Aim

Periprosthetic joint infections (PJI) and surgical site infections (SSI) are one of the most severe complications in joint arthroplasty. Decolonization measures prior to elective orthopedic surgeries have shown to reduce the risk of infection especially in patient identified as carriers of S. aureus. However additional screening measures can be difficult to implement in daily routine.

The objective was to study the influence of universal decolonization with polihaxanid on SSI rates.

Matrix metalloproteinases (MMPs), responsible for extracellular matrix remodelling and angiogenesis, might play a major role in the response of the growth plate to detrimental loads that lead to overuse injuries in young athletes. In order to test this hypothesis, human growth plate chondrocytes were subjected to mechanical forces equal to either physiological loads, near detrimental or detrimental loads for two hours. In addition, these cells were exposed to physiological loads for up to 24 hours. Changes in the expression of MMPs -2, -3 and -13 were investigated.

We found that expression of MMPs in cultured human growth plate chondrocytes increases in a linear manner with increased duration and intensity of loading. We also showed for the first time that physiological loads have the same effect on growth plate chondrocytes over a long period of time as detrimental loads applied for a short period.

These findings confirm the involvement of MMPs in overuse injuries in children. We suggest that training programmes for immature athletes should be reconsidered in order to avoid detrimental stresses and over-expression of MMPs in the growth plate, and especially to avoid physiological loads becoming detrimental.

Cite this article: Bone Joint J 2013;95-B:568–73.

A wide variety of intra- and extramedullary devices for the treatment of trochanteric fractures has been described. The Percutaneous Compression Plate is a minimally invasive and extramedullary device, which requires two 2–2.5 cm long incisions with minimal dissection oft soft tissue on the lateral aspect of the proximal femur. Earlier studies indicated that internal fixation using the PCCP is associated with a decreased perioperative blood loss, reduced transfusion requirements, with less postoperative pain, more rapid mobilisation, and with a reduced incidence of collapse of the fracture when compared with the standard device Dynamic Hip Screw. Aim of this study is to analyze the risk factors for the occurrence of local complications after internal fixation of intertrochanteric fractures of the femur using a Percutaneous Compression Plate.

In a retrospective cohort study patients with trochanteric fractures who underwent internal fixation with a PCCP were included. We investigated the potential risk factors age, gender, experience of the surgeon as indicated by the numbers of surgical procedures with the PCCP device, stability of the fracture according to the AO/OTA classification, and co-morbidities of the patients according to the ASA classification. The operations were performed by ten different surgeons. All local complications which required re-operation were recorded. They included cutting out of the screw, loosening of the screw barrels, local haematoma, and infections. Logistic regression analysis was carried out to determine the risk factors for local complications.

The mean age of the 122 patients included in this study was 78.5 years. 87 patients were female (70.7 %), 36 patients were male (29.3 %). With respect to the stability of the fracture 64 trochanteric fractures (52.5%) were classified as stable according to the AO/OTA classification, whereas 58 (47.5%) were considered to be unstable. Of the total of 122 patients with 122 trochanteric fractures eleven underwent re-operation due to local complications (9 %). The most frequent complication was complete or imminent cutting out of the upper cervical screw (N=5; 4 %). In the multivariate logistic regression model the only statistically significant risk factor was the experience of the surgeon (p=0.0316; odds ratio=4.7; CI 1.1–19.4).

Our data indicate that the experience of the surgeon is a significant risk factor for the occurrence of local complications. The frequent use of this device seems to lower the re-operation rate.

Peri-prosthetic bone loss caused by stress shielding may be associated with aseptic loosening of femoral components. In order to increase primary stability and to reduce stress shielding, a three-dimensional, cementless individual femoral (Evolution K) component was manufactured using pre-operative CT scans. Using dual energy x-ray absorptiometry, peri-prosthetic bone density was measured in 43 patients, three months, six months, 3.6 and 4.6 years after surgery. At final follow-up there was a significant reduction in mean bone density in the proximal Gruen zones of −30.3% (zone 7) and −22.8% (zone 1). The density in the other zones declined by a mean of between −4% and −16%. We conclude that the manufacture of a three-dimensional, custom-made femoral component could not prevent a reduction in peri-prosthetic bone density.