Incorporation of an Allogenic Cortical Bone Graft Following Arthrodesis of the First Metatarsophalangeal Joint in a Patient with Hallux Rigidus

Abstract

Hallux rigidus is degenerative arthritis of the first metatarsophalangeal joint characterized by pain and stiffness in the joint with limitation of motion and functional impairment. Recently, bone grafts have been introduced in orthopedic procedures, namely osteosynthesis and arthrodesis. Allografts can induce bone formation, provide support for vascular and bone ingrowth and have a low risk of immunological rejection. A 52-year-old female patient with hallux rigidus underwent arthrodesis of the first metatarsophalangeal joint using Shark Screw® made of allogenic cortical bone. Corrective surgery was performed after 10 weeks, and a 5 × 3 mm large part of the Shark Screw® with the surrounding patient's bone was removed. A histological evaluation revealed a vascularized graft with the newly formed compact lamellar bone fitting exactly to the cortical graft. The bone surface was lined by plump osteoblasts with osteoid production, and osteocytes were present in the lacunae. The arthrodesis of the first metatarsophalangeal joint using an allogenic cortical bone graft results in fast, primary bone healing without immunological rejection. This case suggests that the cortical allograft is a good and safe treatment option with an excellent graft incorporation into the host bone. However, as the literature evaluating the histology of different bone grafts is scarce, further high-level evidence studies with adequate sample sizes are needed to confirm our findings.

Keywords: allogenic; arthrodesis; cortical bone graft; hallux rigidus; screw.

Conflict of interest statement

Eva Pastl and Klaus Pastl are shareholders of Surgebright GmbH, the manufacturer of Shark Screw® transplants. All other authors declare no conflicts of interest relevant to this work.

Figures

Figure 1

Initial and follow-up imaging findings on anterior-posterior (AP) and latero-lateral (LL) projections. (A,B) Radiograph of the right foot shows osteoarthritis of the 1. metatarsophalangeal joint of the great toe with small bone spurs and a joint space narrowing corresponding to Hallux rigidus. (C,D) Control radiography directly following arthrodesis of the 1st metatarsophalangeal joint of the great toe with two vertically oriented screws extending from the metatarsal head to the base of the proximal phalanx. (E,F) Postoperative radiography 10 weeks following arthrodesis of the 1st metatarsophalangeal joint of the great toe after the second correcting operation (a valgus osteotomy of the first metatarsus after Chevron). Initial bridging of the joint space medially is demonstrated. In addition, an adaptation of the position of the metatarsus with a shortening of the proximal part of the medial screw in the metatarsal head (red circle) and a newly introduced third screw in the distal metadiaphysis of the 1. metatarsal. Inset shows 5 × 3 × 3-mm-large part of the Shark Screw® with the surrounding patient’s bone removed during the reoperation, containing the protruding shaft of the metatarsal bone.

Figure 2

Histological findings highlighted in green and red color. (A) Low power of the whole specimen. The yellow rectangle shows the host-graft interface. (B) A higher view of the host-cortical graft interface marked with a yellow rectangle in A. (Toluidine blue stain). Color legend - Green: cortical graft composed of lamellar bone, the lamellae run from left to right. Red: newly formed bone fitting exactly to the cortical graft surface, the lamellae run tangential to the graft. Blue: host bone.

Figure 3

Histological (toluidine blue stain) and ultrastructural findings. (A) Newly formed vessels within the Haversian canals of the screw. (B–D) Osteoclastic activity (B) at the host-graft interface and (C,D) within the screw. (E,F) Scanning electron microscopy shows osteoclasts shown in (C,D) (rectangles) in the resorption lacunae of the graft.

Figure 4

Histological (toluidine blue stain) and ultrastructural findings. (A,B) The host-graft interface shows a new bone formation fitting exactly to the cortical graft. The bone surface is lined with plump osteoblasts (red rectangle), and osteocytes (black rectangle) are present in the lacunae. Scanning electron microscopy shows (C) osteoblasts at the bone surface and (D) one osteocyte in the lacunae.

Figure 5

Imaging findings on anterior-posterior (AP) and latero-lateral (LL) projections after reoperation. (A,B) The control radiography six weeks after reoperation shows the unchanged position of all three screws. (C,D) On follow-up, 13 months after the operation, the control radiograph shows a complete remodeling of the screws accompanied by a bony proliferation in the joint space resulting in the complete fusion of the 1st metatarsophalangeal joint.