Effect of arthroscopic techniques on joint volume in shoulder instability: Bankart repair versus capsular shift

Abstract

Purpose The evaluation of glenohumeral joint volume in both unstable (with/without laxity) and stable shoulders (subacromial impingement) and volume reduction potential of arthroscopic techniques: (labral anchor repair vs. capsular shift). Methods Material was based on 133 patients: anterior shoulder instability without laxity (group I, n = 49), with laxity (group II, n = 22) and subacromial impingement (control group, n = 62) operated in 2010-2011. Group I received arthroscopic Bankart repair, group; II -arthroscopic anterior capsular plication, control group -subacromial decompression. Joint volume was measured by fluid aspiration into the syringe via arthroscope, before and after procedure. Then volume reduction potential was calculated. Results The following average values of initial joint volume were recorded: group I -26.8 ml group II -43.7 ml and the control group -25.6 ml with significant differences: impingement vs. instability + laxity (p < 0.00001), impingement vs. instability without laxity (p = 0.0001). There was no significant difference between groups I and II. Joint volume was significantly reduced after labral repair (by average of 37 %, 13.8 ml, p < 0.0001). Capsular shift led to an even greater and more significant volume decrease (61 %, 26.7 ml, p < 0.001). Joint volume in the control group was reduced only by 11 %, 3.8 ml (p = 0.046).Conclusions Patients with unstable shoulders have enlarged joint volume as compared to patients with subacromial impingement. Arthroscopic techniques lead to a significant joint volume reduction, with the most powerful effect for capsular shift. Level of Evidence -Level 2.

Arthroscopic Bankart repair with an individualized capsular shift restores physiological capsular volume in patients with anterior shoulder instability

“…Both imaging studies and surgical in vivo studies found pathological capsular enlargements of unstable shoulder joints [ 9 , 10 , 14 , 21 ]. Dewing et al [ 9 ] demonstrated an increased cross-sectional area of the capsule in patients with posterior or multidirectional instability versus controls, as measured by magnetic resonance arthrography [ 9 ].…”

“…This 1.5-mL difference was added to the post-interventional joint volume measurements. A pilot study by Lubiatkowski et al showed that in vivo intraoperative measurement of the shoulder joint volume is a very reliable method with high intraclass correlation coefficients (ICCs), which range from 0.996 to 0.997 [ 21 ].…”

“…A priori power analysis revealed that 28 patients would be needed in each group (instability and control) to detect a volumetric difference of 4.0 mL (± 5.0 mL) at a significance level of P = 0.05 with a power of 90%. According to Lubiatkowski et al [ 21 ], 7 patients per subgroup would be required to detect a volumetric difference of 4.0 mL (± 10.0 mL) between hyperlax and non-hyperlax patients.…”

“…Only one in vivo study has investigated the effect of arthroscopic shoulder stabilization on capsular volume reduction intraoperatively. Lubiatkowski et al found significant capsular volume reduction after labral repair (by an average of 37%) and an even higher capsular volume reduction after capsular plication (by an average of 61%) [ 21 ]. However, this study only analysed and compared labral repair and capsular plication as isolated procedures.…”

Arthroscopic Bankart repair: A matched cohort comparison of the modified Mason Allen method and the simple stitch method

“…Thus, restoring labral tissue height and shifting of the redundant capsule from the anteroinferior direction should be the final result. 13 Recently, the modified Mason Allen stitch has come into favor and has been theorized to be superior to the simple stitch technique. 9 , 14 , 15 The concept of combining capsular shift and arthroscopic Bankart repair (ABR) with the modified Mason Allen stitch technique has been challenged.…”