An update on Anterior Cruciate Ligament (ACL) Reconstruction

The orthopedic literature has a plethora of study on the need to repair or not the anterior cruciate ligament of a traumatic knee in an athlete. I remember while starting medical school, a European debate among orthopedic specialists around the world presenting reasons to reconstruct or not the anterior cruciate ligaments (ACL). Jean-Claude Killy’s knee was described in all test-book and the literature was justifying the reason to avoid any surgical treatment. Gold medalist in the 1968 Winter Olympics, this French competitor became a three-time World champion in Alpine Sky in spite of a deficient ACL knee for years.

Less than forty years later. the discussion is still centered on the same topic after reconstruction has been used and abused all over the world, especially in the United States of America. The question remains the same: Should an anterior cruciate ligament reconstruction (ACL) be performed in an athlete? After a 20 years’ pilot study, it seems that results on non-operative ACL treatment versus ACL operative treatment has shown no significant differences between the two groups when it brings the question of degenerative arthritis in the reconstructed joint with meniscal repair or resection. This study, recently published in the American Journal of Sport Medicine, has surprised many and Daan T. van Yperen MD, in the department of Orthopedic Surgery at Erasmus University Medical Center in Rotterdam, concluded with many others that a non-operative treatment should now be considered in any population, included in the high competitive athletes.

In the study, knee osteoarthritis was discovered in 80% of the knees treated operatively and only in 68% of the non-operated knees. Researchers noted more that 68% of operative knees had a negative pivot-shift while only 13 % in the non-operative group.  A pivot-shift test is one of the three major test used to assess a knee joint for the presence or the absence of an Anterior Cruciate Ligament (ACL). If instability is encountered, the menisci are at risk for further injury.  The knee with an absent ACL may give out and patient may feel unsecure especially in motion. This ligament is best tested while the examinee lays down in a supine position with the hip passively flexed at 30 degrees. The lower leg is held at the ankle by one hand while a 20 degrees of internal tibia rotation is obtained, allowing the knee to sag into complete extension. A valgus force is applied laterally and distal to the knee joint, while flexion is obtained. Any subluxation, which may be felt while the knee is being placed in 30-40 degrees of flexion to a full extension, translate a “Positive Pivot-Shift” test. The reproduction of this instability may be painful and may require general anesthesia.

The Lachman test is also very reliable to check on an ACL and should be performed while the patient is laying supine with the knee flexed at 20-30 degrees of flexion.  One hand is placed behind the tibia and one on the distal thigh The tibia is then pulled forward to assess any anterior translation of the tibia in comparison to the femur. An intact ACL will prevent forward translation, rendering the Lachman test negative. An instrument called KT-1000 can measure the anterior translation in millimeters.

Finally, the anterior Drawer test is mostly used at initial assessment for suspected ACL injury of the knee. Patient is placed supine with the hips flexed at 45 degrees and the feet flat on the bed while the examiner seats on the bed facing the injured extremity. Grab the proximal tibia with both hands just below the knee joint assuring that both thumbs are placed medial and lateral to the distal insertion of the patellar tendon. Then draw the tibia forward to appreciate any anterior translation of the tibia. Any increase in translation, compared to the opposite side may indicate an injury to the anterior cruciate ligament (ACL). Then the test will be considered positive if excessive translation is noted. A posterior drawer test has inversely described the translation of the tibia posteriorly, reporting a (PCL) Posterior Cruciate Ligament injury.

Many have voiced their confusion in performing and interpreting those tests. It was imperative for me to review them prior to continue our discussion. The variation between Pivot Shift and Lachman test described in the paper relating on the 20-years follow-up in the two groups (operative and n0n-oprative), surprised many who were able to appreciate more knee laxity in the non-operative group, not leading to more degenerative arthritis or decrease range of motion.

We always believed that in restoring knee stability and repairing menisci and/or ligaments, we would rebuild a near normal anatomic joint but apparently we failed to obtain the expected results. around the world.  So this bring back the same questions: what are the knees necessitating surgical repair? What are the knees requiring conservative treatment?

We may have to look for bone bruises on MRI, review meniscal injuries and try to develop a pattern which will allow us to hope for better results. Others believe that the role played by the reactive cytokines is still not well understood. Nobody can discuss their beneficial or adverse effects on the repair of any articular cartilage. We have presented facts, recently in an article: “the novel treatment on Osteoarthritis”, published in our AMHE Newsletter, a month ago. We discussed the exciting work of Xu Cao MD, at John Hopkins University Hospital, studying the effects of the TGF-B1 proteins and their inhibitors on the articular cartilage and subchondral bone. One inhibitor linked to Diphosphonates drugs and another one related to “Holofuginone”, old Chinese drug used in the treatment of Malaria, which are experimentally injected in the articular cartilage or in the subchondral bone to avoid degenerative arthritis.

After presenting this explosive article relating to the review of thousand cases around the world in which repair or conservative treatment was offered in a ACL deficient knee, I found myself compelled to describe and review what Orthopedic surgeons have experienced over the years to reconstruct an unstable knee. “Anterior cruciate ligament reconstruction” (ACL) is a surgical procedure allowing a replacement of a deficient or torn ligament by a tissue-graft to restore function in the knee. Nowadays this procedure is performed through an arthroscopic but others have persisted in using an open technique.

The anterior cruciate ligament (ACL) provide stability to the knee in stopping the tibia from sliding anteriorly. It is a very common injury among athletes. One in 3000 athletes will suffer such injury in the United States and we believe that almost 250000 reconstructions are performed yearly in the country, in order to restore stability to a knee joint. Careful consideration in the choice of patient is taken once the procedure is recommended. This injury is seen more often in women in a ratio 1 man to 5 women. It is not sure why this difference but it is believed that hormonal factors and conditioning may play a role as well as anatomical factor like the “Q” angle.

A choice of muscle tendons like the hamstring, the patellar tendon, the iliotibial band can be harvested during the surgical procedure for replacement of the ruptured ACL. They are the best autografts to use but in cases requiring revision the quadriceps tendon, the iliotibial band and even the Achilles or tibialis tendon may be preferred. The rate of rejection is minimal when using an autograft. Otherwise, an “Allograft” from a cadaver can be used to replace the ACL but the rejection rate will be higher. The same will go for the synthetic grafts replacement with carbon fiber, Goretex or Dacron etc.

Autologous stem-cell transplantation (mesenchymal stem cells) is being used to improve the outcome of ACL surgery in athletes. Mesenchymal stems cell can dedifferentiate in Osteoblast (bone), Chondrocytes (cartilage) Adipocytes (fat) depending on the demand. They must be placed on a proper scaffold to grow and differentiate. Generally, scaffolds used for ACL growth are collagen, gelatin, polylactic acid, silk and glycosaminoacid.

The first ACL reconstruction in the world was performed by F. Lange MD in 1903, using silk to hold together the semitendinosus tendon, but it failed. In 1917, Ernest Hey Groove MD used strips of Fascia lata to reconstruct the ACL and published in the British journal his experience. In 1935, W C Campbell of Memphis TN was the first one to use the patellar tendon to reconstruct the ACL. In 1939, Henry Macey of Rochester MN, returned to the use of semitendinosus for reconstruction. The second war slowed down the progress made in restoring stability for a deficient ACL knee. Many researchers and surgeons have contributed to the perfection of the actual technique used to repair a ACL notably: K Lindemann, Robert Augustin, Albert Trillat, J Ritchey, Kenneth Jones, Don Odonoghue, Kurt Franke, D L Mackintosh, and many more like Clancy, Noyes etc.

Prior to schedule an athlete for surgical treatment, a pact/contract is taken to assure the commitment of such candidate to a lengthy rehabilitation generally lasting almost a year with Physical therapy including range of motion and muscle strengthening exercises to regain flexibility in the ligament and prevent scar tissue. We have used a continuous passive motion (CPM) machine in the past to enhance flexibility in the post-operative period but now many in using it, expect an elevation of the extremity to help in the swelling and to facilitate the range of motion.

Isometric exercises are the best way to prevent muscle loss while no strain is placed on the repaired structures (ligament or meniscus). The goal is to re-obtain knee extension in the weeks following surgical treatment. We believe that the graft is at risk prior to 6 weeks until bony attachment is achieved. Walking is permitted with caution after 12 weeks, and then, patient will be allowed to perform in more aggressive exercises program. Soon after, Jogging and Running may be slowly introduced. At 6 months, we expect the ACL to be at full strength because the ligament tissue is expected to have fully grown, then we will have patient involved in cutting and twisting while using a brace. Others may take longer and up to a year, to reach this point.

This is why the process is broken down in different phases to assure proper rehabilitation while minimizing the chances of degenerative arthritis. I needed to expose our standard way in orthopedic surgery to enhance the recovery of an athlete recovering from an ACL reconstruction. The last 20 years has bought a lot of deception in the world of orthopedics. We may not be perfect in reconstructing any ACL but we have tried over the years to restore the damaged and unstable knees to a near anatomical perfection. We may do better with more refined techniques and we may have to make better choice in the candidates chosen for surgical repair.

We need to develop better criteria and decide when conservative treatments may be offered as an alternative. In this time of stem cell therapy, perhaps, genetics will certainly play a role in the reconstruction an injured knee joint. Researchers at John Hopkins just last month, have discovered the “signal” that drive Stem Cell to produce new bone. It is always an adventure of a lifetime when progress in Medicine is at the corner. As physician, we always think that help in on the way.

This paper is dedicated to my son Gerard Maxime Coles who has undergone a patellar tendon, ACL reconstruction, a year ago after an unfortunate sport accident. I am forever, in debt to my friend and classmate Georges Branche MD, from Howard University Hospital, who has performed his successful reconstruction. Gerard-Maxime has resumed competitive basketball activities and we wish him luck.
Maxime Coles MD



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2-     Cohen SB, Yucha DT, Ciccotti MC, Goldstein DT, Ciccotti MA, Ciccotti MG (Sept 2009) “Factors affecting patient selection of graft type in anterior cruciate ligament reconstruction”. Arthroscopy. 25 (9): 1006-10

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5-     Kraeutier MJ, Bravman JT, McCarty EC (2013). “Bone-patellar-bone autograft versus allograft in outcomes of anterior cruciate reconstruction: a meta-analysis of 5182 patients” Am J Sports Med 41 (10):2439-48

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7-     Shelbourne KD, Vandurongwan B, Gray T (Oct 2007). “Primary anterior cruciate ligament reconstruction using contralateral patellar tendon allograft” Clin Sports Med. 26(4): 549-

8-     O’Brien DF, Kraeutler MJ, Koyonos L, Flato RR, Ciccotti SB (2014). (“Allograft anterior cruciate ligament reconstruction in patients younger than 30 years. A matched-pair comparison of bone-patellar tendon-bone and tibialis anterior”. Am J Orthop 43 (3): 132-136

9-     “Anterior Cruciate Ligament (ACL) Surgery”. WebMD 25 April 2016

10-  “Lachman Test” Wheeless Textbook of Orthopedics

11-  Van Eck CF, van den Bekerom MP, Fu FH, Poolman RW, Kerkoffs GM (Aug 2013). “Methods to diagnose acute anterior cruciate ligament rupture, a meta-analysis.of physical examinations with and without anesthesia” Knee Surg Spors Traumatol Arthrosc. 21(8): 1895-903

12-  Pivot Shift Test- Wireless” Textbooks of Orthopedics”.

13-  Clinique du Genou: “La Rupture du Ligament Croise Anterieur”. Webpage

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