Bilateral periprosthetic joint infection with Ureaplasma urealyticum in an immunocompromised patient.

This case study discusses how we diagnosed and treated a patient with a late haematogenous bilateral periprosthetic joint infection (PJI) after total knee arthroplasties caused by Ureaplasma urealyticum. This has never been reported before. We will discuss how we used a PET-CT, synovial fluid cell count, and synovial fluid analysis by 16S rRNA gene sequencing to diagnose this PJI. We will also discuss how we treated this patient to obtain full recovery.

Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome. A prospective randomized double-blind study.

BACKGROUND: Platelet-leukocyte gel (PLG) is being used during various surgical procedures in an attempt to enhance the healing process. We studied the effects of PLG on postoperative recovery of patients undergoing open subacromial decompression (OSD). METHODS: PLG was produced from platelet-leukocyte-rich plasma (P-LRP), prepared from a unit of whole blood. Forty patients were included in the study. Self-assessed evaluations, using the American Shoulder and Elbow Surgeons scoring system of activities of daily living (ADL), joint instability, pain levels, pain medications, and clinical evaluations for range of motion were conducted. RESULTS: Platelet and leukocyte counts were significantly increased in the P-LRP compared to baseline counts. Treated patients demonstrated decreased visual analog scales for pain and used significantly less pain medication, had an improved range of motion during passive forward elevation, external rotation, external rotation with arm at 90 degrees abduction, internal rotation, and cross body adduction compared to control patients (p < 0.001). No differences in the instability score were observed between the groups. Furthermore, treated patients performed more ADL (p < 0.05). CONCLUSION: In the PLG-treated group, recovery was faster and patients returned earlier to daily activities and also took less pain medication than control subjects.

The use of autologous platelet-leukocyte gels to enhance the healing process in surgery, a review.

BACKGROUND: The therapeutic use of autologously prepared, platelet-leukocyte-enriched gel (PLG) is a relatively new technology for the stimulation and acceleration of soft tissue and bone healing. The effectiveness of this procedure lies in the delivery of a wide range of platelet growth factors mimicking the physiologic wound healing and reparative tissue processes. Despite an increase in PLG applications, the structures and kinetics of this autogenously derived biologic material have not been observed. METHODS: A review of the most recent literature was performed to evaluate the use of PLG in various surgical disciplines. RESULTS: The review showed that the application of PLG has been extended to various surgical disciplines including orthopedics, cardiac surgery, plastic and maxillofacial surgery, and recently also endoscopic surgery. CONCLUSION: This review demonstrates the usefulness of PLG in a wide range of clinical applications for improvement of healing after surgical procedures.

Osseointegration of hydroxyapatite-coated and noncoated Ti6Al4V implants in the presence of local infection: a comparative histomorphometrical study in rabbits.

A study was designed to investigate the osseointegration of titanium implants, either noncoated or coated with hydroxyapatite (HA), into rabbit tibiae in the presence of local infection compared with osseointegration in the absence of local infection. HA-coated or noncoated Ti cylinders were implanted into both tibiae of 32 rabbits (New Zealand Whites). Before implantation the left tibia was contaminated with different quantities of Staphylococcus aureus (10(2)-10(5) CFU). Four weeks after surgery the tibiae were explanted and prepared for microbiological and histomorphometrical examination. Histomorphometrical data, as a representation of implant fixation, were obtained by measuring the percentage of bone around the implants (within a radius of 1 mm from the outer diameter of the implants) and the percentage of the circumference of the implant that was in direct contact with bone. Histomorphometry revealed, in particular for the HA implants, a relationship between the inoculum concentration and/or the presence or absence of infection with the bone contact at the distal implant side. This confirms a relationship between peri-implant infection and bone contact or remodeling. HA-coated implants developed, in the presence of bacteria, more easily a more severe infection than noncoated Ti implants, and we show in the present study that local infection will influence histomorphometrical parameters (bone-implant contact) that determine implant fixation. Precautions to prevent contamination (asepsis) and/or infection (perioperative antibiotics) are even more important for the highly biocompatible HA-coated implant.

Hydroxyapatite-coated acetabular components. Histological and histomorphometric analysis of six cups retrieved at autopsy between three and seven years after successful implantation.

BACKGROUND: Important questions remain regarding the use of hydroxyapatite-coated acetabular components in total hip arthroplasty. What is the relation of resorption of the hydroxyapatite coating to enduring fixation? Will unresorbed or dislodged hydroxyapatite particles cause adverse tissue reactions? Retrieval studies of clinically well-functioning acetabular components should help to answer these questions. METHODS: We examined six clinically successful hydroxyapatite-coated cementless acetabular components that were retrieved at autopsy between 3.3 and 6.6 years after implantation. All components were of the same design. The prostheses and the surrounding bone were prepared for qualitative histological and quantitative histomorphometric analysis. The percentage of bone growth onto the implant, the relative bone area around the implant, the extent of residual hydroxyapatite coating, and the coating thickness were measured. RESULTS: All of the cups showed bone ongrowth, with a mean bone-implant contact (and standard deviation) of 36.5% +/- 13.5%. The contact area was the same in all three zones delineated by DeLee and Charnley. The extent and thickness of the hydroxyapatite layer were much reduced in the specimens from older patients and in those associated with a longer duration of implantation. Degradation of the hydroxyapatite coating by osteoclasts was observed. We did not observe loose hydroxyapatite granules far from the coating, nor did we note any adverse tissue reaction to these granules. In contrast, polyethylene debris was noted in approximately half of the empty screw-holes. CONCLUSIONS: Cell-mediated hydroxyapatite resorption seems to be the main reason for loss of hydroxyapatite coating. The area of bone ongrowth was within a certain range (20% to 50%) of the measured surfaces, and it was independent of the amount of hydroxyapatite residue. The hydroxyapatite coating showed a slow rate of resorption with time, without any adverse tissue reactions.

Hydroxyapatite coated hip prosthesis followed up for 5 years.

We prospectively studied 250 patients with a proximal hydroxyapatite coated hip prosthesis. The follow-up period was 5 years. All components showed osseointegration except for one deep infection. The morphology of bone remodeling with either endosteal bone formation or periosteal bone formation was dependent on the way the stem filled the medullary canal. No linear or distal osteolysis around the stems was observed.

Effects of hydrosyapatite coating on Ti-6A1-4V implant-site infection in a rabbit tibial model.

To investigate the effect of implant type after direct contamination, a hydroxyapatite-coated or noncoated Ti-6A1-4V implant was inserted into both tibiae of 32 New Zealand White rabbits. Prior to implantation, the left tibia was contaminated with increasing concentrations of Staphylococcus aureus (10(2)-10(5) colony-forming units), ranging from very low (10(2)) to relatively high (10(5)). Four weeks after implantation, half of the tibial bone adjacent to the implant was harvested for bacteriological examination. Bacterial counts were quantified by plating serial dilutions. For the histological evaluation, sections of the implant with the remaining tibia were examined by semiquantitative scoring of infection parameters. The bacteriological data showed the inoculum dose and implant type to have a significant effect on the culture outcome: more bacteria were retrieved from the hydroxyapatite-coated implants than from the noncoated titanium implants. Histological evaluation showed an increased score for the infected left tibiae compared with their contralateral control. In addition, with increasing inoculum dosage, the difference between the two types of implant increased. We demonstrated that infections can occur with biocompatible, noncemented implants and that they are related to the dose of the original inoculum. Bacteria were more likely to grow onto or next to the hydroxyapatite implants than on titanium implants and resulted in a more severe histopathological characterization of infection.

Nonoperative treatment of Bennett's fracture: a 13-year follow-up.

We reviewed the treatment and results of 22 Bennett's fractures. Of these fractures, treated by closed reduction and plaster immobilization, 20 were available for follow-up. Eighteen patients had a subjectively satisfactory outcome, and seven had a radiographically confirmed arthrosis of the first carpometacarpal joint. Of these, two were severe and painfully impaired. Nonanatomic reduction was seen in six of the seven patients with arthrosis and is thus considered a prognostic factor of posttraumatic arthrosis.

Coagulation activation and reactive fibrinolysis in patients receiving oral anticoagulation after total hip or knee replacement.

Twenty patients having routine laboratory control of oral anticoagulation after total hip or knee arthroplasty were consecutively included in the study and were anticoagulated at an International Normalized Ratio (INR) between 2.5 and 3.5. Patients with mechanical heart valve prostheses (n = 20), deep venous thrombosis or pulmonary embolism (n = 20), at the same level of oral anticoagulation, served as control groups. Plasma concentrations of prothrombin fragment 1 + 2 and D-dimer were measured and compared. In the mechanical heart valve prosthesis and deep venous thrombosis groups the median prothrombin fragment 1 + 2 concentrations were significantly lower than in the orthopaedic patient group (0.15 and 0.17 nmol/l versus 0.29 nmol/l). The D-dimer concentrations displayed a similar picture (150 and 200 micrograms/l versus 840 micrograms/l). The D-dimer/prothrombin fragment 1 + 2 ratios in the patients after total hip or knee arthroplasty were significantly higher (12.4) than in the control groups (5.3 and 6.0). These data show that the fibrinolysis/coagulation balance is enhanced, mainly due to a disproportional rise in D-dimer. After assessing when the D-dimer concentration returns to normal in this anticoagulated group, this parameter may indicate the appropriate duration of oral anticoagulant treatment after surgery for total knee or hip replacement.