Is kinematic total knee replacement better than total hip replacement?

Revision rates, complication rates, and the bone-cement interface reaction of 1,069 condylar total knee replacements were reviewed to help decide if conventional total knee replacement continues to be appropriate for the older low-demand patient. This knee replacement series was also compared with two published series of total hip replacements from the same institution. The conclusions are (1) in medium-term follow-up, total knee replacement is as good as or superior to total hip replacement and (2) based on bone-cement interface analysis, survival of total knee replacement is expected to be superior to conventional total hip replacement ten years postoperatively.     

Results of simultaneous bilateral total knee replacement: a study of 1208 knees in 604 patients

Bilateral symptomatic knee arthritis is a common clinical problem. There are conflicting opinions as to the advisability of simultaneous sequential bilateral total knee replacement. Complication rates of primary unilateral knee replacement are well documented and there are several small series that compare the two techniques. The objective of this study was to identify the complication rate of simultaneous sequential bilateral total knee replacement in a large patient population. Over a 13-year period, 604 primary bilateral sequential simultaneous total knee replacements (1208 knees) were performed. Office notes and hospital charts were retrospectively reviewed to obtain age, sex, diagnosis, knee alignment, associated comorbidities, operative protocol, transfusions, and complications. The study results showed 5.1% local and 15.3% systemic complications and 0.7% mortality rate (none in the past 9 years). With appropriate patient selection and operative technique, patients who present with bilateral symptomatic knee arthritis can enjoy the benefits of simultaneous sequential bilateral total knee replacement without increasing their risks of complications.     

St. Georg knee endoprosthesis system (slide and hinge principle). Observations and results following 10 years' experience with over 3,700 operations

Some 2000 total knee endoprostheses were inserted from 1970-1978 and about 1700 of these have been followed two different types of knee replacement were used, a surface replacement of a non-constrained design and a total hinge prosthesis. Serious complications, such as infection, loosening and fracture of the components were regarded as significant determinants in the evaluation of the durability of total and partial knee replacement. The highest and lowest incidence of complication were recorded. The longevity of knee arthroplasty and the survival rates were estimated by constructing survivorship tables. Patients with knee replacement having no complications were designated "survivals" while patients with an established complication were treated as "deaths". The success rates of total hinge prosthesis were compared with those of the sledge prosthesis. Failure rates of aseptic complications were assessed and compared with failure rates due to septic complications. A differentiation was also made between the sledge prosthesis and the total hinge prosthesis. Furthermore, significant differences in the indication for the insertion of the sledge or the total hinge were determined by group assessment (log-rank-test). Unlike the general trend to use a semiconstrained knee replacement the evaluation of this clinical trial has induced us to improve our hitherto used total knee prosthesis model rather than to develop a new surface replacement.     

Relationship of body mass index to early complications in knee replacement surgery

Background The purpose of this study was to evaluate the relationship between body mass index and early complications following knee replacement. Methods Five hundred and twenty-seven patients who underwent primary knee replacement were recruited. All these patients were subjected to a pre-operative assessment and follow-up at 6 weeks and 1 year following surgery. Any complication occurring during this period was recorded. Complications were grouped into systemic and local, minor and major. Results 12.1% (N = 64) patients had an early complication following knee replacement surgery; 9.2% (N = 48) patients had a major complication. Overall BMI did not seem to influence significantly the rate of complication with a P-value of 0.338. A stronger correlation was found between the surgeon and presence of complication with a P-value of 0.004. Conclusions BMI has a weak correlation to early complications following joint replacement surgery. The operating surgeon seems to have a stronger correlation to early complications as compared with BMI. Investigation performed at Hinchingbrooke Hospital NHS Trust, Huntingdon, Cambridgeshire.     

Das Aneurysma spurium der A. genus superior lateralis

Arterial complications after total knee arthroplasty are rare. If the formation of a false aneurysm does occur, it usually affects the popliteal artery. We report the case of an 77 year old female with a false aneurysm of the lateral superior genicular artery. The patient was suffering from gonarthrosis and received a duocondylar knee replacement without resurfacing of the patella. Postoperatively, she reported anterior knee pain and a revision of the joint with lateral release was carried out. In the third postoperative week, a painful swelling in the lateral and superior aspect of the knee occurred. A scintigraphic investigation with enrichment in the early period was misinterpreted as infection. Ultrasonographic and angiographic investigations gave the right diagnosis of a false aneurysm. In the same angiographic investigation, the aneurysm could be cured by coil embolisation. The interval between the operation leading to the problem and the formation of the aneurysm, as well as the low incidence of this complication, made it hard to diagnose. Ultrasonographic and angiographic examinations allow for proper diagnosis in cases of unclear painful swellings. When dealing with an arterial complication following total knee arthroplasty, a specialized radiologist or vascular surgeon should be consulted immediately.     

The infection of Mycoplasma hominis after total knee replacement: Case report and literature review

The Mycoplasma hominis infection is a rare postoperative complication after joint replacement. Based on our knowledge, there were only two cases reported by Korea all over the world currently. A case of postoperative Mycoplasma hominis infection after total knee replacement in our hospital was reported in this article. It was confirmed through mass spectrometer and Mycoplasma cultivation and treated by the first stage debridement, polyethylene insert replacement, and then drainage and irrigation combined with sensitive antibiotics after the operation. We observed that the C reactive protein (CRP) level correlates with the development of disease, while the erythrocyte sedimentation rate (ESR) remains at a high level, indicating the relevance between the Mycoplasma hominis infection caused by knee joint replacement and CRP. This study aims to report the case and review relevant literature.     

Bilateral femoral neck stress fractures following total knee arthroplasty: a case report and review of literature

Stress fracture of the femoral neck following total knee arthroplasty (TKA) is an uncommon complication with only 20 cases having been described in English literature so far. Stress fractures of femoral neck occurring simultaneously on both sides following a bilateral total knee replacement is an exceptional occurrence, which to the best of our knowledge, has not been described previously. We describe a patient suffering from osteoarthritis of both knees, who was treated with bilateral total knee arthroplasty simultaneously. He developed spontaneous fractures of femoral neck on both sides 9 months following the total knee replacement in the absence of any known risk factors for stress fractures. He was treated with bipolar hemi replacement arthroplasty for displaced fracture on one side and closed reduction/internal fixation on the undisplaced side. A high index of suspicion is needed to diagnose this unusual complication of total knee arthroplasty before the fracture displaces necessitating a prosthetic replacement.     

Sciatic nerve block causing heel ulcer after total knee replacement in 36 patients

Femoral and sciatic nerve blocks are often used for postoperative analgesia following total knee replacement surgery. In this report, we focus on cases of heel ulcers which occurred following the implementation of peripheral nerve block in concert with knee replacement surgery. In some instances, heel ulcers have resulted in delayed rehabilitation and prolonged hospital stays in this group of patients, which makes this phenomenon a potential burden on the healthcare system. Pressure points in the foot should be protected after the implementation of nerve blocks to prevent pressure sores. An awareness of this unusual complication related to knee replacement surgery is necessary to prevent its occurrence and avoid delays in patient rehabilitation and recovery.     

Safety of simultaneous bilateral total knee arthroplasty. A meta-analysis

BACKGROUND: The safety of simultaneous bilateral total knee replacement remains controversial. Some studies have demonstrated a higher rate of serious complications, including death, following bilateral procedures, whereas others have suggested no increase in the complication rate. The objective of this meta-analysis was to compare the safety of simultaneous bilateral total knee replacement with that of staged bilateral and unilateral total knee replacements. METHODS: A computerized literature search was conducted to identify all citations, from 1966 to 2005, concerning bilateral total knee replacement. All of the English-language abstracts were obtained. A multistage assessment was then performed to identify articles fulfilling the inclusion criteria for the study. All randomized, prospective studies reporting the outcome of bilateral total knee replacement were included. The details of the reported data were extracted, and an extensive analysis of relevant variables was carried out. RESULTS: One hundred and fifty published articles were identified, and eighteen that included a total of 27,807 patients (44,684 knees) were included in the meta-analysis. There were 10,930 unilateral total knee replacements, 16,419 simultaneous bilateral total knee replacements, and 458 staged bilateral total knee replacements with at least three months between the operative procedures. The prevalences of pulmonary embolism (odds ratio = 1.8), cardiac complications (odds ratio = 2.49), and mortality (odds ratio = 2.2) were higher after simultaneous bilateral total knee replacement. The prevalence of deep venous thrombosis was lower after simultaneous bilateral total knee replacement, but this difference was not significant. The complication rates after the staged bilateral total knee replacements were similar to those in the patients who had undergone unilateral total knee replacement only. CONCLUSIONS: Compared with staged bilateral or unilateral total knee replacement, simultaneous bilateral total knee replacement carries a higher risk of serious cardiac complications, pulmonary complications, and mortality. The period of time between staged procedures that would eliminate these increased risks could not be determined from this study. LEVEL OF EVIDENCE: Therapeutic Level III.     

Are current thrombo-embolic prophylaxis guidelines applicable to unicompartmental knee replacement?

Symptomatic and asymptomatic deep-vein thrombosis (DVT) is a common complication of knee replacement, with an incidence of up to 85% in the absence of prophylaxis. National guidelines for thromboprophylaxis in knee replacement are derived from total knee replacement (TKR) data. No guidelines exist specific to unicompartmental knee replacement (UKR). We investigated whether the type of knee arthroplasty (TKR or UKR) was related to the incidence of DVT and discuss the applicability of existing national guidelines for prophylaxis following UKR. Data were collected prospectively on 3449 knee replacements, including procedure type, tourniquet time, surgeon, patient age, use of drains and gender. These variables were related to the incidence of symptomatic DVT. The overall DVT rate was 1.6%. The only variable that had an association with DVT was operation type, with TKR having a higher incidence than UKR (2.2% versus 0.3%, p < 0.001). These data show that the incidence of DVT after UKR is both clinically and statistically significantly lower than that after TKR. TKR and UKR patients have different risk profiles for symptomatic DVT. The risk-benefit ratio for TKR that has been used to produce national guidelines may not be applicable to UKR. Further research is required to establish the most appropriate form of prophylaxis for?UKR.     

Can peripheral nerve blocks contribute to heel ulcers following total knee replacement?

Peripheral nerve blocks are widely used for postoperative analgesia following total knee replacement. We would like to present three cases of heel ulcers encountered following a peripheral nerve block for knee replacement surgery. Postoperative heel ulcers have resulted in delayed rehabilitation in all three patients. Attention needs to be given to the pressure points in the foot after the nerve blocks. Awareness of this uncommon complication is necessary to prevent its occurrence.     

Traumatic aneurysm of the inferior lateral geniculate artery after total knee replacement.

A 55-year old man incurred a false aneurysm of the inferior lateral geniculate artery after total knee replacement. The false aneurysm appeared as a pulsatile mass with compressive neuropathy of the posterior tibial nerve. The development of this complication and treatment are discussed.     

Mobile vs. feste Plattform bei unikondylärem Kniegelenkersatz

Although the goal of anatomical and functional joint reconstruction in unicompartmental knee replacement is well defined, no uniform implant design has become established. In particular, the differential indications for implantation of an implant with a mobile or a fixed bearing are still not clear. The long-term results of mobile and with fixed bearings are comparable, but there are significant differences in resulting knee joint kinematics, tribological properties and implant-associated complications.In unicompartmental knee replacement mobile bearings restore the physiological joint kinematics better than fixed implants, although the differences to total knee arthroplasty seem minor. The decoupling of mobile bearings from the tibia implant allows a high level of congruence with the femoral implant, resulting in larger contact areas than with fixed bearings. This fact in combination with the more physiological joint kinematics leads to less wear and a lower incidence of osteolyses with mobile bearings. Disadvantages of mobile bearings are the higher complication and early revision rates resulting from bearing dislocation and impingement syndromes caused by suboptimal implantation technique or instability. Especially in cases with ligamentous pathology fixed bearings involve a lower complication rate. It seems their use can also be beneficial in patients with a low level of activity, as problems related to wear are of minor importance for this subgroup.The data currently available allow differentiations between various indications for implants with mobile or fixed bearings, so that the implants can be matched to the patient and the joint pathology in unicompartmental knee joint replacement.     

人工全膝表面关节置换治疗骨性膝关节炎47例

目的　分析总结人工全膝表面关节置换治疗骨性膝关节炎的临床效果及经验。方法　对 4 7例 5 3膝的骨性膝关节炎病例行人工膝关节置换术 ,单膝关节置换 4 1例 ,双膝关节置换 6例 1 2膝。应用后方稳定型假体 2 1例 2 5个膝关节 ,保留后交叉韧带型假体 2 6例 2 8个膝关节。结果　 39例 4 5个膝关节获 1年以上随访 ,采用HSS评分标准 ,膝关节评分从术前 35分提高到术后 89分 ,术后 4 0个膝关节活动度≥ 90°,4 2 / 4 5膝关节术后膝关节力线正常 ,3例残留 5°～ 7°内翻。结论　人工全膝表面关节置换治疗骨性膝关节炎可取得良好效果。术中精确的截骨操作与正确的软组织松解获得的软组织平衡是手术治疗成功的关键。     

Infected Total Knee Replacements

Deep infection is a devastating complication following total knee arthroplasty. Prompt diagnosis and definitive treatment of this complication are essential for a successful outcome. The treatment options for an infected total knee replacement include (1) antibiotic suppression alone; (2) aggressive wound debridement, drainage, and antibiotic suppression therapy; (3) resection arthroplasty; (4) arthrodesis; (5) two-stage reimplantation; and (6) amputation. Successful salvage of this complication can be accomplished only by extensive investment of surgical and infectious disease efforts in eradicating the infection. Two-stage reimplantation has been the most successful functional option and should be used whenever possible to definitively eradicate the infection and ensure good function of the knee joint.     

全膝关节置换术治疗甲型血友病膝关节病变的疗效分析

目的 评价全膝关节置换术治疗甲型血友病膝关节病变的疗效、手术特点、假体选择及凝血因子替代治疗的有效性和安全性.方法 2003年6月至2009年4月,采用全膝关节置换术治疗甲型血友病膝关节病变患者19例(25膝);年龄18～54岁,平均33.4岁.Ⅷ因子替代治疗方案为手术当天补充至100%,术后3 d内80%以上,术后3 d至一周60%以上.术后进行以持续被动活动器(CPM)为主的功能锻炼,锻炼时机为Ⅷ因子输注后6 h内.观察比较手术前后膝关节HSS评分、疼痛、活动度及并发症.结果 18例(24膝)患者得到随访,随访时间7～54月,平均31个月.术前患者HSS评分为平均(51±14)分(31～64),术后HSS评分为平均(86±9.5)分(62～110).关节活动度由术前平均55°±26.3°(10°～100°),改善为术后平均82°±18.6°(60°～100°).屈曲畸形由术前平均19°±13°(0°～45°),改善为术后平均2.7°±3.2°(0°～10°).所有患者术后1～5 d时间内检测的平均Ⅶ因子浓度为74.07%.术后1例发生关节出血,1例发生腓总神经麻痹,1例患者术后17个月因假体感染行翻修术.结论 在合理补充凝血因子条件下,全膝关节置换术是治疗血友病膝关节病变的有效方法,可明显改善膝关节症状和活动度.     

Myositis ossificans following total knee replacement

Summary Two cases of myositis ossificans involving the quadriceps femoris muscle are described following total knee replacement arthroplasty. This condition appears to be a very rare complication of this operation. One case was helped by ultrasound therapy.

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Zusammenfassung Es wird über zwei Fälle von Myositis ossificans des Quadriceps-femoris-Muskels nach totaler Kniearthroplastie berichtet. Diese Komplikation scheint bei dieser Operation sehr selten aufzutreten. In einem der Fälle wurde mittels Ultraschalltherapie ein Heilungserfolg erzielt.

     

False aneurysm of the lateral superior genicular artery. A complication after the implantation of a knee prosthesis

Arterial complications after total knee arthroplasty are rare. If the formation of a false aneurysm does occur, it usually affects the popliteal artery. We report the case of an 77 year old female with a false aneurysm of the lateral superior genicular artery. The patient was suffering from gonarthrosis and received a duocondylar knee replacement without resurfacing of the patella. Postoperatively, she reported anterior knee pain and a revision of the joint with lateral release was carried out. In the third postoperative week, a painful swelling in the lateral and superior aspect of the knee occurred. A scintigraphic investigation with enrichment in the early period was misinterpreted as infection. Ultrasonographic and angiographic investigations gave the right diagnosis of a false aneurysm. In the same angiographic investigation, the aneurysm could be cured by coil embolisation. The interval between the operation leading to the problem and the formation of the aneurysm, as well as the low incidence of this complication, made it hard to diagnose. Ultrasonographic and angiographic examinations allow for proper diagnosis in cases of unclear painful swellings. When dealing with an arterial complication following total knee arthroplasty, a specialized radiologist or vascular surgeon should be consulted immediately.     

Umstellungsosteotomie vs. unikondyläre Prothese bei Gonarthrose

Background

Osteotomy around the knee and unicondylar knee replacement can both produce excellent results in unilateral knee osteoarthritis. The indications for these procedures differ significantly and are discussed in this article.

Methods

A weight-bearing long-leg radiograph, clinical stability tests and varus-valgus-stress radiographs are mandatory for a preoperative analysis. Osteotomy is a safe and reproducible procedure when a biplanar cutting technique is used and fixation is achieved with a plate fixator. Unicondylar knee replacement can be performed minimally invasive with a quadriceps-sparing arthrotomy.

Evaluation

High tibial osteotomy and unicondylar knee may produce good results in unilateral osteoarthritis of the knee. Our multicenter follow-up study with 533 patients revealed good functional outcome scores with a low complication rate. The subjective ratings were better than in comparable groups with unicondylar knee replacement and with total knee arthroplasty.

Conclusions

The main criterium for osteotomy versus unicondylar knee replacement is constitutional deformity of femur or tibia. In constitutional deformity, osteotomy has a very good prognosis. The results are not dependent on age, BMI, or grade of osteoarthritis. Activity and ligament stability of the knee are secondary criteria in favor of osteotomy. Medial osteoarthritis without constitutional deformity should be treated with unicondylar knee replacement.     

关节假体感染的预防研究进展

针对膝、髋关节严重关节畸形及功能障碍,关节置换是治疗膝、髋关节终末病变的最为有效、安全的治疗措施。然而这一显著提高患者生活质量的手段还有很多并发症,其中人工关节感染是人工关节置换术后最严重的并发症,一旦发生感染,会给患者带来巨大的身体负担和经济压力。而预防是应对关节感染最为经济有效的措施。所以了解人工关节置换术中导致感染的危险因素,及时采取预防措施十分必要。本文针对这些问题作一综述。