Flexor Hallucis Longus Tendon Research Articles

Clinical and biomechanical comparison of suture-external button versus interference screw associated with V-Y advancement or turndown flaps for flexor hallucis longus transfer in chronic Achilles tendon rupture.

Surgical treatment of chronic Achilles tendon rupture is a technically challenging procedure. We aimed to compare the clinical outcomes, range of motion, and strength of ankle plantar- and dorsiflexors between two techniques for fixation of flexor hallucis longus tendon to the calcaneus: interference screw and suture-external button. Twenty-five patients participated in this retrospective comparative study. All patients underwent short harvest FHL tendon transfer for chronic AT rupture were asked for a follow-up visit, at least one year following surgery. The outcomes were evaluated by visual analog scale (VAS), AOFAS ankle-hindfoot score, and VISA-A questionnaire. Ankle ROM with possible restriction in addition to isokinetic strength of ankle plantar- and dorsiflexors was assessed. No statistically significant difference was observed between the groups for pain (P = 0.81), AOFAS ankle-hindfoot scale (P = 0.97), and VISA-A (P = 0.44). Notably, more decrease in ankle dorsiflexion was seen in interference screw group in comparison with suture-external button group (4.4 ± 6.6 vs. 9.5 ± 6.1 degrees, P = 0.06). The difference of active dorsiflexion between operated and non-operated side in interference screw group was statistically significant (P = 0.02). Biotenodesis screw imposed more limb asymmetry in comparison with suture-external button technique. Fixation of transcalcaneal FHL tendon transfer for chronic AT either by interference screw or suture-external button has encouraging postoperative clinical results. Although ROM of the ankle joint reduced in both techniques, interference screw may result in more reduction in dorsiflexion of the ankle.

Foot and Ankle MRI Findings in Asymptomatic Professional Ballet Dancers.

Previous research in sport populations has demonstrated that abnormal magnetic resonance imaging (MRI) findings may be present in individuals without symptoms or known pathology. Extending this understanding to ballet, particularly in relation to the foot and ankle, is important to guide medical advice given to dancers. To assess foot and ankle MRI scans in asymptomatic ballet dancers focusing on bone marrow edema and the posterior ankle and to investigate whether these MRI findings would become symptomatic within 1 year. Case series; Level of evidence, 4. In total, 31 healthy dancers (62 feet/ankles; 15 male and 16 female; age, 26.5 ± 4.3 years) who were dancing in full capacity were recruited from an elite professional ballet company. Orthogonal 3-plane short tau inversion recovery imaging of both feet and ankles was obtained using 3T MRI and the images were reviewed using a standardized evaluation form by 2 musculoskeletal radiologists. Injuries in the company were recorded and positive MRI findings were assessed for correlation with any injuries requiring medical attention during the subsequent 12 months. A total of 51 (82%) of the 62 feet and ankles had ≥1 area of bone marrow edema. The most common locations of bone marrow edema were the talus (n = 41; 66%), followed by first metatarsal (n = 14; 23%). Os trigonum and Stieda process were seen in 5 (8%) and 8 (13%) ankles, respectively. Among them, 2 os trigona showed bone marrow edema. Fluid in the anterior and posterior talocrural joints and the subtalar joint was observed in 48%, 63%, and 63% of these joints, respectively. Fluid around foot and ankle tendons was observed, with the most prevalent being the flexor hallucis longus tendon (n = 13; 21%). Two dancers who had positive findings on their MRI subsequently developed symptoms during the next 12 months. Positive MRI findings are commonplace in the foot and ankle of asymptomatic professional ballet dancers. The majority do not result in the development of symptoms requiring medical attention within 12 months. Careful interpretation of MRI findings with the dancer's clinical picture is required before recommending activity modification or further intervention.

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.

Does FHL Tendon Transfer Alter the Outcome of Haglund Deformity Treatment by Using Debridement and Ostectomy in Patients Older Than 50 Years? A Single-Blinded Randomized Controlled Trial.

Chronic Achilles tendinopathy following Haglund disease is a common ankle condition that is difficult to manage. In this study, we will compare the clinical outcomes of debridement and ostectomy with and without FHL tendon transfer in treating Haglund deformity. Forty eligible patients aged >50 years who did not respond to conservative treatment were randomly divided into 2 groups for surgical approach: using flexor hallucis longus (FHL) tendon transfer (FHL group) or "standard procedure" (control group). The main surgical treatment included debridement and ostectomy. AOFAS and VISA-A scores were obtained from all patients pre- and postoperatively. Twenty patients were assigned to each of the 2 groups and were observed for at least 1 year. The American Orthopaedic Foot & Ankle Society (AOFAS) ankle hindfoot scores and the Victorian Institute of Sports Assessment self-administered Achilles (VISA-A) questionnaires scores improved more in the FHL group; however, the average difference in the change in scores did not reach the levels previously reported for minimal clinically important differences. Surgical complications and hallux function were not significantly different between the 2 groups. We found that FHL tendon transfer may improve the clinical outcome scores of Achilles tendon treatment in patients aged >50 years using debridement and ostectomy. However, tendon transfer increases the time of surgery and creates additional skin incisions, which may cause more short-term wound complications, and the significance of the differences in outcome improvement may not be clinically meaningful. Level II, grade A recommendation.

Anatomy of the Flexor Hallucis Longus and Its Relationship With Hallux Valgus: A Cadaveric Study.

Hallux valgus (HV) is a complex deformity, with many associated risk factors. The flexor hallucis longus (FHL) tendon is a dynamic and potentially deforming force as it bowstrings laterally with HV. We hypothesized that FHL is more laterally inserted in the distal phalanx in cadavers with HV; therefore, it might be also a primary destabilizing force. We aim to compare the FHL distal insertion morphology and its relationship with osseous structures in cadavers with and without HV. Sixteen cadaver specimens, 8 with HV and 8 without (N-HV) were dissected. We evaluated FHL distal morphology in terms of its insertional footprint location and FHL long-axis position in relation to osseous anatomy. Both the HV and N-HV groups displayed a laterally inserted footprint at the distal phalanx, with the HV group exhibiting median lateral translation of the footprint 6% greater than the N-HV group (P < .01). Both groups also demonstrated a laterally displaced position for the FHL long axis. The median FHL long axis for HV vs N-HV specimens 1 cm proximal to the IP joint was 9% more laterally displaced from the midaxis (P < .01), and at 1 cm proximal to the MTP joint was measured to be 15% more laterally displaced from the midaxis (P < .01). FHL demonstrated an eccentric position in terms of insertion and trajectory in both the HV and N-HV groups, with greater lateralization in specimens exhibiting HV deformity. This eccentricity potentially creates a greater deforming force vector contributing to the development of HV. The etiology and progression of HV deformity may include a lateralized insertion of the FHL tendon. Treatment implications remain unknown at this time.

Salvage Reconstruction of a 12-cm Tendon Defect Following Chronic Achilles Rerupture-15-Year Follow-Up: A Case Report.

A 39-year-old man with a chronic Achilles rupture status post (1) failed primary repair and (2) secondary xenograft repair with graft rejection, resulting in a 12-cm Achilles tendon defect, which was reconstructed utilizing an Achilles bone block allograft and flexor hallucis longus (FHL) tendon transfer. At 15-year follow-up, the patient reported good functionality and satisfaction with the repair, with positive patient-reported outcome measures. Physical examination revealed excellent strength and range of motion. Magnetic resonance imaging confirmed the integrity and incorporation of the Achilles/FHL graft composite. This case study provides valuable insight into successful long-term management of complex chronic Achilles ruptures with large defects.

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.

A Review of the Most Common Injuries in Dancers and Therapeutic Options

Sports injuries, including those from dance, are an apparent problem across the United States and United Kingdom with millions of injuries being acquired daily. These injuries can both hinder an individual's day-to-day activities and hamper performances by extending the period of sustained injury and impacting technique. This study details injury prevalence as well as a variety of rehabilitation methods used to treat a specific highly prevalent injury within dance &amp;#91;flexor hallucis longus (FHL) tendinopathy&amp;#93;. The FHL tendon is in the posterior area of the fibula and aids one in conducting plantar flexions. When dysfunction occurs, leading to FHL tendinopathy, this can result in negatively impacting the range of motion in the foot and restricting an individual from many movements. Because FHL tendinopathy is classified as an "overuse" injury, the effects upon an individual such as inflammation and discomfort can worsen the more the tendon is used. By collecting studies detailing impacts upon ballet dancers and sports dancers from varying populations to conduct a systematic review using PubMed, the study can build upon the differences in therapies applied to improve patients’ health after contracting FHL tendinopathy. The study also brings into focus other related conditions such as plantar fasciitis which develops due to straining the plantar fascia ligament. After thoroughly conducting a systematic review, it was determined that conservative management with physical therapy, heel raises, and laser treatment are the most effective in reducing pain as well as shortening the amount of time spent injured.

Minimally-invasive lag screw fixation technique for posterior malleolus fractures: A cadaveric study

Anatomical reduction and lag screw fixation of posterior malleolar (PM) ankle fractures typically involves an open posterolateral approach. The aim of this anatomical study was to assess whether a minimally-invasive, percutaneous posterior-to-anterior lag screw fixation technique is safe to perform. Eighteen cadaveric ankle specimens were used. A transverse incision was made at the lateral border of the Tendo Achilles (TA). Windows were made lateral to and through the substance of the TA and simulated reduction and placement of a single lag screw performed. Specimens were then fully dissected to ascertain proximity and damage to anatomical structures. Lag screw fixation was placed appropriately in all ankles. No injury to the neurovascular structures, ankle joint or syndesmotic ligaments was observed. The mean distance from the soft tissue window to sural nerve was 10.0 mm (range 5–16), and 9.5 mm to short saphenous vein (4–14). Whilst the muscle belly of flexor hallucis longus (FHL) was pierced in six specimens, no injuries to the FHL tendon were observed. The mean distance from screw to syndesmosis was 9.3 mm (range 3–15) and 12.7 mm to the ankle joint (7–17). This study demonstrates that posterior percutaneous lag screw fixation is both safe and accurate. Further work is required to evaluate the precision of reduction and the biomechanical stability of this fixation technique. This novel minimally-invasive technique may be beneficial in avoiding the wound complications associated with open posterolateral ankle approaches and also offer a functional advantage due to minimal soft tissue disruption.

Chronic Achilles Tendon Avulsion Repair: Central Third Fascia Slide Technique with Flexor Hallucis Longus Transfer.

Chronic Achilles Tendon Avulsion Repair: Central Third Fascia Slide Technique with Flexor Hallucis Longus Transfer.

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.

Release of retromalleolar flexor retinaculum and combined flexor digitorum longus and flexor hallucis longus Z-plasty in checkrein deformity: a case report

BackgroundCheckrein deformity is a rare abnormality comprising flexor hallucis longus (FHL) tendon entrapment in the posterior foot due to post-traumatic or ischemic retraction of the FHLtendon following soft tissue trauma. The diagnosis is essentially clinical, but complemented by imaging to rule out unrecognized causes and evaluate the fracture healing process. This case report is the first Indonesian study to describe release of the flexor retinaculum and Z-plasty (lengthening) of flexor digitorum longus (FDL) and FHL tendons through a medial retromalleolar approach to repair the deformity. Case DescriptionWe present the case of a 51-year-old male who complained of clawing of his right first and second toes. The interest of this study lies in the fact that this patient had never experienced ankle or distal tibial fractures, only a trivial injury two years back when the patient kicked a stone at work and had a bruise on his right second toe with no fracture. Exploration of FHL tendons was performed at the level of the midfoot. The patient was planned for surgery with a medial retromalleolar ankle approach, which facilitates the release of the flexor retinaculum, in conjunction with a Z-tenotomy on the FHL and FDL tendons. ConclusionA correction was achieved, and two months post-surgery there were no recurrences of the deformity. However, this surgical procedure requires more cases to support an evaluation of its effectiveness. We suggest that exploration at the ankle and midfoot should be the primary surgical intervention in similar cases of checkrein deformity.

The compensatory hypertrophy of transferred flexor hallucis longus tendon for insertional Achilles tendinopathy: a retrospective MRI study

Flexor hallucis longus (FHL) transfer is an effective surgery in treating insertional Achilles tendinopathy (IAT). However, limited data exist regarding the post-surgery changes in the transferred FHL. The study aimed to compare the sequential changes and hypertrophy of FHL after isolated FHL transfer (FHLT). We retrospectively enrolled patients who underwent isolated FHLT for insertional Achilles pathology from 2015 to 2020 and divided them into two groups based on whether reattachment of the residue Achilles stump to the FHL was performed or not. We recorded demographic characteristics, MRI parameters, and functional outcome. We also analyzed the correlation between the collected data and FHL hypertrophy. Results revealed no significant differences in most MRI parameters of FHL and functional outcomes between the groups. However, the fat distribution within the FHL showed significant reduction and notable 20.2% hypertrophy after FHLT. Interestingly, the hypertrophy of the FHL was significantly more pronounced in the non-reattached group. Furthermore, we observed a positive correlation between the follow-up period and FHL hypertrophy. In conclusion, the FHL demonstrated significant enlargement over time following FHLT. The compensatory hypertrophy of the transferred FHL was particularly evident and the cumulative incidences of FHL enlargement over time were higher in the non-reattached groupcompared to reattached group. However, both reattachment and non-reattachment of Achilles stump on FHL transfer for insertional Achilles tendinopathy carried similar postoperative functional outcomes.

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

To assess outcomes of FHL transfer and V-Y plasty for chronic Achilles rupture due to insertional Achilles tendinopathy. 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. 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). 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.

Exploring morphological variations and clinical significance of interconnections between flexor hallucis longus and flexor digitorum longus tendons

BackgroundThe tendons of the flexor hallucis longus (FHL) and flexor digitorum longus (FDL) are commonly utilized in reconstructive foot surgery to address deformities. These tendons intersect on the plantar surface and exhibit varying interconnections that can significantly impact graft length and complicate the tendon harvesting process. The objective of this study was to comprehensively categorize these interconnections using a modified classification system and precisely determine their positional relationships with surgically significant bony landmarks. MethodsSixty embalmed feet of 30 cadavers were studied to analyze the interconnections between FHL and FDL in the planta pedis, classify them in a modified classification system and measure distances to surgically relevant anatomic landmark. ResultsThe study revealed three primary types of interconnections. Type I, representing a proximal-to-distal connection from the FHL to the FDL, was observed in 85% of the feet. Type II, signifying a proximal-to-distal connection from the FDL to the FHL, was found in 11.66% of the feet. Type III, characterized by a crossed connection, was identified in 3.33% of the feet. The average point of branching for the FHL and FDL tendons was situated 4.5 cm and 3.5 cm distal to the navicular tuberosity, respectively. ConclusionThe presence of atypical proximal-to-distal interconnections from the FHL to the FDL may play a role in preserving residual function in the lesser toes following FDL transfer procedures. Awareness of anatomical variations in the location of these interconnections is crucial for preserving them during surgical interventions, ultimately mitigating the risk of functional impairment in the lateral toes post-tendon grafting.

Flexor Hallucis Longus decompression under ultrasound guidance: A cadaver study

IntroductionThe 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. HypothesisThe 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 methodsThirteen 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. ResultsFive 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. ConclusionTenolysis 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 EvidenceIII; case-control study.

Acute Achilles Tendon Ruptures Treated With Endoscopic Flexor Hallucis Longus Transfer

The Achilles tendon represents the most commonly ruptured tendon of the human body. Numerous studies have evaluated, throughout the years, management options regarding acute Achilles tendon rupture. Minimally invasive techniques have recently gained more popularity. Endoscopic flexor hallucis longus tendon transfer has been mainly described as a treatment method for neglected Achilles tendon ruptures. However, it has recently been described as an applicable treatment option for acute Achilles tendon ruptures as well. Nevertheless, this procedure is technically quite demanding and should be performed by experienced surgeons. This technical note thoroughly describes the endoscopic flexor hallucis longus transfer technique for acute Achilles tendon ruptures, focusing on the most important technical aspects, thus attempting to simplify and render this procedure more widely accepted.

Transfer of the Flexor Hallucis Longus Tendon Improves Joint Kinematics of the Medial Column during Simulated Stance Phase in Progressive Collapsing Foot Deformity

Category: Hindfoot; Midfoot/Forefoot Introduction/Purpose: Medial longitudinal arch collapse is one of the key clinical and radiographic features of progressive collapsing foot deformity (PCFD) and can occur anywhere within its three constituents: first tarsometatarsal (TMT1), naviculo- cuneiform (NC), and talonavicular (TN) joints. Medial column osteotomy or fusion has typically been utilized to address this instability. A new procedure involving transferring the flexor hallucis longus (FHL) tendon to the 1st metatarsal base has shown promising results in restoring radiographic alignment of the entire medial column in conjunction with a hindfoot procedure. However, the mechanism of correction in a dynamic environment is unclear. Thus, this study examined the effect of medial column stabilization using FHL transfer on the foot and ankle kinematics during stance phase. Methods: Twelve mid-tibia cadaveric specimen (6 male; Age 48 ± 16 years) underwent stance phase simulations using a validated six-degree of freedom robotic gait simulator. Three conditions were tested each cadaveric specimen: pre-deformity (Intact), after creating a simulated progressive collapsing foot deformity (sPCFD), and after an FHL transfer (FHL). Motion capture cameras tracked the motion of retroreflective markers inserted into bones of the foot and ankle. The FHL transfer was performed on each specimen by harvesting the FHL tendon at its distal insertion and fixing it in the 1st metatarsal with a biotenodesis screw (Figure 1A). Outcome measures include joint rotations of the TMT1, NC, TN, subtalar, and ankle joint. Significant differences (p &lt; 0.05) in joint kinematics were statistically analyzed by constructing 95% confidence intervals of the repeated measures difference between both the sPCFD and FHL conditions and the intact condition. Results: The FHL condition demonstrated significant differences in the kinematics of the medial column compared to the sPCFD condition (Figure 1B). The TMT1 joint showed increased plantarflexion in early and late stance, as well as increased eversion during early and mid-stance. The NC joint demonstrated increased plantarflexion, eversion, and abduction during early stance. At the TN joint, there was increased inversion during early and late stance, as well as increased adduction during mid-stance. At the subtalar joint, subtalar eversion was decreased during early stance, and no significant differences were observed from the intact condition throughout stance. No differences were found in the ankle joint kinematics across all conditions. Conclusion: The results of our study demonstrate that the medial column stabilization procedure with FHL transfer can improve the kinematics of the medial column in sPCFD. Additionally, the correction at the TN and subtalar joint demonstrates the potential efficacy of this procedure for hindfoot correction. The correction occurred during the earlier stance phase as well when the FHL is not active, suggesting that this procedure provides correction in both a dynamic and static manner. This procedure can be used in conjunction with hindfoot corrective procedures in PCFD, particularly when preoperative imaging suggests multiple levels of instability within the medial column.

Integrity of the First Metatarsal Head Vascularization and Soft-Tissue Envelope Following Minimally Invasive Chevron Osteotomy for Hallux Valgus (HV) Deformity: A Micro-CT and Anatomical Assessment

Category: Bunion; Midfoot/Forefoot Introduction/Purpose: Minimally invasive surgery (MIS) Chevron-osteotomy for HV treatment offers a surgical alternative to open surgery with minimal surgical dissection and a hypothetical decreased risk for soft-tissue complications. During this procedure, there is a concern regarding the injury to the blood supply of the 1st-metatarsal-head. The objective of this study was to assess the incidence of injuries: (1) to the soft-tissue envelope around the first metatarsal head complex and, (2) to the blood supply of the first metatarsal head and also by using Micro-CT, (3) looking for safe zones close to the first metatarsal head to perform MIS Chevron osteotomy. We hypothesized that the MIS Chevron-type osteotomy procedure would preserve the soft-tissue envelope of the first-metatarsal-head complex and the blood supply of the 1st-metatarsal-head. Methods: Sixteen HV deformity cadaveric specimens were used to perform MIS Chevron-type osteotomy of the first metatarsal head. Anatomical dissection of all specimens was then performed to assess macroscopic injury to the first metatarsal head complex soft-tissue structures, including Extensor Hallucis Longus (EHL) tendon, Extensor Hallucis Brevis (EHB) tendon, Flexor Hallucis Longus (FHL) tendon, Flexor Hallucis Brevis (FHB) tendon, Abductor Hallucis tendon, Adductor Hallucis tendon, Sesamoid complex, Dorsolateral and Dorsomedial digital branches of the first toe and the Dorsomedial digital branch to the second. Macroscopic injuries were classified using a calibrated digital caliper. Any chondral damage to the first metatarsal head was quantified in mm². To assess the amount of first metatarsal head blood supply, specimens were perfused with 200 ml of a low viscosity radiopaque polymer, MV 117 (Flowtech), preoperatively, followed by Micro-CT assessment. Descriptive statistics and percentages were utilized for categorical data. Results: We did not find injuries in the EHL, EHB, FHL, Abductor-Hallucis, and Adductor-Hallucis tendons. We found a 2mm injury in the FHB tendon in one specimen. No injuries were found in the Dorsomedial and Dorsolateral nerves of the first-toe, the Dorsomedial-nerve of the second-toe, and Medial branch of the dorsomedial-nerve of the first-toe. In 3 cases, we found an injury on first-metatarsal-head (1mm) due to the passage of the K-wire and, in 1 case, due to the inadvertent passage of the drill (4.41mm). Macroscopically and using Micro-CT, we did not observe injuries in the First-Dorsal-Metatarsal-Artery (FDMA), Lateral-Dorsal-Branch of FDMA, and Plantar-Metatarsal-Artery. Micro-CT helped estimate a safe distance to finish the proximal exit of Chevron-osteotomy (25mm from the most distal point of the first metatarsal head). Conclusion: In this study, the minimally invasive Chevron osteotomy for treating HV seems to be a technically safe procedure, presenting a low rate of iatrogenic injuries with a low degree of severity. In addition, using Micro-CT promoted a better visualization of the microvasculature that nourishes the first metatarsal head. We observed that a proximal distance of 25 mm from the most distal part of the first metatarsal head could be a safe place to finalize the Chevron osteotomy, minimizing the risk of injury to the blood supply of the first metatarsal head.

Long-term outcome of flexor hallucis longus tendon transfer for chronic Achilles tendon rupture with large defect: A retrospective series.

There are multiple surgical options for treatment of chronic Achilles tendon (AT) rupture according to the classifications and length of defect. However, no gold standard method has been confirmed, and there is no clear evidence to support the superiority of 1 procedure over others. This study aimed to evaluate the long-term clinical outcome of flexor hallucis longus tendon (FHL) transfer for chronic AT rupture with large defect. Clinical data of patients treated with FHL transfer due to chronic AT rupture between January 2009 and October 2019 were reviewed retrospectively. All cases were presented with AT rupture for more than 4 weeks after injury. The gap between ruptured ends was > 5 cm after debridement in all patients. The harvest of FHL was performed through a single incision in accordance with AT rupture debridement in all cases. Clinical outcomes were assessed with AOFAS ankle-hindfoot scale, Achilles tendon total rupture score and AOFAS hallux metatarsophalangeal-interphalangeal scale. Twenty-eight patients were followed successfully for 62.6 ± 22.2 months. According to the complete datasets obtained from 28 patients, none of the tendons re-ruptured. The AOFAS ankle-hindfoot scale and Achilles tendon total rupture score at last follow-up visit was 90.4 ± 5.7 and 89.8 ± 5.3 respectively, which revealed statistically significant improvement from the preoperative score of 61.1 ± 6.7 and 53.8 ± 8.3. The AOFAS hallux metatarsophalangeal-interphalangeal scale at last follow-up visit was 87.5 ± 6.1. The FHL transfer through a single incision for chronic AT rupture with large defect is a safe and simple method with low risk of morbidity and complications.