Three-dimensional Capsular Volume Measurements in Multidirectional Shoulder Instability

BACKGROUND: In a previous study undertaken to quantify capsular volume in rotator cuff interval or axillary pouch, significant differences were found between controls and patients with instability. However, the results obtained were derived from two-dimensional cross sectional areas. In our study, we sought correlation between three-dimensional (3D) capsular volumes, as measured by magnetic resonance arthrography (MRA), and multidirectional instability (MDI) of the shoulder. METHODS: The MRAs of 21 patients with MDI of the shoulder and 16 control cases with no instability were retrospectively reviewed. Capsular areas determined by MRA were translated into 3D volumes using 3D software Mimics ver. 16 (Materilise, Leuven, Belgium), and glenoid surface area was measured in axial and coronal MRA views. Then, the ratio between capsular volume and glenoid surface area was calculated, and evaluated with control group. RESULTS: The ratio between 3D capsular volume and glenoid surface area was significantly increased in the MDI group (3.59 ± 0.83 cm³/cm²) compared to the control group (2.53 ± 0.62 cm³/cm²) (p < 0.01). CONCLUSIONS: From these results, we could support that capsular volume enlargement play an important role in MDI of the shoulder using volume measurement.

Comparison of Open and Arthroscopic Inferior Capsular Shifts for Multidirectional Instability of the Shoulder / 대한정형외과학회잡지

PURPOSE: To compare outcomes of open and arthroscopic inferior capsular shifts in multidirectional instability of the shoulder and to evaluate the factors affecting the outcomes. MATERIALS AND METHODS: We measured outcomes in 81 patients (84 shoulders) receiving open or arthroscopic inferior capsular shifts because of multidirectional instability of the shoulder from February, 1994, to April, 2006. There were 76 males and 8 females. Their mean age was 22 years at the time of surgery. The visual analogue scale (VAS) for pain, shoulder range of motion (ROM), and Rowe scores were evaluated preoperatively and postoperatively. RESULTS: In open surgery, the VAS for pain was 5.3 preoperatively and 2.1 postoperatively. VAS for instability changed from 4.6 to 1.7, and the average postoperative Rowe score was 83.7. Forward flexion was 173.7degrees preoperatively and 166.1degrees postoperatively. External rotation on the side changed from 75.5degrees to 62.7degrees. In arthroscopic surgery, the VAS for pain was 4.6 preoperatively and 1.2 postoperatively. VAS for instability changed from 5.9 to 1.2, and the average postoperative Rowe score was 87.4. Forward flexion was 169.5degrees preoperatively and 171.2degrees postoperatively. External rotation changed from 70.8degrees to 61.4degrees. CONCLUSION: Arthroscopic surgery was more effective in decreasing pain and conserving forward flexion of the shoulder than open surgery. Postoperative instability appeared to be related with generalized or bilateral shoulder joint laxity. Pain during motion after the operation was more significant during a voluntary subluxator. Low clinical scores were related with the operation on the dominant side or postoperative instability.

Neer's Inferior Capsular shift for Involuntary Inferior and Multidirectional Instability of the Shoulder / 대한정형외과학회잡지

Multidirectional shoulder instability is often difficult to diagnose and treat and can be cause of significant disability. Nonoperative rehabilitations and life tyle modifications are the primary treatments. Hiwever, the inferior capsular shift procedure, performed either from an anterior or posterior approach, as described by Neer and Foster, is recommended for symptomatic multidirectional instability that is unresponsive to nonoperative therapy. Twenty-seven shoulders in twenty-seven patients with inferior and multidirectional instability were managed with Neer s inferior capsular shift, through anterior or posterior approach depending on the direction in which the shoulder is most unstable. All of the patients were followed up for an average of 3 years (range one to seven years). The postoperative range of motion of the shoulders was well maintained except 1 patient. Three patients had recurrence of symptomatic and disabling multidirectional instability, but twenty-four (89%) of the shoulders continued to function well with no instability, no pain, no recurrence and no remarkable limitation of motion.