Posterior tibial tendon dysfunction: an overlooked cause of foot deformity

Differential Diagnosis of Charcot Neuroarthropathy in Subacute and Chronic Phases: Unusual Diseases

Charcot Neuroarthropaty (CN) is a complication of diabetes with devastating consequences as it produces severe deformities in the foot developing in recurrent ulcers that rise the probability of amputation. There are several diseases mentioned in the literature that have to be considered for the differential diagnosis of CN, often related to the acute phase (gout, ankle sprain, inflammatory arthritis, cellulitis, venous thrombosis) but there is paucity of information related to the differential diagnosis in later stages (coalescence, remodeling) when there is deformity of the foot. Clinicians and diabetologists are not familiarized with orthopedic pathology and do not have in mind certain diseases that could mimic CN in the subacute or chronic phases and this can develop in a wrong diagnosis. It is important to make a correct diagnosis in patients with suspected CN not only in the acute phase but also in the chronic phase to establish an accurate treatment. This article is a review of the differential diagnosis of CN in subacute and chronic phases showing similarities and differences that can help clinicians and diabetologists to make an accurate diagnosis and treatment. We describe unusual diseases like tendon and muscles disorders, Frieberg's disease, complex pain regional syndrome, transient regional osteoporosis and osteomyelitis superimposed to CN and the main features of each one that could help in making a differential diagnosis.

Planovalgus Foot Deformity in Patients Undergoing Total Hip Arthroplasty Is Associated With Increased Risk of Falls, Implant-Related Complications, and Revisions: A Case-Control Analysis

BACKGROUND

Pes planus occurs due to the loss of the longitudinal arch of the foot, resulting in altered gait mechanics. This may lead to increased complications following total hip arthroplasty (THA). Thus, the aim of this study was to assess the effects that pes planus has on rates of falls, implant complications, fall-related injuries, and times to revision among THA patients.

METHODS

A retrospective review of a private insurance claims database was conducted from 2010 to 2021. Patients who had a diagnosis of congenital or acquired pes planus and cases of THA were identified. Patients undergoing THA with a diagnosis of pes planus were matched to control patients 1:5 based on age, sex, and comorbidity profiles. Logistic regression was utilized to assess for differences in complication rates.

RESULTS

A total of 3,622 pes planus patients were matched to 18,094 control patients. The pes planus group had significantly higher rates of falls than the control group (6.93 versus 2.97%, OR [odds ratio]: 2.43; CI [confidence interval]: 2.09 to 2.84; P < .001). Pes planus patients also had significantly greater odds of dislocation (OR: 1.89; CI: 1.58 to 2.27; P < .001), mechanical loosening (OR: 2.43; CI: 2.09 to 2.84; P = .019), and periprosthetic fracture (OR: 2.43; CI: 2.09 to 2.84; P < .001). The pes planus group had significantly greater rates of proximal humerus fractures (P = .008), but no difference was seen in distal radius fractures (P = .102). The time to revision was significantly shorter in the pes planus group (190 versus 554 days, P < .001).

CONCLUSIONS

Pes planus in patients undergoing THA is associated with increased risk of complications and faster time to revision. These findings may allow orthopaedic surgeons to identify those patients at risk and allow for more educated patient counseling and operative planning.

Ankle Telemedicine Planning Considerations

A virtual medical visit, also known as telemedicine or telehealth, is a valuable alternative method of providing health care to patients who do not have easy access to a hospital, or during times when limited social interaction is crucial such as our current COVID-19 pandemic. A virtual approach to evaluating musculoskeletal system ailments is particularly challenging, for diagnosis of these conditions generally rely greatly on physical examination, which may be challenging. However, a properly planned and executed telemedicine visit will yield successful results in most cases. Our aim is to produce a document with instructions and suggestions, including physical examination maneuvers, to help physicians carry out a proper virtual medical visit with patients complaining of ankle musculoskeletal problems. Virtual visits should not be thought of as a replacement for traditional face-to-face medical consultations, but rather a complementary method to provide health care when deemed appropriate. By following this guide, and tailoring it to the specific case at hand, medical providers should be able to effectively carry out a successful telemedicine consultation for musculoskeletal ailments relating to the ankle.Levels of Evidence: Level V.

Chasing footprints in time - reframing our understanding of human foot function in the context of current evidence and emerging insights

In this narrative review we evaluate foundational biomechanical theories of human foot function in light of new data acquired with technology that was not available to early researchers. The formulation and perpetuation of early theories about foot function largely involved scientists who were medically trained with an interest in palaeoanthropology, driven by a desire to understand human foot pathologies. Early observations of people with flat feet and foot pain were analogized to those of our primate ancestors, with the concept of flat feet being a primitive trait, which was a driving influence in early foot biomechanics research. We describe the early emergence of the mobile adaptor-rigid lever theory, which was central to most biomechanical theories of human foot function. Many of these theories attempt to explain how a presumed stiffening behaviour of the foot enables forward propulsion. Interestingly, none of the subsequent theories have been able to explain how the foot stiffens for propulsion. Within this review we highlight the key omission that the mobile adaptor-rigid lever paradigm was never experimentally tested. We show based on current evidence that foot (quasi-)stiffness does not actually increase prior to, nor during propulsion. Based on current evidence, it is clear that the mechanical function of the foot is highly versatile. This function is adaptively controlled by the central nervous system to allow the foot to meet the wide variety of demands necessary for human locomotion. Importantly, it seems that substantial joint mobility is essential for this function. We suggest refraining from using simple, mechanical analogies to explain holistic foot function. We urge the scientific community to abandon the long-held mobile adaptor-rigid lever paradigm, and instead to acknowledge the versatile and non-linear mechanical behaviour of a foot that is adapted to meet constantly varying locomotory demands.

Enhancing Functional Rehabilitation Through Orthotic Interventions for Foot and Ankle Conditions: A Narrative Review

Non-surgical, conservative approaches to foot and ankle conditions are of important consideration. Orthotics play a significant role in treating these conditions, preventing progression, and alleviating pressure on affected areas, thereby promoting normal gait. This article aims to assess the utility and effectiveness of various orthotic treatments in different clinical scenarios. We reviewed 27 peer-reviewed articles using electronic databases, employing keywords such as "orthoses," "orthotic treatment," "arthritis," "neuropathy," and "foot and ankle trauma." Studies conducted in recent decades have explored the effectiveness of orthoses in various conditions, including connective tissue disorders, tendon and ligament injuries, foot arthritis, neuropathic and inflammatory wounds, and sports-related recurrent injuries. Orthotic management has proven effective across diverse foot and ankle conditions. Integrating orthotic treatment with systemic approaches benefits patients with foot and ankle disorders. We believe this review can be utilised by clinicians in the management of foot and ankle disorders.

Cavovarus deformity of one foot with planovalgus deformity of the contralateral foot (Wind-swept heels): A case report

Normal alignment of the arches and adequate stability is essential for the foot to function correctly. Pes planus and pes cavus are fairly common foot deformities, but it is uncommon to see both in the same patient simultaneously. This study aimed to describe the clinical presentation and prognosis of an uncommon combination of bilateral foot abnormalities named “windswept heels” resembling windswept knees. A 43-year-old female employee experienced frequent pain in her right foot and swelling and pain in her left foot, mainly when walking barefoot. She had a severe cavovarus deformity of the right foot with pressure callosities on the lateral side, clawing of the toes, and a positive Coleman’s block test. With the loss of the medial arch, severe heel valgus, and forefoot abduction, the left foot developed a planovalgus deformity. The left foot’s talus-first metatarsal angle and the right foot’s calcaneal inclination angle increased on weight-bearing radiographs. The left foot underwent staged surgical treatments, including medial sliding calcaneal osteotomy, gastrocnemius recession, and cotton osteotomy. For the right foot, lateral sliding calcaneal osteotomy, plantar fasciotomy, and peroneus longus tendon transfer. The American Orthopaedics Foot and Ankle Society Score (AOFAS) was used to measure the clinical and functional outcomes. At 1 year, her AOFAS scale was 85 compared to 59 before surgery. Since this presentation resembles the windswept knee deformity, we propose calling this disorder windswept heel deformity.

A computational model of force within the ligaments and tendons in progressive collapsing foot deformity

Progressive collapsing foot deformity results from degeneration of the ligaments and posterior tibial tendon (PTT). Our understanding of the relationship between their failures remains incomplete. We sought to improve this understanding through computational modeling of the forces in these soft tissues. The impact of PTT and ligament failures on force changes in the remaining ligaments was investigated by quantifying ligament force changes during simulated ligament and tendon cutting in a validated finite element model of the foot. The ability of the PTT to restore foot alignment was also evaluated by increasing the PTT force in a foot with attenuated ligaments and comparing the alignment angles to the intact foot. We found that failure of any one of the ligaments led to overloading the remaining ligaments, except for the plantar naviculocuneiform, first plantar tarsometatarsal, and spring ligaments, where removing one led to unloading the other two. The combined attenuation of the plantar fascia, long plantar, short plantar, and spring ligaments significantly overloaded the deltoid and talocalcaneal ligaments. Isolated PTT rupture had no effect on foot alignment but did increase the force in the deltoid and spring ligaments. Moreover, increasing the force within the PTT to 30% of body weight was effective at restoring foot alignment during quiet stance, primarily through reducing hindfoot valgus and forefoot abduction as opposed to improving arch collapse. Our findings suggest that early intervention might be used to prevent the progression of deformity. Moreover, strengthening the PTT through therapeutic exercise might improve its ability to restore foot alignment.

How Common is Subsequent Posterior Tibial Tendon Dysfunction or Tarsal Tunnel Syndrome After Ankle Sprain Injury?

Posterior tibial tendon dysfunction (PTTD) and tarsal tunnel syndrome (TTS) are debilitating conditions reported to occur after ankle sprain due to their proximity to the ankle complex. The objective of this study was to investigate the incidence of PTTD and TTS in the 2 years following an ankle sprain and which variables are associated with its onset. In total, 22,966 individuals in the Military Health System diagnosed with ankle sprain between 2010 and 2011 were followed for 2 years. The incidence of PTTD and TTS after ankle sprain was identified. Binary logistic regression was used to identify potential demographic or medical history factors associated with PTTD or TTS. In total, 617 (2.7%) received a PTTD diagnosis and 127 (0.6%) received a TTS diagnosis. Active-duty status (odds ratio [OR] 2.18, 95% confidence interval [CI] 1.70-2.79), increasing age (OR 1.03, 95% CI 1.02-1.04), female sex (OR 1.58, 95% CI 1.28-1.95), and if the sprain location was specified by the diagnosis (versus unspecified location) and did not include a fracture contributed to significantly higher (p < 0.001) risk of developing PTTD. Greater age (OR 1.06, 95% CI 1.03-1.09), female sex (OR 2.73, 95% CI 1.74-4.29), history of metabolic syndrome (OR 1.73, 95% CI 1.03-2.89), and active-duty status (OR 2.28, 95% CI 1.38-3.77) also significantly increased the odds of developing TTS, while sustaining a concurrent ankle fracture with the initial ankle sprain (OR 0.45, 95% CI 0.28-0.70) significantly decreased the odds. PTTD and TTS were not common after ankle sprain. However, they still merit consideration as postinjury sequelae, especially in patients with persistent symptoms. Increasing age, type of sprain, female sex, metabolic syndrome, and active-duty status were all significantly associated with the development of one or both subsequent injuries. This work provides normative data for incidence rates of these subsequent injuries and can help increase awareness of these conditions, leading to improved management of refractory ankle sprain injuries.

Outcomes Following the Use of Subtalar Arthroereisis in the Correction of Adult Acquired Flatfoot: A Systematic Review

BACKGROUND

Adult acquired flatfoot deformity (AAFD) is a condition affecting approximately 3% of the adult population. It can lead to severe morbidity, and therefore, prompt treatment is of the upmost importance in maintaining and restoring function. Recently, the use of subtalar arthroereisis has become more widespread in the treatment of AAFD. The purpose of this systematic review is to examine the clinical and radiological outcomes of AAFD when treated with subtalar arthroereisis.

METHODS

Studies involving the use of subtalar arthroereisis for the management of AAFD were reviewed, and appropriate studies selected based on inclusion and exclusion criteria. Studies were reviewed for both clinical and radiological outcomes following the use of subtalar arthroereisis as well as reported complications.

RESULTS

Nine studies met our inclusion criteria, with most of these involving stage II AAFD. A total of 190 subtalar arthroereisis procedures were performed with all studies demonstrating improvement in both clinical and radiological scores with a low rate of complications.

CONCLUSION

Subtalar arthroereisis may have benefits when used as an adjunct to treat stage II AAFD. However, more high-quality studies are needed to establish its best use.

LEVELS OF EVIDENCE

Level IV: Systematic review.

A 3-Dimensional Gait Analysis of the Effects of Fatigue-Induced Reduced Foot Adductor Muscle Strength on the Walking of Healthy Subjects

Dysfunction of the tibialis posterior muscle is the most common cause of adult acquired flat foot. Tibialis posterior muscle weakness has been observed in several patient populations, including those in the early stages of rheumatoid arthritis. However, the influence of tibialis posterior weakness on gait mechanics is not fully understood, although gait instability has been reported. In 24 healthy participants, 3-dimension lower limb kinematics and kinetics during walking were evaluated bilaterally, before and after, a muscle fatigue protocol aiming to decrease the right foot adductor muscles strength, including the tibialis posterior muscle. The 3-dimension gait kinematics and kinetics were analyzed with statistical parametric mapping. The stance phase duration was increased for the right side. The right ankle external rotation moment decreased, and the left hip extension moment increased with reduced muscle strength compared with normal strength conditions. These changes are similar in patients with dysfunction in the tibialis posterior muscle, indicating that compensatory strategies observed in these patients might be related to the loss of tibialis posterior muscle strength. Such strategies may involve the unaffected side.

Lower Macromolecular Content in Tendons of Female Patients with Osteoporosis versus Patients with Osteopenia Detected by Ultrashort Echo Time (UTE) MRI

Tendons and bones comprise a special interacting unit where mechanical, biochemical, and metabolic interplays are continuously in effect. Bone loss in osteoporosis (OPo) and its earlier stage disease, osteopenia (OPe), may be coupled with a reduction in tendon quality. Noninvasive means for quantitatively evaluating tendon quality during disease progression may be critically important for the improvement of characterization and treatment optimization in patients with bone mineral density disorders. Though clinical magnetic resonance imaging (MRI) sequences are not typically capable of directly visualizing tendons, ultrashort echo time MRI (UTE-MRI) is able to acquire a high signal from tendons. Magnetization transfer (MT) modeling combined with UTE-MRI (i.e., UTE-MT-modeling) can indirectly assess macromolecular proton content in tendons. This study aimed to determine whether UTE-MT-modeling could detect differences in tendon quality across a spectrum of bone health. The lower legs of 14 OPe (72 ± 6 years) and 31 OPo (73 ± 6 years) female patients, as well as 30 female participants with normal bone (Normal-Bone, 36 ± 19 years), are imaged using UTE sequences on a 3T MRI scanner. Institutional review board approval is obtained for the study, and all recruited subjects provided written informed consent. A T1 measurement and UTE-MT-modeling are performed on the anterior tibialis tendon (ATT), posterior tibialis tendon (PTT), and the proximal Achilles tendon (PAT) of all subjects. The macromolecular fraction (MMF) is estimated as the main measure from UTE-MT-modeling. The mean MMF in all the investigated tendons was significantly lower in OPo patients compared with the Normal-Bone cohort (mean difference of 24.2%, p < 0.01), with the largest Normal-Bone vs. OPo difference observed in the ATT (mean difference of 32.1%, p < 0.01). Average MMF values of all the studied tendons are significantly lower in the OPo cohort compared with the OPe cohort (mean difference 16.8%, p = 0.02). Only the PPT shows significantly higher T1 values in OPo patients compared with the Normal-Bone cohort (mean difference 17.6%, p < 0.01). Considering the differences between OPo and OPe groups with similar age ranges, tendon deterioration associated with declining bone health was found to be larger than a priori detected differences caused purely by aging, highlighting UTE-MT MRI techniques as useful methods in assessing tendon quality over the course of progressive bone weakening.

Fusion Versus Joint-Sparing Reconstruction for Patients With Flexible Flatfoot

AIMS

Passively correctible, adult-acquired flatfoot deformities (AAFD) are treated with joint-sparing procedures. Questions remain as to the efficacy of such procedures when clinical deformities are severe. In severe deformities, a primary fusion may lead to predictable outcomes, but risks nonunion. We evaluated pre- and postsurgical flexible AAFD patients undergoing joint-sparing or fusion procedures, comparing reoperation and complication rates.

METHODS

We identified patients with flexible AAFD between January 1, 2001 and 2016. Exclusion criteria were incomplete medical record, rigid AAFD, and prior flatfoot surgery. Patient demographics, pre- and postsurgical radiographic measurements, surgery performed, and postoperative complications were evaluated by bivariate analysis, comparing joint-sparing versus fusion procedures.

RESULTS

Of 239 patients (255 feet) (mean follow-up 62 ± 50 months), 209 (87%) underwent joint-sparing reconstructions, 30 (12.6%) underwent fusions. Fifty-four (24.1%) feet underwent joint-sparing reconstruction with reoperation versus 11 (35.5%) in fusion patients (P = .17). Radiographic improvement in talonavicular angle, talar first-metatarsal (anteroposterior view), and Meary's angle was higher in fusion patients (P < .001, P < .001, and P = .003, respectively).

DISCUSSION

More nonunion reoperations among fusion patients were offset by reoperations in joint-sparing patients. Fusion uniquely corrected Meary's angle. Nonunion is of less concern for joint-sparing versus fusion for patients with severe flexible AAFD. Degree of deformity versus advantage of joint motion should improve decision making.

LEVELS OF EVIDENCE

Level IV: Retrospective case series.

The awareness of hindfoot malalignment on non-weight-bearing ankle MRI

OBJECTIVE

Hindfoot malalignment is a relatively common clinical finding and several studies have suggested that hindfoot valgus can be identified on non-weight-bearing ankle MRI. The aim of this study was to determine the awareness of hindfoot malalignment on ankle MRI amongst consultant musculoskeletal radiologists.

MATERIALS AND METHODS

All MRI studies referred by Foot and Ankle Unit Consultants reported by one of 14 consultant musculoskeletal radiologists between March 2016 and August 2019 were retrieved from the Hospital Radiology Information System. These were reviewed independently by a radiology fellow and a consultant radiologist. Tibiocalcaneal angle (TCA) was measured, and extra-articular talocalcaneal (EA-TCI) and calcaneofibular impingement (EA-CFI) were recorded. Radiology reports were then analysed for mention of hindfoot malalignment and the presence of EA-TCI and EA-CFI.

RESULTS

The study group comprised 129 patients, 46 males and 83 females with a mean age of 46.8 years (range 8-84 years). Based on review, hindfoot valgus was present in 78-80 cases (60.5-62%), EA-TCI in 30-36 cases (23.2-27.9%) and EA-CFI in 18-21 cases (14-16.3%). By comparison, MRI reports mentioned hindfoot valgus in 18 cases (2 incorrectly), EA-TCI in 8 cases (1 incorrectly) and EA-CFI in 10 cases (1 incorrectly).

CONCLUSION

Hindfoot valgus, EA-TCI and EA-CFI were present relatively commonly on review of ankle MRI studies in patients referred from a specialist Foot and Ankle Unit but were commonly under-reported highlighting a relative lack of awareness of hindfoot malalignment on ankle MRI amongst musculoskeletal radiologists, which could impact negatively on patient management.

Impact of a dynamic ankle orthosis on acute pain and function in patients with mechanical foot and ankle pain

BACKGROUND

Over two million Americans visit the doctor each year for foot and ankle pain stemming from a degenerative condition or injury. Ankle-foot orthoses can effectively manage symptoms, but traditional designs have limitations. This study investigates the acute impact of a novel "dynamic ankle-foot orthosis" ("orthosis") in populations with mechanical pain (from motion or weight-bearing).

METHODS

With and without the brace, participants (n = 25) performed standing, over-ground level walking, treadmill level walking, stair ascent, stair descent, single leg hold, squat, and sitting. Instrumented insoles captured in-shoe vertical forces and a visual analog scale was used to assess pain levels during each activity. Subsequently, the self-perceived impact of the orthosis on the patient's symptoms and function was ranked on a scale from -10 (most worsened) to +10 (most improved).

FINDINGS

Peak in-shoe force was reduced during level and stair walking (P < 0.05). Average perceived pain was 1.2 to 1.6 points lower in the orthosis than the unbraced control for the active tasks. The majority of participants reported that the brace improved their symptoms (n = 19), while a smaller group reported that the brace did not affect their symptoms (n = 5), although average function scores were improved for both groups (+2.4 to +4.5). The group of individuals with improved symptoms included cases of osteoarthritis, tendon dysfunction, chronic pain, sprains, and nerve disorders.

INTERPRETATION

The orthosis effectively improved pain symptoms and improved the ability of impaired individuals to complete functional activities of daily living such as level walking and stair walking.

Chronic Lower Leg Pain in Athletes: Overview of Presentation and Management

BACKGROUND

Athletes with chronic lower leg pain present a diagnostic challenge for clinicians due to the differential diagnoses that must be considered.

PURPOSE/QUESTIONS

We aimed to review the literature for studies on the diagnosis and management of chronic lower leg pain in athletes.

METHODS

A literature review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The PubMed, Scopus, and Cochrane library databases were searched, and articles that examined chronic lower leg pain in athletes were considered for review. Two independent reviewers conducted the search utilizing pertinent Boolean operations.

RESULTS

Following two independent database searches, 275 articles were considered for initial review. After the inclusion and exclusion criteria were applied, 88 were included in the final review. These studies show that the most common causes of lower leg pain in athletes include medial tibial stress syndrome, chronic exertional compartment syndrome, tibial stress fractures, nerve entrapments, lower leg tendinopathies, and popliteal artery entrapment syndrome. Less frequently encountered causes include saphenous nerve entrapment and tendinopathy of the popliteus. Conservative management is the mainstay of care for the majority of cases of chronic lower leg pain; however, surgical intervention may be necessary.

CONCLUSIONS

Multiple conditions may result in lower leg pain in athletes. A focused clinical history and physical examination supplemented with appropriate imaging studies can guide clinicians in diagnosis and management. We provide a table to aid in the differential diagnosis of chronic leg pain in the athlete.

Surgical Management of Symptomatic Adult Pes Planovalgus Secondary to Stage 2B Posterior Tibial Tendon Dysfunction: A Comparison of Two Different Surgical Treatments

BACKGROUND

This study compares radiological and functional outcomes of patients with symptomatic Adult Acquired Flat Foot Deformity (AFFD) secondary to stage 2B Posterior Tibial Tendon Dysfunction (PTTD) treated with either a Subtalar Arthroereisis (SA) implant or a Lateral Column Lengthening (LCL) procedure. The aim of the study is to determine if the Subtalar Arthroereisis procedure is an acceptable surgical adjunct in our treatment armamentarium.

MATERIALS AND METHODS

21 patients (22 feet) were evaluated. 12 consecutive patients (n = 12) underwent a Subtalar Arthroereisis procedure while 9 patients (n = 10) underwent a Lateral Column Lengthening procedure. Functional outcomes were evaluated using the American Orthopaedic Foot and Ankle Score (AOFAS) midfoot score, Short Form 36 (SF-36) and Visual Analog of Pain Scale (VAS), preoperatively and at 6 and 12 months postoperatively. 10 radiological parameters were analyzed. All complications were tabulated.

RESULTS

Significant improvements in functional outcomes were noted in both groups of patients. Radiographically, some loss of correction was noted in the SA group and no loss of correction in the LCL group, respectively. In the SA group, 6 patients complained of sinus tarsi pain in the postoperative period and 4 required removal of implants. No implants were removed in the LCL group.

CONCLUSION

The results suggest that subtalar arthroereisis may be a reasonable procedure to utilize in the treatment of AAFD, albeit with a relatively high implant-removal rate.

Fluid around the distal tibialis posterior tendon on ankle MRI: prevalence and clinical relevance

OBJECTIVE

It has been stated that the distal 1-2 cm of the tibialis posterior tendon (TPT) does not have a tendon sheath but rather a paratenon, and that any fluid seen around this segment on ankle MRI is considered to represent paratendonitis. The prevalence and clinical significance of isolated TPT paratendonitis diagnosed on ankle MRI is unknown. This study aims to correlate the presence of isolated distal segment TPT paratendonitis on ankle MRI, with the presence or absence of medial midfoot pain.

METHODS

A retrospective database of 195 consecutive 3 T ankle MRI studies was assessed for the presence of isolated TPT paratendonitis. Relevant clinical notes were available in 159 of these cases, and were reviewed for the absence or presence of medial midfoot pain.

RESULTS

Of 133 patients with both ankle MRI studies and clinical notes available, 53 (33.3%) patients had isolated TPT paratendonitis based on MRI. Of these, 37 (69.8%) had reported no medial foot pain on review of clinical records, while medial foot pain was recorded in 16 cases (30.2%). The comparison of TPT paratendonitis with clinically evident medial midfoot pain showed no statistically significant association (p = 0.19).

CONCLUSION

Fluid signal intensity around the distal 1-2 cm of the TPT is a relatively common finding on ankle MRI. Therefore, care should be taken when reporting ankle MRI studies not to overstate the relevance of this finding.

ADVANCES IN KNOWLEDGE

There was no statistically significant relationship between medial midfoot pain and the presence of isolated TPT paratendonitis.

Age-related decrease in collagen proton fraction in tibial tendons estimated by magnetization transfer modeling of ultrashort echo time magnetic resonance imaging (UTE-MRI)

Clinical magnetic resonance imaging (MRI) sequences are not often capable of directly visualizing tendons. Ultrashort echo time (UTE) MRI can acquire high signal from tendons thus enabling quantitative assessments. Magnetization transfer (MT) modeling combined with UTE-MRI—UTE-MT-modeling—can indirectly assess macromolecular protons in the tendon. This study aimed to determine if UTE-MT-modeling is a quantitative technique sensitive to the age-related changes of tendons. The legs of 26 young healthy (29 ± 6 years old) and 22 elderly (75 ± 8 years old) female subjects were imaged using UTE sequences on a 3T MRI scanner. Institutional review board approval was obtained, and all recruited subjects provided written informed consent. T1 and UTE-MT-modeling were performed on anterior tibialis tendons (ATT) and posterior tibialis tendons (PTT) as two representative human leg tendons. A series of MT pulse saturation powers (500–1500°) and frequency offsets (2–50 kHz) were used to measure the macromolecular fraction (MMF) and macromolecular T2 (T2_MM). All measurements were repeated by three independent readers for a reproducibility study. MMF demonstrated significantly lower values on average in the elderly cohort compared with the younger cohort for both ATT (decreased by 16.8%, p = 0.03) and PTT (decreased by 23.0%, p < 0.01). T2_MM and T1 did not show a significant nor a consistent difference between the young and elderly cohorts. For all MRI parameters, intraclass correlation coefficient (ICC) was higher than 0.98, indicating excellent consistency between measurements performed by independent readers. MMF serving as a surrogate measure for collagen content, showed a significant decrease in elderly leg tendons. This study highlighted UTE-MRI-MT techniques as a useful quantitative method to assess the impact of aging on human tendons.

T2* mapping and subregion analysis of the tibialis posterior tendon using 3 Tesla magnetic resonance imaging

OBJECTIVE

Early detection of tibialis posterior tendon changes and appropriate intervention is necessary to prevent disease progression to flat-foot deformity and foot/ankle dysfunction, and the need for operative treatment. Currently, differentiating between early-stage tibialis posterior tendon deficiency patients who will benefit from conservative vs more aggressive treatment is challenging. The objective of this work was to establish a quantitative MRI T2* mapping method and subregion baseline values in the tibialis posterior tendon in asymptomatic ankles for future clinical application in detecting tendon degeneration.

METHODS

26 asymptomatic volunteers underwent T2* mapping. The tendon was divided axially into seven subregions. Summary statistics for T2* within each subregion were calculated and compared using Tukey post-hoc pairwise comparisons.

RESULTS

Results are reported for 24 subjects. The mean tibialis posterior tendon T2* was 7 ± 1 ms. Subregion values ranged from 6 ± 1 to 9 ± 2 ms with significant between-region differences in T2*. Inter- and intrarater absolute agreement intraclass correlation coefficient (ICC) values were all "excellent" (0.75 < ICC=1.00) except for regions 5 through 7, which had "fair to good" interrater and/or and intrarater ICC values (0.4 < ICC=0.75).

CONCLUSION

A tibialis posterior tendon T2* mapping protocol, subregion division method, and baseline T2* values for clinically relevant regions were established. Significant differences in T2* were observed along the tendon length.

ADVANCES IN KNOWLEDGE

This work demonstrates that regional variation exists and should be considered for future T2*-based research on posterior tibias tendon degeneration and when using T2* mapping to evaluate for potential tibialis posterior tendon degeneration.

Surgical Considerations: Repair of Long Segment Defect Posterior Tibial Tendon Using Fresh Frozen Tibial Tendon Allograft

Tibialis posterior (TP) tendon ruptures are common after ankle injuries, degenerative processes, or biomechanical instability. The TP tendon decelerates the subtalar joint pronation and internal rotation of the leg during the contact phase. It also plantarflexes and inverts the foot on the leg during the static phase of gait. When this function is lost, the medial longitudinal arch collapses, increasing the length of time of rearfoot pronation, eventually rupturing the TP tendon. Conservative treatment includes immobilization, strapping, antiinflammatories, custom-fabricated orthotics, and physical therapy. If the TP tendon rupture is severe, conservative treatment will provide little relief and surgery is indicated. This case study presents 53-year-old female who presented with left TP tendon rupture with a defect of 6 cm after sustaining an ankle injury that was surgically repaired using a TP tendon fresh frozen allograft and flexor digitorum longus tenodesis. After a 16-month follow-up, the patient was healed without complications and returned to preinjury activity. We believe that surgically repairing a TP tendon rupture with a TP tendon allograft and flexor digitorum longus tenodesis can be 1 of the treatment options for patients with extensive disruption of the TP tendon.

A proposal for a new classification for the tendon of insertion of tibialis posterior

Although the tendon of the tibialis posterior muscle (TPM) is high morphological variability, its insertion is not well defined in anatomy discussions. The aim of the work is to systematize the classification of tibialis posterior tendon insertion by anatomical dissection. Classical anatomical dissection was performed on 80 lower limbs (40 female, 40 male) fixed in 10% formalin solution. The morphology of the insertion of the tendon was evaluated, and the muscle was subjected to appropriate morphometric measurements. Four types of insertion were observed, the most common being Type III (35 cases - 43.75%): a triple distal attachment where the main tendon inserts to the navicular bone and the medial cuneiform bone, and two accessory bands insert to the medial, lateral, or intermediate cuneiform bone or to the metatarsal bones (II, III, IV, V) depending on subtypes (A-C). The second most common type was Type II (18 cases: 22.5%): a double distal attachment. Type IV (14 cases: 17.5%) was characterized by quadruple distal attachment and was also divided into three subtypes (A-B). The rarest type was Type I (13 cases: 16.25%), which was characterized by a single band: the main tendon inserts to the navicular bone and the medial cuneiform bone. The tendon of the TPM presents high morphological variability. Knowledge of the four particular types of insertions is essential for both clinicians and anatomists. Clin. Anat. 32:557-565, 2019. © 2019 Wiley Periodicals, Inc.

Sonographic and radiographic findings of posterior tibial tendon dysfunction: a practical step forward

The purpose of this article is to describe the sonographic and radiographic findings in the diagnosis and treatment of posterior tibial tendon dysfunction. Ultrasound and radiographs play a crucial role in the diagnosis of posterior tibial tendon dysfunction and in imaging the postoperative changes related to posterior tibial tendon dysfunction. Early detection and diagnosis of posterior tibial tendon dysfunction is important in helping to prevent further progression of disease, obviating the need for more invasive and complex procedures.

Finite element simulation on posterior tibial tendinopathy: Load transfer alteration and implications to the onset of pes planus

BACKGROUND

Posterior tibial tendinopathy is a challenging foot condition resulting in pes planus, which is difficult to diagnose in the early stage. Prior to the deformity, abnormal internal load transfer and soft tissue attenuation are anticipated. The objective of this study was to investigate the internal load transfer and strain of the ligaments with posterior tibial tendinopathy, and the implications to pes planus and other deformities.

METHODS

A three-dimensional finite element model of the foot and ankle was reconstructed from magnetic resonance images of a 28-year-old normal female. Thirty bones, plantar fascia, ligaments and tendons were reconstructed. With the gait analysis data of the model subject, walking stance was simulated. The onset of posterior tibial tendinopathy was resembled by unloading the tibialis posterior and compared to the normal condition.

FINDINGS

The load transfer of the joints at the proximal medial column was weaken by posterior tibial tendinopathy, which was compromised by the increase along the lateral column and the intercuneiforms during late stance. Besides, the plantar tarsometatarsal and cuboideonavicular ligaments were consistently over-stretched during stance. Particularly, the maximum tensile strain of the plantar tarsometatarsal ligament was about 3-fold higher than normal at initial push-off.

INTERPRETATION

Posterior tibial tendinopathy altered load transfer of the medial column and unbalanced the load between the proximal and distal side of the medial longitudinal arch. Posterior tibial tendinopathy also stretched the midfoot plantar ligaments that jeopardized midfoot stability, and attenuated the transverse arch. All these factors potentially contributed to the progress of pes planus and other foot deformities.

Reported selection criteria for adult acquired flatfoot deformity and posterior tibial tendon dysfunction: Are they one and the same? A systematic review

BACKGROUND

Posterior tibial tendon dysfunction (PTTD) and adult acquired flatfoot deformity (AAFD) are used interchangeably, although both suggest quite different pathological processes.

OBJECTIVE

To investigate key differences in selection criteria used for inclusion into research studies.

METHODS

An electronic database search was performed from inception to June 2016. All primary research articles with clear inclusion/diagnostic criteria for PTTD or AAFD were included in the review. All criteria were extracted and synthesised into one aggregate list. Frequencies of recurring criteria were calculated and reported for each stage of the conditions.

RESULTS

Of the potentially eligible papers, 148 (65%) did not specify inclusion/selection criteria for PTTD or AAFD and were excluded. Eligibility criteria were reported 82 times in the 80 included papers, with 69 descriptions for PTTD and 13 for AAFD. After synthesis of criteria from all papers, there were 18 key signs and symptoms. Signs and symptoms were considered to be those relating to tendon pathology and those relating to structural deformity. The total number of individual inclusion/diagnostic criteria ranged from 2 to 9. The majority of articles required signs of both tendon dysfunction and structural deformity (84% for AAFD and 81% for PTTD). Across both groups, the most frequently reported criteria were abduction of the forefoot (11.5% of total criteria used), the presence of a flexible deformity (10.2%) and difficulty performing a single leg heel raise (10.0%). This was largely the case for the PTTD articles, whereas the AAFD articles were more focused on postural issues such as forefoot abduction, medial arch collapse, and hindfoot valgus (each 16.7%).

CONCLUSION

As well as synthesising the available literature and providing reporting recommendations, this review has identified that many papers investigating PTTD/AAFD do not state condition-specific selection criteria and that this limits their clinical applicability. Key signs and symptoms of PTTD and AAFD appear similar, except in early PTTD where no structural deformity is present. We recommend that PTTD is the preferred terminology for the condition associated with signs of local tendon dysfunction with pain and/or swelling along the tendon and difficulty with inversion and/or single leg heel raise characterising stage I and difficulty with single leg heel raise and a flexible flatfoot deformity characterizing stage II PTTD. While AAFD may be useful as an umbrella term for acquired flatfoot deformities, the specific associated aetiology should be reported in studies to aid consolidation and implementation of research into practice.

TRIAL REGISTRATION

Prospero ID: 42016046943.

Coordination among the rearfoot, midfoot, and forefoot during walking

BACKGROUND

Examining coordination between segments is essential for prevention and treatment of injuries. However, traditional methods such as ratio, cross-correlation technique, and angle-time plot may not provide a complete understanding of intersegmental coordination. The present study aimed to quantify the coordination among the rearfoot, midfoot, and forefoot segments during walking.

METHODS

Twenty healthy young men walked barefoot on a treadmill. Reflective markers were fixed to their right shank and foot based on the Leardini foot model. Three-dimensional joint angles were calculated at the distal segment, and were expressed relative to the adjacent proximal segment. The coupling angle representing intersegmental coordination was calculated by using the modified vector coding technique, and categorized into the following four coordination patterns: in-phase with proximal dominancy, in-phase with distal dominancy, tanti-phase with proximal dominancy, and anti-phase with distal dominancy.

RESULTS

The results showed that the midfoot was dominantly everted compared with the rearfoot and forefoot during the early stance (i.e., the rearfoot-midfoot coordination and midfoot-forefoot coordination were mainly in-phase with distal and proximal dominancy, respectively).

CONCLUSION

This result may suggest that the midfoot plays a more significant role than the rearfoot and forefoot during early stance. The results of the present study can help in understanding the interaction of the intersegmental foot kinematic time series during walking. The results could be used as data to distinguish the presence of injuries or abnormal inter-segmental foot motions such as pes planus. Additionally, these data might be used in the future in a comparison with data on foot deformities.

Ultrasound evaluation of adult-acquired flatfoot deformity: Emphasis on the involvement of spring ligament

Adult-acquired flatfoot deformity (AAFD), a condition commonly caused by tibialis posterior tendon (TPT) dysfunction, has recently been recognised to encompass a spectrum of other deformities, including the disruption of the spring ligament complex. This case series reviews eight examples of chronic AAFD, outlines the sonographic assessment of the TPT and spring ligament and depicts various abnormalities of the TPT and spring ligament that are relevant to AAFD. The importance to always include the spring ligament during the assessment of AAFD will be addressed, as misdiagnosis of the involvement of the spring ligament could lead to inappropriate operative management.

Structural damage in rheumatoid arthritis: comparison between tendon damage evaluated by ultrasound and radiographic damage

OBJECTIVE

To compare structural damage assessed by conventional radiography and tendon damage assessed by musculoskeletal US (MSUS) at wrist and ankle in RA patients.

METHODS

We evaluated 72 consecutive patients [56 (77.8%) females] with RA. The MSUS evaluation consisted in a B-mode examination of bilateral extensor carpi ulnaris and tibialis posterior tendons. Tendon damage was defined and scored according to OMERACT. A total score for the tendon damage score (TDS) was calculated by summing the grades for each tendon. For the radiographic evaluations we used the van der Heijde score; a total radiographic score (RTS) was calculated by summing a bone erosion score (ERS) and a joint space narrowing score (JSNS).

RESULTS

We evaluated 288 tendons. The mean (s.d.) of TDS was 2.3 (1.8). Fifty-four (75%) patients presented tendon damage of at least one tendon. From all evaluated tendons, 134 (46.5%) had no tendon damage, 146 (50.7%) had grade 1 and 8 (2.8%) had grade 2 tendon damage. The mean (s.d.) for RTS was 91.4 (97), for ERS was 47.3 (61.9) and for JSNS was 44.1 (37.2). We found a significant correlation between disease duration and both TDS and RTS (r = 0.413 and r = 0.560, respectively; P < 0.0001). We found a good significant correlation between TDS and all variables of radiographic structural damage (RTS, r = 0.65; ERS, r = 0.637; JSNS, r = 0.618; P < 0.001).

CONCLUSION

The MSUS assessment of only four tendons can be an additional feasible method to assess structural damage in RA patients.

Acute tear of tibialis posterior: case report

Tibialis posterior tendon injuries are commonly missed and can result in significant foot deformity. In the young athlete these are best diagnosed acutely with ultrasound and may be treated conservatively or operatively. We present the case of a young serviceman and describe the treatment plan that was successful in allowing an early return to exercise.