Flexor Pollicis Longus Tendoscopy Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S.
Abstract: The deep palmar spaces of the hand include the midpalmar space, the hypothenar space, the thenar space, space of Parona, and the interdigital web spaces. There are various communications between different spaces. These communications are of clinical importance in explaining the spread of inflammatory, infectious, and even neoplasic processes that involve this region. Surgical incision and drainage of all potentially communicating spaces and compartments is mandatory in deep hand infections. The purpose of this technical note is to describe the minimally invasive approach of endoscopic drainage and debridement of the flexor pollicis longus tendon sheath, radial bursa, and thenar space.
T
he anatomy of the hand is complex, containing deep spaces, bursae, and tendon sheaths that can harbor infection. The deep palmar spaces of the hand include the midpalmar space, the hypothenar space, the thenar space, space of Parona, and the interdigital web spaces. The midpalmar and thenar spaces are separated by the oblique (vertical midpalmar) septum, which extends from the palmar aspect of the third metacarpal shaft obliquely and radially toward the palmar aponeurosis. The deep midpalmar space communicates with the space of Parona through the carpal tunnel.1 In the normal hand, all of these spaces are potential rather than actual spaces.2 The radial and ulnar bursae are synovium-lined structures localized in the palmocarpal area.3 Communication of the bursae occurs in 50% to 85% of the population.3 Such communication usually occurs through an intermediate bursa between the deepest layer of the ulnar bursa and radial bursa, behind the flexor digitorum profundus tendon of the index finger.3 The radial bursa surrounds the flexor pollicis longus (FPL) tendon and always communicates with the FPL tendon sheath.2,3 The
From the Department of Orthopaedics and Traumatology, North District Hospital, Hong Kong, China. The author reports that he has no conflicts of interest in the authorship and publication of this article. Received August 21, 2016; accepted September 16, 2016. Address correspondence to Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S., Department of Orthopaedics and Traumatology, North District Hospital, 9 Po Kin Road, Sheung Shui, NT, Hong Kong SAR, China. E-mail: [email protected] Ó 2016 by the Arthroscopy Association of North America 2212-6287/16811/$36.00 http://dx.doi.org/10.1016/j.eats.2016.09.030
ulnar bursa surrounds the superficial and deep flexor tendons and communicates with the flexor tendon sheath of the little finger in about 50% to 80% of wrists.2,3 These communications are of clinical importance in explaining the spread of inflammatory, infectious, and even neoplasic processes that involve this region.3 Hand infections may range from simple cellulitis to deep space abscess, and even to suppurative flexor tenosynovitis.2 The accurate differentiation of these clinical entities is of paramount importance to healing and recovery of function.2 Ultrasonographic study is a useful diagnostic tool. This aids preoperative planning as it determines the extent of the infection and involvement of the potential spaces.2,4 Deep space hand infections can be caused primarily by direct inoculation of the tendon sheath/bursa or secondarily either through hematogenous spread, the lymphatics, or through pus spreading from adjacent fascial spaces.5-7 Apart from antibiotic coverage and immobilization with hand elevation, the surgical incision and drainage of all potentially communicating spaces and compartments is mandatory, along with intraoperative irrigation and, sometimes, continuous postoperative irrigation.5 Postoperative early mobilization is
Table 1. Indications and Contraindications of Flexor Pollicis Longus Tendoscopy Indications
Contraindications
1. Deep infection or inflammatory disease involving the FPL tendon sheath, the radial bursa, or the thenar space
1. Infection of the ulnar bursa or the flexor tendon sheaths of the index to little fingers
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less severe cases.3 In this technical note, we describe the technique of FPL tendoscopy, which allow endoscopic approach to the FPL tendon sheath, the radial bursa, and the thenar space. It is indicated for deep infection or inflammatory disease involving the FPL tendon sheath, the radial bursa, or the thenar space.8 It is contraindicated for infection of the ulnar bursa or the flexor tendon sheaths of the index to little fingers (Table 1).
Technique
Fig 1. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. The surface anatomy of the FPL tendon at the thumb, the flexor retinaculum of the wrist, and the flexor carpi radialis (FCR) tendon just proximal to the flexor retinaculum (FR) are marked. The phalangeal portal (PP) is located close to the phalangeal insertion of the FPL tendon and just proximal to the volar interphalangeal crease of the thumb. The wrist portal (WP) is located at the ulnar side of the FCR tendon and 1 cm proximal to the proximal edge of the flexor retinaculum.
mandatory to avoid stiffness.6 Drainage can be performed through a wide or limited approach. Wide incisions allow excellent exposure and debridement. However, a wide approach has the potential complications of flap necrosis and exposure of the tendons or neurovascular structures.6 Another popular treatment method is limited incisions at the proximal and distal ends of the flexor sheath, catheter insertion into one end, and either continuous or intermittent throughand-through irrigation. Extravasation is common with this technique, probably because of sheath erosions or inaccurate catheter placement resulting in digital swelling and stiffness.6 Surgeons advocating the limited approach claim a better final range of motion, whereas others believe that a limited approach should be used in
Patient Positioning The patient is in supine position with an arm tourniquet (Zimmer, Warsaw, IN) to provide a bloodless operative field. The surface anatomy of the FPL tendon at the thumb, the flexor retinaculum of the wrist, and the flexor carpi radialis (FCR) tendon just proximal to the flexor retinaculum are marked (Fig 1). A 2.7-mm 30 arthroscope (Henke-Sass Wolf, Tuttlingen, Germany) is used for this procedure. Fluid inflow is by gravity and no arthro-pump is used. Portal Placement The phalangeal portal is located close to the phalangeal insertion of the FPL tendon and just proximal to the volar interphalangeal crease of the thumb. A 5-mm longitudinal skin incision is made at this point. The subcutaneous tissue is bluntly dissected down to the flexor tendon sheath by means of a hemostat. The tendon sheath is incised to expose the FPL tendon. The wrist portal is located at the ulnar side of the FCR tendon and 1 cm proximal to the proximal edge of the flexor retinaculum. A 1-cm longitudinal skin incision is made at this point. The subcutaneous tissue is bluntly dissected down to the deep fascia. The deep fascia is incised open to expose the FCR tendon. The FCR tendon is retracted radially to expose the FPL tendon and the radial bursa, which are deep and ulnar to the FCR tendon. It is important to notice that the median nerve is at the ulnar side of the incision.
Fig 2. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. (A) A 2.7-mm Wissinger rod (WR) is inserted into the FPL tendon sheath via the phalangeal portal (PP). An arthroscopic cannula (AC) is inserted along the rod. (B) The rod is removed and the arthroscope (Arth) is inserted into the cannula.
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Fig 3. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. FPL tendoscopy via the phalangeal portal. (A) The first structure in view is the thenar muscles (TMs). (B) When the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL tendon can be examined. (C) It is difficult if not impossible to advance the arthroscope proximally along the tendon sheath because of the turn of the FPL tendon at the proximal palm. (Or, orifice of the tendon sheath to the thenar muscles.)
Excessive ulnar retraction of the wound should be avoided. Examination of Distal Portion of the FPL Tendon and Radial Bursa A 2.7-mm Wissinger rod (Richard Wolf, Knittlingen, Germany) is inserted into the FPL tendon sheath via the phalangeal portal. An arthroscopic cannula
(Henke-Sass Wolf) is inserted along the rod. The rod is removed and the arthroscope is inserted into the cannula (Fig 2). The rod usually penetrates the tendon sheath and reaches the thenar muscles. The first structures that are viewed through the arthroscope are the thenar muscles. When the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL can be examined. It is difficult if not impossible to
Fig 4. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. (A) A 1-cm longitudinal skin incision is made at the wrist portal. The subcutaneous tissue is bluntly dissected down to the deep fascia. The deep fascia is incised open to expose the flexor carpi radialis (FCR) tendon. (B) The FCR tendon is retracted radially to expose the FPL tendon and the radial bursa (RB), which are deep and ulnar to the FCR tendon. (C) A 2.7-mm Wissinger rod (WR) is inserted into the radial bursa at the wrist portal and is advanced distally. An arthroscopic cannula (AC) is inserted along the rod. (D) The rod is removed and the arthroscope (Arth) is inserted into the cannula. (FR, flexor retinaculum; WP, wrist portal.)
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Fig 5. Flexor pollicis longus tendoscopy of the left hand. The patient is in supine position. FPL tendoscopy via the wrist portal. (A) The first structure in view is the thenar space (TS). (B) While the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL tendon can be examined. (AdP, adductor pollicis muscle; O, orifice to the thenar space.)
advance the arthroscope proximally along the tendon sheath because of the turn of the FPL tendon at the proximal palm (Fig 3).
advance the arthroscope distally along the tendon sheath because of the turn of the FPL tendon at the proximal palm.
Examination of Proximal Portion of the FPL Tendon and Radial Bursa and the Thenar Space A 2.7-mm Wissinger rod (Richard Wolf) is inserted into the radial bursa at the wrist portal and is advanced distally. An arthroscopic cannula (Henke-Sass Wolf) is inserted along the rod. The rod is removed and the arthroscope is inserted into the cannula (Fig 4). The rod usually penetrates the tendon sheath and reaches the thenar space. The first structure in view is the thenar space. While the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL can be examined (Fig 5). It is difficult if not impossible to
Working Portals of the Radial Bursa and the Thenar Space By passive adduction and flexion of the thumb, the proximal phalanx of the thumb, first metacarpal, and radius is in a straight line. However, the phalangeal and wrist portals are still not coaxial in this thumb position (Fig 6). The arthroscope or the arthroscopic shaver cannot overcome the turn of the FPL tendon sheath at the proximal palm when it passes through either the phalangeal or the wrist portal. The instruments via the portals will go to different tissue planes at the proximal palm. The solution is to create a thenar portal over the
Fig 6. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. The phalangeal and wrist portals are not coaxial portals even as the thumb is adducted (A) and flexed (B) to align it with the radius. The arthroscope will go to the thenar space via the wrist portal while the arthroscopic shaver will enter the thenar muscles via the phalangeal portal. (C) fluoroscopy confirms that the arthroscope and the shaver are not in line.
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The finger web portal at the second finger web will be the working portal for the thenar space and the radial bursa at the wrist. This is created by an inside-out technique through the wrist portal. The arthroscope is advanced via the thenar space toward the second finger web. The arthroscope is removed leaving the cannula in situ. The Wissinger rod is inserted into the cannula, and the cannula is removed. The rod enters the second finger web and a 5-mm incision is made at the tip of the rod to create the finger web portal (Fig 7). The wrist and finger web portals are coaxial (Video 1, Table 2).
Discussion
Fig 7. Flexor pollicis longus tendoscopy of the left hand. The patient is in supine position. The thenar portal (TP) and flinger web portal (FWP) can be created by Wissinger rod technique through the phalangeal portal and wrist portal, respectively.
thenar muscle. The FPL tendon is not palpable at the thenar muscle. The thenar portal should be created by an inside-out method. When the arthroscope via the phalangeal portal reaches the turn of the FHL tendon sheath, the arthroscope is removed, leaving the cannula in situ. The Wissinger rod is inserted into the cannula and the cannula is removed. The rod passes through the thenar muscle and the skin over the tip of the rod is incised to create the thenar portal. This portal can be used as the working portal for the distal portion of the FHL tendon sheath. It is also the viewing portal for the FHL tendon sheath of the proximal palm. The phalangeal and thenar portals are coaxial. Table 2. Pearls and Pitfalls of Flexor Pollicis Longus Tendoscopy Pearls 1. The median nerve should be gently retracted ulnarly at the wrist portal. 2. Insertion of the instrument to the radial bursa through the wrist portal should be gentle without use of excessive force. 3. The thenar portal should be created by Wissinger rod technique. 4. Introduction of the instrument into the midpalmar space should be deep to the flexor tendons.
FPL tendoscopy is a minimally invasive approach to the FPL tendon sheath, the radial bursa, and the thenar space. It allows continuous postoperative irrigation with catheters through the portals. If the midpalmar space is infected and distended, it can be approached via the wrist portal. The instrument can reach the midpalmar space via the space of Parona, which is deep to the FPL tendon. The median nerve will not be injured as the path is deep to the flexor tendon and the medial nerve. The thenar portal is created by the Wissinger rod technique as it is difficult to palpate the FPL tendon within the thenar muscles. Care should be taken not to injure the branch of the median nerve, which supplies the thenar muscles as it passes across the radial bursa, approximately 1 cm distal to the transverse ligament of the wrist.5 Similarly, the interdigital nerve may be injured during establishment of the finger web portal. The advantages of this technique include small incisions, good cosmetic result, less scar contracture, less stiffness as early mobilization is allowed, and endoscopic debridement of the deep spaces of the radial side of the hand and wrist. The potential risks of this approach include injury to the median nerve and its branches, injury to the interdigital nerve, and spread of infection (Table 3). This is a technically demanding procedure and should be reserved for the experienced hand and wrist arthroscopist.
Pitfalls 1. Arthro-pump should not be used as inflow under pressure will spread out the infection. 2. The wrist portal is not suitable for ulnar bursa endoscopy because the median nerve is at risk and the bursa surrounds the flexor tendon from the ulnar side.
Table 3. Advantages and Risks of Flexor Pollicis Longus Tendoscopy Advantages
Risks
1. Smaller wounds and better cosmetic result 2. Minimal soft tissue dissection 3. Less scar contracture 4. Less stiffness as early mobilization allowed 5. Allows endoscopic debridement of the deep spaces of the radial side of the hand and wrist
1. Injury to the median nerve and its branches 2. Injury to the interdigital nerve 3. Spread of the infection
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References 1. Jamil W, Khan I, Robinson P, Thalava R. Acute compartment syndrome of the forearm secondary to infection within the space of Parona. Orthopedics 2011;34: e584-e587. 2. Marvel BA, Budhram GR. Bedside ultrasound in the diagnosis of complex hand infections: a case series. J Emerg Med 2015;48:63-68. 3. Aguiar RO, Gasparetto EL, Escuissato DL, et al. Radial and ulnar bursae of the wrist: Cadaveric investigation of regional anatomy with ultrasonographic-guided tenography and MR imaging. Skeletal Radiol 2006;35:828-832.
4. Gottlieb J, Mailhot T, Chilstrom M. Point-of-care ultrasound diagnosis of deep space hand infection. J Emerg Med 2016;50:458-461. 5. Rigopoulos N, Dailiana ZH, Varitimidis S, Malizos KN. Closed-space hand infections: Diagnostic and treatment considerations. Orthop Rev (Pavia) 2012;4:e19. 6. Franko OI, Abrams RA. Hand infections. Orthop Clin N Am 2013;44:625-634. 7. Clark DC. Common acute hand infections. Am Fam Phys 2003;68:2167-2176. 8. Evgeniou E, Iyer S. Pyogenic flexor tenosynovitis leading to an amputation. BMJ Case Rep 2012 Aug 24;2012.
Abstract: The deep palmar spaces of the hand include the midpalmar space, the hypothenar space, the thenar space, space of Parona, and the interdigital web spaces. There are various communications between different spaces. These communications are of clinical importance in explaining the spread of inflammatory, infectious, and even neoplasic processes that involve this region. Surgical incision and drainage of all potentially communicating spaces and compartments is mandatory in deep hand infections. The purpose of this technical note is to describe the minimally invasive approach of endoscopic drainage and debridement of the flexor pollicis longus tendon sheath, radial bursa, and thenar space.
T
he anatomy of the hand is complex, containing deep spaces, bursae, and tendon sheaths that can harbor infection. The deep palmar spaces of the hand include the midpalmar space, the hypothenar space, the thenar space, space of Parona, and the interdigital web spaces. The midpalmar and thenar spaces are separated by the oblique (vertical midpalmar) septum, which extends from the palmar aspect of the third metacarpal shaft obliquely and radially toward the palmar aponeurosis. The deep midpalmar space communicates with the space of Parona through the carpal tunnel.1 In the normal hand, all of these spaces are potential rather than actual spaces.2 The radial and ulnar bursae are synovium-lined structures localized in the palmocarpal area.3 Communication of the bursae occurs in 50% to 85% of the population.3 Such communication usually occurs through an intermediate bursa between the deepest layer of the ulnar bursa and radial bursa, behind the flexor digitorum profundus tendon of the index finger.3 The radial bursa surrounds the flexor pollicis longus (FPL) tendon and always communicates with the FPL tendon sheath.2,3 The
From the Department of Orthopaedics and Traumatology, North District Hospital, Hong Kong, China. The author reports that he has no conflicts of interest in the authorship and publication of this article. Received August 21, 2016; accepted September 16, 2016. Address correspondence to Tun Hing Lui, M.B.B.S.(HK), F.R.C.S.(Edin), F.H.K.A.M., F.H.K.C.O.S., Department of Orthopaedics and Traumatology, North District Hospital, 9 Po Kin Road, Sheung Shui, NT, Hong Kong SAR, China. E-mail: [email protected] Ó 2016 by the Arthroscopy Association of North America 2212-6287/16811/$36.00 http://dx.doi.org/10.1016/j.eats.2016.09.030
ulnar bursa surrounds the superficial and deep flexor tendons and communicates with the flexor tendon sheath of the little finger in about 50% to 80% of wrists.2,3 These communications are of clinical importance in explaining the spread of inflammatory, infectious, and even neoplasic processes that involve this region.3 Hand infections may range from simple cellulitis to deep space abscess, and even to suppurative flexor tenosynovitis.2 The accurate differentiation of these clinical entities is of paramount importance to healing and recovery of function.2 Ultrasonographic study is a useful diagnostic tool. This aids preoperative planning as it determines the extent of the infection and involvement of the potential spaces.2,4 Deep space hand infections can be caused primarily by direct inoculation of the tendon sheath/bursa or secondarily either through hematogenous spread, the lymphatics, or through pus spreading from adjacent fascial spaces.5-7 Apart from antibiotic coverage and immobilization with hand elevation, the surgical incision and drainage of all potentially communicating spaces and compartments is mandatory, along with intraoperative irrigation and, sometimes, continuous postoperative irrigation.5 Postoperative early mobilization is
Table 1. Indications and Contraindications of Flexor Pollicis Longus Tendoscopy Indications
Contraindications
1. Deep infection or inflammatory disease involving the FPL tendon sheath, the radial bursa, or the thenar space
1. Infection of the ulnar bursa or the flexor tendon sheaths of the index to little fingers
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less severe cases.3 In this technical note, we describe the technique of FPL tendoscopy, which allow endoscopic approach to the FPL tendon sheath, the radial bursa, and the thenar space. It is indicated for deep infection or inflammatory disease involving the FPL tendon sheath, the radial bursa, or the thenar space.8 It is contraindicated for infection of the ulnar bursa or the flexor tendon sheaths of the index to little fingers (Table 1).
Technique
Fig 1. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. The surface anatomy of the FPL tendon at the thumb, the flexor retinaculum of the wrist, and the flexor carpi radialis (FCR) tendon just proximal to the flexor retinaculum (FR) are marked. The phalangeal portal (PP) is located close to the phalangeal insertion of the FPL tendon and just proximal to the volar interphalangeal crease of the thumb. The wrist portal (WP) is located at the ulnar side of the FCR tendon and 1 cm proximal to the proximal edge of the flexor retinaculum.
mandatory to avoid stiffness.6 Drainage can be performed through a wide or limited approach. Wide incisions allow excellent exposure and debridement. However, a wide approach has the potential complications of flap necrosis and exposure of the tendons or neurovascular structures.6 Another popular treatment method is limited incisions at the proximal and distal ends of the flexor sheath, catheter insertion into one end, and either continuous or intermittent throughand-through irrigation. Extravasation is common with this technique, probably because of sheath erosions or inaccurate catheter placement resulting in digital swelling and stiffness.6 Surgeons advocating the limited approach claim a better final range of motion, whereas others believe that a limited approach should be used in
Patient Positioning The patient is in supine position with an arm tourniquet (Zimmer, Warsaw, IN) to provide a bloodless operative field. The surface anatomy of the FPL tendon at the thumb, the flexor retinaculum of the wrist, and the flexor carpi radialis (FCR) tendon just proximal to the flexor retinaculum are marked (Fig 1). A 2.7-mm 30 arthroscope (Henke-Sass Wolf, Tuttlingen, Germany) is used for this procedure. Fluid inflow is by gravity and no arthro-pump is used. Portal Placement The phalangeal portal is located close to the phalangeal insertion of the FPL tendon and just proximal to the volar interphalangeal crease of the thumb. A 5-mm longitudinal skin incision is made at this point. The subcutaneous tissue is bluntly dissected down to the flexor tendon sheath by means of a hemostat. The tendon sheath is incised to expose the FPL tendon. The wrist portal is located at the ulnar side of the FCR tendon and 1 cm proximal to the proximal edge of the flexor retinaculum. A 1-cm longitudinal skin incision is made at this point. The subcutaneous tissue is bluntly dissected down to the deep fascia. The deep fascia is incised open to expose the FCR tendon. The FCR tendon is retracted radially to expose the FPL tendon and the radial bursa, which are deep and ulnar to the FCR tendon. It is important to notice that the median nerve is at the ulnar side of the incision.
Fig 2. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. (A) A 2.7-mm Wissinger rod (WR) is inserted into the FPL tendon sheath via the phalangeal portal (PP). An arthroscopic cannula (AC) is inserted along the rod. (B) The rod is removed and the arthroscope (Arth) is inserted into the cannula.
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Fig 3. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. FPL tendoscopy via the phalangeal portal. (A) The first structure in view is the thenar muscles (TMs). (B) When the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL tendon can be examined. (C) It is difficult if not impossible to advance the arthroscope proximally along the tendon sheath because of the turn of the FPL tendon at the proximal palm. (Or, orifice of the tendon sheath to the thenar muscles.)
Excessive ulnar retraction of the wound should be avoided. Examination of Distal Portion of the FPL Tendon and Radial Bursa A 2.7-mm Wissinger rod (Richard Wolf, Knittlingen, Germany) is inserted into the FPL tendon sheath via the phalangeal portal. An arthroscopic cannula
(Henke-Sass Wolf) is inserted along the rod. The rod is removed and the arthroscope is inserted into the cannula (Fig 2). The rod usually penetrates the tendon sheath and reaches the thenar muscles. The first structures that are viewed through the arthroscope are the thenar muscles. When the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL can be examined. It is difficult if not impossible to
Fig 4. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. (A) A 1-cm longitudinal skin incision is made at the wrist portal. The subcutaneous tissue is bluntly dissected down to the deep fascia. The deep fascia is incised open to expose the flexor carpi radialis (FCR) tendon. (B) The FCR tendon is retracted radially to expose the FPL tendon and the radial bursa (RB), which are deep and ulnar to the FCR tendon. (C) A 2.7-mm Wissinger rod (WR) is inserted into the radial bursa at the wrist portal and is advanced distally. An arthroscopic cannula (AC) is inserted along the rod. (D) The rod is removed and the arthroscope (Arth) is inserted into the cannula. (FR, flexor retinaculum; WP, wrist portal.)
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Fig 5. Flexor pollicis longus tendoscopy of the left hand. The patient is in supine position. FPL tendoscopy via the wrist portal. (A) The first structure in view is the thenar space (TS). (B) While the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL tendon can be examined. (AdP, adductor pollicis muscle; O, orifice to the thenar space.)
advance the arthroscope proximally along the tendon sheath because of the turn of the FPL tendon at the proximal palm (Fig 3).
advance the arthroscope distally along the tendon sheath because of the turn of the FPL tendon at the proximal palm.
Examination of Proximal Portion of the FPL Tendon and Radial Bursa and the Thenar Space A 2.7-mm Wissinger rod (Richard Wolf) is inserted into the radial bursa at the wrist portal and is advanced distally. An arthroscopic cannula (Henke-Sass Wolf) is inserted along the rod. The rod is removed and the arthroscope is inserted into the cannula (Fig 4). The rod usually penetrates the tendon sheath and reaches the thenar space. The first structure in view is the thenar space. While the arthroscope is retrieved backward, it will go back to the tendon sheath and the FPL can be examined (Fig 5). It is difficult if not impossible to
Working Portals of the Radial Bursa and the Thenar Space By passive adduction and flexion of the thumb, the proximal phalanx of the thumb, first metacarpal, and radius is in a straight line. However, the phalangeal and wrist portals are still not coaxial in this thumb position (Fig 6). The arthroscope or the arthroscopic shaver cannot overcome the turn of the FPL tendon sheath at the proximal palm when it passes through either the phalangeal or the wrist portal. The instruments via the portals will go to different tissue planes at the proximal palm. The solution is to create a thenar portal over the
Fig 6. Flexor pollicis longus (FPL) tendoscopy of the left hand. The patient is in supine position. The phalangeal and wrist portals are not coaxial portals even as the thumb is adducted (A) and flexed (B) to align it with the radius. The arthroscope will go to the thenar space via the wrist portal while the arthroscopic shaver will enter the thenar muscles via the phalangeal portal. (C) fluoroscopy confirms that the arthroscope and the shaver are not in line.
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The finger web portal at the second finger web will be the working portal for the thenar space and the radial bursa at the wrist. This is created by an inside-out technique through the wrist portal. The arthroscope is advanced via the thenar space toward the second finger web. The arthroscope is removed leaving the cannula in situ. The Wissinger rod is inserted into the cannula, and the cannula is removed. The rod enters the second finger web and a 5-mm incision is made at the tip of the rod to create the finger web portal (Fig 7). The wrist and finger web portals are coaxial (Video 1, Table 2).
Discussion
Fig 7. Flexor pollicis longus tendoscopy of the left hand. The patient is in supine position. The thenar portal (TP) and flinger web portal (FWP) can be created by Wissinger rod technique through the phalangeal portal and wrist portal, respectively.
thenar muscle. The FPL tendon is not palpable at the thenar muscle. The thenar portal should be created by an inside-out method. When the arthroscope via the phalangeal portal reaches the turn of the FHL tendon sheath, the arthroscope is removed, leaving the cannula in situ. The Wissinger rod is inserted into the cannula and the cannula is removed. The rod passes through the thenar muscle and the skin over the tip of the rod is incised to create the thenar portal. This portal can be used as the working portal for the distal portion of the FHL tendon sheath. It is also the viewing portal for the FHL tendon sheath of the proximal palm. The phalangeal and thenar portals are coaxial. Table 2. Pearls and Pitfalls of Flexor Pollicis Longus Tendoscopy Pearls 1. The median nerve should be gently retracted ulnarly at the wrist portal. 2. Insertion of the instrument to the radial bursa through the wrist portal should be gentle without use of excessive force. 3. The thenar portal should be created by Wissinger rod technique. 4. Introduction of the instrument into the midpalmar space should be deep to the flexor tendons.
FPL tendoscopy is a minimally invasive approach to the FPL tendon sheath, the radial bursa, and the thenar space. It allows continuous postoperative irrigation with catheters through the portals. If the midpalmar space is infected and distended, it can be approached via the wrist portal. The instrument can reach the midpalmar space via the space of Parona, which is deep to the FPL tendon. The median nerve will not be injured as the path is deep to the flexor tendon and the medial nerve. The thenar portal is created by the Wissinger rod technique as it is difficult to palpate the FPL tendon within the thenar muscles. Care should be taken not to injure the branch of the median nerve, which supplies the thenar muscles as it passes across the radial bursa, approximately 1 cm distal to the transverse ligament of the wrist.5 Similarly, the interdigital nerve may be injured during establishment of the finger web portal. The advantages of this technique include small incisions, good cosmetic result, less scar contracture, less stiffness as early mobilization is allowed, and endoscopic debridement of the deep spaces of the radial side of the hand and wrist. The potential risks of this approach include injury to the median nerve and its branches, injury to the interdigital nerve, and spread of infection (Table 3). This is a technically demanding procedure and should be reserved for the experienced hand and wrist arthroscopist.
Pitfalls 1. Arthro-pump should not be used as inflow under pressure will spread out the infection. 2. The wrist portal is not suitable for ulnar bursa endoscopy because the median nerve is at risk and the bursa surrounds the flexor tendon from the ulnar side.
Table 3. Advantages and Risks of Flexor Pollicis Longus Tendoscopy Advantages
Risks
1. Smaller wounds and better cosmetic result 2. Minimal soft tissue dissection 3. Less scar contracture 4. Less stiffness as early mobilization allowed 5. Allows endoscopic debridement of the deep spaces of the radial side of the hand and wrist
1. Injury to the median nerve and its branches 2. Injury to the interdigital nerve 3. Spread of the infection
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References 1. Jamil W, Khan I, Robinson P, Thalava R. Acute compartment syndrome of the forearm secondary to infection within the space of Parona. Orthopedics 2011;34: e584-e587. 2. Marvel BA, Budhram GR. Bedside ultrasound in the diagnosis of complex hand infections: a case series. J Emerg Med 2015;48:63-68. 3. Aguiar RO, Gasparetto EL, Escuissato DL, et al. Radial and ulnar bursae of the wrist: Cadaveric investigation of regional anatomy with ultrasonographic-guided tenography and MR imaging. Skeletal Radiol 2006;35:828-832.
4. Gottlieb J, Mailhot T, Chilstrom M. Point-of-care ultrasound diagnosis of deep space hand infection. J Emerg Med 2016;50:458-461. 5. Rigopoulos N, Dailiana ZH, Varitimidis S, Malizos KN. Closed-space hand infections: Diagnostic and treatment considerations. Orthop Rev (Pavia) 2012;4:e19. 6. Franko OI, Abrams RA. Hand infections. Orthop Clin N Am 2013;44:625-634. 7. Clark DC. Common acute hand infections. Am Fam Phys 2003;68:2167-2176. 8. Evgeniou E, Iyer S. Pyogenic flexor tenosynovitis leading to an amputation. BMJ Case Rep 2012 Aug 24;2012.
