Biomechanical analysis of the interval slide procedure: a fresh porcine cadaver study

INTRODUCTION

The interval slide procedure (IS) has been introduced to improve mobility in massive, retracted rotator cuff tears. As clinical studies showed controversial results, the benefit of the IS is still widely discussed.

AIM

Aim of this study was to analyze the effect of IS procedure on tendon mobility in a fresh porcine cadaver model.

MATERIALS AND METHODS

In 30 fresh porcine cadaver shoulders with artificial supraspinatus defect tendon mobility was tested by measuring the load (in N) during tendon reduction to the footprint at the greater tubercle using a sensor enhanced arthroscopic grasper (t1). In intervention group (N = 15) anterior IS (t2), posterior IS (t3) and intraarticular capsule release (t4) were successively performed, each followed by tendon mobility assessment. Tendon mobility of the control group (N = 15) was measured in same time schedule without intervention.

RESULTS

Mobility did not differ between groups for native tendons (CG 28.0 ± 11.2 N vs. IG 26.6 ± 11.6 N; P = 0.75). IS procedure significantly improves mobility at about 25.2% (t1 26.6 ± 11.6 N vs. t4 19.9 ± 12.3 N; P < 0.001) compared to the native tendon and 34.1% compared to CG (CG 30.2 ± 13.7 N vs. 19.9 ± 12.3 N; P = 0.026). In posthoc analyzes, anterior IS (P < 0.001) and capsule release (P = 0.005) significantly increased mobility, whereas the posterior IS did not (P = 0.778).

CONCLUSION

The IS procedure results in increased supraspinatus tendon mobility in fresh porcine cadaver shoulders. However, performing the posterior IS subsequent to the anterior IS no significant improvement of mobility has been observed.

Both arthroscopic and open posterior knee capsulotomy are effective in terms of extension recovery and functional improvement-systematic review

PURPOSE

To assess the recovery of extension and improvement in functional scores after an arthroscopic or open posterior knee capsulotomy in the setting of an extension deficit.

METHODS

A systematic search of articles published between 1980 and 2020 was performed in the MEDLINE/PubMed database, EMBASE/Ovid database and Web of Science database. The inclusion criteria consisted of patients with primary extension deficits > 5° who underwent an arthroscopic or open posterior knee capsulotomy. The assessed outcomes were preoperative and postoperative range of motion and functional outcome scores. Randomized controlled trials, cohort studies and case series with a follow-up longer than 6 months were included. The risk of bias was assessed using the Joanna Briggs Institute critical appraisal tool for case series. The certainty of evidence was assessed using the GRADE approach.

RESULTS

Of 226 records identified through database searching, 7 studies were included in the final analysis. The outcomes of 107 patients with a mean age of 34.1 (range 15-63) years were available. In all the included studies, a posterior capsulotomy resulted in the restoration of knee extension to normal or nearly normal values (mean postoperative extension deficit: 0.4-4.2 degrees) with a significant increase in functional outcome scores. No neurovascular complications were reported within the studies. Due to the diverse methodology of studies, the direct comparison of arthroscopic versus open approaches was not possible. Concerning the risk of bias assessment, the greatest concerns raised the selection of participants among the included studies and the methods of outcome measurement. The certainty of evidence was very low according to the GRADE.

CONCLUSIONS

Both arthroscopic and open posterior capsulotomy of the knee results in restoration of normal or nearly normal knee extension and significant improvement in functional outcomes.

LEVEL OF EVIDENCE

IV.