Tedavi yöntemleri hakkındaki yorumlar tıbbi dergilerde yayınlandı.

A natural breakdown is:

• Tedavi yöntemleri hakkındaki yorumlar = the comments about treatment methods
• tıbbi dergilerde = in medical journals
• yayınlandı = were published

So the full sentence is structured like this:

• [subject] [place] [verb]

This is very normal in Turkish. Also, Turkish puts modifiers before the noun they describe, so tedavi yöntemleri hakkındaki yorumlar literally feels like:

• treatment methods-about comments

rather than English comments about treatment methods.

Because tedavi yöntemleri is a very common Turkish noun compound pattern.

• tedavi = treatment
• yöntem = method
• tedavi yöntemi = treatment method
• tedavi yöntemleri = treatment methods

In this pattern, the second noun usually takes a special ending, often called the compound marker or 3rd person possessive-looking suffix. So even though English just puts two nouns together, Turkish usually marks the second noun.

So:

• tedavi yöntemi = treatment method
• tedavi yöntemleri = treatment methods

This is the same kind of pattern as:

• okul kapısı = school door
• şehir merkezi = city center
• ders kitapları = textbooks

hakkındaki means about, regarding, or concerning in a form that can directly modify a noun.

It comes from:

• hakkında = about / concerning
• -ki = a suffix that turns it into something like the one(s) about ... or that is about ...

So:

• tedavi yöntemleri hakkında yorumlar = comments about treatment methods
• tedavi yöntemleri hakkındaki yorumlar = the comments that are about treatment methods

In this sentence, hakkındaki is used because it connects tedavi yöntemleri to yorumlar as a modifier.

Not in exactly the same structure.

You can say:

• Tedavi yöntemleri hakkında yorumlar yayınlandı. = Comments about treatment methods were published.

That is perfectly possible.

But in tedavi yöntemleri hakkındaki yorumlar, the form hakkındaki is acting like an adjective attached to yorumlar:

• the comments regarding treatment methods

So both are possible in Turkish, but they are built differently.

Because it means comments, opinions, or reviews in the plural.

• yorum = comment / interpretation / review
• yorumlar = comments / interpretations / reviews

In this sentence, the subject is plural: yorumlar.

Depending on context, yorumlar could be translated as:

• comments
• opinions
• reviews

Here, comments is probably the most neutral choice.

This is a very common point for English speakers.

In Turkish, the verb often stays in 3rd person singular when the subject is plural, especially when the subject is non-human.

So:

• Yorumlar yayınlandı. = The comments were published.

This is completely normal Turkish.

English requires plural agreement: comments were.
Turkish often does not require a plural verb form here.

With human subjects, Turkish can sometimes show plural agreement more often, but with things like comments, books, articles, methods, singular verb agreement is very common and natural.

Yes.

It comes from the verb:

• yayınlamak = to publish

Its passive/intransitive form is:

• yayınlanmak = to be published / to get published

Then:

• yayınlandı = was published / were published

So the ending here includes:

• passive-related verb stem: yayınlan-
• past tense: -dı / -di / -du / -dü according to vowel harmony

Because the subject is plural in English, we translate it as were published, even though Turkish uses the same verb form.

It means in medical journals.

Breakdown:

• tıbbi = medical
• dergi = journal / magazine
• dergiler = journals
• dergilerde = in the journals / in journals

So:

• tıbbi dergilerde = in medical journals

The ending -de is the locative suffix, meaning in, at, or on, depending on context.

Because -de / -da / -te / -ta is the Turkish locative suffix, and its form changes according to vowel harmony and consonant voicing.

Here:

• dergi has a front vowel, so we get -de rather than -da
• plural first: dergi + ler = dergiler
• then locative: dergiler + de = dergilerde

So dergilerde literally means in journals.

No. Turkish does not have a definite article like English the.

So yorumlar can mean:

• comments
• the comments

And tıbbi dergilerde can mean:

• in medical journals
• in the medical journals

The exact English choice depends on context.

That means this sentence could be understood as:

• Comments about treatment methods were published in medical journals.
• The comments about treatment methods were published in medical journals.

Both are structurally possible from the Turkish alone.

Yes, Turkish word order is fairly flexible, but the neutral order here is very natural:

• Tedavi yöntemleri hakkındaki yorumlar tıbbi dergilerde yayınlandı.

You could move parts around for emphasis, for example:

• Tıbbi dergilerde tedavi yöntemleri hakkındaki yorumlar yayınlandı.

This still means essentially the same thing, but now tıbbi dergilerde is emphasized a bit more.

The verb usually stays at the end in standard Turkish, so yayınlandı naturally comes last.