The on-call orthopaedic surgeon is faced with a wide array of orthopaedic pathology for which intra-articular aspiration, injection, and/or nerve/hematoma block may be used. Efficient use of these diagnostic and therapeutic modalities affords better patient care and a more effective on-call period. Often, these interventions are the rate limiting factor in a reduction or diagnosis. In this review, we describe joint aspirations, saline load tests, hematoma blocks, and nerve blocks in detail to include their indications, techniques, related pharmacology, pearls, and pitfalls.