Stenosing tenosynovitis, or trigger finger, is di-agnosed when a patient presents with a symp-tomatic locking or clicking of a finger or the
thumb. It is caused by a mismatch between the vol-ume of the flexor tendon sheath and its contents. Asthe flexor tendon attempts to glide through a rela-tively stenotic sheath, it catches, producing an inabil-ity to flex or extend the digit smoothly. In moresevere cases the finger may become locked in flex-ion, requiring passive manipulation of the finger intoextension. The patient may complain initially of apainless clicking with finger movement. This oftenprogresses to painful triggering, which is localizedvariably to the palm or the metacarpophalangeal(MCP) or proximal interphalangeal (PIP) joints. Re-luctance to range the digit fully because of pain orlocking can lead to secondary contracture at the PIPjoint. Middle-aged women are the age group mostoften affected. The most commonly involved digit isreported to be the ring finger or thumb—with theindex and small fingers being the least symptomatic.It is not unusual for a single patient to have multipletrigger digits. Trigger fingers first were described byNotta1 in 1850. The diagnosis and treatment of anuncomplicated primary trigger digit is quite familiar
to most primary care providers, orthopedic surgeons,
and hand surgeons. Certain patient populations, how-ever, including children, diabetic patients, those withrheumatoid arthritis, distal triggering, PIP joint con-tractures, or conditions that cause systemic deposi-tion of protein require special consideration. Compli-cations of treatment such as bowstringing of theflexor tendon are unusual but occasionally do occur.A number of surgical techniques in addition to thetraditional open A-1 pulley release have been de-scribed to treat these more complex scenarios.
Primary Trigger FingerThe vast majority of trigger digits are primary idio-pathic trigger fingers or thumbs in which the site ofobstruction is the first annular (A-1) pulley (Fig. 1).Power grip causes high angular loads at the distaledge of the A-1 pulley. Hueston and Wilson2 pro-posed that chronic repetitive friction between theflexor tendon and the enclosing sheath caused a re-active intratendinous nodule. They compared thiswith the fraying that occurs at the end of a piece ofthread after it has been passed numerous timesthrough the eye of a needle.
Histologic analyses of diseased A-1 pulleys andsuperficialis tendons from patients with trigger digitshave shown fibrocartilaginous metaplasia.3 The cells
stain positive for S-100, a protein that is found in
The Journal of Hand Surgery 135
ulley
136 The Journal of Hand Surgery / Vol. 31A No. 1 January 2006
cartilage. The A-1 pulley may triple in thickness asthe histologic inner gliding layer of the A-1 pulleychanges from the spindle-shaped fibroblasts andovoid cells normally seen to cells with chondrocytecharacteristics.
It has been proposed that tendovaginitis is a moreaccurate term to describe the condition than tenosyn-ovitis. This is because the pathologic inflammatorychanges are found in the retinacular sheath and peri-tendinous tissue rather than in the tenosynovium. The2 terms continue to be used interchangeably in theliterature.
Conservative TreatmentActivity modification, nonsteroidal anti-inflamma-tory drugs, splinting, steroid injection, and surgicalrelease all have been used in the management oftrigger finger. If the patient’s history shows that aspecific activity is associated with the onset of trig-gering then avoidance of that activity may result inspontaneous resolution of the tendovaginitis. For pa-tients who do not have a contraindication such asrenal disease or peptic ulcer disease, nonsteroidalanti-inflammatory drugs may be added to an initialtreatment regimen.
Splinting is another conservative treatment option.A custom-made splint to hold the MCP joint of theinvolved finger at 10° to 15° of flexion with the PIPand distal interphalangeal (DIP) joints left free hasbeen applied with some success. The splint is worncontinuously for an average of 6 weeks. In patientswith marked triggering, symptoms of longer than 6
Figure 1. The digital p
months duration, and involvement of multiple digits
or of the thumb, splinting alone does not eliminatethe triggering. Splinting appears to be a reasonableoption for patients with mild triggering who do notwish to undergo a steroid injection or as an adjuvantto injection.
Corticosteroid InjectionLong-acting corticosteroid injection is the mainstayin initial management of the symptomatic triggerdigit. Injection of the involved flexor tendon sheathprovides long-term relief of symptoms in 60% to92% of affected digits with up to 3 injections.4 Be-tamethasone sodium phosphate is the steroid ofchoice because it is water soluble, does not leave aresidue in the tendon sheath, is not known to causetenosynovitis, and it causes less fat necrosis if theinjection is placed in the tissue around the tendonsheath. Other corticosteroids such as triamcinoloneand methylprednisolone also have been used success-fully.
A diminished response to injection has been asso-ciated consistently with an increased duration ofsymptoms, usually more than 4 to 6 months, and withan increasing number of injections.5 This may be aresult of the inability of corticosteroids to reversefibrocartilaginous metaplasia of the stenotic A-1 pul-ley once it has occurred. Benson and Ptaszek6 re-ported a 60% success rate for a single injection. Ofthose treated with a second injection, 36% wereasymptomatic at 3 months. Six patients were injecteda third time, none of whom had long-term relief.
Various techniques of injection have been used
system of the fingers.
effectively. Both palmar and lateral approaches can
s gone
Ryzewicz and Moriatis Wolf / Trigger Digits 137
be used to infiltrate the flexor tendon sheath withcorticosteroid and local anesthetic. Patients should bewarned that fat necrosis or skin depigmentation arepotential complications of subcutaneous injection.Intrasheath injections generally do not result in com-plications; however, tendon rupture has been re-ported and is likely the result of inadvertent intraten-dinous injections leading to collagen necrosis.
Surgical ConsiderationsOpen release of the A-1 pulley has been used to treattrigger digits for more than 100 years. Some sur-geons prefer to perform an open A-1 pulley releaseunder local anesthetic so the absence of triggeringcan be seen intraoperatively before closure of thewound. Others believe that local anesthetic distortsthe surgical anatomy and therefore prefer a Bier
Figure 2. Intraoperative photographs of an open trigger digexposure of the A-1 pulley a knife is used to incise the pullepulley (check for any tightness of the palmar pulley of ManskFDS tendons may be performed to check that all triggering i
block. Transverse, longitudinal, or oblique incisions
on the volar aspect of the hand overlying the MCPjoint and A-1 pulley all have been described. Bluntdissection is continued down to the level of the flexortendon and the A-1 pulley is visualized (Figs. 2A,2B), with care taken to protect the neurovascularbundles that are located on the radial and ulnar sidesof the tendon sheath. The radial neurovascular bun-dle to the thumb is most at risk for injury because ittakes an oblique ulnar to radial course across the A-1pulley. This bundle also is subcutaneous, averaging1.19 mm deep to the dermis at the thumb MCPflexion crease, and may be transected with a deepskin incision. The A-1 pulley should be releasedcompletely for symptoms to resolve reliably.
Generally only supportive dressings are neededafter surgery. Some patients note palmar tenderness
ase. (A) Injection of local anesthetic. (B) After appropriategitudinally. (C) Exposure shows complete release of the A-1if so release as well). (D) A traction tenolysis of the FDP and.
it reley lone and
or finger stiffness after surgery. Incisional tender-
138 The Journal of Hand Surgery / Vol. 31A No. 1 January 2006
ness, however, generally resolves with time and scarmassage and few patients require formal occupa-tional therapy.
The results of open A-1 pulley release generallyare excellent. Turowski et al,7 in a group of 59patients treated by a variety of surgeons, reported97% complete resolution of triggering with no com-plications such as infection, bowstringing, or digitalnerve injury. The 2 patients who did not have com-plete resolution of triggering did have notable im-provement.
Annular Digital PulleysDivision of the A-1 pulley usually causes minimalmorbidity. Near-normal hand function can be main-tained with only the A-2 and A-4 annular pulleysintact.8 The 10% increased work of flexion that hasbeen shown biomechanically after A-1 pulley exci-sion does not appear to be relevant clinically for mostpatients. A-2 pulley injuries in rock climbers andreports of patients who have had part of their A-2pulleys transected surgically show the importance ofpreserving this pulley in preventing bowstringing ofthe flexor tendon. The biomechanical studies of pul-ley excision by Peterson et al8 showed a 44% in-crease in work of finger flexion after A-2 pulleyexcision and a 62% increase after removal of bothA-1 and A-2 pulleys.
A distinct separation between the first and secondannular pulleys is considered the usual configuration.Anatomic studies, however, have shown a nearly50% incidence of continuity between the A-1 andA-2 pulleys.9 The separation between the 2 pulleysgenerally is 0.4 to 4.1 mm. When the separation isnot present, however, several millimeters of pro-nounced thinness of the retinacular tissue is observedat the usual site of separation.10 Care should be takennot to extend a surgical release into the substance ofthe A-2 pulley. Rarely the A-2 pulley may be in-volved critically in producing a trigger digit. Thetreatment strategy for this special situation is dis-cussed later.
Complications of Surgical TreatmentBowstringingBowstringing after A-2 pulley injury manifests as aprotrusion of the flexor tendon into the palm withfinger flexion. It often produces a painful pullingsensation in the palm with associated failure to fullyextend or flex the digit actively.
To understand fully the adverse effects of bow-stringing it must be remembered that the effect of atendon at a joint depends on both the tension on thetendon and the moment arm. Because bowstringing
increases the perpendicular distance of the tendon
from the MCP joint axis of rotation, the moment armis increased.11 With an increased moment arm thebowstrung flexor tendon gains a mechanical advan-tage that cannot be overcome actively by the exten-sors without manual correction of the flexor tendon.
Furthermore the available excursion of the flexortendon does not increase with the increase in radiusfrom the center of the MCP joint to the tendon. A ruleof geometry states that when the radius of a circlemoves through 57.29° (1 radian), any point on thatcircle moves through a distance equal to the radius.The distance and the required tendon excursion re-quired to move the MCP joint through 57.29° in-creases with an increasing radius (Fig. 3). As theflexor tendon bowstrings and the radius of the mo-ment arm across the MCP joints increases, a givendistance of tendon excursion will move the jointthrough a smaller arc of motion. This increases thework of finger flexion. Because the amount of avail-able excursion is generally the same as the requiredexcursion for full range of motion, full excursion ofthe bowstrung flexor tendon moves the fingerthrough a smaller less-than-full arc of motion.11
A-2 Pulley InjuryInadvertent release of the A-2 pulley that results inclinically significant bowstringing is treated with anA-2 pulley reconstruction. The forces generatedagainst the pulley in flexion are considerable. There-fore the reconstructed pulley must be strong, with anideal length of approximately 10 mm, and should betested vigorously under direct visualization on theoperating table.
Bunnell12 described pulley reconstruction by en-circling a single loop of free tendon around theproximal phalanx deep to the extensor mechanism,which then was overlapped and sutured to itself.Either the palmaris longus or a slip of flexor digito-rum superficialis was used as tendon graft. Modifi-cations of this technique include the use of extensorretinaculum or anchoring of the tendon graft throughthe volar plate. The Weilby technique sutures thegraft material to the fibrocartilaginous remnants ofthe rim of the disrupted pulley, which nearly alwaysare present.13
Digital Nerve InjuryDigital nerve injury is an infrequent but serious com-plication of trigger finger release. Special care inprotecting the radial digital nerve to the thumb andthe index finger must be exercised because of theirparticular anatomy. Caution in the use of electrocau-tery is necessary to prevent potential thermal injuryto the nerve. An accurate diagnosis is crucial to
implementing the appropriate treatment. A digital
Ryzewicz and Moriatis Wolf / Trigger Digits 139
nerve that has been cut or cauterized should be ex-plored and undergo microsurgical repair. If the sur-geon is satisfied fully by direct observation beforeclosure that the nerve was not transected or cauter-ized at the time of surgery then the injury likely isneuropraxic in nature and may resolve with expectantobservation. If sensation does not return to the af-fected side of the digit by 3 months, however, thenexploration of the nerve is indicated.
Alternative ProceduresPercutaneous ReleasePercutaneous release of the A-1 pulley first wasdescribed in 1958 by Lorthioir.14 The technique hasgained popularity recently and a number of studieshave evaluated the safety and efficacy of percutane-ous release. Several instruments have been advocatedfor the procedure including a hypodermic needle, atenotome, or specially designed knives.
The main concern with percutaneous release isdigital nerve injury. Lorthioir used a fine tenotomewithout reported complications in 52 patients. East-wood et al15 used a 21-gauge hypodermic needle on35 trigger digits and relieved symptoms in 94% with-out complications. Although Eastwood et al15 re-leased 3 thumbs in their study they noted that theobliquity and volar position of the neurovascularbundles in the thumb required particular caution.Cadaver studies have shown that the digital nerves inthe index finger and thumb lie within 2 to 3 mm of
Figure 3. (A) Normal tendon mechanics with intact pulley sMCP joint when both the A-1 and A-2 pulleys have been remMCP joint to the tendon. The amount of tendon excursion nequal to the distance of this radius. Therefore more tendon exca given arc of motion.
the needle puncture site.16
Incomplete division of the pulley is another con-cern regarding percutaneous techniques. Pope andWolfe16 performed percutaneous releases in 13 trig-ger fingers using a 19-gauge needle and then pro-ceeded to open the wound immediately and inspectthe result. Although all patients showed clinical im-provement, a complete release was found in only 8patients; with the distal 10% to 15% of the pulleyremaining intact in the other patients. They hypoth-esized that triggering resolves even if the distal edgeof the A-1 pulley is not released.
Painful tenosynovitis without triggering often oc-curs in patients after a percutaneous release. Thismay be a result of the high rate of flexor tendonscoring. The rate of longitudinal laceration to thesuperficialis tendon in cadaveric studies has ap-proached 100%.16 The use of a corticosteroid alongwith local anesthetic may prevent the post-procedureinflammatory reaction, and the superficial scoringdoes not appear to have any clinically remarkableconsequences.
The literature has shown both open and percutaneousmethods of A-1 pulley release to be effective and safefor the treatment of trigger finger. In a prospectiverandomized study of 100 patients comparing the 2 tech-niques, Gilberts et al17 successfully relieved symptomsin 100% of patients percutaneously and in 98% ofpatients treated with an open surgical procedure, withno complications. The 1 treatment failure was a resultof excessive scar formation, causing recurrent trigger-
. (B) Bowstringing. The flexor tendon bowstrings across the. This increases the radius from the center of rotation of thery to move the joint through 1 radian (57.29°) of motion isis required to move a joint with a bowstrung tendon through
ystemoved
ecessaursion
ing that required another procedure. These investigators
140 The Journal of Hand Surgery / Vol. 31A No. 1 January 2006
favored the percutaneous technique with the benefits ofshorter procedure time (7 vs 11 min), shorter durationof postoperative pain (3.1 vs 5.7 days), quicker recov-ery of full hand function (7 vs 18 days after the proce-dure), and faster return to work (3.9 vs 7.5 days).17
Technique of Percutaneous ReleasePercutaneous release can be performed in the clinicsetting. Local anesthetic mixed with corticosteroid isadministered and the palmar base of the affectedfinger is prepared sterilely. The patient is asked toflex the affected digit actively. The surgeon thenhyperextends the finger. This brings the flexor tendonsheath directly under the skin and allows the neuro-vascular bundles to displace to either side.
An 18-gauge needle or other device is inserted at theproximal aspect of the A1 pulley. Care should be takento stay centered over the flexor tendon sheath to avoidneurovascular structures and to enter the skin perpen-dicularly with the bevel of the needle parallel to thetendon. Alternatively some investigators have advo-cated inserting the needle slightly more distally in themiddle of the pulley and then proceeding with releaseproximally and distally (Fig. 4).
The proximal edge of the A-1 pulley is located nearthe distal horizontal palmar crease for the small, ring,and middle fingers. For the index finger it is located atthe proximal horizontal palmar crease. Release of thering and middle fingers is believed to be relatively safe.The oblique course of the flexor tendons and neurovas-cular structures to the index and small finger, however,pose a greater challenge. Wilhelmi et al18 describedreliable landmarks for the small finger flexor tendonsheath in the area of the A-1 pulley as lying underneatha line connecting the ulnar border of the scaphoidtubercle proximally to the center of the proximal digitalcrease distally. For the index finger the landmarks werethe radial border of the pisiform proximally and themidline of the proximal digital crease distally. By usingthese landmarks in a cadaver study the A-1 pulley wastransected reliably. The distance from the scoring of theflexor tendon to the neurovascular bundles was 5.4 mmradially and 6.7 mm ulnarly in the small finger. In theindex finger it was 8.5 mm radially and 6.2 mm ulnarly.None of the digital nerves or arteries were transected.
In the thumb the intersection of the proximalthumb digital crease and a perpendicular line up thecentral axis of the palmar aspect of the thumb is thepreferred insertion site.
The needle may be inserted into the tendon. This isconfirmed by needle movement when the patientflexes and extends the distal phalanx. The needle iswithdrawn slowly until this motion ceases. The nee-dle tip is now in the A-1 pulley. The A-1 pulley is cut
by moving the needle forward and back while ad-
vancing it in line with the longitudinal axis of theflexor tendon sheath. A grating sensation indicatesthe A-1 pulley is being cut. Once the surgeon be-lieves the pulley has been released adequately thenthe needle is withdrawn and the patient is asked toflex and extend the digit to show relief fromtriggering.
Proximal Interphalangeal Joint FlexionContracture and Distal TriggeringPatients with long-standing trigger finger rarely maydevelop flexion contracture at the PIP joint that persistsafter division of the A-1 pulley. In some patients this iscaused by intra-articular pathology. Others have a pre-
Figure 4. Use of surface landmarks for percutaneous A-1pulley release. Index finger: at the proximal palmar crease ata line connecting the radial border of the pisiform and thecenter of the proximal digital crease of the index finger.Middle finger: at the distal palmar crease in the midaxis of thedigit. Ring finger: at the distal palmar crease in the midaxis ofthe digit. Small finger: at the distal palmar crease at a lineconnecting the ulnar border of the scaphoid tubercle with thecenter of the proximal digital crease of the small finger.Thumb: at the proximal digital crease in the midaxis of thethumb.
operative flexion contracture that may resolve either
Ryzewicz and Moriatis Wolf / Trigger Digits 141
with a simple surgical release of the A-1 pulley or withadditional postoperative therapy.
In other cases the involved flexor digitorum super-ficialis (FDS) tendon has degenerated markedly. Thedegenerative process may cause the tendon to lose itsnormal surface smoothness, fray its fibers, form anespecially large nodule, and lose its ability to glidesmoothly under the A-2 pulley. Treatment of thesepatients poses a challenge because function is notregained fully after A-1 pulley division and continu-ing the release into the A-2 pulley is not an optiongiven the likelihood of bowstringing. These patientsgenerally have very long-standing disease and likelyalready have had fibrocartilaginous metaplasia oftheir pulley and FDS tendon and may go on to distaltriggering, defined as continued locking of the tendonbecause its excursion is blocked distally.
Ulnar Superficialis Slip ResectionLe Viet et al19 described 228 such fingers in 172patients who were treated with a resection of theulnar slip of the superficialis tendon. His patients hadan average of 48 months of preoperative symptomsand 11 had a previous A-1 pulley release that wasunsuccessful.
The technique starts with a simple open A-1 pulleyrelease. In a patient with a preoperative fixed PIPjoint flexion contracture an attempt then is made bythe surgeon to extend the PIP joint passively. If thisattempt is successful the procedure is ended and theskin is closed. If the PIP joint is not extendable fully,however, the gliding of the flexor tendon throughthe A2 pulley is inspected closely. If direct visual-ization confirms this to be the site of restrictionthen the ulnar slip of the superficialis tendon is re-sected.19
Le Viet et al19 used a Bruner palmar-digital inci-sion to expose the tendon sheath to the middle pha-lanx. The ulnar slip of the FDS tendon is released atthe distal aspect of the carpal tunnel and then at thedistal edge of the A-3 pulley with care taken topreserve that pulley. The tendon slip then is deliveredfrom the sheath through another incision placed be-tween the A-2 and A-3 pulleys (Fig. 5).
In the series by Le Viet et al19 all patients with apreoperative fixed flexion deformity of less than 30°were able to achieve full extension after ulnar super-ficialis slip resection (USSR). Patients with greaterthan 30° deformity improved their PIP joint exten-sion by an average of 30°, with an average residual12° of fixed flexion deformity. Two patients had anintraoperative A-2 pulley rupture that occurred whenpassing the tendon slip distally. Immediate recon-struction was performed and both patients had a good
result despite longer rehabilitation. Three patients
developed permanently restricted finger motion as aresult of reflex sympathetic dystrophy. Conclusionsfrom the study by Le Viet et al19 were limited by thelack of a control group with preoperative PIP jointcontracture treated traditionally. The results for pa-tients who had a previously unsuccessful A-1 pulleyrelease were not analyzed separately.
Reduction Flexor TenoplastyReduction flexor tenoplasty is the removal of a cen-tral core from an enlarged tendon. Seradge andKleinert20 used the technique to treat patients withnodular triggering distal to the A-1 pulley. One oftheir patients had a previously unsuccessful A-1 pul-ley release with subsequent flexion deformity of thePIP joint. The other patient had normal-appearingA-1 pulleys and flexor tendons observed on open A-1pulley release of multiple digits. This prompted fur-ther exploration, showing fusiform enlargement ofthe flexor digitorum profundus (FDP) tendon at thelevel of the A-2 pulleys. Reduction flexor tenoplastyresolved triggering in these patients and has beensuccessful in other series of patients with distal trig-gering.
In principle a reduction flexor tenoplasty could beused in any location that a bulbous hypertrophy ofthe flexor tendon was an impediment to smooth glid-ing through the retinacular sheath. Generally, how-ever, it is used only when there is triggering causedby a nodular swelling at the proximal or distal edgeof the crucial A-2 pulley.
Initially the tendon nodule is exposed. On theproximal edge of the A-2 pulley this can be per-formed through an A-1 pulley release. Distally thesecond cruciform pulley can be resected at the levelof the head of the proximal phalanx. A lateral inci-sion, slightly longer than the bulbous swelling, ismade through the epitenon and superficial tendonfibers. A central core of tendon then is excised (Fig.6) until the remaining tendon is smooth and shows norestrictive nodularity. The tenotomy is closed with arunning 7-0 suture.
A-3 Pulley TriggeringTriggering at the A-3 pulleys has been describedrarely in bowlers as a result of repetitive trauma tothe finger flexor apparatus at this site, in conjunctionwith intratendinous ganglia, or as a consequence ofpartial flexor tendon lacerations.21 Physical findingsin patients with A-3 triggering have been subtlydifferent than the typical palmar tenderness. Pain andtenderness palmar to the PIP joint and swellingwithin the flexor tendon adjacent to the PIP joint issuggestive of this unusual variant. These patients
characteristically have triggering that occurs when
142 The Journal of Hand Surgery / Vol. 31A No. 1 January 2006
the PIP joint is at or beyond 90° of flexion. Incontrast to conventional triggering in which the FDStendon is involved, it is FDP pathology that producesdistal triggering; therefore symptoms are found at theDIP joint. When flexion deformity at the PIP joint iscorrected passively in these patients it causes flexionat the DIP joint. Pain is reproduced with resisted DIPjoint flexion.
A-3 pulley excision has been shown to be success-ful in these patients. In the case of intratendinousganglia or fusiform nodules, which also impinge onthe A-2 pulley, debulking of the enlarged tendon byreduction flexor tenoplasty has been effective.
Trigger Finger in Association With OtherDiseasesCarpal Tunnel SyndromeCarpal tunnel syndrome often is co-existent withtrigger fingers. Patients with endocrine and meta-bolic diseases are known to be predisposed to both
Figure 5. Ulnar superficialis slip resection. The proximal partDistally the ulnar slip has been transected distal to the A-3 puand A-3 pulleys.
conditions. Increased median nerve latency at the
carpal tunnel, however, has been shown in patientswith idiopathic trigger finger alone. It is hypothe-sized that the association between the 2 conditionsmay be caused by an inflammatory process in thetendons at both the level of the A-1 pulley and thecarpal tunnel. Furthermore when a patient avoidsfinger motion because of painful triggering theresultant hand edema may aggravate median nervecompression under the transverse carpal ligament.Clinically the 2 conditions often co-exist. Patientswith trigger fingers should be evaluated thoroughlyfor clinical symptoms of carpal tunnel syndromeand vice versa.22
Systemic DiseaseAmyloidosis. Amyloidosis most frequently resultsfrom the inability of dialysis membranes to remove�-2 microglobulin protein from filtered plasma. Theprotein accumulates in bones and soft tissues, caus-ing a number of musculoskeletal complications. The
ulnar slip has been released at the level of the carpal tunnel.he slip of tendon is delivered in the interval between the A-2
of thelley. T
severity of disease is proportional to the duration of
Ryzewicz and Moriatis Wolf / Trigger Digits 143
time a patient has been on hemodialysis. The mostcommon manifestations in the hand are cystic lesionsin the carpal bones and destructive arthropathy; car-pal tunnel syndrome is the most common conditionrequiring surgery.
Infiltrative amyloid tenosynovitis often extendsdistally to the palm and digits, which may causetrigger fingers, flexion contracture, or even tendonrupture. A large number of these patients will de-velop hand dysfunction that affects activities of dailyliving and self-care.23
Surgical treatment should consist of A-1 pulleyrelease and complete tenosynovectomy with preser-vation of all other annular pulleys. A small numberof older patients with idiopathic trigger digits havebeen found to have amyloid deposits in their excisedtendon sheaths. This, however, is a distinctly differ-
Figure 6. Reduction flexor tenotomy. A central core from theinvolved area of bulbous swelling on the flexor tendon isremoved. (A) Bulbous enlargement with tendon proximal toA-2 pulley. (B) Excision of central core of FDP tendon. (C)Smooth gliding surface of tendon after excision of bulbousportion. (D) Tenotomy closed with running 7-0 suture.
ent type and quantity of amyloid than the abundant
�-2 microglobulin found in dialysis patients.Whether this is a part of the mechanism of idiopathicstenosing tenosynovitis or an incidental part of theaging process is unknown.
Mucopolysaccharidosis. Mucopolysaccharidosesare lysosomal storage diseases that result from ge-netic enzyme deficiencies. Several different clinicalvariants of mucopolysaccharidosis have been de-scribed, each resulting from the deficiency of 1 spe-cific enzyme. The musculoskeletal manifestations re-sult from the accumulation of glycosaminoglycansincluding dermatan, heparan, keratan, or chondroitinsulfate in cartilage, tendon, and joint capsule. Man-agement of these associated conditions has taken onincreased importance since the 1980s when bonemarrow transplantation resulted in improved menta-tion and longer life expectancy for affected patients.
Van Heest et al24 reported their experience treatinghand disorders in 22 children with various mucopo-lysaccharidosis disorders. In their series 17 patientswere treated for carpal tunnel syndrome along with45 trigger digits in 8 affected children. They used acombination of A-1 and A-3 pulley releases withvariable use of USSR. All of their patients had im-proved active digital flexion and overall improvedfunction after this surgical release.
Diabetes mellitus. Diabetic patients are known tobe at risk for developing dysfunction of many differ-ent organ systems. Although attention often is fo-cused on the eyes, kidneys, feet, and cardiovascularsystem, the hand is affected frequently, resulting inboth disability and deformity. Carpal tunnel syn-drome, neuropathy, Dupuytren’s disease, and triggerfinger all have been reported with increased inci-dence in diabetic patients. Not only do patients withdiabetes mellitus have a higher incidence of stenos-ing tenosynovitis, but these patients also are lessresponsive to treatment. The duration of diabetes hasbeen related strongly to the incidence of handcomplications.
Griggs et al25 treated 54 diabetic patients with 121trigger digits by corticosteroid injection, and theyperformed an open A-1 pulley release in those pa-tients who failed conservative measures. Their over-all success rate of 50% with corticosteroid injectionis significantly less than that reported in most studiesof nondiabetic patients. Furthermore insulin-depen-dent diabetic patients had resolution of symptoms inonly 44% of cases with injection. Surgically treatedpatients also had somewhat compromised results,including residual PIP joint flexion contracture andpersistent A-1 pulley tenderness. The reason for di-
minished results in the treatment of diabetic trigger
144 The Journal of Hand Surgery / Vol. 31A No. 1 January 2006
digits may be the higher incidence of a diffuse in-flammatory stenosis of the tendon sheath rather thana focally nodular process.
Studies have reported poor glucose control in pa-tients for several days after steroid injection for trig-ger fingers but none have documented the incidence,extent, or management of such phenomena. Patientsshould be advised of the possibility of increasedblood sugar levels after steroid treatment but thepresence of diabetes should not be considered a con-traindication for flexor tendon sheath injection.
Diabetic hand complications are believed to beprimarily fibrosing processes related to the samepathogenic mechanisms that induce other diabeticcomplications. Hyperglycemia increases collagencross-linking while conferring a resistance to degra-dation, therefore causing collagen accumulation.This could explain the predilection toward triggerfingers in diabetic patients.
Rheumatoid arthritis. In contrast to idiopathictrigger finger, triggering in rheumatoid patients isreferred to correctly as tenosynovitis. Rheumatoidarthritis is a systemic disorder that affects the syno-vial tissues. The digital flexor tendon sheath is linedwith synovium. Inflammation of the tenosynoviumcauses a mismatch between the size of the contents ofthe sheath and the enclosing fibro-osseous canal,producing symptoms that may resemble closely thoseof idiopathic trigger finger. Such symptoms in apatient with rheumatoid arthritis, however, require anentirely different diagnostic and therapeutic approachthan that for idiopathic tendovaginitis.
Flexor tenosynovitis in the rheumatoid patient maycause finger pain, swelling, triggering, limited mo-tion, or rupture of the flexor tendon. The diagnosis ischaracterized by digital triggering or stiffness withpalpable swelling on the volar aspect of the digit.Passive range of motion in the finger that exceeds theactive range of motion is helpful for distinguishingflexor tenosynovitis from articular pathology. Fixedjoint stiffness may develop in chronic cases, how-ever, making the diagnosis of restricted flexor tendonexcursion as a consequence of diffuse tenosynovitismore difficult.
The surgical treatment of rheumatoid flexor teno-synovitis is tenosynovectomy and preservation of theannular pulleys, with selected cases requiring USSRor excision of rheumatoid nodules from the tendon.Although the condition may respond temporarily tocorticosteroid injection, early surgical intervention inthe form of flexor tenosynovectomy with decompres-sion of the carpal tunnel is recommended by manyinvestigators to prevent flexor tendon rupture and
irreversible damage to the median nerve.26
An A-1 pulley release in rheumatoid flexor teno-synovitis is not recommended. Despite pulley re-lease, motion still may be limited by rheumatoidnodules or diffuse flexor tenosynovium in the area ofone of the more distal pulleys. The division of theA-1 pulley will increase the rheumatoid tendency fordigital ulnar drift (Fig. 7), with resultant increase inthe ulnar torque across the MCP joint.
Surgical TechniqueStandard Bruner incisions are used to approach thedigital flexor tendon sheath. The more proximal as-pect of the sheath is approached in the palm throughtransverse incisions in the distal palmar crease. Astandard approach to the carpal tunnel is used toexpose the flexor tendons at this level if necessary.The tendon sheath is opened proximal to the A-1pulley and between the A-2 and A-4 pulleys. TheA-1, A-2, and A-4 pulleys all are preserved.
Diseased tenosynovium surrounding the tendon is
Figure 7. The tendency toward ulnar drift of the flexor ten-dons after the A-1 pulley of the middle and ring fingers isshown.
removed. Intratendinous nodules are excised care-
Ryzewicz and Moriatis Wolf / Trigger Digits 145
fully. Incomplete excision of nodules may be neces-sary to prevent late flexor tendon rupture. Tendonexcursion then is tested passively. If passive fingerflexion is greater than what can be achieved whentraction is applied to the proximal aspect of thetendon then further debulking may be required. Fer-lic and Clayton26 recommended excision of the ulnarslip of the superficialis tendon in these patients.
Trigger Fingers in ChildrenNinety percent of pediatric trigger digits are triggerthumbs. It is a rare condition affecting less than0.05% of children. In children trigger thumbs do nottrigger but remain locked in a flexed position. Pal-pation of a Notta’s node on the flexor pollicis longustendon in the area of the thumb A-1 pulley is animportant clinical sign differentiating a trigger thumbfrom other more severe clasped thumb anomalies.Controversy remains concerning the congenital ver-sus acquired nature of pediatric trigger thumbs andthe rate of spontaneous resolution. Most patients whopresent with a trigger thumb are older than 6 monthsof age.
The reported rate of spontaneous resolution ofpediatric trigger thumbs has varied between 0% and49%. There are multiple conflicting reports in whichsome documented a marked rate of spontaneous res-olution, with other investigators noting that nearly alltrigger thumbs persisted. The rate of successful con-servative treatment is increased with splinting of theMCP joint in some studies.
Pediatric trigger thumbs respond predictably to asimple A-1 pulley release. A thumb with normalrange of motion can be expected immediately afterthe procedure. McAdams et al27 investigated thelong-term results of pediatric A-1 pulley release at anaverage of 15 years after surgery. There was norecurrence of triggering. Five of 21 patients had anaverage of 15° reduced interphalangeal joint motionand 4 of 21 patients showed MCP joint hyperexten-sion; however, no patient complained of functionallimitation. The most common concern was scar ap-pearance, which was associated with a longitudinalinstead of a transverse incision in the skin crease.
A delay in surgical intervention does not haveadverse consequences. Multiple studies have docu-mented good outcomes even in patients for whomsurgical release was delayed up to 4 years after theonset of symptoms. Although the existing literatureis far from conclusive, a trial of splint therapy isappropriate before performing an A-1 pulley releasefor pediatric trigger thumb.
Pediatric trigger finger is about one tenth as com-mon as trigger thumb.28 Some patients present with a
fixed flexion deformity. Similar to adult trigger dig-
its, however, snapping and triggering is often thechief complaint. Cardon et al28 reported a high inci-dence of flexor tendon abnormalities in these chil-dren. In their series of 33 trigger fingers in 18 pa-tients, 8 patients had continued triggering after A-1pulley release. Documented abnormalities included amore proximal than normal decussation of the FDS,a slip of FDS that inserted into the FDP tendon,nodules in the tendon, and a stenotic A-3 pulley.These patients were treated with USSR, with 2 pa-tients also having an A-3 pulley release. No patienthad recurrence of triggering.
ConclusionsA symptomatic trigger digit is a mechanical problemcaused by a mismatch between the relative size of theflexor tendon and its sheath. Appropriate treatment isbased on understanding the location and nature of themismatch. Measures to release sites of sheath im-pingement or to reduce the local volume of the flexortendon will relieve symptoms. Activity modification,anti-inflammatory medication, splinting, corticoste-roid injection, and open and percutaneous A-1 pulleyrelease all have a role in treatment. In select cases anA-3 pulley release, USSR, reduction flexor teno-plasty, and flexor tenosynovectomy are techniquesthat resolve less common types of trigger fingersuccessfully. A thorough understanding of comorbidconditions and the biomechanics of the finger flexorapparatus will facilitate effective care of the affectedpatient with prevention of complications.
No benefits in any form have been received or will be received from acommercial party related directly or indirectly to the subject of thisarticle.
Corresponding author: Jennifer Moriatis Wolf, MD, Assistant Profes-sor, Department of Orthopaedics, University of Colorado Health Sci-ences Center, 4200 E 9th Ave, Box B202, Denver, CO 80262; e-mail:[email protected].
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