[Conventional epiphyseal chondrosarcoma of childhood and adolescence: a case report]. / Konventionelles epiphysäres Chondrosarkom des Kindes- und Jugendalters: ein Fallbericht.

INTRODUCTION: Conventional chondrosarcoma is the second most common primary malignant bone tumor and usually occurs at older adult ages. It is rare in childhood and adolescence. CASE HISTORY: This case report presents the treatment course of a 13-year-old boy with a symptomatic chondrogenic tumor of the right distal femur. Histopathologically, an epiphyseal intermediate-grade chondrosarcoma (G2) was diagnosed. DISCUSSION: Based on the following case, potential radiological and histopathological differential diagnoses, such as chondroblastoma or chondroblastic osteosarcoma, are discussed against the background of current standards in orthopedic oncology.

[Treatment concepts for complications after resection and defect reconstruction of pelvic tumours]. / Behandlungskonzepte von Komplikationen nach Resektion und Defektrekonstruktion pelviner Tumoren.

BACKGROUND: Partial pelvic resection, internal hemipelvectomy or sacrectomy as a result of bone sarcoma is still challenging. No matter what kind of reconstruction is used, there is still a much higher rate of complications in pelvic surgery compared to sarcoma surgery of the long bones. OBJECTIVES: We describe the most common complications in pelvic sarcoma surgery and specific complications related to the reconstruction method. Handling strategies for these complications are specified. METHODS: We performed a literature search and report our own experiences in the troubleshooting of pelvic surgery-related complications to gain an up-to-date overview of the state-of-the-art in management strategies. RESULTS: Prospective randomized trials or meta-analyses on this topic are lacking. The literature search depicted that, besides local recurrence, deep infection after reconstruction is the most serious complication. An early revision with radical debridement has to be performed in order to save the reconstruction. In the case of a deep infection, the removal of all implants with a total loss of the reconstruction is often unavoidable. Therefore, an individualized risk-benefit analysis prior to surgery with respect to the type of reconstruction, or no reconstruction at all (hip transposition), together with the patient is advisable. CONCLUSIONS: Complications-especially infections-after hemipelvectomy or sacrectomy are common. In the case of infection, in some cases, an early revision is the only chance to prevent a reconstruction from explantation.

[Complication management following resection and reconstruction of the upper limbs and shoulder girdle]. / Komplikationsmanagement nach Tumorresektion und Defektrekonstruktion an der oberen Extremität und am Schultergürtel.

BACKGROUND: Sarcomas of the upper limbs commonly affect the proximal humerus or scapula. Complications after tumor resection and reconstruction are rare but cannot be neglected, particularly after tumor endoprosthetic reconstructions. MATERIALS AND METHODS: The most common complications after resection of sarcomas of the upper limbs and shoulder girdle are described, and current knowledge regarding complication management is presented. Additionally, a selective literature search was performed, incorporating personal experiences. RESULTS: Wound healing disorders and infections after tumor resection without specific reconstruction (clavicle resection, scapulectomy) usually respond well to conservative or surgical treatment. However, periprosthetic infections after reconstruction using a megaendoprosthesis constitute a severe and frequent complication, with an incidence of 5-10%. Two-stage implant replacement still represents the gold standard, although in selected cases, one-stage revision with retention of the prosthetic stem appears warranted. Secondary amputation as a result of periprosthetic infection is rare compared to the situation with infections of the lower limb. Mechanical complications necessitating surgical revision are mostly limited to joint dislocation after inverse total shoulder replacement (TSR). (Sub)luxation in anatomic TSR can be tolerated provided there is no tendency toward perforation of the skin in a asymptomatic patient. Biological reconstructions are most often indicated for reconstruction of intercalary defects of the humerus, and revision is necessitated most frequently by mechanical complications. Despite multiple surgical revisions, stable reconstructions and limb salvage can usually be achieved in the upper limb.

What is the Likelihood That Tumor Endoprostheses Will Experience a Second Complication After First Revision in Patients With Primary Malignant Bone Tumors And What Are Potential Risk Factors?

BACKGROUND: Endoprosthetic reconstruction of massive bone defects has become the reconstruction method of choice after limb-sparing resection of primary malignant tumors of the long bones. Given the improved survival rates of patients with extremity bone sarcomas, an increasing number of patients survive but have prosthetic complications over time. Several studies have reported on the outcome of first endoprosthetic complications. However, no comprehensive data, to our knowledge, are available on the likelihood of an additional complication and the associated risk factors, despite the impact of this issue on the affected patients. QUESTIONS/PURPOSES: (1) What are the types and timing of complications and the implant survivorship free from revision after the first complication? (2) Does survivorship free from repeat revision for a second complication differ by anatomic sites? (3) Is the type of first complication associated with the risk or the type of a second complication? (4) Are patient-, tumor-, and treatment-related factors associated with a higher likelihood of repeat revision? METHODS: Between 1993 and 2015, 817 patients underwent megaprosthetic reconstruction after resection of a tumor in the long bones with a single design of a megaprosthetic system. No other prosthetic system was used during the study period. Of those, 75% (616 of 817) had a bone sarcoma. Seventeen patients (3%) had a follow-up of less than 6 months, 4.5% (27 of 599) died with the implant intact before 6 months and 43% (260 of 599 patients) underwent revision. Forty-three percent of patients (260 of 599) experienced a first prosthetic complication during the follow-up period. Ten percent of patients (26 of 260) underwent amputation after the first complication and were excluded from further analysis. Second complications were classified using the classification of Henderson et al. to categorize surgical results. Briefly, this system categorizes complications as wound dehiscence (Type 1); aseptic loosening (Type 2); implant fractures or breakage and periprosthetic fracture (Type 3); infection (Type 4); and tumor progression (Type 5). Implant survival curves were calculated with the Kaplan-Meier method and compared using the log-rank test. Hazard ratios (HR) were estimated with their respective 95% CIs in multivariate Cox regression models. RESULTS: A second complication occurred in 49% of patients (115 of 234) after a median of 17 months (interquartile range [IQR] 5 to 48) after the surgery for the first complication. The time to complication did not differ between the first (median 16 months; IQR 5 to 57) and second complication (median 17 months; IQR 5 to 48; p = 0.976). The implant survivorship free from revision surgery for a second complication was 69% (95% CI 63 to 76) at 2 years and 46% (95% CI 38 to 53) at 5 years. The most common mode of second complication was infection 39% (45 of 115), followed by structural complications with 35% (40 of 115). Total bone and total knee reconstructions had a reduced survivorship free from revision surgery for a second complication at 5 years (HR 2.072 [95% CI 1.066 to 3.856]; p = 0.031) compared with single joint replacements. With the numbers we had, we could not show a difference between the survivorship free of revision for a second complication based on the type of the first complication (HR 0.74 [95% CI 0.215 to 2.546]; p = 0.535). We did not detect an association between total reconstruction length, patient BMI, and patient age and survivorship free from revision for a second complication. Patients had a higher risk of second complications after postoperative radiotherapy (HR 1.849 [95% CI 1.092 to 3.132]; p = 0.022) but not after preoperative radiotherapy (HR 1.174 [95% CI 0.505 to 2.728]; p = 0.709). Patients with diabetes at the time of initial surgery had a reduced survivorship free from revision for a second complication (HR 4.868 [95% CI 1.497 to 15.823]; p = 0.009). CONCLUSIONS: Patients who undergo revision to treat a first megaprosthetic complication must be counseled regarding the high risk of future complications. With second complications occurring relatively soon after the first revision, regular orthopaedic follow-up visits are advised. Preoperative rather than postoperative radiotherapy should be performed when possible. Future studies should evaluate the effectiveness of different approaches in treating complications considering implant survivorship free of revision for a second complication. LEVEL OF EVIDENCE: Level III, therapeutic study.

[Hemipelvectomy for pelvic sarcomas]. / Hemipelvektomie bei Sarkomen des Beckens.

BACKGROUND: Hemipelvectomy is an important technique for the treatment of pelvic sarcomas. OBJECTIVES: Presentation of the technical overview, as well as surgical and oncological outcomes of sarcoma patients treated with pelvic tumor resections and treatment recommendations. METHODS: Retrospective analysis of 160 patients treated by pelvic tumor resection for chondrosarcoma between 1977 and 2014. RESULTS: Chondrosarcoma was the most common diagnosis leading to pelvic tumor resection in this collective (38%). The mean patient age at operation was 49 years. 44 patients were treated for G1, 83 patients for G2 and 33 patients for G3 or dedifferentiated chondrosarcoma. The mean tumor diameter was ≥10 cm in 76.1% of cases. Limb salvaging operations were possible in 82.5% of patients. The most common reconstruction technique was hip transposition (38.7%). Clear resection margins were achieved in 86.9% (R0). Local recurrence was observed in 22.5%. Distant pulmonal metastasis was diagnosed in 25% of patients. Grading-specific survival was 81.8% for G1, 59% for G2 and 24.2% for G3 or dedifferentiated chondrosarcoma with a mean survival of 84.4, 89 and 69.4 months respectively. CONCLUSIONS: Pelvic tumor resection with clear margins is the most important known positive predictive local factor affecting overall outcomes, in addition to uncontrollable factors such as grading and tumor size. Defect reconstruction depends on multiple factors such as patient age and adjuvant therapy. The stage of the disease has the greatest impact on overall survival rates and should be considered when contemplating pelvic tumor resections in sarcoma patients.

[Resection margins in soft tissue sarcomas]. / Resektionsgrenzen bei Weichteilsarkomen.

BACKGROUND: Soft tissue sarcomas (STS) are a rare and heterogeneous group of malignant tumors that arise from the mesenchymal tissue. STS can form anywhere in the human body, with the extremities being preferred sites of predilection. TREATMENT: A fundamental pillar of treatment is the surgical resection of soft tissue sarcomas. The goal is always an R0 resection with a safety margin. There is no consensus in the literature about the desired tumor-free resection margin. The decisive factors for these resection margins are histopathology, presence of anatomical barriers (capsule, tendon, fascia, cartilage, periosteum) and possibilities of (neo-) adjuvant therapy. DISCUSSION: References in the literature support the role of resection margins as a predictor of local recurrence. Regarding the role of resection margins in overall survival, available data is divergent. There are known prognostic factors that influence overall survival, such as histological subtype, tumor size, tumor grading, and presence of metastases. So far, several studies have attempted to quantify the margins of resection, but no consensus has been reached, and debates are ongoing. When analyzing all the results of the data in the literature, it seems appropriate to aim for a negative resection margin >1 mm including an anatomical border structure, if possible.

[Differentiated treatment strategies for bone metastases of the extremities]. / Differenzierte Therapiestrategien bei Knochenmetastasen der Extremitäten.

BACKGROUND: Bone metastases are the most common malignant bone tumours and most commonly occur in the spine, pelvis, proximal femur and proximal humerus. Prostate and breast cancer most often metastasize to the bone. DIAGNOSTICS: In patients with a history of tumours and local unspecific pain in the back and extremities, further diagnostic examinations should be performed. For the initial diagnosis a conventional radiograph of the whole bone in two planes is sufficient. For further diagnostics, the imaging may be supplemented with CT, MRI, scintigraphy and a PET-CT (PET-MRI) if the findings are not inconspicuous on the x­ray. An indication for biopsy exists if the tumor cannot be classified, especially in solitary findings with or without previous tumor anamnesis. THERAPY: Surgical indications for bone metastases are a pathological fracture, an impending fracture, a solitary late metastasis, radiation-resistant osteolysis and therapy-resistant pain. In solitary metastases, the prognosis for patients can be significantly improved by a wide (R0 resection) depending on the primary tumour. For multiple metastases the restoration of mobility and improvement of the quality of life are in the foreground. Depending on the life expectancy and other factors, such as the location of the metastases osteosynthesis, implantations of dual head prothesis, total joint arthroplasty and tumor endoprostheses can be performed.

[Current results of tumour endoprosthetics in adolescents and adults]. / Aktuelle Ergebnisse der Tumorendoprothetik bei Jugendlichen und Erwachsenen.

BACKGROUND: The majority of osteoarticular defects after tumor resection in adolescent and adult patients are reconstructed using megaendoprosthetic implants. However, even infant and pre-teen children undergo reconstruction of defects using so-called growing prostheses with an increasing frequency. OBJECTIVES: Presentation of current techniques, outcomes and the most common complications of megaendoprosthetic reconstruction following tumour resection. METHODS: Selective literature review and discussion of current concepts and knowledge in megaendoprosthetic reconstruction against personal experience and treatment strategies. RESULTS: Megaendoprosthetic reconstructions achieve good functional results and long-term limb salvage (ca. 90% of cases) in adolescent and adult patients. Still, periprosthetic infection and mechanical failure of joint components are among the most common complications observed. In infant and pre-teen children treated by reconstruction using a growing prosthesis, mandatory maintenance operations-in the process of elongating the implant-must also be considered when assessing complication risks. CONCLUSIONS: Megaendoprosthetic reconstructions of osteoarticular defects are a standard procedure in adolescent and adult patients. Despite a substantial complication rate, limb salvage is achieved in a majority of patients. When using growing prostheses in younger children, one needs to be aware of additional servicing procedures that occur independently of those arising from complications.

[Endoprostheses for stump formation after hip disarticulation]. / Endoprothesen zur Stumpfbildung nach Hüftexartikulation.

BACKGROUND: Hip disarticulation is a psychologically and physically demanding procedure. However, it remains a therapeutical option whenever limb salvage proves impossible due to sarcoma, severe implant-associated infections or trauma. The stump lengthening procedure (SLP) is a surgical technique that allows partial salvage of the thigh through endoprosthetic proximal femur replacement after hip disarticulation, depending on the amount of viable soft tissue coverage. This leads to a more appealing visual appearance, facilitates prosthetic fitting and significantly improves limb function. OBJECTIVES: Description of indications for SLP, surgical technique, presentation of clinical and functional outcomes. METHODS: Review of applying literature and presentation of outcomes of our own SLP collective. RESULTS: The risk of local recurrence does not increase after SLP compared to hip disarticulation. While the majority of patients can be fitted with an exoprosthesis, a walking aid is usually necessary for ambulation. Exoprostheses are usually worn throughout the entire day, and patients manage distances of a mean of 2000 metres, even if reconstruction lengths are less than 10 cm. Patients aged 50 years or older tend to wear their exoprosthesis for shorter periods of daywear and achieve significantly poorer functional scores. Postoperative complications are common at a rate of 52%. Periprosthetic infection (21%) and soft tissue perforation of the implant with subsequent implant-associated infection (14%) were the most severe complications observed. CONCLUSIONS: The stump lengthening procedure poses a feasible alternative to classic hip disarticulation in patients with multiple prior operations and/or advanced stages of disease. It leads to satisfactory cosmetic and functional results without jeopardizing local tumor control. Stump perforation presents as the most common complication. Apart from improving the ability to sit down comfortably, both patients treated with a curative and palliative intent manage to ambulate using exoprostheses. With increasing age at the time of operation, walking aids are necessary for ambulation.

Ultra-short stem anchorage in the proximal tibial epiphysis after intercalary tumor resections: analysis of reconstruction survival in four patients at a mean follow-up of 56 months.

INTRODUCTION: Tumors localized in the proximal tibial meta-diaphysis often lead to osteoarticular resections. MATERIALS AND METHODS: In this study, we retrospectively reviewed four patients who underwent intercalary tumor resection and reconstruction using an ultra-short stem in the proximal tibial epiphysis, a procedure that to our knowledge has not been reported in literature so far. RESULTS: At the time of operation, the mean patient age was 26.2 years. Three patients were male and one was female. Patients were diagnosed with osteosarcoma in two cases, Ewing's sarcoma and malignant fibrous histiocytoma of bone in one case each. In all cases, wide tumor resections were achieved (osteotomy 3-3.5 cm below the tibia plateau joint surface, mean resection length of tibial bone 18 cm) at a mean time of operation of 198.8 min. Two superficial wound-healing disorders occurred, leading to one surgical revision in each case. One local tumor recurrence occurred 12 months after operation in a patient who discontinued his adjuvant chemotherapy. This patient died of disease, 31 months after operation. Three patients are alive with no evidence of disease at a mean follow-up of 56 months. Walking is not impaired and light sports activities have been reported in all cases. The mean MSTS score is 28/30. CONCLUSIONS: Therefore, we report this reconstruction technique to be considered for special indications where the functional outcome can be improved by preservation of the knee joint in tumors of the proximal meta-diaphyseal tibial region.

Development of curative therapies for Ewing sarcomas by interdisciplinary cooperative groups in Europe.

Curative therapies for Ewing sarcoma have been developed within cooperative groups. Consecutive clinical trials have systematically assessed the impact and timing of local therapy and the activity of cytotoxic drugs and their combinations. They have led to an increase of long-term disease-free survival to around 70% in patients with localized disease. Translational research in ES remains an area in which interdisciplinary and international cooperation is essential for future progress. This article reviews current state-of-the art therapy, with a focus on trials performed in Europe, and summarizes novel strategies to further advance both the cure rates and quality of survival.

Effects of an exercise intervention on bone mass in pediatric bone tumor patients.

The aim was to evaluate the effects of additional exercises during inpatient stays on bone mass in pediatric bone tumor patients. 21 patients were non-randomly allocated either to the exercise group (n = 10) or the control group (n = 11). DXA of the lumbar spine, the non-affected femur and both calcanei was performed after completion of neoadjuvant chemotherapy (baseline), as well as 6 and 12 months after baseline. Bone mineral content (BMC), bone mineral density (BMD) and height-corrected lumbar spine Z-scores were determined. Group changes after 6 and 12 months were compared by covariance analyses. Additionally, daily physical activities (PA) were assessed by means of accelerometry. After adjusting for initial age, height and weight, mean reductions in lumbar spine and femoral BMC were lower in the exercise group (not significant). Effect sizes during the observational period for lumbar spine and femur BMC were generally small (partial η² = 0.03). The exercise group demonstrated substantially higher PA levels in terms of gait cycles per day, per hour and moderate PA (activities above 40 gait cycles per minute). Additional exercises for bone tumor patients are feasible during hospitalization. Though the intervention did not influence BMC, it appeared beneficial regarding PA promotion with respect to volume and intensity.

[New surgical treatment options for bone tumors]. / Neue Operationsverfahren bei Knochentumoren.

Primary bone neoplasms can be classified into benign, locally/aggressive and rarely metastasizing and malignant tumors. Patients with benign tumors usually undergo surgical treatment in cases of local symptoms, mainly consisting of pain or functional deficits due to compression of important anatomical structures, such as nerves or blood vessels. Locally/aggressive and rarely metastasizing tumors exhibit an infiltrative growth pattern, so that surgical treatment is necessary to prevent further destruction of bone leading to local instability. Finally, the surgical treatment of malignant tumors is, with few exceptions, considered to be a prerequisite for long-term survival, either alone or in combination with systemic chemotherapy. Whereas the main objective of surgery in the treatment of benign tumors is relief of local symptoms with a minimum amount of damage to healthy tissue and minimizing the risk of local recurrence while ensuring bone stability in locally aggressive and rarely metastasizing tumors, the primary goal in the operative treatment of bone sarcomas is the resection of the tumor with clear surgical margins followed by defect reconstruction and the preservation of function. This review examines the current developments in the surgical treatment of primary bone neoplasms with respect to the management of the tumors and novel reconstructive options.

[Bone defect reconstruction in bone sarcoma surgery: tumour endoprosthesis versus biological reconstruction]. / Rekonstruktion knöcherner Defekte in der Knochensarkomchirurgie: Tumorendoprothese vs. biologische Rekonstruktion.

BACKGROUND: Primary bone sarcomas typically arise in the long bones and the pelvis of children and adolescence but may also occur in adults. Meta/diaphysial tumour involvement resulting in the necessity of a joint replacement is more common than diaphysial tumour sites. AIM: In the treatment of these tumours, both endoprosthetic replacement and biological reconstruction techniques are used. Each technique has method-specific advantages and disadvantages. RESULTS: To choose the appropriate surgical method, a multitude of influencing parameters need to be considered. The age at treatment (soft tissue situation/estimated growth/biological potential of the bone), therapeutic concept (palliative vs. curative), the tumour site (upper/lower extremity), tumour expansion (diaphysis/metaphysis) and oncological treatment concept (chemotherapy/radiotherapy) are key factors significantly influencing the surgical technique in terms of functional outcome and longevity of the reconstruction. CONCLUSION: Surgical treatment of bone sarcoma requires broad-based experience of the oncological surgeon. Knowledge of the different surgical technics and reconstruction methods is decisive to offer the individual patient the best oncological and functional outcome.

[Benign cartilage tumors. What should I do with incidental findings?]. / Benigne Knorpeltumoren. Was mache ich mit dem Zufallsbefund?

BACKGROUND: The majority of benign bone tumors are cartilage tumors. Most common are enchondroma and osteochondroma. Often they represent incidental findings in radiological diagnostics. Thus, the incidence of cartilage tumors is unknown, as most of them are never diagnosed due to the absence of any symptoms. OBJECTIVES: This article describes the diagnostic and therapeutic approach of benign cartilage tumors, focusing on incidental findings. METHODS: The current knowledge and our own experience in the diagnostics and treatment of benign condroid tumors are presented. RESULTS: As enchondroma represent most often the classic incidental finding without any symptoms or clinical findings, osteochondroma are often diagnosed in young patients by clinical examination showing a painless swelling that can increase in size according to skeletal growth. Most of these asymptomatic enchondroma and osteochondroma are so called "leave me alone lesions" and do not need any treatment, while other benign tumors (e.g., atypical cartilage tumors, chondroblastoma, chondromyxoidfibroma or osteochondroma with a cartilage cap of over 2 cm) need surgical treatment. These active or local aggressive tumors must be differentiated from the "leave me alone lesions". Additionally, patients with syndromes like Ollier disease (enchondromatosis), Maffucci syndrome or hereditary multiple exostosis must be examined and checked carefully as malignant degradation is possible. CONCLUSION: As most cartilage tumors are benign and remain benign, inappropriate diagnostics or operative treatment just to provide security is obsolete. Plain X-ray is often enough for follow-up and other modalities only become necessary when symptoms occur.

[Management of complications in megaprostheses]. / Komplikationsmanagement bei Megaprothesen.

BACKGROUND: Megaprostheses are frequently used after segmental resection of bone sarcomas, bone metastases, and in large osseous defects in revision arthroplasty. OBJECTIVES: The incidence of the most common complications associated the use of megaprostheses are reported. The management of complications including therapeutic recommendations are described. MATERIALS AND METHODS: The current knowledge and our own experience of complication management with the use of megaprostheses are presented. RESULTS: Prospective, randomized studies or meta-analyses on this topic are lacking. An analysis of the literature shows that beside the occurrence of a local recurrence, periprosthetic infection remains the most serious complication. Two-stage revision remains the gold standard, but a single-stage exchange of the prosthesis without removing the stems might be possible in selected cases. Infection is associated with a higher risk of secondary amputation. In contrast, mechanical failures (e.g., wear of the bushings in knee replacements and aseptic loosening of the stems) can be treated more easily. Dislocation of a proximal femur replacement can mostly be prevented by using bi- or tripolar cups. CONCLUSIONS: Complications with the use of megaprostheses can be successfully treated by revision surgery in most cases.

Impact of topography and added TiN-coating on adult human dermal fibroblasts after seeding on titanium surface in-vitro.

Complications of transcutaneous osseointegrated prosthetic systems (TOPS) focus on the metal-cutaneous interface at the stoma. Besides pain due to scare tissue as well as undefined neuropathic disorders, there is high evidence that the stoma presents the main risk causing hypergranulation and ascending infection. To restore the cutaneous barrier function in this functional area, soft-tissue on- or in-growth providing a vital and mechanically stable bio-artificial conjunction is considered a promising approach. In this study we assessed viability and proliferation of adult human dermal fibroblasts (HDFa) on modifications of a standard prosthetic titanium surface. Un-coated (TiAl6V4) as well as a titanium-nitrite (TiN) coated additive manufactured porous three-dimensional surface structures (EPORE®) were seeded with HDFa and compared to plain TiAl6V4 and polystyrene surfaces as control. Cell viability and proliferation were assessed at 24 h and 7 days after seeding with a fluorescence-based live-dead assay. Adhesion and cell morphology were analyzed by scanning electron microscopy at the respective measurements. Both EPORE® surface specifications revealed a homogenous cell distribution with flat and spread cell morphology forming filopodia at both measurements. Proliferation and trend to confluence was seen on un-coated EPORE® surfaces with ongoing incubation but appeared substantially lower on the TiN-coated EPORE® specification. While cell viability on both EPORE® specifications was comparable to plain TiAL6V4 and polystyrene controls, cell proliferation and confluence were less pronounced when compared to controls. The EPORE® topography allows for fibroblast adhesion and viability in both standard TiAl6V4 and - to a minor degree - TiN-coated specifications as a proof of principle.