A Cadaveric Study of the Thread Trigger Finger Release: The First Annular Pulley Transection Through Thread Transecting Technique

Ultrasound-guided thread versus ultrasound-guided needle release of the A1 pulley: a cadaveric study

PURPOSE

To assess and compare two ultrasound-guided, minimally invasive procedures to release the A1-pulley (needle release and thread release) regarding efficacy and safety in an anatomical specimen model.

MATERIALS AND METHODS

Twenty-one ultrasound-guided needle releases and 20 ultrasound-guided thread releases were performed on digits of Thiel-embalmed anatomical specimens. A scoring system was developed to assess ultrasound visibility, intervention outcome (incomplete, almost complete, or full transection of the A1 pulley), and injury to adjacent structures (neurovascular structures, tendons, A2 pulley). Statistical analysis was performed to compare the score of the two groups (group 1: needle release,group 2: thread release). A P-value of ≤ 0.05 was considered significant.

RESULTS

Needle release was completely successful in 15 cases (71.5%), almost complete release was achieved in four cases (19%), and incomplete transection occurred in two cases (9.5%). Thread release was completely successful in 17 cases (85%), and almost complete transection was observed in the remaining three cases (15%). In both procedures no neurovascular structures were harmed. Slight injury of flexor tendons occurred in two cases (9.5%) in needle release and in five cases (25%) in thread release. There were no significant statistical differences between the groups regarding ultrasound visibility, intervention safety and outcome, (P > 0.05).

CONCLUSION

Ultrasound-guided needle release and ultrasound-guided thread release have similar success of release, both being effective and safe techniques for the release of the A1 pulley.

Ultrasound-guided minimally invasive thread release of Guyon's canal: initial experience in cadaveric specimens

OBJECTIVE

Guyon's canal syndrome is caused by compression of the ulnar nerve at the wrist, occasionally requiring decompression surgery. In recent times, minimally invasive approaches have gained popularity. The aim of this study was to assess the efficacy and safety of ultrasound-guided thread release for transecting the palmar ligament in Guyon's canal without harming surrounding structures, in a cadaveric specimen model.

METHODS

After ethical approval, thirteen ultrasound-guided thread releases of Guyon's canal were performed on the wrists of softly embalmed anatomic specimens. Cadavers showing injuries or prior operations at the hand were excluded. Subsequently, the specimens were dissected, and the outcome of the interventions and potential damage to adjacent anatomical structures as well as ultrasound visibility were evaluated with a score from one to three.

RESULTS

Out of 13 interventions, a complete transection was achieved in ten cases (76.9%), and a partial transection was documented in three cases (23.1%). Irrelevant lesions on the flexor tendons were observed in two cases (15.4%), and an arterial branch was damaged in one (7.7%). Ultrasound visibility varied among specimens, but essential structures were delineated in all cases.

CONCLUSION

Ultrasound-guided thread release of Guyon's canal has shown promising first results in anatomic specimens. However, further studies are required to ensure the safety of the procedure.

RELEVANCE STATEMENT

Our study showed that minimally invasive ultrasound-guided thread release of Guyon's canal is a feasible approach in the anatomical model. The results may provide a basis for further research and refinement of this technique.

KEY POINTS

• In Guyon's canal syndrome, the ulnar nerve is compressed at the wrist, often requiring surgical release. • We adapted and tested a minimally invasive ultrasound-guided thread release technique in anatomic specimens. • The technique was effective; however, in one specimen, a small anatomic branch was damaged.

Ex-vivo evaluation of a percutaneous looped thread desmotomy of the accessory ligament of the deep digital flexor tendon in horses

OBJECTIVE

To determine the ability to completely transect the equine accessory ligament of the deep digital flexor tendon (AL-DDFT) via an ultrasonographically-guided, percutaneous looped thread desmotomy using FiberWire suture as a cutting device.

STUDY DESIGN

Ex-vivo study.

SAMPLE POPULATION

A total of 24 normal equine distal forelimb specimens.

METHODS

Under ultrasonographic guidance, a Jamshidi needle was placed between the suspensory ligament and the AL-DDFT, and between the AL-DDFT and the deep digital flexor tendon, through two stab incisions. FiberWire suture was fed through the needle and looped around the AL-DDFT. Using a sawing motion, the ligament was transected, and the suture exited through the lateral incision. Surgical sites were dissected and assessed for completeness of transection, iatrogenic injuries, and suture remnants. Descriptive statistics were reported.

RESULTS

The procedure met the successful criteria in 18/24 (75%) of the limbs. The median surgical time was 11 min (range 7-25). No suture failure or suture remnants were noted in any of the specimens. Complications included iatrogenic injury to the medial and lateral neurovascular bundles in 4/24 and 1/24 specimens, respectively.

CONCLUSION

Complete transection of the AL-DDFT was achieved in 22/24 (92%) of the specimens; however, the neurovascular bundles were injured in 5/24 (21%) of the specimens.

CLINICAL SIGNIFICANCE

A percutaneous looped thread desmotomy of the AL-DDFT can be studied as an alternative technique for use in equine models prior to its clinical use in patients. Additional studies are required to evaluate efficacy and safety in anesthetized or standing horses.

The advantages of utilizing different ultrasound imaging techniques on joints of human cadavers in the teaching of anatomy - A scoping review

BACKGROUND

A common approach to define sonoanatomy is a reciprocal exchange of macroscopic and microscopic information in ultrasound imaging. High-resolution ultrasound has been long established and is crucial as an inexpensive and adaptable tool, not just in clinical settings but also while teaching anatomy. Early application of ultrasonography provides medical students with a couple of benefits: they acquire an improved understanding of anatomy and learn how to use it.

METHODS

A comprehensive literature review has been carried out, with relevant studies discovered in the following databases: MEDLINE, EMBASE, CENTRAL, BIOSIS Previews and Web of Science Core Collection. Gray literature was also considered in two different ways: (1) Regarding grey literature databases: National Gray Literature Collection. (2) For PhD theses and dissertations, the databases EThOS and Open Access Theses and Dissertations were screened for relevant studies by combining the keywords used in the search string. The reference lists of all relevant papers were scanned. Search process was performed on January 3rd, 2023. The search string was developed with the aid of and finally checked by a professional librarian. Only ultrasound studies on human cadavers were included, not animals or phantoms. If the studied subject was a joint, the article was included. Only B-Mode ultrasound was included, whereas Elastosonography, Doppler sonography and quantitative approaches including among others sound speed, backscatter attenuation were excluded. Intravascular, intraosseous, intraarticular, and three-dimensional or four-dimensional ultrasonography were also eliminated from the analysis. All appropriate information comprising articles, PhD theses, dissertations and chapters in textbooks were considered. There were solely English and German studies covered. There was no additional restriction on the publishing year. The included studies' general characteristics and ultrasound techniques were taken from them and examined. Using VOS viewer, a keyword analysis was also carried out.

RESULTS

142 of the 8899 results that were returned by the search satisfied the requirements. With a quarter of the included studies, the knee joint was the most extensively studied joint, followed by the elbow joint (10.6%) and the shoulder joint (9.2%). The methodological analysis includes 125 studies. Both the sample size and the ultrasonographer's qualifications were diverse. The probe position and the ultrasound method were precisely documented so that a reader could duplicate them in about three-quarters of the included studies (72.8%).

CONCLUSION

The current study, in our perspective, is the first scoping review to screen ultrasound studies on human cadaver joints. A heterogeneous field was shown by the methodological investigation. We suggest using a uniform method for conducting and presenting ultrasound examinations in future studies.

Retrograde Percutaneous Release of Trigger Finger or Thumb Using Sono-Instruments®: Detailed Technique, Pearls, and Pitfalls

Percutaneous release is a common treatment option for trigger finger stenosing tenosynovitis. While surgical and conservative treatments are available, percutaneous techniques offer several advantages, including faster recovery time, reduced complications, and simultaneous treatment of multiple trigger fingers. The sono-instrument is a minimally invasive device designed for surgical release of the A1 pulley in adults. The device is efficient and safe, and in addition, several design features enhance the visibility of the instrument under ultrasound imaging. The technique is truly percutaneous, as the whole operation is done through a single needle puncture. This minimizes postoperative discomfort and allows an immediate return to daily living and professional activities. The technique can be performed in an outpatient clinic under local anesthesia. The learning curve is quick; however, surgeons must acquire experience in hand sonography to master this new form of surgery. The aim of this article is to provide an in-depth exposition of the technical nuances, pearls, and pitfalls of this novel retrograde percutaneous release method. To our knowledge, this is the first retrograde truly percutaneous release technique yet described, facilitated by the novel Sono-Instruments®.

Sonographically controlled minimally-invasive A1 pulley release using a new guide instrument - a case series of 106 procedures in 64 patients

BACKGROUND

With percutaneous and minimally-invasive pulley release becoming more popular, safety and reliability of such minimally-invasive procedures remain a concern. Visualization of the technical steps by ultrasound suggests increased safety but shows the potential for harm to tendons, nerves and vessels without proper instrumentation. We present the results of implementing a sonographically guided minimally-invasive procedure in 106 trigger digits of 64 patients between 2018-2021.

METHODS

A guide instrument for use with a commercially available hook knife was developed and tested in 16 cadaver hands. Due to complication early in our clinical series this guide was modified in due course. A revised design of the guide has been in use since November 2019 with improved performance and safety.

RESULTS

One hundred six procedures in 64 patients were performed. After guide revision, we report a success rate of 97.3%. Complications after instrument revision include two cases of incomplete pulley release and one case of inadvertent skin laceration. The majority of patients report returning to all strenuous activities within two weeks at most apart from four individuals with prolonged postoperative discomfort.

CONCLUSION

We present the results of the development and implementation of a novel guide instrument for use with a hook knife to treat trigger finger. Despite several limitations of this study, we show that sonographically controlled, minimally-invasive A1 pulley release can be performed safely and effectively with appropriate surgical instruments and practice.

Ex vivo evaluation of a percutaneous thread-transecting technique for desmotomy of normal palmar/plantar annular ligaments in horses

OBJECTIVE

To develop and describe a minimally invasive, ultrasound-guided, percutaneous technique for the desmotomy of equine palmar/plantar annular ligaments (PALs) using a transecting thread.

STUDY DESIGN

Ex vivo study.

SAMPLE POPULATION

Twenty-one normal equine distal limb specimens.

METHODS

Under ultrasonographic guidance, a surgical thread was percutaneously placed around the PAL through 2 skin punctures (proximal and distal) using a 18 gauge spinal needle in equine limbs (11 forelimbs, 10 hindlimbs) with normal PALs. The ligament was transected by a back-and-forth motion of the thread until the loop emerged from the proximal skin puncture site. Each specimen was dissected and assessed for completeness of transection and iatrogenic damage under direct visualization. Descriptive statistics were reported.

RESULTS

The PAL was completely transected in 17/21 limbs. The mean duration of the procedure was 16 minutes. Superficial needle puncture or subtle abrasion of the superficial digital flexor tendon was noticed in 4 limbs. No iatrogenic injury to other intrathecal structures was identified. After PAL division, the needle entry and exit points had a mean diameter of 1.2 and 1 mm, respectively.

CONCLUSION

Desmotomy of normal PALs in equine limb specimens was performed effectively using the percutaneous thread-transecting technique with minimal iatrogenic damage to adjacent structures.

CLINICAL SIGNIFICANCE

Information from this study will allow refinement of the technique for use in equine clinical cases either in standing or anesthetized horses.

Ultrasound Measurements of the First Extensor Compartment: Determining the Transection Limits for Ultra-minimally Invasive Release of De Quervain Tenosynovitis

Background: De Quervain syndrome is the second most common compressive tendinopathy. Although the length of the first extensor compartment (FEC) has been studied previously, there is no documented reported comparison study of short-axis and long-axis sonographic measurements. The thread technique, or Guo Technique, has been applied to carpal tunnel syndrome, trigger finger, and superficial peroneal compressive neuropathy. To perform this procedure, it is critically important to accurately identify the boundaries for transection. Methods: Twenty-one fresh frozen cadaver upper extremities were examined under ultrasound to determine the length of the extensor retinaculum (ER) over the FEC. Using the sonographic landmarks, the ERs were measured in short axis and long axis over their proximal to distal margins and from the distal margins to the distal edges of the radial styloids. These sonographic measurements were then compared with gross anatomical measurements. Results: The short-axis sonographic measurement of the ER on average was 22.53 mm (95% confidence interval [CI] = 20.79-24.05 mm). The long-axis sonographic measurement of the ER on average was 15.65 mm (95% CI = 13.70-17.78 mm). The average length of the ER by gross anatomical dissection was 22.40 mm (95% CI = 21.15-23.51 mm). Conclusions: The short axis is not significantly different from the gross anatomical measurement; however, the long axis is significantly lower than the gross anatomical measurement. The results support the idea that the short axis is more accurate than the long axis.

Projection of the A1-Pulley of the Thumb onto Superficial Anatomical Landmarks: An Anatomical Study and a Useful Guide to Surgeons

BACKGROUND

The aim of our study was to project the A1-pulley of the thumb onto the total thumb length to enable its complete division with and without direct sight.

MATERIALS AND METHODS

The study involved 50 hands from adult human cadavers. The proximal and distal borders of the A1-pulley were measured with reference to the first metacarpophalangeal joint (MCPJ). The length of the thumb was defined as the interval between the first carpometacarpal joint (CMCJ) and the apex of the thumb. The length of the pulley is calculated proportionally with reference to the line between the first CMCJ and apex of the thumb.

RESULTS

Approximated by computing 95% confidence intervals, the pulley can be expected to lie in an area between 34.0% (proximal border) and 57.8% (distal border) alongside this line.

CONCLUSION

Percutaneous and minimally-invasive division of the A1-pulley needs to be performed between 34.0 and 57.8% of the length between the first CMCJ and apex of the thumb.

Comparison of the clinical effectiveness of ultrasound-guided corticosteroid injection with and without needle release of the A1 pulley in treating trigger finger

OBJECTIVE

To compare the clinical effectiveness of ultrasound-guided corticosteroid injection with and without needle release of the A1 pulley in treating trigger finger.

METHODS

A total of 60 patients with trigger finger were enrolled in this retrospective study. Among them, 30 patients were treated with ultrasound-guided needle release of the A1 pulley with corticosteroid injection (group A) and 30 patients were treated with single ultrasound-guided corticosteroids injection (group B). The following parameters were evaluated including clinical parameters (pain degree, function of joint, finger tendon function, postoperative satisfaction), and ultrasound parameter (thickness of A1 pulley).

RESULTS

The postoperative visual analogue scale (VAS) and Quinnell scores in two groups were significantly lower than that before operation (p < 0.05). The postoperative Quinnell score of group A was significantly lower than that in group B (p < 0.05). The TAM results showed that the postoperative overall excellent and good rate of group A was significantly higher than that in group B (p < 0.05). The postoperative survey showed that more than 80% patients reported satisfaction in the two groups. The ultrasound imaging results showed that the postoperative thickness of A1 pulley in two groups were thinner than that before operation (p < 0.05). There were no adverse effects and complications in the two groups.

CONCLUSIONS

Both approaches had treatment benefit in trigger finger. Ultrasound-guided needle release of the A1 pulley with corticosteroid injection had better treatment benefits than single ultrasound-guided corticosteroids injection in improving finger tendon function and joint function.

A cadaveric study using the ultra-minimally invasive thread transection technique to decompress the superficial peroneal nerve in the lower leg

BACKGROUND

After successful applications of the ultra-minimally invasive thread transecting technique (Guo Technique) for both thread carpal tunnel release and thread trigger finger release, we hypothesized that this technique could be used for superficial peroneal nerve release in the lower leg by selective crural fasciectomy. This study is aimed at testing the operative feasibility of performing the thread superficial peroneal nerve release (TSPNR) procedure in cadavers.

METHODS

The TSPNR procedure was performed on 15 fresh frozen cadaveric lower-extremity specimens under ultrasound guidance. All cadaveric specimens were dissected and visually assessed immediately after the procedures.

RESULTS

All 15 legs demonstrated a complete transection of the crural fasciae along the course of the superficial peroneal nerve (SPN) including where it penetrated and traversed the crural fascia. There was no evidence of any iatrogenic damage to the neurovascular bundle or adjacent tendons. The average operating time was less than 20 min.

CONCLUSION

This cadaveric study demonstrated that the technique of TSPNR was accurate, reliable, and feasible while causing no injury to adjacent neurovascular structures and avoiding having to make a skin incision. Further studies are warranted to verify the results of this study before implementing this new technique in the clinical setting.

Thread common peroneal nerve release-a cadaveric validation study

OBJECTIVE

To determine if the thread release technique can be applied to common peroneal nerve entrapment at the fibular neck.

METHODS

The thread common peroneal nerve release was performed on 15 fresh frozen cadaveric lower extremity specimens. All procedures were performed under ultrasound guidance and immediately underwent post-procedural gross anatomic inspection for completeness of decompression and presence or absence of iatrogenic neurovascular injury.

RESULTS

All 15 specimens demonstrated complete transection of the deep fascia of the peroneus longus overlying the common peroneal nerve. The transections extended to the bifurcation of the superficial peroneal and deep peroneal nerves. There was no evidence of any iatrogenic damage to the neurovascular bundle or adjacent tendons. The average operating time was less than 30 min.

CONCLUSION

This cadaveric validation study demonstrates the accuracy of the thread common peroneal nerve release. Future pilot studies are warranted to ensure the safety of this procedure in the clinical setting.

Ultrasound-Guided Percutaneous Release of A1 Pulley by Using a Needle Knife: A Prospective Study of 41 Cases

Objective: The purpose of this study was to evaluate the efficacy of ultrasonography-guided percutaneous A1 pulley release with the needle knife for trigger finger. Methods: The prospective study included 21 patients (21 fingers) who underwent blind release with the needle knife and 20 patients (20 fingers) who underwent ultrasonography-guided release with the needle knife. The thickness and width of A1 pulley, clinical grade before and after release, complications, and operation time were compared between the groups. Results: The results showed that the ultrasonography-guided group had significantly better grade postoperatively and reached to 100% complete release in one time compared to the blind group (p < 0.05). Moreover, no any complications had been happened in the ultrasonography-guided group. A relatively longer operation time of the ultrasonography-guided group was observed compared to the time of the blind group. Conclusions: The needle knife is a very good tool for release of triggering fingers. Ultrasound provides a direct and precise visualization of the thickness, width and location of A1 pulley lesion. The combined use of ultrasound and the needle knife can achieve the best result for trigger finger. Moreover, the combination changes the traditional opinion and operator-dependent mode that were once widely adopted in the hospital of Chinese Medicine.

Ultrasound-guided percutaneous compartment release: a novel technique, proof of concept, and clinical relevance

OBJECTIVE

Ultrasound-guided thread release (USGTR) is a minimally invasive technique with excellent clinical outcomes currently used in clinical practice to divide the transverse carpal ligament in carpal tunnel syndrome. The purpose of this study is to determine whether this technique can be modified for use in large anatomical compartments in soft embalmed cadaveric models.

MATERIALS AND METHODS

Two operators adapted the USGTR technique for use in muscular compartments of the forearms and legs in a single soft embalmed cadaver. An iterative approach was used to adapt and improve the technique for use in large compartments, using equipment readily available in most radiology departments.

RESULTS

The USGTR technique was successfully modified and both operators were able to accurately divide fascial layers over distances of up to 30 cm using the modified technique. Fascial division was confirmed with ultrasound and dissection.

CONCLUSIONS

This adapted technique can successfully be used to divide fascial planes over longer distances than is currently achieved in clinical practice. The improved outcomes associated with USGTR at the carpal tunnel may therefore also be achievable in fasciotomy procedures in larger anatomical compartments. Further study is required to investigate the effects of this modified USGTR technique on intracompartmental pressure.

Minimally invasive thread trigger digit release: a preliminary report on 34 digits of the adult hands

The trigger finger release was performed in 34 digits (11 thumbs and 23 fingers) of 24 patients through the thread transecting technique with the tip-to-tip approach, in which a 22-gauge needle inserts into a 18-gauge needle when both needles are inside the hand, guiding the 22-gauge needle to exit the hand at the same access point of 18-gauge needle. We prospectively evaluated the effectiveness and functional recovery of these patients. In all 34 digits, triggering and locking were resolved, and complete extension and flexion occurred immediately following the release. There were no complications, such as incomplete release, neurovascular or flexor tendon or A2 pulley injury, infection, or tendon bow-stringing. Patients did not require prescription pain medications. Most patients used their hands to meet their basic living needs the same day of the procedure. The hand function evaluated with the Quick Disabilities of the Arm, Shoulder and Hand questionnaire, and scored 4 within 3 months. Level of evidence: II.

Morphometric study of pulleys of the thumb

Pulleys are thickened regions in flexor tendons sheaths of the digits. They are essential and act as fulcrum for the flexion and extension of the digits. The arrangement and number of pulley system differs greatly between the thumb and other digits. There is paucity of literature regarding the pulley system of thumb. We aimed to study the morphometry of the pulley system of the thumb in Indian cadavers. Dissection was carried out in 55 adult human cadaveric thumbs. The most common morphologic pattern of pulley observed in the thumb is type III (30 thumbs). The least observed is type I (4 thumbs). The mean width and standard deviation of A1, Av, oblique, and A2 pulleys are 5.06±0.87, 5.38±1.22, 4.68±1.13, and 6.04±1.41 mm, respectively. The gap distances between the pulleys were also measured. The results obtained from the present study may be helpful in surgical treatment of trigger thumb with less complication and also in reconstruction of the closed rupture of the pulley of the thumb.