Determination of radiographic guidelines for percutaneous fixation of proximal humerus fractures using a cadaveric model.

The humeral heads of whole body cadaveric shoulders underwent fluoroscopic evaluation with the head divided into three zones on both anteroposterior (AP) and axillary views creating nine zones. Five AP and three axillary fluoroscopic images in different rotational positions were assessed for pin penetration. All images were evaluated for pin penetration and the AP view was evaluated for lesser tuberosity location. Pins placed appropriately below the subchondral bone did not appear to penetrate the joint on any fluoroscopic image. Pins placed 2 mm beyond the articular surface were appropriately viewed exiting the head on most views (64%) but falsely appeared within the head on several others (36%). Pins perforating the posterior head were problematic for accurate detection on AP views (missed in 87%), but this was avoided by externally rotating the humerus to 60 degrees. Articular penetration cannot always be appreciated radiographically and special efforts are necessary to avoid this problem including the use of various rotational views as well as the use of appropriate landmarks for orientation such as the lesser tuberosity position.

Biomechanical evaluation of 2 techniques for ulnar collateral ligament reconstruction of the elbow.

BACKGROUND: Elbow medial ulnar collateral ligament tears often result in pain and instability that may be career threatening in overhead-throwing athletes. Surgical reconstruction is frequently chosen to treat this injury. Ulnar collateral ligament reconstruction as described by Jobe is the most commonly used technique. Testing of this construct has not demonstrated that the biomechanical parameters of the native ligament are restored. A more recent construct, the docking technique, may more reliably reproduce these factors. HYPOTHESIS: Increasing the number of strands of palmaris longus tendon graft used in ulnar collateral ligament reconstruction and tensioning them using the docking technique result in a construct with improved biomechanical parameters as compared with the Jobe technique. STUDY DESIGN: Controlled laboratory study. METHODS: Thirty-three fresh-frozen human cadaveric elbows were randomized into 3 subgroups: Jobe (11), docking (12), and native (10). The Jobe and docking groups underwent reconstruction using their described palmaris tendon graft constructs. The ulnar collateral ligament was left intact in the native group. Elbows were potted and tested using a servohydraulic materials testing machine to apply a valgus moment at 30 degrees of elbow flexion. Maximal moments to failure, stiffness, and strain at maximal moment and with a 3 N.m force applied were determined using a 2-camera motion analysis system to track reflective markers spanning the site. RESULTS: The docking (14.3 N.m) and native (18.8 N.m) subgroups resulted in higher maximal moment to failure than did the Jobe (8.9 N.m) subgroup (P < .001). There was no significant difference between native and docking groups (P > .05). Native ligaments were stiffer (301.4 N.m) than were Jobe (74.3 N.m) or docking (80.8 N.m; P < .001). Native ligaments demonstrated lower strain at maximal force (0.087 mm/mm) and 3 N.m forces (0.030 mm/mm) than did the Jobe (0.198/0.057 mm/mm) or docking (0.287/0.042 mm/mm) subgroups. There was no difference in stiffness or strain between the Jobe and docking subgroups (P > .05). CONCLUSION: Neither technique reproduced the biomechanical profile of the native ulnar collateral ligament; the findings of this study suggest that the docking construct may offer initial biomechanical advantage over the Jobe construct.

Reliability and reproducibility of radiographs of greater tuberosity displacement. A cadaveric study.

BACKGROUND: Classification of fractures of the greater tuberosity has shown poor reliability, in part as a result of an inability to assess fracture displacement accurately. We used fluoroscopic images of prepositioned osteotomized greater tuberosity fragments in cadavers to determine the accuracy of radiographic interpretation, the interobserver reliability, and the effect that radiographs might have on surgical decision-making. METHODS: Twelve osteotomies of the greater tuberosity (three each with 2, 5, 10, and 15 mm of displacement) were created in whole-body cadavers. Six fluoroscopic images (anteroposterior views in external and internal rotation, anteroposterior views in neutral rotation with 15 degrees of cephalic and 15 degrees of caudal tilt, a lateral outlet view, and an axillary view) were made after each osteotomy. Four experienced orthopaedic surgeons measured displacement in millimeters on seventy-two randomized images. Four views in sequence (the anteroposterior view in internal rotation and the outlet view together, then the axillary view, and then the anteroposterior view in external rotation) of each osteotomy pattern were then viewed, and each surgeon was asked whether surgery would be indicated on the basis of each set of images. RESULTS: No one fluoroscopic view was significantly more accurate than another. There was a trend toward increased accuracy of imaging of minimally displaced (

Functional outcome after centralization for radius dysplasia.

Centralization for radius dysplasia purportedly offers a more normal appearance, provides length to a shortened forearm, and improves upper-extremity function. Limited objective outcome data, however, exist to substantiate its use. To better define functional status after centralization, the Jebsen-Taylor hand test and the Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) were administered to 21 patients (25 wrists) at an average of 20 years after surgery. Jebsen-Taylor scores, a measure of hand function, were significantly altered with an average total score of 48 seconds compared with an average normal score of 30 seconds (62% increase). The DASH questionnaire, a measure of upper-extremity function, showed only a mild disability of 18%. These long-term follow-up data show that hand function remains markedly abnormal while upper-extremity disability is mild. Improved wrist alignment and increased ulna length did not correlate with improved upper-extremity function.