A 37-year-old, right-handed woman presents 5 days after wounding her index finger on a sharp metal edge while cleaning her outdoor grill. She reports only local pain from the injury in the first 2 days, followed thereafter by progressive increases in pain, swelling, redness, and immobility of the digit. The wound is less than 1 cm, oblique, and located at the proximal interphalangeal flexion crease. The finger is moderately swollen and faintly erythematous throughout its length, held in a position of midrange flexion. She is intolerant to passive end range flexion or extension. She is tender along the flexor sheath.