The ancient Latin saying volenti non fit iniuria (loosely translated: if you consent you cannot complain) denotes a legal principle on a par with principles such as pacta sunt servanda or non concedit venire contra factum proprium. As a defence to tort claims well established in both the civil and the common law tradition, the phrase articulates an universal value that has never been seriously contested. Why, then, does a young German scholar devote a complete habilitation (professoral thesis) to the study of such an expression? The answer is clear: as with any general principle of law, the problems start once you try to apply them to a specific case. Unlike rules, principles do not lend themselves to easy execution but require thorough reasoning, taking into account the fact that principles may work both ways. For example, if a seller does not deliver the promised good in time, he may invoke the principle of pacta sunt servanda in order to convince a judge that despite his breach the contract should be upheld. Likewise, the buyer may claim that, since the seller did not keep his promise (i.e., violated the said principle), she does not have to keep hers either.

On 28 June 2008, the German Bundestag (Federal Parliament) passed a bill on the reform of German corporate law. Known as the Gesetz zur Modernisierung des GmbH-Rechts und zur Bekämpfung von Missbräuchen (MoMiG – Law for the Modernization of the GmbH and to Stop its Misuse) the bill is a milestone, the single most important reform of the most commonly used German corporate form. The reform will bring about major changes. Among other things the reform will make it possible to establish a GmbH with a share capital of nothing more than € 1 EURO (previously, € 25,000 had been required) and to establish a GmbH that has no active business in Germany but solely operates abroad. Although the bill still has to be approved by the Bundesrat (Federal Council of the States), which will probably vote on this matter on 19 September, experts have little doubt that the reform easily will pass this last hurdle and enter into force as soon as 1 November.

A diagnosis of perilymphatic fistula is still controversial. Recently, a case report indicated that β-trace protein (prostaglandin D synthase) might be a potential marker for perilymphatic fluid. In this multicentre clinical case series study β-trace protein was used as a marker for perilymphatic fluid fistula. Fifteen fluid samples were collected during diagnostic tympanoscopy. In addition, five samples were collected from patients with tympanic membrane perforation for use as as negative controls. Samples were obtained using precision glass capillaries and were analysed for β-trace protein using laser nephelometry. The diagnosis of perilymphatic fistula was defined by the patient's history, the audiological and vestibular investigation and the findings at tympanoscopy. The cut-off level of β-trace protein for perilymph-positive samples was chosen at 1.11 mg/l. The sensitivity and specificity were calculated using a 2 × 2 contingency table. There was no false positive result, but in two cases a false negative result was found. The specificity was 1 and the sensitivity was 0.81. The material of this first clinical study is small owing to the rarity of patients undergoing diagnostic tympanoscopy for perilymphatic fluid fistula. However, according to these preliminary results β-trace protein might be a promising marker in the diagnosis of perilymphatic fluid fistulas.

The incidence of perilymphatic fistula as cause of sudden hearing loss is not known. We present a case with sudden unilateral hearing loss associated with a positive β-trace protein test of an epipharyngeal fluid sample. The patient presented with sudden sensorineural hearing loss on the right side. A stapedotomy had been performed nine months previously due to otosclerosis. Intravenous therapy for the treatment of sudden hearing loss was unsuccessful. At the time of sudden hearing loss, epipharyngeal fluid was collected using a Raucocel sinus pack. Investigation using rocket immunoelectrophoresis showed the presence of β-trace protein. Upon repeating tympanoscopy there was no obvious labyrinthine fluid egress, but the oval window was sealed with fibrin sponge and fibrin glue. The patient’s hearing improved over a period of five months.