Author Archives: James Hundley, MD

About James Hundley, MD

Dr. Hundley is a retired orthopaedic surgeon and the originator and co-founder of OrthopaedicLIST.com, a resource website for orthopaedic surgeons and related professionals.

Waterproof Cast Padding Enables High School Lacrosse Player to Compete

by AquaCast Liner

Carter has been playing lacrosse since the 3rd grade. Now a sophomore in the Baltimore area, Carter has plans to play in college. His ultimate goal, held since 4th grade, is to become class president and captain of the lacrosse team at Princeton University.

Just days before a major college lacrosse recruiting tournament, however, Carter broke the growth plate in his right arm in a school football game. He was directed to a local orthopaedic practice, and had his arm cast in a traditional, cotton padded cast. The doctor and cast technologist mentioned that if he tried to play lacrosse that weekend, it would be painful and the cast would end up becoming soaked in sweat, resulting in discomfort and a rather unpleasant odor. They also told Carter if he got it wet he would have to be recasted. More time. More costs.

That weekend Carter watched his teammates play tough – from the sidelines – while coaches from Johns Hopkins, North Carolina, Virginia and Princeton, among others, scribbled notes on their next wave of talent.

His competitive juices flowing, Carter wanted to get back on the field at the next tournament, held the weekend prior to Thanksgiving. A friend told Carter’s father, about a waterproof, breathable cast liner made by AquaCast, which allows patients to perform activities without worrying about keeping their cast dry. The father, a former college All-American lacrosse player, contacted Towson Orthopaedic Associates and Scott Tarantino, MD. They stocked the AquaCast Liner and Carter had his arm wrapped in the waterproof product, quickly becoming a fan.

“It’s been really great. I get sweaty, come home and shower, wash it out and it’s dry really quick. It doesn’t smell like the other one. And it doesn’t itch.” Carter played in the following tournament, amassing 5 goals and 8 assists in three games, drawing the attention of several scouts, including Princeton. “I’m glad Dr. Tarantino’s practice had AquaCast,” noted Craig’s father. “We certainly didn’t know it was available. It made a big difference for Carter – it’s made life a lot easier.”

In addition to playing in the lacrosse tournament, Carter was able to finish his football season in comfort. “Two other guys on the team broke their arms and I told them about Dr. Tarantino’s office and the AquaCast. They showed up at the next practice with the AquaCasts.”

As a side note, Carter has seen his dream of attending Princeton come true, formally committing to the Tigers and head coach Chris Bates. We at AquaCast wish Carter and his family the best of luck this season and in the future at Princeton.

Please click on AquaCast Liner to learn more about waterproof cast padding.

You Can Now Get Waterproof Casts

by AquaCast Liner

When you have a cast, it can make everyday tasks difficult and time consuming. Something that used to be simple, like taking a shower or bath, now becomes complicated and involves serious maneuvering to try to keep the cast dry. Now, there are options for casts to be waterproofed, eliminating the need to cover the cast while being around water as explained in this article.

Benefits of a Waterproof Cast

  • Makes bathing easier, facilitating better hygiene
  • Allows for participation in water sports
  • Reduces the odor of a traditional cast
  • Provides kids with a way to maintain their normal routine

Great for Young Children, Adults, and Seniors

Waterproof casts for children work well for those who are too young to understand the importance of keeping their cast dry. It also helps give parents peace of mind that you don’t have to constantly be beside your child when they are near water. Showering or bathing with a cast is very frustrating if you have to work around the cast to keep it dry.  Waterproof cast padding minimizes the lifestyle changes for anyone with a broken bone.  Vocations that require frequent hand washing, from restaurant servers to auto mechanics, can continue to maintain their hygiene even with a cast.  Seniors benefit from independence that may have been limited with a broken bone or cast. They need less help around the house to do simple tasks such as washing the dishes or taking a shower without a slippery plastic bag over one of their limbs.

Gives Older Kids More Independence

If you have a child who is old enough to bathe alone under normal circumstances, they’ll probably prefer to continue that practice, even while wearing a cast. The waterproof cast allows children the privacy they want while bathing or showering. Being able to continue with normal activities helps to lessen the burden felt when wearing a cast or the need to ask for help.

Warm Weather Fun

Having a cast during warm weather can be very disheartening for anyone who enjoys playing in the water or who is active in spring and summer sports. Swimming with a cast is nearly impossible as you can’t immerse a traditional cast in water due to damaging the cast padding or liner. Wearing a cast can put a damper on your family’s summer vacation if someone cannot play in the ocean or get in the pool. Being active in sports also is tough to do with a traditional cast as many wearers and family members of wearers want to keep the cast from getting sweaty and smelly. A waterproof cast allows more freedom with sports and extra-curricular activities during the warmer months.

Keep Life Easy with a Waterproof Cast

Waterproof casts can make life easier for everyone in the home. Paitents are able to better maintain their regular routine, while also keeping some independence. Showering, taking a bath or even washing ones hands and face with a traditional cast can prove to be a task that requires a lot of assistance from a parent to ensure the cast remains dry. Trying to wrap a cast to prevent water seepage is time consuming and not something kids or parents want to deal with. Swimming with a cast is also possible with a waterproof cast, so that a broken bone does not mean you have to miss out on summer fun.

Please click on AquaCast® Liner for information about waterproof cast liners.

 

Injury Prevention in Youth Sports

by Mark Wood, M.D.

Sports injuries are common in youth athletes who often suffer sprains, strains, bruises, or broken bones. The most common injuries are to the leg, ranging from a twisted knee or ankle to a direct blow from a collision.

Fifty percent of youth injuries are due to overuse or over-exertion, without proper rest and recovery.  The most common presentations include shin splints, patella or achilles tendinitis and stress injuries or fractures.

The majority of youth sports injuries may be preventable. Several ways to avoid injury include:

  • Using good equipment. Make sure your child has well-fitting cleats, helmets, mouth and shin guards, and other appropriate protective gear.
  • Staying hydrated. Kids need to be reminded and encouraged to drink plenty of water.
  • Staying in good condition. Athletes who are in better physical shape tend to have fewer injuries. If your child has been away from sports for a while, allow him or her to gradually progress with activities including strength, agility training, and aerobic conditioning.
  • Avoiding overuse injuries. Many young athletes participate in one sport year-round and tend to over train. It is important to allow time for rest and recovery as opposed to continuing to push through pain and discomfort. This leads to burnout and also increases the chance of injury.  Teach your child to listen to his or her body and pay attention to warning signs.

Research has proven that utilizing focused exercise training programs (strength, balance and plyometrics) will decrease the chance of minor and major athletic injuries by greater than 50%.  Coaches and parents can make a difference by encouraging proper warm-up and performing prevention techniques, especially for young female athletes participating in cutting, jumping and pivoting sports (soccer, basketball, lacrosse, etc). The programs are quite simple and require only 10-20 minutes twice a week.

Dr. Wood is Board Certified in Orthopaedic Sports Medicine and practices at Wake Orthopaedics in Raleigh, NC. For further educational information, including the Wake Ortho injury prevention screening program, please visit WakeOrtho.com.

PATRAN® Slide Sheets, an Inexpensive and Efficient Way to Safely Move Patients

By Stefanie Scott

Repositioning and transferring patients are among the most common tasks that lead to healthcare worker injuries, the U.S. Occupational Safety and Health Administration reports. A low-tech, low-cost slide sheet can assist in most of these patient-handling tasks, reducing the risk of injury to caregivers while increasing patient comfort.

With no installation or accessories required, PATRAN® slide sheets (sometimes referred to as friction-reducing devices, slips, glide sheets or lateral transfer devices) allow healthcare organizations to start a safe patient handling and mobility program with little financial investment and quickly prevent some of the most frequent and debilitating musculoskeletal injuries incurred by healthcare professionals.

Slide sheets are designed to slide, not lift a patient, so there is no weight limit to who can be moved with a PATRAN slide sheet. However, larger patients may require using a larger size or multiple slide sheets so the entire body fits.

PATRAN single-patient, multiple-use slide sheets can be used in just about every area of a hospital or health care setting. With the full-body size, log-rolling a patient is not required to insert the PATRAN under a patient, which can prevent pain, dislocation or further injury in orthopedic patients. From pre-hospital emergency response to radiology, surgery and orthopedic medical floors, slide sheets have a number of patient handling and mobility uses.

The following are just a few reasons why PATRAN slide sheets are the industry leader:

PATRAN slide sheets can be used 30+ times with the same patient before they lose their slip, which is generally more than sufficient for an acute care patient.

PATRAN moves in all directions, so one tube-shaped sheet can be used 20+ ways, including lateral transfer, repositioning/boosting in bed, getting slings on patients and even putting on compression hose.

PATRAN is inexpensive, especially based on its size. The original PATRAN at 72×36 fits most patients’ entire body. Smaller slide sheets, many at a higher price point, require additional caregivers to hold the head and feet of the patient or the body parts hanging off the slide sheet increase the friction and skin shear.

PATRAN helps prevent cross-infection. Patients get their PATRAN upon entering a healthcare facility and it stays with them throughout their stay. Then it’s disposed of upon discharge. It can be used in just about every area of a hospital. PATRAN is radio-translucent, is latex-free and contains an anti-stat.

PATRAN comes in more styles than any other single-patient-use (sometimes called disposable) slide sheet brand. In addition to the original PATRAN, smaller and larger (bariatric), as well as individually wrapped versions are available.

PATRAN doesn’t require log-rolling to get it under a patient. The size, flexibility and slipperiness give caregivers options about how to insert it and methods of use that allow them to take the patient’s medical condition into consideration.

Click on PATRAN SLIDE SHEET to see the PATRAN listing on OrthopaedicLIST.com.

Stefanie Scott is President of Jamar Health Products, Inc., manufacturer of PATRAN® slide sheets. She is a Certified Safe Patient Handling Associate through the Association of Safe Patient Handling Professionals.

External Fixator to Volar Plate

by Alejandro Badia, MD

It was not too long ago that the standard of care for a distal radius fracture with displacement was the application of an external fixator. Like the brief internment in a penal colony, the patient was left to deal with this cumbersome device for several months. I highly doubt that many of the little old ladies who had this device applied appreciated its “minimally invasive” nature.

Over 10 years ago, I remember my partner and I applying the standard volar plate from the synthes set to ALL distal radius fractures, regardless of direction of  displacement. I think neither Mrs. Smith nor Mrs. Colles cared about their Frykman classification but likely appreciated the fact that a small palmar based plate on the wrist, as an outpatient under regional anesthesia, could allow them to get right back to their daily routine simply using a small splint or fiberglass cast as protection.

I remember just a few years later lecturing on this very topic in Ho Chi Minh City, or even Buenos Aires, and realizing that this had very quickly become the standard of care worldwide. It was gratifying to be part of a revolution that truly improved patient care of this ubiquitous fracture.

Alejandro Badia, MD

Badia Hand to Shoulder Center

Miami, FL, USA

Energy Transfer: Be Additive.

 by James D. Hundley, MD

            If you’ve never been a patient with a serious problem yourself, you may not have considered this.  Having a medical problem not only drags down your body, it drags down your mind, too.  I’m sure someone taught you about it in medical school, but when we get wrapped up in the technical side of our profession, and it’s absolutely necessary that we do so, this is a lesson that some seem to forget.

Do you know people who are “buzz killers”?  Within a few seconds of being in their presence, you feel your emotional energy being drained and you can’t get away from those people quickly enough.  In contrast, those who are bright and energetic make you feel good and ready to tackle anything.

This is true in the doctor-patient relationship, and it’s serious.  I’ve been around doctors who act so down in the dumps that it seems that they are the ones who need help more than their patients.  Maybe they are tired from working so hard or maybe they are internalizing their worry about the patient, but they sure aren’t helping their patients tackle their problems.  Whatever the case may be, they are sucking needed emotional energy from their patients rather than filling their patients’ tanks with the fuel they need to deal with their problem.

I’m not suggesting that you not show concern.  To the contrary, I’m suggesting that you not only show concern for and interest in your patients, I’m suggesting that you be truly concerned and show it by transferring some of your own positive energy to your patients.

You can’t be silly or trivial.  That’s not what I’m suggesting.  It might take a little practice to find your own best way of approaching this and it’s hard to describe, but it’s about being positive and upbeat to the extent possible in any given situation.

Players play better for certain coaches.  You frequently hear about it.  I’ve seen it with teams that I’ve worked with.  The same players who were losing miraculously start winning.  Surely the reasons for the sudden success are many.  Maybe it’s conditioning or technique.  They’re important.  Without positive energy, however, I don’t think it happens.

Likewise, when you rod someone’s femur or replace someone’s hip, the technical aspects are critical, but that’s not enough.  You have to take care of the other physical needs as well, and I’m sure you do, but that’s still not enough.  You must also help that patient find the energy to get up and go again.  Equally as important, no matter how tired you are or what else is going on with other patients or in your life, you must dig down and find positive energy to share with your patient.

Many will dismiss this as insignificant and/or unrealistic.  I have no scientific studies to support it.  On the other hand, I have had many years of interaction with patients and truly believe that patients do better when they want to please their doctors.  It’s like a player wanting to please his coach.  You can’t fall into the trap of thinking it’s about you personally, of course, but if it’s useful to the patient, it’s certainly not harmful.

Worried that all of your energy will be drained by your patients?  Don’t be.  In fact, the gratification of seeing your patients happily improving or resolutely dealing with serious problems is in itself a source of energy for you.  It’s like heat reflecting off an object and back to you.  Try it.  You either already know that it’s true or you’ll be pleasantly surprised.

Dr. Hundley is a retired orthopaedic surgeon living in Wilmington.  He is the founder and president of OrthopaedicLIST.com a resource website for orthopaedic and other surgeons and related professionals.

How to Tear Tape

by James D. Hundley, MD

You may think that this is silly, but it’s one of those “essential” techniques you don’t learn in the classroom.  Have you ever struggled to tear off a strip of adhesive tape to apply a dressing?  If you’re not in the medical profession, how about tearing duct tape?  Can you do it?

It seems like it takes three hands to hold and cut tape with scissors, and scissors are not always available or accessible.  Typically they are in the wrong pocket and you can’t easily reach them with your free hand.

I don’t know when it was in med school that a tiny little nurse embarrassed me by deftly tearing off a strip from a roll of wide adhesive tape.  I had made a mess of trying and she got a kick out of making fun of me.  Then she taught me how to do it.

It’s simple but not intuitive.  Most people will hold the tape in both hands and try to twist and tear it.  That feels like the natural way to do it, but it bunches up the tape at the top edge and makes the tear hard to start.

The “correct way” is to grasp the tape between the thumb and index fingers of both hands and then pull apart the top edge without twisting the tape.  Think of turning the palms from the palm-down into the palm-up position (i.e. supinating them) while pulling the top edge of the tape apart.  If you can’t pull hard enough without some leverage, you can roll your hands outward leveraging on the backs (dorsal aspects) of the otherwise unused long, ring, and small fingers.  Just don’t twist it.

You can do this.  It just takes a little practice.  Then you can enjoy embarrassing your co-workers and some novice medical student yourself.

Tearing apart telephone books is a different matter.  Maybe we’ll address that sometime in the future.

Dr. Hundley is a retired orthopaedic surgeon living in Wilmington.  He is the founder and president of OrthopaedicLIST.com a resource website for orthopaedic and other surgeons and related professionals.

Using a Soft Tissue Force Sensor in Total Knee Replacement Arthroplasty, Discussion and Case Report

by Scott Hadley, MD and Joseph Fetto, MD

 ABSTRACT

An 82-year old female patient with a fixed 20 degree valgus deformity of her right knee underwent total knee replacement with complete deformity correction with a non-constrained knee design. Preoperatively, the patient’s right knee range of motion was limited to 20 – 110 degrees of flexion with a 20 degree fixed valgus deformity. She was confined to minimal housebound ambulation with a walker. The pt underwent a total knee replacement under epidural anesthesia with intraoperative use of the eLIBRA™ Soft Tissue Force Sensor to assist in soft tissue balancing. No lateral soft tissue releases were needed. The valgus deformity was corrected intra-operatively and ROM achieved 10 – 120 of flexion. By 6 months post-surgery, the patient had achieved 10 – 130 degrees of right knee flexion, and complete correction of her valgus deformity.

INTRODUCTION

Total Knee Replacement (TKR) is a highly successful procedure which can reduce pain and improve range of motion and function by correcting angular deformities and restoring the integrity of articulating surfaces.1–3 TKR, however, is a misnomer as this operation does not actually “replace” the knee joint as is the case of Total Hip Replacement procedures. Rather it is more accurate to describe TKR
as a re-surfacing of the knee joint. Classically, TKR was accomplished with bony cuts which may be supplemented with soft tissue releases, prior to affixing the component parts, by either cement or non-cement techniques, to the bony surfaces. Over the past three decades, instrumentation has been developed to make the outcome of a TKR more reproducible and predictable.4 However, maximizing simultaneous restoration of range of motion (ROM) and stability has remained a significant challenge.

The knee is an inherently unstable articulation, with two large convex condylar surfaces resting on a relatively flat tibial plateau. Its stability, functionality and longevity are totally dependent upon soft tissues: ligaments, muscle-tendons and to a lesser degree the medial and lateral menisci.

In the knee there are four major ligaments (MCL, LCL,
ACL and PCL) that form the static stabilizers of the joint. Each ligament is composed of two parts, one part maximally tightens at the extreme of flexion and the other at the extreme of extention. Compromise of the structural integrity of any of these major ligaments creates significant knee instability, accelerated wear and dysfunction of the articulation. In addition to these four major ligaments, there are many minor ligaments distributed about the perimeter of the knee. As well, there are transversely directed ligaments attached to the medial and lateral aspects of the distal femur which serve to stabilize the patella within the femoral trochlear groove.

The patella is a sesamoid bone imbedded within the quadriceps mechanism. As such, its tracking is determined by the anatomic relationship between the dynamic quadricepsmuscle, the geometry of the trochlear groove and the by the patello-femoral ligaments. The pelvis is wider than the distance between the knees and as a result the normal femur and tibia are not aligned in a straight line, but rather at a 5 – 7 degree valgus angle. This orientation of the bony structures results in a laterally directed force being applied to the patella with active contraction of the quadriceps. This laterally directed force is resisted by a combination of the oblique fibers of the vastus medialis muscle (VMO) dynamically, and statically by the medial retinaculum and the medial patello-femoral ligament.

The muscle-tendon structures at the knee provide dynamic stability, over which an individual may exert some measure of control. Anteriorly, the quadriceps-patellar tendon mechanism, with its broad retinacular expansion, is responsible for active extension and resistance of flexion of the knee. Posteriorly, the medial and lateral hamstrings are well positioned to actively flex the knee, decelerate knee extension and provide some dynamic rotational stability. In addition across the postero-lateral aspect of the knee, there is an obliquely oriented, “upside-down”, popliteus muscle.
Its function is to assist in control of internal rotation of the femur on the tibia, thereby modulating rotational stresses transmitted to the weight-bearing knee through the ankle due to pronation of the subtalar joint.

With such complexity of soft tissue structures determining knee stability and function, it is obvious how important the restoration of “soft tissue balance” is to the successful outcome of a TKR procedure.2,5

There have been significant evolution and development in TKR instrumentation over the past three decades, beginning from very simplistic rectangular “cutting blocks”, which crudely served to determine the location and orientation of femoral and tibial bone resection cuts, to advances in computer assisted navigation, “customized” instrumentation and application of robotic technology designed to restore “normal anatomy”.4, 6–9 While these technological advances have the potential to more accurately guide the surgeon in the restoration of bony alignment, they do not and have not yet resolved the problem of how to accurately and reproducibly restore the soft tissue balance to the damaged knee.

Today “soft tissue balance” is assessed in a very subjective manner. After implantation of provisional components the surgeon visually inspects the ROM of the knee, the tracking of the patella and manually tests medial / lateral, posterior / anterior knee stability by applying stress in the appropriate directions with the knee in full extension, mid-range and full flexion. If not satisfied with the result achieved he / she may then choose to perform what are termed “soft tissue releases” or re-cut the bones, based on what is felt to be lacking in the reconstruction. Most commonly, dissatisfaction occurs due to poor patello-femoral tracking with knee flexion and/or limitation in ROM. Unfortunately, today’s standard of practice does not supply surgeons with any objective methodology or tool with which to measure the result achieved or improve the likelihood of achieving the outcome desired.

In an effort to address this deficiency, a new instrument has been developed which can objectively measure the relative pressures within the medial and lateral compartments before final bony cuts are performed. It is designed to equalize the compressive pressure within the compartments by the controlled application of a distracting force. In so doing this device will permit appropriate internal / external rotational orientation of the femoral component, relative to the longitudinal axis of the femur, and in so doing achieve “soft tissue balance” of the tissues, particularly those responsible for static control of patello-femoral tracking. This device (eLIBRA™ Soft Tissue Force Sensor manufactured by Synvasive, El Dorado Hills, CA) may reduce the necessity of certain soft tissue releases being performed, such as lateral patellar retinacular release.

This case study is presented to demonstrate the use of this device and the possible clinical application in an arthritic knee with a severe flexion-valgus deformity.

 CASE REPORT

N.H. is an 82 year old, slightly built white female with an atraumatic progressive painful deformity of her right knee. The patient had become limited to minimal housebound ambulation requiring a walker and/or wheelchair for independent mobility within her home. She had difficulty transferring from a sitting position and could no longer negotiate stairs without assistance. As a consequence of her growing dependence on her uppe extremities, the patient was developing bilateral carpal tunnel, ulnar nerve irritation and shoulder discomfort. Her pain was in proportion to her activities and was unresponsive to NSAID medication. She had a history of blunt trauma to the right tibia after a fall that was complicated by a brief period of cellulites, treated successfully with oral antibiotics. Otherwise, she had no history of co-morbidities related to her knee complaints.

On physical examination the patient was found to be an alert, oriented female sitting in a wheelchair in no apparent distress. However on attempting to stand and bear weight on the right lower extremity she had significant discomfort. She was able to remove her shoe and stocking from the left foot but required assistance with her right foot. The skin over the right lower extremity was intact and there was no effusion, soft tissue swelling or erythema about the right knee. The right knee was held in a flexed posture. The right knee ROM was relatively painless but limited to 20 –110 degrees of flexion with a 20 degree fixed valgus deformity. (Figures 1 & 2) There was significant crepitus within the patello-femoral and lateral compartments throughout the ROM. ROM of the left knee and both hips were painless and within normal limits. Her left foot had a mild equino-varus contracture limiting left ankle dorsiflexion to -5 degrees from neutral, due to disuse and posterior soft tissue contracture. There was tightness in the posterior calf musculature with the right foot and ankle limited to 0 degrees of dorsiflexion, 30 degrees of plantar flexion, and a fixed 10 degrees of pronation in the subtalar joint. Neurovascular supply to both feet was intact.

X-rays demonstrated a significant valgus deformity of the right knee, erosion of lateral femoral condylar bone and severe tri-compartmental osteo-arthosis. After exhausting all conservative options of treatment, the patient was indicated for right total knee replacement.

The patient underwent a TKR with epidural anesthesia, intra-operative foot pumps and minimal tourniquet utilization except during cementation of the TKR components. The eLIBRA™ Soft Tissue Force Sensor was used to determine optimal external rotation positioning of the femoral component before completion of femoral cuts. (Figure 2) Care was taken throughout the procedure to avoid placing excessive stress on the peroneal nerve. Intra-operatively the patient received a non-constrained TKR with a 9 mm polyethylene insert. The patella was re-surfaced with a 9mm thickness polyethylene component. ROM achieved intra-operatively was 10 – 120 of flexion with no valgus deformity. Post-operatively the patient’s treatment included: routine DVT prophylaxis with epidural PCA × 48 hours, 325mg. enteric coated aspirin, gentle progressive active and active-assisted ROM and weight-bearing activities as tolerance permitted.

The patient had an uneventful post-operative recuperation and was discharged to an acute rehabilitation facility for completion of her early therapy. She returned to her home at three weeks post-surgery, independent in ambulation and full weight bearing with a rolling walker. Rehabilitation continued, initially within the home, and then outside the home by 8 weeks post-surgery. Her limitations at that time were due to the mild equino-varus contracture of her contra-lateral foot and ankle. By 6 months post-TKR, the patient had achieved 10 – 130 degrees of right knee flexion, with no recurrence of her valgus deformity. (Figures 3 & 4) She was ambulatory in her neighborhood with a rolling walker and a splint on her left ankle. Within her home environment, she was able to negotiate short distances without use of a cane or walker.

 DISCUSSION

Soft tissues are extremely important for physiologic functioning of the knee joint.5Severe osteoarthrosis is often associated with deformity and compromise of normal soft tissues. TKR is a highly successful procedure for the relief of painful arthritis.1However, when attempting to restore function and correct abnormalities in ROM and alignment by TKR, it is imperative that attention be given not only to restoration of proper bony alignment, but even more importantly, to soft tissue balancing. Insufficient or incorrect soft tissue balancing may result in limitation in ROM, patellar mal-alignment, knee instability, pre-mature mechanical failure of the TKR components and pain.

Present day instrumentation for TKR offers many approaches for the correction of bony deformity: intra-medullary, extra-medullary guides, cutting blocks based on bony landmarks, computerized navigation, “customized” cutting guides fabricated based on pre-operative radiographic studies, and robotics.4,8 But none of these strategies offer a means to assure reproducible and accurate balancing of the soft tissue structures critical to optimal knee function.

The eLIBRA™ Soft Tissue Force Sensor is a newly developed instrument specifically designed to objectively address the challenge of achieving optimal ligament balancing in TKR. It may be an effective way to restore patello-femoral tracking while reducing the need for lateral release and compromise of the patellar retinaculum. This case report demonstrates the effectiveness of this tool in helping to accurately restore knee kinematics in a knee with significant fixed flexion and valgus deformities. The author has found it to be a very effective tool not only in helping surgeons to objectively assess their surgical technique but also in the training of orthopaedic surgeons to appreciate and achieve proper soft tissue balancing.

 REFERENCES

1. Insall J, Tria AJ, Scott WN. The total condylar knee prosthesis: The first 5 years. Clin Orthop Relat Res. 1979;(145)(145):68 – 77.

2. Insall JN, Binazzi R, Soudry M, Mestriner LA. Total knee arthroplasty. Clin Orthop Relat Res. 1985;(192)(192):13 – 22.

3. Sledge CB, Ewald FC. Total knee arthroplasty experience at
the robert breck brigham hospital. Clin Orthop Relat Res. 1979;(145)(145):78 – 84.

4. Laskin RS, Beksac B. Computer-assisted navigation in TKA: Where we are and where we are going. Clin Orthop Relat Res. 2006;452:127 – 131.

5. Griffin FM, Insall JN, Scuderi GR. Accuracy of soft tissue balancing in total knee arthroplasty. J Arthroplasty. 2000;15(8):970 – 973.

6. D’Lima DD, Patil S, Steklov N, Colwell CW,Jr. An ABJS best paper: Dynamic intraoperative ligament balancing for total knee arthroplasty. Clin Orthop Relat Res. 2007;463:208 – 212.

7. Picard F, Deakin AH, Clarke JV, Dillon JM, Gregori A. Using navigation intraoperative measurements narrows range of outcomes in TKA. Clin Orthop Relat Res. 2007;463:50 – 57.

8. Saragaglia D, Chaussard C, Rubens-Duval B. Navigation as a predictor of soft tissue release during 90 cases of computer-assisted total knee arthroplasty. Orthopedics. 2006;29(10 Suppl):S137 – 8.

9. Viskontas DG, Skrinskas TV, Johnson JA, King GJ, Winemaker MJ, Chess DG. Computer-assisted gap equalization in total knee arthroplasty. J Arthroplasty. 2007;22(3):334 – 342.

Optimal Bone Saw Blade Design

[Note:  This article was initially published in Medco Forum, Volume II, Number 5.  It is being republished with permission from Medco Forum.]

All surgical oscillating blades are not created equal.  There may be many similarities between blades, but the performance characteristics can be significantly different.  Orthopaedic surgeons require a reliable, effective means of making bone resections that enhance surgical control with the same feel every time.  As less-invasive reconstructive procedures evolve and biologic fixation advances, surgeons will need bone resection technology to minimize the possibility of injuring surrounding soft tissue structures as well as the living bone supporting the implants.  Synvasive Technology Inc.’s STABLECUT oscillating blade technology represents a substantial breakthrough in the science of powered bone resection.  STABLECUT is favored by reconstructive knee surgeons as a means of transforming the function of an oscillating blade from an “attachment” into a reconstructive tool, aimed at improving the surgical control of bone removal required to resurface an articulating joint.

Traditional oscillating blades have their teeth oriented on an arc, and when cutting bone, all of the teeth engage at once as the blade progresses and swings through its constantly reversing arc of motion.  This arc-shaped engagement, accentuated by the oscillating motion of the powered hand-piece, creates two primary influences that adversely affect performance.  First, as the blade direction is changed, the contact point of the teeth moves off center.  This reduces hand-piece control as the blade reacts to off-center contact, causing it to deflect right or left of the surgeon’s intended path.  Secondly, the resection path becomes matched to the arc-shaped excursion, preventing the teeth from effectively evacuating bone chips, which build up in front of the advance blade and generate friction.  This limits debris removal and increases both deflection and heat transferred to the adjacent bone tissue, increasing the potential risk cell damage and necrosis can pose to bone healing and biologic fixation.  All of these effects collectively raise the risk of collateral soft-tissue damage and inaccurate cuts.

The patented perpendicular (90 degree) teeth configuration on a STABLECUT blade establishes a centered back-and-forth sawing action within the fixed arc of powered oscillation.  It creates a stabilizing “high spot” in the center of the cut as the blade engages the bone.  This “high spot” makes the blade exceptionally stable, enabling the surgeon to achieve a higher level of precision as the controlled blade advances through a cut and around soft-tissue structures.  Debris is also ejected more efficiently, creating less friction, to enhance tissue care surrounding a resection.  Anthony K. Hedley, MD, Chairman of Orthopaedic Surgery, St. Luke’s Hospital (Phoenix, AZ), uses STABLECUT blades exclusively.  Dr. Hedley finds that “the STABLECUT blades are well designed in terms of tooth design, which provides for very precise cuts.  When a total knee replacement procedure is performed, it is important to use a straight blad that had no arc, so as to avoid loss of control when making cuts.  STABLECUT blades help avoid dimensional changes to the template bone that result in loose fitting components.  This is especially important when implanting press fit prostheses.”

Directional control and reduced temperature are important enablers of MIS total and unicompartmental knee replacement.  Stability of the saw blade greatly improves safety and precision as surgical exposures are reduced.  According to David Dalury, MD, of St. Joseph’s Hospital (Towson, MD), “I am impressed with the reproducibility and accuracy of STABLECUT.  These blades give me the confidence that I will be able to resect the template bone accurately during bone-conserving unicompartmental procedures.  The fact that you can be more precise in cuts means that you will be less likely to damage surrounding tissues – a definite enhancement in patient safety.”

STABLECUT bone resection technology is advancing reconstructive surgery today and will continue into the future as the interest in reduced-exposure reconstructions increases.  The inherent accuracy of STABLECUT technology will be particularly evident as computer-aided reconstructions grow.  STABLECUT blades maintain better directional control during the cutting process and are less likely to “kick-out” of the intended track.  The net benefit is a more accurate cut with less buildup of heat, to improve tissue care.  According to Mike Fisher, President and CEO of Synvasive Technology, Inc., “Our surgeon customers didn’t ask us to reinvent the powered oscillating hand-piece, rather to enhance the blade’s cutting performance and improve their confidence in the OR.”

Since its founding in 1990, Synvasive Technology, Inc. has steadily grown to become one of the most innovative leaders in orthopaedic resection technology.  Synvasive develops, manufactures, and distributes patented and proprietary instruments with a vision to advance and enhance the success of reconstructive procedures.  The company operates in accordance with the ISO 13485 quality management system and European medical device directive.  Synvasive’s products are marketed through a worldwide network of distributors and major orthopaedic companies, as well as a professional team of internal sales and customer service representatives.

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