[Glenoid reconstruction in revision shoulder arthroplasty].

OBJECTIVE

The aim of the surgical technique is the stable fixation of a glenoid baseplate and reconstruction of bone loss with correction of version, inclination, and medialization of the joint line.

INDICATIONS

Significant glenoid bone loss due to glenoid loosening or wear in revision shoulder arthroplasty.

CONTRAINDICATIONS

Active infection, inoperability due to poor health condition.

SURGICAL TECHNIQUE

Reconstruction of advanced glenoid bone stock in case of glenoid loosening of total shoulder arthroplasty can be performed either with autografts and allografts or metallic augmentation together with reverse baseplates in a one- or two-stage procedure. The preferred fixation mode was a transfixation technique using autograft and baseplates with extra-long coated or threaded post with 2-4 locking screws. Baseplates with an extended post and locking screws adjustable in various inclination are required to achieve fixation along the "3-column concept" which is used by the authors based on a recently introduced classification algorithm, which is based on the remaining bone stock available for fixation of the post in native bone stock.

POSTOPERATIVE MANAGEMENT

The standard protocol with an abduction brace for 6 weeks and passive exercises is modified, depending on the extent of reconstruction on the humeral and glenoid side, and the type of implant.

RESULTS

In all, 145 cases of revision total shoulder arthroplasty suffering from moderate or advanced bone loss were retrospectively evaluated and 95 followed up for a mean of 2.7 years (range 1-7 years). We classified the remaining bone stock as grade 4 or 5 in 61 patients and grade 2 and 3 in 84 patients. Our preferred surgical technique was cementless fixation of structural bone grafts using a reverse baseplate in transfixation technique. In all, 56 cases required substantial iliac crest bone grafts, of which 36 patients were operated on in a 2-stage procedure. In 20 patients the bone defect in the iliac crest was secured by a locking plate in order to avoid a fatigue fracture of the anterior iliac spine. Only in 5 cases with intact rotator cuff was an anatomical "platform" component used; the remaining cases were converted to reverse shoulder arthroplasty. A success rate of more than 90% for both one- and two-stage reconstructions, which is mainly related to the high rate of incorporation of autografts taken from the iliac crest, is comparable to the majority of data published in the literature.