Is treating avascular necrosis of the femoral head without hip replacement possible?
Ross A. Hauser, MD.
Treating avascular necrosis of the femoral head without hip replacement
Many patients we see with AVN or Avascular necrosis of the femoral head in the hip joint understand their problem as “dead bone,” or “dead bone from lack of blood supply,” and for the most part, that is what the problem is the dead or dying bone that can lead to eventual hip collapse. The term some of these patients also use is “Osteonecrosis” which also means “dead or dying bone.”
Osteonecrosis, avascular necrosis, AVN, or aseptic necrosis (as this is diagnosed under many names), is a condition where the blood supply to the bone is impeded or disrupted. Bone needs circulating blood to regenerate and repair itself so you can have pain-free, healthy joint motion. Loss of blood flow to the hip is a leading cause of hip degenerative disease and the need for hip replacement surgery. Without blood flow, the bone undergoes wear and tear without the ability to repair the degenerative damage. Eventually, your bone dies, the femoral head (the ball) of the hip joint collapses, and in essence, your hip dies with it.
To avoid this outcome, especially in patients who are deemed too young for total hip replacement, one treatment option that your doctors may have discussed with you in treating your avascular necrosis is core decompression surgery.
Discussion points of this article:
- Caring Medical Research: Avascular Necrosis Case Report of Direct Bone Marrow Injections and Prolotherapy Treatment
- Case histories of patients.
- Patient case: A 76-year-old female.
- Patient case: – A 56-year-old female presented with pain in bilateral knees and right hip.
- Avascular necrosis, or bone death, is an example of a condition that may be due to joint instability or may be due to lifestyle or medication.
- Are the ligaments the factor between symptomatic and asymptomatic AVN patients?
- The person with the physically demanding job and high-level competitive athlete who needs to function.
- Corticosteroids and cause of bone death
- Fewer hip intra-articular corticosteroid injections, less femoral head collapse
- Treating hip pain and necrosis – core decompression or non-surgical injection therapy?
- Core decompression – the surgery – bringing blood back to the bone.
- The failure of core decompression to provide long-term relief has been a challenge for hip surgeons.
- Osteonecrosis is a multifactorial condition that can be caused by many things. This prevents surgeons from developing a single, standardized surgical treatment.
- The failure of core decompression presents a challenge for hip surgeons in converting the hip to total hip replacement.
- Common sense should tell us floating metallic debris in the hip is not optimum and reminds many of the metal on metal hip replacement recalls.
- Making core decompression work better – the use of stem cells and blood platelets during surgery?
- “Therapies such as additive stem cells or platelet-rich plasma (PRP) combined with core decompression have yet to prove their efficacy.”
- Are Bone Marrow-Derived Stem Cells A Realistic Treatment?
- Bone Marrow-Derived Stem Cells use during surgery, more research.
- Bone marrow stem cells and PRP may be beneficial during surgery. How about the treatments without surgery? Treating avascular necrosis without core decompression
- Supportive research: PRP and stem cells
- Research supporting the use of dextrose Prolotherapy injections alone.
The caption of this image reads: AP or front view x-ray of pelvis. Example of a patient whose x-ray shows a completely destroyed hip compared to a nearly normal hip on the other side. This person was referred for a hip replacement. In this image we also see a collapse of the femoral head. Not all patients will be able to avoid a hip replacement if the are in advanced avascular necrosis.
Caring Medical Research: Avascular Necrosis Case Report of Direct Bone Marrow Injections and Prolotherapy Treatment
When we first began publishing research on our results with bone marrow injections, we were able to show a patient case history of the repair of avascular necrosis of the talus (the large bone of the ankle). Later and documented below, we showed the results in cases of advanced hip degeneration.
Back to the ankle patient briefly and writing in the Journal of Prolotherapy, we documented the first case report of using direct bone marrow aspiration into areas of pain in a patient with avascular necrosis of the talus that did not involve core decompression. In this particular case, the bone marrow aspirate was injected into the tibiotalar and subtalar joints. The surrounding painful and injured ligaments on the lateral and medial sides of the ankle were also treated with Prolotherapy. Treating avascular necrosis with bone marrow stem cells is definitely a viable and successful treatment option to explore prior to surgery. (16 Read our research)
In our research published medical journal Clinical Medicine Insights Arthritis and Musculoskeletal Disorders (17), Ross Hauser, MD we documented the following cases of advancing hip osteoarthritis. As of this article update August 4, 2022, this paper has been cited by 24 other papers listed at PubMed Central® at the U.S. National Institutes of Health’s National Library of Medicine and 81 papers listed in Google Scholar. Below are case histories from our research.
Patient case: A 76-year-old female
A 76-year-old female came into our office with pain in both hips that had plagued her for the last 3-4 years. Her left hip pain was more significant than the right. She was unable to walk more than a mile without significant pain. The patient had received a recommendation for hip replacement. X-rays revealed moderate to severe degenerative changes in both hips.
The patient received seven bone marrow/dextrose H3 Prolotherapy treatments to each hip over a period of 12 months and adhered to a program of daily bicycle exercise.
- She reported incremental improvements in pain and function at each visit. At the final visit, the patient reported significant gains since the onset of treatment with respect to the range of motion, resumption of exercise, reduced crepitus, and reduction of pain medication use by two-thirds. She reported her overall improvement as 90%.
Patient case: – A 56-year-old female presented with pain in bilateral knees and right hip.
- Right hip pain had been intermittent for 16 years, but instability and continuous pain began six months before her visit.
- The hip pain prevented sleep on the affected side, bicycle exercise had ceased for more than a year, and walking exercise was limited to three miles.
- MRI with a previous physician showed a labral tear. The patient was diagnosed with hip osteoarthritis and labral tear, and bilateral knee osteoarthritis.
- The patient received bone marrow/dextrose treatment at six visits with 8–10 week intervals.
- At visits 1 and 2, the right knee and right hip were treated with tibial whole bone marrow.
- At visits 3 and 4, both knees and right hip were treated with tibial whole bone marrow.
- The patient reported modest (20%–35%) overall improvement following these treatments.
- At the final two visits, bilateral knees and right hip were treated with iliac whole bone marrow injection. During the treatment period, the left hip was also treated for pain resulting from a flexor injury incurred following visit 1.
- Two months after visit 6, the patient reported 65%–95% overall improvement for the three joints. She is able to walk for two hours, no longer has disturbed sleep, and has been able to resume bicycle exercise with minimal discomfort. The patient still experiences intermittent soreness in a small region in the medial aspect of the right patella.
Patient case: A 63-year-old male presented with bilateral hip pain.
- Pain intensity was 6/10 with a frequency of 50%.
- The patient received five bilateral treatments with dextrose Prolotherapy over a period of 5 months.
- During this period, the patient reported an overall improvement of 50%; however, this reduced to 30%–40% at the conclusion of the treatment period, at which time pain intensity was 6/10 with a frequency of 30%.
- Crepitus, previously absent, was now marked. At this point, the patient began a series of two whole bone marrow/dextrose treatments two months apart.
- At the time of the second treatment, pain intensity was 5/10. Crepitus was reduced.
- Specific pain manifestations previously noted, including ischial tuberosity pain and lateral hip pain, had abated, and the patient reported being able to walk without a cane for the first time in years.
- Two months after the second whole bone marrow/dextrose treatment, pain intensity was 1/10 with a frequency of 10%. Crepitus was absent and the patient reported walking without a limp and no longer needing a cane.
In this research we concluded:
“We have explored whole bone marrow injection in combination with dextrose Prolotherapy is a cost-effective approach with potentially broad application for osteoarthritis. . .Our initial experience has been encouraging, as all patients experienced significant gains in treatment periods of 2–12 months without adverse events.
Additionally, five of seven patients experienced strong functional improvement and/or complete or near-complete pain relief. Patients uniformly expressed satisfaction with outcomes in interviews.
Five patients reported receiving a previous recommendation for joint replacement, and at the final interview, none believed replacement would be needed.
Among the papers citing our work, a December 2018 paper in the publication PM & R: the journal of injury, function, and rehabilitation (32) found “intra-articular injections of bone marrow concentrate for the treatment of early knee or hip osteoarthritis were safe and demonstrated satisfactory results in 63.2% of patients. Future studies are necessary to determine the efficacy of this technique and its safety profile.”
Avascular necrosis, or bone death, is an example of a condition that may be due to joint instability or may be due to lifestyle or medication.
Avascular necrosis, or bone death, is an example of a condition that may be due to joint instability or may be due to lifestyle or medication. There are two reasons why someone develops avascular necrosis: a systemic problem or joint instability. The bone can die due to large doses of medications needed to treat certain systemic conditions, such as chemotherapy or prednisone. Or, avascular necrosis can occur in cases of excessive alcohol use.
- These cases are not due to joint instability and would not be appropriate candidates for our regenerative medicine injections.
Understanding the hip ligaments, joint instability and bone death
Summary: AVN signifies bone cell and tissue death; ligamentosis means ligament cell and tissue death; tendinosis described degeneration and death of tendon cells; degenerated hip meniscus denotes meniscus cell and tissue death; degeneration of the labrum indicates labral cell and tissue death; and finally bone-on-bone means articular cartilage tissue and cell death. Simply put, all these terms mean ‘cell and tissue death’. In hips with ligament injury and resultant hip instability, as the instability progresses, the tissues in and around the hip will continue to degenerate and die. As the tissues get weaker, their shock absorbing properties or their ability to diffuse pressure reduces so that the pressure with walking and standing gets concentrated on small sections of the femoral head and acetabulum. Eventually, femoral head collapse can occur.
In the image below we see how ligaments wrap around the ball and socket of the hip.
- The Pubofemoral ligaments prevent hip abduction or your leg from move to far to the side during walking or movement.
- The iliofemoral ligament prevents your leg from moving too far backward when walking or exercising.
Very often people develop avascular necrosis due to joint instability since avascular necrosis occurs at the end of the bone which is the same place where the ligaments attach. Ligaments hold joints together and in their place. When ligaments, the bone to bone attachments are damaged or weakened, they no longer hold the bones in place and the bones begin to wander. Excessive rubbing of the ball of the hip in the socket of the hip by these wandering out of place bones can interrupt the blood supply. After continued pressure, bone can die. Therefore, avascular necrosis can be yet another MRI finding that really indicates that the person’s pain is coming from joint instability. Regenerative medicine injections can be a good option for these cases.
Are the ligaments the factor between symptomatic and asymptomatic AVN patients?
There are people with asymptomatic AVN and those with terrible hip pain with AVN. Wouldn’t the death of the bone and cartilage always be painful? Not necessarily. There no nerve endings in cartilage. The nerve endings that provide the majority of the pain signals in joints, including the hip joint, are in the hip capsular ligaments and the extracapsular ligaments. Thus, the only difference between asymptomatic and symptomatic AVN may be how much stretch is on the nerve endings in those structures.
The person with a physically demanding job and high-level competitive athlete.
Many people that contact us write because they are high-level athletes. They write to us that their hip pain became more than they could handle on their own. An MRI revealed avascular necrosis, and the first thing they heard from the doctor was: “You must stop running.” When they asked the doctor how did they get that way, the doctor answers, “your history of high-level sports is most likely.” Then the doctor may have already asked about how many times they were treated with high-dose corticosteroids, such as prednisone. As we see in the research, cortisone injections are a concerning cause of avascular necrosis. The same story can be heard in the people who work in restaurants or are landscapers or in construction. They write to us that work is becoming increasingly difficult. Unlike the athlete who can stop running, this person cannot stop working.
There is a great debate in the medical community in regard to the use of corticosteroid for varying health conditions and the accelerated development of hip osteoarthritis in the form of avascular necrosis leading to femoral head collapse. Let’s start looking at some studies.
First, the side that says corticosteroid does NOT appear to cause avascular necrosis. This is an October 2021 study in the Orthopaedic journal of sports medicine.(28)
“Recent studies have suggested there is an increased risk of avascular necrosis (AVN), subchondral insufficiency fracture, femoral head collapse, and osteoarthritis progression in the 12-month period after hip corticosteroid/anesthetic injection; however, these studies have failed to account for pre-injection osteoarthritis severity or preexisting avascular necrosis/ subchondral insufficiency fracture.”
What the researchers are getting at is the “pre-existing condition” of the hip and whether accelerated degeneration of the hip was caused by steroid injections or was simply the natural progression of a pre-existing disease. To determine this one group of patients who had a cortisone injection was matched to another group with similar characteristics for age, sex, level of hip degeneration who did not get a cortisone injection.
What were the findings?
The researchers said they did not find similar conclusions that cortisone caused an accelerated hip degeneration: They write: “In contrast to the findings of recent retrospective investigations, we did not find that patients treated with hip cortisone had significantly higher rates of short-term osteoarthritis progression or femoral head articular surface collapse after controlling for baseline osteoarthritis severity and preexisting avascular necrosis or subchondral insufficiency fracture.”
What the researchers said – “In contrast to the findings of recent retrospective investigations” was the acknowledgement that there is another side to this story.
“Intra-articular steroid injection can cause femoral head AVN, and the patient receiving these injections should be aware about this rare but significant complication that results in poor functional outcome and significant morbidity.”
A February 2020 study in the European journal of orthopaedic surgery & traumatology (29) suggested something for different. This research examined the single injection of cortisone as a cause of accelerated hip osteoarthritis and avascular necrosis.
“Long-term steroid intake was established as a cause of avascular necrosis. . . We review(ed) all cases of avascular necrosis that results from single intra-articular steroid injection and present a case of femoral head AVN developed in a 78-year-old male. The patient, who was not known to have any medical illness, presented complaining of mild left hip pain for 4 months with long distant ambulation (walking) and weight standing. He was diagnosed to have left hip joint osteoarthritis for which he received intra-articular steroid injection two months prior visiting our orthopedics center. MRI of the pelvis revealed AVN of the femoral head. He underwent total hip arthroplasty. The pathological examination confirmed the diagnosis of AVN. To best of our knowledge, this is the fifth case of AVN of femoral head AVN after single intra-articular steroid injection. . . Intra-articular steroid injection can cause femoral head AVN, and the patient receiving these injections should be aware about this rare but significant complication that results in poor functional outcome and significant morbidity.”
An April 2020 paper in the American journal of physical medicine and rehabilitation (30) similarly recorded a case:
“(the case is presented of) osteonecrosis of the femoral head (which) developed in temporal association with a single intra-articular injection of corticosteroid (triamcinolone acetonide) in a 72-yr-old woman, resulting in a total hip arthroplasty. We conclude that the risk of developing osteonecrosis after a single intra-articular injection of corticosteroid needs to be considered in the informed consent process.”
Fewer hip intra-articular corticosteroid injections, less femoral head collapse
A November 2021 study (33) lead by the University of Minnesota found that “Femoral head collapse is a rarely reported complication of hip intra-articular corticosteroid injection.” To address this concern, the researchers examined patients receiving hip intra-articular corticosteroid injection during a 27-month period to determine the rate of femoral head collapse and to identify associated patient factors or practice shortfalls.
- Results: Initial femoral head collapse rate after hip intra-articular corticosteroid injection was 20.4%.
- Patient-related factors included body mass index, history of cancer therapy, Vitamin D level, and multiple injections.
- Among doctor guideline updated recommendation to prevent femoral head collapse from corticosteroid injection.
- fewer treatment referrals
- fewer repeat injections
- resulting in a 5% lower Femoral head collapse rate.
“Long-covid” cortisone injections and avascular necrosis
An new phenomena is what doctors see as an epidemic of formal head collapse and the need for hip replacements. In a July 2021 paper in the journal BMJ case reports researchers suggested: (31)
“By large-scale use of life-saving corticosteroids in COVID-19 cases, we anticipate that there will be a resurgence of avascular necrosis cases. We report a series of three cases in which patients developed avascular necrosis of the femoral head after being treated for COVID-19 infection. The mean dose of prednisolone used in these cases was 758 mg (400-1250 mg), which is less than the mean cumulative dose of around 2000 mg steroid, documented in the literature as causative for avascular necrosis. Patients were symptomatic and developed early avascular necrosis presentation at an average of 58 days after COVID-19 diagnosis as compared with the literature which shows that it generally takes 6 months to 1 year to develop avascular necrosis post steroid exposure.”
Indian doctors working with COVID-19 patients published an April 2022 report (37) on patients diagnosed with osteonecrosis of femoral head following recovery from COVID-19 disease. They found in 22 consecutive patients (17 both hips 5 one hip) who had recovered from COVID-19 received corticosteroids as a supportive treatment during COVID-19. Patients were classified into two types, those with classic osteonecrosis of femoral head and rapidly destructive coxarthrosis (the breakdown of cartilage and bone). What caused the rapidly destructive coxarthrosis? The researchers suggest: “low cumulative dose of steroids in our patients suggests that the COVID-19-associated vasculitis may play a role in the pathogenesis of osteonecrosis of femoral head.”
Treating hip pain and necrosis – core decompression or non-surgical injection therapy?
If you are reading this page it is likely that you have already received the recommendation to go ahead with a core decompression surgery. You may even feel that you got some good news in that your femoral head has not collapsed yet and you do not need a hip replacement. The recommendation to core decompression, while still major surgery, has its appeal. There is a chance that the core decompression surgery will save your hip, you will not need a much larger hip replacement surgery in the near future, and more importantly, you can have restored function and a lot less pain, faster. Or so is the belief.
If you are reading this page you have been researching and you have found some things that may offer you some concern about this procedure.
- Some people report that they had significant pain after the core decompression surgery, lasting 1 – 2 months.
- People are talking about extensive rehabilitation 3 – 6 months
- People are talking that they were told by their surgeon that it could take up to one year to see any benefits.
- People are talking about having to get a hip replacement anyway. Having the core decompression first made the hip replacement a much more complicated procedure.
- People are talking about their regrets about having the surgery.
Please note that many people have core decompression surgery and do very well with it. Some do not. If you are reading this page, you are likely concerned about the problems that post-surgery patients had, or worse, you are one of those post-surgical people who have more pain after the procedure and are waiting for a hip replacement and your doctors are trying to figure out how to do it. You may be reading our article because you are looking for options, and we will present those below.
Core decompression – the surgery – bringing blood back to the bone
If you have been diagnosed with avascular necrosis of the hip, sometimes surgery is needed. If you have some reasonable range of motion remaining, for instance, a 50% or greater normal range of motion, then regenerative medicine injections may help with the pain and exercises like cycling and swimming and this can slowly allow the patient to regain some of the lost range of motion.
Core decompression is considered a “joint sparing” surgery. If it works, a hip replacement can be avoided or delayed. The core decompression surgical procedure involves drilling a hole(s) into the femoral head of the hip to relieve pressure (from bone edema/swelling) in the bone and hopefully create new blood vessels to nourish the affected areas of the hip. The hope is that the new blood circulation will help with bone rebuilding.
According to surgeons who perform this procedure: The overall success of this treatment is unclear.
The failure of core decompression to provide long-term relief has been a challenge for hip surgeons
Early in 2019, United States Army surgeons wrote of the “Low Rate of Return to Impact Activity Following Core Decompression for Femoral Head AVN in Military Service members.” (1) This study was published in the journal Military Medicine. Here is what the army doctors wrote:
- A total of 29 active duty patients were examined (22 male, 7 female; average age 32.3 years).
- Seven patients of the 29 patients (24%) progressed to the need for total hip replacement and they were more likely to have bilateral (both hips) disease (86%) and be older (35.4 years versus 31.2 years).
- At the final follow-up, 86% of patients had significant hip-related activity restrictions, with only 6 of the 29 patients (21%) remaining on active military service.
- Military service members have a low likelihood of returning to preoperative physical function and running activities (13.7%).
Osteonecrosis is a multifactorial condition that can be caused by many things. This prevents surgeons from developing a single, standardized surgical treatment.
In August 2018, doctors at the Institute of Orthopedics and Traumatology at the University of San Paulo in Brazil published their findings in The Brazilian Journal of Orthopedics (2) Which questioned the success of core decompression surgery. These are the learning points:
- Osteonecrosis is a multi-factorial condition that can be caused by many things. This prevents surgeons from developing a single, standardized surgical treatment. (Bone loss/death can be caused by steroids (see the case history below), hormone replacement therapy, joint instability).
- This condition continues to be underdiagnosed in its initial phase; if an early diagnosis is made, decompression is a possible treatment option. If the diagnosis is made in advanced stages, with established femoral head collapse, the indicated treatment is a total hip replacement.
The surgeon/researchers point out that their study was aimed at analyzing the characteristics of patients who underwent decompression in the last two years; all procedures were performed in the same way (guidewire placement in the femoral neck with fluoroscopic aid and drilling with a cannulated burr in the necrotic area).
Drilling relieved pressure and pain
- The authors believe that the symptoms may be related to the presence of bone edema, which was observed in all cases submitted to the procedure. A significant improvement of the patients’ early symptoms was observed in 83.3% of decompressed hips.
Pain relief did not last long
- In scoring patients’ pain symptoms, preoperative and postoperative pain did not present statistically significant alterations after six months, which indicates that the decompression treatment improves the early pain symptomatology, but does not alter the disease prognosis or the subsequent recommendation to hip replacement.
Pain relief did not last long despite new techniques and innovative solutions
The researchers noted that the failure of core decompression to provide long-term relief has been a challenge for hip surgeons, who have used new techniques associated with core decompression, such as the use of vascularized or non vascularized grafts, stem cell injection, shock wave therapy, and anticoagulant drugs. Moreover, various techniques have been described using different types of drills and drillings. The results have been similar, with initial symptom improvement that does not influence disease progression.
The same research team published an updated article in June 2022 confirming (34) “Osteonecrosis of the femoral head has several therapeutic options in its early stages, all for symptom relief, and in an attempt to preserve the joint. . . In advanced cases, osteotomies (surgery to reshape the bone) are an option, and total femoral arthroplasty (a salvage operation after failed hip replacement that replaces the thigh bone) has excellent results, and the procedure should be individualized for each patient.”
“Core decompression provides only short-term clinical improvement”
Similar results were also seen in a March 2021 report published in the journal International Orthopaedics (3). In this paper from a team of international specialists from Balgrist University Hospita in Switzerland, Cambridge University Hospitals in the United Kingdom, Meir Medical Center in Israel, and Harvard Medical School, the researchers wrote:
“Our study shows that core decompression provides only short-term clinical improvement and partial or complete pain relief in most of the cases (33 out of 37 studies reported postoperative clinical improvement). It should however be noted that reduction of pain may be due to temporary reduction of weight-bearing during the rehabilitation phase and further trials evaluating this aspect are necessary.
Our results also demonstrate that approximately 38% of patients underwent a total hip replacement at an average of 26 months following core decompression without augmentation (a patch or biological scaffold) in a large and diverse population with AVN of the femoral head of varied etiology. This review, however, could not determine whether core decompression alone can arrest disease progression due to lack of stratification and heterogeneity of data. (The evidence was not clear).
Extracorporeal shock wave therapy: maybe better than surgery?
An August 2022 paper published in The Physician and sports medicine (36) sought to determine whether ESWT (extracorporeal shock wave therapy) affects ONFH (osteonecrosis of femoral head) in clinical outcomes and radiography outcomes.
To do this, researchers examined nine previously published studies with 409 patients. The pooled results showed improvements in 337 hips. The researchers concluded: “ESWT has an effect on pain relief and has a limited effect on motion function. Its effect may be better than surgical groups (core decompression and core decompression with bone grafting). But it cannot decrease the lesion area of the femoral head on MRI and stop disease progression.”
The failure of core decompression presents a challenge for hip surgeons in converting the hip to total hip replacement
When an MRI shows the presence of AVN, most patients believe hip replacement is inevitable and may not know that there are other treatment options. The orthopedic surgeon may not inform them that many people with AVN are asymptomatic and rarely discuss other viable options. The body has tremendous regenerative capability. Bones are in a continual process of breaking down, absorbing old bone and rebuilding new bone. When bones fracture or break, they rebuild themselves. The reason that joints with AVN may be unable to allow the bone to fully heal is due to joint instability and the increased pressure on the bone. Most surgeries and procedures, even including regenerative treatment methods, often do not work for cases of AVN because they are not addressing the root issue of the issue, which is joint instability.
In this section, we will present the research from the surgeons themselves in the challenges they face with a hip that has already had and failed core compression.
There is a problem with the rods and the metal debris in the hip they may cause.
A research team from Canada and the United Kingdom issued troubling findings in patients where core decompression failed and a subsequent total hip replacement was required.
The doctors, writing in the Bone and Joint Journal, (4) looked at core decompression and insertion of a tantalum rod into the hip joint for stabilization. The doctors were concerned that there may be a high failure rate associated with this procedure and examined failed tantalum rod insertion patients and their move to and subsequent hip replacement outcomes.
- They found that in the short term, tantalum rod implantation does not adversely affect subsequent total joint replacement surgery. However, patients show a high rate of retained tantalum debris on postoperative radiographs, and thus there is an unknown risk of accelerated articular cartilage wear necessitating longer-term study.
An August 2018 study in the journal BioMed Central Musculoskeletal Disorders (5) made similar findings.
“The mid-term clinical outcome of patients who underwent total hip replacement with tantalum rod implantation was not different from those without a tantalum rod, suggesting that tantalum debris did not increase the liner wear rate. However, the distribution of periprosthetic tantalum debris in the proximal, middle, and distal femoral regions may increase the risk of femoral osteolysis (the accelerated degeneration of the hip bone) and radiolucent lines (an indication of fracture. In Hip replacement or resurfacing it is an indication of implant loosening).
Common sense should tell us floating metallic debris in the hip is not optimum and reminds many of the metal on metal hip replacement recalls.
University hospital researchers in China writing in the journal International Orthopaedics (6) shared their equal concerns: “Porous tantalum osteonecrosis implants have been used in femoral head necrosis for several years, while the clinical outcomes were mixed. As a joint-preserving surgery, early necrosis deterioration and conversion to total hip replacement failed our expectation.”
What concerned the Chinese researchers was that the deterioration of early failed tantalum implants exceeds the nature of osteonecrosis progression. In other words, the implant caused accelerated hip degeneration.
They note that it was not the failure of the implant mechanical support, but rather the results of the drill that compromised the bone and led to the early failure of porous tantalum osteonecrosis implants.
In other words, the concern of the Chinese researchers was how fast the surgery failed and caused stress fractures in the bone it was designed to preserve.
American Academy of Orthopaedic Surgeons Illustration of (Left) Core decompression.
(Right) In this x-ray, the drill lines show the pathway of small drill holes used in a core decompression procedure.
An October 2021 paper in the journal BioMed Central surgery (7) evaluated the survival rate of porous tantalum rod implantation in the treatment of osteonecrosis of the femoral head. In 52 hips that received the implants, 24 hips had to be sent to total hip replacement (46.2%), the average time was about 44 months from implant to replacement.
Making core decompression work better – a better drill?
Doctors in Germany examined “Advanced Core Decompression,” a new option that tries to remove the necrotic (dead) tissue in patients with osteonecrosis of the femoral head in a minimally invasive way by the use of a percutaneous expandable reamer (a drill) and refilling with a resorbable and osteoinductive bone-graft substitute.
Simply, a better drill and filling the drill holes with bone grafts. The better idea did not work out. This examination appeared in the April 2017 issue of the Journal of Tissue Engineering and Regenerative Medicine. (8)
- Seventy-two hips of sixty patients with a mean follow-up of 29 months after Advanced Core Decompression were examined.
- The femoral heads collapsed in 24 cases (33%).
- Analysis of the survival rates with regard to defect size revealed that the largest defects had a significantly higher rate of femoral head collapse than the smaller defects.
Making core decompression work better – a better bone graft?
A later study from 2017 suggested that patients would have better success if their own bone graft, as opposed to donor bone, was used. As reported in the journal BioMed Central Musculoskeletal Disorders, in 75.9% the treatment was successful with no collapse of the femoral head or conversion to a total hip replacement. (9)
A May 2022 paper in the journal International orthopaedics (35) focused on the understanding of better bone graft outcomes. The researchers write: “Treatment of osteonecrosis of the femoral head at an early stage is a challenging issue. The modified minimally invasive core decompression combined with bone graft implantation remains controversial.” This study aimed to compare the early-middle outcomes of four groups with different bone grafts. The four bone grafts were: free fibular graft group, free vascularized fibular graft group, autologous iliac bone group, and β-tricalcium bioceramics phosphate graft group. Each group was treated with the modified minimally invasive core decompression and bone graft implantation.
All cases (192) were successful (10 hips would ultimately collapse) without any complications after the operation. The patients were followed up for 42 to 48 months. There were statistically significant differences among the four groups in operation time and blood loss. At the last follow-up, three hips collapsed on the femoral head in the free fibular graft group, two in the free vascularized fibular graft group, two in the autologous iliac bone group, and three in the β-tricalcium bioceramics phosphate graft group.
Making core decompression work better – the use of stem cells and blood platelets during surgery?
In this section, we will talk about treatments that we offer at our clinics, Platelet Rich Plasma therapy and stem cell therapy that is sometimes used by surgeons during decompression surgery to make the surgery work better. Let’s clarify and explain these treatment options.
- In our clinics, we do not perform surgery. The goal of our treatments is to help people avoid surgery by the regeneration of damaged ligament, tendon, cartilage, and bone through the use of various therapeutic and regenerative injections.
- In the many cases of patients presenting degenerative hip disease, we can help these patients alleviate pain and restore function with simple injections. These would be PRP (Platelet Rich Plasma), bone marrow-derived stem cell injections, and the base of our treatment program, simply dextrose or Prolotherapy injections. We have three decades of experience helping patients seek relief with our non-surgical options.
We cannot help everyone with our treatments. Sometimes the hip is completely destroyed, such as in femoral head collapse, or large bone spurs have fused and locked the hip into a “rusted old joint,” that cannot be budged. Sometimes a hip replacement has to be recommended. We are hopeful that we see patients before they have reached this point of significant degeneration.
- PRP is your concentrated blood platelets that offer concentrated healing factors.
- PRP treatment re-introduces your own concentrated blood platelets into the damaged joint. During the surgery, surgeons apply it to the femoral head in an attempt to facilitate healing.
- Your blood platelets contain growth and healing factors. When concentrated through simple centrifuging, your blood plasma becomes “rich” in healing factors, thus the name Platelet RICH plasma.
In 2012 doctors in Spain publishing in Knee Surgery, Sports Traumatology, Arthroscopy (10) wrote:
- Patients with grade I or grade II avascular necrosis of the hip are treated by core decompression performed by drilling under fluoroscopic guidance.
- Liquid platelet-rich plasma (PRP) (your concentrated blood platelets that offer concentrated healing factors) is delivered through a trocar, saturating the necrotic area.
- In more severe conditions, the necrotic bone is decompressed and debrided (removed), through a cortical window at the head-neck junction. A composite graft made of autologous bone and PRP is delivered through the core decompression track.
- Fibrin membranes are applied to enhance the healing of the head-neck window and arthroscopic portals. Platelet-rich plasma is infiltrated in the central compartment.
CONCLUSIONS: Arthroscopic management of avascular necrosis of the femoral head is viable and has significant advantages (especially when PRP is added).
“Therapies such as additive stem cells or platelet-rich plasma (PRP) combined with core decompression have yet to prove their efficacy.”
This is not a widespread adapted procedure. It is what is called in medicine a “novel approach,” meaning new, unusual, not regular procedure. This research was hardly followed up. In 2018, German doctors wrote in the journal Der Orthopäde (The Orthopedist) (11) “therapies such as additive stem cells or platelet-rich plasma (PRP) combined with core decompression have yet to prove their efficacy.”
Are Bone Marrow-Derived Stem Cells A Realistic Treatment?
Bone Marrow is the liquid spongy-type tissue found in the hallow (interior) of bones. It is primarily a fatty tissue that houses stem cells that are responsible for the formation of other cells. These mesenchymal stem cells (MSC), also called marrow stromal cells, can differentiate (change) into a variety of cell types including osteoblasts (bone cells) and chondrocytes (cartilage cells), fibroblasts (ligament and tendon), and others when reintroduced into the body by injection.
In treatment without surgery, the bone marrow is taken from the iliac crest of the pelvic bone in a simple drawing procedure. The bone marrow is either centrifuged to create a bone marrow aspirate concentration which is injected into the problem hip, or the bone marrow is injected directly into the problem hip without the concentration. We have published research on both these methods and this is discussed below.
Bone Marrow-Derived Stem Cells use during surgery, more research
In 2017 Doctors at the University of Milan also examined the role of bone marrow aspirate during core decompression surgery. In their study in the medical journal EFORT Open Reviews,(12) they cited the 2016 work of Greek and English researchers in the journal Acta Orthopaedica (13) showing that the application of autologous bone marrow concentrate in combination with core decompression is superior to core decompression treatment alone, as it was found to markedly decelerate the progression of the disease to the stage of femoral head collapse. This procedure also limited the need for total hip replacement, particularly when employed in the early (pre-collapse) stages of avascular necrosis of the femoral head.
In 2016 Dr. Ahmed M Samy of the Department of Orthopedics, Tanta University, Egypt wrote in the Indian Journal of Orthopaedics that mesenchymal stem cells and platelet-rich plasma (PRP) have been used as an adjunct to core decompression to improve clinical success in the treatment of pre-collapse hips. (14)
Mayo Clinic findings on using PRP and stem cells during the core decompression surgery – corticosteroid-induced osteonecrosis
In February 2018, doctors at the Mayo Clinic reported on their findings in patients who underwent core decompression for steroid-induced bone loss who had bone marrow aspirate stem cells and platelet-rich plasma introduced into the bone during the surgery. The research was published in the journal Clinical Orthopaedics and Related Research. (15)
Here are their learning points:
- Twenty-two patients (35 hips; 11 men and 11 women – 13 people had both hips involved)) with corticosteroid-induced osteonecrosis who met study inclusion criteria were enrolled
- All patients had pre-collapse osteonecrosis, rated either University of Pennsylvania Stage 1 (4 of the hips) or Stage 2 (35 hips).
- The average patient age 43 years old, and the average patient was overweight
- At 3 years – 84% of the hips did not go unto hip replacement
- Two patients (four hips) underwent a second decompression and MSC injection for persistent pain without signs of radiographic collapse.
- All patients with suffered femoral head collapse underwent a hip replacement.
- Core hip decompression with an injection of concentrated bone marrow plus PRP improved pain and function in mo0re than 90% of hips in this series were without collapse at a minimum of 2 years.
- The results of this study should be taken in light of certain limitations. Because this study only includes patients with corticosteroid-induced bone necrosis, results may not be translatable to patients with bone necrosis secondary to an alternative risk factor.
- Furthermore, there is no comparison to patients undergoing decompression alone.
Can you avoid the surgery?
Bone marrow stem cells and PRP may be beneficial during surgery. How about the treatments without surgery? Treating avascular necrosis without core decompression
Using stem cells taken from a patient’s bone marrow is becoming a therapy of interest due to the potential of these mesenchymal stem cells to differentiate into other types of cells such as bone and cartilage. In the more than 26 years of experience, we have worked with patients in varying degrees of osteoarthritis, nothing sounds more terminal and ominous than the patient being told by another doctor that their bone is dying or they have necrosis, dead bone cells. Bone Marrow stem cell therapy may offer benefits to some of these patients. At this point, we would also like to point out that we do not offer stem cell therapy to every patient. Many times simple dextrose or PRP injections will offer the same outcome expectation.
Who would be a good candidate for Prolotherapy and stem cell injections as an alternative to core decompression surgery?
In this video Ross Hauser, MD presents guidelines for determining realistic expectations and when Prolotherapy and Bone Marrow stem cells may provide an option. The video bullet points are below.
- People find us by searching the web for options for core decompression and osteonecrosis treatments.
- When they find our research they wonder how these treatments can work for them? Osteonecrosis or Avascular Necrosis means bone is dead or dying because of lack of blood supply. How can these treatments increase blood circulation to the bone?
- The first question we look to answer is why would the bone die? Is the patient an alcoholic? Is this causing nutritional deficiency? Does the patient have an autoimmune disease and they need high-dose steroids that are causing the bone to die? Is the patient a cancer survivor and had chemotherapy that is causing the bone to die. These are different challenges that could make the treatment of osteonecrosis difficult.
- STRUCTURAL DAMAGE.
- In the patients we see, their damage is caused by structural wear and tear and degenerative hip disease. This is caused by hip instability and excessive unnatural movement in the hip. The symptoms are clear, pain in the hip, crunching, grinding, clicking, and popping sounds. Chronic swelling and chronic muscle spasms are also signs. An x-ray may reveal the formation of bone spurs.
- When you have hip instability and excessive motion that puts a lot of pressure on the cartilage and the area below the cartilage, the subchondral bone area. Avascular Necrosis and Osteonecrosis of the hip affect this bone. This is the area the bone dies. Once you stabilize the hip, restore normal motion by fixing the problem of excessive unnatural movement, the bone begins healing itself. This is how Prolotherapy works, by helping to stabilize the hip and restore normal motion, the pressure on the bone is reduced, the bone can heal.
- We have found Prolotherapy to be effective in stage 1 and stage 2 avascular necrosis. In stage 3 or state 4, where the ball of the hip joint no longer looks like a ball but is flattened out, then the realistic alternative would be a hip replacement procedure.
Supportive research: PRP and stem cells
Clearly, we are not the only researchers showing success with bone marrow stem cell treatments or PRP treatments outside of surgery.
In one case published in PM & R: The Journal of Injury, Function, and Rehabilitation, PRP was found very effective for advanced-stage degenerative AVN of the hip, with the patient demonstrating significant functional improvements and the ultimate outcome of being able to avoid surgery. (18.)
An April 2015 study in the Journal of Cellular Biochemistry reported exciting news about stem cell therapy as a new modality of treatment in bone lesions that could not be treated with autologous bone grafting. However, while successful results were reported from individual studies, the paper said more studies were needed to validate stem cell therapy injections, an established treatment for bone regeneration. (19)
- Since the time of that paper, validation has come from dozens of papers. Doctors writing in the European Review for Medical and Pharmacological Sciences had this to say over a seemingly new weapon that surgeons could use to make surgery more successful.
The application of ‘regenerative medicine’ has given new hope to surgeons for the treatment of several chronic diseases and disorders including severe orthopedic conditions. There is a myriad of orthopedic conditions and injuries that presently have limited therapeutic treatments and could benefit from new developing therapies in regenerative medicine with the help of stem cell therapy. (20)
In other research, doctors confirmed that stem cell therapy for bone regeneration worked outside of surgery.
This was acknowledged in November 2015: Military university researchers in China reviewing the use of mesenchymal stem cells in the medical journal Biological Research say:
“Bone is a unique tissue that could regenerate completely after injury rather than heal itself with a scar. Compared with other tissues the difference is that, during bone repairing and regeneration, after the inflammatory phase the mesenchymal stem cells (MSCs) are recruited to the injury site and differentiate into either chondroblast (cartilage) or osteoblasts (bone) precursors, leading to bone repairing and regeneration. With this multilineage potentiality (the ability to change), the MSCs are probably used to cure bone injury and other woundings in the near future.”(21)
These findings are among the many research papers of the last two years that support the idea of bone regeneration in necrosis patients.
- Medical university researchers in Serbia wrote in the journal International Orthopaedics found that a combination of adipose-derived mesenchymal stem cells and Platelet Rich Plasma regenerated bone mineral matrix in an animal model (regrew bone). (22)
A study published in the Journal of Orthopaedic Surgery and Research found that Fat (adipose) based MSC and PRP stimulated the articular extracellular matrix and reduced damaging inflammation in dogs with osteoarthritis. (23)
Researchers publishing in the publication Cell Journal examined the use of Distraction osteogenesis – large volume expanded bone growth needed for limb lengthening. They tested bone growth using either a combination of stem cells and Platelet Rich Plasma Therapy or Platelet Rich Plasma Therapy alone. They found the combination of stem cell therapy and platelet-rich plasma therapy provided superior results for accelerated bone growth. (24)
In an animal study, doctors examined stem cells for bone regrowth in the jawbones of rats who had bisphosphonate-related osteonecrosis (Bisphosphonates, when administered intravenously for the treatment of cancer, have been associated with osteonecrosis of the jaw). Publishing in the Journal of Cranio-maxillofacial Surgery, they found adipose-derived mesenchymal stem cells provided significant bone regrowth. (25)
Stem cell augmentation may stop the progression of bone degeneration
In October 2020 a paper published in the journal Stem Cell Research & Therapy wrote: (26) “several studies have reported short-term efficacy of stem cells on early-stage osteonecrosis of the femoral head. However, its long-term effect was still unclear, especially on progression events. This study was performed to evaluate the long-term efficacy and safety of stem cells and analyze their optimal age group and cell number. Our findings build solid evidence that stem cell therapy could be expected to have a long-term effect on preventing early-stage osteonecrosis of femoral head patients from progression events, such as the collapse of the femoral head and total hip replacement. Furthermore, patients under 40 may be an ideal age group. . .”
Research supporting the use of dextrose Prolotherapy injections alone
In the June 2019 issue of the journal Alternative Therapies in Health and Medicine (27), doctors discussed a case history of a patient who had developed Avascular necrosis of the femoral head from long-time and uncontrolled glucocorticoid use. In the treatment of the case, the doctors used Prolotherapy injections. After the sixth session of Prolotherapy injections, the patient was able to do daily activities as the same as the previous physical and effort capacity. The doctors noted that: “We obtained successful outcomes in terms of patient satisfaction and clinical and radiological parameters with Prolotherapy injections. Prolotherapy may be useful as an easily applicable and satisfying auxiliary method for the treatment of Avascular necrosis of the femoral head.”
The standard treatments for AVN seemingly lead to a singular destiny – joint replacement. But are there realistic options? Case studies started to appear in the medical literature which explores Prolotherapy, Platelet Rich Plasma, and Stem Cell Therapy as possible solutions to bone death.
In our own clinical experience, we have seen similar results in patients who were given two options only – bilateral core decompression surgery or bilateral total hip replacement surgery. Patients should have been given the non-surgical option.
In summary: AVN cases are typically not treated any differently with Prolotherapy than any other case of hip pain. At our center we will evaluate the amount of instability, the bony contour, functional goals of the person, current physical examination and systemic health in order to develop the best treatment plan. The earlier the AVN is treated, the better the bony contour, the better the health of the person, then the better the prognosis of a good outcome with Prolotherapy. Because of the aggressive nature of AVN progression, typically PRP and/or stem cell Prolotherapy is recommended even on the first visit. This approach may help stop the progression of the disease.
It seems it is time for a new etiology for AVN: hip joint instability. If the vascular system of AVN is intact, then it would make sense that growth factors through PRP and stem cell injections into the joint could make it inside the bone through the femoral head vascular system. Researchers have shown that in AVN, mesenchymal stem cells have a reduced ability to differentiate and thus build bone.(38)
Do you have a question about core decompression? Get help and information from our Caring Medical staff
1 Shaw KA, Mottern E, Parada SA, Burks R, Dumont G, Waterman BR, Nho SJ. Low Rate of Return to Impact Activity Following Core Decompression for Femoral Head AVN in Military Servicemembers. Military medicine. 2018 Jul 3;184(1-2):e243-8. [Google Scholar]
2 Miyahara HD, Rosa BB, Hirata FY, Gurgel HD, Ejnisman L, Vicente JR. What is the role of core decompression in the early stages of osteonecrosis of the femoral head? Evaluation of the surgical result by functional score and radiological follow-up. Revista brasileira de ortopedia. 2018 Oct;53(5):537-42. [Google Scholar]
3 Andronic O, Weiss O, Shoman H, Kriechling P, Khanduja V. What are the outcomes of core decompression without augmentation in patients with nontraumatic osteonecrosis of the femoral head?. International orthopaedics. 2021 Mar;45(3):605-13. [Google Scholar]
4 Olsen M, Lewis PM, Morrison Z, McKee MD, Waddell JP, Schemitsch EH. Total hip arthroplasty following failure of core decompression and tantalum rod implantation. Bone Joint J. 2016 Sep;98-B(9):1175-9. [Google Scholar]
5 Cheng Q, Tang JL, Gu JJ, Guo KJ, Guo WS, Wang BL, Zhao FC. Total hip arthroplasty following failure of tantalum rod implantation for osteonecrosis of the femoral head with 5-to 10-year follow-up. BMC musculoskeletal disorders. 2018 Dec;19(1):289. [Google Scholar]
6 Zhang X, Wang J, Xiao J, Shi Z. Early failures of porous tantalum osteonecrosis implants: a case series with retrieval analysis. Int Orthop. 2016 Sep;40(9):1827-34. [Google Scholar]
7 Zhang Y, Chen W, Yang Z, Sun JN, Hu ZH, Hua ZJ, Chen XY, Feng S. Porous tantalum implant for treatment of early-stage osteonecrosis of the femoral head: a minimum 5-year follow-up study. BMC surgery. 2021 Dec;21(1):1-0. [Google Scholar]
8 Classen T, Warwas S, Jäger M, Landgraeber S. Two-year follow-up after advanced core decompression. J Tissue Eng Regen Med. 2017 Apr;11(4):1308-1314. [Google Scholar]
9 Landgraeber S, Warwas S, Claßen T, Jäger M. Modifications to advanced Core decompression for treatment of Avascular necrosis of the femoral head. BMC musculoskeletal disorders. 2017 Dec;18(1):479. [Google Scholar]
10 Guadilla J, Fiz N, Andia I, Sánchez M. Arthroscopic management and platelet-rich plasma therapy for avascular necrosis of the hip. Knee Surg Sports Traumatol Arthrosc. 2012 Feb;20(2):393-8. doi: 10.1007/s00167-011-1587-9. [Google Scholar]
11 Lüring C, Benignus C, Beckmann J. Joint-preserving operative treatment of avascular necrosis of the femoral head. Der Orthopade. 2018 Jul. [Google Scholar]
12 Calori GM, Mazza E, Colombo A, Mazzola S, Colombo M. Core decompression and biotechnologies in the treatment of avascular necrosis of the femoral head. EFORT Open Reviews. 2017;2(2):41-50. [Google Scholar]
13 Papakostidis C, Tosounidis TH, Jones E, Giannoudis PV. The role of “cell therapy” in osteonecrosis of the femoral head. Acta Orthop. 2015 Jul 29:1-7. [Google Scholar]
14 Samy AM. Management of osteonecrosis of the femoral head: A novel technique. Indian journal of orthopaedics. 2016 Jul;50(4):359. [Google Scholar]
15 Houdek MT, Wyles CC, Collins MS, Howe BM, Terzic A, Behfar A, Sierra RJ. Stem cells combined with platelet-rich plasma effectively treat corticosteroid-induced osteonecrosis of the hip: A prospective study. Clinical Orthopaedics and Related Research®. 2018 Feb 1;476(2):388-97. [Google Scholar]
16 Hauser R, Ostergaard S. Direct bone marrow injections for avascular necrosis of the talus: a case report. Journal of Prolotherapy. 2012;4:e891-e894.
17 Hauser RA, Orlofsky A. Regenerative injection therapy with whole bone marrow aspirate for degenerative joint disease: a case series. Clinical Medicine Insights: Arthritis and Musculoskeletal Disorders. 2013 Jan;6:CMAMD-S10951. [Google Scholar]
18 Ibrahim V, Dowling H. Platelet-rich plasma as a nonsurgical treatment option for osteonecrosis. PM R. 2012 Dec;4(12):1015-9. doi: 10.1016/j.pmrj.2012.07.009. [Google Scholar]
19 Im GI. Stem Cells for Reutilization in Bone Regeneration. Journal of cellular biochemistry. 2015 Apr 1;116(4):487-93. [Google Scholar]
20 Li Y1, Tang J, Hu Y, Peng YH, Wang JW. A study of autologous stem cells therapy assisted regeneration of cartilage in avascular bone necrosis. Eur Rev Med Pharmacol Sci. 2015 Oct;19(20):3833-7. [Google Scholar]
21 Shao J, Zhang W, Yang T. Using mesenchymal stem cells as a therapy for bone regeneration and repairing. Biol Res. 2015 Nov 3;48(1):62. doi: 10.1186/s40659-015-0053-4. [Google Scholar]
22 Cvetković VJ, Najdanović JG, Vukelić-Nikolić MĐ, Stojanović S, Najman SJ. Osteogenic potential of in vitro osteo-induced adipose-derived mesenchymal stem cells combined with platelet-rich plasma in an ectopic model. Int Orthop. 2015 Aug 1. [Google Scholar]
23 Yun S, Ku SK, Kwon YS. Adipose-derived mesenchymal stem cells and platelet-rich plasma synergistically ameliorate the surgical-induced osteoarthritis in Beagle dogs. J Orthop Surg Res. 2016 Jan 15;11(1):9. doi: 10.1186/s13018-016-0342-9. [Google Scholar]
24 Dehghan MM, Baghaban Eslaminejad M, Motallebizadeh N, Ashrafi Halan J, Tagiyar L, Soroori S, Nikmahzar A, Pedram M, Shahverdi A, Kazemi Mehrjerdi H, Izadi S. Transplantation of Autologous Bone Marrow Mesenchymal Stem Cells with Platelet-Rich Plasma Accelerate Distraction Osteogenesis in A Canine Model. Cell J. 2015 Summer;17(2):243-52. Epub 2015 Jul 11. [Google Scholar]
25 Barba-Recreo P, Georgiev-Hristov T, Bravo-Burguillos ER, Abarrategi A, Burgueño M, García-Arranz M. Adipose-derived stem cells and platelet-rich plasma for preventive treatment of bisphosphonate-related osteonecrosis of the jaw in a murine model. Journal of Cranio-Maxillofacial Surgery. 2015 Sep 30;43(7):1161-8. [Google Scholar]
26 Mao L, Jiang P, Lei X, Ni C, Zhang Y, Zhang B, Zheng Q, Li D. Efficacy and safety of stem cell therapy for the early-stage osteonecrosis of femoral head: a systematic review and meta-analysis of randomized controlled trials. Stem cell research & therapy. 2020 Dec;11(1):1-2. [Google Scholar]
27 Solmaz I, Orscelik A, Karasimav Ö, Akpancar S. Is Prolotherapy Effective in the Treatment of Avascular Necrosis of the Femoral Head?. Alternative therapies in health and medicine. 2019 Jun 1. [Google Scholar]
28 Abraham PF, Varady NH, Small KM, Shah N, Beltran LS, Kucharik MP, Martin SD. Safety of Intra-articular Hip Corticosteroid Injections: A Matched-Pair Cohort Study. Orthopaedic Journal of Sports Medicine. 2021 Oct 20;9(10):23259671211035099. [Google Scholar]
29 Al-Omari AA, Aleshawi AJ, Marei OA, Younes HM, Alawneh KZ, Mohaidat ZM. Avascular necrosis of the femoral head after single steroid intra-articular injection. European Journal of Orthopaedic Surgery & Traumatology. 2020 Feb;30(2):193-7. [Google Scholar]
30 Thompson AR, Ensrud ER. Rapid onset of femoral head osteonecrosis after a single intra-articular hip joint injection of corticosteroid. American journal of physical medicine & rehabilitation. 2020 Apr 1;99(4):e54-5. [Google Scholar]
31 Agarwala SR, Vijayvargiya M, Pandey P. Avascular necrosis as a part of ‘long COVID-19’. BMJ Case Reports CP. 2021 Jul 1;14(7):e242101. [Google Scholar]
32 Rodriguez-Fontan F, Piuzzi NS, Kraeutler MJ, Pascual-Garrido C. Early clinical outcomes of intra-articular injections of bone marrow aspirate concentrate for the treatment of early osteoarthritis of the hip and knee: a cohort study. PM&R. 2018 Dec 1;10(12):1353-9. [Google Scholar]
33 Kelly BJ, Williams BR, Gravely AA, Schwanz K, Sechriest VF. Femoral head collapse after hip intra-articular corticosteroid injection: An institutional response to improve practice and increase patient safety. PloS one. 2021 Nov 2;16(11):e0259242. [Google Scholar]
34 Miyahara HD, Ranzoni LV, Ejnisman L, Vicente JR, Croci AT, Gurgel HM. Osteonecrosis of the Femoral Head: Update Article. Revista Brasileira de Ortopedia. 2022 Jul 26;57:351-9. [Google Scholar]
35 Wan J, Hu Y, Li J, Zeng Y, Ren H. Comparison of the outcome of different bone grafts combined with modified core decompression for the treatment of ARCO II stage femoral head necrosis. International Orthopaedics. 2022 May 10:1-8. [Google Scholar]
36 Mei J, Pang L, Jiang Z. The effect of extracorporeal shock wave on osteonecrosis of femoral head: a systematic review and meta–analysis. The Physician and Sportsmedicine. 2022 Jul 4;50(4):280-8. [Google Scholar]
37 Dhanasekararaja P, Soundarrajan D, Kumar KS, Pushpa BT, Rajkumar N, Rajasekaran S. Aggressive Presentation and Rapid Progression of Osteonecrosis of the Femoral Head After COVID-19. Indian Journal of Orthopaedics. 2022 Apr 25:1-9. [Google Scholar]
38 Lee JS, Lee JS, Roh HL. Alterations in the differentiation ability of mesenchymal stem cells in patients with nontraumatic osteonecrosis of the femoral head: comparative analysis according to the risk factor. J Orthop Res. 2006;224(4):604-9. [Google Scholar]
This article was updated August 4, 2022