Purpose: The aim of the study was to compare the clinical and radiographic results after arthroscopic Bankart reconstruction using 2 different types of absorbable implant.
Type of study: Randomized controlled trial.
Methods: A randomized series of 40 patients who had recurrent, unidirectional, post-traumatic shoulder instability were included in the study. All patients underwent an arthroscopic Bankart reconstruction involving either polygluconate co-polymer (PGACP group, n = 20) or self-reinforced poly-L-lactic acid polymer (PLLA group, n = 20) tack implants. The patients underwent clinical and radiographic assessments preoperatively and at 2 years. Additional radiographic assessments were performed at 6 months.
Results: Preoperatively, the study groups were comparable in terms of demographics as well as clinical parameters. One patient in each group had a redislocation (5%) during the follow-up period of 2 years. No subluxations were registered. No statistically significant differences were found between the study groups in terms of strength in abduction, range of motion, and Rowe or Constant scores. There was a significant increase in degenerative changes during the follow-up period in both study groups (P = .004). However, no significant differences in degenerative changes were registered between the study groups either preoperatively or at the 2-year follow-up. There were no significant differences in the radiographic visibility of the drill holes used for the absorbable implants between the study groups at the 6-month assessment. However, at the 2-year assessment, the radiographic visibility of the drill holes was significantly greater (P = .004) in the patients in the PLLA group than those in the PGACP group. At the 2-year assessment, no correlation was found between the appearance of the drill holes and the degenerative findings (PGACP group, rho = 0.44; PLLA group, rho = 0.42).
Conclusions: Two years after arthroscopic Bankart reconstruction using either PGA polymer or PLA polymer implants, the overall clinical results were comparable. Radiographic assessments revealed that the degenerative changes increased in both study groups during the follow-up period. Furthermore, the visibility of the drill holes on the 2-year radiographs was greater after using PLLA implants than after using PGACP implants.
Level of evidence: Level I.