不同原因所致踝关节软骨损伤的关节镜治疗

目的探讨应用关节镜技术治疗不同原因所致踝关节软骨损伤的临床疗效。方法回顾性分析2008年1月至2010年10月在中山大学孙逸仙纪念医院采用关节镜治疗的39例不同原因所致踝关节软骨损伤患者的临床资料,其中骨折18例、软组织撞击综合征7例、剥脱性骨软骨炎5例、痛风性关节炎5例、色素沉着绒毛结节性滑膜炎4例。采用美国足踝外科协会（AOFAS）踝-后足评分系统评价关节功能,前抽屉应力位X线片评估关节稳定性。结果 37例患者获得随访,随访率为95%;随访时间12～24个月（平均18.5个月）。随访结束时踝-后足评分为（84±4）分,优于术前的（54±6）分,两者比较,差异有统计学意义（t=24.249,P=0.000）。18例骨折患者术前和随访结束时的距骨前移距离分别为（15.2±2.5）mm和（3.5±0.2）mm,两者比较,差异有统计学意义（t=19.792,P=0.000）。1例色素沉着绒毛结节性滑膜炎患者术后6个月复发,再次行关节腔病灶清除术后随访15个月未见复发。结论踝关节镜技术可用于治疗不同原因引起的踝关节软骨损伤,近期疗效满意。     

Articular damage caused by metal plugs in a rabbit model for treatment of localized cartilage defects

OBJECTIVE: Currently, the surgical treatment of localized cartilage defects has limitations. Alternatively, localized cartilage defects may be treated with small biocompatible metal cartilage tacks. Our purpose was to investigate the applicability of defect-size femoral implants. Different bearing materials, cobalt-chromium (CoCr) and oxidized zirconium (OxZr), were tested to evaluate the effect on opposing cartilage quality and osseointegration at different insertion depths. METHODS: In 18 adult female New Zealand White rabbits, a medial femoral condyle defect was filled with either an OxZr or a CoCr implant (? articulating surface 3.5 mm; fixating pin of 9.1 mm length), placed flush, 1mm deep or 1mm protruding with respect to the level of the surrounding cartilage. Animals were sacrificed after 4 weeks. Tibial cartilage quality was scored microscopically and osseointegration measured by automated histomorphometry. RESULTS: Considerable articulating cartilage erosion was found in all conditions. Tibial cartilage quality was least compromised when both implants were placed flush compared to deep (P=0.01) or protruding position (P=0.004) and was better for OxZr compared to CoCr (P=0.011) when left protruding, while no differences were found when placed deep of flush. Most bone formation around the fixating pin was observed in a protruding position (P=0.01). In deep position, more bone-implant contact was observed with CoCr compared to OxZr (P=0.02). CONCLUSIONS: OxZr and CoCr implants showed good osseointegration when used as a localized cartilage defect treatment in the rabbit knee; however, opposite cartilage damage was observed in all cases. Placement flush to the surrounding cartilage seems essential and when left protruding OxZr may be less erosive. In conclusion, caution is warranted using small metal implants for the treatment of localized cartilage in the human patient.     

A composition-based cartilage model for the assessment of compositional changes during cartilage damage and adaptation

OBJECTIVE: The composition of articular cartilage changes with progression of osteoarthritis. Since compositional changes are associated with changes in the mechanical properties of the tissue, they are relevant for understanding how mechanical loading induces progression. The objective of this study is to present a computational model of articular cartilage which enables to study the interaction between composition and mechanics. METHODS: Our previously developed fibril-reinforced poroviscoelastic swelling model for articular cartilage was combined with our tissue composition-based model. In the combined model both the depth- and strain-dependencies of the permeability are governed by tissue composition. All local mechanical properties in the combined model are directly related to the local composition of the tissue, i.e., to the local amounts of proteoglycans and collagens and to tissue anisotropy. RESULTS: Solely based on the composition of the cartilage, we were able to predict the equilibrium and transient response of articular cartilage during confined compression, unconfined compression, indentation and two different 1D-swelling tests, simultaneously. CONCLUSION: Since both the static and the time-dependent mechanical properties have now become fully dependent on tissue composition, the model allows assessing the mechanical consequences of compositional changes seen during osteoarthritis without further assumptions. This is a major step forward in quantitative evaluations of osteoarthritis progression.     

关节镜下微骨折术治疗膝关节软骨损伤

[目的]分析关节镜下膝关节软骨损伤的特点并探讨采用微骨折术治疗的手术方法和疗效。[方法]对2003年2月~2005年8月79例膝关节软骨损伤患者采取关节镜下微骨折术治疗,男38例,女41例;左膝35例,右膝34例;平均年龄38.3岁(15~57岁)。术前膝关节症状持续时间平均11个月(3~23个月),其中有明确外伤史48例,占60.7%。软骨成形术基础上采用微骨折尖椎在软骨缺损区钻孔,孔径3 mm,孔间距3 mm,孔深3 mm。[结果]79例患者共发现软骨损伤131处,平均每例存在软骨损伤1.6处,其中股骨内髁和髌骨关节面最常见,分别占33.6%和22.1%;软骨损伤程度按Outerbridge分级最常见为Ⅳ级损伤,占60.3%;软骨损伤面积多数在1~2 cm2,占43.5%。术后随访73例,失访6例,随访率92.4%,平均随访17个月(10~33个月),采用Tegner运动评级和Lysholm膝关节评分进行评价,45例优,18例良,16例差,优良率79.7%;Lysholm膝关节评分由术前平均43分提高到术后88分。[结论]关节镜下微骨折术方法简单,操作方便,是治疗膝关节全层软骨损伤的一种安全有效方法,不管是急性或慢性软骨损伤,均可明显改善患者的关节功能和减轻疼痛症状,提高生活质量。     

Surgical therapeutic possibilities of cartilage damage

Therapy of cartilage damage is a frequent problem, especially in the young and active patient. For the treatment of a cartilage damage we have to consider the size of the defect, age and weight of the patient, meniscal tears, ligament instabilities and varus-/valgus-malalignment. Lavage, shaving and debridement are only sufficient for a short time and have no long term effect. Abrasio and drilling could be useful in eldery people. Microfracturing seems to be an effective alternative for small defects. The restoration of the cartilage surface with the use of autologous chondrocyte transplantation, osteochondral autograft transplantation and posterior condyle transfer seems to be an adequate treatment for younger patients.     

Microfracture for treatment of cartilage detects

Subchondral bone plate microfracture technique (Steadman) has shown to enhance chondral resurfacing by providing a suitable environment for tissue regeneration and taking advantage of the body's own healing potential. Microfracture technique belongs to the bone marrow stimulating methods like abrasion arthroplasty or subchondral bone drilling. Using a specially designed awl or pick, multiple perforations ("microfractures") are placed 3 to 4 mm apart and about 4 mm deep into the subchondral bone to reach a zone of vascularization. The formation of a fibrin clot ("super clot") containing the desired pluripotential stem cells is stimulated. This clot then differentiates and remodels, resulting in a durable fibrocartilage repair tissue. The arthroscopic awls produce essentially no thermal necrosis of the bone compared to hand-driven or motorized drills. In contrary to drills, it is possible with differently curved awls to reach and treat every area of the knee joint or even of the upper ankle or shoulder joint. Between 1992 and 1998 this technique has been used in 351 cases. 162 patients were interviewed with a questionnaire with respect to their subjective judgement of health between 3 and 6 years (mean 4.4) after operation. Pain was the parameter with the greatest improvement. 78% of the patients improved, 18% remained unchanged and 4% were worse. Microfracture is an advisable option for the treatment of full thickness chondral defects.     

Cartilage damage caused by metal implants applied for the treatment of established localized cartilage defects in a rabbit model

The purpose of the current study was to investigate the feasibility of the application of defect‐size femoral implants in a rabbit model of established cartilage defects and compare this treatment to microfracturing. In 31 New Zealand White rabbits, a medial femoral condyle defect was created in each knee. After 4 weeks, 3 animals were killed for defect baseline values. In the other 28 rabbits, knees were sham‐operated, treated with microfracturing, or treated by placing an oxidized zirconium (OxZr) or cobalt‐chromium (CoCr) implant (?? articulating surface 3.5 mm; fixating pin of 9.1 mm length). These animals were sacrificed 4 weeks after treatment. Joints were evaluated macroscopically. Implant osseointegration was measured by automated histomorphometry, and cartilage repair was scored microscopically. Cartilage quality was analyzed macroscopically and microscopically. Bone–implant contact was 63.2% ± 3.2% for CoCr and 62.5% ± 3.2% for OxZr. Cartilage defects did not show complete healing, nor during subsequent sham‐surgery or microfracturing. For all treatments, considerable cartilage damage in the articulating medial tibia, and degeneration of lateral tibial and femoral cartilage was observed (p < 0.05). Both CoCr and OxZr implant‐treated defects showed an increase of cartilage degeneration compared to microfracturing and sham‐operated defects (p < 0.05). Although only a single short‐term follow‐up period was investigated in this study, caution is warranted using small metal implants as a treatment for established localized cartilage defects because, even after 4 weeks in this model, the metal implants caused considerable degeneration of the articulating surface. © 2008 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 27:84–90, 2009     

Approach to cartilage lesions and algorithm for treatment

Cartilage symptoms in the knee may be encountered in various forms in orthopedic practice. The first stage from history to treatment is to establish the diagnosis; if the diagnosis is made as a cartilage lesion in the knee, priority must be given to current treatment approaches. The surgeon must provide information regarding etiology, defect thickness, lesion size, the containment of cartilage, localization, stability, meniscal integrity, anatomic alignment of the knee, previous assessments, radiological assessment (direct radiography, magnetic resonance imaging), and general, medical, and systemic conditions, and family history. In this review, a treatment algorithm is presented for the management of articular cartilage lesions.     

Strategies for prophylaxis and treatment for aspiration

The absolute incidence of aspiration is difficult to define because of its relatively low occurrence and difficulty in diagnosis. The gastric volume predisposing to aspiration is larger than 30 ml. Fasting times for fluids have reduced; however, a large meal may require 9 hours of preoperative fasting. Preoperative carbohydrate-enriched beverages may attenuate postoperative catabolism. Aspiration occurs most frequently during induction and laryngoscopy. Awake fibre-optic intubation may be a suitable alternative in high-risk cases for aspiration. The role of cricoid pressure in anaesthesia needs re-evaluation as radiological and clinical evidence suggest that it may be ineffective and may impede intubation and ventilation. Chemoprophylaxis does not reduce the severity of aspiration pneumonitis as gastric bile is unaffected by these agents and induces a worse pneumonitis than gastric acid. Patients may be discharged home 2 hours after aspirating provided they are clinically unaffected and have postoperative surveillance.     

Conventional therapy and newer drug classes for cardiovascular protection in hypertension

Recently published actively controlled outcome trials in hypertension compared conventional therapy (diuretics and beta-blockers) with newer antihypertensive drug classes, including angiotensin-converting enzyme inhibitors, calcium channel blockers, alpha-blockers, and angiotensin II antagonists. In a quantitative overview of nine trials including 62,605 randomized patients, it was found that conventional therapy and newer drug classes had similar long-term efficacy in preventing cardiovascular complications of hypertension. BP lowering largely accounted for most, if not all, of the observed benefits in cardiovascular outcome. These findings emphasize the desirability of lowering BP as much as possible to maximize the reduction in cardiovascular complications. Furthermore, several clinical trials have been specifically designed to highlight specific mechanisms of action of the newer drugs by measuring intermediate end points, such as carotid intima-media thickening or renal dysfunction, or by studying subgroups of patients with specific disorders, such as diabetes mellitus. In these trials, calcium channel blockers were more effective than conventional therapy in preventing carotid intima-media thickening and mild renal dysfunction, whereas use of calcium channel blockers or angiotensin-converting enzyme inhibitors was associated with a lower incidence of diabetes mellitus in some studies. However, whether or not these specific effects of the newer drugs on intermediary and/or metabolic end points in the long run also lead to fewer cardiovascular complications remains to be proved.     

Experimental arthrosis caused by chemical cartilage damage

In experiments on rabbits the authors studied the dynamics of cartilage degeneration and subsequent pseudorepair processes following what was doubledose chemical damage to articular cartilage. In addition to the classical histological methods they used the histochemical demonstration of hydrolase and dehydrogenase which are of prime importance to cartilage. The intraarticular instillation of sodium iodacetate caused major and irreversible damage to the whole cartilaginous layer. Subsequent pseudorepair proceeded on the one hand from the cells of the peripheral synovial membrane and on the other to a lesser extent from the fibroblasts of the subchondral bone marrow. The most important enzymes depicting these processes can be regarded as AP and LDH. From the viewpoint of accessibility of dystrophic articular cartilage to repair cells one must distinguish the central part of the joint from its periphery. In the latter area of the cartilage it were mainly synovial cells which took part in repair and pseudorepair takes place considerably more actively here than in the central parts of the joint.     

Traumatic cartilage damage of the knee joint

Thirty-five traumatic lesions to cartilage were recorded, together with other injuries, from 225 arthroscopic examinations in two years. Most of the lesions (20) were located at the femoral condyle. The patella was involved in eight cases. However, if the patellar surface was related to the surface of the femoral condyles, the former was just as strongly affected by traumatic effects as the latter. No unambiguous localisation was possible in six cases, most of them smaller cartilage abrasions. Optional therapy proved to be applicable via the arthroscope in seven cases, while small incisions in the form of mini-arthrotomy were necessary in five cases. Arthrotomy was performed on 21 patients, and no therapeutic action at all was required in two cases. Complications included one transient soft-tissue infection and haemarthrosis of one patients who had to be punctured. Following very short-time immobilisation in plaster cast, the use of forearm walking supports was considered appropriate for short-term weight relief. A weight-relieving orthotic device with dynamic partial-loading facility was fitted for longer-term weight relief.     

Basic science and treatment options for articular cartilage injuries

Articular cartilage injuries can produce significant musculoskeletal morbidity for both young and active aging patient populations. The complex and highly specialized composition of normal hyaline cartilage makes treatment of focal chondral injuries a formidable challenge for the basic scientist, surgeon, and physical therapist. The current array of surgical treatment options offers palliative, reparative, and restorative treatment strategies. Palliative options include simple arthroscopic debridement. Reparative strategies utilize marrow stimulation techniques to induce formation of fibrocartilage within the chondral defect. Restorative tactics attempt to replace damaged cartilage with hyaline or hyaline-like tissue using osteochondral or chondrocyte transplantation. Furthermore, while treatment success is obviously dependent on good surgical selection and technique, the importance of sound, compliant postoperative rehabilitation cannot be understated. The purpose of this article is to review the basic science of articular cartilage, current treatment options available, and outline the clinical decision making involved when using these procedures by presenting the algorithm used at our institution for treating focal cartilage lesions.     

Oxidant conditioning protects cartilage from mechanically induced damage

Articular cartilage degeneration in osteoarthritis has been linked to abnormal mechanical stresses that are known to cause chondrocyte apoptosis and metabolic derangement in in vitro models. Evidence implicating oxidative damage as the immediate cause of these harmful effects suggests that the antioxidant defenses of chondrocytes might influence their tolerance for mechanical injury. Based on evidence that antioxidant defenses in many cell types are stimulated by moderate oxidant exposure, we hypothesized that oxidant preconditioning would reduce acute chondrocyte death and proteoglycan depletion in cartilage explants after exposure to abnormal mechanical stresses. Porcine cartilage explants were treated every 48 h with tert‐butyl hydrogen peroxide (tBHP) at nonlethal concentrations (25, 100, 250, and 500 µM) for a varying number of times (one, two, or four) prior to a bout of unconfined axial compression (5 MPa, 1 Hz, 1800 cycles). When compared with untreated controls, tBHP had significant positive effects on post‐compression viability, lactate production, and proteoglycan losses. Overall, the most effective regime was 100 µM tBHP applied four times. RNA analysis revealed significant effects of 100 µM tBHP on gene expression. Catalase, hypoxia‐inducible factor‐1alpha (HIF‐1α), and glyceraldehyde 6‐phosphate dehydrogenase (GAPDH) were significantly increased relative to untreated controls in explants treated four times with 100 µM tBHP, a regime that also resulted in a significant decrease in matrix metalloproteinase‐3 (MMP‐3) expression. These findings demonstrate that repeated exposure of cartilage to sublethal concentrations of peroxide can moderate the acute effects of mechanical stress, a conclusion supported by evidence of peroxide‐induced changes in gene expression that could render chondrocytes more resistant to oxidative damage. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:914–920, 2010     

Systemic administration of glycosaminoglycan polysulphate (arteparon) provides partial protection of articular cartilage from damage produced by meniscectomy in the canine

Bilateral medial meniscectomy was undertaken in 14 mature beagles. Another two underwent arthrotomy (sham-operated controls). One week after surgery, six of the meniscectomised animals were administered glycosaminoglycan polysulphate (Arteparon) (2 mg/kg) subcutaneously three times a week for 3 weeks, then twice weekly until killed 23 weeks later. Two months before death all animals were given Na2(35)SO4 (1.0 mCi/kg) intravenously. At autopsy, articular cartilage (AC) from the medial and lateral compartments, as well as from the femoral trochlear groove and femoral head, was sampled. Proteoglycans (PGs) were isolated by 4.0 M Guanidine hydrochloride (GuHCl) extraction of AC and purified by ultracentrifugation. The PG monomers were assayed for hexuronic acid, protein, and hexosamines (galactosamine/glucosamine), and their ability to aggregate. The results indicated that Arteparon provided some protective effect to AC in the meniscectomised compartment as demonstrated histologically by reduced surface fibrillation, diminished chondrocyte cloning, and maintenance of alcianophilia. The levels of PGs and hexuronate-protein ratios in medial AC of drug-treated meniscectomised animals were found to be comparable to sham controls, whereas these parameters in the nondrug-treated meniscectomized group were depressed.