Late foreign-body reaction after treatment of distal radial fractures with poly-L-lactic acid bioabsorbable implants: a report of three cases

The Effect of Diclofenac Sodium-Loaded PLGA Rods on Bone Healing and Inflammation: A Histological and Histomorphometric Study in the Femur of Rats

Implants made of poly(lactide-co-glycolide) (PLGA) are biodegradable and frequently provoke foreign body reactions (FBR) in the host tissue. In order to modulate the inflammatory response of the host tissue, PLGA implants can be loaded with anti-inflammatory drugs. The aim of this study was to analyze the impact of PLGA 80/20 rods loaded with the diclofenac sodium (DS) on local tissue reactions in the femur of rats. Special emphasis was put on bone regeneration and the presence of multinucleated giant cells (MGCs) associated with FBR. PLGA 80/20 alone and PLGA 80/20 combined with DS was extruded into rods. PLGA rods loaded with DS (PLGA+DS) were implanted into the femora of 18 rats. Eighteen control rats received unloaded PLGA rods. The follow-up period was of 3, 6 and 12 weeks. Each group comprised of six rats. Peri-implant tissue reactions were histologically and histomorphometrically evaluated. The implantation of PLGA and PLGA+DS8 rods induced the formation of a layer of newly formed bone islands parallel to the contour of the implants. PLGA+DS rods tended to reduce the presence of multi-nucleated giant cells (MGCs) at the implant surface. Although it is known that the systemic administration of DS is associated with compromised bone healing, the local release of DS via PLGA rods did not have negative effects on bone regeneration in the femora of rats throughout 12 weeks.

P2 porous titanium implants improve tendon healing in an acute rat supraspinatus repair model

BACKGROUND

Current techniques in rotator cuff repair often lack structural integrity. P² porous titanium-coated constructs (DJO Surgical, Austin, TX, USA) promote osseointegration and soft tissue ingrowth. This study examined the ability of this material to improve the structural integrity of supraspinatus tendon repair in a rat model. We hypothesized that P² implants placed at the tendon-to-bone interface would improve mechanical and histologic measures of supraspinatus healing.

METHODS

Forty rats underwent supraspinatus repairs with P² implants in 1 shoulder and standard repair in the other. Rats were humanely killed at time 0 (n = 3), 2 weeks (n = 8), 4 weeks (n = 15), and 12 weeks (n = 14). Tendon-to-bone composite specimens were harvested and evaluated mechanically and histologically.

RESULTS

Tendon cross-sectional area was decreased in the P² implant group at 4 weeks, percentage of relaxation was increased at 2 weeks, elastic modulus was increased at 4 weeks, and maximum load and maximum stress were both increased at 2 and 4 weeks. Histologic analysis revealed no foreign body reactions within or around the P² implant, and healthy viable bone was visible within the P² implant.

CONCLUSION

The results support our hypothesis, specifically in early healing, in this randomized controlled animal study. These data support the use of P² porous titanium implants to improve tendon-to-bone healing.

Transosseous suturing of patellar fractures with braided polyester - a prospective cohort with a matched historical control study

BACKGROUND

Although tension-band wiring is the most widely used technique to fix patellar fractures, metal implant-related complications including implant failure and postoperative pain are very common and additional procedures are often necessary to treat the complications. The purpose of this study is to evaluate a totally metal-free technique using a transosseous suturing method and to compare it with the traditional fixation technique.

METHOD

A total of 25 patients (mean age of 59.60 years) with displaced patellar fractures treated by a transosseous suturing technique were compared with a 1:1 matched historical control group that underwent modified tension-band-wire fixation. Union time, union rate, operation time, number of procedures, mean hospitalisation days and complications were compared between cases and controls.

RESULTS

Union time (8.43 ± 2.92 vs. 8.64 ± 2.82 weeks) and operation time (69.00 ± 19.31 vs. 64.89 ± 14.27 min) were not different between the two groups. Mean hospitalisation days (4.04 ± 1.40 vs. 5.76 ± 1.50 days; P<0.001), number of procedures and the frequency of complications were significantly lower in the transosseous suturing group.

CONCLUSION

The transosseous suturing technique is safe and effective in the transverse or comminuted fractures of the patella. The complication rate is significantly lower than with the tension-band-wiring technique.