Flexor hallucis longus tendoscopy: a technical note

Metatarsosesamoid Arthroscopy for Management of Plantar Pain of the First Metatarsophalangeal Joint After Surgical Correction of Hallux Valgus Deformity

Residual pain in the early postoperative phase after hallux valgus surgery is common, but persistent plantar pain of the first metatarsophalangeal joint after surgery is rare. This can be due to intra- or extra-articular causes. Metatarsosesamoid arthroscopy is effective for the management of intra-articular causes of plantar pain. The purpose of this technical note is to describe the details of metatarsosesamoid arthroscopy for the management of plantar pain of the first metatarsophalangeal joint after surgical correction of hallux valgus deformity.

Endoscopic Release of the Flexor Hallucis Longus Tendon at Posterior Ankle for Management of Checkrein Deformity of the Great Toe, Second Toe, and Third Toe

Checkrein deformity is rare and involves entrapment or fixed tethering of the flexor hallucis longus (FHL) in the posterior foot, just proximal to the flexor retinaculum of the ankle, and causes the "constant length phenomenon" of FHL. The clinical presentation is a dynamic flexion deformity of the great toe characterized by flexion contracture of the interphalangeal joint with mild extension contracture of the metatarsophalangeal joint, causing difficulty in walking since in the stance phase of gait, the hallux is forced into plantar flexion and impinges onto the ground. Because the FHL tendon has some interconnection to the tendons of the flexor digitorum longus at the master knot of Henry, deformities of the second and third toes are sometimes seen. There is no standard surgical treatment for checkrein deformity. Surgical release of the FHL muscle or release/lengthening of the FHL tendon has been proposed. The purpose of this Technical Note is to report the endoscopic release of the FHL tendon at the posterior ankle for management of checkrein deformity of the great toe, second toe, and third toe.

Flexor Hallucis Longus decompression under ultrasound guidance: A cadaver study

INTRODUCTION

The Flexor Hallucis Longus (FHL) is a muscle that can be subject to multiple impingements caused by exaggerated plantar flexion in athletes. The most common impingement is due to inflammation of the tendon at the retrotalar pulley. The constraints exerted on the FHL are responsible for a pathology called functional Hallux Limitus. Surgical treatment consists of tenolysis of the FHL arthroscopically or via open surgery, by opening the pulley. The objective of this study was to evaluate the risk of lesions of the neurovascular pedicle and the posterior tibial tendon after tenolysis of the Flexor Hallucis Longus under ultrasound guidance.

HYPOTHESIS

The hypothesis of this study is that tenolysis of the Flexor Hallucis Longus could proceed under ultrasound guidance without associated tendon lesions or neurovascular lesions.

MATERIAL AND METHODS

Thirteen cadaveric specimens were studied, resulting in an analysis of 26 feet. Following identification of the Flexor Hallucis Longus, tenolysis with a 19-gauge needle under ultrasound guidance was performed by an orthopedic specialist after hydrodissection to push back the posterior tibial pedicle. The dissection of the cadavers made it possible to verify the positioning of the posterior tibial pedicle, the FHL tendon and the opening of the retrotalar pulley.

RESULTS

Five cadaveric subjects, 10 cases, underwent a complete opening of the retrotalar pulley under ultrasound guidance. In 16 cases, the opening was partial, with a section of the pulley of 65.87±18%. The cases of partial openings showed no neurovascular or tendinous lesions. The 10 cases of complete opening resulted in 5 lesions of the tibial nerve, 4 vascular lesions: 1 venous and 3 arterial, and 6 lesions of the FHL tendon.

CONCLUSION

Tenolysis of the Flexor Hallucis Longus under ultrasound guidance at the level of its retrotalar pulley was systematically associated with neurovascular lesions in the event of complete release of the pulley by the method studied, unlike a partial release where no lesion was found.

LEVEL OF EVIDENCE

III; case-control study.

Endoscopically Assisted Percutaneous Harvesting of the Flexor Hallucis Tendon in Zone 2: An Anatomical Study

BACKGROUND

Flexor hallucis longus (FHL) transfer is a well-established method for treating chronic Achilles tendon ruptures and tendinopathy. Harvesting of the FHL tendon in zone 2 results in greater length but is also associated with an increased risk of injury to the medial plantar nerve and requires an additional plantar incision. Because of the anatomic proximity of the FHL tendon to the tibial neurovascular bundle in zone 2, the purpose of this study was to investigate the risk of vascular or nerve injury with arthroscopic assisted percutaneous tenotomy in zone 2 of the FHL tendon.

METHODS

Endoscopically assisted percutaneous FHL transfer was performed on 10 right lower extremities from 10 cadaveric human specimens. The FHL tendon lengths and the relationship between FHL tendon and the tibial neurovascular bundle at zone 2 was analyzed.

RESULTS

We observed a complete transection of the medial plantar nerve in 1 case (10%). The mean length of the FHL tendon was 54.7 ± 9.5 mm and the mean distance from the distal stump of the FHL tendon to local neurovascular structures was 1.3 ± 0.7 mm.

CONCLUSION

There is a risk of neurovascular injury after endoscopic FHL tenotomy in zone 2. The tenotomy site is within 2 mm of the local neurovascular structures in the majority of cases. The additional length gained from this technique is unlikely to be required for the majority of FHL tendon transfer procedures. If additional length is needed, we would recommend the use of intraoperative ultrasonography or a mini-open approach to minimize injury risk.

LEVEL OF EVIDENCE

Level V, expert opinion.

Combined Arthroscopic and Endoscopic Synovectomy for Diffuse Pigmented Villonodular Synovitis (PVNS) of the Ankle

The current treatment of choice for diffuse-type pigmented villonodular synovitis (PVNS) is surgical excision. Complete synovectomy is necessary because of the local aggressiveness of the disease, with a significant recurrence rate and a minor chance of malignant transformation. The recurrence rate is even greater in those cases with extra-articular extension. Arthroscopic and endoscopic synovectomy have the advantage of avoidance of extensive soft-tissue dissection, which is associated with open synovectomy. The purpose of this Technical Note is to describe the details of combined arthroscopic and endoscopic synovectomy as treatment for diffuse PVNS of the ankle. By a combination of different arthroscopic and endoscopic approaches of the ankle region, a complete synovectomy of both intra-articular and extra-articular components of diffuse-type PVNS is feasible.

Endoscopic Posterior Ankle Decompression and Release After Total Ankle Arthroplasty

Accurate positioning of the total ankle arthroplasty implant components with the absence of any hindfoot deformity does not preclude the development of bony impingement. In cases of ankle stiffness after total ankle arthroplasty, the usual limitation is in dorsiflexion. If triceps surae contracture is excluded or persistent restriction remains in ankle dorsiflexion after gastrocnemius recession or tendo-Achilles lengthening, posterior ankle capsulectomy, debridement of posterior ankle gutter, and release of the deep posterior deltoid ligament and the posterior talofibular ligament are indicated. In this Technical Note, the technical details of endoscopic posterior ankle decompression and release after total ankle arthroplasty are described.

Pigmented Villonodular Synovitis of the Flexor Hallucis Longus Tendon Treated by Means of Tendoscopy and Endoscopic Synovectomy

Pigmented villonodular synovitis (PVNS) of the tendon sheath (tenosynovial giant cell tumor) is a rare disorder that is often misdiagnosed because of slow growth and an atypical presentation. Open surgical excision is the treatment of choice, although recurrence is a common complication. In this report, a case of PVNS of the flexor hallucis longus tendon in the ankle and hindfoot is described. The diagnosis was confirmed by endoscopic inspection and biopsy, and complete synovectomy was performed through the endoscope. The patient remained disease free after 24 months of follow up.

Posterior Ankle Scope Approach to Symptomatic Os Trigonum Removal

INTRODUCTION

Os trigonum can become symptomatic following acute or chronic repetitive compression of the posterior ankle. Following conservative treatment failure, removal is often warranted. Current surgical options include traditional open resection and endoscopic removal. The purpose of this article is to review a population of patients who underwent endoscopic excision of symptomatic accessory os trigonum through a posterior approach and evaluate the outcomes of the procedure.

METHODS

From May 2009 to September 2018, all patients who underwent excision of a symptomatic os trigonum were reviewed. Outcomes of interest were major and minor complications and time to return to full weight-bearing activities. Postoperative protocol included 5 to 7 days non-weight-bearing and 1 to 2 weeks of protected weight-bearing followed by full release to weight-bearing activities.

RESULTS

Twelve patients who met the inclusion criteria were studied. Mean follow-up was 10.2 (±7.4) months with no major complications and 1 minor wound complication. Average advancement to protected weight-bearing was 7.1 days. Average return to full weight-bearing activities without restriction was 24.4 days.

CONCLUSION

The current study describes the technique and results to minimally invasive os trigonum removal with favorable postoperative outcomes. Results demonstrated minimal complications and postoperative pain, also quick return to weight-bearing and full activity.

LEVEL OF EVIDENCE

Therapeutic, Level IV: Case series.

Role of arthroscopy and endoscopy in management of tuberculosis of the foot and ankle

Tuberculosis of the foot and ankle is rare but destructive. It can affect bones, joints and soft tissue and can mimic a wide range of acute and chronic infections or tumorous conditions. The primary treatment objectives for osteoarticular TB include curing the infection, limiting deformity, maintaining mobility, and reducing discomfort. Chemotherapy remains the mainstay of treatment in acute stage. Indications of surgery include biopsy and debridement in early stages to reduce the tuberculosis load and enable better penetration of anti-tuberculous drugs. Other reported indications for surgery in early stage of TB foot and ankle include resection of lesion not responding to chemotherapy and debridement of lesions close to the articular surface, as surgical debridement might halt progression and joint invasion, avoiding worsening of the prognosis. The success of arthroscopic treatment for infectious arthritis with decreased morbidity and postoperative pain makes arthroscopy an excellent alternative to open surgery. The advantages such as minor trauma, short hospitalization time and short post operative rehabilitation period as well as good cosmetic and therapeutic results should lead to a more frequent use of arthroscopy as early as possible as an adjuvant for the tuberculous joint. However, tuberculosis can involve any joints, bone and soft tissue (tendon) of the foot and ankle and surgeons should equip with various arthroscopic and endoscopic techniques in order to deal with the various situations of tuberculosis of the foot and ankle.

Endoscopically Assisted Reduction and Screw Fixation of Acute Fracture of the Posteromedial Talar Process (Cedell Fracture)

Fracture of the posteromedial talar process (Cedell fracture) is a rare injury and is usually associated with other injuries such as medial subtalar dislocation. Diagnosis of the fracture necessitates a heightened clinical suspicion, and computed tomography should be performed in any suspicious cases. Timely treatment is important for restoration of proper anatomy and function of the subtalar joint. Significant morbidity is associated with an undiagnosed or nonoperatively treated fracture of the posteromedial talar process, especially in a larger fracture that is intra-articular at both the ankle and subtalar joints. In this Technical Note, the technical details of endoscopically assisted reduction and screw fixation of acute posteromedial talar fracture is described. This can allow fracture reduction and fracture fixation under endoscopic visualization.

Effect of extensive tenosynovectomy on diffuse flexor hallucis longus tenosynovitis combined with effusion

OBJECTIVE

The objective of this study was to examine the clinical and magnetic resonance imaging (MRI) outcomes of extensive tenosynovectomy on patients with diffuse flexor hallucis longus tenosynovitis combined with effusion (DFHLT-E).

METHODS

Consecutive patients undergoing extensive tenosynovectomy for DFHLT-E in the same foot and ankle center from January 2013 to December 2016 were selected; a total of 14 patients were included in the final analysis. Patients with a minimum 1-year follow-up were evaluated with physical examination, MRI, American Orthopaedic Foot and Ankle Society (AOFAS) clinical midfoot scale, and visual analog scale (VAS) pain scores.

RESULTS

The 14 patients were followed up for an average of 15.0 ± 2.3 months (12-18 months). There were no recurrences in all clinical examinations at the final follow-up. The AOFAS score was improved from 61.57 ± 10.70 before surgery to 90.28 ± 9.41 at the final follow-up. The difference was statistically significant (p = 0.001). The VAS score was improved from 4.00 ± 0.82 before surgery to 0.43 ± 0.53 at the final follow-up (p < 0.001). MRI examination revealed two patients with small residual and limited effusion with no clinical symptoms. Superficial pin infection was observed in one patient, and two patients had transient neurostimulation.

CONCLUSIONS

Extensive tenosynovectomy is an effective alternative for the treatment of DFHLT-E with less complications or recurrence.

Endoscopic Approach to Posterior Ankle via Lateral Portals

Posterior ankle pain is a common foot and ankle problem faced by orthopaedic surgeons. It can have many causes, including posterior ankle joint pathologies (synovitis or osteochondral lesion), ankle impingement (posterior, posterolateral, or posteromedial), flexor hallucis longus pathologies, peroneal tendon problems, posterior tibial tendinopathy, Achilles tendon pathology, posterior subtalar tarsal coalition, or tarsal tunnel syndrome. Most of these pathologies can be managed effectively by an endoscopic approach. The classic endoscopic approach is the 2-portal posterior ankle endoscopy with the portals at the medial and lateral side of the Achilles tendon. This is performed with the patient in prone position. In this technical note, we describe the details of endoscopic approach to the posterior ankle via lateral portals. This allow flexibility of patient positioning (supine, prone, or lateral). It is particularly effective for the management of posteromedial ankle impingement without the risk of injury to the posterior tibial neurovascular bundle. Moreover, any concomitant peroneal tendon pathology can be managed via the same lateral portals.

Anatomical Study of the Compositions and Internal Connections of the Chiasma Plantare (Master Knot of Henry): Exploring Its Possible Clinical Impact

The purposes of this study were to integrate the types of interconnecting fibers among components of the chiasma plantare and to deduce their flexion actions. The chiasma plantare and the long flexor tendons in 52 cadaveric feet (26 left feet and 25 right feet) were dissected and removed via gross anatomic dissection. The connections among the flexor digitorum longus (FDL), flexor hallucis longus (FHL), and quadratus plantae (QP) were then classified and analyzed. The connection between the FHL and FDL was type I in 43 (86%) cases, type III in 2 (4%) cases, and type V in 5 (10%) cases, with the FHL manipulating the first through third toes and the FDL manipulating the first through the fifth toes. The shape of the QP in 28 (56%) cases exhibited a 2-headed QP, and in 22 (44%) cases, a medial-headed QP. The composition of the chiasma plantare was 2 layers in 28 (56%) cases and 3 layers in 22 (44%) cases: 9 (18%) cases were type a, 2 (4%) cases were type b₁, and 1 (2%) case each was classified as type b₂ and b₃. The FHL controlled the second toe in 10 (20%) cases; both the second and third toes in 27 (54%) cases; and the second, third, and fourth toes in 13 (26%) cases. The QP manipulated the third and fourth toes in all cases, the second toe in 38 (76%) cases, and the fifth toe in 11 (22%) cases. These data suggest that such variations might result from tendon transfer. In conclusion, we considered the FDL to be more advanced for the recovery of both the ankle and the forefoot based on this study.

Minimally Invasive and Endoscopic Treatment of Haglund Syndrome

Haglund syndrome is a triad of posterosuperior calcaneal prominence (Haglund deformity), retrocalcaneal bursitis, and insertional Achilles tendinopathy. The sources of pain include the posterior calcaneal wall cartilage, retrocalcaneal and subcutaneous adventitial bursa, and the Achilles tendon. Resection of the posterosuperior calcaneal tubercle, bursectomy, excision of the Achilles tendon pathology, reattachment of the Achilles tendon, gastrocnemius aponeurotic recession, and flexor hallucis longus transfer have been proposed as surgical treatment options. All of them can be performed endoscopically or under minimally invasive approaches.

Arthroscopic and Endoscopic Management of Common Complications After Displaced Intra-Articular Calcaneal Fractures

The list of late complications after calcaneal fracture that can be treated through arthroscopic and/or endoscopic approach continues to expand. The late complications of calcaneal fractures can be classified into 3 groups: (1) those causing focal hindfoot or ankle pain, (2) those causing functional deficit, and (3) those present with diffuse and poorly localized pain. Many group 1 and some group 2 complications can be managed arthroscopically and/or endoscopically. There are usually multiple coexisting sources of the pain. Careful evaluation and analysis of a problem and detailed surgical planning with combination of arthroscopic/endoscopic and open procedures are key to success.

Endoscopic Flexor Hallucis Longus Transfer for Chronic Noninsertional Achilles Tendon Rupture

BACKGROUND:

Operative management of chronic Achilles tendon ruptures is challenging, and numerous techniques have been described. Risk of infection and wound breakdown have been described after open techniques, and minimally invasive methods have been proposed to avoid them. The aim of this study was to describe the clinical and radiological results obtained after endoscopic flexor hallucis longus (FHL) tendon transfer in patients with chronic Achilles tendon rupture.

METHODS:

Between 2012 and 2015, a total of 22 patients were endoscopically treated for chronic Achilles tendon rupture. Mean age was 69 years (range, 59-84 years). Mean follow-up was 30.5 months (range, 18-46 months). Preoperative magnetic resonance imaging (MRI) was obtained and tendon gap measured. An MRI was obtained at 9 to 12 months following surgery to evaluate Achilles tendon changes.

RESULTS:

Preoperative MRI examination showed a mean tendon gap of 6.3 cm (range, 3-10.7 cm). The MRI control was obtained only in 12 patients, and a normal or close to normal Achilles tendon was observed in all but 1 patient. The mean American Orthopaedic Foot & Ankle Society score increased from 55 preoperatively (range, 26-75) to 91 (range, 74-100) at final follow-up. All patients returned to their daily activities without difficulties. No patients reported complaints or symptomatic deficits of great toe flexion strength. No major complications were encountered.

CONCLUSION:

Chronic Achilles tendon ruptures were successfully treated by an all-endoscopic procedure. The endoscopically assisted FHL transfer provided excellent results while benefiting from the minimally invasive procedure advantages. However, it entailed some technical challenges and may not be suitable for less experienced surgeons.

LEVEL OF EVIDENCE:

Level IV, retrospective case series.

Arthroscopic and Endoscopic Management of Posttraumatic Hindfoot Stiffness

Ankle, hindfoot, and toe stiffness can result from hindfoot trauma. It can be due to capsular fibrosis, tendon adhesion, muscle fibrosis, or malunion. For symptomatic stiffness that is resistant to nonoperative treatment, operative treatment should be considered. It is important to tackle the sources of stiffness, and careful preoperative clinical assessment is the key for proper formulation of the surgical plan. Whenever possible, arthroscopic/endoscopic surgery is preferable to open surgery because less extensive dissection and small surgical incisions allow immediate vigorous mobilization of the foot and ankle.

Flexor Hallucis Longus Tenosynovitis and First Metatarsophalangeal Synovitis After Penetrating Nail Prick Injury: Treated by Zone 3 Flexor Hallucis Longus Tendoscopy and Metatarsosesamoid Arthroscopy

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.

Endoscopic Adhesiolysis of Flexor Hallucis Longus Muscle

Adhesion of the flexor hallucis longus (FHL) muscle to the distal tibia can occur after distal tibial fracture, distal fibular fracture, low tibial osteotomy, soft-tissue injury at the posterior ankle, subclinical compartment syndrome of the distal deep posterior compartment of the leg, or Volkmann contracture after deep posterior compartment syndrome of the leg. The purpose of this Technical Note is to report the endoscopic approach of FHL muscle adhesiolysis. It is indicated in patients with symptomatic adhesion of the FHL muscle and contraindicated if there is entrapment of the FHL muscle or tendon in the fracture callus or if there is extensive fibrosis and contracture of the FHL muscle as a result of Volkmann contracture after deep posterior compartment syndrome of the leg.

Arthroscopic Curettage and Bone Grafting of Bone Cysts of the Talar Body

Talar bone cysts can develop as a result of osteochondral lesions of the talus. This can be a source of deep ankle pain. Open debridement and bone grafting of the bone cysts requires extensive soft tissue dissection and malleolar osteotomy. Removal of normal cartilage of the talus is frequently required to approach the bone cysts. Alternatively, the cysts can be grafted arthroscopically with minimal disruption of the normal cartilage surface. The key to success is careful preoperative planning with a computed tomogram of the ankle. Bone cyst of the posterior half of the talar body can be grafted via posterior ankle endoscopy. Bone cyst of the anterior half of the talar body can be debrided and grafted via anterior talar osseous portals. The purpose of this technical note is to describe a minimally invasive approach of curettage and bone grafting of the talar bone cysts with preservation of the articular surfaces.

Endoscopic Calcaneoplasty and Achilles Tendoscopy With the Patient in Supine Position

Insertional and non-insertional Achilles tendinopathy is usually treated conservatively. Surgery is indicated if conservative treatment fails to relieve the pain. Endoscopic surgery has the advantages of less morbidity, a shorter operating time, reduced postoperative pain, and a lower rate of wound and soft-tissue healing problems. Patients will have a short recovery time and quickly resume work and sports because of less soft-tissue disruption. Moreover, the pathology can be better differentiated and precisely treated. Achilles tendoscopy is classically performed with the patient in the prone position, whereas endoscopic calcaneoplasty can be performed with the patient in the prone or supine position. This technical note describes the technique of Achilles tendoscopy and endoscopic calcaneoplasty with the patient in the supine position. This has the advantages of more ergonomic hand motion for the Achilles tendon debridement, easier access to the ventral surface of the Achilles tendon, and better orientation of the inside structures; moreover, concomitant chondral lesions of the ankle can be dealt with arthroscopically.

Arthroscopic Capsular Release of the Ankle Joint

Adhesive capsulitis of the ankle is also known as frozen ankle and results in marked fibrosis and contracture of the ankle capsule. Arthroscopic capsular release is indicated for symptomatic frozen ankle that is resistant to conservative treatment. It is contraindicated for ankle stiffness due to degenerative joint disease, intra-articular malunion, or adhesion of the extensors of the ankle. The procedure consists of endoscopic posterior ankle capsulectomy and arthroscopic anterior ankle capsulotomy. It has the advantages of being minimally invasive surgery and allowing early postoperative vigorous mobilization of the ankle joint.

Endoscopic Removal of Loose Bodies of the Posterior Ankle Extra-articular Space Arising From Flexor Hallucis Longus Tenosynovial Osteochondromatosis

Loose bodies of the posterior ankle can occur either at the posterior recess of the ankle or subtalar joint or at the posterior ankle extra-articular space. Loose bodies at the extra-articular space can be a result of tenosynovial chondromatosis of the tendons of the posterior ankle, especially the flexor hallucis longus tendon. Endoscopic removal of loose bodies of the posterior ankle extra-articular space is indicated for symptomatic cases that are not improved by conservative treatment. It is contraindicated if there is active infection at the planned portal sites or the surgeon is not familiar with the technique of posterior ankle endoscopy. Systematic assessment of the different parts of the posterior ankle will minimize the risk of loose body retention.

Endoscopic Resection of the Tarsal Tunnel Ganglion

The tarsal tunnel ganglion is a cause of posterior tarsal tunnel syndrome. Open resection of the ganglion calls for release of the flexor retinaculum and dissection around the tibial neurovascular bundle. This can induce fibrosis around the tibial nerve. We report the technique of endoscopic resection of the tarsal tunnel ganglion. It is indicated for tarsal tunnel ganglia arising from the adjacent joints or tendon sheaths and compressing the tibial nerve from its deep side. It is contraindicated if there is other pathology of the tarsal tunnel that demands open surgery; if the ganglion compresses the tibial nerve from its superficial side, which calls for a different endoscopic approach using the ganglion portal; or if an intraneural ganglion of the tibial nerve is present. The purpose of this technical note is to describe a minimally invasive approach for endoscopic resection of the tarsal tunnel ganglion.

Decompression of Posterior Ankle Impingement With Concomitant Anterior Ankle Pathology by Posterior Ankle Arthroscopy in the Supine Position

Posterior ankle endoscopy is a safe and effective approach for treatment of posterior ankle impingement. This is usually performed with the patient in prone position. The purpose of this technical note is to describe an arthroscopic approach of decompression of posterior ankle impingement with the patient in supine position. This is indicated if there is posterior ankle impingement together with other ankle pathology requiring anterior ankle arthroscopy. This approach allows treatment of both anterior ankle and posterior ankle pathology with the patient in the supine position. Concomitant anterior ankle arthroscopy can be performed with the usual orientation without the need of change of patient's position.

Posterior ankle and hindfoot endoscopy: A cadaveric study

BACKGROUND

The list of indications of posterior ankle endoscopy is expanding and includes various soft tissue and bony pathologies of the posterior ankle. Some of the indications, e.g. release of frozen ankle, debridement of posteromedial soft tissue impingement of the ankle and debridement or fixation of the posteromedial osteochondral lesion of the talus, require approach to the posterior ankle medial to the flexor hallucis longus tendon. The purpose of this study was to assess the risk of injury to the posterior tibial neurovascular bundle during posterior ankle endoscopy.

METHODS

Fourteen fresh frozen foot and ankle specimens were used. A metal rod was inserted into the posteromedial, posterolateral and modified posteromedial portals and touched the medial border of the posterolateral talar tubercle and the posteromedial corner of the ankle mortise in turn. The neurovascular bundle and FHL tendon were examined for any kink.

RESULTS

The neurovascular bundle was kinked in all specimens (100%) with the rod at the posteromedial corner of the ankle mortise through the posteromedial portal and was kinked in 11 specimens (79%) with the rod through the modified posteromedial portal. The neurovascular bundle was kinked in 1 specimen (7%) with the rod through the posterolateral portal.

CONCLUSIONS

The neurovascular bundle was at risk during instrumentation of the posteromedial ankle through the posteromedial portal but was safe through the posterolateral portal.

Endoscopic Loose Body Removal From Zone 2 Flexor Hallucis Longus Tendon Sheath

Tenosynovial chondromatosis can occur in the flexor hallucis longus tendon sheath. Complete synovectomy and removal of the loose bodies comprise the treatment of choice. An open procedure requires extensive soft-tissue dissection because the flexor hallucis longus tendon is a deep structure except at the hallux. A tendoscopy approach to synovectomy and removal of loose bodies has the advantage of minimally invasive surgery. This technical note outlines pearls and pitfalls and provides a step-by-step guide to performing this procedure.

Safe Zone for the Plantar Portal: A Cadaveric Study

BACKGROUND

Understanding the plantar nerve anatomy is crucial for safe endoscopic surgery of the sole. We aimed to anatomically dissect the lateral aspect and soles of cadaveric feet to investigate the safety of peroneus longus tendoscopy with a plantar lateral portal and the safe zones for plantar portals.

METHODS

We studied 36 feet of 24 cadavers (mean age, 86.5 years). A cannula for 2.7-mm scope was inserted from the plantar lateral portal to the peroneus longus tendon, and the positional relationship between the cannula and sural nerve was observed. Then, the soft tissue of the sole was dissected, and the relationships between the plantar nerve and flexor digitorum longus tendon and flexor hallucis longus tendon was observed. The plantar nerve course was digitally imaged and uploaded into Image J software to determine nerve position. We further observed the positional relationship between the cannula and plantar nerve.

RESULT

The mean minimum distance between the cannula and sural nerve was 13.8 mm, and the closest distance was 4.2 mm, allowing for the relatively safe creation of a plantar lateral portal. The use of the plantar lateral portal and evaluation of the peroneal tendon was safe with respect to the lateral plantar nerve as the nerve was in a different tissue layer of the foot. Dissection of the plantar foot demonstrated a relatively safe zone, 36.4% to 56% along a line between the medial aspect of the base of the first metatarsal bone to the proximal tip of the fifth metatarsal. This region may allow for a plantar endoscopic portal; however an anatomic variation may result in the plantar nerve being within this zone. The flexor digitorum longus tendon and peroneus longus tendon passed through the deep layer of the relatively safe zone.

CONCLUSION

Peroneus longus tendoscopy was relatively safe to perform from a plantar lateral portal. No neurovascular structure exists on the slightly medial aspect of the central region of the sole, potentially allowing for a relatively safe creation of plantar central portal. An approach from the plantar central portal to the flexor digitorum longus tendon, flexor hallucis longus tendon, and peroneus longus tendon allows for a greater range of vision and treatment options as compared with conventional approaches. The combination of the plantar central portal with portals such as the plantar lateral portal may further the development of endoscopic surgery of the sole.

CLINICAL RELEVANCE

We found the anatomic characteristics of a relatively safe zone for the plantar portal for plantar lateral portal.

Endoscopic Release of Master Knot of Henry

A post-traumatic partial tear of the flexor hallucis longus tendon at the master knot of Henry and the resultant fibrosis of the knot can result in pain at the medial foot arch or posteromedial ankle pain with trigger hallux. Open debridement of the master knot of Henry is indicated if the symptoms do not improve with nonoperative treatment. The open procedure requires extensive soft-tissue dissection because the master knot of Henry is a deep structure. Endoscopic release of the master knot of Henry is an alternative to the open procedure and has the advantage of less surgical trauma and potential for less chance of recurrence of fibrosis of the master knot of Henry.

Endoscopic-Assisted Flexor Hallucis Longus Transfer: Harvest of the Tendon at Zone 2 or Zone 3

Flexor hallucis longus (FHL) tendon transfer is indicated for reconstruction of the Achilles tendon with a gap larger than 5 cm. The tendon can be harvested at zone 2 or zone 3 by minimally invasive techniques with the advantage of minimal soft-tissue dissection. The tendon can be harvested under the sustentaculum tali by zone 2 FHL tendoscopy. It is adequate for FHL transfer to the posterior calcaneal tubercle. If a double-thickness reconstruction of a huge gap of the Achilles tendon is indicated, the tendon can be harvested at the level of the hallux by means of a tendon stripper. However, the interconnection tendon of the master knot of Henry can be split together with the FHL or flexor digitorum longus tendon instead of being cut. Zone 2 FHL tendoscopy can be used to release the split tendon to complete the FHL harvest.

Arthroscopic Synovectomy for Zone 2 Flexor Hallucis Longus Tenosynovitis

Tenosynovitis of the flexor hallucis longus tendon is a condition typically found in ballet dancers and sometimes in soccer players and is related to chronic overuse. It mostly involves the portion of the tendon behind the ankle joint. However, the portion of the tendon under the sustentaculum tali can also be involved. Open synovectomy requires extensive dissection. We report the technique of arthroscopic synovectomy of the deep portion of the flexor hallucis longus.

Tenosynovial Osteochondromatosis of the Flexor Hallucis Longus Tendon Treated by Tendoscopy

Tendosynovial chondromatosis of the foot and ankle is a rare disease entity. We reported 3 patients with tenosynovial osteochondromatosis of flexor hallucis longus. They were successfully treated by arthroscopic synovectomy and removal of the loose bodies.

Endoscopic adhesiolysis of the flexor hallucis longus muscle

Flexor hallucis longus muscle can adhere to the distal tibia after tibial fracture. The patient may complain of deep posteromedial ankle pain, checkrein deformity of the hallux, hallux flexus or development of hallux rigidus. Surgical treatment of release of the FHL muscle or lengthening of the FHL tendon has been proposed. We described an endoscopic approach of release of the FHL muscle from the distal tibia with the advantage of minimal soft tissue dissection.

LEVEL OF EVIDENCE

Therapeutic Level V: Expert Opinion/Technique.

Tendoscopic Excision of an Intratendinous Ganglion in the Flexor Hallucis Longus Tendon: A Case Report

Intratendinous ganglion cysts are rare lesions of unknown etiology that originate within a tendon. We report the case of a 34-year-old female with an intratendinous ganglion in the plantar portion of the flexor hallucis longus tendon. The intratendinous ganglion recurred after ultrasound-guided needle aspiration. Tendoscopic excision of the intratendinous ganglion cyst achieved a satisfactorily result without recurrence.

Arthroscopic ganglionectomy of the foot and ankle

PURPOSE

To study the efficacy of arthroscopic ganglionectomy in the management of ganglia of the foot and ankle.

METHODS

From 2006 to 2010, arthroscopic ganglionectomy was performed for 89 ganglia in the foot and ankle of 88 patients. Clinical and intra-operative details were reviewed retrospectively.

RESULT

Ganglion stalk was identified in 6 % of the cases. The overall rate of presence of pathology was 26 %. The overall rate of recurrence or residual lesion was 12 % with high recurrent rate for extensor tendon ganglia and toe pulp ganglia.

CONCLUSIONS

Arthroscopic ganglionectomy of the foot and ankle ganglion by either internal drainage or complete resection is a feasible approach. Good results can be achieved in case of adequate internal drainage of the ganglion to the joints or fibrous tendon sheath.

Peroneal tendoscopy

Peroneal tendoscopy is an innovative technique that allows visualization of the tendons from the myotendinous junction to the peroneal tubercle, together with adjacent anatomic structures such as the recently unveiled vincula. Through a minimally invasive approach, it is possible to diagnose and treat several disorders, such as common tenosynovitis, accessory muscles, hypertrophic bony prominences, and thickened vincula, that can cause pain and tendon catching. Surgical morbidity and postoperative pain are significantly reduced when compared with open procedures. In this paper, the main indications for peroneal tendoscopy are discussed, the available literature is reviewed, and the surgical technique is described. Advantages of this procedure and current limitations are also presented. Anatomic and histological studies were also performed in order to verify: 1) the feasibility of peroneal tendoscopy for evaluation of peroneal tendons, using cadaver specimens; 2) the presence of nervous tissue in cadaver peroneal vincula as well as in tendoscopic vincula biopsies from patients undergoing surgery for chronic lateral ankle pain.

Flexor digitorum longus tendoscopy

The flexor digitorum longus tendon is susceptible to injury along its entire course, and lacerations, ruptures, longitudinal tears, and stenosing tenosynovitis have all been reported. Moreover, this tendon is commonly used for reconstruction of dysfunctional posterior tibial and Achilles tendons. Traditionally, surgery involving the flexor digitorum longus tendon was performed via open incision. We describe a technique of flexor digitorum longus tendoscopy that may encourage the future development of a minimally invasive approach to flexor digitorum longus tendon procedures.

Posterior ankle and subtalar arthroscopy: indications, technique, and results

Over the decades, arthroscopy has grown in popularity for the treatment of many foot and ankle pathologies. While anterior ankle arthroscopy is a widely accepted technique, posterior ankle/subtalar arthroscopy is still a relatively new procedure. The goal of this review is to outline the indications, surgical techniques, and results of posterior ankle/subtalar arthroscopy. The main indications include: 1) osteochondral lesions (of subtalar and posterior ankle joint); 2) posterior soft tissue or bony impingement; 3) os trigonum syndrome; 4) posterior loose bodies; 5) flexor hallucis longus (FHL) tenosynovitis; 6) posterior synovitis; 7) subtalar (or ankle) joint arthritis; 8) posterior tibial, talar, or calcaneal fractures (for arthroscopic reduction and internal fixation). Although posterior ankle/subtalar arthroscopy has shown to be safe and effective in the treatment of many of the above mentioned conditions, thorough knowledge of the anatomy, correct indications, and a precise surgical technique are essential to produce good outcomes.

Treatment of chronic noninsertional Achilles tendinopathy with endoscopic Achilles tendon debridement and flexor hallucis longus transfer

Decompression with debridement has been shown to be effective in pain management in patients with chronic mid-portion Achilles tendinopathy; however, augmentation with the flexor hallucis longus tendon can provide additional mechanical support. The technique of endoscopic debridement of the tendinopathic tendon together with flexor hallucis longus transfer is described to treat patients suffering from chronic painful noninsertional Achilles tendinopathy with the potential advantage of minimally invasive surgery.

LEVELS OF EVIDENCE

Therapeutic, Level IV.

Whole length flexor hallucis longus transfer with a minimally invasive approach: technique tip

Level of Evidence: V, Expert Opinion

Tendoscopy of the ankle

In this article, the peroneus longus and brevis, posterior tibial, Achilles, and flexor hallucis longus tendon endoscopy are discussed individually. Tendoscopic indications and surgical technique are highlighted.

"Intersection syndrome" of the foot: treated by endoscopic release of master knot of Henry

Intersection syndrome of the forearm is a painful condition in the area where the muscle bellies of the abductor pollicis longus and extensor pollicis brevis cross the common wrist extensors. A similar case of the foot with marked fibrosis at the interconnection of flexor hallucis longus and flexor digitorum tendons is reported and the fibrous interconnection was extended proximally. This was successfully treated with endoscopic release of the master knot of Henry.

Extensor tendoscopy of the ankle

The extensor digitorum longus muscle (EDL) arises from the upper three-quarters of the extensor surface of the fibula, the interosseous septum and from a small area of the tibia across the superior tibiofibular joint. It forms its four tendons which are restrained by the superior and inferior extensor retinacula. The two retinacula prevent the EDL and extensor hallucis longus (EHL) tendons from bow stringing. The inferior extensor retinaculum also contributes to the stability of the subtalar joint. Extensor tendoscopy has been performed in 3 patients and no neural injury was noted.

"Intersection syndrome" of the foot: treated by endoscopic release of master knot of Henry

Intersection syndrome of the forearm is a painful condition in the area where the muscle bellies of the abductor pollicis longus and extensor pollicis brevis cross the common wrist extensors. A similar case of the foot with marked fibrosis at the interconnection of flexor hallucis longus and flexor digitorum tendons is reported and the fibrous interconnection was extended proximally. This was successfully treated with endoscopic release of the master knot of Henry.