[Periprosthetic Acetabulum Fractures]

In contrast to periprosthetic fractures of the femur, periprosthetic fractures of the acetabulum are rare complications - both primary fractures and fractures in revision surgery. This topic is largely under-reported in the literature; there are a few case reports and no long term results. Due to an increase in life expectancy, the level of patients' activity and the number of primary joint replacements, one has to expect a rise in periprosthetic complications in general and periprosthetic acetabular fractures in particular. This kind of fracture can be intra-, peri- or postoperative. Intraoperative fractures are especially associated with insertion of cementless press-fit acetabular components or revision surgery. Postoperative periprosthetic fractures of the acetabulum are usually related to osteolysis, for example, due to polyethylene wear. There are also traumatic fractures and fractures missed intraoperatively that lead to some kind of insufficiency fracture. Periprosthetic fractures of the acetabulum are treated conservatively if the implant is stable and the fracture is not dislocated. If surgery is needed, there are many possible different surgical techniques and challenging approaches. That is why periprosthetic fractures of the acetabulum should be treated by experts in pelvic surgery as well as revision arthroplasty and the features specific to the patient, fracture and prosthetic must always be considered.

[Value of microvascular, free flap transplantation in treatment of open tibial fracture]

Between 1986 and 1994, 71 cases of open fractures of the lower leg were treated by transplantation of a free, microvascular flap. Of these, 68 flaps were successful and the complication rate was low. Because of better vascularity subsequent bone reconstruction was shown to be more effective.

[C-reactive protein as infection parameter in clinically suspected postoperative infection after trauma surgery and orthopedic interventions. 2]

Prospectively the levels of C-reactive protein (CRP) of 40 patients were studied twice within 6-12 hours in case of a suspected infection after different osteosynthetic and orthopedic procedures and compared with the levels of the erythrocyte sedimentation rate (ESR). 16 patients showed an increase of CRP in relation to a wound infection, hematoma or effusion in all but one case. 6 patients showed an increase of ESR, which also could be cleared in all but one case. Those patients with a proved wound infection demonstrated a CRP-rise in 8 cases, a CRP-plateau in 4 cases and no CRP-decrease. The same patients showed an ESR-rise in 3, an ESR-plateau in 7 and an ESR-decrease in even 2 cases. This study indicates that the determination of two CRP-levels with a short interval in case of a clinically suspected infection is another, meaningful criterion in making a decision for an operative revision.

[C-reactive protein as a postoperative parameter of infection in hip joint replacement and knee joint operations]

Prospectively 70 male patients with elective arthroplasty of the hip (n = 34) and with operation of the anterior cruciate ligament (n = 36) were studied in respect of the postoperative screening of C-reactive protein (CRP), the erythrocyte sedimentation rate (ESR), the white blood cell count and the clinical signs of infection. There were 9 infectious postoperative complications, all with an increase of CRP. But also 6 other patients with no clear infection showed a rise or a plateau of CRP, which could only be explained by the presence of a hematoma, an effusion or a subclinical infection. The close postoperative screening of CRP appeared to be quite costly and laborious, especially in a population with a low infection rate. We therefore suggest a CRP-screening only on patients or operative procedures with wellknown high risk. In addition we studied the determination of two CRP-levels with a short interval following the clinical suspect of a postoperative infection (described in part II of this paper).