一种新型间隔器技术在膝关节置换术后感染二期翻修中的应用

目的探讨一种新型间隔器制作方法在全膝关节置换术（TKA）后假体周围感染治疗方面的可行性和有效性。方法本研究纳入2009年7月至2012年1月间收入院的6例TKA术后慢性深部感染患者,采用二期翻修手术治疗第一阶段彻底清创后使用消毒后的股骨假体、新内衬和抗生素骨水泥作为关节间隔器,确认感染控制后行第二阶段膝关节翻修手术。术后观察感染控制情况和关节功能恢复情况。结果共5例患者按计划接受新型间隔器的二期翻修术。平均随访时间（24．4±10．5）个月（8—37个月）;术前、间隔器安置后、二期翻修后平均HSS评分分别为（40±5．3）分（32-46分）,（47±2．6）分（43～50分）,（65．4±2．3）分（62～68分）。术前、间隔器安置后、二期翻修后平均关节活动度分别为（75°±3．5°）（70°-80°）,（94°±4．2°）（90°～100°）,（106。±4．20）（100°-110°）。总体感染消除率为83．3％。结论消毒后假体和抗生素骨水泥组成的间隔器在治疗TKA术后假体周围感染上有优良的临床前景。     

Periprosthetic fracture of the proximal tibia after lateral unicompartmental knee arthroplasty

We report a case of periprosthetic fracture of the proximal tibia after lateral unicompartmental knee arthroplasty following a trivial fall. At the time of surgery, the components were found to be loose; and there was a large uncontained tibial defect with bone loss and communition at the fracture site. The patient was treated by revision total knee arthroplasty and proximal structural tibial allograft, with a satisfactory result at 5-year follow up. Our case illustrates that a bone-conserving unicompartmental knee arthroplasty, if complicated by a periprosthetic fracture, can also present with a difficult surgical problem. Attention to preoperative planning and to availability of structural allograft for such difficult cases is recommended.     

Revision total knee arthroplasty: infection should be ruled out in all cases

We hypothesized that some aseptic revision total knee arthroplasty failures are indeed caused by occult infection. This prospective study recruited 65 patients undergoing revision total knee arthroplasty. The mean follow-up period was 19 months. Collected synovial fluid was analyzed by Ibis T5000 biosensor (Abbott Molecular Inc, Ill; a multiplex polymerase chain reaction technology). Cases were considered as infected or aseptic based on the surgeon's judgment and Ibis findings. Based on Ibis biosensor, 17 aseptic cases were indeed infected that had been missed. Of these 17 cases, 2 developed infection after the index revision. A considerable number of so-called aseptic failures seem to be occult infections that were not adequately investigated and/or miscategorized as aseptic failure. We recommend that all patients undergoing revision arthroplasty be investigated for periprosthetic joint infection.     

Clinical outcome after treatment of infected primary total knee arthroplasty

Twenty-six consecutive cases of infected primary total knee arthroplasties were treated at our institution from 1989 through 2000. Eleven patients had debridement and irrigation performed within 2 months of index arthroplasty or hematogenous spread; only one infection was eradicated. Twenty-five patients had their prostheses removed; 17 had two-stage revision arthroplasty, following which infection was eradicated in 15; one had a permanent spacer, 7 had arthrodesis (following failed revision arthroplasty in one) and 2 had a femur amputation (following failed revision arthroplasty in one) at follow-up of mean 24 months. Infections were cured equally well with revision arthroplasty and arthrodesis. Among the 15 patients who ended up with revision arthroplasty, 11 had a better range of motion compared to the index arthroplasty, but 8 had daily pain. We present our treatment protocol, which eradicated 15/17 (88%) infections in patients treated with two-stage revision arthroplasty.     

Custom total femur spacer and second-stage total femur arthroplasty as a novel approach to infection and periprosthetic fracture

Total femur arthroplasty procedures have previously been used after tumor excision and as a last resort for failed revision arthroplasty. The patient in this case presented with massive loss of femoral bone stock, a periprosthetic fracture, and recurrent Staphylococcus epidermidis infection. A specially designed total femoral spacer impregnated with antibiotics was created for a 2-stage revision procedure that successfully restored functional ability and eradicated the infection. Although 2-stage protocols with spacers have been used to treat persistent infections after hip and knee arthroplasty, this is the first reported instance of the creation of a total femur antibiotic-impregnated cement spacer and subsequent total femoral arthroplasty as a 2-stage protocol at our institution.     

Frühergebnisse des einzeitigen septischen TEP-Wechsel mit antibiotikahaltigem Knochenzement

BACKGROUND: Periprosthetic infections will generally require revision arthroplasty. The one-stage revision arthroplasty with antibiotic-laden cement is hence an attractive therapeutic option, since it only requires one operation, has a low morbidity and, if successful, is cost-efficient. MATERIALS AND METHODS: We performed one-stage revision arthroplasties. The exchanged prostheses were fixed with antibiotic-laden cement after biotic resistance was determined. All patients were treated with postoperative systemic antibiotics. RESULTS: After a mean postoperative examination period of 18.4 months, we confirmed eradication of infection in 14 of 15 knee joints and in 15 of 16 hip joints. The mean duration of hospital stay was 23 days. Patients' satisfaction was high (93.55%) and the clinical results were satisfactory. CONCLUSION: Our analysis shows that our low early reinfection rate (6.45%) is within statistical expectation. Furthermore, we have showed that there is evidence to suggest that the rate of successful outcomes in one-stage revision arthroplasties, at least at the hip, is not different from the rate of two-stage revision arthroplasties and that the difference may be interpreted as stochastic deviation (p=0.264494). According to existing studies, an analogy to knee arthroplasties can be assumed. We demonstrated that one-stage revision is an adequate therapeutic option if patients are carefully selected and under the supervision of an experienced surgeon.     

Periprosthetic fracture of the tibial plateau after unicompartmental knee arthroplasty

The authors report three cases of unicompartmental knee arthroplasty (UKA), complicated with peri-operative periprosthetic fracture of the tibial plateau. The surgical technique was held responsible in all cases. The initial treatment was different in every case; all patients ultimately underwent revision total knee arthroplasty with a good functional outcome. The authors emphasise the importance of careful preparation of the tibial plateau during UKA, adequate sizing of the tibial component and caution when using a hammer during implantation of the tibial component. When a tibial plateau fracture occurs, the treatment of choice should be immediate revision total knee arthroplasty.     

Algorithm for the evaluation of the painful total shoulder arthroplasty: Searching for sepsis

One of the most serious complications after shoulder arthroplasty is periprosthetic joint infection. The reported incidence after primary procedures ranges from 0.7% to 4%, and the rates after revision surgery are even higher. Data on periprosthetic joint infection are derived in large part from the reported experience in managing infection at the sites of total knee and total hip arthroplasties; there is much less information available with which to guide decision making for the shoulder. This review focuses specifically on the current and future tools for diagnosing periprosthetic infections after shoulder arthroplasty.     

Results of one-stage endoprosthesis revision in periprosthetic infection cause by methicillin-resistant Staphylococcus aureus

OBJECTIVE: Are the results of one-stage exchange arthroplasties to treat periprosthetic infection caused by methicillin-resistant Staphylococcus aureus (MRSA) comparable to bacteriologically unselected studies of one-stage exchange operations? METHOD: From 1996 to 1997 twenty patients with a periprosthetic infection caused by methicillin-resistant Staphylococcus aureus (MRSA) were treated at the ENDO-Klinik by an one-stage exchange arthroplasty. Mean follow-up of fifteen one-stage exchange total hip replacements and 5 one-stage exchange total knee replacements was 16 months. The patients were examined by means of clinical, laboratory-chemical and radiological tests. In addition, postoperative joint aspiration was performed on 14 patients. RESULTS: In 11 cases (61%) the periprosthetic infection was treated successfully with only one one-stage exchange operation. In cases with persisting infection the period between the first exchange arthroplasty and the repeated clinical manifestation of the infection (second exchange operation) was 2 months on average. 93% of the joint aspirations (n = 14), performed on average 4 weeks postoperatively, correlated with the result of the follow-up tests. CONCLUSION: Periprosthetic infection with MRSA is a problematic infection. Because of the reduced therapeutic possibilities it is associated with a higher rate of recurrence than the unselected group of patients as a whole [6, 11, 16, 17, 19, 20]. The authors recommend one-stage exchange arthroplasty using a combination of vancomycin and ofloxacin as admixture to polymethylmethacrylat (Refobacin Palacos R). This procedure does, however, need further development. Intraoperative use of an antiseptic and systemic administration of rifampicin, as recommended by Zimmerli [23] is a further possibility.     

Severe metallosis-related osteolysis as a cause of failure after total knee replacement

BackgroundMetallosis is a syndrome of metal-induced synovitis caused by friction between two metal surfaces. In contrast to the hip joint after resurfacing arthroplasty or metal-on-metal (MoM) total hip replacement, metallosis of the knee is extremely rare.MaterialsWe describe 4 patients who underwent revision total knee replacement because of disabling pain and implant loosening after a mean time of 21 (range: 13–30) years of knee replacement surgery. They were all females with a mean age of 79 (range: 75–82) years. Septic loosening was excluded through microbiological examination and synovial fluid analysis.ResultsDirect metal-on-metal contact at the tibiofemoral interface was confirmed intraoperatively in all cases. All knees showed severe metallosis with advanced osteolysis and pseudotumor formation. In one knee there was a complete fracture of the tibial tray. All patients had a one-stage revision surgery with implant removal, profound synovectomy and implantation of a constrained modular revision knee system. Long modular stems with offset adapters, wedges and/or blocks were used in all cases.ConclusionMetallosis-associated osteolysis should be suspected in cases with radiologically evident polyethylene wear after knee replacement. Recognizing that revision arthroplasty is very technically demanding in such cases, surgeons should have a back-up with modular revision components and a ready access to reconstructive options at this revision setting.     

Revision total knee arthroplasty for failed unicompartmental replacement

The results in nineteen patients (twenty-one knees) who had a failed unicompartmental knee replacement followed by a revision total knee arthroplasty were evaluated. There were twelve excellent, four good, one fair, and two poor results. The interval between the unicompartmental replacement and the revision total knee arthroplasty ranged from eight months to eight years. At the time of the revision, a major osseous defect was found in sixteen knees (76 per cent). The duration of follow-up after the revision ranged from two to ten years. At the most recent follow-up examination, radiographs revealed at least one radiolucent line in thirteen knees (62 per cent). The technical difficulties associated with the revision operation are evidence that unicondylar arthroplasty is not a conservative procedure that allows a total knee arthroplasty to be done easily later. The results also do not support the argument that a revision performed after failure of a unicondylar arthroplasty is less technically demanding than one performed after a failed primary total knee arthroplasty.     

Osteolysis and wear debris after total knee arthroplasty presenting with extra-articular metallosis in the calf

Component wear after total knee arthroplasty (TKA) with extruded metallosis in the extra-articular tissue of the calf secondary to a periprosthetic fracture is a rare complication. A 77-year-old man with a failed Insall-Burstein II TKA prosthesis presented with calf cellulitis after a fall. Radiologic evaluation revealed severe osteolysis and loosening of prosthetic components and an intramuscular abscess communicating with the medullary canal of the tibia through an undisplaced periprosthetic fracture. The patient developed rhabdomyolysis with acute renal failure. Drainage of the calf abscess showed staining of the muscles with wear debris and metallosis. The patient subsequently had debridement and excision of the infected TKA implant. Prompt diagnosis of this condition should be suspected in cases of failed arthroplasty with osteolysis and periprosthetic fracture.     

Periprothetische Femurfraktur nach Knietotalendoprothese

Nowadays an increasing number of periprosthetic femoral fractures are observed after revision knee arthroplasty. A 59-year-old male patient who underwent revision knee arthroplasty fell down in the rehab centre and suffered a periprosthetic femoral fracture. After exact preoperative CT planning and measurement of the ratio and linear dimensions a custom-made implant was produced and engrafted on the prosthesis stem accompanied by open reposition. Postoperatively the patient was mobilized with pain-related weight–bearing, and after 12 weeks osseous consolidation and pain-free full weight-bearing were observed. In situ coupling of an endoprosthesis with a slotted hollow nail represents a valuable treatment option for periprosthetic fractures.     

Revision surgery after failed unicompartmental knee arthroplasty

This retrospective study evaluates the results of 35 revision procedures after failed unicompartmental knee arthroplasty (UKA) in 34 patients, which were done during the period 1986 to 1996. There were 28 women and 6 men with a mean age of 71 years (range, 54-85 years). In all cases, St. Georg and Endo (W. Link, Hamburg, Germany) unicompartmental prostheses were used except 1 PCA unicondylar implant (Howmedica, Rutherford, NJ) and 1 Böhler unicondylar implant (Allo Pro, Baar, Switzerland). Failures most frequently were due to aseptic loosening followed by polyethylene wear. Two deep infections occurred. Revisions were performed 1 week to 11 years after UKA; 23 were required within the first 5 years. In most cases, revision was to a total knee arthroplasty. Partial component exchange was done in 9 cases. All 34 patients were evaluated clinically after exchange arthroplasty. After a mean follow-up time of 4 years (range, 1-12.2 years), we found 11 excellent, 13 good, 4 fair, and 7 poor results according to the Hospital for Special Surgery score. The fair and poor results were due to aseptic loosening of the knee prosthesis in 6 knees. One of 2 patients with deep infection needed femoral amputation. With correct indication and considerable surgical experience, UKA is still a good alternative, especially in the elderly patient.     

二期翻修治疗膝关节肿瘤型人工关节感染

目的探讨二期翻修术治疗膝关节肿瘤型人工关节感染的疗效。方法 2003年8月-2010年8月,收治22例保肢术后膝关节肿瘤型人工关节感染患者。男11例,女11例;年龄15～55岁,平均29.6岁。其中20例为初次关节置换术后感染,2例为翻修术后;术后15 d～89个月发生感染。感染按照Coventry和Fitzgerald等人工关节感染分型标准:Ⅰ型3例,Ⅱ型15例,Ⅲ型4例。发生感染至该次入院时间为5～47个月,平均10.2个月。细菌培养提示阳性9例,阴性13例。2例出现发热,白细胞计数升高。一期清创术取出假体,临时骨水泥填充旷置;待感染控制后行二期翻修。结果一期清创术前C反应蛋白及红细胞沉降率均明显高于二期翻修术前,差异有统计学意义(P<0.05)。术后患者均获随访,随访时间5～63个月,平均23.6个月。一期清创术后18例(81.8%)感染控制,其中1例拒绝二期翻修,17例行二期翻修术;17例中1例因术后5个月感染复发,行截肢术。4例(18.2%)感染未控制,行截肢术。保肢率为77.3%(17/22)。1例肾癌骨转移患者因原发病于术后1年6个月死亡。末次随访时16例关节功能采用美国骨与软组织肿瘤学会功能评分(MSTS 93)为(69.4±12.7)分。结论肿瘤型人工关节重建后感染,应根据情况及时行二期翻修手术,可获得较好疗效。     

Periprosthetic humeral fractures after total elbow arthroplasty: treatment with implant revision and strut allograft augmentation

BACKGROUND: Periprosthetic fractures are among the most challenging complications of elbow arthroplasty, and published information about the outcome of treatment is limited. The purpose of the present study was to determine the results of implant revision and strut allograft augmentation for the treatment of humeral periprosthetic fractures that occur around a loose humeral component. METHODS: Between 1991 and 1999, eleven periprosthetic fractures that occurred around a loose humeral component were treated with cortical strut allograft augmentation and revision arthroplasty with use of a Coonrad-Morrey semiconstrained implant. Six fractures occurred after a primary arthroplasty, and five occurred after a revision arthroplasty. Two parallel strut grafts were used for fracture fixation in most cases. Patients were followed for an average of three years (range, nine months to 7.8 years) and were evaluated clinically and radiographically. RESULTS: Clinical and radiographic fracture union was obtained in ten of the eleven patients. One patient required revision surgery because of aseptic loosening of the humeral component seven years and nine months after fracture union; there were no other implant failures. Complications included one additional nondisplaced humeral periprosthetic fracture after surgery that failed to heal with closed treatment, one olecranon fracture, one permanent ulnar nerve injury, and one case of triceps insufficiency. At the time of the most recent follow-up, seven of the eight patients with an intact reconstruction had a functional arc of motion and no or slight pain and one had limited motion and moderate pain. CONCLUSIONS: Periprosthetic humeral fractures that are associated with a loose humeral component can be effectively treated with revision elbow arthroplasty and strut allograft augmentation. The technique is associated with a high rate of fracture union, implant survival, and satisfactory clinical results. However, the complication rate is substantial.     

Revision surgery after failed unicompartmental knee arthroplasty: a study of 35 cases

This retrospective study evaluates the results of 35 revision procedures after failed unicompartmental knee arthroplasty (UKA) in 34 patients, which were done during the period 1986 to 1996. There were 28 women and 6 men with a mean age of 71 years (range, 54-85 years). In all cases, St. Georg and Endo (W. Link, Hamburg, Germany) unicompartmental prostheses were used except 1 PCA unicondylar implant (How medica, Rutherford, NJ) and 1 B?hler unicondylar implant (Allo Pro, Baar, Switzerland). Failures most frequently were due to aseptic loosening followed by polyethylene wear. Two deep infections occurred. Revisions were performed 1 week to 11 years after UKA; 23 were required within the first 5 years. In most cases, revision was to a total knee arthroplasty. Partial component exchange was done in 9 cases. All 34 patients were evaluated clinically after exchange arthroplasty. After a mean follow-up time of 4 years (range, 1-12.2 years), we found 11 excellent, 13 good, 4 fair, and 7 poor results according to the Hospital for Special Surgery score. The fair and poor results were due to aseptic loosening of the knee prosthesis in 6 knees. One of 2 patients with deep infection needed femoral amputation. With correct indication and considerable surgical experience, UKA is still a good alternative, especially in the elderly patient.     

Late outcome after implantation of the PFC modular knee system

AIM: The objective of the current, prospective study was the evaluation of long-term results after total knee arthroplasty with the PFC-Modular-knee system. METHOD: A total of 514 total knee arthroplasties were implanted between 1991 and 1994 in 248 female and 55 male patients. Their average age amounted to 62.4 years and 449 of them (87.4%) were re-investigated within the first half-year of 2000. Clinical and radiological data were evaluated according the recommendations of the American Knee Society. RESULTS: Late complications were observed in 6.5% of the cases. They consisted of prosthetic loosening (13 knees), patella problems (11 knees), instability (2 knees), periprosthetic fractures (2 knees), and one prosthesis fracture, 18 patients complained about a therapy-resistant, chronic pain syndrome. These findings lead to revision arthroplasty in 15 cases (3.3%). Preoperative American Knee Society Score values were on average 33, 35 an 17 points and improved to mean values of about 85, 79 and 5 points. Radiological signs of prosthetic loosening were observed in 12 cases (2.7%). CONCLUSION: Long-term results after total knee arthroplasty with the PFC-Modular-knee system showed a significant improvement in the patients' complaints and clinical findings at an average of 7.8 years postoperatively. Complication and revision rates of 6.5% and 3.3%, respectively, were low when compared with the international literature and--apart from this--decreased in the course of the observation time.