The incidence of comminuted proximal femur fractures is increasing, due to the growing proportion of elderly people in the general population. Severely depleted cancellous bone in the femoral head and neck prevent stable proximal purchase, mandatory for intertrochanteric and subtrochanteric fractures. Osteoporotic bones are associated with high implant failure rates, evidenced by cutout and upward screw penetration of the hip joint.

A new method for femoral head fixation is described. The peg consists of a distal end that can expand in diameter from 7.8mm to 10.5mm by using pressurized saline, allowing good abutment into the femoral head. The peg may be connected to a side plate or an intramedullary device for inter or subtrochanteric fractures.

Materials and Methods: Ten femoral heads were retrieved from patients who underwent hip hemiarthroplasty due to subcapital fracture. The heads were covered with a transparent epoxy resin until full solidification was obtained. An 8mm drill-hole was used to drill from the distal femoral neck along the femoral head axis, not penetrating the subchondral bone and cartilage. Afterwards, 1.4mm drill was used to penetrate the cartilage and subchondral bone of the femoral head for insertion of a pressure gage. Intraosseous pressure measurements were then recorded. The peri-prosthetic bone density was evaluated by Dual Energy X-ray Absorptiometry (DEXA) and Microradiography Computer Analysis in two stages: 1) with the peg unexpanded, and 2) with the peg expanded. In addition, Instron 8871 tested axial load, pullout and rotatory strengths of the peg.

Results: Increased periprosthetic bone density following peg expansion was demonstrated on DEXA and microradiography with no increase in the intraosseous pressure. The friction coefficient of the bone implant interface, calculated by axial load measurements, was less than the coefficient of steel to steel. Pullout and rotatory strengths were as good as those reported for the Dynamic Hip Screw (DHS).

Conclusions: Bone stock preservation due to compression of the depleted cancellous bone (rather than removed bone by drilling) may improve the mechanical properties of the periprosthetic bone and the stability of the fixation. Due to the strong abutment of the peg, hardware failure, mainly bone cutout can be reduced. Due to its lower friction coefficient, the hip peg will begin to slide following axial load through the plate or the intramedullary device, rather than penetrating the femoral head.

Preliminary positive results indicate that this new method may be suitable for inter or subtrochanteric femoral fracture fixation.

Purpose of the Study: To determine the efficacy of using the Fixion Intramedullary Nail System – an inflatable, unreamed, self locking nail in humeral pathologic fracture stabilization. To our knowledge no clinical reports regarding this subject have been published.

Patients and Methods: The medical record and radiographs, of 14 patients treated with the “Fixion” Nail, since October 1999, for pathological or impending humeral fractures, were reviewed. Patients included 6 male and 8 female with mean age of 58.8 years (35–83). Skeletal survey or routine radiograms made diagnosis. Patients harboring tumors were evaluated with isotope bone scan. Loss of approximately 33% of the bone substance was the criteria for nailing procedure consideration. Nine acute pathological fractures and 5 impending fractures were treated. The fracture’s site distribution per distal, medial and proximal humeral shaft were as following: 1, 11, 2, accordingly. Nine patients were operated on via antegrade and 5 via retrograde.

All surgeries were minimally invasive using a single 2–4 cm skin incision.

Results: Excellent humeral anatomical reduction and stabilization were achieved in all patients. Reaming was needed in 4 patients (28.5%). No interlocking screws were used. Significant relief of pain and regained functionality were demonstrated. Average surgical time was 32.7 minutes (20–55). Mean X-Ray radiation time was 4.07 minutes (0.5–6.15). No wound dehisces or other complications were reported.

Conclusion: The unreamed in most of the cases, no interlocking screws, minimal invasiveness and high stabilization capacities in addition to perfect torsion resistance confer to this nail the ideal qualities to be used with excellent results in pathological fractures. Oncological patients that might be immunosuppressive due to different administered therapies could benefit from reduced postoperative infection rate because of minimizing entry point for infection.

Between the years 1999 and 2001, approximately 3000 expandable intramedullary nails were used worldwide in various surgical procedures. From this number, 250 of these nails were used for traumatic fractures and are the focus of the study presented here. The subjects consisted of 160 males and 90 females with a mean age of 41 years. Initial radiographs were obtained for all subjects. Additional X-rays and follow-up data were reported for only 75 patients (30%) with follow-up time averaging 18 weeks. Most of the fractures occurred in the midshaft (64%), followed by distal thirds (22%), and then proximal (14%). The group was then divided according to fracture location: humerus, tibial and femur.

The nail was used in 92 humerus fractures. Follow-up data was available for 35 patients with a follow-up time averaging 16 weeks. The nail was inserted retrograde in 61% of the patients and antigrade in 39% of the patients. Partial reaming was done in 42% of the cases. Mean operating time was 52 minutes and fluoroscopy time was 3.8 minutes. Anatomical reduction was achieved in 96% of the cases and in 4% of the cases, acceptable reduction was achieved with a varus < 10°. Surgical outcomes included 28 complete bone union, and 7 partial union. Eight nails were removed after complete union was achieved.

In addition, the inflatable nail was used for treatment of 114 tibial fractures. In 39% of the cases a partial reaming was done. Average operating time was 39 minutes and fluoroscopy time was 3.4 minutes. All the fractures were reduced anatomically. In 25 patients with mean follow-up of 18 weeks, 14 united completely and 11 united partially. Nine nails were removed after completion of the union.

Data on 44 patients with femoral fractures treated by the inflatable nail were also reported. Only 15 patients were available for follow-up with an average of 21 weeks follow-up time.

Nail insertion by the antegrade approach was used in 89% of the patients and the retrograde approach was used in 11% of the patients. Partial reaming was done in 44% of the cases.

Mean operating time was 60 minutes and fluoroscopy time 7.5 minutes. Anatomical reduction was achieved in all with the exception of two patients with mild valgus deformity (< 10°). By the end of the study period, 8 had complete union, 7 had partial union.

In summary, the nail was found to be very effective and safe. The surgeons who performed the surgery reported that surgical and fluoroscopy time were both reduced by half. Reaming was not mandatory and this contributed to the shortened operating time. No complications were encountered during extraction of all the nails after completion of union, even in those patients in whom the nail developed an hour glass configuration according to the size of the medullary canal.

It is still too early to conclude if this nail will produce better or equal results to the conventional interlocking nails. Nevertheless, the lack of reaming, locking, and the low contact area of the nail with the medullary canal, may explain the rapid healing observed in some cases.

We report our clinical experience with the first 54 cases of long bone fractures treated with the Fixion IM Nail. This innovative nailing system eliminates the need for interlocking screws and reaming of the medullary canal when the nailing of a long bone fracture is needed, offers a minimally invasive procedure for intramedullary nailing, and significantly reduces fluoroscopy exposure. Biomechanically, the nail assumes the hourglass shape of the medullary canal by its abutment to the medullary walls. The formation of a supporting forces entity, that could be defined as “the bone-nail supporting forces system entity,” becomes practically an integral part of the medullary walls at the points of attachment.

In order to avoid using interlocking screws and reaming of the medullary canal when the nailing of a long bone fracture is required, the “FIXION IMN” system was proposed.

Since March 1999 we have implanted 54 Fixion Intramedullary Nails for traumatic and pathological fractures in 50 patients with a mean age of 52 years (18 to 85). Among these patients, 33 had humeral fractures, 13 had tibial fractures, and 8 had femoral fractures; the pathological fracture cases consisted of 4 humeral cases and 1 femoral case. The Fixion IM Nail system consists essentially of four longitudinal bars connected radially by four thin membranes. The nail is sealed proximally with a unidirectional valve. During insertion, the nail is connected to a driver handle which assists with insertion and serves as a conduit for the saline during the expansion process. Inflation of the nail is by means of a pump that connects to the driver handle. Once in position, the nail is expanded by inflation under controlled pressure with saline. The expansion causes abutment of the longitudinal bars to the inner surface of the canal along the entire length, resulting in fixation of the fracture. The procedure is monitored fluoroscopically and clinically to ensure accurate reduction of the fracture.

The surgeries were uneventful. Postoperative complications were not reported in any of the cases. The nail was inserted easily and good fixation was achieved. The patients made a complete recovery with early pain-free mobilisation and full range of motion.