The purpose of this study was to compare the diagnostic accuracy for the detection of infection between the culture of fluid obtained by sonication (SFC) and the culture of peri-implant tissues (PITC) in patients with early and delayed implant failure, and those with unsuspected and suspected septic failure. It was hypothesised that SFC increases the diagnostic accuracy for infection in delayed, but not early, implant failure, and in unsuspected septic failure. The diagnostic accuracy for infection of all consecutive implants (hardware or prostheses) that were removed for failure was compared between SFC and PITC. This prospective study included 317 patients with a mean age of 62.7 years (9 to 97). The sensitivity for detection of infection using SFC was higher than using PITC in an overall comparison (89.9% versus 67%, respectively; p < 0.001), in unsuspected septic failure (100% versus 48.5%, respectively; p < 0.001), and in delayed implant failure (88% versus 58%, respectively; p < 0.001). PITC sensitivity dropped significantly in unsuspected compared with suspected septic failure (p = 0.007), and in delayed compared with early failure (p = 0.013). There were no differences in specificity.

Sonication is mainly recommended when there is implant failure with no clear signs of infection and in patients with delayed implant failure. In early failure, SFC is not superior to PITC for the diagnosis of infection and, therefore, is not recommended as a routine diagnostic test in these patients.

Cite this article: Bone Joint J 2013;95-B:244–9.

Patients with infected arthroplasties are normally treated with a two-stage exchange procedure using polymethylmethacrylate bone cement spacers impregnated with antibiotics. However, spacers may act as a foreign body to which micro-organisms may adhere and grow. In this study it was hypothesised that subclinical infection may be diagnosed with sonication of the surface biofilm of the spacer. The aims were to assess the presence of subclinical infection through sonication of the spacer at the time of a second-stage procedure, and to determine the relationship between subclinical infection and the clinical outcome. Of 55 patients studied, 11 (20%) were diagnosed with subclinical infection. At a mean follow-up of 12 months (interquartile range 6 to 18), clinical failure was found in 18 (32.7%) patients. Of the patients previously diagnosed with subclinical infection, 63% (7 of 11) had failed compared with 25% (11 of 44) of those without subclinical infection (odds ratio 5.25, 95% confidence interval 1.29 to 21.4, p = 0.021). Sonication of the biofilm of the surface of the spacer is useful in order to exclude subclinical infection and therefore contributes to improving the outcome after two-stage procedures.

For the treatment of the fractures of the proximal extremity of the femur two predominant systems exist: the intramedular nail and the sliding screw plate.

The variables at the moment, to be considered, are the weight, age and type of fracture. The principal aims are: To develop models of finite elements of both types of implants and of two types of fracture (stable and unstable), and to integrate the models of finite elements of the implants in the model of fractured femur, to obtain the mechanical behavior of both types of implants and them to fit to the model of finite elements.

The analyzed models have been the gamma-3 nail (Stryker, USA) and the PerCutaneus Compression Plate (PCCP), (Gotfried, Israel). The real geometry has been created in the program SolidWorks 11.0 to be treated later in the program of calculation by means of finite elements Ansys.

The assembly with nail is more rigid (11.51 mm) that with plate (11.95 mm) on having had a few minor displacements. The tensions that appear in the nail (446 MPa) are major that those of the plate (132.93 MPa), in the unstable fractures.

In the unstable fractures, the intramedular nail is more rigid than the system of plate. The tensions to which the nail meets submitted are superior to those of break for what the nail would not be capable of supporting the first cycles of load. It is for it, that the system to using in these cases would be the sliding screw plate.

Introduction and purpose: Since 1834 when Smith first described rotator cuff tears we have come far in the treatment of this condition. The greater availability of arthroscopic surgical procedures requires the greatest possible precision in preoperative diagnoses. Our purpose is to determine the accuracy (sensitivity and specificity), in our environment, of the two main diagnostic techniques we use, namely ultrasound and magnetic resonance.

Materials and methods: We reviewed 100 arthroscopic shoulder procedures performed in our centre. We compared retrospectively the intraoperative findings with the reports of the available images of each patient (US and MRI). We focused our attention exclusively on the tendon of the supraspinatus muscle. The sensitivity and specificity of both tests was compared in two different ways. In the first case, by considering as torn tendons those with complete tears (total thickness tears); in the second case, by considering as torn tendons those with complete or partial tears.

Results: With magnetic resonance images we found a sensitivity of 78% and a specificity of 89% for total tears and a sensitivity of 92% and a specificity of 64% for partial tears. With ultrasound we found a sensitivity of 73% and a specificity of 83% for total tears and a sensitivity of 91% and a specificity of 78% for partial tears.

Conclusions: Both diagnostic methods show comparable sensitivity and specificity levels, which were high in our environment for total tears. Specificity is less in the case of partial tears.

Introduction and purpose: There is a controversy about the value and usefulness of the ultrasound screening of hips as well as about what population should be screened. It seems clear that ultrasound is the best method for early screening of developmental dysplasia in infants. The purpose of this paper is to assess the results of the semi-universal ultrasound screening of hips in infants.

Materials and methods: We evaluated the screening carried out of all girls and boys with risk factors delivered in our hospital (3/4 of those in the whole of Navarra) 1n 2001, 2002 and 2003. The number of newborns studied was 4144, 4199 and 4820 respectively. Ultrasounds were carried out when they were one month old. Diagnosed dysplasias accounted for between 6.19 and 6.27 per thousand newborns. Of all patients with diagnosed dysplasias, 4 girls (no boys) had to be operated on (adductor tenotomy and plaster cast).

Results and conclusions: The majority of diagnosed and treated dysplasias were found in breech babies, babies with a family history of the disease and especially in cases where there was no other sign suggesting the disease (only eight of them had had a positive Ortolani-Barlow). The lack of cases of late dysplasia has prompted us to rely on this type of screening since it has helped us reduce the amount of surgical procedures.

Introduction and Objectives: In this retrospective study, we have evaluated the results of treatment of non-unions of the humeral diaphysis using plate osteosynthesis.

Materials and Methods: This is a retrospective study covering the years 1997–2002, with a total of 135 fractures of the humeral shaft: 84% were treated orthopaedically and 16% surgically by means of plate osteosynthesis. We present 14 cases of humeral non-union, all of which occurred after orthopaedic treatment, and 12 of which were surgically treated by means of plate osteosynthesis (the other 2 declined surgical treatment). The most common cause of fracture was accidental fall, and of the 12 cases, 11 were female, and 1 was male. Mean age was 67.6 years. Initial orthopaedic treatments included the following: in 9 cases U-splint + sling, in 1 case U-splint + Velpeau sling, in 2 cases hanging cast + Poulipen. Of these, the initial bandaging was replaced with braces after 2.5-3 months. Definitive surgical treatment was delayed an average of 8.1 months. We used the Müller-AO fracture classification system. There were 4 cases with 12B12, 3 cases with 12A12, 1 case with 12A11, 1 case with 12B22, 1 case with 12B11, 1 case with 12B21, and 1 case with 12A21. Surgical treatment was performed in 7 cases with LD-DCP plates, in 3 cases with DCP plates, in 1 case with a T-plate, and in 1 case with a straight plate. Corticocancellous bone grafts were transferred from the iliac crest in 9 of 12 cases.

Results: Bone healing was achieved in 11 of 12 surgical cases (one case without radiographic consolidation due to detachment of the plate due to trauma). In 2 cases there was a limitation of shoulder abduction at 85° and elbow extension -10°. In one case, there was repeat treatment due to failure of osteosynthesis. In two of the surgical cases, definitive BA will be measured upon completion of rehabilitation. Complications included 2 temporary radial palsies that recovered both motor and sensory function, one distal detachment of the plate due to previous trauma that had borderline BA and was non-painful. There was one case in which consolidation did not occur and where the humeral artery was injured iatrogenically during surgery (the same one that required repeat surgical intervention). There was one case of infection of the site of osteosynthesis due to Pseudomonas aeruginosa, which responded well to initial antibiotic treatment, and no material needed to be removed.

Discussion and Conclusions: Plate osteosynthesis is an effective treatment for non-unions of the humeral shaft and yields good joint mobility and few complications (similar to the results of other treatment methods) and must be performed by experienced surgeons.