Flexor Hallucis Longus Tendon Sheath Research Articles

Imaging evaluation of extraarticular posterior loose bodies in varus ankle osteoarthritis.

Purpose: Multiple loose bodies (LBs) are often found in patients with varus ankle osteoarthritis (OA). This study aimed to investigate the characteristics of extra-articular posterior ankle LBs in patients with varus ankle OA. We also sought to determine whether there were variations in the characteristics of LBs according to the degree of ankle OA. Methods: We retrospectively reviewed 50 patients who had appeared posterior extraarticular LBs on preoperative ankle imaging among the patients who underwent operative treatment for varus ankle OA from March 2011 to February 2023. We categorized the entire patient cohort into four groups according to the degree of ankle arthritis (Takakura stage II, IIIA, IIIB, and IV). Size, number, and location of LBs were evaluated using preoperative computed tomography and magnetic resonance imaging. Results: 142 LBs were identified (mean size: 11.5mm); 76.8% were located within the flexor hallucis longus (FHL) tendon sheath, 20.4% in the posterior recess, and 2.8% in the flexor digitorum longus tendon sheath. Average LB size was significantly larger in Takakura stage IIIB and IV patients (p < .05), and the LB number was significantly lower in stage II patients (p = .013). Conclusion: Extra-articular posterior LBs in varus ankle OA are predominantly located within the FHL tendon sheath and were larger in Takakura stages IIIB and IV patients.Level of Evidence: Level III. Retrospective comparative study.

Migratory Loose Bodies from the Ankle Joint into the Flexor Hallucis Longus Tendon Sheath

Objective: Loose bodies resulting from any form of osteochondral insult can migrate out of their intra-articular position to adjacent compartments. This retrospective study aims to illustrate the phenomenon of loose bodies migration from the ankle joint into the flexor hallucis longus (FHL) tendon sheath. Materials and Methods: Cases of loose bodies in the FHL tendon sheath were identified from the authors' radiological database by way of keyword interrogation, covering the modalities of CT, MRI, and ultrasound over a period of 11 years. The imaging features of the loose bodies were recorded, together with the presence of ankle instability and osteoarthritis. Patient demographics and relevant history, including trauma and surgery, were collected. Results: Thirty-four cases including 33 patients, with a total of 125 loose bodies in the FHL tendon sheath, were identified. There were 58 loose bodies (46.4%) in Zone 1 of the FHL tendon sheath, 65 loose bodies (52%) in Zone 2, and 2 loose bodies (1.6%) in Zone 3. All patients had features of ankle osteoarthritis on imaging, 14 of which had imaging features of ankle instability, and 19 patients had previous ankle trauma. Conclusion: Osteochondral loose bodies originating from the ankle joint can migrate into the FHL tendon sheath. It is important to recognise this phenomenon as a distinct entity, different from primary tenosynovial chondromatosis of the FHL tendon sheath, which may have a different surgical management and clinical outcome. Detection of FHL tendon sheath loose bodies should also prompt closer examination for articular disease in the ankle joint.

Operative Treatment for Ganglion Cyst of Flexor Hallucis Longus Sheath.

Intractable hallucal ganglion cysts (HGCs) are often a symptomatic and recurrent condition. Its connection with the ankle joint is not well understood. Our aim was to evaluate the relationship between tenosynovitis of the flexor hallucis longus (FHL) tendon at the level of the ankle with formation of an HGC. In addition, we sought to analyze the outcomes of cyst excision combined with ankle capsulorrhaphy. Nineteen patients with HGC who underwent surgical intervention were included between June 2016 and June 2019. Eight had known recurrences. Ankle arthrography and cyst excision were performed on all patients. Clinical evaluations included the American Orthopaedic Foot & Ankle Society (AOFAS) scores, visual analog scale (VAS), and evaluation of postoperative complications. The mean follow-up period was 16.5 ± 8.6 months. Thirteen of the 19 HGCs (68.4%) had a connection with the FHL tendon sheath. Combined with ankle capsulorrhaphy, there was no recurrence after cyst excision. The VAS score decreased from 2.1 ± 1.5 to 0.4 ± 0.8, and AOFAS score significantly improved from 84.3 ± 8.7 to 97.4 ± 5.2 at final follow-up (P < .001). Most of these patients had a connection between the HGC and ankle joint. Ankle arthrography appeared to be useful for diagnosis, and cyst excision combined with ankle capsulorrhaphy was an effective treatment without cyst recurrence. Level IV, case series.

Gout in the Flexor Hallucis Longus Tendon Mimicking Cellulitis: A Case Report

A 65-year-old Japanese man was admitted to our hospital with fever and inflammation of the right ankle. We initiated antibiotics on suspicion of cellulitis. After no clinical improvement, we performed magnetic resonance imaging, which showed a fluid collection in the flexor hallucis longus (FHL) tendon sheath. Synovial fluid analysis revealed monosodium uric crystals. Final diagnosis was FHL tendonitis secondary to gout proven by synovial fluid analysis. To our knowledge, this is the first case report of FHL tendonitis caused by gout. When ankle inflammation is examined in clinical situations, FHL tendonitis caused by gout should be considered.

The accuracy of an injection technique for Flexor hallucis longus tendon sheath: A cadaveric study

BackgroundCorticosteroid injections are used in the conservative treatment of Flexor hallucis longus (FHL) tendinopathy. Studies for imaging guided injection are done, however, the accuracy of blind injection has not yet been studied. PurposeThe aim of this study was to determine the accuracy of a blind injection technique into the FHL tendon sheath. HypothesisWe hypothesize that a blind injections technique into the FHL tendon sheath based on clinical examination has a high accuracy. Study designDescriptive cadaveric study. MethodsTen ankles of human cadavers were blindly injected with radiologic contrast mixed with methylene blue into the FHL tendon sheath. After injection, a CT scan of each ankle was performed to evaluate the location of contrast material. CT scans were reviewed by an experienced musculoskeletal radiologist blinded to the procedure. Anatomic dissection was undertaken to assess the location of the injection fluid. ResultsIn nine ankles the radiological contrast was injected in the FHL tendon sheath. In one cadaver there was a technical problem and was therefore excluded. ConclusionThis study shows that the FHL tendon sheath can be blindly injected based on only clinical examination with high accuracy.Level of evidence: Descriptive cadaveric study.

Ultrasound‐Guided Ganglionectomy of a Flexor Hallucis Longus Ganglion Cyst Using Coablation Technology: A Case Report

A 44-year-old woman with a history of an open ganglionectomy 2 years prior presented with a recurrent ganglion cyst. The ganglion cyst, extending from the flexor hallucis longus tendon sheath, was confirmed with magnetic resonance imaging. The patient declined another surgical incision. An experimental procedure was performed: ultrasound-guided ganglionectomy using a coablation wand. She achieved full symptom resolution, with no recurrence 1 year afterwards. To our knowledge, this is the first case report in the literature describing the use of this instrument for treating a ganglion cyst.

Origin of Satellite Ganglion Cysts with Effusion in the Flexor Hallucis Longus Tendon Sheath around the Hallux.

BackgroundTo describe the clinical and magnetic resonance imaging findings of ganglion cysts with effusion in the flexor hallucis longus tendon sheath around the hallux to evaluate their origin.MethodsPatients with recurrent or painful ganglion cysts around the hallux with effusion in the flexor hallucis longus tendon sheath who underwent surgical treatment at St. Vincent's Hospital from February 2007 to August 2016 were investigated. Surgical indication was a painful or recurrent mass caused by the cystic lesions. Those without effusion of the flexor hallucis longus tendon sheath were excluded. We assessed the clinical and magnetic resonance imaging findings.ResultsMagnetic resonance imaging findings in all patients showed several ganglion cysts around the hallux and large fluid accumulations within the flexor hallucis longus tendon sheath. Regarding the location, six ganglion cysts were on the dorsomedial aspect, one on the plantar medial aspect, seven on the plantar lateral aspect, and one in the toe pulp. Ten patients showed joint effusions in both the metatarsophalangeal and interphalangeal joints, two in the metatarsophalangeal joints, and three in the interphalangeal joints. There were communication stalks with a tail shape or abutment between ganglion cysts with surrounding joint effusions. Intraoperatively, connections between ganglion cysts, the synovial cyst of the flexor hallucis longus tendon sheath, and surrounding joints were seen.ConclusionsSynovial fluid accumulation in the metatarsophalangeal or interphalangeal joint supplies the synovial cyst of the flexor hallucis longus tendon sheath and subsequently ganglion cysts in the hallux. In clinical practice, the surgeon should carefully check surrounding joints with tendon sheaths to prevent recurrence of the ganglion cysts around the hallux.

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.

Arthroscopic Release of Flexor Hallucis Longus Tendon Sheath in Female Ballet Dancers: Dynamic Pathology, Surgical Technique, and Return to Dancing Performance

Stenosing tenosynovitis of the flexor hallucis longus (FHL) tendon is known as a major overuse lesion in female dancers. We describe arthroscopic surgical techniques in relation to the dynamic pathology of the disease. Crepitus and pain on moving the great toe with the ankle in plantar flexion on preoperative examination confirm the diagnosis of FHL stenosing tenosynovitis even if the os trigonum is not evident. The ankle is approached through standard posterolateral and posteromedial portals. A 4.0-mm-diameter 30° arthroscope is used. Soft tissues around the talus are cleared with a motorized shaver and a radiofrequency device. The posterior aspects of the talus, os trigonum, and FHL tendon surrounded by the tendon sheath are visualized. The dynamic pathology of the FHL tendon is well observed on passive motion of the great toe. The prominent bone fragment of the talus is removed and the tendon sheath is cut with a retrograde knife and a motorized shaver from the superior border down to the entrance of the fibro-osseous tunnel. Arthroscopic release of the FHL tendon sheath is a useful and easy method to directly approach the dynamic pathology of FHL tenosynovitis in female ballet dancers.

Posterior Approach for Medial Column Beam Screw in Midfoot Charcot Reconstruction: Technique and Structures at Risk

Charcot neuroarthropathy is frequently recognized as a major cause of morbidity in patients with neuropathic diabetes mellitus. Recently, intramedullary beam screw fixation has been used for midfoot Charcot reconstructions. Ten below-the-knee cadaveric specimens were used to demonstrate an antegrade, posterior approach for placement of a medial column beam screw, with specific attention to the proximity of the anatomic structures at risk. Six structures at risk were identified, including the sural nerve, ankle joint, flexor hallucis longus tendon, Achilles tendon, neurovascular bundle, and peroneal tendon sheath. The sural nerve was the most commonly injured structure, injured in 50% of the limbs. The Achilles and flexor hallucis longus tendons were injured in 20% and the ankle joint in 10% of the limbs. The neurovascular bundle and peroneal tendon sheath were located over 1 cm from the reference guidewire and were considered safe structures in this approach. Our results have demonstrated an alternative posterior approach to the delivery of an intramedullary medial column beam screw, instead of a retrograde technique beginning in the metatarsal heads. Our results have also made clear the need to be aware of the potential for damage to the sural nerve, Achilles tendon, flexor hallucis longus tendon, and ankle joint.

Toe Deformity after Pregnancy due to Fibroma of Tendon Sheath: A Case Report and Review of Literature

Toe Deformity after Pregnancy due to Fibroma of Tendon Sheath: A Case Report and Review of Literature

‘Flexor Hallucis Longus Loose Bodies- An Unusual Cause of Plantar Midfoot Pain’

Midfoot pain is a common complaint but occurs less frequently in the plantar aspect. A myriad of causes have been reported including trauma, plantar fasciitis, Flexor hallucis longus (FHL) or posterior tibial tenosynovitis, midfoot osteoarthritis and stress fractures especially during weight-bearing. The FHL tendon sheath has been shown to communicate with the ankle joint. Osseous bodies can be seen within tendon sheaths especially in synovial chondromatosis. We report a rare case of loose bodies, not secondary to an underlying inflammatory or synovial condition but from the ankle traversing into the FHL tendon sheath, causing pain during weight bearing. We believe this to be the first reported case in English literature.

Hindfoot Endoscopic Findings of Posterior Ankle Impingement Syndrome in Ballet Dancers (SS-56)

Introduction Posterior ankle pain is a common but serious problem in ballet dancers. Certain kinds of pathological conditions have been reported, such as os trigonum (OT) syndrome, fracture of the Stieda process, flexor hallucis longus (FHL) tendinosis and/or tenosynovitis, soft tissue impingement, and so on. They are considered as a pathological unit of posterior ankle impingement syndrome (PAIS). The purpose of this study is to elucidate the pathologies of PAIS and to clarify how to approach and treat these conditions. Methods Between September 2007 and August 2010, 35 feet of 32 patients, including only one foot of a male patient, underwent hindfoot endoscopic surgery due to PAIS. Average age was 19.6 years (range, 12-40) at the time of surgery. The pathological conditions were retrospectively analyzed mainly with operative findings, also referring with X-ray, MRI, and histological findings. Surgical technique presented by van Dijk was applied to all feet. Results Synchondrosis injury (SCI) was detected in 14 feet, synovitis associated with one or more movable os trigonum (mOT) in 12, a fracture (or microfracture) in os trigonum or posterior process of the talus in four, DJD beneath the OT in two. Injury to the FHL tendon matrix was observed in 23 feet, distal insertion of FHL muscle fibers in 12, and anomalous muscle (FDAL) in two. Intermalleolar ligament (IML), which is also called a tibial slip, a part of transverse tibiofibular ligament, or a pseudomeniscoid were found in 21 feet (60%), ranging from 1 to 5 mm in width. Among them, five were adherent to the FHL tendon sheath, and three had behavior linked with the FHL motion, which seemed to undergo posterior ankle impingement. Osteochondral lesion of the medial talar trochlea were observed in two feet, nodular fibrosis in posterior talocalcaneal ligament and marked synovitis in ankle and posterior subtalar joint in one, respectively. A great majority of feet were affected with two or more pathologic conditions, except four feet. 22 feet (62.9%) had combined bony impingement (SCI, mOT, fracture) with FHL tendon injury. Conclusion Bony impingement was the major pathological process, related in more than 90 percent of the patients; special attention, however, should be paid to some other conditions that concomitantly existed. The hindfoot arthroscopic approach has great diagnostic potentials to posterior aspect of ankle and posterior subtalar joint. And also enables to treat bony impingement, IML lesions, and tenolysis of the FHL and/or FDAL tendon. But when repair of the severely injured FHL tendonor extirpation of ganglions on the tendon sheath is necessary, the other approach should be considered.

Cadaveric Study of Zone 2 Flexor Hallucis Longus Tendon Sheath

The purpose of this study was to investigate the anatomy of the zone 2 flexor hallucis longus (FHL) tendon sheath. Dissection of the zone 2 FHL tendon sheath was performed in 12 feet of 6 cadavers. The tendon sheath was subdivided into proximal fibrous (zone 2A) and distal fascial (zone 2B) parts. The lengths of the zone 2A and 2B FHL tendon were measured and represented the length of the corresponding tendon sheaths, and the relation of the medial plantar nerve to each part of the zone 2 FHL tendon sheath was studied. In all specimens there were fibrous and fascial components of the zone 2 FHL tendon sheath. The medial plantar nerve crossed the zone 2B tendon sheaths and then became plantar lateral to the sheath in 7 specimens. The distance between the medial plantar nerve and the orifice of the zone 2A tendon sheath averaged 7.6 mm. The distance between the medial plantar nerve and the junction between zones 2A and 2B averaged 3.2 mm. The distance between the medial plantar nerve and the distal end of the zone 2B tendon sheath averaged 4.2 mm. The mean length of the zone 2A tendon sheath was 35.9 mm, and the mean length of the zone 2B tendon sheath was 30.5 mm. The zone 2 FHL tendon sheath can be subdivided into a proximal fibrous zone (2A) and a distal fascial zone (2B). Because of the close proximity of the medial plantar nerve to the tendon sheath, there is a significant risk of iatrogenic nerve injury when surgical procedures are performed in zone 2B. An understanding of the anatomy of the zone 2 FHL tendon sheath is useful for the safe practice of zone 2 FHL tendoscopy.

Accuracy of Sonographically Guided Posterior Subtalar Joint Injections

The primary purpose of this investigation was to determine the accuracy of 3 different sonographically guided posterior subtalar joint (PSTJ) injection techniques in an unembalmed cadaveric model. A single experienced examiner injected the PSTJs of 12 unembalmed cadaveric ankle-foot specimens using the anterolateral, posterolateral, and posteromedial approaches. The injection order for each specimen was randomized, and each technique was completed with a different-color diluted latex solution. Coinvestigators blinded to the injection technique dissected each specimen and graded the colored latex location as accurate (in the PSTJ), accurate with overflow (within the PSTJ but also in other regions), or inaccurate (no latex in the joint). All 3 sonographically guided PSTJ injection approaches accurately placed latex into the PSTJ (100% accuracy). Latex was also found in adjacent regions in 19.4% (7 of 36) of injections: 8.3% (3 of 36) within the tibiotalar joint, 8.3% (3 of 36) in the peroneal (fibularis) tendon sheath, and 2.8% (1 of 36) in the flexor hallucis longus tendon sheath. The anterolateral approach placed latex outside the PSTJ 25% of the time (3 of 12 injections: 1 tibiotalar and 2 peroneal [fibularis] sheath), the posterolateral approach 25% of the time (3 of 12 injections: 1 tibiotalar, 1 peroneal [fibularis] sheath, and 1 flexor hallucis longus tendon sheath), and the posteromedial approach 8.3% of the time (1 tibiotalar). This cadaveric investigation suggests that all 3 sonographically guided PSTJ techniques may be used to access the PSTJ with a high degree of accuracy. Clinicians should consider sonographically guided PSTJ injections as a favorable alternative to fluoroscopy and computed tomographic guidance when diagnostic or therapeutic image-guided PSTJ injections are indicated.

Quantifying normal ankle joint volume: An anatomic study

Background:Many therapeutic and diagnostic modalities such as intraarticular injections, arthrography and ankle arthroscopy require introduction of fluid into the ankle joint. Little data are currently available in the literature regarding the maximal volume of normal, nonpathologic, human ankle joints. The purpose of this study was to measure the volume of normal human ankle joints.Materials and Methods:A fluoroscopic guided needle was passed into nine cadaveric adult ankle joints. The needle was connected to an intracompartmental pressure measurement device. A radiopaque dye was introduced into the joint in 2 mL boluses, while pressure measurements were recorded. Fluid was injected into the joint until three consecutive pressure measurements were similar, signifying a maximal joint volume.Results:The mean maximum ankle joint volume was 20.9 ± 4.9 mL (range, 16–30 mL). The mean ankle joint pressure at maximum volume was 142.2 ± 13.8 mm Hg (range, 122–166 mm Hg). Two of the nine samples showed evidence of fluid tracking into the synovial sheath of the flexor hallucis longus tendon.Conclusion:Maximal normal ankle joint volume was found to vary between 16–30 mL. This study ascertains the communication between the ankle joint and the flexor hallucis longus tendon sheath. Exceeding maximal ankle joint volume suggested by this study during therapeutic injections, arthrography, or arthroscopy could potentially damage the joint.

Sonographically Guided Flexor Hallucis Longus Tendon Sheath Injection

The purpose of this study was to describe a sonographically guided technique to perform flexor hallucis longus (FHL) tendon sheath injections. Scans were performed with an intermediate-frequency (7.5- to 12-MHz) linear transducer with the scan plane corresponding to the anatomic axial plane and the patients positioned prone. The transducer was placed along the posteromedial ankle with the needle entry point being lateral to the Achilles tendon. A 25-gauge, 1.5-in needle or a 22-gauge spinal needle was positioned directly into the tendon sheath during real-time visualization with injection of a standardized therapeutic mixture (anesthetic and long-acting corticosteroid) at the level of the posterior sulcus for the FHL. Distention of the tendon sheath during real-time visualization was considered a successful injection. Twenty-four injections in 20 patients (12 female and 8 male; age range, 22-64 years) were performed with this technique. In each case, distention of the FHL tendon sheath was obtained as the desired end point. Apart from minor paresthesias from local anesthesia, no long-term complications from these injections have occurred to date. We describe a method to perform sonographically guided injections of the FHL tendon sheath. Sonography provides several distinct advantages as a method to provide guidance for delivery of therapeutic injections. The most important of these is the ability to visualize the needle and make adjustments in real time to ensure that medication is delivered to the appropriate location. Given these advantages, we propose that sonographic guidance provides an excellent alternative in the administration of corticosteroids to the FHL tendon sheath.

A Novel Approach to Flexor Hallucis Longus Tenography

This article presents a technically simple and more accurate approach to flexor hallucis longus (FHL) tenography than any we found reported in the literature. Tenography is used to evaluate and treat tenosynovitis. Standard FHL tenography protocol involves either direct percutaneous access of the FHL synovial sheath posterior to the medial malleolus or indirect filling of the FHL sheath from an injection of the flexor digitorum longus (FDL) tendon sheath, which often communicates with the FHL tendon sheath. However, with these methods, difficulty entering the FHL sheath may be encountered. We adapted our technique to access the FHL sheath as it courses below the sustentaculum talus. Our early experience with five cases using this technique reflects a 100% success rate with accurate needle placement within the FHL tendon sheath, thereby improving procedural efficiency.

Posterior ankle impingement syndrome: MR imaging findings in seven patients.

To report the magnetic resonance (MR) imaging findings in seven patients with posterior ankle impingement (PAI) syndrome. Seven patients-three ballet dancers, one badminton player, one soccer player, one hockey player, and one construction worker-who presented with posterior ankle pain were assessed with MR imaging. Their clinical records and imaging studies were reviewed. The MR imaging studies were assessed for the presence of abnormal bone marrow signal intensity, osseous lesions, and soft-tissue abnormalities. One patient was treated surgically. In all patients, MR imaging demonstrated abnormal bone marrow signal intensity in the os trigonum and/or lateral talar tubercle, consistent with bone contusions. Two patients had a fragmented os trigonum or lateral tubercle, and two had a pseudoarthrosis of the posterolateral talus. Increased signal intensity was seen with distention of the posterior recess of the tibiotalar joint in two patients and with distention of the posterior recess of the subtalar joint in four patients. Three patients had fluid accumulation in the flexor hallucis longus tendon sheath. Bone contusions of the lateral talar tubercle and os trigonum are prevalent MR imaging findings of PAI syndrome. MR imaging clearly depicts the osseous and soft-tissue abnormalities associated with PAI syndrome and is useful in the assessment of this condition.

Modified arthroscopic excision of the symptomatic os trigonum and release of the flexor hallucis longus tendon: Operative technique and case study

This article presents an operative technique for modified arthroscopic excision of the symptomatic os trigonum and release of the flexor hallucis longus tendon sheath. The procedure uses two stacked posterolateral subtalar joint portals, rather than the customary anterolateral and posterolateral portal combination. By visualizing the os trigonum with an arthroscope positioned in a distal portal and introducing instrumentation through a proximal portal, the ossicle may be quickly exposed and excised with minimal dissection. A case study with a 22-month follow-up and a discussion of os trigonum syndrome are included to illustrate this procedure as an alternative to open excision or traditional arthroscopic excision.