402 ABSTRACTS

tection to the vital structures during the procedure. Clear visualization of the undersurface of the trans- verse carpal ligament is absolutely necessary in or- der to perform the procedure safely.

The Buford Complex-The Loose Anterior Superior LabrumMiddle Glenohumeral Ligament Complex: An Anatomic Variant. Don Buford, Jr., Stephen J. Snyder, and Hank C. K. Wuh. Van Nuys, Califor- nia, U.S.A.

Two-hundred consecutive shoulder arthroscopies were reviewed. A thorough Wpoint examination of each shoulder was performed from the anterior and posterior portals. The preoperative symptoms and intraoperative findings were reviewed. Sixteen of the cases (8.0%) had the presence of the Buford Complex, defined as a thickened cordlike middle glenohumeral ligament directly attached to the an- terior superior labrum in the presence of a sublabral foramen. There were three females (19%) and 13 males (81%) in the group with the complex, and 41 females (22%) and 143 males (78%) in the group without the complex. In the group with the com- plex, 75% were right shoulders and 25% were left shoulders; in the group without the complex, 65% were right shoulders and 35% were left shoulders. There were no statistically significant differences between the groups in terms of sex or side of body. There was no statistically significant difference be- tween the group with or without the Buford Com- plex in terms of catching pain, instability, or im- pingement preoperatively. Patients with the Buford Complex had a significantly greater incidence of popping and cracking preoperatively. There was no statistically significant difference between the two groups in terms of associated intraoperative pathol- ogy, including labral tears, SLAP lesions, Hill- Sachs lesions, Bankart lesions, rotator cuff tears, synovitis, or biceps ruptures. None of the Buford Complex exhibited evidence of injury as manifested by scarring, fraying, synovitis, or residual tissue hemorrhage. All cases of the Buford Complex were left alone without surgical excision or repair. Ninety percent of the Buford Complex patients with popping and cracking preoperatively were symptom free at postoperative survey.

The Buford Complex is a distinct anatomic entity and is a variant of normal anatomy. The presence of a sublabral foramen associated with an anterior la- bra1 attachment to a thickened cordlike middle

Arthroscopy, Vol. 8, No. 3, 1992

glenohumeral ligament offers the impression of la- bra1 detachment and traction failure. However, no surgical treatment is indicated for the Buford Com- plex.

A Modified Classification of the Supraspinatus Outlet View Based on the Configuration and the Anatomic Thickness of the Acromion. Hank C. K. Wuh and Stephen J. Snyder. Van Nuys, California, U.S.A.

The supraspinatus outlet (arch) view of the shoul- der is an indispensable tool in the evaluation of pa- tients with shoulder pain and impingement. The classification established by Bigliani is excellent. However, it is based on the arch configuration and does not take into account the thickness of the acro- mion. The purpose of this study is to examine a large series of arch views and to offer a modified classification system based on the thickness of the acromion.

Two-hundred supraspinatus outlet views of the shoulder were examined. Age, sex, type of arch and the thickness of the acromion were noted. The acro- mion thickness is measured at the junction of the anterior to middle third of the acromion, correlating clinically to the area of subacromial decompression.

One-hundred thirty-one right shoulders and 69 left shoulders were measured. The patient age ranged from 15 to 88 years. There were 128 males and 72 females. The distribution of arch type was similar for males and females. There were 14 type I (ll%), 49 type II (38%), and 65 type III (51%) arches for males; there were nine Type I (13%), 28 type II (390/o), and 35 type III (48%) arches for fe- males. The acromion thickness ranged from 6 to 15 mm. Acromions <8 mm thick are defined as type A, 8-12 mm thick as type B, and >12 mm thick as type C. There were six type A acromion (4.6%), 112 type B acromion (87.5%), and 10 type C acromion (7.8%) for males. There were 20 type A acromion (28%), 5 1 type B acromion (70.8%), and 1 type C acromion (1.3%) for females. Of the female patients with type III arch configuration, four had a type A acromion (6%). Of the female patients with a type III arch configuration, 12 had a type A acromion (34%). The distribution of acromion thickness was equivalent for all age groups.

If a 5-mm decompression is performed on a type A acromion, only 3 mm of acromion will remain with increased risk of fracture. This is particularly important for females with a type III A acromion.