The NIV seems to be a denomination specific translation, they use word play quite often to make it a point to make the Hebrew writings appear to be speaking of Jesus' coming to save mankind and Israel as their saviour. However in this case they seem to have gone well out of their way.
Most of the time when read in the NT the usage of the title Lord is in reference to Jesus, but in the Hebrew whenever you see LORD (all caps) it is actually covering the name of the Hebrew God YHVH. A few translations add it back to the writings such as the NOG and the NWT (NWT with a twist, they use Jehovah).
When read in the way it is originally written, it is quite different, I'm including verse 5 as well to give context. (On a side note, I seldom use either of these versions, except to point out the names used and covered)
5 “The days are coming,” declares Yahweh,
“when I will grow a righteous Tsemach for David.
He will be a king who will rule wisely.
He will do what is fair and right in the land.
6 In his lifetime, Judah will be saved,
and Israel will live in safety.
This is the name that he will be given:
5 “Look! There are days coming,” is the utterance of Jehovah, “and I will raise up to David a righteous sprout.+ And a king will certainly reign+ and act with discretion and execute justice and righteousness in the land.+ 6 In his days Judah will be saved,+ and Israel itself will reside in security.+ And this is his name with which he will be called, Jehovah Is Our Righteousness.”
5 The days are surely coming, says the Lord, when I will raise up for David a righteous Branch, and he shall reign as king and deal wisely, and shall execute justice and righteousness in the land. 6 In his days Judah will be saved and Israel will live in safety. And this is the name by which he will be called: “The LORD (YHVH) is our righteousness.”
Now can this be applied to Jesus, yes, but the translators of the NIV wanted it to be indicative that it IS assuredly speaking of Jesus, but if read in the original language it says "YHVH is our righteousness". Is this Jesus? That is up to the reader to determine. So in reality the translation is ok, but being the name YHVH is hidden, they interpreted/translated this verse to speak of Jesus alone, by saying "The LORD Our Righteous Savior" when "Savior" is not anywhere in the text.