Marcin returned from the US Open just one day before surgery, essentially moving right into the fasting period required before most surgical procedures. It was definitely time to get it done – he had been taking 75mg of diclofenac 2x/day to control increasing inflammation for several weeks. As his operation was not scheduled until 3:30pm the following afternoon, in his words he was “quite cranky” by the time his number was called. Just prior to surgery he confirmed a follow up interview when he returned home the next day.
He described his experience, ”After an epidural and a nerve-blocking shot to the knee, it was 10, 9, 8…. and lights out . About an hour after waking up in PostOp, the nerve block wore off…”.
According to American Academy of Orthopedic Surgeons, most people who undergo a knee replacement are between the ages of 50 and 80, with the average age around 70. As we age, our peripheral nervous system becomes less sensitive; while we are keenly aware of chronic (persistent) pain and thermal fluctuation, our sensitivity to acute pain (essentially ‘incident’ driven) lessens over time [1,2]. Marcin, at 42, is quite young for this type of joint replacement and his immediate post-op phase was less than comfortable, as his pain management was difficult to nail down.
In the days immediately following surgery, Marcin’s physician felt he would benefit from a Continuous Passive Motion machine (CPM) to assist in improving his range-of-motion (ROM). Marcin started using that two-three hours each day. He had post-op, in-home PT provided by Desert Orthopedic for his first days at home; but his first session with his personal PT, Noé Sariban (Physical Therapy Doctorate) and aka @thepickleballdoctor at Shelley A. Cooper Physical Therapy was just one week following surgery. The sessions were planned for 3x/week, focusing on standard recovery at first, then ramping later to address the higher functional level needed for Marcin’s goals. Marcin was anxious going in as his first in-home sessions hadn’t loosened up his long-impacted musculature and connective tissue. And it hurt. A lot. Along with the assessment that Marcin’s younger nervous system was more sensitive and he had stiffened up after years of extremely limited ROM, we also concluded he had an even lower threshold of pain.
Marcin was very pleased after his first session with Noé – concurrent with that first week of PT with him, Marcin started to taper his pain medication as it had several undesirable side effects. He was also looking forward to resuming his role as Athletic Director at The Lakes Country Club Palm Desert. We’ll cover that and his final ramp into training later.
Desert Othopedics with Eisenhower Health has been fitting Conformis, Inc implants with a 95% success rate – greater than the norm resulting in reduced revision surgeries. I booked a meeting with them after attending the Atlanta Open.
When visiting the Conformis R&D, Manufacturing, and head offices in Boston I was struck with the difference to many innovative medical equipment firms I’d visited in former roles in Europe, Asia and the US. It felt like a Silicon Valley tech firm – vibrant, proud of the talent behind their advanced technology and how it is helping change lives.
Founded in 2004 with first products to market by 2007, Conformis’ roots are actually in imaging software. In this case, a solution actually found a real problem to solve. Their products are approved for use on 3 continents, with hundreds of surgeons specifying regularly. While their value proposition is straight forward and quite logical, they are unique in what they are doing. In a typical off-the-shelf knee replacement, the surgeon has to select an implant from a limited range of standard sizes. Because these implants aren’t designed to your specific anatomy, surgeons often have to compromise on implant fit, rotation, and alignment. This is where Conformis comes in.
Image is everything
After showing me replicas of several patient’s personal implants, Beth Best, VP Corporate Communications for Conformis, introduced me to Elliot (MSc. Engineering Management, BS Bioengineering) and Devin (BS Biomedical Engineering), both members of the CAD team responsible for patient imaging intake, modeling, and implant design. To demonstrate the process, they started by bringing up a CT scan of a patient’s knee. CAMERA OFF, please… crap.
The process to ‘restore’, then translate the image of the joint to the files necessary to create the elements of the implant and the instrumentation needed to install is where Conformis’ secret sauce applies; with over 500 patents I was fortunate to get a look under the hood to see how the curves of Marcin’s restored knee were fine-grain mapped to high-res files to be used for 3D printing and computer-driven machining (CNC). Within that CT-derived model, the bumps that have developed over time due to damage, called osteophytes, were removed – leaving a 3D model of his original joint as it was in his early 20’s, essentially restoring his ‘forgotten knee’. That model is then used to create files for 3d printing, casting or machining of each component; femoral implant of cobalt-chromium alloy which duplicate the condyles with J-curves very specific to the knee’s original shape, the tibial tray where the replacement meniscus, a polyethylene insert, is fixed, and instrumentation for a precision fit of the new elements to the remaining bone structure.
The importance of this design is made clear when you realize the load on the condyles, primarily the medial, is >4x body weight during a strenuous move ! In addition, the joint isn’t a rigid hinge; there is ~5° rotation in either direction necessary for proper functionality. With this implant’s design, as well as the custom, single-use tools created for this ONE installation, the surgeon doesn’t need to do the usual end-of-operation ‘tinkering’ normally needed to enable that rotation.
Size, and shape, matters
Conventional implants are offered only in 11 or fewer sizes ‘off-the-shelf’, the odds that you are exactly size N is unlikely. This means you must move up or down to the next size, which statistically means most patients will have, at minimum, some overhang. Overhang is one of leading causes of pain, irritating surrounding soft tissue; this personalized design yields as close to an exact replacement as is possible. And – if you think the design of this is cool – wait until you see how it’s manufactured and installed! More to come.
Hallmarks of a successful professional athlete are relentless drive, an impatience to improve and an expectation to excel. During the first few weeks a patient can essentially feel helpless, or at minimum, not in control, waiting for the next PT session and to make some real progress. It’s critical to rally a support group to get through this period; Carley, the Rozpedski children and Marcin’s mother, close friends and well-wishing players in the athletic community helped keep Marcin motivated during those difficult weeks.
A teaser for the next chapter – at 2 weeks Marcin exuberantly stated he was able to walk with much better balance and strength, “I was able to vacuum yesterday!”. There is no photographic evidence to support this claim. (spoiler alert) However, there is video evidence that Marcin is back at it: sports after total knee replacement! He’s on the court training for ToC where he’ll team up with Daniel Moore and Christine McGrath, and the Las Vegas Pickleball Open, pairing with Aspen Kern and Corrine Carr Siebenschein.
1. Robert P. Yezierski , Comprehensive Center for Pain Research, University of Florida, THE EFFECTS OF AGE ON PAIN SENSITIVITY: PRE-CLINICAL STUDIES Pain Med. 2012 April ; 13(Suppl 2): S27–S36. doi:10.1111/j.1526-4637.2011.01311.x
2. Wickremaratchi MM, Llewelyn JG. Effects of ageing on touch. Postgraduate Medical Journal. 2006;82(967):301-304. doi:10.1136/pgmj.2005.039651.
2. Darryl D. D’Lima1, Benjamin J. Fregly2, Shantanu Patil1, Nikolai Steklov1, and Clifford W. Colwell Jr Knee joint forces: prediction, measurement, and significance Proc Inst Mech Eng H . 2012 February ; 226(2): 95–102