This study is a retrospective review of 21 patients with 22 elbows that were treated for aseptic failure of a total elbow replacement with proximal ulnar bone deficiency with allograft bone struts. There were 17 women and 4 men with an average age at the time of ulnar reconstruction of 57 years (range, 37 to 79 years). The original implant had been in situ for an average of 6.7 years (range, 18 months to 11 years). The primary diagnosis included rheumatoid arthritis with bone destruction in 10 elbows, juvenile rheumatoid arthritis in 3 elbows and the sequelae of trauma in 9 including posttraumatic arthritis (7), posttraumatic ankylosis and non-union (1), and multiple failed attempts at open reduction and internal fixation (1). Eight patients were on chronic steroid use, 2 patients had osteoporosis and 1 had non-insulin dependent diabetes mellitus. Predominant symptom at presentation was pain in 21 elbows whereas 1 patient had chronic instability. Six patients had weakness of elbow extension and 4 patients had an irritable ulnar nerve located in the cubital tunnel. There were 7 different prosthesis retrieved in these 22 elbows. Seventeen components exhibited aseptic loosening, 1 ulna revealed substantial proximal bone loss and 1 elbow sustained a periprosthetic fracture. The primary indication for re-implantation in this series was aseptic failure with the primary indication for allograft strut reconstruction being proximal granulomatous erosion around the stem in 14 elbows, cortical deficiency with fracture in 7, incompetence of olecranon with erosion in 3, aseptic loosening with expanded proximal part of the elbow in 2, impending fracture of the ulna component tip in 1 and olecranon incompetence with fracture in 1. Twelve elbows required revision of both the humeral and ulnar components. There were 4 proximal ulnar bone deficiency lesions treated with strut grafts including a discrete cortical defect contained with the strut graft, periprosthetic fracture with an osteolytic lesion splinted with the graft, deficient olecranon with utilization of strut graft to provide triceps attachment and improve the lever arm, and expanded proximal ulna treated impaction grafting and augmented with a strut graft.
At a mean of 4 years (range, 2 to 11 years) the average Elbow Performance Score (MEPS) improved from 34 points (range, 15 to 55 points) to 79 points (range, 30 to 100 points). Only 1 patient had a lower functional level at the final review than prior to the revision. The pain scores improved from an average of 9 points (range, 0 to 30 points) to an average of 32 points (range, 15 to 45 points). Seven patients were completely pain free, 4 patients had continued moderate pain and 10 had mild pain. The average score for activities of daily living improved from 8 points (range, 0 to 20 points) to 21 points (range, 5 to 25 points). The flexion arc improved 17 degrees (range, 5 to 20 degrees) in flexion and 18 degrees improvement (range, 5 degrees to 20 degrees improvement) in extension. Eight (36%) of the 22 elbows underwent additional surgery, 2 ulnar components loosened following index revision surgery at 3 and 6 years. One patient, a prison inmate, sustained a periprosthetic fracture at the tip of the ulnar stem in a fall 2 years after the reconstruction. Range of motion did not significantly change following reconstruction. Three patients had incorporation of 26 to 50% of the graft, 5 had 51 to 75 % incorporation and 14 patients had 76 to 100% of graft incorporation. Overall, strut allografts failed to successfully reconstruct the olecranon at triceps insertion site.
Although this article does not compare treatment options for failed total elbow arthroplasties with aseptic loosening or periprosthetic fracture of the ulna, it does outline potential expected results with the use of strut allografts. The authors acknowledge that their preference in this clinical scenario is to restore bone stock with the allograft with reimplantation of a standard prosthesis as opposed to the replacement of a deficient segment of host tissue and loose implant with a custom-made device that replaces deficiency. In addition, this article well illustrates the potential for uses of strut allografts and proximal ulnar deficiencies following revision total elbow arthroplasties. The advantage of structural bone grafts include increased strength to a normally-compromised construct and also they restore bone mass. The authors report that the strut grafts failed to reconstruct bone loss in the olecranon area with no success in 3 patients.
Proximal Ulnar Reconstruction With Strut Allograft In Revision Total Elbow Arthroplasty