PARTIAL VERSUS COMPLETE TRAPEZIECTOMY FOR TREATMENT OF CARPOMETACARPAL JOINT ARTHRITIS: A CADAVERIC BIOMECHANICAL COMPARISON

Purpose: We aimed to evaluate the stability of the thumb carpometacarpal joint following either complete removal of the trapezium(TR) or partial removal of the trapezium and of the base of the first metacarpal (PTR). We utilized local capsular tissue for interposition graft in both cases. Methods: Right and left fresh frozen cadaveric hands from the same donor were randomized so that TR or PTR repair was performed randomly on the right or left hand of each pair. In the TR group we removed the entire trapezium. In the PTR group we removed 2mm of distal trapezium and 2mm of thumb metacarpal base. For both repairs, we interposed a capsular tissue graft. The cadaveric hands were stabilized in a jig designed to apply load across six thumb tendons. We measured gap closure distances prior to and following surgery and examined the joints by radiograph. Distances were measured using the Hough Transform model for measurement of abstract shapes. In order to detect a difference in gap distances between groups of 2mm with an alpha error of 0.05 and a beta error of 0.20, 18 hands were required. Results: The designated surgery was successfully performed on all hands. At baseline, mean gap differences did not vary between groups under load, while after surgery the TR group had greater mean gap closure when compared to the PTR group (4.44mm±1.70 vs 2.42mm±1.92, P\u3c.001). No bone on bone contact was noted in any of the operated joints. Discussion: We found that PTR of the thumb basal joint leads to less gap closure of the joint when placed under simulated physiological load when compared to the complete removal of the trapezium. Clinical Relevance: Decreased gap closure under load may lead to preservation of thumb length and stability. Key words: Arthroplasty; thumb; carpometacarpal joints; trapezium; bone osteoarthriti

Comparison of the Accuracy of X-ray, 2D-CT, 3D-CT, and Physical Modeling in Classification of Fractures about the Elbow Needing Operative Treatment

The goal of this study is to compare the accuracy of using X-ray, 2D-CT, 3D-CT, and physical modeling in classification of fractures about the elbow as a means of evaluating their relative utility in preoperative workup and treatment planning of fractures. Ten patients with fractures about the elbow that required operative fixation underwent preoperative X-ray, 2D-CT, 3D-CT, and physical modeling of their injury. Ten orthopaedic physicians classified each injury using each of those four modalities. The answers given by the 10 physicians were compared to an established correct classification for each case, and that data was used to compare the relative accuracy of each modality. The average accuracy for the given modalities was 62% for X-ray, 76% for 2D-CT, 80% for 3D-CT, and 88% for physical modeling. ANOVA analysis across all modalities revealed findings are statistically significant; however, when compared side by side, only moving from X-ray to 2D-CT yielded significant results. There was greater percentage correct classification achieved using the more advanced modalities, which therefore may theoretically result in more accurate preoperative planning. However, one must view this finding within the context and limits of this study, which is restricted by the relatively small sample size. Future study into methods of fracture characterization should be done to further evaluate findings such as these, with the goal of promoting better patient outcomes

Nonunion After Hybrid Plating with Locking and Nonlocking Screws in Radius and Ulna Shaft Fractures: Report of Two Cases

Conventional compression plating has been found effective in treating forearm diaphyseal fractures, providing stability as well as resistance to axial, torsional, and bending forces. Locked plating has provided stability without frictional force between the bone-plate interface, which may help preserve periosteal blood supply, and is useful in treating metaphyseal, comminuted, and osteoporotic fractures. Hybrid plating has been used in an attempt to combine the strengths of these two techniques; however, in the context of simple forearm diaphyseal fractures with healthy bone, its effectiveness is only theoretical. We describe two patients in whom open reduction and internal fixation with hybrid plating to treat radius and ulna diaphyseal fractures resulted in nonunion. We performed a revision procedure using conventional compression plating and achieved full healing with complete union in both cases. These findings suggest that hybrid fixation for treating such fractures may not lead to better outcomes than conventional plating

Understanding Radiocarpal Rotation Through In Vivo Pronation and Supination of the Hand: A Single Case Study

Background: Studies have not clearly defined the motion of the distal radius in relation to the carpus in vivo. We hypothesized that 1) with the hand fixed by grasping a handle to prevent hand and wrist motion, the resulting load in torsion generated by extrinsic muscle in vivo would create motion at the radiocarpal joint; and 2) the motion measured will be between the distal radius and the proximal row of the carpus. Methods: The data was acquired from the senior author external to our institution; in the current study, we quantify the resulting radiocarpal motion. A K-wire was placed into the second metacarpal, and a second wire was placed in the distal radius. The shoulder was abducted to 90° and the hand was pronated, held stationary gripping a fixed object. The forearm was pronated and supinated to simulate radiocarpal rotation. Photographs were obtained at three points: 1) initial position showing the wire in vertical alignment; 2) same perspective in maximum internal radiocarpal rotation; and 3) same perspective in maximum external radiocarpal rotation. ImageJ (open source) was used to quantify the angle between the wires. Results: Superimposition of the three photographs in vivo allowed us to approximate two angle measurements. The measurements with maximal internal and external rotations were 16° and 24°, respectively. Conclusions: Radiocarpal rotation should be considered in addition to flexion and extension motions and radial ulnar deviations when treating degenerative changes in the wrist

Radiographic Prevalence of Osteoarthritis of the Scaphotrapeziotrapezoid Joint in Patients With Carpometacarpal Osteoarthritis of the Thumb: A Retrospective Case Series

Background: In planning operative treatment of thumb carpometacarpal (CMC) joint osteoarthritis, surgeons should consider the presence of an arthritic scaphotrapeziotrapezoid (STT) joint. We aimed to determine the radiographic prevalence of concomitant (STT) osteoarthritis with thumb CMC osteoarthritis in patients who underwent surgical treatment at our institution. We hypothesized that the prevalence of concomitant arthritis at these 2 joints (STT and CMC) would be lower than previously reported. Methods: Between September 2005 and July 2012, a total of 417 patients were identified from our institution using the Current Procedural Terminology code for thumb CMC joint arthroplasty (25447). After applying exclusion criteria and identifying patients who underwent treatment, a total of 194 patients were included and 218 preoperative radiographs were available for review. Each radiograph was categorized according to the Eaton classification of thumb CMC osteoarthritis, with stage 4 involving the (STT) joint. Evaluation was performed by four reviewers independently. Results: A total of 47 (21.6%) patients had varying degrees of concomitant (STT) joint osteoarthritis with the thumb CMC joint osteoarthritis. Stage 4 was reported in 6.4% (14) of the radiographs. Conclusions: The radiographic prevalence of concomitant (STT) osteoarthritis with thumb CMC osteoarthritis may be lower than previously reported. Further studies that include a similarly large sample size and additional radiographic views can help evaluate the likelihood of these conditions in patients who elect to undergo surgical treatment of thumb CMC osteoarthritis