Tissue restoration after resorption of polyglycolide and poly-laevo-lactic acid screws

• Published in: Journal of bone and joint surgery. British volume Vol. 87; no. 11; pp. 1575 - 1580
• Main Authors: BÖSTMAN, O. M, LAITINEN, O. M, TYNNINEN, O, SALMINEN, S. T, PIHLAJAMÄKI, H. K
• Format: Journal Article
• Language: English
• Published: London British Editorial Society of Bone and Joint Surgery 01.11.2005; British Editorial Society of Bone & Joint Surgery
• Edition: British volume
• Subjects: Absorbable Implants; Adipose Tissue - pathology; Animals; Biocompatible Materials; Biological and medical sciences; Bone and Bones - pathology; Bone Regeneration; Bone Screws; Connective Tissue - pathology; Diseases of the osteoarticular system; Female; Fracture Fixation, Internal - instrumentation; Fracture Fixation, Internal - methods; Hematopoiesis; Internal Fixators; Lactic Acid - analogs & derivatives; Lactic Acid - chemistry; Male; Medical sciences; Orthopedic surgery; Polyglycolic Acid - chemistry; Polymers - chemistry; Postoperative Period; Rabbits; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Resorption; Orthopedic surgery; Treatment; Lactic acid; Restoration; Screw
• ISSN: 0301-620X; 2049-4394; 2044-5377; 2049-4408
• DOI: 10.1302/0301-620X.87B11.16520

Despite worldwide clinical use of bio-absorbable devices for internal fixation in orthopaedic surgery, the degradation behaviour and tissue replacement of these implants are not fully understood. In a long-term experimental study, we have determined the patterns of tissue restoration 36 and 54 months after implantation of polyglycolic acid and poly-laevo-lactic acid screws in the distal femur of the rabbit. After 36 months in the polyglycolic acid group the specimens showed no remaining polymer and loose connective tissue occupied 80% of the screw track. Tissue restoration remained poor at 54 months, the amounts of trabecular bone and haematopoietic elements being significantly lower than those in the intact control group. The amount of trabecular bone within the screw track at 54 months in the polyglycolic acid group was less than in the empty drill holes (p = 0.04). In the poly-laevo-lactic acid group, polymeric material was present in abundance after 54 months, occupying 60% of the cross-section of the core area of the screw track. When using absorbable internal fixation implants we should recognise that the degradation of the devices will probably not be accompanied by the restoration of normal trabecular bone.