Value of high frequency ultrasonography in diagnosis and surgical repair of traumatic finger tendon ruptures

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.

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.

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.

Comparative Accuracy of 1.5T MRI, 3T MRI, and Static Ultrasound in Diagnosis of Small Gaps in Repaired Flexor Tendons: A Cadaveric Study

PURPOSE

We hypothesized that magnetic resonance imaging (MRI) would more accurately diagnose small gaps (<6 mm) after flexor tendon repair than static ultrasound (US) and that suture artifact would negatively impair accuracy.

METHODS

A laceration of the flexor digitorum profundus was created in 160 fresh-frozen cadaveric digits and randomized to either an intact repair (0-mm gap) or repairs using a locked 4-strand suture repair with either 4-0 Prolene, Ethibond, or and gaps of 2, 4,or 6 mm; or no suture in which 2-, 4-, or 6-mm gaps were created without a suture crossing the repair site. We performed 1.5T and 3T MRI and static US studies; gap widths were estimated by radiologists blinded to suture presence and true gap widths.

RESULTS

The 1.5 and 3.0T MRI had a lower mean error than US for gap sizes 0 and 2 mm. All 3 modalities performed similarly for 4- and 6-mm gaps. Documentation of imaging artifact worsened error, and odds of seeing artifacts were 1.72 higher with MRI than with US. Suture did not worsen artifact nor impair accuracy for any of the 3 modalities. When no suture was used, all 3 modalities significantly overestimated the true gap.

CONCLUSIONS

MRI is most accurate for small gaps less than 4 mm. Although all modalities overestimated gap sizes in specimens with a 0-mm gap (intact tendon repair), mean overestimation (<2 mm) was not clinically relevant. Ultrasound overestimated 2-mm gaps (clinically intact repairs), whereas MRIs did not. We recommend MRI for evaluation of gaps after flexor tendon repair. The 1.5T has slightly better sensitivity and specificity for distinguishing clinically intact (gap < 3 mm) from clinically impaired (gap > 3 mm) repairs than the 3T.

CLINICAL RELEVANCE

Accurate diagnosis of intact repairs or small gaps (<3 mm) might prevent unnecessary exploration or allow modification of rehabilitation protocols. Diagnosis of clinically relevant gaps (3-6 mm) may allow for earlier revision surgery before significant tendon retraction and adhesions develop, possibly necessitating a staged reconstruction.

Comparative Sensitivity and Specificity of Static and Dynamic High-Resolution Ultrasound in Diagnosis of Small Gaps in Repaired Flexor Tendons: A Cadaveric Study

PURPOSE

To compare the sensitivity and specificity of high-resolution static and dynamic ultrasound (US) for diagnosing intact repairs and small, clinically relevant gaps (≥4 mm) in repaired flexor digitorum profundus tendons within zone 2 and, secondarily, to evaluate the effect of suture artifact from 3 commonly used suture types.

METHODS

Eighty-eight fresh-frozen cadaveric digits (thumbs excluded) were randomized to either an intact repair (0-mm gap) or repairs using a locked 4-strand suture repair with either 4-0 Prolene, Ethibond, or FiberWire and gaps of 2, 4, or 6 mm and no suture in which 2-, 4-, or 6-mm gaps were created without a suture crossing the repair site. Gap widths were estimated by a blinded musculoskeletal ultrasonographer in static and dynamic modes.

RESULTS

Both static and dynamic modalities tended to overestimate actual gap sizes. For the suture gaps, both modalities had poor sensitivity (29% static; 42% dynamic) for accurately diagnosing a clinically intact repair (<4 mm), but better specificity (83% static; 75% dynamic) for diagnosing a clinically failed repair (≥4-mm gap). Although suture presence decreased the sensitivity of gap width measurement for both modalities, no differences were seen between suture types.

CONCLUSIONS

Static and dynamic US have poor sensitivity for diagnosing clinically intact repairs (gaps < 4 mm) because they typically overestimate gap size. The ability to diagnose failed repairs (gap ≥ 4 mm), based on greater specificity, is much better, but still suboptimal.

CLINICAL RELEVANCE

Based on a receiver operating characteristic analysis cutoff of 5 mm, if a gap of 5 mm or larger is identified with US when evaluating a zone 2 flexor digitorum profundus tendon repair, a failed repair is likely in about 80% of cases. A gap measurement of less than 5 mm may miss a high percentage of repairs that are clinically failed.

Diagnostic accuracy of history taking, physical examination and imaging for non-chronic finger, hand and wrist ligament and tendon injuries: a systematic review update

OBJECTIVE

The diagnostic work-up for ligament and tendon injuries of the finger, hand and wrist consists of history taking, physical examination and imaging if needed, but the supporting evidence is limited. The main purpose of this study was to systematically update the literature for studies on the diagnostic accuracy of tests for detecting non-chronic ligament and tendon injuries of the finger, hand and wrist.

METHODS

Medline, Embase, Cochrane Library, Web of Science, Google Scholar ProQuest and Cinahl were searched from 2000 up to 6 February 2019 for identifying studies. Methodological quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 checklist, and sensitivity (Se), specificity (Sp), accuracy, positive predictive value (PPV) and negative predictive value (NPV) were extracted.

RESULTS

None of the studies involved history taking. Physical examination, for diagnosing lesions of the triangular fibrocartilage complex (TFCC), showed Se, Sp, accuracy, PPV and NPV ranging from 58% to 90%, 20% to 69%, 56% to 73%, 53% to 71% and 55% to 65%, respectively. Physical examination in hand and finger injuries the Se, Sp, accuracy, PPV and NPV ranged from 88% to 99%, 75% to 100%, 34% to 88%, 91% to 100% and 75% to 95%, respectively. The accuracy of MRI with high-resolution (3 T) techniques for TFCC and interosseous ligaments of the proximal carpal row ranged from 89% to 91% and 75% to 100%, respectively. The accuracy of MRI with low-resolution (1.5 T) techniques for TFCC and interosseous ligaments of the proximal carpal row ranged from 81% to 100% and 67% to 95%, respectively.

CONCLUSIONS

There is limited evidence on the diagnostic accuracy of history taking and physical examination for non-chronic finger, hand and wrist ligament and tendon injuries. Although some imaging modalities seemed to be acceptable for the diagnosis of ligament and tendon injuries in the wrist in patients presenting to secondary care, there is no evidence-based advise possible for the diagnosis of non-chronic finger, hand or wrist ligament and tendon injuries in primary care.

Value of Ultrasound-Guided Closed Reduction and Minimally Invasive Fixation in the Treatment of Metacarpal Fractures

OBJECTIVES

To investigate the value of ultrasound-guided closed reduction and minimally invasive fixation in the treatment of metacarpal fractures.

METHODS

Twenty-four patients with acute metacarpal fractures were randomly divided into experimental and control groups, with 12 patients in each group. Ultrasound-guided closed reduction and fixation were performed in the experimental group, whereas C-arm fluoroscopy-assisted fixation was performed in the control group. Patients in both groups were followed to compare the treatment efficacy.

RESULTS

The success rates of ultrasound-guided closed reduction of fractures were 75.00% (9 of 12) in the experimental group and 83.33% (10 of 12) in the control group, and the difference was not statistically significant (χ²  = 0.253; P = .615) between the groups. The mean numbers of C-arm fluoroscopy-assisted procedures ± SD were 1.50 ± 0.67 times in the experimental group and 2.50 ± 0.80 in the control group, and the difference was statistically significant (t = -3.317; P = .003). The mean healing times of fractures were 5.47 ± 0.67 weeks in the experimental group and 5.73 ± 0.81 weeks in the control group; the excellence rates of total active motion were 83.33% (10 of 12) in the experimental group and 91.67% (11 of 12) in the control group; the mean grip strength values were 31.78 ± 3.13 kg in the experimental group and 33.43 ± 3.30 kg in the control group. There were no significant differences in those 3 parameters between the groups (P > .05 in each comparison).

CONCLUSIONS

Ultrasound-guided closed reduction and minimally invasive fixation is an effective treatment of metacarpal fractures and can reduce exposure to x-ray radiation.

[Ultrasound-guided percutaneous Herbert screw for the treatment of fresh nondisplaced carpal scaphoid fracture]

Objective

To explore the effectiveness of ultrasound-guided percutaneous Herbert screw for the treatment of fresh nondisplaced carpal scaphoid fracture.

Methods

Between May 2013 and August 2015, 15 patients with fresh nondisplaced carpal scaphoid fractures (Krimmer type A2) were treated with ultrasound-guided Herbert screw fixation. There were 12 males and 3 females with an average age of 33.4 years (range, 18-51 years). The causes of injury included 9 cases of falls, 3 cases of training injuries, and 3 cases of machine injuries. The interval from injury to surgery was 2-15 days (mean, 5 days). No other complication was found. The operation time, intraoperative blood loss, intraoperative fluoroscopy times, and the fracture healing time were recorded. The wrist function was assessed by the modified Mayo wrist score standard.

Results

The operation time was 28-53 minutes (mean, 33.9 minutes); the intraoperative blood loss was 5-30 mL (mean, 10.5 mL); the intraoperative fluoroscopy was 2-6 times (mean, 2.6 times). All 15 patients were followed up 6-18 months (mean, 10.5 months). One patient developed pain and soreness in the skin of the nail entrance, and gradually relieved after fumigation. No complication such as infection occurred. All fractures healed clinically, and the healing time was 8-16 weeks (mean, 11.6 weeks). At last follow-up, the modified Mayo wrist score was 76-99 (mean, 92.5). Among them, 12 cases were excellent, 2 cases were good, and 1 case was fair, and the excellent and good rate was 93.3%.

Conclusion

Ultrasound-guided fixation with Herbert screw is a reliable treatment method for fresh nondisplaced carpal scaphoid fractures with small invasion, less bleeding, and small radiation damage.

Closed traumatic rupture of the flexor pollicis longus tendon in zone T I: a case report

A healthy 41-year-old male suffered a direct blow on the palmar side of his right thumb when folding a table, which slipped along his thumb until it was stopped at the inter-phalangeal (IP) joint, resulting in a complete rupture of the flexor pollicis longus (FPL) tendon in zone T I. The proximal tendon stump was passed through the oblique pulley, fixed to the base of the distal phalanx with a pull-out wire technique and augmented on it using a part of the distal tendon remnant. After removal of the cast and the pull-out wire three weeks postoperatively, range of motion exercise was initiated and good functional recovery was obtained.

Evidence-based medicine: Flexor tendon repair

LEARNING OBJECTIVES

After studying this article, the participant should be able to: (1) Describe and apply the current evidence-based treatment of acute flexor tendon injuries. (2) Compare and contrast the current postoperative therapy regimens following repair of flexor tendons. (3) Apply an evidence-based decision-making process for suture techniques of flexor tendon injuries.

SUMMARY

Flexor tendon repair remains a challenge for hand surgeons to reliably obtain excellent results. Surgical decisions should rely on the surgeon's experience, outcome studies, and direct evidence. This review is a compilation of the evidence from the literature on optimizing outcomes for flexor tendon repair.