Surgical treatment and reconstruction strategy of knee valgus deformity

doi:10.3969/j.issn.2095-4344.1299

Abstract

Abstract:

BACKGROUND: Knee valgus deformity is often accompanied by bone and soft tissue changes. There are many treatments, such as distal femoral varus osteotomy, supracondylar acetabular osteotomy, total knee arthroplasty, which can correct valgus deformity and restore the normal mechanical axis of lower limbs. Its advantages, disadvantages and indications are different, and corresponding treatment methods should be selected according to the specific conditions of different patients.

OBJECTIVE: To review the research progress of various surgical methods for treating genu valgus deformity at home and abroad in recent years.

METHODS: A computer-based search was conducted in PubMed and CNKI databases from January 2000 to December 2018 with the keywords of “knee joint, valgus deformity, distal femoral varus osteotomy, supracondylar dome osteotomy, total knee arthroplasty, surgery, treatment” in English and Chinese, respectively. A total of 247 relevant literatures were retrieved, and 47 articles were eligible for the inclusion criteria.

RESULTS AND CONCLUSION: (1) Valgus deformity is often associated with some characteristic changes in bone and soft tissue. There are a variety of treatments, for example, distal femoral varus osteotomy, supraorbital iliac crest osteotomy, total knee arthroplasty. They can correct valgus deformity and restore the normal mechanical axis of the lower extremities. Their advantages and disadvantages and indications are different, so different patients should choose appropriate treatment according to the severity of deformity, length of disease history, age and so on. (2) Distal femoral varus osteotomy is suitable for young people and can effectively prevent or delay the occurrence and development of osteoarthritis. There are many kinds of internal fixators for osteotomy, such as Ilizarov external fixator, Puddu plate, Tomofix plate and intramedullary nail, which have their advantages and disadvantages. (3) However, for patients with knee valgus who have already developed intra-articular diseases, the effect of simple distal femoral varus osteotomy is often unsatisfactory. Supracondylar acetabular osteotomy combined with arthroscopy can effectively solve this problem. (4) Total knee arthroplasty is often the best choice for patients with advanced knee arthritis. According to the severity and pathological changes of valgus deformity of the knee joint, the operative approach of total knee replacement is decided. For patients with abnormal patellar track and severe lateral structural contracture, the lateral approach is used and the medial approach is used instead. The choice of prosthesis is also very important, which directly affects the curative effect and life span after operation. The internal and external soft tissue imbalance restores the articular force line by releasing the balance, but the specific soft tissue release strategy is still controversial. The joint and soft tissue of the patient should be considered comprehensively.

Key words:

knee osteoarthritis, knee valgus deformity, distal femoral varus osteotomy, supracondylar dome osteotomy, total knee arthroplasty, alignment, the National Natural Science Foundation of China

CLC Number:

R459.9

','1');return false;" target="_blank">

R459.9

Qin Gang, Liu Xiong, He Kaiyi, Du Mindong, Zeng Ping, Li Jinyi.

Surgical treatment and reconstruction strategy of knee valgus deformity

[J]. Chinese Journal of Tissue Engineering Research, 2019, 23(24): 3889-3894.

Figures/Tables 1

2.1 股骨远端内翻截骨术股骨远端内翻截骨术在膝外翻的手术治疗上应用广泛，能恢复下肢正常机械轴，改善膝关节的结构和功能，能有效防止或延缓骨关节炎的发生发展[3-4]。股骨远端内翻截骨术包括外侧开放楔形截骨和内侧闭合楔形截骨，目前外侧开放楔形截骨在国内应用较少，内侧闭合楔形截骨应用较为广泛。外侧开放楔形截骨可延长下肢，内侧闭合楔形截骨将缩短下肢，两种方式的截骨部位越靠近成角处，矫正的效果越好。 2.1.1 外侧开放楔形截骨外侧开放楔形截骨适合于青年膝外翻患者，可早期预防骨关节炎发生。Dewilde等[5]对19例外侧开放楔形截骨患者进行长期随访，发现膝关节7年内的有效生存率为83%。Jacobi等[6]采用膝关节损伤与骨关节炎评分对股骨远端外侧开放楔形截骨患者进行了(46.94±17.26)个月的随访，发现末次随访较术前的膝关节损伤与骨关节炎评分明显提高，膝关节评分从术前(43±8)分提升到末次随访(78±23)分，膝关节功能显著改善。Ekeland等[7]对24例外侧开放楔形截骨患者进行长期随访(平均随访7.9年)，发现5年内膝关节生存率为88%，10年内生存率为77%，其中6膝行全膝关节置换术，平均生存6.4年。Saithna等[8]采用外侧开放楔形截骨治疗18例膝外翻患者(21膝)，平均随访时间为4.5年(1.6-9.2年)，结果综合评价其5年累积生存率为79%，4例患者在术后的3.3年内转为关节成形术。Madelaine等[9]研究报道29例外侧开放截骨患者有25例术后获得了骨性愈合，1例不愈合需手术处理，1例延迟愈合未行手术，1例早期固定失效，1例因膝关节僵硬行Judet松解术，5年膝关节生存率为91.4%。由此可见该类手术近期临床疗效满意，可有效防止或延缓骨关节炎的发生发展，适用于青年。该术式优点在于手术操作简单，手术过程中可以准确调节下肢力线及矫正度，对软组织损伤小及骨量丢失少，肢体长度影响少，适用合并内侧副韧带松弛患者[10]。但该手术存在一些缺点，如外侧入路截骨后接骨板对外侧髂胫束的刺激较大，但骨质愈合取出内固定物后其刺激症状也随之消失；骨折延迟愈合发生率高；截骨间隙需植骨，若取自体髂骨则增加手术创伤，若用同种异体骨则有术后发热、排斥、感染等风险，总体来说目前该手术应用较少。 2.1.2 内侧闭合楔形截骨膝关节外翻畸形患者存在骨骼畸形的同时多伴有膝外侧间室的骨关节炎，股骨远端内翻截骨术中内侧闭合楔形截骨应用较为广泛。Backstein等[11]对20例膝外翻患者(32膝)行内侧闭合楔形截骨术，平均随访时间(62.12±15.65)个月，末次随访时膝关节损伤与骨关节炎评分提高到(79.59±17.14)分。末次随访结果显示25例(78.1%)膝优异，5例膝退行性进展，2例膝最后行膝关节置换，总体优良率达67.5%。8例膝(20%)已行全膝关节置换术，尚有2例膝准备行全膝关节置换术，其10年内关节生存率为82%，15年生存率为45%。Brinkman等[12]对30例行内侧闭合楔形截骨术患者平均随访了99个月，结果25例膝关节(83%)获得满意结果，10年生存率为87%，与Backstein等[11]的研究结果相近。Buda等[13]对32例外翻性膝关节炎患者采取内侧闭合性楔形截骨术，术后32例获得随访，平均随访时间5.2年，未发现骨延迟愈合及不愈合病例。膝关节损伤与骨关节炎评分由术前(45.21±18.17)分提高到末次随访时的(79.59±17.14)分，最终仅2例行人工关节置换。Wylie等[14]报道了23例患者(24膝)用内侧闭合楔形截骨术治疗，平均随访8.3年，获得了71%的满意结果，63%发生并发症，25%的患者形成了假关节，21%的患者出现了截骨角度的丢失，最终3例行全膝关节置换术。由此可见股骨髁上内侧闭合性楔形截骨治疗外翻性膝关节炎疗效确切，其优势主要有[15-17]：①骨愈合时间短，出现不愈合或延迟愈合的情况较少；②对内固定的要求相对较低，容易实现截骨端的稳定性，尤其适用于双下肢等长的患者；③软组织刺激小。但该术尚有一些不足之处，如术中调整截骨角度不灵活，存在肢体短缩的可能。 2.1.3 开放楔形截骨与内侧闭合楔形截骨比较与闭合楔形技术相比，开放式楔形技术的技术优势可能更容易在术中通过增加或减少楔形开口量来调整下肢力线及矫正度，且骨量无丢失及软组织损伤小，肢体长度无短缩，软组织损伤小，而在闭合楔形中很难实现。然而，闭合楔形截骨在截骨部位的骨折愈合时间比开放楔形截骨短。且开放截骨间隙如果植入自体髂骨则增加手术创伤，如果植入同种异体骨则可能发生术后发热、骨折延迟愈合等。 2.1.4 截骨固定物近年来很多医者及学者在此基础上进行了多次的改良与创新，其固定方式多种多样，包括Ilizarov外固定架、Puddu接骨板、Tomofix接骨板、髓内钉固定等。Ilizarov外固定架优点是可以逐步矫正畸形，尤其是畸形较重患者，可避免损伤神经血管，但给患者的生活带来了不便，并且存在针道感染的风险[18]。Puddu接骨板上的凸块能使骨骼通过钢板轴向载荷从而使螺钉剪切力受到凸块保护显著降低，因此被广泛应用于开放楔形截骨[19]。但其缺点是需要精确预弯才能实现与骨面贴服发挥固定作用，且矫正度数的精确性过于依赖钢板的预弯程度，但钢板预弯容易导致钢板疲劳，增加内固定断裂风险。Tomofix接骨板干部较长及干骺端螺钉可多角度固定，能显著增强骨干支撑性和稳定性，钢板与螺钉构成内固定支架，可充分保护骨折端血运，钢板形态与股骨内侧髁形态基本吻合无需预弯，显著降低螺钉对骨块牵拉作用，可提高矫正度数的精确性，但Tomofix接骨板易引起髂胫束刺激症状[20]。髓内钉固定有利于骨折愈合，微创损伤小，其缺点是髓内钉的入钉口位于膝关节内，易损伤股骨关节面，且存在退钉的风险。股骨远端解剖型锁定钢板其锁定螺钉与钢板结合为一体，形成内固定支架，增加稳定性，且由于钢板不需与骨直接接触，减轻对软组织及骨膜损伤的损伤，更利于骨折的愈合[21]。内固定物的选择种类繁多，各有其优缺点。选择不同的内固定物，临床效果存在明显差异。使用非锁定型Puddu钢板作为内固定的开放式楔形胫骨高位截骨术的总并发症的发生率高达43%。与之相对照的是，张纪等[22]使用Tomofix锁定钢板作为内固定，6.5年的满意率高达98.5%。所以内固定物的选择对膝外翻手术的成败也至关重要。 2.2 髁上杵臼截骨联合关节镜单纯的股骨远端截骨术仅仅矫正了下肢力线，对已经形成的关节内病变是无能为力的，尤其是长期膝外翻，畸形较重，继发外侧间室骨性关节炎较重的患者，若使用单纯的股骨远端截骨术治疗，其效果往往不尽人意。髁上杵臼截骨联合关节镜技术则可以很好的解决已形成的关节内病变。多数学者认为关节镜下探查清理术可以修整破损变性的软骨面，刨除肥厚滑膜组织，摘除损坏变性的半月板及骨赘、游离体等，而关节腔内冲洗术则可以清洗掉关节内碎物和部分炎症递质，恢复关节内正常结构和关节内环境，改善膝关节功能[23-25]。该手术优势：杵臼状截骨位置选择在股骨髁关节面以上约4 cm的干骺端，此处松质骨接触面积大，稳定性好，易愈合，且往往畸形最严重的地方是距关节较远处，在此处截骨易于调整与对位，无需植骨，操作简便。杵臼截骨处后侧及后内、后外侧骨膜不予剥离，骨愈合快，能有效防止术后骨不愈合或延迟愈合。在改变下肢负重力线、减轻外侧间室高压力的同时有效处理关节内病变，可最大限度缓解膝关节肿痛等症状，延缓、阻止甚至逆转膝关节退变。王开玉等[26]采用股骨髁上杵臼截骨联合关节镜手术治疗32例(35膝)膝关节外翻患者，平均随访2年，所有患者外翻畸形均得到良好矫正，截骨端均愈合良好，矫正角度无丢失,术前时的HSS评分由平均60.64分提高到末次随访时的85.40分，膝关节功能得到明显改善。 2.3 全膝关节置换全膝关节置换术是治疗晚期膝关节炎最为持久有效的方法，对减轻膝关节疼痛，恢复膝关节良好的解剖力线，具有良好的效果。膝外翻畸形占全膝关节置换患者的10%-15%[27]。膝外翻畸形分为3型：Ⅰ型外翻小于10°，在内翻应力下可纠正畸形，约占膝外翻总数的 80%，此类患者中内侧副韧带完好；Ⅱ型患者外翻在10°-20°，内侧副韧带虽然被过度拉伸，但保留部分功能，约占15%；Ⅲ型外翻大于20°，内侧副韧带功能丧失，约占5%。如何使关节到达平衡，恢复膝关节力线，则需对手术入路、术中截骨、软组织处理和假体选择等方面进行综合考虑。 2.3.1 手术入路选择 (1)髌旁外侧入路：1991年Keblish等[28]首先报道使用髌旁外侧入路对膝外翻患者施行全膝关节置换，并对 53 例(79膝)患者进行2年随访，获得良好的效果。有学者认为外侧入路存在髌骨内翻困难、无法充分显露关节内侧、影响外侧皮肤血供、外侧软组织的缝合困难等缺点[29]。鉴于此缺点Langen等[30]不建议在髌骨轨迹正常的患者使用常规外侧入路。使用髌旁外侧入路是否需要配合胫骨结节截骨这一观点也存在着争议，Aurich等[31]对63例膝外翻畸形手术，平均随访7年发现，不行胫骨结节截骨也能取得良好效果。Satish等[32]提出胫骨结节截骨可更好的显露术野，但亦有其缺点：增加手术时间、截骨块分离不愈合、内固定物松动等。但Gunst等[33]对24例膝外翻患者手术时，使用髌旁外侧入路配合胫骨结节截骨，发现所有患者术后康复良好，未出现Satish等[32]报道的胫骨结节骨折不愈合、内固定物松动等并发症。 (2)髌旁内侧入路：髌旁内侧入路在20世纪80年代以前较为盛行，被认为是最经典的膝关节置换手术入路。吕厚山等[34]对74例(87膝)膝关节外翻畸形患者行髌旁内侧入路，平均随访33.8个月，末次随访得出患者的平均膝关节协会评分为81.7分，较术前提高了59分，获得了满意的临床疗效。但有学者认为通过此入路进行外侧软组织松解时，膝关节外侧暴露受限，可能破坏髌骨的血供[35]，术中易发生髌骨与髌股关节并发症等。Segur等[36]在比较2种入路对外翻畸形的疗效的长期随访研究中发现，髌旁外侧入路配合胫骨结节截骨组在膝关节协会评分、膝关节屈曲度、患者步行距离等方面都更具优势。但髌旁外侧入路组的翻修率(4.5%)则较内侧入路组(1.5%)高。而Langen等[30]在对32例膝外翻患者的随机对照研究中报道，2种入路在膝关节活动度、膝关节膝关节协会评分上差异无显著性意义，但外侧入路具有更好的髌股轨迹。因此，手术入路的选择应根据患者膝关节外翻畸形的严重程度及病理改变等因素综合考虑，对于髌骨轨迹不正常(髌骨脱位)、外侧结构挛缩严重患者，则使用髌旁外侧入路较为稳妥，这样能更好地软组织松解，同时可减少对髌骨血运的破坏；膝关节外翻程度较轻、由骨缺损引起或软组织挛缩程度较轻的膝关节外翻患者，可考虑使用髌旁内侧入路。 2.3.2 假体的选择膝外翻畸形在假体选择时应首先考虑膝关节内侧韧带的松弛情况及减少外侧支持韧带松解率。膝外翻畸形患者的后交叉韧带往往挛缩，严重限制了畸形的矫正，使内外软组织难以达到平衡，这样对后交叉韧带的完整保留增加了难度[37]。后稳定型假体比后交叉韧带保留型假体更加稳定，因为后稳定型假体的轮柱结构可使股骨的后滚较大，能最大程度模拟正常膝关节矢状位力学，进而改善髌骨轨迹，同时也能减少外侧支持带的松解，可获得更好的稳定性和关节屈伸度[38]。但后稳定型假体术中切骨量大，胫骨中央柱往往磨损最为严重甚至断裂，当股骨后移时可通过中央柱与股骨凸轮装置接触产生的应力传导至骨-骨水泥界面，增加假体松动的风险[39]。Nakano等[40]指出后交叉韧带保留型假体截骨量较少，更适合相对年轻患者，在合并外翻畸形Ⅰ-Ⅱ度患者中使用，仍可达到良好效果。部分学者认为在严重外翻畸形中，挛缩的后交叉韧带可能不利于软组织平衡，往往需要进行松解，除非后交叉韧带严重丧失其功能，则需使用后交叉韧带保留型假体[41-42]。 2.3.3 软组织的平衡膝关节外翻畸形患者，往往伴随着外侧结构的挛缩及内侧结构的松弛，而外侧结构的充分松解对达到间隙平衡尤为关键。膝关节外侧软组织包括髂胫束、外侧副韧带、后外侧关节囊、腘肌腱、腓肠肌外侧头等。若软组织不平衡则会引起金属假体与聚乙烯之间的应力集中，加速内衬磨损而导致假体磨损松动，影响远期疗效。外侧副韧带和腘肌腱附着于股骨外上髁周围韧带，靠近胫骨旋转和膝关节屈伸轴，对膝关节屈曲稳定功能起到重要作用，所以松解外侧副韧带及腘肌腱对屈曲时外侧间隙紧张有良好效果。相反，髂胫束和后外侧关节囊附着点远离股骨外上髁的韧带，对于膝关节伸直功能起重大作用，松解髂胫束及后外侧关节囊，对伸膝时外侧间隙紧张有良好效果。但若松解腘肌腱易造成腓总神经的损伤，增加日后的翻修风险。至今软组织松解的顺序尚有争议，2004年Heller[43]提出了“inside-out”技术，主张先松解后交叉韧带，随后在胫骨切骨平面松解后外侧关节囊，最后松解髂胫束和外侧副韧带。Lee等[44]则建议应该先松解髂胫束，因膝外翻畸形常合并胫骨外翻，而单纯的松解髂胫束即可纠正胫骨外翻，然后再依次考虑外侧副韧带、后外侧关节囊、腘肌腱、后交叉韧带的松解，称为“outside-in”技术；但Roberto等[45]认为应首要松解挛缩最严重的外侧副韧带，然后依次松解髂胫束、后外侧关节囊等股骨附着点，最后再酌情进行髂胫束的松解。Rawal等[46]在对24例外侧副韧带及腘肌腱均被松解的膝外翻患者进行平均11.5年随访，发现患者对疗效均满意，且均未在随访期间翻修过。还有学者提出，在对外侧软组织结构松解的同时，对内侧副韧带进行紧缩，对内外侧间隙有良好的效果[47]。"

References

[1]Madelaine A, Lording T, Villa V, et al.The effect of lateral opening wedge distal femoral osteotomy on leg length. Knee Surg Sports Traumatol Arthrosc. 2016; 24(3):847-854.

[2]张剑坤,覃佳强.重度膝外翻的外科治疗进展[J].现代医药卫生,2014, 30(15):2287-2289.

[3]Van Egmond N, Stolwijk N, Van Heerwaarden R, et al. Gait analysis before and after corrective osteotomy in patients with knee osteoarthritis and a valgus deformity. Knee Surg Sports TraumatolArthrosc. 2017;25(9):2904-2913.

[4]Sherman SL,Thompson SF,Clohisy J. Distal femoral varus osteotomy for the management of valgus deformity of the knee. J Am AcadOrthop Surg.2018; 26(9):1.

[5]Dewilde TR, Dauw J, Vandenneucker H, et al. Opening wedge distal femoral varusosteotomy using the Puddu plate and calcium phosphate bone cement Knee Surg Sports Traumatol Arthrosc, 2013; 21(1):249-254.

[6]Jacobi M, Wahl P, Bouaicha S, et al. Distal femoral varus osteotomy: problems associated with the lateral open-wedge technique. Arch Orthop Trauma Surg. 2011;131(6):725.

[7]Ekeland A, Nerhus TK, Dimmen S, et al. Good functional results of distal femoral opening-wedge osteotomy of knees with lateral osteoarthritis. Knee Surg Sports Traumatol Arthrosc. 2016;24(5): 1702-1709.

[8]Saithna A, Kundra R, Getgood A, et al. Opening wedge distal femoral varus osteotomy for lateral compartment osteoarthritis in the valgus knee. Knee. 2014;21(1):172-175.

[9]Madelaine A, Lording T, Villa V, et al. The effect of lateral opening wedge distal femoral osteotomy on leg length. Knee Surge Sports Traumatol Arthrosc. 2016; 24(3):847-854.

[10]张丰经,林华刚,刘晨宏.股骨远端开放楔形截骨治疗中青年膝外翻畸形的临床效果[J]. 复旦学报(医学版), 2015, 42(1):96-100.

[11]Backstein D, Morag G, Hanna S, et al. Long-term follow-up of distal femoral varus osteotomy of the knee. J Arthroplasty. 2007; 22 (4-supp-S):2-6.

[12]Brinkman JM ,Freiling D, Lobenhoffer P, et al. Supracondylar femur osteotomies around the knee. Der Orthopde. 2014;43 (1 Supplement): 1-10.

[13]Buda R, Castagnini F, Gorgolini G, et al. Distal femoral medial closing wedge osteotomy for degenerative valgus knee: Mid-term results in active patients. Acta Orthopaedica Belgica. 2017;83(1): 140-145.

[14]Wylie JD ,Maak TG. Medial closing-wedge distal femoral osteotomy for genu valgum with lateral compartment disease. Arthrosc Tech. 2016;5(6):e1357-e1366.

[15]Brinkman J, Freiling D, Lobenhoffer P, et al. [Supracondylar femur osteotomies around the knee. Patient selection, planning, operative techniques, stability of fixation, and bone healing. Der Orthopde. 2014;43(11):988-999.

[16]Quirno M, Campbell KA, Singh B, et al. Distal femoral varus osteotomy for unloading valgus knee malalignment: a biomechanical analysis. Knee Surg Sports Traumatol Arthrosc. 2017;25(3):863-868.

[17]Drexler M, Gross A, Dwyer T, et al. Distal femoral varus osteotomy combined with tibial plateau fresh osteochondral allograft for post-traumatic osteoarthritis of the knee. Knee Surg Sports Traumatol Arthrosc. 2015;23(5):1317.

[18]闫秀中. Ilizarov外固定支架治疗膝关节畸形20例疗效探讨[J].中国伤残医学, 2016, 24(12):44-45.

[19]Thein R, Bronak S, Thein R, et al. Distal femoral osteotomy for valgus arthritic knees. J Orthop Sci. 2012; 17(6):745-749.

[20]张丰经,刘晨宏,方礼明.股骨远端外侧开放楔形截骨与内侧闭合楔形截骨治疗膝外翻的疗效比较[J].中国骨与关节损伤杂志, 2016, 31(2): 149-152.

[21]杨胜松,黄雷,滕星.外固定架辅助髓内钉治疗膝外翻或膝内翻畸形[J]. 北京大学学报(医学版), 2016, 48(2):244-249.

[22]张纪,杜辉,黄野.胫骨高位截骨术:闭合与开放楔形截骨对比[J]. 临床军医杂志, 2016,44(2):128-132.

[23]Giri S,Santosha A,Cha S, et al. Role of arthroscopy in the treatment of osteoarthritis of knee. J Clin Diagn Res. 2015; 9(8):RC08.

[24]陈坚,杜丽茹,吕厚山.膝关节镜下清理术改善骨性关节炎患者疼痛和关节功能的中期疗效[J].中国临床康复,2004, 8(29): 6282-6283.

[25]汤月平.关节镜下膝关节有限清理术治疗膝关节骨性关节炎疗效观察[J].黑龙江医药, 2017,30(5):189-190.

[26]王开玉,陈德生,张志刚,等.股骨髁上杵臼截骨联合关节镜手术治疗成人膝关节外翻畸形[J].实用医学杂志, 2014,30(18):2973-2976.

[27]黄润华,尚希福,胡飞.人工全膝关节置换术治疗老年膝关节病变合并膝外翻畸形的疗效分析[J].临床骨科杂志, 2017, 20(3):310-313.

[28]Keblish PA.The lateral approach to the valgus knee. Surgical technique and analysis of 53 cases with over two-year follow-up evaluation. Clin Orthop Relat Res. 1991; 271(271):52-62.

[29]Chalidis BE, Ye K, Sachinis NP, et al. Lateral parapatellarapproach with tibial tubercle osteotomy for the treatment ofnon-correctable valgus knee osteoarthritis: A retrospectiveclinicalstudy. Knee. 2014; 21(1): 204-208.

[30]Langen S,Gaber S, Zdravkovic V, et al. Lateral subvastus approach with tibial tubercle osteotomy for primary total knee arthroplasty: clinical outcome and complications compared to medial parapatellar approach. Eur J Orthop Surg Traumatol. 2016; 26(2):215-222.

[31]Aurich M,Lenz M,Best N. A Modified lateral approach for total knee replacement in type 2 valgus deformity. Orthopedics. 2017;40(5): 1-4.

[32]Satish BRJ, Ganesan JC, Chandran P, et al. Efficacy and mid term results of lateral parapatellar approach without tibial tubercle osteotomy for primary total knee arthroplasty in fixed valgus knees. J Arthroplasty. 2013;28(10):1751-1756.

[33]Gunst S, Villa V, Magnussen R,et al.Equivalent results of medial and lateral parapatellar approach for total knee arthroplasty in mild valgus deformities. Int Orthop. 2016;40(5):945-951.

[34]吕厚山,关振鹏,周殿阁,等. 膝关节外翻畸形的人工全膝关节置换术[J]. 中华外科杂志, 2005, 43(20):1305-1308.

[35]Aurich M, Lenz M, Best N. A modified lateral approach for total knee replacement in type 2 valgus deformity. Orthopedics. 2017; 40(5): 1-4.

[36]Segur JM ,Vilchezcavazos F, Martinezpastor JC , et al. Tibial tubercle osteotomy in septic revision total knee arthroplasty. Arch Orthop Trauma Surg. 2014;134(9):1311-1315.

[37]Bertin KC, Lloyd WW. Effect of total knee prosthesis designon patellar tracking and need for lateral retinacular release. J Arthroplasty. 2013;28(5): 772-777.

[38]Li N, Tan Y, Deng Y, et al. Posterior cruciate-retaining versusposterior stabilized total knee arthroplasty: a meta-analysis ofrandomized controlled trials. Knee Surg Sports Traumatol Arthrosc. 2014;22(3): 556-564.

[39]Sando T, Mccalden RW, Bourne RB, et al. Ten-year results comparing posterior cruciate-retaining versus posterior cruciate-substituting total knee arthroplasty. J Arthroplasty. 2015; 30(2):210-215.

[40]Nakano N, Matsumoto T, Muratsu H, et al. Results of total knee arthroplasty with NexGen LPS-Flex for osteoarthritis in the valgus knee: a study of 26 patients followed for a minimum of 2 years. Eur J Orthop Surg Traumatol. 2015; 25(2):375-380.

[41]Christensen JC, Brothers J, Stoddard GJ, et al. Higher frequency of reoperation with a new bicruciate-retaining total knee arthroplasty. Clin Orthop Relat Res. 2016;475(1):1-8.

[42]Kim YH, Park JW, Kim JS. Clinical outcome of medial pivot compared with press-fitcondylarsigmacruciate-retaining mobile-bearing total knee arthroplasty. J Arthroplasty. 2017;32(10): 3016-3023.

[43]Heller KD. Ursachen und Management der Patellainstabilitätennach künstlichem Gelenkersatz: Lateralisation, Subluxation und Luxation. Der Orthopäde. 2016;45(5):1-8.

[44]Lee KJ, Bae KC, Cho CH, et al. Radiological stability after revision of infected total knee arthroplasty using modular metal augments. Knee Surg Relat Res.2016; 28(1):55-61.

[45]Roberto R, Federica R, Umberto C, et al. Total knee arthroplasty in the valgus knee. Int Orthop. 2014; 38(2):273.

[46]Rawal J,Devany AJ, Jeffery JA. Arthroplasty in the valgus knee: comparison and discussion of lateral vs medial parapatellar approaches and implant selection. Open Orthop J. 2015;9(1):94-97.

[47]Koninckx A, Schwab PE, Deltour A, et al. The minimally invasive far medial subvastus approach for total knee arthroplasty in valgus knees. Knee Surg Sports Traumatol Arthrosc. 2014;22(8): 1765-1770.