A good case can be made for the reading as a verb instead of a noun with a preposition prefixed.
Regarding verse 16, Walter Kaiser (The Messiah in the Old Testament, footnote 10 pg. 115 and 116) lays out his argument for the verb by referencing the Vulgate, the Syriac, and the Septuagint, all of which have verbs. He takes the form ka'ari as the irregular plural for ka'arim. This form is a plural participle of kur. While the proper form would be kar, the vowel points are not without precedent: Hosea 10:14 (qa'm); Ezekiel 28:24, 26 (sa'tim). He then defends the interpretation:
- The Hebrew Usage. kur is then synonomous with the verb karah - "to bore through," which often occurs. Such a permutation of the verbs ayin''waw and lamad''hah is common.
- The testimony of the LXX uses oruxzan cheiras mou kai podas mou ("they have dug/pierced my hands and feet") as well as the Syriac perforarunt and the Vulgate foderunt. (Jerome outside the Vulgate, translates the Hebrew into fixerant.)
- In Arabic, the agreement of kur with karah exists. Though this is not an argument ender, the appearance in a cognate language does lend support.
Regarding the Septuagint rendering the Hebrew as a verb, the rest of the psalm needs to be compared. If the Greek and Hebrew agree closely throughout the rest of the psalm, then we can be more sure that the Hebrew text was a verb. If other parts of this psalm are translated more loosely, then the testimony of the Septuagint here is lessened. Kaiser refers to the LXX as a direct translation. In places, it certainly is (Numbers has even been called "Greek vocabulary on top of Hebrew syntax"). However, in other sections of the Tanakh, the translation is rather freeform.
Aquila, in his Greek translation of the Tanakh first rendered the word in question with the verb eschuan, reading the Hebrew as a later Hebrew word meaning "make dirty." However, as he could not support this related to the rest of the psalm, his second edition agrees with that of Symachius and uses "they have bound." Both Aquila and Symachius are Jewish (converts to Judaism, it appears), though after the time of Jesus.
A discovery of a Hebrew scroll at Nahal Hever renders the word as כר[ו ]ידי. Very detailed grammatical information may be found here. Some scholars debate if the Septuagint translators had a text reading כארו instead of כארי. That is, the final letter is a longer waw instead of the short yod. Such a mistake between the yod and waw has been noted before1 and the misreading is easy to make. Others note that the Hebrew word for "lion" appears in the psalm both before (13/14) and after (21/22), but the spelling is different from verse 16/17. Before and after both use אריה.
- One of my seminary professors graduated from Hebrew Union. His best friend there did his doctoral dissertation on determining yod and waw in parts of the Dead Sea Scrolls where it could not be determined by sight if the letter was one of the above and Hebrew words could be formed by more than one option. His research involved calipers and magnifying glasses.