Implant Design and Its Applications in the Fixation of Osteoporotic Bones: Newer Technologies in Nails, Plates and External Fixators

Abstract

Background: Osteoporosis, characterised by decreased bone mass and degradation of bone tissue, poses a major global health concern, particularly for the ageing population. The traditional fixation techniques often fail in osteoporotic bones due to their diminished density and strength. Technological advancements in orthopaedic implants, specifically nails, plates, and external fixators, have emerged to address these challenges.

Materials and methods: Improvements in implant design focus on material properties, surface modifications, and geometric advancements. Titanium and its alloys are favoured for their biomechanical properties such as lower elastic modulus and high strength-to-weight ratio. The biodegradable materials like polylactic acid and magnesium alloys offer the advantage of gradual resorption as bone heals. Surface modifications, such as coatings with bioactive materials and drug-eluting surfaces, promote osseointegration and enhance fixation strength.

Results and discussion: Intramedullary (IM) nails have evolved to enhance stability and minimise complications associated with osteoporotic fractures. Third and fourth-generation nails incorporate surface treatments for better integration and healing. The advances in screw design, locking mechanisms, and flexible axial stimulation have improved fixation and allowed micromotion, which promotes fracture healing. The use of external fixators, particularly for complex fractures in osteoporotic bones, offers less invasive treatment options with adaptable stiffness for improved healing.

Conclusion: Technological innovations in implant materials, design, and surgical techniques have significantly improved the management of osteoporotic fractures. Newer technologies, including 3D printing, virtual and augmented reality, and artificial intelligence, show promise in enhancing implant customization, surgical planning, and postoperative outcomes. However, further clinical validation and research are needed to expand their clinical applications.

Keywords: Implant designs; Newer technology; Osteoporosis; Recent advances.

Fig. 1

Newer implants from AO: A 10-degree-angled retrograde femoral nail (RFN-A) showing better reduction and clearance from total knee prosthesis by virtue of the increased angle. B VA Locking attachment plate

Fig. 2

Newer implants from the AO Group. A Active plate—the screw hole is placed in a suspended sliding element (SSE) seen in part {a Front view and b profile view} which is mobile within the slot. B Proximal portion of a flexible axial stimulation (FAST) IM tibial nail—a showing the dynamisation slot with bushing and insert. b The mobile insert shown in relation to nail c the Insert along with its bushing shown separately. C Angular Stable Locking System (ASLS)

Fig. 3

Newer implants from the AO Group. A Biphasic plate distal femur, B Patella Plates. a Standard, b  Standard with legs (6 hole plate), C VA-LCP Distal Fibula Plate, D VA LCP Condylar distal femoral plate. VA Variable Angle, LCP Locking Compression Plate

Fig. 4

Elastic self-locking nails (Reproduced from Putame et al. [24]. This is an open access article distributed under the terms of Creative Commons Attribution Licence (CC BY))

Fig. 5

A Proximal femoral bionic nail (PFBN), B Proximal femoral nail – Anti-rotation (PFN-A)

Fig. 6

A Percutaneous Compression Plating (PCCP) (Reproduced from Guo et al. [31]). B The Medoff plate with twin hook. (Reproduced from Paulsson et al. [32]). C Dynamic Locking Blade Plate (Reproduced from Van Walsum et al. [33]). (All the above Images Reproduced from published articles. Copyright The Author (s), Open Access. The articles are open access articles distributed under the terms and conditions of the Creative Commons Attribution License which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. The original figures were slightly modified and collaged into one figure.)

Fig. 7

Representational figures showing different augmentation methodologies in the fixation of osteoporotic proximal humerus fracture. a Cement augmentation b Medial buttress plating c Bone graft

Fig. 8

Use of just unic intramedullary device for osteoporotic proximal humerus fracture

Fig. 9

Use of external fixator in distal femur fracture in the elderly. A Preoperative image, B Radiograph after application of fixator, C Clinical photograph with the fixator