Diagnosis of chronic prosthetic joint infection (PJI) is often challenging. Painful prosthesis is frequently due to an infection but to diagnose it is somethimes difficult. All recent guidelines stress the central role of joint punction in diagnosis of PJI if the infection is not demonstrated. However which test on synovial fluid must be carried out is not so clearly defined. Total white blood cell count and differential leukocite count are usually considered useful in diagnosis but cut offs reported by different studies are quite different. Moreover this test needs a relatively large amount of fluid and blood contamination of it largely affects the result. What's more the synovial fluid WBC count may be unreliable in the setting of a metal-on-metal bearing or corrosion reaction.

Routine cultures should be maintained between 5 and 14 days, their sensitivity appears low in chronic infection even if witholding antimicrobial therapy before the collection of the fluid can increase the likelihood of recovery an organism.

Synovial leukocyte esterase can be performed as a rapid office or intraoperative point of care test using urinalysis strips. It is cheap and easy to perform, but the presence of blood in the sample can affect the result and it needs centrifugation.

Recently a new test has been proposed to detect alfa-defensine in synovial fluid. It shows a high sensitivity and an exellent specificity.

We performed 25 joint punctions on 25 patients with suspected PJI (enrollment is going on). Synovial fluid collected was tested for: leukocite esterase, WBC count and differential, colture in blood colture bottle for anerobe and aerobes (BacT/ALERT Biomerieux, inc) and detection of alfa-defensine level (Synovasure – Zimmer)

In patients who underwent surgery at least 5 samples of periprotesic tissue were collected for microbiologic analysis and the removed implant was sonicated according with the methodic. Furthermore samples for frozen section were sent and a histologic examination was made according to the Moriewitz – Kerr classification. The MSIS criteria was utilized to classify the case as infected or not.

In bone infections, it is of fundamental importance to wrap any orthopaedic surgical procedure in healthy vascularised soft tissue, in order to allow good healing and to prevent infection recurrence.

Vitality of soft tissues around the knee joint can be easily jeopardized in patients undergoing multiple surgical operations as in case of infected arthroprostheses. In addition, there are very few local options in the soft tissue reconstruction of this area, due to the fact that the vascularisation of skin and subcutaneous tissue is based on the genicular arteries’ axes which prohibits the use of random skin flaps.

Preoperative planning of cutaneous incisions and reconstructive procedures is mandatory for a correct surgical treatment.

We analyze retrospectively a series of 8 patients who underwent soft tissue reconstruction of the knee area with local flaps, considering criteria and indications in the choice of each surgical option.

Main variables considered in decision-making were size and location of soft tissue defect, planned orthopaedic surgical procedure, likeliness of the need for further surgery, age, local and general condition of the patient.

Flaps employed have been medial gastrocnemius muscular flap, reverse ALT fasciocutaneous flap and the “propeller” freestyle perforator flap.

Main complications observed have been partial flap necroses and recurrence of the underlying bone infection.

In this work, the authors want to emphasize the importance of a multidisciplinary treatment of bone and prosthetic infections, where the antimicrobial therapy chosen by the Infectious Diseases Specialist must be synergic with an “orthoplastic” surgical procedure, in the effort to reduce the risk of infection persistence or recurrence and to obtain the best possible functional result and quality of life for the patient.

For decades the treatment of chronic posttraumatic osteomyelitis associated with bone exposure has been one of the most serious problems in the field of orthopedic surgery. “Sterilization” of the osteomyelitic site, that is radical debridement of all infected tissue, is the basic requirement of the treatment; in the past, the remaining defect of the debrided area was closed with skin grafts, which were removed in a further stage, when the infection was ceased; then the defect was filled with muscle flap and bone graft of various types. Both soft tissue and osseous reconstruction took a relatively long period of time requiring several-stage treatment.

We performed a retrospective study on 9 patients treated for chronic osteomyelitis of the upper limb (6 forearm – 3 arm) by means of free fibula vascularized bone graft, between 1992 and 2003 (7 male 2 female). All patients had been more than 2 previous surgical attempt with conventional treatment (sterilization and bone graft). In most of them (7 cases) a two-stage treatment was performed (resection and sterilization, eventually with muscle transfer, in the first stage and bone transfer in the second one); in other 3 cases a one-stage treatment was performed. Two cases required a composite tissue transfer with a skin pad to cover the exposure. The length of bone defect after extensive resection of necrotic bone from septic pseudoarthrosis ranged from 5 cm to 12 cm.

In all cases there was no evidence of infection recurrence in the follow-up period. The mean period to obtain radiographic bone union was 4.1 months (range 2.5–6 months). In 2 cases secondary procedures have been carried out due to an aseptic non union in one site of synthesis (cruentation and compression plate). Functional results were always satisfactory although in the forearm a complete range of motion has never been achieved (plurioperated patients with DRUJ problems).

Fibular grafts allow the use of a segment of diaphyseal bone which is structurally similar to the radius, ulna and humerus of sufficient length to reconstruct most skeletal defects. The vascularized fibular graft is indicated in patients where conventional bone grafting has failed or large bone defects, exceeding 5 cm, are observed. The application of microsurgical fibular transfers for reconstruction of the extremities allows repair of bone and soft-tissue defects when shortening is not possible with good functional results.