[Options for surgical treatment of malignant bone tumors]

Fixed-hinge cemented modular implants: An effective reconstruction technique following primary distal femoral bone tumor resection. A 136-case multicenter series

BACKGROUND

Reconstruction by endoprosthesis is widespread after bone tumor resection. The design and type of fixation and of hinge remain a matter of debate. The aim of the present study was to assess survival, complications and functional results in a homogeneous series of adult patients undergoing bone defect reconstruction following distal femoral tumor resection, using a single model of fixed-hinge cemented endoprosthesis, at a minimum 5 years' follow-up.

HYPOTHESIS

The study hypotheses were that loosening and infection are the main causes of failure, and that this type of reconstruction is reliable following distal femoral resection.

PATIENTS AND METHODS

All patients aged over 17 years undergoing reconstruction using the Stanmore Mets® fixed-hinge cemented modular endoprosthesis following distal femoral resection for primary bone tumor in 4 French reference centers between 2004 and 2013 were included. Epidemiological data, MSTS functional score, clinical and radiological examination results, complications and survival with types of failure according to the Henderson classification were assessed.

RESULTS

One hundred and thirty-six patients (68 male, 68 female; mean age, 41.2 years [range, 17-77 years]) were included. Mean follow-up was 81 months [range, 61-134 months]. Thirty-two patients (38%) experienced a total 67 complications requiring surgical revision: mainly infection (n=28) or mechanical failure (n=26). Overall implant survival was 78% at 5 years. There were 30 implant failures on the Henderson classification. Mean MSTS score was 82%.

DISCUSSION

The present results are comparable to those of the literature and for other types of reconstruction. Recent meta-analyses suggest that type of hinge and of stem fixation have little effect on implant survival. International comparative studies are needed to determine the exact role of each type of reconstruction according to the patient profile.

LEVEL OF EVIDENCE

IV, multicenter retrospective series.

[Complication profile and revision concepts for megaprosthetic reconstruction following tumour resection at the hip]

BACKGROUND

Tumourous destruction of the periacetabular region and the proximal femur is a typical consequence of either primary malignant bone tumour manifestation or skeletal metastatic diseases. Pathological fractures of the proximal femur and periacetabular regions due to primary manifestation or metastatic disorders are frequent.

OBJECTIVES

Presentation of the most common complications of tumour endoprostheses at the hip and a description of management strategies, including therapeutic recommendations and concepts for complication avoidance.

MATERIALS AND METHODS

The current knowledge and our own experience of complication management with the use of megaprostheses around the hip are presented.

RESULTS

Compared to elective/primary total hip arthroplasty, megaprosthetic reconstructions following tumour resections have an increased rate of postoperative deep infections, dislocations, incidence of pathological and periprosthetic fractures and of deep vein thrombosis. The postoperative mortality and local tumour recurrence along with deep infections represent the most serious complications.

CONCLUSIONS

In comparison to primary arthroplasty, the risk of failure and complications following tumour-endoprosthetic replacement is increased. Precise surgical planning and careful selection and preoperative preparation of suitable patients should be performed in close interdisciplinary cooperation with final decision-making on an interdisciplinary tumour board. Wide resection and advanced reconstruction, as well as complicated palliative stabilization due to malignant bone tumour growth around the hip joint should be performed in musculoskeletal tumour centres with profound expertise in osteosynthetic and endoprosthetic reconstruction and consecutive complication management of the pelvis and the proximal femur.

Impact of Pathological Fractures on the Prognosis of Primary Malignant Bone Sarcoma in Children and Adults: A Single-Center Retrospective Study of 205 Patients

BACKGROUND

The purpose of this study was to investigate whether pathological fractures (PF) influence the prognosis of patients with osteosarcoma (OS) or Ewing tumor (ET) regarding 5-year survival, occurrence of metastases, and local recurrence.

METHODS

We retrospectively analyzed 205 patients with metastatic and nonmetastatic OS or ET. Survival analysis was performed for all patients and differentiated for patients with OS (n = 127) and ET (n = 78) as well as for adults (n = 101) and children (n = 104).

RESULTS

Patients with PF showed survival rates of 64% compared to 83% for those without PF (p = 0.023). Local recurrence occurred in 7% of the patients without and in 24% of those with PF (p = 0.023). In patients with ET and in children, survival analysis showed no significant difference between patients with and without PF in survival and local recurrence rates. In patients with OS, survival rate decreased from 83 to 59% (p = 0.024) and local recurrence rate increased from 13 to 30% (p = 0.042). In adults, survival rate decreased from 78 to 51% (p = 0.004) and local recurrence rate increased from 13 to 42% (p < 0.001). In multivariate analysis, age and PF were associated with inferior survival.

CONCLUSION

This study suggests that the occurrence of PF has a negative impact on survival and implicates an increased risk of local recurrence. In children and in patients with ET, PF did not have a prognostic impact.

Resection and reconstruction of pelvic bone tumors

The objective of this study was to assess outcome and recurrence rate after limb-salvage surgery with reconstruction for pelvic bone tumors and analyze complications and their relationship with surgery. The authors analyzed 129 patients followed for a mean of 6 years (range, 2-19 years). Chondrosarcoma was the most frequent histotype. Thirty-one cases with no acetabular involvement were reconstructed with allograft only. Acetabular resections were reconstructed with allograft prosthetic composite (n=60), allograft only (n=11), trabecular metal components (n=2), prosthesis only (n=10), saddle prosthesis (n=11), and iliofemoral arthrodesis (n=1). Margins were wide (n=94), wide contaminated (n=22), marginal (n=7), and intralesional (n=6). Oncologic outcomes were as follows: 75 patients were continuously disease free, 6 were disease free after treatment of relapse, 13 were alive with disease, 28 were dead of disease, and 5 were dead of other causes. Survival was 66% at 10 years. Local recurrence rate of malignant tumors was 22.1% and was not statistically influenced by margins (P=.140) or site (P=.933). Metastasis rate was 32.8%. Deep infection was observed in 30 (23.6%) cases, with no statistical difference between reconstructions with and without allograft (P=.09). Final external hemipelvectomy was performed in 16 cases. Newer techniques of reconstruction using stemmed acetabular cups or porous metal components combined with allograft are now available. Local control and satisfactory survival is achievable long term in patients with pelvic tumors, but this surgery implies a high rate of complications. Infection is a major complication, not influenced by the use of allografts. Amputation is rarely needed.

Medium to long-term results after reconstruction of bone defects at the knee with tumor endoprostheses

BACKGROUND AND OBJECTIVES

Limb salvage and reconstruction with tumor endoprostheses is considered as therapeutic standard in the treatment of bone defects at the knee. Few studies report long-term results so far.

METHODS

Seventy-seven patients who had a cementless or cemented MUTARS endoprosthesis implanted were followed-up for a mean period of 46 months (3-128 months). The defects were due to primary tumor lesions in 69 cases or metastases in 8 cases. The distal femur (n = 49) or the proximal tibia (n = 28) was reconstructed predominantly with cementless implants (femur: 69%, tibia: 92%). The resection of the tumor was intraarticular in 46 and extraarticular in 31 patients.

RESULTS

After 10 years probability of limb salvage was 92% with a recurrence rate of 3%. Complications were frequent with a revision rate of 58% and lead to a cumulative probability of survival of the initially implanted prosthesis of 57% after 5 years. Locking mechanism failure (n = 15) and aseptic loosening (n = 13) were the most frequent failure modes.

CONCLUSIONS

Regardless of achieving a low recurrence rate and satisfactory functional results, we found a high complication rate after implantation of a megaprosthesis. This was particularly evident for extraarticular resections and cemented fixation, which should be avoided when possible.

Endoprosthetic replacement of the distal femur for bone tumours: long-term results

We investigated whether improvements in design have altered the outcome for patients undergoing endoprosthetic replacement of the distal femur after resection of a tumour. Survival of the implant and 'servicing' procedures have been documented using a prospective database, review of the design of the implant and case records. In total, 335 patients underwent a distal femoral replacement, 162 having a fixed-hinge design and 173 a rotating-hinge. The median age of the patients was 24 years (interquartile range 17 to 48). A total of 192 patients remained alive with a mean follow-up of 12 years (5 to 30). The risk of revision for any reason was 17% at five years, 33% at ten years and 58% at 20 years. Aseptic loosening was the main reason for revision of the fixed-hinge knees while infection and fracture of the stem were the most common for the rotating-hinge implant. The risk of revision for aseptic loosening was 35% at ten years with the fixed-hinge knee, which has, however, been replaced by the rotating-hinge knee with a hydroxyapatite collar. The overall risk of revision for any reason fell by 52% when the rotating-hinge implant was used. Improvements in the design of distal femoral endoprostheses have significantly decreased the need for revision operations, but infection remains a serious problem. We believe that a cemented, rotating-hinge prosthesis with a hydroxyapatite collar offers the best chance of long-term survival of the prosthesis.

Managementprobleme in Diagnostik und Therapie der pathologischen Schenkelhalsfraktur

Pathological fractures caused by primary bone tumours are rare compared with fractures evolving in response to general osteoporosis or bone metastases. Nevertheless in cases of fracture due to inadequate trauma the underlying causality has to be clarified including histological analysis prior to the operating procedure. This case report demonstrates diagnostic and therapeutic standards in cases of pathological fracture of the proximal femur caused by osteosarcoma.

[Osteosarcoma of the pelvisTwo case reports and review of the literature]

Primary malignant neoplasms of the bone are rare. One of the most common bone tumors is osteosarcoma, most often localized in the metaphysis of adolescent long bones. The sacrum is concerned in only about 1%. Primary bone sarcomas of the pelvis are usually recognized after they have grown to a considerable size. Osteosarcoma patients from Germany, Austria, and Switzerland are treated by neoadjuvant chemotherapy combined with complete surgical excision according to the Cooperative Osteosarcoma Study Group (COSS). Based on a review of the literature, diagnosis, treatment, and complications of two cases of sacrum osteosarcoma are introduced.