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

Julian Stürznickel,Nico Maximilian Jandl,Tim Rolvien,Peter Ueblacker,Emil Von Vopelius,Michael Amling,Maximilian M Delsmann,Florian Barvencik,Ralf Oheim

doi:10.1007/s00167-020-06290-0

Abstract

PurposeMedial 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.MethodsNine 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).ResultsIn 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.ConclusionIn 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 evidenceIII.

Highlights

Materials and methodsMedial tibial stress syndrome (MTSS) or shin splints are stress-induced injuries described by diffuse (≥ 5 cm) pain of themedial tibia [19, 32]
It is a common injury especially in athletes exposed to a repetitive load of the lower limbs [1, 19, 28] and may display osseous signal alterations in magnetic resonance imaging (MRI) [2, 9] or translucent bone structures in radiographs and/or computed tomography (CT) [10]
According to patients’ reports and available files of medical history, 4/9 patients had a history of fractures

Summary

Introduction

Medial tibial stress syndrome (MTSS) or shin splints are stress-induced injuries described by diffuse (≥ 5 cm) pain of the (postero-)medial tibia [19, 32]. It is a common injury especially in athletes exposed to a repetitive load of the lower limbs [1, 19, 28] and may display osseous signal alterations in magnetic resonance imaging (MRI) [2, 9] or translucent bone structures in radiographs and/or computed tomography (CT) [10]. Clinical examination provides sufficient information to diagnose MTSS but especially when symptoms are prolonged or not characteristic, more advanced lesions and differential diagnoses (i.e., pseudofractures or stress fractures) need to be evaluated in more detail by the use of conventional imaging such as MRI/CT [30]

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