[Radiation exposure of the eye lens in orthopedics and trauma surgery : A pilot study]. / Strahlenbelastung der Augenlinse in O&U : Eine Pilotstudie.

BACKGROUND: On 27 June 2017 the Act on new regulation of the law for the protection against the harmful effects of ionizing radiation was passed. One of the main innovations in daily surgical practice in the now legally stipulated provisions is the lowering of the eye lens dose to 20 mSv/year (§§ 78, 212 Radiation Protection Act, StrlSchG). MATERIAL AND METHODS: To estimate the level of exposure of the eye lens to ionizing radiation that is to be expected in the course of surgical interventions, the dose that surgeons receive during surgery was determined. For this, the radiation exposure adjacent to the eye lens was measured using a forehead dosimeter while performing surgical interventions over a period of 8 weeks in 2 different operating rooms. RESULTS: As a result, a mean estimated eye lens radiation dose Hp (3) of 190 µSv could be determined during the 2­month study period. Thus, the estimated cumulative radiation dose in 1 year of approximately 1.2 mSv was significantly below the threshold of 20 mSv/year. CONCLUSION: By complying with the common radiation protection measures in the context of operative interventions in orthopedics and trauma surgery, the legal limit value of 20 mSv/year is generally not expected to be exceeded.

[Periprosthetic fractures of the acetabulum: osteosynthesis]. / Periprothetische Frakturen des Acetabulums: Osteosynthese.

In most cases periprosthetic fractures of the acetabulum are complex injuries and are extremely challenging for the treating medical team. Over the years the frequency of this overall rare entity has increased due to demographic changes. In recent years several treatment algorithms were published and provided the possibility of developing standardized treatment concepts. The classification of the fractures and a dedicated preoperative strategy are highly important for the quality of patient-centered care. In the literature the frequency of intraoperative fractures was initially given as 0.4%; however, several studies have been published in which a far higher rate of intraoperative fractures was detected by computed tomography (CT), often referred to as so-called occult fractures. The causes are multifactorial and there is significant association with whether cement-free press-fit acetabular cups were used or cemented forms. In approximately 75% of the cases a low energy impact was the cause of the fracture. In these patients systemic processes, such as osteoporotic alterations of the bony substance or the possible presence of low-grade infections should be considered. This article gives an overview of the diagnostics, planning, challenges and osteosynthetic treatment options for periprosthetic fractures of the acetabulum.

Balloon Guided Cement Augmentation of Iliosacral Screws in the Treatment of Insufficiency Fractures of the Sacrum - Description of a New Method and Preliminary Results.

PURPOSE OF THE STUDY Fragility fractures of the pelvic ring in the elderly population are a serious problem in orthopaedics. The treatment options range from conservative treatment to diverse operative options. We present a balloon guided new technique of implanting cement augmented screws aiming at improved implant anchorage and reduced cement leakage. MATERIAL AND METHODS We describe a new technique of balloon- guided cement augmented iliosacral screws. After the balloon has been insufflated and contrast medium has been instillated for leakage detection, iliosacral screws can safely be placed with a relevant cement depot. RESULTS All patients (n = 8) treated in this way were allowed to weight bear on both legs and mobilisation was tolerated the next day after surgery. In the post-operative controls including X-ray and CT scan we noticed no cement leakage. Pain level as measured by the visual analog scale was significantly reduced to pre- surgery (mean 7.6 pre-operatively, mean 2.5 postoperatively). In addition pain medication could be reduced gradually soon after surgery. CONCLUSIONS The described procedure to address fragility fractures of the pelvic ring is a safe and easy to handle method. There are three advantages: First the osteoporotic S1 vertebral body can by stabilised by the amount of cement; second the cement leakage can be prevented by the balloon-compaction of the cancellous bone and the possibility to control the created cavity with contrast medium; third the bone - screw interface is much stronger compared to other procedures and is biomechanically superior against vertical shear stress. In contrast to sacroplasty, the cement application is guided by the previous use of a balloon. Key words:pelvic ring, fragility fracture, osteoporosis, elderly.

[Effects of a Pelvic Ring Injury on Earning Capacity]. / Auswirkungen einer Beckenringverletzung auf die Erwerbsfähigkeit.

Introduction: Pelvic ring injuries occur in 3-8 % of patients with fractures. They are rare, with an annual incidence of only 19-37 per 100,000 people annually. There have been publications on the generation of these injuries, as well as their diagnosis and treatment concepts, but there is little information on how these injuries impact the ability to work. Patients: The study covered all hospitalised patients between January 2003 and December 2011 with a pelvic ring injury, who had already been included in the data collection of the AG Becken III and who had had a work-related accident. Data acquisition was completed 12 months after the first cover letter. Data collection was supported by the statutory accident insurance institutions. Responses to the following questions were collected: Results: During the time period, 835 patients were admitted to our hospital with an injury to the pelvic ring or acetabulum. 632 patients (75.7 %) had a pelvic ring injury. 95 patients had a work-related accident, for which 67 records (70.5 %) could be evaluated. Seven patients were in retirement at the time. The average age was 48 years. In the patient population, we identified 9 type A, 16 type B and 42 type C injuries. The mean duration of incapacity for work was 9.5 months. 36 patients were able to return to their old work again, 22 patients did not. For two of these patients, this was due to cerebral haemorrhage. The mean reduction in earning capacity at the 1st and 2nd pension reports was 28 %. The individual rating of the degree of trauma lay between 0 % (B2.1) to 60 % (C1.2). Subgroup analysis was not performed, due to the small number of patients and their lack of homogeneity. As only hospitalised patients were included in the study group, there was excessive accumulation of pelvic B and C fractures in the patient group. The study shows that pelvic ring injuries can have a significant impact on the duration of the incapacity and the ability to work.

[Periprosthetic Acetabulum Fractures]. / Periprothetische Azetabulumfrakturen.

In contrast to periprosthetic fractures of the femur, periprosthetic fractures of the acetabulum are rare complications - both primary fractures and fractures in revision surgery. This topic is largely under-reported in the literature; there are a few case reports and no long term results. Due to an increase in life expectancy, the level of patients' activity and the number of primary joint replacements, one has to expect a rise in periprosthetic complications in general and periprosthetic acetabular fractures in particular. This kind of fracture can be intra-, peri- or postoperative. Intraoperative fractures are especially associated with insertion of cementless press-fit acetabular components or revision surgery. Postoperative periprosthetic fractures of the acetabulum are usually related to osteolysis, for example, due to polyethylene wear. There are also traumatic fractures and fractures missed intraoperatively that lead to some kind of insufficiency fracture. Periprosthetic fractures of the acetabulum are treated conservatively if the implant is stable and the fracture is not dislocated. If surgery is needed, there are many possible different surgical techniques and challenging approaches. That is why periprosthetic fractures of the acetabulum should be treated by experts in pelvic surgery as well as revision arthroplasty and the features specific to the patient, fracture and prosthetic must always be considered.

[Surgical Treatment of Acetabulum Fractures with a New Acetabulum Butterfly Plate]. / Operative Versorgung von Azetabulumfrakturen mit der neuen Azetabulumflügelplatte.

Introduction: There have been significant increases in the number of acetabular fractures in elderly patients with primarily ventral pathology and medial protrusion of the femoral head. We have developed the "acetabulum wing plate", which is designed to facilitate repositioning, with its anatomically precontoured structure, and which offers full support of the quadrilateral surface, thus counteracting the force of the femoral head pushing inwards. Conventional plate osteosynthesis only provides insufficient support to the medial surface. After a successful series of biomechanical tests, we now report a clinical case series. Material and Methods: Between April 2012 and August 2013, a total of twelve patients underwent plate osteosynthesis using the precontoured plate described above. The patients (ten male, two female) were aged between 45 and 87 years, the average age being 62.5 years. We were able to perform all osteosynthesis with the modified Stoppa approach, in combination with the first window of the ilioinguinal approach (according to Letournel). In most patients, the plate was applied without complications, In some patients, it even supported repositioning. In six patients, the fractures were of the anterior collum and six fractures were fractures of both colla. The mean time span of follow-up was 13.1 months, the minimum being 4.5 and the maximum 23 months. Results: In most patients, the intra- and postoperative computed tomographic scans showed anatomically correct placement of the plate, thus confirming the correct repositioning of the bone. Routine follow-ups are part of the hospital's postsurgical care system for acetabular fractures; these revealed no secondary dislocation or loosening of the plate. The radiological examination showed consolidation of the fractures after a mean period of twelve weeks. A full year after the initial procedure, no implant-specific complications were observed. Revision surgery was necessary in one patient due to bleeding five days after surgery. In another patient, necrosis of the femoral head necessitated total hip replacement ten weeks after the first surgical intervention. In summary, the concept of the plate proved to be successful in its first case series. Summary: In spite of increasing surgical expertise and the refinements of standard approaches, there is a recognisable shift in acetabular fractures from mainly posterior fracture patterns to fractures of the anterior column. The new acetabulum wing plate takes these factors into account and is an implant designed to address the anterior aspects of the acetabulum. The outcome of the first application is promising and the acetabulum wing plate produces satisfactory results in our patients.

[The Pitch Angle of a Locked Plate Osteosynthesis Construct]. / Der Nickwinkel einer winkelstabilen Plattenosteosynthese.

UNLABELLED: The aim of the present study is to describe the biomechanical properties of the fracture motion of a locked plate construct. METHOD: The three dimensional fracture motion of a conventional and of a dynamic locked plate construct was observed using an optical measurement system. RESULTS: Fracture motion was described in terms of delta z (mean fracture motion in direction of force application) and the pitch angle (angle between the upper and lower cylinders of osteosynthesis). It could be shown that the fracture motion of a conventional locked plate construct is only possible through the bending of the plate. The ratio of pitch angle and mean fracture motion (delta z) is a measure of the necessary degrees of bending per millimeter fracture motion. At the same pitch angle, dynamic osteosynthesis gave greater fracture motion. CONCLUSION: With the parameters of pitch angle and mean fracture motion (delta z), it is possible to describe the whole fracture motion of locked plate fixation. Furthermore, it is possible to compare different locked plate constructs or fracture motions.

Clinical Relevance of Cement Leakage after Radiofrequency Kyphoplasty vs. Balloon Kyphoplasty: A Prospective Randomised Study.

BACKGROUND: Cement leakage is regarded as a typical complication of cement-based augmentation of vertebral fractures. The gold standard is balloon kyphoplasty (BK). Recent methods, such as radiofrequency kyphoplasty (RFK), must be compared with BK in terms of therapeutic success and complication rates. It is unclear whether the cement leakage rate in RFK is lower than with BK and whether this has any clinical relevance. Therefore, the aim of our prospective clinical study was to compare RFK with BK with respect to cement leakage rates and associated clinical complications. PATIENTS AND METHODS: After prospective randomisation, 100 patients (76 women and 24 men with an average age of 78.5 years) or 162 vertebral bodies were treated by BK (n = 79) or RFK (n = 83). We evaluated the parameters "localisation of cement leakage" (epidural, intradiscal, extracorporal, intravascular) and "clinical relevance". RESULTS: More cement is used in BK (5.2 ml) than in RFK (4.0 ml, p = 0.001). Cement leakage was found in 48/79 patients (60.8 %) with BK and 53/83 patients (63.9 %) with RFK (p = 0.420). Even subanalysis by location showed no significant difference between the two methods. Despite the high leakage rates, we experienced only two cases (1× BK, 1× RFK) with intravascular leakage in the inferior vena cava, with interventional endovascular salvage. CONCLUSION: The two examined kyphoplasty methods (BK vs. RFK) have the same high rates of cement leakage, but are rarely associated with clinically manifest complications. Clinically relevant differences between the two compared kyphoplasty methods could not be found.

[Influence of the pelvic trauma registry of the DGU on treatment of pelvic ring fractures]. / Einfluss des Beckenregisters der DGU auf die Versorgung von Beckenringfrakturen.

Fractures of the pelvic ring are comparatively rare with an incidence of 2-8 % of all fractures depending on the study in question. The severity of pelvic ring fractures can be very different ranging from simple and mostly "harmless" type A fractures up to life-threatening complex type C fractures. Although it was previously postulated that high-energy trauma was necessary to induce a pelvic ring fracture, over the past decades it became more and more evident, not least from data in the pelvic trauma registry of the German Society for Trauma Surgery (DGU), that low-energy minor trauma can also cause pelvic ring fractures of osteoporotic bone and in a rapidly increasing population of geriatric patients insufficiency fractures of the pelvic ring are nowadays observed with no preceding trauma.Even in large trauma centers the number of patients with pelvic ring fractures is mostly insufficient to perform valid and sufficiently powerful monocentric studies on epidemiological, diagnostic or therapeutic issues. For this reason, in 1991 the first and still the only registry worldwide for the documentation and evaluation of pelvic ring fractures was introduced by the Working Group Pelvis (AG Becken) of the DGU. Originally, the main objectives of the documentation were epidemiological and diagnostic issues; however, in the course of time it developed into an increasingly expanding dataset with comprehensive parameters on injury patterns, operative and conservative therapy regimens and short-term and long-term outcome of patients. Originally starting with 10 institutions, in the meantime more than 30 hospitals in Germany and other European countries participate in the documentation of data. In the third phase of the registry alone, which was started in 2004, data from approximately 15,000 patients with pelvic ring and acetabular fractures were documented. In addition to the scientific impact of the pelvic trauma registry, which is reflected in the numerous national and international publications, the dramatically changing epidemiology of pelvic ring fractures, further developments in diagnostics and the changes in operative procedures over time could be demonstrated. Last but not least the now well-established diagnostic and therapeutic algorithms for pelvic ring fractures, which could be derived from the information collated in registry studies, reflect the clinical impact of the registry.

[Effects of Surgically Treated Pelvic Ring and Acetabular Fractures on Postural Control]. / Einfluss von operativ versorgten Beckenring- und Azetabulumfrakturen auf die posturale Kontrolle.

BACKGROUND: The aim of surgical treatment of pelvic ring and acetabular fractures is to allow rapid mobilisation of patients in order to restore stance and gait stability (postural control), as this significantly correlates with a positive outcome. The regulation of postural stability is mainly controlled by transmission of proprioceptive stimuli. In addition, the pelvis serves as a connection between the legs and the spine and thus is also of great importance for mechanical stabilisation. It remains unclear whether surgical treatment of pelvic ring and acetabular fractures affects the regulation of postural control. Therefore, the aim of this study was to examine the impact of surgically treated pelvic ring and acetabular fractures on postural stability by means of computerised dynamic posturography (CDP) after a mean of 35 months and to compare the results with a healthy control group. PATIENTS AND METHODS: A retrospective case control study of 38 patients with surgically treated pelvic ring and acetabular fractures and 38 healthy volunteers was carried out using CDP. The average time of follow-up was 35 (12-78) months. The most important outcome parameter in this investigation was the overall stability index (OSI). Hip joint mobility, the health-related quality of life (SF-12) and pain were supplementary outcome parameters. RESULTS: It was found that surgically treated pelvic ring and acetabular fractures had no influence on postural stability. The OSI was 2.1 ° in the patient group and 1.9 ° in the control group. There was no significant difference between the groups in hip joint mobility. A total of 52 % of patients showed no or only mild pain. Mean health-related quality of life was the same as in the total population. CONCLUSION: Surgically treated pelvic ring and acetabular fractures do not lead to deterioration in postural control in the mid term. This is of high prognostic importance for rapid mobilisation of the patients. Therefore no increase in the risk of falling is expected after successfully treatment of fractures.

[Pearls and pitfalls for the treatment of tibial head fractures]. / Outcome und Komplikationen nach proximalen Tibiafrakturen.

BACKGROUND: Tibial plateau fractures requiring surgery are severe injuries of the lower extremity. Depending on the fracture pattern, the age of the patient, the range of activity and the bone quality there is a broad variation in adequate treatment. In the last decade we have had a tremendous development, might it be the angular stable anatomical plates as well as new approaches to the proximal tibia. Nevertheless in the recent literature there are still many complications reported. Not only for sports professionals, recreational athletes or heavy load workers tibial plateau fractures affect leisure, all day activity and professional life. This article reports the treatment algorithm showing different cases, outlines the pitfalls and explains treatment strategies with a detailed x-ray follow-up. CONCLUSION: After a tibial plateau fracture patients are affected in their sporting activity due to an impaired knee function. Despite a long rehabilitation time and programs, physical activity changes to lower impact sports. Among the usual perioperative complications there are the specific complications of postoperative malalignment, implant infections, osteitis of the tibial head, compartment syndrome, secondary loss of reduction, avascular tibial head necrosis, secondary varus or valgus deformity, post-traumatic arthrosis and lesions of the peroneal nerve. In the literature in up to 43% of the cases complications have been noted. Despite surgery the majority of patients cannot return to their previous level of activity. However, overall about 70% of the patients return to sports after a tibial plateau fracture. For a beneficial outcome a detailed fracture analysis with CT scan and precise planning of the surgical strategies and approaches is mandatory.

[Return to Work after Fractures of the Pelvis and the Acetabulum]. / Berufliche Wiedereingliederung nach Becken- und Azetabulumfrakturen.

BACKGROUND AND INTRODUCTION: Pelvic and acetabular fractures are severe injuries with serious consequences that mainly happen to young people. Therefore it is highly interesting to find out to what extent affected patients succeed in returning to work, which is an important factor concerning quality of live. Thus, the objective of this study was to estimate the "return to work" in a two-year follow-up after rehabilitative treatment of patients with pelvic and acetabular fractures and to identify influencing factors. METHODS: A retrospective cohort study was conducted using population-based administrative data of the Baden-Württemberg statutory pension fund. All patients (age 18 to 63 years) who had participated in a rehabilitation programme between 2004 and 2009 due to a pelvic or acetabular fracture were included. Return to work was modelled using multivariate logistic regression analysis. Rehabilitants were classified as "returned" if they have paid at least one monthly contribution due to employment during 13 to 24 months after rehabilitation. Age, gender, diagnostic group, type of rehabilitation programme, fractures of the spine, nerve injuries of the lumbosacral area and/or the lower limb and employment status before the fractures were considered as prognostic covariates. RESULTS: Two-thirds of the 249 researched patients returned to work. This corresponds to a reduction of employment amounting to 16.6 % for patients with a pelvic fracture and 20.8 % for patients with an acetabular fracture. Main predictor for a return to work was the employment status before the fracture. Younger patients had a better chance to return to work than older ones. Patients with fractures of the spine or nerve injuries of the lumbosacral area and/or the lower limb had a 73 % or, respectively, 78 % higher risk of not returning to work. CONCLUSION: Fractures of the pelvis and the acetabulum currently lead in one of five patients to loss of employment. Thereby the trauma threatens the social security of the young patients. Follow-up care should be intensified to increase recovery rates and reduce the burden of long-term work disability.

[A new anatomical wing plate for osteoporotic acetabular fractures: biomechanical testing and first clinical experience]. / Die neue anatomische Flügelplatte für osteoporotische Azetabulumfrakturen: biomechanische Testung und erste klinische Erfahrungen.

BACKGROUND: Acetabular fractures are rare injuries, but there is an increasing number of elderly people with ventral medial instability in cases of central subluxation of the femoral head in osteoporotic acetabular fractures. Common plate osteosynthesis cannot enable medial support of the quadrilateral surface. The new "acetabular wing plate" is anatomically shaped to fix the arcuate line and the quadrilateral surface. The plate pushes the femoral head back to lateral. The aim of this study was the biomechanical comparison with common plate concepts before clinical use of the new implant. METHODS: For biomechanical testing eight artificial fracture models of the pelvis with anterior column fractures were used. They were implemented into a set-up of a one-leg stand model in the material test machine. Cyclical movements with axial pressure to the sacrum up to 250 N were given to the model. Fracture gap movement was measured with an optoelectronic 3D camera measuring system. In all pelvic models all screw holes were drilled by use of drill guides before first mechanical loading. The measurements were randomly done first with the new acetabular wing plate or with the pelvic low profile plate. Absolute and relative fracture gap movement and movements of the pelvic fragments were measured as well. RESULTS: The fracture gap movement and the fragment rotation were comparable in both groups. There was a slightly higher stability in the group of the acetabular wing plate but without statistical significance. In the pelvic low profile group two screw loosenings were found, but the models were able to be tested also with the acetabular wing plate. The new plate was clinically used in the first eight patients due to the good biomechanical results. In all cases the osteosyntheses were done by use of the Stoppa approach and the first window of the ilioinguinal approach. Application of the plate was mostly easy, the plate was also used as a reduction tool. Postoperative controls show anatomic reduction and correct implant position in all eight cases. The three month follow-up examinations confirm the continuing good reduction during fracture healing with the acetabular wing plate.

[Insufficiency fractures of the pelvic ring]. / Insuffizienzfrakturen des Beckenrings.

The demographic changes in society automatically lead to an increase in specific diseases and injuries in the older generation. Therefore, the proportion of osteoporotic and fatigue fractures increases in total and also the absolute number of insufficiency fractures of the pelvic ring. In younger people pelvic ring fractures are mostly due high speed trauma. In the elderly this often occurs by low energy trauma or even with no trauma which is then designated as insufficiency fracture. The problematic of such fractures is insufficiently covered in the conventional classification. Conventional radiological diagnostics must often be supplemented by slice imaging procedures. The therapy forms must be more closely adapted to the general condition and physical health of the patient than by classical fractures and the substantially reduced sustainability of osteosynthesis in altered bones must be taken into consideration.

[Clinical results of surgically treated paediatric fractures of the medial humeral epicondyle]. / Klinische Ergebnisse bei operativ versorgten kindlichen Frakturen des Epicondylus humeri ulnaris.

OBJECTIVES: Fractures of the medial humeral epicondyle represent approximately 10 % of all paediatric elbow fractures. material and methods: Surgically treated paediatric fractures of the medial humeral epicondyle were analysed retrospectively for their epidemiological, clinical and surgical parameters. Re-evaluation included clinical function, satisfaction, pain level and MAYO elbow performance score (MEPS). RESULTS: 22 children could be included. A re-evaluation of 91 % of our patients after a follow-up of ∅ 4 years (range: 1-9 years; median: 4 years) after initial surgery was possible. Subjective outcome and objective function were good with moderate limitations. 85 % of our patients showed good to excellent results in the MEPS. CONCLUSION: Regarding our own good clinical results and potentially lower rates of pseudarthrosis - in comparison to conservatively treated patients - by trend we recommend internal fixation in paediatric fractures of the medial humeral epicondyle. However, operative or conservative treatment must be indicated individually together with the patient and his/her parents.

[Results of surgically treated paediatric supracondylar humeral fractures]. / Behandlungsergebnisse operativ versorgter kindlicher suprakondylärer Humerusfrakturen.

BACKGROUND: About 80 % of all paediatric distal humerus fractures are supracondylar fractures. PATIENTS AND METHODS: Surgically treated children with supracondylar humeral fractures between 2000-2008 were analysed retrospectively and re-evaluated for function, satisfaction, pain level and with the MAYO elbow performance score (MEPS). RESULTS: 46 patients were included. Open fractures (2 %) and vessel (0 %) or nerve (4 %) lacerations were rare, additional forearm fractures frequent (15 %). Surgery was done by closed/open reduction and crossed K-wire pinning. Main complications were movement restriction and K-wire migration. All fractures healed. 72 % of patients could be re-evaluated Ø 51 months after surgery. The mean differences between non-affected and affected elbows showed 8° for flexion, 1° for extension, 1° for pronation and 0° for supination. In 88 % excellent or good results could be measured with the MEPS. CONCLUSION: Regarding bony healing in all patients, well manageable complications, mostly excellent or good results in the MEPS and good function, crossed K-wire pinning after closed/open reduction is a safe standard surgical procedure for this type of fracture.

[Removal of plates and screws. Tips and tricks for problematic cases]. / Implantatentfernung von Platten und Schrauben. Tipps und Tricks für die problematische Metallentfernung.

BACKGROUND: This overview article addresses the different ways of explanting plates and screws. Once the decision has been taken to remove plates and screws, the situation is resolved by skilled performance of surgical procedures. METHOD: In particular, tips and tricks are offered on how to deal with difficult explantations. In general, implant removal is straightforward and without complications. Special techniques, instruments, tips and tricks are important when implant removal becomes problematic due to screw damage, immovable implants, instrument breakage and suchlike. CONCLUSION: This article describes procedures that will put the surgeon on a direct route to implant removal. Keeping strictly to the pathway will inevitably turn problematic implant removal into a straightforward procedure.

[Refracture of long bones after implant removal. An avoidable complication?]. / Refrakturen nach Entfernung von Osteosynthesematerialien. Eine vermeidbare Komplikation?

Refractures of long bones after implant removal are a rare but serious complication, which in most cases make a reoperation necessary. We analysed our own cases and reviewed the scarce literature on this subject. As a result we found that it is possible to reduce this complication by performing thorough preoperative preparation, observing an adequate interim time between initial osteosynthesis and hardware removal, cautiously exposing the weakened bone to force for a certain time period after implant removal and taking the character of the fracture healing into consideration. It is not possible to entirely eradicate this complication because a lot of patients demand the implant removal even though it is known that demineralisation and residual screw holes both induce a reduction of energy-absorbing capacity and therefore predispose the patient to refracture. In some cases the surgeon should recommend that the implants remain in situ.

[Hardware removal after pelvic ring injury]. / Implantatentfernung nach Beckenringfraktur.

BACKGROUND: Pelvic ring fractures are considered as rare injuries. Minimally invasive sacroiliac screw fixation has been used increasingly in recent years as an operative strategy for the treatment of these injuries, if the dorsal pelvic ring needed to be addressed. Treatment options for the anterior pelvic ring comprise plates, screws or external fixation. METHOD: Based on the limited number of publications on this subject and our own experience with 80 patients who suffered pelvic ring B- or C-type injuries during a period of 8 years we are able to show that the indication for hardware removal in the pelvic ring should be strictly defined. RESULTS: In some cases like external fixation, implant-associated infection, malpositioning, allergic implant reaction, critical soft tissue covering, palpable hardware and consolidated juvenile fractures implant removal is certainly indicated. In patients without symptoms and in patients with trauma-associated symptoms which are not definitely associated with the hardware, the removal should be only indicated after thorough consideration of the risks versus the benefits and additionally by taking the initial injury pattern into account. If despite all these objections the hardware removal has been indicated it should always be considered that hardware removal may be challenging with several possible severe complications.

[Hardware removal after spinal instrumentation]. / Metallentfernung an der Wirbelsäule.

Because of the increasing number of patients with surgically treated injuries of the spine we more often have to answer the question of indication for hardware removal. In the cervical spine and after anterior instrumentations of the thoracic and lumbar spine hardware removal is only indicated as part of the management of postoperative complications. After dorsal instrumentation for fractures of the thoracic and lumbar spine, implant-associated discomfort is possible. In addition, in non-fusion procedures there is the risk of implant failure. In these cases the hardware should be removed. If the consolidation of the fracture is in doubt, a preoperative CT scan is useful.