Purpose

One of the current research topics is the aim to produce tissue engineered osteochondral grafts for future treatment of osteochondral lesions (OCL) of the talus. For the exact anatomic reconstruction, the dimensions of the medial and lateral talar dome must be considered.

Sparse data is available regarding the normal anatomic talar dimensions on standard radiographs of ankle joints [1, 2]. The purpose of this study was to describe normal anatomy of different sections of the talar dome on 3D reconstructions of computertomographic (CT) images.

Purpose

Osteochondral lesions (OCL) of the talus remain a challenging therapeutic task to orthopaedic surgeons. Several operative techniques are available for treatment, e.g. autologous chondrocyte implantation (ACI), osteochondral autograft transfer system (OATS), matrix-induced autologous chondrocyte implantation (MACI).

Good early results are reported; however, disadvantages are sacrifice of healthy cartilage of another joint or necessity of a two-stage procedure. This case describes a novel, one-step operative treatment of OCL of the talus utilizing the autologous matrix-induced chondrogenesis (AMIC) technique in combination with a collagen I/III membrane.

Introduction: Pain is the key symptom of patients suffering of osteochondral lesion (OCL) of the ankle. However, its tissue origin and the pain inducing and modulating mechanisms remain controversial. Cartilage is aneural and unlikely causing pain. Contrary soft and bone tissue show rich nociceptive innervations. Routine radiographic imaging of OCL fails to visualize the pain inducing structure. Recent studies demonstrated the capability of planar scintigraphy and SPECT for localizing painful joints in degenerative joints conditions. However, a limited spatial resolution of bone scans compromises an accurate anatomical localization of an uptake. Single photon emission computed tomography – computed tomography (SPECT-CT) is a new hybrid imaging technique allowing perfect overlay of functional and anatomical images. In OCL, SPECT-CT identifies the exact location of an OCL and determines the spatial extent of pathological bone remodeling. We conducted a study to evaluate the correlation between pathological uptake within an OCL and pain experienced by patients.

Methods: 15 patients (7 female, 8 male; mean age 39, range 20–61 years) were assessed for unilateral OCL of the talus (13 joints) or distal tibia (2 joints). Radiological imaging of the foot and ankle consisted of plain radiographs, MRI and SPECT-CT. Clinical examination included range of motion (ROM), AOFAS Ankle-Hind-foot Scale, and pain status measured by the visual analogue scale (VAS). On completion of radiological and clinical assessment, patients were referred to the interventional radiology department for a diagnostic ankle injection. CTguided ankle joint injection with local anesthetics and iodine contrast medium was performed. Exact location of the deposit was documented.

VAS score was assessed immediately post-infiltration and compared to the pre-interventional VAS score. Pain relief was defined as a reduction of VAS score of more than 50% of the pre-intervention score immediately after infiltration.

The study was approved by the institutional review board and written informed patient consent was obtained. The study was carried out in accordance with the World Medical Association Declaration of Helsinki.

Results: All infiltrations were technically successful. Pre-interventional VAS score was 5.3 (range 2 - 10; SD 2.33). Post-interventional VAS score was 1.1 (range 2 – 4; SD 1.45). This difference was statistically significant (p < 0.01).

Discussion: The results of our study show a highly significant correlation between pain in OCL and pathological uptake seen on SPECT-CT, indicating bone as a major contributor to pain in this disease. Hybrid SPECT-CT technique is a new and powerful approach to diagnosis and staging of osteochondral lesions and provides important data for adequate treatment.

Introduction: Ankle sprains are among the most common injuries in sports and recreational activities. 10 to 40% of the acute ankle sprains lead to chronic ankle instability (CAI), which can be divided into its mechanical and its functional division. The clinical-orthopaedic diagnosis of mechanical ankle instability (MAI) has been well established, whereas the etiology of the functional ankle instability (FAI) is still not objectively allocatable. The aim of this study was to identify neuromuscular patterns in lower leg muscles to objectively describe the FAI.

Methods: 15 patients suffering from unilateral CAI (mean age, 35.5 years) since 2.4 years (1–9 years) were examined. The patients were evaluated etiologically and clinically (VAS pain score, AOFAS Ankle Score, calf circumference, and SF-36). Electromyographic (EMG) measurements of surface EMG with determination of mean EMG frequency and intensity by wavelet transformation were taken synchronously with dynamic stabilometry measurements. Four lower leg muscles were detected: tibialis anterior (TA), gastrocnemius medialis (GM), soleus (SO), and peroneus longus (PL) muscle. 15 healthy subjects were tested identically.

Results: Patients showed higher stability indices, higher VAS score, and lower AOFAS Ankle Score.

The mean EMG frequency was significantly lower for the PL (pathologic leg, 138.3 Hz; normal leg, 158.3 Hz, p< 0.001). Lower mean EMG intensity was found in the pathologic PL and GM. The mean EMG frequency of the TA was lower in the patient group, its intensity higher.

Discusssion and conclusion: Patients suffering CAI demonstrate weakened stability and impaired life quality. Neuromuscular patterns of the GM, PL and TA lead evidently to an objective etiology of the functional ankle instability. EMG patterns of four lower leg muscles indicate chronic changes in muscle morphology, such as degradation of type-II muscle fibres or modified velocity of motor unit action potentials. Accurate prevention and rehabilitation may compensate a MAI with a sufficient functional potential of lower leg muscles. This may also avoid operative treatment of MAI. The present study evidences the etiology of the FAI with objective parameters and indicates chronic changes in muscle morphology within CAI-Patients.

Purpose: Ankle sprains are among the most common injuries in sports and recreational activities. 10 to 40% of the acute ankle sprains lead to chronic ankle instability (CAI), which can be divided into its mechanical and its functional division. The clinical-orthopaedic diagnosis of mechanical ankle instability (MAI) has been well established, whereas the etiology of the functional ankle instability (FAI) is still not objectively allocatable. The aim of this study was to identify neuromuscular patterns in lower leg muscles to objectively describe the FAI.

Method: 15 patients suffering from unilateral CAI (mean age, 35.5 years) since 2.4 years (1–9 years) were examined. The patients were evaluated etiologically and clinically (VAS pain score, AOFAS Ankle Score, calf circumference, and SF-36). Electromyographic (EMG) measurements of surface EMG with determination of mean EMG frequency and intensity by wavelet transformation were taken synchronously with dynamic stabilometry measurements. Four lower leg muscles were detected: tibialis anterior (TA), gastrocnemius medialis (GM), soleus (SO), and peroneus longus (PL) muscle. 15 healthy subjects were tested identically.

Results: Patients showed higher stability indices, higher VAS score, and lower AOFAS Ankle Score. The mean EMG frequency was significantly lower for the PL (pathologic leg, 138.3 Hz; normal leg, 158.3 Hz, p< 0.001). Lower mean EMG intensity was found in the pathologic PL and GM. The mean EMG frequency of the TA was lower in the patient group, its intensity higher.

Conclusion: Patients suffering CAI demonstrate weakened stability and impaired life quality. Neuromuscular patterns of the GM, PL and TA lead evidently to an objective etiology of the functional ankle instability. EMG patterns of four lower leg muscles indicate chronic changes in muscle morphology, such as degradation of type-II muscle fibres or modified velocity of motor unit action potentials. Accurate prevention and rehabilitation may compensate a MAI with a sufficient functional potential of lower leg muscles. This may also avoid operative treatment of MAI. The present study evidences the etiology of the FAI with objective parameters and indicates chronic changes in muscle morphology within CAI-Patients.

Purpose: Osteochondral lesions (OCL) of the talus are a common pathology among patient who suffered a traumatic injury of the ankle joint and involve breakdown of articular cartilage and underlying bone tissue. The estimated incidence of OCL is 6% in all ankle sprains and the importance of a traumatic ankle event was confirmed by several authors by arthroscopical joint assessment. The most common locations for OCL to occur are at the posteromedial and anterolateral aspect/section, involving the mortise/edge of the dome. One of the orthopaedic world’s most current research topics is the aim to produce tissue engineered osteochondral grafts for future treatment of OCL lesions. For the exact anatomic reconstruction, the dimensions of the medial and lateral talar dome must be considered. Few data is available regarding the normal anatomic talar dimensions on standard radiographs of ankle joints. The purpose of this study was to collect data describing the normal talar dome anatomy of the ankle joint on antero-posterior hindfoot radiographs and to assess value distribution in a large patient group. Hypothetically the medial talar dome has a significant greater curvature and a greater edge angle than the lateral talar dome.

Method: 81 patients (81 ankles) (30 female, 51 male; average age 43y (range 20–87y)) without ankle and hindfoot pathologies were included. Weight-bearing standard AP ankle radiographs were performed on a digital flat panel system (Aristos FX®, Siemens Erlangen, Germany) and evaluated on a high resolution case reading monitor (Totoku) using DICOM/PACS review application E-Film.

To measure the edge angle of the medial (alpha) and lateral (beta) talar dome, curves were adjusted along the medial and lateral talar body and on top of the talar dome measuring the angles in-between.

Results: There was a significant difference (p< 00.1) between mean medial edge angle (alpha) with 109.99 degree (range 90–127; SD 7.14) and lateral edge angle (beta) with 91.84 degree (range 79–111; SD 5.56). Also a significant difference (p< 00.1) has been demonstrated between the mean medial talar dome radius (rm) with 4.8 mm (range 2–8; SD 1.3) and lateral talar dome radius (rl) with 3.5 mm (range 1.2–8.5; SD 1.5).

Conclusion: This study shows a significant difference between medial and talar dome configuration. The assessed data provides important aid for engineering of pre-formed, pre-sized osteochondral grafts. Such pre-shaped grafts could help restoring the physiological joint surface by matching exactly into the lesion and consequently achieving the recovery of the physiological joint biomechanics and prevention of secondary degenerative disease.