The study posted did not prove that ibuprofen does not interfere with healing. What it did was to demonstrate that of the NSAIDs administered to rats with knee injuries, all but one - ibuprofen - caused problems. We don't know if a higher dose would have caused problems for the little rats, or if ibuprofen is universally safe for all tendinopathies. This study, for instance, is more recent than the one Prince posted:
Ibuprofen upregulates expressions of matrix metall... [J Orthop Res. 2010] - PubMed result
"In conclusion, ibuprofen upregulates the expressions of collagenases including MMP-1, -8, -9, and -13 without affecting the expressions of types I and III collagen.
These findings suggest a molecular mechanism potentially accounting for the inhibition of tendon healing by ibuprofen." Note that the researchers do not doubt ibuprofen's inhibition of tendon healing - in fact, they are postulating the mechanism.
We have had strong evidence for many years now that ibuprofen causes problems for tendinopathies in primates, which are much closer to humans and thus for whom results are more generalizable:
Oral ibuprofen: evaluation of its effect on perite... [J Hand Surg Am. 1986] - PubMed result
Oral ibuprofen: evaluation of its effect on peritendinous adhesions and the breaking strength of a tenorrhaphy.
Kulick MI, Smith S, Hadler K.
Abstract
In a study of 21 primates, treatment with oral ibuprofen significantly reduced the force required for tendon gliding following flexor tendon injury in zone II. Tendons that were partially lacerated but not repaired required less force for tendon motion than those repaired. Ibuprofen also reduced the breaking strength of completely divided and repaired extensor tendons. The addition of a piece of chromic suture buried across the extensor tenorrhaphy site significantly increased the breaking strength of the repair in control and treated animals alike. These findings were observed at 4 and 6 weeks after tendon injury and repair. No adverse reactions to the medication were observed.
There has been surprising little research done on humans using ibuprofen, but one recent study showed that it interferes with bone healing:
Effect of acetaminophen, ibuprofen and methylpredn... [Arch Oral Biol. 2010] - PubMed result
"CONCLUSION: These results suggest that ibuprofen, acetaminophen and methylprednisolone at therapeutic doses reduce osteoblast growth without affecting other cell parameters, such as antigenic profile or cell cycle. Use of these drugs should be reconsidered in clinical situations that require a rapid healing of bone defects."
So, depending upon your particular persuasion you may choose to identify with the lucky rats in one study, or the unfortunate humans, rats and primates in other studies. NSAIDS interfere with healing because they interfere with inflammation. Sometimes this is helpful. Usually it is not. A notworthy exception is in cases where healing is not desirable (adhesions). If you must take an NSAID, ibuprofen is the one you probably want as it seems to cause the least problems of them all. But I would stop short of recommending it during the acute healing phase of an injury.