Development and initial clinical use of an aiming device for distal boring in interlocking nailing without roentgen image intensifier for the unreamed tibial nail

An aiming technique for an unreamed tibial nail was developed, which uses the relatively constant distance between the first transverse distal nail hole and the anterior aspect of the tibia. This aiming device is set at a distance of 12.3 mm from the anterior cortex, and fine tuning is finally resolved by use of a "working channel" with a 10 mm diameter from the medial side. The aiming system was tested in 20 cases in a video-documented prospective study using the unreamed tibial nail (UTN, Synthes) between July 1993 and March 1995. In all cases (100%) distal locking could be performed without image intensification. With a high percentage (55%) of open fractures (3 O3B fractures) the total operation time was 108 min (median, range 60-180 min). The time for distal locking (always 3 bolts) was 15.5 min (median, range 8.0-39.0 min), while the time for proximal locking (average 1.6 +/- 0.7 bolts) was 4.5 min (median, range 3.0-15.0 min). There were no major intra- or postoperative complications related to the aiming system. The major advantages are that it is not necessary to have image intensification for distal locking, there is a reduction in radiation exposure for the surgeon, and the drill holes are very precise.     

Retrograde nailing of humerus shaft fractures with the unreamed humerus nail. An international multicenter study

Combined with the new unreamed humeral nail (UHN) (Synthes), the retrograde approach to the endomedullary canal of the humeral shaft promises careful reduction and fixation of humeral shaft fractures. This prospective multicenter study reports and analyses 102 retrograde nailings with the UHN and their operative procedures. Seven patients with pathological fractures have died meanwhile, but 75 patients could be followed up until bone healing. Seventy-three fresh humeral shaft fractures, 12 pseudarthrosis, 3 refractures and 14 pathological fractures have been treated with the UHN. In 98 cases (96.1%) the surgeon estimated fracture stability well enough to initiate immediate postoperative elbow and shoulder mobilization. The difficulties involved with free-hand interlocking proximally at the nail tip in 5.9%, fissure or avulsion at the insertion point in 3.9% and radial nerve palsy also in 3.9% of the cases were the most important intraoperative complications. In all 75 patients followed up, bone healing occurred, but five fractures (6.7%) needed more than 8 months connected with a second operative procedure. In one case spongious bone transplantation and new locking bolts had been performed. In three cases a special compression device has been used, whereas in one case also a new nail and in the second spongious bone transplantation had been added. In the fifth case plate osteosynthesis had been performed. At the end of treatment 89.4% of the patients had excellent shoulder function and 88.0% excellent elbow function. Once the indication for surgery is established, the UHN can be considered a reliable and safe implant for stabilizing humeral shaft fractures.     

Modified Küntscher's nail for the proximal femur fixation after corrective osteotomies in children (author's transl)

The authors describe the development in the design of the modified Küntscher's nail with two fins on its upper part, assigned for the fixation of proximal femur after corrective osteotomies in children. Detailed explanation about the nails construction and its biomechanical characteristics are presented. The fixation of the nail in the proximal and distal femoral part, as well as on the site of osteotomy is particularly analyzed. On the base 423 operated cases, where the modified Küntscher's nail was applied, the authors conclusion is that the nail is very suitable for the correction of proximal femur deformities in children.     

Analysis of implantation-induced nail deformation and roentgen morphometric studies as the principle for an aiming device for distal interlocking nailing without roentgen image intensification

While working to develop a distal locking device, we analyzed distal nail position with reference to nail deformation and a radiographic-morphometric investigation. The amount and the direction of implant deformation in unslotted stainless steel unreamed tibial nails (Synthes) were analyzed. Measurement of implant deformation (3 translations, 3 angles) in the center of the distal transverse locking hole was performed with a 3D magnetic motion tracker system before and after nail insertion. Unreamed tibial nails (diameter 8 mm, n = 10; diameter 9 mm, n = 10) were inserted in paired human cadaver tibiae. The results showed lateral translations of -4.5 +/- 3.5 mm (mean and standard deviation, range 14.3 mm) and dorsal translations of -7.8 +/- 5.8 mm (mean and standard deviation, range 19.2 mm). Rotational deformations around the longitudinal axis of the nail were 0.3 +/- 0.7 degree (mean and standard deviation, range 2.4 degrees). The results showed, that a simple aiming arm, mounted on the proximal nail end, alone or even in combination with a large working channel (e.g. 10 mm in diameter), was not adequate to the aiming process. A radiographic-morphometric analysis was subsequently performed in 40 tibiae after experimental (n = 20) or clinical (n = 20) implantation of nails 8 mm and 9 mm in diameter. These measurements showed a relatively constant distance between the upper distal transverse hole and the anterior aspect of the tibia (average 12.3 mm and only a narrow range (7.6 mm). These data were the basis for the development of an aiming technique that exploits the relatively constant distance between the distal nail hole and the anterior aspect of the tibia. This aiming device is set at a distance of 12.3 mm from the anterior cortex, and the fine tuning is finally resolved by the use of a "working channel' 10 mm in diameter.     

Various possibilities for managing subtrochanteric fractures

Subtrochanteric fractures are highly unstable. For treatment, open reduction and internal fixation are the method of choice. The 95 degrees condylar plate is widely used for stabilization of these fractures. Alternative devices are the gamma nail and the recently developed intramedullar nail with a twisted plate which allows immediate postoperative weight bearing. The reported complications of the gamma nail restrict its general application, whereas preliminary reports of the intramedullar nail with the twisted plate are encouraging. Further clinical data are necessary before its general application can be recommended.     

Failure of femoral head fixation: a cadaveric analysis of lag screw cut-out with the gamma locking nail and AO dynamic hip screw

The most commonly reported failure mode of sliding hip screws in published literature is cut-out of the lag screw. This study investigates the resistance to failure of the femoral head, with lag screws used in two types of sliding hip screws, the gamma locking nail (Howmedica) and the dynamic hip screw (DHS) (Synthes). The investigation consisted of biomechanical tests under static loading conditions on 12 pairs of cadaveric femoral heads, to establish the failure loads due to screw cut-out for the two implant lag screws. The gamma nail appeared to reduce the tendency to cut-out in the osteoporotic bone (soft) associated with elderly patients in whom these devices are commonly used (p < 0.05). In high density bone (hard) the gamma lag screw also appeared to be stronger, because the DHS showed a tendency to bend. The larger diameter of the gamma nail lag screw resists bending and appears to reduce the risk of cut-out compared with the DHS.     

Aerial fallout of DDT in southern California

Ender's method of intramedullary fixation of intertrochanteric and subtrochanteric fractures is described. Ender's nail is a pre-bent flexible steel nail with a diameter of 4.5 millimeters. Three to five of these nails are inserted from a small incision proximal to the medial epicondyle of the femur into the medullary canal. They are passed through the femur across the fracture site and into the head of the femur, where they diverage. They are in the lines of force and therefore are not subjected to bending moments. The fracture fixation allows immediate weight-bearing. This method of fixation was used in a series of 203 patients. Their average age was sixty-eight years; the mortality rate was 10.3 per cent. In 3.9 per cent superficial infections occurred, but in no case was there a deep infection involving the bone. Functional return (walking) was achieved in all of the survivors who were able to walk at the time of injury, and there were no nonunions.     

Progress in imaging diagnosis of circulatory diseases

Five patients with femoral nonunion and a broken interlocking nail were treated with the augmentative plating procedure. This group included two male and three female patients whose average age was 25 years (range, 21-35 years). All of the injuries resulted from traffic accidents and were closed fractures. Four of the injuries were initially managed with a Grosse-Kempf interlocking nailing system, and one case was managed with an AO interlocking nailing system. The broken interlocking nail was left in place in situ, and an augmentative plate fixation was applied to the fracture site to provide a rigid fixation. Simultaneous bone grafting was performed in three of the patients to repair the bony defect. All of these patients walked bearing full weight on the extremity without aching at the fracture site within 3 months, and all of these five fractures obtained a bony union within an average of 5.4 months after this treatment. From our experience, we have found this method to be a useful treatment for the nonunion of femoral shaft fracture with a broken interlocking nail.     

Patients treated for nonunions with plate and screw fixation and adjunctive locking nuts

Locking nuts were used as an adjunct to plate fixation in 48 procedures in 44 patients. All the procedures were done by one surgeon during a 4-year period. The patients in this study were treated for nonunion or malunion and thus had difficult technical problems, such as cortical defects or holes left from previous hardware. The use of standard implants were generally unreliable for additional fixation. The locking nuts were used as a cortical substitute in 26 instances, to create a fixed angle relationship between the plate and the screw in 14 instances, to elevate the plate off the bone to help increase vascularity in five instances, and to increase purchase in severely osteoporotic bone in three instances. Complete followup was obtained on 43 of the 44 patients. Forty of the 43 patients achieved complete union after their reconstructive procedure. Three patients had continued nonunions with eventual hardware failure and required reoperation. The use of the locking nuts enabled the surgeons to obtain stable fixation at the time of reoperation with eventual union of all of the ununited bones. The success of the use of this implant is best gauged by the fact that the surgeon could place screws effectively where cortical defects existed, allow improved purchase in osteoporotic bone, and create a fixed angle plate screw relationship that would have been difficult to do without the locking nuts.     

An adult case of extra-hepatic portal obstruction with bleeding from esophageal varices

PURPOSE: This study examined the use of a locking reconstruction bone plate/screw system for use in mandibular surgery. PATIENTS AND METHODS: All patients treated with a locking reconstruction bone plate/screw system for fractures of the mandible or continuity defects in an 18-month period were prospectively studied. Ease of use of the locking plate/screw system, characteristics of the fractures/defects, and complications were tabulated. RESULTS: One hundred two locking bone plates were placed in 84 patients. Most patients (n=75) were treated for fractures of the mandible; there were eight continuity defects and one case of mandibular narrowing. There were no cases of malocclusion or difficulties encountered in using the plate/screw system. Loss of fixation was encountered in only one patient. CONCLUSIONS: The use of a locking plate/screw system was found to be simple, and it offers advantages over conventional bone plates by not requiring the plate to be compressed to the bone to provide stability.     

Compression plate fixation of subtrochanteric osteotomies in children

Compression plates provide a reliable method for stabilizing subtrochanteric osteotomies (and fractures when indicated) in children. Apart from a standard compression set, no special appliances are required. The hazards and inconveniences of nail plates and external fixation devices are avoided.     

Minimally invasive method for treatment of supra-diacondylar femoral fractures

The "gold standard" treatment modality for extra-articular and combined intra-, extra-articular fracture of the distal femur is the condylar blade plate (CP). Large exposure of the distal femur with unavoidable iatrogenic trauma to the soft tissue surrounding the fracture site and perhaps the lack of stiffness of the eccentric lateral cortical location of the CP has been suggested to play a role in the high rate of infections and pseudarthrosis reported in the literature. In an effort to overcome some of the difficulties with the condylar blade plate and to reduce complications, an unreamed, titanium, solid nail, locked proximally with two locking screws and distally with a screw and twisted blade was developed (DFN). The nail was designed for minimal invasive reduction through a small median parapatellar arthrotomy of the articular fracture (percutaneous screw) and of the supracondylar fracture. The DFN is a modular system sharing many components and almost all instrumentation with the AO-UFN and it is expected that the nail is much better in axial stiffness and strength than the condylar blade plate. The treatment of supracondylar femoral fractures should be improved by providing early weight bearing and accelerated fracture healing with a reduced incidence of delayed unions and infections.     

Hyperthermic treatment of canine tibia through RF inductive heating of an intramedullary nail: a new experimental approach to hyperthermia for metastatic bone tumours

Although the incidence of metastatic bone tumours is recently increasing, the local control rate of conventional treatment modalities is not satisfactory. If an intramedullary nail for the fixation of a weakened bone with metastatic lesions can be used as a heat-generating material for hyperthermia, the treatment result is expected to improve. This new approach to hyperthermic treatment of bone tumours has been investigated in a canine tibia. An intramedullary nail made of stainless steel was put into a medullary canal of a canine tibia. The leg was exposed to an alternating magnetic field of 100 kHz in the frequency and 100 Oe in the maximum intensity. The nail was inductively heated for 60 min. The temperature of the nail > 50 degrees C and the cancellous bone 5 mm from the nail was heated to a therapeutic temperature, 42.5 degrees C. After a bone labelling with tetracycline and calcein, the dogs were killed 2, 4 and 12 weeks after the heating. The area of osteonecrosis was evaluated by fluorescence microscopy analysis. The heated cancellous bone around the nail showed osteonecrosis in 2 weeks after the treatment, but it recovered completely in 12 weeks. This experiment has demonstrated the heating capability of the new hyperthermic technique and minimal toxicity to the bone, and suggests the clinical application to metastatic bone tumours.     

Interface pressure measurements of support surfaces with subjects in the supine and 45-degree Fowler positions

The results of treatment of 35 intraarticular distal fractures of the femur are presented. Treatment was performed in 8 cases with a condylar plate, in 8 cases with dynamic compression screw (DCS), in 2 cases with two plates, in 9 cases with screws only, and eight times the fracture was treated with a combination of lag screws and locking nail. Examination took place at an average of 45.5 months after the accident. 19 patients had an isolated fracture, 8 patients one accidental injury and 8 patients had more than one fracture or were polytraumatised. In 75% of the patients treatment lasted for between day 1 and 5. We found 17.1% open fractures and had to face infections in 5.7% (two cases). Bone healing occurred in all fractures, the reported infections could be overcome by early revision and the use of gentamycin-PMMA beds. It is remarkable that locking nails were successfully used in 8 cases of fractures with intraarticular component of the distal femur.     

Percutaneous reduction of fractures of the neck of the radium in children by means of a steinmann nail (author's transl)

Percutaneous reduction of fractures of the neck of the radius or of epiphysiolysis with displacement can be achieved in children by means of a Steinmann nail. No additional means of fragment fixation seems to be necessary. Fracture healing is ensured by cast immobilization. Functional results are equivalent to those after conservative treatment.     

Ender nailing of acute humeral shaft fractures in multiple injuries

From January 1987 to April 1993, 25 multiply injured patients were treated with closed intramedullary Ender nail fixation of the humeral shaft. Criteria for the procedure were humeral diaphyseal fractures with associated multiple injuries. Seventeen distal and mid-shaft fractures were treated via a modified anterograde approach in which the rotator cuff is not violated. Eight proximal third fractures were treated via the standard retrograde approach. Postoperative follow-up averaged 36 months. Full range of motion was attained 17 of the 25 patients. Of the eight remaining patients, three with a slightly limited range of motion achieved full range of motion following nail removal; three had preoperative radial nerve palsy which resolved within 1 year, and two patients required follow-on plating. In 92 per cent (23 of 25) there were no incidences of infection or non-union. Flexible nails avoid complications of reaming. The modified anterograde approach allows excellent shoulder motion since it does not violate the rotator cuff. Ender nails provide excellent fixation and clinical outcome in the multiply injured patient and are cost effective compared with interlocking nails.     

H-reflex changes in the course of amyotrophic lateral sclerosis

This study was directed at establishing the influence of dynamic loading situations on the sliding characteristics of the Gamma locking nail (Howmedica). It was postulated that the changing regions of load contact area that occur within the sliding mechanism during flexion and extension would favourably modify the jamming behaviour observed under static test conditions. The forces required to initiate sliding of the lag screw in the intramedullary device were investigated under a range of conditions representing clinical situations. The optimum sliding performance of the Gamma nail was shown to occur during test conditions of dynamic loading, when the rate of application of the load was rapid and the cyclic angle of flexion was greatest. The size and weight of the patient also influence the sliding characteristics, as a shorter lag screw length protruding from the barrel and a reduced vertical static load (body weight) yielded a lower axial sliding force. The results under dynamic loading conditions suggest that static testing of sliding hip screws does not accurately represent their clinical performance.     

Operative management of diaphyseal fractures of the humerus. Plate versus nail

Although nonoperative treatment is indicated and successful for the majority of diaphyseal humeral fractures, operative intervention is indicated in several situations. Either intramedullary nail or plate fixation commonly is used for the operative management of this problem. Familiarity with the surgical techniques and application of both types (and subtypes) of implants is necessary to allow optimal treatment for the widest range of fracture patterns. In most indications for operative management, internal fixation with plates is preferred. Stable fixation, sparing adjacent joints from iatrogenic injuries, and direct visualization and protection of the radial nerve are of critical importance in maximizing postoperative function and in most cases outweight the potential advantages of a loadsharing implant inserted through a more limited incision.     

Retrograde intramedullary nailing of supracondylar femoral fractures

As an alternative to standard AO/Association for the Study of Internal Fixation plate and screw techniques, retrograde intramedullary locked nailing of supracondylar and intracondylar (AO/Association for the Study of Internal Fixation Type 33) fractures is reviewed. This includes a historic review, the technique for knee arthrotomy, fracture reduction and nail insertion, and the reported clinical and biomechanical results. The retrograde intramedullary locked nail is a viable alternative for the treatment of AO/Association for the Study of Internal Fixation Type 33-A and some C supracondylar femoral fractures and should be part of the internal fixation armamentarium, however, it does not replace the standard biologic plate and screw techniques for most fractures.     

Supplementation of coconut oil from different sources to the diet induces cellular damage and rapid changes in fatty acid composition of chick liver and hepatic mitochondria

PURPOSE OF THE STUDY: Impaction in pertrochanteric fracture sites is a well known phenomenon; the screw-plate system is designed to stabilise the fracture. Although easier to use, the risk with the nail-plate system is postoperative penetration of the nail into the joint. The present study was conducted to determine the exact conditions of the impaction, and to identify possible ways to improve the nail-plate system. MATERIAL-METHOD: The study included 129 cases of pertrochanteric fracture, excluding sub-trochanteric fractures. All fractures were fixed with a 130 degrees angulated nail-plate. In all cases, consolidation was uneventful after 8 to a 12 weeks. The anatomical type of fracture, i.e. stable or unstable, was determined according to the size of the intermediary fragment, including the trochanter minor. The displacement was measured as the difference between the length of the nail and the length of the femoral head and neck measured along the axis of the femoral neck. The parameters examined were: fracture stability degree, bony mineralisation (Singh Index), nail length, femoral neck, length nail position in the femoral head, and above all, fracture reduction. All these parameters were computerised and compared using Stat View statistics software. RESULTS: Impaction was observed in 43 per cent of cases. Among these, 25 per cent were rated as slight (1 to 5 mm), 18 per cent as moderate (over 5 mm) and 9 per cent as marked (10 to 25 mm). Impaction was associated with demineralisation of the bone tissue (p = 0.001). The anatomical classification of the fracture was not a determining factor (p = 0.19), as marked displacements were also recorded in stable fractures. A posterior and inferior position of the intramedullary nail in the femoral head is one of displacement determining factors (p = 0.004, two-sided 1 test). Valgus over-correction is the most important factor, especially when it is associated with bony demineralisation (p = 0.02) and an inadequately centred intramedullary pin (p = 0.02). Shorter the femoral neck, and shorter the nail, greater was the frequency of nail articular penetration. DISCUSSION: The risk of articular penetration therefore reaches 15 per cent in petrochanteric fractures repaired with a nail plate, set at an angle of 130 degrees. A short neck, a cervicodiaphyseal angle superior to 140 degrees, and demineralisation are the three determining parameters. Stable or unstable fracture has in fact little effect on displacement incidence, and therefore does not, on its own, warrant the use of a prosthesis in comminuted fractures. The authors compared their results to literature on progressive sliding system: the incidence of complications associated with this type of fracture treatment is identical, but the determining parameters are different. CONCLUSION: The study shows that the nail-plate is efficient and provides simple and solid fracture fixation. However, this osteosynthesis material needs to be modified in order to improve its fixation in the femoral head.