Tendon Injuries of the Hand

Author Credentials and Financial Disclosure: James R. Roberts, MD, is the Chairman of the Department of Emergency Medicine and the Director of the Division of Toxicology at Mercy Health Systems, and a Professor of Emergency Medicine and Toxicology at at the Drexel University College of Medicine, both in Philadelphia, PA. Dr. Roberts has disclosed that he has no significant relationships with or financial interests in any commercial companies that pertain to this educational activity. Learning Objectives: After reading this article, the physician should be able to: Describe the proper approach to potential extensor tendon injuries in the ED. Delineate the clinical clues that hint at a partial tendon laceration Discuss the proper follow-up and splinting procedures for hand injuries that may harbor tendon injuries and the surgical approaches to extensor tendon injuries. A proper history and physical examination, carefully charting the ED encounter, and informing patients of real and potential problems are vital in treating flexor tendon injuries. And these issues are similar for extensor tendon injuries, except that the extent of injuries to the deep flexor tendons of the palm cannot always be completely defined on the first ED visit. Anticipating at least a partial flexor tendon laceration in any deep hand injury is a prudent approach. Emergency physicians frequently must diagnose and treat hand injuries that may harbor an injury to extensor tendons. The hand is anatomically complex, and its function is complicated, making this organ somewhat unforgiving of a missed diagnosis, incorrect initial treatment, or delayed definitive therapy. Once the deep structures of the hand are seriously injured, it may be difficult to regain 100 percent function, and certainly not without a significant amount of time and energy on the part of a compliant and motivated patient, physical therapist, and hand surgeon. While emergency physicians rarely perform definitive repair of complex hand injuries, we are on the forefront of diagnosis and must have the acumen to diagnose obvious and potential problems, limit morbidity, and initiate proper referral. Patients usually understand that a major hand injury will be a frustrating struggle to regain normal function, but they rarely forgive an emergency physician for failing at least to anticipate a potential problem, uncover a real problem on the first visit, or perform proper initial wound care.Figure: This patient, left, claimed that she cut her hand that Monday morning on a piece of metal at work, making it a worker's compensation case. It's obvious the wound is a few days old, and was in a classic place for a human bite. Despite an explanation that the history was important to her treatment, she continued to deny being in a bar fight, even when the patient in the next bed recognized her as her assailant and was there for evaluation of a swollen and similarly old lip laceration. The second patient, right, also had a fishy story, and could not explain the piece of a tooth that was found in the laceration. Human bites to these areas can injure or rupture extensor tendons, and are associated with fractures, joint infections, and retained foreign bodies.Leaving a foreign body in the hand or missing a tendon, nerve, or vascular injury is relatively easy when one is juggling a bevy of patients with complicated cardiovascular, neurologic, traumatic, or respiratory emergencies. A quick glance, a cursory examination, or a truncated explanation to the patient about potential problems and stressing the need for timely follow-up are common pitfalls that even a gray-haired professor still makes. Therefore, each hand laceration should be approached with the notion that there is something wrong until proven otherwise. Physician hubris, inattention to detail, a hurried evaluation, and a less than ideal patient often lead to problems for both doctor and patient. Few clinicians would miss a completely lacerated extensor tendon, assuming that tendon unction was adequately evaluated; however, a major partial tendon injury, often initially clandestine in the depths of a swollen and tender laceration, can mislead even a hand surgeon on the first examination. This is especially true of flexor tendons, rather deep structures in the hand, but it also holds for extensor tendons. Even a significant extensor tendon injury can be missed unless attention is paid to the details of the examination. Fortunately, the emergency physician's job is usually infinitely easier than that of the hand surgeon who has to deal with reconstruction, tendon repair, and the rigors of physical therapy, dynamic splinting, and hand rehabilitation. Extensor Tendon: Anatomy, Injury, and Reconstruction Rockwell WB, et al Plastic and Reconstructive Surgery 2000;106(7):1592 This in-depth article is a recent summary of various injuries to extensor tendons. It's a terrific reference article. The authors begin their discussion by stating that the anatomy and function of the extensor mechanism of the hand is more intricate and complex than the flexor system. This is because interconnecting components and a extensor apparatus link a variety of systems and tendons. Unlike flexor tendons, extensor tendons are not covered by a synovial sheath in the hand or fingers. This system gives rise to a variety of open and closed injures that can result from hand trauma. The extensor mechanism allows extension of the digits because of the connection and sharing of the extensor apparatus with an adjacent finger, making even complete tendon rupture more difficult to appreciate on a functional basis. Because of a less protected environment and the superficial anatomical location, extensor tendon injuries are encountered more frequently than flexor tendon injuries. Contrary to general belief, extensor tendons do represent a significant challenge in treatment and rehabilitation, and significant efforts are required to attain complete function following injury. Rehabilitating damaged extensor injury to its original function is not a simple task. Although a variety of blunt or sheering forces will produce extensor tendon problems, I will limit this discussion to traumatic lacerations of extensor tendons that commonly confront the emergency clinician. Complete destruction of the extensor tendon as it travels over the distal interphalangeal joint produces a common deformity of the distal interphalangeal (DIP) joint, termed a mallet finger. This specific injury will be covered in detail in a subsequent column. Lacerations of the central slip of the extensor tendons at the dorsal proximal interphalangeal (PIP) joint of the fingers, termed a boutonniere deformity, also is a complex injury that is best covered in a subsequent discussion. This article, however, provides a detailed description of the diagnosis and treatment of these and many other common finger and hand injuries. Injuries over the metacarpophalangeal (MCP) joint to extensor tendons are almost always open. The authors noted the axiom that these should always be considered a human bite until proven otherwise. Because injuries in this area often occur with a joint in flexion, the actual tendon injury may be proximal to the skin laceration when evaluated by the physician. It is well known that examining the hand in extension may cause a clinician to miss a tendon injury that occurred with the joint in flexion or with a closed fist. When the injured hand is placed on the examining table, the lacerated tendon is retracted. Therefore, the portion of the tendon that appears under the skin laceration will be normal. If an extensor tendon is injured from a human bite, the wound is carefully debrided, copiously irrigated, and left open. An infected joint is a well known complication. Primary repair of extensor tendons in a human bite is not considered a reasonable option. Single or partial tendon lacerations over the dorsum of the hand may be difficult to diagnose by merely testing extensor function. Many of the extending forces are transmitted from adjacent and interconnected extensor mechanisms, requiring direct inspection of the tendon to rule in or rule out injury. The ligamentous and fascial connecting are known as the juncturae tendini. This extensive article details many extensor tendon injuries that will not be covered in this discussion. The reader is referred to the original article for a very erudite and complete discussion of these injuries, as well as a very informative set of diagrams showing anatomic detail. Comment:In the past and in some older literature, extensor tendon lacerations were not portrayed as particularly significant injuries. Extensor tendons often took a back seat to the more exotic flexor tendon discussions. However, lacerated extensor tendons are significant injuries that should not be taken lightly. Special attention is required to prevent long-term sequelae. Assuming that function is evaluated, few clinicians would miss a completely ruptured flexor tendon. Unfortunately, because of the fascial and ligamentous interconnections on the dorsum of the hand, many extensor tendon injuries are often quite subtle. They can fool even the most experienced clinician. Entire books have been written about extensor tendon injuries, but I will address only the evaluation of tendons secondary to penetrating trauma. No clinician would disagree that a history of the mechanism of injury and a complete physical exam are paramount to proper medical care. However, I urge you to look at the last chart of a simple hand laceration that you treated, and see if your charting was up to snuff. Assume that a previous patient had a missed partial tendon laceration, but a complete tendon rupture was noted on suture removal. Critically read the chart to see if your documentation demonstrated a careful, conscious, and prudent evaluation and treatment in the ED, and one that would convince the patient that you made a good faith effort to evaluate his injury fully at 2 a.m. The vast majority of clinicians give cursory attention to etiology. “Cut with knife” is hardly an adequate history. I rarely see the timing of the injury placed on the chart. I almost never see the patient's own words quoting their perception of sensation, function, or possibility of foreign body. And it's almost unheard of to encounter documentation of the specifics of such things as the attitude of the hand prior to evaluation or the results of testing against resistance. As a final check, see if you documented response to light touch and two-point discrimination, and evaluate your follow-up instructions and splinting/bandaging techniques. To produce the best possible document, one should be crystal clear about charting etiquette. I find the templated charts, such as the T-charts, to be far superior to free-form handwritten charts. I urge the clinician to note carefully the positive and negatives on a templated charting system. Often the negatives are more helpful than the positives, and I always backslash (“rule out”) the finer points of the exam. The very inadequate “NVT intact” does little to convince anybody that a proper examination was performed if that is all that appears on the record. Although this discussion concentrates on tendons, consider the fact that tendon injuries often accompany nerve and vascular injuries. Tendon evaluation cannot occur in a vacuum that ignores other injuries. History A history of the mechanism of injury is an important part of the ED evaluation and record. A human bite to the clenched fist can lacerate an extensor tendon, but few will admit to a bar fight, even when everybody in the room knows the mechanism. Be especially aware of this injury on a Monday because many patients have learned that if they claim an injury at work, worker's comp will foot the bill. If a patient denies an obvious human bite, note this in bold letters on the chart, and state you asked that specific question a number of times. If the injury is typical, I always treat such injuries as a human bite, regardless of history.Figure: It is almost impossible to lacerate the dorsum of the hand and not injure an extensor tendon. At the time of suture removal (note healed laceration), a complete extensor tendon rupture was obvious but at a time when surgical repair may not yield the best possible result. This was probably a partial laceration that ruptured because it was not recognized or splinted. The ED charting was too inadequate to convince anyone that the doctor had even examined the patient. The laceration occurred with the fist closed, so if the cut was examined with the hand flat on the suturing table, the area of the tendon injury would not have been seen.If a patient can't tell you whether the hand was flexed or opened, such information should be documented. At least you asked! I believe that it is very important to ask the patient and document on the record if he thinks that he has a serious hand injury, if the hand or fingers “work OK,” and if he thinks there is a retained foreign body or a broken bone. You would be surprised how many patients with missed foreign bodies of the hand or ruptured tendons state that the doctor never asked questions, or they specifically told the doctor that they thought glass was in the wound or the finger did not they claim that the clinician their specific or to negatives are it's difficult to patient that the evaluation was hurried or on the chart give the of a cursory I always chart that no foreign body was by the patient and that was by At least I instructions patients that not all foreign bodies or other injuries can be on the first visit. are when there is a possibility of injury, but more can be by A human bite can a the joint, or a tooth in the you will see in the joint if you all glass is on even very At least should be taken to the possibility of a of the patient who on an hand in a his hand in the or out a an is unless the laceration is can in and and foreign bodies can be deep in a hand wound and initially fool the patient and the clinician. I whether it but I you at least the issues of a foreign body or partial tendon injury, and tell the patient that you that such injuries can as as reasonable the and document that you did not give any 100 percent and other foreign bodies that should not be left in the hand are by have a for foreign bodies of the hand who believe they can a foreign body by history or can find foreign bodies in by a examination, I urge to read an article by et al that retained glass was found by in of that were foreign by the patient's history and patient foreign bodies were on in when the physician's wound was should always be more It is important to each finger but the and interconnections of the extensor tendon apparatus normal when a major tendon is completely Many patients who have injuries are to but usually some can be by can a normal tendon or one that is percent that a patient who his finger is in too to too or is being If a finger regardless of the of the injury or an of the of the patient, one should a complete tendon laceration. a little of even a very injury can some Even if a tendon is percent it will some function, and many will normal. If against however, is it is not out of the question and probably prudent to if the patient is in so that you cannot even begin to the tendon function. Extensor Tendon Injuries most a lacerated extensor tendon will not because these are superficial It is impossible to diagnose all partial extensor tendon injuries on the initial ED visit. The most common clinical is to that of a normal tendon. injuries often to complete rupture at the time of follow-up or suture often repair or definitive are some clues that may the doctor to the of a partial tendon laceration. The first is the patient's own description of hand and finger activity. carefully to the patient. The next is extension against resistance. If you a tendon against you will not appreciate this the patient to the finger you do the job A completely tendon is and should not give with an If the patient that he can the finger it may be too if it is always a partial tendon injury unless your own tell you to a partial tendon injury is the of at the area of the wound when extension is of tendons the and well so with or extension or flexion may be of a partial tendon injury. A partial tendon laceration also may result in an of the the body to that a lacerated tendon should not be or vascular may an injury deep or extensive to of tendon Because the extensor tendons are it is almost impossible to lacerate the dorsum of the hand and not at least injure an extensor tendon. This is one that you should on your first in the ED. It is usually quite simple to a laceration of the dorsum of the hand or fingers, and the superficial extensor tendons of only to the laceration place a clear and and a wound to injury to extensor tendons. It's not that simple with a flexor tendon. and or written by hand or state that emergency physicians should all extensor tendon problems to a hand surgeon. This good on but I have to a hand surgeon who will always to the emergency to with this a hand surgeon cannot up an patient an The of this hand is a for a tendon emergency physician can and function as well as a is no need for a hand surgeon to the or examination that has been in the ED. The that I have when a hand surgeon about a the it the patient on and to the also often the response to a complete extensor tendon It's will be there in an to your but most will not patients from the ED to the merely to a laceration. This is especially true if the wound is old, or Unlike flexor injuries, a hand surgeon may an extensor tendon injury to the room for repair, but there is no of on this Many will to this for a few days until and can be or approach to a or obvious extensor tendon injury in the ED is first a with an carefully his and follow-up is a I always give the of examination or their own examination, but they rarely up on When they do and to the the of is usually the as it was over the However, to on your the your and and fully document the No follow-up is required for the dorsal hand lacerations tendons can be the of and a partial tendon injury can be wound and are usually are no to the of for penetrating hand but many clinicians Unlike flexor tendons, one need not about of a tendon sheath with extensor tendons they have Extensor tendons are with a of wound the of an and a finger When the is and the laceration and the of the tendon is often that all hand lacerations incorrect and a axiom to even if the hand surgeon is no than for any laceration, but it's prudent to consider under the of or obvious are not a for proper wound removal of foreign or Patients article on the treatment of hand injuries that the patient must be and to in the examination. Unfortunately, this is not a for an emergency visit, and the emergency physician is often with a that proper evaluation a few of a of or or the of a or can an examination, but it's to believe that you will always the information you are for on the first visit. the patient who has a or examination is a very case. that there is a tendon laceration, and one the for treatment and for a tendon injury. If you are that you were and you look a I the clinician that he should believe a patient when he he can't even a finger. Complete of extension is rarely or to the exam. extensor tendon injuries, even significant are commonly with splinting and without surgical even to this there is about the best of for known partial tendon lacerations I a each time I often from the hand surgeon. of procedures and have been Once tendons are less than to without As a general most will not suture a tendon that is cut percent or even partial lacerations to is some that suturing a partial tendon laceration provides a than splinting and physical therapy. one has to the diagnosis of a partial tendon laceration in the first the of is will a laceration with the thought of definitive information on the extent of injury, and a hand to repair complete extensor tendon lacerations to This with a to follow-up from the ED visit. This however, the of the emergency physician to the of such timely follow-up to the patient, and with the a repair will occur on the as the ED if the wound is I have rarely encountered this probably to simple rather than I against a complete laceration. lacerations can be with lacerated tendons are usually by old hand usually with a few in an extensor tendon is not Because all these patients follow-up and splinting and physical therapy, some emergency physicians even partial repair to the surgeon. and of to of care. A general that any repair of tendons, or be when the wound is and there are no associated injuries, has been has and the wound is of A delayed repair can be performed up to days injury with very reasonable A secondary repair of an extensor tendon can be performed to the results are about with and secondary however, repair of tendons to is often with A missed tendon injury that from partial to complete rupture by the time of suture removal is to a final result similar to that had the diagnosis been made in the ED. this is an and time to the Because tendon injuries often have some under the best of making the diagnosis as as possible is After to a tendon or tendon may be usually with and of of being the result. Patients who are who have financial problems, or are a for emergency can be and all follow-up carefully the patient and the hand surgeon never the to the best possible result. Unfortunately, the emergency physician is often for the regardless of often time and effort the initial visit. The most common response to a are that the emergency physician missed an injury, to proper in the ED, or never that patient of the important issues at This is proper and detailed charting the While extensor tendon injuries can be and proper documentation on the chart of the of the examination, proper wound and splinting, and good timely follow-up are the patient's and emergency physician's best When in the splinting of all potential partial injuries can never be by a examination a few days to out the extent of injury treatment and even an incorrect diagnosis that on the of should be the