Planning for minimally invasive unicompartmental knee arthroplasty

Unicompartmental knee arthroplasty (UKA) is considered the treatment of choice in patients with single compartment arthritis of the knee at early stages or with osteonecrosis limited to one compartment. However, results in the literature are still controversial and it is a technically difficult procedure. The main goal of UKA is to restore the articular space of the afflicted compartment, without influencing the limb alignment. Selection of patients and pre-operative planning are crucial. The necessity to improve functional results and to reduce immobilization of the patients has led to the development of minimally invasive surgery. Applied to UKA, this approach reduces blood loss and surgical time, causes fewer symptomatic postoperative complications, and permits earlier recovery compared to the traditional incision. The shorter incision makes careful pre-operative planning essential. We briefly review the indications for UKA, the pre-operative clinical and radiological assessment, and the surgical procedure. Proocedings of the Consensus Conference “TSS in hip and knee replacement” (Rapallo, Italy 22–24 June 2006)     

TSS and traditional surgery in hip and knee replacement

Surgery passes through a continuous evolution, thanks to the introduction of new technologies and techniques. Tissue-sparing surgery is a concept introduced in the last years to address prosthetic surgery to a more conservative fashion. We discuss the TSS decalogue with a critical eye, pointing out how traditional surgery is evolving in accordance with TSS statements. Proceedings of the Consensus Conference “TSS in hip and knee replacement”, Rapallo, Italy, 22–24 June 2006     

Osteotomy of the tibial tubercle in complex primary total knee replacement

Objective  Stiffness and severe deformity pose a major challenge in total knee arthroplasty. Numerous techniques have been described to gain exposure and improve knee flexion. Tibial tubercle osteotomy provides excellent and safe exposure of the joint, although mechanical and wound complications have been reported. Materials and methods  We present a series of 32 consecutive complex primary total replacements where an osteotomy of the tibial tubercle was utilised. Results  The patients had a mean follow-up of 2 years and 11 months. Following the procedure, with the exception of one case complicated with deep infection, all of the patients had improved clinically. The mean postoperative range of motion had increased to 102° (give P value < 0.005) and there were no cases of delayed union or non-union. A mechanical complication related to technique occurred in one patient; there were no other cases with a postoperative extension lag. Conclusion  In this challenging population group, we have found a tibial tubercle tuberosity osteotomy to greatly facilitate exposure without compromising the clinical and radiographic outcome.     

28 mm Metasul™ bearings in primary total hip arthroplasty

Assessment of possible low-wear with some former metal-on-metal (MoM) total hip arthroplasties (THA) led to the reintroduction of metallic bearings in the late 80’s. The author reports on two studies of Metasul-28 mm cementless THA. In the first one in a general population, impingement has been the main cause of osteolysis and Co level survey has been a good indicator of Metasul bearing behaviour. In the second study, in a group of 83 less than 50-year-old and active patients, Metasul bearings showed good wear resistance at 7.2 years mean follow-up. In both studies, no general toxic effect could have been detected thus far. According to the current knowledge, it is always reasonable to expect low-wear and better THA longevity with use of MoM bearings under the following conditions: 1) use of a CoCr alloy with high carbide concentration; 2) reduce impingement risk (head without sleeve, slimmer as possible neck, perfectly adapted Morse cone from the same manufacturer, well — oriented components); and 3) prefer cementless acetabular fixation.     

关节镜下可吸收性半月板箭治疗半月板损伤的初步报告

目的关节镜下应用可吸收性半月板箭治疗半月板损伤并评价其近期疗效。方法2002年2～10月,关节镜下采用半月板箭缝合固定12例12侧半月板损伤,男5例,女7例;年龄18～58岁,平均33.2岁。左膝4例,右膝8例。内侧半月板损伤4例,外侧半月板损伤8例;前角损伤2例,体部损伤3例,后角损伤7例。红区损伤10例,红-白区损伤2例。病程3d～5个月,平均2.3个月,其中急性损伤(病程<1个月)9例。关节镜下采用新型全内半月板箭技术固定,共使用25枚半月板箭(平均每例2.1枚)。5例同时施行其它类型手术。结果所有病例术后均无早期并发症发生。全部患者均获得随访,随访时间7～13个月,平均10.2个月。随访时所有患者膝关节稳定,无疼痛、绞锁等症状,6周后关节活动度全面恢复。Lysholm评分由术前的平均(45.6±13.4)分增加到术后平均(82.4±16.3)分,差异有显著性(P< 0.05)。2例分别于术后8个月和9个月出现关节积液,考虑为滑膜炎,经治疗后消失。结论对于半月板损伤,如撕裂类型和部位适当,可选择可吸收性半月板箭治疗。半月板箭技术是一种简便快捷、安全有效的半月板缝合方法。     

Cementless total hip arthroplasty in the treatment of severe hip dysplasia or dislocated hips

We present our experience over 6 years with the use of uncemented total hip arthroplasty (THA) for developmental dysplasia of the hip (DDH) with a mean follow-up of 3 years. In a 6-year period, 26 THAs were performed in 19 patients with Hartofilakidis grades 2 and 3 dislocation of the hips. Out of 19 patients, seven had bilateral dislocations. Uncemented acetabular and femoral components were used in all patients. Patients with a minimum follow-up of 1 year were included in the study. The average age at the time of surgery was 38 (range 20–69) years. Approaches used include trochanteric osteotomy in 14 (54%) patients and a lateral approach in 12 (46%) patients. In addition, subtrochanteric osteotomy was performed in four (15%) patients. A Mallory-head femoral stem was used in 15 (58%) patients; a DDH femoral stem was in nine (35%), and the S-ROM femoral prosthesis in two (8%). A Mallory head acetabular shell was used in all cases, a 22.2-mm chrome cobalt head was used in 18 (69%), and a 28-mm chrome cobalt head was used in eight (31%). The average follow-up was 3 (range 1–6) years. The Harris hip score (HHS) improved in the cohort from a mean preoperative score of 51 to a mean postoperative score of 86 (p<0.05). The mean preoperative SF36v2 score was 42 compared to postoperatively of 67(p<0.05). The complication rate was 11% with nonunion of a subtrochanteric osteotomy in one patient, dislocation in one, and trochanteric bursitis due to fracture of Dall-Miles cables in one. THA for DDH is a technically demanding procedure. This short-term follow-up of THA for DDH using uncemented implants is encouraging for arthrosis secondary to DDH. It provides better function compared to arthrodesis or excision arthroplasty, especially in young individuals. A long-term follow-up is required in order to establish the role of this management strategy.     

Intra-articular arteriovenous malformation of the knee

Two young men with longstanding suprapatellar masses are presented. The initial clinical diagnosis was of a synovial or soft tissue tumour. Magnetic resonance imaging showed the features of an arteriovenous malformation (AVM). Surgical exploration and biopsy confirmed the diagnosis. AVMs, although rare, should be considered as a possible diagnosis of a peri-articular swelling of the knee.     

隐性失血对双侧人工全膝关节同期置换手术的影响

[目的]研究双侧人工全膝关节同期置换术术后隐性失血的相关因素。[方法]对2005年2月～2007年2月44例双侧人工全膝关节同期置换术患者进行回顾性分析，通过Gross方程，根据身高、体重及手术前后的红细胞压积推算术后平均显性失血量及平均隐性失血量。[结果]平均总失血量2065ml，其中显性失血量1198ml，隐性失血量867ml，使用自体血回输患者总失血量为2180ml，隐性失血量为937ml（42％）；未使用自体血回输患者的总失血量是1950ml，隐性失血量是799ml（41％）；两组的隐性失血相比差异无统计学意义。[结论]双侧人工全膝关节同期置换术术后隐性失血量占总失血量的比例较高，且使用自体血回输不能完全满足机体恢复体循环的需要，在围手术期要特别注意及时补充血容量。     

胫骨髁间嵴增生在膝关节退行性变诊断中的临床价值探讨

本研究分３组，典型膝关节退行性变组（简称退变组）５０例，早期膝关节退行性变组（简称早退组）１５例，对照组３０例。分别测量每组Ｘ线片的内、外侧胫骨髁间嵴角与内、外侧嵴高平台比值。经统计学处理，两指标所测值在退变组与对照组及早退组与对照组之间有显著性差异（Ｐ＜０．０５），而退变组与早退组之间则无显著性差异（Ｐ＞０．０５）。结果表明：胫骨髁间嵴硬化变尖不仅是膝关节退行性变的特征性表现之一，而且是其早期Ｘ线征象。     

Delayed Reduction of Irreducible Chronic Posterolateral Dislocation of the Knee with Buttonholing of the Medial Femoral Condyle

Abstract Traumatic knee dislocations are relatively rare and almost always respond to closed reduction; however, a small percentage of knee dislocations are irreducible and in these cases open reduction is frequently required. A 65-year-old man with an unreduced posterolateral knee dislocation with laterally dislocated patella was seen 3 weeks after a motor vehicle accident. Medial femoral condyle was found buttonholed through the medial capsule together with the medial collateral ligament and lying in the medial joint space that allowed posterior rotary dislocation of the joint. Both cruciate ligaments and medial meniscus were torn. There was no evidence of any vascular or nerve injury. Reduction was accomplished by removal of the capsuloligamentous structures which were incarcerated in the trochlea and intercondylar notch and by excision of meniscal tear. Following posterior cruciate ligament reconstruction with patellar tendon autograft, lateral patellar release, vastus medialis advancement, and gracilis transfer were done.