A Biomechanical, Cadaveric Evaluation of Single- Versus Double-Row Repair Techniques on Stability of Bony Bankart Lesions

Abstract

Background: Previous studies comparing stability between single- and double-row arthroscopic bony Bankart repair techniques focused only on the measurements of tensile forces on the bony fragment without re-creating a more physiologic testing environment. Purpose: To compare dynamic stability and displacement between single- and double-row arthroscopic repair techniques for acute bony Bankart lesions in a concavity-compression cadaveric model simulating physiologic conditions. Study Design: Controlled laboratory study. Methods: Testing was performed on 13 matched pairs of cadaveric glenoids with simulated bony Bankart fractures with a defect width of 25% of the inferior glenoid diameter. Half of the fractures were repaired with a double-row technique, and the contralateral glenoids were repaired with a single-row technique. To determine dynamic biomechanical stability and ultimate step-off of the repairs, a 150-N load and 2000 cycles of internal-external rotation at 1 Hz were applied to specimens to simulate early rehabilitation. Toggle was quantified throughout cycling with a coordinate measuring machine. Three-dimensional spatial measurements were calculated. After cyclic loading, the fracture displacement was measured. Results: The bony Bankart fragment–glenoid initial step-off was found to be significantly greater ( P < .001) for the single-row technique (mean, 896 µm; SD, 282 µm) compared with the double-row technique (mean, 436 µm; SD, 313 µm). The motion toggle was found to be significantly greater ( P = .017) for the single-row technique (mean, 994 µm; SD, 711 µm) compared with the double-row technique (mean, 408 µm; SD, 384 µm). The ultimate interface displacement was found to be significantly greater ( P = .029) for the single-row technique (mean, 1265 µm; SD, 606 µm) compared with the double-row technique (mean, 795 µm; SD, 398 µm). Conclusion: Using a concavity-compression glenohumeral cadaveric model, we found that the double-row arthroscopic fixation technique for bony Bankart repair resulted in superior stability and decreased displacement during simulated rehabilitation when compared with the single-row repair technique. Clinical Relevance: The findings from this study may help guide surgical decision-making by demonstrating superior biomechanical properties (improved initial step-off, motion toggle, and interface displacement) of the double-row bony Bankart repair technique when compared with single-row fixation. The double-row repair construct demonstrated increased stability of the bony Bankart fragment, which may improve bony Bankart healing.

Arthroscopic Bankart repair with additional footprint fixation using the double-row technique at the 4 o'clock position anatomically restored the capsulolabral complex and showed good clinical results

“…Conversely, some authors have reported that Bankart repair using a double-row repair technique is reliably efective for shoulder instability [11][12][13][14]. Cadaveric studies have shown that double-row capsulolabral repair might restore normal anatomy more efectively than single-row repair [15,16].…”

Glenoid concavity has a higher impact on shoulder stability than the size of a bony defect

“…Small defects can be treated well with an arthroscopic Bankart repair, whereas significant bone defects lead to a recurrence rate of up to 67% when treated with a soft tissue reconstruction alone [3]. A bone loss of 20–25% relative to the glenoid extent of the short axis, hereinafter referred to as defect width, is a widely accepted threshold at which bony reconstruction is preferred over soft tissue Bankart repair [6, 8, 16, 29]. However, current studies and clinical outcomes recommend lower thresholds to indicate subcritical or minor bone loss [11, 24, 25, 30].…”

The Independent Double-Row (IDR) Bony Bankart Repair Technique

“…Millett et al introduced their "bony Bankart bridge" technique in 2009, which allows a double-point fixation of the bony fragment to elude the drawbacks of a single-point fixation [16], and reported durable clinical improvement in clinical outcomes and high return-to-sport rate at a minimum 5-year follow-up [23]. Biomechanical studies were able to demonstrate an improved fracture reduction and stability of the bony fragment using a doublerow bridge reconstruction compared to single row [19,20,21]. In addition, a variety of further double-row reconstruction techniques have been described in the literature [12,14,24].…”

“…However, it has been our experience that with this technique, it is difficult to maintain fragment reduction, as the medial support is lacking and the fragment tends to invert, thus creating a step-off in the articular surface. Although arthroscopic linked double-row fixation allows for better fracture reduction and stability compared to single-row fixation methods [19,20,21], these techniques are increasingly complex and rely on permanent sutures passing over the articular surface of the fractured fragment, which may cause degeneration of the articular cartilage over time. The purpose of this report was to introduce an arthroscopic independent doublerow (IDR) bony Bankart repair technique for fixation of large glenoid fractures (▶ Fig.…”