Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus.

The purpose of this multicenter study was to analyze the results of shoulder arthroplasty for the treatment of the sequelae of proximal humerus fractures and establish an updated classification system and treatment guidelines for these complex situations. Seventy-one sequelae of proximal humerus fractures were treated with shoulder replacement with the use of the same nonconstrained, modular, and adaptable prosthesis: the Aequalis prosthesis (Tornier Inc, St Ismier, France). The average time between initial fracture and shoulder arthroplasty was 5 years and 5 months. On the basis of anatomic classification schemes, sequelae were divided into 4 types: type 1, humeral head collapse or necrosis with minimal tuberosity malunion (40 cases); type 2, locked dislocations or fracture-dislocations (9 cases); type 3, nonunions of the surgical neck (6 cases); and type 4, severe malunions of the tuberosities (16 cases). The mean postoperative follow-up was 19 months (range, 12 to 48 months). Overall, the postoperative Constant score was excellent in 11 cases (16%), good in 19 cases (26%), fair in 18 cases (25%), and poor in 23 cases (33%). There were 18 complications (27%). Fifty-nine of 70 patients (81%) stated that they were satisfied with the result. The most significant factor affecting functional outcome was greater tuberosity osteotomy (P <.005). Regarding both surgical treatment and postoperative prognosis, we identify 2 categories of proximal humerus fracture sequelae: category 1, intracapsular/impacted fractures sequelae (associated with both cephalic collapse or necrosis [type 1] and chronic dislocation or fracture-dislocation [type 2]), in which an articulating joint can be reconstructed without a greater tuberosity osteotomy; and category 2, extracapsular/disimpacted fractures sequelae (associated with both surgical neck nonunions [type 3] and severe tuberosity malunions [type 4]) where the proximal humerus cannot be reconstructed without a greater tuberosity osteotomy. All of the excellent and good postoperative Constant scores were obtained in type 1 and 2, in which osteotomy of the greater tuberosity was not required. All patients in type 3 and 4, who underwent a greater tuberosity osteotomy, had either fair or poor results and did not regain active elevation above 90 degrees. We conclude that a greater tuberosity osteotomy is the most likely reason for poor and unpredictable results after shoulder replacement arthroplasty for the treatment of the complex sequelae of proximal humerus fractures. Shoulder arthroplasty for the treatment of the sequelae of fractures of the proximal humerus should be performed without an osteotomy of the greater tuberosity when possible. If prosthetic replacement is possible without an osteotomy, surgeons should accept the distorted anatomy of the proximal humerus and adapt the prosthesis and their technique to the modified anatomy. A modular and adaptable prosthesis with both adjustable offsets and inclination may allow surgeons to adapt to a large number of malunions and may help to avoid the troublesome greater tuberosity osteotomy in a higher proportion of cases.