Heterotopic ossification after total hip arthroplasty: our experience

Fulminant Heterotopic Ossification of the Lower Extremity After Gunshot Injury and Blunt Trauma: A Case Report

Traumatic heterotopic ossification (HO) of the lower extremity is relatively rare but is of major importance in clinical practice. They are defined as posttraumatic abnormal formations of bone within soft tissue outside of the skeletal system. This article describes the clinical case of a 31-year-old male patient who suffered 2 traumatic events within 12 months-a gunshot wound in the lumbar spine/gluteal region followed by a severe traumatic brain injury with intracranial hemorrhage in a traffic accident as a pedestrian. Clinically, the patient was bedridden because of complete stiffening of the lumbar spine, both hip joints, and the left knee joint. After preoperative diagnosis, 3 surgical ablations of the HO were performed on both the hip joints and the left knee joint. In addition, physiotherapeutic exercise, postoperative nonsteroidal anti-inflammatory drug administration (25 mg of indomethazine for 6 weeks, 3 times a day), and perioperative radiation with 7 Gy for each operation were advised. After 4 years of follow-up, the patient showed significant improvement. In HO treatment, prophylactic local radiotherapy (pre- and postoperative radiation with a local single dose of 7 Gy) and postoperative administration of nonsteroidal anti-inflammatory drugs are often recommended. For therapeutic purposes, surgical resection is still indicated for pronounced cases.

Heterotopic Ossification Formation in Military Beneficiaries Following Hip- and Pelvic-Level Amputations

INTRODUCTION

Traumatic hip and pelvic level amputations are uncommon but devastating injuries and associated with numerous complications that can significantly affect quality of life for these patients. While heterotopic ossification (HO) formation has been reported at rates of up to 90% following traumatic, combat-related amputations, previous studies included few patients with more proximal hip and pelvic level amputations.

MATERIALS AND METHODS

We conducted a retrospective review of the Military Health System medical record and identified patients with both traumatic and disease-related hip- and pelvic-level amputations performed between 2001 and 2017. We reviewed the most recent pelvis radiograph at least 3 months following amputation to determine bony resection level and the association between HO formation and reason for amputation (trauma versus disease related).

RESULTS

Of 93 patients with post-amputation pelvis radiographs available, 66% (n = 61) had hip-level amputations and 34% (n = 32) had a hemipelvectomy. The median duration from the initial injury or surgery to the most recent radiograph was 393 days (interquartile range, 73-1,094). HO occurred in 75% of patients. Amputation secondary to trauma was a significant predictor of HO formation (χ2 = 24.58; P < .0001); however, there was no apparent relationship between the severity of HO and traumatic versus non-traumatic etiology (χ2 = 2.92; P = .09).

CONCLUSIONS

Amputations at the hip were more common than pelvic-level amputations in this study population, and three-fourths of hip- and pelvic-level amputation patients had radiographic evidence of HO. The rate of HO formation following blast injuries and other trauma was significantly higher compared with patients with non-traumatic amputations.

Role of aspirin in the prevention of heterotopic ossification following total hip replacement: a systematic review and meta-analysis

BACKGROUND

To systematically investigate if aspirin (ASA), used as venous thromboembolism (VTE) prophylaxis, plays a role in the prevention of heterotopic ossification (HO) following total hip arthroplasty (THA) and if ASA dosage impacted the rate of HO.

METHODS

Eligible studies published from January 2000 to July 2022 were identified from the computerized searching of PubMed, Scopus and Web of Science. HO was defined according to Brooker Classification. Pooled risk ratios (OR) and 95% confidence interval (CI) were estimated under a random-effect model. Additionally, combined HO incidences were compared according to ASA dosage (a regular dose of 325 bid vs. a low dose of 81 mg bid/162 mg qd).

RESULTS

Thirteen studies were included. ASA administered for VTE prophylaxis was significantly associated with a reduced risk of all-grade HO following THA (univariate, OR: 0.50, 95% CI: 0.34-0.74, P < 0.001; multivariate, OR: 0.60, 95% CI: 0.49-0.73, P < 0.001). Similar results could be observed for high-grade HO (univariate, OR: 0.57, 95% CI: 0.36-0.89, P = 0.015; multivariate, OR: 0.50, 95% CI: 0.27-0.92, P = 0.026). There was a non-significant trend towards a higher incidence of HO formation for low-dose ASA (31%, 95% CI: 29-34%), compared with regular-dose ASA (21%, 95% CI: 11-33%) (P = 0.069 under test of interaction).

CONCLUSIONS

ASA can be an effective option for HO prophylaxis. More well-designed trials with long-term follow-ups are encouraged to confirm the current findings and to investigate the effect of ASA dosage on HO reduction.

The correlates of post-surgical haematoma in older adults with proximal femoral fractures

BACKGROUND

Little is known about the incidence of haematoma, and clinical correlates among orthogeriatric patients.

AIMS

This study aims to describe the incidence of haematoma after surgical repair of hip fracture and to identify the clinical correlates of haematoma among orthogeriatric patients.

METHODS

Two orthopaedic surgeons and a dedicated operator using ultrasound technique, each other in blindness, evaluated 154 orthogeriatric patients during their hospital stay. All patients received a comprehensive geriatric assessment. We investigated the concordance between clinical diagnosis and ultrasound detection of haematoma, and then we explored the clinical correlates of the onset of post-surgical haematoma.

RESULTS

Blood effusion at the surgical site was detected in 77 (50%) patients using ultrasound technique; orthopaedic surgeons reached a clinical agreement about post-surgical haematoma in 18 (23%) patients. The sensitivity of clinical evaluation was 0.66, and the specificity was 0.70. Independent of age, clinical, pharmacological, and surgical confounders, proton pump inhibitors (PPIs) were associated with post-surgical haematoma (OR 2.28; 95% CI 1.15-4.49). A tendency towards association was observed between selective serotonin reuptake inhibitors and post-surgical haematoma (OR 2.10; 95% CI 0.97-4.54), CONCLUSIONS: Half of older patients undergoing surgical repair of proximal femoral fracture develop a post-surgical haematoma. Clinical assessment, even if made by senior orthopaedic surgeons, underestimates the actual occurrence of post-surgical haematoma compared to ultrasound detection. Ultrasound technique may help to detect haematoma larger than 15 mm better than clinical assessment. PPIs's use is a risk factor for post-surgical haematoma independent of several medical and surgical confounders.

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.

Acetabular Reaming Is a Reliable Model to Produce and Characterize Periarticular Heterotopic Ossification of the Hip

Heterotopic ossification (HO) is a pathologic process characterized by the formation of bone tissue in extraskeletal locations. The hip is a common location of HO, especially as a complication of arthroplasty. Here, we devise a first-of-its-kind mouse model of post-surgical hip HO and validate expected cell sources of HO using several HO progenitor cell reporter lines. To induce HO, an anterolateral surgical approach to the hip was used, followed by disclocation and acetabular reaming. Animals were analyzed with high-resolution roentgenograms and micro-computed tomography, conventional histology, immunohistochemistry, and assessments of fluorescent reporter activity. All the treated animals' developed periarticular HO with an anatomical distribution similar to human patients after arthroplasty. Heterotopic bone was found in periosteal, inter/intramuscular, and intracapsular locations. Further, the use of either PDGFRα or scleraxis (Scx) reporter mice demonstrated that both cell types gave rise to periarticular HO in this model. In summary, acetabular reaming reproducibly induces periarticular HO in the mouse reproducing human disease, and with defined mesenchymal cellular contributors similar to other experimental HO models. This protocol may be used in the future for further detailing of the cellular and molecular mediators of post-surgical HO, as well as the screening of new therapies.

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.

NGF-TrkA signaling dictates neural ingrowth and aberrant osteochondral differentiation after soft tissue trauma

Pain is a central feature of soft tissue trauma, which under certain contexts, results in aberrant osteochondral differentiation of tissue-specific stem cells. Here, the role of sensory nerve fibers in this abnormal cell fate decision is investigated using a severe extremity injury model in mice. Soft tissue trauma results in NGF (Nerve growth factor) expression, particularly within perivascular cell types. Consequently, NGF-responsive axonal invasion occurs which precedes osteocartilaginous differentiation. Surgical denervation impedes axonal ingrowth, with significant delays in cartilage and bone formation. Likewise, either deletion of Ngf or two complementary methods to inhibit its receptor TrkA (Tropomyosin receptor kinase A) lead to similar delays in axonal invasion and osteochondral differentiation. Mechanistically, single-cell sequencing suggests a shift from TGFβ to FGF signaling activation among pre-chondrogenic cells after denervation. Finally, analysis of human pathologic specimens and databases confirms the relevance of NGF-TrkA signaling in human disease. In sum, NGF-mediated TrkA-expressing axonal ingrowth drives abnormal osteochondral differentiation after soft tissue trauma. NGF-TrkA signaling inhibition may have dual therapeutic use in soft tissue trauma, both as an analgesic and negative regulator of aberrant stem cell differentiation.

Abdominal wall heterotopic ossification following damage control laparotomy: an unusual bone to pick

BACKGROUND

Heterotopic ossification (HO) refers to the development of extra-skeletal bone in muscle and soft tissues, following tissue insult secondary to surgery or trauma. This pathological process is considered as the result of severe inflammatory cell cascade initiated after local trauma and subsequent attempt at tissue repair involving resident mesenchymal cells. We present a series of 12 cases of abdominal HO (AHO), over 8 years, following damage control laparotomies (DCLs).

METHODS

Medical records of 50 patients who underwent DCLs at Alice Springs Hospital between 2010 and 2018 were retrospectively reviewed for AHO. Demographic data were extracted. Abdominal X-rays and computed tomography scans of 47 patients were reviewed for AHO.

RESULTS

Twelve patients (25%) developed AHO of varying diversity ranging from small insignificant lesions to clinically palpable lesions in the abdominal wall. Data revealed relatively younger male preponderance. DCL for severe acute pancreatitis (SAP) was associated with AHO (P < 0.1, 90% CI). Longer periods of ventilation, intensive care unit stay and admission to hospital were strongly associated with AHO (P < 0.01, 95% CI). Occurrence of AHO with SAP was significantly higher compared to patients without SAP (relative risk 3.54, P < 0.001). Only two patients required surgical excision of HO prior to definitive closure of the abdomen.

CONCLUSION

The authors conclude that AHO occurred more frequently in younger males. DCL for SAP was a significant risk factor. Extended periods of ventilation, intensive care unit stay and hospital admission were strongly associated with the development of AHO. Preoperative detection of HO is essential prior to planning definitive closure of the abdomen.

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.

Pronounced Heterotopic Ossifications after Traumatic Hamstring Rupture: Is an Ossification Prophylaxis Useful?

Hamstring injuries include a wide range of injuries and affect mainly athletes with high eccentric loads (football, athletics, rugby, climbing). According to the latest literature, unrecognized traumatic ruptures can cause permanent discomfort and may be associated with a poorer postoperative outcome when delayed surgical therapy is performed. Heterotopic ossifications (HO) after hamstring rupture have been described in individual case reports and smaller studies so far. Heterotopic ossifications are mainly known in hip surgery and elbow fractures. In this case report, a 48-year-old patient presented with an increasing swelling with hardening in the area of the right ischial tuberosity. One year before, an impact trauma was the reason for a traumatic hamstring rupture which was diagnosed with a delay. The HO was excised and the tendon refixed with two suture anchors. By limiting the range of motion with a hip-knee orthosis for 9 weeks, a regular postoperative healing process was observed. Heterotopic ossifications after hamstring ruptures have been reported repeatedly but have not been evaluated in any major study so far. It should therefore be considered whether prophylaxis with NSAIDs should be used for conservatively and surgically treated hamstring ruptures, analogous to the ossification prophylaxis for hip endoprostheses or fractures in the elbow region.

Heterotopic Ossification in Orthopaedic and Trauma surgery: A Histopathological Ossification Score

Heterotopic Ossification (HO) is a potential long-term complication in orthopaedic surgery. It is commonly classified according to the Brooker classification, which is based on radiological findings. To our knowledge the correlation of histological features to the Brooker grade is unknown as is the association between HO and the indication for revision. The aim of this paper is to analyze the ossification grade of HO tissue in patients undergoing revision hip and knee arthroplasty and to propose a histologically based classification system for HO. We also assess the relationship between the grade of HO and the indication for revision (septic and aseptic revision). From January to May 2019 we collected 50 human HO samples from hip and knee revision arthroplasty cases. These tissue samples were double-blinded and sent for histopathological diagnostic. Based on these results, we developed a classification system for the progression of HO. The grade of ossification was based on three characteristics: Grade of heterotopic ossification (Grade 1–3), presence of necrosis (N0 or N1) and the presence of osteomyelitis (HOES-Score Type 1 to 5). Demographic data as well as surgical details and indication for surgery was prospectively collected from clinical records. Fifty tissue samples were harvested from 44 hips and 6 knee joints. Of these 33 exhibited Grade I ossifications (66%), followed by 11 Grade II (22%) and one Grade III (2%). Necrosis was noted in two tissue samples (4%) and 2 more had osteomyelitis findings according to HOES-Score. Six samples (12%) with radiologically suggestive of HO turned out to be wear-induced synovitis, SLIM Type 1. Of these cases 16 were septic (32%) and 34 aseptic (68%) revisions. Most of the HO tissue samples were classified as a low-grade. High-grade ossification-Score is rare. Higher grades of ossification seem to be associated with septic revision cases. Wear-induced synovitis potentially influences HO development. A histological scoring system for ossification grading can be derived from the data presented in this study.

Incidence of and risk factors for the development of asymptomatic heterotopic ossification after elbow fracture fixation

OBJECTIVE

This study was performed to investigate the incidence of and risk factors for asymptomatic heterotopic ossification (HO) after open reduction and internal fixation of elbow fractures.

METHODS

This retrospective analysis involved 197 patients with elbow fractures treated operatively from 2014 to 2017 at our institution. Patient-related and clinical variables were recorded. Univariate analysis and multivariate logistic regression were performed to reveal independent risk factors for postoperative HO. In addition, a receiver operating characteristic (ROC) curve was performed to assess the ability of risk factors to predict the development of postoperative HO.

RESULTS

The overall rate of asymptomatic HO after surgery was 18.78%. The incidence was highest in terrible triad injuries and lowest in capitellum fractures. Independent predictors of asymptomatic HO identified by the multivariate analysis were underlying diseases, fracture dislocation, and a prolonged operative time. The area under the ROC curve for underlying diseases, fracture dislocation, and a prolonged operative time were 0.593, 0.596, and 0.694, respectively.

CONCLUSIONS

The incidence of postoperative asymptomatic HO in patients with elbow fractures is high. Clinicians should employ prophylaxis to avoid HO when treating patients with elbow fractures who have underlying diseases, fracture dislocation, or a prolonged operative time.

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.

Heterotopic Ossification in Primary Total Hip Arthroplasty: which is the role of drainage?

Background and aim of the work: The Heterotopic Ossification (HO) is a common complication following Total Hip Arthroplasty (THA). Although there is no concordance in Literature regarding the etiopathogenic mechanism, various HO risk factors have been recognized, both related to the patient and associated with the surgical procedureLiterature does not consider the use of intra-articular drainage as a possible risk factor. Our hypothesis is that this item can contribute to the development of HO. Materials and Methods: 425 implants of hip arthroplasty performed between 2014 and 2017 at the Ortopedic Clinic of Udine were included in the study. No patient performed pre-operative or post-operative anti-HO prophylaxis during follow-up. Radiographs of preoperative and postoperative at 1 year were analyzed according to the Brooker Classification.Results: The incidence of HO in patients with intra-articular drainage is 24.6%, while the incidence of HO in patients without intra-articular drainage is 15.3%, with a statistically significant difference. Conclusions: The data obtained suggest to consider the use of intra-articular drainage as a possible intra-operative risk factor for HO. This is a retrospective cohort study, so we need more studies and more robust experimental designs to confirm these results. (www.actabiomedica.it)

Comparison of Outcomes of Total Hip Arthroplasty between Patients with Ankylosing Spondylitis and Avascular Necrosis of the Femoral Head

BACKGROUND

The objective of this study was to compare clinical and radiological outcomes of total hip arthroplasty (THA) between ankylosing spondylitis (AS) of the hip joint and avascular necrosis (AVN) of the femoral head.

METHODS

Thirty patients (30 hips) underwent cementless THA for AS between 2003 and 2012. They were compared to 30 patients (30 hips) who underwent the same procedure for AVN of the femoral head. Each group was matched for age and gender, and both groups had similar preoperative demographic characteristics. All cases were followed for minimum 4 postoperative years. Clinical evaluation was based on operation time, intraoperative blood loss, quantity of postoperative drainage, Harris Hip Score (HHS), and range of motion (ROM). Radiological results were evaluated by acetabular cup anteversion and inclination, femoral stem orientation, pre- and postoperative leg length discrepancy, and postoperative complications.

RESULTS

The operation time was significantly longer in the AS group (120.2 ± 26.2 min) than in the AVN group (79.5 ± 11.1 min). The volume of postoperative drainage was significantly greater in the AS group (764.5 ± 355.4 mL vs. 510.5 ± 195.6 mL). Preoperative HHS was lower in the AS group (55.6 ± 13.8 vs. 59.2 ± 2.8). Similarly, postoperative HHS was significantly lower in the AS group (92.8 ± 2.7 vs. 97.4 ± 2.6). The arc of ROM was improved from 146.5° ± 13.2° preoperatively to 254.7° ± 17.2° postoperatively in the AS group and from 182.6° ± 15.5° to 260.4° ± 13.7° in the AVN group. Implant position and postoperative leg length discrepancy were not different between the groups. However, three cases of heterotopic ossification was observed in the AS group, whereas only 1 case was found in the AVN group. One deep infection and one aseptic stem loosening were found in the AS group, whereas none was observed in the AVN group.

CONCLUSIONS

Cementless THA showed satisfactory clinical and radiological results in both groups, despite the longer operation time, larger blood loss volume, and lower HHS score of the AS group. Our findings suggest that cementless THA is an effective and reliable treatment for both AS and AVN.

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.

Heterotopic Ossification: Basic-Science Principles and Clinical Correlates

➤ Heterotopic ossification occurs most commonly after joint arthroplasty, spinal cord injury, traumatic brain injury, blast trauma, elbow and acetabular fractures, and thermal injury.➤ The conversion of progenitor cells to osteogenic precursor cells as a result of cell-mediated interactions with the local tissue environment is affected by oxygen tension, pH, availability of micronutrients, and mechanical stimuli, and leads to heterotopic ossification.➤ Radiation and certain nonsteroidal anti-inflammatory medications are important methods of prophylaxis against heterotopic ossification.➤ Well-planned surgical excision can improve patient outcomes regardless of the joint involved or the initial cause of injury.➤ Future therapeutic strategies are focused on targeted inhibition of local factors and signaling pathways that catalyze ectopic bone formation.

Heterotopic ossification after hemiarthroplasty of the hip - A comparison of three common approaches

OBJECTIVE

Heterotopic ossification (HO) about the hip after total hip arthroplasty and internal fixation of the hip, pelvis, and acetabulum has been linked to surgical approach. However, no study has investigated surgical approach and HO in patients undergoing hemiarthroplasty. We therefore aimed to explore the influence of operative approach in patients undergoing hemiarthroplasty.

METHODS

Through a retrospective case series at an Urban level I trauma center, we found 80 patients over the age of 60 undergoing hemiarthroplasty for femoral neck fractures from 2000 to 2009. Patient charts, operative notes, and radiographs were reviewed for demographics, operative approach (anterior: A, anterior-lateral: AL, posterior: P), and any development of HO. Fisher's exact test compared rates of HO among the three approaches. Student's t-tests compared Brooker Classification levels of HO among the approaches.

RESULTS

82 hemiarthroplasties (26 A, 32 AL, 24 P) were included for analysis. 22 patients (27%) had HO. There was no significant difference in the development of HO based upon surgical approach: A: 19% (n = 5); AL: 34% (n = 11); P: 25% (n = 6). There was a significant difference in the grade of HO based on Brooker Classification (BC) with the posterior approach resulting in significantly lower grade of HO: A (BC: 2.60); AL (BC: 2.64); P (BC: 1.50) (p = 0.012).

CONCLUSIONS

Our data is the first to evaluate surgical approach and HO in patients with hemiarthroplasty. Patients have a significant risk of developing higher grade HO based on surgical approach (A or AL). Orthopedists should be mindful of these risks when considering A or AL approaches.

Cemented or cementless THA in patients over 80 years with fracture neck of femur: a prospective comparative trial

BACKGROUND

Total hip arthroplasty is associated with a better long term outcome and lesser reoperation rates in the elderly but the risk of complications are believed to be higher in very elderly patients. The study aims to compare the short-term results of cemented and cementless total hip arthroplasty (THA) in active patients >80 years of age with femoral neck fractures.

METHODS

Sixty-two consecutive patients underwent THA during the study period (cemented--31 and cementless--31). The mean age was 84 years (81-94 years). Patients in both groups were comparable in their preoperative variables. Functional and radiological assessments were carried out using validated outcome measures. Complications were recorded.

RESULTS

Fifty-one patients were available for final analysis after accounting for deaths and cases lost in follow-up. Of the 51 patients, 25 (49%) regained their pre-injury mobility status and 36 (70%) were community ambulant. Cementless THA was associated with significantly less surgical time, blood loss, transfusion rates and hospital stay. The overall mortality rates, complications, functional and radiological results were similar in both groups though the number of deaths in the perioperative period was significantly high in patients undergoing cemented THA.

CONCLUSION

Satisfactory improvement in function with low reoperation rates can be achieved irrespective of the technique used. Complication rates are higher when compared to younger patients undergoing the procedure. Risks and benefits should be carefully assessed and explained before subjecting these patients to THA.

Incidence of heterotopic ossification in direct anterior total hip arthroplasty: a retrospective radiographic review

Heterotopic ossification (HO) is a complication following total hip arthroplasty (THA) with traditional approaches. The direct anterior approach (DAA) has become a popular approach for THA; however, no study has evaluated HO formation following DAA THA. We examined the incidence of HO in a consecutive series of THA using the DAA in two separate hospitals. Standard preoperative radiographs were examined to determine the type of degenerative arthritis, and follow-up radiographs of at least 6 months after surgery were evaluated for the presence and classification of HO. The overall incidence of HO after DAA THA in this study was 98/236, or 41.5%, which falls within the reported range from recent studies involving more traditional approaches to the hip.

Wound drainages in total hip arthroplasty: to use or not to use? Review of the literature on current practice

Aim of this study is to analyze data reported in literature concerning the efficacy of using wound low-vacuum suction drainages in orthopedic surgery after total hip arthroplasty. We analyzed studies concerning the use of drainages in prosthetic hip replacement surgery, performing our research through Pubmed, Cochrane database and Google Scholar, and selecting the ones evaluating the following parameters: bleeding, the need for blood transfusions, number or reinforcement of post-operative medications, length of hospitalization, functional results, periprosthetic and surgical wound infection, post-operative hematoma. Our review did not show any demonstrated advantage from the use of wound drainages in total hip arthroplasty. Moreover, some studies enlighted a possible complication related to their employment, represented by the greater need for blood transfusions. Despite the absence of a statistically demonstrated positive influence on wound outcome using suction drains after total hip replacement, many orthopedic surgeons still recommend using drainages, just because there is no certified proof of a negative effect.

Intralesional autologous mesenchymal stem cells in management of osteonecrosis of femur: a preliminary study

BACKGROUND

Management of early stages of osteonecrosis aims to prevent the collapse of the femoral head by attempts at restoring the vascularity of femoral head. Bone marrow-derived mononuclear cells with their angiogenic and osteogenic properties appear to have the potential to halt the disease process when injected intralesionally following core decompression.

MATERIALS AND METHODS

Forty patients (60 hips) with stage I, II or III (ARCO system) osteonecrosis of femoral head were treated by either core decompression and isolated mononuclear cells (group A) or core decompression and unprocessed bone marrow injection (group B). The patients were followed up clinically and radiologically for a minimum of 2 years. The functional outcome was assessed in terms of Harris hip score, and disease progression was assessed radiologically by comparing the preoperative and follow-up MRI at the end of 2 years.

RESULTS

On 2-year follow-up, there was considerable improvement in the hip function as measured by the Harris hip score in both the groups (p = 0.031). On MRI, there was a decrease in the size of the lesion in group A (p = 0.03). Three of 30 hips (10.0 %) in group B required total hip replacement.

CONCLUSIONS

Implantation of autologous bone marrow stem cells in avascular necrosis of femoral head is a safe and effective procedure and has better outcome than bone marrow for early stage of avascular necrosis of femoral head.

Fracture of ceramic bearing surfaces following total hip replacement: a systematic review

Ceramic bearing surfaces are increasingly used for total hip replacement, notwithstanding that concern is still related to ceramic brittleness and its possible mechanical failure. The aim of this systematic review is to answer three questions: (1) Are there risk factors for ceramic component fracture following total hip replacement? (2) Is it possible to perform an early diagnosis of ceramic component failure before catastrophic fracture occurs? (3) Is it possible to draw guidelines for revision surgery after ceramic components failure? A PubMed and Google Scholar search was performed and reference citations from publications identified in the literature search were reviewed. The use of 28 mm short-neck femoral head carries an increased risk of fracture. Acetabular component malposition might increase the risk of ceramic liner fractures. Synovial fluid microanalysis and CT scan are promising in early diagnosis of ceramic head and liner failure. Early revision is suggested in case of component failure; no consensus exists about the better coupling for revision surgery. Ceramic brittleness remains a major concern. Due to the increased number of ceramic on ceramic implants, more revision surgeries and reports on ceramic components failure are expected in the future. An algorithm of diagnosis and treatment for ceramic hip failure is proposed.