Outcomes of total hip arthroplasty in patients with osteonecrosis of the femoral head-a current review

Evaluation of the long-term patient-reported outcomes after hip arthroplasty or joint preserving with Sugioka femoral osteotomy in patients with femoral head osteonecrosis

PURPOSE

This study retrospectively evaluated long-term clinical outcomes and patient-reported outcome measures (PROMs) in patients with osteonecrosis of the femoral head (ONFH) who underwent transtrochanteric rotational osteotomy (TRO), curved varus osteotomy (CVO), and total hip arthroplasty (THA).

METHODS

We retrospectively reviewed the 109 hips in 96 patients (46 men, 50 women) who underwent CVO, TRO, or THA for ONFH treatment. The mean follow-up period for the TRO, CVO, and THA groups was 14.8, 11.5, and 13.3 years, respectively.

RESULTS

The THA conversion rate of the TRO patients was significantly higher than that of the patients with CVO, and the final clinical scores in the patients with TRO did not improve compared with preoperative scores. Postoperative PROMs showed that the total and pain scores of the patients with THA were significantly higher than those of patients with TRO and CVO, while the PROM score did not change between patients with TRO and CVO. The analysis further showed that the preoperative type C2, stage 3A, or postoperative type C1 and C2 were significant predictors of decreased final PROM scores.

CONCLUSION

This study found that CVO and THA are clinically effective treatments for ONFH, with significant improvements compared with preoperative scores. However, THA was associated with significantly higher PROMs and pain scores than those of CVO and TRO in long-term follow-up. Furthermore, our results suggest that postoperative PROMs depend mainly on the preoperative level of collapse and postoperative transposed intact ratio of the articular surface of the femoral head.

3D printing-assisted total hip arthroplasty and internal fixation for the treatment of fresh acetabular fracture and femoral head necrosis: A case report

RATIONALE

Posterior wall comminuted fractures of the acetabulum are typically caused by high-energy trauma, and the complex anatomical structure of the acetabulum makes their treatment challenging. However, reports of the treatment of fresh acetabular fractures combined with femoral head necrosis are extremely rare.

PATIENT CONCERNS

A 57-year-old male, injured in a car accident, presented with right hip pain and limited mobility. At the age of 50, the patient was diagnosed with avascular necrosis of the right femoral head, experiencing right hip pain and a limp while walking, for which conservative treatment was initiated.

DIAGNOSIS

The patient was clinically diagnosed with fresh comminuted posterior wall acetabular fracture and late-stage femoral head necrosis.

INTERVENTIONS

We applied 3D printing technology and computer-assisted virtual surgical techniques for preoperative planning, simulated fracture reduction, and designed personalized bone plates and screws for fixation of the posterior wall of the acetabulum. A single-stage total hip arthroplasty was performed to treat femoral head necrosis.

OUTCOMES

He began walking with the assistance of a walker 1 month after surgery, and at 6 months post-surgery, the acetabular posterior wall fracture had effectively healed, allowing the patient to return to work.

LESSONS

The application of 3D printing technology in acetabular internal fixation and total hip arthroplasty is helpful for fracture assessment, facilitates smooth surgery, promotes fracture reduction and healing, restores hip joint function, and ensures a high level of safety.

Increased Risk of In-Hospital Complications and Costs After Total Hip Arthroplasty for Primary and Secondary Osteonecrosis

BACKGROUND

An increasing proportion of patients are undergoing total hip arthroplasty (THA) for osteonecrosis (ON). Comorbid conditions and surgical risk factors are known to be greater in ON patients compared with patients who have osteoarthritis (OA) alone. The purpose of our study was to quantify the specific in-hospital complications and resource utilization associated with patients undergoing THA for ON versus OA.

METHODS

A large national database was queried to identify patients undergoing primary THA from January 1, 2016 to December 31, 2019. A total of 1,383,880 OA, 21,080 primary ON, and 54,335 secondary ON patients were identified. Demographics, in-hospital complications, costs, lengths of stay, and discharge dispositions for primary and secondary ON cohorts were compared to OA only. Age, race, ethnicity, comorbidities, Medicaid, and income status were controlled with binary logistic regression analyses.

RESULTS

The ON patients were often younger, African American or Hispanic, and had more comorbidities. Those undergoing THA for primary and secondary ON had a significantly higher risk of perioperative complications, including myocardial infarction, postoperative blood transfusion, and intraoperative bleeding. Total hospital costs and lengths of stay were significantly higher for both primary ON and secondary ON and both cohorts were less likely to be discharged home.

CONCLUSION

While rates of most complications have decreased over recent decades in ON patients undergoing THA, the ON patients still have worse outcomes even when controlling for comorbidity differences. Bundled payment systems and perioperative management strategies for these different patient cohorts should be considered separately.

Does Adjunction of Autologous Osteoblastic Cells Improve the Results of Core Decompression in Early-stage Femoral Head Osteonecrosis? A Double-blind, Randomized Trial

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a disabling disease that can ultimately progress to collapse of the femoral head, often resulting in THA. Core decompression of the femoral head combined with cell therapies have shown beneficial effects in previous clinical studies in patients with early-stage (Association Research Circulation Osseous [ARCO] Stage I and II) ONFH. However, high-quality evidence confirming the efficacy of this treatment modality is still lacking.

QUESTIONS/PURPOSES

(1) Is core decompression combined with autologous osteoblastic cell transplantation superior to core decompression with placebo implantation in relieving disease-associated pain and preventing radiologic ONFH progression in patients with nontraumatic early-stage ONFH? (2) What adverse events occurred in the treatment and control groups?

METHODS

This study was a Phase III, multicenter, randomized, double-blind, controlled study conducted from 2011 to 2019 (ClinicalTrails.gov registry number: NCT01529008). Adult patients with ARCO Stage I and II ONFH were randomized (1:1) to receive either core decompression with osteoblastic cell transplantation (5 mL with 20 x 10 6 cells/mL in the study group) or core decompression with placebo (5 mL of solution without cells in the control group) implantation. Thirty percent (68 of 230) of the screened patients were eligible for inclusion in the study; of these, 94% (64 of 68) underwent a bone marrow harvest or sham procedure (extended safety set) and 79% (54 of 68) were treated (study group: 25 patients; control group: 29). Forty-nine patients were included in the efficacy analyses. Similar proportions of patients in each group completed the study at 24 months of follow-up (study group: 44% [11 of 25]; control: 41% [12 of 29]). The study and control groups were comparable in important ways; for example, in the study and control groups, most patients were men (79% [27 of 34] and 87% [26 of 30], respectively) and had ARCO Stage II ONFH (76% [19 of 25] and 83% [24 of 29], respectively); the mean age was 46 and 45 years in the study and control groups, respectively. The follow-up period was 24 months post-treatment. The primary efficacy endpoint was the composite treatment response at 24 months, comprising the clinical response (clinically important improvement in pain from baseline using the WOMAC VA3.1 pain subscale, defined as 10 mm on a 100-mm scale) and radiologic response (the absence of progression to fracture stage [≥ ARCO Stage III], as assessed by conventional radiography and MRI of the hips). Secondary efficacy endpoints included the percentages of patients achieving a composite treatment response, clinical response, and radiologic response at 12 months, and the percentage of patients undergoing THA at 24 months. We maintained a continuous reporting system for adverse events and serious adverse events related to the study treatment, bone marrow aspiration and sham procedure, or other study procedures throughout the study. A planned, unblinded interim analysis of efficacy and adverse events was completed at 12 months. The study was discontinued because our data safety monitoring board recommended terminating the study for futility based on preselected futility stopping rules: conditional power below 0.20 and p = 0.01 to detect an effect size of 10 mm on the 100-mm WOMAC VA3.1 pain subscale (improvement in pain) and the absence of progression to fracture (≥ ARCO Stage III) observed on radiologic assessment, reflecting the unlikelihood that statistically beneficial results would be reached at 24 months after the treatment.

RESULTS

There was no difference between the study and control groups in the proportion of patients who achieved a composite treatment response at 24 months (61% [14 of 23] versus 69% [18 of 26]; p = 0.54). There was no difference in the proportion of patients with a treatment response at 12 months between the study and control groups (14 of 21 versus 15 of 23; p = 0.92), clinical response (17 of 21 versus 16 of 23; p = 0.38), and radiologic response (16 of 21 versus 18 of 23; p = 0.87). With the numbers available, at 24 months, there was no difference in the proportion of patients who underwent THA between the study and control groups (24% [six of 25] versus 14% [four of 29]). There were no serious adverse events related to the study treatment, and only one serious adverse event (procedural pain in the study group) was related to bone marrow aspiration. Nonserious adverse events related to the treatment were rare in the study and control groups (4% [one of 25] versus 14% [four of 29]). Nonserious adverse events related to bone marrow or sham aspiration were reported by 15% (five of 34) of patients in the study group and 7% (two of 30) of patients in the control group.

CONCLUSION

Our study did not show any advantage of autologous osteoblastic cells to improve the results of core decompression in early-stage (precollapse) ONFH. Adverse events related to treatment were rare and generally mild in both groups, although there might have been a potential risk associated with cell expansion. Based on our findings, we do not recommend the combination of osteoblastic cells and core decompression in patients with early-stage ONFH. Further, well-designed studies should be conducted to explore whether other treatment modalities involving a biological approach could improve the overall results of core decompression.

LEVEL OF EVIDENCE

Level II, therapeutic study.

Increasing trend toward joint-preserving procedures for hip osteonecrosis in the United States from 2010 to 2019

INTRODUCTION

The incidence of osteonecrosis of the femoral head is estimated at about 10 to 20,000 patients annually, and, when left untreated, 80% or more of cases progress to femoral head collapse. A series of joint-preserving procedures have been developed to prevent/delay the need for hip arthroplasty. The aim of this study was to provide a five-year update: (1) evaluating temporal trends of arthroplasty vs. joint-preservation techniques such as core decompression, bone grafting, osteotomies, and arthroscopy; (2) determining proportions of procedures in patients aged less than vs. over 50 years; and (3) quantifying rates of specific operative techniques.

METHODS

A total of 10,334 patients diagnosed with osteonecrosis of the femoral head and having received hip surgery were identified from a nationwide database between 1 January 2010 and 31 December 2019, by using the International Classification of Disease, the Ninth/Tenth revision (ICD-9/10) codes. The percentage of patients managed by each operative procedure was calculated annually. To identify trends, patients were grouped by age under/over 50 years and divided into a joint-preserving and a non-joint-preserving (arthroplasty) group. Chi-squared tests were performed to compare the total number of procedures per year.

RESULTS

Rates of arthroplasty far exceeded those for joint-preserving procedures. However, from 2015 to 2019, significantly more joint-preserving procedures were performed than in 2010 to 2014 (4.3% vs. 3.0%, P < 0.001). Significantly more joint-preserving procedures were performed in patients aged < 50 years relative to those ≥ 50 years (7.56% vs. 1.86%, P < 0.001). Overall, total hip arthroplasty was the most common procedure (9,814; 94.97%) relative to core decompression (331; 3.20%), hemiarthroplasty/resurfacing (102; 0.99%), bone grafting (48; 0.46%), and osteotomy (5; 0.05%).

CONCLUSION

Management of patients who have osteonecrosis of the femoral head continues to be predominantly arthroplasty procedures, specifically, total hip arthroplasty. Our findings suggest a small, but significant trend toward increased joint-preserving procedures, especially in patients under 50 years. In particular, the proportion of patients receiving core decompression has increased significantly from 2015 to 2019 relative to prior years.

Avascular Necrosis of Femoral Head-Overview and Current State of the Art

Avascular necrosis (AVN) of the femoral head is caused by disruption of the blood supply to the proximal femur. The alterations in the blood supply may occur following a traumatic event or result from a non-traumatic cause. Femoral neck fracture and hip dislocation and associated surgical procedures, corticosteroid therapy, and alcohol abuse frequently lead to AVN development. Type of fracture (displaced or undisplaced) and time between injury and surgery are the most critical factors in assessing the risk of developing AVN. Diagnosis of AVN can be established based on patients’ complaints, medical history, and radiographic findings. There is no consensus on the treatment of patients with AVN to date. Non-surgical methods are dedicated to patients in the early pre-collapse stages of the disease and consist of pharmacotherapy and physiotherapy. Surgery is recommended for patients with advanced disease.

Osteonecrose da cabeça femoral: Artigo de atualização

Among the pathologies that affect the hip joint, osteonecrosis of the femoral head (ONFH) is probably the most intriguing and challenging. It consists of a multifactorial disease with a highly-variable spectrum in its clinical presentation. It has a devastating effect, due to disabling painful conditions, both for usual activities and sports. Given the huge range of risk factors, such as prolonged use of corticosteroids (especially in cases of rheumatologic diseases), trauma sequelae, sickle cell anemia, HIV, alcoholism, smoking, blood dyscrasias, and several other diseases that compromise the blood supply to the femoral head, ONFH has a varied clinical presentation and prognosis, which makes it difficult to determine a specific treatment, especially in cases in which chondral involvement has not yet occurred and the hip joint is still preserved. These are the main factors found in the literature that determine the classifications of this pathology. The range of treatments includes several options for cases in which an attempt is made to save the joint: conservative treatment, traditional decompression and/or combined with some type of adjuvant treatment (homologous grafting, synthetic grafting, vascularized grafts, tantalum screws, and bone marrow aspirate injection), and, for cases in which there is already a subchondral fracture and/or collapse of the femoral head and/or a reduction in the joint space, femoral osteotomies or total hip arthroplasty are commonly performed.

Ten-year results of mesenchymal stromal cell transplantation augmented with vascularised bone grafts for advanced osteonecrosis of the femoral head

Background

A prospective, open-label clinical trial, in which transplantation of cultured autologous bone marrow-derived multipotent mesenchymal stromal cells in combination with vascularised bone grafts for the treatment of post-collapse extensive osteonecrosis of the femoral head in ten patients, was conducted previously. The aim of this study was to assess the 10-year clinical and radiographic results of that study.

Methods

Patients were evaluated for radiographic progression of osteonecrosis of the femoral head using anteroposterior radiographs at 10 years postoperatively. Clinical score and hip function, including the timed up and go test, were also estimated.

Results

Osteoarthritic changes in the affected hip were found in five of the ten patients, two of whom had undergone total hip arthroplasty at 7 and 9 years postoperatively. Five of the six cases (83.3%) in which pre-operative femoral head collapse was less than 3 mm, had no further collapse. On the other hand, all four cases in which pre-operative femoral head collapse was ≥3 mm, showed osteoarthritic changes within 10 years. The average clinical score significantly improved postoperatively and was maintained at 10 years.

Conclusions

Considering that eight of 10 post-collapse cases could avoid total hip arthroplasty conversion with good clinical results for 10 years and five of 6 post-collapse cases (collapse <3 mm) could avoid further collapse and osteoarthritic changes for 10 years, mesenchymal stromal cell transplantation in combination with vascularised bone grafts could be an effective treatment for post-collapse osteonecrosis of the femoral head.

Does prior core decompression have detrimental effect on subsequent total hip arthroplasty for osteonecrosis of the femoral head: A systematic review and meta-analysis

BACKGROUND

Core decompression (CD) is effective in relieving pain and delaying the progression to total hip arthroplasty (THA) for osteonecrosis of the femoral head (ONFH). However, the influence of CD on subsequent THA has not yet been established. Therefore, we performed this systematic review to answer: does prior CD have detrimental effect on subsequent THA for ONFH, especially with regards to survivorship and functional results, as well as perioperative and postoperative complications.

PATIENTS AND METHODS

After registration on PROSPERO (CRD42019118861), literature published up to and including November 2018 was searched in the PubMed, Embase and Cochrane library databases with predetermined terms. Comparative studies on the clinical outcomes between conversion to THA with prior CD (the Prior CD group) and primary THA (the Control group) for ONFH were included. The outcomes of interest included survivorship free from revision, the postoperative functional performance, perioperative and postoperative complications. Data was extracted systematically and a meta-analysis was performed.

RESULTS

Overall, 5 retrospective cohort studies with 110 hips were identified for the Prior CD group and 237 hips were identified for inclusion in the Control group. All of the studies were of high quality in terms of the Newcastle-Ottawa Scale. No difference in the rate of revision between the two groups (2/42 (4.8%) vs. 4/160 (2.5%); RR=1.92; 95% CI=0.34 to 10.75; p=0.46) was detected after a minimum two-year follow-up. The mean postoperative Harris Hip Score was similar between the two groups in all 5 studies. The two groups experienced similar blood loss (Mean difference=12.17ml; 95% CI= -15.28 to 39.61ml; p=0.38). Moreover, intraoperative fracture was increased in the Prior CD group, though this did not reach statistical significance (3/31 (9.7%) vs. 0/55 (0.0%); RR=7.05; 95% CI=0.82 to 60.78; p=0.08). Similarly, osteolysis or radiolucent lines were more likely to occur in the Prior CD group without statistical significance (9/81 (11.1%) vs. 6/200 (3.0%); RR=3.14, 95% CI=0.98 to 10.06; p=0.05).

DISCUSSION

The present evidence indicated that prior CD does not detrimentally affect the survivorship nor hip scores of subsequent THA. Attention should be paid, however, to the potential for intraoperative fracture, postoperative osteolysis or radiolucent lines.

LEVEL OF EVIDENCE

III; systematic review and meta-analysis of level III retrospective comparative studies.

Diagnosis of Osteonecrosis of the Femoral Head: Too Little, Too Late, and Independent of Etiology

BACKGROUND

Joint preservation is more effective in early-stage osteonecrosis of the femoral head (ONFH); thus, prompt diagnosis when the femoral head is still salvageable is important. We report a 20-year retrospective study that summarizes age at presentation, etiology, and Association Research Circulation Osseous stage at diagnosis.

METHODS

Our database was reviewed to identify patients younger than 65 years of age who were diagnosed with atraumatic ONFH between 1998 and 2018. Demographic characteristics of patients were evaluated and categorized into different subgroups.

RESULTS

Four hundred thirteen patients were identified. At initial presentation, 23% were diagnosed with early-stage ONFH, while 77% were diagnosed with late-stage ONFH. Forty-nine percent had a history of corticosteroid use, of which 13% were diagnosed with hematologic malignancy and 8% were diagnosed with lupus. Ethanol abuse, idiopathic, sickle cell disease, and human immunodeficiency virus were present in 11%, 30%, 3%, and 3%, respectively. The mean age of patients with corticosteroid use (40 ± 14 years) was significantly younger than ethanol use (46 ± 11 years, P = .014) and idiopathic causes (48 ± 11 years, P < .001), but significantly older than sickle cell disease (32 ± 11 years, P = .031). There was no difference in the age of presentation for early-stage and late-stage ONFH by etiology.

CONCLUSION

Nearly 80% of the patients presented with late-stage ONFH. Hence, we have a narrow window of opportunity for hip preservation surgery before femoral head collapse. A multidisciplinary approach to improve screening awareness for early detection by focusing on the etiologic identification and patient education might reduce the incidence of hip arthroplasty in young patients.

Triaging Total Hip Arthroplasty During the COVID-19 Pandemic

PURPOSE OF REVIEW

The purpose of this review was to evaluate the available literature to determine what may be considered urgent indications for total hip arthroplasty, in the unprecedented setting of the worldwide COVID-19 pandemic.

RECENT FINDINGS

SARS-CoV-2 is a novel coronavirus currently presenting in the form of a global pandemic, referred to as COVID-19. In this setting, multiple states have issued executive orders prohibiting "elective" surgery, including arthroplasty, in order to preserve healthcare resources. However, during this unprecedented reduction in elective surgery, there is likely to be some controversy as to what constitutes a purely "elective" procedure, versus an "urgent" procedure, particularly regarding hip arthroplasty. We reviewed the available literature for articles discussing the most commonly encountered indications for primary, conversion, and revision hip arthroplasty. Based upon the indications discussed in these articles, we further stratified these indications into "elective" versus "urgent" categories. In patients presenting with hip arthroplasty indications, the decision to proceed urgently with surgery should be based upon (a) the potential harm incurred by the patient if the surgery was delayed and (b) the potential risk incurred by the patient in the context of COVID-19 if surgery was performed. The authors present a decision-making algorithm for determining surgical urgency in three patients who underwent surgery in this context. Urgent total hip arthroplasty in the setting of the COVID-19 pandemic is a complex decision-making process, involving clinical and epidemiological factors. These decisions are best made in coordination with a multidisciplinary committee of one's peers. Region-specific issues such as hospital resources and availability of PPE may also inform the decision-making process.

Modified technique of advanced core decompression for treatment of femoral head osteonecrosis

BACKGROUND

Osteonecrosis of the femoral head (ONFH) is a destructive condition most commonly affecting young and middle-aged patients. The leading consequence of ONFH is often a significant articular disability. Effective joint-preserving surgical treatments are urgently needed for patients with early stage ONFH when outcomes of treatment are in general better than the advanced stage disease.

AIM

To introduce a new surgery procedure called percutaneous expanded core decompression and mixed bone graft technique, which is a new way of joint-preserving surgical treatments.

METHODS

The clinical data of 6 patients with ONFH diagnosed and treated with the procedure called percutaneous expanded core decompression and mixed bone graft technique at The First Hospital of Qiqihar from March 2013 to August 2019 were retrospectively analyzed; the follow-up ended in December 2019.

RESULTS

There were 6 male patients with an average age of 43 years in our study. Gratifying results have been obtained from the comparison of Harris hip score, visual analogue scale, and imaging examination before and after operation.

CONCLUSION

This new modified technique is simple, safe, and reliable. No serious perioperative complications were observed in our cases. Advantages of the single blade expandable reamer are obvious. The adjuvant substance is inexpensive and easy to obtain. Thus, this technique is an effective joint-preserving surgical treatment for patients with early stage of ONFH.

Management of osteonecrosis of the femoral head

Aims

Earlier studies dealing with trends in the management of osteonecrosis of the femoral head (ONFH) identified an increasing rate of total hip arthroplasties (THAs) and a decreasing rate of joint-preserving procedures between 1992 and 2008. In an effort to assess new trends in the management of this condition, this study evaluated the annual trends of joint-preserving versus arthroplasties for patients aged < or > 50 years old, and the incidence of specific operative management techniques.

Methods

A total of 219,371 patients with ONFH were identified from a nationwide database between 1 January 2009 and 31 December 2015. The mean age was 54 years (18 to 90) and 105,298 (48%) were female. The diagnosis was made using International Classification of Disease, Ninth revision, Clinical Modification (ICD-9-CM) and Tenth Revision, Clinical Modification (ICD-10-CM) procedure codes. The percentage of patients managed using each procedure during each year was calculated and compared between years. The trends in the use of the types of procedure were also evaluated.

Results

The rate of joint-preserving procedures was significantly higher in patients aged < 50 years compared with those aged > 50 years (4.93% vs 1.52%; p < 0.001). For the overall cohort, rates of arthroplasty were far greater than those for joint-preserving procedures. THA was the most commonly performed procedure (291,114; 94.03%), while osteotomy (3,598; 1.16%), partial arthroplasty (9,171; 2.96%), core decompression (1,200; 0.39%), and bone graft (3,026; 0.98%) were performed markedly less frequently. The annual percentage of patients managed using a THA (93.56% to 89.52%; p < 0.001), resurfacing (1.22% to 0.19%; p < 0.001), and osteotomy (1.31% to 1.05%; p < 0.001) also decreased during the study period.

Conclusion

We found that patients with ONFH have been most commonly managed with non-joint-preserving procedures. Our findings provide valuable insight into the current management of this condition and should increase efforts being made to save the hip joint. Cite this article: Bone Joint J 2020;102-B(7 Supple B):122–128.

A Mid- to Long-Term Follow-Up Experience with a Specific Metal-on-Metal Total Hip Arthroplasty Design

Purrpose  Metal-on-metal (MoM) total hip arthroplasty (THA) has been a subject of recent discussion and concern due to the early failures caused by local and systemic adverse reactions related to specific designs. The aim of this study is to analyze the outcomes and survival rates of a single brand of MoM implants implanted in a consecutive series of patients at a single institution.

Methods  Between 2007 and 2012, 116 (118 hips) patients were evaluated at a mean follow-up of 6.6 years after primary THA. The diagnosis leading to surgery was osteoarthritis (80 patients) and proximal femoral fracture (36 patients). A single design of THA was implanted. All patients were evaluated before surgery and postoperatively at 1, 3, 6, and 12 months by clinical scores and radiographic studies. The data analysis was made using Student's t -test.

Results  The minimum follow-up was of 4 years, with a mean follow-up of 6.6 years. Two aseptic loosenings of the acetabular component were recorded (one per group), which were not associated with local or systemic complications related to metal ion release. Both were revised by an isolated acetabular cup substitution with metal-on-polyethylene couplings. Nonprogressive radiolucency lines < 2 mm in zone 2 were observed in other six patients around the acetabular component without clinical manifestation (four in the arthritis group and two in the fracture group). Postoperative Harris Hip Score and SF-36 (36-Item Short Form Survey) score improved in both groups.

Conclusion  Despite several MoM implants showing early complications and failures, a specific MoM design may be associated with good clinical results at a mid- to long-term follow-up.

Level of Evidence  This is a therapeutic case series, Level 4 study.

[Total hip replacement in avascular femoral head necrosis]

BACKGROUND

Avascular necrosis of the femoral head is a progressive perfusion disorder of the hip joint. Progress in avascular necrosis causes structural damage to the affected joint, often requiring total hip replacement.

AIM

This article is intended to give the reader an overview of the current literature on total hip replacement of patients with an avascular necrosis of the femoral head.

RESULTS

Before 1990, patients with avascular necrosis of the femoral head had significantly higher revision rates after total hip replacement. Recent studies, however, showed no significant differences in clinical outcomes after total hip replacement in femoral head necrosis and primary osteoarthritis. Despite the young age of the patients, good long-term clinical results can be expected even in patients with an avascular necrosis of the femoral head after total hip replacement.

Osteonecrosis of the Hip: A Primer

In this report, we deliver a concise and up-to-date review of osteonecrosis, a pathologic, painful, and often disabling condition that is believed to result from the temporary or permanent disruption of blood supply to an affected area of bone. We will discuss the epidemiology (disease distribution), pathogenesis (mechanism of development), etiology (associated risk factors, causes, and disorders), clinical manifestations (reported symptoms and physical findings), diagnosis and classification, and treatment options for hip osteonecrosis.

Osteonecrosis of the Femoral Head

Osteonecrosis of the femoral head most commonly arises from trauma or corticosteroid and alcohol use but is also associated with blood dyscrasias and metabolic and coagulation disorders. Initial evaluation includes a history and physical examination and plain radiographs. Early-stage osteonecrosis is best evaluated by MRI. The Ficat and Arlet classification system is the most widely used. Nonoperative treatment has been studied using bisphosphonates, anticoagulants, vasodilators, statins, and biophysical modalities. Operative treatment includes core decompression with or without adjuvants, such as autologous bone marrow, whereas total hip arthroplasty is reserved for advanced-stage osteonecrosis in older patients or those who have failed joint-preserving treatment.

Radiographic evaluation of linear wear of bipolar hemiarthroplasty devices in vivo

BACKGROUND

The indications for bipolar hemiarthroplasty (BHA) have been narrowing as those for total hip arthroplasty (THA) have been expanding in cases of femoral neck fracture and initial stages of osteonecrosis of femoral head (ONFH). It is difficult to measure wear in vivo after BHA because the equipment used has a dual bearing system with an inner head inside a metal outer cup. The present study aimed to (1) use a roentgenograph to measure linear wear in vivo after BHA with different acetabular conditions around the bipolar cup, and (2) compare the linear wear of polyethylene between integral bipolar cup (IBC) and Centrax prostheses.

METHODS

From among patients who had undergone BHA in our department after 1996, we analyzed 48 joints with osteoarthritis (OA) and without acetabular cartilage, as well as 25 joints with ONFH of stage 3 or less, in which the acetabular cartilage remains. Two types of bipolar cup prostheses were used: the IBC, which was gamma-sterilized in air using 2-Mrad irradiation, and the Centrax, which was gamma-sterilized in nitrogen using 3-Mrad irradiation. To image the inner head in vivo, we used high-pressure X-ray photography; we measured linear wear of the polyethylene with software using Martell Method 1.

RESULTS

Comparing mean annual linear wear between the OA and ONFH groups, using IBC prostheses in both groups, there was a significant difference (0.213 mm vs. 0.096 mm, respectively; P = 0.0177). There was a significant difference between the Centrax and IBC prostheses in OA patients in terms of linear wear (0.04 mm vs. 0.213 mm; P = 0.0181).

CONCLUSION

The linear wear of polyethylene in BHA implants can be affected by the material used to manufacture the bipolar cup. Such implants should only be used for appropriate indications.

Biomechanical bearing-based typing method for osteonecrosis of the femoral head: ABC typing

Type classification of osteonecrosis of the femoral head (ONFH) is important for collapse prediction in ONFH, which depends on a complexity of factors. At present, most typing is based on single factors, including the location or size of the necrosis, or the bone repair capacity after ONFH, and is therefore limited. The present study proposes an 'ABC' method for ONFH typing based on biomechanics and the stress distribution characteristics of the femoral head's bone trabeculae. In total, 132 ONFH patients (223 hips) were enrolled at Guanganmen Hospital (Beijing, China). Each of the hip joints included was subjected to computerized tomography and/or magnetic resonance imaging. The images with the maximum necrotic area in the coronal femoral head were selected, and the femoral head's maximum transverse diameter was divided into three pillars (A, B and C, from the outside to the inside) according to a 3:4:3 diameter ratio. ONFH was typed according to the number of pillars involved in the necrosis. Differences in the collapse rate of different ONFH types, and the correlation between the theoretical collapse risk and the observed collapse rate was analysed. The ONFH types significantly differed in their collapse rate (χ²=76.93, P<0.001) in the following order: A-C (88.6%)>AB (74.1%)>BC (52.4%)>A (50%)>B (9.5%)>C (0%). The collapse risk was significantly correlated with the collapse rate (correlation coefficient R=1). The types A-C and AB had high collapse rates/risks, whereas types B and C had a satisfactory prognosis. The ABC typing proposed in the present study is thus suitable for collapse risk prediction in ONFH. Type classification using this method may provide a valuable reference for selecting regimens for ONFH treatment.

Bone morphogenetic protein-2 exhibits therapeutic benefits for osteonecrosis of the femoral head through induction of cartilage and bone cells

Osteonecrosis of the femoral head is an orthopedic disease caused by femoral head damage or insufficient blood supply, which leads to the death of bone cells and bone marrow. Osteonecrosis of the femoral head leads to changes in the structure of the femoral head, femoral head collapse and joint dysfunction. Bone morphogenetic protein-2 (BMP-2) exhibits beneficial effects on bone formation, repair and angiogenesis at the femoral head. In the present study, the therapeutic effects of recombinant human BMP-2 containing an Fc fragment (rBMP-2/Fc) were investigated on a steroid induced mouse model of osteonecrosis of the femoral head. Bone cell viability was used to determine the in vitro effects of rBMP-2/Fc. The therapeutic efficacies of rBMP-2/Fc on mice with osteonecrosis of the femoral head were evaluated using clinical arthritis scores. The expression levels of inflammatory factors in the mice were analyzed by reverse transcription-quantitative polymerase chain reaction. Histological analysis was used to evaluate the effects of rBMP-2/Fc on the femoral head. The results revealed that rBMP-2/Fc treatment significantly increased the IL-6, IL-10, vascular endothelial growth factor and macrophage colony-stimulating factor expression levels in synovial cells compared with the control group (P<0.01). Furthermore, it was observed that rBMP-2/Fc significantly improved the viability and growth of synovial cells (P<0.01) through the nuclear factor (NF)-κB signaling pathway. Treatment with rBMP-2/Fc significantly decreased receptor activator of NF-κB ligand expression levels. Furthermore, in vivo experiments demonstrated that rBMP-2/Fc treatment markedly relieved the arthralgia and damage caused by osteonecrosis of the femoral head. In conclusion, rBMP-2/Fc treatment may be beneficial for articular cartilage repair by the upregulation of angiogenesis factors through the down regulation of the NF-κB signaling pathway in mice with osteonecrosis of the femoral head. This preclinical data suggests that rBMP-2/Fc may be a promising novel agent for treatment of osteonecrosis of the femoral head.

Platelet-rich plasma has beneficial effects in mice with osteonecrosis of the femoral head by promoting angiogenesis

Platelet-rich plasma (PRP) is autologous and multifunctional. Platelet concentrate from blood contains highly concentrated platelets and various types of cells, including growth factors. PRP promotes the recovery of cell proliferation and differentiation. Osteonecrosis of the femoral head is a disease caused by femoral head damage or an insufficient blood supply, which leads to the death of bone cells and abnormal bone marrow composition. The subsequent repair of bone cells may result in changes to the structure of femoral head, femoral head collapse and joint dysfunction. PRP may promote the repair of injured articular cartilage in patients with joint diseases through the removal of harmful inflammatory factors. In the present study, the therapeutic effects and primary mechanism of PRP action were investigated using a glucocorticoid-induced femoral head osteonecrosis mouse model. Dexamethasone (DEX) and phosphate-buffered saline were used as controls. The therapeutic efficacy of PRP to treat osteonecrosis in murine femoral heads was evaluated by assessing clinical arthritis scores. The present study indicated that mice with osteonecrosis of the femoral head treated with PRP exhibited downregulated expression of interleukin (IL)-17A, IL-1β, tumor necrosis factor-α, receptor activator of nuclear factor κ-B ligand, IL-6 and interferon-γ in the inflammatory tissue. In addition, the levels of hepatocyte growth factor, intercellular adhesion molecule-1, osteopontin, platelet-derived endothelial cell growth factor, vascular endothelial growth factor, platelet-derived growth factor, insulin-like growth factor-1 and transforming growth factor-β were increased following treatment with PRP. Joint tissue histological staining demonstrated that PRP alleviated osteonecrosis of the femoral head and reduced humoral and cellular immune responses that promoted beneficial effects on the histological parameters. Furthermore, the concentration of glucocorticoids were significantly decreased in the serum of PRP-treated mice with osteonecrosis compared with the DEX group (P<0.01). Notably, PRP promoted beneficial effects in mice with osteonecrosis of the femoral head by stimulating angiogenesis. Therefore, the present study indicated that treatment with PRP promotes beneficial effects by preventing joint inflammation, cartilage destruction and bone damage, and stimulating the repair of joint tissue in mice with osteonecrosis of the femoral head. These preclinical data suggest that PRP may be developed as a novel method of treating osteonecrosis of the femoral head.

Platelet-rich plasma shows beneficial effects for patients with knee osteoarthritis by suppressing inflammatory factors

Knee osteoarthritis is a degenerative disease that may develop due ageing, obesity, strain, congenital abnormal joints, joint deformity or trauma. It is caused by many factors, such as degradation of articular cartilage injury, joint edge and subchondral bone hyperplasia of reactivity. Platelet-rich plasma (PRP) is an autologous blood sample that contains highly concentrated platelets and multiple cell growth factors. PRP promotes synovial cell proliferation and differentiation and may recover cartilage morphology. In the present study, the clinical efficacy of PRP was investigated in patients with knee osteoarthritis aged between 18 and 30 years in a phase-III clinical study. Following an 8-week baseline, patients with knee osteoarthritis were randomized into once-weekly, double-blind treatment with PRP (2-14 ml) or placebo groups. The results indicated that patients with osteoarthritis treated with PRP had modulated plasma concentrations of inflammatory factors and pro-angiogenic factors compared with the placebo group. Treatment responses were assessed by median percent reduction in inflammatory and pro-angiogenic factors and these improved with PRP treatment compared with the placebo. Clinical data indicated that PRP alleviated knee osteoarthritis and reduced humoral and cellular immune responses that led to beneficial effects on histological parameters. Inflammation was significantly alleviated in patients receiving PRP compared with the placebo group. The most common treatment-emergent adverse events in the presence of PRP were hypertension and proteinuria. In conclusion, treatment with PRP for patients with knee osteoarthritis presented beneficial effects in alleviating joint inflammation, cartilage destruction and bone damage, and repairing joint tissue. These results suggested that PRP may be a potential therapeutic agent for knee osteoarthritis.

Short stem total hip arthroplasty for osteonecrosis of the femoral head in patients 60 years or younger: a 3- to 10-year follow-up study

Background

In young patients with osteonecrosis of the femoral head (ONFH), short-stem total hip arthroplasty (THA) could allow a potential advantage in preserving metaphyseal bone-stock, when revision surgery might become necessary. However, only a few studies have evaluated the outcome of short-stem THAs in ONFH. We reviewed the prospectively collected data of a cementless partial neck-retaining short-stem with ceramic-on-ceramic bearings in ONFH patients.

Methods

Thirty patients (37 hips) younger than 60 years (mean age at surgery, 51.5 years) underwent THA with the NANOS® stem (Smith and Nephew, Marl, Germany) from January 2006 to December 2012. All patients received a 32-mm or 36 mm ceramic femoral head. Harris hip score, WOMAC and UCLA activity score were recorded. Postoperative radiographs were evaluated for bone-implant fixation and osteolysis. Further analysis correlated clinical findings with implants characteristics and patient demographics at mean 5.6 years’ follow-up (range, 3–10 years).

Results

The clinical and functional results improved significantly (p < 0.001). At latest follow-up, mean HHS, WOMAC, and UCLA activity scores were 90 (range, 71–100), 94 (range, 76–100), and 6.3 (range, 4–10) points, respectively. The diameter of the femoral head did not influence the clinical outcome (p = 0.661). All hips showed bone ingrowth fixation of the acetabular and femoral components. No patients showed osteolysis. No revision for any reason was performed during the study period.

Conclusions

The excellent clinical results and fixation pattern at mean 5.6 years’ follow-up reveal this implant as a reliable option in advanced stage of ONFH either. Further investigations are crucial to determine the long-term durability and to assess whether the association of ceramic-on-ceramic bearings, can be useful to achieve longer survivorship and lower complications rates.

Trial registration

Registry number: ISRCTN 91336248; date of registration: 04/07/2017.

Ipsilateral femoral head osteochondral transfers for osteochondral defects of the femoral head

Osteochondral defects of the femoral head are rare. Several treatment options have been described, though there is currently no consensus on the appropriate management of these lesions. Five patients underwent femoral head osteochondral autograft transfer for treatment of ipsilateral femoral head osteochondral defects via surgical hip dislocation between 2011 and 2014 at our institution. The mean age of the patients was 24.8 (16–37) years. There were four females and one male. Mean follow-up was 53.8 (30–64) months. Four patients reported complete resolution of preoperative pain, return to baseline activities and were satisfied with their results. Harris hip scores improved from a mean 60.8 (30–87) to 86.6 (44–100). There was no radiographic evidence of progression of the femoral head defects. There were no operative complications. Osteochondral autograft transfer from the ipsilateral femoral head using a surgical hip dislocation demonstrated good clinical and radiographic outcomes at midterm follow-up in our cohort and may be considered a suitable option for management of these lesions in select patients. Further research and follow-up is warranted to more clearly define the indications and outcomes of this procedure.