This text has been removed at the authors' request.

Introduction

Extensive bone loss and poor residual bone quality can make implant fixation difficult to achieve in revision of failed megaprostheses. While newer porous components are available to address various periarticular cavitary and segmental defects, diaphyseal fixation remains challenging without resorting to cemented techniques, or cementless fully-coated stems that achieve fixation over long segments of bone. In cases of previous infection, it may be advantageous to avoid the use of such devices as they can be difficult to remove and may result in even greater bone loss if the infection were to persist. Compressive osseointegration technology has been become a valuable device in the management of these challenging situations.

Introduction

Radiolucencies beneath the tibial component are well recognized in knee arthroplasty; the aetiology and significance are poorly understood. Non-progressive narrow radiolucencies with a sclerotic margin are thought not to be indicative of loosening. Factors which decrease the incidence of radiolucencies include cementless fixation and the use of pulse lavage. Leg/component alignment or BMI do not influence radiolucency. We are not aware of any studies that have looked at the effect of load type on radiolucency.

The Oxford domed lateral tibial component was introduced to decrease the bearing dislocation rate that was unacceptably high with the flat tibial tray. However, the introduction of the domed tibial component alters the forces transmitted through the implant-cement-bone interface. As the Oxford UKR uses a fully congruent mobile bearing, the forces transmitted through the interface with a flat tray are compressive, except for the effect of friction. However, with the domed tibial component shear forces are introduced. The aim of this study was to assess the prevalence of radiolucency beneath the previous flat design and the new domed tibial tray.

Soft tissue sarcomas (STS) arising in the adductor compartment of the thigh are frequently large before clinical detection, posing particular challenges with surgical resection and associated with a high risk of wound complications. This study compares oncological and functional outcomes and complications following treatment of adductor compartment soft tissue sarcomas from three international centres with different treatment philosophies.

184 patients with new primary, non-metastatic, deep STS in the adductor compartment diagnosed between 1990 and 2001 were identified from the centres' local databases. The Toronto Extremity Salvage Score (TESS) was used to assess function in patients.

There were 94 male and 90 female patients, with ages ranging from 13 to 88 years (median age 57 years). The period of follow-up ranged from 1 to 162 months. The overall survival was 65% at 5 years and related to grade and size of the tumour. There was no difference in overall survival or systemic relapse between the three centres. There was however a significant difference in local control (28% LR in centre 1 compared to 10% in centre 2 and 5% in centre 3, which appeared to be principally related to the use of radiotherapy and surgical margins.)

66 patients (36%) from the three centres developed wound complications post-operatively and it was shown to be associated with high grade and large tumours (>10cm).

Functional scores averaged 78% but were significantly worse for patients with wound complications or high-grade tumours; however, they were not affected by timing of radiotherapy or use of prophylactic free muscle flaps.

Between 1986 and 1999, 94 patients (96 hips) including 31 male and 63 female (mean age 59.5 years), with massive bone loss had a revision hip arthroplasty using an allograft-prosthesis composite (APC). A previous history of infection was present in 21 of these cases.

At an average follow-up of 11 years (range, 8 to 20 years), 72 patients were alive, 21 patients died, and 1 patient was lost to follow-up. Major complications occurred in 33 cases: femoral stem loosening (12); dislocation (15); periprosthetic fracture (10); and infection (7). Further revision surgery was performed in 21 of the 96 cases including revision of the acetabular component (3), femoral APC (16) or both (2). The 10 year survival of the APCs was 68.8% (95% CI 58.6%–79%, 26 cases remaining at risk). There was no statistically significant difference in survival time between gender, age, indication for APC (including infection), surgical approach and APC technique. Statistically significant factors negatively impacting APC survival included two or more prior revisions, severity of preoperative bone loss (Paprosky type IV) and use of plates and screws (p< 0.05). Statistically significant improvement in APC survival was identified in those reconstructions in which cement was used for proximal fixation of the femoral component within the allograft (p< 0.05).

Reconstruction with an allograft-implant composite is a demanding procedure. However, preservation of bone stock is a major advantage.

Aim: The purpose of our study is to present the survival results, clinical outcome and complications from the use of APC in cases with a history of periprosthetic infection.

Materials and Methods: Between 1986 and 1999, twenty-two patients (twenty-two hips) 11 male and 11 female (mean age 57.5 years – range 38 to 77 years) with massive bone loss (Paprosky IIIA 2 cases, IIIB 4 cases, and IV 16 cases) were included to our study. They all had a history of periprosthetic infection after an average of 3.3 (range 1 to 5) revision hip arthroplasties and were submitted to a two stage revision arthroplasty using an allograft-prosthesis composite.

Results: At an average follow-up of eleven years (range, eight to twenty years), 14 patients were alive, 7 patients died, and 1 patient was lost to follow-up. The ten year survival of the allograft-prosthesis composites was 74.9 per cent (95 per cent confidence interval 55.1 to 94.7 per cent, 4 cases remaining at risk). Seven cases presented with APC failure needing re-revision, 2 due to re-infection (4 and 23 months from revision by the same microorganism species as for the initial infection (Staph aureus to both cases), 3 due to allograft non union (at 21, 43, 79 months) and 2 cases due to graft resorption (164, 175 months post revision). Delayed healing and wound drainage occurred to 2 more cases.

Conclusion: Reconstruction of massive proximal femoral bone loss with an allograft-implant composite is a demanding procedure. Biologic means of reconstruction is a major advantage preserving bone stock for future surgery. However, high complication rate should be considered.

Background: Massive bone loss from the proximal femur is a complex problem, occurring in multiple-revision hip arthroplasties, and malignancy. Allograft prosthetic composites (APCs) are used to restore bone loss and provide better function of the limb.

Material and Methods: Between 1986 and 1999, 94 patients (96 hips) including 31 male and 63 female (mean age 59.5 years), with massive bone loss due to an average of 2 previous revisions, had a revision hip arthroplasty using an allograft-prosthesis composite (APC). A previous history of infection was present in 21 of these cases.

Results: At an average follow-up of 11 years (range, 8 to 20 years), 72 patients were alive, 21 patients died, and 1 patient was lost to follow-up. Major complications occurred in 33 cases: femoral stem loosening (12); dislocation (15); periprosthetic fracture (10); and infection (7). Minor complications occurred in 13 other cases. Further revision surgery was performed in 21 of the 96 cases including revision of the acetabular component (3), femoral APC (16) or both (2). The 10 year survival of the APCs was 68.8% (95% CI 58.6%–79%, 26 cases remaining at risk). There was no statistically significant difference in survival time between gender, age, indication for APC (including infection), surgical approach and APC technique. Statistically significant factors negatively impacting APC survival included two or more prior revisions, severity of preoperative bone loss (Paprosky type IV) and use of plates and screws (p< 0.05). Statistically significant improvement in APC survival was identified in those reconstructions in which cement was used for proximal fixation of the femoral component within the allograft (p< 0.05).

Conclusion: Reconstruction of massive proximal femoral bone loss with an allograft-implant composite is a demanding procedure. Preservation of bone stock is a great advantage of this biologic means of reconstruction. Specific technical issues should be known and followed so to avoid failure and need for early re-revision

Curative treatment of malignancies in the sacrum and lower lumbar spine frequently requires en bloc spinopelvic resection. There is no standard classification of these procedures. We present outcomes and a classification scheme with oncologic and reconstructive guidelines for spinopelvic tumors based on an analysis of 30 cases of en bloc resection and reconstruction performed with curative intent.

Mean follow-up of surviving patients was 38 months. Tumors included osteosarcoma (n=9), chondrosarcoma (n=6), chordoma (n=5), other sarcomas (n=5), neurogenic tumors (n=4), and local extension of carcinoma (n=1). Resections could be divided into 4 types. Type 1 resections (n=12) included a total sacrectomy with lower lumbar spine and bilateral medial iliac resections. Type 2 resections (n=6) included hemisacrectomy, partial lumbar spine excision, and medial iliac resection. Type 3 resections (n=9) encompassed external hemipelvectomy with hemisacrectomy and partial lumbar spine excision. Type 4 resections (n=3) encompassed external hemipelvectomy, total sacrectomy, and lumbar spine excision.

For each resection type, we have developed staged surgical approaches to allow resection with wide margins and reconstruction of spinopelvic continuity. Tumor free margins were achieved in all cases. Perioperative mortality was 3/30. Seven additional patients have died of disease, two died of other causes, two are alive with disease, and 16 have no evidence of disease. 13/18 surviving patients are independent in their activities of daily living.

In our practice en bloc excision and reconstruction of spinopelvic neoplasms may be classified into four types. For each type, we have devised surgical treatment guidelines to allow for wide resection and reconstruction of spinopelvic continuity. Long term survival and independent function can be achieved in this challenging patient population. This represents the first standardised classification of oncologic spinopelvic resections and reconstructions.

Pigment epithelium-derived factor (PEDF) is the most potent endogenous inhibitor of angiogenesis and decreased PEDF expression has been shown, in many tumours, to be associated with increased intratumoural microvascularity, enhanced tumour growth and metastases and poor patient prognosis. We evaluated the role of PEDF in osteosarcoma growth inhibition and examined it’s potential as a possible anti-cancer therapeutic agent.

We investigated the effects of overexpressed and recombinant PEDF (rPEDF) in several cell-based assays and in two orthotopic models of osteosarcoma (UMR 106-01 and SaOS-2).

In vitro, overexpression of PEDF significantly decreased cell proliferation, migration, invasion and increased adhesion to collagen-1. rPEDF resulted in a dose-dependent inhibition of cell proliferation, increased collagen adhesion, decreased invasion, and down-regulation of VEGF. The pro-differentiation ability of rPEDF was confirmed by upregulation of several osteoblastic markers after treatment of a pre-osteoblastic cell line (UMR 201). Furthermore, both cell lines displayed increased mineralised nodule formation after administration. In vivo, PEDF inhibited osteosarcoma growth and metastasis when overexpressed and in the recombinant form. In addition, anti-tumour activity was observed upon testing with shorter peptides of PEDF. Pharmacoevaluation of rPEDF demonstrated stability within media over several days, and no significant side effects in terms of wound healing.

From these results, PEDF demonstrates multi-modal anti-tumour activity via anti-proliferation, anti-angiogenesis, pro-differentiation and anti-metastasis. PEDF may be a promising therapeutic agent for the treatment of patients with osteosarcoma.

Introduction and Aims: Matrix metalloproteinases can contribute to the processes of tumor invasion and metastasis. One proposed mechanism that could augment MMP-1 expression in individual patients is the existence of an Ets transcription factor-binding site in the MMP-1 promoter sequence. The aim of our study was to identify the prevalence of this single nucleotide polymorphism in chondrosarcoma patients and investigate its impact on disease outcome.

Method: Sixty-seven chondrosarcoma specimens were selected from an established tumor bank. DNA was extracted, amplified with polymerase chain reaction, and sequenced to determine the proportion of genotypes demonstrating the presence (GG) or absence (G) of the SNP at the base pair of interest. The presence of the Ets binding site was correlated with disease-free survival.

Results: Eighteen (27%) samples were G/G homozygous for absence of the Ets site, 34 (51%) were G/GG heterozygous for the SNP, and 15 (22%) were GG/GG homozygous for the SNP. The five-year overall survival rate for patients with the G/G homozygote was 78%, compared with 80% and 84% in patients with the G/GG heterozygotes and GG/GG homozygotes, respectively (p=0.5527). The disease-free survival rate of patients with the G/G genotype were 34%, compared with 74% and 100% in patients with the G/GG and GG/GG genotypes, respectively (p=0.0365).

Conclusion: The disease-free survival in patients having a GG allele was statistically better than the G allele. The observed correlation between the presence of the Ets binding site and better prognosis suggests a down-regulation of MMP-1 expression.

Introduction and Aims: Multimodal treatment has dramatically improved the outcome of patients with Ewing’s sarcoma. However, little is known about treatment-related complications in patients who are long-term survivors.

Method: Forty-one patients with Ewing’s sarcoma treated at the authors’ institution between 1963 and 1980 and who survived by at least 20 years were included in this study. This patient group comprises 17 men and 24 women. The mean age at presentation was 16.8 (range five to 51) years. Three patients presented with metastatic disease. The location included 14 axial, and 27 appendicular lesions. All but nine patients had chemotherapy as part of their multimodality treatment.

Results: The overall follow-up averaged 297 (range 240–430) months. All except one patient were alive at final follow-up, the latter dying of radiotherapy-induced secondary malignancy after 33 years. Five patients survived, despite developing local recurrence or metastatic disease. Only 16 (39%) patients were free of any complication. These included metastases (12%), local recurrence (7%), secondary malignancies (7%), pathologic fractures (20%), and radiation (32%), and chemotherapy-associated morbidities (20%). The complication rate in this series of long-term survivors treated prior to 1980 is surprisingly high. Current treatment advances should result in improved long-term results.

Conclusion: Even when patients with Ewing’s sarcoma survive the primary cancer, only a minority of them remain without treatment-associated morbidities.

Introduction and Aims: Sacrococcygeal chordoma presents a difficult diagnostic and therapeutic problem with a high incidence of local recurrence. The report aims to define the importance of adequate surgical treatment on outcome and survival.

Method: Fifty-eight patients underwent surgical treatment for sacrococcygeal chordoma between 1979 and 2001. The series included 19 women and 39 men with an average age of 56.2 (range 13–76) years at diagnosis. Depending on the level and extent of the lesion, a posterior approach was performed in 25 patients, and a combined antero-posterior approach in 33 patients. A wide surgical margin was achieved in 22 patients, 14 marginal and 22 intralesional.

Results: At average follow-up of 92.2 (range 18–276) months. Thirty-three patients were alive with no evidence of disease. Twenty-one patients had local recurrence. Recurrence-free survival at five years was 67% and at 10 years 57%. The overall survival was 74%, 51%, 42% at five years, 10 years, and 15 years, respectively. All patients with wide margins survived (100%), which was significantly different from patients who had either marginal or intralesional excision (p=0.0001). The type of surgical approach (p=0.138) does not influence the likelihood to obtain a good margin, although patients with wide margins were also more likely to have small tumors. A wide margin was achieved in 48% using a combined antero-posterior approach, whereas this was the case only in 29% using a posterior approach. Tumor volume univariately assessed, however, does not seem to compromise the possibility of obtaining a wide margin (p=0.21). Multivariate analysis identified – in contrast to tumor volume (p=0.13) – margin (p=0.0001) and age (p=0.04) as predictors of survival. Whereas survival is independent of age in the case with wide margins, patients with marginal or intralesional margins and an age above 60 years have a better survival (43% at 10 years) than patients younger than 60 years with those parameters (20% at 10 years; p=0.0776).

Conclusion: A wide margin is the most important predictor of survival in patients with sacrococcygeal chordoma. Tumor volume per se has no negative impact on survival as long as a wide margin is obtained. Therefore, for large tumors and tumors above S3 we prefer combined antero-posterior approach. If a wide margin cannot be obtained, then young patients have a worse prognosis than older patients.

Background: Amputation of the distal fibula for malignant tumors is accepted practice. Few studies have reported limb salvage surgery for malignant tumors of the distal fibula. After distal fibulectomy, the main concerns are local recurrence of the tumor and ankle instability and deformity related to total resection of the lateral malleolus. Our objective was to analyze the oncologic and functional outcome of lateral malleolus en bloc resection for malignant tumors of the distal fibula, with special attention to operative techniques, reconstruction methods, and postoperative complications.

Methods: The authors identified ten patients who had malignant tumors of the distal fibula requiring total resection of the lateral malleolus. The patients’ medical records, operative reports, radiographs, and the histologic specimens were reviewed. There were four children (mean age, 7.5 years) and six adults (mean age, 42.16 years). The distal metaphysis was involved in seven patients and the epiphysis in three. There were four osteosarcomas, three chondrosarcomas, two Ewing sarcomas, and one adamantinoma. The most common symptoms at presentation were a palpable mass in nine patients, ankle pain in six, and pathologic fracture in one. The mean duration of symptoms before diagnosis and treatment was nineteen months. All patients had operative treatment; two patients with osteosarcoma had perioperative chemotherapy and one patient with Ewing sarcoma had radiotherapy and chemotherapy and another patient with Ewing sarcoma had chemotherapy only. Two types of “en bloc” resection of the distal fibula were performed. Wide (type II) extra-articular resection was performed in seven patients. Marginal (type I) intra-articular resection of the distal fibula was performed in three patients. After resection, a primary ankle arthrodesis was performed in four adults and postoperative bracing without any reconstruction in four children and two adults.

Results: Within a mean follow-up time of 14.4 years (range, three to thirty years), tumor recurred locally in two patients after a marginal type I resection of a chondrosarcoma, and in one after a type II wide extra-articular resection of an osteosarcoma. All ten patients were disease-free at latest follow-up examination. Six patients had reoperation. A below-knee amputation was performed in three patients for chronic osteomyelitis, for local recurrence of chondrosarcoma, and for a late adamantinoma of the tibia. One patient had further soft tissue and bone reconstructive surgery for lateral talus subluxation and cavovarus deformity. Another patient required ankle arthrodesis for recurrent ankle instability and ankle joint degenerative changes. One patient had wide re-resection for local recurrence of an osteosarcoma. All ten patients were ambulatory at latest follow-up evaluation. Four adult patients who underwent primary arthrodesis and one child who had no initial reconstruction and had late ankle arthrodesis had a satisfactory outcome, with an ISOLS functional score of 27.6 (92%). Two adolescents who had postoperative bracing without any soft tissue reconstruction had an ISOLS functional score of 24 (80%) with no ankle pain and satisfactory function; they used an ankle-foot orthosis during sports activities. Three patients who subsequently required below-knee amputation used a below-knee prosthesis for ambulation.

Conclusions: Limb salvage surgery for high-grade malignant tumors of the distal fibula can be achieved by wide extra-articular resection. For low-grade malignant tumors or high-grade tumors responding to adjuvant therapy, a more conservative marginal intra-articular resection may be adequate. Primary arthrodesis is indicated in adults after wide extra-articular resection. In children, repair of the lateral soft tissues and reconstruction of the tibiofibular mortise is necessary after tumor resection to avoid late ankle deformity or instability.