Partial Flexor Tendon Injury Causing Locking: Illustration of the Utility of Dynamic Ultrasound

Clinical diagnosis of partial flexor tendon lacerations is challenging because tendon function may be preserved. Although some partial flexor tendon tears can be managed conservatively, pain, stiffness, and triggering/locking may result, requiring surgical management. The mechanism by which this occurs has been investigated in animal and cadaver studies but has not been demonstrated in patients with real-time, in vivo imaging. Here, we present a case of partial tendon tear presenting with severe pain and locking that was diagnosed before surgery and characterized with dynamic ultrasound.

Role of Ultrasound in Flexor Tendon Injuries of the Hand: A New Insight

This study was aimed at validating the diagnostic accuracy of ultrasound (US) scans in pre-operative evaluation of flexor tendon injuries in the hand and to determine its value in the management of such injuries and in the prediction of patient outcome. This descriptive cross-sectional prospective study included 35 patients with penetrating trauma to the volar aspect of the hand or wrist with questionable clinical findings. They had 50 injured tendons and were candidates for exploratory surgery versus physiotherapy. They underwent pre-operative US to guide their management. Ultrasound results were compared with the operative findings as the gold standard test. Patients were followed up postoperatively, and functional outcome was assessed and correlated with pre-operative sonographic findings. Our results indicate that sonographic examination of hand tendon injury has high accuracy in diagnosing complete or partial flexor injuries, with 100% accuracy, sensitivity and specificity in diagnosing full-thickness tears as well as tenosynovitis of hand flexor tendons. Zonal II injury was the most frequent among our study population and correlated with poorest functional outcome after rehabilitation at 3 mo follow-up. US of the hand is a fast, inexpensive and potentially indispensable dynamic tool for accurate assessment of flexor tendon injuries. It provides data on the extent of injury that effectively helps both set up an appropriate operative plan and predict the patient's functional outcome post-operatively, which in turn will have a direct impact on the patient's rehabilitation plan and lifestyle. Thus, it should be a fundamental part of the management of patients with tendon injuries.

Comparison of Magnetic Resonance Imaging and Ultrasound Evaluations of Zone II Partial Flexor Tendon Lacerations: A Cadaveric Study

OBJECTIVES

Surgical intervention for zone II high-grade partial flexor tendon lacerations is often required when more than half of the tendon width is torn. Reliable noninvasive tests are critical for optimizing clinical decision making. Our team previously investigated the use of ultrasound (US) for identification of high-grade zone II flexor digitorum profundus lacerations. In this study, we compared magnetic resonance imaging (MRI) to US for the evaluation of high-grade partial flexor tendon lacerations in cadaveric specimens.

METHODS

Dissection of 32 digits in 8 fresh-frozen upper extremity cadaveric specimens was performed. The flexor digitorum profundus tendons were randomized into 3 groups: intact, low-grade laceration, and high-grade laceration. A dynamic US examination was performed by a blinded musculoskeletal radiologist. The same specimens underwent hand coil MRI, which was read by the same blinded radiologist. Magnetic resonance imaging test performance metrics were calculated and compared to those computed for the US evaluation.

RESULTS

For US evaluation of high-grade lacerations, the sensitivity and specificity were 0.5 and 1.0, with positive likelihood ratio (LR+) and negative likelihood ratio (LR-) values of ∞ and 0.50, respectively. The sensitivity and specificity for MRI evaluation were 0.2 and 1.0, with LR+ and LR- values of ∞ and 0.80.

CONCLUSIONS

Both US and MRI are adequate at determining the presence of a high-grade laceration. Magnetic resonance imaging was more specific than US in identification of high-grade partial flexor tendon lacerations. Although less specific, US is a reasonable and less-expensive alternative to MRI when evaluating for clinically significant high-grade partial flexor tendon lacerations.

Ultrasonography for the orthopaedic surgeon

The recent development of high-frequency ultrasonography transducers has provided better accuracy and improved the ability to image more superficial body structures. Ultrasonography is a widely available, inexpensive, comparative, and dynamic imaging technique that involves no radiation exposure and has no other adverse effects. Ultrasonography must always be combined with a medical history, physical examination, and radiographic assessment. What is ultrasound-assisted orthopaedic surgery? This approach consists in the use of ultrasonography by orthopaedic surgeons during patient visits and/or in the operating room. Similar to arthroscopy, ultrasonography is used as a complementary technique by physicians involved in the management of musculo-skeletal disease (e.g., radiologists, rheumatologists, and sports physicians). What knowledge of biophysics is needed to use ultrasonography? The surgeon must be familiar with the mechanisms by which the ultrasound waves are generated and received during B-mode and Doppler ultrasonography and with possible types of image artefacts. What is the procedure for examining a structure by ultrasonography? Each anatomic component must be assessed along two perpendicular planes in scanning mode. What does ultrasonography contribute during patient visits? Ultrasonography provides additional diagnostic information and helps to explain the pathological process to the patient. How does the contribution of ultrasonography vary across body sites and pathological processes? Ultrasonographic imaging is easier at some body sites than at others. Ultrasonography can provide useful information in patients with joint disease, sports injuries, osteo-articular infections, peripheral neuropathy, or tumours. What is interventional ultrasonography in orthopaedic surgery? Ultrasound-guided orthopaedic interventions include injections, aspirations, and minimally invasive surgical procedures. How can orthopaedic surgeons incorporate ultrasonography into their practice? The surgeon must purchase an ultrasound machine dedicated to the musculo-skeletal system and follow the necessary training courses.

Entrapment and traumatic neuropathies of the elbow and hand: An imaging approach

Ultrasound and magnetic resonance imaging currently offer a detailed analysis of the peripheral nerves. Compressive and traumatic nerve injuries are the two main indications for imaging investigation of nerves with several publications describing the indications, technique and diagnostic capabilities of imaging signs. Investigation of entrapment neuropathies has three main goals, which are to confirm neuronal distress, search for the cause of nerve compression and exclude a differential diagnosis on the entire nerve. For traumatic nerve injuries, imaging, predominantly ultrasound, occasionally provides essential information for management including the type of nerve lesion, its exact site and local extension.

The emergent evaluation and treatment of hand injuries

The hand is especially prone to traumatic injury. Some sources indicate that injuries to the hand account for somewhere between 10% and 30% of patients treated in emergency care settings. Fractures are the most common injury, followed by tendon injury, then skin lesions. Because the mechanism of injury often results in damage to multiple tissue structures, a detailed history and evaluation are vital to properly identifying and managing these injuries. This article provides the emergency physician with tools to identify and manage orthopedic injuries to the hand.

[Primary flexor tendons repair in zone 2]

Primary flexor tendon repair is still challenging even in the most experienced hands. With atraumatic surgery, the goal is to suture the tendon in a way that it will be strong enough to allow for tendon gliding without the risk of rupture or adhesions during the 12 weeks needed for the tendon to heal. After reviewing the zone 2 anatomy, the authors describe the state of art for flexor tendon repair along with their personal preferences. Although suture methods and postoperative rehabilitation programs are not universal, most specialized teams now use multistrand suturing techniques with at least 4 stands along with protected and controlled early active mobilization. Although the published rates of failure of the repair or postoperative adhesions with stiffness have decreased, these complications are still a concern. They will continue to pose a challenge for scientists performing research into the mechanics and biology of flexor tendon repairs, especially in zone 2.

Diagnostic accuracy of preoperative clinical examination in upper limb injuries

Background:

Injuries in hands and forearms may cause significant discomfort and disability.

Aim:

To evaluate the accuracy of preoperative clinical examination in depicting lesions caused by penetrating wounds of hands or forearms.

Setting and Design:

This prospective study was conducted from August 2006 to September 2009 at Kashani University Hospital, Isfahan University of Medical Sciences, Iran.

Materials and Methods:

Two hundred and fifty patients with clean penetrating injury to the hand/forearm were enrolled in this study. After patient's data registration, a careful clinical examination and routine exploration without expansion of wound were done by an orthopedic resident. Each tendon was tested at each joint level. Nerves were evaluated with a two-point discrimination test, and arteries were tested with palpable pulses. Surgical exploration was done by a single hand surgeon in operation room. Accuracy of clinical examination was compared to surgical examination.

Results:

During the study period, 180 (72%) males and 70 (28%) females with mean age of 28±4 years participated. The preoperative examination showed a predominance of the volar zone IV injuries followed by volar zone II, III, thumb zone II, volar zone V and thumb zone III. Despite the enough accuracy of preoperative examinations in dorsal side injuries of hands and forearms (error rate = 8.3%), the preoperative examinations significantly underestimated the amount of damage to soft tissues on the volar side of hands and forearms (error rate = 14%).

Conclusions:

The precise surgical evaluations should be considered in patients with penetrating injury to the hand or forearm, especially in those with volar side injuries.

Post-traumatic combined flexion of the thumb, index and middle finger after intrinsic muscles reconstruction of the hand: a case report

We report a case in which simultaneous flexion of the thumb, index and middle finger occurred 6 months after the surgical reconstruction of the adductor (AM) and first dorsal interosseous (IO) muscles. An anomalous connection in the form of tendon slip associated to fibrous adhesions between the flexor pollicis longus (FPL) tendon, flexor digitorum profundus indicis (FDPI) and middle finger (FDPM) tendons were found. Either ultrasound (US) examination or magnetic resonance imaging (MRI) were unable to detect the site of adhesion. Excision of the slip and radical tenosynoviectomy led to early functional recovery.