Custom ulna megaprosthesis use in revision total elbow replacement

Revision total elbow arthroplasty (TEA) is increasing as more primary TEAs are performed. Bone loss in the proximal ulnar can provide a complex challenge in the revision setting. Limited options are discussed in the literature, including use of impaction grafting, strut allograft, and allograft prosthetic composite. Custom ulna megaprosthesis (CUMP) is another viable option for this problem, but there remains a significant lack of evidence on its use in revision TEA for nontumor indications. We present our institution's experience with CUMP use in revision TEA for nontumor indications.

Records were reviewed for all patients who had undergone CUMP at our tertiary referral center. Variables collected included patient demographics, indication, number of previous surgeries, follow-up, range of movement, complications, Oxford Elbow Score, Pain, EuroQol-5 Dimensions (EQ-5D), and Single Assessment Numeric Evaluation (SANE) scores. Bone loss was graded using Mansat grading. Radiographic implant stability and integration scoring was approved by all authors. For completeness, patients were telephoned for outcome data when variables were missing.

The cohort comprised 15 elbows. The mean age was 67.6 years (range 54-78). The median follow-up for the cohort was 2 years (range 6 months-6 years). The mean number of prior surgeries was 3 (standard deviation [SD] 0.92). Indications for the revision TEA were 8 for infection, 4 for periprosthetic fracture, and 3 for aseptic loosening. Radiographic bone loss grading was as follows: type I, n = 3; type II, n = 7; type III, n = 5. Postoperative implant fixation assessment was as follows: type A, n = 5; type B, n = 6; type C, n = 4. The mean postoperative arc of movement was 118° (SD 18.31°). The cohort demonstrated improvements in the mean Oxford Elbow Score, SANE, EQ-5D, and their pain score. There have been 2 complications to date, with both patients having recurrent deep infection requiring a 2-stage revision to another CUMP. It was noted that in both cases the CUMP remained well fixed, and it was the humeral component that was loose.

The use of CUMP for revision TEA has evolved as a result of the challenges associated with alternative strategies for these patients. However, there is a lack of data in the literature regarding outcomes for CUMP. We report good early to mid-term clinical and radiographic outcomes. Complications are relatively low, and patient-reported outcomes are satisfactory. The use of CUMP offers a reliable solution in challenging revision TEA cases but requires careful planning.