Trigger finger following partial flexor tendon laceration

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.

Partially Divided Flexor Tendon Injuries: Should They Be Repaired or Not?

The correct management of partially divided flexor tendon injuries is still controversial. Opinions vary regarding whether partially divided flexor tendon injuries should be repaired. Flexor tendon injuries are common because the tendons lie close to the skin. The tendons are therefore exposed to injuries like lacerations and crush injuries, and occasionally they can rupture from where they are joined to the bone. Tendon injuries are the second most common hand injuries in orthopedic patients.

A Comparison of Two Monofilament Suture Materials for Repair of Partial Flexor Tendon Lacerations: A Controlled In-vitro Study

BACKGROUND

Surgical repair is advocated for flexor tendon lacerations deeper than 70%. Repair can be undertaken with different suturing techniques and using different materials. Different materials used for tendon repair will have a different gliding resistance (GR) at the joint. Previous studies have compared strength of repair and gliding resistance for various braided suture materials and for 100% laceration of flexor tendons. We directly compare the GR of two monofilament sutures when used for a peripheral running suture repair of partially lacerated tendons.

METHODS

Sixteen flexor tendons and A2 pulleys were harvested from Turkey feet. They were prepared, partially lacerated to 50% depth, and then repaired with a core suture (modified Kessler technique with 4-0 Ethibond) as well as an additional superficial running suture of either 6-0 Prolene or Nylon (half randomised to each). Gliding resistance was measured for all tendons before and after repair, at different flexion angles (40 and 60 degrees) and for different loads (2N and 4N).

RESULTS

After surgical repair, gliding resistance was increased for all tendons (P < 0.01). The tendons repaired with Prolene had a higher mean gliding resistance than those repaired with Nylon (P = 0.02). Increased flexion angle and load amplified the gliding resistance (both P < 0.01).

CONCLUSIONS

6-0 Nylon was associated with a lower gliding resistance than 6-0 Prolene but the minor differences bare unknown clinical significance.

Effect of triggering and entrapment on tendon gliding properties following digital flexor tendon laceration: in vitro study on turkey tendon

The optimal management of partial flexor tendon laceration is controversial and remains a clinical challenge. Abnormal tendon gliding (triggering and entrapment) was assessed at the A2 pulley in 40 turkey tendons in three groups: intact, partially divided (palmar or lateral), and trimmed. Testing was of gliding resistance and friction coefficient at 30° and 70° of flexion, loaded with 2 and 4 N. We observed for triggering and entrapment. The changes in gliding properties were compared and analysed using Wilcoxon matched pair testing. A significant difference was found in the change in gliding properties of intact to lacerated and lacerated to trimmed tendons and between tendons that glided normally compared with those exhibiting triggering or entrapment. This suggests that palmar and lateral lacerations which, through clinical examination and visualization, are found to glide normally should be treated with early mobilization. However, partial lacerations that exhibit triggering or entrapment should be trimmed.

Support for partial lesions of the flexor tendons of the fingers: a retrospective study of 36 cases

The treatment of traumatic partial injuries of the flexor tendons of the fingers is seldom published. The only published clinical series states that the therapeutic approach depends on the existence or absence of a preoperative trigger. We hypothesized that the therapeutic attitude mainly depends on the percentage of the injured cross-section. Our retrospective series included 36 partial lesions of 31 fingers in 29 patients. The average age was 42 years, there were 19 men. We noted 8 lesions in zones I, 21 in zone II and 2 in zone III. The average percentage of the injured cross-section was 35% and ranged from 10% to 90%. If the lesion was less than 50% (29 tendons), a tangential resection was performed. If the lesion exceeded 50% (seven tendons), a direct suture was performed, supplemented by a running suture. At a follow-up of 34 months, the average pain on a visual analogue scale was 0.7. The average percentage of strength compared to the contralateral side was 93%. The Quick DASH score was 6.2. The range of motion averaged 214° with extremes ranging from 90° to 260°. We observed no cases of hypertrophic callus, neither through the MRI nor through the ultrasonography. Complications such as trigger finger, pseudoblocage or rupture were not observed. Based on our results, in case of partial injury of a flexor tendon, we propose to perform a tangential resection in cross-section lesions up to 50%, and a suture for those which exceeded 50%.

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

We report a rare case of trigger finger caused by an old partial laceration of the flexor digitorum superficialis. The triggering occurred five months after injury. This case was the latest presentation of triggering in the literature. The patient was managed by incising the A1 pulley and suturing the flexor tendon flap after trimming. He was relieved of triggering and there was no recurrence.

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.

Effect of laceration and trimming of a tendon on the coefficient of friction along the A2 pulley

We carried out lacerations of 50%, followed by trimming, in ten turkey flexor tendons in vitro and measured the coefficient of friction at the tendon-pulley interface with loads of 200 g and 400 g and in 10°, 30°, 50° and 70° of flexion. Laceration increased the coefficient of friction from 0.12 for the intact tendon to 0.3 at both the test loads. Trimming the laceration reduced the coefficient of friction to 0.2. An exponential increase in the gliding resistance was found at 50° and 70° of flexion (p = 0.02 and p = 0.003, respectively) following trimming compared to that of the intact tendon.

We concluded that trimming partially lacerated flexor tendons will reduce the gliding resistance at the tendon-pulley interface, but will lead to fragmentation and triggering of the tendon at higher degrees of flexion and loading. We recommend that higher degrees of flexion be avoided during early post-operative rehabilitation following trimming of a flexor tendon.

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.

Biomechanical analysis of partial flexor tendon lacerations in zone II of human cadavers

PURPOSE

The aims of this study were to examine nonrepaired 90% partial lacerations of human cadaver flexor digitorum profundus (FDP) tendon after simulated active motion, and to assess the residual ultimate tensile strength.

METHODS

Partial, transverse zone II flexor tendon lacerations were made in the volar 90% of the tendon substance in 10 FDP tendons from 5 fresh-frozen human cadaver hands. The tendons were cycled in the curvilinear fashion described by Greenwald 500 times to a tension 25% greater than the maximum in vivo active FDP flexion force measured by Schuind and colleagues. The tendons were then loaded to failure using the same curvilinear model.

RESULTS

No tendons ruptured during cycling. Triggering occurred in 3 tendons. All 3 began triggering early in the cycling process, and continued to trigger throughout the remainder of the 500 cycles. The observed triggering mechanics in each case involved the interaction of the proximal face of the lacerated tendon with Camper's chiasm and the pulley edges during extension. The load to failure value of the 90% partially lacerated tendons averaged 141.7 +/- 13 N (mean +/- standard deviation). Tendon failure occurred by delamination of the intact collagen fibers from the distal, discontinuous 90% of the tendon.

CONCLUSIONS

Cadaveric transverse zone II partial flexor tendon lacerations have residual tensile strength greater than the force required for protected active mobilization.

A case of trigger finger following partial laceration of flexor digitorum superficialis and review of the literature

Trigger finger is a common condition, and the usual cause is stenosing tenosynovitis. Trigger finger caused by trauma is extremely rare. We examined a patient in whom an apparently trivial laceration caused partial laceration of the flexor tendon, leading to trigger finger. In this case, ultrasonography was useful in establishing the presurgical diagnosis. Removal of the impinging tag cured the trigger finger. We also review nine previously reported cases. When triggering occurs after an injury near the base of a finger, partial laceration of the flexor tendon should be kept in mind as the cause. Ultrasonography may be valuable for the diagnosis.

Treatment of partial lacerations in flexor tendons by trimming. A biomechanical in vitro study

BACKGROUND

Treatment of a partial laceration in zone 2 of a flexor tendon is controversial. The intact part of the tendon can usually sustain forces of normal unresisted motion, and repaired partially lacerated tendons can actually be weaker than unrepaired ones. However, complications such as triggering or entrapment have been reported in association with unrepaired tendons. The purpose of this study was to measure the biomechanical behavior following trimming of the tendon as an alternative to repair.

METHODS

Thirty-six flexor digitorum profundus tendons were harvested from sixteen unpaired fresh-frozen cadaveric human hands and were randomly assigned to be subjected to either 50% or 75% partial laceration, which was either lateral or volar, and were then assigned to no repair, repair with a running suture, or trimming. Mean and maximum gliding resistances were measured as the flexor digitorum profundus glided through the bone-A2 pulley complex and the flexor digitorum superficialis. Values were normalized to those measured in the intact tendon. The tendons were then distracted to failure, and maximum load and stiffness were recorded.

RESULTS

There was triggering or entrapment of eight unrepaired tendons; two cases were severe, and six were minor. When no severe trigger was obvious, the unrepaired tendons had the lowest tendency for gliding resistance, followed by the tendons treated with trimming and then by those treated with the running suture. Overall, the tendons with a volar laceration had higher mean and maximum gliding resistance than those with a lateral laceration (p < 0.05), those with a 75% partial laceration had higher mean gliding resistance than those with a 50% laceration (p < 0.05), and the tendons that were repaired with running suture had higher mean gliding resistance than those treated with trimming (p < 0.05). Tendon strength was not significantly different among the three types of treatment.

CONCLUSIONS

From the perspective of gliding resistance after partial tendon laceration, no repair appears necessary unless triggering is a problem. If triggering occurs, then trimming of a partially lacerated tendon may be a reliable alternative to repair, at least in terms of gliding resistance and strength.

Tensile properties of suture methods for repair of partially lacerated human flexor tendon in vitro

The decision to treat zone II partially lacerated flexor tendons is challenging, because there can be justification for either repair or no repair, depending on the surgeon's assessment of the strength of the residual intact portion of the tendon. In this study tensile properties of various repair techniques were compared. Cadaveric human flexor tendons (n = 118) were lacerated to 75% of their cross-section and repaired with either a core suture method (Kessler, modified Kessler, Savage, Lee, augmented Becker, or Tsuge all finished with a circumferential running suture), an epitendinous suture alone (circumferential or partial), or the tendons were left unrepaired. Among the core suture methods there was no significant difference (p >.05) in maximum failure force (overall mean, 211.2 N; SD, 53.2) or force to produce a 1.5-mm gap (74.1 N; SD, 49.7). Likewise there was no significant difference (p >.05) in tendon stiffness (41.0 N/mm; SD, 14.0) or resistance to gap formation (52.3 N/mm; SD, 23.1). In comparison, repairs without the core suture, including unrepaired tendons, were significantly weaker (144.7 N, p <.001) and had a marginally lower stiffness (p =.04) but had a similar resistance to gap formation (43.5 N/mm).

Conservative management of zone II partial flexor tendon lacerations greater than half the width of the tendon

Over a 5-year-period 15 patients with zone II partial flexor tendon lacerations that were larger than half the width of the tendon were treated conservatively without tendon suturing. Surgical exploration was done with a digital block and the flexor tendons were observed as the patient fully extended and flexed the finger. If present, the cause of triggering was determined and eliminated by trimming any beveled tendon edge, resection of the involved pulleys, and repair of the flexor sheath. Early protected mobilization was started the first day after injury using a dorsal splint. At 4 weeks after injury the splint was removed and exercises against resistance were started. None of the patients had triggering or rupture of the flexor tendons. Using the Strickland-Glogovac evaluation method, results were excellent in 93% of cases and good in the remaining 7%. It was concluded that conservative management of zone II partial flexor tendon lacerations larger than half the width of the tendon is safe as long as certain guidelines regarding the prevention of triggering and protected mobilization are applied.

Flexor tendon entrapment of the digits (trigger finger and trigger thumb)

Flexor tendon entrapment of the digits is a disorder characterized by snapping or locking of the thumb or fingers (with or without pain). Most cases are secondary to thickening of the digit's A1 pulley, but other pathogeneses include tendon abnormalities at the level of the carpal tunnel, thickening of other pulleys, and abnormalities of the metacarpal-phalangeal joint. Its historical name, stenosing tenosynovitis of the digits, is inappropriate because histological studies document a lack of inflammation. Flexor tendon entrapment of the digits is a relatively common, uncomplicated, and non-controversial musculotendinous disorder of the distal upper extremity. The purpose of this invited review is to summarize information from the medical literature on aspects of this condition likely to be of interest and relevant to occupational medicine practitioners. Topics covered include normal anatomy and kinesiology, history, clinical observations related to diagnosis, pathology, pathophysiology, clinical observations on etiology, descriptive epidemiology, epidemiological studies, and case management. Models for the pathogenesis of flexor tendon entrapment of the digits are proposed, and opportunities for future research are presented.

Post-traumatic triggering of extensor pollicis longus at the dorsal radial tubercle

A case of post-traumatic triggering of the tendon of extensor pollicis longus around Lister's tubercle is described. This condition was successfully treated by surgical release.

[Incomplete section of a superficial flexor tendon in zone II: successive complications and quadriga syndrome]

Partial section of the flexor tendon may be asymptomatic and heal without sequelae. However, in the absence of primary treatment, they may lead to subsequent complications such as: tendon locking due to incarceration of a partially detached slip of tendon, jump phenomena due to irregularity of the surface or the volume of the tendon, which induces a sudden jerk as the tendon passe through the retinaculum, and lastly, secondary tendon rupture. These complications all occurred in the case reported here, who also presented with syndrome of the quadriga. Locking of the intact deep flexor tendon by the ruptured superficial tendon interfered with the movements of the other fingers. Resection of the ruptured tendon was able to restore complete function. Opinions diverge concerning the need to suture partial sections of the flexor tendons, but the authors agree on the great importance of meticulous surgical exploration and immediate controlled mobilisation, which ensures the best functional results.

Triggering secondary to an untreated partially-cut flexor tendon

A case is reported where a flap cut of the radial slip of the flexor digitorum superficialis triggered on the proximal border of the A2 pulley within a healed intact tendon sheath. Shaving the flap resolved the problem. This illustrates another post-traumatic mechanical cause of triggering after partial division of flexor tendons.

Partial flexor tendon laceration: a cause of trigger finger

This paper reports four cases of trigger finger that resulted from partial laceration of the flexor tendons. Of the four cases, there were one profundus and three superficialis tendons in three males and one female, ranging from 13 to 36 years of age. They were all treated surgically by excision of the "tag" with full functional recovery.

"Trigger finger" secondary to partial rupture of the superficial flexor tendon

A case of "trigger finger" due to flexor digitorum superficialis tendon "tag" following a hyperextension injury to the metacarpophalangeal joint is reported. The tag formed as a result of avulsion of the flexor digitorum superficialis tendon slip from its insertion in the middle phalanx.