Since publication of the results of a first-generation intercalary humeral spacer, a newer design has been available that
addressed the weaknesses of the first. This study evaluated the hypothesis that the second-generation lap joint junction intercalary
humeral spacer reduced complications compared with the original male-female taper design. We retrospectively reviewed the
charts of 32 consecutive patients who had undergone placement of an intercalary humeral spacer. Twenty-one with the male-female
taper (minimum followup 0 months, mean 19.2 months) were compared with 11 with the lap joint configuration (minimum followup
0 months, mean 20.3 months). Demographic, tumor, treatment, and radiographic variables were similar between groups. We observed
a lower complication rate in the lap joint group (three of 11 versus 11 of 21). The most common complications in the male-female
group, neuropraxia, periprosthetic fracture, and disengagement, were not seen in the lap joint group. Aseptic loosening was
more frequent in the lap joint group. There were no differences in blood loss, operative time, or Musculoskeletal Tumor Society
scores between groups. We noted improvement in Musculoskeletal Tumor Society scores from preoperatively to postoperatively
in both groups. Use of these implants should be reserved for patients with limited life expectancy.
Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
Each author certifies that he or she has no commercial associations (eg, consultancies, stock ownership, equity interest,
patent/licensing arrangements, etc) that might pose a conflict of interest in connection with the submitted article.
Each author certifies that his or her institution has approved the human protocol for this investigation, and that all investigations
were conducted in conformity with ethical principles of research.