Aim & introduction

Infected knee with bone defect resulting from failed total knee arthroplasty (TKA) or destruction of native joint can necessitate restoration of segmental defect and arthrodesis for therapy of infection and maintenance of walking ability. In segmental knee defect external fixators or KAFO are not suitable, not comfortable and poor tolerated by elderly patients. Both custom-made Femoro-Tibial Nail (FTN) combined with acrylic cement spacer and Knee Arthrodesis Nail System (KANS) offer maintenance of supportive function of extremity and avoidance of leg length discrepance after removal of TKA.

The aim of the study was to determine the effectiveness and complications of hinged TKA revisions and the results of periprosthetic joint infection (PJI) treatment in such cases.

We have retrospectively reviewed 14 hinged TKA (Orthopedic Solution System, OSS, Biomet) in 14 patients. The patient average age was 70 years (range 56 to 83). The indication for the hinged TKA was: implant loosening (4 cases), periprosthetic fracture (3 cases), TKA instability (1 case) revision after spacer removal (1 case), advanced knee instability during primary TKA (3 cases), pseudoarthrosis due to previous tibial osteotomy (1 case) and tumor resection of the distal femur (1 case). The mean follow up was 26 months (range 6 to 60).

There have been 8 revisions in six patients. The indications for revision have been: infection (5 cases), skin necrosis (1 case), flexion contracture (1 case), and patellar luxation with extensor mechanism rupture (1 case). No aseptic loosening has been noted. In septic cases debridement was performed in 4 knees (debridement, antibiotics, implant retention, DAIR) and in one case two-stage revision with spacer. The average time from hinged TKA to revision due to any of the reasons was 13 months (range 2 to 41 months) and in case of septic revision 17 months (range 2 to 41). The mean follow up after septic revision was 30 months (range 24 to 41). In all the cases infection has healed. All the patients have been satisfied with the procedure and reported significant increase in the quality of life (mean HSS score 85). The mean pain score (NRS) has decreased from 7 preoperatively to 1. All the patients have reached at least 90 degrees of knee flexion.

The revisions of large implants are both demanding and expensive. In 4 of 5 cases DAIR has been successful in the treatment of PJI even though performed over the recommended time. The authors believe it could be considered in some PJI cases when implant removal is not an option.

The aim of the study is to determine reimbursement cost of treating periprosthetic joint infection (PJI) in Poland, the rate of THR and TKA septisc revisions in the years 2009–2013, the type of revision, comparison of the costs of septic and aseptic revisions.

Data published on the website of the National Health Fund (NHF) were analysed on revision arthroplasty for aseptic and septic recisions in the years 2009–2013. To calculate the cost of revision NHF report for 2013 was analysed giving the average cost of the group of septic and aseptic revision.

According to NHF „point system”, in therapy of PJI three types of revisions can by choosen: partial revision (305 points), one-stage revision (490 points), and two-stage revision with spacer (728 points for two stages). In the years 2009–2013 a total of 260030 THR and TKA were performer, including 23027 revisions. There were 4221 septic revisions: 1677 hips and 1430 knees. In 2013 septic revisions stated 1.38% (556 of 40152) of all hip and 2.56% (325 of 12654) of all knee replacements. Septic revisions constituted 14.67% of all hip revisions and 30.23% of all knee revisions. The average refund of the NHF for a minor revision for PJI in 2013 was 3889 Euro and the average cost for hospital was 4127 Euro. The average refund of the NHF for a one-stege revision (for any reason) in 2013 was 6124 Euro, and the average cost for hospital was 6339 Euro. The average refund of the NHF for a two-stage revision (for two stages) in 2013 was 10013 Euro, and the average cost for hospital was 10466 Euro for two hospital stays. Data revealed that in 2013 all 921 revisions performed for PJI were reimbursed as „minor revisions” for 3889 Euro. In 2013 the difference between the average cost incurred by the hospital and the refund of the NHF for septic revision was at least 238 Euro and for the entire year undervalued refund for treatment of 921 infected prostheses was at least 219198 Euros.

The reimbursement for revision due to infection encourages surgeons to perform two-stage septic revision instead of debridement or one-step, because two-step treatment in the final bill is better paid.

Staphylococcus aureus gene locus sdr is encoding proteins responsible for adhesion to bone tissue and therefore for the invasiveness of this bacteria. The aim of the study was to determine possible mechanism of activation of this gene and its role in bone infections.

S. aureus strain 838/05 was isolated from the bone adjacent to infected joint prostheses. The strain contains all sdrC,D, and E genes. It was grown in liquid TSB medium (Bio Merieux) with gentle aeration or on Columbia agar plates containing 5% sheep blood (Bio Merieux). The presence of putative promoters and transcriptional organization of the sdr region was detected using BPROM and FGENESB algorithms (www.softberry.com) based on region 611262bp-623152bp (GeneBank number CP000730.1) of the Staphylococcus aureus subsp. aureus USA300_TCH1516 complete genome sequence. In order to determine interaction of S. aureus with human blood, 50 ml of bacteria grown in TSB medium to ML growth phase were collected and washed twice with sterile PBS to remove the medium and re-suspended in 50ml of sterile PBS. 10 ml of cells were mixed with ∼100ml of mixed fresh human blood collected from healthy volunteers. Immediately after mixing blood with bacteria, 30 ml of the sample (Time 0) were mixed with two volumes of RNA Protect reagent (Qiagen), centrifuged to sediment cells, and frozen at −800C. Additional samples were collected after 30 and 90 minutes of incubation of bacteria with blood. Samples collected after 30 and 90 minutes were treated the same as samples collected at the beginning of the experiment. RNA was isolated, and cDNA was generated. The expression level of the sdr genes was calibrated to the gyrA level and then normalized to the expression level at time 0 using the ΔΔCT method.

Results and conclusions. The study confirms separation of the Sdr region into three transcriptional units and suggests its dissimilar functions, based on differential reaction of the sdrD transcript to environmental conditions and blood.

SdrE has been previously proposed to play role in bone infections; our results indicate that sdrD can play a role in the interactions between the pathogen and human immune system.

Infected nonunion of the femur or tibia diaphysis requires resection of infected bone, stabilization of bone and reconstruction of bone defect. External fixation of the femur is poorly tolerated by patients. In 2004 authors introduced in therapy for infected nonunions of tibia and femur diaphysis coating of IMN with a layer of antibiotic loaded acrylic cement (ALAC) containing 5% of culture specific antibiotic.

Seven patients with infected nonunion of the diaphysis of femur (2) and tibia (2) were treated, aged 20–63 years, followed for 2–9 years (average 5,5 years). All have been infected with S. aureus (MSSA: 2 and MRSA: 4) or Staph. epidermidis (1) and in one case with MRSA and Pseudomonas aeruginosa. All patients underwent 3 to 6 operations before authors IMN application. Custom-made IMN coated with acrylic cement (Palamed) loaded fabrically with gentamycin with admixture of 5% of culture-specific antibiotic: vancomycin (7 cases) and meropeneme (1 case) was used for bone stabilization. Static interlocking of IMN was applied in 4 cases and dynamic in 2 cases. In 1 case the femur was stabilized with IMN without interlocking screws. In 2 cases IMN was used for fixation of nonunion at docking site after bone transport. In 3 cases ALAC was used as temporary defect filling and dead space management. In one case after removal of IMN coated with ALAC, a new custom made Gamma nail and tubular bone allograft ranging 11 cm was used for defect reconstruction.

Infection healing was achieved in all 7 cases, bone union was achieved in 4 from 7 cases. In 1 case of segmental diaphyseal defect ranging over 12 cm infection was healed, but bone defect was not reconstructed. This patient is waiting for total femoral replacement. In another case of segmental defect of 11 cm infection is healed, but allograft substitution and remodeling by host bone is poor. In the 3rd case of lacking bone healing, the 63 year old patients was noncooperative and not willing to walk in walker with weight bearing. This patient refused further treatment.

Custom-made intramedullary nail coated with a layer of acrylic cement loaded with 5% of culture specific antibiotic can provide local infection control, offer comfortable bone stabilization, and replace standard IM nail in therapy for difficult to treat infected diaphyseal nonunion of femur or tibia.

The aim of the study is to evaluate the effect of acrylic cement CMW1 (DePuy) containing 2,5% of gentamicin and addition of 5 % and 10 % of respective vancomycin, meropeneme and ceftriaxone on growth inhibition of reference strains of MRSA, E. faecalis, S. aureus, P. aeruginosa and E. coli.

From every portion of investigated acrylic cement CMW1 discs were cut with a diameter of 15mm and a thickness of 5mm, average weight 1.365 g (+/− 0,257g). Inoculum was prepared with the reference strains: MR3 S. aureus methicillin-resistant (MRSA), ATCC 29219 E. faecalis, ATCC 25923 S. ureus, ATCC 27853 P. aeruginosa and ATCC 25922 E. coli. A colonies of bacteria taken from a 18-hour culture on solid medium were addend to tubes with sterile physiological saline solution to obtain a density of 0.5 McFarland (5 × 105 CFU / ml). The suspension was distributed evenly over the Mueller-Hinton (MH) medium (Biomerieux, France). Prepared discs of CMW1 cement were put with a sterile forceps on the plate with a dry medium. The plates were incubated aerobically at 24 hr and the temp. 37°C.

After 24 hours the diameter of zone of inhibition of bacterial growth on a plate was measured (in mm) and average size of the inhibition zone was calculated. The CMW1 cement inhibited to a comparable degree growth of reference strains with the exception of E. faecalis. The addition of vancomycin increased by 1/5 inhibitory potential of CMW1 cement on growth of MRSA, S. aureus, P. aeruginosa and E. coli. and significantly for E. faecalis. Changing the concentration of vancomycin, meropeneme and ceftriaxone from 5% to 10% do not increased the inhibitory potential of CMW1 cement on the growth of MRSA, S. aureus, P. aeruginosa, E. coli and E. faecalis. Addition of meropeneme increased inhibitory potential of CMW1 cement against MRSA by 1/3, P. aeruginosa and E. coli by ½, E. faecalis by 3/4 and against S. aureus by 100%. Addition of ceftriaxone to CMW1 cement increased the inhibiting of the growth of MRSA similiarly to 5% and 10% of vancomycin, E. faecalis as meropeneme 5% and 10 %, while the growth of S. aureus and P. aeruginosa, less than meropeneme.

Addition of antibiotics to acrylic cement increased its antibacterial properties. Increase if vancomycine concentrations from 5 to 10% had no stronger antibacterial effect.

Introduction: Failed total knee replacement due to the daemage of bone stock and infection requires removal of prosthesis. Successful arthrodesis is strongly related to the quality of bone stock. Both external fixators and KAFO are not comfortable and thus poor tolerated by elderly patients. Instable knee is very disabling condition. Custom-made femoro-tibial nail combined with acrylic cement spacer offers maintenance of supportive function of extremity after removal of knee prosthesis. Avoidance of leg length discrepance is possible. Nailing can be considered only as salvage procedure for one knee.

Material and Method: Six elderly patients underwent unilateral arthrodesis of the knee after removal of knee prosthesis due to the daemage to the bone stock and periprosthetic infection. They have had conical shape of the lower leg and poor quality to the bone. Thus they were not suitable for conventional knee arthrodesis using external fixator or for pseudoarthrosis and KAFO. After removal of TKR and debridement of periprosthetic tissues an ortograde, custom-made femoro-tibial interlocking nail was inserted. The gap betveen distal femur and proximal tibia was filled with hand-made acrylic cement spacer loaded with vancomycin (2g per 40 g cement) so that the spacer finally gained tubular shape.

Results: No recurrence of infection was noted. Early postoperative full-weight bearing was possible. Implant failure occurred in one case and required replacement of nail and cement spacer. Stress fracture of femoral neck occurred in another case. Despite of this problems all patients has better ADL than with KAFO or after

Conclusion: femoro-tibial nail for failed TKR is good accepted and comfortable for patient. Disadvantage of this type of nail is stiff knee and risk for nail fracture.

Bacteriophage state currently an attractive alternative for antibiotics, especially due to the strong in vitro activity and lack of side effects.

Eight patients with chronic infection in musculoskeletal system.are presented

This group includes: 3 cases of deep periprosthetic infection, posttraumatic osteomyelitis of tibia in 2 cases, infected pseudoarthrosis of femur in 1 case, chronic hematogenous osteomyelitis of tibia in 1 case, chronic infection in diabetic foot in 1 case.

Adequate tissue specimen for bacteriology was taken during operation and selection of bacteria strains was subsequently done and appropriate phage were cultured. Phage were taken orally by patients 4–6 weeks after operation. Despite of paralel phage and systemic antibiotic administration all patients underwent operative debridement of infected bone.

Simultaneously, every 7 days parameters of immunological response was measured in peripheral blood. They were: lymphocyte B activity (PFC and SAC test), lymphocyte T (NK) activity and phagocytose stimulation (PMA 30 test).

There was a two-fold increase of lymphocyte B activity in PFC test with peak on day 7 after phage administration. Additionally slightly increase of NK cells and phagocytic activity and both increase and decrease of lymphocyte B and T activity in SAC test was observed. Eventually remission of infection was achieved in 6 from 8 patients.

It is difficult to state a correlation between in vitro bactericidal effect of bacteriophage, immunological stimulation in peripheral blood and clinical results achieved after both operative and antimicrobial therapy.