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Home , Prepatellar bursitis

Topics in 607 Primary Care Medicine

Olecranon and Prepatellar Diagnosis and Treatment JOHN H. McAFEE, MD, and DAVID L. SMITH, MD, Portland "Topics in Primary Care Medicine" presents articles on common diagnostic or therapeutic problems en- countered in primary care practice. Physicians interested in contributing to the series are encouraged to contact the series editors. BERNARD LO, MD STEPHEN J. McPHEE, MD Series' Editors

Abursa is a synovial pouch that reduces friction between septic. Nonseptic bursitis is further categorized as idio- adjacent tissues. More than 150 bursae have been iden- pathic, traumatic, or crystal-induced. tified in the human body. Of these, the olecranon and prepa- Features of the Condition tellar bursae are particularly predisposed to infection and . In this article, we briefly review the Septic Bursitis of the olecranon and prepatellar bursae and discuss the clin- Septic bursitis usually arises from trautna resulting in ical features and treatment of both septic and nonseptic bur- direct inoculation of the bursal space. Blunt trauma, a skin sitis. wound, or repetitive pressure applied over the or elbow may precipitate an infection. Septic bursitis arising from Anatomy and Incidence infection in nearby sites, such as in cases of paronychia, has The olecranon bursa is the only bursa ofthe elbowjoint. It also been reported. In contrast, hematogenous bacterial is positioned subcutaneously on the extensor aspect of the seeding of the bursal sac is rare, probably because of the elbow over the olecranon process of the ulna. The bursal limited vascular supply ofthe bursal tissue. anatomy of the knee is more complex, with four bursae The population at risk for the development of septic bur- recognized over the extensor aspect ofthe kneejoint (Figure sitis includes laborers such as miners, gardeners, carpet 1). The suprapatellar bursa located between the femur and layers, and mechanics, in whom repetitive knee or elbow quadriceps tendon communicates with the knee joint as an trauma is common. Those with a history of are extension of that synovial cavity. The deep infrapatellar also prone to septic bursitis due to the repeated traumas they bursa lies between the patellar ligament and proximal tibia receive while intoxicated, coupled with their impaired host and rarely becomes symptomatic. The subcutaneous infra- immunity. Likewise, septic bursitis has developed in some patellar bursa is positioned between the skin and tibial tuber- patients with impaired host defense due to the use ofsystemic osity, and the is between the skin and pa- glucocorticoids or to certain medical conditions such as ma- tella. Though anatomically distinct, the prepatellar and sub- lignancy, leukopenia, mellitus, or chronic renal cutaneous infrapatellar bursae are affected by similar failure. The presence of intrabursal rheumatoid nodules or processes and are collectively referred to as the "prepa- gouty tophi, or a prior history of septic bursitis increases a tellar" bursa. The olecranon and prepatellar bursae are person's risk of bursal infection. Iatrogenic - may closed spaces that ordinarily do not communicate with the follow an intrabursal injection for nonseptic bursitis. associatedjoint space. The incidence of olecranon and prepatellar bursitis is not Nonseptic Bursitis known. Several articles suggest that septic olecranon and Traumatic and idiopathic bursitis likely have a common prepatellar bursitis account for between 0.01 % and 0.1 % of origin, and idiopathic cases result from unrecognized olec- hospital admissions. The overall incidence of olecranon and ranon or prepatellar trauma. The inciting event may be rela- prepatellar bursitis is probably underestimated by these hos- tively trivial, such as when a person leans on the elbow or pital-based studies because only about 30 % of cases are bumps the knee. The same population predisposed to septic septic, and only patients with the most severe cases of septic bursitis is at risk for the development of traumatic bursitis. bursitis require admission. Crystal-induced bursitis most often occurs in patients with a The approach to diagnosing olecranon and prepatellar history of . In one series of 15 patients, approximately bursitis is to broadly classify the condition as septic or non- 40 % of those examined had concurrent gouty

(McAfee JH, Smith DL: Olecranon and prepatellar bursitis-Diagnosis and treatment. West J Med 1988 Nov; 149:607-610) From the Division of General Medicine, Ambulatory Care and Medical Service (Drs McAfee and Smith), Section of Arthritis and Disease (Dr Smith), Oregon Health Sciences University School ofMedicine, and the Veterans Administration Medical Center, Portland. Reprint requests to John H. McAfee, MD, VA Outpatient Clinic, PO Box 1036, Portland, OR 97207. 608608 TOISTOPICS IN PMAPRIMARY CARCARE MMEDICINEE at an adjacent or nearby joint. A minor bursal trauma may be a precipitating factor by causing intrabursal crystal shedding. TABLE 1.-Clinical Features of Septic and Nonseptic Olecranon and Prepatellar Bursitis Although seen infrequently, a case ofcalcium pyrophosphate crystal-induced bursitis from localized chondrocalcinosis Forms of Bursitis may produce similar features. Finally, rheumatoid arthritis Traumatic and Clinical Feature Septic idiopathic Crystal-induced may be associated with nonseptic olecranon or prepatellar bursitis. Intrabursal rheumatoid nodules are occasionally History of trauma ...... Common Common Occasional present. Bursal tenderness . Very common Occasional Very common Skin or wound . . Common Occasional Rare Clinical Evaluation Local warmth ...... Common Rare Common Local erythema ...... Common Rare Common On , the findings of olecranon and Surrounding . Common Occasional Rare prepatellar bursitis vary, although several features are usu- .Common Absent Occasional ally present. Localized bursal swelling over the extensor aspect of the elbow or knee is universally seen. Localized other systemic signs of infection do not complicate cases of bursal fluctuance is usually present, with bursal fluid vol- traumatic and idiopathic bursitis. umes ranging from a few drops to 40 ml. An especially The physical findings in patients with crystal-induced important finding is that painless passive range of motion of bursitis reflect an acute inflammatory process. Canoso and the knee or elbowjoint is preserved except at extreme flexion Yood reported 15 cases of acute gouty bursitis. All patients where the swollen bursal compartment may become com- had signs of acute bursal inflammation. Three ofthe patients pressed. Generalized joint swelling, inflammation, and a re- had low-grade fever, and six patients had concurrent gouty stricted range of motion imply that arthritis is present. In arthritis. most cases, an arthrocentesis should be done. Characteristics of Bursal Fluid Septic Bursitis The medical history and physical examination may not Septic bursitis involves the olecranon bursa about four suffice to distinguish septic from nonseptic bursitis (Table 1). times more often than the prepatellar bursa. Bursal tender- An aspirate of fluid from the affected bursa should be exam- ness is present in 90% to 100% of patients, and an abrasion ined routinely to establish the cause of the bursitis and to or laceration over the bursa is present in about 50% of pa- direct therapy. Using aseptic precautions, an 18- or 20-gauge tients. Most patients with septic olecranon or prepatellar needle is introduced into the bursal cavity from a lateral bursitis present with swelling and peribursal cellulitis. Other approach. Aspiration from the extensor side of the knee or findings include fever-40% to 90% of cases-or a mild elbow should be avoided because ofthe higher risk ofchronic "sympathetic" effusion ofthe adjacentjoint. fluid drainage. Unless a history of significant trauma exists, routine knee or Nonseptic Bursitis elbow radiographs are not necessary. A nontender bursal effusion is typical of traumatic and Septic Bursitis idiopathic bursitis, although as many as 45 % ofpatients may Bursal fluid is septic when clinically unmistakable pus is have mild bursal tenderness. About 25% of patients have aspirated. In a few cases, however, the fluid will be straw mild peribursal edema, warmth, and erythema. Fever and colored or serosanguineous. Leukocyte counts of bursal fluid tend to be lower than those for joint . Thus, although the count may be more than 200,000 per Al, septic bursitis must be suspected with counts as low as 1,500 per fd. The glucose concentration of bursal fluid is often less than 50% of the serum glucose concentra- tion. We routinely measure bursal fluid glucose, although the usefulness of this value for distinguishing septic and non- septic bursitis is not established. Gram's stains of culture- proven septic bursal fluid are negative in about 30% ofcases and cannot be relied on to exclude a diagnosis of septic bur- sitis. Aspirated fluid should be cultured routinely. In most aspi- rates of infected fluids, positive cultures will yield Staphy- lococcus aureus or Staphylococcus epidermidis (90%), or streptococcal species (9%). Rarely is septic bursitis caused by anaerobes, mycobacteria, fungi, Haemophilus influenzae, or other gram-negative organisms. Nonseptic Bursitis Fluid specimen cultures in cases of traumatic and idio- pathic bursitis are sterile by definition. The gross appearance of the bursal fluid ranges from straw colored to bloody. The leukocyte count of the fluid is usually less than 1,500 per yd, Figure 1.-The drawing shows a lateral view of the bursal anatomy of with mononuclear cells predominating. A leukocyte count in the anterior knee. the range of 10,000 to 20,000 per 1A is rare. The erythrocyte - o - 609 THE WESTERN JOURNAL OF MEDICINE * NOVEMBER 1988 * 149 * 5 609

TABLE 2.-Characteristics of Bursal Fluid in Patients With Septic and Nonseptic Olecranon and Prepatellar Bursitis Type of Bursitis Characteristic Septic Traumaiuc and Idiopathic Crystal-Induced Appearance .Purulent; may be straw colored or Straw colored, serosanguineous, or Straw colored to bloody serosanguineous bloody Leukocytes, per dl ...... Range, 1,500 to 300,000; mean, 75,000 Range, 50 to 11,000; mean, 1,100 Range, 1,000 to 6,000; mean, 2,900 Differential count ...... Predominantly polymorphonuclear cells Predominantly mononuclear cells Highly variable Ratio of bursal fluid to serum glucose <50% >50% Unknown Gram's stain ...... Positive in 70% of cases Negative Negative Crystals present ...... No No Yes Culture results ...... Positive Negative Negative count averages 20,000 to 30,000 per yd. The fluid-to-serum centration of S aureus when administered intravenously or glucose ratio is usually greater than 50%. Bursal fluid typi- orally. Ho and Su have shown that semisynthetic penicil- cally has a low viscosity, and tests such as the mucin clot or lins-for example, oxacillin or dicloxacillin-were effica- string sign offer no diagnostic information. cious in treating 25 cases of septic prepatellar and olecranon Crystal-induced bursitis is most often caused by gout, and bursitis. Repeat bursal aspirations were analyzed every one negatively birefringent, needle-shaped monosodium urate to three days, and therapy was continued for five crystals will be visible by polarized light microscopy. One days after the fluid was sterile. It took an average offour days case of caused by deposits of calcium py- of treatment until the aspirate contained no S aureus, though rophosphate dihydrate crystals has been reported. The gross occasionally a duration of as long as two weeks was required. appearance of gouty bursal fluid varies greatly, ranging from No recurrences were noted on follow-up. This study indi- straw colored to bloody. Cell counts overlap those of bursal cates that a 14-day course of oral will cure most fluid in cases of septic and nonseptic bursitis, ranging from cases of septic bursitis. Severe bursal infection, character- 1,000 to 6,000 per with a highly variable differential ized by intense peribursal cellulitis or wound infection, high count. Fluid glucose values in cases ofgouty bursitis have not fever, and systemic toxicity, requires more aggressive inpa- been reported. A high index of suspicion for concurrent tient treatment. Under these circumstances, initial treatment septic and gouty bursitis should be maintained, as this has with a regimen of intravenous antibiotics followed by a two- been reported. week course oforal antibiotics will generally achieve cure. Table 2 summarizes the typical fluid characteristics in Several factors may prolong the usual course of septic patients with septic, traumatic, and gouty bursitis. We rec- bursitis. The presence of infection for more than two weeks ommend that all olecranon and prepatellar effusions be aspi- before antibiotic therapy is begun is associated with persis- rated at the time of the initial presentation. Fluid analysis tently positive cultures of serial bursal aspirations. In addi- should include a cell count with differential, Gram's stain, tion, patients with a history of septic or nonseptic bursitis, culture and sensitivity tests, and crystal examination. We rheumatoid nodules, gouty tophi, impaired host immunity, also include serum and fluid glucose determinations. severe bursal infection, or infection with unusual organisms may require an extended course ofantibiotic therapy. Treatment In all patients, purulent material should be aspirated at The findings of an inflamed olecranon or prepatellar one- to three-day intervals as long as effusion persists. Sur- bursa coupled with a positive Gram's stain of bursal fluid gical incision and drainage are rarely necessary and may require prompt, empiric antibiotic coverage. In addition, prolong the overall healing time. Percutaneous suction and empiric therapy for septic bursitis in a case of a negative continuous irrigation, however, are beneficial in patients Gram's stain is warranted when clinical and laboratory fea- with severe septic bursitis when antibiotic therapy and re- tures suggest the presence ofseptic bursitis. Given that septic peated bursal aspiration have not been successful. Additional bursitis is usually caused by S aureus, the drug of choice for supportive measures include warm soaks, frequent dressing initial treatment is a penicillinase-resistant penicillin, such as changes for an associated wound, and protecting the bursa oxacillin sodium, 2 grams taken orally per day. Subsequent from further trauma. Injecting antibiotics into the bursal therapy can be modified when results of culture and sensi- space has no documented efficacy for bacterial septic bur- tivity tests are known. Patients with mild penicillin aller- sitis. In rare cases when infection with Prototheca (an algae- gy-that is, urticarial reactions-can probably be treated like microorganism) induced olecranon bursitis, the intra- with a first-generation cephalosporin such as cephradine, 1 to bursal administration ofamphotericin B was effective. 2 grams per day, although its efficacy in septic bursitis is Little information is available regarding the treatment of unknown. Patients with severe penicillin allergy should be nonseptic bursitis. Weinstein and colleagues retrospectively admitted to hospital and treated with intravenous vanco- reviewed the usefulness of intrabursal steroid injection for mycin hydrochloride, 2 grams per day in divided doses. An traumatic and idiopathic olecranon bursitis: 22 patients who alternative outpatient treatment with oral erythromycin, 2 received no therapy beyond an initial bursal aspiration were grams per day, can be instituted for mild cases. Treatment compared with 25 patients who received a single injection of failures with erythromycin have been documented, however, 20 mg of triamcinolone hexacetonide. In patients treated and its use requires careful follow-up and repeat bursal aspi- conservatively, the bursal effusions tended to gradually re- ration to verify a cure. solve, with about 70% ofall effusions resolved a month after Penicillins have been shown to achieve sustained bursal aspiration, and 90% of all effusions resolved after six concentrations several times the minimum bactericidal con- months. In contrast, there was a prompt response to intra- 61061 TOPICS IN PRIMARY CARE MEDICINE bursal steroid injection, with about 85% of effusions re- Most cases of olecranon and prepatellar bursitis resolve solved after one week. Significant complications were noted without complication. Bacteremia arising from a septic bur- in the group given , however. These included skin sitis has rarely been reported. This complication should be atrophy over the bursa in 20%, associated with considered in immunocompromised patients with septic bur- pressure applied to the elbow in 30%, and the development of sitis who have signs of systemic toxicity such as chills, fever, septic bursitis in 10%. Until further data are available, we or hypotension. These patients may be infected with patho- recommend a conservative approach to treating traumatic gens other than the usual skin flora. In this setting, even with and idiopathic bursitis. This includes initial aspiration, ap- a negative bursal fluid Gram's stain, empiric treatment with plying compressive dressings, such as an Ace bandage, and broad-spectrum intravenous antibiotics is warranted after the administering nonsteroidal anti-inflammatory agents for 10 results ofblood cultures are obtained. Septic bursitis extends to 14 days. Repeated bursal aspiration is generally of little to involve the associated joint or underlying bone in cases of value. Steroid injection using 10 to 20 mg of a short-acting immunocompromised hosts or where antibiotic therapy was corticosteroid-such as triamcinolone acetonide-is best re- delayed. served for refractory cases. Other unproved but reported GENERAL REFERENCES therapies for protracted cases include the use of a "blood Canoso JJ: Idiopathic or traumatic olecranon bursitis-Clinical features and patch injection" into the bursal compartment, or the tempo- bursal fluid analysis. Arthritis Rheum 1977; 20:1213-1216 Canoso JJ, Yood RA: Reaction of superficial bursae in response to specific rary (three-day) use of a percutaneous intrabursal drainage disease stimuli. Arthritis Rheum 1979; 22:1361-1364 catheter. Canoso JJ, Yood RA: Acute gouty bursitis: Report of 15 cases. Ann Rheum Dis Crystal-induced bursitis usually responds to treatment 1979; 38:326-328 Cochran RK, Pierson CL, Sell TL, et al: Protothecal olecranon bursitis: Treat- with nonsteroidal anti-inflammatory agents or oral colchi- ment with intrabursal amphotericin B. Rev Infect Dis 1986; 8:952-954 cine. An intrabursal steroid injection could also be consid- Gerster JC, Lagier R, Boivin G: Olecranon bursitis related to calcium pyrophos- ered, though the potential for complications noted above phate dihydrate crystal deposition disease. Arthritic Rheum 1982; 25:989-996 Ho G Jr, Mikolich DJ: Bacterial infection ofthe superficial subcutaneous bursae. exists. Clin Rheum Dis 1986; 12:437-457 Ho G Jr, Su EY: Antibiotic therapy of septic bursitis-Its implication in the Prevention and Complications treatment ofseptic arthritis. Arthritis Rheum 1981; 24:905-91 1 Ho G Jr, Tice AD: Comparison ofnonseptic and septic bursitis-Further obser- Avoiding local trauma is important in preventing and suc- vations on the treatment ofseptic bursitis. Arch Intern Med 1979; 139:1269-1273 cessfully treating both septic and nonseptic bursitis. Persons Ho G Jr, Tice AD, Kaplan SR: Septic bursitis in the prepatellar and olecranon with or bursae: An analysis of25 cases. Ann Intern Med 1978; 89:21-27 prepatellar olecranon bursitis should be encouraged Hoffmeyer P, Chalmers A, Price GE: Septic olecranon bursitis in a general to avoid leaning on their or elbows. When an occupa- hospital population. Can Med Assoc J 1980; 122:874-876 tion or avocation places a person at risk for recurrent knee or Knight M, Thomas JC, Maurer RC: Treatment of septic olecranon and prepa- tellar bursitis with percutaneous placement of a suction-irrigation system-A report elbow trauma, protective pads used over the extensor aspect of 12 cases. Clin Orthop 1986; 206:90-93 of the knees and elbows may also be beneficial. Recurrent Strickland RW, Raskin RJ, Welton RC: Sympathetic synovial effusions associ- ated with septic arthritis and bursitis. Arthritis Rheum 1985; 28:941-943 olecranon bursitis may be caused by an underlying olecranon Weinstein PS, Canoso JJ, WohlgethanJR: Long-term follow-up ofcorticosteroid bone spur. Resection ofthe spur is occasionally necessary. injection fortraumatic olecranon bursitis. Ann Rheum Dis 1984; 43:44-46