Introduction
This project, the International Fingertip Injury Study, is directed to collecting data on the outcomes of fingertip injuries. It was started by a discussion at the International Federation of Societies for Surgery of the Hand (IFSSH) meeting in Vancouver in May of 1998, at a symposium on fingertip injuries. It was observed that there has never been a prospective study performed to evaluate the many techniques that have been developed to treat fingertip injuries. David Nelson, MD, was appointed to be the investigation leader, charged with directing the study, defining the study method, and obtaining financing. The goal is to report back to the IFSSH at the 2001 meeting.
Background
Fingertip injuries are to be differentiated from finger amputations. If a finger is amputated at the level of the distal interphalangeal (DIP) level or proximally, it is potentially a candidate for a replantation, using microvascular techniques. These injuries are not the object of this study. If a finger is amputated distal to the DIP level (termed a "fingertip amputation" as opposed to a "finger amputation"), it is not a candidate for replantation, due to the fact that the artery trifurcates at this level and microvascular techniques are not adequate to reanastomose the vessels.
The approach for fingertip injuries is quite different from the microvascular techniques for replantation. There are many techniques for treating these injuries, at least 25 that we have identified. Many of these techniques have been developed out of the microsurgical techniques developed for microvascular surgery and out of the increased anatomical knowledge of the fingertip and its blood supply. Some are quite ingenious. In fact, there has been quite a fascination with the various techniques, in part due to the technical skill required to perform them and in part due to the frequency of the problem. Indeed, most hand surgery training centers see dozens of these injuries a year, whicle some may see hundreds. Hand surgery and plastic surgery texts have whole chapters devoted to the problem of treating fingertip amputations, with sections on each of the techniques As noted above, we have found at leat 25 different techniques delineated in texts and journals.
While there are many papers on the results of these techniques, the studies are often by the originators, with no other support for a specific technique. There has been only one prospective study comparing techniques, but it is from 1963 (Sturman, 1963), prior to the time when the majority of current techniques were described. This may surprise many, who would presume that such a common problem would have been addressed in many prospective, randomized studies. However, there may be at least a partial explanation for the lack of prospective, randomized studies.
Studies of fingertip amputations are difficult to perform, due to the complexities both of fingertip classification and result evaluation. First, fingertip injuries can be of many different types and attempts to classifiy them have been only partly successful. The best-known classification system, described by M. J. Allen (1980), has failed to be widely adopted, and some texts even omit it entirely (D.S. Louis, 1999). A modification of the Allen classification has been proposed by Brunelli (1991), but it also has not been widely adopted. Many of the classic texts of hand surgery do not attempt to classify fingertip amputations at all, with the result that hand surgeons in training usually are not exposed to any classification system.
Second, the evaluation of results of fingertip amputations is complex. A consensus on the best manner to evaluate outcomes has not been reached, even on such seemingly simple topics as how to evaluate sensation. Moberg first drew attention to this problem in the 1960's and popularized the two-point discrimination test (Moberg, 1990). The two-point discrimination test is now the standard test. However, it has been shown that the Semmes-Weinstein monofilaments are a more sensitive test of sensation (Szabo, 1984). This is primarily due to differences in the fundamental nature of the tests: two-point discrimination is a density test and Semmes-Weinstein monofilaments are a threshold test. There are additional problems related to standardization of these tests (Mielke K, 1996).
However, sensation is not the only parameter that needs to be evaluated in cases of fingertip amputation. Painful sensitivity to light touch or firm pressure is often disabling for these patients a year or more after their injury and can often be the reason that the patient cannot return to their original employment. Cold sensitivity is the rule, and it is unusual for a patient not to have it. The problem usually lasts two years, even for such a simple task as picking up a glass of water. There is no standardization for testing either painful sensation or cold sensitivity. Sturman and Duran (1963), in the only published prospective study of fingertip amputations, did not test cold sensitivity due to the "many statements in the literature (which) indicate the unreliability and difficulties of this test."
The problems in designing a study of fingertip amputations should be fairly evident from this discussion. It should be added that a very large study would be needed to reach statistical significance due to the large variation in both injury types and treatment alternatives. A study of twenty-five methods of treatment for a problem that can be classified into four types would need hundreds of patients in order to reach statistical significance. Only a multi-center study would be able to reach these numbers.
A final complication to performing a prospective, randomized study is the fact that, despite the almost complete lack of data supporting any one technique, surgeons and institutions usually have a very strong devotion to a particular method. Lacking any justification (ie, a prospective, randomized clinical study) for adopting a different approach, it is difficult to entice them to change. The circular nature of the problem should be evident.
Additional Reasons to Perform the Study
The fact that there has not been a prospective, randomized study of the at least 25 different methods of treating fingertip amputations is sufficient justification for conducting such a study. There are at least two additional reasons such a study needs to be performed. First, it has been a commonly expressed opinion by experienced hand surgeons that the more complex methods of treatment do not offer any advantages in terms of clincal outcome, have much higher rates and degrees of complications, and are vastly more expensive. However, there are no prospective studies supporting this opinion. Textbooks, lacking a foundation for recommending one technique over another, describe all techniques, with the unfortunate result that many hand surgeons in training try many of them before settling on those that work in their hands. If a properly conducted, prospective, randomized study is completed, textbooks would have a basis for recommending some techniques and discouraging others. Second, a new technique using a semi-permeable membrane has been published (Mennen, 1993) that has suggested improved results with a very simple method that is superior to other treatments. In addition, it is cost-effective and could be performed in countries with very little in the way of medical assets without any loss of effectiveness. Several of the surgeons present at the IFSSH symposium had experience with this technique and agreed with the Mennen's recommendation. However, lacking a prospective, randomized trial of this method, it is unlikely that it will be widely adopted. The study will be designed as a prospective, randomized trial, without any bias towards the semi-occlusive membrane technique, or any other technique. The study should have the methodology to establish which technique is superior for any particular clinical situation.
The Current Study
The initial approach of this study is to conduct a large, multi-center, prospective, non-randomized study of fintertip amputations. The study will collect data on the outcomes of a large group of surgeons, allowing them to use the technique of treatment that they currently use. The reason for this approach is two-fold. First, we have no scientific way of selecting among the various treatment methods as a superior method, and second, we have no scientific justification for suggesting that a surgeon use any treatment over what the surgeon currently feels is the best technique in their hands. Therefore, the initial (present) study is to classify injuries in a standardized manner and to rate outcomes in a standardized manner, but to allow the surgeons to use the treatment that they currently use and feel is best in their hands. It is the hope that the data from the initial study will allow the elimination of some techniques as clearly inferior and the identification of some techniques as worthy of further study. A proposed, future second study would be a prospective, randomized study based on what was learned in the first study.
Multi-center Study
As outlined in the Background section, hundreds of patients will be needed to reach statistical significance. We also need to enlist the participation of many surgeons and many institutions in order to include the many different approaches to fingertip amputations, if we are to eliminate some of them in the first study. At the International Federation of Societies for Surgery of the Hand meeting in 1998, which gave rise to this study, there were requests for participation from 19 medical centers in 15 countries. A preliminary meeting was held and many of the participants were present. It was anticipated that some individuals and institutions would drop out and that new ones will be added, and that has been the case. Recruitment of additional study sites is ongoing, due to the fact that adding additional sites does not retard the progress of the study as a whole and because the method of conducting the study allows the addition of new sites without adding any expense.
Initial Meeting and Study Design
The initial meeting in 1998 outlined the basic purpose and method of the study. David Nelson, MD, was charged with conducting the study and the meeting participants confirmed this appointment. A proposed study outline was adopted at the meeting and has been refined subsequently. The database template has been designed. It was proposed and adopted that the study be coordinated over the internet, with each site able to upload their own data to decrease cost to the study coordinator. Each site will also be able to download the entire database, so as to allow each center to analyze the data according to the conditions at their site. For example, complex methods of treatment that are common in a developed country may simple be unavailable in a lesser developed country. Sites will not be able to upload the entire database, however, to avoid corrupting the database. Funding was obtained in late 1998 for 1999 and additional funding secured for 2000.
Protocol
The database template has been agreed upon by the participating centers at the start of the study. Each investigator in charge at each institution will be responsible for collecting the data and uploading it into the ITIP database via the internet. A website has been established as a focal point for the study; it is rudimentary now and is currently being developed. In the near future it will have information to assist each investigator in conducting the study. Preliminary data will be uploaded as available. A contract was signed in December, 1999, to write the necessary program to allow coordination of the study via the internat. It should be up on the site in the second or third quarter of 2000 to allow each investigator to upload their data, and to download the aggregate data, but not to upload the aggregate data (to avoid data corruption).
Human Study and Informed Consent Issues
Institutional Review Board (IRB) approval was obtained from Dr. Nelson's institution, since he is the study coordinator. It was the IRB's opinion that the initial study, allowing participating surgeons to use any method of treatment but classifiying all injuries according to the same system and rating all results in the same manner, would be exempt from IRB supervision. IRB approval will be needed for the second study, in which participating surgeons will be restricted to using only those methods which showed promise in the first study.
There will not be any informed consent in the first study. This study is only collecting data on the outcomes of the techniques of treating fingertip injuries already used by the investigators. As such, seeking informed consent that would be possible, since the patient would not be consenting to anything. That is, there is no difference between participating and not participating in the study. This opinion has been confirmed by the IRB at the study coordinator's institution.
It should be noted that the database template does not have a location for uploading the patient's name, address, etc. The local investigator will be responsible for maintaining his or her own patient information. The main database will not need this data, and not having a place where it can be uploaded will ensure confidentiality in any report based on the data.
Each investigator is responsible for sending to Dr. Nelson a written explanation of the human subject research protocol for their country. They will be responsible to ensure compliance with any regulations and to send Dr. Nelson confirmation of such compliance. Dr. Nelson's IRB waiver will cover any study site in the US.
References
Allen, MJ. Conservative management of finger tip injuries. Hand 1980;257-265.
Brunelli, F. Treatment of fingertip amputations. In: Clayton Peimer, Editors. Surgery of the hand and upper extremity. New York: McGraw Hill,1996: 1069-1099.
Moberg E. Two-point discrimination test. A valuable part of hand surgical rehabilitation, e.g. in tetraplegia. Scand J Rehabil Med 1990;22(3):127-34.
Mielke K, Novak CB, Mackinnon SE, Feely CA. Hand sensibility measures used by therapists. Ann Plast Surg 1996 Mar;36(3):292-6.
Szabo RM, Gelberman RH, Dimick MP. Sensibility testing in patients with carpal tunnel syndrome. J Bone Joint Surg [Am] 1984 Jan;66(1):60-4.
Sturman MJ and Duran RJ. Late results of finger-tip injuries. JBJS 1968;45A: 289-298.
Mennen U and Wwiese A. Fingertip injuries management with a semi-occlusive dressing. J Hand Surg 1993;18B:416-422.
ITIP is now actively seeking participating surgeons and medical centers. Please examine the database template below. If you feel that you would like to participate in the study, please contact David L. Nelson, MD.
Click here to go to the template