Biomechanical Testing of Scapular Spine Autograft for Anterior Glenoid Bone Augmentation.

Background: Augmentation of anterior glenoid defects with bone graft can improve shoulder stability and reduce the risk of redislocation. Several characteristics of the scapular spine may make it a suitable harvest site, avoiding the disadvantages associated with other glenoid augmentation procedures. Purpose: To evaluate the capacity of scapular spine autograft to restore the stabilizing joint-reaction forces of the shoulder in simulated scenarios of bony anterior shoulder instability. Study Design: Controlled laboratory study. Methods: We obtained 6 matched pairs of fresh-frozen cadaveric shoulders. Skin, subcutaneous tissues, and non-rotator cuff muscles were removed from the specimens, leaving intact the rotator cuff musculature and shoulder capsule. A customized testing device was used to translate the humerus 1 cm anteriorly on the glenoid under 25 N of axial compression force. The peak joint-reaction force of the glenohumeral joint was then measured under 3 conditions: (1) specimen with intact glenoid, (2) specimen after a bone defect measuring 25% of the maximal width of the glenoid was made in the anteroinferior glenoid, and (3) specimen after size-matched glenoid augmentation with a scapular spine tricortical autograft. The primary outcome was the change in peak joint-reaction forces between the defect state and augmented state. Results: One matched pair was removed from final analysis secondary to anatomic concerns that undermined the accuracy of test results. Among the 10 remaining specimens, all showed a significant decrease in peak joint-reaction force after the glenoid defect was created compared with the intact state (P < .001). All remaining specimens showed an increase in peak joint-reaction force in the augmented state compared with the defect state (P < .001). On average, the augmented state restored 81% of the peak reaction force of the glenohumeral joint compared with the intact state, a nonsignificant difference (P = .07). Conclusion: The study findings indicated that autograft harvested from the scapular spine increased the bony restraint to anterior shoulder dislocation in shoulders with glenoid bone loss. Clinical Relevance: The scapular spine is an alternative for bony augmentation of glenoid defects in shoulder instability.

Scapular Spine Dimensions and Suitability as a Glenoid Bone Graft Donor Site.

BACKGROUND: Current structural bone graft options used for glenoid augmentation in glenohumeral instability have known drawbacks. The scapular spine may be a possible alternative graft choice, but its dimensions and anatomy are not fully reported. HYPOTHESIS: The scapular spine's harvestable graft dimensions will be similar to harvestable dimensions of the coracoid and iliac crest. STUDY DESIGN: Descriptive laboratory study. METHODS: The scapular spine, coracoid, and iliac crest dimensions were recorded and compared bilaterally in 50 patients with 3-dimensional computed tomography imaging. The portion of the scapular spine with the largest harvestable dimensions was quantified and its location defined. Measurements were independently taken by 2 investigators and averaged for the final result. RESULTS: The scapular spine has 81.5 mm of harvestable length and a "flare" located approximately 49.6 mm lateral to the medial scapular border, where the widest harvestable cross section is located (mean harvestable dimensions: 10.9-mm height, 11.5-mm width). Mean coracoid dimensions were 24-mm length, 14.2-mm height, and 10.6-mm width. Mean iliac crest width was 14.7 mm. In sum, 96% of scapular spines, 85% of coracoids, and 100% of iliac crests exceeded minimum dimensions of 8 mm × 8 mm × 20 mm. The coronal radius of curvature of the glenoid was significantly different from the corresponding plane of all measured structures. CONCLUSION/CLINICAL RELEVANCE: The scapular spine has dimensions similar to the coracoid and iliac crest in the majority of patients and is therefore appropriate for further investigation as a potential graft choice in glenohumeral instability. A harvest location 49.6 mm lateral to the medial scapular border will provide the largest cross-sectional graft while avoiding the acromial base.

Preoperative Antibiotics in Wrist Arthroscopy.

PURPOSE: This study seeks to evaluate the need for preoperative antibiotics for wrist arthroscopy. METHODS: A retrospective review of 576 consecutive wrist arthroscopies was performed over a 10-year period at a single ambulatory surgery center. The chart of each included patient was reviewed for postoperative infections following the National Nosocomial Infections Surveillance criteria for diagnosis. RESULTS: Of the 576 wrist arthroscopies reviewed, 324 met the inclusion criteria. Preoperative antibiotics were administered in 209 cases (65%) and not administered in 115 cases (35%). There were 116 cases (36%) with concomitant open soft tissue procedures. We identified 2 infections (0.6% overall infection rate), both of which were in patients who had received preoperative antibiotics. Both of these patients underwent concomitant percutaneous pinning of carpal bones with Kirschner wires, which were buried beneath the skin. CONCLUSIONS: Administering preoperative antibiotics for routine wrist arthroscopy does not appear to lower the surgical site infection rate. The rate of surgical site infection is so low in both cohorts that a meaningful difference cannot be determined between the 2 groups. This study adds to the current body of literature suggesting that it is acceptable practice to withhold preoperative antibiotics for surgeries that have a very low rate of infection. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.