Rigid Intramedullary Nailing Research Articles

High Success Rate With Exchange Nailing to Treat a Tibial Shaft Aseptic Nonunion

To investigate the effects of tibial exchange nailing in treating a tibial shaft aseptic nonunion and to establish optimal indications for using this technique. Prospective, consecutive. University hospital. Twenty-five consecutive tibial shaft aseptic nonunions were prospectively treated with the exchange nailing technique. Indications for this procedure were a tibial shaft aseptic nonunion that had previously been treated with an inserted nonreamed or reamed intramedullary nail, displayed less than one centimeter of shortening, was with or without rotational or angular deformity, exhibited no segmental bony defects, and was anatomically suited for conventional or locked reamed intramedullary nail stabilization. The marrow cavity was reamed as extensively as possible, and a rigid intramedullary nail with stable fixation was inserted. During a follow-up period of two to four years (median thirty-two months), twenty-four nonunions healed, on average, in four months (range three to six months). The one remaining nonunion healed four months after a cancellous bone grafting procedure. No wound infection or malunion was noted. Because of its high union rate, low complication rate, and simplicity of method, we believe that the exchange nailing technique should be considered preferentially for all indicated cases.

Intramedullary Nailing and Cortical Bone Mineral Content

A transverse diaphyseal osteotomy of the tibia was stabilized using rigid intramedullary nailing in rabbits. In a 2nd group, nailing was performed without osteotomy. The rabbits were sacrificed 3 to 24 weeks postoperatively, and the nails were removed. The mineral content (BMC) was measured by dual photon absorptiometry and the mineral density (BMD) was calculated. At 24 weeks the osteotomized bones had significantly lower BMC values than did the respective nonosteotomized bones or the intact bones. The BMC of the nonosteotomized bones remained above the control level throughout the experiment. The minimum BMD values of the osteotomized bones were detected at 3 weeks, whereafter they gradually approached the control level over time. The results suggest that rigid intramedullary nailing in connection with osteotomy causes a significant decrease in cortical bone mineral mass, seen at 24 weeks postoperatively. The photon absorption method used seemed sensitive enough to detect changes in cortical bone mineral quantity in these experimental conditions.

Different healing patterns of experimental osteotomies treated by intramedullary nailing.

The healing of 52 diaphyseal osteotomies in rabbit tibiae was followed up histologically from 3 to 24 weeks after rigid intramedullary nailing. The histological evaluation was made from longitudinal sections through the osteotomy area. Particular attention was paid to the fracture healing pattern. A bulky periosteal response was visible in every specimen. At 24 weeks, the external callus was always well remodeled. The osteotomy line rapidly filled with bone from 6 weeks onwards. At 24 weeks, the site of osteotomy was detectable only on the basis of slight irregularity in the cortex. The secondary gap healing seen in 19 specimens was the most common type of bone union from 6 weeks onwards. In 13 specimens, the exact type of osteonal healing was not definable, since a solid union with good cortical reconstruction was always the final outcome. Altogether, four nonunions were detected throughout the study, none of these, however, in the specimens at 24 weeks. Considerable endosteal resorption was detected at 24 weeks, at which time at least one third of the original cortex had disappeared in all specimens. The rigid nail seems to ensure a relatively uneventful healing of the experimental osteotomies. Vast endosteal resorption and some nonunions make the use of medullary reaming in this connection doubtful.

Clinical comparative study between flexible intramedullary nail and rigid intramedullary nail in the treatment of the tibial shaft fracture

Clinical comparative study between flexible intramedullary nail and rigid intramedullary nail in the treatment of the tibial shaft fracture

The use of Ender nails in femoral shaft fractures: what are the remaining indications?

The use of Ender nails for the treatment of femoral shaft fractures has been described as technically easier and less time consuming than current intramedullary nailing techniques. We reviewed our results with unlocked Ender nails in 26 stable and 17 unstable fracture patterns an average of 3-4 years after injury. Because of continued instability, 42% of the stable and 76% of the unstable groups required adjunctive stabilization in the form of skeletal traction, a cast, or an external fixator. Additionally, nail migration and shortening and loss of motion at the knee were seen in 14 fractures in each group. Although two thirds of the patients with stable fracture patterns obtained good or excellent results, no outcome in the unstable group was rated excellent and only 19% were considered good. We therefore recommend that rigid locked intramedullary nails be used in femoral diaphyseal injuries. The use of Ender nails should be limited to stable fracture patterns and locked with screws or wires. They may be particularly useful for fractures in femora with small medullary canals (less than or equal to 8 mm), fractures below noncemented femoral prostheses, and fractures in young children requiring intramedullary stabilization without injuring the physeal plates.

Delayed Union of Fibular Fractures Accompanying Fractures of the Tibial Shaft

Among 440 adult patients with tibial shaft fracture and accompanying fibular fracture there were eight cases with radiographically ununited fibulae 4 months after the injury, each with uneventful tibial union. Fractures with severe soft-tissue injuries were excluded from this study. In 293 patients the treatment method of the tibial fracture was conservative, comprising closed reduction and immobilization by long plaster cast. In 147 patients it was intramedullary Küntscher nailing, and all the eight cases with delayed fibular union occurred among these, the frequency being 5.4%. The typical accompanying fibular fracture to develop delayed union was a comminuted one in the middle or distal third of the bone. At a followup examination 5 to 8 years after the original injury four of the eight fractures were found to have ultimately spontaneously united, while three showed a radiographically indisputable nonunion. One patient had undergone segmental fibular ostectomy because of persistent local pain but in the remaining patients the subjective symptoms were negligible. The occurrence of delayed fibular union in association with rigid intramedullary nailing of concomitant tibial shaft fracture is a phenomenon of which trauma surgeons should be aware even if the natural course of the condition often seems to be benign.

Biomechanics of Rigid Tibial Nail Insertion Sites

The use of a very proximal insertion site for rigid intramedullary nailing was evaluated in a biomechanical study. The purpose of this study was to compare the bursting strains generated in a proximal tibia fracture fragment during rigid nailing, using the recommended insertion sites versus a more proximal site just anterior to the tibial plateau in the midline. Proximal one-third tibia fractures were created in 12 pairs of fresh cadaver specimens. Strain gauges were applied to the medial and lateral cortices of the proximal fragments. Lottes nails, Grosse-Kempf nails, and unreamed Russell-Taylor nails were inserted in four successive pairs of specimens. In each pair, one side used the recommended starting point, and the other side used the proximal insertion site. The strain was recorded at successive 2- to 4-cm depth intervals during nail insertion. In the Lottes group, much larger bursting strains were generated in the lateral cortex when using a distal starting point (P < 0.05). In the unreamed Russell-Taylor group, the anteromedial surface strains were significantly increased using a distal starting point (P < 0.05). The Grosse-Kempf group showed no significant difference in strains associated with any insertion point during tibial intramedullary nailing.

Strain shielding 12 weeks after femoral reaming and nailing in rats.

The purpose of this study was to investigate the in vivo strain-shielding in rat femora 12 weeks after intramedullary nailing with either flexible or rigid implants. Five days prior to death, unidirectional strain gauge units were implanted on the anterior bone surface bilaterally. Median strain values of reamed only and polyacetal-nailed femora ranged from 67 to 90 percent of the intact side. Removal of polyacetal nails and sham operations gave negligible changes in strain. Strain of the steel-nailed femora was 51 percent of the intact side. Removal of nails increased strain to 91 percent of the intact side. Testing of femora after removal of implants revealed stiffness of 116 and 103 percent of normal in reamed-only and polyacetal-nailed groups, respectively. Stiffness in the steel-nailed group was reduced to 85 percent of normal. None of these changes were statistically significant. This study indicates that rigid intramedullary nails cause strain shielding at the anterior, mid-diaphyseal surface of rat femora 12 weeks after insertion. Removal of rigid implants seems to restore the loading configuration immediately.

Management of femoral fractures and pseudofractures in adult hypophosphatasia.

Ten pseudofractures and six complete fractures occurred in five patients with adult hypophosphatasia. The four pseudofractures that were treated non-operatively progressed to complete fracture. The six pseudofractures and six complete fractures that were treated by internal fixation united. New fractures occurred in four patients after the removal of the internal fixation. We recommend that complete fractures, symptomatic pseudofractures, and progressive asymptomatic pseudofractures in patients with adult hypophosphatasia be treated with load-sharing internal-fixation devices, such as rigid intramedullary nails. These should not be removed unless it is absolutely essential. If removal is necessary, however, they should be replaced, preferably during the same anesthetic session. In our opinion, the guidelines developed from this study may be applied reasonably to patients with osteomalacia from causes other than hypophosphatasia, especially if medical therapy has been unsuccessful.

Gunshot fracture of the femur with segmental bone loss: Management by fixation with a Huckstep nail

The maintenance of bony length is of major importance in the management of lower limb injuries in which bone loss has occurred. We report a case of the successful use of a rigid intramedullary nail with transfixion screws (the Huckstep nail) after segmental loss of bone due to a gunshot injury.

Fracture healing after rigid intramedullary nailing in rats.

Rigid intramedullary nailing of the right tibia after osteotomy with resection of the fibula was performed on 48 male Wistar rats weighting 300-400 g. Nailing was performed with 1.4-mm nails after reaming. Nail stiffness was similar to that of intact tibias. The left leg remained unoperated as control. The animals were sacrificed after 4, 8, 12 or 16 weeks, and both tibiae were tested in a 3-point bending test. Of the 35 animals with the nail in situ, nine animals showed non-union at the time of testing. At 8 weeks stiffness had reached normal values, while strength and deflection showed about half of normal values. Poor strength and small deflectability combined with near normal stiffness may be taken as evidence that Wolf's law is valid also in newly formed tissues of fracture healing; the protection given by a rigid nail makes normal strength and pliability unnecessary.

Osteolysis after Rigid Fixation

Rigid intramedullary fixation in the rat tibiofibular bone of a tibial fracture caused the development of nonunion in the associated fibular fracture, with marked osteolytic resorption of the fibular fragments. In contrast, with flexible fixation, the associated fibular fracture healed normally. The tibial fractures healed uneventfully in both cases. Histologic examinations showed that there exists a plexus of encapsulated nerve endings (Pacinian corpuscles) in the periosteum of the fibula, at the distal tibiofibular junction. The rat fibula forms a bony contact with the lower midshaft of the anteriorly curved tibia, acting as a supporting shaft. The periosteal neural mechanoreceptors probably sense the fibular loading when the tibia is bent during weight-bearing. Fibular resorption in rigid fixation could be attributed to the rigid intramedullary nail preventing tibial bending and loading of the receptor area. In other words the neural elements could detect the stress protection due to rigid fixation and coordinate the adverse remodeling process.

The effect of delayed internal fixation on fracture healing. An experimental study.

In the application of internal fixation to certain closed fractures the rationale for early surgery has long been accepted (Murray 1941), and the proper use of improved internal fixative devices, particularly those employing compression or rigid intramedullary nails, may result in a rapid return of function and very low rates of non-union. Nevertheless, there is now abundant clinical evidence that delayed internal fixation, performed after a waiting period, produces a significant drop in the overall incidence of non-union. This conclusion is based on the operative results of different surgeons working with differing fixative devices (Charnley 1961, Emery 1965, Lam 1964, Smith 1959, 1964, Borden & Smith 1952). The waiting period constitutes a time interval of one to three weeks after fracture; though some reports indicate a period longer than this. Published material allows no such conclusions in the case of compound fractures. Furthermore, there is clinical evidence that in the case of femoral shaft fractures, delayed internal fixation may be followed by an increase in callus formation (Charnley & Guindy 1961 ). The discovery that closed fractures heal more readily if operated upon “late” rather than “early” must mean that, after a delayed period, healing is rendered more efficient. This can only be due to effective callus, itself the result of local, or possibly remote, factors. Some consideration must also be given to variations in operative technique; for example, although procedures for internal fixation may often be more effective as a formal operation than as an emergeney measure, the broad scope of the clinical series does not support the