http://informahealthcare.com/mor ISSN 1439-7595 (print), 1439-7609 (online) Mod Rheumatol, 2014; 24(2): 243–249 © 2014 Japan College of Rheumatology DOI: 10.3109/14397595.2013.854058
ORIGINAL ARTICLE
Outcomes of knee arthrodesis following infected total knee arthroplasty: a retrospective analysis of 8 cases Kota Watanabe1, Takeshi Minowa1, Shintaro Takeda1, Hidenori Otsubo1, Takuma Kobayashi1, Hideji Kura2, and Toshihiko Yamashita1 1Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan, and 2Department of Orthopaedic Surgery,
Hitsujigaoka Hospital, Sapporo, Japan Abstract
Keywords
Background. There is insufficient information regarding patient-based outcomes after knee arthrodesis following infected total knee arthroplasty (TKA). The purpose of this study was to analyze outcomes in patients who underwent knee arthrodesis following infected TKA using clinical and radiographic measurements including a patient-based outcome measuring system. Methods. We evaluated 8 patients (mean age 72.9 years) who were followed for more than 3 years after arthrodesis. Clinical and radiographic evaluation was performed, including examination of the patient’s function and use of supportive equipment for walking. The Japanese knee osteoarthritis measurement (JKOM) was used for measuring patient-based outcomes and health-related quality of life. Result. Knee fusion was achieved in 7 patients. The mean limb-length discrepancy was 5.4 cm. All patients could walk at least inside the house, and activity of daily living (ADL) independence was achieved by the patients with successful knee fusion, although walking aids, including a shoe lift causing little discomfort, were required. The results of JKOM for the patients with successful fusion were comparable to the data for patients who underwent TKA. Conclusions. When knee arthrodesis was performed for infected TKA cases, pain was reduced and ADL independence was established when knee fusion was achieved. This study demonstrated that information from subjective and functional evaluations of knee arthrodesis patients is useful in understanding postoperative activity and situations, and revealed the importance of supportive elements for walking.
Arthrodesis, Infection, Patient-based outcome, Total knee arthroplasty
Introduction Total knee arthroplasty (TKA) is the preferred treatment for patients with painful and disabling knee joint pathologies. Although failure of TKA is rare, infection is a particularly difficult therapeutic problem. If the prosthesis cannot be retained, surgical options include revision arthroplasty, resection arthroplasty, and arthrodesis. Revision arthroplasty is typically the next choice of treatment; however, it is not always feasible, and higher infection rates have been reported compared with primary TKA. Knee arthrodesis is a salvage procedure believed to reduce pain and achieve knee stability for walking. There are many concerns associated with patients undergoing this procedure after TKA infection, such as poor bone stock, previous repeated surgical interventions, soft tissue compromise, limb shortening, and long treatment duration. These factors may influence postoperative outcome and patient satisfaction even if successful bony fusion is achieved. Many authors have used different techniques for performing knee arthrodesis following infected TKA and have reported postoperaCorrespondence to: Kota Watanabe, Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, South-1, West-16, Chuoku, Sapporo, Hokkaido 060-8543, Japan. Tel: +81-11-6112111. Fax: +81-11-
6416026. E-mail: [email protected]
History Received 18 June 2012 Accepted 4 March 2013 Published online 19 March 2013
tive results showing fusion rates, limb alignment, pain reduction, and walking ability. However, there is still insufficient information regarding patient-based outcomes following this procedure. Information regarding subjective patient evaluation and function after arthrodesis is important and helpful for both surgeons and patients to understand postoperative situations and improve postoperative results or patient satisfaction. The purpose of this study was to analyze patient outcomes following knee arthrodesis for infected TKA using clinical and radiographic measurements, including a patient-based outcome measuring system.
Materials and methods Patients Subjects of the study were 8 patients who were diagnosed with infected TKA between 2005 and 2007, had their artificial joints removed, and had undergone knee arthrodesis at least 3 years previously (Table 1). These included 1 male and 7 females with an average age of 72.9 years (range 63–80 years) at the time of the final surgery and an average postoperative follow-up period of 39 months (range 36–45 months). The patients and/or their families were informed that their data would be submitted for publication, and they provided written
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Table 1. Clinical data Age Case gender 1 69 Female 2 80 Female 3 66 Female 4 63 Female 5 73 Female 6 77 Female 7 79 Female 8
76Male
Diagnosis at TKA Past history OA DM
Infecting organism Not identified
Durationa (months) Remarks 24
OA
DM
MRSA
70
RA
HT
MRSE
7
RA
None
MRSA
24
OA OA
Asthma, pulmonary emphysema S. capitis, Bacillus sp. 21 (home oxygen therapy) DM, HT, asthma Not identified 5
OA
HT
OA
Infected spinal implant removal MRSA
S. capitis
30 6
Debridement surgery performed before implant removal Infection after revision TKA
Infection after intramedullary nailing for femoral supracondylar fracture Debridement surgery performed before implant removal
OA osteoarthritis of the knee, RA rheumatoid arthritis, DM diabetes mellitus, HT hypertension, MRSA methicillin-resistant Staphylococcus aureus, MRSE methicillin-resistant Staphylococcus epidermidis, TKA total knee arthroplasty aDuration between onset of symptom suggesting infection and implant removal
informed consent. The underlying condition requiring TKA was osteoarthritis of the knee in 6 patients and rheumatoid arthritis in 2 cases. We diagnosed infection after comprehensive consideration of findings including swelling (rubor) of the knee joint, effusion, fever, new onset of pain, a sinus tract or open wound in communication with the joint, elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values, and culturepositive joint fluid. Triple-phase bone scintigraphy also revealed an increased uptake of radioisotope. Two patients (cases 2 and 8) underwent a debridement procedure to preserve the implant following TKA infection. One patient (case 7) contracted infection following retrograde intramedullary nailing of a post-TKA femoral supracondylar fracture to achieve osteosynthesis, while another (case 4) developed infection following revision TKA. The mean duration between onset of any symptom suggesting infection and implant removal was 23.3 months (range 5–70 months). All patients except 1 (case 3) underwent primary TKA at other facilities. Infected TKA of the remaining 7 patients at other facilities had been treated conservatively or surgically (cases 2 and 8) in those facilities until they were referred to our facility. The bacterium responsible for TKA infection was methicillin-resistant Staphylococcus aureus (MRSA) in 3 cases, Staphylococcus capitis in 2 cases, and methicillin-resistant Staphylococcus epidermidis in 1. Identification of the pathogen was not possible in 2 cases. Treatment We performed 2-stage surgery in the patients with postoperative TKA infection. In stage 1, we removed the infected knee joint implant and performed intra-articular debridement with placement of an intra-articular antibiotic-containing cement spacer. We then administered intravenous antibiotics for 6 weeks and oral antibiotics for 2–4 weeks, and then established a waiting period. We opted for re-replacement surgery using an artificial joint in cases in which the signs of local infection had disappeared and CRP, ESR, and radioisotope uptake in triple-phase bone scintigraphy had normalized [1]. However, if at least 1 above-mentioned sign suggesting infection was observed, a culture of specimens obtained by aspiration or/and a deep-tissue specimen, or/and histological evaluation of intra-articular tissue including neutrophil counts in frozen sections were performed. Then, if these examinations confirmed infection, additional debridement surgery or arthrodesis
was performed. Arthrodesis was performed in cases in which the infection failed to subside completely, soft tissue was observed to be compromised, or revision TKA using an artificial joint was deemed impossible as a result of major bone defects. For arthrodesis, we used an external fixator (Monotubeâ; Stryker Howmedica Osteonics, New Jersey) that allows the femur and tibia to be in partial contact with each other. In all the patients, the existing bone defect was filled with autogenous bone transplanted from the ilium. We instructed our patients to not bear any weight during the early postoperative period and to gradually start bearing weight 4–5 weeks after the surgery. Full weight-bearing was permitted only after knee fusion had been confirmed. Evaluation Clinical evaluation Japanese knee osteoarthritis measurement (JKOM). We used JKOM [2] as a clinical evaluation tool for postoperative subjective assessment of patients in this study. JKOM is a measure of patient-based outcomes and health-related quality of life (QOL) in a Japanese social and cultural background. JKOM consists of 4 major categories: (1) pain and stiffness in knees, (2) condition in daily life, (3) general activity, and (4) health condition. In addition to a visual analog scale (VAS) for evaluating the degree of knee pain through self-administered measures, JKOM consists of a total of 25 questions with 5 possible responses to each question. For each of the 5 categories, a score of “5” designates the severest disability, and the total score (full mark) is 125. For reference, the JKOM scores of 37 patients (31 females and 6 males) with osteoarthritis of the knee 1 year after TKA are displayed in Table 2 [4]. The average age of these 37 patients was 72.5 years (range 60–81 years). The Knee Society score. We also assessed our patients using the Knee Society score and a function score [3]. The Knee Society score consists of 3 parameters: pain (50 points), stability (25 points), and range of motion (25 points). Flexion contracture, extension lag, and misalignment are considered deductions. The function score consists of 2 parameters, i.e., walking distance (50 points) and stair climbing (50 points) with deductions for walking aids. Thus, the maximum score for both parameters is 100.
Knee arthrodesis following infected total knee arthroplasty 245
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Table 2. Results of clinical evaluation using the Japanese knee osteoarthritis measurement (JKOM) and the reported normative scores after total knee arthroplasty (TKA) [4] Case 1 2 3 4 5 6 7 8 Mean ⫾ SD in fused knee patientsa Normative data; TKA [4]
Knee pain: VAS (100) 5 39 0 (0) 0 49 4 1 35 14.0 ⫾ 20.8
Pain and stiffness (40) 9 16 8 (8) 8 31 8 12 17 13.1 ⫾ 8.4
Condition in daily life (50) 13 23 22 (44) 12 38 15 34 40 20.5 ⫾ 9.7
General activities (25) 6 20 8 (17) 5 25 6 25 6 11.7 ⫾ 8.6
Health conditions (10) 3 7 6 (4) 2 7 3 6 7 4.7 ⫾ 2.3
Total (125) 31 66 44 (73) 27 101 32 77 70 50.2 ⫾ 28.7
1.1 ⫾ 1.4
11.4 ⫾ 4.1
16.2 ⫾ 4.5
9.1 ⫾ 2.8
2.4 ⫾ 0.8
39.2 ⫾ 10.4
Scores after her cerebral infarction in parentheses in Case 3 In case 7, scores of condition in daily life, general activities, and health conditions were affected by her age-related changes Case 8 was a case of non-union VAS visual analogue scale aCase 7 was excluded when calculating the mean scores for condition in daily life, general activities, health conditions, and the total score in fused knee patients because her activities of daily living were reduced because of aging
Walking function and satisfaction. Walking ability, use of supportive equipment, and level of satisfaction are other parameters assessed in this study using a 5-stage scale recording patients’ responses to questions. Scoring criteria for these clinical evaluations were as follows: (a) for walking ability: 1, shopping possible; 2, around the house; 3, in the house; 4, wheel chair; and 5, bedridden; (b) for supportive equipment for walking: 1, none; 2, shoe lift only; 3, cane; 4, shoe lift and cane; and 5, walker; (c) for use of shoe lift: 1, not bothered; 2, somewhat bothersome; 3, bothersome; 4, very bothersome; and 5, did not want to use; and (d) for satisfaction: 1, satisfied; 2, somewhat satisfied; 3, non-committal; 4, somewhat disappointed; and 5, very disappointed. Radiological evaluation Bone union, lower limb alignment, and leg-length discrepancy were evaluated by assessment of radiographic findings. Lower limb alignment was determined by both the femorotibial angle (FTA) assessed from plain frontal-view radiographs and the lateral flexion angle (LFA) assessed from plain lateral-view radiographs.
Results Knee fusion was achieved in 7 patients. In 1 patient (case 8), there was recurrence of infection following arthrodesis and knee fusion was not achieved (non-union). Details regarding this patient are provided in the case description below. Clinical evaluation In the JKOM assessment for the patients with fused knees, the mean VAS score for knee pain was 14.0 and the pain and stiffness score was 13.1 (Table 2). Five patients had little or no knee pain. Patients having a high VAS score (35–49) included patients who complained of relatively strong preoperative knee pain (cases 2 and 5) as well as the patient with non-union (case 8). However, even these 3 patients experienced reduced pain compared with that experienced before surgery. The average knee pain by the VAS score was higher than the normative data of patients with knee osteoarthritis after TKA (Table 2). The scores for pain and stiffness for the patients with fused knees in our study were comparable to the normative data obtained from patients after TKA.
For patients in our study, the mean score for condition in daily life was 20.5, general activity was 11.7, and health condition was 4.7; the total score was 50.2. Case 7 was excluded because the patient’s activities of daily living (ADLs) were reduced because of aging. In TKA patients (normative data), the mean score for condition in daily life was 16.2, general activity was 9.1, and health condition was 2.4; the total score was 39.2. Half of the patients (cases 1, 4, and 6) showed better scores in these categories than TKA patients, except in health conditions. The mean scores of our patients for these 3 categories were comparable to the normative data of patients after TKA. The cases with a high JKOM total score included the 1 patient with postoperative non-union (case 8) and another who required nursing care as a result of reduction in general condition because of aging (case 7). A patient with upper limb disability and RA developed a cerebral infarction 2 years after the arthrodesis, which resulted in hemiplegia (case 3). The patient had been walking with a shoe lift until she experienced cerebral infarction. The scores after the cerebral infarction are presented in parentheses in Table 2. The mean Knee Society score in patients with fused knee joints was 64.6 at the final follow-up. The function score in the patients with fused knee joints, except case 7, was 52.5 (Table 3). These scores were lower than the normative data after TKA [4]. The patients’ average preoperative Knee Society score of 38.5 ⫾ 18.7 and function score of 47.2 ⫾ 15.0 demonstrated statistically significant improvement to 89.9 ⫾ 9.4 and 72.3 ⫾ 15.6, respectively, 1 year after surgery. The Knee Society score in postarthrodesis patients is 0 for range of motion, which influences the total score, and the full mark is 75. In terms of mobility, all patients could walk at least inside the house, but the mobility of cases 7 and 8 with high JKOM scores was limited to a wheelchair (Table 4). ADL independence was achieved in all other cases, although a walking aid was required. Three patients could walk with only a shoe lift. Six patients required an external shoe lift. In addition, none of the patients considered the use of a shoe lift to be unduly burdensome. The level of patient satisfaction for 5 patients was recorded as “satisfied” or “somewhat satisfied.” In case 3, the patient satisfaction level was reduced after she developed a cerebral infarction. The knee condition in this patient was reported as unchanged; however, this patient was unable to stand without support because knee flexion was not possible.
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Table 3. Results of clinical evaluation using the Knee Society score A. Case 1 2 3 4 5 6 7 8 Mean ⫾ SD in fused knee patients B. Case 1 2 3 4 5 6 7 8 Mean ⫾ SD in fused knee patientsa
Pain (50) 45 45 50 (50) 50 10 50 50 30 42.9 ⫾ 14.7
Range of motion (25) 0 0 0 (0) 0 0 0 0 12 0.0 ⫾ 0.0
Walking (50) 30 20 20 (0) 40 20 30 10 10 26.7 ⫾ 8.2
Stability (50) 25 25 25 (25) 25 25 25 25 0 25.0 ⫾ 0.0
Stairs (50) 30 30 30 (0) 30 30 30 0 0 30.0 ⫾ 0.0
Deductions 0 0 0 (0) 0 0 20 3 30 3.3 ⫾ 7.5 Deductions 5 5 5 (20) 5 5 0 20 20 4.2 ⫾ 2.0
Total (100) 70 70 75 (75) 75 35 55 72 12 64.6 ⫾ 14.7 Total (100) 55 45 45 (0) 65 45 60 0 0 52.5 ⫾ 8.8
A. The Knee Society score B. The Knee Society function score Scores after her cerebral infarction in parentheses in Case 3 In case 7, the Knee Society function score was affected by her age-related changes Case 8 was a case of non-union aCase 7 was excluded when calculating the mean function scores in fused knee patients because her activities of daily living were reduced because of aging
Radiological evaluation The average FTA and LFA were 175° and 4.6°, respectively (Table 4). In 1 case with the knee fixed in hyperextension (case 5), there were almost no symptoms and the satisfaction level was high. The average discrepancy in leg length was 54.1 mm.
Cases Case 2 This patient (female) had swelling and pain in her left knee 1 year after TKA. Oral antibiotics had been administered; her symptoms worsened 5 years later. She was referred to our hospital after debridement surgery (Fig. 1a). MRSA was identified from cultured surgical specimens. Three months later, the implant was removed, antibiotic cement placed, and knee arthrodesis was performed
with the Monotube® external fixator (Fig. 1b, c). Knee fusion was achieved 3 months after the surgery. At 3 years follow-up, she was walking with a shoe lift and cane (Fig. 1d). Case 8 This patient was referred to our hospital 3 months after a failed surgical debridement for infected TKA. The swelling and pain in his left knee occurred 6 months previously. MRSA was identified from cultured surgical specimens. Implant removal, antibiotic cement placement, and knee arthrodesis were performed with the Monotube® external fixator 3 months after debridement. The patient experienced swelling and pain in his left knee, CRP became positive 2 months after the arthrodesis, and the external fixator was removed. Arthrodesis was again performed using the Ilizarov ring fixator (Fig. 2a). However, the infection recurred 2 months after surgery, and the external fixator was removed. Enterobacter aerogenes was identified, and 2 more debride-
Table 4. Results of clinical evaluation for walking ability, supportive elements, and satisfaction; radiographic evaluation Case 1 2 3 4 5 6 7 8 Mean ⫾ SD
Walking ability 1 3 1 (4) 1 2 2 4 4 2.3 ⫾ 1.3
Supportive equipment for walking 4 4 2 (2) 2 4 2 5 5 3.5 ⫾ 1.3
Shoe lift use 1 1 2 (2) 1 1 2 – – 1.3 ⫾ 0.5
Satisfaction 2 2 3 (5) 1 2 2 4 3 2.4 ⫾ 0.9
FTA (degrees) 173 172 175 174 174 181 176 – 175.0 ⫾ 2.9
LFA (degrees) 10 3 5 ⫺9 10 9 4 – 4.6 ⫾ 6.7
Leg-length discrepancy (mm) 65.6 49.1 59.1 49.6 33.0 43.5 70.0 63.0 54.1 ⫾ 12.5
Walking ability: 1, shopping possible; 2, around the house; 3, in the house; 4, wheel chair; 5, bedridden. Supportive equipment for walking: 1, none; 2, shoe lift only; 3, cane; 4, shoe lift and cane; and 5, walker. Use of shoe lift: 1, not bothered; 2, somewhat bothersome; 3, bothersome; 4, very bothersome; and 5, did not want to use. Satisfaction: 1, satisfied; 2, somewhat satisfied; 3, non-committal; 4, somewhat disappointed; and 5, very disappointed Scores after her cerebral infarction in parentheses in Case 3 In case 7, scores related to walking ability were affected by her age-related changes Case 8 was a case of non-union FTA femorotibial angle, LFA lateral flexion angle
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Fig. 1 Radiographs of Case 2. (a) Preoperative radiographs of loose infected total knee arthroplasty. (b) The antibiotic cement spacer filling the bone loss during the interval period. (c) Knee arthrodesis with the Monotube® external fixator. (d) Final result. Knee fusion was achieved
ment surgeries were performed, including antibiotic cement placement and continuous irrigation. The infection eventually subsided, and at 4 years follow-up, the patient could walk in a room using a walker and knee brace (Fig. 2b). This patient had undergone spinal fusion with pedicle screws, and the spinal implants had been removed because of infection 1 year before TKA infection was identified.
Discussion There are many methods for performing successful arthrodesis after TKA infection, including internal fixation with an intramedullary nail or a plate and external fixation. The reported fusion rates for failed TKA with an external fixation range from 43 to 100 %, and with an intramedullary nail they range from 67 to 100 % [5, 6]. Mabry et al. [7] analyzed the outcomes of knee arthrodesis in 85 consecutive patients treated for infected TKA using 2 different fixation techniques. External fixation achieved successful
fusion in 67 % of patients and was associated with a 4.9 % rate of deep infection. Fusion using intramedullary nailing was successful in 96 % of patients and was associated with an 8.3 % rate of deep infection. They concluded that intramedullary nailing resulted in a higher rate of successful union but was also associated with a higher risk of recurrent infection when compared with external fixation knee arthrodesis. We performed knee arthrodesis using the Monotube® unilateral external fixation system. Placement of the external fixator is a simple procedure, and the device exerts adequate compression at the arthrodesis site to allow for the rigid fixation needed for successful fusion. Use of an external fixation device in the presence of infection has the advantage of leaving no residual foreign implants when a plan for revision arthroplasty is abandoned. A relatively high fusion rate (87.5 %) was achieved through external fixation in our patients. Several authors have evaluated patient symptoms and function following knee arthrodesis for infected TKA. Lai et al. [8] performed knee arthrodesis using a short Huckstep nail in 33
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Fig. 2 Radiographs of Case 8. (a) The second knee arthrodesis with the Ilizarov ring fixator. (b) Final result. Bony fusion was not achieved and bone formation was observed between the femur and tibia
patients (infected TKA: 12; Charcot joint: 2). Thirty of these patients achieved bone union, and all could walk at least inside the house and could bear full weight on the limb; however, 4 patients (union: 2 patients; non-union: 2 patients) had mild pain in the involved knee. Eighteen patients in the study could walk without a walking aid, 7 used a cane, 6 used crutches, and 2 used a walker. The average limb-length discrepancy was 2.6 cm (range 2–4 cm). All patients reported inconvenience caused by the stiff knee when they visited the toilet. David et al. [9] reported the results of 13 patients with failed TKA due to infection (12 patients) or aseptic loosening (1 patient), who underwent arthrodesis using the Ilizarov external fixator. All their patients recovered successfully and could walk using a cane. The affected leg was shortened between 1 and 6 cm (mean 3.7 cm) and was treated with a shoe lift when needed. The results of previous reports demonstrate that patients who undergo knee arthrodesis following infected TKA do recover and can walk with walking aids such as a cane or shoe lift. Our patients did not complain of using a shoe lift. Equipment for walking should be prescribed positively to improve patient walking ability and satisfaction. Recently, a few authors have reported subjective patient evaluations following knee arthrodesis. Benson et al. [10] performed a subjective patient evaluation using the short form-36 score (SF-36) and the arthritis impact measurement score (AIMS). They compared 9 patients who underwent knee arthrodesis with 9 patients who underwent primary TKA. SF-36 scores were similar in both groups. AIMS, which assesses patient function, was better after TKA because of increased mobility and physical activity. Furthermore, patients had a better mean score on the pain scale following arthrodesis. Klinger et al. [11] and De Vil [12] also used SF-36 and other self-administered disease- and site-specific questionnaires including the knee injury and osteoarthritis outcome score and the Oxford 12-item knee score, respectively. They compared their data on general health status measured by the SF-36 score
with reported normative scores after TKA. Physical functioning and role-emotional scores were lower or similar to the normative data after TKA. Social functioning and mental health scores were lower and role-physical and vitality scores were higher than the normative data. Body pain and general health scores were higher or similar to the normative data. These data and our findings indicate that the results of patients following successful knee arthrodesis for infected TKA are generally comparable to those after primary TKA, when assessed by patient-based outcome measures. We performed a subjective patient evaluation using JKOM as a self-administered disease- and site-specific questionnaire and compared our data with the reported normative JKOM scores after TKA. Patients reporting pain included 1 who had undergone multiple surgeries prior to removal of the artificial joint, 1 who had experienced pain and numbness around the knee prior to removal of the artificial joint, and 1 in whom knee fusion was not achieved. However, even these 3 patients experienced reduced pain compared with that experienced before surgery. In cases in which knee fusion was achieved, the pain was generally relieved, and QOL comparable to that after TKA was observed. In addition, all our patients could walk at least inside the house. Three patients could walk with only a shoe lift, and 6 required an external shoe lift. Patients experience a lesser burden when using an external shoe lift. Discrepancy in leg length is a problem when knee arthrodesis is performed following TKA infection, and there are reports describing attempts made to rectify this by bone grafting and leg extension surgery. Although our procedure led to some amount of limb shortening, we achieved a relatively high rate of bone union, and the patients with bone union could walk with a shoe lift with less discomfort. The limb-length discrepancy was relatively large in our patients (mean 5.4 cm) compared with that in previous reports; however, we do not believe that the discrepancy in leg length exerted a significant effect in lowering the level of patient satisfaction.
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We also assessed our patients using the Knee Society rating system, which is perhaps the most widely used system. Using this system, Lee et al. [13] assessed patients who underwent distraction arthrodesis with an intramedullary nail and mixed bone grafting after infected TKA. The mean postoperative limb shortening was only 1.1 cm. The mean Knee Society score was 59.9 and the functional score was 38.8, which were comparable with our data. In conclusion, when knee arthrodesis was performed for cases of infected TKA, pain was reduced and ADL independence was established when knee fusion was achieved. Analysis of our patients using a patient-based outcome measuring system revealed that the results of successful arthrodesis were comparable with that of TKA. Half of those patients subjectively reported achieving QOL that was similar to or even higher than that of patients after TKA. However, patients who underwent multiple surgeries or experienced strong pain and numbness around the knee prior to implant removal complained of pain following knee arthrodesis. Some walking aids are necessary, especially in patients with a limb-length discrepancy. Medications for pain, use of an appropriate shoe lift, walking aids, and adequate postoperative rehabilitation may contribute to a higher level of postoperative satisfaction, and are encouraged to improve ADL in patients after arthrodesis.
2. Akai M, Doi T, Fujino K, Iwaya T, Kurosawa H, Nasu T. An outcome measure for Japanese people with knee osteoarthritis. J Rheumatol. 2005;32:1524–30. 3. Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the Knee Society clinical rating system. Clin Orthop. 1989;248:13–4. 4. Kikuchi Y, Ohta M, Watanabe J, Sasaki K, Hosokawa N, Kogure A, et al. Evaluation of quality of life after total knee arthroplasty using JKOM (Japanese knee osteoarthritis measure) (in Japanese). Higashinihon Seisaikaishi (J East Jpn Orthop Traumatol). 2010;22: 154–7. 5. Wiedel JD. Salvage of infected total knee fusion: the last option. Clin Orthop. 2002;404:139–42. 6. Damron TA, McBeath AA. Arthrodesis following failed total knee arthroplasty: comprehensive review and meta-analysis of recent literature. Orthopedics. 1995;18:361–8. 7. Mabry TM, Jacofsky DJ, Haidukewych GJ, Hanssen AD. Comparison of intramedullary nailing and external fixation knee arthrodesis for the infected knee replacement. Clin Orthop. 2007;464:11–5. 8. Lai KA, Shen WJ, Yang CY. Arthrodesis with a short Huckstep nail as a salvage procedure for failed total knee arthroplasty. J Bone Jt Surg Am. 1998;80:380–8. 9. David R, Shtarker H, Horesh Z, Tsur A, Soudry M. Arthrodesis with the Ilizarov device after failed knee arthroplasty. Orthopedics. 2001;24:33–6. 10. Benson ER, Resine ST, Lewis CG. Functional outcome of arthrodesis for failed total knee arthroplasty. Orthopedics. 1998; 21:875–9. 11. Klinger HM, Spahn G, Schultz W, Baums MH. Arthrodesis of the knee after failed infected total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2006;14:447–53. 12. De Vil J, Almqvist KF, Vanheeren P, Boone B, Verdonk R. Knee arthrodesis with an intramedullary nail: a retrospective study. Knee Surg Sports Traumatol Arthrosc. 2008;16:645–50. 13. Lee S, Jang J, Seong SC, Lee MC. Distraction arthrodesis with intramedullary nail and mixed bone grafting after failed infected total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2012;20: 346–55.
Conflict of interest None.
References 1. Nagoya S, Kaya M, Sasaki M, Tateda K, Yamashita T. Diagnosis of peri-prosthetic infection at the hip using triple-phase bone scintigraphy. J Bone Jt Surg Br. 2008;90:140–4.
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ORIGINAL ARTICLE
Outcomes of knee arthrodesis following infected total knee arthroplasty: a retrospective analysis of 8 cases Kota Watanabe1, Takeshi Minowa1, Shintaro Takeda1, Hidenori Otsubo1, Takuma Kobayashi1, Hideji Kura2, and Toshihiko Yamashita1 1Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, Sapporo, Japan, and 2Department of Orthopaedic Surgery,
Hitsujigaoka Hospital, Sapporo, Japan Abstract
Keywords
Background. There is insufficient information regarding patient-based outcomes after knee arthrodesis following infected total knee arthroplasty (TKA). The purpose of this study was to analyze outcomes in patients who underwent knee arthrodesis following infected TKA using clinical and radiographic measurements including a patient-based outcome measuring system. Methods. We evaluated 8 patients (mean age 72.9 years) who were followed for more than 3 years after arthrodesis. Clinical and radiographic evaluation was performed, including examination of the patient’s function and use of supportive equipment for walking. The Japanese knee osteoarthritis measurement (JKOM) was used for measuring patient-based outcomes and health-related quality of life. Result. Knee fusion was achieved in 7 patients. The mean limb-length discrepancy was 5.4 cm. All patients could walk at least inside the house, and activity of daily living (ADL) independence was achieved by the patients with successful knee fusion, although walking aids, including a shoe lift causing little discomfort, were required. The results of JKOM for the patients with successful fusion were comparable to the data for patients who underwent TKA. Conclusions. When knee arthrodesis was performed for infected TKA cases, pain was reduced and ADL independence was established when knee fusion was achieved. This study demonstrated that information from subjective and functional evaluations of knee arthrodesis patients is useful in understanding postoperative activity and situations, and revealed the importance of supportive elements for walking.
Arthrodesis, Infection, Patient-based outcome, Total knee arthroplasty
Introduction Total knee arthroplasty (TKA) is the preferred treatment for patients with painful and disabling knee joint pathologies. Although failure of TKA is rare, infection is a particularly difficult therapeutic problem. If the prosthesis cannot be retained, surgical options include revision arthroplasty, resection arthroplasty, and arthrodesis. Revision arthroplasty is typically the next choice of treatment; however, it is not always feasible, and higher infection rates have been reported compared with primary TKA. Knee arthrodesis is a salvage procedure believed to reduce pain and achieve knee stability for walking. There are many concerns associated with patients undergoing this procedure after TKA infection, such as poor bone stock, previous repeated surgical interventions, soft tissue compromise, limb shortening, and long treatment duration. These factors may influence postoperative outcome and patient satisfaction even if successful bony fusion is achieved. Many authors have used different techniques for performing knee arthrodesis following infected TKA and have reported postoperaCorrespondence to: Kota Watanabe, Department of Orthopaedic Surgery, Sapporo Medical University School of Medicine, South-1, West-16, Chuoku, Sapporo, Hokkaido 060-8543, Japan. Tel: +81-11-6112111. Fax: +81-11-
6416026. E-mail: [email protected]
History Received 18 June 2012 Accepted 4 March 2013 Published online 19 March 2013
tive results showing fusion rates, limb alignment, pain reduction, and walking ability. However, there is still insufficient information regarding patient-based outcomes following this procedure. Information regarding subjective patient evaluation and function after arthrodesis is important and helpful for both surgeons and patients to understand postoperative situations and improve postoperative results or patient satisfaction. The purpose of this study was to analyze patient outcomes following knee arthrodesis for infected TKA using clinical and radiographic measurements, including a patient-based outcome measuring system.
Materials and methods Patients Subjects of the study were 8 patients who were diagnosed with infected TKA between 2005 and 2007, had their artificial joints removed, and had undergone knee arthrodesis at least 3 years previously (Table 1). These included 1 male and 7 females with an average age of 72.9 years (range 63–80 years) at the time of the final surgery and an average postoperative follow-up period of 39 months (range 36–45 months). The patients and/or their families were informed that their data would be submitted for publication, and they provided written
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Table 1. Clinical data Age Case gender 1 69 Female 2 80 Female 3 66 Female 4 63 Female 5 73 Female 6 77 Female 7 79 Female 8
76Male
Diagnosis at TKA Past history OA DM
Infecting organism Not identified
Durationa (months) Remarks 24
OA
DM
MRSA
70
RA
HT
MRSE
7
RA
None
MRSA
24
OA OA
Asthma, pulmonary emphysema S. capitis, Bacillus sp. 21 (home oxygen therapy) DM, HT, asthma Not identified 5
OA
HT
OA
Infected spinal implant removal MRSA
S. capitis
30 6
Debridement surgery performed before implant removal Infection after revision TKA
Infection after intramedullary nailing for femoral supracondylar fracture Debridement surgery performed before implant removal
OA osteoarthritis of the knee, RA rheumatoid arthritis, DM diabetes mellitus, HT hypertension, MRSA methicillin-resistant Staphylococcus aureus, MRSE methicillin-resistant Staphylococcus epidermidis, TKA total knee arthroplasty aDuration between onset of symptom suggesting infection and implant removal
informed consent. The underlying condition requiring TKA was osteoarthritis of the knee in 6 patients and rheumatoid arthritis in 2 cases. We diagnosed infection after comprehensive consideration of findings including swelling (rubor) of the knee joint, effusion, fever, new onset of pain, a sinus tract or open wound in communication with the joint, elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values, and culturepositive joint fluid. Triple-phase bone scintigraphy also revealed an increased uptake of radioisotope. Two patients (cases 2 and 8) underwent a debridement procedure to preserve the implant following TKA infection. One patient (case 7) contracted infection following retrograde intramedullary nailing of a post-TKA femoral supracondylar fracture to achieve osteosynthesis, while another (case 4) developed infection following revision TKA. The mean duration between onset of any symptom suggesting infection and implant removal was 23.3 months (range 5–70 months). All patients except 1 (case 3) underwent primary TKA at other facilities. Infected TKA of the remaining 7 patients at other facilities had been treated conservatively or surgically (cases 2 and 8) in those facilities until they were referred to our facility. The bacterium responsible for TKA infection was methicillin-resistant Staphylococcus aureus (MRSA) in 3 cases, Staphylococcus capitis in 2 cases, and methicillin-resistant Staphylococcus epidermidis in 1. Identification of the pathogen was not possible in 2 cases. Treatment We performed 2-stage surgery in the patients with postoperative TKA infection. In stage 1, we removed the infected knee joint implant and performed intra-articular debridement with placement of an intra-articular antibiotic-containing cement spacer. We then administered intravenous antibiotics for 6 weeks and oral antibiotics for 2–4 weeks, and then established a waiting period. We opted for re-replacement surgery using an artificial joint in cases in which the signs of local infection had disappeared and CRP, ESR, and radioisotope uptake in triple-phase bone scintigraphy had normalized [1]. However, if at least 1 above-mentioned sign suggesting infection was observed, a culture of specimens obtained by aspiration or/and a deep-tissue specimen, or/and histological evaluation of intra-articular tissue including neutrophil counts in frozen sections were performed. Then, if these examinations confirmed infection, additional debridement surgery or arthrodesis
was performed. Arthrodesis was performed in cases in which the infection failed to subside completely, soft tissue was observed to be compromised, or revision TKA using an artificial joint was deemed impossible as a result of major bone defects. For arthrodesis, we used an external fixator (Monotubeâ; Stryker Howmedica Osteonics, New Jersey) that allows the femur and tibia to be in partial contact with each other. In all the patients, the existing bone defect was filled with autogenous bone transplanted from the ilium. We instructed our patients to not bear any weight during the early postoperative period and to gradually start bearing weight 4–5 weeks after the surgery. Full weight-bearing was permitted only after knee fusion had been confirmed. Evaluation Clinical evaluation Japanese knee osteoarthritis measurement (JKOM). We used JKOM [2] as a clinical evaluation tool for postoperative subjective assessment of patients in this study. JKOM is a measure of patient-based outcomes and health-related quality of life (QOL) in a Japanese social and cultural background. JKOM consists of 4 major categories: (1) pain and stiffness in knees, (2) condition in daily life, (3) general activity, and (4) health condition. In addition to a visual analog scale (VAS) for evaluating the degree of knee pain through self-administered measures, JKOM consists of a total of 25 questions with 5 possible responses to each question. For each of the 5 categories, a score of “5” designates the severest disability, and the total score (full mark) is 125. For reference, the JKOM scores of 37 patients (31 females and 6 males) with osteoarthritis of the knee 1 year after TKA are displayed in Table 2 [4]. The average age of these 37 patients was 72.5 years (range 60–81 years). The Knee Society score. We also assessed our patients using the Knee Society score and a function score [3]. The Knee Society score consists of 3 parameters: pain (50 points), stability (25 points), and range of motion (25 points). Flexion contracture, extension lag, and misalignment are considered deductions. The function score consists of 2 parameters, i.e., walking distance (50 points) and stair climbing (50 points) with deductions for walking aids. Thus, the maximum score for both parameters is 100.
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Table 2. Results of clinical evaluation using the Japanese knee osteoarthritis measurement (JKOM) and the reported normative scores after total knee arthroplasty (TKA) [4] Case 1 2 3 4 5 6 7 8 Mean ⫾ SD in fused knee patientsa Normative data; TKA [4]
Knee pain: VAS (100) 5 39 0 (0) 0 49 4 1 35 14.0 ⫾ 20.8
Pain and stiffness (40) 9 16 8 (8) 8 31 8 12 17 13.1 ⫾ 8.4
Condition in daily life (50) 13 23 22 (44) 12 38 15 34 40 20.5 ⫾ 9.7
General activities (25) 6 20 8 (17) 5 25 6 25 6 11.7 ⫾ 8.6
Health conditions (10) 3 7 6 (4) 2 7 3 6 7 4.7 ⫾ 2.3
Total (125) 31 66 44 (73) 27 101 32 77 70 50.2 ⫾ 28.7
1.1 ⫾ 1.4
11.4 ⫾ 4.1
16.2 ⫾ 4.5
9.1 ⫾ 2.8
2.4 ⫾ 0.8
39.2 ⫾ 10.4
Scores after her cerebral infarction in parentheses in Case 3 In case 7, scores of condition in daily life, general activities, and health conditions were affected by her age-related changes Case 8 was a case of non-union VAS visual analogue scale aCase 7 was excluded when calculating the mean scores for condition in daily life, general activities, health conditions, and the total score in fused knee patients because her activities of daily living were reduced because of aging
Walking function and satisfaction. Walking ability, use of supportive equipment, and level of satisfaction are other parameters assessed in this study using a 5-stage scale recording patients’ responses to questions. Scoring criteria for these clinical evaluations were as follows: (a) for walking ability: 1, shopping possible; 2, around the house; 3, in the house; 4, wheel chair; and 5, bedridden; (b) for supportive equipment for walking: 1, none; 2, shoe lift only; 3, cane; 4, shoe lift and cane; and 5, walker; (c) for use of shoe lift: 1, not bothered; 2, somewhat bothersome; 3, bothersome; 4, very bothersome; and 5, did not want to use; and (d) for satisfaction: 1, satisfied; 2, somewhat satisfied; 3, non-committal; 4, somewhat disappointed; and 5, very disappointed. Radiological evaluation Bone union, lower limb alignment, and leg-length discrepancy were evaluated by assessment of radiographic findings. Lower limb alignment was determined by both the femorotibial angle (FTA) assessed from plain frontal-view radiographs and the lateral flexion angle (LFA) assessed from plain lateral-view radiographs.
Results Knee fusion was achieved in 7 patients. In 1 patient (case 8), there was recurrence of infection following arthrodesis and knee fusion was not achieved (non-union). Details regarding this patient are provided in the case description below. Clinical evaluation In the JKOM assessment for the patients with fused knees, the mean VAS score for knee pain was 14.0 and the pain and stiffness score was 13.1 (Table 2). Five patients had little or no knee pain. Patients having a high VAS score (35–49) included patients who complained of relatively strong preoperative knee pain (cases 2 and 5) as well as the patient with non-union (case 8). However, even these 3 patients experienced reduced pain compared with that experienced before surgery. The average knee pain by the VAS score was higher than the normative data of patients with knee osteoarthritis after TKA (Table 2). The scores for pain and stiffness for the patients with fused knees in our study were comparable to the normative data obtained from patients after TKA.
For patients in our study, the mean score for condition in daily life was 20.5, general activity was 11.7, and health condition was 4.7; the total score was 50.2. Case 7 was excluded because the patient’s activities of daily living (ADLs) were reduced because of aging. In TKA patients (normative data), the mean score for condition in daily life was 16.2, general activity was 9.1, and health condition was 2.4; the total score was 39.2. Half of the patients (cases 1, 4, and 6) showed better scores in these categories than TKA patients, except in health conditions. The mean scores of our patients for these 3 categories were comparable to the normative data of patients after TKA. The cases with a high JKOM total score included the 1 patient with postoperative non-union (case 8) and another who required nursing care as a result of reduction in general condition because of aging (case 7). A patient with upper limb disability and RA developed a cerebral infarction 2 years after the arthrodesis, which resulted in hemiplegia (case 3). The patient had been walking with a shoe lift until she experienced cerebral infarction. The scores after the cerebral infarction are presented in parentheses in Table 2. The mean Knee Society score in patients with fused knee joints was 64.6 at the final follow-up. The function score in the patients with fused knee joints, except case 7, was 52.5 (Table 3). These scores were lower than the normative data after TKA [4]. The patients’ average preoperative Knee Society score of 38.5 ⫾ 18.7 and function score of 47.2 ⫾ 15.0 demonstrated statistically significant improvement to 89.9 ⫾ 9.4 and 72.3 ⫾ 15.6, respectively, 1 year after surgery. The Knee Society score in postarthrodesis patients is 0 for range of motion, which influences the total score, and the full mark is 75. In terms of mobility, all patients could walk at least inside the house, but the mobility of cases 7 and 8 with high JKOM scores was limited to a wheelchair (Table 4). ADL independence was achieved in all other cases, although a walking aid was required. Three patients could walk with only a shoe lift. Six patients required an external shoe lift. In addition, none of the patients considered the use of a shoe lift to be unduly burdensome. The level of patient satisfaction for 5 patients was recorded as “satisfied” or “somewhat satisfied.” In case 3, the patient satisfaction level was reduced after she developed a cerebral infarction. The knee condition in this patient was reported as unchanged; however, this patient was unable to stand without support because knee flexion was not possible.
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Table 3. Results of clinical evaluation using the Knee Society score A. Case 1 2 3 4 5 6 7 8 Mean ⫾ SD in fused knee patients B. Case 1 2 3 4 5 6 7 8 Mean ⫾ SD in fused knee patientsa
Pain (50) 45 45 50 (50) 50 10 50 50 30 42.9 ⫾ 14.7
Range of motion (25) 0 0 0 (0) 0 0 0 0 12 0.0 ⫾ 0.0
Walking (50) 30 20 20 (0) 40 20 30 10 10 26.7 ⫾ 8.2
Stability (50) 25 25 25 (25) 25 25 25 25 0 25.0 ⫾ 0.0
Stairs (50) 30 30 30 (0) 30 30 30 0 0 30.0 ⫾ 0.0
Deductions 0 0 0 (0) 0 0 20 3 30 3.3 ⫾ 7.5 Deductions 5 5 5 (20) 5 5 0 20 20 4.2 ⫾ 2.0
Total (100) 70 70 75 (75) 75 35 55 72 12 64.6 ⫾ 14.7 Total (100) 55 45 45 (0) 65 45 60 0 0 52.5 ⫾ 8.8
A. The Knee Society score B. The Knee Society function score Scores after her cerebral infarction in parentheses in Case 3 In case 7, the Knee Society function score was affected by her age-related changes Case 8 was a case of non-union aCase 7 was excluded when calculating the mean function scores in fused knee patients because her activities of daily living were reduced because of aging
Radiological evaluation The average FTA and LFA were 175° and 4.6°, respectively (Table 4). In 1 case with the knee fixed in hyperextension (case 5), there were almost no symptoms and the satisfaction level was high. The average discrepancy in leg length was 54.1 mm.
Cases Case 2 This patient (female) had swelling and pain in her left knee 1 year after TKA. Oral antibiotics had been administered; her symptoms worsened 5 years later. She was referred to our hospital after debridement surgery (Fig. 1a). MRSA was identified from cultured surgical specimens. Three months later, the implant was removed, antibiotic cement placed, and knee arthrodesis was performed
with the Monotube® external fixator (Fig. 1b, c). Knee fusion was achieved 3 months after the surgery. At 3 years follow-up, she was walking with a shoe lift and cane (Fig. 1d). Case 8 This patient was referred to our hospital 3 months after a failed surgical debridement for infected TKA. The swelling and pain in his left knee occurred 6 months previously. MRSA was identified from cultured surgical specimens. Implant removal, antibiotic cement placement, and knee arthrodesis were performed with the Monotube® external fixator 3 months after debridement. The patient experienced swelling and pain in his left knee, CRP became positive 2 months after the arthrodesis, and the external fixator was removed. Arthrodesis was again performed using the Ilizarov ring fixator (Fig. 2a). However, the infection recurred 2 months after surgery, and the external fixator was removed. Enterobacter aerogenes was identified, and 2 more debride-
Table 4. Results of clinical evaluation for walking ability, supportive elements, and satisfaction; radiographic evaluation Case 1 2 3 4 5 6 7 8 Mean ⫾ SD
Walking ability 1 3 1 (4) 1 2 2 4 4 2.3 ⫾ 1.3
Supportive equipment for walking 4 4 2 (2) 2 4 2 5 5 3.5 ⫾ 1.3
Shoe lift use 1 1 2 (2) 1 1 2 – – 1.3 ⫾ 0.5
Satisfaction 2 2 3 (5) 1 2 2 4 3 2.4 ⫾ 0.9
FTA (degrees) 173 172 175 174 174 181 176 – 175.0 ⫾ 2.9
LFA (degrees) 10 3 5 ⫺9 10 9 4 – 4.6 ⫾ 6.7
Leg-length discrepancy (mm) 65.6 49.1 59.1 49.6 33.0 43.5 70.0 63.0 54.1 ⫾ 12.5
Walking ability: 1, shopping possible; 2, around the house; 3, in the house; 4, wheel chair; 5, bedridden. Supportive equipment for walking: 1, none; 2, shoe lift only; 3, cane; 4, shoe lift and cane; and 5, walker. Use of shoe lift: 1, not bothered; 2, somewhat bothersome; 3, bothersome; 4, very bothersome; and 5, did not want to use. Satisfaction: 1, satisfied; 2, somewhat satisfied; 3, non-committal; 4, somewhat disappointed; and 5, very disappointed Scores after her cerebral infarction in parentheses in Case 3 In case 7, scores related to walking ability were affected by her age-related changes Case 8 was a case of non-union FTA femorotibial angle, LFA lateral flexion angle
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Fig. 1 Radiographs of Case 2. (a) Preoperative radiographs of loose infected total knee arthroplasty. (b) The antibiotic cement spacer filling the bone loss during the interval period. (c) Knee arthrodesis with the Monotube® external fixator. (d) Final result. Knee fusion was achieved
ment surgeries were performed, including antibiotic cement placement and continuous irrigation. The infection eventually subsided, and at 4 years follow-up, the patient could walk in a room using a walker and knee brace (Fig. 2b). This patient had undergone spinal fusion with pedicle screws, and the spinal implants had been removed because of infection 1 year before TKA infection was identified.
Discussion There are many methods for performing successful arthrodesis after TKA infection, including internal fixation with an intramedullary nail or a plate and external fixation. The reported fusion rates for failed TKA with an external fixation range from 43 to 100 %, and with an intramedullary nail they range from 67 to 100 % [5, 6]. Mabry et al. [7] analyzed the outcomes of knee arthrodesis in 85 consecutive patients treated for infected TKA using 2 different fixation techniques. External fixation achieved successful
fusion in 67 % of patients and was associated with a 4.9 % rate of deep infection. Fusion using intramedullary nailing was successful in 96 % of patients and was associated with an 8.3 % rate of deep infection. They concluded that intramedullary nailing resulted in a higher rate of successful union but was also associated with a higher risk of recurrent infection when compared with external fixation knee arthrodesis. We performed knee arthrodesis using the Monotube® unilateral external fixation system. Placement of the external fixator is a simple procedure, and the device exerts adequate compression at the arthrodesis site to allow for the rigid fixation needed for successful fusion. Use of an external fixation device in the presence of infection has the advantage of leaving no residual foreign implants when a plan for revision arthroplasty is abandoned. A relatively high fusion rate (87.5 %) was achieved through external fixation in our patients. Several authors have evaluated patient symptoms and function following knee arthrodesis for infected TKA. Lai et al. [8] performed knee arthrodesis using a short Huckstep nail in 33
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Fig. 2 Radiographs of Case 8. (a) The second knee arthrodesis with the Ilizarov ring fixator. (b) Final result. Bony fusion was not achieved and bone formation was observed between the femur and tibia
patients (infected TKA: 12; Charcot joint: 2). Thirty of these patients achieved bone union, and all could walk at least inside the house and could bear full weight on the limb; however, 4 patients (union: 2 patients; non-union: 2 patients) had mild pain in the involved knee. Eighteen patients in the study could walk without a walking aid, 7 used a cane, 6 used crutches, and 2 used a walker. The average limb-length discrepancy was 2.6 cm (range 2–4 cm). All patients reported inconvenience caused by the stiff knee when they visited the toilet. David et al. [9] reported the results of 13 patients with failed TKA due to infection (12 patients) or aseptic loosening (1 patient), who underwent arthrodesis using the Ilizarov external fixator. All their patients recovered successfully and could walk using a cane. The affected leg was shortened between 1 and 6 cm (mean 3.7 cm) and was treated with a shoe lift when needed. The results of previous reports demonstrate that patients who undergo knee arthrodesis following infected TKA do recover and can walk with walking aids such as a cane or shoe lift. Our patients did not complain of using a shoe lift. Equipment for walking should be prescribed positively to improve patient walking ability and satisfaction. Recently, a few authors have reported subjective patient evaluations following knee arthrodesis. Benson et al. [10] performed a subjective patient evaluation using the short form-36 score (SF-36) and the arthritis impact measurement score (AIMS). They compared 9 patients who underwent knee arthrodesis with 9 patients who underwent primary TKA. SF-36 scores were similar in both groups. AIMS, which assesses patient function, was better after TKA because of increased mobility and physical activity. Furthermore, patients had a better mean score on the pain scale following arthrodesis. Klinger et al. [11] and De Vil [12] also used SF-36 and other self-administered disease- and site-specific questionnaires including the knee injury and osteoarthritis outcome score and the Oxford 12-item knee score, respectively. They compared their data on general health status measured by the SF-36 score
with reported normative scores after TKA. Physical functioning and role-emotional scores were lower or similar to the normative data after TKA. Social functioning and mental health scores were lower and role-physical and vitality scores were higher than the normative data. Body pain and general health scores were higher or similar to the normative data. These data and our findings indicate that the results of patients following successful knee arthrodesis for infected TKA are generally comparable to those after primary TKA, when assessed by patient-based outcome measures. We performed a subjective patient evaluation using JKOM as a self-administered disease- and site-specific questionnaire and compared our data with the reported normative JKOM scores after TKA. Patients reporting pain included 1 who had undergone multiple surgeries prior to removal of the artificial joint, 1 who had experienced pain and numbness around the knee prior to removal of the artificial joint, and 1 in whom knee fusion was not achieved. However, even these 3 patients experienced reduced pain compared with that experienced before surgery. In cases in which knee fusion was achieved, the pain was generally relieved, and QOL comparable to that after TKA was observed. In addition, all our patients could walk at least inside the house. Three patients could walk with only a shoe lift, and 6 required an external shoe lift. Patients experience a lesser burden when using an external shoe lift. Discrepancy in leg length is a problem when knee arthrodesis is performed following TKA infection, and there are reports describing attempts made to rectify this by bone grafting and leg extension surgery. Although our procedure led to some amount of limb shortening, we achieved a relatively high rate of bone union, and the patients with bone union could walk with a shoe lift with less discomfort. The limb-length discrepancy was relatively large in our patients (mean 5.4 cm) compared with that in previous reports; however, we do not believe that the discrepancy in leg length exerted a significant effect in lowering the level of patient satisfaction.
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We also assessed our patients using the Knee Society rating system, which is perhaps the most widely used system. Using this system, Lee et al. [13] assessed patients who underwent distraction arthrodesis with an intramedullary nail and mixed bone grafting after infected TKA. The mean postoperative limb shortening was only 1.1 cm. The mean Knee Society score was 59.9 and the functional score was 38.8, which were comparable with our data. In conclusion, when knee arthrodesis was performed for cases of infected TKA, pain was reduced and ADL independence was established when knee fusion was achieved. Analysis of our patients using a patient-based outcome measuring system revealed that the results of successful arthrodesis were comparable with that of TKA. Half of those patients subjectively reported achieving QOL that was similar to or even higher than that of patients after TKA. However, patients who underwent multiple surgeries or experienced strong pain and numbness around the knee prior to implant removal complained of pain following knee arthrodesis. Some walking aids are necessary, especially in patients with a limb-length discrepancy. Medications for pain, use of an appropriate shoe lift, walking aids, and adequate postoperative rehabilitation may contribute to a higher level of postoperative satisfaction, and are encouraged to improve ADL in patients after arthrodesis.
2. Akai M, Doi T, Fujino K, Iwaya T, Kurosawa H, Nasu T. An outcome measure for Japanese people with knee osteoarthritis. J Rheumatol. 2005;32:1524–30. 3. Insall JN, Dorr LD, Scott RD, Scott WN. Rationale of the Knee Society clinical rating system. Clin Orthop. 1989;248:13–4. 4. Kikuchi Y, Ohta M, Watanabe J, Sasaki K, Hosokawa N, Kogure A, et al. Evaluation of quality of life after total knee arthroplasty using JKOM (Japanese knee osteoarthritis measure) (in Japanese). Higashinihon Seisaikaishi (J East Jpn Orthop Traumatol). 2010;22: 154–7. 5. Wiedel JD. Salvage of infected total knee fusion: the last option. Clin Orthop. 2002;404:139–42. 6. Damron TA, McBeath AA. Arthrodesis following failed total knee arthroplasty: comprehensive review and meta-analysis of recent literature. Orthopedics. 1995;18:361–8. 7. Mabry TM, Jacofsky DJ, Haidukewych GJ, Hanssen AD. Comparison of intramedullary nailing and external fixation knee arthrodesis for the infected knee replacement. Clin Orthop. 2007;464:11–5. 8. Lai KA, Shen WJ, Yang CY. Arthrodesis with a short Huckstep nail as a salvage procedure for failed total knee arthroplasty. J Bone Jt Surg Am. 1998;80:380–8. 9. David R, Shtarker H, Horesh Z, Tsur A, Soudry M. Arthrodesis with the Ilizarov device after failed knee arthroplasty. Orthopedics. 2001;24:33–6. 10. Benson ER, Resine ST, Lewis CG. Functional outcome of arthrodesis for failed total knee arthroplasty. Orthopedics. 1998; 21:875–9. 11. Klinger HM, Spahn G, Schultz W, Baums MH. Arthrodesis of the knee after failed infected total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2006;14:447–53. 12. De Vil J, Almqvist KF, Vanheeren P, Boone B, Verdonk R. Knee arthrodesis with an intramedullary nail: a retrospective study. Knee Surg Sports Traumatol Arthrosc. 2008;16:645–50. 13. Lee S, Jang J, Seong SC, Lee MC. Distraction arthrodesis with intramedullary nail and mixed bone grafting after failed infected total knee arthroplasty. Knee Surg Sports Traumatol Arthrosc. 2012;20: 346–55.
Conflict of interest None.
References 1. Nagoya S, Kaya M, Sasaki M, Tateda K, Yamashita T. Diagnosis of peri-prosthetic infection at the hip using triple-phase bone scintigraphy. J Bone Jt Surg Br. 2008;90:140–4.
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