Bildgebende Diagnostik akuter und chronischer osteochondraler Läsionen am Talus

Acute fractures involving the articular surface of the talus run parallel to the surface and are confined to the cartilage and/or the immediate subchondral cancellous bone. Subchondral microfractures ("bone bruises"), osteochondral fractures and solely chondral fractures are different manifestations of impaction injuries that affect the articular surface. This article reviews the radiologic appearance of acute osteochondral lesions of the talus and comments on the role of the noninvasive imaging modalities. Conventional radiography and MRI provide the most relevant information and are widely discussed. A MRI classification is presented emphasizing the distinction between lesions with intact and disrupted cartilage. Osteochondrosis dissecans (OCD) is a chronic osteochondral lesion. It is diagnosed in most cases by conventional radiography. MRI has become a decisive tool in staging the lesions. Intact cartilage and contrast enhancement of the lesions are findings of MRI stage I. Cartilage defects with or without incomplete separation of the fragment, fluid around an undetached fragment, cysts larger than 5 mm in diameter and a dislodged fragment are MRI findings observed in stage II and operative treatment has to be considered.     

自体髂骨移植治疗伴有囊性变的距骨骨软骨损伤

目的:观察采用自体带骨膜髂骨移植治疗伴有软骨下骨囊性缺损的距骨骨软骨损伤的临床疗效。方法 :回顾性分析2011年1月至2014年12月采用自体带骨膜髂骨移植治疗的22例伴有软骨下骨囊性缺损的距骨骨软骨损伤患者的临床资料,其中男18例,女4例;年龄34～58(46.4±6.9)岁;所有患者存在踝关节疼痛肿胀,7例踝关节活动部分受限,2例踝关节不稳,2例后足力线不良。所有患者的距骨骨软骨损伤位于距骨内侧,关节软骨损伤面积为64～132(101.6±27.1) mm~2,囊性病变直径9～15(10.5±1.8) mm。术前,术后12、24个月采用视觉模拟评分(VAS)评估关节疼痛,采用美国足踝外科(AOFAS)踝-后足评分系统评估关节功能。术后12个月取出内踝空心钉的同时行踝关节镜探查评估移植物愈合情况。结果:所有患者获得随访,时间24～60(42.5±9.9)个月。术后12个月MRI显示植骨愈合良好,部分可见散在的小的囊性区域。二次关节镜探查发现,植骨与距骨愈合良好,表面纤维软骨形成良好。术后24个月MRI显示植骨与周围骨质结合良好,仍可见散在的小的囊性区域,但较前有所减少。术后12个月VAS评分2.8±0.8,优于术前6.2±1.5,而与术后24个月2.6±0.8比较差异无统计学意义(P0.05)。术后12个月AOFAS评分83.0±5.6,优于术前55.3±13.7,与术后24个月83.7±6.6比较差异无统计学意义(P0.05)。结论:采用自体带骨膜髂骨移植治疗伴有软骨下骨囊性缺损的距骨骨软骨损伤可以获得良好的骨性愈合和表面纤维软骨形成,有效地缓解了患者的临床症状。     

Quantification of ankle articular cartilage topography and thickness using a high resolution stereophotography system

OBJECTIVE: To describe the topography and to measure thicknesses, surface areas and volumes in the cartilage layers of the ankle. METHODS: Twelve cadaveric ankle joints were disarticulated and the cartilage surfaces of each bone were imaged with a highly accurate (+/-2 microm) stereophotography system (ATOS). The cartilage was then dissolved and the subchondral bone imaged. The geometric data were then used to measure the quantitative parameters in each cartilage layer. RESULTS: The mean cartilage volume across the 12 specimens ranged from 0.32+/-0.08 ml for the fibula to 2.44+/-0.48 ml for the talus. The mean thickness of both the talar (1.1+/-0.18 mm) and tibial (1.16+/-0.14 mm) cartilage was significantly thicker than the fibula (0.85+/-0.13 mm). The talus had the greatest mean maximum cartilage thickness (2.38+/-0.4 mm). CONCLUSIONS: The reported stereophotographic technique may be used as an independent gold standard for validation of the accuracy of quantitative cartilage measurements made using magnetic resonance imaging. The thickness distribution maps show that the thickest articular cartilage occurs over the talar shoulders where osteochondral lesions commonly occur and not in the centre of the talar dome as commonly believed.     

Editorial Commentary: Osteochondral Lesions of the Talus: All,Nothing, or Something in Between

Osteochondral lesions of the talus occur with relatively frequency, often as the sequelae of benign ankle sprains, and are only surpassed by the knee and elbow as more common locations. While microfracture of the talus is the most common first-line surgical treatment performed at the time of ankle arthroscopy, marrow stimulation alone results in fibrocartilaginous repair tissue rather than true hyaline-like articular cartilage. In addition, the benefits of bone marrow stimulation for the treatment of large (>150 mm²), deep (>7 mm), or cystic lesions is limited. Autologous osteochondral transplant has emerged as one such treatment option for large lesions that may address underlying bone loss and reconstitute articular cartilage. The utility of autologous osteochondral transplant also must be interpreted with an understanding of the potential complications, including donor-site morbidity. In addition, it is important to decompress, curettage, and back fill associated cysts with bone graft. When cysts are not treated aggressively, patients may have ongoing bone marrow edema and pain.     

Fresh osteochondral allograft transplantation (FOCAT) for definitive management of a 198 square millimeter osteochondral lesion of the talus (OLT): A case report

An osteochondral lesion of the talus (OLT) is an idiopathic acquired lesion of the subchondral bone that can lead to debilitating sequelae. The causes of OLT’s are still debatable, however, most agree that the etiology is repetitive microtrauma associated with vascular impairment. OLTs are most commonly described in the medial portion of the talus, while lateral involvement is less frequent. If not properly recognized and treated, an OLT may lead to numerous secondary conditions including premature osteoarthritis and functional limitations of the ankle joint. Multiple surgical and non-surgical treatment modalities have been described with varying results. Treatments are usually guided by the patients age, onset of symptoms, severity, and the disease stage according to the Berndt and Harty classification. Recent literature recommends curettage, drilling, or microfracture techniques for lesions which are no larger than 15 mm in diameter and no deeper than 7 mm. On the other hand, for large lesions or lesions that failed from primary bone marrow stimulation, surgery should be considered for autologous chondrocyte implantation (ACI), osteochondral autograft transplantation (OATs or mosaicplasty), or osteochondral allograft transplantation [1]. This case study examines surgical treatment of an extensive OLT in a 53 year old man who suffered with continuous ankle pain for over 10 years, misdiagnosed as ankle joint arthritis.Level of clinical evidence: Level of evidence 4.     

Bony Lesion Recurrence After Mosaicplasty for Osteochondritis Dissecans of the Talus

Autogenous osteochondral grafts have recently become popular for use in small, isolated, contained articular cartilage defects. We treated a 26-year-old man who had a cartilage defect measuring 10 × 20 mm in the anteromedial area of the right talus. We performed multiple osteochondral grafting of the lesion with medial malleolar osteotomy from a donor site in the ipsilateral knee joint. Two years after the operation, the patient’s ankle pain recurred and the bony lesion in the talus also became osteolytic. Because we believed that only the cartilaginous portions of the osteochondral plugs grafted 2 years previously were fully fixed and viable, and that recurrence had occurred at the bony portions, at reoperation we performed curettage of the bony lesions and grafted iliac bone into the lesions with fenestration of the inferomedial ankle joint cartilage, not grafted plug cartilage. Therefore, probably because of overuse, the bony lesion in the talus had recurred 2 years after the first operation, but the grafted hyaline cartilage had survived. Autogenous osteochondral grafting into the talus, unlike the knee joint, should be done with care to ensure there is no sclerotic bone surrounding the lesion in patients with long-standing symptoms and recurrence of bony lesions.     

Osteochondral lesions of the talus in adolescents

Osteochondral lesions of the talus range from those confined to the hyaline cartilage covering the articular surface to those involving the subchondral bone. The lesion may not be apparent on the surface of the cartilage or it may be confined to the subchondral bone without cartilage involvement. These complex presentations often necessitates the use of computed tomography and magnetic resonance imaging to delineate the exact nature of the lesions. It has been shown that the frequency of osteochondral lesions increase following repetitive ankle sprains. Although the etiology is not well understood, both traumatic and atraumatic causes are thought to be effective. Nevertheless, early diagnosis and treatment of these lesions have improved considerably thanks to the developments in imaging techniques. It seems that arthroscopic chondral reconstruction methods using autologous chondrocyte and osteochondral transplantations will gain much interest in the near future.     

Autologe osteochondrale Transplantate

Osteochondral transplantation is a treatment option for restoring lesions of the cartilage surface and the underlying subchondral bone. For this technique, osteochondral cylinders are taken from less loaded regions of the knee joint and brought into the defect. It is based on press-fit implantation of osteochondral cylinders that are harvested from the mediocranial or laterocranial aspect of the patellofemoral joint with subsequent stable bony integration of the transplant.Indications for osteochondral transplantation must consider clinical, radiological, and magnetic resonance aspects, and concomitant pathologies of the joint should be eliminated. Isolated grade III and IV cartilage lesions in the load-bearing area of the medial or lateral femoral condyle are considered to be ideal indications for osteochondral transplantations. Further indications are retropatellar defects and lesions of the medial aspect of the talus. The technique is established for defects from 1 cm(2) to 3 cm(2).At this time, osteochondral transplantation is the only surgical method to achieve long-term coverage of the defect with hyaline cartilage. Donor site morbidity at the patellofemoral joint needs to be discussed because, particularly after the harvest of several cylinders, pain syndromes can develop. Therefore, the technique should be limited to two cylinders with a maximum diameter of 12 mm and one further cylinder with a smaller diameter.     

Diagnosing,planning and evaluating osteochondral ankle defects with imaging modalities

This current concepts review outlines the role of different imaging modalities in the diagnosis, preoperative planning, and follow-up of osteochondral ankle defects. An osteochondral ankle defect involves the articular cartilage and subchondral bone (usually of the talus) and is mostly caused by an ankle supination trauma. Conventional radiographs are useful as an initial imaging tool in the diagnostic process, but have only moderate sensitivity for the detection of osteochondral defects. Computed tomography (CT) and magnetic resonance imaging (MRI) are more accurate imaging modalities. Recently, ultrasonography and single photon emission CT have been described for the evaluation of osteochondral talar defects. CT is the most valuable modality for assessing the exact location and size of bony lesions. Cartilage and subchondral bone damage can be visualized using MRI, but the defect size tends to be overestimated due to bone edema. CT with the ankle in full plantar flexion has been shown a reliable tool for preoperative planning of the surgical approach. Postoperative imaging is useful for objective assessment of repair tissue or degenerative changes of the ankle joint. Plain radiography, CT and MRI have been used in outcome studies, and different scoring systems are available.     

Osteochondral defects of the talus treated with autologous bone grafting

We reviewed, retrospectively, 13 patients who had undergone open anterograde autologous bone grafting of the talus for symptomatic osteochondral defects of the dome of the talus. The mean age of the seven men and six women was 38.4 years. The defects included the full thickness of articular cartilage, extended through the subchondral plate and were associated with subchondral cysts. Six patients (46%) were clinical failures requiring further surgery. Of the remaining seven, functional outcome results were obtained at a mean of 51.9 months after surgery. The mean outcome scores for the Musculoskeletal Outcomes Data Evaluation and Management System foot and ankle questionnaire and the American Orthopaedic Foot and Ankle Society ankle-hindfoot scale were 87.0 and 84.3, respectively. There was an overall 46.2% patient satisfaction rate. We believe that the technique of autologous bone grafting presented should be used with extreme caution, when considered as the primary treatment for the adult patient with a symptomatic advanced osteochondral defect of the talus.     

Arthroskopische Behandlung von Knorpelverletzungen am Sprunggelenk

Ankle sprains are the most relevant injuries of the lower extremities and can lead to damage to ligaments and osteochondral lesions. Up to 50?% of patients with a sprained ankle later develop a lesion of the cartilage in the ankle joint or an osteochondral lesion of the talus. This can lead to osteoarthritis of the injured ankle joint. Spontaneous healing is possible in all age groups in cases of a bone bruise in the subchondral bone but in isolated chondral injuries is only useful in pediatric patients. In many cases chondral and osteochondral injuries lead to increasing demarcation of the affected area and can result in progressive degeneration of the joint if not recognized in time. There also exist a certain number of osteochondral changes of the articular surface of the talus without any history of relevant trauma, which are collectively grouped under the term osteochondrosis dissecans. Perfusion disorders are discussed as one of many possible causes of these alterations. Nowadays, chondral and osteochondral defects can be treated earlier due to detection using very sensitive magnetic resonance imaging (MRI) and computed tomography (CT) techniques. The use of conservative treatment only has a chance of healing in pediatric patients. Conservative measures for adults should only be considered as adjuvant treatment to surgery.     

距骨骨软骨损伤的治疗研究进展

距骨骨软骨损伤是运动医学中具有挑战性的疾病之一。临床治疗策略包括保守治疗和手术治疗,保守治疗在儿童患者中效果最佳,对于成人患者常常选择进行手术治疗。目前常见的外科手术治疗方案包括关节镜下骨髓刺激、自体软骨细胞植入、自体骨软骨移植、同种异体骨软骨移植或同种异体青少年软骨微粒移植等。关节镜下骨髓刺激技术(特别是微骨折)适用于较小的病灶,是常见的一线治疗方案,中短期临床疗效令人满意,但长期疗效有待进一步观察。自体骨软骨移植常用于伴有较大囊性病变的距骨骨软骨损伤患者,有着较好的中短期临床疗效,然而术后存在囊肿复发和供区并发症的发生。近年来有大量文献报道其他生物治疗措施,如骨软骨损伤区域注射富含血小板血浆、或者浓缩骨髓细胞等,均有一定的临床疗效。本文对这些技术的应用细节和疗效进行综述,目的是为临床医生能够更好地治疗距骨骨软骨损伤提供依据。     

Operative treatment of osteochondral lesions of the talar dome: current concepts review

Osteochondral lesions of the talar dome are common problems encountered in orthopaedics. Procedures for the treatment of osteochondral lesions of the talus, including debridement of the joint, shaving of fibrillated cartilage, and resection or perforation of subchondral bone in the last decade, have been performed arthroscopically with very low morbidity. These seem to be inadequate in lesions larger than 1.5 cm(2) and have not been histologically effective in restoring the hyaline cartilage sheath. Osteochondral allografts or autogenous grafts and autologous chondrocyte transplantation have proven to be capable of restoring the articular hyaline cartilage surface, including defects larger than 2 cm(2), although with higher costs and morbidity. In this review, the aforementioned methods of operative treatment are examined and issues that are related to these methods are discussed.     

How to Manage Cartilage Injuries?

Although small cartilage injuries are commonly found in knee arthroscopy procedures, significant chondral and osteochondral injuries are relatively infrequent. Incidence of cartilage injury rises when considering traumatic origin, especially when approaching significant ligamentous or meniscal pathology. Options for restoration span the gamut from benign neglect to open procedures that restore both cartilage and subchondral bone. The best choice of procedure largely depends on lesion size, depth, and location. Smaller lesions isolated to cartilage <2 cm² can be treated with marrow stimulation techniques such as microfracture with or without biologic options (bone marrow aspirate concentrate or platelet-rich plasma with or without cartilage precursors or scaffolds). Microfracture alone in larger lesions has been reported to be less durable and it is therefore not recommended for larger lesions. Smaller lesions <2 cm² that include a subchondral injury can be treated with osteochondral autograft implantation, in which a core of cartilage and bone is transferred from a relative non-weightbearing surface to the lesion.Larger osteochondral lesions >2 cm² are better treated with osteochondral allograft transplantation, where osteochondral cores from a size-matched, fresh cadaver are matched to the patient's lesion. This option may require multiple cores to be placed in a “snowman” pattern; however, recent literature demonstrated that a single plug might produce better outcomes. Alternatively, for large chondral-only lesions, a resurfacing procedure may be chosen that may include biologic options. Autologous chondrocyte implantation (ACI), currently in its third iteration (matrix ACI [MACI]), is an excellent choice with good long-term durability. In addition, MACI may be used for chondral lesions in the patellofemoral joint where matching the native joint topology may be more difficult. If the patient has an underlying bone marrow lesion but an intact cartilage cap that appears healthy on arthroscopic examination, one may consider a core decompression and injection with biologics such as BMAC and bony scaffold with fibrin glue (also known as bioplasty).It is also critical that the surgeon address any concomitant knee pathology that would compromise cartilage restoration. This includes addressing malalignment with distal femoral, proximal tibial, or tibial tubercle osteotomy, significant meniscal deficiency with meniscal transplant, and any instability from lack of cruciate or collateral ligaments with ligament reconstruction.     

The Biomechanical Influence of Defected Cartilage on the Progression of Osteochondral Lesions of the Talus: A Three-dimensional Finite Element Analysis

Objectives

Osteochondral lesions of the talus (OLTs) are common injuries in the general population. Abnormal mechanical conditions applied to defected cartilage are believed to be the culprits to deteriorating OLTs. This study aims to investigate the biomechanical effects of defect size of talar cartilage on OLTs during ankle movements.

Methods

A finite element model of the ankle joint was created based on the computed tomography images of a healthy male volunteer. Different defect sizes (S = 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 1.75, and 2.0 cm²) of talar cartilage were modeled to simulate the progression of OLTs. Mechanical moments were applied to the model to generate different ankle movements, including dorsiflexion, plantarflexion, inversion, and eversion. The effects of varying defect sizes on peak stress and its location were evaluated.

Results

The maximum stress on the talar cartilage increased as the area of the defect enlarged. Additionally, as the defect size of OLTs increased, the areas with peak stress on talar cartilage tended to move closer to where the injury was located. High stresses were present in the medial and lateral areas of the talus at the neutral position of the ankle joint. The concentrated stresses were mainly located in the anterior and posterior defect areas. The peak stress in the medial region was higher than on the lateral side. The order of peak stress from highest to lowest was dorsiflexion, internal rotation, inversion, external rotation, plantar flexion, and eversion.

Conclusions

Osteochondral defect size and ankle joint movements significantly modulate the biomechanical features of the articular cartilage in osteochondral lesions of the talus. The progression of osteochondral lesions in a talus deteriorates the biomechanical well-being of the bone tissues of the talus.     

Chondral and osteochondral lesions of the talus associated with capsuloligamentous lesions of the ankle joint

The author reports 46 cases of chondral and osteochondral lesion of the talus observed in 256 patients treated surgically between 1974 and 1986 for capsulo-ligamentous lesions of the ankle joint. Four cases were observed in the 18 patients operated for pure lesion of the medial collateral ligament; the remaining 42 cases in the 238 patients operated for lesions of the lateral ligaments. The lesions observed, which were substantially symmetrical in the two sides of the talus, were: cartilage contusion: 20 cases; cartilage chapping: 13 cases; osteochondral fracture with no fragment displacement: 6 cases; osteochondral detachment with loosening of the detached fragment: 7 cases. The author emphasizes the problem of the frequency of lesions of the talus associated with capsulo-ligamentous lesions of the ankle joint (18% in his experience), and that of the site of osteochondral lesions on the lateral side of the trochlea. Finally, the author lists the reasons for which it is his belief that it is essential to know whether or not a capsulo-ligamentous lesion of the ankle joint is associated with osteocartilaginous lesions of the talus.     

Editorial Commentary: Bone Marrow Lesion as a Prognostic Factor for Osteochondral Allograft Transplantation of Cartilage Defects in the Knee Joint

Bone marrow lesions (BML) can be categorized as ischemic, mechanical, or reactive. BML are associated with cartilage loss and can be interpreted as a “stress-related bone marrow edema,” and are a consequence of subchondral overload due to lack of cartilaginous cushioning and load distribution. The prevalence, depth, and cross-sectional area of BML increase with the degree cartilage defect. There is a risk that bone marrow edema will progress to subchondral cysts, and cysts are a point of no return of a BML. Thus, successful treatment of cartilage damage requires causally addressing the bone marrow edema, and it is also crucial for the therapy of the BML that cartilage damage is completely treated. A postoperative BML is associated with incomplete defect coverage due to incomplete ingrowth of the osteochondral allograft with missing closure of the cartilage surface, or insufficient containment. Ideal treatment for a circumscribed subchondral BML is a single cylinder replacing the damaged cartilage and the entire BML with an osteochondral allograft. In the case of larger defects or larger BML, successful treatment of the cartilage defect is the critical point.     

Radiographic changes and clinical results of osteochondral defects of the talus with and without subchondral cysts

BACKGROUND: Subchondral cysts are a type of osteochondral defect of the talus and can be a source of chronic ankle pain. The treatment modality of this cystic lesion is similar to that of other osteochondral defects, but results from previous reports are controversial. Therefore, we compared the clinical results and radiographic changes in small subchondral talar cystic lesions (less than 1.5 cm2) to other noncystic defects after arthroscopic operations without bone grafting. METHODS: The review covered about 2 years (January, 2001 to April, 2003) and included 38 patients with an average age of 36.9 years. Followup ranged from 24 to 36 months. Arthroscopic microfracture or abrasion arthroplasty was performed on 20 defects with subchondral cysts and 18 defects without cysts. Clinical results were assessed by the ankle-hindfoot scale of the American Orthopaedic Foot and Ankle Society (AOFAS); radiographic changes were assessed by the transverse long diameter and the area (mm2) of the cyst on digital radiographs using a PACS (Picture Archiving Communication System). RESULTS: At the last followup, AOFAS clinical scores improved similarly in cystic and noncystic defects. The average diameter of the cysts decreased from 8 +/- 2 mm to 6 +/- 2 mm (p < 0.01). The area attributed to the cyst also decreased, from 49 +/- 17 mm2 (24 to 84 mm2) to 23 +/- 8 mm2 (4 to 34 mm2) (p < 0.01). There were no differences in the clinical results between the cystic and noncystic defects. CONCLUSIONS: Good clinical and radiographic results were obtained after arthroscopic treatment of osteochondral defects with a small subchondral cyst. Our results suggest that a small cystic lesion can be treated by arthroscopic microfracture or abrasion arthroplasty and that the existence of a small cyst in an osteochondral defect lesion may not affect the postoperative prognosis.     

Microfracture technique for the treatment of articular cartilage lesions of the talus

The microfracture technique is an established method for treating articular cartilage lesions of the talus. Symptomatic chondral or osteochondral lesions of grade II or higher with softening or fraying of the chondral surface or an unstable rim are indications for débridement of the lesion and use of the microfracture technique. In advanced degenerative lesions, the indication must be determined critically. In a prospective study, significant (p<0.001) improvement was observed at a mean follow-up of 5.2 years (range 3.8-6.6 years) in 23 ankles. According to the Hannover scoring system, 87% of the patients were rated as excellent or good. Results for patients older than 50 years were not inferior to those for younger patients. Results for overweight patients were significantly (p=0.03) worse compared with patients of normal weight. Magnetic resonance imaging findings revealed that filling of the defect is accomplished in the majority of cases with an inhomogeneous structure of the cartilage repair tissue and a high incidence of subchondral alterations. The microfracture technique appears to be a reliable method for treating chondral and osteochondral lesions of the talus, with good outcomes in a mid-term follow-up.     

The effect of fibroblast growth factor-2 on autologous osteochondral transplantation

In this study, we performed a mechanical analysis of the effect of fibroblast growth factor-2 (FGF-2) on autologous osteochondral transplantation in a rabbit model. A full-thickness cartilage defect (diameter: 5 mm; depth: 5 mm) made in the right femoral condyle was treated with osteochondral transplantation using an osteochondral plug (diameter: 6 mm; depth: 5 mm) taken from the left femoral condyle. The animals were divided into three groups: Group I, the defect was filled with 0.1 ml of gelatin hydrogel containing 1 microg of FGF-2; Group II, the defect was filled with 0.1 ml of gelatin hydrogel only; Group III, the defect was left untreated. Thereafter, osteochondral plugs were transplanted and the transplanted osteochondral grafts were evaluated mechanically and histologically at postoperative weeks 1, 3, 8 and 12. The structural property of the osteochondral graft was significantly greater in Group I than in Groups II and III at postoperative week 3. Histological analysis at 3 weeks revealed a tendency towards increased subchondral bone trabeculae in Group I compared with the other groups. Autologous osteochondral grafts transplanted with gelatin hydrogel containing FGF-2 acquired adequate stiffness at an early postoperative phase.