Reviewed by – Dr. Satish Reddy
Many considering an ACL surgery have questions on what type of screws, biodegradable screws or metallic screws, would give the best outcome. There are many factors to be considered before choosing one. Let’s see the details about choosing the biodegradable screws or metallic screws for ACL Surgery.
What Is An ACL Surgery?
An ACL reconstruction surgery involves the replacement of anterior cruciate ligament by a tissue graft. A new ligament grows on the tissue graft approximately six months after the procedure.
Tissue grafts can be obtained from a patient’s own body (autograft), such as from patellar tendon or hamstrings tendon; or from other sources (allograft).
During the surgery, a tissue graft is secured by interference screws which help in securing the tendon into bones (tibia and femur).
Read More: Best Treatment For ACL Injury
Type Of Screws For ACL Surgery
Initially, titanium was the material of choice for interference screws, used in ACL reconstruction surgeries owing to its biocompatibility. Lately, biodegradable screws are widely used.
A bioabsorbable or biodegradable screw automatically resorbs or disintegrates in our body, unlike a metallic (titanium) screw.
An anterior cruciate ligament reconstruction surgery is minimally invasive and requires small incisions. Post-surgical rehabilitation is an important determinant to a successful recovery.1
Read More – How to decide you need an ACL Surgery
How To Decide On The Type Of Screw And Graft?
Usually, a surgeon decides on the type of tissue graft to be used, but you will be asked to choose between biodegradable or metallic screws, prior to surgery. The total cost of surgery varies with the type of screw chosen since biodegradable screws cost higher than their titanium counterparts.
An ACL reconstruction surgery costs between 75,000 and 1.5 lac rupees in India. Sometimes, patients also choose metallic screws in the case of a budget constraint.
Read More: How Does A Tendon Graft Grow Into An ACL?
Biodegradable Or Metallic Screws For ACL Reconstruction?
Recently, biodegradable interference screws have been widely used in ACL reconstructions. Apart from being more expensive, biodegradable implants have other major drawbacks such as foreign body reaction, incomplete bone formation (after implant/screw resorption), and a slower rate of graft tissue formation.
Titanium screws, though biocompatible may result in an increased risk for infection if retained; hence a second surgery is required for removal of the screw. Additionally, these implants interfere with diagnostic imaging; make revision surgery difficult, and may induce stresses in the surrounding bone causing a reduction in bone density.
Now the question is, which of these interference screws will provide you with better long-term results?
In 2014, British Medical Bulletin reviewed the outcomes of different materials for fixation screws in ACL reconstruction. It was observed that both biodegradable screws and metallic screws had similar results with regard to the clinical scores, evaluation, and imaging assessment of patients. Biodegradable screws were considered superior due to their property of osteointegration (integration with the surrounding bone). However, higher costs of these screws could not be justified, since the long-term results of metallic screws were equivalent.2
In 2015, The Journal of Arthroscopic and Related Surgery published a study which showed that biodegradable screws caused prolonged fluid accumulation around the joint (fluid effusion), increased femoral tunnel widening (widening of the bone surrounding the screw), and screw breakage. Here, functional comparisons between the two types of screws did not show significant differences.3
Another interesting study in 2015 conducted a 5-year follow-up post-surgery, comparing metallic screws to PLLA-HA (L-lactic acid with hydroxyapatite) screws – a type of biodegradable screw. It was shown that unlike metallic screws, PLLA-HA screws were not associated with femoral tunnel widening or increased cyst formation. Although these screws showed incomplete ossification of the surrounding bone after screw resorption, no adverse effects were noted over 5 years.4
A recent study in 2016, searched medical databases to compare the functional outcomes of ACL surgeries with bio-degradable screws and metallic screws, in 944 patients. Patients from both groups (with biodegradable screws and metallic screws) reported similar knee functions, one, two and five or more years post-surgery. Furthermore, the levels of activity of patients with either screw-type did not show any differences.
However, biodegradable screws were associated with more treatment failures, like screw breakage during placement and graft rupture.5
Read More: ACL Surgery Post Care Instructions
So let us summarize the advantages and disadvantages of biodegradable screws and metallic screws used in ACL reconstruction surgeries.
Biodegradable Screws – Advantages and Disadvantage 6,8
|MRI imaging is possible post-surgery.||Do not necessarily resorb at defined rates – i.e., they vary in their rates of degradation.|
|No long-term interference with surrounding tissues.||Slower rates of biological tissue (new ligament) regeneration.|
|The need for a second operation for screw removal is eradicated.||May cause inflammatory or foreign body reactions leading to osteolysis or cyst formation.|
|Reduced risk of infection.||Require precise technique due to inadequate stiffness and a higher rate of breakage.|
|No osteoporosis (brittle bone disease) or stress in tissues surrounding the screw.||May result in incomplete ossification (bone formation) and tunnel widening in the surrounding bone.|
|Have rapid loss of implant (screw) strength leading to higher fracture rates.|
|Cause fluid-effusion – collection of fluid around the joint.|
Titanium Screws – Advantages and Disadvantages 7,9
|No foreign-body reaction.||Do not resorb over time – causing distortion of diagnostic images and making visualization of surrounding tissues difficult.|
|No tunnel widening of the surrounding bone.||MRI imaging cannot be done post-surgery.|
|Faster biological tissue (new ligament) regeneration.||Interfere with revision surgeries as they are difficult to remove.|
|Easier placement.||Second surgery is required for screw removal.|
|No fluid effusion.||May cause metal sensitivity or localized irritation and pose a risk of infection if retained.|
|No osteolysis (bone depletion) or cyst formation.||Cause stress shielding or reduction in bone density in the surrounding area.|
Read More: ACL Surgery Cost In India
Do You Need A Specialist?
An ACL reconstruction surgery is a technique sensitive procedure, hence it will be performed by an experienced orthopedic surgeon. If you are choosing to go for a biodegradable screw, you must find out whether the surgeon performs such procedures often.
Biodegradable screws require more precision during placement. If your surgeon has experience in similar surgeries, chances of the procedure being a success, increases.
You could ask your physician or family members if they know of an experienced orthopedic surgeon. Patient reviews may also help to a certain extent, in this aspect.
Since most of the medical research findings suggest that long-term outcomes of both biodegradable screws and metallic screws are similar and satisfactory, main criteria for selection depend on the patient’s age and budget.
If you are young, you may require revision surgery at a later stage, hence the best option for you would be to choose a biodegradable screw.
Whereas, if your doctor does not anticipate a need for revision surgery in your case or if your activity aspirations after recovery are limited and you have a limited budget, a metallic screw would be a good choice for an ACL reconstruction surgery.
Ultimately, it is important to know that although a biodegradable screw costs more, its superiority over metallic screws with respect to outcome and function has not been proven on long-term analysis. Your orthopedic surgeon can be your best guide in deciding on the type of interference screw best suited for your joint, based on your medical condition and the pros and cons of ACL reconstructions with biodegradable screws and metallic screws.
An injury to ACL is one of the most common sports injuries, in particular when a person is engaged in any high-contact sports such as soccer, basketball etc. ACL injury can be of different severity or grades, and the treatment may vary based on various factors. Recently our team got together with Dr. Satish Reddy, a highly experienced Orthopedic surgeon who has handled thousands of ACL injury cases in over 20 plus years of practice. Here are the most common questions people have about ACL injury and its treatment, with answers provided by Dr. Satish Reddy.
1. Can ACL heal without surgery?
ACL does not heal without surgery. In some patients it can be compensated by the action of muscles around the knee joint, thereby avoiding surgery.
2. What’s happens to an untreated torn ACL?
If the patient’s muscles don’t compensate for the loss of ACL, the patient develops instability of the knee, leading to secondary injuries within the knee, there is a chance of early onset of osteoarthritis. The torn ACL scars up and lies in the joint.
3. How much does an ACL surgery cost in India?
The cost of any surgery depends on the implants, which are available from 5000 to 50000 for each knee. Will need to discuss with the surgeon regarding pros and cons. Also, the cost of hospital expenditure varies from hospital to hospital, the reason being the facilities provided and the status of the operation rooms. The procedure can cost anywhere from about 80,000 to a couple of lakhs.
4. Does a torn ligament require surgery?
Depends on the ligaments, any muscles ends as a ligament, and the importance can vary from part to part.
5. Which graft is good for ACL reconstruction?
The commonest are autografts, i.e harvested from our own body. Patellar tendon and hamstring tendons are commonly used. Allografts i.e harvested from cadavers are also available.
6. Does a grade 2 ACL tear require surgery?
Grading is immaterial, it is only a radiological finding, the presence of instability is an important factor.
7. What is the recovery time after ACL surgery?
Patients can do activities of daily living immediately after surgery, but the rehabilitation period lasts for 4 to 6 months. There will be restrictions on certain activities for that period.
8. Can I run after ACL reconstruction surgery?
Good surgery and proper rehabilitation can restore a professional sports career also, there is no need to worry about activities after ACL surgery.
9. How long does it take to completely recover from partial ligament tear?
Again it depends on the ligament and the part involved, usually, it takes about 6 weeks for the inflammation to come down and swelling to subside.
10. Why do my knees make noise?
Noise alone without pain is sometimes seen in normal people, noise associated with pain is pathological, this needs to be examined by a doctor to find out the reason.
Dr. Satish Reddy is an experienced Orthopedic surgeon associated with Aster Prime Hospitals, with special expertise in handling sports and trauma cases. He has successfully performed thousands of ligament reconstruction surgeries over more than 20+ plus years of practice and helped many more patients rehabilitate successfully with non-surgical, conservative means where suitable. Dr. Satish is highly approachable and believes in providing as much information as possible to the patients so they feel comfortable about the suggested treatment options.
For more information, do get in touch with us through email at [email protected] or message us on WhatsApp at +91-9640378378, or submit your question below.
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Dr. Kaleem Mohammed graduated as a Bachelor of Physiotherapy in 2014 from Deccan College of Physiotherapy, affiliated to Dr. N.T.R. University of Health Sciences, Vijayawada, India. Dr. Kaleem is an expert at handling physiotherapy needs of patients suffering from orthopedic and spinal conditions and post-surgery rehabilitation. Dr. Kaleem is associated with HealthClues since its inception where he facilitates diagnosis and advanced consultation with senior doctors. He is also a medical researcher and prolific writer who loves sharing insightful commentaries and useful tips to educate the patient community about fitness, treatment options, and post-treatment recovery.