Bilateral Looser zones or pseudofractures in the anteromedial tibia as a component of medial tibial stress syndrome in athletes.

PURPOSE: Medial tibial stress syndrome (MTSS) represents a common diagnosis in individuals exposed to repetitive high-stress loads affecting the lower limb, e.g., high-performance athletes. However, the diagnostic approach and therapeutic regimens are not well established. METHODS: Nine patients, diagnosed as MTSS, were analyzed by a comprehensive skeletal analysis including laboratory bone turnover parameters, dual-energy X-Ray absorptiometry (DXA), and high-resolution peripheral quantitative computed tomography (HR-pQCT). RESULTS: In 4/9 patients, bilateral pseudofractures were detected in the mid-shaft tibia. These patients had significantly lower levels of 25-hydroxycholecalciferol compared to patients with MTSS but similar levels of bone turnover parameters. Interestingly, the skeletal assessment revealed significantly higher bone mineral density (BMD) Z-scores at the hip (1.3 ± 0.6 vs. - 0.7 ± 0.5, p = 0.013) in patients with pseudofractures and a trend towards higher bone microarchitecture parameters measured by HR-pQCT at the distal tibia. Vitamin D supplementation restored the calcium-homeostasis in all patients. Combined with weight-bearing as tolerated, pseudofractures healed in all patients and return to competition was achieved. CONCLUSION: In conclusion, deficient vitamin D levels may lead to pseudofractures due to localized deterioration of mineralization, representing a pivotal component of MTSS in athletes with increased repetitive mechanical loading of the lower limbs. Moreover, the manifestation of pseudofractures is not a consequence of an altered BMD nor microarchitecture but appears in patients with exercise-induced BMD increase in combination with reduced 25-OH-D levels. The screening of MTSS patients for pseudofractures is crucial for the initiation of an appropriate treatment such as vitamin D supplementation to prevent a prolonged course of healing or recurrence. LEVEL OF EVIDENCE: III.

The effect of pads on foot morphology in athletes with medial tibial stress syndrome.

BACKGROUND: Evaluation of the effect of a pad on foot morphologies in patients with medial tibial stress syndrome (MTSS) requires more reliable and objective methods, rather than conventional subjective observations. OBJECTIVE: The objective of this study was to investigate the effect of pads on foot morphologies during quiet standing in athletes with MTSS. METHODS: We measured three-dimensional foot morphologies in 30 feet with MTSS and 40 healthy feet. RESULTS: The analysis showed that Hallux valgus degree, calcaneal angle, arch height, and arch height ratio differed significantly as a result of the pad support, compared to no pad support in the MTSS group. The pad support only resulted in significant differences in arch height, compared to no support in the control group. Furthermore, thumb side angle, calcaneal angle, and arch height ratio were significantly different between the MTSS and control groups. CONCLUSIONS: Our study results suggest that changes in foot morphologies because of the use of a pad can be measured objectively in patients with MTSS.

Fatigue reliability analysis for medial tibial stress syndrome.

Medial Tibial Stress Syndrome MTSS is frequently diagnosed as a severe clinical issue which occurs due to the cycle loadings (fatigue failure). Since the mechanical properties of the bones are random variables, therefore, there is a need for a probabilistic approach to rationally assess the reliability level of the fatigue failure of the tibia. The main contribution of this paper is to introduce a novel limit state function to determine the fatigue damage state and the reliability index of MTSS based on the different loading and aging conditions. In this study, the tibias of the several people at the different ages are subjected to the fatigue loadings. The load carrying capacities of the considered specimen are determined based on the reliability analysis. Indeed, several 3D finite element analyses are performed to find out the damage states of the tibias. Accordingly, the reliability-based stress analysis is accomplished to localize the most vulnerable zone of the bone. As it was expected, the higher loading cycles associated with the elder bones is related to the lowest fatigue reliability level. Finally, the target reliability level of MTSS is proposed to deliberate the safe level of the loading condition on the tibia in terms of the walking distance.

Microcrack-associated bone remodeling is rarely observed in biopsies from athletes with medial tibial stress syndrome.

The pathology of medial tibial stress syndrome (MTSS) is unknown. Studies suggest that MTSS is a bony overload injury, but histological evidence is sparse. The presence of microdamage, and its potential association with targeted remodeling, could provide evidence for the pathogenesis of MTSS. Understanding the pathology underlying MTSS could contribute to effective preventative and therapeutic interventions for MTSS. Our aim was to retrospectively evaluate biopsies, previously taken from the painful area in athletes with MTSS, for the presence of linear microcracks, diffuse microdamage and remodeling. Biopsies, previously taken from athletes with MTSS, were evaluated at the Department of Anatomy and Cell Biology at the Indiana University. After preparing the specimens by en bloc staining, one investigator evaluated the presence of linear microcracks, diffuse microdamage and remodeling in the specimens. A total of six biopsies were evaluated for the presence of microdamage and remodeling. Linear microcracks were found in 4 out of 6 biopsies. Cracking in one of these specimens was artefactual due to the biopsy procedure. No diffuse microdamage was seen in any of the specimens, and only one potential remodeling front in association with the microcracks. We found only linear microcracks in vivo in biopsies taken from the painful area in 50% of the athletes with MTSS, consistent with the relationship between linear cracks and fatigue-associated overloading of bone. The nearly universal absence of a repair reaction was notable. This suggests that unrepaired microdamage accumulation may underlie the pathophysiological basis for MTSS in athletes.

Are ultrasonographic findings like periosteal and tendinous edema associated with medial tibial stress syndrome? A case-control study.

OBJECTIVES: Medial tibial stress syndrome (MTSS) is one of the most common sporting injuries. As of yet, the development of effective therapeutic interventions to treat MTSS is hindered by the fact that its pathology is unknown. Our aim was to explore the pathology of MTSS, by assessing whether the presence of MTSS is related to periosteal, bony or tendinous abnormalities in the lower leg. DESIGN: Case-control study. METHODS: Participants with MTSS and athletic control participants were recruited from the same (high-risk) base population. Musculoskeletal ultrasonography was performed on the posteromedial tibial border and deep plantar flexor muscles by an experienced radiological specialist who was blinded to group membership. Associations between MTSS and tissue abnormalities were expressed in odds ratios (OR). RESULTS: A total of 42 participants, 15 MTSS cases and 27 control athletes completed the study. Overall, periosteal and tendinous abnormalities were common in cases with and without MTSS. Periosteal edema was present in 8 (53.3%) MTSS cases and in 10 (37.0%) control athletes, in specific painful spots in the distal 2/3 of the posteromedial tibial border OR=1.9 (95% CI 0.54-6.99, p=0.35). Also, tendinous abnormalities in the tibialis posterior muscle were frequently seen in MTSS cases (N=7, 46.7%) and in control athletes (N=13, 48.1%) (OR=0.97, 95% CI 0.27-3.51, p=0.96). No bone abnormalities were observed in either group. CONCLUSIONS: Periosteal and tendinous findings seem to be common in both athletes with and without MTSS, and consequently are not associated with MTSS.

Structural deformation of longitudinal arches during running in soccer players with medial tibial stress syndrome.

The purpose of this study was to compare angular change and translational motion from the medial longitudinal arch (MLA) and lateral longitudinal arch (LLA) during running between medial tibial stress syndrome (MTSS) and non-MTSS subjects. A total of 10 subjects volunteered, comprising 5 subjects with MTSS and 5 subjects without injury (non-MTSS) as the control group. All subjects performed the test movement that simulated running. Fluoroscopic imaging was used to investigate bone movement during landing in running. Sagittal motion was defined as the angular change and translational motion of the arch. A Mann-Whitney U-test was performed to determine the differences in the measured values between the MTSS and non-MTSS groups. The magnitude of angular change for the MLA and LLA was significantly greater for subjects with MTSS than for control subjects. Translational motion of the MLA and LLA of the MTSS group was also significantly greater than that of the non-MTSS group (all p < 0.05). Soccer players with MTSS have an abnormal structural deformation of foot during support (or stance) phase of running, with a large decrease in both the MLA and LLA. This abnormal motion could be a risk factor for the development of MTSS in these subjects.

A prospective study on MRI findings and prognostic factors in athletes with MTSS.

In medial tibial stress syndrome (MTSS) bone marrow and periosteal edema of the tibia on the magnetic resonance imaging (MRI) is frequently reported. The relationship between these MRI findings and recovery has not been previously studied. This prospective study describes MRI findings of 52 athletes with MTSS. Baseline characteristics were recorded and recovery was related to these parameters and MRI findings to examine for prognostic factors. Results showed that 43.5% of the symptomatic legs showed bone marrow or periosteal edema. Absence of periosteal and bone marrow edema on MRI was associated with longer recovery (P = 0.033 and P = 0.013). A clinical scoring system for sports activity (SARS score) was significantly higher in the presence of bone marrow edema (P = 0.027). When clinical scoring systems (SARS score and the Lower Extremity Functional Scale) were combined in a model, time to recovery could be predicted substantially (explaining 54% of variance, P = 0.006). In conclusion, in athletes with MTSS, bone marrow or periosteal edema is seen on MRI in 43,5% of the symptomatic legs. Furthermore, periosteal and bone marrow edema on MRI and clinical scoring systems are prognostic factors. Future studies should focus on MRI findings in symptomatic MTSS and compare these with a matched control group.