Predictive factors of effective tibial nerve release in tarsal tunnel syndrome.

BACKGROUND: Factors that may affect surgical decompression results in tarsal tunnel syndrome are not known. METHODS: A retrospective single-center study included patients who had undergone surgical tibial nerve release. The effectiveness of decompression was evaluated according to whether the patient would or would not be willing to undergo another surgical procedure in similar preoperative circumstances. RESULTS: The patients stated for 43 feet (51%) that they would agree to a further procedure in similar circumstances. Six feet with space-occupying lesions on imaging had improved results, but neurolysis failed in 9 feet with bone-nerve contact. Neurolysis was significantly less effective when marked hindfoot valgus (p = 0.034), varus (p = 0.014), or fasciitis (p = 0.019) were present. CONCLUSIONS: If imaging reveals a compressive space-occupying lesion, surgery has a good prognosis. In feet with static hindfoot disorders or plantar fasciitis, conservative treatment must be optimized. Bone-nerve contact should systematically be sought.

Tarsal Tunnel Syndrome: Outcome According to Etiology.

Surgical results in tarsal tunnel syndrome are variable, and etiology seems to be a factor. Three possible etiologies can be distinguished. The aim of the present study was to compare surgical results according to etiology. Three continuous retrospective series (45 patients overall) of tarsal tunnel syndrome were compared. Group 1 presented a permanent intra- or extra-tunnel space-occupying compressive structure. Group 2 presented intermittent intra-tunnel venous dilatations. Group 3 comprised idiopathic tarsal tunnel syndrome. The mean follow-up was 3.6 +/- 1.8 years. The main endpoint was subjective postoperative improvement on Likert scale. Group 1 reported greater improvement than groups 2 and 3. Preoperative neuropathy on ultrasound was associated with poorer improvement, which was not the case for neuropathy on electromyography. Surgical treatment of tarsal tunnel syndrome provides better results in etiologies involving structural compression.

Can the axial cross-sectional area of the tibial nerve be used to diagnose tarsal tunnel syndrome? An ultrasonography study.

INTRODUCTION: The axial cross-sectional area (CSA) of the tibial nerve can be measured with ultrasonography. In patients who have posteromedial tarsal tunnel syndrome (TTS), there is little information on the nerve's CSA even though this information could be useful for determining whether the nerve is damaged. This led us to carry out a case-control study in which the tibial nerve's axial CSA was measured in healthy patients and in patients with TTS. HYPOTHESIS: The tibial nerve's axial CSA can be used as a diagnostic criterion for TTS. METHODS: Twenty-three patients (27 feet) (11 men, 12 women, mean age=54±14 years), who had clinical and electroneuromyography signs of TTS, were compared to 21 healthy adults (8 men, 13 women, mean age 39±10 years). An ultrasonography examination was carried out to look for a source of nerve compression, then the axial CSA of the tibial nerve was measured 10cm above the tarsal tunnel (lCSA) and inside the tunnel itself (ttCSA). The difference between the two measurements was then calculated: ΔCSA=ttCSA-lCSA. The data were analysed using correlation tests and non-parametric tests, a multivariate linear regression and ROC tests. RESULTS: A compressive cause was found by ultrasonography in 13 patients. The mean values of ttCSA and ΔCSA were 20.1±8.8 mm2 [6-42] vs. 10.3±2.3 mm2 [8-14] (p=0.0001) and 9.8±6.7 mm2 [0-29] vs. -0.2±1.8 mm2 [-3-4] (p<0.0001) in the patients and the controls, respectively. The differences in ΔCSA remained significant in the multivariate analysis after adjusting for age and weight. The best threshold for ttCSA in the TTS group was 15 mm2 with 74% sensitivity and 100% specificity. The best threshold for ΔCSA was 5mm2 with 81% sensitivity and 100% specificity. DISCUSSION: The difference in the measured axial CSA of the tibial nerve by ultrasonography between the posteromedial tarsal tunnel and 10cm above the tunnel is a key data point for the diagnosis of tarsal tunnel syndrome with and without compressive etiology. LEVEL OF EVIDENCE: III, diagnostic case-control study.

Ultrasound in Total Hip Replacement: Value of Anterior Acetabular Cup Visibility and Contact With the Iliopsoas Tendon.

OBJECTIVES: To assess visibility of the acetabular cup in total hip replacement and to determine the value of direct and indirect signs of iliopsoas impingement syndrome with ultrasound. METHODS: Ultrasound examinations were performed by a single operator in 17 patients with iliopsoas impingement syndrome and 48 control patients. Cup visibility, contact between the cup and psoas tendon, and the presence of indirect signs of iliopsoas impingement syndrome were investigated in all patients. When the acetabular cup was visible, its size and position in relation to the psoas tendon were recorded. RESULTS: Anterior cup visibility (P = .03), contact with the psoas tendon (P < .001), psoas tendinopathy (P = .02), and iliopsoas bursitis (P < .001) were significantly associated with iliopsoas impingement syndrome, the latter reported with specificity of 100%. In the sagittal plane at the level of the psoas tendon, a maximum sagittal length of greater than 5 mm and a posteroanterior cup shift of 3 mm or greater yielded respective sensitivities of 82% and 59% and specificities of 81% and 100%. CONCLUSIONS: When iliopsoas impingement syndrome is clinically suspected, the presence of iliopsoas bursitis or a posteroanterior cup shift of greater than 3 mm under the psoas tendon serve to confirm the diagnosis. In the absence of these conditions, a therapeutic test may be necessary because of the incomplete, albeit high, specificity of other signs.

Role of ultrasound in posteromedial tarsal tunnel syndrome: 81 cases.

Posteromedial tarsal tunnel syndrome is a disorder affecting the tibial nerve or its branches. Diagnosis is established on the basis of physical examination and can be confirmed by electrophysiological evidence. However, diagnostic imaging is always required to identify the possible site of compression. High-resolution ultrasound (US) is playing an increasingly important role in the study of the nerves thanks to a series of advantages over magnetic resonance imaging, such as lower costs and widespread availability, high spatial resolution, fast examination using axial scans, dynamic and comparative studies, possibility of carrying out a study with the patient in the standing position, US Tinel sign finding, and the contribution of color/power Doppler US. We present the results obtained in a series of 81 patients who underwent US imaging between 2008 and 2013 due to posteromedial tarsal tunnel syndrome.

Conflicts, snapping and instability of the tendons. Pictorial essay.

Conflicts, snapping and instability of the tendons are common, and ultrasound (US) is the method of choice for evidencing these conditions thanks to the possibility to perform dynamic maneuvers during imaging studies. A conflict can occur between a tendon and a bone structure, other tendons, the retinacula or pulleys. Snapping can occur due to instability caused by rupture of the retinaculum, conflict between a thickened retinaculum and a bone prominence or due to an abnormal position of the tendon. Instability can occur due to insufficient ability of the retinaculum to keep the tendons in the bone groove or its failure to hold the tendons applied to the bone.The technique for evidencing conflicts, snapping and instability of the tendons is very demanding because it requires a thorough knowledge of the US appearance and dynamic maneuvers. However, at the present time US examination completed with dynamic maneuvers is the investigation of choice for evidencing these disorders and providing the clinicians with the necessary information.