[Oncological outcomes and prognostic factors in surgically treated patients with synovial sarcoma]

INTRODUCTION

Synovial sarcoma is an unusual tumor with an incidence of 1-3 cases per million. It is more frequent in teenagers and young adults under 30. It develops anywhere, but the extremities are the most frequent place of appearance (80% extremities, 20% other locations: 8% trunk, 7% retroperitoneal/abdominal, 5% head and neck). Oncological results are different depending on the study. Survival rate free of local recurrence, survival rate free of events and global survival rate vary upon published studies. The same happens with the disease's prognostic factors.

METHODS

The objective was to analyze a group of 43 patients with diagnosis of synovial sarcoma of the extremities treated surgically and determine (1) global survival rate, (2) survival rate free of events, (3) local recurrence rate and (4) oncological risk factors.

RESULTS

The global survival rate at 2 years was 90% (IC95%: 76 - 96%) and 67% (IC95%: 49-80%) at 5 years. The survival rate free of events at 2 years was 68% (IC95% 51-80%) and 48% (IC95% 32-52%) at 5 years. The recurrence rate at 2 years was 9% (IC95% 3-25%) and 25% (IC95% 13-46%) at 5 years. The histological grade and metastatic presence were bad prognostic factors.

DISCUSSION

We can conclude that our oncological results are in line with those published in previous series and that there were two factors associated with poor prognosis.

[Chondrosarcoma of bone in young patients]

Chondrosarcoma is the second most frequent primary malignant bone tumor. It is typically described in adults between 40 and 70 years of age, being the majority of the series published in this age group. The objective of this study was to report a series of young adults (16-40 years old) with a diagnosis of chondrosarcoma of bone in order to describe the particularities of this tumor in this population. From a total of 37 patients between 16 and 40 years old, surgically treated for chondrosarcoma in our institution, 18 had low-grade tumors (G1/atypical cartilaginous tumor), 16 had an intermediate-grade (G2), and a minority had high-grade tumors (2 with a G3 and 1 with a dedifferentiated chondrosarcoma). The overall survival rate was 97% (95% CI 82%-99%) at 2 years of follow-up and 90.5% (95% CI 73-96) at 5 years of follow-up. The local recurrence free rate was 92% (95% CI % 77%-97.5%) at 1 year of follow-up and 89% at 2 and 5 years of follow-up (95% CI 73%-96%). Histological grade was the most relevant prognostic factor. The concordance of the histological grade between the preoperative diagnosis of the biopsy and the surgical resection material was 81% (30/37).

Profiling of three H3F3A-mutated and denosumab-treated giant cell tumors of bone points to diverging pathways during progression and malignant transformation

Giant cell tumor of bone (GCTB) is a locally aggressive lesion of intermediate malignancy. Malignant transformation of GCTB is a rare event. In 2013, the humanized monoclonal antibody against receptor activator of nuclear factor-κb-Ligand (RANKL) denosumab was approved for treatment of advanced GCTB. Since then, several reports have questioned the role of denosumab during occasional malignant transformation of GCTB. We report on three patients with H3F3A-mutated GCTBs, treated with denosumab. The tissue samples were analysed by histomorphology, immunohistochemistry, and in two instances by next generation panel sequencing of samples before and after treatment. One patient had a mutation of ARID2 in the recurrence of the GCTB under treatment with denosumab. One patient developed a pleomorphic sarcoma and one an osteoblastic osteosarcoma during treatment. Sequencing revealed a persisting H3F3A mutation in the osteosarcoma while the pleomorphic sarcoma lost the H3F3A mutation; however, a FGFR1 mutation, both in the recurrence and in the pleomorphic sarcoma persisted. In addition, the pleomorphic sarcoma showed an AKT2 and a NRAS mutation. These data are inconclusive concerning the role denosumab plays in the event of malignant progression/transformation of GCTB and point to diverging pathways of tumor progression of GCTB associated with this treatment.

[Denosumab as a treatment for giant cell tumor of bone. Indications, results and side effects]

Giant cell tumor of bone is an intermediate, locally aggressive and rarely metastasizing, primary bone neoplasia. In recent years denosumab emerged as a treatment alternative for this pathology. The objective of this work was to analyze its indications as well as the clinical outcomes, side effects and local recurrence rates in patients diagnosed with giant cell tumor of bone, who received denosumab as neoadjuvant treatment. Between 2010 and 2018, 80 patients with giant cell tumor were analyzed, of whom 14 received denosumab as a neoadjuvant treatment. The minimum follow-up was 12 months. In 8 patients it was a primary tumor, while 6 showed tumor recurrence. In all cases, clinical improvement was evident. Thirteen patients presented radiographic changes, and 11 showed complete histological response. A local recurrence was evidenced in 6 of 14 patients, and at least one adverse effect related to denosumab (including tumor malignancy) was identified in 7. Despite being a useful tool for treating giant cell tumor, the use of denosumab is associated with a higher rate of local recurrences and is not free of adverse effects.

Long-Term Clinical Outcomes of Intercalary Allograft Reconstruction for Lower-Extremity Bone Tumors

BACKGROUND

Improved survival rates for patients with primary bone tumors of the extremities have increased the demand for reliable and durable reconstruction techniques. Some authors have stated that, after successful ingrowth, allografts are a durable long-term solution. This hypothesis is largely based on small studies with short-to-midterm follow-up. In order to determine the durability of intercalary allograft reconstructions in the lower extremities, we evaluated the long-term clinical outcomes at a minimum of 10 years.

METHODS

All patients who received an intercalary allograft reconstruction in a lower extremity between 1980 and 2006 were included in this retrospective multicenter cohort study. One hundred and thirty-one patients with a median age of 19 years were included. Eighty-nine (68%) had a femoral reconstruction, and 42 (32%) had a tibial reconstruction. The most prevalent diagnoses were osteosarcoma (55%), Ewing sarcoma (17%), and chondrosarcoma (12%). The median follow-up was 14 years. A competing risk model was employed to estimate the cumulative incidences of mechanical failure and infection. Patient mortality or progression of the disease was used as a competing event.

RESULTS

Nonunion occurred in 21 reconstructions (16%), after a median of 16 months, and was associated with intramedullary nail-only fixation (p < 0.01) and fixation with nonbridging plate(s) (p = 0.03). Allograft fracture occurred in 25 reconstructions (19%) after a median of 42 months (range, 4 days to 21.9 years). Thirteen (52%) of the allograft fractures occurred within 5 years; 8 (32%), between 5 and 10 years; and 4 (16%), at >10 years. With failure for mechanical reasons as the end point, the cumulative incidences of reconstruction failure at 5, 10, and 15 years were 9%, 14%, and 21%, respectively.

CONCLUSIONS

Intercalary allograft reconstruction is an acceptable reconstructive option, mainly because of the absence of superior alternatives with a known track record. However, a considerable and continuing risk of mechanical complications should be taken into account.

LEVEL OF EVIDENCE

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

[Ewing sarcoma of the bone. Multidisciplinary approach and oncological results in 88 patients]

Ewing sarcoma of the bone is a rare, highly aggressive tumor that typically affects children and young adults. In Argentina, the lack of Ewing's sarcoma registries reflects in the absence of information regarding prevalence, treatment protocols and patient's outcome. The purpose of this study was to analyze, in a group of patients diagnosed with Ewing sarcoma of the bone, treated with chemotherapy and limb-conserving surgery, their overall survival rate, local recurrence rate, and oncological risk factors. A retrospective research was conducted between 1990 and 2017. Eighty-eight patients with Ewing sarcoma of the bone matched the inclusion criteria. Median age was 14.5 years and median follow-up was 8.8 years. Overall survival rate was 79.5%, 69% and 64% at 2, 5 and 10 years respectively. Negative prognostic factors, associated with less survival rate after univariate analysis, were: bad response to chemotherapy (tumoral necrosis 0-89%), age > 16 years-old, central tumor localization and local recurrence. Gender and tumor size were not significant prognostic factors. After multivariate analysis, response to chemotherapy remained statistical significant. Local recurrence-free survival rate at 2 and 5 years was 87%. Tumor response to chemotherapy (0-89%) was the only significant factor for local recurrence. We consider that limb-salvage surgery, with neoadjuvant and adjuvant chemotherapy, are the mainstays of treatment for Ewing's sarcoma, with an overall survival rate, at 5 years, of 69%. In this population, response to chemotherapy is the most relevant prognostic factor, being associated with both local recurrence and overall survival.

Modular prosthesis reconstruction after tumour resection, evaluation of failures and survival

OBJECTIVE

To analyze a series of patients with bone tumours reconstructed with modular prostheses and to evaluate: 1) Survival of the implant. 2) Causes of failure. 3) Complication rates. 4) Limb salvage overall survival. 5) Functional results and full weight bearing.

MATERIALS AND METHODS

A retrospective study from longitudinally maintained oncology databases was undertaken. All patients with bone tumours reconstructed with endoprosthesis were analysed. A toal of 106patients matched the inclusion criteria. They were divided into groups: group 1, primary bone tumours; group 2, bone metastasis; group 3, osteoarticular allograft reconstruction revisions. The type of failures were classified according to Henderson et al. (2014) and functional results assessed by the Musculoskeletal Tumor Society (MSTS). Demographic analysis, survival and the differences between groups were recorded.

RESULT

The mean follow-up of the patients was 68 months. Mean age was 43 years. Overall implant survival was 86.4% at 2 years (95% CI: 79-94) and 73% at 5 years (95% CI: 60-80). Nineteen patients (18%) developed a prosthetic failure. The limb salvage overall survival was 96% at 5 years (95% CI: 91-99). The mean functional results according to the MSTS was 24 and mean time to full weight bearing was 2.3 weeks.

CONCLUSIONS

Limb conservation surgery and endosprosthetic reconstruction is a valid option for patients with bone tumours with failure rates similar to other reconstruction methods.

What Are the Complications of Allograft Reconstructions for Sarcoma Resection in Children Younger Than 10 Years at Long-term Followup?

BACKGROUND

Preservation of limb function after resection of malignant bone tumors in skeletally immature children is challenging. Resection of bone sarcomas and reconstruction with an allograft in patients younger than 10 years old is one reconstructive alternative. However, long-term studies analyzing late complications and limb length discrepancy at skeletal maturity are scarce; this information would be important, because growth potential is altered in these patients owing to the loss of one physis during tumor resection.

QUESTIONS/PURPOSES

At a minimum followup of 10 years after reconstructions in children younger than 10 years of age at the time of reconstruction, we asked what is (1) the limb length discrepancy at skeletal maturity and how was it managed; (2) the risk of amputation; (3) the risk of allograft removal; and (4) the risk of second surgery resulting from complications?

METHODS

Between 1994 and 2006, we performed 22 bone allografts after bone sarcoma resections in children younger than 10 years of age. Of those, none were lost to followup before the minimum followup of 10 years was reached, and an additional six had died of disease (of whom three died since our last report on this group of patients), leaving 16 patients whom we studied here. Followup on these patients was at a mean of 13.5 years (range, 10-22 years). During the period in question, no other treatments (such as extendible prostheses, amputations, etc) were used. The mean age at the time of the original surgery was 7 years (range, 2-10 years), and the mean age of the 16 alive patients at last followup was 20 years (range, 15-28 years). This series included 10 boys and six girls with 14 osteosarcomas and two Ewing sarcomas. Ten reconstructions were performed with an intercalary allograft and six with an osteoarticular allograft. The growth plate was uninvolved in three patients, whereas in the remaining 13, the growth plate was included in the resection (seven intercalary and six osteoarticular allografts). Limb length discrepancy at skeletal maturity was measured with full-length standing radiographs, and data were collected by retrospective study of a longitudinally maintained institutional database. The risk of amputation, allograft removal, and secondary surgery resulting from a complication was calculated by a competing-risk analysis method.

RESULTS

We observed no limb length discrepancy at skeletal maturity in the three patients with intercalary resections in whom we preserved the physes on both sides of the joint (two femurs and one tibia); however, one patient developed malalignment that was treated with corrective osteotomy of the tibia. The remaining 13 patients developed limb length discrepancy as a result of loss of one physis. Seven patients (four femurs, two tibias, and one humerus) developed shortening of ≤ 3 cm (mean, 2.4 cm; range, 1-3 cm) and no lengthening was performed. Six patients developed > 3 cm of limb discrepancy at skeletal maturity (all distal femoral reconstructions). In four patients this was treated with femoral lengthening, whereas two declined this procedure (each with 6 cm of shortening). In the four patients who had a lengthening procedure, one patient had a final discrepancy of 4 cm, whereas the other three had equal limb lengths at followup. The risk of amputation was 4% (95% confidence interval [CI], 0-15) and none occurred since our previous report. The risk of allograft removal was 15% (95% CI, 1-29) and none occurred since our previous report on this group of patients. The risk of other operations resulting from a complication was 38% (95% CI, 19-57). Eleven patients underwent a second operation resulting from a complication (three local recurrences, five fractures, one infection, one nonunion, and one tibial deformity), of which three were performed since our last report on this group of patients.

CONCLUSIONS

Limb length inequalities and subsequent procedures to correct them were common in this small series of very young patients as were complications resulting in operative procedures, but overall most allografts remained in place at long-term followup. In skeletally immature children, bone allograft is one alternative among several that are available (such as rotationplasty and endoprosthesis), and future studies with long followup may be able to compare the available options with one another.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Is Navigation-guided En Bloc Resection Advantageous Compared With Intralesional Curettage for Locally Aggressive Bone Tumors?

BACKGROUND

The treatment of locally aggressive bone tumors is a balance between achieving local tumor control and surgical morbidity. Wide resection decreases the likelihood of local recurrence, although wide resection may result in more complications than would happen after curettage. Navigation-assisted surgery may allow more precise resection, perhaps making it possible to expand the procedure's indications and decrease the likelihood of recurrence; however, to our knowledge, comparative studies have not been performed.

QUESTIONS/PURPOSES

The purpose of this study was to compare curettage plus phenol as a local adjuvant with navigation-guided en bloc resection in terms of (1) local recurrence; (2) nononcologic complications; and (3) function as measured by revised Musculoskeletal Tumor Society (MSTS) scores.

METHODS

Patients with a metaphyseal and/or epiphyseal locally aggressive primary bone tumor treated by curettage and adjuvant therapy or en bloc resection assisted by navigation between 2010 and 2014 were considered for this retrospective study. Patients with a histologic diagnosis of a primary aggressive benign bone tumor or low-grade chondrosarcoma were included. During this time period, we treated 45 patients with curettage of whom 43 (95%) were available for followup at a minimum of 24 months (mean, 37 months; range, 24-61 months), and we treated 26 patients with navigation-guided en bloc resection, of whom all (100%) were available for study. During this period, we generally performed curettage with phenol when the lesion was in contact with subchondral bone. We treated tumors that were at least 5 mm from the subchondral bone, such that en bloc resection was considered possible with computer-assisted block resection. There were no differences in terms of age, gender, tumor type, or tumor location between the groups. Outcomes, including allograft healing, nonunion, tumor recurrence, fracture, hardware failure, infection, and revised MSTS score, were recorded. Bone consolidation was defined as complete periosteal and endosteal bridging visible between the allograft-host junctions in at least two different radiographic views and the absence of pain and instability in the union site. All study data were obtained from our longitudinally maintained oncology database.

RESULTS

In the curettage group, two patients developed a local recurrence, and no local recurrences were recorded in patients treated with en bloc resection. All patients who underwent navigation-guided resection achieved tumor-free margins. Intraoperative navigation was performed successfully in all patients and there were no failures in registration. Postoperative complications did not differ between the groups: in patients undergoing curettage, 7% (three of 43) and in patients undergoing navigation, 4% (one of 26) had a complication. There was no difference in functional scores: mean MSTS score for patients undergoing curettage was 28 points (range, 27-30 points) and for patients undergoing navigation, 29 (range, 27-30 points; p = 0.10).

CONCLUSIONS

In this small comparative series, navigation-assisted resection techniques allowed conservative en bloc resection of locally aggressive primary bone tumors with no local recurrence. Nevertheless, with the numbers available, we saw no difference between the groups in terms of local recurrence risk, complications, or function. Until or unless studies demonstrate an advantage to navigation-guided en bloc resection, we cannot recommend wide use of this novel technique because it adds surgical time and expense.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Virtual Planning and Allograft Preparation Guided by Navigation for Reconstructive Oncologic Surgery: A Technical Report

Introduction

Advanced virtual simulators can be used to accurately detect the best allograft according to size and shape.

Indications & Contraindications

Step 1 Acquisition of Medical Images

Obtain a multislice CT scan and a magnetic resonance imaging (MRI) scan preoperatively for each patient; however, if the time between the scans and the surgery is >1 month, consider repeating the MRI because the size of the tumor may have changed during that time.

Step 2 Select an Allograft Using Virtual Imaging to Optimize Size Matching

Load DICOM images into a virtual simulation station (Windows 7 Service Pack 1, 64 bit, Intel Core i5/i7 or equivalent) and use mediCAS planning software (medicas3d.com) or equivalent (Materialise Mimics or Amira software [FEI]) for image segmentation and virtual simulation with STL (stereolithography) files.

Step 3 Plan and Outline the Tumor Margins on the Preoperative Imaging

Determine and outline the tumor margin on manually fused CT and MRI studies using the registration tool of the mediCAS planning software or equivalent (Materialise Mimics software.).

Step 4 Plan and Outline the Same Osteotomies on the Allograft

Determine and outline the osteotomies between host and donor using the registration tool of the mediCAS planning software or equivalent (Materialise Mimics software.).

Step 5 Assess the Patient and Allograft in a Virtual Scenario

Be sure to consider the disintegration of bone tissue that occurs during the osteotomy and corresponds to the thickness of the blade (approximately 1.5 mm).

Step 6 Navigation Settings

A tool of the mediCAS planning software allows the virtual preoperative planning (STL files) to be transferred to the surgical navigation format, DICOM files.

Step 7 Patient and Allograft Intraoperative Navigation

The tumor and allograft are resected using the navigated guidelines, which were previously planned with the virtual platform.

Results

The 3D virtual preoperative planning and surgical navigation software are tools designed to increase the accuracy of bone tumor resection and allograft reconstruction³.

Pitfalls & Challenges

Proximal Tibia Reconstruction After Bone Tumor Resection: Are Survivorship and Outcomes of Endoprosthetic Replacement and Osteoarticular Allograft Similar?

BACKGROUND

The proximal tibia is one of the most challenging anatomic sites for extremity reconstructions after bone tumor resection. Because bone tumors are rare and large case series of reconstructions of the proximal tibia are lacking, we undertook this study to compare two major reconstructive approaches at two large sarcoma centers.

QUESTIONS/PURPOSES

The purpose of this study was to compare groups of patients treated with endoprosthetic replacement or osteoarticular allograft reconstruction for proximal tibia bone tumors in terms of (1) limb salvage reconstruction failures and risk of amputation of the limb; (2) causes of failure; and (3) functional results.

METHODS

Between 1990 and 2012, two oncologic centers treated 385 patients with proximal tibial resections and reconstruction. During that time, the general indications for those types of reconstruction were proximal tibia malignant tumors or bone destruction with articular surface damage or collapse. Patients who matched the inclusion criteria (age between 15 and 60 years old, diagnosis of a primary bone tumor of the proximal tibia treated with limb salvage surgery and reconstructed with endoprosthetic replacement or osteoarticular allograft) were included for analysis (n = 149). In those groups (endoprosthetic or allograft), of the patients not known to have reached an endpoint (death, reconstructive failure, or limb loss) before 2 years, 85% (88 of 104) and 100% (45 of 45) were available for followup at a minimum of 2 years. A total of 88 patients were included in the endoprosthetic group and 45 patients in the osteoarticular allograft group. Followup was at a mean of 9.5 (SD 6.72) years (range, 2-24 years) for patients with endoprosthetic reconstructions, and 7.4 (SD 5.94) years for patients treated with allografts (range, 2-21 years). The following variables were compared: limb salvage reconstruction failure rates, risk of limb amputation, type of failures according to the Henderson et al. classification, and functional results assessed by the Musculoskeletal Tumor Society system.

RESULTS

With the numbers available, after competitive risk analysis, the probability of failure for endoprosthetic replacement of the proximal tibia was 18% (95% confidence interval [CI], 10.75-27.46) at 5 years and 44% (95% CI, 31.67-55.62) at 10 years and for osteoarticular allograft reconstruction was 27% (95% CI, 14.73-40.16) at 5 years and 32% (95% CI, 18.65-46.18) at 10 years. There were no differences in terms of risk of failures at 5 years (p = 0.26) or 10 years (p = 0.20) between the two groups. Fifty-one of 88 patients (58%) with proximal tibia endoprostheses developed a reconstruction failure with mechanical causes being the most prevalent (32 of 51 patients [63%]). A total of 19 of 45 osteoarticular allograft reconstructions failed (42%) and nine of 19 (47%) of them were caused by early infection. Ten-year risk of amputation after failure for endoprosthetic reconstruction was 10% (95% CI, 5.13-18.12) and 11% (95% CI, 4.01-22.28) for osteoarticular allograft with no difference between the groups (p = 0.91). With the numbers available, there were no differences between the groups in terms of the mean Musculoskeletal Tumor Society score (26.58, SD 2.99, range, 19-30 versus 27.52, SD 1.91, range, 22-30; p = 0.13; 95% CI, -2,3 to 0.32). Mean extension lag was more severe in the endoprosthetic group than the osteoarticular allograft group: 13.56° (SD 18.73; range, 0°-80°) versus 2.41° (SD 5.76; range, 0°-30°; p < 0.001; 95% CI, 5.8-16.4).

CONCLUSIONS

Reconstruction of the proximal tibia with either endoprosthetic replacement or osteoarticular allograft appears to offer similar reconstruction failures rates. The primary cause of failure for allograft was infection and for endoprosthesis was mechanical complications. We believe that the treating surgeon should have both options available for treatment of patients with malignant or aggressive tumors of the proximal tibia. (S)he might consider an allograft in a younger patient to achieve better extensor mechanism function, whereas in an older patient or one with a poorer prognosis where return to function and ambulation quickly is desired, an endoprosthesis may be advantageous.

LEVEL OF EVIDENCE

Level III, therapeutic study.

What Happens to the Articular Surface After Curettage for Epiphyseal Chondroblastoma? A Report on Functional Results, Arthritis, and Arthroplasty

BACKGROUND

Chondroblastoma is an uncommon, benign, but locally aggressive bone tumor that occurs in the apophyses or epiphyses of long bones, primarily in young patients. Although some are treated with large resections, aggressive curettage and bone grafting are more commonly performed to preserve the involved joint. Such intralesional resection may result in damage to the growth plate and articular cartilage, which can result in painful arthritis. Prior studies have focused primarily on oncologic outcomes rather than long-term joint status and functional outcomes.

QUESTIONS/PURPOSES

(1) What local complications can be expected after aggressive intralesional curettage of epiphyseal chondroblastoma? (2) What is the joint survival of a joint treated in this way for chondroblastoma? (3) What additional procedures are used in treating symptomatic joint osteoarthritis after treatment of the chondroblastoma? (4) What are the functional outcomes in this group of patients?

METHODS

A retrospective study of our prospectively collected database between 1975 and 2013 was done. We found 64 patients with a diagnosis of chondroblastoma of bone. After applying our selection criteria, 53 patients were involved in this study. We excluded seven patients with tumors initially treated with en bloc resection (five located in the extremities and two in the axial skeleton) and two patients with apophyseal tumors. One patient who underwent nonsurgical treatment and one patient lost to followup were also excluded. The mean age was 18 years (range, 11-39 years); the minimum followup was 2 years with a mean followup 77 months (range, 24-213 months). We analyzed all patients with a diagnosis of epiphyseal chondroblastoma of the limb treated with aggressive curettage and joint preservation surgery. During the period in question, our general indications for curettage were patients with active, painful tumors and those with more aggressive ones that remained intracompartmental, whereas initial wide en bloc resection was indicated in patients who had tumors with an extracompartmental extension breaching the adjacent joint cartilage and massive articular destruction. The tumor location was the distal femur in 14 patients, proximal tibia in 11, proximal humerus in 10, proximal femur in eight, the talus in seven, and elsewhere in the lower extremity in three. Local complications including joint degeneration and tumor recurrence were evaluated. Based on radiographic analysis, secondary osteoarthritis was classified by using the Kellgren-Lawrence grading system from Grade 0 to Grade IV. Patients who underwent joint replacement resulting from advanced symptomatic osteoarthritis were considered to have had joint failure for purposes of survivorship analysis, which was estimated using the Kaplan-Meier method. Functional results were evaluated with the Musculoskeletal Tumor Society functional score by the treating surgeon, who transcribed the results on the digital records every 6 months of followup.

RESULTS

Twenty-two patients (42%) developed 26 local complications. The most common local complication was osteoarthritis in 20 patients (77% [20 of 26 complications]); tumor recurrence was observed in four patients; an intraarticular fracture and superficial infection treated with surgical débridement and antibiotics developed in one patient each. Joint survival was 90% at 5 years (95% confidence interval [CI], 76%-100%) and 74% at 10 years (95% CI, 48%-100%). Proximal femoral tumor location was associated with lower survivorship of the joint than other locations showing a 5-year survival rate of 44% (95% CI, 0%-88%; p = 0.000). Of the 20 patients with osteoarthritis, four were symptomatic enough to undergo joint replacement, all of which were for tumors in the proximal femur. The mean Musculoskeletal Tumor Society functional score was 28 of 30 points (93%).

CONCLUSIONS

Osteoarthritis was a frequent complication of aggressive curettage of epiphyseal chondroblastoma, and tumors located in the proximal femur appeared to be at particular risk of secondary osteoarthritis and prosthetic replacement. Because chondroblastoma is a tumor that disproportionately affects younger patients, the patient and surgeon should be aware that arthroplasty at a young age is a potential outcome for treatment of proximal femoral chondroblastomas.

LEVEL OF EVIDENCE

Level III, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

In Vitro Comparative Study Between Conventional and Computer-Assisted Surgery Methods for Planning and Resection of Bone Sarcomas

This poster aims to achieve an "in vitro" comparative study between three methods: 2D digital images planning and execution without navigation (freehand with ruler and caliper), 3D planning and execution without navigation (freehand with ruler and caliper) and 3D planning and execution guided with navigation. 3D planning and navigated procedures potentially improve sarcoma resection.

Structural allograft reconstruction of the foot and ankle after tumor resections

BACKGROUND

Structural allografts have been used to correct deformities or to fill bone defects secondary to tumor excisions, trauma, osteochondral lesions, or intercalary arthrodesis. However, the quality of published evidence supporting the use of allograft transplantation in foot and ankle surgery has been reported as fair. The purpose of this study was to report the overall survival of structural allograft in the foot and ankle after tumor resection, and the survival according to the type of allograft and the complication rates in the medium to long term.

MATERIALS AND METHODS

From January 1989 to June 2011, 44 structural allograft reconstructions of the foot and ankle were performed in 42 patients (28 men and 14 women) due to musculoskeletal tumor resections. Mean age at presentation was 27 years. Mean follow-up was 53 months. Demographic data, diagnosis, site of the neoplasm, operations performed, operative complications, outcomes after surgery, date of last follow-up evaluation, and local recurrences were reviewed for all patients. Regarding the type of 44 allograft reconstructions, 16 were hemicylindrical allografts (HA), 12 intercalary allografts (IA), 10 osteoarticular allografts (OA), and 6 were total calcaneal allograft (CA).

RESULTS

The overall allograft survival rate, as calculated with the Kaplan-Meier method, at 5 and 10 years was 79 % (95 % CI 64-93 %). When allocated by type of allograft reconstruction the specific allograft survival at 5 and 10 years was: 83 % for CA, 80 % for HA, 77 % for OA, and 75 % for IA. The complications rate for this series was 36 % including: articular failure, local recurrence, infection, fracture and nonunion.

CONCLUSION

This study showed that structural allograft reconstruction in the foot and ankle after tumor resection may be durable with a 79 % survival rate at 5 and 10 years. The two types of allografts that showed better survival rate were hemicylindrical allografts (80 %) and calcaneus allografts (83 %). The highest complication rates occurred after calcaneus allografts and osteoarticular allografts.

LEVEL OF EVIDENCE

IV.

Proximal humeral osteoarticular allografts: technique, pearls and pitfalls, outcomes

Allograft transplantation is a biologic reconstruction option for massive bone defects after resection of bone sarcomas. This type of reconstruction not only restores bone stock but it also allows us to reconstruct the joint anatomically. These factors are a major concern, especially in a young and active population.We are describing indications, surgical techniques, pearls and pitfalls, and outcomes of proximal humeral osteoarticular allografts, done at present time in our institution.We found that allograft fractures and articular complications, as epiphyseal resorption and subchondral fracture, are the main complications observed in proximal humerus osteoarticular allograft reconstructions. Nevertheless, only fractures need a reconstruction revision. Joint complications may adversely affect the limb function, but for this reason, an allograft revision is rarely performed.

Oncologic and clinical outcomes in pelvic primary bone sarcomas treated with limb salvage surgery

PURPOSE

We propose to study a group of patients with primary bone sarcoma of the pelvis treated with limb salvage surgery and analyze overall survival, local recurrence rates and functional outcomes.

METHODS

A retrospective review was performed, and all patients diagnosed with pelvic primary bone sarcomas between 1990 and 2012 were analyzed. Patients treated with limb salvage surgery and with a minimum of 12-month follow-up for patients alive were included. The overall survival and the local recurrence rate were calculated for the assessment of oncological results. The associations with gender, age, histological grade, type of surgery, margins chemotherapy response and use of navigation were examined.

RESULTS

Fifty-two patients were included in the study. The mean age was 37 years (range 10-82), and mean follow-up was 44 months (range 8-189). Forty-five (86 %) tumors were histologically classified as high-grade sarcomas, four (8 %) as low-grade sarcomas and three (6 %) as dedifferentiated sarcomas. Cancer-specific overall survival was 37.5 % for 5 years and 31 % for 10 years. Local recurrence rate was 30 %. High-grade tumors and chemotherapy necrosis below 90 % were negative prognosis factor. Postoperative complication rate was 34.5 % (n:18), being deep infection the most prevalent (n:13). Reconstruction of the pelvis after an oncology resection for primary pelvic sarcomas increased the incidence of complication significantly (p < 0.001).

CONCLUSION

Primary bone sarcomas involving the pelvis are suggestive of a high-grade tumor and present poor oncologic outcomes. Pelvic reconstruction after a limb salvage surgery is associated with a high risk of complication.

LEVEL OF EVIDENCE

Case series, Level IV.

Use of Massive Allografts to Manage Hydatid Bone Disease of the Femur

Hydatid disease is caused by the parasitic tapeworm Echinococcus granulosus. Osseous involvement accounts for 0.5% to 4% of cases in humans. Patients usually are from endemic zones and are initially asymptomatic, presenting with pain and edema at a later stage of disease. However, large lesions may present initially as pathologic fractures. Standard radiographs usually show expansive osteolytic lesions associated with initial cortical thinning, with compromise of the metaphysis or epiphysis, and may involve the diaphysis. The finding of periosteal reaction, osteocondensation, calcification, and clear delimitation of the lesions excludes the diagnosis of osseous hydatidosis. However, there are no specific radiographic signs in the affected bone. There is no generally accepted treatment algorithm for osseous hydatid disease. The usual treatment is surgical resection of the affected bone, followed by antihelmintic therapy. Some patients can be treated with intralesional procedures, such as curettage and allograft or polymethyl methacrylate cement. However, in some advanced cases, such as those with pathologic fractures or recurrences, wide resection may be needed. Several reconstructive alternatives have been reported, such as megaprosthesis, massive allograft, or alloprosthesis composite. The authors retrospectively reviewed 2 cases of femoral hydatidosis treated with wide resection and reconstruction with massive bone allograft. One patient had 5 years of follow-up, and the other had 9 years. No signs of relapse or complications were recorded, and functional outcomes evaluated with the Musculoskeletal Tumor Society scale showed excellent results. These 2 cases support the use of a massive bone allograft as a valid alternative to reconstruction after extensive bone resection for hydatidic disease.

Techniques in surgical navigation of extremity tumors: state of the art

Image-guided surgical navigation allows the orthopedic oncologist to perform adequate tumor resection based on fused images (CT, MRI, PET). Although surgical navigation was first performed in spine and pelvis, recent reports have described the use of this technique in bone tumors located in the extremities. In long bones, this technique has moved from localization or percutaneous resection of benign tumors to complex bone tumor resections and guided reconstructions (allograft or endoprostheses). In recent years, the reported series have increased from small numbers (5 to 16 patients) to larger ones (up to 130 patients). The purpose of this paper is to review recent reports regarding surgical navigation in the extremities, describing the results obtained with different kind of reconstructions when navigation is used and how the previously described problems were solved.

A High-grade Sarcoma Arising in a Patient With Recurrent Benign Giant Cell Tumor of the Proximal Tibia While Receiving Treatment With Denosumab

BACKGROUND

A giant cell tumor of bone is a primary benign but locally aggressive neoplasm. Malignant transformation in a histologically typical giant cell tumor of bone, without radiotherapy exposure, is an uncommon event, occurring in less than 1% of giant cell tumors of bone. Although surgery is the standard initial treatment, denosumab, a monoclonal antibody drug that inhibits receptor activator of nuclear factor-κB ligand (RANKL), has shown considerable activity regarding disease and control of symptoms in patients with recurrence, unresectable, and metastatic giant cell tumors of bone.

CASE DESCRIPTION

We report the case of a 20-year-old woman with a recurrent benign, giant cell tumor of bone, who had a bone sarcoma develop while receiving denosumab treatment.

LITERATURE REVIEW

To our knowledge, there have been no reports of infection or malignancy with low-dose denosumab administration for osteoporosis. However, while there are relatively few reported side effects, the safety of denosumab and adverse events seen with higher doses, as used in treatment of giant cell tumors of bone are not well defined.

CLINICAL RELEVANCE

Denosumab has become a valuable adjunct for treatment of recurrent or unresectable giant cell tumor of bone. It is not clear if our patient's malignant transformation of a giant cell tumor of bone while receiving denosumab treatment was caused by denosumab, but it is important to be aware of the possibility if more cases occur. Future studies should focus on the safety of high-dose denosumab administration in patients with a benign unresectable giant cell tumor of bone.

[Low grade parosteal osteosarcoma. Clinical and oncological outcomes]

The objective of the study was to analyze a group of patients with low grade parosteal osteosarcoma treated with limb salvage surgery and reconstructed with bone allograft. A retrospective review from our oncologic data base between 1980 and 2010 was done and all patients with diagnosis of low grade parosteal osteosarcoma, treated with limb salvage surgery and reconstructed with allograft were included. Twenty-two patients were included for the analysis. The mean age was 32±11 years (10-59) y the mean follow-up 93±69 months (8-237). Ten year overall survival of the series was 91% (95% CI: 79-100). Four patients developed local recurrence, 2 of them histological classified after the resection dedifferentiated parosteal osteosarcoma. Two patients developed distant recurrence, being the lung the only site of metastasis. Ten year limb salvage reconstruction survival was 65% (95% CI: 44-86). Long term survival rate in low grade parosteal osteosarcoma is over 90%. Surgical resection wide margin should be the elective treatment and biological limb salvage reconstruction is a good alternative.

Virtual Microscopy Large Slide Automated Acquisition: Error Analysis and Validation

The aim of this work is to assess and analyze the discrepancies introduced in the reconstruction of an entire tumoral bone slice from multiple field acquisitions of a large microscopy slide. The reconstruction tends to preserve the original structural information and its error is estimated by comparing the reconstructed images of eight samples against single pictures of these samples. This comparison is held using the Structural Similarity index. The measurements show that smaller samples yield better results. The detected errors are introduced by the insufficiently corrected optical distortion caused by the camera lens, which tends to accumulate along the sample. Nevertheless, the maximum error encountered does not exceed 0.39 mm, which is smaller than the maximum tolerable error for the intended application, stated in 1 mm.

[Osteosarcoma lung metastases. Survival after chemotherapy and surgery]

Five years overall survival in osteosarcoma patients is around 70%, although in patients with metastatic disease it is only 10-30%. The objective of this study was to analyze overall survival and prognostic factors in a group of patients with metastatic osteosarcoma treated with surgical removal of the lung metastases. A retrospective review from our oncology data base revealed 38 patients treated between 1992 and 2006. The mean age at diagnosis was 18 ± 9.4 years (3-45) and mean follow-up was 57 ± 53.8 months (12-231). All patients were treated with chemotherapy and oncologic resection of the primary tumor and surgical removal of the lung metastases. We analyzed overall survival and prognostic factors: age, gender, site, time of metastasis, local recurrences, number of lung metastasis and chemotherapy response (necrosis). Overall survival of the entire series was 29% at 5 years (CI 95%: 14.5-43.5) and 26% at 10 years (CI 95%: 12-40). Significant difference in 5 year overall survival was found between good and bad responders to chemotherapy, 53% (IC 95%: 28-78) vs. 8% (IC 95%: 0-20) (p = 0.0008). No statistically significant relationship between other prognostic factors analyzed was observed. Five and ten years overall survival rates in osteosarcoma patients with lung metastasis treated with chemotherapy and surgically resection is poor. Patients with good response to chemotherapy have better prognosis.

The principles and applications of fresh frozen allografts to bone and joint reconstruction

Fresh frozen allograft reconstruction has been used for a long time in massive bone loss in orthopedic surgery. Allografts have the advantage of being biologic reconstructions, which gives them durability. Despite a greater number of complications in the short term, after 5 years these stabilize with high rates of survival after 10 years. The rate of early complications and the need for careful management in the first years has led the orthopedic surgeon to the use of other options. However, the potential durability of this reconstruction makes this one of the best options for younger patients with high life expectancy.

[Surgical treatment of locally aggressive and malignant tumors of the proximal third of the fibula. Oncology results and functional evaluation]

INTRODUCTION

Proximal fibula malignant and locally aggressive benign bone tumors are uncommon and usually treat by surgery. Bloc resection of the knee can compromise knee stability due to of the resection of the posterolateral ligament complex.

MATERIAL AND METHODS

We analyzed 28 consecutive patients treated for a proximal fibula bone tumor between 1980 and 2006 (osteosarcoma: 9, giant cell tumor: 9, Ewing sarcoma: 8 and chondrosarcoma: 2). Sixty-one percent were male and the median age was 21 years (range: 8-60). The mean follow-up was 86 months. The posterolateral complex was reinserted at tibial metaphyseal level. Patients were evaluated functionally using the Musculoskeletal Tumor Society scale (MSTS).

RESULTS

Overall survival rate was 89%, local recurrence rate was 11%, and secondary amputation rate was 6% at 7 years of median follow-up. The average MSTS score was 93%. Five patients had neurological complications. No patient experienced subjective instability or vascular insufficiency.

CONCLUSIONS

Bloc resection of the proximal fibula for the treatment of aggressive or malignant primary bone tumors allowed us to obtain local tumor control, and overall survival rate for sarcomas of 89% at 7 years. The posterolateral ligament complex tibial reinsertion provided functional knee stability without major functional consequences in the medium term.

[Survival and complications analysis of 97 patients with bone metastases treated surgically]

BACKGROUND

The purpose of this paper is to assess the survival and the different factors predisposing to increased local and overall complications in a group of patients treated surgically for bone metastases.

MATERIAL AND METHODS

A total of 97 patients were included in our study, 45 females and 52 males. Mean age was 59 years (range 22-81) and the mean follow-up was 23 months (range 3-76). Were performed 104 surgical interventions. Patient survival was estimated with the Kaplan-Meier method. Complications, recurrences and the most significant factors were analyzed.

RESULTS

Overall patient survival was 73% at one year, 47% at 2 years, and 6% at 5 years. Patient survival was greater in patients with a histologic diagnosis of metastatic renal cancer (p > 0.05) and a higher incidence of local relapses (p > 0.05). Intralesional surgery significantly affected the relapses.

CONCLUSIONS

Patients with metastatic renal cancer had the greatest survival rate. However, they were associated with a higher rate of local relapses and postoperative failure.

Accuracy of 3-D planning and navigation in bone tumor resection

Surgical precision in oncologic surgery is essential to achieve adequate margins in bone tumor resections. Three-dimensional preoperative planning and bone tumor resection by navigation have been introduced to orthopedic oncology in recent years. However, the accuracy of preoperative planning and navigation is unclear. The purpose of this study was to evaluate the accuracy of preoperative planning and the navigation system. A total of 28 patients were evaluated between May 2010 and February 2011. Tumor locations were the femur (n=17), pelvis (n=6), sacrum (n=2), tibia (n=2), and humerus (n=1). All resections were planned in a virtual scenario using computed tomography and magnetic resonance imaging fusion. A total of 61 planes or osteotomies were performed to resect the tumors. Postoperatively, computed tomography scans were obtained for all surgical specimens, and the specimens were 3-dimensionally reconstructed from the scans. Differences were determined by finding the distances between the osteotomies virtually programmed and those performed. The global mean of the quantitative comparisons between the osteotomies programmed and those obtained through the resected specimen was 2.52±2.32 mm for all patients. Differences between osteotomies virtually programmed and those achieved by navigation intraoperatively were minimal.

Multiplanar osteotomies guided by navigation in chondrosarcoma of the knee

Surgical resection with adequate margins is the treatment of choice in chondrosarcoma. However, well-circumscribed lesions can be completely resected by performing multi-planar osteotomies guided by computer-assisted navigation. This type of resection had been recently described in select patients with sarcomas; however, these osteotomies are technically demanding to plan and perform intraoperatively. The use of navigation to assist in surgery is becoming more frequently described in orthopedic oncology.The authors performed multiplanar osteotomy resections guided by navigation and reconstruction with intercalary allografts in 5 patients with chondrosarcoma around the knee. All the patients were women, with a mean age of 56 years. Four tumors were located in the distal femur and 1 in the proximal tibia. The 5 surgical anatomic specimens were 3-dimensionally reconstructed postoperatively and superimposed on a preoperative plan to check whether the resected specimen was consistent with the preoperative planned resection. At final follow-up, no patient experienced a local recurrence or metastasis. Four osteotomies each were performed in 3 patients, and 3 osteotomies each were performed in 2 patients, so 18 planes were evaluated. Mean difference in distance between preoperative vs final planes was 2.43 mm. Average functional score was 29 points. All patients resumed activities of daily living without restriction. This study's results show that navigation with adequate preoperative planning allows surgeons to intraoperatively reproduce the planned resection with accuracy in complex multiplanary resections.

Bone tumor resection: analysis about 3D preoperative planning and navigation method using a virtual specimen

The use of three-dimensional preoperative planning and bone tumor resection guided by navigation has increased in the last ten years. However, no study to date, as far as we know, has directly provided evidence of accuracy of this method. The objective of this study was to describe a method capable of determining the accuracy of osteotomies performed for tumor resection planned and guided by navigation. We hypothesize that matching the 3D reconstructed surgical specimen is an acceptable method to determine the accuracy of virtual planning and navigation. A total of seven patients and 14 osteotomies were evaluated. After surgery, all surgical specimens were 3D reconstructed from CT images. The mean of quantitative comparisons between osteotomies planned and osteotomies obtained through the resected specimen was in a global mean of 1.56 millimeters (SD: 2.91) for all the cases. Based on our observations, a three-dimensional model obtained from the tumor surgical specimen is a useful tool to determine accuracy of 3D planning and surgical navigation.

Complications in total knee arthroplasty after high tibial osteotomy

The outcome of total knee arthroplasty (TKA) after high tibial osteotomy remains uncertain. Compared with primary TKA, the results in some studies are not significantly different. Others report adverse effects on the outcome. The purpose of this study was to determine (1) the middle- and long-term survival of TKA performed after high tibial osteotomy, (2) their clinical and radiographic results, and (3) what complications could be expected in this group of patients.The study group comprised 31 patients (34 knees) undergoing cemented TKA after high tibial osteotomy. Average follow-up was 8 years (range, 6-213 months). Survival of the TKA was estimated using the Kaplan-Meier method. Outcomes were documented using the Hospital for the Special Surgery score. The results showed that the Kaplan-Meier survival rate was 82% at 5 years and 76% at 10 years. Excellent and good clinical results were obtained in 67% of patients. Complications occurred in 12 (35%) knees: stiffness in 4, aseptic loosening in 2, patellofemoral subluxation in 1, instability in 1, inexplicable pain in 1, and deep infection in 3.Great care with technical details is necessary when high tibial osteotomy is indicated because a future conversion to TKA may occur.

Intraoperative ultrasound assistance for excision of impalpable musculoskeletal soft tissue tumors

Intraoperative ultrasonography is a useful tool for the detection and extirpation of liver metastases, breast masses, and melanoma. However, the efficacy of this technology in intraoperative localization and resection of small soft tissue tumors has not been addressed. The purpose of this study is to report on the efficacy of intraoperative ultrasound assistance in excising impalpable musculoskeletal soft tissue tumors. Twenty-two soft tissue tumors <3 cm (range, 0.7-3 cm) were resected with intraoperative ultrasound assistance. All tumors were localized in the deep panniculus, fascia, or muscle. Surgical time and length of incisions was recorded in all the cases. Intra- and postoperative reregistration was made to confirm the tumor resection. Ultrasound assistance was successful in obtaining an accurate localization in all treated cases. Mean surgical time was 30 minutes (range, 13-87 minutes). Average incision length was 5.7 cm (range, 2.5-10.6 cm). Reregistration allowed intraoperative confirmation of the adequacy of the excision. The procedure allowed recognized and excised additional nodules not previously diagnosed in 3 cases. Postoperative echography done in all patients confirmed complete extirpation of the tumors, and histopathology confirmed adequate margins obtained. Intraoperative ultrasound can be used as an efficient tool to localize and treat impalpable small soft tissue tumors.

Proximal tibia osteoarticular allografts in tumor limb salvage surgery

BACKGROUND

Resection of large tumors of the proximal tibia may be reconstructed with endoprostheses or allografts with fixation. Endoprosthetic replacement is associated with high failure rates and complications. Proximal tibia osteoarticular allografts after tumor resection allows restoration of bone stock and reconstruction of the extensor mechanism, but the long-term failure rates and complications are not known.

QUESTIONS/PURPOSES

We therefore determined (1) the middle- and long-term survival of proximal tibia osteoarticular allografts, (2) their complications, and (3) functional (Musculoskeletal Tumor Society score) and radiographic (International Society of Limb Salvage) outcomes in patients treated with this reconstruction.

PATIENTS AND METHODS

We retrospectively reviewed 52 patients (58 reconstructions including six repeat reconstructions) who underwent osteoarticular proximal tibia allograft reconstructions after resection of a bone tumor. The minimum followup of the 46 surviving patients was 72 months (mean, 123 months; range, 10-250 months). Survival of the allograft was estimated using the Kaplan-Meier method. We documented outcomes using the Musculoskeletal Tumor Society functional scoring system and the International Society of Limb Salvage radiographic scoring system.

RESULTS

Six patients died from tumor-related causes without allograft failure before the 5-year radiographic followup. At last followup, 32 of the 52 remaining allografts were still in place; 20 failed owing to infections, local recurrences, or fractures. Overall allograft survival was 65% at 5 and 10 years, with an average Musculoskeletal Tumor Society functional score of 26 points and an average radiographic result of 87%.

CONCLUSIONS

Based on these data we believe proximal tibia osteoarticular allograft is a valuable reconstructive procedure for large defects after resection of bone tumors.

LEVEL OF EVIDENCE

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

Proximal femur allograft-prosthesis with compression plates and a short stem

Proximal femur allograft-prosthesis composites (APCs) performed with compression plates and a short stem theoretically could minimize the resorption or nonunion that reportedly occurs with long stems bypassing the diaphyseal osteotomy. To confirm this theoretical consideration, we retrospectively reviewed 34 patients with 38 proximal femoral APCs using a short-cemented femoral stem and compression plates for diaphyseal osteotomy fixation. In 26 patients, the plate fixation extended over at least half the femoral stem and in 12, it did not. We reinserted the abductor mechanism with two techniques: in 10 cases the host trochanter was reattached to the APC, and in 28 the host tendons were sutured to the tendinous insertion of the allograft. The overall survival of the entire series was 72% at 5 years and 69% at 10 years. Eleven of the 38 (29%) APCs were removed: three for infection, one for local recurrence of tumor, and seven for fractures. Trendelenburg gait occurred in four of 21 patients with direct tendon-to-tendon suture of the abductor mechanism and in three of six patients with trochanteric osteotomy. The overall APC survival rate was greater in patients in whom the allograft was adequately protected with internal fixation than in patients in whom it was not.

LEVEL OF EVIDENCE

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

Massive bone loss from fungal infection after anterior cruciate ligament arthroscopic reconstruction

Although there are numerous reports of septic pyogenic arthritis after arthroscopic anterior cruciate ligament (ACL) reconstruction, there is limited information regarding the outcomes of fungal infection. We determined the outcomes of six patients with mycotic infection after regular ACL reconstruction. There were four males and two females with a mean age of 33 years. We determined the number of procedures performed, bone loss originating to control infection, and final reconstruction in these patients. An average of five arthroscopic lavage procedures had been performed at the referring centers. Fungal infection was diagnosed based on pathologic samples; five infections were the result of mucormycosis and one was Candida. After final débridement, the mean segmental bone loss was 12.8 cm. All patients were treated with intravenous antifungal coverage and cement spacers before final reconstruction. At final followup, all patients were free of clinical infection. Three had reconstruction with an allograft-prosthesis composite, two with hemicylindrical allografts, and one with an intercalary allograft arthrodesis. Despite the extremely unusual presentation of this complication, surgeons should be aware of potential and catastrophic consequences of this severe complication after ACL reconstruction.

Unicondylar osteoarticular allografts of the knee. Surgical technique

BACKGROUND

In the management of a resected distal femoral or proximal tibial condyle as the result of tumor or trauma, a unicondylar osteoarticular allograft is currently the only reconstructive option that avoids the sacrifice of the unaffected condyle. The purposes of this study were to perform a survival analysis of unicondylar osteoarticular allografts of the knee and to evaluate the complications.

METHODS

We retrospectively reviewed the results of forty large unicondylar osteoarticular allograft procedures in thirty-eight patients who were followed for a mean of eleven years. Twenty-nine allografts were femoral transplants and included eleven medial and eighteen lateral femoral condyles. Eleven allografts were tibial transplants, including four medial and seven lateral tibial condyles. The procedure was performed after a tumor resection in thirty-six patients and to replace condylar loss after a severe open fracture in the remaining two patients. Complications were analyzed, and allograft survival from the date of implantation to the date of revision or the time of the latest follow-up was determined. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up.

RESULTS

One patient died of tumor-related causes without allograft failure before the two-year follow-up evaluation. The global rate of allograft survival at both five and ten years was 85%, with a mean follow-up of 148 months. In six patients, the allografts were removed at an average of twenty-six months (range, six to forty-eight months) and these were considered failures. All six patients underwent a second allograft procedure including two new unicondylar and four bicondylar reconstructions. The mean radiographic score for the thirty-three surviving allografts evaluated was 89%, with an average functional score of 27 of a possible 30 points.

CONCLUSIONS

Unicondylar osteoarticular allografts of the knee appear to be a reliable alternative for patients in whom reconstruction of massive osteoarticular bone loss is limited to one condyle of the femur or tibia.

Unicondylar osteoarticular allografts of the knee

BACKGROUND

In the management of a resected distal femoral or proximal tibial condyle as the result of tumor or trauma, a unicondylar osteoarticular allograft is currently the only reconstructive option that avoids the sacrifice of the unaffected condyle. The purposes of this study were to perform a survival analysis of unicondylar osteoarticular allografts of the knee and to evaluate the complications.

METHODS

We retrospectively reviewed the results of forty large unicondylar osteoarticular allograft procedures in thirty-eight patients who were followed for a mean of eleven years. Twenty-nine allografts were femoral transplants and included eleven medial and eighteen lateral femoral condyles. Eleven allografts were tibial transplants, including four medial and seven lateral tibial condyles. The procedure was performed after a tumor resection in thirty-six patients and to replace condylar loss after a severe open fracture in the remaining two patients. Complications were analyzed, and allograft survival from the date of implantation to the date of revision or the time of the latest follow-up was determined. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up.

RESULTS

One patient died of tumor-related causes without allograft failure before the two-year follow-up evaluation. The global rate of allograft survival at both five and ten years was 85%, with a mean follow-up of 148 months. In six patients, the allografts were removed at an average of twenty-six months (range, six to forty-eight months) and these were considered failures. All six patients underwent a second allograft procedure including two new unicondylar and four bicondylar reconstructions. The mean radiographic score for the thirty-three surviving allografts evaluated was 89%, with an average functional score of 27 of a possible 30 points.

CONCLUSIONS

Unicondylar osteoarticular allografts of the knee appear to be a reliable alternative for patients in whom reconstruction of massive osteoarticular bone loss is limited to one condyle of the femur or the tibia.

Effect of erroneous surgical procedures on recurrence and survival rates for patients with osteosarcoma

To determine whether inappropriate surgical procedures based on an initial misdiagnosis affected recurrence and survival rates, we retrospectively reviewed the surgical treatment and results of 117 patients with high-grade osteosarcomas treated from January 1, 1990 to December 31, 2000. Nine patients had intralesional curettage performed at other institutions based on an erroneous diagnosis of a benign lesion. Two of the nine patients had amputations and seven patients had limb-salvage procedures. Of the 108 patients who were not misdiagnosed, six patients had amputations and 102 patients had limb-salvage procedures. All patients received neoadjuvant therapy. Fifteen of the 117 patients had local recurrences. Patients who had erroneous surgical procedures based on the initial misdiagnosis of osteosarcoma had an increased risk of local recurrence and decreased 10-year survival rate. Response to adjuvant therapy and the amount of previous violation of natural tumor barriers should be evaluated carefully before deciding surgical treatment.

Continuity and function of patellar tendon host-donor suture in tibial allograft

Reconstruction of extensor mechanism after proximal tibia tumor resection is a major concern, especially in young and physically active patients. We evaluated patellar tendon host-donor reattachments in 42 consecutive proximal tibia allo- graft reconstructions after bone tumor resection to determine if patellar tendon length and integrity was maintained, and if active knee extension and adequate function was achieved. Patellar tendon length was radiographically measured in all patients by the Insall-Salvati index while magnetic resonance was available in 19 patients to evaluate imaging integrity. Eight patients were not available for functional assessment, leaving 34 patients for clinical evaluation with the Musculoskeletal Tumor Society scoring system. According to the Insall-Salvati index evaluation, the reconstructed patellar tendon remained stable with no elongation between preoperative and postoperative measurements (1.15 versus 1.13). Postoperative magnetic resonance images showed a continuous patellar host-donor tendon in all. Active knee extension was restored in all functionally evaluated patients with an average functional score of 26.6 points. Twenty-four patients had no extensor lag, while ten had an average residual extensor lag of 6.5 degrees . Our findings suggest patellar tendon reconstruction with allogeneic tissue from the proximal tibia allograft sutured to the recipient's remnant patellar tendon can restore and stabilize active knee extension.

LEVEL OF EVIDENCE

Therapeutic study, level IV (case series).

Use of distal femoral osteoarticular allografts in limb salvage surgery. Surgical technique

BACKGROUND

As diagnostic and therapeutic techniques improve, patients with a musculoskeletal sarcoma should expect longer survival, fewer complications and side effects, and an improved quality of life. Functional longevity of the reconstruction after resection of the tumor becomes a major concern, especially in young and physically active patients. The purpose of this study was to analyze the mid-term and long-term survival of reconstructions with a distal femoral osteoarticular allograft in a series of patients.

METHODS

We retrospectively reviewed the results of eighty reconstructions with a distal femoral osteoarticular allograft following resection of a bone tumor in seventy-six patients. The mean duration of follow-up was eighty-two months. The rates of survival of the allograft and the joint surface were estimated with use of the Kaplan-Meier method. Cox regression analysis was performed to determine whether age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were independent prognostic factors. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up.

RESULTS

Five patients were lost to follow-up, leaving seventy-five allografts in seventy-one patients available for study. Thirteen patients (thirteen allografts) died of tumor-related causes without allograft failure before a two-year radiographic follow-up could be performed. Of the remaining sixty-two allografts, fourteen failed: six failed as a result of infection; four, because of local recurrence; one, because of massive resorption; and three, as a result of fracture. At the time of final follow-up, at a mean of 125 months, forty-eight allografts were still in place. The overall rate of allograft survival was 78% at both five and ten years, and the rate of allograft survival without the need for resurfacing with a knee prosthesis was 71% at both five and ten years. With the numbers available, age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were not found to have a significant effect on the overall allograft survival rates. The patients who retained the original allograft had good or excellent functional and radiographic results.

CONCLUSIONS

The life expectancy for most patients with a highly aggressive or malignant tumor in the distal part of the femur is now several decades. In this study, we found a high rate of survival of distal femoral allograft reconstructions at both five and ten years.

Massive allograft use in orthopedic oncology

Allograft transplantation is a functional reconstructive option for large-extremity osseous defects. Improvements in anatomic matching, infection prevention, allograft fixation, soft tissue reconstructions, and rehabilitation protocols have greatly influenced predictability and longevity of massive allografts. These demanding reconstructions require time, an experienced group of orthopedic surgeons working at an institution with access to a large volume of patients, and a reliable, modern bone bank to select the appropriate graft for each individual under safe conditions. This article discusses the current use of total condylar osteoarticular allografts, hemicondylar allografts, allograft arthrodesis, intercalary segmental allografts, hemicylindric intercalary allografts, and allograft-prosthesis composites.

Use of distal femoral osteoarticular allografts in limb salvage surgery

BACKGROUND

As diagnostic and therapeutic techniques improve, patients with a musculoskeletal sarcoma should expect longer survival, fewer complications and side effects, and an improved quality of life. Functional longevity of the reconstruction after resection of the tumor becomes a major concern, especially in young and physically active patients. The purpose of this study was to analyze the mid-term and long-term survival of reconstructions with a distal femoral osteoarticular allograft in a series of patients.

METHODS

We retrospectively reviewed the results of eighty reconstructions with a distal femoral osteoarticular allograft following resection of a bone tumor in seventy-six patients. The mean duration of follow-up was eighty-two months. The rates of survival of the allograft and the joint surface were estimated with use of the Kaplan-Meier method. Cox regression analysis was performed to determine whether age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were independent prognostic factors. Functional and radiographic results were documented according to the Musculoskeletal Tumor Society scoring system at the time of the latest follow-up.

RESULTS

Five patients were lost to follow-up, leaving seventy-five allografts in seventy-one patients available for study. Thirteen patients (thirteen allografts) died of tumor-related causes without allograft failure before a two-year radiographic follow-up could be performed. Of the remaining sixty-two allografts, fourteen failed: six failed as a result of infection; four, because of local recurrence; one, because of massive resorption; and three, as a result of fracture. At the time of final follow-up, at a mean of 125 months, forty-eight allografts were still in place. The overall rate of allograft survival was 78% at both five and ten years, and the rate of allograft survival without the need for resurfacing with a knee prosthesis was 71% at both five and ten years. With the numbers available, age, gender, the percentage of the femur that had been resected, and the use of chemotherapy were not found to have a significant effect on the overall allograft survival rates. The patients who retained the original allograft had good or excellent functional and radiographic results.

CONCLUSIONS

The life expectancy for most patients with a highly aggressive or malignant tumor in the distal part of the femur is now several decades. In this study, we found a high rate of survival of distal femoral allograft reconstructions at both five and ten years.

Partial epiphyseal preservation and intercalary allograft reconstruction in high-grade metaphyseal osteosarcoma of the knee

BACKGROUND

The purpose of this study was to analyze a series of patients with a high-grade metaphyseal osteosarcoma of the knee who had been treated with a transepiphyseal resection, with preservation of the distal femoral and the proximal tibial (articular) portions of the epiphysis, and an intercalary allograft reconstruction.

METHODS

The cases of thirteen patients with a high-grade metaphyseal osteosarcoma around the knee who had transepiphyseal resection and reconstruction with an intercalary allograft were retrospectively reviewed at a mean of sixty-three months. Complications, disease-free survival of the patient, final preservation of the limb and epiphysis, and functional results according to the Musculoskeletal Tumor Society scoring system were documented at the time of the latest follow-up.

RESULTS

At the final follow-up examination, eleven of the thirteen patients continued to be disease-free. One patient died of bone and pulmonary metastases with no evidence of local recurrence, and the remaining patient had no evidence of disease after resection of a local recurrence of the tumor in the soft tissues. No patient had a local recurrence in the remaining epiphysis. Seven patients had complications that included a fracture (three patients), diaphyseal nonunion (two), deep infection (one), and a local recurrence in the soft tissues (one). The allograft was removed in only four of these patients. At the latest follow-up examination, twelve patients were alive with preserved limbs. In one patient, the epiphysis, which originally had been preserved, was resected because of a metaphyseal fracture, and the limb was reconstructed with an osteoarticular allograft. The patients with a preserved epiphysis had an average functional score of 27 points (maximum, 30 points).

CONCLUSIONS

Preservation of the epiphysis in high-grade metaphyseal osteosarcoma at the knee is an alternative in carefully selected patients. Crucial factors needed to obtain local tumor control and achieve an acceptable functional result are a positive response to chemotherapy, accurate preoperative assessment of tumor extension to the epiphysis, and appropriate fixation techniques for intercalary allografts.

Partial epiphyseal preservation and intercalary allograft reconstruction in high-grade metaphyseal osteosarcoma of the knee

BACKGROUND

The purpose of this study was to analyze a series of patients with a high-grade metaphyseal osteosarcoma of the knee who had been treated with a transepiphyseal resection, with preservation of the distal femoral and the proximal tibial (articular) portions of the epiphysis, and an intercalary allograft reconstruction.

METHODS

The cases of thirteen patients with a high-grade metaphyseal osteosarcoma around the knee who had transepiphyseal resection and reconstruction with an intercalary allograft were retrospectively reviewed at a mean of sixty-three months. Complications, disease-free survival of the patient, final preservation of the limb and epiphysis, and functional results according to the Musculoskeletal Tumor Society scoring system were documented at the time of the latest follow-up.

RESULTS

At the final follow-up examination, eleven of the thirteen patients continued to be disease-free. One patient died of bone and pulmonary metastases with no evidence of local recurrence, and the remaining patient had no evidence of disease after resection of a local recurrence of the tumor in the soft tissues. No patient had a local recurrence in the remaining epiphysis. Seven patients had complications that included a fracture (three patients), diaphyseal nonunion (two), deep infection (one), and a local recurrence in the soft tissues (one). The allograft was removed in only four of these patients. At the latest follow-up examination, twelve patients were alive with preserved limbs. In one patient, the epiphysis, which originally had been preserved, was resected because of a metaphyseal fracture, and the limb was reconstructed with an osteoarticular allograft. The patients with a preserved epiphysis had an average functional score of 27 points (maximum, 30 points).

CONCLUSIONS

Preservation of the epiphysis in high-grade metaphyseal osteosarcoma at the knee is an alternative in carefully selected patients. Crucial factors needed to obtain local tumor control and achieve an acceptable functional result are a positive response to chemotherapy, accurate preoperative assessment of tumor extension to the epiphysis, and appropriate fixation techniques for intercalary allografts.

LEVEL OF EVIDENCE

Therapeutic study, Level IV (case series [no, or historical, control group]). See Instructions to Authors for a complete description of levels of evidence.

Spontaneous remission of massive solitary eosinophilic granuloma of the femur

The authors describe two children with a history of pain and limping who showed a solitary extensive diaphyseal lesion of the femur. A needle biopsy confirmed the diagnosis of eosinophilic granuloma. Without any treatment, both patients went into spontaneous total remission after the percutaneous biopsy. At last follow-up (after 4 years), there was no clinical evidence of disease, and a femur x-ray appeared normal. These two cases suggest that until additional biologic parameters of disease behavior are clarified, some patients with eosinophilic granuloma might be grossly overtreated due to misinterpretation of radiographic images.

Survivorship analysis of 141 modular metallic endoprostheses at early followup

Although our institution historically has been known for its use of osteoarticular allografts in limb salvage surgery for tumors, during the last 8 years there has been an increase in the use of metallic modular endoprostheses. A retrospective review of 141 patients in whom a modular endoprosthesis was implanted in the past 8 years was done, and survival data were compiled using Kaplan-Meier survival analysis, clinical score was determined using a previously described system, and a multivariate regression analysis was done to identify independent risk factors. There were 13 failures (defined as need for revision of the majority of the prosthetic components, excluding cases of local recurrence) yielding an overall implant survival of 91%. Based on Kaplan-Meier estimates, the endoprosthetic survival rate was 88% at 3 years and 76% at 5 years; per location, it was 100% for the proximal humerus, 100% for the proximal femur, 87% for modular knees, and 53% for total femoral implants at 3 years. The clinical scores were good to excellent in 74% of the patients. Multivariate analysis showed that only location and infection were independent risk factors for prosthesis failure. Loosening, infection, and dislocation were independently predictive of a fair or poor clinical score. Age, gender, diagnosis, length of implant, dislocation, nor failed prior allograft had an independent effect on implant survival or clinical outcome. The proximal humeral and proximal femoral implants had greater survival rates than modular knee and total femoral implants. Conversion of failed allografts to modular endoprostheses had a trend for a higher failure rate, but after a multivariate analysis, did not prove to be an independent risk factor for failure. We think that our experience is similar to other endoprosthesis survivorship reports in the literature with short-term followup.

Tumors about the knee misdiagnosed as athletic injuries

BACKGROUND

Musculoskeletal tumors may originally mimic a traumatic condition, and, on the basis of an erroneous diagnosis of an athletic injury, an invasive diagnostic or therapeutic procedure may be performed. We determined the number of such cases treated at our institution, and we analyzed the initial and final diagnoses as well as the changes in the indicated oncologic surgical technique due to the initial erroneous diagnosis.

METHODS

Twenty-five patients who had a bone or soft-tissue tumor about the knee that originally had been diagnosed as an athletic injury were referred to our institution. The complete clinical, radiographic, and pathological records were reviewed. Studies that had been performed prior to the invasive procedure and at the time of admission to our institution were evaluated to determine differences in the tumor stage and the oncologic treatment that was indicated at each time.

RESULTS

Of 667 knee tumors diagnosed in our institution, twenty-five (3.7%) previously had been treated with an intra-articular procedure as a result of a misdiagnosis of an athletic injury. The final diagnoses made at our institution were a benign tumor in eleven patients and a malignant tumor in fourteen. Oncologic surgical treatment was affected in fifteen of the twenty-five patients.

CONCLUSIONS

When a knee tumor is initially misdiagnosed as an athletic injury, treatment may be adversely affected by the delay in diagnosis or an inappropriate invasive procedure that results in extension of the tumor. Initial poor-quality radiographs and an unquestioned original diagnosis despite persistent symptoms were the most frequent causes of an erroneous diagnosis.

Epiphyseal primary location for osteosarcoma and Ewing sarcoma in patients with open physis

Conventional osteosarcoma and Ewing sarcoma are the most common childhood malignant tumors of bone. These tumors arise in the metaphysis and diaphysis of long bones and may extend secondarily into the epiphysis. Primary epiphyseal location for these tumors is rare and may constitute a diagnostic and therapeutic challenge. The authors report two skeletally immature patients with an osteosarcoma and Ewing sarcoma limited to the epiphysis. Clinical, radiographic and histopathologic findings are discussed.

Survivorship and radiographic analysis of knee osteoarticular allografts

An evaluation of long-term survival and radiographic deterioration of 118 knee osteoarticular allografts in 114 patients was performed. Radiographic analysis was done according to the Musculoskeletal Tumor Society grading system. A failure was defined as when the allograft was removed during a revision procedure or amputation. Ten patients were lost to followup during the first 2 years after surgery. Eighteen patients without allograft failures died of complications related to the tumor. Twenty-six allografts failed because of infection (13 allografts), local recurrence (eight allografts), massive resorptions (three allografts) and fractures (two allografts). Sixty-four allografts still were in place at a mean of 98 months (range, 36-360 months) after implantation. The Kaplan-Meier 5-year survival rate for the knee osteoarticular allografts was 73% and the limb preservation rate was 93%. The mean radiographic score was 83%. Sixty-four percent of the allografts showed no radiologic changes or minor articular deterioration. Fourteen percent had narrowing of the joint space of more than 2 mm, and 22% had some form of subchondral bone collapse. Five patients required joint resurfacing to preserve the original allograft. Most of the allograft failures occurred during the first 4 years, and the allograft survival rate for the current series remained unchanged after 5 years.