Flexor hallucis longus impingement syndrome: A case report.

INTRODUCTION AND IMPORTANCE: Long-term friction of the FHL tendon's sheath (caused by sporting activities) can result in tendinitis, which causes pain in the foot and ankle and consequently interferes with everyday life and foot function. The FHL tendon is crucial for maintaining foot stability and can be damaged by overuse. FHL tendinitis can be also caused by inflammatory tendon sheath filled. Arthroscopy can play a role in the diagnosis and treatment of this condition. CASE PRESENTATION: A 28-year-old female with left ankle pain was brought to our clinic after slipping on a train platform nine months ago. X-rays and MR imaging revealed a complete tear of the ATFL, minimal joint effusion, and a bony protrusion causing impingement. Arthroscopic surgery was performed, and the patient's pain sensation improved to 0-1 in the visual analogue scale (VAS) within three weeks. The Foot and Ankle Ability Measure (FAAM) score increased from 8 % to 100 %, and the patient was able to walk and perform daily activities normally. CLINICAL DISCUSSION: The FHL tendon sheath begins at the posterior tubercles of the talus and forms a fibroosseous tunnel along the medial calcaneus, potentially leading to impingement during ankle or hallux dorsiflexion. FHL tendon impingement and tendinitis share clinical manifestations, and if conservative treatments (NSAIDs, physical therapy) fail after 6 months, arthroscopic surgery is recommended for its minimally invasive benefits. Both arthroscopic and open surgical techniques yield positive outcomes for FHL pathologies; however, they carry risks such as neurovascular complications, highlighting the necessity for surgical precision and expertise. CONCLUSION: We concluded that in this case, FHL impingement was caused by the bony protrusion from Stieda process fragment. It was demonstrated that the arthroscopic surgery with loose body removal was successful and practical.

Anatomical evaluations of the adipose tissue surrounding the flexor hallucis longus tendon.

This study aimed to evaluate the presence of adipose tissue surrounding the flexor hallucis longus (FHL) tendon through gross dissection and magnetic resonance imaging (MRI). Grossly, we observed the FHL tendon and surrounding tissues in nine cadavers. Using MRI, we quantitatively evaluated each tissue from the horizontal plane in 40 healthy ankles. Macroscopic autopsy revealed the presence of adipose tissue behind the ankle joint between the FHL and fibula, and horizontal cross-sections showed an oval-shaped adipose tissue surrounding the tendon. The cross-sectional area on MRI was 14.4 mm2 (11.7-16.7) for the FHL tendon and 120.5 mm2 (100.3-149.4) for the adipose tissue. Additionally, the volume of the adipose tissue was 963.3 mm3 (896.2-1115.6). There is an adipose tissue around FHL tendon and maybe this close anatomical relationship might influence the function of the tendon and be involved in its pathologies.

Four Tendinous Slips of Flexor Hallucis Longus Tendon: A Case Report.

Interindividual variability presents a rich field of study in medical sciences. During a cadaveric dissection at Louisiana State University Health Sciences Center, a rare anatomical variation was discovered in the pedal anatomy of a female cadaver. Medical students, while dissecting the sole of the foot, identified a variant tendinous structure. This aberrant tendinous slip from the flexor hallucis longus (FHL) extended to the lateral four tendons of flexor digitorum longus (FDL) along the plantar aspect of the foot. The discovery suggested that the FHL shares a functional relationship with the FDL. Application of tension to the FHL was found to result in simultaneous flexion motion in the lesser toes, from the second to the fifth digit. The presence of this anatomical variant holds considerable importance for surgical interventions, especially as a potential graft source in tendon reconstructions, warranting its documentation in this report.

Effect of simultaneous bilateral surgery or simultaneous arthroscopic ankle lateral ligament repair in hindfoot endoscopic surgery for posterior ankle impingement syndrome in athletes.

BACKGROUND: Posterior ankle impingement syndrome (PAIS) is sometimes complicated by bilateral cases and lateral ankle ligament injuries. Reports on bilateral surgery for PAIS and simultaneous surgery for lateral ankle ligament injury are scarce in the literature. METHODS: We present a 2-year follow-up of 76 athletic patients who underwent endoscopic hindfoot surgery for PAIS. Patients were divided into those who underwent unilateral or simultaneous bilateral surgery and PAIS surgery alone or simultaneous bilateral PAIS surgery without arthroscopic ankle lateral ligament repair. RESULTS: All patients returned to full athletic activities postoperatively. There was no difference in all subscales of the SAFE-Q score between groups except for mean days after surgery for full return to athletic activities. CONCLUSION: Simultaneous bilateral surgery and simultaneous arthroscopic lateral ankle ligament repair had no negative effect on subjective clinical evaluation 2 years after surgery in hindfoot endoscopic surgery for PAIS. LEVEL OF EVIDENCE: III, retrospective case-control study.

Intermittent flexor hallucis longus dislocation: ultrasound findings.

We report a case of intermittent dislocation of the flexor hallucis longus at its passage in the retro-malleolar area, related to a post-traumatic detachment of the retrotalar pulley from the medial tubercle of the talus. High-resolution ultrasound depicted the anterior dislocation of the tendon during dynamic stress, by asking the patient to flex his hallux against the examiner resistance, with the ankle in slight dorsiflexion. The tendon normally relocated after the dynamic maneuver. Tendon dislocation was associated with a painful snap.

Free vascularized fibula leads to hallux toe flexion deformity due to ischemic muscle contracture of flexor hallucis longus.

BACKGROUND: This study aimed to investigate the incidence of toe flexion deformity after fibular free flap transplantation and to analyze the etiology of the deformity. METHODS: Fifty patients underwent vascularized fibular free flap transplantation were retrospectively included. Statistical analysis examined correlations between deformity occurrence and resected fibula length and residual distal fibula length using the χ2 test. Doppler ultrasound and anatomical evaluations were conducted. RESULTS: Flexion deformity of the first toe was observed in all patients (100%), exacerbated by ankle dorsiflexion. χ2 test revealed no significant correlation between fibula length, distal residual fibula length, and flexion deformity. Doppler ultrasound revealed elevated echoes and blurred textures in the flexor hallucis longus post-fibular transplantation, while anatomical evaluation confirmed the peroneal artery as its primary nutrient supplier. CONCLUSION: This study reports a 100% incidence of toe flexion deformity post-transplantation. The deformity correlated strongly with ischemic contracture of the flexor hallucis longus.

Ganglion Cysts in the Hallux: A Report of Two Cases.

We experienced two cases of intractable hallux ganglion. Case 1 was a 70-year-old woman with a recurrent ganglion and severe pain on the plantar aspect of the hallux. The continuity between the mass and the distal flexor hallucis longus (FHL) tendon sheath was confirmed. The ganglion was resected along with part of the tendon sheath, and the tendon sheath was incised as proximally as possible. Case 2 was a 69-year-old woman with a ganglion on the dorsal aspect of the interphalangeal joint that repeatedly ruptured due to thinning of the skin. The ganglion was contiguous with the joint capsule but not with the FHL tendon sheath, and the entire capsule was resected. There was no recurrence one year after surgery in either case. The risk of recurrence of an intractable hallux ganglion can be reduced by blocking the synovial supply route and lowering the pressure inside the joint or tendon sheath.

Pigmented villonodular synovitis of the flexor hallucis longus tendon: A rare cause of leg pain in a 12-year-old girl.

Pigmented villonodular synovitis is an uncommon benign neoplastic proliferation associated with the synovium, bursa, or tendon sheaths; most commonly occurring in the third to fourth decade of life. It is rare in children and may be painful or painless. Magnetic resonance imaging is the diagnostic study of choice. In this report, the radiologic, ultrasound, and magnetic resonance imaging findings of pigmented villonodular synovitis of the flexor hallucis longus in a 12-year-old girl are discussed. We briefly review the surgical findings as well. To our knowledge, this is the first case report that simultaneously synthesizes the imaging findings of 3 diagnostic imaging modalities for optimal visualization and is the youngest reported case of pigmented villonodular synovitis of the flexor hallucis longus tendon.

Flexor hallucis longus tendon morphology in dancers clinically diagnosed with tendinopathy.

PURPOSE: The unique demands of dance technique make dancers more prone to certain pathologies especially of the foot and ankle. Flexor hallucis longus (FHL) tendinopathy, colloquially known as "dancer's tendinopathy," is common in dancers and not well studied. The purpose of this study was to assess if morphological alterations in tendon structure occur as an adaptive response to dance activity by comparing the FHL tendon in dancers to non-dancers, and if pathology further alters tendon morphology in dancers clinically diagnosed with tendinopathy. METHODS: Three groups of ten participants were recruited (healthy non-dancers, healthy dancers, and dancers with FHL tendinopathy). Ultrasound images of the FHL tendons were analyzed for macromorphology by measuring the tendon thickness. The micromorphology was analyzed by determining the peak spatial frequency radius of the tendon. Our study did find increased tendon proper and composite tendon thickness in dancers with tendinopathy but no difference between asymptomatic dancers and non-dancers. RESULTS: There was no significant difference in micromorphology found between any of the groups. As expected, dancers with tendinopathy demonstrated increased composite tendon and tendon proper thickness however, there was no evidence of adaptive thickening of the FHL tendon as might be expected for the dance population. There was also no evidence of micromorphological changes in the presence of clinically diagnosed FHL tendinopathy. CONCLUSION: Because of the limited normative data for this pathology, these results can help improve diagnosis and therefore treatment for dancers to decrease the impact of this injury on their careers.

Treatment of Dynamic Claw Toe Deformity Through Lengthening of the Flexor Tendons of the Hallux and Toes at the Midfoot Level.

The claw toe deformity is characterized by the flexion of interphalangeal joints (IPJs) with hyperextension of the metatarsophalangeal (MTP) joint. It can be flexible and reducible or rigid and irreducible, or dynamic. The most common cause of dynamic claw toes is a neurological disorder, like sequelae of an ischemic contracture of the muscle belly after a compartment syndrome. Most of the surgical techniques require multiple procedures and may be associated with complications such as toe stiffness, persisting metatarsalgia, and toe malalignment. The aim of this study is to present an option for the surgical treatment of the dynamic claw toe deformity, by simultaneous tenodesis and lengthening of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) tendons at Henry's knot through a single midfoot incision.Levels of Evidence: V; Therapeutic Study; Expert Opinion.

Flexor Hallucis Longus Transfer And V-Y Plasty: An Effective Treatment Modality for Chronic Achilles Rupture - A Case Series.

Introduction: To assess outcomes of FHL transfer and V-Y plasty for chronic Achilles rupture due to insertional Achilles tendinopathy. Materials and methods: A case series of 12 patients was conducted between 1st January 2017 and 31st December 2018. The patients had short flexor hallucis longus tendon transfer with gastrocnemius lengthening by V-Y plasty for Achilles tendon rupture. Patients were allowed full weight bearing at six weeks post-operatively, and were followed up at three months and six months post-operatively, when the range of motion of the ankle was examined, and the outcome was assessed using the EFAS score. Results: Of the 12 patients in the study, the majority were males; the mean age was 50.6±8.96 years. A significant improvement in dorsiflexion and plantarflexion was noted at the six-month follow-up compared to the three-month follow-up (P=<0.001 for both). When compared to the normal side, dorsiflexion and plantarflexion of the affected ankle were significantly less at three months but were comparable at six months post-operatively. A significant improvement was noted in the mean EFAS score at the six-month follow-up (25.5±5.71) compared to three months (18.6±0.90) post-surgery (P=0.001). Males were also noted to have significantly higher EFAS scores at their six-month follow-up than females (P=0.022). In contrast, a negative correlation was noted between the European Foot and Ankle Society (EFAS) score at the final follow-up and age (P=0.011). Conclusion: FHL tendon transfer with V-Y plasty in chronic Achilles rupture due to insertional Achilles tendinopathy is an effective procedure resulting in the restoration of the ankle range of motion and improvement in functional scores.

Evaluation of arthrokinematics and posterior soft tissues of the ankle during ankle dorsiflexion using ultrasound.

BACKGROUND: Arthrokinematics (caudal and posterior movements of the talus) and posterior soft tissues of the ankle during ankle dorsiflexion have not been objectively evaluated in detail. This study aimed to investigate the characteristics of arthrokinematics and posterior soft tissues of the ankle during ankle dorsiflexion using ultrasound. METHODS: Thirteen healthy adults participated in the study. Participants whose passive dorsiflexion range of motion (ROM) of the ankle joint was <35° were classified as the restricted group (n = 6), and participants whose passive ankle dorsiflexion ROM was ≥35° were classified as the control group (n = 7). Passive ankle dorsiflexion was performed to measure the ankle arthrokinematics. Strain elastography was performed to measure the elasticity of the flexor hallucis longus (FHL) and Kager's fat pad (KFP) at each dorsiflexion angle. RESULTS: A significant difference in the posterior movement of the talus at the ankle dorsiflexion of 30° was observed between the two groups (P = 0.04). The elasticity of the restricted group was increased at all angles in both FHL and KFP (P < 0.05). CONCLUSION: This study showed that it is possible to objectively evaluate the direction of ankle arthrokinematics and posterior ankle soft-tissue restrictions using ultrasound.

Arthroscopic Tenotomy of the Flexor Hallucis Longus to Treat Checkrein Deformity.

Checkrein deformity is a rare entity that results in alteration of the normal flexion and extension of the hallux, caused by a retraction or adhesion of the flexor hallucis longus (FHL) in its tendinous or muscular portion. It is usually caused by the sequelae of ankle and tibia fractures, such as adhesions and neuropathies, and often undiagnosed compartment syndromes. Its treatment is mainly surgical, and different techniques of release or lengthening of the FHL have been described. We present the clinical case of a 61-year-old patient treated by a simple arthroscopic tenotomy of the FHL at the retromalleolar level of the ankle, with complete functional recovery and absence of recurrence after 2 years of evolution. We recommend that this procedure should be considered for this pathology due to its technical simplicity, low iatrogenicity, early recovery, and theoretical absence of recurrence.Level of Evidence: Level V: Expert opinion, case report.

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.

Impact of lower muscle stiffness on ankle dorsiflexion restriction in children with cerebral palsy evaluated using ultrasound elastography.

BACKGROUND: Plantar flexor muscles always contribute to limiting the range of motion of ankle dorsiflexion in children with spastic cerebral palsy, but the individual contributions of these muscles are not well defined. This study aimed to identify which muscles' stiffness impacts the dorsiflexion range of motion in children with cerebral palsy. METHODS: Twenty-five children with cerebral palsy were included. The maximum passive dorsiflexion range of motion was measured in two positions: hip and knee joints in flexion, and both joints in full extension. Strain ratios indicating muscle stiffness were measured using strain elastography of the lateral and medial gastrocnemius, soleus, flexor hallucis longus, peroneus longus, peroneus brevis, and tibialis posterior muscles. To analyze which muscles impact the limitation of the dorsiflexion range, multiple regression analyses were conducted. The values of muscle stiffness were included as independent valuables, and the values of the dorsiflexion range were included as dependent valuables. A p-value <0.05 was considered statistically significant. FINDINGS: In the analyses, the soleus and flexor hallucis longus muscle stiffness were significant independent factors for the dorsiflexion range of motion of hip and knee flexion (adjusted R2: 0.50). The lateral gastrocnemius muscle stiffness was a significant independent factor for the dorsiflexion range of motion with both joints in full extension (adjusted R2: 0.61). INTERPRETATION: Flexor hallucis longus muscle stiffness, in addition to triceps surae muscle stiffness, was shown to impact dorsiflexion range; attention should be paid to muscle stiffness in children with cerebral palsy.

Surgical treatment of chronic achilles tendon rupture: An anatomical consideration of various autograft options.

Background: Acute Achilles tendon rupture is a common injury and when missed leads to the development of a chronic Achilles tendon rupture. Studies suggest surgical treatment (either repair or reconstruction) for most patients with a chronic Achilles rupture due to the functional deficit caused by the lack of an intact Achilles tendon. Numerous autograft options such as the flexor hallucis longus, hamstrings, peroneal and quadriceps tendon have been used to reconstruct the Achilles tendon, either as a tendon transfer or as an interposition graft. The choice of autograft used usually depends on the size of the defect left after debridement of the Achilles tendon edges, but is often dictated by surgeon preference and tissue availability. Currently, there is no consensus as to the best autograft option. Aims and methodology: The aim of this study was to evaluate the various autograft options used to reconstruct the Achilles tendon, and the advantages and disadvantages of using each tendon, focussing specifically on the harvesting technique, anatomical and biomechanical properties. This was done by reviewing the current published literature, supplemented by carrying out anatomical dissection in the cadaveric lab. Results: The flexor hallucis longus is synergistically related to the Achilles tendon and biomechanically strong, however harvesting can result in weakness in big toe flexion. The peroneus brevis whilst being biomechanically strong is a much shorter tendon compared to the other autograft options. Similarly, the quadriceps tendon is also a strong tendon option, but may not be appropriate for larger chronic Achilles tendon rupture gaps. The semitendinosus tendon can be tripled/quadrupled to resemble the Achilles tendon, but is associated with higher risks of patient morbidity when harvesting the tendon. Conclusion: Treatment of chronic Achilles tendon ruptures remains a challenge. Each autograft option has its own unique advantages and disadvantages which should be considered on a case-specific basis. Further work is required to analyse the biomechanical properties of the autograft options to determine if one option is superior.

Endoscopic flexor hallucis longus tendon transfer with horizontal calcaneal fixation and suturing onto itself.

Endoscopic flexor hallucis longus (FHL) tendon transfer to replace the calcaneal tendon is being increasingly performed. The main advantage is minimisation of approach-related morbidity. Fixation of the FHL tendon is usually achieved with a tenodesis screw placed in a vertical calcaneal tunnel. Here, we describe an endoscopic technique with FHL fixation by tenodesis in a horizontal calcaneal tunnel combined with suturing of the tendon onto itself. LEVEL OF EVIDENCE: IV.

Navicular Tuberosity: A Surface Landmark for the Masterknot of Henry.

Background: Medial aspect of foot is unexplored due to its complex anatomy. Masterknot of Henry is an important landmark in this region, which plays a key role during tendon transfer procedures especially in those involving the flexor hallucis longus and flexor digitorum longus. We aim to determine the exact anatomical location of masterknot of Henry with respect to the bony prominences of the medial aspect of the foot and compare these measurements to the length of the foot. Methods: Twenty cadaveric below-knee specimens were dissected. Structures on the medial side of the foot were exposed. Distance of the masterknot of Henry from surrounding bony landmarks was measured. Depth of the masterknot from skin of the plantar aspect was also measured. Means of all parameters were calculated. Relation between measurements and the foot length was determined using correlation and regression analysis. P value of less than 0.05 was considered significant. Results: Distance of masterknot of Henry from navicular tuberosity was found to be fairly constant of 19.965 mm. Foot length was found to be correlating with the distance between masterknot of Henry and medial malleolus, navicular tuberosity and its depth from the skin. Conclusions: Navicular tuberosity can be considered an important surface landmark for the location of masterknot of Henry. Correlation of length of the feet with various measurements helps to find the masterknot considering the foot length to be an important variable. Good knowledge of surface anatomy leads to shorter operating time and less morbidity during procedures involving the flexor hallucis longus and flexor digitorum longus.

Posterior Ankle Impingement.

This article is devoted to managing posterior ankle impingement syndrome and its management using endoscopic to arthroscopic surgical instrumentation. The authors explore the critical anatomy, pathogenesis, and clinical examination. Operative techniques, including the approach, and instrumentation used, are outlined. The postoperative protocol is discussed. Finally, a literature review is provided, which also defines known complications.