Brachioradialis tendon transfer and palmaris longus tendon graft for thumb avulsion:A case report and review of literature

BACKGROUND Thumb replantation following complete traumatic avulsion requires complex techniques to restore function,especially in cases of avulsion at the level of the metacarpophalangeal joint(MCP I)and avulsion of the flexor pollicis longus(FPL)at the musculotendinous junction.Possible treatments include direct tendon suture or tendon transfer,most commonly from the ring finger.To optimize function and avoid donor finger complications,we performed thumb replantation with flexion restoration using brachioradialis(BR)tendon transfer with palmaris longus(PL)tendon graft.CASE SUMMARY A 20-year-old left-handed male was admitted for a complete traumatic left thumb amputation following an accident while sliding from the top of a handrail.The patient presented with skin and bone avulsion at the MCP I,avulsion of the FPL tendon at the musculotendinous junction(zone 5),avulsion of the extensor pollicis longus tendon(zone T3),and avulsion of the thumb’s collateral arteries and nerves.The patient was treated with two stage thumb repair.The first intervention consisted of thumb replantation with MCP I arthrodesis,resection of avulsed FPL tendon and implantation of a silicone tendon prosthesis.The second intervention consisted of PL tendon graft and BR tendon transfer.Follow-up at 10 months showed good outcomes with active interphalangeal flexion of 70°,grip strength of 45 kg,key pinch strength of 15 kg and two-point discrimination threshold of 4 mm.CONCLUSION Flexion restoration after complete thumb amputation with FPL avulsion at the musculotendinous junction can be achieved using BR tendon transfer with PL tendon graft.

Degradability of absorbable sutures in tendon grafts following anterior cruciate ligament reconstruction

Objective To observe the degradability of absorbable sutures in tendon grafts and the histology of tendon healing in a rabbit model.Methods Semitendinosus tendons were harvested from 15 healthy adult New Zealand rabbits in this study.

Novel hybrid biocomposites for tendon grafts:The addition of silk to polydioxanone and poly(lactide-co-caprolactone)enhances material properties,in vitro and in vivo biocompatibility

Biopolymers play a critical role as scaffolds used in tendon and ligament(TL)regeneration.Although advanced biopolymer materials have been proposed with optimised mechanical properties,biocompatibility,degradation,and processability,it is still challenging to find the right balance between these properties.Here,we aim to develop novel hybrid biocomposites based on poly(p-dioxanone)(PDO),poly(lactide-co-caprolactone)(LCL)and silk to produce high-performance grafts suitable for TL tissue repair.Biocomposites containing 1-15%of silk were studied through a range of characterisation techniques.We then explored biocompatibility through in vitro and in vivo studies using a mouse model.We found that adding up to 5%silk increases the tensile properties,degradation rate and miscibility between PDO and LCL phases without agglomeration of silk inside the composites.Furthermore,addition of silk increases surface roughness and hydrophilicity.In vitro experiments show that the silk improved attachment of tendon-derived stem cells and proliferation over 72 h,while in vivo studies indicate that the silk can reduce the expression of pro-inflammatory cytokines after six weeks of implantation.Finally,we selected a promising biocomposite and created a prototype TL graft based on extruded fibres.We found that the tensile properties of both individual fibres and braided grafts could be suitable for anterior cruciate ligament(ACL)repair applications.