Capsular distension in high-energy femoral shaft fractures is associated with occult femoral neck fracture: a preliminary retrospective comparative study.

OBJECTIVES: To determine the association between hip capsular distension, the computed tomography (CT) capsular sign, and lipohemarthrosis as they relate to occult femoral neck fracture (FNF) in the setting of ipsilateral femoral shaft fracture (FSF). DESIGN: Retrospective comparative study. SETTING: Level 1 trauma center. PATIENTS/PARTICIPANTS: Two hundred and forty-two patients with high-energy FSF and no evidence of FNF on preoperative radiographs and pelvis CT. All patients were stabilized with non-reconstruction style nails. INTERVENTION: Pelvis CT scans were examined for hip capsular distension irrespective of the other side, differing side-to-side measurements of capsular distension (i.e., the CT capsular sign), and lipohemarthrosis. MAIN OUTCOME MEASUREMENTS: FNF was observed for on postoperative radiographs. Relative risk (RR), number needed to treat (NNT), sensitivity (SN), and specificity (SP) were determined. RESULTS: Fifty-eight patients (24.0%) had capsular distension. Forty-two patients (17.4%) had differing capsular measurements (i.e., the CT capsular sign), and 16 (6.6%) had symmetrical distension from bilateral hip effusions. Eight patients (3.3%) had lipohemarthrosis. Four FNFs (1.7%) were identified. Three patients had capsular distension, 2 had CT capsular signs, and 1 had lipohemarthrosis. The last patient had no CT abnormalities. Only capsular distension (RR = 10, CI = 1.001-90, P = 0.049; SN = 75%, SP = 77%; NNT = 22) and lipohemarthrosis (RR = 23, CI = 1.6-335, P = 0.022; SN = 50%, SP = 96%; NNT = 8) were associated with occult FNF. CONCLUSIONS: Capsular distension is associated with FNF irrespective of the contralateral hip. Preemptive stabilization using a reconstruction nail could be considered in the setting of capsular distension or lipohemarthrosis to prevent displacement of an occult FNF. LEVEL OF EVIDENCE: Diagnostic Level III.

Evaluation of Appropriate Venous Thromboembolism Prophylaxis in Patients With Orthopaedic Trauma With Symptom-Driven Vascular and Radiographic Studies.

OBJECTIVE: To evaluate venous thromboembolism (VTE) prophylaxis adherence and effectiveness in orthopaedic trauma patients who had vascular or radiographic studies showing deep vein thromboses or pulmonary emboli. DESIGN: Retrospective review. SETTING: A level I trauma center that independently services a 5-state region. PATIENTS: Four hundred seventy-six patients with orthopaedic trauma who underwent operative treatments for orthopaedic injuries and had symptom-driven diagnostic VTE studies. INTERVENTION: The medical records of patients treated surgically between July 2010 and March 2013 were interrogated using a technical tool that electronically captures thrombotic event data from vascular and radiologic imaging studies by natural language processing. MAIN OUTCOME MEASUREMENTS: Patients were evaluated for hospital guideline-directed VTE prophylaxis adherence with mechanical or chemical prophylaxis. Patient demographics, associated injuries, mechanism of injury, and symptoms that led to imaging for a VTE were also assessed. RESULTS: Of the 476 orthopaedic patients who met inclusion criteria, 100 (mean age 52.3 median 52, SD 18.3, 70% men) had positive VTE studies. Three hundred seventy-six (age 47.3, SD 17.3, 69% men) had negative VTE studies. Of the 100 patients with VTE, 63 deep vein thromboses, and 49 pulmonary emboli were found. Eight-five percent of all patients met hospital guideline-VTE prophylaxis standards. CONCLUSION: The study population had better than previously reported VTE prophylaxis adherence, however, patients still developed VTEs. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Iatrogenic syndesmosis malreduction via clamp and screw placement.

OBJECTIVES: The purpose of this study was to assess the impact of variations in angulation of clamp placement to hold syndesmotic reduction and how subsequent syndesmotic screw placement affects malreduction of the syndesmosis. We hypothesized that an anatomic syndesmosis reduction cannot be reliably achieved with a clamp alone; and, inaccurate placement of intraoperative clamps and trans-syndesmotic screws after reduction can malreduce the ankle syndesmosis. METHODS: After computed tomography scanning of the intact limbs, 14 cadaver legs were dissected; the syndesmosis was completely disrupted in all. Using planned drill holes, clamps were first placed at 0°, 15°, and 30° angles from the fibula, then separate posterolateral, followed by lateral, screws were placed. After each intervention, the limb had a computed tomography scan so the fibular reduction could be evaluated precisely. RESULTS: Clamps placed at 15° and 30° significantly displaced the fibula in external rotation and caused significant overcompression of the syndesmosis. Thirty-degree lateral screws caused significant anteromedial displacement, external rotation, and overcompression of the syndesmosis. The 15° posterolateral screws also caused significant external rotation and overcompression of the syndesmosis. CONCLUSIONS: Our study demonstrates that intraoperative clamping and fixation can cause statistically significant malreduction of the syndesmosis. This article should alert clinicians that clamp and screw placement can cause iatrogenic malreduction of the syndesmosis and make them aware that these dangers occur with specific clamp and screw angles in particular.

The effect of suture fixation of type I coronoid fractures on the kinematics and stability of the elbow with and without medial collateral ligament repair.

The objective of this study was to determine the effect of suture repair of type 1 coronoid fractures on elbow kinematics in ligamentously intact and medial collateral ligament (MCL)-deficient elbows. Cadaveric testing was performed in stable and MCL-deficient elbows with radial head arthroplasty and with the coronoid intact, with the coronoid fractured, and after suture repair. Ulna versus humerus angulation was measured during active motion. Varus and valgus motion pathways were measured during passive gravity-loaded flexion. With intact ligaments, there was a small increase in valgus angulation after a type 1 fracture that was not corrected with suture fixation. With MCL deficiency, there was no change in kinematics regardless of coronoid status. Type 1 coronoid fractures cause only small changes in elbow kinematics that are not corrected with suture repair. MCL repair, rather than type 1 coronoid fixation, should be considered if the elbow remains unstable after radial head repair or replacement and lateral ligament repair.

Kinematics and stability of the fractured and implant-reconstructed radial head.

Controversy exists as to the optimal management of radial head fractures. Biomechanical studies have been conducted to quantify elbow stability for simulated wedge fractures, head excision, and head replacement, with and without the integrity of the collateral ligaments. Our in vitro studies have demonstrated that in the ligamentously intact elbow, kinematics and stability are slightly altered with simulated depressed wedge fractures up to 120 degrees of the radial head, markedly altered with head resection, and improved after radial head replacement. Radial head excision decreases elbow stability in the ligament-deficient elbow, and radial head replacement improves stability similar to that of the native radial head. The ligaments have the most marked influence on stability, particularly when the upper limb is positioned such that valgus and varus gravity loads are applied to the elbow. Whereas the radial head acts as a secondary stabilizer to the collateral ligaments with the arm in these positions, its relative role is greater when the arm is in the dependent position and elbow flexion is simulated, particularly in extension. Further studies are needed to elucidate the complex interaction of the radial head with the capitellum, the ulnohumeral joint, and the ligamentous structures for different activities of daily living.

The effect of radial head excision and arthroplasty on elbow kinematics and stability.

BACKGROUND: Radial head fractures are common injuries. Comminuted radial head fractures often are treated with radial head excision with or without radial head arthroplasty. The purpose of the present study was to determine the effect of radial head excision and arthroplasty on the kinematics and stability of elbows with intact and disrupted ligaments. We hypothesized that elbow kinematics and stability would be (1) altered after radial head excision in elbows with intact and disrupted ligaments, (2) restored after radial head arthroplasty in elbows with intact ligaments, and (3) partially restored after radial head arthroplasty in elbows with disrupted ligaments. METHODS: Eight cadaveric upper extremities were studied in an in vitro elbow simulator that employed computer-controlled actuators to govern tendon-loading. Testing was performed in stable, medial collateral ligament-deficient, and lateral collateral ligament-deficient elbows with the radial head intact, with the radial head excised, and after radial head arthroplasty. Valgus angulation and rotational kinematics were determined during passive and simulated active motion with the arm dependent. Maximum varus-valgus laxity was measured with the arm in a gravity-loaded position. RESULTS: In specimens with intact ligaments, elbow kinematics were altered and varus-valgus laxity was increased after radial head excision and both were corrected after radial head arthroplasty. In specimens with disrupted ligaments, elbow kinematics were altered after radial head excision and were similar to those observed in specimens with a native radial head after radial head arthroplasty. Varus-valgus laxity was increased after ligament disruption and was further increased after radial head excision. Varus-valgus laxity was corrected after radial head arthroplasty and ligament repair; however, it was not corrected after radial head arthroplasty without ligament repair. CONCLUSIONS: Radial head excision causes altered elbow kinematics and increased laxity. The kinematics and laxity of stable elbows after radial head arthroplasty are similar to those of elbows with a native radial head. However, radial head arthroplasty alone may be insufficient for the treatment of complex fractures that are associated with damage to the collateral ligaments as arthroplasty alone does not restore stability to elbows with ligament injuries.

The effect of radial head fracture size on radiocapitellar joint stability.

OBJECTIVE: The purpose of this study was to determine the effect of radial head fracture size on radiocapitellar stability. DESIGN: Repeated measures using Instron materials testing machine. BACKGROUND: Radial head fractures are common injuries and controversy exists as to the optimal management of displaced wedge fractures. METHODS: Fractures were simulated in six fresh-frozen cadaveric radiocapitellar joints by removing sequential 20 degree wedges from the anterolateral aspect of each radial head until 140 degrees of the radial head was removed. Decreased shear load at the radial head during joint loading was used as an indicator of decreased stability at the radiocapitellar joint. Using a custom designed jig and employing a compressive joint load of 100 N, the maximum shear load at the radiocapitellar joint was measured at 30, 60, 90 and 120 degrees of elbow flexion. RESULTS: There was no difference in the shear load between the intact specimen and that with a 20 degree wedge removed at all flexion angles (P>0.05). Shear load decreased with each increase in wedge size between 20 and 120 degrees (P<0.05). After 120 degrees, one-third the diameter of the radial head, the shear load was always less than 0.8 N. CONCLUSIONS: This study demonstrated an inverse relationship between radiocapitellar joint stability and radial head fracture size. RELEVANCE: Small radial head fracture fragments are biomechanically significant. Therefore, the use of an arbitrary fragment size as an indication for surgery should be reconsidered, particularly if there is an associated ligamentous injury.