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Biomedical subjects

C Krettek

Publications and source records attributed to C Krettek.

At least 163 records · Page 9Linked to original sources
PubMed1999

Long-term outcome in children with fractures of the proximal femur after high-energy trauma.

BACKGROUND: Fractures of the femoral head and neck in children have a risk of severe complications, especially femoral head necrosis. We performed a long-term follow-up study of patients treated at our institution. METHODS: Patients were reexamined at least 3 years after trauma and were included if they were younger than 17 years old at the time of injury, if there was no history of previous fracture, and if there was no history of underlying bone disease. Fractures were classified according to Delbet, and outcome was graded according to Ratliff. Anterior capsulotomy was not performed, and stabilization devices were placed short of the epiphysis except for type I fractures. RESULTS: Of 32 patients, 28 were reexamined. Among these patients, the mean age at the time of injury was 11.8 years and the mean follow-up time was 11.1 years (range, 3-21 years). There were 3 patients with type I fractures, 8 patients with type II fractures, 12 patients with type III fractures, and 5 patients with type IV fractures. Thirteen patients had Injury Severity Scores > 18. At last follow-up, 20 patients presented with good function, 5 with fair outcome, and 3 with poor results; all of the latter suffered type I fractures. Eighteen patients had no restrictions in activities of daily living or during sports activities. In six other patients, the inability to participate in sports was attributable to head trauma, amputation, or peripheral neurologic damage. CONCLUSION: We found favorable long-term outcome in type II to type IV fractures. In these patients, restrictions of function were usually caused by other associated injuries. All patients with type I fractures presented with poor outcome secondary to their proximal femoral fractures, and not because of other associated injuries. Type I fractures during childhood and adolescence represent an unsolved problem.

Accidents↗
PubMed1999

The use of Poller screws as blocking screws in stabilising tibial fractures treated with small diameter intramedullary nails.

Intramedullary nailing of metaphyseal fractures may be associated with deformity as a result of instability after fixation. Our aim was to evaluate the clinical use of Poller screws (blocking screws) as a supplement to stability after fixation with statically locked intramedullary nails of small diameter. We studied, prospectively, 21 tibial fractures, 10 in the proximal third and 11 in the distal third in 20 patients after the insertion of Poller screws over a mean period of 18.5 months (12 to 29). All fractures had united. Healing was evident radiologically at a mean of 5.4+/-2.1 months (3 to 12) with a mean varus-valgus alignment of -1.0 degree (-5 to 3) and mean antecurvatum-recurvatum alignment of 1.6 degrees (-6 to 11). The mean loss of reduction between placement of the initial Poller screw and follow-up was 0.5 degrees in the frontal plane and 0.4 degrees in the sagittal plane. There were no complications related to the Poller screw. The clinical outcome, according to the Karström-Olerud score, was not influenced by previous or concomitant injuries in 18 patients and was judged as excellent in three (17%), good in seven (39%), satisfactory in six (33%), fair in one (6%), and poor in one (6%).

Adolescent↗
PubMed1999

The topography of the perforating vessels of the deep femoral artery.

This study evaluated the anatomic relationship between the femur and the vessels that arise from the deep femoral artery, that is, the perforating arteries and the nutrient artery. Blue silicone dye was injected through the common femoral artery in 20 fresh human cadavers. An anteromedial and a posterolateral dissection were performed to identify the femoral perforating arteries and the nutrient artery of the femur. The length of the femur and the distances between the tip of the greater trochanter and the perforating arteries and nutrient artery were measured. This study showed that a reliable, clinically applicable topographic relationship exists between the femur and the perforating arteries and the nutrient artery.

Aged↗
PubMed1998

Deformation of femoral nails with intramedullary insertion.

Current methods of distal interlocking of intramedullary femoral nails are dependent on image intensification. However, radiation exposure to the patient, the operating room staff, and the surgeon remains a concern. Proximally mounted, radiation-free aiming systems for distal interlocking of femoral nails have reportedly failed because of nail deformation with insertion. To better understand this deformation, a three-dimensional magnetic motion tracking system was used to determine the position of the distal interlocking hole following nail insertion. The amount and direction of deformation of commercially available small-diameter implants (unslotted 9-mm nails inserted without reaming) and large-diameter implants (slotted 13-mm nails inserted with reaming) from a single manufacturer were analyzed. Measurements of deformation (three translations and three angles), based on the center of the distal transverse locking hole, were performed on 10 paired intact human cadaveric femora before and after insertion. The technique produced the following results for the small and large-diameter nails, respectively: lateral translations of 18.1+/-10.0 mm (mean+/-SD, range: 47.8 mm) and 21.5+/-7.9 mm (range: 26.4 mm), dorsal translations of -3.1+/-4.3 mm (range: 15.2 mm) and 0.4+/-9.8 mm (range: 30.1 mm), and rotation about the longitudinal axes of -0.1+/-0.2 degrees (range: 0.7 degrees) and 10.0+/-3.1 degrees (range: 7.8 degrees). This technique is useful for measuring insertion-related femoral nail deformation. The data for the nails tested suggest that a simple aiming arm, mounted on the proximal end of the femoral nail alone, will not sufficiently provide accurate distal aiming.

Bone Nails↗
PubMed1998

[Complex injuries of the spine].

3 different types of complex spinal trauma are defined: Type I means a multilevel contiguous or non contiguous unstable injury, type II is described as a spinal injury with concomitant thoracic or abdominal lesion, type III stands for the coincidence of spinal injury and polytrauma. Overlapping of different types occurs. Type I: The incidence amounts according a german multicenter study to about 2.5%. Multilevel injuries need to be stabilized for a long distance from posterior. With a thorough analysis the segments to be fused are determined. Type II: The leading thoracic injury is a lung contusion which occurs in up to 50% of the cases. A CT scan of the thorax during the first diagnostic screening is recommended. Early reduction and stabilization from posterior should be aimed at. During the first two weeks anterior procedures are contraindicated. Abdominal injuries are to be found in 3-4% of all spinal injuries. All organs could be affected. A typical constallation is the "seat-belt syndrome" with lesions of the upper abdominal organs and a flexiondistraction injury of the upper lumbar spine. The main problem is to make the diagnosis of both components initially. Most of the patients may be treated in one operation by first taking care of the abdominal injury and than stabilizing the spine. The prognosis of this combination is favorable. Type III: In 17-18% of all polytraumatized patients lesions of the spine are to be diagnosed. From these only one third need surgical care. From 680 patients with operatively treated fractures of the thoracolumbar junction 6.2% were polytraumatized according to the multicenter study mentioned above. The risk of missing a spinal injury in polytrauma totals approximately 20%. Surgical stabilization should be performed in the primary phase (day-1-surgery). Additional injuries, potentially time consuming operations with a high blood loss sometimes necessitate a different approach. Non stabilized spinal injuries apparently do not have the same negative effect on the whole organism as long bone fractures. In the early phase of treatment on the C-spine only anterior procedures and on the thoracolumbar spine only posterior techniques should be applied.

Adolescent↗
PubMed1998

[Not Available].

Explore the source record for details and available documents.

Journal Article↗
PubMed1998

[Comparison of a radiation-independent aiming system and free-hand technique for distal locking of unslotted femoral nails].

Although the free-hand technique remains the most popular method for distal interlocking screw insertion, proximally mounted "radiation-independent" devices which compensate for implant deformation recently have been developed for rotationally stiff, unslotted femoral nails. However, the benefits of such systems have not been determined. This study prospectively compared the duration of the nailing procedure, the length of radiation time, and the accuracy of interlocking screw placement with a radiation-independent distal aiming system to those using the free-hand technique. In twenty paired intact cadaveric femora, a single surgeon experienced only in the free-hand technique performed statically locked intramedullary nailing using the two methods. For the aiming system and free-hand technique respectively, the total operation time was 19.1 +/- 8.4 versus 20.9 +/- 11.3 minutes (p = 0.9), the distal locking time was 6.6 +/- 2.4 versus 4.8 +/- 1.5 minutes (p = 0.002), the total fluoroscopy time was 23 +/- 17 versus 69 +/- 34 seconds (p < 0.0001), and the distal locking fluoroscopy time was 0 versus 37 +/- 15.5 seconds (p < 0.0001). There were no failures in either group. Drill nail contact (p < 0.0001) and distal screw damage (p = 0.02) were both greater with the free-hand technique.

Aged↗
PubMed1998

A new mechanical aiming device for the placement of distal interlocking screws in femoral nails.

Although the free-hand technique remains the most popular method for distal interlocking screw insertion, a proximally mounted "radiation-independent" device which compensates for implant deformation has been developed. In 15 intact human cadaveric femora the same surgeon performed statically locked intramedullary nailing using the distal aiming system. Operation time, distal screw insertion, total radiation time and accuracy of the interlocking screw placement were measured using a radiation-independent distal aiming system. The average total operation time was 21.2+/-8.6 min, and the average distal locking time (2 screws) was 7.1+/-2.4 min. The total operation time and the distal locking time declined over the first 10 cases. These times did not significantly improve in the subsequent 5 procedures. The average total fluoroscopy time was 28.1+/-16.6 s. None of the screw placements using the distal aiming device required the use of fluoroscopy. Drill-nail contact was absent in 5 drillings, mild in 9 drillings, moderate in 16 drillings, and severe in none. Measurement of screw damage showed in 55 of 60 measurements wear of less than 15 microm. There were no failures or major complications. A minor complication related to distal locking was observed in one specimen. This study suggests that distal interlocking screws can be placed successfully using a radiation-independent aiming arm-based system, which accounts for nail deformations. The distal aiming device (DAD) can be learned easily. The main advantages of the aiming arm include the elimination of radiation during distal interlocking and precise screw placement with little insertion-related hardware damage.

Aged↗
PubMed1998

Effects of percutaneous and conventional plating techniques on the blood supply to the femur.

A cadaveric arterial injection study was performed to study the effects of percutaneous and conventional surgical plating techniques on femoral vascularity. Sixteen-hole dynamic condylar screw and condylar buttress plates were applied on the proximal and distal shafts, respectively, of intact femora in ten human cadavers. On one side, the plate was inserted using a lateral conventional plate osteosynthesis (CPO) technique with elevation of the vastus lateralis muscle to expose the shaft. On the contralateral side, the plate was inserted percutaneously beneath the muscle using a minimally invasive plate osteosynthesis (MIPPO) technique. After plating, blue silicone dye was injected through the common femoral artery. A dissection was then performed to identify the femoral perforating arteries (PAs). The pattern of periosteal filling of the injected dye was analyzed. The MIPPO technique maintained the integrity of the PAs and exhibited superior periosteal perfusion. The results of this study indicate that the MIPPO technique maintains femoral vascularity and perfusion better than the CPO technique.

Aged↗
PubMed1998

Management priorities in patients with polytrauma.

BACKGROUND: The basic principles for the treatment of the polytraumatized patient is early resuscitation, followed by a physical examination and diagnostic studies. These are performed to establish the priorities for life-saving management and further treatment. DISCUSSION: Trauma management regarding musculoskeletal injuries is discussed in four different distinguished periods: (1) acute or resuscitation period (0-3 h); (2) primary or stabilization period (3-72 h); (3) secondary or regeneration period (days 3-8); and (4) tertiary or rehabilitation period (beyond day 8). For management during the acute period, a trauma algorithm is described, which consists of four different steps: (1) first look; (2) shock treatment; (3) check up; and (4) control and diagnosis. During the acute period, decompression of organ cavities (tension pneumothorax, cardiac tamponade) is performed along with life-saving operations for hemorrhage control of thoracic, abdominal, pelvic or external bleeding. The primary period (3-72 h) of treatment starts when the vital functions have been stabilized. During this period, so-called 'day-one' surgery is performed. During the secondary period (days 3-8), a phase of regeneration, a secondary deterioration of organ function must be prevented. During the tertiary phase (beyond day 8), in most cases, recovery usually continues and final reconstructive operations can be performed.

Algorithms↗
PubMed1998

CT-based analysis of the geometry of the distal femur.

When applying minimally invasive techniques (MIO, Minimally Invasive Osteosynthesis) to the fixation of the distal femur, the surgeon has access to a limited number of anatomical landmarks: namely the articular surface of the distal femur and a small portion of the distal lateral femoral cortex. A detailed knowledge of the local anatomy facilitates the technique and prevents complications. Using Kirschner wires placed at set positions in the distal femur, we analyzed the measurements obtained from the 3D reconstructed helical CT scans of 33 embalmed femora and we report on the anatomy of the distal femur as it relates to supracondylar fracture fixation.

Femur↗
PubMed1998

Intraoperative control of axes, rotation and length in femoral and tibial fractures. Technical note.

In an effort to limit the amount of soft tissue dissection at the fracture site, indirect reduction and minimally invasive fixation techniques have been developed to treat femoral and tibial fractures. These techniques, which do not rely upon anatomical reduction of the fracture fragments, are technically difficult. Correct limb length, axial alignment in the frontal and sagittal plane, and rotation must be assessed using means other than open reduction. In this technical note, some simple and effective intraoperative clinical examination and radiographic techniques to determine limb alignment are described. These include: the 'cable techniques' for the determination of varus-valgus malalignment; the 'hypertension test', 'radiographic recurvatum sign', 'tibial plateau sign', and 'meterstick technique' for length analysis; and the 'hip rotation test', 'lesser trochanter shape sign', 'cortical step sign', and 'diameter difference sign' for rotational analysis. For each of the listed techniques, basic principles, technical instructions, limitations, advantages, and disadvantages are described.

Bone Malalignment↗
PubMed1998

Management of calcaneal fractures in adults. Conservative versus operative treatment.

Significant progress had been made in the management of calcaneal fractures. This is reflected in the marked decrease in complication rates associated with the current intervention of these potentially devastating injuries. The treatment priorities that are key to achieve best results in a displaced calcaneal fracture are an anatomic reconstruction of the entire calcaneus including articular surfaces, height, alignment, and length, with a function directed postoperative management. The value of these priorities is confirmed by long term followup results. Conservative treatment should be considered only in cases of extraarticular fractures, in cases of minor displaced intraarticular fractures in patients who are nonambulatory, and in cases where there is a clear contraindication for surgery. An anatomic reconstruction of an os calcis fracture is difficult to obtain. In two-part fractures, according to the classification described by Sanders et al, an anatomic reduction is obtainable in more than 80% of cases. However, if the articular cartilage damage that is typically present is considered, a 70% rate of good to excellent clinical results is more realistic. In three-part fractures, anatomic reduction is attainable in approximately 60% of cases with a 70% rate of good results. These two subgroups comprise approximately 90% of all calcaneal fractures. It has been put into practice recently to optimize the extended lateral approach using posteromedial and anterolateral windows, so that an anatomic reduction can be achieved in more than 60% of os calcis fractures considered as Type III according to the classification described by Sanders et al. Additional scientific work in this area of trauma orthopaedics would benefit most from a general consensus on a fracture classification system and on a clinical scoring system, with 5-year followup studies using these treatment methods and evaluation systems.

Algorithms↗
PubMed1998

Experimental study of distal interlocking of a solid tibial nail: radiation-independent distal aiming device (DAD) versus freehand technique (FHT).

OBJECTIVES: Recently, radiation-independent aiming devices for the tibia that compensate for insertion-related implant deformation have been developed, but the benefits of such systems have not been determined. This study prospectively evaluated the duration of the nailing procedure, the length of radiation time, and the accuracy of interlocking screw placement when using a radiation-independent distal aiming device (DAD) versus the freehand technique (FHT). MATERIALS AND METHODS: In an oblique cadaveric tibial fracture, a surgeon inexperienced in both techniques (DAD and FHT) performed statically locked intramedullary nailing. RESULTS: For the DAD and the FHT, respectively, the total operation time was 25.4 +/- 11.3 (mean +/- standard deviation) versus 30.9 +/- 14.3 minutes (p = 0.029), the distal locking time was 16.7 +/- 8.6 versus 21.9 +/- 10.5 minutes (p = 0.004), the total fluoroscopy time was 9 +/- 5 versus 93 +/- 34 seconds (p < 0.0001), the distal locking fluoroscopy time was zero versus 88 +/- 33 seconds (p < 0.0001), and the screw wear was -0.7 +/- 5.2 versus 26.8 +/- 31.6 micrometers (p = 0.001). The failure rate was 1.6 percent (one of sixty screws) in both groups. CONCLUSION: These results suggest that the DAD can eliminate the need for radiation during placement of distal interlocking screws.

Adult↗
PubMed1998

Internal fixation of multiple fractures in patients with polytrauma.

Within the last decade understanding of the pathogenetic consequences of trauma has been improved significantly. An additional reduction of lethality has been achieved that in part is related to increasing discrimination of complex injury patterns. Accordingly, additional staging in fracture management of these injuries has been developed. An overview of the current status of fracture management in polytrauma is given and certain regimens that are still controversially are discussed. The principles determined are based on the treatment experience of 4003 multiply injured patients within the past 23 years. The most important principles within the first hours after trauma represent adequate hemorrhage control. In fracture treatment the primary goal remains to perform primary stable osteosynthesis. In severe polytrauma with severe injuries to the extremities, the first decision is whether limb salvage can be achieved without risk of deterioration of the patient's condition. If this is the case, open fractures Grades III b and c usually can be stabilized primarily by unreamed intramedullary nailing or percutaneous plating. The priority pattern in multiple closed fractures is as follows: (1) tibia; (2) femur; (3) pelvis; (4) spine; and (5) upper extremity. Exceptions may ensue if severe head or thoracic trauma is present. Delayed treatment is performed for complex joint reconstruction, definitive treatment of maxillofacial injuries, and soft tissue reconstruction.

Algorithms↗
PubMed1998

Plate osteosynthesis of the distal femur: surgical techniques and results.

Over the past three decades, the techniques for internal fixation of the distal femur have evolved to provide reliably successful results. The improved outcomes of plate osteosynthesis of distal femur fractures are because of better implants, techniques of anatomic reduction and soft tissue handling, and post-fixation stability with early motion. We review the traditional Arbeitsgemeinschaft für Osteosynthesefragen (AO) surgical techniques for plate osteosynthesis of the distal femur and the results reported using these methods.

Bone Plates↗
PubMed1998

[Distal femoral fractures].

Techniques of operative treatment of supra- and intercondylar fractures have changed in recent years. These changes refer to reduction techniques and implant selection. Operative approach concepts, which remained unchanged for several decades were critically evaluated and modified to a minimal invasive osteosynthesis [MIO]. This included for intraarticular fractures a trans-articular joint reconstruction and a retrograde plate osteosynthesis (TARPO). This technique result in better operative visualization and management of intraarticular comminution, saver fracture healing and better functional outcome. For extraarticular fractures a minimally invasive percutaneous plate osteosynthesis (MIPPO) via stab incisions only or retrograde intramedullary nailing is available. Beside that new strategies and techniques for the avoidance of axial malalignment, rotational deformities and leg length discrepancies are described, as well as a new plate generation (LISS: less invasive stabilization system), which behaves more like an internal fixator. The complex nature of combined fractures and soft tissue injuries of the distal femur and proximal tibia needs special attention and specific management. Distal femoral and proximal tibial fractures in young patients are usually caused by a high energy trauma. They are complicated by a high rate of systemic and local injuries to cartilage, ligaments and skin. The patients in this group with severe injuries need a detailed treatment algorithm, because the surgeon's individual skill, enthusiasm and wishful thinking frequently led to unsatisfactory results. A decision making scheme is presented specifically addressing timing and treatment modalities.

Equipment Design↗