全膝关节置换术中髌骨的处理

全膝关节置换术中是否置换髌骨仍有争论。术后膝前疼痛及与髌骨有关的并发症是争论的焦点。假体设计的改进及手术技术的提高,是全膝关节置换术后髌股关节并发症减少的关键。     

全膝关节置换术中髌骨假体内置的临床研究

目的探讨髌骨置换时髌骨假体内置对髌股关节运动轨迹的影响。方法2001年9月～2002年3月48例(75膝)行全膝关节置换患者,采用髌骨假体内置的方法置换髌骨,并在术中髌骨置换前后测试髌股关节运动轨迹,术后对患者进行随访。观察髌骨假体安放位置对髌股关节运动轨迹及术后关节功能的影响。结果75膝术中胫骨、股骨截骨完成并安装试模后测试髌股关节运动轨迹,69膝可达到“nothumbtest”,髌骨内置2～5mm后再次测试仍全部达到“nothumbtest”;余6膝未达到“nothumbtest”,经髌骨内置4～8mm后5膝达到,1膝经髌外侧支持带松解最终实现“nothumbtest”。术后经12～18个月随访,膝关节活动度平均为116.5°(95°～125°)。无一例出现髌骨脱位、半脱位、髌骨坏死、髌骨骨折、髌腱撕脱、髌骨不稳以及皮肤坏死等并发症。结论在全膝关节置换术中,髌骨假体内置可有效地改善髌股关节运动轨迹,减少对髌外侧支持带松解的需求,降低髌骨相关的并发症。     

人工全膝关节置换术中髌骨置换的临床研究

目的通过与非髌骨置换比较,探讨髌骨置换对人工全膝关节置换术疗效的影响。方法将2010年9月-11月符合选择标准的63例(63膝)拟行人工全膝关节置换术的骨关节炎患者随机分为两组,其中32例关节置换术中行髌骨置换(置换组),31例不作置换(非置换组)。两组患者性别、年龄、病程、骨关节炎分级、美国膝关节协会评分系统(KSS)标准临床评分及关节功能评分、髌骨评分、髌骨倾斜角、胫股角及髌韧带比值等一般资料比较,差异均无统计学意义(P>0.05),具有可比性。术后6周及3、6、12个月对疗效进行临床及影像学评定。结果两组患者术后切口均Ⅰ期愈合,置换组6例、非置换组8例出现下肢深静脉血栓形成。患者均获12个月随访。置换组术后3、6、12个月时膝前疼痛发生率均低于非置换组(P<0.05)。两组术后各时间点KSS临床评分比较,差异无统计学意义(P>0.05);除术后6周及3个月,其余各时间点置换组关节功能评分明显高于非置换组(P<0.05)。两组髌骨评分除术后12个月外,其余各时间点组间比较差异均无统计学意义(P>0.05)。X线片复查示,两组均无髌骨骨折、髌骨脱位、髌骨不稳、假体松动及断裂发生;术后12个月两组股胫角、髌韧带比值、髌骨倾斜角比较,差异均无统计学意义(P>0.05)。结论人工全膝关节置换术中行髌骨置换可以一定程度改善膝关节功能评分、髌骨评分及降低术后膝前疼痛的发生率。     

人工全膝关节置换术中髌股关节轨迹运行不良的纠正

目的 总结人工全膝关节置换(total knee arthroplasty,TKA)中,纠正髌股关节轨迹运行不良的方法. 方法 2000年1月-2007年5月,对48例49膝TKA中出现髌股关节轨迹运行不良患者采用平衡髌骨内外侧支持带张力、适当调整胫骨假体位置或重建髌韧带止点的方法进行纠正.患者均为女性:年龄53～76岁,平均66.8岁.病程6～23年,平均16.2年.其中骨性关节炎37例38膝,类风湿性关节炎11例11膝.患膝均有不同程度膝外翻和胫骨外旋畸形.膝外翻角为23～42 °,平均33 °;Q角为16～23 °,平均190 °23例有8～35 °屈曲畸形,平均220 °.术前膝关节KSS评分21～51分,平均32分;KSS功能评分29～45分,平均33分. 结果 术中髌股关节运行轨迹恢复正常,髌骨未再出现向外脱位倾向.术后切口均I期愈合,无相关并发症发生.所有患者术后均获随访,随访时间7～82个月,中位随访时间52个月.膝关节外翻畸形均获得矫正,3例残留5 °左右的屈曲畸形,重建的髌韧带未出现撕裂或断裂现象.术后膝关节KSS评分为76～89分,平均82分;KSS功能评分为81～90分,平均85分.术后至随访期末X线片均显示人工关节位置正常. 结论 TKA中出现髌股关节轨迹运行不良时,平衡髌骨内外侧支持带张力、适当调整胫骨假体位置或重建髌韧带止点是纠正这一现象的有效方法,对膝关节的功能康复无不利影响.     

全膝关节置换术髌骨置换与否的比较

目的回顾性分析、比较全膝关节置换术髌骨置换与否的疗效及优缺点,为临床治疗提供参考。方法自1994年1月～2000年12月间住院治疗的骨关节炎及类风湿性关节炎患者86例(109膝)。对髌骨置换和未置换的两组患者进行随访,膝关节评分采用美国HSS评分系统,髌骨评分采用Feller等的髌骨评分标准。随访时拍摄膝关节正、侧位及髌骨30°、90°轴位X线片。结果使用SPSS统计软件进行统计学分析。结果置换组与未置换组术后疗效及并发症的发生率无明显差异,髌骨功能评分差异有非常显著性意义(P<0.01)。置换组部分功能(上下楼梯及从椅子上坐起)略好于未置换组,未置换组术后膝前痛的发生率高于置换组,但多为轻度,差异有显著性意义(P<0.05)。术后髌骨不稳定和半脱位的发生率无统计学差异。结论髌骨不稳定的发生与术前畸形明显及术前髌骨外侧偏移倾向有关,是造成未置换组膝前痛的因素之一。未置换组髌骨不稳定与髌骨分型有关,建议如果术前拍摄髌骨轴位X线片时发现髌骨属于Ⅲ型者应置换髌骨。     

全膝关节置换术中髌骨假体内置应用的体会

自2000年3月～2002年10月对6例9膝行全膝关节置换,均采用髌骨假体内置的方法进行髌骨置换,获得了良好的效果。     

髌骨钻孔减压改善全膝关节置换术后膝前疼痛

目的探讨通过髌骨钻孔减压术改善全膝关节置换术(TKA)后膝前痛的临床疗效。方法将符合标准的113例行TKA的骨关节炎患者按数字法随机分为两组:54例为减压组,TKA术中联合髌骨钻孔减压术;59例为非减压组,仅施行TKA不联合髌骨钻孔减压术。术后观察两组患者切口愈合情况、相关并发症、KSS评分及膝前痛发生率。结果两组患者切口均一期愈合,无严重并发症发生,113例均获满12个月的完整随访。KSS评分:减压组术后明显高于非减压组;术后膝前痛的发生率明显低于非减压组,差异均有统计学意义(P0.05)。结论 TKA术中联合髌骨减压术可以在一定程度上改善膝关节KSS评分及降低术后膝前疼痛的发生率。     

全膝关节置换术中是否置换髌骨的比较

在人工膝关节置换术中，是否置换髌骨仍是一个有争议的问题。虽然多数学者认为对炎性关节炎应进行髌骨置换，但对骨性关节炎髌骨是否置换仍有争议。我们对2001年1月至2004年12月在我院行全膝关节置换术的62例（82膝）骨性关节炎患者进行回顾性研究，比较了置换与未置换髌骨患者的疗效。     

膝关节表面置换术中髌骨是否置换?

对于全膝人工关节置换（TKA）术中髌骨是否置换，学术上一直存在着不同意见的争论。不同的观点主要集中在：髌骨不置换、全部置换以及选择性置换。许多相关文献的报道有不同的结果和结论，这些结论的得出在很大方面受到了病例选择、手术技术、选用假体的设计等因素的影响，因此需要具体情况具体分析。     

髌骨置换与否对全膝关节置换效果的影响

目的评价髌骨置换与否对全膝关节表面置换的影响。方法对2000年1月至2001年6月间行膝关节表面置换的165例病人随机分为髌骨置换组和不置换组。置换组均采用同一种膝关节假体系统，由同组医生完成，术前和随访时评价HSS评分、髌骨评分和髌骨适合角、髌骨高度等影像学结果。所有评价均采用双盲的方式。结果在HSS评分和髌骨评分方面，两组无统计学差异。影像学评价两组无统计学差异。髌骨置换组的手术时间明显长于非置换组。结论对于骨关节炎病人，不置换和置换髌骨临床效果相当，影像学表现无明显区别。但置换组的手术时间更长。不论置换与否，手术时应注意对下肢力线的矫正。     

Asymmetric patella resurfacing in total knee arthroplasty

Three hundred consecutive primary, cemented, condylar total knee arthroplasties (TKAs) were reviewed for the presence of asymmetric patella resurfacing using a postoperative Merchant or sunrise patellar radiograph. Twenty-one knees in 14 patients were found to have the patella asymmetrically resurfaced. Asymmetric resurfacing typically involved the inadvertent preferential resurfacing of the lateral facet with underresection of bone from the medial patellar facet. All patients underwent follow-up for a minimum of 5 years, with a mean follow-up of 7.5 years. Of the 21 knees, 3 revisions were required for patellar complications. One patellar component was loose on radiographs and there was marked patellofemoral pain in 6 knees. Overall, 11 of 21 knees (52%) underwent revision or were recommended for revision for patellar complications or had anterior knee pain that limited activities. Inadvertent asymmetric patella resurfacing using the kinematic condylar implant adversely affects the outcome after TKA.     

The patella in total knee arthroplasty.

Controversy persists as to whether the patella should be resurfaced in total knee arthroplasty. Can the good results of patellar cartilage against the metal femoral component be expected to endure? Attention to technique can be expected to reduce some of the complications of resurfacing, notably fracture, rupture, and instability. Component breakage results from metal-backed designs, and the causes of patellar clunks have not been fully understood.     

Medialization of the patella in total knee arthroplasty

Patellar complications of total knee arthroplasty remain the most common cause of pain and reoperation. Laboratory studies have suggested that medialization of the patella will improve tracking of the patella on the trochlea of the femoral component. The purpose of this study was to determine if clinical medialization of the patellar component on the patellar bone would improve tracking of the patella as demonstrated radiographically. Sixty-two knees were randomized so that 31 knees had a centrally placed patellar component and 31 had the patellar component placed on the medial two thirds of the patellar bone. There was no difference between the two groups with respect to either clinical or radiographic results in the first year after surgery. There was no improvement compared with previous reports in the incidence of tilt and displacement. The one improvement was a reduction in the incidence of lateral release. Thus, consequences of lateral release such as postoperative morbidity, avascular necrosis of the patella, and stress fracture of the patella can be avoided. It is recommended that the patellar component be placed on the medial two thirds of the patella to reduce the occurrence of lateral release. Tracking of the patella during surgery can be assessed using a single suture placed at the superior pole of the patella, and this technique in combination with the no-thumbs test provides an additional means of evaluation for patellar tracking.     

Treatment of the patella at reimplantation for septic total knee arthroplasty

The results of treatment of the patella at the time of aseptic revision of a total knee arthroplasty (TKA) have been better with resurfacing of the patella than other modes of treatment such as leaving a bony shell. Treatment of the patella at the time of reimplantation of a TKA has not been addressed in prior studies. The ability to resurface the patella will be determined by the amount of bone remaining, integrity of the patella, vascularity, the location of the joint line, and soft tissue coverage for wound closure. The current review addresses the technique of patellar resurfacing and patellar bone defect treatment at the time of reimplantation of a TKA.     

Fracture of the patella following total knee arthroplasty

The charts of 21 patients (22 knees) with significant radiographic changes of the patella after total knee arthroplasty were reviewed. The average patient age was 73 years, and average follow-up after arthroplasty was 7.3 years. Lateral release, fat pad excision, quadriceps tendon release, and previous surgery were implicated in the etiology of fracture of the patella. Five cases had type 1 pattern (sclerosis, fragmentation, and no fracture), 5 cases had type 2 pattern (undisplaced fracture and fragmentation), and 12 cases had type 3 pattern (displaced fracture and fragmentation). Type 1 and 2 patterns required no surgical treatment and were rated good to excellent according to the Hospital for Special Surgery Disability Score Sheet. Patients with a type 3 pattern who did not undergo surgery were rated poor to fair, while patients with a type 3 pattern who underwent surgical treatment (patellectomy, removal of the patellar component, or excision arthroplasty for infection) were rated good. Patellectomy is the treatment of choice for patients with displaced fractures of the patella. A classification system for the pattern of patellar changes is proposed.     

Fracture of the patella after total knee arthroplasty

Patellar fracture after knee arthroplasty was found in 11 patients (12 knees) during a 15-year period. Causes of this fracture include trauma, technical factors, and biophysical factors. The incidence of this infrequent complication was significantly increased after patella resurfacing and revision arthroplasty. Minimally displaced, non-comminuted fractures were immobilized, whereas displaced, comminuted fractures with loose patellar prostheses were treated operatively. At a mean follow-up period of 28 months, the average knee score was 75 points. The average arc of motion was 87 degrees, and six of the 11 patients have returned to their prefracture functional level. Treatment should be individualized on the basis of fracture displacement, comminution, and button fixation.     

Effect of patella thickness on patella strain following total knee arthroplasty

Patellar complications following total knee arthroplasty (TKA) have begun to emerge as a major cause of failure. In an effort to understand some of the mechanical factors that might contribute to patellar component failure, a biomechanical study was performed. Quadriceps force and anterior patellar strain were measured during dynamic flexion in 10 fresh, paired human cadaver knee joints. First, tests were performed in the intact knee, followed by either posterior cruciate ligament (PCL) retention or sacrifice of TKA without patellar resurfacing. Tests were then performed following patellar resurfacing with an overly thick, optimum and thin, bony patella. Patellar strain increased in each specimen (with flexion angles of up to 80 degrees), was most pronounced as the bony patella became thinner, was closest to the intact knee when the patella was not resurfaced, and was unaffected by PCL retention or sacrifice. Patellar osteotomy, resulting in a bony patellar thickness of less than 15 mm, resulted in significantly increased strain. TKA systems should include instrumentation that allows precise restoration of overall patellar thickness while maintaining a bony patellar thickness of at least 15 mm.     

Management of the patella in revision total knee arthroplasty

Problems with the patellofemoral joint comprise the most common complication in primary and revision total knee arthroplasty (TKA). The difficulties can range from instability and anterior knee pain at one end of spectrum of severity, to fracture and extensor mechanism disruption at the other end. These complications are generally higher in revision TKA due to compromised bone stock and blood supply. Despite the particular challenges posed by the bone-deficient patella, reasonable results can be achieved.     

Accurate preparation of the patella during total knee arthroplasty

The development of a resection guide that facilitates accurate preparation of the patella during total knee arthroplasty is reported. Use of the guide prevents tilting of the prosthesis, as well as over or underresection of the patella.