[Challenges to endoprosthetic reconstruction after tumor resection around the knee : Management of intra- and postoperative complications]. / Herausforderungen in der Tumorendoprothetik des Kniegelenks : Management von intra- und postoperativen Komplikationen.

BACKGROUND: The good functional outcomes of endoprosthetic knee reconstructions combined with modern oncosurgical concepts have resulted in a decreased rate of primary amputations following tumor resection in the region of the knee, thereby improving the quality of life of affected patients. OBJECTIVE: This study aimed to reappraise complications which are more common than in conventional arthroplasties performed for arthritis or trauma due to the complexity of the surgical procedures, the size of the endoprosthetic reconstructions, and neo-/adjuvant therapies. MATERIAL AND METHODS: Possible intra- and postoperative complications and treatment options are presented. RESULTS: Typical intraoperative complications include malalignment (axis, length, rotation) in implant positioning, unplanned soft tissue defects, impaired implant fixation due to poor bone stock, periprosthetic fractures, vessel/nerve injuries, and lesions/defects of the extensor mechanism. The relevant postoperative complication profile is characterized by local recurrences, periprosthetic infections, thromboembolic events, and mechanical failures (loosening, failure of the constraining mechanism). CONCLUSION: Depending on anatomic conditions and the systemic oncological status of the patient, these complications represent tremendous challenges to reconstructive management. Knowledge of the potential problems enables them to be avoided. This requires profound experience in oncosurgery and tumor endoprosthesis revisions.

Skeletal metastatic disease of the femur: results by management with intramedullary nailing.

PURPOSE OF THE STUDY This study aimed to analyse the outcome following intramedullary nailing for metastases of the femur in a large cohort with special regard to mechanical, implant associated complications and patient survival. Furthermore, we aimed to identify factors influencing the overall survival. MATERIAL AND METHODS All patients (n = 74) that underwent intramedullary nailing for metastatic disease of the femur between 2004 and 2008 and were retrospectively reviewed. Data were recorded from the patients' medical record and the outpatients' clinics files. Details about the tumour biology, the surgery performed as well as the postoperative care were documented. Survival data were extracted from patient records or obtained via communication with outpatient oncologists or the community registration office. RESULTS 74 (28 (37.8%) male, 46 (62.2%) female; p = 0.048) patients with a mean age of 64.4 ± 11.7 years were included. Breast (25, 33.8%), lung (18, 24.3%), bone marrow (7, 9.5%) and kidney (6, 8.1%) were the primary tumours in more than 75% of all patients. The mean overall survival was 17.5 (95% CI: 9.6 - 25.5) months. Patients with osseous metastases had a significant longer survival than patients with visceral and/or cerebral metastases (p = 0.025 and p = 0.032). CONCLUSION Intramedullary nailing represents a valuable fixation method for pathologic fractures or impending fractures of the femur in patients with an advanced stage of metastatic disease. It provides adequate stability to outlast the patient s remaining life-span. However, the balance must be found between therapeutic resignation and surgical overtreatment since operative treatment may be accompanied with serious complications. Key words: bone metastases, intramedullary nailing, metastatic disease, cement augmentation, osteolytic defect.

[Management of complications following resection and defect reconstruction of tumors near the hip joint]. / Komplikationsmanagement nach Resektion und Defektrekonstruktion hüftgelenknaher Tumoren.

BACKGROUND: Tumorous destruction of the periacetabular region and the proximal femur are a consequence of either primary malignant bone tumor manifestation or metastatic disease, which is observed much more frequently and occurs typically in these skeletal segments. Pathological fractures of the proximal femur and periacetabular regions of the pelvis have a high incidence and ultimately lead to severe pain and immobilization. TREATMENT METHODS: Advanced resection techniques and different types of defect reconstruction, allowing for oncologically sufficient resection of extensive tumors have contributed to a marked increase in the limb salvage rate. However, these procedures are associated with an increasing rate of several, sometimes severe intraoperative and postoperative complications. COMPLICATIONS: Compared to elective total hip arthroplasty, the rate of postoperative deep infections, dislocations, the incidence of pathological and periprosthetic fractures and the prevalence of deep vein thrombosis are increased with high rates of postoperative mortality and local tumor recurrence, being the most serious complications. Pelvic involvement and subsequent periacetabular resection have the highest complication rate when compared to proximal femur resection with endoprosthetic treatment. CONCLUSION: In order to minimize the risk of these intraoperative and postoperative complications wide resection and advanced reconstruction as well as complicated palliative stabilization due to malignant bone tumor growth around the hip joint should be performed in musculoskeletal tumor centers with profound expertise in osteosynthetic and endoprosthetic reconstruction of the pelvis and the proximal femur. Only in specialized centers an effective, multidisciplinary emergency management of these complications and, more importantly, reliable prevention of complications can be ensured.

[Benign cystic bone lesions]. / Benigne zystische Knochenläsionen.

BACKGROUND: Bone cysts are benign tumor-like lesions which often present as a fluid-containing cavity in the bone. They can occur in the skeletal bone as solitary or sometimes multiple bone lesions. OBJECTIVES: This review discusses the diagnostics, radiological appearance and therapeutic strategies of the most important benign cystic bone lesions, such as simple bone cysts, aneurysmal bone cysts, intraosseous ganglia, epidermoid cysts and subchondral cysts. The differential diagnoses with respect to cystoid formations and tumors with cystic components are discussed. METHOD: A selective literature search was performed taking own experiences into consideration. RESULTS: These tumor-like lesions can have the radiological appearance of bone tumors but show no autonomic, stimulus-independent growth and can resolve spontaneously. In the majority of cases open biopsy is necessary to confirm the diagnosis. In some cases no surgical intervention is necessary (e.g. do not touch and leave me alone lesions), whereas in other cases the focus of treatment is on the prevention and therapy of pathological fractures as well as prevention of recurrence. CONCLUSION: Cystic bone formations are among the most commonly occurring non-traumatic bone lesions. To eliminate differential diagnostic unclarity, histological investigation of biopsy material is essential. In terms of surgical intervention there exists a trend towards multimodal therapy mostly based on a meticulous curretage.

Surgical management and outcome of skeletal metastatic disease of the humerus.

PURPOSE OF THE STUDY Evaluation of outcome after surgical treatment of humerus metastases with a focus on tumour and patient derived factors, timing and strategy of intervention, surgical outcome and complications. MATERIAL AND METHODS Sixty-fie patients with a mean age of 64.3 years (range 25-89) with 66 metastases of the humerus were surgically treated in a 7-year time-period and retrospectively reviewed. RESULTS Renal cell carcinoma and breast cancer were the most abundant types of primary tumour. The mean time from diagnosis of primary tumour to fist metastasis was 14.5 months (range 0-173). The mean time from diagnosis of metastasis to surgery was 21.4 months (range 0-173). 38/28 intramedullary nails/locking plates were used for 58/8 manifest/impending pathological fractures. Mean cumulative survival was 16.3 months and implant failure rate was 6.1% with a mean time from initial surgery to revision of 22.2-20.6 months. CONCLUSIONS Our data indicate that treatment with intramedullary fiation or cement augmented plate osteosynthesis is successful for the vast majority of patients, but thorough clinical evaluation and precise decision making adapted to the patient's estimated life expectancy must be applied to avoid overtreatment or risk of implant failure. Key words: bone metastases, skeletal metastatic disease, humerus metastasis, pathologic fracture, impending fracture.

[Solitary spinal metastases. Is aggressive surgical management justified?]. / Solitäre Metastasen der Wirbelsäule. Indikationen für eine aggressive chirurgische Therapie?

Advances in oncological and surgical therapies have led to a significant increase in life expectancy of cancer patients and also prolonged survival of patients with isolated or multiple metastases. Among the skeletal manifestations the spine is the most often affected site. Using novel imaging techniques with higher resolution and use of metabolic signatures, the screening of cancer patients has improved considerably. Consequently, the diagnosis of metastases is becoming increasingly more sensitive. Therefore, but also due to more effective polychemotherapy protocols, singular or solitary metastases are more frequently observed either in the early stages or as a result of a controlled malignant tumor entity (stable disease). The questions whether a solitary metastasis really exists (illusion or reality?) and its radical oncological and surgical treatment as a circumscribed singular tumor manifestation, is really relevant for the overall prognosis, remains controversial. However, it seems evident that a biologically favorable underlying tumor biology, radical treatment of the primary tumor and a long metastasis-free interval are valid predictors of a good oncological outcome. In the presence of a solitary metastasis under these circumstances (typical example: solitary metastasis of renal cell carcinoma many years after radical tumor nephrectomy) a radical surgical procedure (en bloc spondylectomy) can significantly improve the long-term prognosis of this patient group in combination with adjuvant chemotherapy and/or radiotherapy. However, a thorough evaluation of the overall survival prognosis, a detailed and complete staging followed by a treatment consensus in the interdisciplinary tumor board has to precede any therapeutical decisions.

[Manifestation of osteosarcoma of chronic osteomyelitis: 2 case reports]. / Osteosarkommanifestation bei chronischer Osteomyelitis: 2 Fallberichte.

The treatment and outcome of two patients suffering from osteosarcoma of the lower extremity evolving many years after manifestation of chronic osteomyelitis are reported. After neoadjuvant polychemotherapy in one patient en bloc resection, interposition of a cement spacer and stabilization was performed in both cases. After eradication of infections final segmental reconstruction was accomplished by knee arthrodesis using rotation plasty of the split femoral condyle, free local fibula transposition and gastrocnemius muscle transfer. A custom-made diaphyseal replacement (3D-rapid prototyping titanium mesh) was used for defect reconstruction. After 1 year postoperative follow-up and restaging both patients showed no evidence of recurrent disease and had no local or systemic signs of infection.

Surgical management of recurrent thoracolumbar spinal sarcoma with 4-level total en bloc spondylectomy: description of technique and report of two cases.

INTRODUCTION: The descriptions of total spondylectomy and further development of the technique for the treatment of vertebral sarcomas offered for the first time the opportunity to achieve oncologically sufficient resection margins, thereby improving local tumor control and overall survival. Today, single level en bloc spondylectomies are routinely performed and discussed in the literature while only few data are available for multi-level resections. However, due to the topographic vicinity of the spinal cord and large vessels, the multisegmental resections are technically demanding, represent major surgery and only few case reports are available. Surgical options are even more limited in cases of revision surgery and local recurrences when en bloc spondylectomy was considered to be not feasible due to high risk of vital complications in expanding resection margins. Deranged anatomy, implants in situ and extensive intra-/paraspinal scar tissue formation resulting from previously performed approaches and/or radiation are considered the principal complicating factors that usually hold back spine surgeons to perform revision for resection leaving the patient to palliative treatment. METHODS: We present two patient cases with previously performed piecemeal vertebrectomy in the thoracic spine due to a solitary high-grade spinal sarcoma. After extensive re-staging, both patients underwent a multi (4)-level en bloc spondylectomy in our department (one patient with combined en bloc lung resection). Except a local wound disturbance, there was no severe intra- or postoperative complication. RESULTS: After multilevel en bloc spondylectomy both patients showed a good functional outcome without neurological deficits, except those resulting from oncologically scheduled resection of thoracic nerve roots. After a median follow-up of 13 months, there was no local recurrence or distant metastasis. The reconstruction using a posterior screw rod system that is interconnected to an anterior vertebral body replacement with a carbon composite cage showed no implant failure or loosening. In summary, the approach of a multilevel en bloc surgery for revision and oncologically sufficient resection in cases of spinal sarcoma recurrences seems possible. However, interdisciplinary decision making in a tumor board, realistic evaluation of surgical resectability to attain tumor free margins, advanced experiences in spinal reconstructions and involvement of vascular, visceral and thoracic surgical expertise are essential preconditions for acceptable oncological and functional outcome.

[Surgical management of thoracolumbar spinal sarcoma]. / Chirurgisches Management von Sarkomen der thorakolumbalen Wirbelsäule.

Primary malignant tumors of the thoracolumbar spine are very rare. The most common entities are chordoma, followed by osteosarcoma, Ewing's sarcoma and chondrosarcoma. Detailed imaging and a sequential biopsy are the most important diagnostic steps. The surgical staging system of Weinstein and Boriani permits a precise analysis of tumor expansion. Therapy under a multimodal concept consists of (neo-) adjuvant therapy and possible radiation. The surgical therapy should be performed as an en bloc excision with sufficient resection borders. The reconstruction of the defects must include methods of vertebral body replacement and long posterior instrumentation. En bloc spondylectomy is a very demanding technique and demands strict indications, close cooperation with adjacent specialties and exact planning of the operation. Only in this manner is the operation possible and offers the only sufficient form of resection. The execution of the en bloc spondylectomy should be left to spine centers with great experience, as they could also guarantee the respective complication management.

[Biomechanical aspects of complex reconstructions following radical resection of thoracolumbar spinal tumors]. / Biomechanische Aspekte radikaler Resektionen und deren Rekonstruktion an der thorakolumbalen Wirbelsäule.

The total number of spinal tumors has increased over the past decade. However, the average survival time of tumor patients has increased due to improvements in the multidisciplinary treatment regimes. Therefore, radical tumor resection and complex reconstruction were developed in spinal surgery. Various reconstructive options for the throracolumbar spine are nowadays available and are depicted in this article. The success of complex reconstructive surgery relies on biomechanical principles and reconstruction is dependent on the size and location of the lesion, bone porosity and implant systems used. Special emphasis of this article focuses on en bloc vertebrectomy which is the most radical approach of spinal tumor surgery. The biomechanical aspects of different types of lesions and the reconstructive options are discussed in the context of the currently published literature.

Minimally invasive combined anterior kyphoplasty for osteolytic C2 and C5 metastases.

Kypho- and vertebroplasty are widely accepted for treating patients suffering from pathologic thoracolumbar lesions, in particular diffuse metastatic-induced fractures. They provide rapid pain relief and the restoration of spinal stability. In the cervical spine, attempts have been made to use cement augmentation for these indications. However, the cervical spine's anatomy complicates the transpedicular approach, as well as the pre-formation of a vertebral body cavity and the application of bone cement. We report the case of a 46-year-old woman suffering from symptomatic C2 and C5 osteolysis caused by metastatic breast cancer. Following a surgical staging and classification (Tokuhashi-Score) that indicated palliative procedures, we performed a C2 and C5 kyphoplasty using one minimal-invasive anterior approach through a small incision. We observed an uneventful procedure and postoperative course as well as immediate pain relief and patient mobilization. Last patient follow-up at 3 months showed an excellent outcome. Our observations showed cervical spine kyphoplasty via a minimally invasive anterior approach to be feasible, successful and safe surgical method in the interdisciplinary palliative treatment.

Bone sarcoma of the spine.

Primary malignant bone tumors of the vertebral column, i.e., bone sarcomas of the spine, are inherently rare entities. Vertebral osteosarcomas and chordomas represent the largest groups, followed by the incidence of chondro-, fibro-, and Ewing's sarcomas. Detailed clinical and neurological examination, complete radiographic imaging [radiographs, computed tomography (CT), magnetic resonance imaging (MRI)], and biopsy are the decisive diagnostic steps. Oncosurgical staging for spinal tumors can serve as a decision-guidance system for an individual's oncological and surgical treatment. Subsequent treatment decisions are part of an integrated, multimodal oncological concept. Surgical options comprise minimally invasive surgery, palliative stabilization procedures, and curative, wide excisions with complex reconstructions to attain wide or at least marginal resections. The most aggressive mode of surgical resection for primary vertebral column tumors is the total en bloc vertebrectomy, i.e., single- or multilevel en bloc spondylectomy. En bloc spondylectomy involves a posterior or combined anterior/posterior approach, followed by en bloc laminectomy, circumferential (360 degrees) vertebral dissection, and blunt ventral release of the large vessels, intervertebral discectomy and rotation/ en bloc removal of the vertebra along its longitudinal axis. Due to the complex interdisciplinary approach and the challenging surgical resection techniques involved, management of vertebral bone sarcomas is recommended to be performed in specific musculoskeletal tumor centers.

Balloon kyphoplasty in the treatment of metastatic disease of the spine: a 2-year prospective evaluation.

There is currently little data on the longer term efficacy and safety of balloon kyphoplasty (BKP) in patients with metastatic vertebral compression fractures (VCFs). To prospectively assess the long-term efficacy and safety of BKP in treating thoracic and lumbar spinal metastatic fractures that result in pain or instability. Sixty-five patients (37 men, mean age: 66 years) underwent 99 BKP procedures. Patient-related outcomes of pain visual analogue scale (VAS) and Oswestry Disability Index were assessed pre- and post-operatively and after 3, 6, 12 and 24 months. Correction of vertebral height and kyphotic deformity were assessed by radiographic measurements. Mean pain VAS and Oswestry Disability Index significantly improved from pre- to post-treatment (P < 0.0001), this improvement being sustained up to 24-month follow up. A gain in height restoration and a reduction of the post-operative kyphotic angle were seen post-operatively and at 3 months although these radiographic outcomes returned to pre-operative levels at 12 months. BKP was associated with a rate of cement leakage and incidence vertebral fracture of 12 and 8%, respectively. No symptomatic cement leaks or serious adverse events were seen during the 24 months of follow up. BKP is a minimally invasive procedure that provides immediate and long-term pain relief and improvement in functional ability in selected patients with metastatic VCFs. The procedure appears to have good long-term safety.

En bloc spondylectomy reconstructions in a biomechanical in-vitro study.

Wide surgical margins make en bloc spondylectomy and stabilization a referred treatment for certain tumoral lesions. With a total resection of a vertebra, the removal of the segment's stabilizing structures is complete and the instrumentation guidelines derived from a thoracolumbar corpectomy may not apply. The influence of one or two adjacent segment instrumentation, adjunct anterior plate stabilization and vertebral body replacement (VBR) designs on post-implantational stability was investigated in an in-vitro en bloc spondylectomy model. Biomechanical in-vitro testing was performed in a six degrees of freedom spine simulator using six human thoracolumbar spinal specimens with an age at death of 64 (+/- 20) years. Following en bloc spondylectomy eight stabilization techniques were performed using long and short posterior instrumentation, two VBR systems [(1) an expandable titanium cage; (2) a connected long carbon fiber reinforced composite VBR pedicle screw system)] and an adjunct anterior plate. Test-sequences were loaded with pure moments (+/- 7.5 Nm) in the three planes of motion. Intersegmental motion was measured between Th12 and L2, using an ultrasound based analysis system. In flexion/extension, long posterior fixations showed significantly less range of motion (ROM) than the short posterior fixations. In axial rotation and extension, the ROM of short posterior fixation was equivalent or higher when compared to the intact state. There were only small, nonsignificant ROM differences between the long carbon fiber VBR and the expandable system. Antero-lateral plating stabilized short posterior fixations, but did not markedly effect long construct stability. Following thoracolumbar en bloc spondylectomy, it is the posterior fixation of more than one adjacent segment that determines stability. In contrast, short posterior fixation does not sufficiently restore stability, even with an antero-lateral plate. Expandable verses nonexpandable VBR system design does not markedly affect stability.

[Differential diagnosis of intramedullary osteosarcomas]. / Differenzialdiagnose intramedullärer Osteosarkome.

Intramedullary high-grade osteosarcomas are aggressive tumors with a high metastatic capacity. The many subtypes and variants of these tumors often make the differential diagnosis difficult. Therefore, a critical review of both radiology and histomorphology is mandatory. Low-grade central osteosarcomas are a completely different tumor group. Due to their strong similarity to benign bone tumors they are frequently misdiagnosed as such. The correct diagnosis followed by radical surgery, however, is essential to reduce the high risk of local recurrences, typically seen for of these lesions. Unlike conventional high grade osteosarcomas, distant metastases are much less frequent than in low grade osteosarcomas.

[Ventral stabilization of the lumbar spine of a 2-year-old boy with an expandable cage : 7-year course]. / Ventrale Stabilisierung der LWS mit einem expandierbaren Cage bei einem 2-jährigen Jungen : 7-Jahres-Verlauf.

This case report describes the first implantation of an expandable cage into the lumbar spine of a 2-year-old boy. Due to incomplete remission of a teratoma, it was necessary to replace the second lumbar vertebral body with an expandable cage implantation and subsequent dorsoventral stabilization. During the follow-up period with annual x-ray examinations, a loss of correction without increased pain or neurological deficits could be shown in the now 9-year-old boy.

Three-dimensional stiffness in a thoracolumbar en-bloc spondylectomy model: a biomechanical in vitro study.

BACKGROUND: In selected cases, en-bloc spondylectomy is the only option to reach wide resection margins for patients with malignant tumours of the thoracolumbar spine. These patients must be also provided a secure initial stabilization of the spine and this is the role of vertebral body replacements employed with posterior fixation systems. The aim of this study was to determine the postimplantation stiffness of a connected vertebral body replacement pedicle screw system in different implantation scenarios following an en-bloc spondylectomy. Reconstruction was varied by posterior fixation lengths and axial compression forces during implantation. METHODS: Three-dimensional stiffness was assessed in 6 fresh frozen human spinal specimens (Th11-L3) using a six degree of freedom spine simulator. Following en-bloc spondylectomy reconstruction was performed using a carbon composite fibre vertebral body replacement connected to a posterior fixation system by two artificial pedicles. The spines were loaded with pure moments (7.5Nm) in the three main motion planes. The intersegmental rotations were measured between Th12 and L2. FINDINGS: Reconstructions using long posterior fixation modes demonstrated significant (P<0.05) higher stiffness compared to short posterior fixations in all motion planes. In axial rotation short posterior fixation modes failed to reach the values of the intact state. Neither high nor low axial compression force during implantation showed a significant impact on postfusional stiffness. INTERPRETATION: In this biomechanical model, the employed system should be implanted with a posterior fixation of two adjacent segments to the lesion in order to achieve a secure stabilization of the treated segment.

Surgical treatment of bone metastases in breast cancer.

Breast cancer is an osteotropic primary tumor. For the patient metastases to the skeleton imply functional restriction with immobility and pain. Unlike other primary carcinomas breast cancer shows a distinctly longer life expectancy after occurrence of skeletal filiae. LOTE even states a mean survival rate of 4 years. Impending or manifest pathologic fractures as well as pain refractory to medication therapy are indications for operative treatment. As a function of the estimated life expectancy, the number and localisation of metastases and possible adjuvant therapy (hormonal or chemotherapy, radiotherapy) the operative procedure must be chosen. Available options are' intramedullary stabilizing procedures, compound osteosynthesis or endoprothetic means. The objective is the restitution of the weight bearing capacity of the affected skeletal region in addition to pain reduction. This leads to early function and mobility and improves the patient's quality of life.

Unknown AV-fistula as reason for post-traumatic hematoma of the thigh.

A case is reported of a 28-year-old patient with gradually developing massive swelling of the right thigh after sustaining a blunt trauma. 3 1/2 months after the injury, surgery was performed because of a persisting tumor at the thigh. Intraoperatively, massive bleeding occurred, the bleeding vessel was sutured. Postoperative angiography disclosed arteriovenous (av) fistulae from the internal iliacal artery to a gluteal vein as source for the bleeding. The feeding artery was closed by coiling, the patient recovered completely. To the authors' knowledge, development of an av-fistula following blunt trauma has not been described previously. Similarly, the differential diagnosis of a posttraumatic bleeding of a congenital av-malformation was not yet reported. The authors emphasize, that prior to the surgery of inadequately behaving hematomas, an angiography should be performed.

[Metastases compromising physical stability]. / Die stabilitätsgefährdenden Metastasen.

Multimodal therapy of tumor patients with osseous metastases is an interdisciplinary task. The surgical treatment requires optimal integration, in terms of timing and extent of the procedure, into the overall treatment plan. In addition to surgery, modern therapeutic approaches include systemic chemotherapeutic, hormonal and immunological therapy, radiotherapy, and other drug therapy (i.e. biophosphonates). We use classical stabilization methods with plates and bone cement or intramedullary nailing and also new implants with angular stability like an internal fixator and modular endoprothesis systems in operative therapy. Such stabilizing systems allow bridging of tumor defects in almost all parts of the skeleton. The ultimate goal of any treatment and especially of operative intervention is a mobile patient with little or no pain and a good quality of life.