Flexor hallucis longus dysfunction

Injury of flexor halluics longus tendon in amateur marathon runners results in abnormal plantar pressure distribution: observational study

OBJECTIVE

To analyze the changes of plantar pressure in amateur marathon runners with flexor halluics longus (FHL) tendon injury using the Medtrack-Gait plantar pressure measurement system, and to explore whether the plantar pressure data can be used as an index for the diagnosis of injury.

METHODS

A total of 39 healthy amateur marathon runners without any ankle joint symptoms were recruited. Dynamic and static plantar pressure data were measured using the pressure plate of Medtrack-Gait. According to MRI imaging findings, whether the FHL tendon was injured or not was judged, and the dynamic and static data were divided into the injury group and control group. The data with statistically significant differences between the two groups were used to make the receiver operating characteristic (ROC) curve.

RESULT

The maximum contact area (PA) of the first metatarsal(M1) region, the maximum load-bearing peak value (PW) and the time pressure integral (PMPTI) of the second metatarsal(M2) region in the injury group were lower than those in the control group, respectively (P < 0.05). The maximum contact area (PA) of the fifth metatarsal(M5) region was higher than that in the control group (P < 0.05). The area under curve (AUC) value of the ROC curve of the PA of M1 region, the PW and PMPTI of M2 region were statistically (P < 0.05).

CONCLUSION

FHL tendon injury resulted in decreased PA in M1, decreased PW and PMPTI in M2, and increased PA in the M5 region, suggesting that FHL tendon injury resulted in a force shift from the medial to the lateral side of the foot. The PA of M1, PW and PMPTI of M2 have certain diagnostic value for early FHL injury in amateur marathon runners.

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.

Presurgical Perspective and Postsurgical Evaluation of Non-Achilles Tendons of the Ankle and Retinaculum

The vast majority of non-Achilles ankle tendinopathies are related to overuse. This article discusses the clinical aspect, imaging appearance, and management of tendinopathies of the lateral, medial, and the anterior compartments with a focus on presurgical perspective and postsurgical evaluation.

Flexor Hallucis Longus Tendon Impingement Syndrome: All-inside Arthroscopic Treatment and Long-term Follow-up

This study aimed to evaluate the surgical technique and long-term clinical outcomes of all-inside arthroscopic treatment for flexor hallucis longus (FHL) tendon impingement syndrome. We retrospectively evaluated 34 FHL tendon impingement syndrome patients with complete follow-up data who were admitted from June 2015 to August 2018 and underwent the all-inside arthroscopy technique. The subjects consisted of 20 (58.82%) males and 14 (41.18%) females, with a mean age of 32.7 ± 10.2 (range 21-52) years. The cases consisted of 19 (55.88%) right and 15 (44.12%) left feet. The mean disease duration was 18.5 ± 9.1 (range 10-43) months. The visual analogue scale (VAS), American Orthopaedic Foot & Ankle Society (AOFAS), Karlsson Ankle Functional Score (KAFS), and 36-item Short Form Health Survey questionnaire (SF-36) scores for pain were 3.6 ± 1.2, 84.1 ± 9.6, 86.3 ± 10.7, and 94.7 ± 9.3, respectively. All patients were treated with all-inside posterior arthroscopy for the debridement of the FHL tendon sheath combined with partial muscle belly resection. Post-operative follow-up and observation of the patients' pain and ankle movement were evaluated using VAS, AOFAS, KAFS, and SF-36. All incisions were healed in the first stage, and no complications such as nerve, blood vessel, or tendon injuries occurred. The hospital stays were 3 to 5 days, with a mean of 3.7 ± 1.3 days. All patients were followed up for 12 to 36 months, with a mean follow-up time of 25.4 ± 8.5 months. By the last follow-up, the ankle joint and hallux movement were normal and returned to the pre-pain state for these patients. The VAS score decreased to 0.2 ± 0.1, while the AOFAS, KAFS, and SF-36 scores increased to 97.7 ± 8.5, 97.9 ± 8.2, and 118.2 ± 8.4, respectively. Advantages of all-inside posterior arthroscopic partial muscle belly resection for the treatment of FHL tendon impingement syndrome include small surgical trauma, fast functional recovery, and reliable outcomes. This procedure is therefore worthy of clinical attention and promotion.

Recalcitrant Flexor Hallucis Longus Dysfunction: A Case Study Demonstrating the Successful Application of an Adaptable Rehabilitation Program With a Two-Year Follow-Up

Flexor hallucis longus (FHL) dysfunction is a condition experienced primarily by athletes, including ballet dancers and runners. Accurate diagnosis and definitive treatment at the initial evaluation can often be difficult given the number of foot and ankle pathologies that share similar signs and symptoms. The evaluation process tends to be a diagnosis of inclusion rather than a specific pathology with an accepted rehabilitation plan. For example, patients with medial arch pain may undergo an extended rehabilitation period with an evolving differential diagnosis requiring several treatment modifications. A more appropriate rehabilitation paradigm should adapt to the potential changes in patient symptoms and presentation, addressing functional impairments as they arise. This case study describes the successful management of a patient with chronic FHL dysfunction, leveraging a flexible, multimodal treatment approach to address the evolving functional impairments rather than focusing on a single, discrete diagnosis. At a two-year follow-up, the patient remains pain-free.

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

BACKGROUND

Corticosteroid 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.

PURPOSE

The aim of this study was to determine the accuracy of a blind injection technique into the FHL tendon sheath.

HYPOTHESIS

We hypothesize that a blind injections technique into the FHL tendon sheath based on clinical examination has a high accuracy.

STUDY DESIGN

Descriptive cadaveric study.

METHODS

Ten 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.

RESULTS

In nine ankles the radiological contrast was injected in the FHL tendon sheath. In one cadaver there was a technical problem and was therefore excluded.

CONCLUSION

This 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.

Tarsal tunnel disease and talocalcaneal coalition: MRI features

OBJECTIVE

To assess, utilizing MRI, tarsal tunnel disease in patients with talocalcaneal coalitions. To the best of our knowledge, this has only anecdotally been described before.

MATERIALS AND METHODS

Sixty-seven ankle MRIs with talocalcaneal coalition were retrospectively reviewed for disease of tendons and nerves of the tarsal tunnel. Interobserver variability in diagnosing tendon disease was performed in 30 of the 67 cases. Tarsal tunnel nerves were also evaluated in a control group of 20 consecutive ankle MRIs.

RESULTS

Entrapment of the flexor hallucis longus tendon (FHL) by osseous excrescences was seen in 14 of 67 cases (21 %). Attenuation, split tearing, tenosynovitis, or tendinosis of the FHL was present in 26 cases (39 %). Attenuation or tenosynovitis was seen in the flexor digitorum longus tendon (FDL) in 18 cases (27 %). Tenosynovitis or split tearing of the posterior tibial tendon (PT) was present in nine cases (13 %). Interobserver variability ranged from 100 % to slight depending on the tendon and type of disease. Intense increased signal and caliber of the medial plantar nerve (MPN), indicative of neuritis, was seen in 6 of the 67 cases (9 %). Mildly increased T2 signal of the MPN was seen in 15 (22 %) and in 14 (70 %) of the control group.

CONCLUSIONS

Talocalcaneal coalitions may be associated with tarsal tunnel soft tissue abnormalities affecting, in decreasing order, the FHL, FDL, and PT tendons, as well as the MPN. This information should be provided to the referring physician in order to guide treatment and improve post-surgical outcome.

Plantar tendons of the foot: MR imaging and US

Tendon disorders along the plantar aspect of the foot may lead to significant symptoms but are often clinically misdiagnosed. Familiarity with the normal anatomy of the plantar tendons and its appearance at magnetic resonance (MR) imaging and ultrasonography (US) is essential for recognizing plantar tendon disorders. At MR imaging, the course of the plantar tendons is optimally visualized with dedicated imaging of the midfoot and forefoot. This imaging should include short-axis images obtained perpendicular to the long axis of the metatarsal shafts, which allows true cross-sectional evaluation of the plantar tendons. Normal plantar tendons appear as low-signal-intensity structures with all MR sequences. At US, accurate evaluation of the tendons requires that the ultrasound beam be perpendicular to the tendon. The normal tendon appears as a compact linear band of echogenic tissue that contains a fine, mixed hypoechoic and hyperechoic internal fibrillar pattern. Tendon injuries can be grouped into six major categories: tendinosis, peritendinosis, tenosynovitis, entrapment, rupture, and instability (subluxation or dislocation) and can be well assessed with both MR imaging and US. The radiologist plays an important role in the diagnosis of plantar tendon disorders, and recognizing their imaging appearances at MR imaging and US is essential.

Pyogenic tenosynovitis of the flexor hallucis longus in a healthy 11-year-old boy: a case report and review of the literature

Pyogenic tenosynovitis of the flexor hallucis longus (FHL) is a rare condition in young healthy patients. We report the case of a healthy 11-year-old boy who presented with a history of fever and painful swelling below the medial malleolus of the left ankle. Imaging and laboratory findings suggested infectious tenosynovitis of the FHL. Methicillin-sensitive Staphylococcus aureus was isolated on culture following surgery. Antibiotherapy was initiated and continued until inflammatory markers returned to normal. Six months post-surgery, he resumed sport activities and inflammatory markers remained within normal limits. We review also the literature and discuss the clinical characteristics of this condition.

Subcutaneous rupture of the flexor hallucis longus tendon: a case report

It is well known that rupture of the flexor hallucis longus tendon can be associated with open injuries and that closed rupture of the flexor hallucis longus tendon is rare. Tendon injuries of the foot can occur secondary to direct, indirect, or repetitive injury. Repetitive tendon injuries can cause tendinitis or stenosing tenosynovitis. Tendinitis is associated with internal tendon injury that can present with tendon thickening, mucinoid degeneration, nodule development, or in situ partial tears. Stenosing tenosynovitis is the development of tendon adhesions within the tendon sheath that interfere with tendon gliding, known as trigger toe. The flexor hallucis longus tendon is susceptible to injury along its entire course. A total of 35 cases of complete or partial closed ruptures of the flexor hallucis longus tendon have been reported. We present the case of complete subcutaneous rupture of the flexor hallucis longus tendon associated with trauma at the proximal phalangeal head.

Hindfoot endoscopy for accessory flexor digitorum longus and flexor hallucis longus tenosynovitis

We present a case report involving the flexor digitorum accessorius longus (FDAL) tendon which travels through a fibro-osseous tunnel together with the flexor hallucis longus (FHL) tendon, causing a stenosing tenosynovitis. The patient was admitted with posteromedial ankle pain and diagnosed clinically as FHL tenosynovitis. We found two tendons in the tunnel during hindfoot endoscopy. The stenosis was relieved by endoscopic debridement. After the operation, we checked the MRI images and observed two tendons. We concluded that the accessory tendon was the FDAL. Two years later the patient was admitted with the same symptoms. We excised the FDAL muscle and the patient's symptoms resolved. The FDAL muscle is a cause of FHL tenosynovitis. Because of its variability and mostly asymptomatic nature, it may not be noticed it on an MRI scan. Hindfoot endoscopy is a safe tool for the diagnosis of this condition and curative treatment is afforded by excision of the FDAL muscle.

The Flexor Hallucis Longus: Tenographic Technique and Correlation of Imaging Findings with Surgery in 39 Ankles

PURPOSE

To examine the use of tenography for evaluation of the flexor hallucis longus (FHL) sheath.

MATERIALS AND METHODS

Institutional review board approval was waived, patient consent was obtained, and the study was HIPAA compliant. Retrospective review of 192 FHL tenograms and associated surgical records identified 39 ankles in 37 patients (17 male, 20 female; mean age +/- standard deviation, 38 years +/- 13.8; range, 14-68 years) in which both tenography and surgery had been performed. Two radiologists reviewed tenographic findings, including contrast agent extravasation, synovial irregularity, stenosis, fibrous bands, sheath outpouching, extent of opacification, and communications with adjacent structures. Alterations in pain after anesthesia of the tendon sheath were also recorded. Surgical reports were reviewed.

RESULTS

Thirty-four of 39 tenograms were diagnostic. Some extravasation occurred in nine (45%) of 20 injections with an initial injection method and in two (11%) of 19 with a new injection technique. Synovial irregularity was present in all 34 studies (15 mild, 16 moderate, three severe). Stenoses were identified in 23 (68%) of 34 ankles, fibrous bands were seen in 16 (47%) of 34 ankles, and outpouching of the sheath above a stenosis was present in 13 (38%) of 34 ankles. Communication of the FHL sheath with the ankle, flexor digitorum longus, or subtalar joint occurred in half the cases. Most patients with pain reported relief; relief was complete (100% reduction from preprocedural pain) in eight of 27, moderate (50%-90% reduction) in nine of 27, and mild (<50% reduction) in eight of 27 patients.

CONCLUSION

Tenography of the FHL sheath produced diagnostic images in almost all patients and effectively demonstrated abnormalities of the tendon sheath. Pain relief with anesthetic injection helped confirm the FHL sheath as the pain generator.

Blood supply of the flexor hallucis longus tendon with regard to dancer's tendinitis: injection and immunohistochemical studies of cadaver tendons

The flexor hallucis longus is the most common site of lower extremity tendon disorders in ballet dancers. Reduced vascularity is an important factor contributing to tendon degeneration and rupture under strain. A study was conducted on the vascular pattern of the human flexor hallucis longus tendon with injection techniques and immunohistochemically by using antibodies against laminin. Blood supply arose from the posterior tibial and the medial plantar artery. Peritendinous blood vessels penetrated the tendon and anastomosed with a longitudinally oriented intratendinous network. Injection specimens and immunohistochemistry revealed one avascular zone in which the tendon passed behind the talus and a second in which the tendon wrapped around the first metatarsal head. These are the most typical areas for tendon degeneration and rupture.

Acute tarsal tunnel syndrome following partial avulsion of the flexor hallucis longus muscle: a case report

An acute posterior tibial nerve compression from a partially ruptured flexor hallucis longus (FHL) muscle is reported. This etiology for acute tarsal tunnel syndrome has not been previously described. A 17-year-old male sustained multiple injuries in a motor vehicle accident, including a tibial shaft fracture and a posterior medial right ankle laceration of the same limb. The injured limb had no sensation on the plantar aspect of the foot and heel, decreased active great toe flexion, and associated leg pain. Exploration of the posterior tibial nerve for presumed laceration revealed the nerve to be intact, but compressed in a tense tarsal tunnel from a retracted partially ruptured flexor hallucis longus tendon. Decompression of the tunnel and resection of the devascularized muscle resulted in complete neurologic recovery.

Flexor hallucis longus dysfunction: an overview

Whereas acute and chronic injuries of the tibialis posterior, peroneal and Achilles tendon are frequently encountered, disorders of the flexor hallucis longus tendon are often overlooked, which may contribute to chronic pain and disability. Patients with stenosing tenosynovitis of the flexor hallucis longus tendon frequently present with overlapping signs and symptoms of flexor hallucis longus tendinitis, plantar fasciitis and tarsal tunnel syndrome, which the authors collectively refer to as "flexor hallucis longus dysfunction." A keen awareness of the presenting signs and symptoms and use of ancillary MR imaging and FHL tenography will assist the practitioner in recognizing this commonly misdiagnosed condition.

Physical examination of the ankle for ankle pathology

Injury to the ankle joint is very common, but the etiology of the ankle pain can be difficult to determine due to the complexity of the joint. Without a proper diagnosis, treatment is delayed or inappropRiate which can lead to further ankle morbidity. This article is to assist foot and ankle specialists in making an accurate diagnosis of ankle pathology by showing how to perform a thorough ankle examination. Specific tests and examination techniques are described. No exact treatment plan to a particular diagnosis is given, but rather a general approach to treating ankle injuries is shown.

Forefoot pain involving the metatarsal region: differential diagnosis with MR imaging

Many disorders produce discomfort in the metatarsal region of the forefoot. These disorders include traumatic lesions of the soft tissues and bones (eg, turf toe, plantar plate disruption, sesamoiditis, stress fracture, stress response), Freiberg infraction, infection, arthritis, tendon disorders (eg, tendinosis, tenosynovitis, tendon rupture), nonneoplastic soft-tissue masses (eg, ganglia, bursitis, granuloma, Morton neuroma), and, less frequently, soft-tissue and bone neoplasms. Prior to the advent of magnetic resonance (MR) imaging, many of these disorders were not diagnosed noninvasively, and radiologic involvement in the evaluation of affected patients was limited. However, MR imaging has proved useful in detecting the numerous soft-tissue and early bone and joint processes that occur in this portion of the foot but are not depicted or as well characterized with other imaging modalities. Frequently, MR imaging allows a specific diagnosis based on the location, signal intensity characteristics, and morphologic features of the abnormality. Consequently, MR imaging is increasingly being used to evaluate patients with forefoot complaints. Radiologists should be familiar with the differential diagnosis and MR imaging features of disorders that can produce discomfort in this region.

Painful heel: MR imaging findings

Heel pain is a common and frequently disabling clinical complaint that may be caused by a broad spectrum of osseous or soft-tissue disorders. These disorders are classified on the basis of anatomic origin and predominant location of heel pain to foster a better understanding of this complaint. The disorders include plantar fascial lesions (fasciitis, rupture, fibromatosis, xanthoma), tendinous lesions (tendinitis, tenosynovitis), osseous lesions (fractures, bone bruises, osteomyelitis, tumors), bursal lesions (retrocalcaneal bursitis, retroachilleal bursitis), tarsal tunnel syndrome, and heel plantar fat pad abnormalities. With its superior soft-tissue contrast resolution and multiplanar capability, magnetic resonance (MR) imaging can help determine the cause of heel pain and help assess the extent and severity of the disease in ambiguous or clinically equivocal cases. Careful analysis of MR imaging findings and correlation of these findings with patient history and findings at physical examination can suggest a specific diagnosis in most cases. The majority of patients with heel pain can be successfully treated conservatively, but in cases requiring surgery (eg, plantar fascia rupture in competitive athletes, deeply infiltrating plantar fibromatosis, masses causing tarsal tunnel syndrome), MR imaging is especially useful in planning surgical treatment by showing the exact location and extent of the lesion.

Foot and ankle sonography

Sonography of the foot and ankle offers many advantages. Currently, sonographic evaluation rivals or exceeds MR imaging for evaluation of tendons, joint and bursal pathology, and specific soft tissue pathology. The advantages of sonographic evaluation provide a strong impetus for applying this modality to imaging of foot and ankle pathology. Those who accept the challenge will have an expanded repertoire to offer in the pursuit of efficient and effective patient care.