About one-third of lower-limb amputees have problems with the socket connecting their residuum to a prosthetic limb. This has led to the development of osseointegrated implants, which consist of a press-fit intramedullary implant that protrudes through the skin to accommodate an abutment to which the prosthetic limb is rigidly attached.
Concerns about ascending infection and related complications with such constructs led Al Muderis et al. to conduct a multicenter prospective cohort study on the safety of osseointegrated implants, published in the June 1, 2016 JBJS. The authors found that mild infection and irritation of soft tissue were common, but that “these complications can be managed with simple measures,” such as outpatient antibiotic treatment.
Specifically, among the 86 patients with a transfemoral amputation and an implant who were followed for a median of 34 months:
- 31 had no complications
- 29 had one or more infections (all grade 1 or 2, four of which required surgical debridement)
- 26 had non-infectious complications (including hypergranulation of the stoma, soft-tissue redundancy, traumatic intertrochanteric fracture, and intramedullary implant breakage)
Smoking and female sex were associated with recurrent and more severe infections, prompting the authors to suggest that those patient characteristics could be “useful criteria for patient counseling and selection.”
In their commentary on the study, Paul Dougherty, MD and Douglas Smith, MD encourage continued research into bactericidal or mechanical barriers to microbial colonization in areas where the implant enters the body. Although no formal cost studies have been done on osseointegrated implants, the commentators reckon that such costs “are likely greater than those for conventional prosthetic management.”