Custom Ulna Megaprosthesis use in revision total elbow replacement.

Abstract

Revision total elbow arthroplasty (rTEA) is increasing as more primary TEA 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 non-tumor indications. We present our institution's experience with custom ulna megaprosthesis use for revision TEA for non-tumor 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, EQ5D and SANE scores. Bone loss was graded using Mansat's grading. Radiographic implant stability and integration scoring was agreed 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 (SD 0.92). Indications for the rTEA were 8 for infection, 4 for periprosthetic fracture and 3 for aseptic loosening. Radiographic bone loss grading: Type 1- 3, Type 2- 7, Type 3- 5. Postoperative implant fixation assessment: Type A- 5 Type B- 6, Type C-4. The mean postoperative arc of movement was 118 degrees (SD 18.31). The cohort demonstrated improvements in the mean Oxford elbow score, SANE, EQ5D and their pain score. There have been two complications to date, with both patients having recurrent deep infection requiring a two-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 rTEA has evolved due to 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 rTEA cases but requires careful planning.