Heterotopic ossification following hip arthroplasty: a comparative radiographic study about its development with the use of three different kinds of implants

Severe heterotopic ossification after total hip arthroplasty in male patients under 70 years of age: effectiveness of prophylactic protocol

BACKGROUND

This study aims to evaluate the incidence of clinically significant heterotopic ossification (HO) in primary total hip arthroplasty (THA), comparing outcomes with and without the adoption of an HO prophylactic protocol in male patients under 70 years of age.

METHODS

The prophylactic protocol involved the administration of 50 mg of Indomethacin twice daily for 3 weeks. HO presence was classified according to the Brooker classification system, considering "severe" clinically significant HO (Brooker grade 3 and 4).

RESULTS

Two hundred and seventy-nine patients were included in our study, and an overall HO rate of 68.2% versus a rate of 61.5% was found respectively in patients not subjected and subjected to prophylactic protocol, without significant difference (PR 0.062). However, patients not subjected to the HO prophylactic protocol exhibited a severe HO rate of 22.4% compared to 7.7% in the prophylactic group, with a statistically significant difference (P = 0.008).

CONCLUSIONS

Our study demonstrated that prophylactic protocol adoption is significantly associated with lower rate of severe HO in male patients under 70 years of age. Currently, there are no orthopedic guidelines for the prevention and management of HO after THA, but in the absence of contraindications, the adoption of a prophylactic protocol for HO should always be considered in high-risk patients.

Pseudotumor in total knee revision arthroplasty resembling heterotopic ossification: A case report

INTRODUCTION

Pseudotumors are well-known complications following total hip arthroplasty (THA), usually attributed to debris-induced inflammation from direct metal-on-metal contact between implants. In total knee arthroplasty (TKA), the traditional use of polyethylene as a bearing surface prevents direct metal articulation. Thus, pseudotumor formation in TKA usually suggests atypical metal interaction between the prosthetic components.

PRESENTATION OF CASE

We presented the case of a 65-year-old male who developed a progressively growing mass in the left posterior knee after revision TKA, debuting as heterotopic ossification (HO) based on the radiographic assessment. Subsequent histopathological examination establishes the diagnosis of a pseudotumor.

DISCUSSION

Pseudotumors impose a diagnostic challenge in TKA due to their non-specific presentation and imaging, which may overlap with other etiologies. Currently, there are no standardized guidelines for pseudotumor assessment in TKA, and each case should be approached individually without relying on a simple diagnostic tool.

CONCLUSION

Physicians should consider a comprehensive approach supported by a high index of suspicion to include pseudotumors within the differential diagnosis of knee periprosthetic masses.

Heterotopic ossification following total hip arthroplasty. Which is the predominant risk factor: surgical approach or post-operative prophylaxis?

PURPOSE

To investigate the impact of surgical approach and post-operative prophylaxis on heterotopic ossification (HO) development after total hip arthroplasty (THA).

METHODS

A retrospective analysis of 312 patients who underwent THA between January 2009 and April 2016. Patients were categorized by surgical approach (direct lateral or posterolateral), prosthesis type, and post-operative prophylaxis (Etoricoxib 60 mg daily for two weeks). Two orthopaedic surgeons independently assessed radiographs at serial intervals, and HO was graded as per Brooker classification. Bivariate analysis and regression modelling were performed to assess the associations and confounding effects of different variables, RESULTS: Bivariate analysis identified factors correlated with higher HO incidence: absence of prophylaxis, older age, longer symptom evolution, and lower pre-surgery physical activity. Regression modelling showed a correlation between the direct-lateral approach, post-operative prophylaxis, symptom evolution, and higher HO incidence.

CONCLUSION

Patients with longer symptom evolution before surgery and without post-operative prophylaxis are at higher risk of developing HO. While the direct lateral approach showed higher HO rates, the difference was insignificant. A two-week prophylactic regimen of Etoricoxib 60 mg daily after THA effectively reduced HO formation. Pharmacological prophylaxis should be evaluated case-by-case, considering patient characteristics and risk factors.

Unipolar Hip Hemiarthroplasty in Geriatric Patients: A Prospective Study and Analysis of Clinical and Radiological Outcomes

Introduction

Femoral neck fractures (FNF) in the geriatric population are commonly treated with hip replacement procedures, such as total hip arthroplasty, unipolar hip hemiarthroplasty (UHA), and bipolar hip hemiarthroplasty (BHA). The optimal treatment remains controversial, considering outcomes and cost-effectiveness, with UHA often being cheaper. This prospective observational study aims to evaluate UHA's clinical and radiological outcomes, safety, and survivorship compared to existing literature.

Methods

We followed 90 elderly patients who underwent UHA following FNF. We assessed patients using the Parker score before and after surgery, as well as Harris Hip Score (HHS), and Postel-Merle d'Aubigné (PMA) scores postoperatively. All complications, acetabular erosions and heterotopic ossifications (HO), were documented.

Results

One year post-surgery, 26.7% of patients had passed away, mostly due to declining general health status. Systemic complications occurred in 14.4% of cases, with a 1.1% rate of deep surgical site infections. A single dislocation resulted from excessive stem anteversion. UHA implant survival rate was 97.8% after 4 years. The Parker score remained stable, and HHS at 6 and 12 months was 71.5 ± 12.9 and 70.9 ± 11.8, respectively, while PMA score was 14.3 ± 2.4 and 14.5 ± 2.1, respectively. Five hips showed Baker I acetabular wear. HO were noted as Brooker I in 12 patients, II in 4 patients, and IV in 1 patient.

Discussion

UHA exhibited comparable systemic complication rates, implant survivorship, and dislocation rates to those in the literature for both UHA and BHA. The deep surgical site infection rate was lower than reported for BHA. Patients' functional and mental abilities did not decline based on clinical scores. Acetabular wear in UHA was similar to its bipolar counterpart, while HO were only minor findings with no clinical implications.

Conclusion

In elderly patients, UHA demonstrated clinical and radiological outcomes similar to BHA in existing literature. UHA may represent a cost-effective alternative for patients with limited life expectancy.

Clinical and radiological outcomes of an uncemented metaphyseal short stem at minimum 10 years of follow-up: a prospective observational study

PURPOSE

There is growing interest around short stems as they provide a less invasive approach for total hip arthroplasty preserving bone stock for a possible revision surgery if required. The main purpose of this work was to assess the long-term performance of an uncemented metaphyseal short stem in terms of survival rate and in addition its clinical and radiological outcomes.

MATERIALS AND METHODS

From January to December 2010, we prospectively enrolled all consecutive patients undergoing primary total hip arthroplasty with an uncemented metaphyseal short stem in our institution with a minimum follow-up of 10 years. The radiographic features investigated were the varus-valgus stem orientation, areas of osteolysis and radiolucencies, stress shielding, and heterotopic calcifications. The clinical outcomes were measured using the HHS.

RESULTS

A total of 163 patients (172 hips) were finally included and the measured survival rate at 10 years was 99.6%. The average HHS increased from 55.0 preoperatively to 97.8 at the last follow-up (p < 0.0001). Among them, 137 patients (164 hips) were also available for radiographic assessment. Mild varus malalignment was observed in 40% of cases and remained stable in the serial X-rays and was not associated with step loosening. Mild stress shielding was observed around 13 stems (9%) and moderate only around 3 implants.

CONCLUSION

In conclusion, the uncemented metaphyseal short stems showed excellent survival and clinical results at 10 years and at a radiographical level very low stress shielding was observed; moreover, besides the high frequency of varus alignment the implanted stems was not associated with revision surgery or with worse clinical outcomes.

Effect of mechanical stimulation on tissue heterotopic ossification: an in vivo experimental study

Background: Heterotopic ossification of tendons and ligaments (HOTL) is a common clinical condition characterized by the absence of discernible features and a lack of effective treatment. In vitro experiments have demonstrated that mechanical stimulation can induce cell differentiation toward osteogenesis, thereby promoting heterotopic ossification. Currently, there are few experimental designs aimed at inducing ligament stretching in mice, and the mechanism of heterotopic ossification may not entirely mirror that observed in clinical cases. Therefore, there is an urgent imperative to develop a novel and feasible animal model. Methods: In this study, all the Enpp1 gene deficiency mice (a mouse model with heterotopic ossification of multiple ligaments) were divided into three groups: the control group, the spinal brake group, and the hyperactive group (treadmill training group). An external spinal fixation device was designed to restrict mice's spinal flexion and extension at 6 weeks of age. The brace was adjusted weekly according to the changes in the size of the mice. Additionally, treadmill training was used to increase activity in the spinal ligaments and Achilles tendons of the mice. Micro-CT scanning and HE staining were performed at 12, 20, and 28 W to evaluate the degree of ossification in the spinal ligament and Achilles tendon. What's more, As one of the mechanical stimulation transduction signals, YAP plays a crucial role in promoting osteogenic differentiation of cells. Immunofluorescence was utilized to assess YAP expression levels for the purpose of determining the extent of mechanical stimulation in tissues. Results: Our findings showed that a few ossification lesions were detected behind the vertebral space of mice at 8 weeks of age. Spinal immobilization effectively restricts the flexion and extension of cervical and thoracic vertebrae in mice, delaying spinal ligament ossification and reducing chronic secondary spinal cord injury. Running exercises not only enhance the ossification area of the posterior longitudinal ligament (PLL) and Achilles tendons but also exacerbate secondary spinal cord injury. Further immunofluorescence results revealed a notable increase in YAP expression levels in tissues with severe ossification, suggesting that these tissues may be subjected to higher mechanical stimulation. Conclusion: Mechanical stimulation plays a pivotal role in the process of heterotopic ossification in tissues. Our study provided valid animal models to further explore the pathological mechanism of mechanical stimulation in HOTL development.

Heterotopic ossification in primary total hip arthroplasty: risk factor analysis

BACKGROUND

Aim is to identify if age, sex, type of posterolateral approach (mini vs standard), surgical time and time from surgery to drainage removal were independent risk factors for heterotopic ossifications after total hip arthroplasty.

MATERIALS AND METHODS

Patients who underwent a THA with posterolateral approach during a 15 years period were included. The exclusion criteria were absence of X-rays follow-up or HO prophylaxis protocol adoption. The following data were collected: age, sex, type of approach (classical/minimal-invasive), surgical time, time from surgery to drainage removal. Two orthopedic surgeons independently reviewed the 2 years follow-up X-rays and classified the HO according to Brooker classification. Severe HO was defined if HO were classified as major than grade 2. Correlation between severe HO and risk factor has been tested with multivariable analysis.

RESULTS

About 1225 patients were included: mean age of 63.8 years, 504 were men. HO were found in 67.6%. Men showed higher severe HO rate than woman (44.1% vs 29.1%, p = 0.001). Patients older than 65 years showed higher severe HO rate (30.3% vs 39.9%, p = 0.002). Standard posterolateral approach was performed in 75.4% and severe HO rate was 32.8% versus 27.1% in those treated with the minimally invasive approach (p = 0.067). In 75.6% of cases surgery lasted less than 90 min and this group showed a severe HO rate in 29.1%, while patient with longer surgical time showed a rate of 35.7% (p = 0.033). In 47.4% of patients, the drainage was removed in the first post-operative day, in this group severe HO rate was significantly lower than the others: 24.8 versus 36.2% (p = 0.001).

DISCUSSION

Male sex, age older than 65 years, surgical time longer than 90 min and delayed drainage removal are risk factors for severe HO. Patients with one or more of those risk factors should be identified as good candidates for HO prophylaxis.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

LEVEL OF EVIDENCE

III.

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.

Predicting the Poor Clinical and Radiographic Outcomes after the Anatomical Reduction and Internal Fixation of Posterior Wall Acetabular Fractures: A Retrospective Analysis

Anatomical reduction is the fundamental principle of hip function restoration after posterior acetabular wall fractures (PWFs). Some patients exhibit poor outcomes despite anatomical reduction, and the prognostic factors leading to poor outcomes remain elusive. This study aimed to investigate the clinical and radiographic outcomes in patients with PWFs who had undergone anatomical reduction and internal fixation and to identify the predictors that impair clinical and radiologic outcomes. The clinical records of 60 patients with elementary PWFs who had undergone anatomical reduction and internal fixation between January 2005 and July 2015 were reviewed retrospectively. The Harris hip score (HHS) and modified Merle d’Aubigné clinical hip scores (MMAS) were used to evaluate the clinical outcome. Preoperative and final follow-up radiographs were cross checked to identify poor radiographic outcomes that included the presence of advanced osteoarthritis and osteonecrosis, as well as the need for conversion to total hip arthroplasty. Acetabular dome comminution was assessed from computerized tomography, and the outcomes were further evaluated according to the involvement of fragment comminution. The fracture comminution and age were negatively correlated with functional outcomes (correlation coefficients were −0.41 and −0.39 in HHS and MMAS, respectively) and were significantly related to the severity of osteoarthritis and osteonecrosis as well as the need for total hip arthroplasty. Regarding the radiographic factors, significantly worse post-operative HHS and MMAS were found in the fracture comminution group. In the subanalysis of the status of fracture comminution, patients with fragment comminution involving the acetabular dome had significantly lower functional scores than those with other fracture patterns. In conclusion, age, fracture comminution, and dome comminution were the prognostic indicators of advanced osteoarthritis and poor functional scores after the anatomical reduction and internal fixation of PWFs. We emphasized the relevance of acetabular dome comminution as an important contributing factor to clinical and radiographic outcomes.

Are there really specific risk factors for heterotopic ossifications? A case report of 'non-risk factor' after total hip replacement

Femoral neck fractures are one of the most common fractures in the elderly population. Due to frequent complications of the fixation of these fractures, patients are more and more often eligible for hip replacement surgery. One of the most frequently mentioned postoperative complication is the formation of heterotopic ossification. This case report describes as a 70-year-old male patient that presented with an old hip fracture accompanied by a mild craniocerebral trauma. The patient underwent total cementless hip arthroplasty followed by rehabilitation. At 8 months after surgery, the patient was diagnosed with Brooker IV° heterotopic ossification in the area of the operated hip joint. Due to the persistent pain and complete loss of mobility in the operated joint, computed tomography imaging was performed and the patient was recommended for a revision surgery. The procedure was performed 14 months after the original surgical treatment, resulting in a significant improvement in the range of motion and reduction of pain.

Increased risk of high-grade heterotopic ossification using direct lateral approach versus a muscle-sparing anterolateral approach to the hip: radiological results from a randomised trial in patients with a femoral neck fracture treated with hemiarthroplasty

BACKGROUND AND PURPOSE

Hemiarthroplasty is a common treatment in patients with displaced femoral neck fracture. Due to positive claims of less pain, earlier mobilisation and favourable functional outcome, the anterior approaches to the joint are gaining in popularity. This randomised controlled trial investigated if component placement and heterotopic ossification differed between a muscle sparing anterior approach and a direct lateral approach.

PATIENTS AND METHODS

150 patients operated with an uncemented hemiarthroplasty, were randomised to anterolateral or direct lateral approach and assessed postoperatively radiologically. Measurements included leg-length discrepancy, femoral offset, femoral stem position, canal fill ratio and the presence of heterotopic ossification after 12 months.

RESULTS

There was an increased risk of high-grade heterotopic ossification in the direct lateral approach (p < 0.05). We found no statistically significant differences in leg-length discrepancy, femoral stem position or femoral offset.

CONCLUSIONS

Hemiarthroplasty performed in the direct lateral approach resulted in a higher incidence of Brooker grade 3 heterotopic ossification. Our results support equal geometrical restoration and similar component placement with both approaches.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov Identifier: NCT03974698Uncemented Hemiarthroplasty, Radiological Features Comparing Lateral Versus Anterolateral Approach https://www.clinicaltrials.gov/ct2/show/NCT03974698?term=raymond+tellefsen…draw=2…rank=1.

Factors influencing the outcomes of minimally invasive total hip arthroplasty: a systematic review

Introduction

The present systematic review investigated possible factors which may influence the surgical outcome of minimally invasive surgery for total hip arthroplasty (MIS THA).

Methods

In January 2022, the Embase, Google Scholar, PubMed, and Scopus databases were accessed. All the clinical trials investigating the clinical outcome of MIS THA were considered.

Results

Data from 9486 procedures were collected. Older age was moderately associated with greater Visual Analogue Scale (VAS) (P = 0.02) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) (P = 0.009) at last follow-up, and shorter surgical duration (P = 0.01). Greater body mass index (BMI) at baseline was moderately associated with greater cup anteversion (P = 0.0009), Oxford Hip Score (OHS) at last follow-up (P = 0.04), longer surgical duration (P = 0.04), increased leg length discrepancy (P = 0.02), and greater rate of infection (P = 0.04). Greater VAS at baseline was weakly associated with greater VAS at last follow-up (P < 0.0001), total estimated blood lost (P = 0.01), and lower value of Harris Hip Score (HHS) (P = 0.0005). Greater OHS at baseline was associated with greater post-operative VAS (P = 0.01). Greater WOMAC at baseline was associated with lower cup anteversion (P = 0.009) and greater VAS (P = 0.02). Greater HHS at baseline was associated with shorter hospitalisation (P = 0.001).

Conclusion

Older age and greater BMI may represent negative prognostic factors for MIS THA. The clinical outcome is strongly influenced by the preoperative status of patients.

Intervertebral bridging ossification after kyphoplasty in a Parkinson’s patient with Kummell’s disease: A case report

BACKGROUND

The short-term therapeutic efficacy of kyphoplasty on Kummell’s disease is obvious. However, postoperative refracture and adjacent vertebral fracture occur occasionally and are difficult to treat. Parkinson's disease (PD) is a pathological disorder associated with heterotopic ossification. In a patient with PD, an intervertebral bridge was formed in a short period of time after postoperative refracture and adjacent vertebral fracture, providing new stability.

CASE SUMMARY

A 78-year-old woman had been suffering from PD for more than 10 years. Three months before operation, she developed lower back pain and discomfort. The visual analog scale (VAS) score was 9 points. Preoperative magnetic resonance imaging indicated collapse of the L2 vertebra. Kyphoplasty was performed and significantly decreased the severity of intractable pain. The patient’s VAS score for pain improved from 9 to 2. Fifty days postoperatively, the patient suddenly developed severe back pain, and the VAS score was 9 points. X-ray showed L2 vertebral body collapse, slight forward bone cement displacement, L1 vertebral compression fracture, and severe L1 collapse. The patient was given calcium acetate capsules 0.6 g po qd and alfacalcidol 0.5ug po qd, and bed rest and brace protection were ordered. After conservative treatment for 2 mo, the patient's back pain was alleviated, and the VAS score improved from 9 to 2. Computed tomography at the 7-mo follow-up indicated extensive callus formation around the T12-L2 vertebrae and intervertebral bridging ossification, providing new stability.

CONCLUSION

Kyphoplasty is currently a conventional treatment for Kummell's disease, with definite short-term effects. However, complications still occur in the long term, and these complications are difficult to address; thus, the treatment needs to be selected carefully. To avoid refracture, an interlaced structure of bone cement with trabeculae should be created to the greatest extent possible during the injection of bone cement. Surgical intervention may not be urgently needed when a patient with PD experiences refracture and adjacent vertebral fracture, as a strong bridge may help stabilize the vertebrae and relieve pain.

Treatment of Pauwels type III femoral neck fracture with medial femoral neck support screw: a biomechanical and clinical study

A femoral neck fracture is currently one of the most common types of fracture in clinical practice. The incidence continues to increase due to traffic accidents, trauma, and osteoporosis. This research includes a biomechanical study and a clinical retrospective study. In the biomechanical studies, three groups' effects (Control Group: 3CCS, DHS group, and study Group: 3CCS + mFNSS group) were compared by vertical compression tests, torsion tests, and fatigue tests. All the data were collected and analyzed. We subsequently performed a retrospective analysis of 131 patients with femoral neck fractures. The operative time, intraoperative blood loss, quality of postoperative fracture reduction, and follow-up observation of fracture healing, screw retreatment rates and fixation failure rates, as well as femoral head necrosis rates and hip function in two groups with 3CCS and 3CCS + mFNSS were compared. By the biomechanical study, we found that 3CCS + Mfnss group were biomechanically superior to 3CCS group and superior to the DHS group in terms of resistance to torsion. However, it was less effective than the DHS group in compressive strength and fatigue resistance. In terms of clinical application, 3CCS + mFNSS group was found to have lower screw retreatment rates and femoral head necrosis rates, and to have better fracture healing rates than group with 3CCS, indicating that medial support screws can effectively resist the vertical shear forces of fracture ends and promote the stability and healing of fracture ends, as well as to reduce the incidence of postoperative complications.

Simplified biplanar classification for heterotopic ossification is more predictive of patient-reported outcomes than the Brooker classification after anterior total hip arthroplasty

BACKGROUND

Heterotopic ossification (HO) commonly occurs after total hip arthroplasty (THA) and can adversely impact clinical outcomes. The purpose of this study is to propose a more reliable HO grading method that is better predictive of patient-reported outcomes (PROs) after THA than the Brooker classification.

METHODS

513 THAs (62 ± 10 years old) were reviewed. The incidence and grade of HO was evaluated using the Brooker grading system and a simplified biplanar classification system (grade 1: ⩾1 cm between bone on both anteroposterior and lateral views, grade 2: <1 cm between bone on either view). The modified Harris Hip Score (mHHS), Forgotten Joint Score (FJS), and visual analogue scale (VAS) for pain were collected at minimum of 2 years after surgery and were compared between HO grades using multiple regression models.

RESULTS

The incidence of HO varied by Brooker grade (grade 1, 23.4%; grade 2, 22.4%; grade 3, 7.2%; grade 4, 0%) and biplanar grade (grade 1: 45.6%; grade 2: 7.4%). The biplanar classification demonstrated higher interobserver reliability than the Brooker classification (κ = 0.95 and 0.91, respectively). Brooker grade 3 HO decreased the mHHS by 6.5 (standard error: 2.7) but did not have a significant effect on FJS or VAS. Biplanar grade 2 HO decreased the mHHS by 9.9 (standard error: 2.7), the FJS by 12.9 (standard error: 4.51) and increased the VAS pain score by 0.81 (standard error: 0.35). The Cox test was used to compare the fit of regression models and determined the biplanar classification was a significantly better predictor than the Brooker classification (p < 0.001).

CONCLUSIONS

Biplanar grade 2 HO had a significant negative influence on PROs. Contrary to previous literature, these results show clinical significance of non-bridging HO. Compared with the Brooker classification, the biplanar classification has greater interobserver reliability and is more predictive of outcomes after THA.

Total hip arthroplasty or hemiarthroplasty for femoral neck fractures in elderly patients with neuromuscular imbalance

AIM

This study aimed at comparing clinical outcomes between total hip arthroplasty (THA) and hemiarthroplasty (HA) in elderly patients with neuromuscular imbalance (stroke, Parkinsonism, etc.).

METHODS

A total of 226 elderly patients with neuromuscular imbalance and femoral neck fractures treated with THA or HA were recruited at a single center, and their clinical data retrospectively reviewed. Mean follow-up time was 40.5 months (range 24-78), the primary outcome was secondary hip procedure while secondary outcomes included function, pain, health-related quality of life, complications, and death. Kaplan-Meier survival curves were used to determine the estimated survivorship, with re-operation as the end point. Logistic regression analyses were performed to assess the effects of different surgical procedures on mortality while linear regression analysis was used to evaluate the function, pain and quality of life.

RESULTS

Kaplan-Meier survivorship, with an end point of re-operation for any reason in the THA group, was 90.3% (95% CI 82.3-98.3), which was not significantly different from 95.9% (95% CI 93.0-98.8) for the HA group (p = 0.137). The most common cause of re-operation in both groups was dislocation. There were no significant differences with regards to postoperative complications (including dislocation). Compared to HA, THA exhibited better functional outcomes, quality of life and low pain intensity. Notably, there was no difference in 2 year mortality rates between the groups, however, HA was associated with a higher mortality rate beyond 2 years (OR 0.137; 95% CI 0.030-0.630; p = 0.011).

CONCLUSION

THA is an effective therapeutic procedure for femoral neck fractures in elderly patients with neuromuscular imbalance.

Comparison of functional outcome of cemented total hip replacement versus cemented dual-mobility cup total hip replacement for the management of displaced femoral neck fractures in the active elderly patients

INTRODUCTION

Current guidelines recommend treating displaced femoral neck fractures with a total hip replacement in fit and active elderly patients. Dislocation remains the main complication. Dual-mobility cup (DMC) hip replacements maybe a solution to decrease dislocation, with the benefit of increasing stability, achieving better range of motion and functional outcomes.

PATIENTS AND METHODS

This is a prospective randomised controlled trial which included 62 patients with Garden III and IV femoral neck fractures. The mean age was 67.2 years. 30 males and 32 females were included, randomised and allocated to 2 treatment groups; a cemented DMC replacement group, or a cemented 32-mm head total hip replacement (THR). The posterior approach was used in all patients. Postoperative functional outcome was assessed using Harris Hip Score (HHS). Health-related quality of life (HRQoL) was assessed using the SF-36 questionnaire.

RESULTS

The mean HHS for the DMC group at 4, 6 and 12 months were higher than mean HHS scores for the THR group (p < 0.001). The range of motion at 1 year was statistically better in the DMC group compared to the THR group (p < 0.001). The DMC showed a statistically better effect on the HRQoL measurements as compared to the THR group. There were no dislocations in both groups.

CONCLUSIONS

DMC hip replacements provide better functional, patient reported outcomes, and range of motion than the conventional THR. Combined with its stability, DMC replacements are a useful solution in managing femoral neck fractures in active elderly patients.Trial serial number 020841 (IRB Number 00007555).

Cemented and uncemented hemiarthroplasty for femoral neck fracture in elderly patients: a systematic review and meta-analysis

BACKGROUND

Cemented hemiarthroplasty to treat femoral neck fractures (FNFs) in elderly patients is controversial. Therefore, this study aimed to compare cemented vs uncemented outcomes.

METHODS

A literature review using Pubmed, EMBASE, Cochrane Library, and Science Citation Index databases was conducted. Studies comparing outcomes of cemented with uncemented hemiarthroplasty for FNFs in elderly patients up to March 2020 were included. Dichotomous outcomes were pooled and reported as relative risk (RR) or odds ratio (ORs), while continuous outcomes were pooled and reported as the mean difference (MD) or standardized mean difference (SMD).

RESULTS

The analysis included 39 studies with a total of 112 576 patients. Pooled analysis revealed that compared with cemented, patients with uncemented intervention had better outcomes for intraoperative blood loss (OR 0.19; 95% CI 0.01-0.37), systolic blood pressure (OR 2.83; 95% CI 1.51-5.28), surgery duration (SMD, 0.51; 95% CI 0.2-0.81), length of anesthesia (OR 0.28; 95% CI 0.11-0.45), 6-month mortality (OR 1.11; 95% CI 1.03-1.2), cardiovascular accidents (OR 2.14; 95% CI 1.07-4.28), respiratory failure (OR 8.26; 95% CI 1.38-49.4), fat embolisms (OR 1.58; 95% CI 1.29-1.93), and heterotrophic ossification (OR 2.3; 95% CI 1.3-4.06), but more intraoperative accidents (OR 0.34; 95% CI 0.26-0.45), postoperative fractures (OR 0.27; 95% CI 0.21-0.34), reoperations (OR 0.59; 95% CI 0.53-0.65), and revisions (OR 0.62; 95% CI 0.44-0.88).

CONCLUSIONS

Meta-analysis of hemiarthroplasty outcomes shows that elderly patients who underwent uncemented vs cemented procedures had better results for several factors that are important for not only improved recovery in elderly populations, but also more intraoperative and postoperative risks.

Heterotopic Ossification Following Arthroplasty for Femoral Neck Fracture

BACKGROUND

Heterotopic ossification (HO) is a frequent complication following hip surgery. Using data from the Hip Fracture Evaluation with Alternatives of Total Hip Arthroplasty versus Hemiarthroplasty (HEALTH) trial, we aimed to (1) determine the prevalence of HO following total hip arthroplasty (THA) for femoral neck fracture in patients ≥50 years of age, (2) identify whether HO is associated with an increased risk of revision surgery within 24 months after the fracture, and (3) determine the impact of HO on functional outcomes.

METHODS

We performed a multivariable Cox regression analysis using revision surgery as the dependent variable and HO as the independent variable. We compared Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores between participants with and those without HO at 24 months.

RESULTS

Of 1,441 participants in the study, 287 (19.9%) developed HO within 24 months. HO was not associated with subsequent revision surgery. Grade-III HO was associated with statistically significant and clinically relevant deterioration in the total WOMAC score, which was mainly related to the function component of the score, compared with grade I or II.

CONCLUSIONS

The impact of grade-III HO on the functional outcomes and quality of life after THA for hip fracture is clinically important, and HO prophylaxis for selected high-risk patients may be appropriate.

LEVEL OF EVIDENCE

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

A Rare Case of Extremely Severe Heterotopic Ossification after Primary Total Hip Arthroplasty due to Persistent Mild Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) caused by coagulase-negative staphylococci (CNS) can be a mild, persisting infection. Although heterotopic ossification (HO) is common following total hip arthroplasty (THA), the etiology of severe HO remains unclear. Herein, we describe a rare case of extremely severe HO after a PJI associated with a Staphylococcus caprae infection in a 78-year-old male patient. The patient had poorly controlled diabetes mellitus with no diabetic complications. The patient had no previous history of hip surgery, hip injury, or systemic bacterial infection. Immediately after the initial THA, he developed intermittent low-grade fever (37°C), which persisted for 3 months; consequently, he also reported mild hip pain during walking. He experienced a gradual decrease in hip range of motion within 5 years after the surgery, with progressive gait impairment. Two revision surgeries were required for the successful treatment of this difficult case. The patient's hip function improved, and the PJI was controlled following the second revision surgery. Based on the clinical course, CNS-caused PJI may lead to severe HO. This possibility warrants verification from an accumulated number of cases.

Critical implication of the PTEN/PI3K/AKT pathway during BMP2-induced heterotopic ossification

Heterotopic ossification (HO) is characterized by extraskeletal ossification in soft tissue. Thus far, there is a lack of effective drug therapy against HO. Loss of PTEN in osteoblasts has been reported to accumulate bone mass in skeletal development and promote fracture healing in association with the activation of the PI3K/AKT pathway. However, the role of the PTEN/PI3K/AKT signaling in HO pathogenesis remains unknown. The present study investigated the implication of this pathway during BMP2-induced osteogenic differentiation and ectopic bone formation. It was shown that overexpression of PTEN inhibited proliferation but stimulated apoptosis in mesenchymal pluripotent C3H10T1/2 cells. PTEN also inhibited BMP2-induced osteoblast differentiation, whereas BMP2 repressed PTEN expression and subsequently activated PI3K/AKT. The PI3K inhibitor, LY294002, blocked BMP2-induced osteoblastogenesis, suggesting that the PI3K/AKT pathway is critically required for BMP2 to initiate osteoblastogenesis. In vivo, implantation of BMP2 in muscle induced ectopic endochondral ossification. Strikingly, this bone-forming capacity was notably suppressed by the PI3K inhibitor LY294002. Hence, the results of the present study demonstrated that the PI3K/AKT signaling activity is indispensable for BMP2 to induce ectopic new bone. Targeting the PI3K/AKT pathway using inhibitor(s) may represent a potential molecular therapy for the treatment against HO.

The Impact of Heterotopic Ossification on Self-Reported Outcomes After Total Hip Arthroplasty Using the Direct Anterior Approach

BACKGROUND

Heterotopic ossification (HO) is a known finding after total hip arthroplasty (THA) that potentially affects clinical outcomes. The incidence of HO is related to various factors, including soft-tissue trauma, postoperative medication, surgical approach, and the surgeon's experience. Because use of the direct anterior approach (DAA) is gaining popularity, we aimed (1) to determine the incidence of HO after DAA-THA and (2) to evaluate the impact of HO on patient-reported outcomes (PROs).

METHODS

We retrospectively reviewed 401 THAs (67 ± 10 years old, 210 men). The incidence and grade of HO were evaluated using the Brooker classification with anteroposterior and lateral radiographs. PROs were collected with use of the Oxford Hip Score (OHS) and the Core Outcome Measures Index (COMI)-Hip and were correlated with HO grades using generalized multiple regression models.

RESULTS

The incidence of HO was 29.9% on the anteroposterior radiographic views (Brooker grade 1, 14.5%; grade 2, 11.1%; grade 3, 2.7%; and grade 4, 0.57%); the lateral radiographic views detected 9% additional HO when compared with the anteroposterior radiographs alone (Brooker grade 1, 8%, and grade 2, 1%). HO was more frequent in men. The American Society of Anesthesiologists (ASA) grade, age in women, and higher body mass index (BMI) in men were associated with higher HO grades. A transverse "bikini" incision was associated with a lower rate (4%) of Brooker grades 3 and 4 HO when compared with a longitudinal incision (12%). A Brooker grade of 0 to 3 HO did not impact outcomes. Only Brooker grade-4 HO was associated with significantly worse PROs; however, pain was not affected.

CONCLUSIONS

Low-grade HO after DAA-THA is not uncommon, and its rate is underestimated when anteroposterior radiographic views are evaluated without lateral views. The risk factors for developing HO in our cohort were an ASA grade of >3, male sex (especially with a high BMI), older age in women, and use of longitudinal incisions. With use of the bikini incision, patients had lower rates of severe HO, but mostly senior surgeons with more experience performed their surgery. Age, ASA grade, experience level of the surgeon, and Brooker grade-4 HO all had a significant influence on PROs. Clinically important HO (Brooker grade 4) remains rare after DAA-THR.

LEVEL OF EVIDENCE

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

Is dual mobility cup total hip replacement associated with increased incidence of heterotopic ossification compared to conventional total hip replacements in fracture neck of femur patients?

INTRODUCTION

The incidence of heterotopic ossification after total hip replacement is variable in the literature. If symptomatic, it may cause pain and reduced range of motion. Dual mobility total hip replacements have been considered a valuable option for the treatment of femoral neck fractures in the active patients, achieving good range of motion with reduced risk of dislocation. The occurrence of HO may have detrimental effect on this type of articulation and may accelerate polyethylene wear and predispose to intra-prosthetic dislocation. We compared the incidence of HO in DMC versus conventional THR in femoral neck fracture patients across 3 large trauma institutes PATIENTS AND METHODS: This is a retrospective cohort study which included 334 patients, 223 received DMC replacements, 111 received conventional total hip replacement (THR). Mean age for the DMC group was 72.3 ± 9.9 years and was 72.1 ± 6.8 years for the THR group. Patients were stratified according to specific inclusion and exclusion criteria, and the 1-year follow up X rays were evaluated for the presence of heterotopic ossification by 3 assessors.

RESULTS

The incidence of HO in the DMC group was 27.1% compared to 12.2% in the THR group (χ² p value = 0.0001, Relative Risk = 2.22, 95% CI 1.22-4.03, p value = 0.0091). There was no significant effect of gender or age on the incidence of HO in both groups CONCLUSIONS: Patients receiving DMC hip replacements are more likely to develop HO as compared to patients receiving conventional THR for femoral neck fractures. Further prospective studies are required to confirm our findings and to assess the indication of HO prophylaxis in patients receiving DMC hip replacements, and the long-term outcomes in these patients.

Heterotopic Ossification following Total Elbow Arthroplasty in a Patient with Parkinson's Disease: Case Report and Literature Review

Introduction. Heterotopic ossification (HO) usually develops following surgery or trauma. Risk factors for HO following elbow fractures include delay to surgery (>7 days), floating fractures, and elbow subluxation. Systemic risk factors for HO include male sex; concurrent cranial, neurological, or abdominal injury; high-energy trauma; previous development of HO; and contralateral fracture. To date, no studies have reported on Parkinson's disease (PD) as a risk factor for the development of HO. Case Presentation. A 68-year-old female with PD (treated with levodopa-carbidopa) sustained a right closed (OTA type A3) distal humerus fracture and was treated with a total elbow arthroplasty. Postoperatively, development of significant near-ankylosing HO was observed and contributed to significant restriction of elbow motion with activities of daily living. After HO maturation, the osseous growth was excised, and the area irradiated. The patient regained excellent elbow motion with no recurrence of HO. Discussion. A literature review revealed six cases of HO development in PD patients following arthroplasty. Patients with PD have higher serum concentrations of interleukins (IL) and tumor necrosis factor- (TNF-) α. These factors stimulate BMP-2 production which may promote osteogenesis. Levodopa-carbidopa may also influence HO through stimulation of growth hormone and IGF-1. Conclusion. Parkinsonism may promote heterotopic bone growth through the release of osteoinductive factors. HO development may also be mediated by levodopa-carbidopa therapy. Future research should highlight the link between HO and PD and identify if prophylaxis is warranted in PD patients undergoing arthroplasty.

Awareness of Heterotopic Ossification in Total Joint Arthroplasty: A Primer

Heterotopic ossification (HO) is the presence of normal bone in soft tissue where bone should not exist. After direct musculoskeletal trauma of the surrounding soft tissue, HO is hypothesized to develop from a dysfunction of normal lamellar bone formation and remodeling that appears in nonskeletal areas of the body. Acquired HO related to total joint arthroplasty (TJA) of the hip and knee forms outside the joint capsule and can be a challenging condition when it impairs the essential healing process after elective surgery. Although HO is rare after elective TJA and thus clinically immaterial, when clinically relevant HO develops, patients may experience the following: 1) limited ambulation, 2) restricted range of motion, and 3) severe pain and discomfort that may lead to loss of function. Ultimately, patients with clinically relevant HO after elective TJA may require additional treatment, including medication, radiation therapy, manipulation under anesthesia, surgical excision of the HO, and possibly revision TJA. Awareness of HO and an understanding of the associated risk factors along with the various management options will enable health care practitioners and their patients to optimize their surgical outcomes.

Heterotopic ossification and clinical results after total hip arthroplasty using the anterior minimally invasive and anterolateral approaches

INTRODUCTION

Total hip arthroplasty (THA) is considered the gold standard in the treatment of advanced osteoarthritis of the hip. The aim of this study was to compare the incidence of heterotopic ossification (HO), the quality of life and the function in two groups of patients who underwent total hip arthroplasty (THA), performed using the anterior minimally invasive (MIS) and the anterolateral approaches.

MATERIAL AND METHODS

Retrospective analysis of 597 patients who underwent THA in 2009-2013 was performed. In all 597 cohort data on medical history were retrieved. HO occurrence was recorded for 331 patients and was evaluated based on Brooker's scale in the X-ray scan. Functional and quality of life scores were obtained for 238 patients. The following scales were used for the survey: Harris Hip Score, Western Ontario and McMaster Universities Osteoarthritis Index, Visual Analogue Scale, and Hip and Knee Arthroplasty Satisfaction Scale.

RESULTS

Patients operated on from the MIS approach had statistically significantly (p < 0.05) better results with all the clinical scales used, except the Visual Analogue Scale (p > 0.05). HO was slightly more common after the MIS approach (52.5%) compared to the anterolateral approach (49.76%), though the difference was not statistically significant (p > 0.05).

CONCLUSIONS

The MIS approach was associated with better clinical and functional outcomes. In the aspect of HO, we were not able to show the superiority of the MIS approach in terms of incidence.

Incidence of Heterotopic Ossification in Anterior Based Muscle Sparing Total Hip Arthroplasty: A Retrospective Radiographic Review

Heterotopic ossification (HO) is a known complication following total hip arthroplasty (THA). The anterior based muscle sparing (ABMS) approach is a variation of a direct anterior approach through the Watson–Jones interval. To date, few studies have evaluated HO formation following this surgery. We examine the incidence of HO in a consecutive series of THAs using this approach by three different surgeons at a single center. Standard preoperative radiographs were examined to determine the type of degenerative arthritis, and follow-up radiographs a minimum of 9 months after surgery were evaluated for the presence and classification of HO. The overall incidence of HO after ABMS THA in this study was 86/233, or 36.9%, which is comparable to recent studies of direct anterior and traditional approaches. Class III and IV HO is uncommon in ABMS surgery (3.9% and 1.3%, respectively) and appears to decrease with increased surgical experience with this technique.

Heterotopic Ossification: A Comprehensive Review

Heterotopic ossification (HO) is a diverse pathologic process, defined as the formation of extraskeletal bone in muscle and soft tissues. HO can be conceptualized as a tissue repair process gone awry and is a common complication of trauma and surgery. This comprehensive review seeks to synthesize the clinical, pathoetiologic, and basic biologic features of HO, including nongenetic and genetic forms. First, the clinical features, radiographic appearance, histopathologic diagnosis, and current methods of treatment are discussed. Next, current concepts regarding the mechanistic bases for HO are discussed, including the putative cell types responsible for HO formation, the inflammatory milieu and other prerequisite “niche” factors for HO initiation and propagation, and currently available animal models for the study of HO of this common and potentially devastating condition. © 2019 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.

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

PURPOSE

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.

METHODS

We followed 103 consecutive patients (43 males, 60 females, mean age 61 years) who underwent unilateral cementless THA for primary hip osteoarthritis and investigated the incidence of HO within the first 12 months 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 12 months post-operatively.

RESULTS

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 (3.0 mm vs. 2.3 mm, p = 0.001) and horizontal (47.9 mm vs. 39.1 mm, p = 0.025) dimensions of FO than patients without HO. Patients with FO and a vertical dimension of ≥ 2.5 mm were more likely to develop HO (55.6%) than patients with a vertical FO dimension of less than 2.5 mm (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.

CONCLUSION

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.

Incidence and factors associated with development of heterotopic ossification after damage control laparotomy

INTRODUCTION

The incidence of heterotopic ossification (HO) following damage control laparotomy (DCL) is unknown. Abdominal wall reconstruction may prove more challenging in patients with HO. This study examines the incidence and factors associated with HO in patients with an open abdomen following DCL.

METHODS

A retrospective review of all patients with an open abdomen after DCL at a level 1 trauma centre from 2009 to 2015 was conducted. Demographics and peri-operative outcomes of patients with and without HO were compared. Univariate and multivariable binary logistic regression models were used to determine the association of peri-operative factors with the development of HO.

RESULTS

68 patients were included, of which 36 (53%) developed HO. On univariate analysis, development of HO was significantly associated with hollow viscus injury (OR, 3.89; CI 1.42-10.7), greater number of abdominal surgeries prior to definitive closure (OR, 1.84; CI, 1.10-3.05), non-fascial closure (OR, 4.33; CI, 1.44-13.1) and higher peak ALP (OR 1.01; CI, 1.00-1.02). The presence of a hollow viscus injury remained an independent predictor of HO on multivariable analysis after adjusting for covariates (OR, 3.77; CI, 1.22-11.6).

CONCLUSION

Heterotopic ossification develops in a high proportion of trauma patients following damage control laparotomy, particularly in the presence of hollow viscus injury. Its impact on delayed abdominal wall reconstruction and the efficacy of prophylaxis strategies merit further investigation.

Results from the surgical resection of severe heterotopic ossification of the hip: a case series of 26 patients

INTRODUCTION

Surgical resection of heterotopic ossification (HO) around the hip joint is often challenging. The aim of this study is to evaluate the clinical and radiological outcomes following surgical resection of Brooker's type III and IV HO of the hip.

METHODS

We retrospectively reviewed clinical and radiological data, between November 2006 and January 2013, of all patients who underwent surgical resection of severe HO of the hip. Brooker's grading, range of motion and the Harris Hip Score before and after surgery were recorded in all cases. The combined radiation (700 cGy preoperatively) and indomethacin regimen was used to prevent heterotopic ossification recurrence.

RESULTS

Twenty-six patients (22 males and 4 females) were included in our study. Mean patient age was 47.38 years (range 24-72). The HO was graded as Brooker grade III in 3 patients (11.5%) and Brooker grade IV in 23 patients (88.5%). Mean time interval between HO development and resection was 40.8 months (range 13-156 months). All patients had CT scans prior to surgery. Mean follow-up was 31.4 months (range 24-40 months). There was no severe HO recurrence. Complications included one intraoperative injury of a femoral artery branch, one intraoperative femoral neck fracture treated with intramedullary nailing, one sciatic nerve injury and one superficial infection treated conservatively.

CONCLUSIONS

Surgical resection of severe HO of the hip along with preoperative radiation and indomethacin provides excellent results; however, the complication rate is relatively high. Careful evaluation of the preoperative CT scan and wide exposure are required in order to identify all the involved neurovascular structures.

Paraprosthetic Complications After Endoprosthesis Replacement of Pelvis Joint with Implants

PURPOSE

The purpose of the paper is shaping of ideas about possible ways of decreasing complications of the analyzed types of operations and identification of opportunities of the impact on the socio-economic environment among the Afro-American population of USA. The paper demonstrates that the issue of coxofemoral prosthesis is not only a purely medical but also a social problem. In particular, availability of timely aid, as well as insurance in the form of surgery, refer to relevance of the range of problems.

METHODOLOGY

The experimental method was used in the study. Patients were implanted different types of endoprostheses. 90 patients were implanted customized endoprostheses, 27 patients were implanted foreign module endoprostheses. The research subject is prediction of complications after endoprosthesis replacement surgeries depending on methods, types and forms.

RESULTS

As a result, we can see that available health insurance is more acceptable understanding of the need for endoprosthesis replacement. Post-operative care issues fall into the range of social policy problems. A comparative aspect of a country with general insurance and differentiated coverage among the Afro-America population appears innovative.

CONCLUSIONS

In the context of the current situation it can be concluded that surgery is the last stage for already established support system of the population. For this reason, it's worth mentioning that state bodies of the U.S. should put a greater emphasis on the health care of the Afro-American population.

Influence of surgical approach on heterotopic ossification after total hip arthroplasty - is minimal invasive better? A case control study

BACKGROUND

Heterotopic ossification (HO) is a well-known complication after total hip arthroplasty (THA). Recently, the trend is to operate THA minimally invasive being less traumatic than standard approaches and promising a faster return to activity. The purpose of the study was to investigate if minimal invasive surgery (MIS), leads also to less HO after THA.

METHODS

This retrospective study included 134 consecutive patients undergoing THA. In 42 (31.3%) patients a standard modified anterolateral (STD-Watson-Jones), in 28 (20.9%) patients a standard transgluteal Bauer approach (STD-Bauer), in 39 (29.1%) a MIS direct anterior approach (AMIS) and in 25 (18.7%) patients a MIS anterolateral (MIS-AL) approach was used. Standard preoperative anterior-posterior and lateral radiographs were assessed for occurrence of HO. HO was classified according to Brooker. In addition, short- and long-term adverse events were noted. Data was statistically analyzed using Chi-square tests, analysis of variance, multivariate data analysis and Pearson's correlation (p < 0.05).

RESULTS

Overall, HO was found in 38 caucasian patients (28.4%) after THA. The STD-Watson-Jones group showed the highest HO rate (45.2% n = 19) with a significant difference to the AMIS (23.1% n = 9) and STD-Bauer approach (14.3% n = 4). No statistical difference was found to the MIS-AL approach (24.0% n = 6). Postoperative complications did not differ significantly except for a higher incidence of Trendelenburg`s sign in STD-Bauer.

CONCLUSIONS

The rate and degree of HO after THA were significantly different with regards to the surgical approach. The standard modified anterolateral approach resulted in the highest HO rate, however, MIS approaches showed higher HO rates than the STD-Bauer.