A new study describes the results of a systematic literature search of device-related complications in people with amputations who were treated with a bone-anchored prosthetic device. The researchers who conducted the study searched the MEDLINE, Cochrane, EMBASE, CINAHL, and Web of Science databases, and included studies that reported on device-related complications and interventions occurring in individuals with bone-anchored prostheses. The outcomes evaluated were death, infection, bone/device breakage, implant loosening, soft tissue complications, systemic events, and antibiotic and surgical treatment. Subgroup analyses were performed for the following groups: implant type (screw, press-fit and other types of implants) and level of amputation (above-knee, below-knee, and upper-limb).

Of 309 studies, 12 cohort studies were eligible for inclusion, all of which had methodological shortcomings, according to the study’s authors. The eligible articles described 537 individuals with a lower-limb amputation and 67 individuals with an upper-limb amputation, who were treated with bone-anchored prostheses in eight centers worldwide.

The research team found that implant infections were rare in certain above-knee implants (screw 2-11 percent, press-fit 0-3 percent, Compress 0 percent) but common in below-knee implants (29 percent). The same was observed for implant loosening in above-knee implants (screw 6 percent, press-fit 0-3 percent, Compress 0 percent), below-knee implants (29 percent), and upper-limb implants (13-23 percent).

Intramedullary device breakage was rare in above-knee implants (screw 0 percent, press-fit 1 percent, Compress unknown) but frequent in individuals with below-elbow implants (27 percent) and absent in below-knee implants. Soft tissue infections and complications were common and underreported in most articles, according to the authors.

Major complications (e.g. implant infection, implant loosening, and intramedullary device breakage) were rare in above-knee bone-anchored prosthesis and seemed to occur less frequently in individuals with press-fit implants. Minor complications, such as soft tissue infections and complications, are common but are substantially influenced by the learning curve for the treatment and adaptation of technique, implant design, and surgical technique.

The researchers noted that data for patients treated with a below-knee, upper-limb, or Compress implants are underreported, which precludes definitive conclusions. They suggest that there is a need for either an international database to report on complications or a standard core set of complications, as well as the need to follow classification systems that result in unequivocal data.

The open-access study was published August 9 in PLOS One.