You are in: eMedicine Specialties > Orthopedic Surgery > HAND AND UPPER EXTREMITY Malunion of Hand FractureArticle Last Updated: Nov 10, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 12
  Author: Palaniappan Lakshmanan, MBBS, MS (Orth), AFRCS, Specialist Registrar, Department of Trauma and Orthopedics, Wansbeck General Hospital, UK Palaniappan Lakshmanan is a member of the following medical societies: British Orthopaedic Association Coauthor(s): Puthur R Damodaran, MBBS, Consulting Surgeon, Madras Institute of Orthopaedics and Traumatology, India; Lester Sher, MBBCh, FRCS, Honorary Clinical Lecturer, Department of Orthopedics, Wansbeck Hospital, UK Editors: Michael S Clarke, MD, Clinical Associate Professor, Department of Orthopedic Surgery, University of Missouri-Columbia School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Robert J Nowinski, DO, Clinical Assistant Professor of Orthopaedic Surgery, Ohio University College of Osteopathic Medicine; Private Practice, Orthopedic Specialists and Sports Medicine, Newark, Ohio; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Harris Gellman, MD, Consulting Surgeon, Broward Hand Center, Voluntary Clinical Professor of Orthopedic Surgery and Plastic Surgery, Departments of Orthopedic Surgery and Surgery, University of Miami School of Medicine Author and Editor Disclosure Synonyms and related keywords: malunited hand fractures, deformed hand, phalangeal malunion, metacarpal malunion, carpal malunion, poorly healed hand fracture, nonunion of hand fracture, hand fracture nonunion, hand malalignment, hand malrotation, hand shortening, abnormal anatomic alignment of the hand, phalangeal fracture, pseudoclawing INTRODUCTIONSection 2 of 12
  Malunion may be defined as healing of a fracture in an abnormal (nonanatomic) position. In the hand, it presents a combined functional and aesthetic problem. The management of malunion of hand fractures is more complex than the management of malunion of fractures elsewhere in the skeleton. Good hand function depends on joint mobility, sensibility, good skin coverage, adequate vascularity, and the gliding of a complex flexor and extensor tendon mechanism. Preexisting problems related to any of these factors may limit the usefulness of the digit, and surgical intervention can cause additional scarring and dysfunction. As a consequence, the management of malunion in the hand is predicated on a careful analysis of the risks and benefits of surgical intervention and on the functional goals and the likelihood that the operation can achieve them. History of the ProcedureFractures of the hand are among the most common fractures of the skeletal system. Most of these fractures are acquired in the workplace or as a result of crush injuries, falls, or sports injuries. Most of these injuries can be managed nonoperatively, but certain fractures, such as intra-articular fractures, open fractures, unstable fractures, and displaced or angulated fractures, may require surgical correction with Kirschner wires (K-wires), plates, or screws. If these fractures are not treated properly, malunited fractures may result, leading to considerable loss of function and cosmetic disfigurement. Malunited fractures involving the joint surfaces can ultimately lead to posttraumatic osteoarthritis. ProblemMost fractures of the hand bones occur in young, active adults who are involved in many various occupational and sporting activities. If these fractures are not carefully managed, they may result in malunion. This may lead to loss of function due to malalignment, malrotation, or shortening, which may result in decreased and disordered motion of fingers and poor outcomes. FrequencyMalunion strictly implies union with abnormal anatomic alignment. However, in the hand, this does not necessarily mean a dysfunctional hand or finger, because this is not often the case. The frequency of malunited fractures may be high in the hands, but few require treatment. This is especially true with malunion of metacarpal neck fractures of the little fingers, which typically do not require treatment because they seldom produce deformity or interfere with function. In 1985, Tubiana showed that, of 10,000 hand injuries, only 30 malunions required treatment. EtiologyMalunion of hand fractures may result from inadequate treatment or failure of treatment. Accurate anatomic restoration may not be the goal of nonoperative treatment or even certain operative treatments for hand fractures. Hence, inaccurate anatomic restoration after treatment may not be considered evidence of inadequate treatment. PathophysiologyPatterns of malunion Malunion is the most common bony complication of phalangeal fractures. Four patterns of deformity are recognized: malrotation, volar angulation, lateral angulation, and shortening. Malrotation is usually seen after oblique or spiral fractures of the proximal and middle phalanges. The best method to assess malrotation is asking the patient to make a fist and looking for digital overlap. In adults with proximal phalangeal fractures, volar angulation >25-30° may result in pseudoclawing. This deformity makes using the hand awkward and can result in a fixed flexion contracture of the proximal interphalangeal joint. The appearance may be aesthetically unacceptable. Lateral angulation and malrotation often occur concomitantly. If correction is considered, carefully identify the components of the deformity. Shortening may occur after a comminuted fracture is allowed to heal in a collapsed fashion or after a long spiral fracture. Other aspects of malunion Intra-articular malunion occurs when intra-articular anatomy is not restored. Unreduced condylar fractures that extend into the proximal interphalangeal joint may produce pain, angulatory deformity, limited mobility, and, ultimately, degenerative arthritis. Regarding metacarpal fractures, malunion can follow a transverse fracture, which results in dorsal angulation in the sagittal plane. Compensatory hyperextension (pseudoclawing) at the metacarpal phalangeal can result. Malunion after a spiral or oblique fracture results in malrotation. In patients with second and third metacarpal fractures, dorsal angulation is bothersome both cosmetically (pseudoclawing) and functionally. The prominent metacarpal head in the palm can be painful when the individual grips. Rotational malunion of metacarpal fractures results in overlapping of the affected finger over an adjacent finger. The cosmetic deformity is often marked, and the grip is often impaired. After crushing injuries or open fractures, shortening and associated problems of the soft tissue (eg, tendon adhesions, poor skin coverage, neurologic deficit) may occur. Malunion most commonly affects the scaphoid among the carpal bones Malalignment after union is evident as carpal collapse initially and later reflected in direct measurements of intrascaphoid alignment. The lateral appearance on radiographs shows the typical humpback scaphoid, which describes a deformity resulting from flexion angulation between the proximal and distal poles. Scaphoid malunion can alter carpal mechanics, leading to pain, weakness, limited motion, and degenerative arthritis. ClinicalHistory Malunited hand fractures are not usually difficult to diagnose. Most patients provide a history of injury associated with the deformity. The form of treatment the patient received should be noted. Such treatment may include both nonoperative measures such as splinting, immobilization, and physiotherapy and operative measures such as internal or external fixation or both. The history must include the patient's age, occupation, hand dominance, function and restriction of hand function after the fracture, and the effect of the malunion on his or her activities. Physical examination Physical examination is of vital importance in evaluating the malunited hand. Commence the hand examination by comparing the affected hand with the uninjured hand. Note any obvious swelling or deformity. Look for the anatomic bony landmarks and their interrelationships, and compare them with those of the healthy hand. Abnormal positioning may indicate a malunited fracture or tendon rupture or adherence. The deformity should be categorized in each plane, to include the ulnar-radial and the volar-dorsal plane. Also important is the rotational alignment. The most important aspect of the examination is the functional assessment of the hand. Because the fingers converge with flexion and diverge with extension, certain deformities can be appreciated with the fingers in flexion. The ability to make a complete fist must be assessed. Because the flexor digitorum profundus tendons of the fingers work in unison, any restriction in movement of 1 finger or any decrease in length of 1 finger may seriously affect the power of the patient's hand grip. Hence, it may notably interfere with normal function of the hand. Grip strength should be measured by using a dynamometer, and the results can be compared with those of the healthy hand. Normal maximum grip strength is 52 kPa in men and 31 kPa in women. The pinch-grip strength can be measured by using a manual pinch meter. However, a pinch-grip analyzer can be used to measure both pinch and grip strengths, and it may be a useful tool for objectively assessing hand function. The examination must include neurologic and vascular assessments. Any previous scar due to surgery or injury should be assessed to plan incisions if surgery is contemplated. INDICATIONSSection 3 of 12
Indications for surgery include pain, loss of function, cosmetic deformity, loss of motion in the neighboring joint, and bony exostosis causing skin irritation and posing a threat of tendon attrition. When treating hand malunions, one must remember that the potential risks of surgery (eg, tendon adhesions, joint stiffness) may outweigh any anticipated advantage. RELEVANT ANATOMYSection 4 of 12
The hand is a highly complex structure that requires integrated function of extrinsic and intrinsic motor units across a complex and limited bony and articular framework. The hand also functions as a sensory organ and an organ of communication. All these factors should be considered before reconstruction is undertaken. CONTRAINDICATIONSSection 5 of 12
The absolute contraindication for surgery is local infection. Relative contraindications include functionless limb, poor bone quality, and poor general medical condition. WORKUPSection 6 of 12
Imaging Studies
TREATMENTSection 7 of 12
Surgical therapyThe goals of treatment are to restore disordered function and, occasionally, to correct cosmetic deformity. The malunion should be carefully studied to understand the original deforming forces. A carefully planned osteotomy is necessary and must be executed with the least possible further damage to soft tissues. Techniques of osteotomy must be tailored to the biomechanical requirements for proper realignment of the malunited fracture. Important principles in the management of malunions are as follows:
Malunion of phalangeal fractures Clinically significant malrotation results in functional impairment and usually requires osteotomy through the phalanx or the metacarpal. Phalangeal osteotomy offers the advantage of correcting the malunion at its site of origin, it allows for simultaneous correction of angular deformities, and it permits concomitant soft-tissue procedures such as tenolysis or capsulotomy. Phalangeal osteotomies can be either step-cut or transverse, which are performed with a power saw. Step-cut osteotomies are fixed with either small AO (Arbeitsgemeinschaft für Osteosynthese or Association for the Study of Osteosynthesis) screws or K-wires, whereas transverse osteotomies can be held with a plate or with K-wires. Metacarpal-base osteotomies for malrotation correction can achieve up to 18-19° of correction in the index, long, and ring fingers and up to 20-30° in the small fingers. Volar angulation of 25-35° results in fixed flexion deformity of the proximal interphalangeal joint. This requires correction by means of either closed- or open-wedge osteotomy and fixation with K-pins. The open wedge requires a bone graft to fill the gap, whereas the closed wedge may result in shortening of the finger. Lateral angulation of phalangeal fractures is corrected in the same manner as volar angulation, by performing osteotomies with a power saw. Shortening due to a comminuted fracture that is allowed to heal in a collapsed fashion or that occurs after a long spiral fracture can be corrected with an appropriately fashioned intercalary graft insertion. When a spiral fracture of the phalanx heals in a shortened position with a distal spike on the proximal fragment, blocking flexion of the digit, careful removal of the spike may be all that is required. Unreduced condylar fractures extending into the joint require corrective osteotomy, arthrodesis, or arthroplasty. Malunion of metacarpal fractures Dorsal angulation usually occurs in the second or third metacarpal and is bothersome, both cosmetically and functionally, as it weakens the grip of the hand. Correction is achieved with closed- or open-wedge osteotomies or fixation with K-wires or AO plates. The closed wedge is preferred over the open wedge for 2 reasons. First, only 1 surface requires healing, unlike with the open wedge, in which 2 surfaces are required to heal. Second, the intrinsics can accommodate for some shortening with a closed wedge, whereas with an open wedge, lengthening of the bone occurs, and this may aggravate the intrinsic tightness, especially when posttraumatic intrinsic muscle contraction has occurred. Rotational malunion results from overlapping of the affected finger over the adjacent finger. Cosmetic deformity is often marked, and grip is impaired. Correction is achieved through a metacarpal base osteotomy. During the operation, a longitudinal mark is made on the metaphysis with an osteotome prior to the osteotomy. Then, the osteotomy is performed with a power saw perpendicular to the mark. The rotation is corrected and fixed with several K-wires or AO plates. Intra-articular metacarpal malunions are difficult to correct with osteotomies. However, correction can be achieved by maintaining reduction with screws and plates or with screws and cancellous bone grafts. Malunion in carpal bones The scaphoid is the usual site for carpal malunion. Malunion of other carpal bones is rare. Malunion of the scaphoid is best prevented. If malunion of the scaphoid is detected soon after union, corrective osteotomy can be considered. Late malunion of the scaphoid is best managed symptomatically. Finally, scaphoid cheilectomy or radial styloidectomy can be considered if symptoms persist. Preoperative detailsAdequate surgical planning requires adequate preoperative assessment. The patient's neurovascular status should be assessed before any intervention is performed. Intraoperative detailsIntraoperative fluoroscopy or radiography should be used to ensure that adequate fixation is achieved before the patient leaves the operating room. Joint motion should be assessed after fixation so that postoperative expectations can be established. Postoperative detailsMost surgery in the hand is undertaken to promote function. Early mobilization is essential to ensure a good outcome. Delaying motion beyond 3 weeks leads to arthrofibrosis and a poor functional outcome. Optimal surgical treatment should allow for adequate postoperative motion, and to achieve a good outcome, patients should be encouraged to move their fingers daily. COMPLICATIONSSection 8 of 12
Complications may include recurrence of deformity, neurovascular complications, or both. OUTCOME AND PROGNOSISSection 9 of 12
If treated carefully, with adherence to the principles described, most phalangeal and metacarpal malunions heal without clinically significant complications. Some patients may develop stiffness and decreased mobility. Most poor results are documented in elderly patients (>65 y) and in patients with crush injuries or extensive soft-tissue contractures. A combination of these factors increases the risk of compromised results. Selecting proper implants and quick rehabilitation may improve the prognosis. FUTURE AND CONTROVERSIESSection 10 of 12
In the future, expanded use of bioabsorbable implants made of polyglycolic acid or poly-L-lactic acid may have advantages over the traditionally used pins, screws, and plates. These bioabsorbable plates will help avoid the need for second procedures to remove the implants, which are the main causes of loss of function from iatrogenic causes. Further development of low-profile implants with high tensile strength will allow for adequate mobility during postoperative rehabilitation and, thereby, help prevent stiffness. MULTIMEDIASection 11 of 12
REFERENCESSection 12 of 12
Malunion of Hand Fracture excerpt Article Last Updated: Nov 10, 2006 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
