C. Krettek

A minimally invasive medial approach for proximal tibial fractures

Numerous techniques have been described for MIPPO (minimally invasive percutaneous plate osteosynthesis) for metaphyseal or combined metaphyseal-articular fractures of the proximal tibia. Surgical management is often complicated by the initial soft tissue damage, malalignment, remaining instability, or infection. In this prospective cohort study, we describe the diagnostic procedures vital for preoperative planning. These include plain radiographs and CT scans in case of articular fracture components. The techniques for temporary stabilization and definitive fracture care using 4.5 mm DCP, LC-DCP, and LISS (Less Invasive Stabilization System) by limited medial incisions are described in a stepwise protocol. From 1996 to 1998, six fractures in six patients were studied. According to the AO classification, there were four type 41 fractures and two type 42 fractures. One patient died of ARDS. All patients had an intact medial soft tissue coverage allowing a medial approach. One patient developed a compartment syndrome, which was addressed by lateral dermato-fasciotomy prior to osteosynthesis. A LISS was used in three patients. The only complication related to surgery was in a patient with a four-part fracture with lateral comminution and a dislocated postero-medial fragment, which was reduced and buttressed with a short posteromedial 3.5 mm small fragment plate. This patient developed a deep, intraarticular infection, which was successfully treated with revision surgery; the implants were left in situ. At her latest follow-up at 18 months, she had a range of motion of 0/10/110, was back at work, and able to participate in recreational sports. The average time to healing was between 12 and 20 weeks postoperatively. There was no delayed healing, pseudarthrosis, recurrent fracture or late infection. None of the cases needed bone grafting. At the most recent follow-up, all patients were bearing full weight without walking aids. All cases achieved a neutral alignment and satisfactory range of movement. Though further data are needed we have sound reason to propagate a single medial approach and minimally invasive osteosynthesis as a sufficient and subtle technique for stabilization of these complicated fractures.

Routine application of the pinless external fixator

One serious disadvantage of conventional fixator systems is the need to open the medullary space, hence creating a direct communication with the exterior. The new pinless external fixator does not have this major disadvantage, because the fixator clamps simply rest on the cortical bone without penetrating it. Clinically, this easily managed system is intended for fractures of the tibia in cases in which primary internal fixation is precluded either by precarious local or general conditions or by infrastructural problems. In such situations the new pinless fixator is an excellent device with which to achieve good stabilization of the fracture rapidly, while leaving open all options for subsequent alteration of treatment. If the surgeon decides to convert to locked intramedullary nailing, the pinless fixator facilitates the new approach, because it can be used as a distractor and makes it unnecessary to transfer the patient to a fracture table.

Two-stage late reconstruction with a fresh large osteochondral shell allograft transplantation (FLOCSAT) for a large ostechondral defect in a non-union after a lateral tibia plateau fracture 2-year follow up

This is the description of a 58-year-old female patient presenting 8 months after a horse riding accident with significant pain and inability to walk independently. Imaging revealed a large osseous defect of the lateral tibia plateau which was not united posteriorly. The patient refused knee replacement and we developed a patient specific two-step procedure for her. Step 1: Filling of the defect with a large cortico-cancellous autograft from the posterior iliac crest; step 2: Transplantation of a fresh large osteochondral shell allograft (FLOCSAT). The postoperative protocol included continuous passive motion (CPM), partial weight bearing for three months, and physiotherapy. Based on the concept of immuno-privileged cartilage tissue, the patient did not get any immuno-suppressive therapy. Pain-, activity of daily living, Lysholm and Tegner scores were evaluated before defect filling surgery with autograft, before allograft transplantation, and at 12 and 24 months after allograft transplantation. There were no complications. Radiographic analyses with plain films and CT scans revealed solid osseous integration within 3 month. The patient regained excellent functionality in both, activities of daily living and sports (back to horse riding, trampolin jumping). Knee arthroscopy after 1year showed excellent condition of the lateral meniscus and the cartilage of the lateral tibia plateau. Chimerism/DNA analysis of a cartilage biopsy showed, that at 1year 32% of the donor cells have been already replaced by the patients own cells. To our knowledge, this is the first case of a patient who sustained such a large defect during a tibia plateau fracture, and got successfully treated with a fresh large osteochondral shell allograft transplantation in a two-step procedure.

Komplexe Gelenkrekonstruktion und Gelenktransplantation mit dem FLOCSAT-Konzept – Planung und chirurgische Umsetzung

Cartilage defects in adult patients are so far incurable. Fresh osteochondral allograft (OCA) transplantation is based on the insertion of mature, living, mechanically sound hyaline cartilage into an osteochondral defect where it undergoes osseointegration. Intact hyaline cartilage of OCA does not cause immune reactions in the recipient. Many reports show that small OCA have good osseointegration and show good long-term results. These observations have been incorporated into the development of the fresh large (> 10 cm2) osteochondral shell allograft transplantation (FLOCSAT) concept, which is based on the following principles: 1) the thickness of the osseous layer should be kept as thin as possible (target < 6-8 mm) so that the transplant remains stable and fixable. This results in reduced segments of vascularization, simplified ossification and reduced immunogenic bone volume. 2) The bone surface is processed and enlarged (oscillating saw: pie crust technique, drill holes) and areas of sclerosis are simultaneously broken off. 3) Cell reduction and washing out of the bony layer with a pulsatile jet lavage. 4) Prevention of impaction and dessication: cartilage with its living chondrocytes are very sensitive to mechanical contusion and dessication. When introducing the transplant, the tissue must therefore be continually moistened and the pressure acting on the cartilage must be controlled. 5) Stable fixation: extensive uniplanar osteochondral transplants cannot be inserted by the press-fit method; therefore, fixation is carried out with small implants. In this publication we demonstrate how severe and complex posttraumatic or degenerative delayed problems can be solved using FLOCSAT.

Posttraumatic nonunions and malunions of the proximal humerus. Possibilities and limitations of corrective osteotomy

BACKGROUND According to the future demographic trends the incidence of proximal humeral fractures and subsequent posttraumatic malunions and nonunions of the proximal humerus are expected to substantially increase. OBJECTIVES This article reviews the indications, techniques and outcomes of corrective osteotomy for the treatment of posttraumatic nounions and malunions of the proximal humerus. METHODS A selective literature search was performed and personal surgical experiences are reported. RESULTS Malunions of the proximal humerus can occur after both surgical and conservative management of fractures. Due to the complex anatomy of the proximal humerus, malunions have to be systematically assessed regarding epiphyseal and metaphyseal malpositioning. Furthermore, the objective anatomical disorder has to be completely correlated with the subjective patient complaints. The associated soft tissue structures, such as the glenohumeral joint capsule and ligaments, long head of the biceps tendon, rotator cuff and muscles inserting in the metaphysis, can independently cause discomfort to the patient and need to be meticulously identified as such. CONCLUSION A variety of corrective surgical strategies are available, which are indicated depending on the location and extent of the malunion. The depicted single-cut osteotomy technique represents an elegant therapeutic option for multidimensional deformities of the proximal humerus. Nonunions of the proximal humerus can usually be successfully managed with autologous cancellous bone grafting and locking plate osteosynthesis.ZusammenfassungHintergrundAufgrund der demographischen Entwicklung ist zukünftig mit einer deutlichen Zunahme der Inzidenz proximaler Humerusfrakturen und konsekutiv posttraumatischer Fehlstellungen und Pseudarthrosen zu rechnen.FragestellungDiese Übersichtsarbeit stellt Indikation, Technik und Ergebnisse von Korrekturosteotomien für Patienten mit posttraumatischer Fehlstellung oder Pseudarthrose nach proximaler Humerusfraktur dar.MethodenEs erfolgte eine selektive Literaturrecherche unter Berücksichtigung eigener Erfahrungen.ErgebnisseFehlstellungen des proximalen Humerus können nach konservativer und operativer Therapie entstehen. Aufgrund der komplexen Geometrie des proximalen Humerus muss die Analyse der Fehlstellung systematisch erfolgen (epi-, metaphysär). In einem nächsten Schritt muss evaluiert werden, inwieweit die objektivierte Fehlstellung für die vom Patienten berichteten Beschwerden verantwortlich gemacht werden kann. Die benachbarten Weichteilstrukturen (glenohumeraler Kapsel-Band-Apparat, lange Bizepssehne, Rotatorenmanschette, an der Metaphyse inserierende Muskulatur) können unabhängig von der Fehlstellung zu Beschwerden führen und müssen als solche identifiziert werden.SchlussfolgerungenIn Abhängigkeit von der Lokalisation und dem Ausmaß der posttraumatischen Fehlstellung kommen prinzipiell diverse Korrekturverfahren als Option in Frage. Die hier vorgestellte Single-cut-Osteotomie stellt eine elegante Möglichkeit zur Korrektur mehrdimensionaler Fehlstellungen am proximalen Humerus dar. Pseudarthrosen des proximalen Humerus können durch eine Spongiosaplastik und winkelstabile Plattenosteosynthese in der Vielzahl der Fälle erfolgreich saniert werden.AbstractBackgroundAccording to the future demographic trends the incidence of proximal humeral fractures and subsequent posttraumatic malunions and nonunions of the proximal humerus are expected to substantially increase.ObjectivesThis article reviews the indications, techniques and outcomes of corrective osteotomy for the treatment of posttraumatic nounions and malunions of the proximal humerus.MethodsA selective literature search was performed and personal surgical experiences are reported.ResultsMalunions of the proximal humerus can occur after both surgical and conservative management of fractures. Due to the complex anatomy of the proximal humerus, malunions have to be systematically assessed regarding epiphyseal and metaphyseal malpositioning. Furthermore, the objective anatomical disorder has to be completely correlated with the subjective patient complaints. The associated soft tissue structures, such as the glenohumeral joint capsule and ligaments, long head of the biceps tendon, rotator cuff and muscles inserting in the metaphysis, can independently cause discomfort to the patient and need to be meticulously identified as such.ConclusionA variety of corrective surgical strategies are available, which are indicated depending on the location and extent of the malunion. The depicted single-cut osteotomy technique represents an elegant therapeutic option for multidimensional deformities of the proximal humerus. Nonunions of the proximal humerus can usually be successfully managed with autologous cancellous bone grafting and locking plate osteosynthesis.

Unfälle im Reitsport@@@Accidents in equestrian sports: Analyse von Verletzungsmechanismen und -mustern@@@Analysis of injury mechanisms and patterns

BACKGROUND Equestrian sports are one of the most popular forms of sport in Germany, while also being one of the most accident-prone sports. Furthermore, riding accidents are frequently associated with a high degree of severity of injuries and mortality. Nevertheless, there are insufficient data regarding incidences, demographics, mechanisms of accidents, injury severity and patterns and outcome of injured persons in amateur equestrian sports. Accordingly, it was the aim of the present study to retrospectively analyze these aspects. METHODS A total of 503 patients were treated in the emergency room of the Hannover Medical School because of an accident during recreational horse riding between 2006 and 2011. The female gender was predominantly affected with 89.5 %. The mean age of the patients was 26.2 ± 14.9 years and women (24.5 ± 12.5 years) were on average younger than men (40.2 ± 23.9 years). A special risk group was girls and young women aged between 10 and 39 years. The overall injury severity was measured using the injury severity score (ISS). RESULTS Based on the total population, head injuries were the most common location of injuries with 17.3 % followed by injuries to the upper extremities with 15.2 % and the thoracic and lumbar spine with 10.9 %. The three most common injury locations after falling from a horse were the head (17.5 %), the upper extremities (17.4 %), the thoracic and lumbar spine (12.9 %). The most frequent injuries while handling horses were foot injuries (17.2 %), followed by head (16.6 %) and mid-facial injuries (15.0 %). With respect to the mechanism of injury accidents while riding were predominant (74 %), while accidents when handling horses accounted for only 26 %. The median ISS was 9.8 points. The proportion of multiple trauma patients (ISS > 16) was 18.1 %. Based on the total sample, the average in-hospital patient stay was 5.3 ± 5.4 days with a significantly higher proportion of hospitalized patients in the group of riding accidents. Fatal cases were not found in this study but the danger of riding is not to be underestimated. The large number of sometimes severe injuries with ISS values up to 62 points can be interpreted as an indication that recreational riding can easily result in life-threatening situations. CONCLUSION Girls and young women could be identified as a group at particular risk. It has been demonstrated in this study that the three most common injury locations after falling from a horse were the head, the upper extremities, the thoracic and lumbar spine. The most frequent injury locations while handling horses were foot injuries, followed by head and mid-facial injuries.

Posttraumatische Fehlstellungen und Pseudarthrosen des proximalen Humerus@@@Posttraumatic nonunions and malunions of the proximal humerus: Möglichkeiten und Grenzen der Korrekturosteotomie@@@Possibilities and limitations of corrective osteotomy

BACKGROUND According to the future demographic trends the incidence of proximal humeral fractures and subsequent posttraumatic malunions and nonunions of the proximal humerus are expected to substantially increase. OBJECTIVES This article reviews the indications, techniques and outcomes of corrective osteotomy for the treatment of posttraumatic nounions and malunions of the proximal humerus. METHODS A selective literature search was performed and personal surgical experiences are reported. RESULTS Malunions of the proximal humerus can occur after both surgical and conservative management of fractures. Due to the complex anatomy of the proximal humerus, malunions have to be systematically assessed regarding epiphyseal and metaphyseal malpositioning. Furthermore, the objective anatomical disorder has to be completely correlated with the subjective patient complaints. The associated soft tissue structures, such as the glenohumeral joint capsule and ligaments, long head of the biceps tendon, rotator cuff and muscles inserting in the metaphysis, can independently cause discomfort to the patient and need to be meticulously identified as such. CONCLUSION A variety of corrective surgical strategies are available, which are indicated depending on the location and extent of the malunion. The depicted single-cut osteotomy technique represents an elegant therapeutic option for multidimensional deformities of the proximal humerus. Nonunions of the proximal humerus can usually be successfully managed with autologous cancellous bone grafting and locking plate osteosynthesis.ZusammenfassungHintergrundAufgrund der demographischen Entwicklung ist zukünftig mit einer deutlichen Zunahme der Inzidenz proximaler Humerusfrakturen und konsekutiv posttraumatischer Fehlstellungen und Pseudarthrosen zu rechnen.FragestellungDiese Übersichtsarbeit stellt Indikation, Technik und Ergebnisse von Korrekturosteotomien für Patienten mit posttraumatischer Fehlstellung oder Pseudarthrose nach proximaler Humerusfraktur dar.MethodenEs erfolgte eine selektive Literaturrecherche unter Berücksichtigung eigener Erfahrungen.ErgebnisseFehlstellungen des proximalen Humerus können nach konservativer und operativer Therapie entstehen. Aufgrund der komplexen Geometrie des proximalen Humerus muss die Analyse der Fehlstellung systematisch erfolgen (epi-, metaphysär). In einem nächsten Schritt muss evaluiert werden, inwieweit die objektivierte Fehlstellung für die vom Patienten berichteten Beschwerden verantwortlich gemacht werden kann. Die benachbarten Weichteilstrukturen (glenohumeraler Kapsel-Band-Apparat, lange Bizepssehne, Rotatorenmanschette, an der Metaphyse inserierende Muskulatur) können unabhängig von der Fehlstellung zu Beschwerden führen und müssen als solche identifiziert werden.SchlussfolgerungenIn Abhängigkeit von der Lokalisation und dem Ausmaß der posttraumatischen Fehlstellung kommen prinzipiell diverse Korrekturverfahren als Option in Frage. Die hier vorgestellte Single-cut-Osteotomie stellt eine elegante Möglichkeit zur Korrektur mehrdimensionaler Fehlstellungen am proximalen Humerus dar. Pseudarthrosen des proximalen Humerus können durch eine Spongiosaplastik und winkelstabile Plattenosteosynthese in der Vielzahl der Fälle erfolgreich saniert werden.AbstractBackgroundAccording to the future demographic trends the incidence of proximal humeral fractures and subsequent posttraumatic malunions and nonunions of the proximal humerus are expected to substantially increase.ObjectivesThis article reviews the indications, techniques and outcomes of corrective osteotomy for the treatment of posttraumatic nounions and malunions of the proximal humerus.MethodsA selective literature search was performed and personal surgical experiences are reported.ResultsMalunions of the proximal humerus can occur after both surgical and conservative management of fractures. Due to the complex anatomy of the proximal humerus, malunions have to be systematically assessed regarding epiphyseal and metaphyseal malpositioning. Furthermore, the objective anatomical disorder has to be completely correlated with the subjective patient complaints. The associated soft tissue structures, such as the glenohumeral joint capsule and ligaments, long head of the biceps tendon, rotator cuff and muscles inserting in the metaphysis, can independently cause discomfort to the patient and need to be meticulously identified as such.ConclusionA variety of corrective surgical strategies are available, which are indicated depending on the location and extent of the malunion. The depicted single-cut osteotomy technique represents an elegant therapeutic option for multidimensional deformities of the proximal humerus. Nonunions of the proximal humerus can usually be successfully managed with autologous cancellous bone grafting and locking plate osteosynthesis.

New therapy approaches for giant cell tumors

BACKGROUND Giant cell bone tumors (GCT) are benign but partially locally aggressive osteolytic tumors which typically occur around the knee joint in the epiphysis and metaphysis of long bones after maturation of the skeleton is completed. Due to the locally aggressive growth behavior with destruction of the bone structure, the rare possibility of pulmonary metastases in recurrent cases and a very rare possibility of malignancy, GCTs were previously also described as semimalignant bone tumors. THERAPY The established therapy of these tumors at the typical locations consists of intralesional curettage, extension of resection margins using a high speed trephine and defect reconstruction with bone cement. The local recurrence rate is high (10-40 %) and lowest after using thermal extension of resection margins with a high speed trephine and defect reconstruction with bone cement. For uncommon localizations, such as the spinal column and the sacrum as well as in cases of recurrence, surgical treatment is more complicated. HISTOLOGY Histologically, GCTs consist of osteoclastic giant and oval-shaped stromal cells which show a high expression of receptor activator of nuclear factor-κB ligand (RANKL) and decisively contribute to the osteolytic activity of the tumor. Novel pharmaceutical therapy approaches with human monoclonal RANKL antibodies interfere in this osteodestructive process in an inhibitory manner and can represent alternative treatment options just as the osteosupportive therapy with bisphosphonates. CONCLUSION After unsatisfactory attempts at surgical treatment of GCT patients, the new treatment option with denosumab is a promising alternative due to its effect as a monoclonal RANKL inhibitor.ZusammenfassungHintergrundRiesenzelltumoren (RZT) des Knochens sind benigne, jedoch teils lokal aggressive osteolytische Tumoren, die typischerweise kniegelenknah in der Epi-/Metaphyse langer Röhrenknochen nach Abschluss der Skelettreife auftreten. Wegen ihres lokal aggressiven Wachstumsverhaltens mit Destruktion der Knochenstruktur, der seltenen Möglichkeit pulmonaler Metastasen im Rezidivfall und einer sehr seltenen Möglichkeit der malignen Entartung wurden RZT früher auch als „semimaligne“ Knochentumoren bezeichnet.Etablierte TherapieDie etablierte chirurgische Behandlung dieser Tumoren besteht an den klassischen Lokalisationen aus einer intraläsionalen Kürettage, Resektionsranderweiterung durch eine Hochgeschwindigkeitsfräse und Defektfüllung mittels Knochenzement. Die lokale Rezidivrate ist mit 10–40 % hoch und nach Anwendung einer thermischen Resektionsranderweiterung durch die Hochgeschwindigkeitsfräse sowie Knochenzementauffüllung am niedrigsten. An den selteneren Lokalisationen der Wirbelsäule und des Sakrums und im Rezidivfall zeigt sich die chirurgische Behandlung erschwert.HistologieHistologisch bestehen RZT aus osteoklastischen Riesen- und ovalen Stromazellen, die eine hohe Receptor-activator-of-NF-κB(RANK) und RANK-Ligand-Expression aufweisen und entscheidend zur osteolytischen Aktivität des Tumors beitragen. Neuere medikamentöse Therapieansätze mit humanen monoklonalen RANKL-Antikörpern greifen inhibitorisch in diesen osteodestruktiven Prozess ein und können wie auch die osteosupportive Therapie mit Bisphosphonaten alternative Behandlungsoptionen darstellen.SchlussfolgerungNach unbefriedigenden chirurgischen Therapieversuchen bei RZT-Patienten ist Denosumab durch seine Wirkung als monoklonaler RANKL-Inhibitor als neue Behandlungsoption eine vielversprechende Alternative.AbstractBackgroundGiant cell bone tumors (GCT) are benign but partially locally aggressive osteolytic tumors which typically occur around the knee joint in the epiphysis and metaphysis of long bones after maturation of the skeleton is completed. Due to the locally aggressive growth behavior with destruction of the bone structure, the rare possibility of pulmonary metastases in recurrent cases and a very rare possibility of malignancy, GCTs were previously also described as semimalignant bone tumors.TherapyThe established therapy of these tumors at the typical locations consists of intralesional curettage, extension of resection margins using a high speed trephine and defect reconstruction with bone cement. The local recurrence rate is high (10–40 %) and lowest after using thermal extension of resection margins with a high speed trephine and defect reconstruction with bone cement. For uncommon localizations, such as the spinal column and the sacrum as well as in cases of recurrence, surgical treatment is more complicated.HistologyHistologically, GCTs consist of osteoclastic giant and oval-shaped stromal cells which show a high expression of receptor activator of nuclear factor-κB ligand (RANKL) and decisively contribute to the osteolytic activity of the tumor. Novel pharmaceutical therapy approaches with human monoclonal RANKL antibodies interfere in this osteodestructive process in an inhibitory manner and can represent alternative treatment options just as the osteosupportive therapy with bisphosphonates.ConclusionAfter unsatisfactory attempts at surgical treatment of GCT patients, the new treatment option with denosumab is a promising alternative due to its effect as a monoclonal RANKL inhibitor.Nach unbefriedigenden chirurgischen Therapieversuchen bei RZT-Patienten ist Denosumab durch seine Wirkung als monoklonaler RANKL-Inhibitor als neue Behandlungsoption eine vielversprechende Alternative.

Biopsie und Zugangswege bei Knochentumoren@@@Biopsy and approach routes for bone tumors: Wo und wie viel ist genug?@@@Where and how much is sufficient?

Although biopsies are a key step in the diagnosis of bone tumors, they are often still referred to as a minor intervention which can be carried out by any surgeon as an outpatient procedure or quickly carried out between other more important tasks. A biopsy should, however, be regarded as the final part of the diagnostic procedure preceded by careful evaluation of the clinical course and analysis of the required imaging studies. Although the biopsy procedure seems technically simple to perform, an incorrectly performed biopsy can become an obstacle to correct tissue analysis (sampling error) and adequate tumor resection and may reduce the patients chances of survival. The principles by which an adequate and safe biopsy of bone tumors should be planned and executed are reviewed and the surgical approaches to different anatomical locations are presented.ZusammenfassungObwohl die Biopsie den „Schlüsselschritt“ in der Diagnose von Knochentumoren darstellt, wird sie nach wie vor als „kleiner Eingriff“ aufgefasst, der von jedem chirurgisch Tätigen ambulant oder „einmal schnell“ als dazwischen geschobener Operationspunkt „abgearbeitet“ werden kann. Nicht selten wird die Biopsie als sog. „Anfängereingriff“ deklariert und auf „Zuruf“ assistiert. Auch wenn der Eingriff selbst technisch einfach erscheinen mag, so erfordert bereits die Biopsie in Kenntnis der erforderlichen definitiven operativen Versorgung eine vorgezogene Planung des adäquaten Zugangsweges. Eine unsachgemäß durchgeführte Biopsie liefert günstigenfalls nicht repräsentatives Gewebe („sampling error“), kann jedoch die onkologische Resektabilität beeinträchtigen bis hin zur Erfordernis einer Amputation und letztendlich eine Verschlechterung der Heilungschancen des Patienten bedeuten. Im Nachfolgenden werden die Prinzipien der Zugangsplanung und Techniken einer angemessenen und sicheren Biopsie bei primären Knochentumoren verschiedener anatomischer Lokalisationen dargestellt.AbstractAlthough biopsies are a key step in the diagnosis of bone tumors, they are often still referred to as a minor intervention which can be carried out by any surgeon as an outpatient procedure or quickly carried out between other more important tasks. A biopsy should, however, be regarded as the final part of the diagnostic procedure preceded by careful evaluation of the clinical course and analysis of the required imaging studies. Although the biopsy procedure seems technically simple to perform, an incorrectly performed biopsy can become an obstacle to correct tissue analysis (sampling error) and adequate tumor resection and may reduce the patient’s chances of survival. The principles by which an adequate and safe biopsy of bone tumors should be planned and executed are reviewed and the surgical approaches to different anatomical locations are presented.

Biopsy and approach routes for bone tumors. Where and how much is sufficient

Although biopsies are a key step in the diagnosis of bone tumors, they are often still referred to as a minor intervention which can be carried out by any surgeon as an outpatient procedure or quickly carried out between other more important tasks. A biopsy should, however, be regarded as the final part of the diagnostic procedure preceded by careful evaluation of the clinical course and analysis of the required imaging studies. Although the biopsy procedure seems technically simple to perform, an incorrectly performed biopsy can become an obstacle to correct tissue analysis (sampling error) and adequate tumor resection and may reduce the patients chances of survival. The principles by which an adequate and safe biopsy of bone tumors should be planned and executed are reviewed and the surgical approaches to different anatomical locations are presented.ZusammenfassungObwohl die Biopsie den „Schlüsselschritt“ in der Diagnose von Knochentumoren darstellt, wird sie nach wie vor als „kleiner Eingriff“ aufgefasst, der von jedem chirurgisch Tätigen ambulant oder „einmal schnell“ als dazwischen geschobener Operationspunkt „abgearbeitet“ werden kann. Nicht selten wird die Biopsie als sog. „Anfängereingriff“ deklariert und auf „Zuruf“ assistiert. Auch wenn der Eingriff selbst technisch einfach erscheinen mag, so erfordert bereits die Biopsie in Kenntnis der erforderlichen definitiven operativen Versorgung eine vorgezogene Planung des adäquaten Zugangsweges. Eine unsachgemäß durchgeführte Biopsie liefert günstigenfalls nicht repräsentatives Gewebe („sampling error“), kann jedoch die onkologische Resektabilität beeinträchtigen bis hin zur Erfordernis einer Amputation und letztendlich eine Verschlechterung der Heilungschancen des Patienten bedeuten. Im Nachfolgenden werden die Prinzipien der Zugangsplanung und Techniken einer angemessenen und sicheren Biopsie bei primären Knochentumoren verschiedener anatomischer Lokalisationen dargestellt.AbstractAlthough biopsies are a key step in the diagnosis of bone tumors, they are often still referred to as a minor intervention which can be carried out by any surgeon as an outpatient procedure or quickly carried out between other more important tasks. A biopsy should, however, be regarded as the final part of the diagnostic procedure preceded by careful evaluation of the clinical course and analysis of the required imaging studies. Although the biopsy procedure seems technically simple to perform, an incorrectly performed biopsy can become an obstacle to correct tissue analysis (sampling error) and adequate tumor resection and may reduce the patient’s chances of survival. The principles by which an adequate and safe biopsy of bone tumors should be planned and executed are reviewed and the surgical approaches to different anatomical locations are presented.