hip-knee mechanics and joint pain

Many people suffer from osteoarthritis and, contrary to popular misconceptions, it is not just a condition that affects older people. In fact, it is believed to affect between 12 and 15 per cent of the population who are aged between 25 and 74. It is much more prevalent in older people, but its presence in younger men and women as well means that there are a variety of causes which are not just explained by the natural ageing process and the inevitable wear and tear on joints as we get older.

According to a report published by the National Center for Biotechnology Information (NCBI) in the US, factors that affect patients’ likelihood to develop osteoarthritis are vast. These range from genetics and molecular structure, to what is described as environmental factors such as ‘biomechanical stress’. What this means is the stresses and strains that are put on people’s knee and hip joints through the lifestyles that they choose to live. Scientists are of the belief that biomedical stresses play a highly significant role in the likelihood of developing osteoarthritis.

The right balance needs to be struck

It is widely accepted that certain lifestyle activities can increase the chance of developing osteoarthritis in joints like the knees and hips. High impact sports, for example, especially those with very repetitive motions, have been linked with the development of the condition. It is a delicate balance that needs to be struck, though, as conditions such as obesity are also proven to be linked with the development of osteoarthritis.

Data that has contributed to this includes a study of 506 young female athletes in the US. The study looked at this group because their lifestyle choices suggested that they could be in a higher risk bracket for developing osteoarthritis. The results concluded that there were indeed patterns to be seen in the development of the condition in girls who had been impacted by ‘biomechanical stress’ on their joints, both during pre-puberty and when they were nearing adulthood.

Data such as this is particularly interesting to researchers, as it has been proven that women are at a greater risk than men of developing injuries to their knee and hip joints as a result of environmental factors, compared with men. The Journal of Orthopaedic and Sports Physical Therapy looks in detail at the factors that affect degeneration of the knee and hip joints and concludes that environment factors, coupled with gender, can be regarded as ‘red lights’ in terms of risk categories for those undertaking strenuous sports “the knee has been reported to be the most common site of overuse injuries in runners, 74 triathletes, 18 and military recruits ….. females sustain a higher number of traumatic and overuse knee injuries when compared to males.”

The benefits of understanding more about biomechanical stresses

Identifying these trends gives medical professionals the knowledge and statistics required to ensure that preventative steps to ensure that those in higher-risk categories are educated accordingly and advised of the risk associated with their lifestyles.

Sometimes, a relatively simple chance to how people are living can make a big difference in terms of their propensity for developing conditions like osteoarthritis. The report authors summarise some of the benefits in this type of case: “Female athletes may benefit from hip targeted exercises prior to puberty and more global (hip and knee focused) neuromuscular training following pubertal maturation to reduce their risk to develop PFP [patellofemoral pain].”

hip implant technology

Researchers at the University of Warwick have been working to develop a new device which helps identify patients who have more ‘flex’ than they should do in their pelvis. These people are at a higher risk of developing problems with prosthetic hip joints following surgery (especially issues such as dislocation), so with the help of this device, patients would be able to take steps to ensure that the flex in the hip joint does not put their new hip replacement joint under unnecessary stresses. It would essentially ensure that surgeons are fully informed of who is most at risk and take steps accordingly to mitigate.

As things stand currently, surgeons are aware of the increased risk for people with this type of pelvic position, but it is time-consuming and more difficult to diagnose: “Patients who have pelvises that rotate large amounts during movement are at higher risk of dislocation, particularly if the replacement hip is not fitted accurately. Those patients can receive a more advanced surgical plan, but it is currently difficult to identify who requires this without a number of time-consuming and expensive x-rays.”

The new pelvic tracking device is able to detect immediately which patients have high levels of ‘pelvic rotation’ and to ensure that this is woven into their surgical plan and aftercare. Not only does this device have the potential to help ensure that the quality of care is aligned more closely to patients’ needs, the speed at which the diagnosis is possible means that it also provides a significant cost saving.

Dr Mark Elliott explains, “this new device has been developed to allow surgeons to screen patients for a flexible pelvis in a matter of minutes, identifying those who are at increased risk of complications if it is not fitted accurately. This will hopefully reduce costs and save time by identifying those patients who require more accurate surgical procedures. The research team working on the project have created a design and algorithm that can accurately track the pelvis movements comparable to that currently measured by x-rays.”

The device has been available for surgeons to test out first hand at the recent British Orthopaedic Association exhibition in central Birmingham, which allowed the device’s creators, a company called Corin, to explain the benefits they believe the device can bring to patient care and surgical outcomes.

In terms of future proofing hip replacements for patients with overly flexible pelvises, this is a clear step in the right direction in terms of the evolution of medical technology in this area. There are other exciting developments too which would work in tandem with this, such as the MAKO robotic-assisted hip replacement surgery. This technology allows surgeons to scan patients and output a bespoke 3D model of the affected area, which gives them a unique opportunity to design the patients’ surgical plan especially around the issues that they are struggling with. The benefits of these improved technologies are that there is a much greater likelihood of getting it right first time, which leads to fewer issues such as dislocation, and less of a requirement for revision surgery to correct work done on less informed patient assessments.

Mr Simon Bridle is one of the first orthopaedic surgeons in London to be able to offer his patients robotic-assisted hip replacement surgery. Call 020 8947 9524 to find out more.

hip implant dislocation

Hip and knee replacements are recommended for over 150,000 patients every year in the UK, and they are proven to improve mobility, quality of life and reduce pain for many people who are struggling with issues affecting their original joints. They have been practiced by surgeons for decades and are very successful, but as with everything, over time they can be subject to continued wear and tear and can begin to deteriorate.

Issues with hip implant dislocation and the subsequent challenges this brings

For patients who have undergone a total hip replacement, one of the issues that they could face in the years following the surgery is dislocation of the replacement joint and as a result, surgeons are always looking for methods, techniques and materials that can help reduce the risk of implant dislocation.

Dislocation is an issue that is more prevalent in patients who have had more than one hip replacement, a process known as ‘revision surgery’. There is now a new type of artificial hip joint called a ‘modular dual mobility’ joint, which has been proven to reduce the risk of revision surgery as a result of dislocation.

A report published recently by an orthopaedic hospital in the US explains the difference of a modular dual mobility joint and how this compares more favourably to the traditional method: “Modular dual mobility implants provide an additional bearing surface compared to a traditional implant. With the dual mobility hip, a large polyethylene plastic head fits inside a polished metal hip socket component, and an additional smaller metal or ceramic head is snap-fit within the polyethylene head.”

The findings of this new report are from a study undertaken by Dr Geoffrey Westrich and his colleagues at the Hospital for Special Surgery, a leading academic medical centre for musculoskeletal health. The study comprised data from 370 patients who underwent revision hip surgery and had a dual mobility implant. Data was collected between April 2011 and April 2017. The research assessed data from a variety of different perspectives, including clinical information, radiographic data and patient reported-outcome information.

Impact for Mr Bridle’s hip replacement patients

Mr Bridle is in support of the benefits of using a dual mobility sockets, with the first-hand experience of the benefits this brings to his patients. He agrees that the greater risk of instability seen with high risk and more complex revisions is reduced when using this type of socket. Not only are these sockets better for those who are at risk of revision surgery. Mr Bridle also favours this type of artificial joint when treating patients who are undergoing total hip replacement for the first time but who have one or more factors which put them in a higher risk category. Risk factors that mean patients would benefit more from a modular dual mobility joint include conditions such as chronic back problems, spinal fusion or certain neurological conditions.

For more information on dual mobility hip replacements, call 020 8947 9524 to arrange a consultation.

depression and arthritis

Scientists are always looking for links between conditions, as a way of understanding how and why they interact and establishing the cause and effect of different disorders. The results of an interesting new study have found hip arthritis is more prevalent in those suffering from depression – for many years it’s been thought that depression is a risk factor for those suffering from joint pain but now the suggestion is that the converse might be true.

What came first, chicken or the egg?

The challenge for scientists has always been establishing the order effect of these conditions. There has been a recognised overlap between these two conditions for many years, as both are prone to affect people as they get older. Arthritis causes symptoms such as pain and restricted mobility, and due to its degenerative nature, this can cause many sufferers to feel depressed.

However, researchers have recently published findings suggesting that those first suffering from depression are much more likely to develop arthritis. The research team, based at Dartmouth College in the US, revealed: “arthritis is more common among depressed patients than those who were not suffering from the mood disorder, suggesting that depression may be a risk factor for arthritis, too.”

The research team assessed data from almost 5,000 patients over the age of 50 and looked at those who were diagnosed as having mild, moderate and severe depression, and also a control group of those without. The links they found were conclusive, those with more severe depression had a direct correlation with the incidence of arthritis.

The concern for medical practitioners is whether or not patients are receiving suitable care for both of these complaints in parallel, as many experts are concerned that the mental wellbeing of patients may be overlooked is favour of treating the physical symptoms associated with recovering from operations related to arthritis in hip joints.

Jessica Brookes, PhD, from the Geisel School of Medicine and Centres for Health and Aging comments “depression is highly prevalent yet one of the most undertreated and poorly understood psychosocial factors associated with arthritis, with nearly half of older adults with both chronic pain and depression receiving either inadequate or no mental health care.”

Interesting overlap between mind and body

The links between mental and physical conditions are fascinating and research into the connections between the two can enable scientists to learn much more about the body and mind and how they affect one another. “The more we learn about various diseases traditionally thought to ail the body and the mind, respectively, the more scientific study supports the notion that the two categories are not so separate.”

It has long since been recognised that your mindset can play a really important role in recovering from any illness, as a positive mental attitude and positive outlook can have a surprising effect on your overall wellbeing.

People who approach their recovery from operations such as total hip replacements with a positive attitude have been found to enjoy a quicker recovery period compared with those who adopt a more negative mindset. The Journal of Bone and Joint Surgery reports “it is well established that the emotional health of the patient influences the outcome of many common orthopaedic surgeries… Poor functional outcomes [of orthopaedic operations] have been correlated with poor emotional health, such as anxiety, depression, anxiety, poor coping skills and poor social support.”

women and hip replacement surgery

Typically, when we think about hip replacement surgery, we think of the older generation, as this demographic were historically much more likely to need medical intervention to help problems associated with ageing joints. But it seems there has been a surge in the number of younger, female patients who require this type of operation. Women’s Health recently reported that “hip replacements have increased 40 per cent among 45- to 54-year-olds”. So, why might this be?

Women and hip replacement surgery: increased interest in high impact sports

Over recent decades, women have been converts to high impact exercise routines, such as running or HIIT, better known as high intensity interval training, all of which put pressure on joints. Recreational jogging and competitive sports such as 10ks, half and full marathons have grown in popularity, but over time, these impact sports can wear away at joints, leaving them prone to degeneration at a younger age.

Although this isn’t just a problem for women, anatomical differences between men and women mean that a number of impact-related hip conditions are more likely to affect women.

An example of this is a condition called femoroacetabular impingement (FAI), which is where the ball and socket joint in your hip becomes misaligned and begins to cause friction, wear and, ultimately, arthritis inside the joint. Women are also more prone to hip dysplasia, where the socket of the joint is shallow and this also predisposes to the development of arthritis. Women’s gluteal muscles have to compensate more for these anatomical differences, and if they don’t, then problems can begin to develop.

Women and hip replacement surgery: advances in technology

The knowledge we have about the different conditions that can affect hip joints, and the ability of modern technology to aid in effective diagnosis, has improved significantly over time. Previously, conditions that affected hip mobility in otherwise young and healthy females could have been misdiagnosed as groin or muscle problems, and therefore would not have been treated effectively.

Armed with greater understanding now of what causes degenerative hip conditions, and the knowledge of the differences male and female biology has on the likelihood to develop problems, surgeons are much more adept at making quicker and more accurate diagnoses.

Women and hip replacement surgery: what to do next?

Balancing high impact exercise with workouts that strengthen the muscles around the hips is key to supporting your joints. Strengthening these key muscles can help give a protective cushion around your hips, which won’t remove the risk entirely, but will certainly help.

It is never too early to consult an expert if you are worried about your hip joints, because if you have been experiencing pain for a period of time and you are not able to manage to this pain adequately with over-the-counter anti-inflammatory drugs or you are finding that your mobility is restricted, then it is probably time to have a proper medical assessment with a hip specialist.

infection and revision joint replacement

Hip replacement surgery is a very common operation nowadays with an excellent success rate. Over 100,000 patients per year undergo this type of operation, and it is commonly used to treat chronic, debilitating conditions such as osteoarthritis. Total hip replacements are proven to make significant improvements to quality of life, including mobility, reduction of pain and an improvement of patients’ general well-being, but as with all surgeries, there is a small risk of complications developing post-operatively.

One risk is that patients could develop a prosthetic joint infection, or PJI. This is a rare complication, affecting around 1% of patients.  The consequences of a PJI are not to be underestimated.  A study from Bristol University published in the Lancet Infectious Diseases medical journal describes it as a ‘devastating complication’ following joint replacement surgery.  A PJI can lead to “severe pain, poor function, reduced quality of life, and even death.” Treatment to cure a PJI can also be tough and gruelling for patients and usually requires revision joint replacement surgery to get rid of the infection.

With this in mind, a cohort of doctors have been analysing data collected over many years of joint replacement surgery to see whether they can identify patterns of who might be at greatest risk of developing a PJI following surgery for total hip replacement.

Risk factors for infection and revision joint replacement

The study used data from the UK National Joint Registry over 11 years and concluding in March 2018, with over 600,000 cases.  Risk factors for the development of PJI were identified.

The following were identified that correlated with a higher chance of developing a PJI:

  • Younger patients (under 60 years old)
  • Patients with a high BMI
  • Those already reporting chronic pulmonary disease, liver disease, or dementia
  • Hip replacement performed for a hip fracture

These factors seemed to reduce the risk of infection:

  • The use of a posterior approach
  • The use of ceramic as the bearing material

This news is encouraging and supports the approach undertaken at Mr Simon Bridle’s London hip replacement clinic as he prefers to operate using the posterior approach and using ceramic bearings for the artificial joints.

These results give a very clear steer regarding heightened risks for certain groups of the population and, armed with this information, surgeons are able to more accurately advise patients and can take steps to help manage/reduce the associated risks for these groups. Work will now be undertaken to understand whether the same patterns are identified for patients who undergo knee replacement surgery, to see if there are parallels found between the two types of operation.

obesity and hip replacement

Obesity is a serious global concern and has been linked with many different illnesses and conditions, causing excess healthcare expenditure and costing countries in the form of lost productivity. It is believed to affect two-thirds of the adult population in the UK, and according to recent reports, over 1 million people in Britain are claiming sickness benefit as a result of their weight.

There are some operations which patients are advised not to undergo if they are classed as obese, as excess weight is known to affect how well patients can recover from surgery and the NHS’s recent rationing measures will mean that severely overweight and often even mildly overweight patients will just not have access to joint replacement surgery through the NHS.

Interestingly, a recent study has found that total hip replacement surgery is still a more cost-effective option than other means of managing a patient’s pain and lack of mobility as a result of joint wear and tear, whatever the weight of the patient. Results of this Canadian study have been published in The Journal of Arthroplasty and make interesting reading.


It is accepted that the risks associated with total hip replacement increase for overweight patients, but the report suggests that despite these risks, the outcomes are still more positive compared with the available alternatives.

Some surgeons feel that it is simply a case of weighing up the risks against the potential benefits. In terms of managing the decision-making process, it is important to fully discuss the risks and rewards with patients in higher risk categories, such as those with a high BMI, so that the patient and surgeon can agree on the most suitable course of action and manage the risks accordingly.

Obesity and hip replacement surgery: using weight as a screening factor for hip replacement

The report authors suggest that obesity, as assessed by the Body Mass Index (BMI), is being used as a screening technique to help manage budget constraints, in the face of limited financial resources.  BMI is one of the factors used by NHS purchasers when assessing patients’ suitability for this type of operation.

Study co-author Edward Vasarhelyi explains that “many developed countries are facing increasing budgetary pressures across the spectrum of healthcare. We have seen changes in funding models, such as bundled care payments. These models have put pressure on clinicians and administrators which, in some healthcare systems, has resulted in the refusal of surgery for patients above arbitrary BMI cut offs.”

Many feel that restricting life-changing surgeries such as total hip replacements for those who are carrying too much weight is not the solution. They recognise that obesity is a challenge for patients and for the NHS and that more needs to be done to reduce the number of people who are classed as overweight.

For patients, making subtle changes to lifestyle can have a marked effect. Paying more attention to what is in the foods we buy and taking steps to cook with fresh ingredients, rather than overly processed meals is a great starting point. Couple this with efforts to exercise more, for example, walking rather than taking the car or bus, and patients will soon notice differences to how they look and feel.

Losing weight before a joint replacement is ideal, as taking steps to try and lose weight will give them a greater chance of a faster, simpler recovery, with reduced complications.  Mr Simon Bridle understands that this is often difficult for people with limited mobility and that patients will decide that the potential benefits of surgery outweigh the risks.

hip replacement recovery

Any patient contemplating a total hip replacement procedure will want to know when they will be back up on their feet.  The question ‘how long does it take to recover from a hip replacement’, is probably one of the most commonly asked in Mr Simon Bridle’s London hip surgery consultations.

There is no definitive answer, as each individual differs in terms of their recovery.  Typically patients return to fairly normal day to day activities, including driving, by 6 weeks, but it takes more like three to six months to get back to their normal routine, including sports.  It can even take a bit longer to get back to strenuous sports like skiing.  Successful surgery allows patients to embrace the activities that their hip pain has prevented them from enjoying for many years.

Hip replacement recovery: enhanced recovery

The first phase of patients recovery is while they are in hospital, usually only for 2 or 3 days.  We focus on early mobilization, with techniques to reduce pain and get people back to feeling normal as quickly as possible.

All of Mr Simon Bridle’s patients that are seen at the Fortius Joint Replacement Centre (FJRC) at BUPA Cromwell Hospital follow a standardised Enhanced Recovery Pathway that aims to transform the short-term recovery experience for hip replacement patients. The goals are to ensure a quicker recovery and improved outcome by improving all aspects of the recovery process, from pain management, surgical technique, patient education and return to mobility.

Hip replacement recovery: what happens after I go home? 

Patients go home with walking support, but generally are managing without by 4 to 6 weeks and by then people don’t usually need any painkillers.  The physiotherapists provide an exercise programme for individual patients and physiotherapy is also usually arranged as an outpatient, to supervise rehabilitation.  You can expect to be getting back to a fairly normal day to day life by 6 weeks, including driving.  Light sports like tennis and golf are usually possible by 3 months, but it can be a least 6 months before people get back to strenuous sports like skiing.

Hip replacement recovery: prepare to succeed

The preparation period can be as important as the rehabilitation stage and increase the chances of a successful and quicker recovery. This can cover everything from preparing your home environment and ensuring you have adequate assistance when you return home. Hip pain and lack of mobility may be the reason you’re undergoing joint replacement surgery, but doing your hip exercises and practising mobility techniques beforehand can be invaluable.

Mr Simon Bridle’s physio team at the BUPA Cromwell Hospital are now running a pre-assessment ‘joint school’, to prepare patients for surgery, teach them pre-op exercises etc, which patients find very helpful.

For more information on hip replacement recovery and you, call 020 8947 9524 to book a consultation.

Stryker Polyethylene Revision Hip Replacement

Results of a long-term study undertaken in Australia that analysed data from more than 240,000 patients with hip osteoarthritis who underwent total hip replacement surgery have just been published. The objective of the research was to glean a greater understanding of the relative durability of ‘cross-linked’ polyethylene bearings hip implants (ie the moving parts), compared with other materials.

Although total hip replacement surgery is recognised as a very effective resolution for patients who are experiencing long-term and significant osteoarthritis, it is not without its challenges. The current materials favoured for artificial joint bearings will eventually wear, which can damage bone and lead to the artificial joint working loose, meaning a proportion of patients will require revision surgery. Researchers were keen to explore the effectiveness of new bearing materials, and this study, one of the largest of its kind, afforded them the data and time to conduct a very in-depth piece of research.

What are cross-linked polyethylene implants?

To understand the implications of this research, it is important to understand more about what exactly was being analysed. This technique uses different materials than those conventionally used for hip replacement bearing surfaces. The driving force behind needing to find a more durable, hard wearing material was the prevalence of total hip replacements amongst younger patients, those who had led a more active lifestyle – and those who were hoping to continue to engage in more active pursuits once they had recovered from their hip replacement surgery.

The challenge for conventional hip replacement materials was that the greater wear and tear that patients were placing on the artificial joint was leading to more revision surgeries in the years following the initial operation.

Key statistics from the study design are as follows:

  • The study was huge – over 240,000 patient records were assessed
  • It was conducted over 17 years, taking place from 1999 to 2016
  • These contained a mix of cross-linked polyethylene implants and conventional polyethylene (CPE) components: 199,000 of the cases analysed were cross-linked polyethylene bearings and 41,000 cases were CPE bearings

The results are extremely positive in favour of the longevity of cross-linked polyethylene bearings, with the study finding: “As early as six months after hip replacement, revision rates were substantially lower in patients with XLPE [cross-linked polyethylene] bearings. Over 16 years, the cumulative rate of revision surgery was 11.7 percent in the CPE [conventional polyethylene] group compared to 6.2 percent in the XPLE group”.

Implications of these results

What this essentially means is great news for patients in general, but particularly good news for younger patients who would be hoping that their new hip joint(s) would be able to stand the test of time. Owing to the length of the study (looking at data collected over 17 years), researchers were able to conclusively report that they had found that using cross-linked polyethylene bearings in total hip replacement joints provides “a significant reduction in the rate of revision at 16 years following THA for osteoarthritis.”

For patients at Mr Simon Bridle’s hip replacement clinic in London, the good news is that this is the material that he routinely uses in these procedures due to its safety and effectiveness for long-term results. For more information, call 020 8947 9524 to book a consultation.

private hip surgery alternatives

A recent report published by the Independent outlined a concerning trend of patients not being able to access hip and knee operations on the NHS due to new ‘operation rationing’ that is being enforced. For operations that are widely to considered to be routine, and cost-effective, the report outlines that barriers are being put in the way of patient care, and “GPs are increasingly asked to make ‘exceptional funding applications’ which are judged by local NHS panels, some of which include lay officials with no medical background.” These applications can take a long time to be processed, and have no guarantee of being approved, which leaves patients in limbo, sometimes waiting months to know if they have been accepted for their required procedure.

While they are waiting, conditions such as deteriorating joints will be getting steadily worse and could leave patients in a worse position then when they originally sought medical care. The report cites concerns from leading industry bodies, such as the Royal College of Surgeons. Ian Eardley, senior vice president of the Royal College of Surgeons, explains “the use of funding requests means patients will spend more time in pain with potential deterioration of their condition, thereby generating further costs for a system already under acute financial strain.”

Previously, exceptional funding applications were reserved for non-essential procedures (such as cosmetic requirements such as removal of skin tags and certain fertility treatments) – things that were sought by the patient but that were not clinically necessary. Nowadays it appears that clinical commissioning groups (those in charge of commissioning most of the hospital and community NHS services in the local areas for which they are responsible) are pushing GPs to refer patients via exceptional funding applications for standard, necessary procedures in an attempt to make meagre budgets stretch further.

The term ‘postcode’ lottery is used again, as there are certain criteria that the judging panels will use to help decide which applications are granted and which are refused, and these are not consistent across the differing areas of the country. Factors such as BMI (body mass index) and evidence of physiotherapy in joint replacement applications are required by some panels, but not by others.

The rate in which operations are being refused under this new system is alarming. According to a Freedom of Information (FOI) request report by the British Medical Journal (BMJ), “In 2017-18 a total of 1675 exceptional funding requests (1188 for knee surgery and 487 for hip surgery) were turned down by clinical commissioning groups (CCGs).” This FOI request also shows just how different the regional variance of operation acceptance is.


Exploring private hip surgery alternatives

For many patients, the most effective solution to this problem is finding private hip surgery alternatives. The waiting time is significantly reduced; you will have a real choice over your surgeon and when and where the operation is done.  Mr Simon Bridle at the Fortius Joint Replacement Centre at the BUPA Cromwell Hospital offers an enhanced recovery programme, which helps makes the surgery safer and patients are much more comfortable, allowing earlier mobilization and a shorter hospital stay, meaning you can be up and about and back in the comfort of your own home much faster.