Deep infection in tumor endoprosthesis around the knee: a multi-institutional study by the Japanese musculoskeletal oncology group.
BACKGROUND
The incidence of endoprosthesis failure has been well studied, but few studies have described the clinical characteristics of deep infection in tumor prostheses. This study aimed to analyze the characteristics of deep infection in tumor endoprostheses around the knee.


METHODS
We analyzed clinical data of 57 patients with deep infections involving tumor endoprostheses around the knee enrolled from the Japanese Musculoskeletal Oncology Group. Profile of clinical presentation including time between surgery and infection, initial symptoms/blood tests and microbial cultures was evaluated. In addition pre-, intra-, and postoperative clinical factors influencing clinical presentation and treatment outcomes of infections were analyzed.


RESULTS
Mean interval between the initial operation and diagnosis was 13 months, and mean time required for infection control was 12 months. The most common pathogen was Staphylococcus. Infection control rates were significantly higher when prostheses were removed rather than salvaged. Ten-year prosthesis survival and limb salvage rates were 41.6% and 75.6%, respectively. Analysis of underlying clinical factors suggested that soft-tissue condition significantly influenced the duration of the infection control period and likelihood of limb salvage.


CONCLUSIONS
Infection control is a prolonged process. Deep infection frequently results in amputation or prosthesis loss. Intensive analysis of clinical characteristics may aid infection control.
Department of Orthopaedic Surgery, Kyorin University, 6-20-2, Shinkawa, Mitaka, Tokyo 181-8611, Japan. t-morii@gb3.so-net.ne.jp
Takeshi
T
Morii
Hideo
H
Morioka
Takafumi
T
Ueda
Nobuhito
N
Araki
Nobuyuki
N
Hashimoto
Akira
A
Kawai
Kazuo
K
Mochizuki
Shoichi
S
Ichimura
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000671:Amputation, Surgical; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000295:instrumentation*; D001859:Bone Neoplasms / Q000473:pathology / Q000601:surgery*; D002648:Child; D020878:Device Removal; D005260:Female; D006801:Humans; D017053:Infection Control; D007564:Japan; D053208:Kaplan-Meier Estimate; D007720:Knee Prosthesis / Q000009:adverse effects*; D023821:Limb Salvage; D008297:Male; D008875:Middle Aged; D016459:Prosthesis-Related Infections / Q000175:diagnosis / Q000382:microbiology* / Q000628:therapy; D012086:Reoperation; D012189:Retrospective Studies; D012307:Risk Factors; D013203:Staphylococcal Infections / Q000175:diagnosis / Q000382:microbiology* / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome; D055815:Young Adult