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

Heterotopic ossification (HO) prophylaxis in total hip arthroplasty (THA): A systematic review of level I and level II evidence since 2000

Introduction

Heterotopic ossification (HO) is a somewhat common occurrence after total hip arthroplasty (THA), particularly with certain approaches. This complication can be detrimental to the success of the surgical outcome. Indomethacin and radiotherapy remain common treatment modalities; however, no true gold-standard treatment is universally agreed upon. This study aims to evaluate Level I and Level II evidence for treatment practices of HO prophylaxis since 2000.

Methods

To evaluate HO prophylaxis in total hip arthroplasty, a search was conducted across MEDLINE/Pubmed, Cochrane, and Embase databases using keywords and Medical Subject Heading (MeSH) terms. Titles and abstracts were screened for eligibility for inclusion criteria. Full texts were screened and included if they met eligibility criteria.

Results

HO chemical prophylaxis was more effective than no HO prophylaxis, except for aspirin. Multiple NSAIDs showed equivalence and better side effect profiles than indomethacin. No one superior NSAID was found, and numerous modalities showed efficacy. The most effective dosages of radiation therapy and combination therapy remain unclear. Additionally, both etidronate and salmon calcitonin showed benefit in preventing HO in one study each.

Conclusion

Radiation, NSAIDs, and combination therapy all showed efficacy as HO prophylaxis modalities. HO prophylaxis treatment and modalities should be guided upon patient and surgical factors such as surgical approach, side effects and tolerability of modalities, comorbidities, and available facility resources to optimize the prevention of HO.Level of evidence: Level IV Therapeutic.

Heterotopic ossification: Current developments and emerging potential therapies

ABSTRACT

This review aimed to provide a comprehensive analysis of the etiology, epidemiology, pathology, and conventional treatment of heterotopic ossification (HO), especially emerging potential therapies. HO is the process of ectopic bone formation at non-skeletal sites. HO can be subdivided into two major forms, acquired and hereditary, with acquired HO predominating. Hereditary HO is a rare and life-threatening genetic disorder, but both acquired and hereditary form can cause severe complications, such as peripheral nerve entrapment, pressure ulcers, and disability if joint ankylosis develops, which heavily contributes to a reduced quality of life. Modalities have been proposed to treat HO, but none have emerged as the gold standard. Surgical excision remains the only effective modality; however, the optimal timing is controversial and may cause HO recurrence. Recently, potential therapeutic strategies have emerged that focus on the signaling pathways involved in HO, and small molecule inhibitors have been shown to be promising. Moreover, additional specific targets, such as small interfering RNAs (siRNAs) and non-coding RNAs, could be used to effectively block HO or develop combinatorial therapies for HO.

Resection of Heterotopic Ossifications and Total Hip Arthroplasty Using a Single Ludloff Medial Approach: A Case Report

CASE

Heterotopic ossification (HO) is a relatively rare but severe clinical finding around the hip joint, characterized by the formation of extraskeletal bone in soft tissue. We present the case of a 66-year-old man with a severe, painful gait disorder caused by extensive neurogenic bilateral HO. In this case, due to the medial HO localization, we performed a staged bilateral, combined HO resection and total hip arthroplasty using the single medial Ludloff approach.

CONCLUSION

Our case highlights that, for combined hip osteoarthritis and medial HO, a Ludloff approach can be an effective option for achieving favorable surgical outcomes.

Systematisation of the causes that required revision hip replacement, methods of their solution, treatment results in Ukraine

BACKGROUND

The objective of this study is to organise data on complications following total hip replacement (THA) over a span of 10 years, specifically focussing on cases that necessitated revision endoprosthetic surgeries. The objective is to create a recommendation for an All-Ukrainian registry of initial and repeated hip arthroplasty (HA) and standardise the terminology used to define "revision of total hip replacement surgery".

METHODS

The retrospective analysis examined 236 instances of revision hip arthroplasty (rTHA) performed at the Institute of Traumatology and Orthopaedics Centre between January 2005 and December 2021. The primary factors for revision were identified through an analysis of the patient's medical records, laboratory results, visual inspection, and the state of the previously implanted prosthesis. Demographic information, primary and revision HA dates, diagnoses, and causes of complications were recorded. The statistical analysis was conducted using the Statistica package (StatSoft), version 12.6 (2015), with a significance level of p < 0.05.

RESULTS

Out of the 364 patients who were diagnosed with complications, 236 of them (55.17%) needed a procedure called 1rTHA. Among these cases, 152 (41.76%) were specifically diagnosed with aseptic component instability. Significant factors for mechanical loosening were a high body mass index (BMI ≥ 30) and older age, with respective t-values of 2.08 (p = 0.004) and 2.59 (p = 0.045). Osteoporosis significantly contributed to aseptic loosening and fractures around the implant. The occurrence of infectious complications was frequently linked to chronic infectious diseases (t = 3.37, p = 0.001). The overall percentage of need for 2rTHA was 27.22% (43 cases), with one case of infectious lesion following the revision.

CONCLUSIONS

The study emphasises the urgent requirement for standardised terminology and a comprehensive registry for hip arthroplasty procedures. Primary results indicate that cement-free fixation is more effective than cement-based fixation for revision in patients with aseptic instability and that two-stage arthroplasty is effective for treating infectious inflammation. Furthermore, the most effective treatment for femoral fractures with periprosthetic involvement was determined to be open repositioning and osteosynthesis with metal retainers. The aforementioned observations emphasise the need to create a comprehensive registry across Ukraine to support patient care, enable evidence-based practices, and enhance the overall effectiveness of hip arthroplasty operations.

CLINICAL TRIAL NUMBER

Not applicable.

Estrogen Deficiency Exacerbates Traumatic Heterotopic Ossification in Mice

Background

Traumatic heterotopic ossification (HO) is a devastating sequela of orthopedic surgeries and traumatic injuries; however, few studies have explored the effects of the estrogen-deficient state on HO formation. In the present study, we investigated the impact of estrogen deficiency on ectopic cartilage and bone formation in tendon after Achilles tenotomy in an ovariectomized mouse model.

Methods

A total of 45 female C57BL/6 mice were randomly divided into three groups: sham-operated (control), estrogen depletion by ovariectomy (OVX) and OVX with 17β-estradiol supplementation (OVX + E2), with 15 animals in each group. Three weeks after OVX, all mice were subjected to an Achilles tenotomy using a posterior midpoint approach to induce HO. At 1, 3 and 9 weeks after tenotomy, the left hind limbs were harvested for histology, immunohistochemistry and immunofluorescence evaluations. The volume of ectopic bone was assessed by micro-CT.

Results

Mice in the OVX group formed more ectopic cartilage 3 weeks after tenotomy, as well as ectopic bone 9 weeks after tenotomy, compared to the control group. Estrogen deficiency resulted in more severe inflammatory infiltration at the injury sites 1 week after tenotomy, involving the recruitment of more macrophages and mast cells, as well as increasing the expressions of pro-inflammatory mediators, including IL-1β, IL-6, and TNF-α. Moreover, the local TGF-β/SMAD signaling pathway was dysregulated after OVX, which manifested as upregulated expressions of TGF-β and pSMAD2/3. E2 supplementation protected against OVX-induced HO deterioration, inhibited inflammatory infiltration, and downregulated the TGF-β/SMAD signaling pathway.

Conclusion

Estrogen deficiency exacerbated HO formation in the Achilles tenotomy model. These findings might be attributable to the disturbance of the inflammatory response and the activation of TGF-β/SMAD signaling at the injury sites during the early stages of HO development.

Trauma patient heterotopic ossification diagnosis is associated with increased hospital length of stay

BACKGROUND

Traumatic heterotopic ossification (tHO) refers to the development of extra-skeletal bone in muscle and soft tissues following tissue insult secondary to surgery or trauma. This presents a persistent clinical concern associated with significant patient morbidity and expense to diagnose and treat. Traumatic HO is a substantial barrier to rehabilitation for trauma-injured patients. As such, the development of tHO after burn and other trauma is hypothesised to prolong inpatient length of stay (LOS) and thus increase health care costs.

OBJECTIVE

To investigate the association between an inpatient tHO diagnosis and hospital LOS in trauma patients.

METHODS

A retrospective audit of trauma patients over a 14-year period was completed using data from four WA hospitals. Burn and neurological trauma patients diagnosed with tHO as an inpatient (tHO+) and control subjects (tHO-), matched (1:3) by age, gender, and injury severity factors, were identified using medical diagnostic codes. Data relating to patient and injury-related determinants of LOS from tHO+ and tHO- subjects were analysed to model the association of tHO on total hospital length of stay.

RESULTS

188 identified patients were hospitalised due to traumatic injury; 47 patients with tHO following burn injury (n = 17), spinal cord injury (n = 13) and traumatic brain injury (n = 17), and 141 control patients. Those who developed tHO during hospitalisation had a significantly higher median LOS than matched trauma patients who did not develop tHO (142 days vs. 61 days). Multivariate regression analyses identified the following independent predictive factors of a prolonged hospital LOS: tHO diagnosis, mechanical ventilation hours, injury to the hip region and thigh area, other ossification disorder, pressure injury, admission to intensive care unit and deep vein thrombosis. Trauma patients diagnosed with tHO during their hospital admission stayed 1.6 times longer than trauma patients matched for injury severity without a tHO diagnosis (IRR 1.56, 95% CI 1.35-1.79, p<0.001).

CONCLUSION

Traumatic heterotopic ossification is an independent explanatory factor for increased hospital LOS in patients following burns, spinal cord, and traumatic brain injury. Early diagnosis may assist in reducing the impact of tHO on acute hospital stay after trauma.

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.

New insights into the role of long non-coding RNAs in osteoporosis

Osteoporosis is a common disease in elderly individuals, and osteoporosis can easily lead to bone and hip fractures that seriously endanger the health of elderly individuals. At present, the treatment of osteoporosis is mainly anti-osteoporosis drugs, but there are side effects associated with anti-osteoporosis drugs. Therefore, it is very important to develop early diagnostic indicators and new therapeutic drugs for the prevention and treatment of osteoporosis. Long noncoding RNAs (lncRNAs), noncoding RNAs longer than 200 nucleotides, can be used as diagnostic markers for osteoporosis, and lncRNAs play an important role in the progression of osteoporosis. Many studies have shown that lncRNAs can be the target of osteoporosis. Therefore, herein, the role of lncRNAs in osteoporosis is summarized, aiming to provide some information for the prevention and treatment of osteoporosis.