Athletic injuries of the wrist and hand: part II: overuse injuries of the wrist and traumatic injuries to the hand

A Case Report of Traumatic Partial Extensor Carpi Ulnaris Subluxation in an Elite Hockey Player With Review of the Literature

In this article, we present a unique case of traumatic partial recurrent extensor carpi ulnaris (ECU) subluxation in an elite hockey player. To the best of our knowledge, this is the only report of partial ECU subluxation due to a split in the ECU tendon presented in the literature. This case illustrates the importance of proper diagnosis and treatment of such a lesion. We also emphasize that dynamic ultrasound is an excellent and cost-effective imaging modality that can help with the diagnosis of partial ECU subluxation. Finally, surgical treatment for failed conservative management showed excellent results in an elite athlete.

Casting and Splinting Management for Hand Injuries in the In-Season Contact Sport Athlete

Context:

Upper extremity injuries are extremely common in contact sports such as football, soccer, and lacrosse. The culture of competitive athletics provides an environment where hand injuries are frequently downplayed in an effort to prevent loss of game time. However, studies have shown that many sport-induced hand injuries do not actually require immediate surgical attention and can be safely treated through immobilization so that the athlete may complete the athletic season. In these cases, appropriate casting and splinting measures should be taken to ensure protection of the injured player and the other competitors without causing loss of game time.

Evidence Acquisition:

Articles published between 1976 and 2015 were reviewed to capture historical and current views on the treatment of hand injuries in the in-season athlete.

Study Design:

Clinical review.

Level of Evidence:

Level 5.

Results:

Although traditionally many sports-induced traumatic injuries to the hand held the potential to be season-ending injuries, experience has shown that in-season athletes do not necessarily need to lose game time to receive appropriate treatment. A thorough knowledge of converting everyday splints and casts into game day, sport-approved protective immobilization devices is key to safely allowing athletes with select injuries to play while injured.

Conclusion:

Protective techniques allow for maximum functionality during gameplay while safely and effectively protecting the injury from further trauma while bony healing takes place.

Thumb Injuries in Athletes

Thumb injuries are common in athletes and present a challenging opportunity for upper extremity physicians. Common injuries include metacarpal base fractures (Bennett and Rolando types), ulnar and radial collateral ligament injuries, dislocation of the carpometacarpal and metacarpophalangeal joints, and phalanx fractures. This review, although not exhaustive, highlights some of the most common thumb injuries in athletes. The treating physician must balance pressure from athletes, parents, coaches, and executives to expedite return to play with the long-term well-being of the athlete. Operative treatment may expedite return to play; however, one must carefully weigh the added risks involved with surgical intervention.

Imaging of Sports-related Hand and Wrist Injuries: Sports Imaging Series

Hand and wrist injuries are common occurrences in amateur and professional sports and many of them are sport-specific. These can be divided into two categories: traumatic injuries and overuse injuries. The aim of this article is to review the most common hand and wrist sports-related lesions. Acute wrist injuries are predominantly bone fractures, such as those of the scaphoid, hamate hook, and ulnar styloid. Ligament lesions are more challenging for radiologists and may lead to carpal instability if undiagnosed. Overuse wrist injuries are mainly represented by tendinous disorders, with De Quervain syndrome and extensor carpi ulnaris tendon disorders being the most common among them; however, there are other possible disorders such as impaction syndromes, stress fractures, and neurovascular lesions. Finally, finger lesions, including closed-tendon injuries (mallet and boutonniere injuries, jersey finger, and boxer's knuckle), flexor pulley injuries, and skier's thumb, should also be detected. (©) RSNA, 2016 Online supplemental material is available for this article.

Ulnar-Sided Wrist Pain in the Athlete

Ulnar-sided wrist pain can be a challenging entity for the hand surgeon and even more so in the athletic population. The authors present 8 causes of ulnar-sided wrist pain in an athlete (hook of hamate fracture, pisiform fracture, hypothenar hammer syndrome, triangular fibrocartilage complex injuries, ulnocarpal impaction syndrome, lunotriquetral ligament tears, extensor carpi ulnaris tendinitis, subluxation of extensor carpi ulnaris) and their associated imaging and treatment options.

Extensor Tendon Impingement in a Gymnast

Wrist injuries in the gymnast are due to the transformation of the upper extremity into a weight bearing entity. Gymnast wrist pain presents a difficult diagnostic and therapeutic challenge. Here, we present a new case of extensor tendon impingement in an elite gymnast. To our knowledge, there is no similar report in the literature.

A Classification for Extensor Carpi Ulnaris Groove Morphology as an Aid for Ulnar Sided Wrist Pain

BACKGROUND

Distal ulna groove morphology is likely to have a significant role in extensor carpi ulnaris (ECU) tendon stability. The development of a robust anatomical classification system, would be beneficial to further research into ulnar sided wrist pain and would be of use in rationalising treatment regimes.

METHODS

Cadaveric specimens as well as MRI scans of patients with non-specific wrist pain were analysed independently by 3 orthopaedic surgeons twice to test the integrity of the classification system. The following classification system was developed for the distal ulna groove; Flat = L-shaped slope, S slope = S shaped, Reverse C = C-shaped slope. Findings were then subjected to Fleiss Kappa statistical analysis to evaluate how robust the classification system was.

RESULTS

From the cadaveric arm of the study, 61 patients had their distal ulna groove morphology categorised according to types C, L, and S. For the MRI arm of the study 103 MRI scans were classified. ECU grove subtype C showed 8% dislocation compared to 33% and 47% for the L subtype and S sub type respectively.

CONCLUSIONS

Our classification system of ECU groove morphology will help identify different components to ulnar sided wrist problems and may help establish guidelines for treatment. This classification system has been validated for both cadaveric specimens and the MRI scans. It showed substantial agreement to almost perfect agreement in the data tested, thus proving good interand intra-observer reliability. It is a useful tool to help in further research into ulnar sided wrist pain and ECU instability, and may help develop further treatment strategies in the future.

Jam Injuries of the Finger: Diagnosis and Management of Injuries to the Interphalangeal Joints Across Multiple Sports and Levels of Experience

Context:

Jam injuries of the finger are frequently encountered in general orthopaedic and sports medicine practice. The finger joints in particular are very susceptible to traumatic injury, but in the absence of severe deformity, digital trauma is often downplayed in the hopes of a more rapid return to game play.

Evidence Acquisition:

Articles published from 1966 to 2015 were reviewed to capture historical and current views on the presentation, diagnosis, and treatment of jam injuries in athletes.

Study Design:

Clinical review.

Level of Evidence:

Level 5.

Results:

Although jam injuries are frequently grouped together, they represent a host of injuries that can be challenging to differentiate. A thorough knowledge of finger joint anatomy and injury mechanism is critical to perform an appropriate examination, establish an accurate diagnosis, and identify a treatment plan for each patient.

Conclusion:

Every member of the athletic care team must be aware of the spectrum of digital injuries, including the basic signs present on examination, which may indicate the need for more formal workup. Additionally, preventing injury through athlete education is paramount to athletic care.

New developments in prosthetic arm systems

Absence of an upper limb leads to severe impairments in everyday life, which can further influence the social and mental state. For these reasons, early developments in cosmetic and body-driven prostheses date some centuries ago, and they have been evolving ever since. Following the end of the Second World War, rapid developments in technology resulted in powered myoelectric hand prosthetics. In the years to come, these devices were common on the market, though they still suffered high user abandonment rates. The reasons for rejection were trifold - insufficient functionality of the hardware, fragile design, and cumbersome control. In the last decade, both academia and industry have reached major improvements concerning technical features of upper limb prosthetics and methods for their interfacing and control. Advanced robotic hands are offered by several vendors and research groups, with a variety of active and passive wrist options that can be articulated across several degrees of freedom. Nowadays, elbow joint designs include active solutions with different weight and power options. Control features are getting progressively more sophisticated, offering options for multiple sensor integration and multi-joint articulation. Latest developments in socket designs are capable of facilitating implantable and multiple surface electromyography sensors in both traditional and osseointegration-based systems. Novel surgical techniques in combination with modern, sophisticated hardware are enabling restoration of dexterous upper limb functionality. This article is aimed at reviewing the latest state of the upper limb prosthetic market, offering insights on the accompanying technologies and techniques. We also examine the capabilities and features of some of academia's flagship solutions and methods.

Ultrasound-Guided Interventional Procedures of the Wrist and Hand: Anatomy, Indications, and Techniques

Acute and chronic wrist and hand conditions are commonly seen by neuromuscular and musculoskeletal specialists. High-frequency diagnostic ultrasonography (US) has facilitated advances in the diagnosis and interventional management of wrist and hand disorders. US provides excellent soft tissue resolution, accessibility, portability, lack of ionizing radiation, and the ability to dynamically assess disorders and precisely guide interventional procedures. This article review the relevant anatomy, indications, and interventional techniques for common disorders of the wrist and hand, including radiocarpal joint arthritis, scaphotrapeziotrapezoidal joint arthritis, trapeziometacarpal joint arthritis, phalangeal joint arthritis, first dorsal compartment tenosynovitis, ganglion cysts, and stenosing tenosynovitis.

Radiological intervention of the hand and wrist

The role of radiological guided intervention is integral in the management of patients with musculoskeletal pathologies. The key to image-guided procedures is to achieve an accurately placed intervention with minimal invasion. This review article specifically concentrates on radiological procedures of the hand and wrist using ultrasound and fluoroscopic guidance. A systematic literature review of the most recent publications relevant to image-guided intervention of the hand and wrist was conducted. During this search, it became clear that there is little consensus regarding all aspects of image-guided intervention, from the technique adopted to the dosage of injectate and the specific drugs used. The aim of this article is to formulate an evidence-based reference point which can be utilized by radiologists and to describe the most commonly employed techniques.

User-Centered Design of a Controller-Free Game for Hand Rehabilitation

OBJECTIVE

The purpose of this study was to develop and test a hand therapy game using the Microsoft (Redmond, WA) Kinect(®) sensor with a customized videogame.

MATERIALS AND METHODS

Using the Microsoft Kinect sensor as an input device, a customized game for hand rehabilitation was developed that required players to perform various gestures to accomplish a virtual cooking task. Over the course of two iterative sessions, 11 participants with different levels of wrist, hand, and finger injuries interacted with the game in a single session, and user perspectives and feedback were obtained via a questionnaire and semistructured interviews.

RESULTS

Participants reported high levels of enjoyment, specifically related to the challenging nature of the game and the visuals. Participant feedback from the first iterative round of testing was incorporated to produce a second prototype for the second round of testing. Additionally, participants expressed the desire to have the game adapt and be customized to their unique hand therapy needs.

CONCLUSIONS

The game tested in this study has the potential to be a unique and cutting edge method for the delivery of hand rehabilitation for a diverse population.

Tennis injuries: epidemiology, pathophysiology, and treatment

Tennis places high loads on the joints of players, with supraphysiologic forces being generated at the shoulder and elbow hundreds of times per match. Acute injuries tend to affect the lower extremity; chronic injuries usually involve the upper extremity. Commonly encountered upper extremity conditions include rotator cuff injury, internal impingement, superior labral tears, and epicondylitis of the elbow. Serving is the most strenuous stroke in tennis, with the highest peak muscle activity in the shoulder and forearm occurring during this stroke. The kinetic chain links upper extremity, lower extremity, and core muscle segments by transmitting coordinated activation and motion; in this regard, any pathologic process that disturbs the groin, hip, and abdominal musculature can further result in an increased risk of injury to the shoulder and upper extremity. Evolution in equipment and in play surfaces has also affected the type and frequency of injuries. Prevention programs that address the muscular imbalances throughout the kinetic chain may help reduce the incidence of both acute and chronic injuries experienced by tennis athletes.

Playing hurt: hand and wrist injuries and protected return to sport

When treating hand and wrist injuries, there is often an opportunity to allow an athlete to return to play before complete healing of the injury and/or surgery. Protective devices can make this possible. The risks of returning to play in this manner depend on many factors including the injury itself, position played, hand dominance, etc. Communication between treating health care professional, athlete, trainer, and coaches is critical in this decision process. Protective options include taping, custom-made splints, commercially available braces, soft casts, and hard casts. Ability to use these devices during competition is governed by the rules of each individual sport and often dependent on final approval by referee or game official.

Injury to ulnar collateral ligament of thumb

Injury of the ulnar collateral ligament (UCL) of thumb can be incapacitating if untreated or not treated properly. This injury is notorious for frequently being missed by inexperienced health care personnel in emergency departments. It has frequently been described in skiers, but also occurs in other sports such as rugby, soccer, handball, basketball, volleyball and even after a handshake. The UCL of the thumb acts as a primary restraint to valgus stress and is injured if hyperabduction and hyperextension forces are applied to the first metacarpophalangeal joint. The diagnosis is best established clinically, though MRI is the imaging modality of choice. Many treatment options exist, surgical treatment being offered depending on various factors, including timing of presentation (acute or chronic), grade (severity of injury), displacement (Stener lesion), location of tear (mid-substance or peripheral), associated or concomitant surrounding tissue injury (bone, volar plate, etc.), and patient-related factors (occupational demands, etc.). This review aims to identify the optimal diagnostic techniques and management options for UCL injury available thus far.

In-game Management of Common Joint Dislocations

Context:

Sideline management of sports-related joint dislocations often places the treating medical professional in a challenging position. These injuries frequently require prompt evaluation, diagnosis, reduction, and postreduction management before they can be evaluated at a medical facility. Our objective is to review the mechanism, evaluation, reduction, and postreduction management of sports-related dislocations to the shoulder, elbow, finger, knee, patella, and ankle joints.

Evidence Acquisition:

A literature review was performed using the PubMed database to evaluate previous and current publications focused on joint dislocations. This review focused on articles published between 1980 and 2013.

Study Design:

Clinical review.

Level of Evidence:

Level 4.

Results:

The clinician should weigh the benefits and risks of on-field reduction based on their knowledge of the injury and the presence of associated injuries.

Conclusion:

When properly evaluated and diagnosed, most sports-related dislocations can be reduced and initially managed at the game.

Adductor pollicis longus strain in a professional baseball player: case report and review of thenar pain

Thenar pain can represent a significant morbidity for a baseball player who relies on manual dexterity for gripping a bat and precise and accurate throws. While osseous, ligamentous, and neurovascular pathologies are commonly considered, musculotendinous injuries are often neglected in the differential diagnosis of thenar pain. We present a case of adductor pollicis longus strain as a cause of acute thenar pain in a baseball player. Adductor pollicis longus strains should be considered in any baseball player sustaining a hyperabduction force to the thumb.

Acupuncture in De Quervain's disease: a treatment proposal

De Quervain's disease is a painful stenosing tenosynovitis of the first dorsal compartment of the hand affecting the tendons of the abductor pollicis longus and extensor pollicis brevis, caused mainly by overuse. Conventional treatments include rest, immobilisation, oral anti-inflammatory drugs, corticosteroid injection and even surgery, but none of these is established as clearly effective. Acupuncture is rarely mentioned and the points suggested are rather general-regional, tender and ah shi points. Tendinopathy is almost always associated with problems in the relevant muscles and this paper calls attention to the correct identification and needling of the affected muscles, in order to increase the specificity of acupuncture treatment.

Short-term effects of self-mobilization with a strap on pain and range of motion of the wrist joint in patients with dorsal wrist pain when weight bearing through the hand: a case series

Dorsal wrist pain frequently occurs in weight bearing through the hand in patients with distal radius stress injuries, scaphoid impaction syndrome, and dorsal impingement. To improve the wrist extension motion, joint mobilization has been used. However, there is no report on the effects of mobilization on the range of motion (ROM) and pain onset in patients with dorsal wrist pain when weight bearing through the hand. This study determined the effects of self-mobilization with a strap (SMWS) while weight bearing through the hand on the ROM and force generated at the onset of pain (FGOP) and intensity in the wrist joints of patients with dorsal wrist pain. Fifteen patients (six men, nine women) with dorsal wrist pain during weight bearing through the hand were recruited from a workplace-based work-conditioning center. SMWS was applied during five visits for a 1-week period. Both passive and active wrist extension ROM, FGOP, and pain intensity (PI) while pushing down through the hand were measured before and after SMWS. Passive and active ROM of wrist extension and FGOP increased significantly after the five sessions over 1 week of SMWS (p < 0.05). PI decreased significantly after the five sessions of SMWS (p < 0.05). These results suggest that SMWS can be used to increase wrist extension ROM and decrease wrist pain in patients with dorsal wrist pain during weight bearing through the hand.

Proximal interphalangeal joint fracture dislocations: stable and unstable

Injuries to a competitive athlete's hand are common occurrences routinely treated by team training staff and physicians. These injuries are particularly prevalent in contact and ball catching sports. Although timely recognition and treatment of these injuries can avoid lifelong morbidity, the initial presentation may be deceptively benign. These injuries are classified according to the pattern of fracture and the resultant stability of the joint. Treating physicians must have an understanding of the biomechanics, injury patterns, assessment, and treatment guidelines in order to identify these injuries and provide for the earliest safe return to play with the best functional outcome for the athletes.

Proximal interphalangeal joint fracture dislocations in professional baseball players

Treatment of professional baseball players with PIP injuries requires careful evaluation and prompt treatment. Stability of the injury dictates treatment and return to play. The majority of injuries can be managed with minimal splinting or buddy taping, but the most complex injuries require operative intervention to ensure stable reduction. Consideration of players' position and handedness is important in determining return to practice and play.

Pediatric overuse injuries in sports

Overuse injuries in the pediatric and adolescent population are a growing problem in the United States as more children participate in recreational and organized sports. It is not uncommon for children and adolescents to play on multiple teams simultaneously or to be involved in sports year-round. Without adequate rest, the demands of exercise can exceed the body's ability to repair tissues, leading to repetitive microtrauma and overuse injury. Unlike in adults, the consequences of overuse injury in the pediatric and adolescent athlete are far more serious because the growing bones are vulnerable to stress. The ability to identify individuals who are at risk of overuse injuries is key so that education, prevention, and early diagnosis and treatment can occur. Preventive measures of modifying training factors (ie, magnitude, intensity, and frequency of sports participation) and correcting improper biomechanics (alignment, laxity, inflexibility, and muscle imbalance) should always be part of the management plan.

Treatment of bony boutonniere deformity with a loop wire

Boutonniere deformity associated with a dorsal avulsion fracture of the central slip overlying the proximal interphalangeal joint results in loss of extension of the joint and hyperextension of the distal interphalangeal joint. This article reports a surgical technique for treatment of the injury in 21 digits, which involves application of loop stainless steel wire. We also present the long-term results using the technique on the digits. Loop wire fixation is a successful surgical technique for the treatment of displaced central slip avulsion fracture.

Sport injuries: a review of outcomes

Injuries can counter the beneficial aspects related to sports activities if an athlete is unable to continue to participate because of residual effects of injury. We provide an updated synthesis of existing clinical evidence of long-term follow-up outcome of sports injuries. A systematic computerized literature search was conducted on following databases were accessed: PubMed, Medline, Cochrane, CINAHL and Embase databases. At a young age, injury to the physis can result in limb deformities and leg-length discrepancy. Weight-bearing joints including the hip, knee and ankle are at risk of developing osteoarthritis (OA) in former athletes, after injury or in the presence of malalignment, especially in association with high impact sport. Knee injury is a risk factor for OA. Ankle ligament injuries in athletes result in incomplete recovery (up to 40% at 6 months), and OA in the long term (latency period more than 25 years). Spine pathologies are associated more commonly with certain sports (e.g. wrestling, heavy-weight lifting, gymnastics, tennis, soccer). Evolution in arthroscopy allows more accurate assessment of hip, ankle, shoulder, elbow and wrist intra-articular post-traumatic pathologies, and possibly more successful management. Few well-conducted studies are available to establish the long-term follow-up of former athletes. To assess whether benefits from sports participation outweigh the risks, future research should involve questionnaires regarding the health-related quality of life in former athletes, to be compared with the general population.

Basketball injuries in children

Basketball is a popular, worldwide sport played outdoors and indoors year-round. Patterns of injury are related to abrupt changes in the athlete's direction, jumping, contact between athletes, the hard playing surface and paucity of protective equipment. Intensity of play and training in the quest of scholarships and professional careers is believed to contribute to an increasing occurrence of injury. Radiologists' appreciation of the breadth of injury and its relation to imaging and clinical findings should enhance the care of these children. Some of the patterns of injury are well known to radiologists but vary due to age- and size-related changes; the growing skeleton is affected by differing susceptibilities from biomechanical stresses at different sizes. Beyond screening radiographs, the accuracy of MRI and CT has improved diagnosis and treatment plans in this realm. Investigations to detect symptoms and signs in an attempt to prevent the tragedy of sudden cardiac death in basketball players may lead to MRI and CTA studies that compel radiologists to evaluate cardiac function along with myocardial and coronary artery anatomy. Worthy of mention also is the female athlete triad of disordered eating, amenorrhea, and osteoporosis that is observed in some young women participating in this and other sports.

Ultrasound imaging of normal displacement of the extensor carpi ulnaris tendon within the ulnar groove in 12 forearm-wrist positions

OBJECTIVE

Instability of the extensor carpi ulnaris (ECU) tendon can be a difficult clinical diagnosis because of normal changes in tendon position during wrist motion. Our goal was to determine the normal variation of ECU tendon displacement in 12 forearm-wrist positions.

SUBJECTS AND METHODS

Ultrasound imaging of the ECU tendons of 40 symptom-free wrists of healthy volunteers (13 women, seven men; mean age, 22.3 years; range, 20-25 years) was performed. Each ECU tendon was examined in 12 positions: four wrist positions (ulnar deviation, radial deviation, flexion, and extension) in each of three forearm positions (pronation, supination, and neutral).

RESULTS

ECU tendon displacement in the right hand was not significantly different from that in the left, and displacement in men did not differ significantly from that in women. There was a small but significant difference between displacement in the dominant and that in the nondominant hand (p < 0.02). Mean ECU tendon displacement was greatest in the supinated forearm position (p < 0.001) followed by the neutral position (p < 0.001) and was least in the pronated position (p < 0.001). Both ulnar deviation (p < 0.001) and flexion (p < 0.002) were associated with greater ECU tendon displacement than were radial deviation (p < 0.001) and extension (p < 0.002). Maximum percentage displacement volar to the ulnar border of the groove was 50% in flexed supination and ulnar deviation. The maximum displaced distance volar to the ulnar border of the groove was 5 mm.

CONCLUSION

Sonographic evaluation of the ECU tendon is simple and practical. Knowledge of normal ECU displacement relative to the ulnar groove may help in evaluation of ulnar-sided wrist pain.

Sideline evaluation and treatment of bone and joint injury

Athletes can sustain a large variety of injuries, from simple soft-tissue sprains to complex fractures and dislocations. This article reviews and provides the most recent information for sports medicine professionals on the initial assessment and treatment from the sports sidelines without the benefit of imaging of bone and joint injuries (excluding facial injuries). This information will aid sports medicine professionals by giving them basic suggestions that may allow for the safe and prompt return of athletes to the field of play.

Sports and performing arts medicine: 1. Upper extremity injuries

OBJECTIVE

This self-directed learning module highlights upper limb sports and performing arts injuries. It is part of the study guide on sports and performing arts medicine in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. Using a case vignette format, this article specifically focuses on shoulder, elbow and finger pain in athletes and wrist pain in musicians. The goal of this article is to enhance the learner's understanding on how to approach common upper limb pain conditions and injuries in these populations.

Effect of finger posture on the tendon force distribution within the finger extensor mechanism

Understanding the transformation of tendon forces into joint torques would greatly aid in the investigation of the complex temporal and spatial coordination of multiple muscles in finger movements. In this study, the effects of the finger posture on the tendon force transmission within the finger extensor apparatus were investigated. In five cadaver specimens, a constant force was applied sequentially to the two extrinsic extensor tendons in the index finger, extensor digitorum communis and extensor indicis proprius. The responses to this loading, i.e., fingertip force/moment and regional strains of the extensor apparatus, were measured and analyzed to estimate the tendon force transmission into the terminal and central slips of the extensor hood. Repeated measures analysis of variance revealed that the amount of tendon force transmitted to each tendon slip was significantly affected by finger posture, specifically by the interphalangeal (IP) joint angles (p<0.01). Tendon force transmitted to each of the tendon slips was found to decrease with the IP flexion. The main effect of the metacarpophalangeal (MCP) joint angle was not as consistent as the IP angle, but there was a strong interaction effect for which MCP flexion led to large decreases in the slip forces (>30%) when the IP joints were extended. The ratio of terminal slip force:central slip force remained relatively constant across postures at approximately 1.7:1. Force dissipation into surrounding structures was found to be largely responsible for the observed force-posture relationship. Due to the significance of posture in the force transmission to the tendon slips, the impact of finger posture should be carefully considered when studying finger motor control or examining injury mechanisms in the extensor apparatus.

Monopolar radiofrequency energy application to the dorsal extensor tendon apparatus in a canine model of tendon injury

PURPOSE

To evaluate the use of monopolar radiofrequency energy (MRFE) to shorten stretched dorsal extensor tendon apparatus (DETA) tissues in a canine model.

METHODS

Eleven adult canine forelimbs were used in this in vitro investigation. The DETA tissue was isolated between the metacarpophalangeal and proximal interphalangeal joints in the third and fourth digits of each limb. Isolated tissue was stretched in all but 2 of the digits (control group). After tissue stretching, monopular radiofrequency energy (MRFE) was applied to 18 of the digits at 1 of 3 temperatures: 50 degrees C, 60 degrees C, or 70 degrees C (stretch-treatment group). Two digits were treated identically, but MRFE was not applied (stretch-only group). Tissue length was measured before and after stretching and after treatment. Percent stretch, percent shortening, and percent original length were compared among the 3 stretch-treatment groups. All DETA specimens were examined with light microscopy.

RESULTS

Histologic changes were apparent in the stretch-treatment and stretch-only specimens compared with controls. Percent stretch was not significantly different between groups. Percent shortening and percent original length were significantly lower and higher, respectively, in the 50 degrees C group than in the 60 degrees C and 70 degrees C stretch-treatment groups, which were not significantly different from each other. There was a significant linear correspondence between percent shortening and treatment temperature.

CONCLUSIONS

The application of MRFE at a temperature of 60 degrees C and a power of 10 W appears to shorten stretched DETA tissue to approximately the prestretched length in an in vitro canine model. Further investigation is necessary to determine the effect of treatment on the tissue's mechanical properties.