Epidemiology, Management, and Outcomes of Large and Small Native Joint Septic Arthritis in Adults.

BACKGROUND: Native joint septic arthritis (NJSA) is poorly studied. We describe the epidemiology, treatment, and outcomes of large joint NJSA (LNJSA) and small joint NJSA (SNJSA) in adults at Middlemore Hospital, Auckland, New Zealand. METHODS: This was a coding-based retrospective study of patients ≥16 years old admitted between 2009 and 2014. Prosthetic joint infections were excluded. RESULTS: Five hundred forty-three NJSA episodes were included (302 LNJSA, 250 SNJSA). Only 40% had positive synovial fluid culture. Compared to SNJSA, LNJSA has higher incidence (13 vs 8/100 000 person-years [PY]), occurs in older, more comorbid patients, and is associated with greater rates of treatment failure (23% vs 12%) and mortality, despite longer antibiotic treatment. Total incidence is higher than previously reported (21/100 000 PY), with marked interethnic variation. Incidence rises with age (LNJSA only) and socioeconomic deprivation (LNJSA and SNJSA). Tobacco smokers and males are overrepresented. The most commonly involved joints were knee (21%) and hand interphalangeal (20%). Staphylococcus aureus was the most common pathogen (53%). Mean antibiotic duration was 25 days for SNJSA and 40 days for LNJSA, and the mean number of surgical procedures was 1.5 and 1.6, respectively. Treatment failure was independently associated with LNJSA, age, intra-articular nonarthroplasty prosthesis, and number of surgical procedures. CONCLUSIONS: This is the largest contemporary series of adult NJSA. SNJSA has better outcomes than LNJSA and may be able to be safely treated with shorter antimicrobial courses. Incidence is high, with significant ethnic and socioeconomic variation. Microbiological NJSA case ascertainment underestimates case numbers as it frequently excludes SNJSA.

Fate of the infrapatellar branch of the saphenous nerve post total knee arthroplasty.

BACKGROUND: The infrapatellar branch of the saphenous nerve is a known cause of morbidity following knee surgery. The incidence of sensory changes following total knee arthroplasty, and its effect on patient satisfaction with arthroplasty surgery remain undocumented. Our aim was to document the incidence of infrapatellar nerve palsy following total knee arthroplasty and its effect on patient satisfaction. METHODS: Between 1 January 2002 and 31 December 2003 all patients attending outpatients clinic for primary total knee joint arthroplasty were prospectively tested for sensory defects. Patients were then assessed postoperatively and satisfaction was measured using the British Orthopaedic Satisfaction Score and a visual analogue scale. RESULTS: Thirty-one patients satisfied inclusion criteria of which 21 agreed to participate. One patient was excluded later in the study leaving 20 patients. Seventy per cent of patients had sensory changes in the area supplied by the infrapatellar branch of the saphenous nerve. Patient satisfaction scores did not correlate to the presence of a sensory deficit. Two patients stated that the sensory deficit was a significant factor in their dissatisfaction with their arthroplasty surgery. CONCLUSIONS: Sensory changes due to damage to the infrapatellar branch of the saphenous nerve during total knee joint arthroplasty is a common occurrence and can interfere with patient satisfaction. Patients should be informed of this risk in the preoperative discussion.

Radiologic landmark accuracy for optimum coronal placement of total disc arthroplasty in the lumbar spine.

OBJECTIVE: This study was performed to determine which of the radiographic markers visible on an anteroposterior (AP) radiograph of the spine-the vertebral body, the pedicles, and the spinous process-provided the most accurate guide to correctly placing an intervertebral disc replacement in the coronal midline. METHOD: The coronal midline was defined as the perpendicular bisector of a line drawn between the midpoints of the two facet joints. Axial CT images were reconstructed from 35 abdominal and renal computed tomograms to compare how consistently the midpoints of the above structures fell on the coronal midline. RESULTS: The mean distance (SD) from the vertebral body midpoint, the interpedicular midpoint, and the spinous process midpoint from the coronal midline, respectively, were 0.55 mm (SD 0.45 mm), 0.19 mm (SD 0.40 mm), and 1.30 mm (SD 1.30 mm). Sixteen percent of the distances from the coronal midline to the spinous process midpoint were greater than or equal to 3 mm compared with 0% of the distances to the interpedicular midpoint or the vertebral body midpoint. CONCLUSIONS: We concluded that the interpedicular midpoint is the most accurate guide to the coronal midline. We recommend that this landmark be used in preference to the spinous processes or the midpoint of the vertebral bodies when placing the implant in intervertebral disc arthroplasty.