A review of 71 cases of infected total knee arthroplasty: mid-term to long-term follow-up

Departamentul de Chirurgie Ortopedică și Reabilitare, Universitatea Tech din Texas, Centrul de Știinţe ale Sănătaţii, Școala de Medicină Paul L. Foster, El Paso, Texas, Statele Unite ale Americii, Departamentul de Chirurgie Ortopedică, Spitalul General Buffalo, Universitatea de Stat din New York, Buffalo, New York, Statele Unite ale Americii, Departamentul de Chirurgie Ortopedică a Universităţii Harvard, Spitalul General Massachusetts, Boston, Statele Unite ale AmericiiIntroducere. În cadrul acestui studiu au fost evaluate caracteristici și rezultate la termen mediu și lung ale cazurilor de artroplastie totală de genunchi (ATG) și ale infecţiilor asociate cu acestea, care au fost tratate prin diferite metode. Material și metode. Studiul retrospectiv reflectă rezultatele a 71 de cazuri de ATG, infectate și tratate în perioada august 1993 – august 2005. Datele colectate includ înregistrări medicale cu privire la sexe, clasificarea infecţiilor periprotetice (IPP), comorbiditatea pacienţilor, criteriile de diagnostic ale IPP, rezultatele microbiologice și histopatologice, tratamentele chirurgicale și antimicrobiene, modalitaţile de tratament, complicaţiile, consecinţele, precum și rezultatele tratamentului. Nivelul de evidenţă: nivel terapeutic III. Rezultate. Vârsta medie a pacienţilor a constituit 70 de ani (extreme, 43–88 de ani). Mediana duratei de supraveghere – 10,8 ani (extreme, 5 – 20 de ani). Treizeci și trei (46,5%) de pacienţi au prezentat multipli factori de risc pentru IPP. Principalii patogeni izolaţi au fost stafilococii coagulazo-negativi – 26 (37%), Staphylococcus aureus – 16 (22,4%). Metodele de tratament ale ATG infectate au fost: înlocuirea în două etape – 59 (83%) de cazuri, debridare și retenţie – 5 (7,2%) cazuri, artrodeza – 5 (7,2%) cazuri, excizie-artroplastie – 2 (2,8%) cazuri. La sfârșitul perioadei de supraveghere, 17 genunchi (24%) au suportat intervenţie repetată, dintre care 10 (14%) – îndepărtarea componentelor din cauza reinfectării. Doi genunchi s-au reinfectat de 3 ori, trei genunchi – de două ori. Prima reintervenţie după reinfectare a fost efectuată după 1,2 ani (mediana), cu extreme cuprinse între 0,04 și 2,5 ani. Analiza curbelor Kaplan-Meier „de supravieţuire” a constatat că la 5 ani fără reintervenţie au ajuns 90,5% (95% CI între 85,3% și 96,1%) dintre pacienţi, iar la 10 ani – 82% (95% CI între 70,3% și 94,5%). Scorurile Asociaţiei Genunchiului (engl. Knee Society score): scorurile de durere, scorurile funcţionale, amplituda mișcării (engl. range of motion, ROM) – îmbunătăţite. Concluzii. Tratamentul ATG infectate este o sarcină dificilă, cu rezultate nesatisfăcătoare la termen mediu și lung. Aproximativ fiecare al patrulea pacient a necesitat o reintervenţie, iar 14% dintre pacienţi s-au reinfectat în primii 2,5 ani. Jumă- tate dintre pacienţii cu reinfecţie a ATG s-au reinfectat din nou. În majoritatea cazurilor, pacienţii s-au reinfectat cu același microorganism, dar mai virulent. Tratamentul unei ATG infectate ar putea fi ales în funcţie de tipul de infecţie (acută sau cronică), durata ei, stabilitatea implantului, specia agentului patogen, calitatea și integritatea osului și ţesutului moale.Introduction. In the present study, the characteristics and mid-term to long-term outcomes of total knee arthroplasty (TKA) associated infections treated with different types of approaches were evaluated. Material and methods. A retrospective study of the results of 71 infected TKA treated between August 1993 and August 2005. The data included medical records, gender, periprosthetic infection (PPI) classification, patients’ comorbidities, PPI diagnostic criteria, microbiology and histopathology results, surgical and antimicrobial therapy, treatment modality, complications, follow up, and treatment results. Level of Evidence: Therapeutic Level III. Results. Median age was 70 years (range, 43–88). Median follow-up 10.8 years (range, 5–20). Thirty-three patients had multiple risk-factors for PPI. The main pathogens isolated were Coagulase-negative staphylococci 26 (37%), Staphylococcus aureus 16 (22.4%). The treatment methods of TKA infection were two-stage exchange in 59 (83%), debridement and retention – 5 (7.2%), arthrodesis – 5 (7.2%), excision arthroplasty 2 (2.8%). At final follow up, 17 knees (24%) had required reoperation: 10 knees (14%) – component removal for reinfection. Two knees were reinfected 3 times, three knees – two times. The median time to first reoperation for reinfection was 1.2 years (range, 0.04–2.5 years). By Kaplan-Meier survival analysis the estimated survivals free of reoperation for infection were 90.5% (95% confidence intervals, 85.3% to 96.1%) at 5 years and 82% (95% confidence intervals, 70.3% to 94.5%) at 10 years. The Knee Society scores: Pain scores, Functional scores, ROM improved. Conclusions. TKA infections treatment is a difficult task leading to a high rate of unsatisfactory mid-term and longterm results. About one forth of patient require reoperation, 14% become reinfected in first 2.5 years. Half of reinfected patients get reinfected repeatedly. In most cases patients are reinfected with the same microorganism but more virulent. TKA infection treatment option should be chosen according to the type of infection (acute or chronic), the duration of infection, the stability of the implant, the type of microorganism causing infection, bone quality and integrity, and the quality of the soft-tissue

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Abstract Soft-tissue balancing during total knee arthroplasty is an important step in optimizing the mechanical balance of the knee joint. Softtissue contractures that result from varus coronal plane deformity can pose a difficult problem, and the surgeon should have a standard procedure for managing such situations in the operating room. Balance may be assessed intraoperatively with the use of spacer blocks, laminar spreaders, and tensioning devices as well as by placement of trial components. Techniques used to balance the varus knee during primary total knee arthroplasty include femoral component rotation, osteophyte resection, soft-tissue release, and bone resection. Flexion and extension gap balancing is crucial for long-term success and patient satisfaction

Patellar Meniscus in Total Knee Arthroplasty

ABSTRACT Twenty-four clinically successful, autopsy retrieved porous-coated anatomic total knee arthroplasty (TKA) specimens were evaluated to determine the structure and function of the patellar meniscus. Mean implant duration was 76 months (range: 11-135 months). Histological examination showed the patellar meniscus to be composed of dense fibrous tissue with scattered regions of chronic granulomatous response to polyethylene debris. Patellar wear and polyethylene exposed patellar surface area were correlated with implant duration (r=0.47, P =.03; r = 0.52, P .06). Postoperative patellar tilt was also associated with patellar component wear (r=0.64, P=.03). No other clinical measures were significantly associated with patellar wear or exposed surface area. Additional research is needed to determine what role, if any, the patellar meniscus plays in TKA outcomes