The use of ultrasound for monitoring reduction and ulnar nerve subluxation in pediatric humeral supracondylar fractures.

BACKGROUND: Traditional treatment for displaced humeral supracondylar fractures (SCFs) in children involves closed reduction (CR) under fluoroscopic guidance, percutaneous pinning, and immobilization with a long-arm cast. This study aims to explore the viability of using radiation-free ultrasound (US) for guiding CR and tracking ulnar nerve dynamics during medial pinning, contrasting the US method with the conventional cross pinning technique. MATERIALS AND METHODS: We assessed 70 children with acute displaced SCFs. The US group (n = 30) underwent US-guided reduction, whereas the traditional group (n = 40) underwent fluoroscopy-guided reduction. Both groups received percutaneous cross pinning and subsequent cast immobilization. Postoperative outcomes were compared between the two methods after a 6-month follow-up. In the US group, ultrasonography assessed fracture displacement distances before and after CR. The angle at which the ulnar nerve relocated to the cubital tunnel during elbow extension was documented using real-time US monitoring during medial pinning. RESULTS: The US group demonstrated improved reduction accuracy, increased range of motion, superior restoration of both Baumann and Humeroulnar angles, and a decreased incidence of malunions compared to the traditional group (all p < 0.05). The ultrasonographic measurement of fracture displacement was comparable with that of fluoroscopy (intraclass correlation coefficient > 0.90). In the US group, no ulnar nerve injury was noted, compared to 2.5 % in the traditional group, and real-time US observations revealed ulnar nerve hypermobility, with 53.3 % of patients exhibiting anterior ulnar nerve subluxation at 120° elbow flexion, 40 % at 90°, 16.7 % at 60°, and none at 30° flexion. CONCLUSION: Ultrasound is as reliable as fluoroscopy for evaluating fracture reductions. The use of intra-operative ultrasound significantly improves reduction accuracy and radiographic outcomes while reducing the risk of ulnar nerve injury.

Safe Zones for Percutaneous Carpal Tunnel Release.

Carpal tunnel release (CTR) is an effective procedure used in open, endoscopic, or ultrasound-guided methods. The complications are rare but potentially devasting. Most complications come from errors related to intraoperative technique, especially in the minimally invasive approach. An understanding of the "safe zones" is essential to perform percutaneous CTR safely. This article reviews the anatomy of safe zones and the ultrasound-guided CTR (UCTR) techniques in an attempt to prevent intraoperative complications. In strict accordance with the concepts of safe zones, UCTR is an effective and reliable procedure. Substantial experience for ultrasound-guided injection and surgery is required.

Effect of metacarpophalangeal joint position on A1 pulley and flexor digitorum tendons in trigger digit.

BACKGROUND: The aim of this study was to evaluate and compare the cross-sectional area (CSA) of flexor digitorum tendons and the thickness of first annular (A1) pulleys between contralateral normal digits and trigger digits (TDs) at positions of finger flexion and extension using a noninvasive ultrasound system. METHODS: Seventeen affected fingers of 17 patients (6 men and 11 women) with TDs in one hand, and 17 contralateral normal digits without trigger finger symptoms were examined. The sonographic appearances of flexor digitorum tendons and A1 pulleys were observed at two positions of metacarpophalangeal (MCP) joint flexion: 0° and 60°. RESULTS: The findings of this study indicate that CSA of flexor digitorum tendons and A1 pulley thickness were significantly larger in both positions of 0° and 60° flexion of MCP joint compared with contralateral normal digits (p < 0.01). In TDs, there was a significantly thicker A1 pulley at 60° flexion of MCP joint than that at 0° flexion (p < 0.01), but no significant change on CSA of flexor tendons. CONCLUSION: Our results suggested that TDs lead to the thicker A1 pulley and larger CSA of the flexor digitorum tendons. The mismatch in volume change between CSA of flexor digitorum tendons and A1 pulley thickness during MCP flexion may lead to the trigger phenomenon.

Ultrasound-guided percutaneous carpal tunnel release in patients on hemodialysis: early experiences and clinical outcomes.

Purpose: The purpose of the current study was to evaluate the effectiveness of ultrasound-guided percutaneous carpal tunnel release in hemodialysis patients with carpal tunnel syndrome. Methods: From February 2009 to April 2013, a prospective review of 113 consecutive cases of ultrasound-guided percutaneous carpal tunnel release was carried out in 84 hemodialysis patients. Results were analyzed by clinical subjective scale, two self-administered questionnaires, and functional evaluations at seven time points (1 week and 1, 3, 6, 12, 18, and 24 months). Results: Satisfactory symptom improvement in patients was 82%, 80%, 86%, 89%, 90%, 91%, and 90% at 1 week and 1, 3, 6, 12, 18, and 24 months postoperatively, respectively. Moderate pain was suffered in 11.5% of patients within 1 week, 8.8% within 1 month, 2.7% within 3 months, and none after 12 months postoperatively. Static two-point discrimination and Semmes-Weinstein monofilament examinations presented significant improvements after 1 week and 1 month postoperatively and with time. Postoperative grip power demonstrated recovery and a significant increase after 3 and 6 months postoperatively. Three-jaw chuck-pinch strength showed significant increase after 1 month postoperatively. There were no operative complications. Conclusion: Ultrasound-guided percutaneous carpal tunnel release is an effective and safe procedure in hemodialysis patients with carpal tunnel syndrome. The advantages include a less invasive procedure, no tourniquet needed, only limited infiltration anesthesia, minimal soft-tissue exploration, and relatively short operation time. Our data suggest this technique can reliably relieve clinical symptoms, with early restoration of grip and pinch strength.

Synovial fluid biomarkers: association with chronic rotator cuff tear severity and pain.

BACKGROUND: We tested the hypothesis that biomarkers in the synovial fluid of the glenohumeral (shoulder) joint are correlated with visual analog scale (VAS) scores, functional scores, and ultrasound findings of chronic rotator cuff tear (RCT) severity. METHODS: We measured biomarkers in shoulder joint synovial fluid of 42 patients with partial-thickness (21), nonmassive full-thickness (10), and massive full-thickness (11) RCTs. Pain duration, tear severity, and VAS and functional scores were compared with interleukin (IL) 1ß, IL-6, matrix metalloproteinase (MMP) 1, and MMP-13 levels. RESULTS: Both MMP-1 and MMP-13 levels were significantly highest in the massive full-thickness group. MMP-13 levels were significantly different between groups, but proinflammatory cytokine IL-1ß and IL-6 levels were not. However, IL-1ß levels were significantly positively correlated with VAS (r = 0.66; P <.01) and functional scores (r = 0.61; P <.01), but IL-6, MMP-1, and MMP-13 levels were not. CONCLUSIONS: IL-1ß levels in shoulder synovial fluid correlated positively with shoulder pain and functional scores in patients with chronic RCTs. Both MMP-1 and MMP-13 levels were altered and increased with cuff tear severity.

Ultrasonographically Guided Percutaneous Carpal Tunnel Release: Early Clinical Experiences and Outcomes.

PURPOSE: To present the technique and results of ultrasonographically guided percutaneous carpal tunnel release (PCTR) in a consecutive series of patients with carpal tunnel syndrome (CTS). METHODS: We used previously defined landmarks with the "safe zones," localization, estimated size, and extent of the transverse carpal ligament (TCL) for this prospective clinical study of 91 consecutive cases of carpal tunnel release treated with this technique. The follow-up consisted of 4 time points (1 week and 2, 6, and 12 months) and a final evaluation at an average of 22.5 months. RESULTS: The sensory disturbances disappeared in 76.8%, 93.4%, 100%, and 100% of the patients at 1 week and 2, 6, and 12 months postoperatively, respectively. Moderate pain was experienced in 24.2% of patients within 1 week, in 6.6% of patients within 2 months, and in 1.1% of patients within 12 months after the operation. In the final evaluation, 2 hands were graded as unsatisfactory: one hand had moderate wrist pain without sensory disturbance, and one hand had a recurrence 14 months after the operation. There were no intraoperative or postoperative complications. CONCLUSIONS: Ultrasonographically assisted PCTR is a safe and effective procedure, but it is technically demanding and requires substantial training to be proficient in its use. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

A cadaveric and preliminary clinical study of ultrasonographically assisted percutaneous carpal tunnel release.

The aim of this study was to assess the effectiveness and safety profile of a new technique for ultrasonographically assisted percutaneous carpal tunnel release. Experiments were performed on 40 hands in 20 cadavers. We first performed a detailed ultrasonographic examination and correlation study that included surgical dissection of the transverse carpal ligament, the related neurovascular structures and the bony landmarks of the radiocarpal, midcarpal and carpometacarpal joints of the right hand. We then used the measurements we made for percutaneous carpal tunnel release of the transverse carpal ligament using intra-operative ultrasonography for guidance and a hook knife on the left-hand side. The completeness of the release and the potential risks of injury to the flexor tendon and neurovascular bundles were examined. Using real-time intra-operative ultrasonographic monitoring to clearly delineate these targets, we were able to percutaneously release the transverse carpal ligament completely in 18 (90%) of the 20 hands and partially release it in 2 without injuring any neurovascular bundles. We then performed the procedure on 91 consecutive cases of carpal tunnel syndrome and found that the sensory disturbances disappeared in 100% patients 12 mo post-operatively; only 2 hands were graded as unsatisfactory. There were no intra- or post-operative complications. Based on the results from the cadaveric studies and our successful preliminary clinical outcomes, we conclude that this method is tolerable and that its clinical application can be encouraged.

The value of high-frequency ultrasonographic imaging for quantifying trigger digits: a correlative study with clinical findings in patients with different severity grading.

Trigger digit is recognized as thickening and constriction of the flexor tendon sheath at the base of digits. This study investigates the correlation between the severity grading of trigger digits and clinical findings from high-frequency ultrasonography. We measured and compared thicknesses, areas and pathological changes of the flexor digit tendons among total, contracture and noncontracture trigger digits and noninvolved contralateral digits. Forty-seven patients with 55 idiopathic trigger digits (36 contracture and 19 noncontracture) and 55 noninvolved contralateral digits were examined using high-frequency ultrasonography. The thickness of the flexor tendons was measured in a longitudinal plane at the A1 pulley: Inlet (metacarpal head-neck junction), Outlet (proximal phalangeal base-shaft junction) and Interpulley (middle of Inlet and Outlet). The cross-sectional and extratendinous tissue areas of the flexor tendons in a transverse plane at the point of Interpulley were measured. Pathological changes including irregular internal echotextures, fluid collection, dominant A1 pulley and abnormal metacarpophalangeal joint were analyzed. All thicknesses and areas of total and contracture trigger digits were significantly greater than those of noninvolved contralateral digits (p < 0.05), whereas no significant difference was observed in noncontracture trigger digits. The pathological changes were all significantly different from noninvolved contralateral digits in total, contracture and noncontracture trigger digits (p < 0.05). In contracture and noncontracture trigger digits, there were significant differences only in the thickness of the Inlet and the pathological change of the dominant A1 pulley (p < 0.05). In conclusion, the results of the ultrasonographic measurements and findings provided evidence of Notta's node and correlated with clinical findings and severity grades.

Sonographically assisted percutaneous removal of screws in dynamization of the interlocking intramedullary nail.

OBJECTIVES: Dynamization is a method of removing the interlocking screw(s) farthest from the fracture site for improving healing in femoral and tibial fractures that show delayed healing after static interlocking nailing. We describe a simple sonographically assisted technique for percutaneous dynamization of deep-seated impalpable screws. METHODS: Between March 2001 and March 2005, 20 dynamization procedures were completed using the developed technique under the diagnosis of delayed healing or a nonunion at a mean of 4.8 months after index surgery. After adequately positioning the involved leg, the transducer was placed on the area of the inlet of the screw. Longitudinal and transverse sonographically scanned sections, used to show the head of the screw, were then marked on the skin where the two sections intersected. After this precise marking, a small incision on the mark allowed insertion of the screwdriver and easy percutaneous removal of the screw using only local anesthesia for pain control. RESULTS: We removed 31 screws: 9 proximal femoral screws, 20 distal femoral screws, and 2 proximal tibial screws. The mean depth of the screws was 3.4 cm. The mean operation times were 1.6 minutes for the sonographic examination and 3.5 minutes for removal of one screw. No infections or morbidities were caused by the procedure. CONCLUSIONS: Sonography is an effective tool for localizing a locked screw and facilitates percutaneous removal of screws under only local anesthesia for dynamization. This method needs no special instruments and reduces the time needed for dissecting the tissue and locating the screw.

Ultrasonography for diagnosing carpal tunnel syndrome: a meta-analysis of diagnostic test accuracy.

Ultrasonography is widely used to diagnose carpal tunnel syndrome (CTS), a common peripheral neuropathy, but the reported diagnostic accuracy varies. This meta-analysis focused on the diagnostic test accuracy of ultrasonography for diagnosing CTS. Structured searches of PubMed for 1990-2010 were done and the data were extracted and meta-analyzed by pooling estimates of sensitivity, specificity, likelihood ratios and diagnostic odds ratios. Diagnostic performance was also judged by using a summary receiver operating characteristic curve. Twenty-eight trials involving 3995 wrists were included. A greater cross-sectional area (CSA) of the median nerve at the carpal tunnel inlet (CSA-I) and a greater flattening ratio at the level of the hamate were seen in CTS wrists than in control wrists. A CSA-I ≥9 mm(2) is the best single diagnostic criterion, with a diagnostic odds ratio of 40.4 (sensitivity 87.3%, specificity 83.3%).

Synovial osteochondromatosis of the second metatarsophalangeal joint: a case report.

Synovial osteochondromatosis is usually monoarticular, involving a large joint. Common locations include the knee, elbow, shoulder, and hip. It is not very common in the ankle, and it is very rare in the smaller joints of the foot. To our knowledge, and with the exception of 4 cases that occurred in the great toe, this condition has never been described in other metatarsophalangeal joints. In this report, we presented a case of synovial osteochondromatosis in the second metatarsophalangeal joint and reviewed the literature.

Cadaveric study of sonographically assisted percutaneous release of the A1 pulley.

The purpose of this study was to assess the value of using intraoperative sonography to assist percutaneous release of the A1 pulley in cadavers. By detailed sonographic examination and anatomical exploration, the authors determined the correlation of the actual A1 and A2 pulleys (and adjacent neurovascular bundles not visualized by sonography) to the clearly visualized flexor tendons and the metacarpophalangeal joint. The authors also evaluated their effectiveness as landmarks and the effectiveness of real-time sonographic monitoring during percutaneous release. Experiments were performed on 80 fingers and 20 thumbs in 10 cadavers. All digits were sonographically examined. The clearly delineated bony landmarks of the metacarpophalangeal joint were measured and marked. The A1 and A2 pulleys and the neurovascular bundles were surgically exposed, and their relation to the markers made during sonographic examination was measured. Using these parameters, sonographically assisted percutaneous release of the A1 pulley with a custom-made hook knife was performed on the contralateral side. The completeness of the A1 release and the potential risk of injuries to the A2, flexor tendon, and neurovascular bundles in each digit were examined. Results showed good correlation between the actual length of the A1 pulleys and the sonographically determined distance between the bony prominences of the metacarpophalangeal joint in all digits. Release was complete in 48 of the 50 digits (96 percent) and partial in two, with no injuries to neurovascular bundles. Sonography can clearly delineate the flexor tendon and underlying bony boundary of the metacarpophalangeal joint, which is useful in directing the percutaneous release of the A1 pulley. Sonography can also provide real-time intraoperative monitoring. The results using this new release technique were adequate. The method is safe and its clinical application should be encouraged.

The effect of normal saline irrigation at different temperatures on the surface of articular cartilage: an experimental study in the rat.

PURPOSE: To determine, with an electron microscope, the effects of irrigation fluid at different temperatures on the surface of articular cartilage. TYPE OD STUDY: Experimental in vivo study. METHODS: With a scanning electron microscope, we investigated the effect of 2 hours of irrigation with normal saline at 3 different temperatures (4 degrees C, 25 degrees C, and 37 degrees C) on articular hyaline cartilage in an in vivo rat knee model study. The contralateral knees were used as controls. We then compared the results. RESULTS: Specimens irrigated with cold (4 degrees C) fluid seemed to show the most uneven surface and apparent fibril exposure. Those irrigated with fluid close to body temperature (37 degrees C) showed the most even surface without fibril exposure. CONCLUSIONS: Although further work is needed to evaluate the long-term effects, using warm irrigation fluid to maintain the intra-articular environment at a more physiologically normal temperature may help reduce damage to cartilage during irrigation.

Effects of desflurane on spinal somatosensory-evoked potentials and conductive spinal cord evoked potential.

STUDY DESIGN: Spinal somatosensory-evoked potential (interspinous-space-recorded evoked potentials after peripheral nerve or dermatomal stimulation) and conductive spinal cord evoked potential (interspinous-space-recorded evoked potentials after spinal cord stimulation) were analyzed in rats under different concentrations of the anesthetic desflurane. OBJECTIVES: To investigate and compare the effects of a new volatile anesthetic, desflurane, on the common intraoperative neuromonitoring models. SUMMARY OF BACKGROUND DATA: Intraoperative evoked potentials are sensitive to most anesthetics. Interpretation of the data becomes complicated because of a suppression effect caused by the anesthesia. Desflurane has become a valuable anesthetic in neurosurgery because of its pharmacokinetic advantages. METHODS: Fifteen rats were placed under general anesthesia, and vital signs were closely monitored. Needle recording electrodes were placed stereotactically into the thoracolumbar interspinous ligament; dermatomal somatosensory-evoked potential by L5 dermatome, mixed-nerve somatosensory-evoked potential by sciatic nerve stimulation, and spinal cord evoked potential of the same recording electrodes elicited by C2-C3 interspinous stimulation were obtained. The effects of desflurane were examined at end-tidal concentrations of 6% (1.05 minimal alveolar concentration), 9% (1.57 minimal alveolar concentration), and 12% (2.10 minimal alveolar concentration). RESULTS: Amplitude decreased and latency was delayed in all three kinds of potentials, and the more so with higher concentrations. Comparing 9% with 6% desflurane, the amplitude in dermatomal somatosensory-evoked potential, mixed-nerve somatosensory-evoked potential, and spinal cord evoked potential decreased to 84.3%, 88.9%, and 70.8%, respectively, values with no statistically significant difference. However, at 12%, again compared with 6%, the amplitude decreased further to 64.4%, 70.3%, 41.8%, respectively; mixed-nerve somatosensory-evoked potential and dermatomal somatosensory-evoked potential were significantly more preserved than spinal cord evoked potential (P = 0.04). CONCLUSIONS: The concentration of desflurane alters the amplitude of somatosensory-evoked potential and spinal cord evoked potential, and, to a lesser degree, delays the latency; spinal cord evoked potential is more liable to be suppressed than somatosensory-evoked potential. The dose-dependent suppression effect on amplitude should be considered when interpreting changes during surgery. Furthermore, the potential benefit of somatosensory-evoked potential elicited by direct major nerve stimulation should be considered because of its large amplitude and higher resistance, even with a greater concentration of volatile anesthetics.

Spinal somatosensory evoked potential evaluation of acute nerve-root injury associated with pedicle-screw placement procedures: an experimental study.

Pedicle screws for spinal fixation risk neural damage because of the proximity between screw and nerve root. We assessed whether spinal somatosensory evoked potential (SSEP) could selectively detect pedicle-screw-related acute isolated nerve injury. Because pedicle screws are too large for a rat's spine, we inserted a K-wire close to the pedicle in 32 rats, intending not to injure the nerve root in eight (controls), and to injure the L4 or L5 root in 24. We used sciatic-nerve-elicited SSEP pre- and postinsertion. Radiologic, histologic, and postmortem observations confirmed the level and degree of root injury. Sciatic (SFI), tibial (TFI), and peroneal function indices (PFI) were calculated and correlated with changes in potential. Although not specific for injuries to different roots, amplitude reduction immediately postinsertion was significant in the experimental groups. Animals with the offending wire left in place for one hour showed a further non-significant deterioration of amplitude. Electrophysiologic changes correlated with SFI and histologic findings in all groups. SSEP monitoring provided reliable, useful diagnostic and intraoperative information about the functional integrity of single nerve-root injury. These findings are clinically relevant to acute nerve-root injury and pedicle-screw insertion. If a nerve-root irritant remains in place, a considerable neurologic deficit will occur.

Sonography for monitoring closed reduction of displaced extra-articular distal radial fractures.

BACKGROUND: Closed reduction and cast immobilization are employed in the primary treatment of most distal radial fractures, and conventional radiographic techniques have been essential and effective in monitoring these reductions. Radiation-free ultrasonography, however, can provide both real-time and dynamic multiple-plane images with a small and simple-to-use transducer that can be operated with only one hand. We therefore wanted to see if the real-time and dynamic multiple-plane observation capabilities of ultrasonography would allow an orthopaedic surgeon to perform a closed reduction without multiple attempts, as are frequently required when only conventional radiographic techniques are used. METHODS: Sonographically guided closed reduction was performed in twenty-seven consecutive wrists with an acute distal radial fracture. The efficacy of this method was evaluated and compared with that of conventional radiographic techniques. RESULTS: The sonographic images delineated the fractures as accurately as did the conventional radiographs. All parameters measured on the sonograms and radiographs showed substantial restoration of anatomic alignment after reduction, and all measurements were similar on the two types of images. CONCLUSIONS: Sonographically guided monitoring compared well with conventional radiographic techniques during closed reduction of extra-articular distal radial fractures. Sonography is an accurate, simple, and radiation-free tool that provides the substantial benefits of dynamic multiple-plane and real-time observation.