Development of Bioabsorbable Interference Screws: How Biomaterials Composition and Clinical and Retrieval Studies Influence the Innovative Screw Design and Manufacturing Processes - Biologically Responsive Biomaterials for Tissue Engineering - page 110

Table 6.1 Properties of some biod egradable polymers used in clinical practice

Elastic
modulus
(GPa)

Crystallinity
(%)

Degradation time
(month)

Elongation
(%) Polymer abbreviation and name T g (°C) Notes

PGA Polyglycolic acid 35°C 50% 3-6 months

50% strength lost
at 2 weeks
100% strength lost
at 4 weeks

7.0 15-20% - First used as biodegradable suture

(DEXON®)

- Strong, stiff

- Rapid degradation may be limiting

- Used for rods

PLLA Poly- L -lactic acid 58°C 40% >24 months (up to

60 months)

2.7 5-10% - Used for interference screw, suture anchor,

meniscus repair

- May be self-reinforced and combined with

biodegradable ceramic filler for improved
strength and improved bone growth

PDLLA Poly- D,L-lactic acid 55°C 0% 12-16 months 1.9 3-10% - As a homopolymer, generally used for drug

delivery due to low strength

LPLG Poly- L -lactic

acid-co-glycolic
acid

- 0% 5-6 months - - - 25-70% glycolic acid will disrupt the

crystallinity of PLLA

- Used for suture anchors, screws, and plates

DLPLG Poly- D,L -lactic

acid-co-glycolic
acid

85/15
~50°C
75/25
~50°C
50/50
~45°C

0% 1-5 months ~2.0 3-10% - Copolymer of 50/50 DL-lactic acid and lactic

acid

- Will decompose faster than either PGA or

PDLLA

- Not crystalline like PGA

- More hydrophilic than PDLLA

- Used for suture anchors, interference

screws, plates

PCL Polycapro-lactone −60°C <40% >24 month 0.4 300-500% - May be copolymerized with PGA to reduce

PGA's stiffness

- Used for sutures, pins

PDS (or
PDO)

Polydioxanone −10°C <40% 6-12 months 1.5 - - Used for fracture fi xation pins