There is a great deal of discussion about the dynamization and if it is necessary or not. I am a supporter of dynamization and the time is controlled by the type of the fracture, the position and the healing progress. The earliest could be in six weeks for a short oblique stable fracture. For a transverse stable fracture I am a believer (and I know that this will raise some different opinions) of non locking or lock the most unstable part (the fragment that is closer to the metaphysis; so a distal third transverse fracture will be locked distally only and so on). All is based on series of X-rays and healing progress.

thank you Dr,George Zafiropoulos for your interesting answer

Yes, time for dynamization depends on the type of fracture and healing progress as George already mentioned above. In any case it also depends upon what bone is fractured. For example, in femoral fractures it can be done after 4 months, especially in cases with delayed healing in an attempt to stimulate consolidation.  

Though there is still controversy over the utility

of dynamization in closed intramedullary interlocking

nailing of the femur, the present series of

open interlocking nailing with and without

dynamization indicates that, while dynamization

does not change the union rate of the fracture as

compared to static nailing, it definitely shortens the

mean time to union. Dynamization after open interlocking

nailing is also capable of achieving healing

times comparable to closed interlocking nailing.

However, it has the disadvantage of causing

femoral shortening in some instances. Open interlocking

nailing itself is responsible for increasing

the incidence of postoperative infection and should

be resorted to only in cases in which closed nailing

is not possible or suitable. Therefore, it is concluded

that dynamization should be considered 8 to

12 weeks post-operatively in those cases of

intramedullary interlocking nailing of femurs that require open reduction

Dynamisation with a screw preserved in the dynamic locking hole was associated with a higher success rate in bone union than all screws removed from one end of the nail for patients with delayed healing FSFs. (2) Early dynamisation (10-24 weeks) had a better outcome than late dynamisation (>24 weeks). Late dynamisation with all screws removed from one end of the nails resulted in a poor success rate. Alternative treatment should be considered if the latter approach is to be adopted

Treatment of a long bone and mainly in a weight bearing limb with the use of an IM nail has some controversies as mentioned above. The static or dynamic fixation or the dynamisation of a static fixation is one of them. There are surgeons who fill every possible hole of the nail and others who do not. This maybe for a reason or not a reason at all. There is literature supporting either side of the argument. Dynamisation is there to be done if it is necessary and has to be done at the correct time. This is determined by the close follow up and the "fears" that the responsible operating surgeon has and only he can apply the treatment correctly. There is a routine that patients may never see after surgery their surgeon, but a member of the team who may has an alternative understanding for the treatment and may apply this in a different way. Also the application of dynamisation can be done or consider to be done on the wrong fracture configuration. Kuntscher, the father of the IM nail, was dynamising at all times but he had a certain pattern of fractures who was allowing such treatment. Protocols may exist but the question is if they are followed and how these are interpreted by all treating doctors. Literature never goes to such an extend of detail to tell us why treatment A or treatment B is failing. This maybe because it is difficult to know or that all we maybe biased towards our results.We must not forget that we need to treat the patient at all times and every one of them is unique with their unique necessities and comorbidities. Finally we must be honest when reporting our results. This is part of our professional behaviour

 I agree with all what written upove by my colleagues . I follow the patient x rays and if there is no signs of healing I prefer to do dynanization  after 12 weeks of operation. 

 I agree with all what written upove by my colleagues . I follow the patient x rays and if there is no signs of healing I prefer to do dynanization  after 12 weeks of operation. 

Dear Medhat

This article may be useful for you:

Injury. 2012 Oct;43(10):1747-52. .

Evaluation of methods and timing in nail dynamisation for treating delayed healing femoral shaft fractures.

Huang KC1, Tong KM, Lin YM, Loh el-W, Hsu CE.

sir need opinion from seniors regarding the topic in line..i operated this 2months back closely reamed nail..last xray being 8wk postop...was again confused whether to go for dynamization ..and when and whether to remove proximal or distal screws with fibulectomy

Dynamization is related with weight bearing.

In theory, with "static" locking not WB shoud be allowed until callus formation is clearly visible in Xray and there is no pain at the racture site. In locked nails , weight is transmitted to the screws, not to the fracture. If the fracture pattern is stable enough as to permit WB , then, a "dynamic" locking is prefered (certain amount of compression at the fracture site, if it has adecuate "angular and rotational stablility ", promotes healing).

For understandig that, is good to have experience with non operative treatment of tibial fractures, as recomended by Augusto Sarmiento, with long leg cast , knee in extension, and early partial WB , followed by a "functional" PTB cast and full WB. Before the interlocking nails era, we have treated a lot of tibial fractures with Küntcher nails ( non locking) plus a PTB cast and, frecuently, early BW .

The "oval dynamic hole" is in the nails for a reason: For allow earlier weight bearing, compression, and earlier healing of "stable enough" fractures.