Prompt and effective treatment of a patient diagnosed with a septic ankle joint serves to lower the potential for morbidity. There have traditionally been few recommendations regarding medical and surgical management. The consensus put forth by the British Society for Rheumatology recommends immediate antibiotic therapy and removal of purulent material from the joint space [14]. This consensus has been consistent with the recommendations put forth by several other studies as well [22–24]. Staphylococci and streptococci have been reported as the most common pathologic organisms in joint sepsis [4, 6, 25–27]. Staphylococcus aureus has been reported as the most common pathogen, followed by Streptococcus and, rarely, gram-negative rods [4]. While the typical patient without risk factors for gram-negative or resistant bacteria can be treated with the appropriate parenteral penicillin or clindamycin, those considered high-risk for such colonization, such as the diabetic patient, should receive the appropriate empiric therapy. Interdisciplinary management with the involvement of Infectious Disease is often prudent to effectively manage the patient with pyarthrosis.

The means by which the joint is to be evacuated has been a source of debate between the two options of serial joint aspirations versus arthroscopic or open surgical intervention. However, a number of sources recommend immediate arthroscopic irrigation and debridement [1, 28–34]. Given the relatively high mortality rate and potential for morbidity with pyarthrosis, surgical intervention should be performed in an urgent or emergent fashion.

Arthroscopic surgery for pyarthrosis is typically performed under general anesthesia without regional or local anesthetic. External distraction is not used to avoid further disturbance to the edematous soft tissues in the region. Standard anteromedial and anterolateral ankle portals are used as described by Ferkel [35]. The use of lactated Ringer’s solution without impregnated antibiotics or antiseptics is well described and is our preference [1]. Use of 3 L unimpregnated lactated Ringer’s solution followed by 6 L impregnated with 50,000 units of Bacitracin powder per bag have also been described [34]. Antiseptics are discouraged when healthy cartilage remains due to concerns of chondrotoxicity [1]. A 2.7 mm or 4.0 mm arthroscope is utilized based on surgeon preference. The 4.0 mm arthroscope may allow for more timely debridement and quicker passing of fluid through the joint but may create difficulty in accessing the joint without distraction, particularly in the patient with osteoarthritis-related joint narrowing. When creating the standard portals for joint access, the anteromedial portal is established first followed by the anterolateral portal with the aid of transillumination (Fig. 9.4a). Intraoperative fluoroscopy can be utilized to help determine the appropriate level for portal placement, which is often more challenging in the septic ankle due to the degree of swelling and extensive internal joint derangement (Fig. 9.4b). When introducing the camera into the joint, difficulty visualizing the articular surface should be anticipated due to a commonly high degree of synovitis with pyarthrosis. The anterolateral portal is then made immediately lateral to the extensor digitorum longus tendon. Care is taken to avoid the intermediate dorsal cutaneous nerve, which can sometimes be visualized with transillumination. An alternate technique involves palpating the nerve on the unaffected limb as the location of this nerve is typically consistent on the contralateral limb [36]. A doppler ultrasound can be used to assess the location of the perforating peroneal artery which is often non-palpable (Fig. 9.4c). After inserting the camera into the medial portal and establishing a lateral portal, a shaver is placed in the anterolateral portal to assist in evacuating fluid for arthroscopic lavage of the joint. In order to maintain continuous egress of fluids, the shaver often needs to remain running as hypertrophied synovial tissue will otherwise obstruct a standard suction tip. High-volume joint lavage allows for arthroscopic inspection and debridement of hypertrophied synovial tissue while passing fluid through the joint. The surgeon should anticipate difficulty finding the shaver and visualizing the joint in advanced cases of joint sepsis. Because the anterior joint recess is frequently filled with hypertrophied tissue, initial blind debridement may be necessary while being careful to orient the shaver away from the articular surface (Fig. 9.5). At this time a pre-debridement synovial culture and biopsy are obtained.