Ugradnja totalne proteze zgloba kolena predstavlja jednu od najčešćih ortopedskih operacija danas u svetu. Statistička analiza predviđa da će se od 2030. godine ugrađivati 3,5 miliona proteza kolena godišnje. Samim tim i broj operativnih komplikacija će neminovno rasti. Ukupan broj komplikacija u dosadašnjoj literaturi iznosi od 3-6%. Komplikacije operativne rane nisu česte i prema navodima iz literature se javljaju u nešto manje od 1% slučajeva. Značaj ovih kompikacija se sastoji u viskom riziku za septično razlabavljenje proteze, gubitku ekestremiteta, a u najtežim slučajevima, moguć je i fatalan ishod. Komplikacije se ispoljavaju u vidu nesrastanja operativne rane u regiji ligamenta patele, nekroze kože lateralno od ivice reza, raslojavanja dubljih struktura, nekroze ligamenta patele i ekspozicije proteze. Preoperativna procena faktora rizika može značajno smanjiti mogućnost nastanka komplikacija. Najznačajniji faktori rizika su komorbiditet i operativna tehnika. Način lečenja zavisi od veličine i dubine defekta, prisustva infekcije, ekspozicije tetiva, kosti ili implanta. Rani debridman i pokrivanje rane kvalitetnim mekotkivnim pokrivačem su bazični principi koji obezbeđuju visok procenat uspešnog lečenja (90%) komplikacija operativne rane posle implantacije totalne proteze kolena.

Ključne reči : totalna proteza kolena, operativna rana, komplikacije

Introduction: Periprosthetic infections represent one of the most severe complications, not only in the therapeutic but also in the diagnostic sense. Clinical signs, laboratory, and standard microbiological tests cannot always differentiate aseptic loosening from infection. Determining the causative agent by conventional cultures is difficult in the cases of formed biofilm, intracellular bacteria, or small colony variants. An additional problem is antibiotic therapy, which leads to false negative findings. An undiscovered causative agent, i.e., a wrong diagnosis, is the main reason for unsuccessful treatment. Methods: Implant sonication is the application of low-frequency, low-energy ultrasound waves that disintegrate the biofilm, and bacteria become available for further diagnostics. After extraction, the implant is placed in a sterile sealed container with Hartmann's solution. Before the sonication, the vessel is mechanically vibrated for 30 seconds and then placed in an ultrasonic bath for 7 minutes. The mechanical vibration of the container is applied again, after which the sediment is sampled with a sterile pipette, centrifuged, and cultivated on a blood culture medium. Results: In this paper, we present the results and experiences after three years of applying this method in a single medical center. Conclusion: This technique is relatively simple and cheap, so it can be applied in most microbiological laboratories. Its advantages include the possibility of detecting microorganisms in "low-grade" infections, previously applied antibiotic therapy, and also polymicrobial flora. Sonication should become a routine diagnostic procedure.

Introduction A serious complication after TKA is periprosthetic joint infection, with an incidence of 2%. Infection is the second most common cause of revision after TKA in the UK. Chronic infection of primary knee arthroplasty can be treated with one or two stage revision. In one-stage, the infected prosthesis is removed followed by radical debridement of infected tissue and direct reimplantation of prosthesis. In a revision in two stage, the infected prosthesis is removed, tissue debridement is performed and, more often, an antibiotic joint spacer is inserted. The role of the antibiotic spacer includes reduction of dead space, reduction of intra-articular hematoma, preservation of soft tissue balance and local release of antibiotics. After a certain time interval, when we have no signs of infection, a new knee endoprosthesis is implanted, usually revision type.
Case reports We presents the complete treatment of 3 patients with chronic infection of primary knee arthroplasty. The patients were female, 68, 71, 72 years old. All patients underwent revision in two stage with the application of a two-component joint antibiotic spacer. Reimplantation of the revision knee prosthesis was performed 7, 13 and 15 months after the first operation. All patients were followed up for 12 months postoperatively. There was no reinfection and a good functional result was achieved.
Conclusion. Revision in two stage using an antibiotic joint spacer is an excellent method of treating chronic infection of primary knee arthroplasty. The method is accompanied by a low percentage of reinfection and a good functional result.

Posteriorly stabilized total knee arthroplasty represents one of the most frequently used total knee prosthesis types in modern orthopaedics. Among all total knee arthroplasty complications one regarding the tibial post fracture is rare with a reported incidence of <1% and with very limited literature support, predominantly in the form of case reports and systemic reviews with only one retrospective observational study.
On our patient catastrophic implant failure occurred 10 years after the initial operation with the patient's main complaint being knee instability and without known trauma. Revision surgery was performed with intraoperatively confirmed tibial post fracture with a broken polyethylene part in the form of a loose intraarticular body. The revision was performed by inserting a larger polyethylene which resulted in a stable joint.
The literature states that the majority of these complications occur less than 5 years after surgery. Predominantly revisions surgery was done by increasing polyethylene size, but in some cases, a more constrained implant was needed to achieve joint stability. There is still no undisputed cause of this complication, while the most common explanation was the initial undersized polyethylene insert. This case is shedding new light on the time needed for this catastrophic failure to occur and is valuable for increasing knowledge on this topic.

Introduction: This study investigates the effectiveness of reconstructing neglected or chronic patellar tendon injuries using hamstring tendon autografts, based on the analysis of three cases. The presented cases are thoroughly documented, outlining the surgical procedure steps, the evolution of the patients' recovery, and the achieved functional outcomes. Methods: Three patients (two females, one male), of mean age 38.6 (26-58years) presented with chronic patellar tendon injury, with the time since injury ranging between three months and two years. Active extension was not possible in all three patients. All patients had severe functional limitation with an average IKDC score of 32.7 (range 24–48). Patellar tendon reconstruction was performed on all of them, employing autografts sourced from the hamstring tendon. Results: Following orthopedic surgery, patients were longitudinally monitored postoperatively, with a mean follow-up duration of 12.3 months (range 6-18). All patients exhibited a stable knee joint with complete flexion. Among them, two patients attained full extension, while one patient manifested an extension lag of 10 degrees. The IKDC score averaged at 64 (range 54-78). All three patients demonstrated favorable outcomes post-surgery. Conclusion:
While previous research has supported the use of hamstring tendon autografts in similar situations, these cases further confirm the success of this technique in addressing specific issues with neglected patellar ligament injuries. These results provide a valuable contribution to existing medical knowledge in this field and support the continued research and application of hamstring tendon autografts as an effective therapeutic option in this context.

Introduction: Patella fracture is a relatively rare injury, accounting for 1-2% of total skeletal trauma. The operative treatment technique with Kirschner needles and tension wire cerclage is the gold standard. Although this technique provides good healing and a good functional result, there are numerous complications that are mainly related to the implant material. An additional operation is often necessary to remove the implant. According to data from the literature, the percentage of complications ranges between 22%-30%, while the percentage of revision surgery is 65%.

Methodology: Non-absorbable thread and tapes in osteosynthesis of bone fractures and joint instability have been applied for the last few years. The patients included in this study have a simple two-part patellar fracture. The technique used for osteosynthesis uses two Fiberwire 5 non-resorbable threads, which are used to suture the tendon of m. quadriceps. Then, through the longitudinal transosseous tunnels, threads are passed from proximal to distal pole of patella, connecting the fracture fragments. The sutures are then brought back from the front of the patella and again passed through the transosseous tunnels, but one suture is transferred from the lateral side to the medial side and vice versa. In this way, an "X box" configuration is achieved.

Result: Osteosynthesis of a two-part patella fracture performed in this way ensures dynamic compressive effect at the fracture site. There is no migration of implant material and no need for additional surgical treatment.

Conclusion: The most importat advantage of the technique is significantly lower frequency of postoperative complications.