[Treatment of acetabular bone defects in revision hip arthroplasty using the Revisio-System]

BACKGROUND

Many different systems for the management of primary and secondary acetabular defects are available, each with its inherent advantages and disadvantages. The Revisio-System is a press-fit oval mono-block implant that makes a defect-oriented reconstruction and restoration of the center of rotation possible.

MATERIAL AND METHODS

In this study, we retrospectively reviewed the outcome of 92 consecutive patients treated with this oval press-fit cup due to periacetabular bone loss. The average follow-up was 58.2 months. Defects were classified according to D'Antonio. There were 39 type II, 38 Type III, and 15 type IV defects. After an average of 4.9 years, the implant survival rate was 94.6% with cup revision as the end point and 89.1% with revision for any reason as the end point. The Harris Hip Score increased from 41.1 preoperatively to 62.3 postoperatively. The mean level of pain measured with the Visual Analogue Scale (VSA) was reduced from 6.9 preoperatively to 3.8 postoperatively.

RESULTS

The Revisio-System represents a promising toolbox for defect-orientated reconstruction of acetabular bone loss in revision hip arthroplasty. Our results demonstrate that the implantation of the Revisio-System can result in a good mid-term clinical outcome.

[Refixation of the biceps tendon onto the radial tuberosity using two suture anchors]

OBJECTIVE

Reinsertion of the distal biceps tendon onto the radial tuberosity restoring full force of flexion and supination.

INDICATIONS

Distal biceps tendon avulsion from the radial tuberosity. Acute and chronic tears with a tendon stump, which can be mobilized and reduced to the radial tuberosity in flexion and supination.

CONTRAINDICATIONS

Tears of the musculotendinous junction. Chronic distal biceps tendon tears with wide retraction and the need for tendon graft augmentation. Severe atrophy of the biceps muscle.

SURGICAL TECHNIQUE

In supination, the skin is incised longitudinally for 4 cm, centered over the medial border of the radial tuberosity. Incision starts 2 cm distal from the humeroradial joint line. Bluntly the distal biceps tendon stump is found and mobilized. Preparation and debriding of the radial tuberosity sparing neurovascular structures. Crossing vessel branches are ligated, if needed. Positioning of two spreading anchors into the radial tuberosity and reinsertion of the tendon stump.

POSTOPERATIVE MANAGEMENT

Adjustable elbow movement orthosis adapted to tendon quality and tissue tension for 6 weeks without active flexion or supination. Degree of extension is gradually increased by 20° every 2 weeks. After orthosis treatment is finished after 6 weeks, flexion and supination with weights is not allowed for another 6 weeks.

RESULTS

In a retrospective study of 30 patients with a mean follow-up of 45 months (range 15-80 months), the clinical outcome was good or excellent in 99% of cases. On average, a Mayo Elbow Performance Score of 93 points (range 65-100 points) and a QuickDash of 5 points (range 0-39 points) were achieved.

Comparative reject analysis in conventional film-screen and digital storage phosphor radiography

The aim of this study was comparative analysis of rejected radiographs in conventional and digital radiology under the aspects number of rejected images and reasons for rejection. During 2 months waste films of conventional radiography were collected; in digital radiography each image-delete command at the postprocessing workstation was documented. Rejected images were analysed and assigned to four categories. The overall reject rate was 27.6% in the conventional and 2.3% in the digital department. Whereas in the conventional department the main reason for rejection was "exposure" and "others" (i.e. problems related to film handling), the main reason in the digital environment was "positioning". The high exposure tolerance of digital systems markedly reduces the amount of faulty images. This is not only economically rewarding, but may also reduce unnecessary X-ray exposure of patients due to image retake.

Comparison of different methods for separation and ex vivo expansion of cord blood progenitor cells

Umbilical cord blood is capable of hematopoietic stem cell reconstitution in children. However, the major limitation of cord blood is a relatively low content of pluripotent progenitor cells. Thus, safe engraftment for adolescents and for adults is still not predictable and a technology for ex vivo expansion of umbilical cord blood cells is desirable. In a first step, four different methods of red cell depletion followed by magnetic cell sorting of CD34+ cells were evaluated in this study in order to assess the efficacy and safety of optimal stem cell recovery. A modified two-step Ficoll gradient separation and a hydroxyethyl starch separation tended to produce a better WBC/MNC recovery (median 94.2+/-2.44% vs. 90.2+/-5. 8%) as compared with standard Ficoll gradient separation and a gelatin-based procedure (median 78.35+/-7.1% vs. 67.2+/-5.5%). However, the recovery of CD34+ cells after magnetic cell sorting did not reach a statistically significant difference after the four different methods of red cell depletion, indicating that the recovery of WBC/MNC is not predictably correlated with the recovery of stem cells within these fractions. In a second step, we established three different cytokine combinations by adding the megakaryocyte growth and development factor +/- erythropoietin and granulocyte colony-stimulating factor to a fetal calf serum containing medium with Flt 3, stem cell factor, and interleukin-3. Net expansion of total colony-forming cells 20- to 50-fold and expansion of colony-forming cells after 5 weeks of culture 1.5- to 3-fold were obtained over a period of 7-14 days. These results demonstrate that cord blood stem cells can be expanded substantially in this short-term culture system.