Outcome of infected total knee arthroplasty

The results of 44 cases of deep infection after total knee arthroplasty were reviewed. The average age of the patients was 62 years (range, 31–81 years), and all had positive bacterial cultures from deep aspiration or tissue biopsy. Osteitis was revealed in 22 cases. One case was initially treated with antibiotics only, 27 cases were treated with surgical debridement and antibiotics, and 16 cases had immediate removal of the prosthesis. In 21 cases, failed debridement was followed by removal of the prosthesis. Revision arthroplasty was attempted in 15 of the 37 cases in which the prosthesis was removed; the infection was cured in 11 cases. A total of 25 cases that underwent removal of the prosthesis had an arthrodesis performed, and 4 ultimately underwent amputation. In no case of osteitis was the infection cured merely by dedridement and antibiotics, and the index prostheses were retained mainly in cases in which osteitis did not develop.     

人工全膝关节置换术后感染的治疗

目的：探讨人工全膝关节置换术后感染的治疗方法及效果。方法：6例TKA术后感染患者。感染发生时间为TKA术后1个月－11年,2例为早期感染,4例迟发性感染,平均4年2月。其中骨关节炎4例,类风湿性关节炎2例。单纯清创、抗感染治疗3例;清创、一期假体再置术1例;清创、二期假体再置换术1例;关节融合术1例。结果：在3例单纯清创、抗感染治疗中,1例经5次清创后痊愈,1例2次清创后感染未控制,改行关节融合术,1例3次清创,感染未愈;2例关节再置换术病例痊愈,功能恢复满意;2例关节融合术后痊愈。所有病例平均随访4年,除1例失去随访外,其余感染均未复发。结论：对全膝关节置换术后感染可行的治疗包括：单纯清创、抗感染治疗;清创、一期或二期假体再置换术;关节融合术等方法。每种方法都有其适应证,应根据患者的具体病情采用合适的治疗方法。     

Salvage of infected total knee arthroplasty

Between 1981 and 1986, 25 patients with 26 infected total knee arthroplasties (TKAs) were treated with complete debridement of the knee, prosthetic removal, and six weeks of intravenous antibiotics, followed by insertion of a new prosthesis. The patients were followed for 12-57 months (average, 29 months). There was no evidence of residual infection at follow-up examination in any case. Applying the Hospital for Special Surgery knee rating system, 12 patients (50%) were rated excellent, six patients (25%) good, two patients (9%) fair, and four patients (6%) poor. Of the six patients with fair and poor results, five had reduced scores due to joint problems unrelated to the infected TKA. Fourteen patients had no pain at follow-up examination, and four had only slight pain. Nine patients had no limp, ten had a slight limp, one had a moderate limp, and the remainder either had a severe limp or were bedridden due to other joint problems. Eight patients could walk an unlimited distance and four could walk at least one-half mile. Twenty-one knees had a range of flexion greater than 90 degrees. Three patients had extensor lags of 20 degrees or greater. Only one patient required bracing for ambulation.     

Vancomycin-resistant Enterococcus infected total knee arthroplasty

Use of vancomycin to treat infections and hospital colonization with methicillin-resistant Staphylococcus aureus has contributed to the development of vancomycin resistance in Enterococcus. Postoperative infection with vancomycin-resistant Enterococcus developed in 2 patients after total knee arthroplasty, indicating that the infections were nosocomial. Both patients required multiple procedures. The infections were controlled with serial open débridements. One knee was fused successfully, and the other was managed with resection arthroplasty.     

Management of infected total knee arthroplasty

A retrospective study of the Mayo Clinic experience with the management of 61 infected total knee arthroplasties treated between 1970 and 1980 revealed rheumatoid arthritis as an underlying diagnosis in 47%. Previous operations had been performed in 58%. Arthrodesis was the most frequently utilized salvage technique and was successful in 83%. Reimplantation of a new prosthesis was successful in 63%. Debridement alone was successful in six knees when performed early for acute infections.     

Arthroscopy following total knee arthroplasty

Conservative treatment had previously been used in our institution to treat the painful stiff knee joint following total knee arthroplasty (TKA). However, the result was not satisfactory. Arthroscopic surgery was then performed in 11 patients with painful knee joints with limited motion who had previously undergone TKA. Good results were achieved in eight patients. An average improvement of 56.3 degrees was achieved for knee range of motion. Flexion improved up to 90 degrees in all patients in the early postoperative period following arthroscopy. However, the benefits declined with time. To avoid the potential complications of manipulation and open arthrotomy, arthroscopic surgery is an option for treating the painful stiff knee joint.     

Implant salvage in infected total knee arthroplasty

In a retrospective study of 60 infected total knee arthroplasties (TKAs), attempted implant salvage of 39 knees was performed with surgical debridement and antibiotic therapy. In seven of the 39 knees (17.9%), infection was successfully eradicated, with a mean follow-up examination of 4.1 years. In comparing knees with successful salvage to those with persistent infection, the following factors strongly correlated with successful salvage: (1) short duration of symptoms of infection (less than 2 weeks); (2) susceptible gram-positive organism (Streptococcus or Methicillin-sensitive Staphylococcus aureus); (3) absence of prolonged postoperative drainage or the development of a sinus tract; and (4) no prosthetic loosening or roentgenographic evidence of infection. Only five knees in this series satisfied all these criteria, and in each case, implant salvage with eradication of infection and maintenance of good knee function was achieved. Although a higher salvage rate was obtained with the less-constrained prostheses, an infected hinge prosthesis did not preclude successful implant salvage. No patient with a draining sinus tract (0/17), infection with a virulent organism (0/9), or earlier revision arthroplasty (0/9) had successful salvage of the infected implant. Of the 22 knees with postoperative drainage for longer than two weeks or failure of primary wound healing at the time of TKA, only two were successfully salvaged and both required a local muscle flap. Therefore, early aggressive management of persistently draining wounds after TKA is imperative. In TKA complicated by infection, implant salvage with aggressive surgical debridement and antibiotic therapy should be strongly considered, provided that these strict criteria for attempted salvage are adhered.     

Two-stage reimplantation in infected total knee arthroplasty

Twenty-one infected total knee arthroplasties (TKA) in 21 patients were treated from September 1980 through October 1987. Of these, 15 were followed for more than one year. Treatment of these patients consisted of thorough debridement of all infected tissue and components; a cement spacer was used in ten patients. The cement was impregnated with antibiotics. This procedure was followed for an average of 4.2 weeks with intravenous antibiotics and TKA utilizing antibiotic-impregnated cement. Five patients had rheumatoid arthritis and ten had osteoarthritis. The organisms included Staphylococcus coagulase negative (seven patients), Streptococcus group B (two patients), Streptococcus bovis (one patient), Enterococcus (one patient), Staphylococcus coagulase positive and Bacillus circulans (one patient), Staphylococcus coagulase negative and Enterococcus (one patient), Staphylococcus coagulase negative and Pseudomonas aeuriginosa (one patient), and Clostridium perfringens (one patient). Of the 15 patients, 12 appeared to be free of infection, two were obvious failures and required knee fusion, and one was suspected of having continued infection at five years and was treated elsewhere. Eleven patients with revision TKA were available for follow-up examinations at an average of 2.9 years (range, one to six years). One patient died five years after reimplantation but had been functioning well. One patient functioning at three years postreimplantation did not return for a later follow-up examination. The average knee score (modification of the Hospital for Special Surgery Knee Score) was 75.5 points (range, 48-94); average flexion was 81 degrees (range, 52 degrees-120 degrees), and average extension was +6 degrees (range, 0 degrees-30 degrees).(ABSTRACT TRUNCATED AT 250 WORDS)     

Resection arthroplasty following infected total hip replacement arthroplasty

Thirty-nine patients with 41 hips with resection arthroplasty for infected total hip replacement arthroplasty were evaluated for functional level and factors that contribute to that level. Eighty-three percent were either minimal community ambulators or nonambulators, and only two patients walked without assistive devices. At last follow-up, 93% of the patients had pain in their hips. The best function was obtained in patients with a healed wound and heterotopic ossification. The worst functional result was in patients with chronic drainage. Fifteen of the patients with resection arthroplasties had foot-switch studies to determine gait velocity and single-limb stance time. Ten patients also had oxygen consumption studies performed. The average gait velocity was 35 m/minute (41% of normal). The average oxygen consumption was 0.41 ml/gm (264% normal) with an average heart rate of 121. The energy consumption was greater than that recorded in patients with above-knee amputation.     

Anterior knee pain following primary total knee arthroplasty

Despite improvements in technique and technology for total knee arthroplasty (TKA), anterior knee pain impacts patient outcomes and satisfaction. Addressing the prosthetic and surgical technique related causes of pain after TKA, specifically as it relates to anterior knee pain, can aid surgeons in addressing these issues with their patients. Design features of the femoral and patellar components which have been reported as pain generators include: Improper femoral as well as patellar component sizing or designs that result in patellofemoral stuffing; a shortened trochlear groove distance from the flange to the intercondylar box; and then surgical technique related issues resulting in: Lateral patellar facet syndrome; overstuffed patella/flange combination; asymmetric patellar resurfacing, improper transverse plane component rotation resulting in patellar subluxation/tilt. Any design consideration that allows impingement of extensor mechanism anatomical elements has the possibility of impacting outcome by becoming a pain generator. As the number of TKA procedures continues to increase, it is increasingly critical to develop improved, evidence based prostheses that maximize function and patient satisfaction while minimizing pain and other complications.     

Fever following total knee arthroplasty.

This study investigated the incidence and clinical significance of postoperative fever in 118 consecutive patients undergoing 141 total knee arthroplasties (TKAs). A postoperative fever was recorded in 63 (66%) of 95 unilateral and 17 (74%) of 23 bilateral TKA patients. Nine of the unilateral and five bilateral TKA patients developed positive clinical or laboratory findings to explain the pyrexia. Unilateral TKA patients who experienced postoperative fever were statistically more likely to have a complication in the immediate postoperative period. None of the surgical variables examined had any predictive value on the incidence of postoperative fever. Aggressive pulmonary toilet, repeated physical examinations, and urine analysis are recommended when evaluating TKA patients with postoperative fever. Fever following TKA was common and was not necessarily a contraindication to discharge.     

Popliteal pseudoaneurysm following total knee arthroplasty

Arterial injuries complicating total knee arthroplasty are rare but may result in significant morbidity. There are three reports of popliteal artery pseudoaneurysm resulting from arterial trauma during total knee replacement. We report a case of a popliteal pseudoaneurysm with rupture into the surrounding muscle, its evaluation, and successful repair 5 months after arthroplasty.     

Salvage of infected total knee arthroplasty with Ilizarov external fixator

Background:

Knee arthrodesis may be the only option of treatment in cases of chronic infected total knee arthroplasty (TKA) with concomitant irreparable extensor mechanism disruption, extensive bone loss or severe systemic morbidities. Circular external fixation offers possible progressive adjustment to stimulate the bony fusion and to make corrections in alignment. We evaluated the results of knee arthrodesis with one or two stage circular external fixator for infected TKA.

Materials and Methods:

16 cases of femoro-tibial fusion were retrospectively evaluated. Male-to-female ratio was 10:6. Mean age of the patients was 62.2 years. Cierney-Mader classification was used for anatomical and physiological evaluation while the bone stock deficiency was classified into mild, moderate and severe. Surgical technique involved either single or two stage arthrodesis using circular external fixator.

Results:

Union was achieved in 15 patients (93.75%). The mean duration for union (frame application time) in these patients was 28.33 weeks (range 22 to 36 weeks). Analysis showed that in the group with frame application time of less than 28 weeks, the incidence of mild to moderate bone deficiency was 83.33%, while in the frame application time more than 28 weeks group the incidence was 20% (P-value 0.034). Similarly the incidence of Cierney-Mader 4B (Bl, Bs, Bls) was found to be 33.33% in the group of frame application time of less than 28 weeks, while it was 90% in the group with frame application time more than 28 weeks (P-value 0.035).

Conclusion:

Circular external fixator is a safe and reliable method to achieve knee arthrodesis in cases of deep infection following TKA. Severe bone stock deficiency and Cierney- Mader type B host are likely risk factors for prolonged frame application time. We recommend a two-stage procedure especially when there is compromised host or severe bone loss.