TRIGGER FINGER CAUSED BY AN OLD PARTIAL FLEXOR TENDON LACERATION: A CASE REPORT

Ultrasound Features of Trigger Finger: Review of the Literature

Trigger finger is a common pathologic condition of the digital pulleys and flexor tendons in the hand. The key clinical finding is a transient blockage of the digit when it is flexed with subsequent painful snapping when it is extended. Imaging is a helpful guide for establishing the severity of the disease, identifying the underlying cause, and deciding the appropriate management. This narrative review aims to recall the anatomic and pathologic bases and describe the ultrasound features of trigger finger, also including common ultrasound findings and complications after therapy. Ultrasound enables an accurate static and dynamic evaluation of trigger finger as well as a comparison with the adjacent normal digits and thus should be considered the radiologic modality of first choice for its diagnosis.

Trigger finger secondary to a neglected flexor tendon rupture

Secondary trigger finger caused by trauma to the hand, especially associated with partial flexor tendon rupture, is not a common condition. Thus, the clinical manifestations of these patients are not well-known. The aim of this study is to present secondary trigger finger caused by a neglected partial flexor tendon rupture including discussion of the mechanism and treatment.We retrospectively reviewed the records of 6 patients with trigger finger caused by a neglected partial flexor tendon rupture who had been treated with exploration, debridement, and repairing of the ruptured tendon from August 2010 to May 2015. The average patient age was 41 years (range, 23-59). The time from injury to treatment averaged 4.7 months. The average follow-up period was 9 months (range, 4-18). Functional outcome was evaluated from a comparison between the Quick-disabilities of the arm, shoulder, and hand (DASH) score and the visual analogue scale (VAS) for pain, which were measured at the time of preoperation and final follow up.Four patients showed partial rupture of the flexor digitorum profundus (FDP) tendon and 3 showed partial rupture of the flexor digitorun superficialis (FDS) tendon. Both the FDP and FDS tendons were partially ruptured in 2 patients, and the remaining patient had a partial rupture of the flexor pollicis longus tendon. All patients regained full range of motion, and there has been no recurrence of triggering. The average VAS score decreased from 3.6 (range, 3-5) preoperatively to 0.3 (range, 0-1) at the final follow up. The average Quick-DASH score decreased from 33.6 preoperatively to 5.3 at the final follow up.When we encounter patients with puncture or laceration wounds in flexor zone 2, even when the injury appears to be simple, partial flexor tendon laceration must be taken into consideration and early exploration is recommended.

The Management of Partial Zone II Intrasynovial Flexor Tendon Lacerations: A Literature Review of Biomechanics, Clinical Outcomes, and Complications

BACKGROUND

Penetrating trauma or lacerations within zone II of the flexor sheath may result in partial tendon injury. The proper management of this injury is controversial; the literature contains differing indications for surgical treatment and postoperative rehabilitation.

METHODS

A literature review of the Cochrane, MEDLINE, and PubMed databases was performed using the following search criteria: partial, flexor, tendon, and laceration. All English language studies that evaluated biomechanical strength, complications, and outcomes after partial tendon injury in human and animal studies were included and reviewed by two of the authors.

RESULTS

Animal and cadaveric biomechanical studies have demonstrated that partial lacerations involving up to 95 percent of the tendon cross-sectional area can safely tolerate loads generated through unresisted, active finger flexion. Suture tenorrhaphy of partial tendon injury is associated with decreased tendon tensile strength, increased resistance, and decreased tendon gliding. Complications of nonsurgical management include triggering and entrapment, which can be managed by tendon beveling or pulley release. Late rupture is extremely uncommon (one report).

CONCLUSIONS

Partial tendon lacerations involving 90 percent of the cross-sectional area can be safely treated without surgical repair and immediate protected active motion. Indications for exploration and treatment include concern for complete injury, triggering of the involved digit, or entrapment of the tendon. Surgical treatment for tendon triggering or entrapment with less than 75 percent cross-sectional injury is beveling of the tendon edges and injuries greater than 75 percent should be repaired with a noncircumferential, simple epitendinous suture. All patients should be allowed to perform early protected active motion after surgery.

Closed Partial Flexor Digitorum Profundus Rupture: An Unusual Cause of Pediatric Trigger Finger

BACKGROUND

Trigger finger is a common condition, causing impaired gliding of the digital flexor tendons. Chronic inflammation is the usual cause, but acute trigger finger following partial tendon laceration has also been described.

METHODS

We describe the case of a four year old girl who presented with inability to flex her index finger. Operative exploration revealed a closed partial rupture of the flexor digitorum profundus tendon, catching on the A2 pulley and preventing normal tendon gliding.

RESULTS

Excision of the damaged section of tendon allowed normal gliding motion, and once the wound had healed the patient regained full painless motion.

CONCLUSION

Acute trigger finger caused by partial flexor tendon injury is an uncommon but well-documented presentation. Surgical exploration not only confirms the diagnosis, but allows for excision of the damaged segment to return normal movement without compromising strength.

Accuracy of Visual Estimates of Partial Flexor Tendon Lacerations

PURPOSE

To determine whether hand surgeons could accurately and consistently estimate the size of partial flexor tendon lacerations.

MATERIALS AND METHODS

Thirty-two partial flexor tendon lacerations were made in the flexor digitorum profundus tendons of a fresh-frozen cadaveric hand. Four hand surgeons and 5 residents estimated the size of the lacerations. Estimates were repeated 3 days later. Magnified images of the laceration cross-section were used to calculate the true size of each laceration. Inter- and intrarater reliability were calculated using the intraclass correlation coefficient. Accuracy was measured with the mean bias error and the mean absolute error.

RESULTS

Interrater and intrarater reliabilities were both high. There was a high level of consistency for both surgeons and residents. In terms of accuracy, there was a 3% bias toward underestimation. The mean absolute error was 11%. There was no statistically significant difference between the accuracy of attending hand surgeons and that of residents. Participants were less accurate when estimating lacerations close to a 60% laceration threshold for surgical repair (lacerations in the 50%-70% range). For lacerations within this range, an incorrect management decision would have been made 17% of the time, compared with 7% of the time for lacerations outside that range.

CONCLUSIONS

The accuracy and reliability of surgeon estimates of partial flexor tendon laceration size were high for surgeons and residents. Accuracy was lower for lacerations close to the threshold for repair.

CLINICAL RELEVANCE

Visual estimation is acceptable for evaluating partial flexor tendon lacerations, but it may be less reliable for lacerations near the threshold for repair. Therefore, surgeons should be cautious when deciding whether or not to repair partial lacerations in the borderline range.

Trigger finger following partial flexor tendon laceration: Magnetic resonance imaging-assisted diagnosis

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Partial flexor tendon lacerations are usually diagnosed clinically.

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The clinical findings include pain and clicking.

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Magnetic resonance imaging (MRI) can aid in diagnosis in the presence of confounding factors.

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A visible tendon tag can be seen on the MRI.

Introduction

Post-traumatic trigger finger is considerably rarer than normal trigger finger. The diagnosis is usually made on a clinical basis. This can be obscured; however, by concurrent pathological conditions. We report a case of post-traumatic trigger finger in which diagnosis was aided by magnetic resonance imaging (MRI).

Presentation of case

Our patient is a 32-year-old male who had a previous laceration with a subsequent surgery for infectious tenosynovitis. The MRI showed the impinging tendon tag. Surgical excision of the tag successfully solved the case.

Discussion

The use of imaging studies for the diagnosis of post-traumatic trigger finger has been previously reported, the authors described a variation on the contour of the pulley system. The full lacerated tendon tag can be seen on our patient's MRI.

Conclusion

On this case, the use of MRI was a useful aid for the differential diagnosis of post-traumattic trigger finger.

Locking finger due to a partial laceration of the flexor digitorum superficialis tendon: a case report

A 39-year-old woman sustained a small wound on the palm of her right hand, which quickly healed naturally; however, a month later pain and limited range of motion were noted in her right finger. Surgery revealed the radial half of the flexor digitorum superficialis (FDS) tendon was ruptured and formed a flap, which hooked at the entrance of the A1 pulley. The proximal stump was sutured to the remaining ulnar (normal) side of the FDS tendon. Locking occurs between the tendon flap and the tendon sheath; therefore, when there is no fibrous tendon sheath near the partially ruptured tendon, locking will not occur.

Partial laceration of the flexor tendon as an unusual cause of trigger finger

We present two cases of trigger finger caused by partial laceration of a flexor tendon. Both patients had preceding skin injury and required operative treatment with resection of the lacerated portion of the tendon and incision of the A1 pulley. We describe keys to the diagnosis of this type of lesion.

Pseudo triggering finger caused by a giant cell tumour of the extensor aspect of the right index finger

Peudo-triggering of a finger due to a giant cell tumour of the dorsal aspect of a finger has not been reported in the literature. Hence the authors wish to report this unique case of interest.

Complications after flexor tendon injuries

Management of flexor tendon injuries is one of the most demanding tasks in hand surgery. Despite substantial improvements in surgical technique and postoperative rehabilitation protocols, functional outcomes may still be somewhat unreliable. In the present article, the authors present complications encountered after flexor tendon repair and provide their preferred methods of prevention and treatment.

Sonographic appearance of trigger fingers

OBJECTIVE

The purpose of this study was to describe the sonographic appearance of the first annular (A1) pulley-flexor tendon complex in patients with trigger fingers.

METHODS

Thirty-three trigger fingers in 33 patients were examined with a 7- to 15-MHz probe. A control group consisted of 20 patients without trigger fingers. The study included systematic measurement of the thickness of the A1 pulley and a power Doppler assessment of the pulleys, tendons, and tendon sheaths.

RESULTS

Thickening and hypoechogenicity of the A1 pulley were found in all patients with trigger fingers. Measurements of A1 pulley thickness were significantly different (P < .0001) between the groups without trigger fingers (mean, 0.5 mm; range, 0.4-0.6 mm) and with trigger fingers (mean, 1.8 mm; range, 1.1-2.9 mm). Hypervascularization of the A1 pulley on power Doppler imaging was found in 91% of the trigger fingers but was never found in the healthy control group. Flexor tendinosis was found in 48% of the trigger fingers; tenosynovitis was found in 55%; and both were found in 39%. In the control group, tenosynovitis and tendinosis were not found.

CONCLUSIONS

Thickening and hyper-vascularization of the A1 pulley are the hallmarks of trigger fingers on sonography. Other frequently observed features include distal flexor tendinosis and tenosynovitis.