Infected knee treated by total knee arthroplasty

The perceived wisdom in orthopaedics precludes insertion of implants in cases of post-recent active joint sepsis. However, revision knee surgery after infected arthroplasty has now been recognised to be safe and efficacious in specialised centres. We illustrate the concept of using principles of revision surgery to successfully treat knees destroyed by primary staphylococcal septic arthritis.     

Reconstruction of soft tissue defects following total knee arthroplasty

Soft tissue defects following total knee arthroplasty can represent serious problems for the patient and the surgeon. Perioperative soft tissue complications can result in loss of the prosthesis or limb. In this study, we present 17 cases with complex wounds following total knee arthroplasty who had surgery between May-1994 and July-2001. Patient-related factors, wound factors, surgical operation, secondary procedures, and duration of follow-up have been analysed for each patient. After local wound care and debridement, soft tissue defects have been covered with either a fasciocutaneous or gastrocnemius myocutaneous flap. All the knees (100%) have been salvaged although in 1 patient (6%) replacement of the prosthesis was necessary. In 5 patients (30%) secondary surgical procedures have been performed. Even though there is no consensus in the management of soft tissue defects following total knee arthroplasty, adequate wound care, including identification of infection, debridement, and early appropriate defect coverage should be the main points to consider.     

全膝关节置换治疗晚期骨性关节炎

目的探讨全膝关节置换（totalknee arthroplasty,TKA）在膝关节骨性关节炎治疗中的疗效,手术要点及注意事项。方法对35例（41膝）晚期骨性关节炎患者行初次人工全膝关节置换术,采用膝前正中纵形切口和内侧髌旁入路,术后进行随访,对比术前术后膝关节功能评分（the Hospital for Special Surgery Knee Score,HSS）及膝关节活动度（range of motion,ROM）以观察疗效。结果全部病例均得到平均24个月的随访,均未出现感染、下肢静脉血栓等并发症。HSS评分由术前平均（69±7）分提高到术后平均（91±4．6）分。膝关节活动范围由术前平均95°提高到术后平均115°。结论全膝关节置换是治疗晚期膝关节骨性关节炎的最佳治疗手段。选择恰当的病例,良好的假体设计,精确的手术技术,术后积极的康复锻炼是影响术后结果的主要因素。     

乌司他丁在全膝关节置换中的应用

背景：乌司他丁是从人尿液中分离纯化提取的广谱胰蛋白酶抑制药。其主要药理机制是抑制溶酶体酶等多种水解酶的过度释放,从而改善组织灌注和微循环。目前关于乌司他丁对全膝关节置换后急慢性疼痛及置换后深静脉血栓发生率的影响报道较少。 目的：观察乌司他丁对应用充气式止血带条件下接受双侧全膝关节置换患者的炎性递质、置换后疼痛、置换后凝血功能、下肢深静脉和浅静脉血栓发生率及置换后肢体功能恢复的影响。 方法：选择接受双侧全膝关节置换的患者72例,随机分为对照组和试验组,各36例。试验组静脉给予乌司他丁,对照组给予等剂量生理盐水。所有患者麻醉镇痛方案及置换后功能康复方案均相同。在不同时间点检测患者炎症指标、凝血指标,观察静息和活动时的疼痛评分及置换后恢复质量评分。根据下肢血管超声检查结果分析置换后血栓形成情况。 结果与结论：试验组部分时间点的炎症因子水平低于对照组(P < 0.05)。试验组置换后4 h的静息疼痛目测类比评分显著低于对照组(P < 0.05)。各时间点两组患者凝血功能指标差异无显著性意义(P > 0.05)。与推入手术室时比较,置换后4,24 h时两组患者纤维蛋白原水平均明显下降,置换后48 h时明显升高(P均 < 0.05);置换后24,48 h时两组活化部分凝血活酶时间均明显延长(P < 0.05);置换后4-48 h时两组D-二聚体表达水平明显升高(P < 0.05)。与对照组相比,试验组血栓条数显著减少,血栓总长度明显短,差异均有显著性意义(P < 0.05)。试验组在置换后4 h、置换后1,3,5,7 d置换后恢复质量评分均高于对照组(P < 0.05)。提示乌司他丁可以减轻全膝关节置换患者的炎性反应,缓解置换后早期的疼痛,减少下肢肌间静脉血栓形成数量,减缓血栓形成的速度,提高患者置换后恢复质量。 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程 全文链接：      

同时双侧全膝表面置换与单侧全膝关节置换围手术期康复的比较

背景：目前对于双膝严重骨性关节炎行两组同时双侧全膝表面置换的围手术期康复的相关研究尚不多见。 目的：比较双膝骨性关节炎两组同时双侧全膝表面置换术与单侧全膝关节置换围手术期康复训练的效果。 方法：两组医生对59例(118膝)患者双膝骨性关节炎同台同时全膝表面置换,与同期80例单膝骨性关节炎行单侧全膝关节置换患者(对照组)进行疗效比较。两组患者置换前均进行康复教育及预备康复,置换后康复方法标准一致。 结果与结论：同时双侧全膝表面置换组置换前通过压腿平均减小屈曲畸形角度11.2°(5°~22°)。置换后3~6周,股四头肌、腘绳肌肌力5级,较置换前平均增加0.8级;平均ROM≥95°(110±15) °;无痛行走500 m以上;独自无痛上下10级楼梯,无肿胀;出院时HSS评分较置换前增加。置换后3个月没有发现松动表现及不良反应,其康复疗效与对照组对比差异无显著性意义。表明,在围手术期对双膝骨性关节炎两组医生行同时双侧全膝表面置换,通过系统而量化的康复,有利于减少置换中截骨量和置换后并发症,促进患者膝关节功能恢复,与单侧全膝关节置换相比康复结果无明显差异。     

Bilateral non-union of high tibial osteotomies treated by total knee arthroplasty: a case report

Non-union following high tibial osteotomy (HTO) is very uncommon. We present a case of bilateral non-union of HTOs with end-stage knee arthritis treated with staged, bilateral, posterior stabilized knee replacements. A 77-year-old female presented to our clinic with complaints of debilitating knee pain. She used a frame to get about in her home, she was unable to get up stairs, and she rarely went outside. Simple radiographs revealed bilateral non-unions of her osteotomies, subluxation of the tibial plateauxs and severe knee osteoarthritis. At the time of surgery, the non-unions were found to be fibrous stable. We took a minimal tibial plateaux resection and used long stem tibial stems with offset couplers to bypass the non-unions. At minimum 1 year follow-up, she was walking pain free with full knee range of motion. We found that primary total knee replacement (TKR) using tibial stems and without treating the tibial non-union gave satisfactory results.     

Clinical outcomes and patient satisfaction following revision of failed unicompartmental knee arthroplasty to total knee arthroplasty are as good as a primary total knee arthroplasty

BackgroundWith unicompartmental knee arthroplasty (UKA) being increasingly performed for medial compartment osteoarthritis (OA) of the knee, revision total knee arthroplasty (TKA) for failed UKA is expected to increase. Our primary aim is to evaluate patients in our tertiary institution who underwent revision of failed UKA to TKA to compare their pre-operative clinical scores (patient-reported outcome measures, PROMs) to those of primary TKA.MethodsRetrospective review of our institutional arthroplasty registry between 2001 and 2014 was performed. We identified 70 patients who underwent revision of UKA to TKA. The revision UKA to TKA patients was matched with 140 patients who underwent primary TKA for OA in terms of preoperative demographics, gender, age at time of surgery, body mass index (BMI), primary surgeon, and PROMs. Intra-operative data and postoperative complications or re-revision surgeries performed were reviewed.ResultsIn the revision UKA to TKA group, more stems, augments or constrained implants were used compared to primary TKA. A greater proportion of patients with metal-backed UKA revision to TKA required stems, augments or constrained implants as compared to all-polyethylene UKA revision to TKA, but not a significant proportion (P = 0.250). At two years postoperatively, there were no significant differences observed between the groups in terms of patient satisfaction and PROMs.ConclusionsThis study showed similar outcomes following revision of failed UKA to TKA and primary TKA. There were significant improvements in PROMs for revision UKA to TKA, which is comparable to that of primary TKA.     

Sensitivity of knee soft-tissues to surgical technique in total knee arthroplasty

Restricted range of motion and excessive laxity are both potential complications of total knee arthroplasty (TKA). During TKA surgery, the surgeon is frequently faced with the question of how tightly to implant the prosthesis. The most common method of altering implantation tightness is to vary the thickness of the polyethylene inlay after the bone cuts have been made and the trial components inserted. We have sought to quantify how altering the polyethylene thickness may affect post-operative soft tissue tension for a range of prosthetic designs.Four different prosthetic designs were implanted into fresh-frozen cadaveric knee joints. All four designs were implanted in the standard manner, with a 100 Newton distraction force used to set soft tissue balance. The tibiofemoral force was then recorded at 15° intervals throughout the passive flexion range. After the standard implantation of each prosthesis, the tibial component was raised or lowered to mimic increasing and decreasing the polyethylene thickness by 2 mm and the force measurements repeated.Tibiofemoral force in extension correlated with implantation tightness for all prosthesis designs. Between 15° and 90°of knee flexion, all four designs were insensitive to changes in implantation tightness. Beyond 90° the effect was more notable in rotating platform mobile-bearing and cruciate-retaining prostheses than in posterior-stabilised mobile-bearing designs.The findings of this research may be useful in assisting surgical decision-making during the implantation of TKA prostheses.     

Relationships between the changes in flexion contracture and standing flexion angle of the knee and sagittal spinal alignment after total knee arthroplasty

BackgroundThe sagittal spinal alignment interacts with the lower extremity in patients with combined degenerative disease of the spine and lower extremity. This study aimed to clarify the relationships between the reciprocal changes in sagittal alignment of the knee, pelvis, and spine after total knee arthroplasty (TKA) in osteoarthritis patients.MethodsProspectively, 36 patients who underwent primary TKA for severe knee osteoarthritis were enrolled. Their clinical and radiological evaluation included assessments of the knee flexion contracture (KFC) and standing knee flexion angle (KFA), as well as spinopelvic parameters and the global sagittal spinal alignment from standing whole-lower-extremity and whole-spine radiographs preoperatively and at postoperative 2 weeks, 6 weeks, 6 months, 1 year, and 2 years. Linear mixed models were used to assess the relationships between KFC/KFA and between spinopelvic/global sagittal spinal alignments.ResultsThe KFC decreased abruptly immediately after TKA, and the correction was maintained for 2 years postoperatively. The KFA decreased gradually and approached the value of the KFC after 2 years. Of the spinopelvic parameters, sacral slope and pelvic incidence decreased significantly, in ways related to changes in KFA. There was no significant relationship between sagittal spinal alignment and postoperative changes in KFC.ConclusionAlthough the flexion contracture was corrected immediately after TKA, the standing KFA improved gradually over 2 years. The pelvic parameters showed compensatory changes according to the KFA. The decompensated sagittal spinal malalignment was not related to a relapse in flexion contracture.     

Postoperative outcomes of total knee arthroplasty compared to unicompartmental knee arthroplasty: A matched comparison

BackgroundThe purpose of this study was to evaluate early postoperative outcomes in patients following UKA (unicompartmental knee arthroplasty) compared to a matched cohort of TKA (total knee arthroplasty) patients.MethodsPatients who met radiographic criteria for a medial UKA who underwent either a TKA or UKA at a single institution were matched based on age, gender, and BMI.ResultsOne hundredy and fifty UKA in 138 patients and 150 TKA in 148 patients were included in this retrospective analysis. Mean age was 62.6 ± 9 years and 65.2 ± 9 years in the UKA and TKA groups respectively (p = .01). Patients who underwent UKA had significantly less pain at two and six weeks postoperatively compared to TKA patients with mean Numeric Pain Rating Scale (NPRS) scores of 3.7 ± 1.1 vs. 7.8 ± 1.2, p < .001 and 2.6 ± 1.3 vs. 4.6 ± 1.6, p < .001 respectively. Knee Society Scores (KSS) were higher in the UKA group at six weeks and two years postoperative (86.5 ± 2.8 vs. 81.4 ± 3.6, p < .001 and 89.5 ± 2.4 vs. 84.5 ± 3.3, p < .001 respectively). Return to work was faster in the UKA group (mean 20.6 ± 7.89 vs. 38.6 ± 6.23 days, p < .001). The UKA group also had higher mean Forgotten Joint Scores of 90.5 ± 3.6 vs. 79.5 ± 9.5 (p < .001).ConclusionsPatients with primarily medial compartment OA who underwent UKA had less postoperative pain, earlier return to work, and higher KSS compared to a matched group who underwent TKA.     

Total knee arthroplasty infection due to Abiotrophia defectiva

The first documented case of knee alloarthroplasty infection due to Abiotrophia defectiva, formerly known as nutritionally variant streptococci (NVS) and Streptococcus defectivus, is presented. The microbiology of this bacterium is discussed and clinical features of previously reported cases of infections by NVS are reviewed briefly.     

Measurement of soft tissue imbalance in total knee arthroplasty using electronic instrumentation

The existence of soft tissue contractures in arthritis and the presence of soft tissue imbalance at the time of a total knee arthroplasty causing deformity in the coronal plane has been debated extensively. This discussion was based on the use of instrumentation which tensed the medial and lateral soft tissues in an uncontrolled manner during the operation. Previous work by this research team has developed a surgical instrument to quantify soft tissue imbalance independently of the compressive passive loads through the knee. In order to validate this assumption, an electronic measuring system was developed to record the soft tissue imbalance at 0.25 mm distraction intervals of the knee. This soft-tissue measuring system consists of a surgical instrument containing electronic transducers, an analogue conditioning unit and a portable computer. The surgical instrument introduces a pivot to the centre of the knee in the coronal plane so that the clockwise and counterclockwise moments produced by the collateral soft tissues produce an angular deviation at the equilibrium position. Measurements of angular deviation and separation gap are recorded by the electronic transducers. Eight patients were measured whilst undergoing total knee replacement at Bretby Hall Orthopaedic Hospital. The mean change in angular deviation over an average distraction of the knee of 7.15 mm was 0.4° with a standard deviation of 0.4. It is concluded that this is an acceptable error band for surgical measurement, and soft tissue imbalance can be defined as angular deviation independently of the passive compressive loads through the knee.     

How to address the patella in revision total knee arthroplasty

Patellar issues need to be carefully addressed during any revision TKA and the surgeon often faces the question of what to do with the patella at the time of revision. The choice of treatment is often made by balancing what is technically feasible with the risk of potential complications and takes into account the reason for the revision, the type of implant (i.e., metal-backing or all-polyethylene), the duration of implantation, the fixation, the stability, the sterilization technique, the wear, the presence of osteolysis, the compatibility with the femoral component, and most importantly the remaining bone stock. The various treatment options then include retention of the patellar component, revision of the patellar component, removal of the component with retention of the patellar bony shell (patelloplasty or resection arthroplasty), excision of the patella (partial or total patellectomy), secondary resurfacing, and reconstruction/augmentation of the patellar bone stock. Isolated patellar revision is associated with a high complication rate and recurrent failure when poor patellar tracking, incongruent designs and malalignment of the femoral and tibial components exist. Retention of a well-fixed all-PE (non-oxidized) patella is advocated where possible and revision of metal-backed patella is recommended (unless well fixed with poor bone stock). In the situation of a deficient patella, patelloplasty, augmentation procedures and very rarely patellectomy are other viable options.     

A novel intraoperative sensor for soft tissue balancing in total knee arthroplasty

Ligament balancing during total knee arthroplasty (TKA) is a controllable and critical procedure necessary for the longevity of the prosthesis. Intraoperative knowledge of the magnitude and location of tibiofemoral forces, can guide the surgeon to an accurate balancing throughout the operation. We developed a novel sensor device in order to monitor tibiofemoral forces during TKA ligament balancing procedure. The device predicts loads with an error of ±1.5%, following a linear trend of slope?=?0.9933 and R²?=?0.9987; while the location of load is predicted with a practically acceptable error of ±0.5?mm. The device was subjected to a surgical validation with in situ application during simulated TKAs on composite and cadaveric knees, with a very satisfactory outcome and no operative time elongation. The device can be a useful intraoperative instrument for accurate TKA ligament balancing procedures based on objective and graphically demonstrated and recorded evidence.     

全膝关节置换后创面的皮瓣转移修复

BACKGROUND: Wound complications probably result in severe soft tissue defects after total knee arthroplasty, which brings orthopedic surgeon a big challenge. Some treatment options, such as frequent sterile dressings changes, persistent drainage, minor or thorough debridement, negative pressure wound therapy and split-thickness skin grafts, fail to help those quite large and deep wounds around the knee, with exposed fascia or prosthesis, bone, joint, tendon, large vessels and nerve, heal by secondary intention. Under these situations, orthopedic surgeon should consult plastic surgery and propose flap re-construction.     

Intraoperative measurements of knee motion in total knee arthroplasty

A photostereometric technology-based knee motion analysis system was developed and intraoperative kinematics during total knee arthroplasty (TKA) was investigated. Ten knees were evaluated and two different types of posterior-cruciate-retaining TKA (Genesis-I and Genesis-II) were used. Both TKA showed posterior translation of the medial and lateral femoral condyle with knee flexion. The motion pattern of the estimated contact point of Genesis-II was small initial rollback followed by sliding motion, then rollback again more than 60 degrees. In Genesis-II, the amount of translation of the medial condyle was significantly larger than that of the lateral, suggesting that the lateral condyle acted as a rotational pivot. Our developed knee motion analysis system was non-contact, high resolution and can evaluate both kinematics and estimated contact pattern. The results of this study suggest that intraoperative measurement using this analysis system has advantages for the investigation of in-vivo kinematics and contact condition in TKA.     

Arthroscopic treatment of patellofemoral soft tissue impingement after posterior stabilized total knee arthroplasty

Patellar clunk syndrome is due to a suprapatellar fibrous nodule which develops at the junction between the proximal patella and the quadriceps tendon after total knee arthroplasty. Twelve patients (12 knees) who underwent arthroscopic treatment for the painful patellar crepitus or clunk after total knee arthroplasty had been followed at least for 1 year were enrolled. The average onset of symptom was 10.2 months (from 3 to 21 months) after total knee arthroplasty. All of the patients presented a painful crepitus, catching or clunk at the proximal patella, especially climbing stairs or rising from sitting. Both radiographic and clinical evaluations were done and for the clinical assessment, Knee Society Scores were recorded preoperatively and postoperatively. On their radiographic assessment, there was no evidence of component failure and in only one patient, joint line was elevated more than 8 mm. On arthroscopic examination, hypertrophic synovial tissue was identified at the junction of patella and quadriceps tendon in all patients. The hypertrophic synovial tissue did not engage completely in the intercondylar notch during flexion, but on extension, the lesion impinged on the distal part of anterior flange of femoral component at about 30 degrees to 40 degrees of knee flexion. On clinical assessment at the latest follow-up, the average knee score and function score increased from 63.8+/-4.6 to 90.9+/-3.2, 65.4+/-3.2 to 90.4+/-4.3 respectively. Arthroscopic debridement for soft tissue impingement at the patellofemoral joint following total knee arthroplasty showed satisfactory results.     

Five-year results of the Sigma total knee arthroplasty

The DePuy Sigma total knee arthroplasty (TKA) was introduced in 1997 as a modification of the Press Fit Condylar Knee (PFC) TKA and has been used extensively in the United Kingdom and worldwide. It is the most commonly used TKA in England and Wales, where it accounts for 36% of all primary TKA. The PFC was well established, with reported 10-year survival rates of 93-97%, but this study reports the first 5-year clinical and radiographic follow-up data for the Sigma TKA. Over a 10-month period, 212 Sigma TKAs were performed in 180 patients. Patients were seen at a specialist nurse-led clinic 7 to 10 days before admission and at 6 months, 18 months, 3 years and 5 years after surgery. Data were recorded prospectively at each visit. Radiographs were obtained at the 5-year follow-up appointment. Of 212 knees, 178 (151 patients) were alive at 5 years. Three were lost to follow up. Six knees (3.0%) were revised, five for infection and one underwent change of polyethylene insert at 4.9 years. Five-year survival with an endpoint of revision for any reason was 97.0%; with an endpoint of revision for aseptic failure it was 99.5%. The median American Knee Society knee rating score was 93 out of 100 at 5 years compared with 25 out of 100 at admission. Of 147 radiographs, none showed radiographic loosening of either component. Seventeen (11.6%) showed radiolucent lines. Twenty-eight (19.0%) had alignment outside the range of 7+/-3 degrees valgus. These results suggest that the Sigma TKA gives acceptable clinical results after 5 years. Further follow-up studies are required to see if this performance is maintained in the long term.     

Revision of Oxford medial unicompartmental knee arthroplasty to total knee arthroplasty - results of a multicentre study

The advantages of Unicompartmental Knee Replacement (UKR) over Total Knee Replacement (TKR) includes the preservation of soft tissue as well as bone stock, and better function with improved range of motion and more natural gait. It is therefore believed that the revision of failed UKR to TKR is technically easier than revision of failed TKR. In our study we tested this hypothesis by assessing the reconstruction requirements and early clinical and radiological outcome following the revision of UKR to TKR. During a 15-year period 1060 primary Oxford medial UKR procedures were performed at three centres, 36 of which underwent revision to TKR due to aseptic failure. The mean operating time for revision surgery was 113 min. Among the revision prostheses used, 28 were standard TKRs, six were constrained, and two were semi-constrained. Thirty had no intramedullary stems whereas six had intramedullary stems. In 30 cases reconstruction for bone loss was not required whereas metal augmentation was used in two knees, contained peg defects in the femur were filled with cement in two knees and contained keel defects in the tibia were grafted using the bone from revision cuts in two knees. After a mean follow-up of 2 years, the mean 'total knee score' was 86.3 and the mean functional score was 78.5. These findings suggest that the complexity of operation and complications encountered during Oxford medial UKR revision and the clinical outcome compare favorably with those of TKR revision.     

单髁置换与全膝关节置换后隐性失血的对比研究

文题释义： 隐性失血：一般是指较大的创伤或手术后,排除手术创面失血、术中及术后引流丢失等可计算的显性失血之外,患者机体内丢失的血量。试验中由于所有患者术后均未放置引流管,未观察到显性失血,所以术后第4,21,42天的总失血量为隐性失血量,用血红蛋白和红细胞比容数值变化来体现隐性失血的变化。 显性失血：一般是指较大的创伤或者手术后,手术创面失血、术中及术后引流丢失等可计算的失血量。 背景：单髁置换相较于全膝关节置换的术中失血量相比较低,但二者之间的术后隐性失血量差异尚未得到广泛研究。 目的：对比单髁置换与全膝关节置换后隐性失血的差异,分析术前贫血患者是否也可以在无输血风险的情况下进行单髁置换手术。 方法：选择2014年1月至2016年12月联勤保障部队第904医院收治的膝关节骨性关节炎患者148 例,其中58例进行单髁置换手术,90例进行全膝关节置换手术。术前及术后第1,4,21,42天,检测两组血红蛋白水平、红细胞比容,计算隐性失血量与输血率。试验获得联勤保障部队第904医院伦理委员会批准,批准号：2019-01-03。 结果与结论：①单髁置换组术后第1,4天的血红蛋白水平高于全膝关节置换组(P < 0.01),两组术前及术后21,42天的血红蛋白水平比较差异无显著性意义(P > 0.05);②单髁置换组术后第1,4天的红细胞比容高于全膝关节置换组(P < 0.01),两组术前及术后21,42天的红细胞比容比较差异无显著性意义(P > 0.05);③在术后第1,4天之间,单髁置换组中女性没有隐性失血,男性平均血红蛋白下降量为 4 g/L;全膝关节置换组中女性平均血红蛋白下降量为 10 g/L,男性为 7 g/L,单髁置换组男性与女性的隐性失血量均低于全膝关节置换组的对应性别患者(P < 0.05或P < 0.01);④单髁置换组的输血率为0%,全膝关节置换组的输血率为4.4%;术前中度贫血的患者(血红蛋白60-89 g/L),单髁置换组3例均无需输血,而全膝关节置换组6例中2例(33%)需输血;⑤结果表明,单髁置换较全膝关节置换在术后隐性失血方面有明显优势。 ORCID: 0000-0002-7314-5548(彭超) 中国组织工程研究杂志出版内容重点：人工关节;骨植入物;脊柱;骨折;内固定;数字化骨科;组织工程