Exegesis:

kai idou gunē lit. ‘and behold, a woman…,’ hence, ‘and there was a woman.’

pneuma echousa astheneias lit. ‘having a spirit of sickness,’ i.e. ‘possessed by a spirit that caused sickness,’ or, ‘having a sickness caused by a spirit.’ The spirit and the sickness are conceived as being one, cf. 11.14.

etē deka oktō ‘eighteen years,’ accusative of duration.

kai ēn sugkuptousa ‘and she was bent double,’ i.e. as a result of the sickness.

kai mē dunamenē anakupsai eis to panteles ‘and completely unable to straighten herself up.’ eis to panteles is best understood as going with dunamenē.

anakuptō (also 21.28) ‘to raise oneself up,’ ‘to straighten oneself,’ less probably ‘to lift up the head’ (cf. Lagrange, The Four Gospels – a New Translation).

eis to panteles ‘completely,’ ‘wholly,’ ‘at all.’

Translation:

To have a spirit of infirmity often is to be described by, ‘to have (or, to be possessed/entered by) a spirit/demon that makes (a person) ill,’ or with a resultative clause, ‘so that one becomes ill’ (cf. East and Toraja-Sa’dan), cf. also, ‘to be the host of a spirit that took away her strength’ (Shona 1966). In Tzeltal the idiom is, ‘to be molested by the devil’; Ekari uses a form that may mean both ‘having seen a spirit’ and ‘a spirit having seen her,’ either event being thought of as a cause of illness. For spirit cf. 9.39, for infirmity see “disease” in 4.40.

She was bent over …, sometimes introduced by, ‘because of that,’ ‘so that.’ Idiom may require another subject, e.g. ‘her back was bent’ (Bahasa Indonesia, similarly Sranan Tongo, lit. ‘was-broken’), ‘her body was crooked’ (Batak Toba).

Straighten herself, or, ‘her body/back,’ or, “stand up straight” (New English Bible, similarly Sranan Tongo).

Quoted with permission from Reiling, J. and Swellengrebel, J.L. A Handbook on the Gospel of Luke. (UBS Handbook Series). New York: UBS, 1971. For this and other handbooks for translators see here . Make sure to also consult the Handbook on the Gospel of Mark for parallel or similar verses.