Comparison between clinical and radiologic outcome measures after reconstruction of acetabular fractures

Low interobserver and intraobserver reliability using the Matta radiographic system for intraoperative assessment of reduction following acetabular ORIF

INTRODUCTION

The system described by Matta for rating acetabular fracture quality of reduction following ORIF has been used extensively throughout the literature. However, the reliability of this system remains to be validated. We sought to determine the interobserver and intraobserver reliability of this system when used by fellowship-trained pelvic and acetabular surgeons to evaluate intraoperative fluoroscopy.

METHODS

This is a retrospective evaluation of a prospectively collected acetabular fracture database at an academic level I trauma center. The quality of reduction of all acetabular fractures treated with open reduction internal fixation (ORIF) between May 2013 and December 2015 was assessed using three standard intraoperative fluoroscopic views (anteroposterior and two 45˚ oblique Judets). Displacement of ≤1 mm was considered to be an anatomic reduction, 2-3 mm imperfect, and >3 mm poor according to the system described by Matta. A total of 107 acetabular fractures treated with ORIF with complete intraoperative fluoroscopic images during that time period were available for review. Acetabular fracture reductions were reviewed by the operative surgeon at the time of surgery and subsequently reviewed by two fellowship-trained pelvic and acetabular surgeons. All reduction assessments were performed in a blinded fashion. The primary outcome measure was interobserver reliability for assessing reduction quality. This was evaluated using a weighted kappa (κ_w) statistic between each evaluator and the operative surgeon and a generalized kappa (κ_g) for all 3 surgeons. After a 6-week "washout interval," the surgeons reviewed the images again and intraobserver agreement was calculated using a weighted kappa statistic.

RESULTS

Interobserver reliability based on the initial assessment was low (κ_g = 0.09); however, did slightly improve with the second assessment to fair (κ_g = 0.24). Intraobserver reliability ranged from slight (κ_w = 0.20) to moderate (κ_w = 0.53) among the surgeons.

DISCUSSION

Low interobserver and intraobserver reliability was found when quality of reduction was assessed with intraoperative fluoroscopic images by the operative and two other pelvic and acetabular surgeons using the Matta system. Given the importance of an anatomic reduction on functional and radiographic outcomes, an accurate and reliable system for assessing intraoperative quality of reduction is essential.

Surgical hip dislocation in fixation of acetabular fractures: Extended indications and outcome

BACKGROUND

Surgical hip dislocation has been described as an excellent method for reduction and fixation of acetabular fractures. It allows a 360-degree access to the acetabulum and acetabular dome. However, reproducibility of this technique is still a concern. The primary outcome of this study was to investigate the short term functional and radiological outcome with the use of surgical hip dislocation in acetabular fractures. The secondary outcome was to describe different indications and methods of reduction using this technique.

METHODS

This is a retrospective consecutive case series for the use of surgical hip dislocation in acetabular fractures. Between July 2013 and February 2017, we used this technique to manage 36 cases of acetabular fractures. Two patients were lost to follow up leaving 34 patients eligible for the study. All surgeries were done by a 5-years and a 10-years' experience surgeons in pelvic and acetabular trauma surgeries. Through Gibson approach, we used the technique of surgical hip dislocation as described by the Bernese group. Different methods of fracture reduction were used. Intraoperative grading of cartilage injury was done using Disler's grading system. Postoperative fracture reduction was evaluated using the criteria described by Matta. Clinical evaluation was done using the modified Merle d'Aubigne ́ and Postel system.

RESULTS

The mean intra-operative blood loss was about 700 ± 35.4 ml. The mean units of blood transfused were 1 ± 0.1 unit. The mean surgical time was 135 ± 11.7 minutes. Anatomical reduction was achieved in 27 patients (79.4%). At a mean of 30 ± 16.8 months (median = 26 and IQR 22) follow up, the functional score was excellent in 5 (14.7 %), very good in 8 (23.5%), good in 9 (26.5%), fair in 2 (5.8%), and poor in 10 (29.4%) patients. Four patients (11.7%) developed AVN at a mean of 8 months postoperatively. Conversion to THA was done in 5 patients (14,7%). Trochanteric osteotomy showed osseous healing in all cases. No patient developed nerve injury or infection. One patient developed severe (grade III) heterotopic ossification.

CONCLUSIONS

Besides the indications of surgical hip dislocation mentioned before as reduction of the anterior column in T and Transverse fractures, associated femoral head fractures, intraarticular fragments, and labral injuries, it can be used in other indications as entrapped posterior wall, roof impaction, pure impaction injuries and cranial extension of the posterior wall fractures. The technique is reproducible; however, the learning curve is steep and needs to be performed by experienced acetabular trauma surgeons.

Factors influencing functional outcomes following open reduction internal fixation of acetabular fractures

INTRODUCTION

Recent large series of patient-reported outcomes after acetabulum fracture are limited, and potentially modifiable risk factors may be unidentified. The goal of this study was to describe patient and injury factors which negatively influence functional outcomes following operative management of acetabular fractures.

METHODS

699 patients with acetabular fractures were treated with open reduction and internal fixation (ORIF). Musculoskeletal Function Assessment (MFA) questionnaire was completed after a minimum 12 months post-injury by 283 adults. MFA scores range from 1 to 100 and higher scores represent greater dysfunction. Factors were assessed for potential association with MFA scores, and univariate and multiple linear regression analyses were performed.

RESULTS

Survey respondents were more severely injured than non-respondents, with more chest injury (38% vs 22%, p<0.001) and higher Injury Severity Score (19.3 vs 16.8, p=0.003). Patients were 69% male with mean age 44.0 years. Approximately one-third were smokers (31%), while 14% had comorbid diabetes mellitus type II. The majority of injuries occurred during a motor vehicle collision (65%); low-energy mechanisms were rare (4.2%). The most common fracture pattern was isolated posterior wall (23%), followed by transverse/posterior wall (21%). Heterotopic ossification (HO) was noted in 22%: Brooker 1: 29.5%, 2: 23.0%, 3: 32.8%, and 4: 14.8%. Tobacco use (β = 18.4, p<0.001), obesity (β = 0.39, p=0.009), diabetes (β = 8.2, p=0.029), post-traumatic arthrosis (PTA) (β = 5.94 p=0.035), and increasing HO severity (β = 8.93, p<0.001) were independently associated with worse MFA scores. Tobacco use had the strongest association, followed by the severity of HO.

CONCLUSION

In a large series of patient-reported functional outcomes following fixation of acetabular fractures, tobacco use, obesity, comorbid diabetes, PTA, and HO were associated with worse MFA scores. Further study to mitigate HO should be considered.

LEVEL OF EVIDENCE

III.

Prognostic factors and quality of life after pelvic fractures. The Brabant Injury Outcome Surveillance (BIOS) study

Introduction

Pelvic fractures can have long-term consequences for health-related quality of life (HRQoL). The main purpose of this study is to provide insight into short-term HRQoL in the first year after pelvic injury and to identify short-term prognostic factors of decreased outcome.

Methods

This is a prospective, observational, multicenter, follow-up cohort study in which HRQoL and functional outcomes were assessed during 12-month follow-up of injured adult patients admitted to 1 of 10 hospitals in the county of Noord-Brabant, the Netherlands. The data were collected by self-reported questionnaires at 1 week (including preinjury assessment) and 1, 3, 6 and 12 months after injury. The EuroQoL-5D (EQ-5D), visual analog scale (VAS), Merle d’Aubigné Hip Score (MAHS) and Majeed Pelvic Score (MPS) were used. Multivariable mixed models were used to examine the course of the HRQoL and the prognostic factors for decreased HRQoL and functional outcomes over time.

Results

A total of 184 patients with pelvic fractures were identified between September 2015–September 2016; the fractures included 71 Tile A, 44 Tile B and 10 Tile C fractures and 59 acetabular fractures. At the pre-injury, 1 week, and 1, 3, 6 and 12 months after injury time points, the mean EQ-5D Index values were 0.90, 0.26, 0.45, 0.66, 0.77 and 0.80, respectively, and the mean EQ-VAS values were 83, 45, 57, 69, 75 and 75, respectively. At 6 and 12 months after injury, 22 and 25% of the MPS < 65 year group, 38 and 47% of the MPS ≥ 65 year group and 34 and 51% of the MAHS group, respectively, reached the maximum score. Pre-injury score, female gender and high Injury Severity Score (ISS) were important prognostic factors for a decreased HRQoL, and the EQ-5D VAS β = 0.43 (95% CI: 0.31 − 0.57), -6.66 (95% CI: -10.90 − -0.43) and -7.09 (95% CI: -6.11 − -5.67), respectively.

Discussion

Patients with pelvic fractures experience a reduction in their HRQoL. Most patients do not achieve the HRQoL of their pre-injury state within 1 year after trauma. Prognostic factors for decreased HRQoL are a low pre-injury score, high ISS and female gender. We do not recommend using the MAHS and MPS in mid- or long-term follow-up of pelvic fractures because of ceiling effects.

Trial registration number NCT02508675.

Long-term outcomes of a dual-mobility cup and cementless triple-taper femoral stem combination in total hip replacement: a multicenter retrospective analysis

BACKGROUND

The separate design concepts of dual-mobility cups and triple-taper femoral stems were developed to improve survivorship following total hip replacement (THR) by reducing instability/dislocation and enabling enhanced fixation. Successful outcomes at over two decades have been reported with earlier-generation devices based on these concepts. The current study aimed to provide the first long-term results with a unique pairing of later-generation dual-mobility cup and triple-taper cementless femoral stem after a decade of use in patients undergoing THR.

METHODS

In this retrospective analysis, records were reviewed for all subjects implanted with this dual-mobility cup/cementless femoral stem combination at three centers between 2002 and 2005. Any subject who had not already had follow-up visit beyond 10 years, was not previously revised, and still living were invited for a single follow-up visit consisting of Merle d'Aubgine Scores, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index, and standard radiographs.

RESULTS

There were 244 THRs available for analysis. At a mean follow-up of 11.9 years, the Kaplan-Meier survivorship (endpoint: revision for any reason) was 99.1% (95% CI, 97.6-99.7) for the stem and 95.9% (95% CI, 93.1-97.6) for the cup. Merle d'Aubigne Scores were significantly improved from baseline and WOMAC scores were in the satisfactory range at the final follow-up. Radiographic analysis revealed no cases of stem subsidence, no cases of bone hypertrophy, 1 (0.4%) case of bone atrophy, and 3 (1.2%) cases of osteolysis around the stem. No subjects had radiolucent lines greater than 1 mm in any femoral Gruen zone. Evidence of cup migration was seen in 1 (0.4%) subject and 1 (0.4%) subject had evidence of osteolysis that was seen in Gruen zones I, II, IV, and V.

CONCLUSIONS

This combination of a later-generation dual-mobility cup and cementless triple-taper stem was associated with excellent survivorship and satisfactory functional outcomes at over 10 years follow-up.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02648152. Date of registration: January 6, 2016. Retrospectively registered.

Low-dose CT of postoperative pelvic fractures: a comparison with radiography

BACKGROUND

Computed tomography (CT) is superior to conventional radiography (CR) for assessing internal fixation of pelvic fractures, but with a higher radiation exposure. Low-dose CT (LDCT) could possibly have a sufficient diagnostic accuracy but with a lower radiation dose.

PURPOSE

To compare postoperative diagnostic accuracy of LDCT and CR after open reduction and internal fixation of pelvic fracture.

MATERIAL AND METHODS

Twenty-one patients were examined with LDCT and CR 0-9 days after surgery. The examinations were reviewed by two musculoskeletal radiologists. Hardware, degree of fracture reduction, image quality, and reviewing time were assessed, and effective radiation dose was calculated. Inter-reader agreement was calculated.

RESULTS

LDCT was significantly better than CR in determining whether hardware positioning was assessable ( P < 0.001). Acetabular congruence was assessable in all fractured patients with LDCT. In 12 of the 32 assessments with CR of patients with an acetabular fracture, joint congruence was not assessable due to overlapping hardware ( P = 0.001). Image quality was significantly higher for LDCT. Median time to review was 240 s for LDCT compared to 180 s for CR. Effective dose was 0.79 mSv for LDCT compared to 0.32 mSv for CR ( P < 0.001).

CONCLUSION

LDCT is more reliable than CR in assessing hardware position and fracture reduction. Joint congruency is sometimes not possible to assess with CR, due to overlapping hardware. The image quality is higher, but also the effective dose, with LDCT than with CR.

Long-term patient reported outcomes following acetabular fracture fixation

INTRODUCTION

Patient reported outcome scores may be the preferred method to assess clinical results following acetabular fracture fixation. However, in current acetabular fracture research, there is a scarcity of studies using these scores and long-term follow-up is lacking. The aim of this study is to describe long-term patient reported outcomes following acetabular fracture surgery and to evaluate the association between reduction quality and these outcome measures.

METHODS

Patients who received operative fixation for acetabular fractures (1992-2012) were sent questionnaires (short musculoskeletal functional assessment (SMFA) function index and short form (SF)-12), which was returned by 106 patients (22%) (mean age 51 years, 74% male). Mean follow-up was 11.3 years and hip survivorship 78%. Reduction quality was assessed on postoperative CT or plain pelvic radiography (PXR) (3 patients). Reductions were graded as adequate (CT: <1 mm step and <5 mm gap/PXR: ≤3 mm displacement) or inadequate (CT: ≥1 mm step and/or ≥5 mm gap/PXR: >3 mm displacement). Outcome scores between native hip versus total hip arthroplasty (THA) and adequate versus inadequate reduction groups were compared and association between reduction quality and hip survivorship was determined. Subgroup analysis was performed in older patients (≥50 years).

RESULTS

Patients with native hips reported overall superior relevant outcome scores (SMFA function index (p = 0.047), mobility (p = 0.048) and SF-12 physical component (p = 0.008)) compared to THA patients. Hip survivorship was associated with adequate reductions (p = 0.019). In the native hip group, an adequate reduction was also associated with lower (better) clinical scores (exceeding the minimal clinical important difference) (MCID) specifically for SMFA function index (p = 0.117) and mobility (p = 0.022). In elderly patients, the native hip versus THA group had similar outcomes, and adequate reductions were associated with hip survivorship as well as superior clinical scores (at least exceeding the MCID) in those who retained their native hip.

CONCLUSION

At long-term follow-up, acetabular fracture surgery is associated with excellent patient reported outcomes. Patients who retain their native hip have overall superior relevant (SMFA and SF-12) function scores compared to those who convert to THA. Adequate reductions (on CT) were associated with both hip survivorship and superior outcome scores in patients who retain their hip.

Long-term survival and risk factors for failure of the native hip joint after operatively treated displaced acetabular fractures

Aims

Our aim in this study was to describe the long-term survival of the native hip joint after open reduction and internal fixation of a displaced fracture of the acetabulum. We also present long-term clinical outcomes and risk factors associated with a poor outcome.

Patients and Methods

A total of 285 patients underwent surgery for a displaced acetabular fracture between 1993 and 2005. For the survival analysis 253 were included, there were 197 men and 56 women with a mean age of 42 years (12 to 78). The mean follow-up of 11 years (1 to 20) was identified from our pelvic fracture registry. There were 99 elementary and 154 associated fracture types. For the long-term clinical follow-up, 192 patients with complete data were included. Their mean age was 40 years (13 to 78) with a mean follow-up of 12 years (5 to 20). Injury to the femoral head and acetabular impaction were assessed with CT scans and patients with an ipsilateral fracture of the femoral head were excluded.

Results

A total of 36 patients underwent total hip arthroplasty (THA). The overall ten-year survival of the hip joint was 86% (95% confidence interval (CI) 81% to 90%) and the 20-year survival was 82% (95% CI 76% to 87%). Injury to the femoral head and acetabular impaction were the strongest predictors of failure, with the long-term survival rate falling towards 50% in these patients. The survival fell to 0% at three years when both these risk factors were present in patients aged > 60 years.

Conclusion

The long-term survival of the native hip joint after acetabular fractures was good, but the presence of injury to the femoral head and acetabular impaction proved to be strong predictors of failure, especially in patients aged > 60 years. These patients may be better treated with a combination of open reduction and internal fixation and primary arthroplasty. Cite this article: Bone Joint J 2017;99-B:834–40.

Predictive value of clinical scoring and simplified gait analysis for acetabulum fractures

BACKGROUND

Fractures of the acetabulum show a high, long-term complication rate. The aim of the present study was to determine the predictive value of clinical scoring and standardized, simplified gait analysis on the outcome after these fractures.

METHODS

Forty-one patients with acetabular fractures treated between 2008 and 2013 and available, standardized video recorded aftercare were identified from a prospective database. A visual gait score was used to determine the patients walking abilities 6-m postoperatively. Clinical (Merle d'Aubigne and Postel score, visual analogue scale pain, EQ5d) and radiological scoring (Kellgren-Lawrence score, postoperative computed tomography, and Matta classification) were used to perform correlation and multivariate regression analysis.

RESULTS

The average patient age was 48 y (range, 15-82 y), six female patients were included in the study. Mean follow-up was 1.6 y (range, 1-2 y). Moderate correlation between the gait score and outcome (versus EQ5d: r_s = 0.477; versus Merle d'Aubigne: r_s = 0.444; versus Kellgren-Lawrence: r_s = -0.533), as well as high correlation between the Merle d'Aubigne score and outcome were seen (versus EQ5d: r_s = 0.575; versus Merle d'Aubigne: r_s = 0.776; versus Kellgren-Lawrence: r_s = -0.419). Using a multivariate regression model, the 6 m gait score (B = -0.299; P < 0.05) and early osteoarthritis development (B = 1.026; P < 0.05) were determined as predictors of final osteoarthritis. A good fit of the regression model was seen (R² = 904).

CONCLUSIONS

Easy and available clinical scoring (gait score/Merle d'Aubigne) can predict short-term radiological and functional outcome after acetabular fractures with sufficient accuracy. Decisions on further treatment and interventions could be based on simplified gait analysis.

Heterotopic Ossification following acetabular fixation: Incidence and risk factors: 10-year experience of a tertiary centre

BACKGROUND

Heterotopic Ossification (HO) is a well-recognized complication following acetabular fracture fixation and its presence is prognostic for suboptimal clinical outcome. There are many controversies pertaining to its aetiology, including surgical approach, associated injuries and the use of HO prophylaxis. Long term data from high volume centres is necessary to address these issues.

AIM

To determine the incidence of HO post open reduction and internal fixation (ORIF) of acetabular fractures and to examine the associated risk and prognostic factors.

METHOD

We studied a cohort of 369 consecutive acetabular fractures that underwent ORIF at our institution over a 10 year period. Data was analyzed using univariate and multivariate logistic regression.

RESULTS

The existence of HO was evident in 65 patients (17.62%), of these 39 (60.0%) were Class I, 16 (24.6%) were Class II, 8 (12.3%) were Class III, and 2 (3.1%) were Class IV according to Brooker Classification. We found a significant association between admission to an Intensive Care Unit (ICU) (P-value=0.039), chest injury (P-value=0.013), multiple fractures (P-value=0.005), and the time lapse between injury and operation (P-value=0.025), and some statistical significance with surgical approach, ipsilateral fractures, open fractures, tibial and patellar fractures. Age over 30 years as the only prognostic factor for severe HO. Prophylaxis with Indomethacin did not appear to confer any benefit in our patient group.

CONCLUSION

The risk factors for developing HO following acetabular fracture fixation are multifactorial and include admission to ICU, associated chest injuries, multiple fractures and delay between injury and surgery. Surgical approach, ipsilateral fractures and tibia and patellar fractures may also play a role. Age over thirty years was the only prognostic factor for developing severe HO.

Radiographic Measurement of Displacement in Acetabular Fractures: A Systematic Review of the Literature

OBJECTIVES

To report methods of measurement of radiographic displacement and radiographic outcomes in acetabular fractures described in the literature.

METHODS

A systematic review of the English literature was performed using EMBASE and Medline in August 2014. Inclusion criteria were studies of operatively treated acetabular fractures in adults with acute (<6 weeks) open reduction and internal fixation that reported radiographic outcomes. Exclusion criteria included case series with <10 patients, fractures managed >6 weeks from injury, acute total hip arthroplasty, periprosthetic fractures, time frame of radiographic outcomes not stated, missing radiographic outcome data, and non-English language articles. Basic information collected included journal, author, year published, number of fractures, and fracture types. Specific data collected included radiographic outcome data, method of measuring radiographic displacement, and methods of interpreting or categorizing radiographic outcomes.

DATA SYNTHESIS

The number of reproducible radiographic measurement techniques (2/64) and previously described radiographic interpretation methods (4) were recorded. One radiographic reduction grading criterion (Matta) was used nearly universally in articles that used previously described criteria. Overall, 70% of articles using this criteria documented anatomic reductions.

CONCLUSIONS

The current standard of measuring radiographic displacement in publications dealing with acetabulum fractures almost universally lacks basic description, making further scientific rigor, such as testing reproducibility, impossible. Further work is necessary to standardize radiographic measurement techniques, test their reproducibility, and qualify their validity or determine which measurements are important to clinical outcomes.

LEVEL OF EVIDENCE

Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Assessment of functional outcomes of surgically managed acetabular fractures

We performed a systematic review of the literature pertaining to the functional outcomes of the surgical management of acetabular fractures. A total of 69 articles met our inclusion criteria, revealing that eight generic outcome instruments were used, along with five specific instruments. The majority of studies reported outcomes using a version of the d’Aubigne and Postel score, which has not been validated for use in acetabular fracture. Few validated outcome measures were reported. No psychometric testing of outcome instruments was performed. The current assessment of outcomes in surgery for acetabular fractures lacks scientific rigour, and does not give reliable outcome data for either scientific comparison or patient counselling.

Take home message: The use of non-validated functional outcome measures is a major limitation of the current literature pertaining to surgical management of acetabular fractures; future studies should use validated outcome measures to ensure the legitimacy of the reported results.

Cite this article: Bone Joint J 2016;98-B:690–5.

Estimating pre-traumatic quality of life in patients with surgically treated acetabular fractures and pelvic ring injuries: Does timing matter?

BACKGROUND AND PURPOSE

Evaluation of patient-assessed functional outcome in traumatic conditions has specific challenges. To obtain pre-traumatic data to allow for comparison during follow-up, retrospective assessments are needed. How such data is affected by posttraumatic time-point chosen for evaluation is unknown. The primary purpose of this study was to investigate how the time-point chosen for retrospective assessment of pre-traumatic quality of life (QoL) in patients with surgically treated acetabular fractures and pelvic ring injuries influenced the results. A secondary purpose was to examine the pre-traumatic QoL-profile in patients with these injuries.

PATIENTS AND METHODS

73 patients were included, where 50 had an acetabular fracture and 23 a pelvic ring injury. Pre-traumatic QoL was evaluated using the generic instruments SF-36 and EQ5D in conjunction with the condition-specific Pelvic Trauma Questionnaire (PTQ). Questionnaires were completed at three time points: 0, 1 and 2 months post-surgery.

RESULTS

Number of responders were 73 patients at 0 months, 61 patients at 1 month and 53 patients at 2 months. 50 patients answered the questionnaires at all three time-points. A trend was observed with all instruments where patients estimated a better pre-traumatic status with narrower distributions when assessment was delayed. At 2 months, scores for 4 out of 8 SF-36 domains where significantly higher compared to 0 months. For EQ5D, EQ VAS improved at 1 and 2 months compared to month 0 results but no other significant differences between time-points were found. Results from the PTQ demonstrated no significant differences over time. Pre-traumatic quality of life was high and for SF-36 comparable to a population norm. A very low level of pre-existing discomfort from the pelvic region was reported through the PTQ.

CONCLUSION

Patients with surgically treated acetabular fractures and pelvic ring injuries estimate a higher pre-traumatic functional status when assessment is carried out at 1 or 2 months post-surgery compared to perioperative measurements. The SF-36 seems to be more sensitive than the EQ5D in this respect. Pre-traumatic QoL in patients with surgically treated acetabular fractures and pelvic ring injuries is generally high and pre-existing discomfort from the pelvic region is uncommon.

Surgical dislocation of the hip for reduction of acetabular fracture and evaluation of chondral damage

PURPOSE

To assess the outcome of open reduction and internal fixation combined with surgical dislocation of the hip for displaced acetabular fractures.

METHODS

20 men and 2 women aged 20 to 55 (mean, 28) years underwent open reduction and internal fixation combined with surgical dislocation of the hip for displaced acetabular fracture. The most common fracture pattern was bicolumnar (n=12), followed by transverse (n=6) and T-type (n=4). Femoral head chondral lesions were classified as grade 0 (no defect) to grade 4 (osteochondral defect). Fracture fragments were fixed with titanium plates and screws, and the femoral head was redislocated to inspect for intraarticular screws. The association between functional status and acetabular fracture pattern and femoral head chondral lesions was explored.

RESULTS

Nine patients had chondral lesions in the femoral head (mostly in the anterosuperior zone), but none in the acetabulum. All femoral heads were viable. Reduction was anatomic in 6 patients and satisfactory in 16. Functional outcome was very good in 6 patients, good in 13, medium in 2, and fair in one. No patient developed avascular necrosis of the femoral head. Four patients had iatrogenic sciatic nerve palsy. One patient developed early degenerative hip arthritis and underwent total hip arthroplasty 14 months later.

CONCLUSION

Surgical dislocation of the hip facilitated anatomic reduction and inspection of any chondral lesions. It did not result in avascular necrosis of the femoral head.

The study of broken quadrilateral surface in fractures of the acetabulum

PURPOSE

Three-dimensional computerised tomography (3DCT) can provide comprehensive patho-anatomy of complex bone on a single image. Though important, the key articular quadrilateral [Q] surface has not been a part of the systems developed for classifying acetabulum fractures. The purpose of the study was to simplify the complexity of classification by the direct sign of the broken Q surface which lies opposite the entire floor of the acetabulum.

METHODS

The study reviewed 84 acetabular fractures using 3DCT images of the interior lateral view (IL) taken between June 2002 to December 2009. Fractures were traditionally classified using the anatomical disruption, plane of the fracture line breaking through or not through the bone column described by Judet and Letournel.

RESULTS

The 3D images clearly show the primary site of impaction acting on the acetabulum and the whole course of fracture. The image could not illustrate disruption of the lips of acetabulum and congruity of hip joints in 20 cases of wall (W) fracture. There were 30 transverse (T) fractures classified when the acetabulum was divided horizontally from front to back into upper and lower parts and 34 cases of column (C) fracture when the main vertical lines run and collide along the anterior and posterior column.

CONCLUSIONS

This study showed that the well-known complex fractures can be satisfactorily classified with the broad flat inner plane of the Q surface.

Quality of life after operative fixation of displaced acetabular fractures

OBJECTIVE

The aim of this study was to determine quality of life (QoL) changes over time after internal fixation of acetabular fractures.

DESIGN

This pertains to a prospective cohort study, which was single centered.

SETTING

The study was conducted at the University Hospital.

PATIENTS

One hundred thirty-six patients (108 men, 28 women), age 17-83 years operated for an acetabular fracture during 2004-2008 were prospectively included and followed up for 2 years.

MAIN OUTCOME MEASURES

QoL was evaluated via Short Form-36 (SF-36) and Life Satisfaction-11 at 6, 12, and 24 months. Radiographs were evaluated according to Matta at 2 years.

RESULTS

The most frequent fracture types were posterior wall (n31), associated anterior-posterior hemitransverse (n34), and associated both column (n29). One hundred twenty-nine patients could be assessed at 2 years, 4 did not respond, and 3 had died. The patients scored lower than norms in all 8 SF-36 domains with improvement over time for Physical Function (P < 0.0001) and Role Physical (P < 0.0001). The patients with postop reduction 0-1 mm scored better (P < 0.001-0.039) in 7 domains, all except vitality (P = 0.07), when compared with patients with residual displacement of ≥2 mm. Life satisfaction did not change with time and showed lower scores than normative in 9 of 11 items. Nineteen patients had undergone total hip replacement, and the strongest predictor was acetabular or femoral head impaction.

CONCLUSIONS

QoL in surgically treated patients with displaced acetabular fracture keeps improving in physical SF-36 domains over a 2-year period although still lower than norms, and anatomical reduction results in better QoL outcome in most dimensions.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Changes in the treatment of acetabular fractures over 15 years: Analysis of 1266 cases treated by the German Pelvic Multicentre Study Group (DAO/DGU)

Epidemiological, clinical and radiological data of 1266 patients with a unilateral acetabular fracture of up to 29 hospitals was reviewed. Three time periods, 1991-1993 (Registry I; n=359), 1998-2000 (Registry II; n=503), and 2005-2006 (Registry III; n=404) were compared with regard to injury pattern and severity, fracture type, and chosen nonoperative vs. operative treatment to elucidate changes over time in the treatment of acetabular fractures. In the operatively treated group, time to operation, surgical approach, fracture fixation implants and fracture reduction quality were examined. 641 (50.6%) patients with isolated acetabular fractures, 410 (32.4%) multiple injured and 215 (17.0%) polytrauma patients with 642 (50.7%) simple and 624 (49.3%) associated acetabular fractures were evaluated. In the time period from 1991 to 2006, the rate of operative treatments increased nationwide to 77% (rho<0.001). The distribution of fracture types involving the anterior and posterior wall changed with age (rho<0.001). Across all registries, 583 (68.0%) operations were performed within 7 days, 212 (24.7%) operations between 7 and 14 days and 54 (6.3%) operations were performed later than 14 days after injury. An anatomical reduction (0-1mm displacement) was achieved in 551 (64%) acetabular fractures. The obtained reduction quality did not correlate with time to operation, was lower in associated than in simple fracture types, and also lower in patients with isolated acetabular fractures than in polytrauma patients. Most importantly, the fracture reduction quality did not improve over time despite a higher frequency of surgical interventions. The Kocher-Langenbeck approach was preferred in the nineties in nearly three quarters of all operative procedures. Currently, the Kocher-Langenbeck and the ilioinguinal approaches are used equally often. The fracture fixation did not change over time and is achieved in 51% with plates in combination with single screws. This multisurgeon series illustrates a nationwide performance in acetabular fracture management. Despite changes in the chosen approaches and an increased surgical frequency, the operative treatment of acetabular fractures of the last 15 years did not lead to an increased reduction quality. Therefore, the rarity and complexity of acetabular fractures demands further specific teaching by experienced acetabular surgeons, scientific research and clinical outcome evaluation.

Functional Outcome after Operative Treatment of Displaced Fractures of the Acetabulum: A 12-month to 5-year Follow-up Investigation

PURPOSE

To review our experience with 82 surgically treated displaced acetabular fractures over a 4-year period.

PATIENTS AND METHODS

Ninety-three consecutive displaced acetabular fractures were consecutively operated on at Level I Trauma Center from January 1, 2000 through December 31, 2003, and 82 were available for review with a minimum of 12-month follow-up. Clinical (Merle D'Aubigné modified by Matta et al.) and radiographic (Matta) outcomes were evaluated. Complications and secondary operative procedures were documented.

RESULTS

Anatomical reduction was achieved in 89% of the patients. At follow-up examination 12-60 months postoperatively (mean 32 months), clinical results were satisfactory in 65 patients (79.2% of the cases), with 14 excellent and 51 good results, and roentgenographic results were satisfactory in 70 patients (85.4% of the cases). Complications included a 12.2% incidence of sciatic nerve palsy (10 patients, two postoperative and eight posttraumatic), a 2.4% incidence of intraoperative vascular lesion (one external iliac artery and one external iliac vein), a 1.2% incidence of postoperative loss of reduction, a 1.2% incidence of infection, a 1.2% incidence of Brooker et al. class IV heterotopic ossification, a 2.4% incidence of posttraumatic osteoarthritis, and a 2.4% incidence of osteonecrosis of the femoral head.

CONCLUSIONS

Operative treatment is an effective method for the management of displaced acetabular fractures. Clinical and roentgenographic results correlate closely with an anatomic reduction. Low complication rate can be expected if adequate preoperative assessment and planning is performed. Strategies to minimize the risk of thromboembolism and heterotopic ossification on the basis of mechanical pneumatic compression and antiinflammatory nonsteroidal drugs, respectively, are reliable techniques for these injuries.

Predictors of clinical and radiological outcome in patients with fractures of the acetabulum and concomitant posterior dislocation of the hip

We aimed to identify variables associated with clinical and radiological outcome following fractures of the acetabulum associated with posterior dislocation of the hip. Using a prospective database of 1076 such fractures, we identified 109 patients with this combined injury managed operatively within three weeks and followed up for two or more years. The patients had a mean age of 42 years (15 to 79), 78 (72%) were male, and 84 (77%) had been involved in motor vehicle accidents. Using multivariate analysis the quality of reduction of the fracture was identified as the only significant predictor of radiological grade, clinical function and the development of post-traumatic arthritis (p < 0.001). All patients lacking anatomical reduction developed arthritis whereas only 25.5% (24 patients) with an anatomical reduction did so (p = 0.05).

The quality of the reduction of the fracture is the most important variable in forecasting the outcome for patients with this injury. The interval to reduction of the dislocation of the hip may be less important than previously described.

The usefulness of computed tomography following open reduction and internal fixation of acetabular fractures

PURPOSE

To investigate the role of a supplemental imaging modality in postoperative assessment of acetabular fractures following open reduction and internal fixation.

METHODS

Postoperative axial computed tomographic (CT) scans were compared with plain radiographs of 20 patients with regard to their sensitivity for detecting articular fracture reduction in terms of gap displacement and step deformity or offset. Three observers independently reviewed the plain radiographs and CT scans at 2 separate time points and categorised the outcome as either anatomical or non-anatomical. The inter-observer reliability and intra-observer reproducibility of these measurements was expressed as a kappa statistic. The radiological result was correlated with the clinical outcome measures using the Merle D'Aubigne scale, the Harris Hip Score, and the SF-36 score.

RESULTS

Plain radiography was less effective in the detection of postoperative articular displacement (mean, 75.1% sensitive). The inter-observer and intra-observer agreement between reviewers was good to excellent in detecting reduction quality between the 2 modalities. Patient management was not altered by the findings of the CT scans.

CONCLUSIONS

Although postoperative CT scanning of acetabular fractures in selective cases may be useful, issues such as higher cost, less effective allocation of resources, and excessive radiation doses do not support its routine use.

Comparison of distribution, agreement and correlation between the original and modified Merle d'Aubigné-Postel Score and the Harris Hip Score after acetabular fracture treatment: moderate agreement, high ceiling effect and excellent correlation in 450 patients

BACKGROUND

In acetabular fracture treatment, 3 disease-specific outcome scores are mainly used: the original and modified Merle d'Aubigné-Postel Score, and the Harris Hip Score.

METHODS

The original and modified Merle d'Aubigné-Postel Score and the Harris Hip Score were recorded in 1,153 follow-ups of 450 patients. 492 follow-ups were excluded because factors other than the acetabular fracture were found to affect the outcome scores. This gave 661 patient records for the study.

RESULTS

The Spearman correlations were between 0.81 and 0.89. The quartile analyses showed Kappa agreement between 0.45 and 0.55. About 40% of the observations were classified into another quartile when switching from one outcome score to another. The 25th and 50th percentiles comprised 85% and 95% of the total numeric scores, respectively, while the 75th percentiles showed ceiling value (100% of the maximum) in all 3 scores.

INTERPRETATION

Despite the excellent overall correlation between the outcome scores, the Kappa agreements were only moderate. The scores were all skewed in distribution with considerable ceiling effects that could limit their clinical use. The scores did not capture any differences in 25% of the observations at the upper end of the scales.

Acetabular fractures: a 16-year prospective epidemiological study

We prospectively analysed the epidemiology of acetabular fractures over a period of 16 years in order to identify changes in their incidence or other demographic features. Our study cohort comprised a consecutive series of 351 patients with acetabular fractures admitted to a single institution between January 1988 and December 2003. There was no significant change in the overall incidence of acetabular fractures, which remained at 3 patients/100 000/year. There was, however, a significant reduction in the number of men sustaining an acetabular fracture over the period (p < 0.02). The number of fractures resulting from falls from a height < 10 feet showed a significant increase (p < 0.002), but there was no change in those caused by motor-vehicle accidents. There was a significant reduction in the median Injury Severity score over the period which was associated with a significant decrease in mortality (p < 0.04) and a reduction in the length of hospital stay. The incidence of osteoarthritis noted during follow-up of operatively-treated fractures declined from 31% to 14%, reflecting improved results with increasing subspecialisation. Our findings suggest that there will be a continuing need for some orthopaedic surgeons to specialise in the management of these fractures. In addition, the reductions in the Injury Severity score and mortality may be associated with improved road and vehicle safety.

Incongruity versus instability in the etiology of posttraumatic arthritis

The etiology of posttraumatic arthritis is understood poorly but it clearly has a pathomechanical component. Posttraumatic arthritis likely results from irreversible cartilage damage sustained at the time of injury and chronic cartilage overloading resulting from articular incongruity and instability. However, the relative importance of instability and incongruity is unknown. Clinical studies show that the hip, knee, and ankle tolerate incongruity differently. However, all three joints poorly tolerate instability. Basic mechanical studies have shown that static loading of articular surface incongruities have caused relatively modest increases in contact pressure. However, static testing poorly replicates normal viscoelastic properties of cartilage, which may mask important transient stress elevations that occur during motion. Static tests also ignore potential abnormal loads that may accumulate throughout a motion cycle. We review the clinical and basic scientific evidence linking incongruity and instability to posttraumatic arthritis. Preliminary data from a newly developed dynamic ankle testing device are presented. Dynamic testing allows measurement of transient contact loads and loading rates that occur through the entire motion cycle and it opens the door to measure mechanical abnormalities associated with instability.

The "Gull Sign": a harbinger of failure for internal fixation of geriatric acetabular fractures

OBJECTIVES

To identify factors affecting the outcomes of surgery for acetabular fracture in patients over the age of 60 years.

DESIGN

Retrospective review of records and radiographs; current examination, radiographs and outcome surveys when possible.

SETTING

Academic, Level 1 trauma center.

PATIENTS/PARTICIPANTS

Forty-eight patients over age 60 with displaced acetabulum fractures.

INTERVENTION

Surgical reduction and fixation.

MAIN OUTCOME MEASUREMENTS

Clinical ratings and radiographic evaluations, Short Musculoskeletal Functional Assessment survey (SMFA), SF-36, and hip-specific questions. Radiographs were evaluated using the criteria of Matta.

RESULTS

Ten patients died since surgery. Four were lost to follow-up. Seven had >12 months of follow-up information in the chart. Twenty-seven had current evaluations for the study. Average follow-up was 37 months, range 1-114 months. The average age at surgery was 71.6 years (range 61-88). No perioperative deaths occurred. Initial reductions achieved: 61% anatomic, 34% imperfect, and 5% poor. A specific radiographic finding (superomedial dome impaction) predictive of failure was identified. This was designated the "Gull Sign." These patients had inadequate reduction, early fixation failure, or medial/superior joint narrowing and subluxation. Functional outcomes in patients with current examination were similar to age-matched controls. Radiographic outcomes: 30% excellent, 30% good, 9% fair, 23% poor, and 7% arthroplasty. Anatomic reduction was closely related to good or excellent radiographic result.

CONCLUSIONS

While some patients over sixty years of age can have satisfactory functional outcomes after acetabular fracture fixation, a significant number will have failure of the procedure. Osteopenic patients with superomedial dome impaction (the Gull Sign) did not benefit from attempted open reduction and internal fixation in this series.