Pitching mechanics, revisited.

UNLABELLED: The overhead pitching motion is described as a coordinated sequence of body movements and muscular forces that have an ultimate goal of achieving high ball velocity and target accuracy. An understanding of the dynamic overhead throwing motion outlined in this clinical commentary can assist the clinician in addressing the unique injuries experienced by the pitcher. The potential biomechanical sources for injury have been studied utilizing videography and electromyographic techniques due to the rapid pace with which the pitching motion occurs. This clinical comentary will describe what is widely accepted as the six phases of the pitching motion and the relationship to the kinetic chain theory as well as outline the common mechanical faults that can lead to increased tissue stress and potential injury. LEVEL OF EVIDENCE: 5.

Twelve-year follow-up on anterior cruciate ligament reconstruction: long-term outcomes of prospectively studied osseous and articular injuries.

BACKGROUND: Although successful at restoring near normal laxity to the knee in the short term, anterior cruciate ligament reconstructions have not been shown to prevent the development of posttraumatic arthritis. HYPOTHESIS: Bone bruises and articular cartilage injuries sustained at the time of initial injury (1991) would not resolve. Our secondary hypothesis was that the presence of a bone bruise or articular cartilage injury originally identified on magnetic resonance imaging would not be associated with long-term outcomes after anterior cruciate ligament reconstruction evaluated by the International Knee Documentation Committee questionnaire. STUDY DESIGN: Cohort study (prognosis); Level of evidence, 1. METHODS: We attempted to contact all patients from an original cohort (N = 54) for follow-up evaluation, which included repeat radiographs, magnetic resonance images, physical examination, and International Knee Documentation Committee questionnaire more than a decade postoperatively. RESULTS: Forty-four patients (82% of the original cohort) returned for on-site follow-up. No patient with a bone bruise identified on original magnetic resonance imaging had one identified at 12-year follow-up. The mean ( +/- SD) International Knee Documentation Committee score at follow-up with no bone bruise originally present was 70.6 ( +/- 12.7) versus 70.0 ( +/- 8.1) when a bone bruise was observed (P > .05). No consistent association was observed between the presence of an initial articular cartilage lesion with a lesion on follow-up magnetic resonance images. The mean ( +/- SD) International Knee Documentation Committee score at follow-up with no articular cartilage injury was 69.0 ( +/- 11.9) versus 72.8 ( +/- 12.0) with articular cartilage lesion (P > .05). CONCLUSION: All bone bruises identified in our study with magnetic resonance imaging at the time of initial injury had resolved at 12-year follow-up. The presence of a bone bruise at the time of initial injury did not significantly alter the patient-oriented outcome by International Knee Documentation Committee after anterior cruciate ligament reconstruction. Additionally, articular cartilage abnormality on magnetic resonance imaging did not influence the International Knee Documentation Committee score.