Pincer Procedure

Pincer impingement in the hip occurs when the acetabulum provides anterior overcoverage of the femoral head. The first step to resecting a pincer lesion is defining the margins by probing with a flexible instrument (Fig. 6A). As mentioned above, other clues to recognizing pincer impingement may include observing a bruised, flattened, degenerative, or cystic labrum [6]. After assess-

Fig. 6. Sequence for treatment of pincer-type impingement (A) A sclerotic bony overhang is observed arthroscopically in the region of the anterosuperior acetabular rim (A). L, labrum; FH, femoral head. (B) An arthroscopic osteotome resects small portions of the anterosuperior acetabular rim (A) until a majority of the lesion is removed. L, labrum. (C) A motorized burr completes the resection by reshaping the acetabulum (A) into its normal contour. L, labrum. (D) The labrum is reattached to the anterosuperior acetabular rim using suture anchor repair.

Fig. 6. Sequence for treatment of pincer-type impingement (A) A sclerotic bony overhang is observed arthroscopically in the region of the anterosuperior acetabular rim (A). L, labrum; FH, femoral head. (B) An arthroscopic osteotome resects small portions of the anterosuperior acetabular rim (A) until a majority of the lesion is removed. L, labrum. (C) A motorized burr completes the resection by reshaping the acetabulum (A) into its normal contour. L, labrum. (D) The labrum is reattached to the anterosuperior acetabular rim using suture anchor repair.

ing the lesion, three different surgical options may be pursued depending on the size of the lesion. If the overhang is slight and the labral attachment is intact, it may be possible to perform a cam-type procedure to create more clearance on the femoral side. However, medium to large pincer lesions require resection of the acetabulum to avoid excessive bony resection at the distal femoral neck and potential injury to the lateral epiphyseal vessels.

After the margins of a pincer lesion have been recognized, a motorized shaver is used to clear all soft tissue from the overhanging acetabulum and to define the plane between the labrum and the acetabular rim. If the lesion is moderately sized, a motorized burr is inserted into the anterior portal and the overhang is carefully resected in a "rim trimming" procedure. If the lesion is large, an arthroscopic osteotome may be used through the anterior portal to carefully separate the anterosuperior labrum from its insertion on the pincer lesion. The osteotome is then placed on the anterosuperior acetabulum and small portions of the rim are resected until a majority of the lesion has been removed (Fig. 6B). The motorized burr then completes the resection by reshaping the acetabulum (Fig. 6C). A maximum of approximately 5 mm of acetabular rim should be removed. It is critical to avoid overresection of the rim to prevent future instability in the patient. In all resections of the acetabular rim, microfracture of the subchondral bone should be performed until punctate bleeding is achieved. If detached during the pincer procedure, the labrum should be reattached to the superior acetabular rim with suture anchors [22,23] (Fig. 6D).

Following resection of the pincer impingement, it is important to slide the arthroscope into the peripheral compartment through the anterior portal to visualize the head-neck junction. Mixed cam-pincer impingement disorders are a very common finding [2] and for best postoperative outcomes, it may be necessary to surgically address both pathologies.

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