Abstract
Pedal penetrating nail prick injury around the first metatarsal head can result in persistent synovitis of the first metatarsophalangeal joint and tenosynovitis of the flexor hallucis longus tendon. Exploration and debridement is indicated if the condition does not improve with antibiotics. Open surgery requires extensive dorsal and plantar incisions. The purpose of this Technical Note is to report the combined arthroscopic and tendoscopic approaches to address the first metatarsophalangeal joint and flexor hallucis longus tendon pathologies. Because it is a result of a pedal injury, the layer-by-layer exploration and debridement is from plantar dorsally. It starts with zone 3 flexor hallucis longus tendoscopy, followed by arthroscopy of the metatarsosesamoid compartment, and finally arthroscopy of the metatarsophalangeal compartment.
Pedal penetrating nail prick injury can occur as a result of household or construction site injury. The injury may be so trivial that the patient may not seek proper medical consultation at the beginning. Some of the injuries lead to cellulitis or sinus, ulcer, or abscess formation, which, if neglected or improperly managed, results in osteomyelitis or septic arthritis of foot structures.1 Antibiotics may be the first line of treatment. The source of infection should be considered so that the most proper antibiotic regime is prescribed.2 However, the response to empirical antibiotics is not usually good. This may be due to a retained foreign body, deep infection, bacterial infection resistant to empirical antibiotics, and atypical infection, for example, fungal or mycobacterial infection.3, 4 Surgical exploration and debridement is indicated in the face of a refractory response to empirical antibiotics.2 Pedal nail prick injury around the first metatarsal head can cause tenosynovitis of the flexor hallucis longus (FHL) and synovitis of the first metatarsophalangeal (MTP-1) joint. It is a result of direct inoculation of microorganisms to the flexor tendon sheath and the first metatarsal joint by the penetrating injury. The infection can spread proximally and distally along the FHL tendon. The infection can also spread from the metatarsosesamoid compartment of the MTP-1 joint to the lateral, medial, and dorsal capsular recess of the metatarsophalangeal compartment of the joint. Open surgery requires both dorsal and plantar incisions to achieve thorough exploration and debridement of the FHL tendon, the sesamoid bones, and the MTP-1 joint. The extensive soft tissue dissection may result in painful scarring especially on the plantar side. Recently, techniques such as FHL tendoscopy5, 6 and arthroscopy of the metatarsosesamoid compartment7, 8, 9 have been reported. For performing tendoscopy, the FHL tendon can be divided into 3 zones: zone 1 from the musculotendinous junction to the fibro-osseous orifice of the posterior talar processes; zone 2 from the orifice to the master knot of Henry; and zone 3 from the master knot of Henry to phalangeal insertion of the tendon. Zone 3 FHL tendoscopy provides access to the FHL tendon around the MTP-1 joint.5, 6 These techniques together with the classic MTP-1 arthroscopy allow thorough exploration and debridement of the MTP-1 joint and the flexor tendon sheath. The purpose of this Technical Note is to report the combined arthroscopic and tendoscopic approaches to address the MTP-1 joint and FHL tendon pathologies. Exploration and debridement is indicated in MTP-1 synovitis and FHL tenosynovitis after pedal penetrating nail prick injury around the first metatarsal head region. In the presence of sinus tract or ulcer, ulcer endoscopy10 can be combined with these minimally invasive approaches to achieve complete exploration and debridement. It is contraindicated when the infection spreads to the deeper layers of the sole or to the lateral part of the foot. It is also contraindicated in the presence of a sizable foreign body warranting open exploration or when the infection is superficial to the plantar aponeurosis, and the FHL tendon and the MTP-1 joint are not involved (Table 1).
Table 1.
Indications and Contraindications of Zone 3 Flexor Hallucis Longus (FHL) Tendoscopy and Metatarsosesamoid Arthroscopy
| Indications | Contraindications |
|---|---|
| 1. It is indicated for first metatarsophalangeal synovitis and FHL tenosynovitis after pedal penetrating nail prick injury around the first metatarsal head region | 1. Infection spread to the deeper layers of the sole or to the lateral part of the foot 2. Presence of a sizable foreign body warranting open exploration 3. The infection is superficial to the plantar aponeurosis, and the FHL tendon and the first metatarsophalangeal joint are not involved |
Technique
Preoperative Assessment and Patient Positioning
A detailed history taking and clinical examination can establish the diagnosis. The location of tenderness over the joint line of the MTP-1 joint, sesamoid bones, and along the FHL tendon is determined. Radiographs of the foot may identify any radio-opaque foreign body. Besides localization of any radio-opaque foreign body, computed tomogram can detect any soft tissue swelling around the FHL tendon and the first metatarsophalangeal joint. The computed tomogram scans can also correctly predict the presence or absence of osteomyelitis of the metatarsal head and sesamoid bones (Fig 1).1 Magnetic resonance imaging (MRI) is an important preoperative investigation after the presence of a metallic foreign body is excluded. It can identify any nonmetallic foreign body and allows precise preoperative localization of fluid collections.2 However, requesting MRI may well have caused an unnecessary delay in definitive treatment due to the limited availability and long waiting list for this investigation in our hospital. Ultrasound is another useful tool for localizing non–radio-opaque foreign bodies especially when there is lack of MRI facility.1
Fig 1.
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. Computed tomogram of the illustrated case. The coronal view shows soft tissue swelling around the first metatarsal head and FHL tendon. The lateral sesamoid bone (LS) is partially destructed.
The patient is in the supine position with the legs spread. A thigh tourniquet is applied to provide a bloodless operative field. Fluid inflow is by gravity. The arthropump should not be used to minimize extravasation and spread of infection.
A 2.7-mm 30° arthroscope (Henke Sass Wolf GmbH, Germany) is used for zone 3 FHL tendoscopy and a 1.9-mm 30° arthroscope (Henke Sass Wolf GmbH, Germany) is used for arthroscopy of the metatarsosesamoid and metatarsophalangeal compartments of the MTP-1 joint.
Because it is a result of a pedal injury, the layer-by-layer exploration and debridement is from plantar dorsally. It starts with zone 3 FHL tendoscopy, followed by arthroscopy of the metatarsosesamoid compartment, and finally arthroscopy of the metatarsophalangeal compartment.
Portals of Zone 3 FHL Tendoscopy
Zone 3 FHL tendoscopy is performed through the proximal and distal portals along the FHL tendon. The distal portal is located just proximal to the hallux interphalangeal joint. A 3- to 4-mm longitudinal incision is made at the distal portal site. The subcutaneous tissue is bluntly dissected down to the fibrous tendon sheath by a haemostat. The tendon sheath is incised longitudinally. A 2.7-mm Wissinger rod (Richard Wolf GmbH, Knittlingen, Germany) is inserted into the tendon sheath and advanced proximally. This should be performed gently to avoid injury to the flexor tendon. The rod penetrates through the plantar aponeurosis at the level of the Lisfranc joint. A 3- to 4-mm longitudinal incision is made at the tip of the rod to establish the proximal portal. The rod then passes through both the proximal and distal portals.
Zone 3 FHL Tendoscopy
The proximal portal is the viewing portal. An arthroscopic cannula (Henke Sass Wolf GmbH, Germany) is inserted into the proximal portal along the Wissinger rod. The rod is removed and the arthroscope is inserted into the cannula. The distal portal is the working portal. An arthroscopic shaver (Dyonics, Smith & Nephew, Andover, MA) is inserted via the distal portal. Arthroscopic synovectomy of the FHL tendon is performed. The sesamoid bones are then examined for any destruction. Resection of the destructed part of the sesamoid bone is then performed. After this, the plantar capsule of the first metatarsophalangeal joint is examined for any perforation (Fig 2). The plantar side of the first metatarsal head can be examined through the perforated plantar capsule. A biopsy of inflamed synovium can be performed through this fenestration. Arthroscopic synovectomy of the metatarsosesamoid compartment can also be performed through this fenestration. However, the examination and debridement of the metatarsosesamoid compartment through this capsular fenestration will be limited and incomplete.
Fig 2.
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. Zone 3 FHL tendoscopy is performed through the proximal and distal portals along the FHL tendon. (A) The distal portal (DP) is located just proximal to the hallux interphalangeal joint (IPJ). (B) A 2.7-mm Wissinger rod (WR) is inserted into the tendon sheath and advanced proximally. The rod penetrates through the plantar aponeurosis at the level of the Lisfranc joint. A 3- to 4-mm longitudinal incision is made at the tip of the rod to establish the proximal portal (PP). The rod then passes through both the proximal and distal portals. An arthroscopic cannula (AC) is inserted into the proximal portal along the Wissinger rod. (C) The rod is removed and the arthroscope is inserted into the cannula. An arthroscopic shaver is inserted via the distal portal. (D) Arthroscopic view with the proximal portal as the viewing portal. (AS, arthroscopic shaver; C, plantar capsule of the first metatarsophalangeal joint; LS, lateral sesamoid bone; MT, plantar side of the first metatarsal head seen through the perforated plantar capsule.)
After the completion of debridement of the distal part of the FHL tendon, the arthroscope is removed and the cannula is left in situ. The Wissinger rod is inserted into the cannula and passed through both portals. The cannula is then removed and reinserted along the rod via the distal portal. The cannula passes through both portals and the rod is removed. The arthroscope is inserted half way into the cannula via the distal portal. The arthroscopic shaver is inserted into the cannula via the proximal portal. Keeping the arthroscope and the arthroscopic shaver in position, the cannula is retrieved backward and incorporated into the arthroscope. This manoeuvre can ensure the correct positioning of the shaver. The distal portal is the viewing portal. The inflamed tissue adjacent to the FHL tendon is resected endoscopically (Fig 3).
Fig 3.
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) The Wissinger rod passes through both portals and the arthroscope cannula is inserted along the rod via the distal portal. (B) The cannula passes through both portals and the rod is removed. The arthroscope is inserted half way into the cannula via the distal portal. The arthroscopic shaver is inserted into the cannula via the proximal portal. (C) Keeping the arthroscope and arthroscopic shaver in position, the cannula is retrieved backward and incorporated into the arthroscope. This manoeuvre can ensure the correct positioning of the shaver. (D) Distal portal is the viewing portal. The inflamed tissue adjacent to the FHL tendon is resected endoscopically. (AC, arthroscope cannula; Ar, arthroscope; AS, arthroscopic shaver; DP, distal portal; IPJ, hallux interphalangeal joint; IT, inflamed tissue; PP, proximal portal; WR, Wissinger rod.)
Although the arthroscope or the arthroscopic shaver passing through the distal portal is confined in the fibrous flexor tendon sheath, it can be moved sideways as the hallux can be abducted and adducted. This allows a wider field of arthroscopic visualization and debridement proximal to the proximal end of the fibrous tendon sheath.
Portals of Arthroscopy of the Metatarsosesamoid Compartment of the First Metatarsophalangeal Joint
Arthroscopy of the metatarsosesamoid compartment of the MTP-1 joint is performed through the medial and proximal medial portals. The medial portal is at the midpoint of the medial joint line of the MTP-1 joint. The proximal medial portal is located 4 cm proximal to the first metatarsophalangeal joint line in between the medial head of the flexor hallux brevis and the abductor hallucis tendon. A needle is inserted into the metatarsosesamoid compartment via the proximal medial portal to confirm the proper position of the portal before making the incision. Three- to four-millimeter incisions are made at the portal sites. The underlying soft tissue is dissected bluntly down to the joint capsule with a haemostat. The capsule is perforated by the hemostat tip.
Arthroscopy of the Metatarsosesamoid Compartment of the First Metatarsophalangeal Joint
The proximal medial portal is the viewing portal. Synovectomy of the medial part of the compartment is performed via the medial portal (Fig 4). After the completion of debridement of the medial part of the compartment, the arthroscope is switched to the medial portal. Synovectomy of the lateral part of the compartment is performed via the proximal medial portal. After the complete synovectomy of the compartment, the articular cartilage of the plantar side of the first metatarsal head and sesamoid bones is examined. Any destructed cartilage or bone is resected (Fig 5).
Fig 4.
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) The proximal medial portal (PMP) is the viewing portal and the medial portal (MP) is the working portal. (B) Arthroscopic view showed inflamed synovium (IS) at the metatarsosesamoid compartment. (MT, first metatarsal head.)
Fig 5.
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 FHL tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) The medial portal (MP) is the viewing portal and the proximal medial portal (PMP) is the working portal. (B) Arthroscopic view showed inflamed synovium (IS) at the metatarsosesamoid compartment. (AS, arthroscopic shaver; LS, lateral sesamoid bone; MT, first metatarsal head.)
Arthroscopy of the Metatarsophalangeal Compartment of the First Metatarsophalangeal Joint
First, metatarsophalangeal arthroscopy is performed via the medial and dorsolateral portals. The dorsolateral portal is located at the dorsal joint line lateral to the extensor hallucis longus tendon. The articular cartilage of the metatarsophalangeal compartment is examined. Synovectomy of the dorsal capsular recess is performed with the dorsolateral and medial portals interchanged as the viewing and working portals. Synovectomy of the medial capsular recess is performed with the dorsolateral portal as the viewing portal and the medial portal as the working portal. Synovectomy of the lateral capsular recess is performed with the medial portal as the viewing portal and the dorsolateral portal as the working portal (Fig 6, Video 1, Table 2).
Fig 6.
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. (A) Arthroscopic synovectomy of the dorsal capsular recess of the metatarsophalangeal compartment with the medial portal (MP) as the viewing portal and the dorsolateral portal (DLP) as the working portal. (B) Arthroscopic synovectomy of the medial capsular recess of the metatarsophalangeal compartment with the DLP as the viewing portal and the MP as the working portal. (C) Arthroscopic synovectomy of the lateral capsular recess of the metatarsophalangeal compartment with the MP as the viewing portal and the DLP as the working portal.
Table 2.
Pearls and Pitfalls of Zone 3 Flexor Hallucis Longus (FHL) Tendoscopy and Metatarsosesamoid Arthroscopy
| Pearls | Pitfalls |
|---|---|
| 1. Preoperative clinical examination and investigations are important to determine the structures involved 2. The exploration and debridement is layer by layer from plantar dorsally 3. No arthropump is used to minimize extravasation and spread of infection |
1. If lateral sesamoidectomy is indicated, it is better performed through metatarsosesamoid arthroscopy than FHL tendoscopy. The arthroscopic approach allows preservation of a soft tissue envelop of the lateral sesamoid bone and reduces the risk of hallux varus deformity or injury to the lateral digital nerve7 |
Discussion
The key of success of surgical treatment of persistent inflammation after pedal nail prick injury to the first metatarsal head is accurate determination of the structures involved and thorough exploration and debridement of the involved structures. Prompt and early operation can prevent permanent damage to the articular cartilage, bone, and tendon. The reported technique allows exploration and debridement of most of the structures involved in the pedal injury. However, it has the blind spot that cannot approach the subcutaneous layer in the first metatarsal head region as it is superficial to the plantar aponeurosis and fibrous flexor tendon sheath. This technique is not technically difficult and can be handled by an average foot and ankle arthroscopist.
The advantages of this technique include small incisions and better cosmetic results; less chance of painful scar formation because of minimal dissection and surgical scars away from the weight-bearing region; and thorough exploration and debridement of the zone 3 FHL tendon and the MTP-1 joint. The potential risks of this technique include incomplete exploration and debridement, injury to the FHL tendon, injury to the digital nerves, and spread of the infection (Table 3). Nerve injury can occur during creation of the portals and debridement of the lateral sesamoid bone. The “nick and spread” technique during creation of portals can reduce the risk of cutaneous nerve injury. The branches of the medial plantar nerve can be injured during passage of the Wissinger rod for the creation of the plantar portal. The rod of the conical blunt end is used. The rod should be passed gently, and resistance should be encountered only when the plantar aponeurosis is reached. Any resistance encountered before reaching the plantar aponeurosis implies that either nerve or tendon is encountered. The rod should be withdrawn and re-entered in a slightly different direction to bypass it. The plantar lateral digital nerve is at the lateral side of the lateral sesamoid bone. Debridement in this region should be performed under strict arthroscopic visualization. The shaver or burr should face medially and the suction should be kept minimum. Lateral sesamoidectomy, if indicated, can be performed by enucleation of the bone and keeping the soft tissue envelop intact. This can preserve the ligamentous attachments of the sesamoid apparatus and reduce the risk of injury to the plantar lateral digital nerve. The risk of breakdown of the previous puncture wound is minimal after this procedure, as it is performed mainly deep to the plantar aponeurosis. If the punctured wound does not heal and a sinus tract is formed, the tract can be debrided via ulcer endoscopy.10 On the other hand, the portal incisions are away from the injury zone and the risk of breakdown should be low. Moreover, the incisions are longitudinal in orientation and should be safe during weight bearing and great toe mobilization.
Table 3.
Advantages and Risks of Zone 3 Flexor Hallucis Longus (FHL) Tendoscopy and Metatarsosesamoid Arthroscopy
| Advantages | Risks |
|---|---|
| 1. Smaller wounds and better cosmetic results | 1. Incomplete exploration and debridement |
| 2. Less scar pain | 2. Injury to the FHL tendon |
| 3. Scars away from the weight-bearing area | 3. Injury to the digital nerves |
| 4. Less soft tissue dissection | 4. Spread out of the infection |
| 5. Thorough exploration and debridement of the zone 3 FHL tendon and first metatarsophalangeal joint |
Footnotes
The author reports that he has no conflicts of interest in the authorship and publication of this article.
Supplementary Data
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. The first step is FHL tendoscopy via the proximal and distal portals. The proximal portal is the viewing portal. The distal part of the FHL tendon sheath and destructed sesamoid bone is debrided via the distal portal. Synovial biopsy of the metatarsosesamoid compartment is performed through the perforated capsule. The arthroscope is switched to the distal portal. The proximal part of the FHL tendon is debrided via the proximal portal. The next step is arthroscopy of the metatarsosesamoid compartment. The proximal medial portal is the viewing portal. Arthroscopic synovectomy is performed via the medial portal. The arthroscope is switched to the medial portal. The debridement is continued via the proximal medial portal. The third step is arthroscopy of the metatarsophalangeal compartment. Arthroscopic synovectomy of the dorsal, medial, and lateral capsular recesses is performed via the medial and dorsolateral portals.
References
- 1.Chandrashekara C.M., George M.A., Al-Marboi B.S.K. Neglected foreign body, the cause of navicular osteomyelitis in a paediatric foot: A case report. J Orthop Case Rep. 2013;3:26–29. doi: 10.13107/jocr.2250-0685.111. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Elledge R.O.C., Mohan D. A penetrating injury with a cocktail stick resulting in a spreading infection with Streptococcus milleri. BMJ Case Rep. 2009;2009 doi: 10.1136/bcr.02.2009.1592. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Asly M., Rafaoui A., Bouyermane H. Mycetoma (Madura foot): A case report. Ann Phys Rehabil Med. 2010;53:650–654. doi: 10.1016/j.rehab.2010.10.003. [DOI] [PubMed] [Google Scholar]
- 4.Bhagavatula S., Vale L., Evans J., Carpenter C., Barnes R.A. Scedosporium prolificans osteomyelitis following penetrating injury: A case report. Med Mycol Case Rep. 2014;4:26–29. doi: 10.1016/j.mmcr.2014.03.002. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Lui T.H., Chow H.T. Role of toe flexor tendoscopy in management of an unusual cause of metatarsalgia. Knee Surg Sports Traumatol Arthrosc. 2006;14:654–658. doi: 10.1007/s00167-005-0016-3. [DOI] [PubMed] [Google Scholar]
- 6.Lui T.H. Flexor hallucis longus tendoscopy: A technical note. Knee Surg Sports Traumatol Arthrosc. 2009;17:107–110. doi: 10.1007/s00167-008-0623-x. [DOI] [PubMed] [Google Scholar]
- 7.Chan P.K., Lui T.H. Arthroscopic fibular sesamoidectomy in the management of the sesamoid osteomyelitis. Knee Surg Sports Traumatol Arthrosc. 2006;14:664–667. doi: 10.1007/s00167-005-0030-5. [DOI] [PubMed] [Google Scholar]
- 8.van Dijk C.N., Kirsten M., Nuesch B.C. Arthroscopic surgery of the metatarsophalangeal first joint. Arthroscopy. 1998;14:851–855. doi: 10.1016/s0749-8063(98)70023-4. [DOI] [PubMed] [Google Scholar]
- 9.Lui T.H. Arthroscopic release of first metatarsophalangeal arthrofibrosis. Arthroscopy. 2006;22:906.e1–906.e4. doi: 10.1016/j.arthro.2005.12.061. [DOI] [PubMed] [Google Scholar]
- 10.Lui T.H. Technical tip: Percutaneous bone shaving and ulcer endoscopy to manage abnormal pressure point of the sole. The Foot. 2014;24:190–194. doi: 10.1016/j.foot.2014.08.010. [DOI] [PubMed] [Google Scholar]
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Supplementary Materials
Flexor hallucis tenosynovitis and first metatarsophalangeal synovitis of the right foot after penetrating nail prick injury: treated by zone 3 flexor hallucis longus (FHL) tendoscopy and metatarsosesamoid arthroscopy. The patient is in the supine position with the legs spread. The first step is FHL tendoscopy via the proximal and distal portals. The proximal portal is the viewing portal. The distal part of the FHL tendon sheath and destructed sesamoid bone is debrided via the distal portal. Synovial biopsy of the metatarsosesamoid compartment is performed through the perforated capsule. The arthroscope is switched to the distal portal. The proximal part of the FHL tendon is debrided via the proximal portal. The next step is arthroscopy of the metatarsosesamoid compartment. The proximal medial portal is the viewing portal. Arthroscopic synovectomy is performed via the medial portal. The arthroscope is switched to the medial portal. The debridement is continued via the proximal medial portal. The third step is arthroscopy of the metatarsophalangeal compartment. Arthroscopic synovectomy of the dorsal, medial, and lateral capsular recesses is performed via the medial and dorsolateral portals.