By Stan Dorsey, Knee1 Staff
Dr. Houseworth specializes in Sports Medicine and Orthopaedic Surgery and sub-specializes the care of the knee and shoulder. He is a graduate of the United States Military Academy and Emory University School of Medicine. He is a Sports Medicine Consultant to Bahrain in the Middle East and currently practices in Colorado Springs, CO.
Knee1: What are the origins of the ACL shrinkage?
Dr. Houseworth: I was inspired by the work of Gary Fanton MD, his colleagues, and the research team from Oratec in their work on the use of monopolar radiofrequency energy to treat shoulder instability.
I began using the Oratec device for subluxing shoulders in July 1997 and was extremely pleased with my patients’ early results. I believe that George Thabit MD, a partner of Dr. Fanton’s was the first to perform ACL tightening with the Oratec probe. Other orthopaedic surgeons including myself soon began to use the Oratec monopolar devices for the ACL and other joints as well.
Knee1: You mention in your presentation that the ACL tightening, when performed appropriately, will be seldom used. Why is that?
Dr. Houseworth: I strongly believe that the success of any knee or shoulder surgery depends on four basic principles: proper patient selection, proper procedure selection, exquisite attention to detail during surgery, and faithful adherence to a carefully executed physical therapy program after surgery. In my mind the patients that may be considered for the ACL tightening procedure must have all of the following symptoms and findings:
The patient should have a chronic (>3 months after injury), "partial", interstitial ACL tear that is symptomatic under loading conditions such as running and cutting. I do not believe that this technology should be used on an acute ACL injury. The femoral and tibial insertions of the ACL as well as the remainder of the ACL must be intact and not partially shredded. Tightening a partially shredded ACL makes as much sense as repelling off a mountain using a significantly frayed rope.
Patients arriving in my office often have undergone rehabilitation and are not happy with their knees. Some patients have seen other orthopaedic surgeons in my community and elsewhere, have occasionally even undergone arthroscopy and have been told, "there is nothing wrong with your knee" or "that there is nothing we can do to help you." However they continue to have symptoms especially during cutting activities and even occasionally with simple walking.
On examination in the office, the amount of objective instability should be no more than a 1-2+ Lachman test with a firm end point and no more than a 1-2+ Pivot Shift. It is absolutely critical to compare the injured knee with the uninjured knee repeatedly in order to obtain an accurate examination. Of course, the possibility of subtle patellar instability must be excluded.
I have admired and respected Dr. Ron Losee from Ennis, Montana for many years. His work on the treatment of ACL instability was revolutionary in the late 1970s. In his landmark 1978 JSJS article, he described what was known in my training as the "Losee maneuver". This is one way of performing what we call the "pivot shift". Inherent to performing this maneuver is simultaneously asking the patient "Is this what you feel when your knee gives out?" I have to hear the patient tell me "yeah doc, that’s it!" Often the findings noted with my hands are quite subtle. Unfortunately, use of the KT-2000 (a device that measures the laxity between the two knees) has not been very helpful in selecting patients for surgery.
I will always order an MRI on someone I am considering for an ACL tightening procedure. The ACL on the MRI must be described as "normal" or perhaps "mild ACL sprain". Since the MRI is a static study and not a dynamic one, it obviously will not describe the ACL under the loads experienced during sports. I feel that any patient who has significant MRI changes in the ACL itself, such as scarring or partial detachment from the femur and/or the tibia, should not have this procedure. In addition, a patient with MRI findings of bone bruising consistent with a "pivot shift event" should not undergo this procedure. These MRI findings demonstrate that at least at one instant, the knee was significantly out of position and the ACL was severely stretched.
Knee1:Can this technology be used to tighten stretched ACL reconstructions?
Dr. Houseworth:It has been used for this problem. However, before proceeding with repeat surgery, the surgeon must find out the reasons for the graft stretch. Very careful attention needs to be placed at evaluating the position of the ACL graft itself within the knee. I am seeing more ACL failures due to placement of the ACL on the roof of the posterior intercondylar notch. In each case, the surgeon created the femoral graft tunnel by drilling through the tibial tunnel. At the ISAKOS meeting in Montreux, Switzerland, Dr. Bill Clancy from Birmingham, Alabama, described a "central cruciate rather than an anterior cruciate" that he has seen as a cause for ACL failure. The MRI obtained before considering ACL tightening will help to determine the ACL graft positions and also will help evaluate for graft impingement as Dr. Steve Howell from Sacramento, California, has so clearly demonstrated. I understand that Dr. Clancy is working with Smith+Nephew Endoscopy (a sponsor of this site) to develop a flexible drill to better position the ACL femoral tunnel within the knee.
Knee1: It sounds like your indications for this procedure are very specific and exclusive. Tell me about the surgery itself.
Dr. Houseworth: Prior to surgery, the patient is counseled extensively about the surgery, the need for use of a protective brace for the first 6 weeks after surgery, and the detailed physical therapy program that he/she will need to follow after surgery. In the operating room a detailed examination under anesthesia of both knees is performed. The actual procedure is done using arthroscopic instruments. Any other problems noted during the knee arthroscopy are treated as well. These often include meniscal tears.
I will only use the Oratec Vulcan device from Smith & Nephew Endoscopy for tightening procedures. This device uses monopolar radiofrequency energy rather than the bipolar energy employed by other vendors’ products. Although I continue to read research material and articles regarding radiofrequency energy applications to various tissues, I have not found any papers that compare to the work of Drs. Mark Markel and Kai Hayashi from the University of Wisconsin School of Medicine / Veterinarian Medicine. I have challenged the local vendors of bipolar radiofrequency devices who have told me "that our product is just as good as the Oratec device for shrinking tissue" to prove their assertions with research in side-by-side studies comparing the use of each of these products. One local Arthrocare salesman told me "We (Arthrocare) simply do not have any research to compare with the research performed using the Oratec devices."
During surgery itself, I create a grid or vineyard pattern on the ACL rather than "painting" the entire ligament. In addition, I will penetrate into the ACL itself to a depth of approximately 2/3 and leave the posterior 1/3 of the ACL alone in order to preserve some of the blood supply to the ligament. I will monitor the progress of tightening several times during the procedure. At the end of the procedure, I will repeat the detailed examination under anesthesia. If I do not obtain the desired stability of the knee, I will convert to a formal ACL reconstruction. If I find that the ACL is detached from the femur or is partially absent I won’t even try to shrink the remaining ligament and proceed to an ACL reconstruction.
Knee1: You have stated that the use of a brace for 6 weeks and a detailed physical therapy program is critical to the success of this operation. Why is this?
Dr. Houseworth: We know from the basic science research that radiofrequency energy weakens and stiffens tissue. Robert Johnson MD, Bruce Benyon PhD, and other talented researchers from the University of Vermont have studied the actual loads on the ACL in living human knees. Throughout the 1980s, we limited knee motion after ACL reconstructions fearing that active straightening of the knee would cause the ACL graft to loosen. In 1989, Don Shelbourne MD from Indianapolis and others showed us that we could progress with an aggressive rehabilitation program after ACL reconstruction with no loss of knee stability.
However, the ACL tightening procedure is clearly not an ACL reconstruction. Forces placed on the ACL, now weakened and stiffened by the radiofrequency probe, must be controlled with the use of a brace during the initial time after surgery. The application of the radiofrequency energy to the ligament is only the start of a cascade of cellular events that needs to proceed for many weeks in order to maintain stability of the knee.
Jim Moran RPT, the best physical therapist that I have ever known, and I have developed the detailed physical therapy program that we currently use. Initially, we sought advice from the physical therapists working with Drs. Thabit and Fanton on the West Coast. We have since created our own therapy program. We start by maintaining the patient in a hinged knee brace allowing active range of motion from 20-90 degrees for the first 6 weeks. The patient does attend PT during this time in order to minimize loss of thigh strength. The knee is passively extended to 0 degrees by the therapist during therapy visits in order to help prevent knee stiffness. At 6 weeks, the brace wear is discontinued and progressive exercises are started. The patient is restricted from cutting sport activities for a minimum of 4 to 6 months after the operation. Essentially, we use the same reverence for soft tissue healing and maturation as we do for ACL reconstructions.
The biggest enemy that we have faced in the rehabilitation time is that our patients feel so well so soon after surgery that they want to progress too fast.
I sincerely believe that failure to brace a knee and follow a detailed physical therapy program after surgery is a recipe for failure if not a guarantee of failure for the ACL tightening procedure.
Knee1: Is this procedure effective on high-level athletes as well as recreational ones?
Dr. Houseworth: Definitely! I am a Sports Medicine Consultant to Bahrain in the Middle East. Tom Hahn, the senior Smith & Nephew Endoscopy representative in Colorado Springs, has allowed me to take the Oratec Vulcan on each of my visits to Bahrain. In October 2001, I saw a Bahraini national soccer team hero who was unable to return to the team because his knee would swell and be painful with cutting activities. He had already undergone two arthroscopies, one in Germany and one in the Czech Republic. Review of the English translations of the operation summaries noted that each surgeon had not found anything significantly wrong within the knee. On my examination, I found that the “Losee maneuver” clearly reproduced his symptoms and that his Lachman test was 1+ with a definite end point. In addition, his recent MRI showed that his ACL was “normal”. I performed radiofrequency tightening of his ACL in October 2001. He faithfully wore his knee brace as well as continued in his physical therapy program under the excellent care of Ron Levan, ATC, MS in Bahrain. I saw him again in April 2002 on my next visit to Bahrain. He had a normal knee examination at that time and returned to play with the Bahraini national team. He has returned to World Cup competition and scored goals at the recent Asian Games in Korea, October 2002.
Knee1: Are you aware of complications from this procedure?
Dr. Houseworth: Absolutely yes! I presented my data at the International ACL Study Group Meeting in Big Sky, Montana, March 2002. At that time, various talented surgeons relayed their concerns about this technology.
Drs. Perry and Higgins from Duke have published in Journal of Arthroscopy, Oct. 2000, a case report of anterior and posterior cruciate ligament ruptures after radiofrequency treatment. A review of this article demonstrates that ALL of the parameters that I recommend for ACL thermal tightening were violated by the original surgeon: the Arthrocare ArthroWand was used, it appears that the original surgeon may have completely "painted" all of the ACL and PCL, no brace was used for protection after surgery, no physical therapy was prescribed, and apparently, the patient received no caution about return to activity. It should be no surprise that this case was a disaster, as the patient needed both ACL and PCL reconstructions after radiofrequency application to both the ACL and PCL.
I fully agree with Drs. Perry and Higgins concluding statement "We recommend great caution when contemplating RF (radiofrequency) energy treatment for patholaxity of the cruciate ligaments."
Knee1: Can this technology be used in other joints?
Dr. Houseworth: I have had very pleasing results in tightening the ankle of carefully selected patients with 25 of 25 successes. My partner, Dr. Steve Topper, a very talented Mayo Clinic trained Hand Surgeon, has also had success with the Oratec Vulcan micro probe to fix selected patients with wrist instability. He will be presenting an Instructional Course Lecture at the American Society of Hand Surgery meeting in Hawaii in January 2003.
Knee1: What is the future of electrothermal ACL tightening?
Dr. Houseworth: I believe that this technique will be a useful tool added to the experienced ACL surgeon’s toolbox. However, if employed properly, it will be used only occasionally and with the utmost discretion.