Two-stage exchange technique is currently considered the standard treatment for the infected total knee arthroplasty, but the clinical outcomes associated with the use of articulating bone cementspacers are not well established. Spacer-K is a pre-formed articulatingspacer made of genta-micin-impregnated acrylic cement. The aim of this prospective study was to assess safety and effectiveness of Spacer-K for the management of the infected total knee arthroplasty.

Twenty-two consecutive patients were operated on in two centres. Infection was caused by Coagulase neg. Staphylococcus (11cases), Staphylococcus aureus (3), and others (5). In 3 cases microorganisms were not identified. The mean implantation time of the spacer was 11 weeks(range, 7 to 28 weeks). The rehabilitation program between stages consistedin early range of motion exercises and partial weight-bearing. In one patient removal of the spacer and insertion of a molded cement block with vancomycin was necessary because of insurgence of MRSA.

The mean follow-up of 21 knees after removal of the spacer and insertion of the new prosthesis was 28 months (6 to 45 months). In one patient removal of the spacer and insertion of a molded cement block with vancomycin was necessary following insurgence of methi-cillin-resistant Staphylococcus aureus isolated between stages. No patient had recurrence of infection at latest follow-up. The mean Knee Society functional score during spacer management was rated 76 points (range 55 to 80 points) and was rated 86 points (range, 76 to 90 points) at latest follow-up. Preoperative range of motion improved markedly after removal of the infected pros-thesis and insertion of the spacer. Neither breakage, nor clinically relevant wear of the spacer were detected, and no complications related to the device were observed

The Spacer-K is safe and effective for the management of the infected total knee arthroplasty.

Aim: The study was conducted to evaluate differences between simultaneous and sequential cementing of the tibial and femoral components in total knee joint replacement in relation to final component alignment. Our hypothesis was that cementing the components sequentially increases accuracy of the final position.

Method: This was a prospective and randomised study, performed using a computer navigation system as the evaluation technique to determine the accuracy of implant positioning. All knee replacements (Scorpio, Stryker) were implanted with the assistance of computer navigation. The patients were divided into two groups of 20 patients each. The first group had implants cemented simultaneously where the tibial and femoral components were implanted with a single mix of cement and then pressurized by extending the leg. The second group of patients had the tibial component inserted with the first mix of cement and then impacted. Then the femoral component was inserted using a second mix of cement. Computer navigation was used to measure varus/ valgus cut of the femur, varus/ valgus cut of the tibia, and sagital slope of the tibia. Measurements were made with the components in place, both before cementing and then after cement cure.

Results: Our results show a statistically significant improvement in accuracy of femoral varus/ valgus alignment using the sequential cementing technique.

The study was conducted to investigate differences between simultaneous and sequential cementing of the tibial and femoral components in total knee joint replacements. Our hypothesis was that cementing the components sequentially increases accuracy of the final position.

This was a prospective and randomized study, performed using a computer navigation system as the evaluation technique to determine the accuracy of implant positioning. All knee replacements (Scorpio, Stryker) were implanted using navigation technique.

The patients were divided in two groups. The first group had implants cemented simultaneously where the tibial and femoral components were implanted with a single mix of cement and then pressurized by extending the leg.

The second group of patients had the tibial component inserted with the first mix of cement and then impacted. The cement was allowed to set before proceeding with insertion of the femoral component using a second mix of cement.

The computer navigation system was utilized for bone cuts. It was then used to measure 3 sets of angles. The first set was varus/valgus cut of the femur, varus/valgus cut of the tibia and posterior slope of the tibia. The second set of measurements were the same angles, this time of the position of the prosthetic components before cementing, and the third set after cementing.

Our interim results show just a small difference between the two techniques.

It does not appear there is substantial difference in positioning of the implants between these two different techniques.

Introduction Antibiotic-loaded cement spacers are commonly used in the two-stage management of the infected total knee replacement (TKR). Static spacer blocks make exposure and reimplantation difficult because of soft-tissue retraction and muscle shortening. To avoid these problems, a temporary articulating moulded implant has been recently introduced in the marketplace. The device is industrially preformed in three sizes (two articulating components), has standardised mechanical and pharmacological characteristics.

Methods We present a multicentre study designed to assess the safety of the device, patients’ satisfaction and functional outcome at a minimum follow-up of six months. Twenty-four knees have been treated for TKR deep infection due to CNS (15),S.aureus (three),E.coli (one),mixed flora (two), unidentified (three). Continuous passive motion and partial/touch weight-bearing were started after surgery. Second-stage surgery was performed after normalisation of serological parameters, a minimum period of six weeks of antibiotic therapy, and a sterile aspiration of the joint. The spacer was removed and a new prosthesis was inserted in all patients. The mean implantation time of the spacer was 16 weeks (range 8 to 38).

Results Suppression of infection was observed in all patients at a minimum follow-up of six months (mean 14 months). No spacer-related complication (instability, dislodgment, severe wear, fracture) was observed. The range of motion of the knees remained unchanged between the first and second stages and improved after definitive reimplantation. The mean Knee Society Score at last-follow up was 88 points (knee score and functional score). The patients judged the result excellent (three), good (15), satisfactory (five), poor (one).

Conclusion The use of an articulating spacer in the two-stage treatment of infected TKR improves the quality of life of the patient, the ultimate range of motion, facilitates second-stage surgery and the functional recovery. Severe bone loss is a relative contraindication for articulating spacers, as these knee joints may require immobilisation during the resection time interval.

In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source.

Introduction Considerable advances have been made in improving cementing techniques in total hip replacement. Recently, the increasing need to minimize healthcare costs has led to the development of methods to reduce surgical time. It has been proposed that the curing time for bone cement can be markedly reduced by preheating the femoral component before insertion. A reduction of the period between insertion of the implant and ultimate curing decreases operative time, bleeding into the bone-cement interface and the likelihood of accidental loss of position. In a previous in-vitro study, preheating the femoral component to a temperature of about 50° resulted in a reduction in the bone cement curing time of approximately 50%. No adverse changes of the mechanical properties of cement were found. E-modulus, fracture toughness and fatigue strength were unaffected by increased temperature. A uniform trend of decreasing porosity of bone cement with increased temperature of the implant was also observed. To-date, there have been no reports on the in-vivo outcome of the preheating cementing technique. The aim of this prospective study was to assess the clinical and radiological five year follow-up results of the preheating cementing technique used for the fixation of the femoral stem (Lubinus, Link, Germany).

Methods One hundred consecutive patients (100 hips) with osteoarthritis and an average age of 72 years (range 65 to 85) have been operated on by one surgeon in a single institution. In a cohort of 50 hips a conventional cementing technique was used. The cement used was Cemex (Tecres, Italy). The anterior-posterior and lateral radiographs have been evaluated with a computer-aided system. The quality of cement mantle was assessed on the radiographs according to the A-B-C1-C2-D classification.

Results The curing time of the bone cement was markedly reduced (average five minutes, range four to seven minutes) by preheating the femoral component (40° to 50°). The estimated reduction of intra-operative blood loss was 75 ml (range 45 to 130). The mean Harris Hip Score was 94.8 points at follow-up (range 79 to 100). The clinical status of 92% of hips was rated good or excellent, eight percent was rated fair. A satisfactory cementing technique was obtained in 96% of hips. Small voids in the cement mantle (grade C1) were present in four percent of hips. Non-progressive radiolucent lines at the bone-cement interface were observed at Gruen zone one in four hips, at zone eight in three hips and at zone 14 in three hips. No signs of osteolysis were observed at follow-up, all stems were rated radiologically stable.

Conclusion A reduction in curing time of bone cement provides a significant time saving without compromising implant performance. We recommend preheating of femoral components to surgeons experienced in joint replacement and have a skilled surgical team, because of the potential risk of premature polymerization before complete seating of the implant.

In relation to the conduct of this study, one or more of the authors is in receipt of a research grant from a non-commercial source.

Introduction: There is a paucity of published data concerning major thoracolumbar spine trauma in the paediatric population, reflecting the rarity of these injuries.

Aim: To review retrospectively 11 cases of thoracolumbar paediatric spinal fractures and dislocations requiring operative management by one surgeon from 1991 to 2001 at Starship Children’s Hospital.

Methods and results: The mean age was 10 years (range: four to 15). Four patients had a neurological deficit (three were incomplete, one was complete). All patients underwent surgery with internal fixation. Canal decompression was achieved by operative realignment in most patients although two patients underwent additional decompression by corpectomy. Seven patients had flexion-distraction injuries with facet joint dislocations. These patients were treated with posterior instrumentations in compression. A further two patients with fracture-dislocations were also treated by posterior instrumentation and the remaining two patients (one burst fracture and one fracture-dislocation) by anterior instrumentation. The general principles for surgical management of thoracolumbar spine trauma in adults were found to be applicable to the children in this series. Suitably sized internal fixation devices were available to allow stabilisation in all cases. The preponderance of dislocations presumably reflects differing biomechanics in the immature versus the adult spine and necessitated a posterior operative approach in most cases.