Lajos Bartha1, László Hangody2, Novak Pal Kaposi3, András Vajda4

1Orthopedic Clinic of Semmelweis Medical School, Budapest Uzsoki Hospital, Budapest, Hungary
2Department of Orthopedics and Trauma, Budapest Uzsoki Hospital, Budapest, Hungary
3Musculoskeletal Diagnostic Centre at the National Institute of Rheumatology and Physiotherapy, Budapest, Hungary
4Orthopedic Clinic of Semmelweis Medical School, Budapest Uzsoki Hospital, Budapest, Hungary

Keywords: Biocompatible materials; cartilage, articular/surgery; extracellular matrix; polymers; tissue engineering.


Objectives: This prospective randomized study was designed to evaluate the safety and efficacy of polymer Polyactive B as a bone-graft substitute for filling up donor defects caused by removal of mosaicplasty grafts.
Patients and methods: The study included 10 patients (7 males, 3 females) who underwent mosaicplasty using 6.5-mm grafts. The donor sites of the grafts were filled up with 2 to 6 pieces (average 3.5 pieces) of Polyactive B cylinders, 7.5 mm in diameter. The control group consisted of 10 patients in whom the donor sites were left empty. Surgical interventions were performed either arthroscopically or by open exposure. All the patients had preoperative, 3- and 9-month clinical scores; preoperative, 7-day, and 3-month magnetic resonance imaging (MRI) scans. Control arthroscopy was performed in all Polyactive B-filled patients and in four control patients nine months postoperatively.
Results: No postoperative bleeding or other complications occurred. Clinical scores were similar in two groups. Magnetic resonance imaging showed congruent surfaces in all cases. In control arthroscopies, no signs of inflammatory reaction were seen. All surfaces of the filled donor areas were congruent, whereas mild protrusions were observed on the surfaces of the control areas. Macroscopically, the Polyactive B plugs were well integrated into the surroundings. Histological analysis showed proper subchondral ossification in each Polyactive-B case, and a large number of polymer fragments, suggesting partial biodegradation.
Conclusion: The absence of inflammation and evidence of mild foreign body reaction suggest that the Polyactive B is biocompatible and may be appropriate to fill up the donor areas.