Heterotopic ossification rates after acetabular fracture surgery are unchanged without indomethacin prophylaxis

The impact of heterotopic ossification prophylaxis after surgical fixation of acetabular fractures: national treatment patterns and related outcomes

BACKGROUND

Heterotopic ossification (HO) is a common complication after surgical fixation of acetabular fractures. Numerous strategies have been employed to prevent HO formation, but results are mixed and optimal treatment strategy remains controversial. The purpose of the study was to describe current national heterotopic ossification (HO) prophylaxis patterns among academic trauma centers, determine the association between prophylaxis type and radiographic HO, and identify if heterogeneity in treatment effects exist based on outcome risk strata.

METHODS

We used data from a subset of participants enrolled in the Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities (PREPARE) trial. We included only patients with closed AO-type 62 acetabular fractures that were surgically treated via a posterior (Kocher-Langenbeck), combined anterior and posterior, or extensile exposure. PREPARE Clinical Trial Registration Number: NCT03523962 Patient population This cohort study was nested within the Pragmatic Randomized Trial Evaluating Pre-Operative Alcohol Skin Solutions in Fractured Extremities (PREPARE) trial. The PREPARE trial is a multicenter cluster-randomized crossover trial evaluating the effectiveness of two alcohol-based pre-operative antiseptic skin solutions. All PREPARE trial clinical centers that enrolled at least one patient with a closed AO-type 62 acetabular fracture were invited to participate in the nested study.

RESULTS

277 patients from 20 level 1 and level 2 trauma centers in the U.S. and Canada were included in this study. 32 patients (12%) received indomethacin prophylaxis, 100 patients (36%) received XRT prophylaxis, and 145 patients (52%) received no prophylaxis. Administration of XRT was associated with a 68% reduction in the adjusted odds of overall HO (OR 0.32, 95% CI, 0.14 - 0.69, p = 0.005). The overall severe HO (Brooker classes III or IV) rate was 8% for the entire cohort; XRT reduced the rate of severe HO in high-risk patients only (p=0.03).

CONCLUSION

HO prophylaxis patterns after surgical fixation of acetabular fractures have changed dramatically over the last two decades. Most centers included in this study did not administer HO prophylaxis. XRT was associated with a marked reduction in the rate of overall HO and the rate of severe HO in high-risk patients. Randomized trials are needed to fully elucidate the potential benefit of XRT. PREPARE Clinical Trial Registration Number: NCT03523962.

Perioperative management of acetabular and pelvic fractures: evidence-based recommendations

PURPOSE

The American Academy of Orthopaedic Surgeons does not currently provide clinical practice guidelines for management of PAF. Accordingly, this article aims to review and consolidate the relevant historical and recent literature in important topics pertaining to perioperative management of PAF.

METHODS

A thorough literature review using PubMed, Cochrane and Embase databases was performed to assess preoperative, intraoperative and postoperative management of PAF fracture. Topics reviewed included: time from injury to definitive fixation, the role of inferior vena cava filters (IVCF), tranexamic acid (TXA) use, intraopoperative cell salvage, incisional negative pressure wound therapy (NPWT), intraoperative antibiotic powder use, heterotopic ossification prophylaxis, and pre- and postoperative venous thromboembolism (VTE) prophylaxis.

RESULTS

A total of 126 articles pertaining to the preoperative, intraoperative and postoperative management of PAF were reviewed. Articles reviewed by topic include 13 articles pertaining to time to fixation, 23 on IVCF use, 14 on VTE prophylaxis, 20 on TXA use, 10 on cell salvage, 10 on iNPWT 14 on intraoperative antibiotic powder and 20 on HO prophylaxis. An additional eight articles were reviewed to describe background information. Five articles provided information for two or more treatment modalities and were therefore included in multiple categories when tabulating the number of articles reviewed per topic.

CONCLUSION

The literature supports the use of radiation therapy for HO prophylaxis, early (< 5 days from injury) surgical intervention and the routine use of intraoperative TXA. The literature does not support the routine use of iNPWT or IVCF. There is inadequate information to make a recommendation regarding the use of cell salvage and wound infiltration with antibiotic powder. While the routine use of chemical VTE prophylaxis is recommended, there is insufficient evidence to recommend the optimal agent and duration of therapy.

Total Hip Arthroplasty in the Setting of Post-Traumatic Arthritis Following Acetabular Fracture: A Systematic Review

Background

Acetabular fractures are frequently associated with post-traumatic arthritis (PTA), for which total hip arthroplasty (THA) has emerged as the established procedure. The purpose of this systematic review is to report the patient outcomes, complications, and implant survival of delayed THA for patients with PTA following acetabular fracture.

Methods

A systematic review was performed in December 2021 as per Preferred Reporting Items for Systematic Review and Meta-Analysis Guidelines to identify all studies reporting outcomes of delayed THA performed for PTA with a history of acetabular fracture. From an initial screen of 893 studies, 29 studies which met defined inclusion criteria including minimum 12 months of follow-up and minimum 10 THA were included in the final review.

Results

A total of 1220 THA were reported across 29 studies, with 1174 THA completing a minimum of 1-year follow-up at a mean of 86 months. All 29 studies reported upon complications, with a control included in 6 for comparison. Higher complication rates were observed both in patients who had prior open reduction internal fixation and conservative treatment, most notably infection which was observed following 3.6% THA. The total joint revision rate was 9.7%. An improvement was noted in all 25 studies which recorded patient-reported outcomes, with a mean rise in the Harris hip score from 45 to 86 across 18 studies.

Conclusions

THA may reduce reported pain levels and improve functional outcomes in selected patients experiencing PTA following acetabular fractures. There is an increased risk of complications, necessitating careful consideration when planning the operation and open discussion with prospective patients and caregivers.

Treatment of acetabular fracture involving anterior and posterior columns using a single pararectus approach: surgical experience and preliminary results

PURPOSE

This study aims to evaluate the efficacy of single pararectus approach in patients confirmed with acetabular fracture involving anterior and posterior columns.

METHODS

A total of 58 patients confirmed with acetabular fracture involving anterior and posterior columns and treated at our hospital between January 2015 and January 2020 were retrospectively analyzed. A single pararectus approach was applied for all patients. Routine X-rays were performed at follow-up of one, three, six, 12, and 18 months, and three-dimensional CT scans were added at six and 18 months. Fracture reduction quality was assessed using the Matta score system, and functional assessment used the Modified Merle D'Aubigné and Postel score system. Post-operative complications, including fat liquefaction and deep vein thrombosis, were recorded and analyzed.

RESULTS

The median operation time was 186 min while the intra-operative blood loss was 421 mL. The rate of good-to-excellent reduction was 94.8%, and the rate of good-to-excellent hip function score reached 93.1%. Seven patients presented with post-operative complications, including three intra-operative small vascular injuries, two peritoneal small perforations, one fat liquefaction, and one deep vein thrombosis.

CONCLUSION

Using a single pararectus approach is convenient and effective for treating acetabular fracture involving anterior and posterior columns, especially those involving the quadrilateral area.

TRIAL REGISTRATION

ChiCTR, ChiCTR2100054604. Registered 21 December 2022. Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=144783 .

Outcomes of acute versus delayed total hip arthroplasty following acetabular fracture

PURPOSE

Post-traumatic arthritis is known complication following acetabular fracture. The aim was to compare mid- to long-term outcomes of acute THA (aTHA) for acetabular fracture and delayed THA (dTHA) following failure of ORIF or conservative management.

METHODS

We retrospectively analysed 60 THA (21 aTHA; 39 dTHA) performed for acetabular fracture between 2004 and 2014 in 60 patients with a mean age of 59 years (20-94). Functional and Radiographic outcomes were assessed at a mean follow-up of 5 years (2-13) utilizing Oxford, Harris Hip (HHS), and Postel Merle d'Aubigné (PMA) scores and Brooker classification.

RESULTS

The mean HHS (73), Oxford (32) and PMA (12) scores were significantly lower in the aTHA group. Acute THA was significantly associated with lower postoperative Oxford (β = -4.2), HHS (β = -7.8), and PMA (β = -2.2) scores at mean 5 years (2-13). Eleven patients returned to the operating room. There were no significant differences between THA performed in acute or delayed fashion. The two primary reasons for revision were periprosthetic joint infection (n = 5) and aseptic loosening (n = 4). Survivorship free from reoperation at 10 years was 91% and 82% for aTHA and dTHA, respectively (p = 0.24). Increased PMA scores were associated with decreased overall survival of the THA free from reoperation (HR = 0.60). The degree of heterotopic ossification was significantly higher in the aTHA group (p < 0.001).

CONCLUSION

Acute THA in the setting of acetabular fracture is a technically challenging procedure. However, in the present series, aTHA provided satisfactory immediate stability and good survivorship at 10 years in a medically vulnerable patient population.

LEVEL OF EVIDENCE

Level 3; Therapeutic study.

Heterotopic Ossification after Trauma

Heterotopic ossification (HO) refers to benign ectopic bone formation in soft tissue and is common following trauma surgery. HO bone can restrict movement and progress into ankylosis that may necessitate surgical intervention. This article discusses the current literature on the pathophysiology, prophylaxis, treatment, and epidemiology of postoperative HO following orthopedic trauma.

Outcome of surgically treated acetabular fractures: risk factors for postoperative complications and for early conversion to total hip arthroplasty

INTRODUCTION

The gold standard of Acetabular fractures treatment is open reduction and internal fixation (ORIF). Our purpose is to assess the short- to medium-term outcomes and complications of surgically treated acetabular fractures. We analysed factors influencing clinical outcomes, incidence of complications and predictors of conversion in total hip arthroplasty (THA).

MATERIALS AND METHODS

We retrospectively analysed 102 patients with acetabular fracture surgically treated between December 2017 and September 2020. We evaluated the quality of reduction with x-ray measuring residual displacement, classified into 3 groups (Matta Radiological Score). At the final follow-up, radiographs were graded according to Matta's Radiological Outcome Grading, and the clinical outcomes were graded using Oxford Hip Score (OHS).

RESULTS

62 patients were enrolled. OHS was influenced by quality of reduction (p = 0.031), injury severity score (ISS) (p = 0.003) and BMI > 30 (p < 0.0001). The late sequelae were heterotopic ossification (HO) in 13 patients, osteoarthritis (OA) in 22 and avascular necrosis (AVN) in 4. HO was significantly affected by posterior approach and ISS > 15. The analysis showed a correlation between AVN and posterior hip dislocation. OA had a correlation with postoperative quality of reduction (p = 0.014). Eight patients required THA with a significant correlation between THA and posterior dislocation, isolated posterior wall fracture and ISS > 15.

CONCLUSION

A high rate of patients with acetabular fractures still develop complications and require THA. Identification of predictors for poor outcome may help to inform surgical decision-making regarding options of plate osteosynthesis or 'Fix and Replace', to avoid poor outcomes and early revision surgery.

Risk Factors for the Development of Heterotopic Ossification Following Acetabular Fractures: A Systematic Review

BACKGROUND

Heterotopic ossification (HO) following acetabular fractures is a common complication that may affect clinical outcomes. However, the effects of prophylactic treatment with nonsteroidal anti-inflammatory drugs or radiation therapy remain controversial. While several factors have been related to the development of HO, there is considerable uncertainty regarding their importance or effect size in the setting of acetabular surgery. Therefore, this systematic review aims to summarize the risk factors for HO following the operative fixation of acetabular fractures and clarify their interrelationships.

METHODS

In accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, PubMed, MEDLINE, Embase, and CINAHL databases were searched from inception to February 2021. Studies that assessed factors related to HO development among patients with operatively repaired acetabular fractures were included. Outcomes were risk factors and their effect size (p values, odds ratios, and 95% confidence intervals).

RESULTS

Twenty-five studies and 1 conference abstract with a total of 3,940 patients were included. The following risk factors for HO were identified. Patient factors were increased body mass index, male sex, and increased age. Injury factors were intensive care unit (ICU) admission and length of stay, non-ICU hospitalization for &gt;10 days, the need for mechanical ventilation for ≥2 days, abdominal and/or chest injuries, the number and type of associated fractures, traumatic brain injuries, T-type acetabular fractures, pelvic ring injuries, and hip dislocation. Care factors were a delay to surgery, extensile and posterior surgical approaches to the hip, trochanteric osteotomy, postoperative step-off of &gt;3 mm, and a delay to prophylaxis following injury or surgery. Ethnicity, Injury Severity Score, cause of the fracture, femoral head injuries, degloving injuries, comminution, intra-articular debris, the type of bone void filler, gluteus minimus muscle preservation, prolonged operative time, and intraoperative patient position were not risk factors for developing HO.

CONCLUSIONS

HO following operative fixation of acetabular fractures is not uncommon, with severe-grade HO associated with substantial disability. Careful consideration of the risk factor effect sizes and interdependencies could aid physicians in identifying patients at risk for developing HO and guide their prophylactic management. The results of this study could establish a framework for future studies.

LEVEL OF EVIDENCE

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

Identification of Risk Factors in the Development of Heterotopic Ossification After Primary Total Hip Arthroplasty

PURPOSE

Heterotopic ossification (HO) is a process by which bone forms abnormally in soft tissues. Known risk factors for developing HO include male sex, spinal cord injury, trauma, and surgery. We investigated additional risk factors in the development of HO after hip arthroplasty.

METHODS

We performed a retrospective review of electronic medical records of 4070 individuals who underwent hip arthroplasty from September 2010 to October 2019 at the University of California, San Francisco Hospital. Demographics, anthropometrics, medications, and comorbid conditions were used in logistic regression analysis to identify factors associated with the development of HO.

RESULTS

A total of 2541 patients underwent primary hip arthroplasty in the analyzed timeframe (46.04% men, mean age at procedure: 62.13 ± 13.29 years). The incidence of postsurgical HO was 3% (n = 80). A larger proportion of individuals who developed HO had underlying osteoporosis (P < 0.001), vitamin D deficiency (P < 0.001), spine disease (P < 0.001), type 1 or 2 diabetes (P < 0.001), amenorrhea (P = 0.037), postmenopausal status (P < 0.001), parathyroid disorders (P = 0.011), and history of pathologic fracture (P = 0.005). Significant predictors for HO development were Black/African American race [odds ratio (OR) 2.97, P = 0.005], preexisting osteoporosis (OR 2.72, P = 0.001), spine disease (OR 2.04, P = 0.036), and low estrogen states (OR 1.99, P = 0.025). In the overall group, 75.64% received perioperative nonsteroidal anti-inflammatory drugs (NSAIDs), which negatively correlated with HO formation (OR 0.39, P = 0.001).

CONCLUSIONS

We identified new factors potentially associated with an increased risk of developing HO after primary hip arthroplasty, including African American race, osteoporosis, and low estrogen states. These patients may benefit from HO prophylaxis, such as perioperative NSAIDs.

Contemporary perspectives on heterotopic ossification

Heterotopic ossification (HO) is the formation of ectopic bone that is primarily genetically driven (fibrodysplasia ossificans progressiva [FOP]) or acquired in the setting of trauma (tHO). HO has undergone intense investigation, especially over the last 50 years, as awareness has increased around improving clinical technologies and incidence, such as with ongoing wartime conflicts. Current treatments for tHO and FOP remain prophylactic and include NSAIDs and glucocorticoids, respectively, whereas other proposed therapeutic modalities exhibit prohibitive risk profiles. Contemporary studies have elucidated mechanisms behind tHO and FOP and have described new distinct niches independent of inflammation that regulate ectopic bone formation. These investigations have propagated a paradigm shift in the approach to treatment and management of a historically difficult surgical problem, with ongoing clinical trials and promising new targets.

A comprehensive update on the pharmacological management of heterotopic ossification following hip arthroplasty: a level I evidenced based expert opinion

INTRODUCTION

Heterotopic ossification (HO) of the hip joint may happen accompanying skeletal muscle trauma or surgical procedures. The pharmacological prophylaxis of heterotopic ossification (HO) following total hip arthroplasty (THA) is debated.

AREAS COVERED

This expert opinion aims to systematically investigate the efficacy of current pharmacological options as prophylaxis for HO following THA.

EXPERT OPINION

The current evidence identified celecoxib, naproxen, and diclofenac as best option for the prevention of HO in patients who undergo primary THA. The most appropriate pharmacotherapy for the prevention of HO is still debated and should be customized according to patients' comorbidities and medical history. For patients with cardiovascular comorbidities, naproxen, or diclofenac should be considered along with proton pump inhibitors to prevent gastrointestinal complications. For patients with history of gastrointestinal disease, celecoxib can be recommended. These conclusions must be considered within the limitations of the present investigation. Between studies, heterogeneities in the administration protocols were evident. In some RCTs, the length of the follow-up was shorter than 12 months. The current clinical practice would benefit of high-quality recommendations and the development of the shared official guidelines.

Low-dose Preoperative Unshielded Radiation Is Effective in Heterotopic Ossification Prophylaxis and Does Not Affect Porous Fixation in Total Hip Arthroplasty at 2 Years Minimum Follow-up: A Radiographic Study

BACKGROUND

Heterotopic ossification (HO) is a frequent complication of total hip arthroplasty (THA). HO can cause pain, limitation of range of motion, and instability. Radiation therapy (RT) for HO prophylaxis is well established but may interfere with early porous ingrowth and pullout strength of implants, as suggested by two animal studies. Although shielding of the bone from irradiation may theoretically protect ingrowth, it has been found to reduce RT effectiveness. Despite the popularity of porous implants in THA, the frequency of HO, and use of RT in its prophylaxis, the effect of RT on porous implant fixation in THA has not been previously reported. At our institution, we use unshielded, single-dose, preoperative 700 to 800 centigrays RT for HO prophylaxis in high-risk patients. We hypothesize that this RT protocol is effective and the press-fit technique protects porous implants during early ingrowth; therefore, long-term implant fixation is not compromised.

METHODS

This was a retrospective study aiming to determine fixation of porous THA implants, healing of trochanteric osteotomies, and efficacy of HO prophylaxis with this RT protocol.

RESULTS

Thirty-nine patients with follow-up of 24 to 144 months (average 59.7 months) were included. All 26 porous-coated femoral implants (11 revisions and 15 primary) were well fixed. There were 33 porous-coated acetabular implants (18 revisions and 15 primary). Thirty (91%) were well fixed, and three revision implants (9%) demonstrated radiolucent lines in two zones, but patients were clinically asymptomatic. All nine trochanteric osteotomies healed uneventfully. RT provided effective HO prophylaxis in 33 of 39 hips (85%).

CONCLUSIONS

Single, low-dose, preoperative RT without shielding does not increase aseptic loosening of porous implants manufactured with plasma porous spray or nonunion of extended trochanteric osteotomies. This protocol provides effective HO prophylaxis in high-risk patients undergoing primary and revision THA.

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.

Solutions for failed osteosynthesis of the acetabulum

Osteosynthesis of the acetabulum is complex and requires very careful planning and preoperative preparation. The goal is to achieve anatomical reduction without steps or gaps in the articular surface. If it has not been possible to achieve an optimal reconstruction, one has to consider whether it makes sense to carry out reosteosynthesis or revise the fixation. The risk of infection, heterotopic ossification, avascular necrosis of the femur and cartilage damage is much higher than with the primary procedure. Often, especially in older patients, it may make more sense to achieve fracture union and to implant a total hip prosthesis in due course. In younger patients, every attempt should be made to achieve optimum anatomical reduction and this may mean consideration of reosteosynthesis after careful planning and counselling of the patient. If reosteosynthesis is considered adequate imaging including a postoperative CT is essential as part of the planning. This article looks at the possible solutions for failed osteosynthesis of the acetabulum.

Inhibition of Nf-ҝb prevents trauma-induced heterotopic ossification in rat model

PURPOSE

To investigate the pathogenesis and find a better prophylactic method of acquired heterotopic ossification (HO).

MATERIALS AND METHODS

In the first part, we designed the brain-traumatic/burn/tenotomy rat model and testified its efficacy as HO model. 44 rats were randomly divided into experimental group and control group. After operation, the bilateral tendons of 2 rats were collected at the 2^nd, 3^rd, 4^th, 6^th, 8^th, and 10^th weeks to determine the expression levels of p65. Additionally, the remaining rats were exposed to X-Ray examination at the 10th week. In the second part, 124 rats were randomly divided into four groups based on the administration dosage of Ammonium pyrrolidinedithiocarbamate (PDTC). Then, three rats of each group were euthanized every week in the first seven weeks to collect tendon to detect the expression levels of p65 by qRT-PCR and Western Blot. The remaining rats were exposed to X-Ray examination at the 10th week to assess the size of HO before being euthanized for HE staining.

RESULTS

The success rate of Brain-traumatic/Burn/Tenotomy model was 100%. Pharmacologic inhibition of Nf-ҝb signaling pathway by PDTC could significantly reduce the expression levels of p53 and the size of HO, and the reduction was most significant in the 0.6mg dosage group.

CONCLUSIONS

Brain-traumatic/Burn/Tenotomy model was highly reliable HO model. Inhibition of Nf-ҝb signaling pathway by PDTC could significantly reduce HO formation, and the most effective concentration was 6 mg/ml for local injection.

Rescue of ankylosing hip following open reduction and internal fixation of acetabular fracture by surgical resection of heterotopic ossification: A case report

•

Heterotopic ossification is a major complication after surgical treatment of acetabular fractures.

•

Whether delayed or early surgical resection of heterotopic ossification is more effective remains controversial.

•

Early surgical resection is not necessarily contraindication.

Introduction

Heterotopic ossification is a major complication after surgical treatment of acetabular fractures. Heterotopic ossification generally involves the large joints, often limits the range of motion, and may cause ankylosis.

Presentation of case

This case report describes a 59-year-old man with severe heterotopic ossification who developed an acetabular fracture and resultant hip ankylosis, which was rescued by surgical resection of the heterotopic ossification. He had accompanying head injury and multiple other fractures, which were treated conservatively. Open reduction with internal fixation of the acetabular fracture was performed through the ilioinguinal and Kocher–Langenbeck combined approach. The patient unexpectedly returned to our hospital 7.5 months after the fracture surgery. We found that his left hip joint was completely ankylosed by severe heterotopic ossification. We performed surgical resection of the heterotopic ossification through a direct lateral approach 9.5 months after the initial surgery. At the final follow-up, 5.5 years after the heterotopic ossification resection surgery, the hip function including the range of motion was satisfactory. Radiographs showed no signs of recurrence, and he could walk with no support.

Discussion

The only effective treatment for established HO is surgical excision. Whether delayed or early surgical resection of heterotopic ossification is more effective remains controversial.

Conclusion

We considered that waiting for a long time before surgical resection of the heterotopic ossification would lead to more disability, and early resection of the heterotopic ossification was not a contraindication despite the fact that the uptake on the bone scan was still intense.

Combat-related acetabular fractures: Outcomes of open versus closed injuries

INTRODUCTION

Since the onset of the Global War on Terror close to 50,000 United States service members have been injured in combat, many of these injuries would have previously been fatal. Among these injuries, open acetabular fractures are at an increased number due to the high percentage of penetrating injuries such as high velocity gunshot wounds and blast injuries. These injuries lead to a greater degree of contamination, and more severe associated injuries. There is a significantly smaller proportion of the classic blunt trauma mechanism typically seen in civilian trauma.

METHODS

We performed a retrospective review of the Department of Defense Trauma Registry into which all US combat-injured patients are enrolled, as well as reviewed local patient medical records, and radiologic studies from March 2003 to April 2012. Eighty seven (87) acetabular fractures were identified with 32 classified as open fractures. Information regarding mechanism of injury, fracture pattern, transfusion requirements, Injury Severity Score (ISS), and presence of lower extremity amputations was analyzed.

RESULTS

The mechanism of injury was an explosive device in 59% (n=19) of patients with an open acetabular fracture; the remaining 40% (n=13) were secondary to ballistic injury. In contrast, in the closed acetabular fracture cohort 38% (21/55) of fractures were due to explosive devices, and all remaining (n=34) were secondary to blunt trauma such as falls, motor vehicle collisions, or aircraft crashes. Patients with open acetabular fractures required a median of 17units of PRBC within the first 24h after injury. The mean ISS was 32 in the open group compared with 22 in the closed group (p=0.003). In the open fracture group nine patients (28%) sustained bilateral lower extremity amputations, and 10 patients (31%) ultimately underwent a hip disarticulation or hemi-pelvectomy as their final amputation level.

DISCUSSION

Open acetabular fractures represent a significant challenge in the management of combat-related injuries. High ISS and massive transfusion requirements are common in these injuries. This is one of the largest series reported of open acetabular fractures. Open acetabular fractures require immediate damage control surgery and resuscitation as well as prolonged rehabilitation due to their severity. The dramatic number of open acetabular fractures (37%) in this review highlights the challenge in treatment of combat related acetabular fractures.

Effects of the acetabular fracture index and other factors of posterior wall acetabular fracture on functional outcome

Objective To analyze the effects of the acetabular fracture index (AFI) and other factors on the functional outcome of patients with acetabular fractures involving the posterior wall. Methods Forty-eight patients who underwent surgery in our department were reviewed. According to the AFI, which indicates the percentage of remaining intact posterior acetabular arc, the patients were divided into Group A (AFI ≤ 25%, 11 patients), Group B (25% < AFI ≤ 50%, 23 patients), Group C (50% < AFI ≤ 75%, 7 patients), and Group D (75% < AFI ≤ 100%, 7 patients). The AFI was measured with a computed tomography picture archiving and communication system or calculated with the cosine theorem. A nonparametric test and ordinal regression were used to determine the role of the AFI and other factors on the functional outcome. Perioperative information, including demographic and fracture-related data, reduction quality, physical therapy duration, association with a lower limb fracture and avascular necrosis of the femoral head were prospectively gathered. Results The mean AFIs of A, B, C, and D groups were 14.3%, 35.9%, 59.5%, and 81.2%, respectively. No statistically significant differences were observed among the groups for demographic and fracture-related data. A better reduction quality (OR = 4.21, 95%CI 1.42 ∼ 12.43, χ2 = 6.781, P = 0.009) and a larger value of AFI (OR = 2.56, 95%CI 1.18 ∼ 5.55, χ2 = 5.648, P = 0.017) result in a higher functional score. The functional outcome of a physical therapy duration of more than 12 months (OR = 0.15, 95%CI 0.02 ∼ 0.90, χ2 = 4.324, P = 0.038) was better than that of less than 12 months. Lower limb fracture (OR = 0.13, 95%CI 0.02 ∼ 0.74, χ2 = 5.235, P = 0.022) and avascular necrosis of femoral head (OR = 0.02, 95%CI 0.00 ∼ 0.87, χ2 = 4.127, P = 0.042) were found to correlate with a lower functional score. Conclusion With a greater of AFI, the functional outcome score would be better. Other factors, including reduction quality, physical therapy duration, association with a lower limb fracture, and avascular necrosis of the femoral head, most likely also affect hip functional recovery.

Heterotopic Ossification in Trauma

Better understanding of the biology of heterotopic ossification (HO) formation will lead to treatment and prevention modalities that can be directed specifically at the cellular level. Early identification of HO precursor cells and target genes may provide prognostic value that guides individualized prophylactic treatment. Better understanding of molecular signaling and proteomics variability will allow surgeons to individualize preemptive treatment to suppress inflammation and formation of HO. Careful surgical technique to avoid muscle damage is important. Damaged muscle should be debrided as a prophylactic measure. Hemostasis and avoidance of a postoperative hematoma may decrease the chance of formation of HO.

Operative management of acetabular fracture: A 10-year experience in Isfahan, Iran

Background:

Pelvic and acetabular fractures constitute 2% of all fractures. The aim of the present study was to present acetabular fracture outcome in patients who underwent operative treatment.

Materials and Methods:

This study was a prospective cohort study, which was performed in Isfahan, Iran. During the period study, all patients who admitted to Alzahra Hospital with acetabular fracture and underwent acetabular surgery were evaluated. Data about age, sex, associated fractures, Intensive Care Unit admission, the time between admission and surgery were gathered. Patients were encouraged to return to the hospital after 1 week, 4 weeks, 6 months, and then yearly for the follow-up.

Results:

Sixty-five patients with acetabular fractures were referred to our hospital. Of them, 30 patients were indicated for surgical intervention and recruited in the study. The most frequent type of fracture involved posterior wall accounting for 49.9% of all fractures. More than 80% of study patients reached satisfactory results (excellent or good) based on Harris Hip Score (HHS). Female patients had significantly lower HHS in comparison with male patients (P = 0.01). Heterotopic ossification (HO) formation was more common in whom surgery was performed after 2 weeks (P = 0.005), however, there was no significant difference in HHS between these groups (P = 0.28).

Conclusions:

It is concluded that the female gender had an impact on the surgical outcome of acetabular fracture and indicated the lower functional outcome. Although there is an increase in HO formation in patients who do not undergo surgery during 2 weeks after the trauma, however, it does not influence the surgical outcome.

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.

Acetabular fractures: what radiologists should know and how 3D CT can aid classification

Correct recognition, description, and classification of acetabular fractures is essential for efficient patient triage and treatment. Acetabular fractures may result from high-energy trauma or low-energy trauma in the elderly. The most widely used acetabular fracture classification system among radiologists and orthopedic surgeons is the system of Judet and Letournel, which includes five elementary (or elemental) and five associated fractures. The elementary fractures are anterior wall, posterior wall, anterior column, posterior column, and transverse. The associated fractures are all combinations or partial combinations of the elementary fractures and include transverse with posterior wall, T-shaped, associated both column, anterior column or wall with posterior hemitransverse, and posterior column with posterior wall. The most unique fracture is the associated both column fracture, which completely dissociates the acetabular articular surface from the sciatic buttress. Accurate categorization of acetabular fractures is challenging because of the complex three-dimensional (3D) anatomy of the pelvis, the rarity of certain acetabular fracture variants, and confusing nomenclature. Comparing a 3D image of the fractured acetabulum with a standard diagram containing the 10 Judet and Letournel categories of acetabular fracture and using a flowchart algorithm are effective ways of arriving at the correct fracture classification. Online supplemental material is available for this article.

Comparative clinical study of the prophylaxis of heterotopic ossifications after total hip arthroplasty using etoricoxib or diclofenac

PURPOSE

This study investigated whether etoricoxib (COX-II blocker) has a superior efficacy of preventing heterotopic ossification (HO) after total hip arthroplasty (THA) compared to diclofenac (non-selective NSAID).

METHODS

One hundred patients were included (50 in each group) in this single centre, prospective, double-blinded, randomized, controlled trial. Etoricoxib (90 mg) was administered once and diclofenac (75 mg) twice per day for a perioperative period of nine days. The incidence of HO was evaluated on radiographs of the pelvis six months after surgery.

RESULTS

Eighty nine of 100 (89 %) patients could be analysed. The overall HO incidence was 37.8 %. There was no significant difference between both study groups. Twelve patients (27.3 %) of the DIC group and 13 patients (28.9 %) of the ETO group showed Brooker grade I ossifications. Five patients (11.4 %) of the DIC and four patients of the ETO (8.9 %) group showed grade II HO formations. No class III or IV HO formations occured in both groups. Ad hoc analysis detected a negative correlation between HO incidence and limited abduction and internal rotation of the hip.

CONCLUSIONS

Etoricoxib and diclofenac are equally effective for oral HO prophylaxis after primary cementless THA when given for nine peri-operative days to ensure a full recovery and high patient satisfaction.

Current therapeutic strategies of heterotopic ossification--a survey amongst orthopaedic and trauma departments in Germany

Background

Heterotopic ossification (HO) is a complication after tissue trauma, fracture and surgery (i.e. total hip arthroplasty). Prophylaxis is the most effective therapy. If HO formations become symptomatic and limit patients’ quality of life, revision surgery is indicated and is usually combined with a perioperative oral prophylaxis (NSAIDs) and/or irradiation. However, a long-term use of NSAIDs can induce gastro-intestinal or cardiac side-effects and possible bony non-unions during fracture healing. Subject of this study was to assess the current status of HO prophylaxis after injuries or fractures and to evaluate current indications and strategies for excision of symptomatic HO.

Methods

Between 2013 and 2014, a questionnaire was sent to 119 orthopaedic and trauma surgery departments in Germany. Participation was voluntary and all acquired data was given anonymously.

Results

The cumulative feedback rate was 71 %. Trauma and orthopaedic surgery departments in Germany recommend oral HO prophylaxis after acetabulum and femoral neck fractures, elbow dislocation, and fracture or dislocation of the radial head. Pain upon movement and an increasing loss of range of motion in the affected joint are considered to be clear indications for HO surgery. A partial removal of ROM-limiting HO formations was also considered important. The vast majority of all departments include perioperative oral HO prophylaxis and/or irradiation if surgical HO removal is planned. The choice and duration of NSAIDs is highly variable.

Conclusion

HO is of clinical significance in current traumatology and orthopaedics. Certain fractures and injuries are prone to HO, and prophylactic measures should be taken. The respondents in this survey assessed current therapeutic strategies for HO formations similarly. These concepts are in line with the literature. However, the duration of perioperative oral HO prophylaxis varied greatly among the specialist centres. This is significant as a long-term use of NSAIDs fosters a potential risk for the patients’ safety and could influence the clinical outcome. National and international guidelines need to be developed to further reduce HO rates and improve patients’ safety in trauma and orthopaedic surgery.

Surgical Approaches to the Acetabulum and Modifications in Technique

Acetabular injuries are often difficult to treat because the acetabulum is surrounded by many important structures, making access difficult and sometimes dangerous. Surgical exposures of the acetabulum are complex and require significant skill and in-depth knowledge of pelvic anatomy. Each approach has its limitations, and the potential morbidity associated with these exposures can be daunting. Recent modifications to traditional acetabular approaches have been developed to address these issues. Knowledge of the ilioinguinal, Kocher-Langenbeck, and extended iliofemoral surgical exposures and the potential drawbacks associated with each approach are essential to optimize treatment and minimize morbidity.

Incidence and clinical relevance of heterotopic ossification after internal fixation of acetabular fractures: retrospective cohort and case control study

Objective

The aim of the study was to evaluate predictors and clinical relevance of heterotopic ossification (HO) in patients treated for acetabular fractures in a tertiary referral centre.

Patients and methods

The study is a retrospective cohort study with a nested case–control study. All patients treated with internal fixation of acetabular fractures from January 2004 to October 2013. Ninety patients had postoperative imaging available at 6 and 12 months postoperatively and received no prophylaxis. Plain radiographs were used to grade HO. The Hip disability and Osteoarthritis Outcome Score (HOOS) was used to compare outcomes between patients suffering from HO with patients who did not.

Results

Sixteen patients (17.7%) suffered from HO. According to the Brooker classification, 5 had class I, 4 class II, 3 class III and 4 class IV HO. Traumatic brain injury (TBI) was the only significant risk factor for developing HO (odds ratio (OR) 8.6, 95% confidence interval (CI) (1.693–43.753), p = 0.014). The HO rate in patients with an anterior (ilioinguinal) or posterior (Kocher-Langenbeck) surgical approach was 20% and 21% respectively, and the HO rate in patients with a combined approach was much lower at 11%. Neither fracture type nor gender nor age increased the risk of HO significantly. The outcome measured by HOOS was not significantly different between patients with HO and patients in the control group. Patients with HO Brooker class II–IV had slightly lower (effect estimate +4.25, 95% CI (−10.2 to +12.10), p = 0.220) HOOS compared to the majority of the control group.

Conclusion

A very low rate of HO was found compared to the HO rates described in other studies with similar patient cohorts who received prophylaxis. Based on our findings and the current literature, we do not recommend giving prophylaxis against HO to patients after internal fixation of acetabular fractures.

The impact of race on the development of severe heterotopic ossification following acetabular fracture surgery

OBJECTIVES

To determine the association between race on severe heterotopic ossification (HO) following acetabular fracture surgery.

DESIGN

Retrospective case control study.

SETTING

Level I university trauma centre.

METHODS

Two hundred and fifty-three patients who were surgically treated for acetabular fractures were retrospectively evaluated. Postoperative radiographs were evaluated for HO by a blinded musculoskeletal radiologist, and classified based on a modified Brooker classification.

RESULTS

Of the 253 patients that met inclusion and exclusion criteria, 175 (69%) were male and 78 (31%) were female. One hundred and fifty-four (61%) patients were Caucasian, and 99 (39%) were African American (AA). Fifty-five (21%) patients developed severe HO. Of those who developed severe HO, 25 were Caucasian (45%), 30 were African American (55%). Forty-one patients (75%) with severe HO were male, and 14 (25%) were female. No statistical differences (p>0.05) were found between groups in terms of age, days to surgery, GCS at presentation, surgical approach, perioperative HO prophylaxis, or AO/OTA fracture classification. The patient population was then stratified by race, gender, and race/gender. AA were more likely than Caucasians to develop severe HO (odds ratio [OR], 2.24; confidence interval [CI], 1.22-4.11). When gender was considered independent of race, no statistical differences (p>0.05) were observed (OR, 1.40; CI, 0.71-2.75). AA males were much more likely to develop severe HO when compared to Caucasian females (OR, 4.4; CI, 1.38-14.06).

CONCLUSION

Race is associated with different rates of severe HO formation following acetabular fracture surgery. AA patients are significantly more likely to develop severe HO following acetabular fracture surgery when compared to Caucasian patients.

Risk factors for the development of heterotopic ossification after acetabular fracture fixation

BACKGROUND

Heterotopic ossification (HO) is a common complication of the operative treatment of acetabular fractures. Although the surgical approach has been shown to correlate with the development of ectopic bone, specific risk factors have not been elucidated.

QUESTIONS/PURPOSES

The purposes of this study were to determine specific risk factors associated with the development of severe HO and the frequency with which patients develop severe HO after acetabular fracture fixation through an isolated Kocher-Langenbeck approach.

METHODS

Using an institutional orthopaedic trauma database at a regional Level I trauma center, patients undergoing open treatment of acetabular fractures during the study period (January 2000 to January 2010) were identified. A review of medical records and imaging studies was performed on 508 patients who were treated by the senior author (MR) through an isolated Kocher-Langenbeck approach. During the study period, the senior author used indomethacin for HO prophylaxis in patients who had ipsilateral femur fracture treated with antegrade reamed medullary nailing or severe local soft tissue injury; 49 (10%) of the patients he treated with the Kocher-Langenbeck approach received prophylaxis, and they were excluded from this study, leaving a total of 459 patients who met inclusion criteria. Of those, 147 (29%) were lost to followup or did not have radiographs both before and at a minimum of 6 weeks (median, 1 week; range, 0-3 weeks), leaving 312 (61% of the patients treated with the Kocher-Langenbeck approach during this time) available for this analysis. Demographic data as well as information related to cause of injury, associated periacetabular findings, other system injuries, and treatment were gathered. Final followup radiographs were assessed for the presence of ectopic bone by two of the authors (TJO, AS) using the modified Brooker classification. Logistic regression was performed to identify possible predictors of development of severe ectopic bone.

RESULTS

The only predictor we identified for the development of severe HO was the need for prolonged mechanical ventilation (odds ratio, 7.1; 95% confidence interval, 2.9-17.3; p=0.001). Injury Severity Score, sex, presence of comminution, femoral head impaction, dislocation, degloving injury, debris in the joint, number of other fractures, and head and chest Abbreviated Injury Score>2 did not correlate with severe HO. Severe HO (Brooker Class III or IV) developed in 38 of 312 patients (12%).

CONCLUSIONS

Patients with prolonged mechanical ventilation might benefit from HO prophylaxis given the increased risk of developing severe HO in this patient population. However, future prospective studies need to be performed to verify this finding given the fact that a considerable number of patients were prophylactically treated in this study.

LEVEL OF EVIDENCE

Level IV, prognosticstudy. See Guidelines for Authors for a complete description of levels of evidence.

Prophylactic radiotherapy against heterotopic ossification following internal fixation of acetabular fractures: a comparative estimate of risk

OBJECTIVE

Radiotherapy (RT) is effective in preventing heterotopic ossification (HO) around acetabular fractures requiring surgical reconstruction. We audited outcomes and estimated risks from RT prophylaxis, and alternatives of indometacin or no prophylaxis.

METHODS

34 patients underwent reconstruction of acetabular fractures through a posterior approach, followed by a 8-Gy single fraction. The mean age was 44 years. The mean time from surgery to RT was 1.1 days. The major RT risk is radiation-induced fatal cancer. The International Commission on Radiological Protection (ICRP) method was used to estimate risk, and compared with a method (Trott and Kemprad) specifically for estimating RT risk for benign disease. These were compared with risks associated with indometacin and no prophylaxis.

RESULTS

28 patients (82%) developed no HO; 6 developed Brooker Class I; and none developed Class II-IV HO. The ICRP method suggests a risk of fatal cancer in the range of 1 in 1000 to 1 in 10,000; the Trott and Kemprad method suggests 1 in 3000. For younger patients, this may rise to 1 in 2000; and for elderly patients, it may fall to 1 in 6000. The risk of death from gastric bleeding or perforation from indometacin is 1 in 180 to 1 in 900 in older patients. Without prophylaxis risk of death from reoperation to remove HO is 1 in 4000 to 1 in 30,000.

CONCLUSION

These results are encouraging, consistent with much larger series and endorse our multidisciplinary management. Risk estimates can be used in discussion with patients.

ADVANCES IN KNOWLEDGE

The risk from RT prophylaxis is small, it is safer than indometacin and substantially overlaps with the range for no prophylaxis.

Massive heterotopic ossification associated with late deficits in posterior wall of acetabulum after failed acetabular fracture operation

Background

Heterotopic ossification is a common postoperative complication of acetabular fracture. However, functionally significant heterotopic ossification with associated late bone defects in the posterior wall of the acetabulum is rare and challenging to treat. When heterotopic ossification is a late complication of failed acetabular fracture operation, it is disabling and may only be treated by THA. THA is highly susceptible to premature failure in young and active patients and may require numerous revisions.

Case presentation

This article describes a 40-year-old man with massive heterotopic ossification associated with late bone defects in the posterior wall of the acetabulum after a failed acetabular fracture operation. The primary fracture type was a 62-A2.3 fracture according to the AO/OTA Classification.Surgical excision and anatomical reconstruction of the acetabular wall using heterotopic ossific bone were performed 10 months after the fracture repair. Postoperatively, indomethacin was administered for prophylaxis against recurrence of heterotopic ossification, and hip range of motion was progressively increased. At 5 years and 6 months follow-up, the patient’s pain was relieved and hip function had recovered. Though radiography and CT showed minimal subchondral cysts and mild joint-space narrowing, there was no evidence of graft resorption, progressive posttraumatic osteoarthritis or necrosis of the femoral head.

Conclusion

To the authors’ knowledge, this is the first case of such a challenging condition. Although it is an extremely rare case, it provides an attractive option for avoiding THA, as the long-term follow-up shows a satisfactory outcome.