cells did not express Pgp. No changes in IC50 and Pgp expression and activity were observed in cells grown with the NSC23925 alone. CONCLUSIONS: Our findings suggest that NSC23925 may prevent the development of MDR by specifically preventing the overexpression of Pgp. Given the significant incidence of MDR in osteosarcoma and the lack of effective agents for prevention of MDR, NSC23925 and derivatives hold the potential to improve the outcome of cancer patients with poor prognosis due to drug resistance.

Pleomorphic spindle cell sarcoma (PSCS) formerly known as malignant fibrous histiocytoma (MFH): a complex malignant soft-tissue tumor.

A presentation defining the nature, characteristics, causation, treatment and outcome of patients with lesions formerly known as malignant fibrous histiocytoma and now as pleomorphic spindle cell sarcoma is clearly a very difficult subject. Many authors do not believe that the tumor exists and instead describe them as forms of fibrosarcomas, fibromyxoid lesions, dedifferentiated chondrosarcomas or even leiomyosarcomas. The reasons for this confusion are presumably related to the fact that the malignant pleomorphic spindle cell sarcoma does not seem to be a distinct type of lesion with specific histologic and genetic characteristics. Instead, the tumor has at least four separate histologic variations and no specific gene signature and in fact does not seem to be either familial or ethnic in presentation. In view of the fact that the tumor was traditionally the most frequently encountered malignant soft-tissue neoplasm, the world of orthopedic oncology is clearly distressed by the problems that these patients have and is joined by the radiation oncologists and chemotherapists in seeking new solutions.

Molecular characterisation of two human cancer cell lines selected in vitro for their chemotherapeutic drug resistance to ET-743.

ET-743 (Yondelis(TM), Trabectedin) isolated from the tunicate Ecteinascidia turbinata, is being tested in phase II clinical trials in Europe and the United States of America (USA). Studies with different solid tumours have shown antitumour activity in advanced, pre-treated sarcomas as well as in drug-resistant breast and ovarian cancer. The primary mechanism of action for ET-743 has not been fully elucidated and different models have been suggested to explain its molecular mechanism of action. ET-743 binds tightly to the minor groove of DNA and previous data have suggested that ET-743 acts by interfering with RNA transcription. To further investigate the mechanism of in vitro drug resistance, we evaluated the gene expression profile in ovarian and chondrosarcoma cell lines selected for resistance to ET-743. We found 70 genes whose expression was modulated in both drug-resistant cell lines when compared with their respective parental drug-sensitive cell lines. This pattern of gene expression seems to be selective for ET-743-resistant cells, since ovarian cancer cells resistant to paclitaxel did not share the same gene expression changes. Data presented in this study reveal different molecular pathways that could be involved in the cellular mechanism of ET-743 resistance.

Salvage of humeral nonunions with onlay bone plate allograft augmentation.

Eight women and one man were treated for 10 established diaphyseal humeral nonunions. Six patients sustained fractures in motor vehicle accidents and two patients sustained fractures in a fall. Two of the fractures were open. One patient with multiple myeloma originally was treated conservatively and received local radiation, followed by open reduction and internal plate fixation. The other patients previously were treated with fracture braces, intramedullary nails, dynamic compression plates, or a combination of these techniques. After removal of the surgical hardware and fibrous tissue at the nonunion site, stable fixation was accomplished using a cortical long bone plate allograft (femoral and tibial) or fibular shaft allograft and a dynamic compression plate. All humeral nonunions had united at an average of 2.9 months. Radiographic incorporation of the allograft cortical bone plate and fibular shaft into the host cortex occurred in all but one patient by 3 months. Graft to host junction healing was accomplished by incorporation of the cortical allograft plate into the host cortex, resulting in an increased diameter of the bone. Cortical allograft bone plates and fibular grafts provide structural and probably osteoinductive support to enhance healing of these nonunions.

The effect of adjuvant chemotherapy on osteoarticular allografts.

Two hundred lower extremity osteoarticular allografts (in 200 patients) performed for aggressive or malignant bone tumors between 1976 and 1997 included 124 grafts of the distal femur, 46 of the proximal tibia, and 30 of the proximal femur. Seventy-four patients did not receive chemotherapy, and 126 received either adjuvant or neoadjuvant therapy. The diagnoses, mean ages, and length of followup were different for the two groups because most of the patients in the chemotherapy group had osteosarcoma, whereas the largest number in the control group had chondrosarcoma or parosteal osteosarcoma. The extent of the surgery was essentially the same for both patient groups, as is reflected by a low recurrence rate (7% for the control and 6% for the chemotherapy group). A statistical comparison of the various parameters showed that the infection, fracture, and amputation rates were the same, but the nonunion rate was markedly increased in the patients who received chemotherapy (32% versus 12%). Cox regression and Kaplan-Meier studies showed that chemotherapy had a significant effect on outcome, with the success rates for the two groups being quite different (72% versus 56%). The results for the distal femur showed a greater effect than for either the proximal tibia or the proximal femur. Analysis of these data suggest the distal femur is perhaps the most prone to healing problems, possibly based in part on the extent of the surgery. A final study supports the concept that the results improved in later years, suggesting a modification or application of the drugs used, better selection of patients, and improvements in surgical technique.

Allograft fractures revisited.

A retrospective review of patients with allograft fractures was done at the authors' institution. Between 1974 and 1998, 185 of 1046 (17.7%) structural allografts fractured in 183 patients at a mean of 3.2 years after transplantation. Initial allograft fixation included internal fixation with plates and screws in 181 patients. Patients with grafts that were longer than the average length (15.5 cm) tended to have worse results. Adjuvant therapy had no effect on fracture rate. Seventy-three patients with fractures had other allograft complications. Infection and nonunion with allograft fracture significantly worsened the outcome. The incidence of fracture in the patients with osteoarticular and arthrodesis transplants was significantly higher than those patients who had intercalary and composite reconstructions. Treatment of the allograft fractures included open reduction and internal fixation in 41 patients, reconstruction with a new allograft in 38, allograft-prosthesis composite in five, oncologic prosthesis in 19, amputation in 15, arthroscopic removal of loose bodies in three, resurfacing of fractured osteoarticular allograft surfaces in 39, allograft removal and cement spacer placement in 15. Twenty patients did not receive treatment. Eight of the fractures in patients who were not treated healed spontaneously. Outcomes were judged as excellent in nine patients (4.9%), good in 72 patients (38.9%), fair in 17 patients (9.2%), and in 85 patients (45.9%) the allograft reconstruction failed.

Factors affecting nonunion of the allograft-host junction.

Nonunion of allograft-host junction after bone transplantation is not uncommon, and its treatment frequently is problematic. To improve the understanding of these nonunions, a retrospective review was performed of 163 nonunions in 945 patients who underwent allograft transplantation (17.3%) for various benign and malignant tumors at the authors' institution between 1974 and 1997. Of these 945 patients, 558 did not receive adjuvant therapy. Chemotherapy was administered to 354 patients and only 33 patients received radiation therapy alone. Seventy-one patients had radiation treatment and chemotherapy. Of the 163 patients who had nonunion develop at the allograft-host junction, there were 269 reoperations performed on the involved extremity. In 108 patients, treatment was successful resulting in union of the allograft-host junction. Forty-nine patients did not respond to multiple surgical treatment attempts. The greater the number of surgical procedures, the worse the outcome. The rate of nonunions increased to 27% for the patients who received chemotherapy as compared with 11% for the patients who did not receive chemotherapy. The order of allografts from highest rate of nonunion to lowest was as follows: alloarthrodesis, intercalary, osteoarticular, and alloprosthesis. Infection and fracture rates were higher in the patients with nonunions as compared with the patients without nonunions.

Internal hemipelvectomy for solitary pelvic thyroid cancer metastases.

BACKGROUND AND OBJECTIVES: Radioactive iodine (RAI) therapy remains a primary treatment modality for metastatic thyroid carcinoma, but poor tumor uptake of the agent can limit its usefulness. While offering effective palliation, radiation therapy is not curative, and chemotherapy is even less useful. Surgical resection occasionally remains the only hope of offering a long-term cure in the case of isolated metastases. METHODS: We describe 3 cases of thyroid cancer metastatic to the pelvic girdle that were unresponsive to RAI and other nonoperative therapies, which presented over a 15-year time period. The pelvic disease was the only site of active disease in all cases, and all 3 patients were suffering considerable pain. All 3 patients underwent internal hemipelvectomy with reconstruction in 2 cases using a pelvic bone allograft. RESULTS: All 3 experienced symptomatic relief and early mobilization. While the infection rate was 100%, these all responded completely to operative debridement, irrigation, and antibiotics. One patient, found postoperatively to have a positive surgical margin, developed a local recurrence at 4 months and died. A second patient developed a local recurrence at 11 months and died. The third patient underwent a revision of her hip arthroplasty because of acetabular loosening after a fall 21 months postoperatively. She is alive, disease-free, and ambulatory with the aid of a cane 32 months after the original procedure. CONCLUSIONS: We propose this surgical procedure in selected patients with metastatic pelvic thyroid cancer. It provides symptomatic relief with a chance for prolonged disease-free survival some patients.

P-glycoprotein levels predict poor outcome in patients with osteosarcoma.

To evaluate the relationship between the expression of P-glycoprotein by osteosarcomas and the rate of metastasis and death, a retrospective review of 172 patients who were diagnosed with osteosarcoma between 1987 and 1992 was performed. Forty patients had P-glycoprotein levels available. The majority of the osteosarcomas were Stage II-B (33 patients), with the remaining seven being Stage III. Tumor sites included 25 femurs, seven humeri, five tibias, and one each of pelvis, radius, and fibula. The patients with Stage III disease at presentation were treated differently from the time of diagnosis and therefore, these seven patients with Stage III osteosarcoma were excluded from additional analyses. The expression of P-glycoprotein by cultured tumor cells from biopsy specimens was determined using immunofluorescent microscopy. In the 33 patients with Stage IIB osteosarcoma with detectable P-glycoprotein, 67% (10 of 15) had metastases develop as compared with 28% (five of 18) of patients with undetectable P-glycoprotein. Similarly, 53% (eight of 15) of patients with tumors expressing P-glycoprotein died of disease compared with 11% (two of 18) with no detectable P-glycoprotein. Expression of P-glycoprotein by tumor cells seems to be associated with an estimated ninefold increase in the odds of death and a fivefold increase in the odds of metastases in patients with Stage IIB osteosarcoma. Kaplan-Meier survivorship analysis revealed that patients with detectable P-glycoprotein fared worse in terms of survival time and metastasis-free survival. Adjusting for covariates in the Cox proportional hazards model, expression of P-glycoprotein and its level were significantly predictive of time to death in patients with Stage IIB osteosarcoma.

Dedifferentiated parosteal osteosarcoma with rhabdomyosarcomatous differentiation.

Dedifferentiated parosteal osteosarcomas are characterized histologically by the combination of low-grade fibroblastic osteosarcoma admixed with a high-grade component that typically has the appearance of malignant fibrous histiocytoma or osteosarcoma. Herein we report a case of dedifferentiated parosteal osteosarcoma of the distal femur, in which the high-grade component consisted of rhabdomyosarcoma. To our knowledge, a rhabdomyosarcomatous component has not been described previously in a dedifferentiated parosteal osteosarcoma. The clinical, radiologic, and pathologic features of this rare type of surface osteosarcoma are described.

Tumor reconstruction.

This article discusses opinions for reconstruction of bony defects created by tumor resections. The literature is reviewed, and the results of different reconstruction methods from the Massachusetts General and Children's Hospitals' database are discussed. The authors' treatment goals and algorithms are reviewed as well as the rationale behind them.

Decreasing length of hospital stay in treatment of osteoid osteoma.

Ninety-eight operative procedures were performed for treatment of osteoid osteoma since 1978 at the authors' institution. During these years there was a progressive decrease in the length of hospital stay, decreasing from a mean of 6.8 days between 1978 and 1980 to 2.6 days between 1994 and 1996. Factors that influenced the length of stay after a surgical procedure include patient age, lesion location, choice of procedure, and surgeon. However, the decline in length of stay with time is independent of these factors, and antedates the era of managed care. Increased reliance on more conservative surgical procedures has markedly diminished the length of hospital stay required in the care of these patients.