Precise repair of small joint defect of hand with free second metatarsophalangeal joint tissue flap based on digital technology / 中华显微外科杂志

Objective:To explore the clinical effect of repairing interphalangeal joint defect of hand with free transfer of part of the 2nd metatarsophalangeal joint tissue flap precisely cut with the aid of digital 3D printing technology.Methods:From December 2016 to December 2020, 7 patients with partial joint defects of proximal interphalangeal joints of fingers were treated in Department of Hand and Foot Surgery, Shunde Hospital Affiliated to Guangzhou Medical University(Foshan Shunde Lecong Hospital). Before surgery, three-dimensional data of hand and foot bones were collected, and the 3D printing model was used to simulate the operation in vitro. During the operation, the first dorsal metatarsal artery-the 2nd dorsal metatarsal artery was used as the pedicle, and the 2nd metatarsophalangeal joint composite tissue flap with a required size was harvested with the assistance of the navigation template to tranfer and repair the small joint defects of hand. All 7 cases entered follow-up at outpatient and telephone. Results:All 7 cases survived. Postoperative follow-up was 3-24(mean 9.5) months, Range of motion of the repaired interphalangeal joint was (56 ± 6)°; According to the Evaluation Standard of Thumb and Finger Reconstruction Function of the Society of Hand Surgery of the Chinese Medical Association, 2 cases were excellent, 4 cases were good, and 1 case was poor.Conclusion:Transfer of the free 2nd metatarsophalangeal joint tissue flap assisted by 3D printing technology in repair of the small joint defect of the hand can accurately harvest the tissue flap, which is clinically reliable.

3D-printing in preoperative design of internal fixation for Sanders Ⅲ calcaneal fractures / 中华创伤骨科杂志

Objective To investigate the application of 3D-printing and digital technology in the preoperative design of internal fixation for intra-articular calcaneal fractures.Methods Thin-layer CT images of bilateral calcanei were collected from 12 patients who had been treated for calcaneal fracture of Sanders type Ⅲ from November 2015 to October 2016.They were 7 men and 5 women,aged from 23 to 53 years (average,38.7 years).The images were uploaded into Mimics software for 3D reconstruction,virtual reduction and digital surgical design.Real-size calcaneal models and navigation modules were produced using 3D printing technology for plate preshaping and surgical simulation.The operations were carried out according to preoperative design.The postoperative calcaneal morphological parameters were evaluated.Comparisons were made between postoperative results and preoperative digital design.Results The operating time for the 12 patients ranged from 60 to 90 minutes,averaging 77.9 minutes.Their follow-ups ranged from 4 to 8 months,averaging 6.2 months.No complications affecting their soft tissues happened.The postoperative B(o)hler angle (32.6° ± 3.6°) and Gissane angle (123.9° ± 9.5°) were significantly improved compared with the preoperative values (12.4° ± 2.1° and 143.9° ± 7.8°) (P ＜ 0.001).The shape of postoperative calcaneus was similar to that of the preoperative reduction model.The internal fixation locations and nail directions were in agreement with the preoperative design.Their average Maryland score was 87.8 and excellent to good rate 91.7％.Conclusion This technique can transform a digital design for intra-articular calcanealfracture into real operation tools to help realize a precise surgical design for such fractures.

3D-printing in preoperative design of internal fixation for Sanders Ⅲ calcaneal fractures / 中华创伤骨科杂志

Objective To investigate the application of 3D-printing and digital technology in the preoperative design of internal fixation for intra-articular calcaneal fractures.Methods Thin-layer CT images of bilateral calcanei were collected from 12 patients who had been treated for calcaneal fracture of Sanders type Ⅲ from November 2015 to October 2016.They were 7 men and 5 women,aged from 23 to 53 years (average,38.7 years).The images were uploaded into Mimics software for 3D reconstruction,virtual reduction and digital surgical design.Real-size calcaneal models and navigation modules were produced using 3D printing technology for plate preshaping and surgical simulation.The operations were carried out according to preoperative design.The postoperative calcaneal morphological parameters were evaluated.Comparisons were made between postoperative results and preoperative digital design.Results The operating time for the 12 patients ranged from 60 to 90 minutes,averaging 77.9 minutes.Their follow-ups ranged from 4 to 8 months,averaging 6.2 months.No complications affecting their soft tissues happened.The postoperative B(o)hler angle (32.6° ± 3.6°) and Gissane angle (123.9° ± 9.5°) were significantly improved compared with the preoperative values (12.4° ± 2.1° and 143.9° ± 7.8°) (P ＜ 0.001).The shape of postoperative calcaneus was similar to that of the preoperative reduction model.The internal fixation locations and nail directions were in agreement with the preoperative design.Their average Maryland score was 87.8 and excellent to good rate 91.7％.Conclusion This technique can transform a digital design for intra-articular calcanealfracture into real operation tools to help realize a precise surgical design for such fractures.

On the preparation and mechanical properties of PVA hydrogel bionic cartilage/bone composite artificial articular implants / 生物医学工程学杂志

In view of the problems that conventional artificial cartilages have no bioactivity and are prone to peel off in repeated uses as a result of insufficient strength to bond with subchondral bone, we have designed and prepared a novel kind of PVA-BG composite hydrogel as bionic artificial articular cartilage/bone composite implants. The effects of processes and conditions of preparation on the mechanical properties of implant were explored. In addition, the relationships between compression strain rate, BG content, PVA hydrogels thickness and compressive tangent modulus were also explicated. We also analyzed the effects of cancellous bone aperture, BG and PVA content on the shear strength of bonding interface of artificial articular cartilage with cancellous bone. Meanwhile, the bonding interface of artificial articular cartilage and cancellous bone was characterized by scanning electron microscopy. It was revealed that the compressive modulus of composite implants was correspondingly increased with the adding of BG content and the augments of PVA hydrogel thickness. The compressive modulus and bonding interface were both related to the apertures of cancellous bone. The compressive modulus of composite implants was 1.6-2.23 MPa and the shear strength of bonding interface was 0.63-1.21 MPa. These results demonstrated that the connection between artificial articular cartilage and cancellous bone was adequately firm.

Review of poly(vinyl alcohol) hydrogel and its compounds in the application of artificial cartilage materials / 生物医学工程学杂志

Poly(vinyl alcohol) (PVA) hydrogel is a kind of material which has excellent biocompatibility and mechanical properties. In this paper, the researches and developments of PVA hydrogel preparation and the modifications of PVA with other material were introduced. The potential for the use of PVA hydrogels as implant materials in cartilage reparation was reviewed.

Studies of poly(vinyl alcohol)/hydroxylapatite hydrogels compounds for cartilage implantation / 生物医学工程学杂志

The structures and properties of polyvinyl alcohol (PVA)/hydroxylapatite(HA) composites were investigated. The components and processing conditions were studied for preparation of optimum compound hydrogels with good lubricating feature and high bioactivity. The properties, such as stretch strength, compress strength, friction, compress stress relaxation of various compound hydrogels were compared. The micro-morphology of PVA hydrogels and PVA/HA hydrogels were investigated by use of SEM. It was found that the addition of HA could improve the lubricating feature and mechanical strength of hydrogels, and its compress stress relaxation properties were closer to those of natural cartilages.