Matthew I. Leibman

Quantitative 3-Dimensional CT Analyses of Intramedullary Headless Screw Fixation for Metacarpal Neck Fractures

PURPOSE Fixation countersunk beneath the articular surface is well accepted for periarticular fractures. Limited open intramedullary headless compression screw (HCS) fixation offers clinical advantages over Kirschner wire and open techniques. We used quantitative 3-dimensional computed tomography to assess the articular starting point, surface area, and subchondral volumes used during HCS fixation of metacarpal neck fractures. METHODS We simulated retrograde intramedullary insertion of 2.4- and 3.0-mm HCS and 1.1-mm Kirschner wires for metacarpal neck fracture fixation in 3-dimensional models from 16 adults. We used metacarpal head articular surface area (mm(2)) and subchondral volumes (mm(3)) and coronal and sagittal plane arcs of motion, during which we analyzed the center and rim of the articular base of the proximal phalanx engaging the countersunk entry site. RESULTS Mean metacarpal head surface area mated to the proximal phalangeal base in neutral position was 93 mm(2); through the coronal plane arc (45°) was 129 mm(2), and through the sagittal plane arc (120°) was 265 mm(2). The mean articular surface area used by countersunk HCS threads was 12%, 8%, and 4%, respectively, in each of these arcs. The 1.1-mm Kirschner wire occupied 1.2%, 0.9%, and 0.4%, respectively. Mean metacarpal head volume was 927 mm(3). Mean subchondral volume occupied by the countersunk portion was 4%. The phalangeal base did not overlap the dorsally located countersunk entry site through most of the sagittal plane arc. During coronal plane motion in neutral extension, the center of the base never engaged the dorsally located countersunk entry site. CONCLUSIONS Metacarpal head surface area and subchondral head volume occupied by HCS were minimal. Articular surface area violation was least during the more clinically relevant sagittal plane arc of motion. CLINICAL RELEVANCE The dorsal articular starting point was in line with the medullary canal and avoided engaging the center of the articular base through most of the sagittal plane arc. Three-dimensional computed tomography data support the use of an articular starting point for these extra-articular fractures.

Scaphoid Fracture in the Elite Athlete

Scaphoid fracture remains a common, potentially devastating, injury that can impair upper extremity function. Early recognition with proper imaging and treatment provides the best opportunity to heal and return to a normal activity level. Surgical treatment offers the patient a quicker return to the rehabilitation of the extremity and therefore an earlier return to elite play. There is evidence that healing occurs faster if the fractured scaphoid is fixed with internal fixation. Absolute compliance by the athlete and the training program that surrounds the athlete is critical to protect the wrist while maintaining the necessary conditioning of an elite athlete.

Headless bone screw fixation for combined volar lunate facet distal radius fracture and capitate fracture: case report.

We report a case of concomitant fractures of the volar lunate facet of the distal radius and capitate body. Surgical fixation was achieved with open reduction internal fixation using headless compression screws for both fractures. Because of the nature of complications seen after both operative and nonsurgical management, these fractures warrant particular attention.

Adductor pollicis jamming injuries in the professional baseball player: 2 case reports.

We characterize a mechanism of injury, injury pattern, and treatment algorithm for adductor pollicis myotendinous injuries in 2 professional baseball players. Similar to myotendinous eccentric injuries in other anatomical areas, the adductor pollicis sustains a sudden forceful eccentric load during a jammed swing, resulting in intramuscular strain or tendon rupture. Based on the reported injury mechanism, and magnetic resonance imaging features of these myotendinous injuries, the thumb of the top hand during a jammed swing was suddenly and forcefully eccentrically abducted from a contracted and adducted position, resulting in injury patterns.