Measuring Outcomes: Pain and Quality of Life 48 Months After Acute Postoperative Total Knee Prosthetic Joint Infection.

BACKGROUND: Measuring HRQOL is simple, inexpensive, permits the health status to be measured over time, and is useful to compare or initiate treatments and evaluate results, facilitating homogenization in patient inclusion. OBJECTIVES: To evaluate disease-specific and generic HRQOL and influence of associated factors in patients undergoing open debridement for acute postsurgical knee prosthetic joint infection after TKR at 12 and 48 months after completing antibiotic treatment and considered cured of infection. METHODS: Health-related quality-of-life measures were administered at baseline (WOMAC) and 12 and 48 months (WOMAC and SF-36) in patients with prosthesis retention, no symptoms of infection, and CRP (≤ 1 mg/dL). RESULTS: Thirty patients were included, and 24 were evaluated at 48 months. WOMAC scores improved significantly (P < 0.01) at 12 and 48 months. The effect size was 0.72 for stiffness, 2.01 for pain, and 2.15 for function. At 48 months, improvements were greater (P < 0.02) except for stiffness. The most frequently isolated microorganisms were Staphylococcus aureus (14 patients) and coagulase-negative staphylococci (9 patients). SF-36 physical role, bodily pain, emotional role, and mental health dimension scores at 12 and 48 months were significantly worse in patients with isolates of Staphylococcus aureus (P < 0.05). CONCLUSIONS: Health-related quality-of-life measures detected significant differences in outcomes in patients infected by S. aureus compared with patients infected by other microorganisms. HRQOL measures may provide useful complementary information on outcomes after acute postoperative infection.

[Bone defects in revision knee arthroplasty: filling with bone allograft plus platelet-derived growth factors]. / Defectos óseos en artroplastia de revisión de rodilla tratados con aloinjerto óseo y plasma rico en plaquetas.

BACKGROUND: One of the most challenging aspects of a revision knee arthroplasty is the management of bone loss. The OBJECTIVE of the study is to show the capability to augment bone mineral density in areas with bone loss with platelet-derived growth factors. METHODS: Randomized, prospective, blinded study in patients who underwent a total knee replacement revision with tibial-damaged metaphyseal bone were randomly allocated to have a revision total knee arthroplasty and to fill the bone defects with lyophilized bone allograft mixed with platelet growth factors (experimental group, n= 9) or with lyophilized bone allograft alone (control group, n= 7). To evaluate bone mineral density between groups, dual-energy X-ray absorptiometry (DEXA) was performed preoperatively, at 1 month, 6 months and 1 year after surgery. RESULTS: The study was comprised of a total of 16 patients. We found no significant differences observed during the follow-up between groups in mineral bone density. CONCLUSIONS: Use of platelet-derived growth factors does not improve bone mineral density in patients with revision knee arthroplasty.

ANTECEDENTES: uno de los aspectos más desafiantes de la artroplastia de revisión de rodilla es el manejo de la pérdida ósea. OBJETIVO: demostrar la capacidad de incrementar la densidad mineral ósea en áreas con pérdida ósea, mediante el uso de plasma rico en plaquetas. MATERIAL Y MÉTODOS: estudio prospectivo, aleatorizado, cegado; efectuado con pacientes a quienes se realizó artroplastia de revisión de rodilla con pérdida ósea metafisiaria de tibia. Los pacientes se asignaron al azar a dos grupos para rellenar los defectos con aloinjerto óseo liofilizado con plasma rico en plaquetas (grupo experimental, n= 9), y otro grupo que sólo recibió el injerto óseo liofilizado (grupo control, n= 7). En ambos grupos la evaluación de la densidad mineral ósea se hizo con absorciometría de rayos X de energía dual (DXA) antes de la operación, al mes, seis meses, y un año después de la cirugía. RESULTADOS: se estudiaron 16 pacientes sin diferencias significativas entre ambos grupos en la densidad mineral ósea durante el periodo de seguimiento. CONCLUSIONES: el plasma rico en plaquetas no demostró incrementar la densidad mineral ósea en pacientes con defectos óseos por artroplastia de revisión de rodilla.

Acute infection in total knee arthroplasty: diagnosis and treatment.

Infection is one of the most serious complications after total knee arthroplasty (TKA). The current incidence of prosthetic knee infection is 1-3%, depending on the series(.) For treatment and control to be more cost effective, multidisciplinary groups made up of professionals from different specialities who can work together to eradicate these kinds of infections need to be assembled. About the microbiology, Staphylococcus aureus and coagulase-negative staphylococcus were among the most frequent microorganisms involved (74%). Anamnesis and clinical examination are of primary importance in order to determine whether the problem may point to a possible acute septic complication. The first diagnosis may then be supported by increased CRP and ESR levels. The surgical treatment for a chronic prosthetic knee infection has been perfectly defined and standardized, and consists in a two-stage implant revision process. In contrast, the treatment for acute prosthetic knee infection is currently under debate. Considering the different surgical techniques that already exist, surgical debridement with conservation of the prosthesis and polythene revision appears to be an attractive option for both surgeon and patient, as it is less aggressive than the two-stage revision process and has lower initial costs. The different results obtained from this technique, along with prognosis factors and conclusions to keep in mind when it is indicated for an acute prosthetic infection, whether post-operative or haematogenous, will be analysed by the authors.