Risk Factors For Heterotopic Ossification Research Articles

Incidence and risk factors of heterotopic ossification after cervical Baguera C disc arthroplasty.

This retrospective study was designed to evaluate the incidence and predisposing factors of heterotopic ossification (HO) after cervical disc arthroplasty (CDA) with a specific implant at 1 and 2 levels, and to investigate the biomechanical effects related to HO. The study goal was to identify ways to reduce the likelihood of HO formation after surgery. The study included patients who underwent only 1- or 2-level CDA with the Baguera C disc between November 2014 and December 2021 at a single medical center. All patients were operated on by the same neurosurgeon. The surgical indication included 1-level or 2-level disc herniation between C3 and C7 with radiculopathy, myelopathy, or both, with minimal spondylosis. The various factors were assessed by evaluating plain radiographs and cervical CT scans. The presence of HO was evaluated at different intervals postsurgery, and HO severity was graded using the McAfee classification. Of 107 patients who underwent CDA, 47 (43.9%) had HO at 63 of 171 levels (36.8%). Most cases with HO were grade 1, and no grade 4 was observed. Statistically significant risk factors for HO were the length of endplate coverage ratio and inferior anterior residual exposed endplate (AREE); sex, age, implant height and width, shell angle, and pre- and postoperative functional spinal unit (FSU) angle were not significant. More AREE and greater kyphotic postoperative FSU angle in the flexion position were significant factors differentiating HO grades 0 and 1 from grades 2 and 3. Furthermore, the non-HO group showed a trend of higher range of motion at any postoperative time compared to the HO group, especially at 1 month after surgery. The HO incidence after CDA was correlated with the residual length of endplate coverage and inferior AREE. Additionally, the AREE and kyphotic postoperative FSU angle in the flexion position were associated with HO grade progression. Patients with HO also showed a trend of lower range of motion at 1 month after surgery. Using an adequately sized implant and encouraging neck motion may help prevent HO development and progression.

Incidence and Risk Factors of Heterotopic Ossification in the Knee After Reamed Tibial Nailing.

Heterotopic ossification (HO) in the knee after tibial intramedullary nailing (IMN) has yet to be thoroughly investigated. Our aim was to assess frequency and associated factors for HO in the knee after tibial IMN. This is a retrospective review at a single level 1 urban trauma center of 213 patients who underwent reamed tibial IMN. Plain radiographs were reviewed postoperatively and on final follow-up (≥6 weeks). Chart review was performed for surgical approach (suprapatellar versus infrapatellar), demographics, injury characteristics, and clinical follow-up. The primary outcome was frequency of HO. HO on final follow-up (mean: 41.43 weeks) was recorded in 15% cases. Postsurgical retroinfrapatellar reaming debris (odds ratio [OR], 4.73), Injury Severity Score (OR, 1.05), intensive care unit admission (OR, 2.89), chest injury (OR, 3.4), and ipsilateral retrograde femoral IMN (OR, 5.08) showed a notable association with HO development. No association was observed in HO formation between surgical approach, knee pain, or range-of-motion deficits. Radiographic evidence of HO in the knee after reamed tibial IMN is not uncommon and is associated with retained reaming debris, Injury Severity Score, chest injury, intensive care unit admission, and ipsilateral retrograde femoral nailing. No differences were noted in HO formation between approaches. HO was not associated with knee pain or range-of-motion deficits.

Pelvic heterotopic ossification following total hip replacement causing fusion of femur shaft to pelvis

BackgroundThere is scarcity of literature exploring the risk factors for Heterotopic Ossification (HO) after Total Hip Replacement (THR) being performed for comminuted proximal femur fractures. HO occurring after THR usually involves the lateral side. HO occurring between the pubis and femur has rarely been reported, and if occurring, have not been reported to be joining the femur and pelvis. Case detailsWe present a case of HO occurring in a 60 year old gentleman after THR was done for a comminuted proximal femoral fracture. The HO was noted to be joining the medial aspect of the femur shaft to the pelvis. This bridging HO was found to restrict the range movements of the hip and adversely impact the functional outcome of the THR. ConclusionThis report is a lesson for orthopaedic surgeons performing THR following proximal femoral fractures to avoid leaving behind any loosely attached fracture fragments as they could increase the risk of HO.

Prevalence, Timing, Locational Distribution, and Risk Factors for Heterotopic Ossification After Elbow Arthroscopy

Background: Arthroscopic techniques aim to reduce complications and accelerate recovery of the elbow after treatments for posttraumatic stiffness, arthritis diseases, lateral epicondylitis, ligament reconstruction, and elbow trauma. However, data on the true prevalence and characteristics of heterotopic ossification (HO) formation after elbow arthroscopy are limited. Purpose: To investigate the prevalence, timing, locational distribution, and risk factors of HO after elbow arthroscopy. Study Design: Cohort study; Level of evidence, 4. Methods: Data on 205 patients undergoing elbow arthroscopy by a single senior elbow surgeon at a single institution between May 2011 and January 2022 were retrospectively reviewed. The patients were evaluated at 2 weeks, 8 weeks, 6 months, and then annually after surgery or more frequently if HO developed, with a minimum of 1 year of postoperative follow-up. Postoperative anteroposterior and lateral elbow radiographs were taken at 2 weeks to rule out fracture and at 8 weeks to identify HO. The clinical outcomes were evaluated based on the pain visual analog scale; the shortened version of the Disabilities of the Arm, Shoulder and Hand score; Mayo Elbow Performance Score; and the Single Assessment Numeric Evaluation scores before and after surgery. Bivariate logistic regression analyses were used to determine factors affecting HO prevalence. Results: Thirteen (12 male, 1 female) of 205 (6.3%) patients developed HO, with 10 (76.9%) with HO that formed on the medial compartment of the elbow. Ten (76.9%) patients were diagnosed at 8 weeks after arthroscopic surgery, 1 (7.7%) at 6 months after surgery, and 2 (15.4%) at 12 months after surgery. HO was not found at 2 weeks after surgery in any patient. The mean follow-up time was 3.5 years (range, 1.0-11.8 years). Eleven asymptomatic patients were treated nonoperatively, and 2 symptomatic patients underwent HO excision arthroscopically or had a combination of open surgery and arthroscopy. Age was a protective factor for HO formation (odds ratio [OR], 0.953; 95% CI, 0.910-0.999; P = .047). The risk factors for HO formation were tourniquet time (OR, 1.042; 95% CI, 1.019-1.065; P < .001) and surgical time (OR, 1.026; 95% CI, 1.011-1.041; P < .001). Conclusion: Among 205 patients who underwent elbow arthroscopy, HO was a minor complication of elbow arthroscopy, with a prevalence rate of 6.3%, and was usually located on the medial compartment of the elbow. Although the presence of HO may not affect the clinical outcomes in most patients, it should be carefully monitored for a minimum of 8 weeks postoperatively. Younger age, longer tourniquet time, and longer surgical time contributed to HO formation after elbow arthroscopy.

The Incidence of Heterotopic Ossification in Surgically and Non-surgically Treated Elbow Fractures at a Municipal Hospital in Japan.

Background: Heterotopic ossification (HO) is a well-recognised complication of after elbow trauma. The prevalence and risk factors of HO have been previously reported. However, these reports were based on elbow trauma that had undergone surgical treatment and most of them were from Western countries. This study aimed to assess the incidence of HO in patients with elbow fractures who were treated surgically and non-surgically in Japan. Methods: We retrospectively identified consecutive patients who were treated of elbow fractures and fracture-dislocations at our institution in recent consecutive 3-year periods. We extracted patient demographics, injury mechanisms and treatment details from the medical records. Furthermore, we reviewed radiographs to classify the fracture pattern and identify the presence or absence of HO. Results: HO was identified in 6/97 (6%) patients. Fracture-dislocation was noted in 4/6 patients. The fracture types with HO included terrible triad injury (n = 2), isolated coronoid process fractures (n = 2), distal humerus A-type fractures (n = 1) and radial head fracture (n = 1). According to the Hastings and Graham classification, HO was classified as Class I in five patients and Class II B in one patient who underwent additional surgery for HO resection. Conclusions: The incidence of HO was relatively low in our patients. However, of the 20 conservatively treated elbows, one patient developed clinically relevant HO and required excision of HO. Even patients with elbow fractures treated conservatively should be informed of the potential risk of developing severe HO requiring surgical excision. In addition, surgeons in this region could use these data to inform patients about the risk of HO development after an elbow injury. Level of Evidence: Level IV (Therapeutic).

Is Heterotopic Ossification Associated With Surgical Approach in Total Hip Arthroplasty?

Although risk factors for heterotopic ossification (HO) have been defined, the effect from surgical approach is not fully understood. The primary objective of our study was to evaluate the effect that surgical approach has on the risk for developing severe HO after total hip arthroplasty (THA) and compare this with other known risk factors. We hypothesized that there would be no difference in HO formation based on the surgical approach. We retrospectively reviewed all patients who underwent primary THA at our hospital between March 2011 and March 2021. Patients with HO documented in the radiology reports were cross-referenced with our THA data set and manually reviewed to determine Brooker classification. Patient demographics, medical comorbidities, surgical details, and medication information were collected from the electronic medical record and compared. Of 3,427 patients who underwent THA, 677 (19.8%) developed HO postoperatively. A multivariable analysis confirmed that surgical approach was independently associated with increased odds for HO development. The anterolateral (odds ratio [OR], 3.43; P < 0.001) and posterior (OR, 2.24; P < 0.001) approaches had increased odds for developing HO compared with the direct anterior approach. However, only the anterolateral approach (OR, 1.85; P = 0.033) demonstrated an increased association with the development of severe HO (Brooker 3, 4) postoperatively. Although the use of the direct anterior approach had the lowest overall OR for developing HO after THA, this is likely only clinically notable when compared with the anterolateral approach. III.

Incidence and Risk Factors of Heterotopic Ossification in a Matched Cohort Pediatric Population Undergoing Hip Arthroscopy

Background:The development of heterotopic ossification (HO) is a known complication after hip arthroscopy in adults and has been associated with male sex, older age, larger CAM resection, and obesity. However, the incidence after hip arthroscopy in the pediatric population is not well-documented.Hypothesis/Purpose:The purpose of this retrospective case-control study was to determine the incidence and risk factors for the development of HO in pediatric patients following hip arthroscopy over a ten-year period.Methods:Internal clinical and surgical records from a single pediatric institution were queried to identify all patients under the age of 21 years who underwent hip arthroscopy between 2008 and 2018. For analyses, the 27 cases that developed HO were matched 1:4 on age and sex with 107 controls that did not. Univariate logistic regression analysis was conducted to assess the relationship between demographic and perioperative factors on the development of HO. Multivariate logistic regression was utilized to determine what association, if any, the use of prophylactic NSAIDs (indomethacin 75 mg for three weeks) had on the development of HO when controlling for the change in alpha angle.Results:Twenty-seven of 693 (3.9%) hips that underwent hip arthroscopy developed HO within two years of surgery. The use of indomethacin prophylaxis (n=27) was not significantly associated with the development of HO (n=8, p=0.06), even when controlling for the change in alpha angle (p=0.12)—nor were age, sex, and BMI percentile (Table 1). For each degree increase in the change in alpha angle, there was an 8% increase in the odds of development of HO (OR=1.08; 95% CI=1.02, 1.15; p=0.01). After controlling for preoperative alpha angle and prophylactic NSAID use, there was a 19% increase in the odds of developing HO for every degree increase in the change in alpha angle (OR=1.19; 95% CI=1.08, 1.31; p<0.001). For each degree increase in the preoperative alpha angle, the odds of developing HO increased by 11% (OR=1.11; 95% CI=1.03, 1.20; p=0.006).Conclusion:The incidence of HO within two years of hip arthroscopy in pediatric patients is 3.9%. Prophylactic indomethacin was not found to be protective against HO, while resection of larger CAM lesions is a risk factor for the development of HO. Although studies in the adult hip arthroscopy population have pointed to a protective role of NSAIDs in HO formation, this relationship may not be applicable to the pediatric population.Table 1.Cohort demographics separated by development of HO (N=134).

Incidence and Risk Factors for Heterotopic Ossification in a Matched Cohort Adolescent Population Undergoing Hip Arthroscopy.

Heterotopic ossification (HO) is a known complication after hip arthroscopy in adults, positively associated with larger cam resection, male sex, older age, and obesity, and negatively associated with nonsteroidal anti-inflammatory drug (NSAID) use and capsular closure. However, it has not been well-documented in adolescents. The purpose of this study was to determine the incidence and risk factors for the development of HO in adolescent patients undergoing hip arthroscopy. Clinical and operative records from a pediatric institution were queried to identify patients aged 21 years or younger who underwent hip arthroscopy between 2008 and 2018. The 27 cases that developed HO were matched 1:4 on age and sex with 107 controls. The bivariate analysis assessed the relationship between demographic and perioperative factors on the development of HO. Multivariable logistic regression evaluated the association between prophylactic NSAID use (indomethacin 75 mg, 3 wk) and HO, controlling for surgeon and extent of cam resection (change in alpha angle). Twenty-seven of 595 (4.5%) hips that underwent hip arthroscopy developed HO within 2 years of surgery. Prophylactic indomethacin was not significantly associated with developing HO [30% (8/27), P=0.83], after controlling for surgeon and extent of cam resection-nor were age, sex, and body mass index percentile. Of patients who developed HO, a smaller proportion underwent reoperation for HO excision among those who received prophylactic indomethacin than those who did not [13% (1/8) vs. 63% (12/19), P=0.03]. The incidence of HO within 2 years of hip arthroscopy in this adolescent population was 4.5%. Although studies in the adult hip arthroscopy population have pointed to a protective role of NSAIDs (eg, indomethacin) in radiographic HO, the effect was less certain in this adolescent sample. Larger studies are important to further evaluate the role of prophylactic NSAIDs and variations in arthroscopic technique in developing HO. Level III-therapeutic, case-control study.

Heterotopic Ossification after Arthroscopic Elbow Release.

ObjectivesTo evaluate the incidence and risk factors of heterotopic ossification (HO) after arthroscopic elbow release.MethodsThe present study included 101 elbows, with arthroscopic release performed on 98 patients over the 5‐year period from November 2011 to December 2015. Patients were divided into three groups: group 1, with elbow arthritis, including 46 elbows in 43 patients; group 2, with posttraumatic extrinsic elbow stiffness (without intraarticular adhesion), including 23 elbows in 23 patients; and group 3, with intrinsic contractures (with intraarticular adhesion), including 32 elbows in 32 patients. Arthroscopic elbow release was performed under general anesthesia. For intrinsic stiffness, a radiofrequency device was applied to release intraarticular scar tissue and create work space, which was rarely necessary in groups 1 and 2. In the postoperative period, X‐rays and CT scans were assessed at follow up to determine if there was HO formation, which was diagnosed when new calcifications were identified. The functional recovery was evaluated by comparing the range of motion (ROM) and pain relief preoperativley and postoperatively in each group. Other complications were also assessed postoperatively.ResultsThe patients’ mean age was 38.6 years (range, 12–66), with 57 males and 41 females. Mean follow‐up was 21 months (range, 4–56). The active ROM and Mayo elbow performance index (MEPS) were improved from 93° ± 8.3° to 126° ± 12.4° (P < 0.05) and 71.4 ± 7.6 to 91.3 ± 8.7 (P < 0.001) in group 1, 66° ± 10.3° to 121° ± 10.7° (P < 0.005) and 65.6 ± 9.2 to 93.5 ± 11.2 (P < 0.05) in group 2, and 46° ± 6.7° to 91° ± 11.1° (P < 0.001) and 52.3 ± 6.4 to 80.6 ± 9.4 (P < 0.005) in group 3. HO developed in 25/101 cases (25%) and 4 patients with severe cases underwent repeat surgery. Those in group 1 were primarily arthritis patients; there were 3 out 46 cases with minor HO evident on X‐ray. In group 2, 1/23 had minor HO. In group 3, 21/32 patients had HO; 4 cases were considered severe, 4 were considered moderate, and 13 were considered minor. The average flexion–extension arc was improved by 47° at the last follow up. Other postoperative complications included 8 cases of prolonged drainage from portal sites, 17 transient nerve palsies, 1 permanent radial nerve injury, and 1 patient who developed delayed‐onset ulnar neuritis. This patient was fully recovered 5 months after surgery.ConclusionsThe high incidence of HO formation after arthroscopic elbow release may relate to improper application of a radiofrequency device. Minimizing thermal injury from these radiofrequency devices could reduce HO formation and improve postoperative functional recovery.

Risk factors for heterotopic ossification in operatively treated proximal humeral fractures.

Heterotopic ossification (HO) is a potentially devastating complication of the surgical treatment of a proximal humeral fracture. The literature on the rate and risk factors for the development of HO under these circumstances is lacking. The aim of this study was to determine the incidence and risk factors for the development of HO in these patients. A retrospective analysis of 170 patients who underwent operative treatment for a proximal humeral fracture between 2005 and 2016, in a single institution, was undertaken. The mean follow-up was 18.2 months (1.5 to 140). The presence of HO was identified on follow-up radiographs. The incidence of HO was 15% (n = 26). Our multivariate model revealed that male sex (odds ratio (OR) 3.57, 95% confidence interval (CI) 1.30 to 9.80 compared to female) and dislocation as the initial injury (OR 5.01, 95% CI 1.31 to 19.22) were significantly associated with the formation of HO (p < 0.05) while no significant associations were seen for the age of the patient, the characteristics of the injury, or the type of operative treatment. This retrospective radiological study is the first to investigate the association between the method of surgical treatment for a proximal humeral fracture and the formation of HO postoperatively. We found that male sex and dislocation as the initial injury were risk factors for HO formation, whereas the method of surgical treatment, the age of the patient, and the pattern of the fracture were not predictive of HO formation. While additional studies are needed, these findings can help to identify those at an increased risk for HO formation under these circumstances. Cite this article: Bone Joint J 2020;102-B(4):539-544.

The Effect of Footprint Mismatch on Heterotopic Ossification After Cervical Disk Replacement.

This was a retrospective study. The objective of this study was to analyze risk factors of heterotopic ossification (HO) after cervical disk replacement (CDR) and evaluate the effect of footprint mismatch on HO. Incidence of HO after CDR is high, but the exact related factors have not been fully elucidated. Radiographic data of patients who had undergone CDR with Prestige LP or Discover prosthesis in Tongji Hospital from July 2012 to December 2015 were reviewed. HO was graded according to McAfee classification and classified according to Jin morphologic classification. Footprint matching degree was evaluated using 3-dimensional computed tomographic images. Cervical sagittal alignment, functional spinal unit height, and range of motion were measured on radiographs. Preexisting degeneration was scored using Walraevens scoring system. Postulated risk factors including general factors, cervical sagittal alignment, functional spinal unit height, range of motion, postoperative biomechanical changes, preexisting degeneration, number of surgical levels, prosthesis type, use of nonsteroid anti-inflammatory drugs, and footprint matching degree were analyzed by first univariate tests, and then multivariate logistic regression was done to examine the relation with HO occurrence. Effect of footprint mismatch on type 1 HO of morphologic classification was evaluated. Data of 46 patients were collected; 43 were finally evaluated with a total 57 prostheses implanted, with a mean follow-up duration of 41.16±12.49 months. No significant differences in basic characteristics existed between 2 prosthesis groups, except follow-up time. Incidence of HO was 66.7%. Mean footprint matching degree in sagittal plane was 0.877±0.068 and in coronal plane was 0.852±0.092. Mean overall footprint matching degree was 0.699±0.102 (range: 0.388-0.993). Prosthesis type and footprint matching degree were significantly related with HO among all postulated risk factors in both univariate and multivariate analyses (P<0.05); the latter had larger Exp(B). Type 1 HO occurrence significantly related with footprint mismatch. Incidence of HO after CDR was high, and serious footprint mismatch existed. HO occurrence was significantly related with prosthesis type and footprint matching degree; the latter played a more important role.

Prevalence of and Risk Factors for Heterotopic Ossification After Cervical Total Disc Replacement: A Systematic Review and Meta-Analysis.

Study Design:A systematic review and meta-analysis.Objectives:The results from previous meta-analyses are limited by the small number of included studies. Moreover, the risk factors of heterotopic ossification (HO) have not been well studied. Therefore, this study aims to estimate the prevalence of HO after cervical total disc replacement (CTDR) at different follow-up time points and explore potential risk factors for HO.Methods:We searched databases to identify eligible studies that reported the rate of HO after CTDR. The pooled prevalence of HO, according to different grades of HO, length of follow-up and types of prosthesis, and 95% confidence intervals (CIs) were calculated. Multivariable meta-regression analyses were performed to identify factors that may contribute to the heterogeneity between estimates.Results:Of the 94 studies included, 82 studies reported an overall rate of HO, encompassing a total of 5861 cervical spinal levels that underwent CTDR. The overall pooled prevalence of HO was 32.5% (95% CI 26.7% to 38.4%). Single-level CTDR was associated with a higher overall rate of HO. When the rate of HO was stratified by McAfee/Mehren classification, the pooled prevalence of range of motion (ROM)–limiting HO was 11.0% (95% CI 9.2% to 12.8%). Latest publication, single-level CTDR, longer follow-up period, and studies published outside were associated with a higher rate of ROM-limiting HO.Conclusions:We provide a comprehensive overview of the prevalence of different grades of HO. This meta-analysis also identifies and rules out some risk factors for HO after CTDR.

Advances in the research of heterotopic ossification caused by burns

Heterotopic ossification is a rare complication of burns, and its incidence and risk factors are still unclear. Through summarizing the literature on heterotopic ossification caused by burns at home and abroad, the author searched for the risk factors of heterotopic ossification after burn and the new progress of its prevention and treatment. It was realized that the size, depth and healing time of burn wounds were related to heterotopic ossification; the nonsteroidal anti-inflammatory drugs, radiation therapy, and their combination therapy can be used for the prevention of heterotopic ossification; surgery is an effective means of treating heterotopic ossification.

Does Heterotopic Ossification in Cervical Arthroplasty Affect Clinical Outcome?

To investigate the occurrence and progression of heterotopic ossification (HO) in patients treated by anterior cervical discectomy with arthroplasty. It was evaluated if HO affects clinical outcome and range of motion (ROM). Risk factors of HO was studied as well. Patients who underwent anterior cervical discectomy with arthroplasty for a cervical radiculopathy because of a herniated disc from the NECK and PROCON trial were analyzed for HO at 12 and 24 months postoperatively. HO was scored according to the McAfee-Mehren classification. The index ROM was defined by a custom developed image analysis tool, and global cervical ROM was measured by Cobb's angle. Clinical outcome was evaluated by means of the Neck Disability Index and the 36-Item Short Form Health Survey. The occurrence of HO was 60% at 1 year, and it increased to 76% at 2-year follow-up. A total of 31% of patients were scored as high-grade HO at 1-year follow-up, and this percentage increased to 50% at 2-year follow-up. Clinical outcome does not correlate to HO grade, and no risk factor for high-grade HO could be identified. The ROM at the index level was significantly higher in low-grade HOgroup than those patients with high-grade HO, but in 15%-38% HO grade does not correspond to ROM. HO occurs in three fourths of the patients at 2 years after surgery, but does not necessarily correspond to clinical outcome, nor loss or preservation of ROM. The McAfee-Mehren classification should be combined with ROM evaluation to properly study HO.

Symptomatic heterotopic ossification: incidence and risk factors of a musculoskeletal complication in a general Intensive Care Unit

Background: Heterotopic ossification is a musculoskeletal complication in patients in intensive care unit which expects to impair their mobility and quality of life after discharge. The aim of the study was to examine the incidence and the risk factors of heterotopic ossification in critically ill patients. Methods: One hundred-ninety seven consecutive patients evaluated through clinical and laboratory screenings for heterotopic ossification upon admission and discharge and 123 of them were eligible for the study. Symptomatic heterotopic ossification was confirmed to 9 patients (7.31%) by means of ultrasonography and radiography. Many risk factors examined by logistic regression such as age, admission of Glasgow Coma Scale score, length of stay in intensive care unit, duration of mechanical ventilation, duration in Venturi mask and in mask tracheostomy, days in coma, traumatic and non-traumatic brain injury, increased intracranial pressure monitoring, autonomic dysregulation and days in respiratory alkalosis. Results: The risk factors that predict heterotopic ossification were: age, duration of mechanical ventilation, respiratory alkalosis, days in coma, admission of Glasgow Coma Scale score, increased intracranial pressure monitoring, autonomic dysregulation, and non–traumatic brain injury. In multivariate analysis were found significant the autonomic dysregulation, the respiratory alkalosis, the increased intracranial pressure monitoring and the duration of mechanical ventilation (F=17.44, p&lt;0.00).Conclusions: The incidence of symptomatic heterotopic ossification appears to be significant in a general intensive care unit. A few factors seem to predict the occurrence of it, confirming previous studies. Larger studies are needed to be done for better prevention and early identification of this frequent musculoskeletal complication in critical ill patients.

Incidence and risk factors for heterotopic ossification following periprosthetic joint infection of the hip.

Heterotopic ossifications (HOs) commonly occur following total hip arthroplasty. Data regarding the appearance of HO after periprosthetic joint infection (PJI) of the hip are rare. Therefore, the aim of this study was to analyze the incidence and potential risk factors for the development of HO in patients with PJI of the hip. We performed a single-center, retrospective study including patients treated with a two- or multistage operation and patients undergoing salvage procedure in cases of PJI of the hip with a minimum follow-up of 6months. A total of 150 patients were included in the analysis. The Brooker-scale was used to classify HO. Patients were divided in three groups: (1) No HO, (2) HO Brooker type 1-4, and (3) high-grade HO (HO Brooker type 3 and 4). In each group, we checked possible risk factors for the development of HO for statistical significance. Patients included in our study had a mean age of 70.4 ± 12.1years. Of all patients, 75 were women (50%). HOs could be found in 70 patients (46.7%). Twenty-seven patients showed HO Brooker type 1, 23 type 2, 15 type 3 and 5 type 4. Male gender [odds ratio (OR) 2.14; p = 0.022], smoking (OR 5.75; p = 0.025) were significant risk factors for HO. A chronic infection (OR 3.54; p = 0.029) and a higher number of procedures (p = 0.009) were significant risk factors for the development of high-grade HO. HOs often occur following surgical care of PJI. Male gender, smoking, a chronic infection and high number of operations are risk factors for developing HO after PJI.

Size of ischial fibro-ostosis is associated with heterotopic ossification after total hip arthroplasty.

The hypothesis of the present study was that degenerative fibro-ostosis (FO) of the ischial hamstring tendon insertion is a risk factor for heterotopic ossification (HO) following THA. We followed 103 consecutive patients (43 males, 60 females, mean age 61years) who underwent unilateral cementless THA for primary hip osteoarthritis and investigated the incidence of HO within the first 12months after surgery. On pre-operative radiographs, a standardized evaluation for FO of the ischial hamstring tendon insertion concerning horizontal, vertical, and square dimensions was performed. HO was classified according to Brooker on radiographs at 12months post-operatively. At follow-up, 56 patients (54%) had no radiographic evidence of HO, 23 (22%) were classified as Brooker I, 17 (17%) as II, 6 (6%) as III, and 1 (1%) as IV, respectively. Patients with post-operative HO had significantly greater vertical (3.0mm vs. 2.3mm, p= 0.001) and horizontal (47.9mm vs. 39.1mm, p= 0.025) dimensions of FO than patients without HO. Patients with FO and a vertical dimension of ≥ 2.5mm were more likely to develop HO (55.6%) than patients with a vertical FO dimension of less than 2.5mm (34.7%, OR = 2.35 p= 0.047). A weak correlation between the vertical and horizontal size of FO and the severity of HO was observed. Radiographic evidence of asymptomatic FO is a potential risk factor for the development of HO following THA and may be used as a simple diagnostic tool to pre-operatively identify patients at risk for post-operative HO. This association has not been previously described and further research to confirm the present findings and to justify additional prophylactic treatment in these patients is warranted.

Prophylactic Celecoxib Administration Is Associated With Decreased Incidence and Severity of Heterotopic Ossification After Hip Resurfacing by Direct Lateral Approach in Male Patients.

Heterotopic ossification is a potential complication that may have a particularly higher association with hip resurfacing. The 2 current mainstays for heterotopic ossification treatment and prophylaxis are administration of nonsteroidal anti-inflammatory drugs and radiotherapy. Recent studies have determined that celecoxib is effective in heterotopic ossification prophylaxis after total hip arthroplasty. However, considering the reportedly higher incidence and severity of heterotopic ossification in these patients, relatively few studies have evaluated its role in hip resurfacing. Therefore, the authors assessed the incidence, severity, and risk factors of heterotopic ossification in patients who had hip resurfacing and did or did not receive celecoxib. Of the 198 patients, 83 received celecoxib and 115 did not. Radiographs were examined to grade heterotopic ossification using the Brooker classification system. The rate of heterotopic ossification differed between patients who did and patients who did not receive celecoxib prophylaxis (25% vs 65%, P<.001). Celecoxib was an independent predictor of decreased heterotopic ossification (odds ratio, 0.16; 95% confidence interval, 0.08-0.35). Celecoxib administration is associated with decreased incidence and severity of heterotopic ossification after hip resurfacing performed using the direct lateral approach in male patients. [Orthopedics. 2018; 41(6):e807-e812.].

131 - Clinical Implications and Risk Factors of Heterotopic Ossification at 7 Years after Cervical Total Disc Replacement

BACKGROUND CONTEXT: Heterotopic ossification (HO) is a known risk following cervical total disc replacement (CTDR) surgery, but potential risk factors and impacts on outcomes remain unknown. Reported HO rates vary, and few studies are specifically designed to report HO. The effects on outcomes, and the risk factors for development of HO have been hypothesized and reported in literature, but the studies included small populations, retrospective analyses, and the use of univariate statistics.

Heterotopic Ossification after Arthroscopic Elbow Contracture Release

The excessive use of a radiaofrequency device in arthroscopic elbow release will result in an increased incidence of heterotopic ossification. This study investigates the prevalence and risk factors of heterotopic ossification (HO) in arthroscopic elbow release surgery. There were 101 elbows with arthroscopic release performed on 98 patients over the 5-year period from November 2011 to December 2015. They were divided into 3 groups. Group 1, elbow arthritis, included 46 elbows in 43 patients. Group 2, posttraumatic extrinsic elbow stiffness, included 23 elbows in 23 patients, and 32 elbows in 32 patients with intraarticular fractures and severe intrinsic contractures were in Group 3. Arthroscopic elbow release was performed under general anesthesia. In the postoperative period, x-ray or CT was followed up regularly to determine if there was HO, which was diagnosed when significant new calcifications were identified. The functional recovery was evaluated by comparing the range of motion and Mayo Elbow Performance Score (MEPS) pre and postoperatively in each group. Other complications were also assessed postoperatively. The patients’ mean age was 38.6 (range, 12–66) years old, with 57 males and 41 females. Mean follow-up was 21 (range, 4–56) months. HO developed in 25/101 (25%) elbows and 4 severe cases underwent repeat surgery. Group 1 patients were primarily arthritis and 3/46 (6.5%) elbows had minor HO on x-ray. In Group 2, 1/23 (4.3%) elbows had minor HO. However, in Group 3, 21/32 (65.6%) elbows developed HO, including 4 severe cases, 4 moderate cases and 13 minor cases. The average flexion– extension arc was improved from 93° to 126° in Group 1, 66° to 121° in Group 2, 46° to 91° in Group 3 at the last follow up. MEPS increased from 71.4 to 91.3 in Group 1, 65.6 to 93.5 in Group 2 and 52.3 to 80.6 in Group 3. In these severe intrinsic contractures cases, we routinely applied the radiofrequency device to create space for visualization and release, which was rarely used in Group 1 and 2. The occurrence of HO after arthroscopic elbow release for intrinsic posttraumatic stiffness was unexpectedly high. The predominant risk factor for the increased incidence of heterotopic ossification in this series was excessive use of radiofrequency, and this complication apparently impaired the otherwise predictable outcome.