Fractures of the distal femur in the elderly treated with a carbon fibre supracondylar plate

Fracture fixation in extremity trauma with carbon fiber-reinforced polyetheretherketone (CFR-PEEK) plates: evidence today

Purpose

To compare the CFR-PEEK plates with conventional plates in fracture fixation with regards to clinical and radiological outcomes and complications.

Methods

A systematic literature search was conducted in four online databases independently by two reviewers using the Cochrane methodology for systematic reviews. The identified relevant studies were assessed against predetermined inclusion/exclusion criteria. Independent data extraction and assessment of risk of bias and study quality was carried out.

Results

Nine studies (patient n = 361) out of 6594 records were included for analysis: 2 RCTs (n = 63), 3 prospective cohort studies (n = 151), and 4 retrospective cohort studies (n = 147). Studies were grouped per anatomic area of fixation. Four studies (n = 200) examined fixation of proximal humerus fractures. Two studies (n = 74) examined fixation of distal radius fractures. Two studies (n = 53) assessed outcomes of fixation of distal femur fractures. One study (n = 87) assessed the outcomes of fixation of ankle fractures. All nine studies reported very high union rates (from 91% in distal femur to 100% in upper limb) for the CFR-PEEK plate groups and low complication rates. There was no significant difference in clinical outcomes, and rate of complications as compared to the conventional plate groups.

Conclusion

CFR-PEEK plates have high union rates in extremity fracture fixation similar to conventional plates with comparable good clinical outcomes and a very low and comparable rate of complications. Considering their advantages, CFR-PEEK plates seem to be valid alternative to conventional plating.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00068-021-01778-x.

Biostable glass fibre-reinforced dimethacrylate-based composites as potential candidates for fracture fixation plates in toy-breed dogs: Mechanical testing and finite element analysis

In toy-breed dogs (bodyweight <5 kg), the fractures of the radius and ulna are particularly common and can be caused by minimal trauma. While fracture fixation using metallic plates is a feasible treatment modality, the excessive stiffness of these devices produces the underloading of the bone which may result in the adverse bone remodelling and complications in the healing of the fracture. In this study, we investigated bisphenol A glycidylmethacrylate -based glass fibre reinforced composites as potential alternatives to metals in the devices intended for the fracture fixation of the distal radius in toy-breed dogs. Four composites with different glass fibre reinforcements were prepared as rectangular specimens and as fracture fixation plates. These were mechanically tested in three-point and four-point bending. There were two controls: polyether etherketone reinforced with short carbon fibres (specimens and plates) and commercially available stainless-steel plates. Finite element simulations were used for the assessment of the behaviour of the plates. For the control stainless steel plate, the bending strength was 1.358 N*m, superior to that of any of the composite plates. The composite plate with the matrix reinforced with continuous unidirectional glass fibres had the bending strength of 1.081 N*m, which is sufficient in this clinical context. For the plates made of polyether etherketone reinforced with carbon fibres, the strength was 0.280 N*m. Similar conclusions on the biomechanical behaviour of the plates could be made solely based on the results of the finite element simulations, provided the geometries and the material properties are well defined.

PEEK biomaterials in trauma, orthopedic, and spinal implants

Since the 1980s, polyaryletherketones (PAEKs) have been increasingly employed as biomaterials for trauma, orthopedic, and spinal implants. We have synthesized the extensive polymer science literature as it relates to structure, mechanical properties, and chemical resistance of PAEK biomaterials. With this foundation, one can more readily appreciate why this family of polymers will be inherently strong, inert, and biocompatible. Due to its relative inertness, PEEK biomaterials are an attractive platform upon which to develop novel bioactive materials, and some steps have already been taken in that direction, with the blending of HA and TCP into sintered PEEK. However, to date, blended HA-PEEK composites have involved a trade-off in mechanical properties in exchange for their increased bioactivity. PEEK has had the greatest clinical impact in the field of spine implant design, and PEEK is now broadly accepted as a radiolucent alternative to metallic biomaterials in the spine community. For mature fields, such as total joint replacements and fracture fixation implants, radiolucency is an attractive but not necessarily critical material feature.

Principles of internal fixation and selection of implants for periprosthetic femoral fractures

Periprosthetic femoral fractures (PFF) are increasing as a result of changes in population demographics and the increase in the number of total hip replacements performed. The overall incidence has been reported to range from 0.1% to 6% of all total hip arthroplasties. Management of these fractures is often particularly demanding, complex and expensive. In many cases, the surgeon has to solve the simultaneous problems of implant loosening, bone loss and fracture. A thorough understanding of the unique characteristics of the different fracture types, the principles of PFF treatment and a familiarity with the various fixation devices, grafts and prosthetic implants are all of paramount importance. Internal fixation is used either alone or as an adjunct to stem revision. The stability of the original implant and the configuration of the fracture itself are the basic factors that influence the decision-making process. The current study reviews the existing literature on internal fixation of femoral periprosthetic fractures.

A mechanical study of gap motion in cadaveric femurs using short and long supracondylar nails

OBJECTIVE

To determine the relative stability achieved in unstable supracondylar femur fractures treated with long (36 cm) and short (20 cm) retrograde intramedullary nails using 1 or 2 proximal locking bolts. We hypothesized that longer nails would reduce fracture site motion compared with short nails and that 2 proximal locking bolts would improve stability compared with 1 proximal locking bolt.

DESIGN

Nine pairs of matched human cadaveric femurs were instrumented with 20-cm and 36-cm retrograde intramedullary nails (all 12-mm diameter, Biomet, Warsaw, IN) following reaming to 13 mm. Transverse supracondylar gap (6 mm) osteotomies were created. The femurs were mounted and cyclically tested separately in coronal plane bending and sagittal plane bending on a materials testing system. Fracture site translation was measured using a digital caliper in the respective plane.

SETTING

Orthopaedic biomaterials laboratory.

RESULTS

With 2 proximal locking bolts, average sagittal translation was 7.2 mm and 1.8 mm, respectively, for the 20-cm and 36-cm nails. Coronal translation was 6.3 mm and 4.3 mm, respectively. With a single proximal locking bolt, average sagittal translation was 7.6 mm and 2.2 mm, respectively, for the 20-cm and 36-cm nails. Coronal translation was 13.6 mm and 4.4 mm, respectively. A statistically significant difference in fracture site translation was found in each pairing by Student t test (P < 0.005), except coronal translation with 2 proximal locking bolts (P = 0.056). Free-body analysis predicts higher local stresses at the proximal interlocks of the shorter nail.

CONCLUSIONS

Longer nails provide improved initial fracture stability when compared with short retrograde nails for supracondylar femur fractures due to a more stable mechanical interaction between the femoral diaphysis and the nail. A second proximal locking bolt in the long nail provides no additional stability.

Carbon fibre plates in the treatment of femoral periprosthetic fractures

A retrospective review of fractures occurring around the femoral component of total hip replacements was performed using patient notes and X rays. Between 1996 and 2002, 12 patients with total hip replacement had fixation of their periprosthetic femoral shaft fracture with carbon fibre plates. The mean patient age was 76 years (range 57-94). With regard to fracture type (Johansson Classification), three were Type 2 and nine were Type 3. In 11 cases the average time to union was 4 months (range 3-6). There was one non-union leading to implant failure. This was subsequently treated with a revision arthroplasty. There were no other significant complications. Although designed to fit the supracondylar region of the femur, we had no difficulty in applying the plate over the trochanteric region. Our results indicate that carbon fibre plates are effective in the management of femoral periprosthetic fractures in the elderly and this may be related to the unique properties of the plate.

The use of a carbon fiber plate for periprosthetic supracondylar femoral fractures

Operative management of periprosthetic supracondylar femoral fractures in poor-quality bone presents a challenging task for the orthopaedic surgeon. We report our experience with the use of a semirigid carbon fiber-reinforced plate in the treatment of 5 patients, all of whom were elderly women with severe osteoporosis and highly restricted mobility. All 5 of the fractures were sustained after low-energy trauma at least 2 years after primary knee arthroplasty. Except for 1 patient who died of pulmonary embolism, all 4 surviving patients progressed uneventfully to fracture union with good mobility and no residual pain. The use of this method for the treatment of periprosthetic femoral fractures has not been reported previously, and we believe it provides a successful and technically undemanding solution to this difficult problem.

The fixation properties of carbon fiber-reinforced liquid crystalline polymer implant in bone: an experimental study in rabbits

A novel composite material with ultra-high strength and a low elastic modulus called carbon fiber-reinforced liquid crystalline polymer (LCP/CF) has been developed. We studied the fixation properties of an intramedullary LCP/CF rod in rabbit bone. The medullary canals of both femora were reamed with a drill 3.2 mm in diameter starting from the trochanteric fossa in eleven New Zealand White rabbits weighing on average 4.8 kg. A smooth LCP/CF rod 3.2 mm in diameter and 50 mm in length was introduced into the medullary canal of both femora. The follow-up intervals were 0, 6, 12, and 52 weeks. The upper part of the harvested femora was cut into two pieces, each 25 mm in length. A mechanical push-out test was performed within 48 h to determine bone-implant interface attachment strength in the proximal (cancellous) and distal (cortical) locations. The mean push-out strength values at 0, 6, 12, and 52 weeks were 61, 250, 382, and 612 KPa in the cancellous location and 0, 32, 41, and 68 KPa in the cortical location, respectively. The strength of the bone/implant interface appeared to be quite low, similar to other uncoated or nonporous implants, but it was found to increase with time.

The supracondylar intramedullary nail in elderly patients with distal femoral fractures

From February 1994 until July 1997, a prospective study of all elderly patients with a displaced distal femoral fracture, who were treated with an intramedullary supracondylar nail, was made. The outcome of 31 fractures in 30 elderly patients was studied. The average age was 82 years (55-98). Two-thirds of the patients had had previous ipsilateral femoral pathology. Average acute hospital stay was 17 days. All patients were reviewed at 6 months and all cases have been followed for over 1 year. More than 90% of surviving fractures had healed within 6 months of the operation. Outcome scores were; 22 (85%) excellent or satisfactory, 2 (7.5%) unsatisfactory and 2 (7.5%) failures. The mortality rate was 17% at 6 months and 30% at 1 year, which is similar to patients with a fractured neck of femur. This nail is recommended for its versatility and favourable outcome scores in this age group.

Fixation of distal femoral osteotomy with an intramedullary rod: early failure of carbon fibre composite implant in rabbits

A novel composite material with an ultra-high strength and a low elastic modulus, comprising a carbon fibre reinforced liquid crystalline polymer (LCP/CF) has been developed. An experimental osteotomy of the distal femur in nineteen rabbits weighing on average 4.8 (3.7-6.3) kg was fixed with an intramedullary LCP/CF rod of 3.2 mm in diameter and 50 mm in length. The initial mechanical properties of the rods had a mean shear strength of 180 MPa, a flexural strength of 450 MPa, and a flexural modulus of 40 GPa. The rods were implanted for periods of 3, 6, 12, 24, and 52 weeks. The healing of the osteotomy was analyzed by radiographic, histological, microradiographic, and oxytetracycline fluorescence studies. The strength retention of the LCP/CF rods was measured by mechanical testing. Solid union of the osteotomy was seen within 6 weeks. The implants retained their original strength properties up to 52 weeks. In three rabbits, a non-union with granulation tissue and carbon fibre particles was noticed at the osteotomy site, where disruption of the implant surface was seen at the level of the osteotomy. Further studies with a special interest in the fabrication process of the LCP/CF-implants are needed.