1
|
Tucker NJ, Stacey S, Kim YJ, DeLeon J, Richard R, Heare A, Mauffrey C, Parry JA. Variables Associated With Loss of Fixation of Retrograde Rami Screws in Minimally Displaced Lateral Compression Type 1 Pelvic Ring Injuries. J Orthop Trauma 2024; 38:215-219. [PMID: 38176888 DOI: 10.1097/bot.0000000000002756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 12/30/2023] [Indexed: 01/06/2024]
Abstract
OBJECTIVES To evaluate variables associated with loss of fixation of retrograde rami screws in the treatment of stress-positive minimally displaced lateral compression type 1 (LC1) injuries. METHODS DESIGN Retrospective comparative study. SETTING Level 1 trauma center. PATIENT SELECTION CRITERIA Stress-positive minimally displaced (<1 cm) LC1 pelvic ring injuries treated with retrograde rami screws. OUTCOME MEASURES AND COMPARISONS Loss of fixation, defined as >5 mm of pelvic fracture displacement based on the radiographic tear-drop distance or >5 mm of implant displacement on follow-up radiographs; revision surgery for loss of fixation. RESULTS Thirty-eight patients with 40 retrograde rami screws were analyzed. Median patient age was 64 years (interquartile range 42.5-73.3 years), 71.1% (n = 27/38) were female, and 52.6% (n = 20/38) of injuries were secondary to low-energy mechanisms. Loss of fixation occurred in 17.5% (n = 7/40) of screws with 10% (n = 4/40) requiring revision surgery. On univariate analysis, patients who had a loss of fixation were more likely to have greater dynamic displacement on stress radiographs (22.0 vs. 15.2 mm; median difference 5.6 mm, confidence interval [CI] -19.2 to 10.3; P = 0.04), unicortical rami screws (71.4% vs. 9.1%; proportional difference 62.3%, CI 8.8%-22.6%; P = 0.001), and partially threaded rami screws (71.4% vs. 21.2%; proportional difference 50.2%, CI 10.0%-77.6%; P = 0.01). The remaining variables had no observed association ( P ≥ 0.05) with loss of fixation, including age, sex, body mass index, energy of injury mechanism, tobacco use, American Society of Anesthesiologist score, sacral fracture type, distal rami fractures, rami comminution, number of sacral screws, fully threaded sacral screws, transsacral screws, or rami screw diameter. On multivariate analysis, only unicortical rami screws ( P = 0.01) remained associated with loss of fixation. CONCLUSIONS Retrograde rami screws had a high rate of loss of fixation in minimally displaced LC1 pelvic ring injuries, and this was associated with unicortical screws. These screws should be avoided when possible. LEVEL OF EVIDENCE Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Collapse
Affiliation(s)
- Nicholas J Tucker
- Department of Orthopaedics, Denver Health Medical Center, University of Colorado School of Medicine, Denver, CO
| | | | | | | | | | | | | | | |
Collapse
|
2
|
Saiz A, Lee C, DeKeyser G, Morellato J, Patterson J, Parry JA, Haller J, Marchand L, Wharton M, Tucker N, Kellam P, Shymon S, Warner S, Kim Y, Working Z. Fracture displacement of lateral compression type 1 (LC1) Pelvic Ring Injuries: Which measurement methods are reliable and does displacement correlate with adverse events? EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY & TRAUMATOLOGY : ORTHOPEDIE TRAUMATOLOGIE 2023:10.1007/s00590-023-03776-8. [PMID: 37991594 DOI: 10.1007/s00590-023-03776-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 10/26/2023] [Indexed: 11/23/2023]
Abstract
PURPOSE To determine the interobserver reliability of perceived displacement (PD) ≥ 1 cm of lateral compression type 1 (LC1) pelvic ring fractures and to determine if PD correlated with published methods of measuring fracture displacement and adverse events. METHODS The injury and follow-up radiographs of 10 patients with nonoperative minimally displaced LC1 injuries were reviewed by 27 orthopaedic trauma surgeons to determine if they perceived an interval fracture displacement ≥ 1 cm. Perceived displacement (PD) was compared to 11 measurements of displacement: the difference in heights of iliac crests (IC), sourcils, and ischial tuberosities on AP/outlet radiographs; the distance from femoral head (FH) to the sacral midline and the distance between the radiographic teardrops (TD) on the AP; the distance from the TD to sacral midline and the difference in distances between the SI joints and the contralateral TD on the inlet. The interobserver reliability and correlation of PD and measured displacement was calculated. The association between PD and adverse events was also evaluated. RESULTS PD had weak interobserver reliability (kappa = 0.46). Many of the measurements of displacement were poorly sensitive for PD. The magnification-corrected AP TD measurement had the highest sensitivity (100%) for PD and excellent interobserver reliability (Intraclass correlation 0.97), but had a low specificity (57.1%). All three patients with PD had adverse events while patients without PD had uneventful recoveries (p = 0.008). CONCLUSIONS The AP TD measurement detected all cases of PD and had excellent reliability. PD was associated with adverse events, suggesting that accurate and reliable measurements of displacement are warranted. LEVEL OF EVIDENCE III Diagnostic.
Collapse
|
3
|
Brostowitz NJ, Heimke IM, Furdock RJ, Vallier HA. Postmobilization Plain Radiography After Lateral Compression Type 1 Pelvic Ring Injury Does Not Affect Treatment. J Am Acad Orthop Surg Glob Res Rev 2023; 7:01979360-202311000-00005. [PMID: 37947428 PMCID: PMC10635594 DOI: 10.5435/jaaosglobal-d-23-00182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Accepted: 09/15/2023] [Indexed: 11/12/2023]
Abstract
INTRODUCTION The purpose of this study was to describe the practice of postmobilization radiography after lateral compression type 1 pelvis ring injury. We hypothesized that postmobilization radiographs would be more frequent over time and would not influence treatment. METHODS Displacement of pelvis ring injury on initial and final plain radiographs was measured. Frequency of postmobilization radiography was determined, and the impact on treatment and final radiographical outcome were assessed. RESULTS Of the 156 patients reviewed, 98 (62.8%) were women and mean age was 60.1 years. Thirty-three of 156 patients (21.2%) had a postmobilization radiograph. Over 5 years, radiographs increased to 67% of presenting patients. None of the patients who received postmobilization plain radiographs (n = 33) had any change in clinical plan afterward; all continued with nonsurgical care. Initial fracture characteristics and alignment were no different for patients with postmobilization radiographs. Final alignment was unchanged in nearly 70%. Overall, 74% of all nonsurgical patients experienced no change in alignment, with similar rates among the patients with postmobilization radiographs. DISCUSSION Patients with an lateral compression type 1 fracture demonstrated no changes in care after receiving postmobilization radiographs. However, the frequency of postmobilization radiographs increased over time, denoting opportunities to reduce costs and to improve efficiency and safety.
Collapse
|
4
|
Tucker NJ, Scott BL, Heare A, Stacey S, Mauffrey C, Parry JA. Early Outcomes of Operative Versus Nonoperative Management of Stress-Positive Minimally Displaced Lateral Compression Type 1 Pelvic Ring Injuries. J Orthop Trauma 2023; 37:506-512. [PMID: 37296089 DOI: 10.1097/bot.0000000000002642] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/30/2023] [Indexed: 06/12/2023]
Abstract
OBJECTIVES To compare the early outcomes of patients with stress-positive minimally displaced lateral compression type 1 (LC1b) pelvic ring injuries managed with or without operative fixation. DESIGN Retrospective comparison study. SETTING Level 1 trauma center. PATIENTS/PARTICIPANTS Forty-three patients with LC1b injuries. INTERVENTION Operative versus nonoperative. MAIN OUTCOME MEASUREMENTS Discharge to subacute rehabilitation (SAR); 2- and 6-week pain visual analog score, opioid use, assistive device use, percentage of normal single assessment numerical evaluation, SAR status; fracture displacement; and complications. RESULTS The operative group did not differ in age, gender, body mass index, high-energy mechanism, dynamic displacement stress radiographs, complete sacral fractures, Denis sacral fracture classification, Nakatani rami fracture classification, follow-up length, or American Society of Anesthesiologists classification. The operative group was less likely to be using an assistive device at 6 weeks [observed difference (OD) -53.9%, 95% confidence interval (CI) -74.3% to -20.6%, OD/CI 1.00, P = 0.0005], less likely to remain in an SAR at 2 weeks (OD -27.5%, CI, -50.0% to -2.7%, OD/CI 0.58, P = 0.02), and had less fracture displacement at follow-up radiographs (OD -5.0 mm, CI, -9.2 to -1.0 mm, OD/CI 0.61, P = 0.02). There were no other differences in outcomes between treatment groups. Complications occurred in 29.6% (n = 8/27) of the operative group compared with 25.0% (n = 4/16) of the nonoperative group resulting in 7 and 1 additional procedures, respectively. CONCLUSIONS Operative treatment was associated with early benefits over nonoperative management, including shorter time using assistive devices, less SAR use, and less fracture displacement at follow-up. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Collapse
Affiliation(s)
- Nicholas J Tucker
- Department of Orthopaedics, Denver Health Medical Center, University of Colorado School of Medicine, Denver, CO
| | | | | | | | | | | |
Collapse
|
5
|
Tucker NJ, Scott BL, Heare A, Stacey SC, Mauffrey C, Parry JA. Nonoperative management of minimally displaced lateral compression type 1 (LC1) injuries with comminuted rami fractures is associated with late displacement. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY & TRAUMATOLOGY : ORTHOPEDIE TRAUMATOLOGIE 2023:10.1007/s00590-023-03646-3. [PMID: 37542555 DOI: 10.1007/s00590-023-03646-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Accepted: 07/11/2023] [Indexed: 08/07/2023]
Abstract
PURPOSE Rami comminution has been found to be predictive of lateral compression type 1 (LC1) injury instability on examination under anesthesia (EUA) and lateral stress radiographs (LSR). The purpose of this study was to evaluate how rami comminution and subsequent operative vs. nonoperative management impact the late displacement of these injuries. METHODS Retrospective review of a prospectively collected LC1 database was performed to identify all patients with minimally displaced LC1 injuries (< 1 cm) and follow-up radiographs over a four-year period (n = 125). Groups were separated based on the presence of rami comminution and subsequent management, including rami comminution/operative (n = 49), rami comminution/nonoperative (n = 54), and no comminution/nonoperative (control group, n = 22). The primary outcome was late fracture displacement, analyzed as both a continuous variable and as late displacement ≥ 5 mm. RESULTS As a continuous variable, late fracture displacement was lower in the comminuted rami/operative group as compared to the comminuted rami/nonoperative group (PD: -3.0 mm, CI: -4.8 to -1.6 mm, p = 0.0002) and statistically non-different from control. Late displacement ≥ 5 mm was significantly more prevalent in the comminuted rami/nonoperative group than in the comminuted rami/operative and no comminution/nonoperative groups (control)(PD: -33.9%, CI: -49.0% to -16.1%, p = 0.0002 and PD: -30.0%, CI: -48.2% to -6.5%, p = 0.02, respectively). CONCLUSION Late fracture displacement was greatest in the group with rami comminution/nonoperative management. Rami comminution, which has been previously associated with dynamic displacement on EUA and LSR, is also associated with a higher incidence of late displacement when managed nonoperatively. LEVEL OF EVIDENCE Level III, prognostic retrospective cohort study.
Collapse
Affiliation(s)
- Nicholas J Tucker
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Bryan L Scott
- Department of Orthopedic Surgery, Massachusetts General Hospital, Boston, MA, USA
| | - Austin Heare
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Stephen C Stacey
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Cyril Mauffrey
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Joshua A Parry
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA.
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA.
| |
Collapse
|
6
|
Tucker NJ, Scott B, Mauffrey C, Parry JA. Geriatric Patients Presenting With Isolated Pubic Rami Fractures and Inability to Mobilize May Have Occult Lateral Compression Pelvic Ring Injuries With Dynamic Instability. J Orthop Trauma 2023; 37:356-360. [PMID: 36696401 DOI: 10.1097/bot.0000000000002576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/20/2023] [Indexed: 01/26/2023]
Abstract
OBJECTIVES To determine the incidence of patients with isolated pubic rami fractures on computed tomography scans who have dynamic instability secondary to occult lateral compression pelvic ring injuries. DESIGN Retrospective comparison study. SETTING Urban level 1 trauma center. PATIENTS/PARTICIPANTS This study included geriatric patients with isolated pubic rami fractures and inability to mobilize secondary to pain. INTERVENTION Lateral stress radiographs of pelvis to evaluate for ≥1 cm dynamic instability. MAIN OUTCOME MEASUREMENTS Physical therapy clearance, hospital length of stay, and discharge location. RESULTS A total of 19 patients were identified over 12 months. Patients were predominantly geriatric (median age: 75 years, interquartile range: 67 to 90), woman (11/19), with unilateral (17/19) comminuted distal rami fractures (12/19) sustained in ground-level falls (12/19). Dynamic instability was identified in 42% of patients (8/19). Magnetic resonance imaging, obtained in 6 of these patients, demonstrated occult posterior ring fractures in all cases. Patients with dynamic instability were more likely to have comminuted distal rami fractures (Nakatani type 1b) and a longer hospital length of stay. There was also a trend for these patients to be unable to clear physical therapy by discharge (63% (5/8) versus 36% (4/11)). The 90-day mortality rate of the cohort was 16% (3/19). CONCLUSIONS Patients presenting with seemingly isolated pubic rami fractures on radiographs and computed tomography scans who are unable to mobilize may have occult lateral compression injuries with dynamic instability. LEVEL OF EVIDENCE Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Collapse
Affiliation(s)
- Nicholas J Tucker
- Department of Orthopaedics, Denver Health Medical Center, University of Colorado School of Medicine, Denver, CO
| | | | | | | |
Collapse
|
7
|
Tucker NJ, Scott BL, Heare A, Stacey SC, Mauffrey C, Parry JA. Combined Anterior-Posterior versus Posterior-Only Fixation of Stress-Positive Minimally Displaced Lateral Compression Type 1 (LC1) Pelvic Ring Injuries. J Orthop Trauma 2023; 37:189-194. [PMID: 36395075 DOI: 10.1097/bot.0000000000002519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 11/07/2022] [Indexed: 11/18/2022]
Abstract
OBJECTIVES To compare hospital outcomes and late displacement between stress-positive minimally displaced lateral compression type 1 (LC1) pelvic ring injuries treated with combined anterior-posterior versus posterior-only fixation. DESIGN Retrospective comparative cohort. SETTING Urban level-one trauma center. PATIENTS/PARTICIPANTS LC1 injuries managed operatively. INTERVENTION Anterior-posterior versus posterior-only fixation. MAIN OUTCOME MEASUREMENTS Physical therapy (PT) clearance, discharge location, hospital length of stay (LOS), inpatient morphine equivalent doses (MED), and fracture displacement at follow-up. RESULTS Groups were similar in demographic and injury characteristics (age, high energy mechanism, ASA score, stress displacement, and rami/sacral fracture classifications). Anterior-posterior fixation resulted in longer operative times (median difference (MD): 27.0 minutes, 95% confidence interval (CI): 17.0 to 40.0, P < 0.0001) and had a trend of increased estimated blood loss (MD: 10 mL, CI: 0 to 30, P = 0.07). Patients with anterior-posterior fixation required less inpatient MEDs (MD: -180.0, CI: -341.2 to -15.0, P = 0.02), were more likely to clear PT by discharge (100% vs. 70%, proportional difference (PD): 30%, CI: 2.0%-57.2%, P = 0.02), were less likely to discharge to rehabilitation facilities (0% vs. 30%, PD: 30%, CI: 2.0%-57.2%, P = 0.02), and had a trend of less days to clear PT after surgery (MD: -1, CI: -2 to 0, P = 0.09) and decreased LOS (MD: -1, CI: -4 to 1, P = 0.17). Late fracture displacement did not differ between groups. CONCLUSION Anterior-posterior fixation of LC1 injuries was associated with an improved early hospital course-specifically, reduced inpatient opioid use and an increased number of patients who could clear PT and discharge home. LEVEL OF EVIDENCE Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
Collapse
Affiliation(s)
- Nicholas J Tucker
- Department of Orthopedics, Denver Health Medical Center, Denver, CO
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO
| | - Bryan L Scott
- Department of Orthopedics, Denver Health Medical Center, Denver, CO
| | - Austin Heare
- Department of Orthopedics, Denver Health Medical Center, Denver, CO
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO
| | - Stephen C Stacey
- Department of Orthopedics, Denver Health Medical Center, Denver, CO
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO
| | - Cyril Mauffrey
- Department of Orthopedics, Denver Health Medical Center, Denver, CO
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO
| | - Joshua A Parry
- Department of Orthopedics, Denver Health Medical Center, Denver, CO
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO
| |
Collapse
|
8
|
Tucker NJ, Heare A, Stacey SC, Mauffrey C, Parry JA. The lateral stress radiograph: an effective alternative to examination under anesthesia for identifying occult instability in minimally displaced lateral compression pelvic ring injuries. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY & TRAUMATOLOGY : ORTHOPEDIE TRAUMATOLOGIE 2022:10.1007/s00590-022-03373-1. [PMID: 36056970 DOI: 10.1007/s00590-022-03373-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
PURPOSE The purpose of this study was to review the practice of utilizing lateral stress radiographs (LSRs) to identify occult instability (≥ 10 mm of dynamic displacement on LSRs) of minimally displaced lateral compression type 1 (LC1) pelvic ring injuries and to evaluate for associations between instability and patient demographics, injury characteristics, and hospital course. METHODS A retrospective review of a prospective registry from 2018 to 2022 identified 151 patients with LC1 injuries. LSRs were obtained in 86.8% (131/151) of patients. Three (2.2%) patients were excluded for malrotation of LSRs, leaving 128 patients for analysis. RESULTS The median maximum dynamic displacement on LSRs was 12.2 mm (IQR: 5.9 to 17.3). Occult instability was present in 62.5% (80/128) of patients and was associated with older age (Median difference 11.0 years, 95% CI 3.0 to 20.0), Nakatani type 1 rami fractures (73.7% vs. 47.9%, p = 0.001), and rami fracture comminution (Proportional difference 58.7%, 95% CI 42.8 to 71.3%), but not gender, high-energy mechanism, bilateral rami fractures, Denis classification, sacral fracture completeness, or sacral comminution. Patients with occult instability took longer to ambulate 15 feet and clear physical therapy (PT), were more likely to be unable to clear PT by hospital day 3 or by time of discharge, had longer hospital stays, and were more likely to require rehabilitation facilities. CONCLUSION LSRs were obtained in a majority of patients. Occult instability was frequently present and associated with older age, comminuted distal pubic rami fractures, longer hospital stays, longer times to mobilize and clear PT, and an increased need for rehabilitation facilities.
Collapse
Affiliation(s)
- Nicholas J Tucker
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, Denver, CO, MC 0188, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Austin Heare
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, Denver, CO, MC 0188, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Stephen C Stacey
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, Denver, CO, MC 0188, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Cyril Mauffrey
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, Denver, CO, MC 0188, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Joshua A Parry
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, Denver, CO, MC 0188, USA.
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA.
| |
Collapse
|
9
|
Tucker NJ, Scott BL, Heare A, Stacey SC, Mauffrey C, Parry JA. The effect of pelvic ring rotation and tilt on the radiographic teardrop distance: an important consideration in the assessment of dynamic displacement on stress radiographs. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY & TRAUMATOLOGY : ORTHOPEDIE TRAUMATOLOGIE 2022:10.1007/s00590-022-03377-x. [PMID: 36048261 DOI: 10.1007/s00590-022-03377-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 08/22/2022] [Indexed: 06/15/2023]
Abstract
PURPOSE The purpose of this study was to determine the effect of rotation and tilt on the radiographic teardrop distance (TD) on anteroposterior (AP) pelvis radiographs. METHODS Radiographic examination of a pelvis models was conducted utilizing increasing degrees of beam rotation and tilt on portable C-arm fluoroscopy. The TD, x-plane rotation (symphyseal-mid-sacrum distance (SMS)), and y-plane tilt (sacroiliac joint-symphysis distance (SIS)) were measured by four independent observers. Interobserver reliability was assessed using intraclass correlations. RESULTS TD was altered by less than 2 mm with up to 7.5° fluoroscopic rotation (SMS: 3 cm) and up to 30° of inlet and 15° of outlet (SIS: ± 3.3 cm). SMS distance effectively corresponded to the degree of rotation present (r = 1.00, CI: 0.97 to 1.00, p < 0.0001) and was strongly correlated to TD (r = -0.95, CI: -0.99 to -0.67, p = 0.001). SIS distance effectively corresponded to the degree of tilt present (r = -0.97, CI: -0.99 to -0.88, p < 0.0001) and was correlated to TD (r = 0.94, CI: 0.75 to 0.99, p = 0.0001). Linear regression models determined that, with every degree of rotation and tilt, TD was altered by 0.4 mm and 0.09 mm, respectively (p = 0.0004, r2 = 0.93 and p < 0.0001, r2 = 0.94, respectively). Interobserver reliability among observers was excellent (0.92). CONCLUSION The TD has excellent interobserver reliability and is minimally impacted by up to 7.5° of rotation, 30° inlet tilt, and 15° of outlet tilt. Utilization of these thresholds may ensure reliability of TD measurements when assessing pelvis stress radiographs.
Collapse
Affiliation(s)
- Nicholas J Tucker
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Bryan L Scott
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
| | - Austin Heare
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Stephen C Stacey
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Cyril Mauffrey
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA
| | - Joshua A Parry
- Department of Orthopedics, Denver Health Medical Center, 777 Bannock St, MC 0188, Denver, CO, 80204, USA.
- Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA.
| |
Collapse
|