关节外全膝关节切除术的解剖学观察和临床应用

Anatomical research and clinical application of extraarticular total knee resection

目的探讨关节外全膝关节切除术中伸膝装置保留与重建的手术方法。方法新鲜全膝关节标本（6个）关节囊和髌下深囊内注人不同浓度泛影葡胺后行CT检查。关节囊内注入美兰后按关节外切除术要求处理伸膝装置，观察关节囊、髌下脂肪垫、髌下深囊的关系及关节外切除的可行性。累及关节内的膝关节周围恶性骨肿瘤4例，2例术前髌下深囊造影证实髌下脂肪垫未受累者保留完整髌韧带、2例未行髌下深囊造影者行髌韧带冠状面剖开，髌骨冠状面截骨，关节外分离完整切除。观察近期局部控制效果及肢体功能。结果标本观察见髌上囊，腓肠肌内、外侧头腱下囊，胭肌囊，股二头肌腱下滑囊可与关节囊相通，而髌下脂肪垫位于髌韧带和关节腔之间，且髌下深囊未发现与关节腔相通，对脂肪垫未受累者可保留完整髌韧带。4例患者随访10-28个月，平均19个月，均未发现局部肿瘤复发及转移，膝关节屈曲度平均为105°（95°-118°），伸膝延迟平均22°（10°-40°），MSTS评分平均为72．5％。结论累及关节内的膝关节周围恶性骨肿瘤术前应常规行髌下深囊造影，髌下深囊与关节腔不相通及髌下脂肪垫的存在者关节外全膝关节切除术中可完整保留髌韧带，少数情况下仅保留髌韧带的浅层1，2也可满足伸膝装置重建的要求，初步临床应用获得了良好的肿瘤局部控制和功能学结果。

Objective To investigate technique of reservation and reconstruction of the extensor mechanism in extraarticular total knee resection. Methods There were 6 cases of fresh total knee joint specimen for anatomical observation. After meglumine diatrizoate was injected into the joint capsule and the deep infrapatellar bursa, the CT examination of the knee specimen was performed. The specimens were detached according to the requirement of extraartieular knee resection, after methylene blue was injected into the joints capsule. The relationships between articular capsule, infrapatellar fat pad and deep infrapatellar bursa were observed, as well as feasibility of extraarticular total knee resection. Four patients with malignant bone tumor around the knee were performed extraarticalar total knee resection. The patellar ligament was reserved completely in 2 patients whose infrapatellar fat pads were not be involved by tumor confirmed by deep infrapatellar bursa radiography. However, the patellar ligament was split along the coronal plane in 2 patients who had not undergone deep infrapatellar bursa radiography. The patients were followed up to observe results of tumor control and function of the affected knees. Results Through anatomical observation, some bursas around the knee joints, such as the suprapatellar bursa and popliteal bursa, communicated with the joint cavity, while the deep infrapatellar bursa did not. Furthermore, the infrapatellar fat pad located between the patellar tendon and joint cavity to form a good barrier to tumor invasion. So the patellar tendon could be reserved completely if the infrapatellar fat pad was not involved. Four patients were followed up for 10 to 28 months （average, 19 months）. At final follow-up, there was no local recurrence and metastasis in all 4 patients. The range of flexion of the affected knees ranged from 95° to 118 ° （average, 105 °）, and the average extension lag was 22° （ range, 10°to 40 °）. The MSTS score was 72.5%. Conclusion For patients with malignant bone tumor involving the knee, the deep infrapatellar bursa radiography should be performed routinely. The patellar ligament could be reserved completely in the extraarticular total knee resection when the deep infrapatellar bursa doesn＇t communicate with the joint cavity combined with presence of the infrapatellar fat pad. Sometimes, only reserving the superficial half of the patellar ligament also could meet the need of extension. The short-term result of tumor control and function of the affected knee are satisfactory.