- Email: [email protected]
The septic knee—Arthroscopic treatment
Arthroscopy: The Journal of Arthroscopic and Related Surgery
1(3):194-197 © 1985ArthroseopyAssociationof North America
The Septic Knee Robert
Arthroscopic Treatment W. J a c k s o n ,
M.D.
Abstract: It is well known that infection of a major weight-bearing joint can be a disastrous occurrence. Arthroscopy- has been found to aid immeasureably in the diagnosis and treatment of this condition. Under arthroscopic control, adhesions can be broken down, necrotic tissue can be lavaged from the joint and, following the installation of drainage tubes, the processes of distension and irrigation can be carried out. By so doing, and in conjunction with systemic
antibiotic therapy, a significant improvement in results of sepsis in major joints has been achieved, with all cases so treated being considered good to excellent at follow-up. It may be that the major benefit of the distention/irrigation method lies in the distension process which prevents loculation of necrotic tissue in the recesses of the joint and also prevents adhesion formation which might later restrict range of motion. Key Words: Septic knee--Arthroscopy-Distension/irrigation.
The experience of the past has shown us that an acute joint infection may relentlessly progress to a disastrous result. While there may be many predisposing factors, most'joint infections start with some form of trauma and the resultant introduction of pathogenic bacteria into the joint. One of the most common forms of such trauma is an orthopedic surgical p r o c e d u r e . B a c t e r i a can also be i n t r o d u c e d into the joint by puncture wounds (e.g., the injection of steroids) or occasionally the infection may be introduced hematogenously from a distant septic focus. If an infective process occurring in a joint cavity is ineffectively treated, the end result is destruction of the articular cartilage (and in some instances, the underlying bone), and perhaps more importantly, obliteration of the joint cavity by adhesions or scar formation. Such adhesions result in loculation of bacteria and dead tissue. Consequently, what might appear to be an early good result of treatment, can be compromised by subsequent acute recurrences. In severe instances, the final result is a painful stiff
joint with recurrent infections that are extremely debilitating. In some instances, the end result is arthrodesis or even amputation. This article outlines a m e t h o d o f a r t h r o s c o p i c treatment that has been very successful in the management of septic joints. Although most of the following comments can be applied to any arthrodial joint, we will restrict our discussion to the knee joint as this, in our experience, is the most commonly affected major joint. CLINICAL PICTURE The diagnosis of a septic knee joint is entertained on the clinical p r e s e n t a t i o n of severe pain, with swelling and i n c r e a s e d local t e m p e r a t u r e in the joint. On inquiry, some history of a predisposing situation or an obvious etiologic mechanism for the infection is usually revealed. Systemic signs that are commonly present include an increased body temp e r a t u r e and an i n c r e a s e in the white blood cell count and the e r y t h r o c y t e sedimentation rate. The most c o m m o n clinical features, however, are pain on m o v e m e n t of the joint and localized swelling. Gout and an acute exacerbation of rheumatoid arthritis must be considered in the differential diagnosis. Infecting organisms are m o s t c o m m o n l y gram
From the Department of Surgery, Toronto Western Hospital, Toronto, Ontario, Canada. Address correspondence and reprint requests to Dr. R. W. Jackson at 405-25 Leonard Avenue, Toronto, Ontario M5T 2R2, Canada.
194
THE SEPTIC K N E E - - A R T H R O S C O P I C T R E A T M E N T positive staphylococcus, beta hemolytic streptococcus, or pneumococcae. Gram negative organisms such as Esherichia coli, pseudomonas, and hemophilus influenzae are occasionally seen, and Neisseria gonorrhoea has become a frequent cause of joint infection through hematogenous spread. Gram positive infections tend to be more aggressive in their clinical course, with "hotter" joints and a fairly fast clinical course. Gram negative infections are more indolent, frequently causing significant delays in making the diagnosis. Experimental studies show that chondrolysis begins in the first 24 hours following the introduction of an infection into a joint. The prognosis therefore becomes increasingly serious after 3 or 4 days of untreated infection. There are many predisposing conditions including a variety of primary infections such as pneumonia or the presence of carbuncles elsewhere in the body, pre-existing joint disease such as gout, degenerative arthritis, rheumatoid arthritis, recent antibiotic usage, which has produced a resistant or suppressed organism, immunosuppression such as in rheumatoid arthritis or in the treatment of cancer or in renal transplants, and coexisting medical conditions such as diabetes, sickle cell anemia, alcoholism, and lupus erythematosus. Aspirations of joint fluid, in addition to culture and sensitivity, may be subjected to various biochemical tests. If the glucose level is under 40 rag/ dl blood level, and if the cell count is greater than 100,000 with mainly polymorphonuclear leukocytes, one suspects an infectious process. Gram stain may be helpful but can also be misleading. If blood cultures are positive, one must consider subacute bacterial endocarditis. The erythrocyte sedimentation rate remains a sensitive index of the presence of disease. The course of the infection can be monitored by repeated erythrocyte sedimentation rates. As Gallium 67 is taken up by white blood cells and by fibroblasts, radionuclide scanning is a sensitive indicator of an infective process. However, Gallium 67 is not an effective way of following the progress of the infection after treatment, as it often remains positive for a fairly lengthy period of time due to the presence of fibroblasts in the area. Technetium 99 diphosphonate is a sensitive indicator of coexistent osteomyelitis, as it is bound to immature collagen and hydroxyapatite, and reflects the involvement of adjacent bone. Routine radiological
195
examinations may show soft tissue swelling or occasionally rarefaction of subchondral bone or erosions adjacent to bone. Joint space narrowing may be seen in late cases, or osteomyelitis adjacent to the joint may also be identified. TREATMENT In the past, treatment involved drainage of the pus, then rest of the extremity to allow nature to aid in the healing process. Since the introduction of system antibiotics, infections have been more easily controllable. After cultures are obtained, the appropriate systemic antibiotic therapy is instituted. In addition, local antibiotics can also be instilled directly into the joint space. In the treatment of sepsis anywhere else in the body, it is a basic principle to obliterate dead space, and to avoid collections of fluid or blood that might tend to perpetuate the infection. However, if the infection involves a major synovialjoint, and if you successfully obliterate the joint space, you inevitably promote the development of adhesions and subsequent painful stiffness. Therefore, in treating a joint infection, all of the basic principles for the treatment of sepsis should be applied, except for the principle of obliterating dead space. Prior to the advent of arthroscopy, one of the common ways of treating a major knee joint infection was by repeated aspiration of the pus and the instillation of antibiotics. Occasionally, excision and drainage of the joint by formal arthrotomy, along with break-down of adhesions and removal of all dead and devitalized tissue, would be instituted. In recent years, suction irrigation has been carried out with the insertion of a tube or tubes, so that antibiotics could be continuously instilled into the joint and pus could be suctioned out. Often, this was arranged as a "continuous irrigation" system, with the tendency to develop a "super highway" between the inflow and the outflow tubes, and provide little in the way of diffusion to the outer reaches of the joint cavity. A more logical application of the "continuous irrigation" technique is the "distention/irrigation" technique, whereby the joint space is progressively filled to capacity with an antibiotic solution and, after maximum distention has been achieved, is drained dry by suction. The cycle is then repeated at regular intervals. By so doing, all the principles of treatment of sepsis are adhered to with the ex-
Arthroscopy, Vol. 1, No. 3, 1985
196
R. W. J A C K S O N
ception that the joint space is maintained rather than obliterated by the treatment process. Distention avoids loculation, permits antibiotic diffusion to the corners of the joint, and prevents adhesions from forming. ARTHROSCOPIC TREATMENT The arthroscopic treatment of a septic knee joint involves the insertion of an arthroscope usually by the anterior inferolateral approach. With the blunt obturator in the sheath, the scope is moved around the suprapatellar pouch, the lateral gutter, the medial gutter, and across the anterior aspect of the joint. This maneuvering of the scope provides the blunt trauma necessary to break down adhesions that are already forming. The joint is then thoroughly irrigated with saline solution and as much debris as possible is washed out of the joint. A visual examination can then be carried out to examine the articular cartilage (color and firmness to palpation changes with the length of time the infection has been present), to determine whether or not any foreign material or loose sequestrated fragments of bone or cartilage are present within the joint, and, in general, to assess the state of the joint. The material that is aspirated from the joint is obviously sent for culture and sensitivity. The arthroscope is then removed, and through the arthroscope sheath, a 1/8 inch plastic drainage tube is inserted into the joint and the sheath is withdrawn leaving the drain in situ. The joint is then once again fully distended and through a second stab wound in the suprapatellar region, the sheath is again introduced into the joint. Again, a 1/8 inch plastic drainage tube is inserted, and the sheath is withdrawn. At this stage, most of the immediate principles of treatment have been achieved as the joint has been evacuated and flushed, material has been obtained for culture and sensitivity, adhesions have been broken down, and, presumably, as much dead tissue and debris as possible have been removed from the joint. We also have two tubes in situ, sutured to the skin so that they cannot be inadvertently withdrawn. One of these tubes is then connected to an irrigation solution; the other tube is connected to gentle suction. The irrigating solution that is normally used is a dilute solution o f the a p p r o p r i a t e antibiotic in normal saline. Usually, a rnucolytic agent is added to the solution to enhance the breakdown of any
Arthroscopy, Vol. 1, No. 3, 1985
clusters of bacteria and to prevent further fibrin formation from loculating the infection in corners of the joint. The mucolytic agent that is commonly used is called "Alevaire." Ten centimeters of full strength Alevaire is diluted in 100 cc of saline, and added to a bottle of 1,000 cc of normal saline. Also, in the liter of irrigating solution, appropriate antibiotics (depending on culture reports) should be added in the following concentrations: penicillin 50,000 units/L, cloxacillin 100 mg/L, cefazolin 100 mg/L. The distention/irrigation process is then started, with the slow infusion of the antibiotic solution into the knee over a 3-hour period. As the fluid capacity of the average knee joint ranges from 110 to 150 cc, one should strive to instill approximately 40 cc/ h, or 120 cc over a 3-h period. At the end of 3 hours, distention should be quite marked and may be slightly uncomfortable. The joint is then drained dry, using a "hemovac suction" or a "Gomco suction" apparatus. Drainage is carried out for a period of 1 hour. The cycle of 3 h distention and 1 h of drainage is then repeated continuously. The intelligent patient can often regulate the 4-hourly irrigation and suction cycle throughout the day, but of course, this must be carried out by a nursing staff during the hours that the patient is asleep. It is necessary to keep the patient on bedrest and splint the leg for the first 4 or 5 days of treatment to avoid dislodging the irrigating tubes. During the early stages, some leakage of the antibiotic irrigating solution occurs through the puncture wounds or through the wounds of previous surgery. However, this is not a difficult problem and usually ceases after the first 24 to 48 h. In addition to the local distention/irrigation process, intravenous antibiotics using the appropriate antibiotic are also administered for at least 1 week, and then the individual is changed to oral antibiotics for a minimal period of 6 weeks following any initial joint infection. The distention/irrigation tubes are removed after 6 to 8 days and usually after two negative cultures of the effluent have been obtained. Frequently, we discontinue irrigating, but continue suctioning for a period of 48 h prior to removing the tubes. The patient is then allowed to mobilize gently but is kept on protected weight bearing for a period of 4 to 6 weeks to allow the articular cartilage, w h i c h has been existing in an abnormal medium for a lengthy period of time, an opportunity to recover.
THE SEPTIC KNEE--ARTHROSCOPIC
Some problems are occasionally encountered with the distention/irrigation system. One of the most common (in addition to leakage) is tube blockage. The fibrin debris that is being suctioned from the joint frequently blocks the outflow tube. It then becomes necessary to reverse the direction of flow, making the superior tube the inflow and suctioning through the lower tube. Secondary infection is also a possibility, as the tubes are leading percutaneously into the joint, but this has not proven to be a major problem to date. RESULTS A series of 24 major joint infections were collected from two teaching hospitals in the Toronto area. These results were previously reported (1). Fourteen of the cases were treated by the distention/irrigation system, and 10 were treated by other methods. All of the knees in the distention/irrigation group were treated arthroscopically. The other cases were treated by open operation and the insertion of tubes. The results were heavily in favor of the distention/irrigation method of treatment. All of the distention/irrigation cases followed up 2 to 8 years after treatment were placed in the good to excellent category, whereas only 40% of the cases treated by other methods were considered to have good to excellent results. A patient with an excellent result had no pain, a full range of motion, and no sign of recurrence at the time of follow-up. A patient with a good result had occasional mild pain, only slight reduction of movement, and no sign of recurrence. A patient with fair result had moderate pain, less than three quarters of the normal range of motion, and/or some sign of recurrence. A patient with a poor result, of course, had a severely painful, stiff knee with recurrence of infection. We concluded that the better results in the distention/irrigation groups were due to the distention process, which prevents loculation and prevents the antibiotic to diffuse to the furthest corners of the joint. The value of antibiotics in the irrigating so-
TREATMENT
197
lution is perhaps questionable, as the diffusion of antibiotics across the synovial membrane has been proven to be adequate using systemic antibiotics in high dosage. Other authors have reported the use of suction shavers to perform synovectomy and to remove fibrin debris at the time of the initial treatment, with a repeat "shave" at 48 h. Generally, the results with this routine were not good, probably due to increased scarring and adhesions (2). Every author mentions the dramatic relief of pain following the arthroscopic breakdown of adhesions, washing of the joint, insertion of the tubing, and commencement of irrigation. In the late stages of a chronic infection, one is faced with synovectomy, arthroplasty, arthrodesis, or amputation as treatment modalities. Synovectomy in the late stages can be an effective method of treatment. Since it may be difficult to do under arthroscopic control, a formal synovectomy may be necessary to remove all of the scarred and adhesed lining of the joint. Arthroplasty is risky under the best of conditions and arthrodesis is probably the most reasonable way of treating a late unresolved and difficult problem in management.
SUMMARY
When an infection of a major joint is suspected, treatment should be aggressive and prompt. Arthroscopy can aid immeasurably in establishing the diagnosis and implementing the appropriate treatment when a septic knee is suspected. Results to date suggest that the distention/irrigation process can be a very effective treatment method.
REFERENCES 1. Jackson RW, Parsons CJ. Distension-irrigation treatment o f major joint sepsis. Clin Orthop Rel Res 1973;96:160-4. 2. Mason JL, Jr. Arthroscopic treatment o f septic arthritis o f the knee. Presented at the Annual Meeting of the International Arthroscopy Association, Rio de Janeiro, 1981.
Arthroscopy, Vol. 1, No. 3, 1985
1(3):194-197 © 1985ArthroseopyAssociationof North America
The Septic Knee Robert
Arthroscopic Treatment W. J a c k s o n ,
M.D.
Abstract: It is well known that infection of a major weight-bearing joint can be a disastrous occurrence. Arthroscopy- has been found to aid immeasureably in the diagnosis and treatment of this condition. Under arthroscopic control, adhesions can be broken down, necrotic tissue can be lavaged from the joint and, following the installation of drainage tubes, the processes of distension and irrigation can be carried out. By so doing, and in conjunction with systemic
antibiotic therapy, a significant improvement in results of sepsis in major joints has been achieved, with all cases so treated being considered good to excellent at follow-up. It may be that the major benefit of the distention/irrigation method lies in the distension process which prevents loculation of necrotic tissue in the recesses of the joint and also prevents adhesion formation which might later restrict range of motion. Key Words: Septic knee--Arthroscopy-Distension/irrigation.
The experience of the past has shown us that an acute joint infection may relentlessly progress to a disastrous result. While there may be many predisposing factors, most'joint infections start with some form of trauma and the resultant introduction of pathogenic bacteria into the joint. One of the most common forms of such trauma is an orthopedic surgical p r o c e d u r e . B a c t e r i a can also be i n t r o d u c e d into the joint by puncture wounds (e.g., the injection of steroids) or occasionally the infection may be introduced hematogenously from a distant septic focus. If an infective process occurring in a joint cavity is ineffectively treated, the end result is destruction of the articular cartilage (and in some instances, the underlying bone), and perhaps more importantly, obliteration of the joint cavity by adhesions or scar formation. Such adhesions result in loculation of bacteria and dead tissue. Consequently, what might appear to be an early good result of treatment, can be compromised by subsequent acute recurrences. In severe instances, the final result is a painful stiff
joint with recurrent infections that are extremely debilitating. In some instances, the end result is arthrodesis or even amputation. This article outlines a m e t h o d o f a r t h r o s c o p i c treatment that has been very successful in the management of septic joints. Although most of the following comments can be applied to any arthrodial joint, we will restrict our discussion to the knee joint as this, in our experience, is the most commonly affected major joint. CLINICAL PICTURE The diagnosis of a septic knee joint is entertained on the clinical p r e s e n t a t i o n of severe pain, with swelling and i n c r e a s e d local t e m p e r a t u r e in the joint. On inquiry, some history of a predisposing situation or an obvious etiologic mechanism for the infection is usually revealed. Systemic signs that are commonly present include an increased body temp e r a t u r e and an i n c r e a s e in the white blood cell count and the e r y t h r o c y t e sedimentation rate. The most c o m m o n clinical features, however, are pain on m o v e m e n t of the joint and localized swelling. Gout and an acute exacerbation of rheumatoid arthritis must be considered in the differential diagnosis. Infecting organisms are m o s t c o m m o n l y gram
From the Department of Surgery, Toronto Western Hospital, Toronto, Ontario, Canada. Address correspondence and reprint requests to Dr. R. W. Jackson at 405-25 Leonard Avenue, Toronto, Ontario M5T 2R2, Canada.
194
THE SEPTIC K N E E - - A R T H R O S C O P I C T R E A T M E N T positive staphylococcus, beta hemolytic streptococcus, or pneumococcae. Gram negative organisms such as Esherichia coli, pseudomonas, and hemophilus influenzae are occasionally seen, and Neisseria gonorrhoea has become a frequent cause of joint infection through hematogenous spread. Gram positive infections tend to be more aggressive in their clinical course, with "hotter" joints and a fairly fast clinical course. Gram negative infections are more indolent, frequently causing significant delays in making the diagnosis. Experimental studies show that chondrolysis begins in the first 24 hours following the introduction of an infection into a joint. The prognosis therefore becomes increasingly serious after 3 or 4 days of untreated infection. There are many predisposing conditions including a variety of primary infections such as pneumonia or the presence of carbuncles elsewhere in the body, pre-existing joint disease such as gout, degenerative arthritis, rheumatoid arthritis, recent antibiotic usage, which has produced a resistant or suppressed organism, immunosuppression such as in rheumatoid arthritis or in the treatment of cancer or in renal transplants, and coexisting medical conditions such as diabetes, sickle cell anemia, alcoholism, and lupus erythematosus. Aspirations of joint fluid, in addition to culture and sensitivity, may be subjected to various biochemical tests. If the glucose level is under 40 rag/ dl blood level, and if the cell count is greater than 100,000 with mainly polymorphonuclear leukocytes, one suspects an infectious process. Gram stain may be helpful but can also be misleading. If blood cultures are positive, one must consider subacute bacterial endocarditis. The erythrocyte sedimentation rate remains a sensitive index of the presence of disease. The course of the infection can be monitored by repeated erythrocyte sedimentation rates. As Gallium 67 is taken up by white blood cells and by fibroblasts, radionuclide scanning is a sensitive indicator of an infective process. However, Gallium 67 is not an effective way of following the progress of the infection after treatment, as it often remains positive for a fairly lengthy period of time due to the presence of fibroblasts in the area. Technetium 99 diphosphonate is a sensitive indicator of coexistent osteomyelitis, as it is bound to immature collagen and hydroxyapatite, and reflects the involvement of adjacent bone. Routine radiological
195
examinations may show soft tissue swelling or occasionally rarefaction of subchondral bone or erosions adjacent to bone. Joint space narrowing may be seen in late cases, or osteomyelitis adjacent to the joint may also be identified. TREATMENT In the past, treatment involved drainage of the pus, then rest of the extremity to allow nature to aid in the healing process. Since the introduction of system antibiotics, infections have been more easily controllable. After cultures are obtained, the appropriate systemic antibiotic therapy is instituted. In addition, local antibiotics can also be instilled directly into the joint space. In the treatment of sepsis anywhere else in the body, it is a basic principle to obliterate dead space, and to avoid collections of fluid or blood that might tend to perpetuate the infection. However, if the infection involves a major synovialjoint, and if you successfully obliterate the joint space, you inevitably promote the development of adhesions and subsequent painful stiffness. Therefore, in treating a joint infection, all of the basic principles for the treatment of sepsis should be applied, except for the principle of obliterating dead space. Prior to the advent of arthroscopy, one of the common ways of treating a major knee joint infection was by repeated aspiration of the pus and the instillation of antibiotics. Occasionally, excision and drainage of the joint by formal arthrotomy, along with break-down of adhesions and removal of all dead and devitalized tissue, would be instituted. In recent years, suction irrigation has been carried out with the insertion of a tube or tubes, so that antibiotics could be continuously instilled into the joint and pus could be suctioned out. Often, this was arranged as a "continuous irrigation" system, with the tendency to develop a "super highway" between the inflow and the outflow tubes, and provide little in the way of diffusion to the outer reaches of the joint cavity. A more logical application of the "continuous irrigation" technique is the "distention/irrigation" technique, whereby the joint space is progressively filled to capacity with an antibiotic solution and, after maximum distention has been achieved, is drained dry by suction. The cycle is then repeated at regular intervals. By so doing, all the principles of treatment of sepsis are adhered to with the ex-
Arthroscopy, Vol. 1, No. 3, 1985
196
R. W. J A C K S O N
ception that the joint space is maintained rather than obliterated by the treatment process. Distention avoids loculation, permits antibiotic diffusion to the corners of the joint, and prevents adhesions from forming. ARTHROSCOPIC TREATMENT The arthroscopic treatment of a septic knee joint involves the insertion of an arthroscope usually by the anterior inferolateral approach. With the blunt obturator in the sheath, the scope is moved around the suprapatellar pouch, the lateral gutter, the medial gutter, and across the anterior aspect of the joint. This maneuvering of the scope provides the blunt trauma necessary to break down adhesions that are already forming. The joint is then thoroughly irrigated with saline solution and as much debris as possible is washed out of the joint. A visual examination can then be carried out to examine the articular cartilage (color and firmness to palpation changes with the length of time the infection has been present), to determine whether or not any foreign material or loose sequestrated fragments of bone or cartilage are present within the joint, and, in general, to assess the state of the joint. The material that is aspirated from the joint is obviously sent for culture and sensitivity. The arthroscope is then removed, and through the arthroscope sheath, a 1/8 inch plastic drainage tube is inserted into the joint and the sheath is withdrawn leaving the drain in situ. The joint is then once again fully distended and through a second stab wound in the suprapatellar region, the sheath is again introduced into the joint. Again, a 1/8 inch plastic drainage tube is inserted, and the sheath is withdrawn. At this stage, most of the immediate principles of treatment have been achieved as the joint has been evacuated and flushed, material has been obtained for culture and sensitivity, adhesions have been broken down, and, presumably, as much dead tissue and debris as possible have been removed from the joint. We also have two tubes in situ, sutured to the skin so that they cannot be inadvertently withdrawn. One of these tubes is then connected to an irrigation solution; the other tube is connected to gentle suction. The irrigating solution that is normally used is a dilute solution o f the a p p r o p r i a t e antibiotic in normal saline. Usually, a rnucolytic agent is added to the solution to enhance the breakdown of any
Arthroscopy, Vol. 1, No. 3, 1985
clusters of bacteria and to prevent further fibrin formation from loculating the infection in corners of the joint. The mucolytic agent that is commonly used is called "Alevaire." Ten centimeters of full strength Alevaire is diluted in 100 cc of saline, and added to a bottle of 1,000 cc of normal saline. Also, in the liter of irrigating solution, appropriate antibiotics (depending on culture reports) should be added in the following concentrations: penicillin 50,000 units/L, cloxacillin 100 mg/L, cefazolin 100 mg/L. The distention/irrigation process is then started, with the slow infusion of the antibiotic solution into the knee over a 3-hour period. As the fluid capacity of the average knee joint ranges from 110 to 150 cc, one should strive to instill approximately 40 cc/ h, or 120 cc over a 3-h period. At the end of 3 hours, distention should be quite marked and may be slightly uncomfortable. The joint is then drained dry, using a "hemovac suction" or a "Gomco suction" apparatus. Drainage is carried out for a period of 1 hour. The cycle of 3 h distention and 1 h of drainage is then repeated continuously. The intelligent patient can often regulate the 4-hourly irrigation and suction cycle throughout the day, but of course, this must be carried out by a nursing staff during the hours that the patient is asleep. It is necessary to keep the patient on bedrest and splint the leg for the first 4 or 5 days of treatment to avoid dislodging the irrigating tubes. During the early stages, some leakage of the antibiotic irrigating solution occurs through the puncture wounds or through the wounds of previous surgery. However, this is not a difficult problem and usually ceases after the first 24 to 48 h. In addition to the local distention/irrigation process, intravenous antibiotics using the appropriate antibiotic are also administered for at least 1 week, and then the individual is changed to oral antibiotics for a minimal period of 6 weeks following any initial joint infection. The distention/irrigation tubes are removed after 6 to 8 days and usually after two negative cultures of the effluent have been obtained. Frequently, we discontinue irrigating, but continue suctioning for a period of 48 h prior to removing the tubes. The patient is then allowed to mobilize gently but is kept on protected weight bearing for a period of 4 to 6 weeks to allow the articular cartilage, w h i c h has been existing in an abnormal medium for a lengthy period of time, an opportunity to recover.
THE SEPTIC KNEE--ARTHROSCOPIC
Some problems are occasionally encountered with the distention/irrigation system. One of the most common (in addition to leakage) is tube blockage. The fibrin debris that is being suctioned from the joint frequently blocks the outflow tube. It then becomes necessary to reverse the direction of flow, making the superior tube the inflow and suctioning through the lower tube. Secondary infection is also a possibility, as the tubes are leading percutaneously into the joint, but this has not proven to be a major problem to date. RESULTS A series of 24 major joint infections were collected from two teaching hospitals in the Toronto area. These results were previously reported (1). Fourteen of the cases were treated by the distention/irrigation system, and 10 were treated by other methods. All of the knees in the distention/irrigation group were treated arthroscopically. The other cases were treated by open operation and the insertion of tubes. The results were heavily in favor of the distention/irrigation method of treatment. All of the distention/irrigation cases followed up 2 to 8 years after treatment were placed in the good to excellent category, whereas only 40% of the cases treated by other methods were considered to have good to excellent results. A patient with an excellent result had no pain, a full range of motion, and no sign of recurrence at the time of follow-up. A patient with a good result had occasional mild pain, only slight reduction of movement, and no sign of recurrence. A patient with fair result had moderate pain, less than three quarters of the normal range of motion, and/or some sign of recurrence. A patient with a poor result, of course, had a severely painful, stiff knee with recurrence of infection. We concluded that the better results in the distention/irrigation groups were due to the distention process, which prevents loculation and prevents the antibiotic to diffuse to the furthest corners of the joint. The value of antibiotics in the irrigating so-
TREATMENT
197
lution is perhaps questionable, as the diffusion of antibiotics across the synovial membrane has been proven to be adequate using systemic antibiotics in high dosage. Other authors have reported the use of suction shavers to perform synovectomy and to remove fibrin debris at the time of the initial treatment, with a repeat "shave" at 48 h. Generally, the results with this routine were not good, probably due to increased scarring and adhesions (2). Every author mentions the dramatic relief of pain following the arthroscopic breakdown of adhesions, washing of the joint, insertion of the tubing, and commencement of irrigation. In the late stages of a chronic infection, one is faced with synovectomy, arthroplasty, arthrodesis, or amputation as treatment modalities. Synovectomy in the late stages can be an effective method of treatment. Since it may be difficult to do under arthroscopic control, a formal synovectomy may be necessary to remove all of the scarred and adhesed lining of the joint. Arthroplasty is risky under the best of conditions and arthrodesis is probably the most reasonable way of treating a late unresolved and difficult problem in management.
SUMMARY
When an infection of a major joint is suspected, treatment should be aggressive and prompt. Arthroscopy can aid immeasurably in establishing the diagnosis and implementing the appropriate treatment when a septic knee is suspected. Results to date suggest that the distention/irrigation process can be a very effective treatment method.
REFERENCES 1. Jackson RW, Parsons CJ. Distension-irrigation treatment o f major joint sepsis. Clin Orthop Rel Res 1973;96:160-4. 2. Mason JL, Jr. Arthroscopic treatment o f septic arthritis o f the knee. Presented at the Annual Meeting of the International Arthroscopy Association, Rio de Janeiro, 1981.
Arthroscopy, Vol. 1, No. 3, 1985