CHRONIC RUPTURE OF THE POSTERIOR TIBIAL TENDON

Sinus tarsi and sinus tarsi syndrome: An imaging review

The sinus tarsi is a funnel-shaped region at the junction of mid-foot and hind-foot which contains fat, vessels, nerves and ligaments. The ligaments help stabilise the subtalar joint and maintain the longitudinal arch of the foot. The nerve endings contain proprioceptive fibres indicating a role for the sinus tarsi in movement of the foot. Sinus tarsi syndrome is a clinical entity characterised by lateral hind-foot pain with worsening on palpation and weight-bearing, and perceived instability. It is associated with both traumatic and non-traumatic causes. Magnetic resonance imaging is the imaging modality of choice for assessment of the sinus tarsi and sinus tarsi syndrome. In this review article, we review the anatomy and various aetiologies of sinus tarsi syndrome, along with the imaging appearances.

Does tibialis posterior dysfunction correlate with a worse radiographic overall alignment in progressive collapsing foot deformity? A retrospective study

BACKGROUND

Posterior Tibial Tendon (PTT) dysfunction is considered to have an important role in Progressive Collapsing Foot Deformity (PCFD). The objective of our study was to assess the relationship between PTT status and three-dimensional foot deformity in PCFD.

METHODS

Records from 25 patients with PCFD were included for analysis. The PTT was considered deficient in patients with a positive single heel rise test or a deficit in inversion strength. Three-dimensional foot deformity was assessed using the Foot and Ankle Offset (FAO) from Weight-Bearing-CT imaging. Hindfoot valgus, midfoot abduction and medial longitudinal arch collapse were assessed on X-Rays using hindfoot moment arm, talonavicular coverage angle and Meary's angle respectively. Deland and Rosenberg MRI classifications were used to classify PTT degeneration.

RESULTS

PCFD with PTT deficit (13/25) had a mean FAO of 7.75 + /- 3.8% whereas PCFD without PTT deficit had a mean FAO of 6.68 + /- 3.9% (p = 0.49). No significant difference was found between these groups on the hindfoot moment arm and the talonavicular coverage angle (respectively p = 0.54 and 0.32), whereas the Meary's angle was significantly higher in case of PCFD with PTT deficit (p = 0.037). No significant association was found between PTT degeneration on MRI and FAO.

CONCLUSION

PCFD associated three-dimensional deformity, hindfoot valgus and midfoot abduction were not associated with PTT dysfunction. PTT dysfunction was only associated with a worse medial longitudinal arch collapse in our study. Considering our results, it does not appear that PTT is the main contributor to PCFD.

LEVEL OF EVIDENCE

Level III, Retrospective Comparative Study.

Posterior tibial tendon dysfunction: Imperfect specificity of magnetic resonance imaging

MRI is frequently used in the evaluationand treatment of tibialis posterior tendon (PTT) dysfunction. MRI is reported to have sensitivity up to 95%, with 100% specificity, in the detection of rupture of the PTT. We present three cases where MRI demonstrated complete or partial rupture of the PTT, where subsequent surgery showed an intact PTT with tenosynovitis. In all cases, there was a source of inflammation external to the tendon. It is hypothesized that this exogenous origin of inflammation caused changes in the MRI signal in the PTT that resemble that seen in ruptures. These cases show that in the presence of inflammation near the tibialis posterior tendon, the MRI may falsely indicate a high-grade rupture of the tendon. Recommendations for treatment of suspected PTT rupture in the presence of significant other sources of inflammation are proposed.

Tenosynovial fluid as an indication of early posterior tibial tendon dysfunction in patients with normal tendon appearance

OBJECTIVE

Our primary aim was to quantify the posterior tibial tendon (PTT) sheath fluid volume in individuals with the clinical diagnosis of stage 1 posterior tibial tendon dysfunction (PTTD) and no MRI-detectable intra-substance tendon pathology and compare them with patients with other causes of medial ankle pain, also without MRI-detectable intra-substance PTT pathology and with normal controls. We also wanted to determine if there is a fluid measurement that correlates with the clinical diagnosis of PTTD.

MATERIALS AND METHODS

A total of 326 individuals with medial ankle pain and no intra-substance PTT pathology were studied. Group 1 included 48 patients with a clinical diagnosis of stage 1 PTT dysfunction, group 2 comprised 278 patients with other causes of medial ankle pain, and a third control group consisted of 56 patients without any medial ankle pain. MRI-based geometric measurements included PTT fluid volume, maximum cross-sectional fluid area, and fluid width. Fluid measurements were compared between groups and measurement reliability was tested.

RESULTS

Group 1 showed greater PTT fluid volume, area, and width compared with groups 2 (other causes of medial ankle pain) and 3 (asymptomatic controls) (all p values < 0.001). A 9-mm threshold maximum fluid width was associated with PTTD (sensitivity 84%, specificity 85%). Measurements were reliable (all p values < 0.03) among three observers blinded to the gold standard.

CONCLUSION

Patients with stage 1 PTT dysfunction displayed greater volumes of tendon-sheath fluid than those with other causes of medial ankle pain and compared with asymptomatic controls. A threshold maximum fluid width greater than or equal to 9 mm distinguishes those with PTTD. An association between tendon sheath fluid distension and the clinical diagnosis of stage 1 posterior tibial tendon disease in the setting of no MRI-detectable intra-substance tendon pathology may allow for differentiation of medial ankle pain from other sources and may allow for early intervention aimed at preventing progressive PTTD. The level of evidence was prognostic (level III).

Posterior tibial tendon dysfunction: Clinical and magnetic resonance imaging findings having histology as reference standard

OBJECTIVE

To investigate the correlation between MRI, clinical tests, histopathologic features of posterior tibial tendon (PTT) dysfunction in patients with acquired adult flatfoot deformity surgically treated with medializing calcaneal osteotomy and flexor digitorum longus tendon transposition.

MATERIALS AND METHODS

Nineteen patients (11 females; age: 46 ± 15 year, range 18-75) were pre-operatively evaluated using the single heel rise (HR) and the first metatarsal rise (FMR) sign tests. Two reviewers graded the PTT tears on a I-III scale and measured the hindfoot valgus angle on the pre-operative MRI of the ankle. The specimens of the removed portion of PTT were histologically analysed by two pathologists using the Bonar and Movin score. Linear regression, Spearman's rank-order, and intraclass correlation coefficient (ICC) statistics were used.

RESULTS

ICC for MRI was excellent (0.952). Correlation between FMR and HR tests was at limit of significance (r = 0.454; P = 0.051). The HR and FMR tests were significantly correlated to the Movin score (r = 0.581; P = 0.009 and r = 0.538; P = 0.018, respectively) and were not significantly correlated to the Bonar score (both with a r = 0.424; P = 0.070). PTT tendinopathy grading at MRI was significantly correlated to the FMR test (p = 0.041) but not to the hindfoot valgus angle (p = 0.496), the HR test (p = 0.943), the Bonar score (p = 0.937), and the Movin score (p = 0.436). The hindfoot angle was not correlated to any of the other variables (p > 0.264).

CONCLUSION

For PTT dysfunction, there is high correlation between HR and FMR test and histology evaluated using the Movin score, while no correlation was seen for the Bonar score. Semiquantitative grading of PTT dysfunction at MRI only correlates to the FMR and not to histology. The hindfoot valgus angle is not correlated to any of the considered variables.

Posterior Tibial Tendon Dysfunction: An Overview

BACKGROUND

Adult acquired flatfoot deformity is a commonly seen condition with a large clinical spectrum. It ranges from asymptomatic subjects to severely disabled arthritic patients. Posterior tibialis tendon dysfunction is a common cause of adult acquired flatfoot deformity.

METHODS

This article systematically reviews the published literature from books and journals that were either originally written or later translated into the English language regarding the subject of posterior tibialis tendon dysfunction.

RESULTS

Posterior tibialis tendon dysfunction is a primary soft tissue tendinopathy of the posterior tibialis that leads to altered foot biomechanics. Although the natural history of posterior tibialis tendon dysfunction is not fully known, it has mostly been agreed that it is a progressive disorder. While clinical examination is important in diagnosing adult acquired flat-feet; further investigation is often required to delineate the different aetiologies and stage of the disease. The literature describes many different management choices for the different stages of posterior tibialis tendon dysfunction.

CONCLUSION

Because of the wide range of symptom and deformity severity, surgical reconstruction is based on a-la-carte. The consensus is that a plethora of reconstructive options needs to be available and the list of procedures should be tailored to tackle the different symptoms, especially when managing complex multi-planar reconstructions.

Diagnostic Characteristics of Standard Radiographs and Magnetic Resonance Imaging of Ruptures of the Tibialis Posterior Tendon

The present study aimed to diagnose complete rupture (CR) and longitudinal rupture (LR) of the posterior tibial tendon (PTT) from the magnetic resonance imaging findings in patients with PTT dysfunction and to analyze and compare the radiographs from each group to identify radiographic indicators related to the progression of PTT injury that would allow the radiographic diagnosis of CR. We evaluated 32 feet in 27 patients with PTT dysfunction (mean age 66.5, range 49 to 82, years). Radiographs were used to acquire weightbearing anteroposterior images of the foot, which were used to measure the talonavicular coverage angle. Lateral images of the foot were also acquired with the patients in the standing position. These were used to measure the lateral talometatarsal angle, calcaneal pitch angle, and medial cuneiform-fifth metatarsal height. From the axial MRI findings, the patients were divided into a CR group and an LR group, and the radiographic attributes of the CR group were analyzed. Of the 32 feet in 27 patients, 12 feet (37.5%) in 11 patients displayed CR and 20 feet (62.5%) in 18 patients displayed LR. The talonavicular coverage angle was 48.3° ± 17.3° in the CR group and 33.6° ± 13.6° in the LR group (p = .012), and the talometatarsal angle was -28.8° ± 22.5° in the CR group and -25.4° ± 14.4° in the LR group (p = .596). The calcaneal pitch angle was 10.4° ± 6.7° in the CR group and 10.2° ± 8.0° in the LR group (p = .935). Finally, the medial cuneiform-fifth metatarsal height was -4.2 ± 7.1 mm in the CR group and 2.1 ± 4.7 mm in the LR group (p = .005). When a medial cuneiform-fifth metatarsal height of ≤0 mm or talonavicular coverage angle of ≥50° was used as the diagnostic criterion for CR on weightbearing radiographs, the sensitivity was 71.4%, specificity 88.9%, and diagnostic accuracy 81.3%; hence, we believe these to be satisfactory diagnostic criteria for CR.

Effect of posterior tibial tendon dysfunction on unipedal standing balance test

BACKGROUND

Foot pain and diminished functional capacity are characteristics of tibialis posterior tendon dysfunction (TPTD). This study tested the hypotheses that women with TPTD would have impaired performance of a unipedal standing balance test (USBT) and that balance performance would be related to the number of single limb heel raises (SLHR).

METHODS

Thirty-nine middle-aged women, 19 with early stage TPTD (stage I and II), were instructed to perform 2 tasks; a USBT and repeated SLHR. Balance success was defined as a 10-second stance. For those who were successful, center of pressure (COP) data in anterior-posterior (AP) and medial-lateral (ML) directions were recorded as a measure of postural sway. SLHR performance was divided into 3 bins (≤2; 3-9 and > 10 repetitions). The between-balance success on performing the SLHR test was analyzed using the Fisher's exact test (2 × 3). Independent t tests were used to compare between-group differences in postural sway. Relationship of postural sway to the number of heel raises was assessed using Spearman's rho.

RESULTS

The success rate of the USBT was significantly lower in women with TPTD than the controls (47% vs 85%, P = .041). In addition, women with TPTD who completed the USBT exhibited increased AP COP displacement (14.0 ± 7.4 vs 8.4 ± 1.3 mm, P = .008), and a strong trend of increased ML COP displacement (8.3 ± 4.5 vs 6.1 ± 1.2 mm, P = .050). The success rate of USBT was correlated with the number of SLHR (P = .01). The AP and ML COP displacement were correlated with SLHR (r = -.538 and .495), respectively.

CONCLUSIONS

Women with TPTD have difficulty in performing the USBT. Performance of the USBT and SLHR are highly correlated and predictive of each other.

CLINICAL RELEVANCE

A unipedal balance test may be used as a proxy TPTD assessment tool to the heel raising test when pain prevents performance.

LEVEL OF EVIDENCE

Level III, case control study.

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.

3-Tesla magnetic resonance imaging evaluation of posterior tibial tendon dysfunction with relevance to clinical staging

The posterior tibial tendon (PTT) is the most important dynamic stabilizer of the medial ankle and longitudinal arch of the foot. PTT dysfunction is a degenerative disorder of the tendon, which secondarily involves multiple ligaments, joint capsules, fascia, articulations, and bony structures of the ankle, hindfoot, midfoot, and forefoot. When the tendon progressively attenuates, the patient develops a painful, progressive collapsed flatfoot or pes planovalgus deformity. This comprehensive review illustrates the 3-Tesla magnetic resonance imaging (3T MRI) features of PTT dysfunction. In addition, the reader will gain knowledge of the expected pathologic findings on MRI, as they are related to clinical staging of PTT dysfunction.

A posterior tibial tendon skipping rope

This report presents an athletic patient with swelling and progressive pain on the posteromedial side of his right ankle on weight bearing. MRI demonstrated tenosynovitis and suspicion of a length rupture. On posterior tibial tendoscopy, there was no rupture, but medial from the tendon a tissue cord came into view, causing impingement on the tendon at the level of maximum pain. The cord was released and 2 weeks and 1 year after the procedure the patient reported no complaints.

Magnetresonanztomographie des Sprunggelenkes

The ankle represents an anatomically complex region with a broad spectrum of pathologies. Magnetic resonance imaging (MRI) of the ankle offers detailed, high-resolution imaging of the bones, the ligaments and the surrounding soft tissue structures and therefore has a major role in the diagnostic evaluation of traumatic sequelae, infectious diseases or ankle pain of unknown origin. MRI is especially valuable in the detection of radiographically occult stress reactions or osteomyelitis because it can visualize bone marrow edema earlier than any other imaging method. MRI is superior to any other imaging method for visualizing the tendons and ligaments of the foot and is an important basis for further treatment planning.

MR imaging findings of painful type II accessory navicular bone: correlation with surgical and pathologic studies

OBJECTIVE

To evaluate the MR imaging findings of painful type II accessory navicular bone and to correlate these with the surgical and pathologic findings.

MATERIALS AND METHODS

The MR images of 17 patients with medial foot pain and surgically proven type II accessory navicular abnormalities were reviewed. The changes of signal intensity in the accessory navicular, synchondrosis and adjacent soft tissue, the presence of synchondrosis widening, and posterior tibial tendon (PTT) pathology on the T1-weighted and fat-suppressed T2-weighted images were analyzed. The MR imaging findings were compared with the surgical and pathologic findings.

RESULTS

The fat-suppressed T2-weighted images showed high signal intensity in the accessory navicular bones and synchondroses in all patients, and in the soft tissue in 11 (64.7%) of the 17 patients, as well as synchondrosis widening in 3 (17.6%) of the 17 patients. The MR images showed tendon pathology in 12 (75%) of the 16 patients with PTT dysfunction at surgery. The pathologic findings of 16 surgical specimens included areas of osteonecrosis with granulomatous inflammation, fibrosis and destruction of the cartilage cap.

CONCLUSION

The MR imaging findings of painful type II accessory navicular bone are a persistent edema pattern in the accessory navicular bone and within the synchondrosis, indicating osteonecrosis, inflammation and destruction of the cartilage cap. Posterior tibial tendon dysfunction was clinically evident in most patients.

The anatomy of the navicular and periarticular structures

The navicular bone, located in the midfoot, articulates with the head of the talus, cuboid, and the three cuneiform bones that are involved in the acetabulum pedis. It gives attachment to the spring ligament (superomedial and inferior calcaneonavicular ligament)that can be injured in a failure of the posterior tibialis tendon and cause an adult acquired flatfoot deformity. The navicular bone provides insertion for the posterior tibialis tendon. Some pathologies can be related to the presence of an accessory navicular bone. Osteonecrosis or stress fractures can affect the navicular bone because of its poor vascularization, especially in its central portion.

Association of posterior tibial tendon injury with spring ligament injury, sinus tarsi abnormality, and plantar fasciitis on MR imaging

OBJECTIVE

The purpose of this study was to investigate the frequency of abnormalities of the spring ligament, sinus tarsi, and plantar fascia revealed on MR imaging in a group of patients with advanced injury of the posterior tibial tendon. MATERIALS AND METHODS; MR images from 25 patients with advanced posterior tibial tendon injury were retrospectively examined for spring ligament, sinus tarsi, and plantar fascia abnormalities. These images were randomly compared with those obtained from 25 control patients with normal-appearing posterior tibial tendons.

RESULTS

The spring ligament was abnormal in 23 (92%) of 25 patients with a posterior tibial tendon injury and seven (28%) of 25 patients with a normal posterior tibial tendon (p < 0.0001). The sinus tarsi was abnormal in 18 (72%) of 25 patients with posterior tibial tendon injury and nine (36%) of 25 patients with a normal posterior tibial tendon (p < 0.0132). The plantar fascia was abnormal in seven (32%) of 22 patients with posterior tibial tendon injury and two (9%) of 22 patients with a normal posterior tibial tendon (p < 0.0768). Two or more associated abnormalities were present in 20 (80%) of 25 patients with posterior tibial tendon injury and four (16%) of 25 patients with a normal posterior tibial tendon (p < 0.0001).

CONCLUSION

Advanced posterior tibial tendon injury has a high association with spring ligament and sinus tarsi abnormalities on MR imaging. There was a low association between advanced posterior tibial tendon injury and plantar fascia abnormality. Patients with posterior tibial tendon injury often have abnormalities of two or more associated structures.

Tenosynovitis of the posterior tibial tendon

PTT tenosynovitis is a recognized entity no longer confused with an ankle sprain. Three possible causes are (1) overuse or age related (mechanical in cause, true stage I disease), (2) seronegative spondyloarthropathies (clinical suspicion, hematologic analysis), and (3) rheumatoid arthritis (deformity may be owing to ligamentous or capsular destruction). The PTT has a hypovascular zone 40 mm proximal to the insertion of the tendon and 14 mm in length. Pain often is localized to this portion of the tendon (primarily in stage I disease). Ultrasound is an inexpensive and accurate method to assist in the diagnosis of this condition and may replace MR imaging as more experienced ultrasonographers appear. The initial management of PTT tenosynovitis includes tendon rest and nonsteroidal anti-inflammatory medication and physical therapy. Surgical synovial débridement is performed early (6 weeks) in patients with enthesopathies (seronegative disease). This procedure may be delayed 3 months in patients with true stage I disease. At surgery, the undersurface of the tendon must be inspected for longitudinal split tears, and these must be repaired with nonabsorbable suture, burying the knots. The excursion of the tendon should be checked intraoperatively. Patients with stage I disease should be evaluated carefully for preoperative structural deformity to choose the appropriate surgical procedure and prevent failure of isolated tenosynovectomy.

From the RSNA Refresher Courses. Radiological Society of North America. MR imaging of the ankle and foot

Magnetic resonance (MR) imaging has opened new horizons in the diagnosis and treatment of many musculoskeletal diseases of the ankle and foot. It demonstrates abnormalities in the bones and soft tissues before they become evident at other imaging modalities. The exquisite soft-tissue contrast resolution, noninvasive nature, and multiplanar capabilities of MR imaging make it especially valuable for the detection and assessment of a variety of soft-tissue disorders of the ligaments (eg, sprain), tendons (tendinosis, peritendinosis, tenosynovitis, entrapment, rupture, dislocation), and other soft-tissue structures (eg, anterolateral impingement syndrome, sinus tarsi syndrome, compressive neuropathies [eg, tarsal tunnel syndrome, Morton neuroma], synovial disorders). MR imaging has also been shown to be highly sensitive in the detection and staging of a number of musculoskeletal infections including cellulitis, soft-tissue abscesses, and osteomyelitis. In addition, MR imaging is excellent for the early detection and assessment of a number of osseous abnormalities such as bone contusions, stress and insufficiency fractures, osteochondral fractures, osteonecrosis, and transient bone marrow edema. MR imaging is increasingly being recognized as the modality of choice for assessment of pathologic conditions of the ankle and foot.