Front Knee Pain After ACL Surgery?

ACL marked 20mm from each end by Dr Nuelle

While looking for a topic to write this week, I came across a research paper by Rahardja et al (2023) comparing knee pain and difficulty with kneeling between the bone-patella tendon bone (BTB) and hamstring graft after anterior cruciate ligament (ACL) reconstruction. 

I subsequently found a Twitter thread concerning the article where an orthopaedic surgeon says he "don't believe" what the paper says (see picture below).

Compared to now, there were more patients whose surgeons used the BTB graft when they tore their ACL's when I started work as a physiotherapist in the late 1990's. The hamstring autograft (not cadaver graft) is most commonly used now. 

One of the main reasons patients are told not to use a BTB graft  is because it (supposedly) causes anterior (or front) knee pain. 

A total of 10,999 patients who had ACL reconstructions were analyzed at 2-year follow-up. 9.3 percent (420 cases out of 4492 reported consequential knee pain (CKP) while 12 percent (537/4471) reported severe kneeling difficulty (SKP). For those into research, the Knee and Osteosrthritis Outcome Score (KOOS) was used to identify patients reporting CKP, defined as a KOOS Pain subscore of ≤ 72 points. 

The authors wrote that the most important predictor of CKP at 2-year follow-up was having significant pain before surgery while the most important predictor of SKP was the use of a BTB versus hamstring graft.

I do not agree with the authors' observation. I have treated many patients who had ACL reconstructions in the past 24 years. In the first few weeks after the ACL reconstruction, patients who choose either graft do have a little anterior knee pain presumably from the operation itself. After 6 weeks, anterior knee pain is very rare especially for those with the BTB graft. Very occasionally if they kneel onto the BTB graft site, they may have some kneeling pain which goes away quickly once they change position.

In fact, an orthopaedic surgeon commented that his few "non BTB" (i.e. hamstring graft) patients tend to have more anterior knee pain than his BTB graft patients (see picture below).

Moreover if you have read my earlier post, Spindler et al (2020) suggests that the HS graft is 2.1 times more likely to tear again compared to the BTB graft. Surely this is supporting evidence that the BTB graft is the 'better' and 'stronger' graft? 

There should be no reason to use "anterior knee pain" as an 'excuse' to use other graft choices rather than the BTB graft. 

Choosing your graft after tearing your ACL will definitely be influenced by discussions with your doctor, surgeon and physiotherapist. If you do not want to use your own BTB and hamstring graft, you can also use an allograft (cadaver) now. 

Please keep this information in mind if you were to tear your ACL. Come talk to us if you have any questions.

References

Rahardja R, Love H, Clatworthy MG et al (2023). Comparison Of Knee Pain And Difficulty With Kneeling Between Patella Tendon And Hamstring Tendon Autografts After Anterior Cruciate Ligament Reconstruction: A Study From the New Zealand ACL Registry. AJSM. DOI: 10.1177/03635465231198063

Spindler KP, Huston LJ, Zajichek A et al (2020). Anterior Cruciate Ligament Reconstruction In High School And College-age Athletes: Does Autograft Choice Influence Anterior Cruciate Ligament Revision Rates? 48(2): 298-309. DOI: 10.1177/0363546519892991.

Optimal Exercise Form Is Not Always Right

Aized and I had an interview with a physiotherapist last week. She found out physiotherapists in our clinic worked 4 days a week and she was keen to join our team. The interview had a practical component where she had to ask questions, assess and treat my "mid and low back pain" (for my twice broken back). 

After some questions and assessments, she decided that my weight lifting form was causing my discomfort. She then proceeded to "correct my form" for my weight training.

I understand the need to be very strict with textbook form for lifting and making sure technique is efficient to complete the task at hand whether it is during a rehab exercise or just moving a barbell in a strength movement from A to B.

Just so we can be on the same page, I am writing about what most personal trainers, strength coaches and physiotherapists consider textbook form. Feet shoulder width apart, back straight during a squat/ deadlift for instance.

That being said, there are definitely situations where less than "ideal" or "optimal" form is indicated and this is what I will be writing about.

Patients who have anatomical or even mobility limitations cannot do an exercise with textbook form or through full range correctly. Consider the following pictures above and below. Our bones and joints are shaped and angled differently and this will mean that there will be a large variability in individual ranges of motion and variations in exercise form and technique. You may have to squat wider with toes out while others may squat in a narrower stance with toes facing inwards.

Different femoral head angles

The squat technique is usually advised when lifting heavy objects over the stoop technique since this technique is thought to result in lowering intervertebral disc (IVD) compression and shear forces compared to the stoop technique.

Squat (a) versus stoop (b) lifting

However, when we compare squat versus stoop lifting, the squat lifting is not favored over stoop lifting (this is in contrast to current recommendations). 

The following study actually showed that lifting with a flexed spine produced LOWER spinal compression forces than lifting with a neutral spine (Van Arx et al, 2021).

Then there are patients who have widespread chronic pain but no tissue pathology. There is often lots of fear and avoidance of activity in these patients that if you focus too much on form it will be counter productive.These patients may be in a deconditioned state and I will be happy just to get them moving compared to someone who wants to deadlift a 100 kg.

Similarly with patients who are not active and had never play sport their whole lives. They often struggle with what we think are really simple movements and exercises. So long as there is no pain and they are not aggravating anything in low level exercises (example a half squat), I am fine with form that is not ideal for the time being and may work at improving it later.

Older patients often have other multiple health conditions and they may be other things to work on instead of spending too much time trying to teach a single exercise.

Physiotherapists who treat patients with neurological conditions like Parkinson's disease and stroke, will tell you that these patients definitely cannot do exercises with textbook form.

This post is not meant to ridicule anyone who insists on teaching textbook form while teaching exercises. Nor am I suggesting you let your patients have freedom to do whatever they want when exercising. I am simply suggesting that there are situations where insisting on textbook form is not ideal nor practical.

Reference

Von Arx M, Liechti M, Connolly L et al (2021). From Stoop To Squat: A Compressive Analysis Of Lumbar Loading Among Different Lifting Styles. Front Bioend Biotech 4: 9: 769117. DOI: 10.3389/fbioe.2021.769117

Please read this for more on squat versus stoop lifting.

Different shaped pelvis

Steroid Injections Accelerate Damage To Joint Surfaces

Picture from Ortho Arizona

Many patients with knee osteoarthritis (OA) who come to see us in our clinics often tell us that they were given intra articular (inside the joint) corticosteroid injections (IACS). ICAS is a common treatment choice that is considered minimally invasive to delay knee replacements for patients with severe OA. 

Other than providing brief pain relief, the pain often comes back. I wrote earlier this year that steroid/ cortisone injections significantly increases the risk of tendon tears.

Perhaps it's time to think more than twice before you allow anyone to inject into you knee joint. Make it any other joint for that matter as latest published research shows that individuals who got IACS were twice as likely to have harmful effects on knee articular cartilage structure than those who received no or placebo treatment.

Different stages of articular cartilage damage

A group of researchers investigated the effect of IACS on articular cartilage structure in patients with knee OA using joint space width on x-ray and articular cartilage thickness with MRI.

They found 6 studies consisting of a total pf 1437 participants. The estimated effect of IACS on articular cartilage structure showed significant odds of it worsening as measured by joint space narrowing and articular cartilage thickness. The authors concluded that their meta- analysis showed that IACS increases the likelihood of knee joint deterioration.

Other than increasing the risk of tendon tears, steroid/ cortisone  injections into knee joints may be doing more harm than good by accelerating joint surfaces degeneration. The short lasting pain relief is definitely not worth the long term consequences of your articular cartilage degenerating. 

Reference

Ibad HA, Kasaeian A, Ghotbi G et al (2023). Longitudinal MRI-defined Cartilage Loss And Radiographic Joint Space Narrowing Following Intra-articular Corticosteroid Injection For Knee Osteoarthritis: A Systematic Review And Meta-analysis. Osteo Imaging. DOI: 10.1016/j.ostima.2023.100157

PS Sim Summits K2

Summit of K2

Yes, it was last month that many of you would have read about PS Sim reaching the top of K2 - the second highest mountain in the world after Everest.

Straits Times article on 240823

Well, she came by our clinic today and both MJ and Kaylee were both ecstatic to meet her. In fact, they have been asking about her ever since they have seen her pictures in our clinic. The 2 fan girls got to ask her whatever questions they wanted. And of course they wanted pictures with her (below).

Kaylee asked her to compare Everest to K2. In her words, "Everest is a walk in the park compared to K2". To which I replied that it's not a walk in the park definitely.

We are all inspired by you PS!! Please put up an exihibition/ show and tell of all your pictures/ videos from Everest, K2 and the rest of 7 summits, we will definitely come.

Hip Adductor Related Groin Pain

If you follow Aussie Rules Football (or AFL), yesterday was the 2nd second semi final with GWS Giants defeating Port Adelaide 93-70. Aized and I had to help Aussie Rules football players back when we were  doing our post graduate physiotherapy studies in 2003. I still follow the AFL league from time to time. AFL footballers often suffer from groin pain.

Other than AFL footballers, soccer (also known as football), rugby players and those who play badminton and squash etc are involved in rapid acceleration, deceleration and sudden changes in direction are all more prone to groin injuries.

Athletes with a previous groin injury are at a greater risk than those with no previous injury. This can be up to 2.4 times greater over consecutive seasons with football players (Haglund et al, 2006).

The hip adductors

Football players have a yearly incidence of adductor related groin pain of 10-18 percent. 53 percent of theses cases are from overuse. Groin injuries in male club footballers accounted for 4-19 percent of all injuries and 2-14 percent in women club footballers.

Different types or groin pain

It can be difficult to diagnose groin injuries since there can be many different complex causes. Hip adductor related groin pain is defined as hip adductor tenderness and pain with resisted hip adduction testing. It is also the more common causes of groin pain. Other than hip adductor groin pain, the iliopsoas, inguinal and pubic symphysis are other causes of groin pain (pictured above).

Exercise therapy is commonly prescribed for groin pain although there is no specific exercise protocol. Exercises, particularly adductor eccentric strengthening seems to be beneficial for pain reduction and return to sports at 16 week follow up in comparison to stretching, electrotherapy (ultrasound, interferential currents) and transverse friction massage.

We do see many patients with groin pain in our clinics. However, our approach to treatment is different. We do not get our patients to do the strengthening exercises when they are in the clinic. We prefer to treat them using mostly our hands instead. For example, for a patient with groin pain, they may also have a higher hip on one side (pictured below).

R hip lower

We can treat the hip with respect to the shorter side. Short in terms of length. It also depends on what our assessments show. The patients can do the strengthening exercises they need on their own. We treat what they cannot do themselves in the time they have with us. Come see us in our clinics if you have groin or hip pain.

References

Haglund M, Walden M and Ekstrand J (2006). Previous Injury As A Risk Factor For Injury In Elite Football: A Prospective Study Over Two Consecutive Seasons. BJSM. 40: 767-772. DOI: 10.1136/bjsm.2006.026609

Weir A, Brukner P, Delahunt E et al (2015). Doha Agreement Meeting On Terminology And Definitions in Groin Pain In Athletes. BJSM. 49: 768-774. DOI: 10.1136/bjsports-2015-09486

Yosefzadeh A, Shadmehr A, Olyaei GR et al (2018). Effect Of Holmich Protocol Exercise Therapy On Long-standing Adductor-related Groin Pain In Athletes. BMJ Open Sp Ex Med. 4: e000343. DOI: 10.1136/bmjsem-2018-000343

Avascular Necrosis

Picture by Frank Gillard from Radiopaedia

Seeing this x-ray reminds me of what I was suspected of having when I started having persistent knee pain back in early 2002, which then led me to having 3 knee surgeries. A doctor I consulted suspected I had early avascular necrosis in my lateral femoral condyle. 

Avascular necrosis (also know as osteonecrosis) is the dying of bone tissue due to lack of blood supply. Depending on where it is, it can lead to tiny breaks in the bone and cause the bone to collapse. This process can take years to occur.

A dislocated joint or a fracture in parts of the bone can also hinder or stop blood flow to a section of the remaining bone. This commonly occurs at the epiphysis (end part) of long bones at weight bearing joints. Some common sites include the femoral head, talus, humeral head, knee and the scaphoid bone (in the wrist).

Avascular necrosis is associated with long term use of steroid medications and injections and too much alcohol. Anyone can be affected. It tends to be most common in people between the ages of 30 and 50.

Repetitive trauma can also cause avascular necrosis. This is not as commonly discussed in the medical journals. This form of avascular necrosis is most common in athletes. Rafael Nadal has a chronic left foot ailment, Mueller-Weiss syndrome where there is avasular necrosis in his navicular bone. Young gymnasts that I have previously treated are also prone to this in the wrist, knee and hips.

The doctor I consulted for my persistent knee pain back then felt that my super high mileage  (I was training for the 100 km Trailwalker event in Hong kong and the full Ironman) caused my knee pain.

The cause of avascular necrosis brought on by trauma (or repetitive stress like running and jumping) is not fully understood. Genetics combined with certain medication (like corticisteroids), excessive alcohol intake and other diseases like sickle cell anemia and Gaucher's disease can play a role as well.

Fatty deposits (or lipids) in blood vessels can block blood vessels and reduce blood flow to bone as well. There are suggestions that long term and high doses of corticisteroids (like prednisone) can increase lipid levels in blood, reducing blood flow to the bones.

Some people have no pain or symptoms at all in the early stages of avascular necrosis. As it worsens, the affected joints may hurt when weight bearing. Eventually there may be pain even at rest. Pain can be mild or severe and develops gradually. 

Having too many alcoholic drinks over several years can also cause fatty deposits to form in blood vessels.

Certain medical treatments like radiation therapy for cancer can also weaken bone. Kidney transplant patients have also been known to be associated with avascular necrosis.

To reduce the risk of avascular necrosis, please limit your alcohol intake since heavy drinking is one of the top risk factors for developing avascular necrosis. 

Keep your cholesterol levels low as tiny bits of fats (lipids) are the most common substance blocking blood supply to bones. Stop smoking as smoking narrows blood vessels which will reduce blood flow.

For those doing repetitive sports, I always suggest running on softer surfaces like grass or sand. Do not be in a hurry to increase your mileage, your bones and joints need time to get used to the load.

Lessen the junk miles or better still ride the stationary bike or use the elliptical trainer to target different areas. Strength training is very important for your bone health.

Reference

Shah KN, Racine J, Jones LC et al (2015). Pathophysiology And Risk Factors For Osteonecrosis. Curr Rev Muscu Med. 8(3): 201-209. DOI: 10.1007/s12178-015-9277-8

Best Vehicle Seat Position For Driving

Picture from the European Spine Journal

The laundry (towels, bed covers, pillowcases) in our clinics get picked up twice a week for the past 16 years by a husband and wife team - Ray and Elaine. Elaine does the driving while Ray does the pickup and delivery of the huge laundry bags. I spoke to them and Elaine was complaining about her back pain after all that driving and I told her it's probably linked to her lumbar (lower back) load from all the driving and sitting in their van.

Picture from the European Spine Journal

A recently published study used a Christophy spine model (inclusive of head, neck and limbs, pictured above) and compared calculated lower back loads and muscle forces while driving to experimental data from previous studies. 

Using data from previous radiology studies, this Christophy spine model was tested in different driving positions with different back supports. The load on the lower back was then calculated with the various back supports and backrest inclination angles.

0 cm, 2 cm and 4 cm lumbar supports were used along with inclinations of the backrest from 23 degrees to 33 degrees (by 2 degrees intervals).  

Ready for the results? Especially for those of you who drive a lot.

The overall lower back spinal loads and muscular forces at the L3-L4, L4-L5 and L5-S1 decreased very obviously with the 4 cm back support, with the seat inclination angle set to 10 degrees. With the 4 cm back support, the overall lower back spinal load decreased by 11.3 percent while  muscular forces were reduced by 26.24 percent.

The recommended backrest inclination angles are between 29 to 33 degrees with a 10 degrees seat cushion to the horizontal. 

This is a useful study to explain the association of drivers' sitting postion and the change in lower back load. It helps provide a reference for the prevention of low back pain.

Now if someone can send these recommendations to car manufacturers to improve the design of vehicle seats, that would be great.

References

Christophy M,  Faruk Senan NA, Lotz JC et al (2012). A Musculoskeletal Model For the Lumbar Spine. Biomech Model Mechanobiol. 11: 19-34. DOI: 10.1007/s10237-011-0290-6

Gao K, Du J, Ding R et al (2023). Lumbar Spinal Loads And Lumbar Muscle Forces Evaluation With Various Lumbar Supports And Backrest Inclination Angles In Driving Posture. Eur Spine J. 32: 408-419. DOI: 10.1007/s00586-022-07446-x.