Superselective angiography of the wrist in patients with Kienböck's disease.

BACKGROUND: Microvascular problems like increased intraosseous pressure or venous congestion may influence the development of Kienböck's disease. We examined if wrist position modifies the blood flow in the nutrient vessels. METHODS: Retrospective analysis of 17 patients with Kienböck's disease who had a superselective microangiography of the radial, ulnar and interosseous artery in different wrist positions under general anaesthesia. We analysed the data with Fisher's exact and Wilcoxon-test. RESULTS: We found vessels that entered the bone, that ended at the bone edge, and that supplied a vascular plexus. The origins were the anterior interosseous artery in 10 of 17 cases, the radial artery in seven cases, and the ulnar artery in five cases. Movement of the wrist could reduce or stop the blood flow. Type of lunate configuration showed no significant influence on the blood supply in neutral position. CONCLUSION: The radial, ulnar, and anterior interosseous artery contribute to the vascular supply of the lunate bone in different combinations. Wrist movement can reduce blood flow to the lunate bone.

[Pedicled vascularized bone graft for scaphoid reconstruction after Zaidemberg]. / Das gestielte vaskularisierte Knochentransplantat zur Skaphoidrekonstruktion nach Zaidemberg.

BACKGROUND: Nonunion of the scaphoid as a result of proximal fractures, failed surgical reconstruction, and especially avascular fragment necrosis are possible indications of vascularized bone grafts. Various techniques of vascularized (pedicled and free) grafts have been described. Pedicled grafts from the direct vicinity of the wrist provide several benefits. Harvest-site morbidity is reduced and preserved graft perfusion, without the need for blood vessel anastomosis, may lead to an improved consolidation. METHODS: A common pedicled vascularized bone graft for reconstruction of the scaphoid was first described by C. Zaidemberg and colleagues in 1991. We describe 49 consecutive patients, who underwent vascularized bone-grafting, pedicled on the 1.2 intercompartmental, supraretinacular artery in a modified technique based on Zaidemberg's description. The fixation of the bone graft was performed by Kirschner wires. RESULTS: A consolidation was detected in 37 cases, and 9 cases showed a persistent nonunion (3 patients did not follow up). According to the classification of Herbert, 44 patients had a nonunion grade D2 or higher, of which 36 patients showed a bony consolidation (8 non-consolidated). Complications occurred in individual cases (1x intraoperative fracture of the radius, 4x transient irritations of the superficial branch of the radial nerve). A loss in the range of motion of the affected wrist was frequent. An indication for a pedicled graft was seen if the preoperative contrast-enhanced MRI showed an impaired perfusion of scaphoid fragments. DISCUSSION: The more advanced the changes in MRI, the more frequently treatment failed. The vascularized bone graft from the dorsal distal radius described by C. Zaidemberg et al. is one of several ways to address a circulation-impaired nonunion of the scaphoid.

[Pedicled vascularized iliac bone graft for treatment of osteonecrosis of the femoral head]. / Gefäßgestieltes Beckenkammtransplantat zur Behandlung der Femurkopfnekrose.

OBJECTIVE: Illustration of a nowadays only rarely performed operative procedure for the treatment of osteonecrosis of the femoral head to prevent or at least delay advanced arthrosis and the need for a total hip replacement. The pedicled vascularized iliac bone graft is raised without the need for special microsurgical techniques and has less vascular complications often seen in free vascularized grafts. INDICATIONS: Early stages of osteonecrosis of the femoral head stages II and III according to the Association Research Circulation Osseous (ARCO) up to the detection of fracture lines (crescent sign) but without mechanical insufficiency. CONTRAINDICATIONS: Osteonecrosis of the femoral head with collapse of the femoral head (ARCO stage ≥IIIB) and mechanical insufficiency. Patients who are noncompliant or a not able to take the weight off the operated leg. Patients who had radiotherapy or an operation on ipsilateral inguinal lymph nodes and patients who have vascular anomalies or severe arteriosclerosis. SURGICAL TECHNIQUE: Debridement of the femoral head osteonecrosis and implantation of a pedicled vascularized iliac bone graft. POSTOPERATIVE MANAGEMENT: Free movement of the hip joint 4 weeks after surgery. Outward rotation of the hip joint allowed after 3 months and restriction of weight load on the operated leg for at least 3-6 months postoperatively depending on the bony consolidation. RESULTS: Vascularized bone grafts for the treatment of femoral head necrosis show better clinical and radiological results than avascular bone grafts. Nevertheless, after 5 years follow-up approximately 25% of the operated hips formerly in stage II show further progression of radiological necrosis. In stage III all hips eventually show progress of femoral head collapse and the need of a total hip replacement. Concerning the outcome of a free vascularized bone graft (fibula flap) compared to the pedicled vascularized graft from the iliac crest for treatment, the anatomically demanding area and a higher complication rate should be considered even though the cancellous bone of the iliac crest is biologically ideal. Nowadays a free vascularized fibular graft is the most frequently used bone graft for treatment of femoral head necrosis.

Proximal interphalangeal joint arthrodesis using a compression wire: A comparative biomechanical study.

Arthrodesis of the proximal interphalangeal joint is a proven technique for treating of a range of pathological conditions, including osteoarthritis. There are multiple surgical procedures. A biomechanical study was conducted to compare the stability of a compression wire to intraosseous wiring for the arthrodesis. Seventeen formalin-fixed human fingers were randomly assigned into two groups and the bone mineral density was determined. Arthrodesis in 20° flexion was performed using an oblique compression wire (n=8) or intraosseous wiring (n=9). The stability of the arthrodesis was tested by applying a tensile bending force until failure. The mean force needed to fail the compression wire arthrodesis and intraosseous wire arthrodesis was not significantly different (76.2N, SD 31N and 63.0N, SD 28N). There was no correlation between bone density and force to failure. The compression wire was within the approximate range achieved by intraosseous wiring in withstanding substantial force before failure. From a biomechanical point of view, a compression wire is feasible for PIP arthrodesis.