Incidence, treatment techniques, and results of distal humeral coronal shear fractures in children and adolescents-a multicenter study of the German Section of Pediatric Traumatology (SKT).

PURPOSE: Distal humeral coronal shear fractures (CSF) are uncommon and may be challenging to treat due to their size, location, and intraarticular nature. The purpose of this study was to analyze treatment concepts of this rare entity in the growing age. METHODS: Based on a multi-center data analysis we retrospectively reviewed patients below 16 years of age with CSF treated at 13 high-volume pediatric trauma centers. RESULTS: Data from 51 patients with a CSF treated between 01/2012 and 12/2021 were analyzed. The mean age was 12.9 years (10-15), and there was a trend towards male patients (30: 21). The initial diagnostic approach was conventional X-ray in all cases. In addition, a CT scan (n = 33), MRI scan (n = 9), or both (n = 3) were performed. All fractures except two showed relevant displacement. Consequently, only two cases received conservative treatment consisting of plaster immobilization. Surgical treatment was performed in 49 cases consisting of open or mini-open reduction and metal/resorbable screw osteosynthesis (n = 39), plates (n = 4), K-wire pinning (n = 6), and others (n = 6), as well as combinations. In 1 case open reduction without osteosynthesis was performed. Postoperative additional plaster immobilization was performed in 40 cases (for a mean of 19 days (2-42)), physiotherapy was initiated in 29 cases, and metal removal was performed in 28 cases (after a mean of 18.1 weeks (4-44)). After a mean follow-up of 9.9 months (2-25), elbow axial deviation (5° valgus) was observed in one case and mild loss of elbow ROM in six cases (11.7%). Complications included revision of the osteosynthesis because of insufficient articular reconstruction (n = 4), removal of a free joint body (n = 1), an osteonecrosis (n = 1), and a cartilage defect (n = 1). CONCLUSION: In pediatric patients CSFs start to occur at the age of 10, but are typically observed at the age of 13 and older. Because of their intraarticular nature and predilection toward displacement, these fractures are frequently treated operatively. The surgical strategy requires open reduction and anatomic reconstruction of the articular surface. Stable internal fixation, most often achieved by screws, permits early mobilization and leads to good outcomes in most cases. This is presumably due to the fact that mostly simple fractures occur in children and mostly complex injuries in older adults. LEVEL OF EVIDENCE: III, retrospective analysis.

Paediatric fractures of carpal bones other than the scaphoid.

OBJECTIVES: Fractures of carpal bones other than the scaphoid are rare in children. The aim of this study was to analyze results and identify risk factors for an unfavorable outcome. MATERIAL AND METHODS: Children and adolescents up to the age of 16 years who sustained a carpal fracture other than in the scaphoid between 2004 and 2021 were reviewed in this single-center retrospective study. RESULTS: In a series of 209 children and adolescents with carpal fractures, 22 had fractures other than the scaphoid. Mean age was 13 years (range 8-16) years, with a total of 41 fractures, with highest incidences for the capitate (10), trapezium (6), triquetrum (4) and pisiform (4). Twenty-nine of these 41 fractures were missed on initial X-ray. Non-displaced fractures were treated with a short arm spica cast including the thumb. Four patients were operated on for displacement fracture or carpometacarpal subluxation. All fractures united, and patients returned to full activities. At the final consultation at a median 14 months (range 6-89) post-injury, all patients with non-displaced fractures were free of symptoms, with excellent Mayo Wrist Scores (MWS). However, three patients with operated trapezium fractures developed early radiological signs of osteoarthritis, two of them with residual pain and MWS rated only good. CONCLUSION: Non-displaced pediatric carpal fractures treated by forearm cast have excellent prognosis. Fractures of the trapezium with displacement or first carpometacarpal subluxation incur a risk of osteoarthritis despite anatomical reduction and internal fixation.

Rational Usage of Fracture Imaging in Children and Adolescents.

In this paper, authors introduce the basic prerequisite for rational, targeted, and above all, child-oriented diagnosis of fractures and dislocations in children and adolescents is in-depth prior knowledge of the special features of trauma in the growth age group. This review summarizes the authors' many years of experience and the state of the current pediatric traumatology literature. It aims to provide recommendations for rational, child-specific diagnostics appropriate to the child, especially for the area of extremity injuries in the growth age. The plain radiograph remains the indispensable standard in diagnosing fractures and dislocations of the musculoskeletal system in childhood and adolescence. Plain radiographs in two planes are the norm, but in certain situations, one plane is sufficient. X-rays of the opposite side in acute diagnostics are obsolete. Images to show consolidation after conservative treatment is rarely necessary. Before metal removal, however, they are indispensable. The upcoming diagnostical tool in pediatric trauma is ultrasound. More and more studies show that in elected injuries and using standardized protocols, fracture ultrasound is as accurate as plain radiographs to detect and control osseous and articular injuries. In acute trauma, CT scans have only a few indications, especially in epiphyseal fractures in adolescents, such as transitional fractures of the distal tibia or coronal shear fractures of the distal humerus. CT protocols must be adapted to children and adolescents to minimize radiation exposure. MRI has no indication in the detection or understanding of acute fractures in infants and children. It has its place in articular injuries of the knee and shoulder to show damage to ligaments, cartilage, and other soft tissues. Furthermore, MRI is useful in cases of remaining pain after trauma without radiological proof of a fracture and in the visualization of premature closure of growth plates after trauma to plan therapy. Several everyday examples of rational diagnostic workflows, as the authors recommend them, are mentioned. The necessity of radiation protection must be taken into consideration.

[Intraoperative imaging of children and adolescents, for selected fractures and in follow-up after conservative and operative treatment : Part 2 of the results of a nationwide online survey of the Pediatric Traumatology Section of the German Trauma Society]. / Bildgebung bei Kindern und Jugendlichen intraoperativ, bei ausgewählten Frakturen und im Verlauf nach konservativer und operativer Behandlung : Teil 2 der Ergebnisse einer bundesweiten Online-Umfrage der Sektion Kindertraumatologie der Deutschen Gesellschaft für Unfallchirurgie.

The indication for radiographic examinations in pediatric and adolescent trauma patients should follow ALARA (as low as reasonably achievable). Because of the effect of radiation on the growing sensitive tissues of these young patients, a strict indication should always be given for radiation use and during controls after fracture repair. METHODS: An online survey by the Pediatric Traumatology Section (SKT) of the German Trauma Society (DGU) from Nov. 15, 2019, to Feb. 29, 2020, targeting trauma, pediatric, and general surgeons and orthopedic surgeons. RESULTS: Participants: 788. Intraoperative applications: Collimation 50% always, postprocessing for magnification 40%, pulsed x-ray 47%, and 89% no continuous fluoroscopy; 63% osteosynthesis never directly on image intensifier. Radiographic controls after implant removal never used by 24%. After operated supracondylar humerus fracture, controls are performed up to 6 times. After distal radius greenstick fracture, 40% refrain from further X-ray controls, after conservatively treated clavicular shaft fracture, 55% refrain from further controls, others X-ray several times. After nondisplaced conservatively treated tibial shaft fracture, 63% recommend radiographic control after 1 week in two planes, 24% after 2 weeks, 37% after 4 weeks, and 32% after 6 weeks. DISCUSSION: The analysis shows that there is no uniform radiological management of children and adolescents with fractures among the respondents. For some indications for the use of radiography, the benefit does not seem evident. The ALARA principle does not seem to be consistently followed. CONCLUSION: Comparing the documented results of the survey with the consensus results of the SKT, differences are apparent.

[Imaging after trauma in clinics and practice for children and adolescents : Part 1 of the results of a nationwide online survey of the Pediatric Traumatology Section of the German Trauma Society]. / Bildgebung nach Unfall in Klinik und Praxis bei Kindern und Jugendlichen : Teil 1 der Ergebnisse einer bundesweiten Online-Umfrage der Sektion Kindertraumatologie der Deutschen Gesellschaft für Unfallchirurgie.

BACKGROUND: The indication for radiography should strictly follow the ALARA (as low as reasonably achievable) principle in pediatric and adolescent trauma patients. The effect of radiation on the growing sensitive tissue of these patients should not be disregarded. QUESTION: The Pediatric Traumatology Section (SKT) of the German Trauma Society (DGU) wanted to clarify how the principle is followed in trauma care. METHODS: An online survey was open for 10 weeks. Target groups were trauma surgeons, pediatric surgeons, general surgeons, and orthopedic surgeons. RESULTS: From Nov. 15, 2019, to Feb. 29, 2020, 788 physicians participated: branch office 20.56%, MVZ 4.31%, hospital 75.13%; resident 16.62%, senior 38.07%, chief 22.59%. By specialist qualification, the distribution was: 38.34% surgery, 33.16% trauma surgery, 36.66% special trauma surgery, 70.34% orthopedics and trauma surgery, 18.78% pediatric surgery. Frequency of contact with fractures in the above age group was reported as 37% < 10/month, 27% < 20/M, 36% > 20/M. About 52% always request radiographs in 2 planes after acute trauma. X-ray of the opposite side for unclear findings was rejected by 70%. 23% use sonography regularly in fracture diagnosis. In polytrauma children and adolescents, whole-body CT is never used in 18%, rarely in 50%, and standard in 14%. DISCUSSION: The analysis shows that there is no uniform radiological management of children and adolescents with fractures among the respondents. CONCLUSION: Comparing the results of the survey with the consensus findings of the SKT recently published in this journal, persuasion is still needed to change the use of radiography in primary diagnosis.

[X-ray diagnostics of fractures in childhood and adolescence-Consensus report of the scientific working group of the pediatric traumatology section of the German Society for Trauma Surgery (DGU)]. / Röntgendiagnostik bei Frakturen im Kindes- und Jugendalter ­ Konsensusbericht des Wissenschaftlichen Arbeitskreises der Sektion Kindertraumatologie der DGU.

For decades projection radiography has been the standard in the diagnostics of fractures and injuries, including patients in childhood and adolescent; however, each examination with X­rays should also be based on an individual assessment of the benefits and risks. The pediatric traumatology section of the DGU has developed a consensus paper on various aspects of imaging for diagnostics and assessment of progression, on setting options for intraoperative imaging, on X­ray imaging of the opposite side, on polytrauma and computed tomography (CT), on postoperative radiological checks and the use of sonography after an accident.

Dislocations of the acromioclavicular and sternoclavicular joint in children and adolescents: A retrospective clinical study and big data analysis of routine data.

BACKGROUND: Dislocations of the sternoclavicular joint (anterior/posterior) and acromioclavicular joint (SCJ and ACJ, respectively) are rare injuries in childhood/adolescence, each having its own special characteristics. In posterior SCJ dislocation, the concomitant injuries in the upper mediastinum are most important complication, while in anterior SCJ dislocation there is a risk of permanent or recurrent instability. METHODS: In a retrospective analysis from seven pediatric trauma centers under the leadership of the Section of Pediatric Traumatology of the German Trauma Society, children (<18 years) were analyzed with focus on age, gender, trauma mechanism, diagnostics, treatment strategy and follow-up results. Additional epidemiological big data analysis from routine data was done. RESULTS: In total 24 cases with an average age of 14.4 years (23 boys, 1 girl) could be evaluated (7x ACJ dislocation type ≥ Rockwood III; 17x SCJ dislocation type Allman III, including 12 posterior). All ACJ dislocations were treated surgically. Postoperative immobilization lasted 3-6 weeks, after which a movement limit of 90 degrees was recommended until implant removal. Patients with SCJ dislocation were posterior dislocations in 75%, and 15 of 17 were treated surgically. One patient had a tendency toward sub-dislocation and another had a relapse. Conservatively treated injuries healed without complications. Compared to adults, SCJ injuries were equally rarely found in children (< 1% of clavicle-associated injuries), while pediatric ACJ dislocations were significantly less frequent (p<0.001). CONCLUSIONS: In cases of SCJ dislocations, our cohort analysis confirmed both the heterogeneous spectrum of the treatment strategies in addition to the problems/complications based on previous literature. The indication for the operative or conservative approach and for the specific method is not standardized. In order to be able to create evidence-based standards, a prospective, multicenter-study with a sufficiently long follow-up time would be necessary due to the rarity of these injuries in children. The rarity was emphasized by our routine data analysis.

Effect of malpositioned anterior cruciate ligament replacement on knee joint structures: a biomechanical model.

Any sort of malpositioning of anterior cruciate ligament (ACL) replacement leads to an overload of single fibers of the ACL replacement. As long as this does not result in a tear of these fibers so that isometry of the ACL replacement is restored, the abnormal forces acting in and on the ACL replacement are transmitted from the ACL replacement to the remainder of the knee joint structures. We assumed that the posterior cruciate ligament (PCL) is notably affected. The present biomechanical model illustrates the relevant force vectors and reveals the extent of the effect of malpositioned ACL replacement on knee joint structures, particularly the PCL. Further investigations are needed to find out if the presumably occurring overload of a malpositioned ACL replacement can be calculated from its position on an individual basis. This may help deduce recommendations for ACL replacement procedures in the future.

Physiological closure of the physeal plate of the distal radius: An MRI analysis.

To have knowledge of the physiological closure of a particular physeal plate is necessary to understand fractures close to the end of growth (transitional fractures). Most frequent fractures involve the distal radius in adolescents. However, there are no systematic investigations on the topic of growth plate closure concerning the distal radius plate, so far. Twenty-two healthy female volunteers underwent MRI investigations of their left wrist. Absolute width, percentage and localization of the physeal part, closed at the time of investigation were recorded. Sequential MRI scans were performed. In this series T1-weighted sequences were most useful to distinguish open and closed parts of the physis. Total area was 291-469 mm(2) (average, 399 mm(2) ). It did positively correlate with body height (P < 0.01), but not with weight (P = 0.241) or BMI (P = 0.394). Physeal closure took place at 15-18 years. There was no significant correlation between menarche and closure (P = 0.091). Bony bridging of the growth plate begins centroradial and ends with a small limbus dorsoradial. Sequential scans showed that there are only a few months from beginning to end of physeal closure. Physiological closure of the distal radius growth plate takes place in late adolescence, varying individually. There seems to be no influence of the menarche in female individuals. The process happens within a very short time of less than a year. This may be one rationale for the fact, that transitional fractures of the distal radius are rare.

Development and validation of a paediatric long-bone fracture classification. A prospective multicentre study in 13 European paediatric trauma centres.

BACKGROUND: The aim of this study was to develop a child-specific classification system for long bone fractures and to examine its reliability and validity on the basis of a prospective multicentre study. METHODS: Using the sequentially developed classification system, three samples of between 30 and 185 paediatric limb fractures from a pool of 2308 fractures documented in two multicenter studies were analysed in a blinded fashion by eight orthopaedic surgeons, on a total of 5 occasions. Intra- and interobserver reliability and accuracy were calculated. RESULTS: The reliability improved with successive simplification of the classification. The final version resulted in an overall interobserver agreement of κ = 0.71 with no significant difference between experienced and less experienced raters. CONCLUSIONS: In conclusion, the evaluation of the newly proposed classification system resulted in a reliable and routinely applicable system, for which training in its proper use may further improve the reliability. It can be recommended as a useful tool for clinical practice and offers the option for developing treatment recommendations and outcome predictions in the future.

Missed elbow fractures misdiagnosed as radial head subluxations.

Over a 36-month period, 11 children were treated in our department for fractures about the elbow which initially went undiagnosed, as they had first undergone reduction maneuvers for a suspected radial head subluxation, without prior imaging. The most frequent final diagnosis was supracondylar humerus fracture (n = 4). A fall was reported for six children (54.5%); the mechanism of injury remained unknown in four children (36.4%). In four of eleven children (36.4%) there was moderate or major soft tissue swelling at the time of first presentation, which is uncommon in radial head subluxation. Reduction of a suspected radial head subluxation without any prior radiological investigation can be recommended exclusively when the typical history of an abrupt traction by an (adult) attending person is positively reported. In every other case, radiographs should be done prior to any attempt at reduction.

Arthroscopic treatment of post-traumatic shoulder instability in children and adolescents.

Traumatic dislocation of the shoulder in childhood is rare, accounting for only 0.01% of all injuries in this age class. However, the literature does contain indications that post-traumatic instabilities and redislocations occur with more than average frequency in children and adolescents. This study describes the technique and results of arthroscopic stabilization of the shoulder joint before the completion of growth. Over a period of 4 years, seven patients were treated prior to reaching skeletal maturity. Five patients were treated by means of arthroscopically assisted labral refixation using suture anchor systems. Clinical follow-up was undertaken after between 6 and 48 months using a modified Constant-Murley score. Instabilities, re-dislocations and postoperative impairment of mobility did not occur after arthroscopic treatment, with a score of 92 points. Arthroscopic labral refixation is a reliable, surgical treatment procedure for post-traumatic shoulder instability in adults. This study showed that it can be used successfully in children and young people prior to skeletal maturity. No alteration of the surgical procedure of Bankart repair in adults is necessary. Considerable experience in adult shoulder reconstruction promises excellent results in children and adolescents, too. There is no evidence of growth disturbance or biodegradation associated problems in this group of children and adolescents. Delay of labral refixation until adulthood is therefore not indicated.

The treatment of upper limb fractures in children and adolescents.

BACKGROUND: The treatment of fractures in children and adolescents must be based on an adequate knowledge of the physiology of the growing skeleton. Treatment failures usually do not result from technical deficiencies, but rather from a misunderstanding of the special considerations applying to the treatment of fractures in this age group. METHODS: We selectively reviewed recent publications on the main types of long bone fracture occurring in the period of skeletal development. RESULTS: Alleviating pain is the first step in fracture management, and due attention must be paid to any evidence of child abuse. The goals of treatment are to bring about healing of the fracture and to preserve the function of the wounded limb. The growth that has yet to take place over the remaining period of skeletal development also has to be considered. Predicting the growth pattern of fractured bones is a basic task of the pediatric traumatologist. During the period of skeletal development, conservative and surgical treatments are used in complementary fashion. Particular expertise is needed to deal with fractures around the elbow, especially supracondylar humeral fractures, displaced fractures of the radial condyle of the humerus, radial neck fractures, and radial head dislocations (Monteggia lesions). These problems account for a large fraction of the avoidable cases of faulty fracture healing leading to functional impairment in children and adolescents. CONCLUSION: The main requirements for the proper treatment of fractures in children and adolescents are the immediate alleviation of pain and the provision of effective treatment (either in the hospital or on an outpatient basis) to ensure the best possible outcome, while the associated costs and effort is kept to a minimum. Further important goals are a rapid recovery of mobility and the avoidance of late complications, such as restriction of the range of motion or growth disorders of the fractured bone. To achieve these goals, the treating physician should have the necessary expertise in all of the applicable conservative and surgical treatment methods and should be able to apply them for the proper indications.

Biodegradable beta-Tri-Calciumphosphate/hydroxyethyl methacrylate enhanced three component bone adhesive demonstrates biocompatibility without evidence of systemic toxicity in a rabbit model.

Bone gluing is an attractive surgical technique; however, its use in patients is hampered by a variety of side effects. Therefore, it was the aim of this ethically approved study to evaluate a novel biodegradable beta-Tri-Calciumphosphate (beta-TCP, Cerasorb)-enhanced bone adhesive regarding its toxicity and biocompatibility in a rabbit model. Fifty healthy New Zealand White rabbits were assigned in the study (n = 21) and sham-operated control group (n = 29). In the study group, a cylindrical part (4.6 x 10.0 mm) of the proximal tibia and distal femur was removed, reimplanted, and bone adhesive was applied. Blinded physical examination and sampling for hematology, clinical chemistry, and acute phase proteins (haptoglobin, C-reactive protein (CRP)) was performed before surgery and after 12, 24, 48, 72, 240, and 504 h. Significant findings of the physical examination included a slightly higher grading of warmth (p = 0.0019) and pain (p < 0.0001) of the wound 240 h after surgery in the study group. No significant differences between albumin, haptoglobin, CRP, and urea concentrations in both groups were evident, whereas the study group demonstrated significantly lower leukocyte count, total protein, and globulin concentrations (p < 0.0001). As expected, both groups showed a marked transient increase in muscle enzymes (Creatine Kinase and Aspartate Aminotransferase) following the surgery (p < 0.0001). Twelve to 24 h after surgery, a significant decrease in ionized calcium from 1.38 +/- 0.12 mmol/L to 1.06 +/- 0.13 mmol/L was noted in the study group (p < 0.0001). The results clearly indicated that the novel beta-TCP-enhanced bone adhesive showed good biocompatibility without significant evidence of acute or subacute local or systemic toxicity.

[Bond strength of a bioresorbable bone adhesive: results of a biomechanical study in a sheep model]. / Biomechanische Analysen zur Verbundfestigkeit eines bioresorbierbaren Knochenklebers: experimentelle Untersuchungen am Schafsmodell.

The purpose of this study was to investigate the bond strength of a new bone adhesive based on ethylene glycol-oligolactide-bismethacrylate on 36 sheep. A 2-cm metaphysial segment was produced on the ulna of each sheep by an oscillating saw and it was not stabilized by any type of additional osteosynthesis. Adhesive was applied to the osteotomy gaps in 18 sheep, the remaining 18 animals served as controls. A total of 6 animals with glue and 6 controls were euthanized after 21, 42 and 84 days. The bond strength after repair of the gaps through bone adhesive compared to a control group was studied by using a four-point bending test. There was a continual increase of bending stiffness from 21 to 84 days in all sheep, with the highest bending stiffness of 102.83 N/mm2 by the glue group after 84 days as opposed to the control group with 58.48 N/mm2 (p = 0.25). Morphological investigations showed more callus formation by the control group than the adhesive group after 84 days (p = 0.04). In addition, an in vitro gluing of the ulna segment was performed with a four-point bending test after 10, 60 and 360 min polymerization time. The in vitro gluing of the ulna segment showed a continual increase of bending stiffness to 17.32 N/mm2 after 360 min (p = 0.59).

Delayed healing of forearm shaft fractures in children after intramedullary nailing.

BACKGROUND: In displaced and unstable forearm shaft fractures, elastic stable intramedullary nailing represents the current treatment of choice. Delayed healing has been observed in single cases, but the incidence of healing disturbances remains unclear. METHODS: Retrospective analysis of all patients with forearm shaft fractures and open epiphyseal plates, treated with elastic stable intramedullary nailing between 2000 and 2004 in 5 pediatric trauma units, was conducted. Evaluation of cases with insufficient consolidation 90 days after osteosynthesis was performed. RESULTS: Ten (1.9%) of 532 cases showed delayed healing. Mean age (12.3 years), part of open fractures (30%), and part of open reductions (60%) were clearly higher than in a nonselected collective; the ulna was concerned in 70%. One refracture, 1 local soft tissue infection, and 1 small sequestration were found. In 5 children, nails were extracted with (2x) or without (3x) local surgical intervention. In the other 5 children, the nails were left in place. All fractures healed within 13 months posttrauma without relevant functional restrictions. CONCLUSIONS: Delayed healing is possible especially in open fractures or open reduced fractures of the ulna in older children, but healing takes place up to 13 months. Therefore, no change of treatment principles is necessary. Protection of ulna periost has to remain in the center of surgical focus. LEVEL OF EVIDENCE: Retrospective comparative study, Level III.

Elastic stable intramedullary nailing in pediatric femur and lower leg shaft fractures: intraoperative radiation load.

BACKGROUND: Elastic stable intramedullary nailing (ESIN) is currently the therapy of choice in unstable, transverse and short oblique femoral and tibial-fibular shaft fractures in childhood and adolescence. As with every intramedullary technique, it requires a greater intraoperative reliance on radiological imaging. Literature concerning intraoperative radiation load in ESIN is rare, results having a wide range from less than 1 minute to more than 15 minutes. METHODS: We performed a retrospective analysis of 53 femoral and 24 tibial shaft fractures. In addition, image intensifier times of several steps of the operative procedure in 10 femoral shaft fractures were evaluated prospectively. RESULTS: The average radiation time in femoral fractures was 70.3 (range, 12-193) seconds, in tibial shaft fractures, 42.4 (range, 16-108) seconds. The prospective analysis of femur shaft fractures was able to show the most intense use of imaging during fracture passage (43.2%) and placement of the nail tips (26.6%). Image intensifier times in educational operations were not significantly higher than in operations performed by experienced surgeons. CONCLUSIONS: The actual intraoperative radiation load is influenced by bone mass and soft tissue coverage. Surgeons are able to reduce it only by decreasing the fluoroscopy time. According to our results, image intensifier time should not exceed 3 minutes in ESIN of femoral shaft fractures and 2 minutes in ESIN of lower-leg fractures. Low intraoperative radiation times are a mark of quality with respect to the interests of patients, surgeons, and operation theater staff.

Intraoperative radiation exposure in displaced supracondylar humeral fractures: a comparison of surgical methods.

Crossed K-wires, descending elastic stable intramedullary nailing and radial external fixator are alternatives in the operative treatment of displaced supracondylar humeral fractures. Only little knowledge of intraoperative radiation exposure exists in those procedures. We found average image intensifier times of 30.7 s for K-wires, 41.4 s for the external fixator and 80.0 s for elastic stable intramedullary nailing. Extensively increased fluoroscopy times was seen in cases switched from closed to open reduction intraoperatively. To avoid unnecessary intraoperative radiation exposure for patient, surgeon and staff, limits of radiation time are recommended as an additional indicator to change the surgical procedure to another fixation method or open reduction.

The effects of combined gentamicin-hydroxyapatite coating for cementless joint prostheses on the reduction of infection rates in a rabbit infection prophylaxis model.

Infections remain a critical issue in total joint arthroplasty. Addition of antibiotics to bone cement was shown to significantly improve antimicrobial prophylaxis in cemented joint arthroplasty. In cementless joint arthroplasty a comparable prophylaxis by local antibiotics has not been possible yet. The aim of the current study was to investigate the antimicrobial effect of two different gentamicin-hydroxyapatite (HA) coatings for cementless prostheses in a rabbit infection model. Staphylococcus aureus with a dose of 10(7) CFUs was inoculated into the intramedullary canal of the tibia of 30 rabbits followed by the implantation of standard steel HA K-wires (n=10), steel K-wires coated with a gentamicin-HA combination (n=10), and steel K-wires coated with a gentamicin-RGD-HA combination (n=10), respectively. The animals were sacrificed after 28 days and clinical, histological and microbiological assessment on the bone and on the removed K-wire itself by agar plating and DNA-pulsed field gel electrophoresis were carried out to detect infection. There was a statistically significant reduction of infection rates by both gentamicin-coating types (0 infections in both groups) compared to standard HA coating (7 infections in 8 animals; 2 animals were lost due to acute diarrhea) (p<0.001). An excellent correlation between agar plating testing results of the K-wires and of the bone samples was found. Detailed histology showed cortical lysis, abscess and sequester formation in the infected animals. Both gentamicin-coating types showed significant improvement of infection prophylaxis compared to standard HA coating and, therefore, this coating technology could help to improve infection prophylaxis in cementless total joint arthroplasty. In further studies biocompatibility of the coatings has to be assessed.

Derotation of post-traumatic femoral deformities by closed intramedullary sawing.

Different techniques and devices have been used for correction osteotomies of bones in patients with malalignments. The most frequently used technique for rotational deformities of the femur and tibia is open osteotomy with an oscillating saw and pre-drilled holes with all well-known drawbacks of open surgery. An intramedullary device with an adapted minimal-invasive surgical technique allows intramedullary osteotomy of the bone preserving the surrounding soft tissue. We performed femoral osteotomies with an intramedullary saw followed by static interlocking nailing in 14 patients with post-traumatic rotational deformity in the femur. Twelve patients had an external rotational deformity of the femur ranging between 26 and 63 degrees , one had an additional leg-shortening of about 4 cm. Two patients had internal rotational deformities. In two patients with delayed fracture healing union was achieved within one year without secondary surgery. Post-operative clinical assessment and CT-scans revealed good derotation results with deformities of less than 4 degrees in all cases. No device-related complications were observed. Therefore, we conclude that "closed" osteotomy with an intramedullary saw is a minimal-invasive, safe and reliable option for derotation procedures in the femur.