Biomedical subjects

Hans Zwipp

Publications and source records attributed to Hans Zwipp.

25 records · Page 2Linked to original sources

PubMed2004

Impact of helicopter transport and hospital level on mortality of polytrauma patients.

BACKGROUND: Despite numerous studies analyzing this topic, specific advantages of helicopter transport of blunt polytrauma patients as compared with ground ambulances have not yet been identified unequivocally. METHODS: Four possible pathways in 403 polytrauma patients (Injury Severity Score [ISS] > 16) who were in reach of the helicopter emergency medical service (HEMS) Dresden were analyzed as follows: HEMS-UNI group (n = 140), transfer by HEMS into a university hospital; AMB-REG group (n = 102), transfer by ground ambulance into a regional (Level II or III) hospital; AMB-UNI group (n = 70), transfer by ground ambulance into the university hospital; and INTER group (n = 91), transfer by ground ambulance into a regional hospital, followed by transfer to the university hospital. Scores used were the ISS and the TRISS. Tests used for statistical analysis included chi2 and Fisher's tests. Statistical significance was set at p > 0.05. RESULTS: Age, gender, and mean ISS (range, 33.3-35.6) revealed extensive homogeneity of the groups. Mortality of the AMB-REG group was almost doubled (41.2%) compared with HEMS-UNI (22.1%) patients (p = 0.002). The AMB-UNI group displayed the lowest mortality (15.7%, p = not significant). TRISS analysis (PRE-Chart) revealed identical outcome for AMB-UNI and HEMS-UNI patients. Rescue time averaged 90 +/- 29 minutes for HEMS-UNI patients, 68 +/- 25 minutes for AMB-UNI patients, and 69 +/- 26 minutes for the AMB-REG group. CONCLUSION: Primary transfer by HEMS into a Level I trauma center reduces mortality markedly. In principle, this benefit can be attributed to superior preclinical therapy, primary admission to a Level I trauma center, or both. However, the identical probability of survival of the AMB-UNI and HEMS-UNI groups in this and comparable studies does not confirm generally better survival rates on account of a more aggressive on-site approach.

Adult↗

PubMed2004

Collagen type I increases bone remodelling around hydroxyapatite implants in the rat tibia.

The early interface reaction of cancellous bone to a nanocrystalline hydroxyapatite (HA) cement containing 3 wt% collagen type I (HA/Coll) with a setting under physiological temperature and pH was observed using immunohistochemical techniques. Pure HA served as a control. Cylinders with a diameter of 2 mm were implanted into the proximal tibia of 72 adult Wistar rats. Histological sections of 6 animals were prepared after 1, 2, 4, 6, 14 and 28 days. First, osteoblast-like cells as well as a marked reaction for osteonectin, osteopontin and its ligand CD44 were observed as early as 2 days after implantation at the interface around HA/Coll implants. Further, reactivity for ED1 and cathepsin D, both markers for phagocytotic cells, appeared earlier and stronger around HA/Coll. In cell counts, a significantly higher average number of ED1- and cathepsin D-positive phagocytotic cells was observed around the HA/Coll implants on days 6 (p < 0.01), 14 and 28 (p < 0.05). The number of osteopontin-positive cells was significantly higher around HA/Coll implants at days 6 and 14 (p < 0.05). Two weeks after the implantation, first islands of newly formed woven bone were observed around the HA/Coll implant, but not around the control implant. The amount of direct bone contact after 28 days averaged 28% around pure HA and 51% around HA/Coll implants (p < 0.05). While both implants displayed a good osteoconductivity, a higher bone remodelling activity was observed around collagen-containing HA implants compared to pure HA implants. It appears that the addition of collagen to HA implants can enhance both phagocytotic and osteogenic processes. This may result in an earlier acceptance and better osseointegration of the HA/Coll implants into the surrounding tissue.

Animals↗

PubMed2003

Peroneus longus ligamentoplasty for chronic instability of the distal tibiofibular syndesmosis.

The distal tibiofibular syndesmosmotic ligament complex is important for dynamic stability and congruency of the ankle joint. Syndesmotic lesions in the ankle fracture-dislocations are well recognized and classified systematically. Chronic insufficiency of the syndesmosis leads to a lateral shift of the talus and under eversion stress permits a pathological rotation of the talus. There is also retroversion of the distal fibula representing a painful deformity. Little experience exists with surgical reconstruction of the syndesmosis. This article describes a new ligamentoplasty with a split peroneus longus tendon graft that mimics the normal anatomic conditions of the syndesmotic complex in 16 patients with symptomatic chronic syndesmotic insufficiency after pronation-external rotation and pronation abduction injuries to the ankle joint. Postoperatively, no infections or hematomas were seen. One patient had asymptomatic breakage of the syndesmosis screw; one patient had a 10 degree decrease of dorsiflexion at the ankle because of a partial anterior tibiofibular synostosis. Fifteen of 16 patients had pain relief at a mean follow-up period of 16.4 months (range, 13-29 months); all patients had relief of the chronic swelling of the ankle and the giving way. The mean Karlsson score at follow-up was 88 (range, 70-100) points. It may be concluded that peroneus longus ligamentoplasty in a preliminary series resulted in reliable ankle stability and considerable pain relief in patients with chronic syndesmotic instability.

Adult↗

PubMed2002

Percutaneous, arthroscopically-assisted osteosynthesis of calcaneus fractures.

BACKGROUND: The development of major and minor wound complications is a major concern in the open reduction and internal fixation of displaced intra-articular calcaneus fractures. Percutaneous, arthroscopically assisted screw osteosynthesis was developed to minimize the surgical approach without risking inadequate reduction of the subtalar joint. The method was applied in selected cases of displaced intra-articular calcaneus fractures with one fracture line crossing the posterior calcaneal facet (Sanders type II fractures). METHODS: Between March 1998 and July 2000, 15 patients were treated with that method. Percutaneous leverage was carried out with a Schanz screw introduced into the tuberosity fragment (the Westhues maneuver) under direct arthroscopic and fluoroscopic control. After anatomic reduction was achieved, the fragments were fixed with three to six cancellous screws introduced via stab incisions. RESULTS: The functional results of 10 patients at a minimum of 1 year follow-up are good to excellent, with an average AOFAS ankle-hindfoot score of 93.7 (range 87-100) and an average Maryland Foot Score of 95.8 (range 93-100). Overall patient comfort and satisfaction were superior to open reduction for similar fracture patterns, and the in-hospital time could be reduced. CONCLUSIONS: Percutaneous, arthroscopically assisted osteosynthesis offers exact assessment of the articular surface and allows anatomical reduction while adhering to the principles of minimally invasive surgery. The short-term results are excellent, while long-term results with greater patient cohorts are awaited.

Adult↗

PubMed2002

The use of subtalar arthroscopy in open reduction and internal fixation of intra-articular calcaneal fractures.

Congruency of the subtalar joint is a major predictor of outcome after intra-articular calcaneal fractures. Because of the irregular shape of the posterior joint facet, minor steps may be overlooked with direct vision or intra-operative fluoroscopy during open reduction and internal fixation (ORIF). In a preliminary series of 15 subtalar arthroscopies during hardware removal after ORIF of intra-articular calcaneal fractures, patients with visible steps of 1 mm or more had significantly inferior functional results compared to those with an intact subtalar joint (117 vs. 158 points with the 200-point score, 71.3 vs. 91.2 points with the Maryland Foot Score, P<0.01). Congruency of the posterior facet was controlled arthroscopically in 47 intra-articular calcaneus fractures after open reduction and temporary K-wire-fixation. In 12 cases (25.5%), despite seemingly correct reduction as judged fluoroscopically, incongruencies in the posterior calcaneal facet were detected and reduction was repeated, temporarily removing the K-wires. After anatomical reduction a standard AO calcaneal plate was fixed to the lateral wall. Intra-operative arthroscopy appears to be useful in detecting minor incongruencies after ORIF of intra-articular calcaneus fractures. In the hands of an experienced surgeon it is less time demanding than intra-operative X-rays and more precise than fluoroscopy.

Adult↗

PubMed2002

Ligamentous injuries about the ankle and subtalar joints.

Ligamentous injuries at the ankle and subtalar joint range from simple sprains to severe talar dislocations. While lateral ankle sprains are among the most frequently encountered injuries and do not pose a greater diagnostic problem, the surgeon must be suspicious not to overlook associated ligamentous injuries at the subtalar and midtarsal level that may result in chronic painful conditions. Syndesmotic instabilities with or without ankle fractures must be assessed carefully and treated properly, since these are prearthrotic conditions. In the treatment of chronic ankle or subtalar instability tenodeses provide mechanical stability while reducing subtalar mobility. Anatomic reconstruction methods therefore should be considered for both conditions.

Ankle Joint↗

PubMed2002

The value of subtalar arthroscopy in the management of intra-articular calcaneus fractures.

UNLABELLED: A wealth of clinical and experimental data suggests, that anatomical restoration of the posterior calcaneal facet is a major predictor of outcome after intra-articular calcaneus fractures. The value of subtalar arthroscopy was examined in three clinical study groups (I-III. MATERIALS AND METHODS: (I) The subtalar joint was inspected arthroscopically in 28 patients during hardware removal one year after open reduction and internal fixation (ORIF). This procedure was accompanied by subtalar arthrolysis in all cases. (II) Open subtalar arthroscopy was performed to evaluate the quality of reduction after ORIF of intra-articular calcaneus fractures in 59 cases. Arthroscopy was performed after seemingly exact reconstruction of the posterior facet as judged visually and fluoroscopically. (III) Arthroscopically assisted percutaneous reduction and screw fixation (PRSF) was performed in 18 patients with Sanders II fractures. Reduction was achieved with a Schanz screw introduced percutaneously into the tuberosity fragment and controlled fluoroscopically, while fine corrections were made under arthroscopic guidance. RESULTS: (I) Clinical results after ORIF of intra-articular calcaneus fractures were highly correlated to the degree of residual incongruities and chondromalacia of the posterior facet as seen arthroscopically during hardware removal (P < 0.01). (II) In 13 of 59 cases (22.0%) during ORIF despite seemingly accurate reduction, steps between 1-2 mm were detected arthroscopically in the posterior calcaneal facet and reduction was repeated subsequently in these cases. (III) Fifteen patients who underwent arthroscopically guided PRSF were re-evaluated after a minimum of one year with excellent clinical results (94.1 pts. with the AOFAS scales). No wound complications were seen. CONCLUSIONS: Subtalar arthroscopy provides a most precise and thorough view of the posterior facet of the calcaneus both in assessing the quality of initial reduction as well as evaluation during hardware removal after intra-articular calcaneus fractures. It is more precise than intra-operative fluoroscopy and less time consuming than standard Brodén views during surgery. The use of arthroscopy allows anatomical percutaneous reduction and screw fixation of Sanders II fractures. It therefore provides a useful additional tool in treating intra-articular calcaneus fractures.

Adult↗