Dustin Pedroia Update, 10/25/17 – Microfracture, Most Likely, for Miniature Midfielder

It has been known for several weeks now that the Red Sox’ second baseman has been wrestling with his options for his painful left knee. With the announcement today that Pedroia had undergone a “cartilage restoration” procedure on his knee yesterday, the logical question is – what does this mean for Pedroia in 2018 and moving forward? 

Image courtesy of edraft.com

As has been detailed in a previous post here, http://chrisgearyortho.com/2017/10/11/pedroias-patellofemoral-pain-potentially-problematic-possibly-permanent/, the Sox’ second baseman had been considering non-surgical and surgical options for his painful left knee, which had undergone previous knee arthroscopy but had continued to cause him issues throughout the 2017 season. The downside of another surgical procedure on the knee was the long rehab, with a good portion of his 2018 season likely being sacrificed to rehabilitation for his knee and getting back into playing shape. The drawback of not going under the knife was the specter of another season of on-and-off knee pain, with additional trips to the disabled list likely if not definite. With this in mind, Pedroia yesterday elected for a “cartilage restoration” procedure at the Hospital for Special Surgery in New York City.

If this story sounds painfully familiar to Sox fans, it should- it is the same type of surgery that Steven Wright underwent earlier this year, at the same hospital. While it has not been announced exactly what kind of surgery Pedroia underwent – “cartilage restoration” is a broader category of surgeries which includes multiple different potential techniques- he most likely had a microfracture to address his cartilage injury. In this procedure, multiple holes are poked in the exposed bone of the knee joint in an effort to stimulate new cartilage growth and thereby remove the source of pain.

Arthroscopic image of a microfracture of the femoral condyle of the knee (image courtesy of mayoclinic.org)
This is a well-established procedure with a proven track record for returning players to action – depending on the study you read, between 75-90% of patients have good results with this surgery. There are several examples of players in MLB who have had the procedure and returned to play – in the last few years, examples include Carlos Beltran (2010), Victor Martinez (2012), and Brad Ziegler (2014). There are also cautionary tales such as Grady Sizemore (2013), who had the surgery but never fully recovered to being the player he was before. It’s also possible that Pedroia underwent a different type of cartilage surgery – possibly the insertion of a plug of cadaver (allograft) bone and cartilage (OATS procedure). This is different from a technical standpoint but has the same goal (the growth of new cartilage) and largely the same recovery. 

The downside of the procedure is the long and arduous rehab – Pedroia will be fully non weight-bearing with crutches for up to two months, and will be in a continuous passive motion (CPM) device for 4-6 hours a day during that time. The CPM will bend his knee for him, with the goal of more successful cartilage growth. Following this will be a gradual return to weight-bearing, strengthening and eventually full activities.  The Sox have announced a goal of seven months for Pedroia to return to full baseball activities, a timeline which would potentially have him back at Fenway by mid-May. The caveat to this projection is that every rehab is different, and depending on the particular area of the knee affected -the patella (kneecap) and femur are the most common areas to undergo this type of surgery- the timeline may vary. It’s also important to not be too quick to compare Pedroia to Steven Wright, as the demands of playing second base (especially the way Pedroia plays it), batting, and running the bases are substantially different from throwing a knuckleball. That being said, the odds are in Pedroia’s favor that following his long rehab, he will be able to return with a knee which should allow him to stay on the field more reliably than in 2017.

Red Sox Post-Op Analysis, Wednesday October 18

Full disclosure – I (obviously) did not perform either of the Red Sox’ surgeries yesterday. However, I did perform several orthopedic surgeries today and I have stayed at a Holiday Inn Express in the past, so let’s do this…

Two prominent members of the Red Sox had surgery yesterday, both performed by Dr. James Andrews in Pensacola, Florida. Let’s tackle the “easier” of the two first – Hanley Ramirez’ left shoulder surgery. The Sox’ DH/occasional first baseman underwent a left shoulder arthroscopic debridement – in simpler terms, a “cleanup”. Ramirez has dealt with shoulder issues in the past, including in 2015 when he ran into the left field wall at Fenway, and his shoulder issues caused the Sox to be hesitant to use him at first base on a regular basis this year. Despite being used sparingly in the field, it seemed that Ramirez’ shoulder woes may have sapped him of his usual power, given that he finished the season with only 62 RBI and an OPS of .750, both well below his career averages. With an eye towards restoring some of his lost slugging capabilities for next season, the DH went under the knife for a shoulder arthroscopy and debridement. The idea of this surgery is that if Dr. Andrews was able to clean up some loose cartilage or inflamed bursal tissue Ramirez’ shoulder might feel more comfortable and allow him to be more productive at the plate. With nothing being repaired, recovery should be quick, with a sling for only a few days for comfort and a return to full activities in a month or so. Whether or not Ramirez benefits from the procedure is yet to be determined, but the potential downside was so minimal it was likely worth a shot.

Sox starting pitcher Eduardo Rodriguez also had surgery with Dr. Andrews yesterday, in his case on his right knee. Rodriguez had several patellar subluxations (partial dislocations, where the kneecap slides to the side but does not come out all the way) of his right knee over the last year, which caused him to miss significant chunks of time over the last year and contributed to the lefty’s disappointing 2017 season. Patellar subluxations or dislocations are a source of significant pain and can cause athletes or patients to not trust their knee. Once someone has had a dislocation or subluxation of their patella, they inevitably stretch or tear their medial patellofemoral ligament (MPFL), one of the ligaments on the inside of the knee responsible for stabilizing the kneecap through its range of motion. In a way, it is like the ACL of the kneecap – important for stability but somewhat easy to injure.

Also similar to the ACL, once the MPFL has been torn or stretched the ligament has little inherent healing capacity, so recurrent instability can be a problem. Most patients with this condition can manage it without surgery, through physical therapy exercises and activity modification. Rodriguez obviously did not fall into this category, as his recurrent patellar subluxations caused his need for surgery.

There are several different techniques for this particular surgery, but the basic idea is to make a new medial patellofemoral ligament (MPFL) out of either the patient’s own tendons, typically the hamstrings, or a cadaver tendon (an allograft).

Diagram of MPFL Reconstruction

The new ligament is attached to the patella and femur by means of screws or anchors, and usually a knee arthroscopy is performed at the same time to address any cartilage issues. Post-operatively the patient is usually on crutches and in a brace for 6-8 weeks, with physical therapy at first focusing on range of motion, followed by strengthening at around three months and cutting/jumping sports between 6-8 months. The Red Sox have announced that Rodriguez is expected to resume pitching in about six months, which is consistent with this timeframe.  I would anticipate this would mean he would begin pitching in six months, but would have to gradually increase his arm strength and pitching activities, so it might be closer to 8-9 months before he is back to the big leagues, so a return to the Sox after the all-star break might be more realistic.

In terms of results, the odds are in Rodriguez’ favor for a full return with a stable knee. A recent meta-analysis (a group of studies whose results are pooled together) looking at results of MPFL reconstruction surgeries from the American Journal of Sports Medicine showed very favorable results, with 84.1 percent of patients returning to their sports and with recurrent instability being very low, at 1.2 percent. It is safe to say that while Rodriguez’ recovery may be long, his results should be predictable and reliable, while Ramirez will have a quick recovery but potentially less durable results.

Pedroia’s Patellofemoral Pain – Potentially Problematic, Possibly Permanent

After a season marred by struggles with knee pain which resulted in two stints on the disabled list, there is one lingering question – is there a feasible surgical remedy and if so, is it worth it?

One of Dustin Pedroia’s hallmark characteristics has always been his toughness – his willingness, sometimes insistence, on playing through injuries is one of the things that has endeared him to Sox fans and allowed him to be a productive player throughout his career. This is a player, after all, who once took ground balls on his knees while recovering from a foot injury and played an entire season with a torn ligament in his thumb. His left knee, however, may prove to be a problem that even Pedroia can’t out-tough. Last offseason he had an arthroscopic “cleanout” of his painful knee – despite that he still spent time on the disabled list twice and by the end of the season he was clearly not moving well on the leg and seemed to lack the ability to drive the ball at the plate. At the end of the season he alluded to the possibility of additional surgery on the knee but seemed unsure of the best plan of action, referring to the  “long recovery” surgery would entail.

Given what we know about Pedroia’s knee (his previous surgery, his persistent issues with the knee this year) and what we can read between the lines from his comments about the potential for an extended recovery from any additional surgery, what can we infer as to the status of his knee? My best estimate is that he has some early arthritic changes of the knee – rough spots of cartilage that were the target of his arthroscopic cleanout last year, likely in the patellofemoral part of the knee (under the kneecap). The goal of this type of procedure, a chondroplasty, is to remove any loose edges of cartilage which might be causing symptoms. However, it does not replace any lost or worn cartilage, it merely smooths the edges of whatever is damaged.  The advantage of a procedure such as this is that it is a quick recovery- typically only a couple days on crutches with no running for a month or so.  Pedroia could have easily had a procedure such as this in the offseason and been back in plenty of time for spring training.

Area of abnormal femoral cartilage (blue circle in first picture) undergoing arthroscopic chondroplasty with shaver (green dot in second picture) 

The downside of a chondroplasty is that it doesn’t address the root of the problem, the loss/wear of the surface cartilage, so while it frequently gives at least temporary relief, the symptoms will usually return sooner or later.  If Pedroia was older or less active, he might be a candidate for some sort of knee replacement, either partial or total.  Knee replacement surgery is an excellent procedure for relieving pain, but it’s not compatible with high-level athletic activity.  What, then, are the surgical options for a young, active patient like Pedroia?

Younger patients with cartilage injuries may be candidates for cartilage restoration procedures such as microfracture (poking holes in the bone to stimulate new cartilage growth), OATS (osteochondral allograft transfer surgery, where bone and cartilage is taken from one part of the knee or a cadaver knee and transferred to the abnormal area of cartilage) or ACI (autologous chondrocyte implantation, where a small amount of normal cartilage from the knee is harvested surgically, grown in a lab, and reimplanted in the knee at a later date).

Microfracture, showing holes being poked in bone to stimulate new cartilage growth

OATS procedure, showing two cartilage/bone plugs implanted into knee

The obvious advantage of these procedures over a chondroplasty, or “cleanout”, is that the root of the problem is being addressed- new cartilage is being grown or transferred to the area of cartilage loss. The downsides, especially when it comes to an athlete like Pedroia, are the extended rehabilitation (4-6 weeks on crutches, no running for 3-6 months, no sports activity for 6-12 months depending on the specific procedure) and the lack of guaranteed success. While the odds are good, there are certainly patients who don’t do well or get back to their previous level of activity- one recent example from baseball was Grady Sizemore, who had microfracture on his knees prior to signing with the Red Sox and while he did make it back to MLB, was never quite the same player.

So where does this leave the protagonist of this tale, the Red Sox diminutive second baseman? As a 34-year-old with four years left on a contract that will pay him an average of 14 million dollars a year, the Red Sox would certainly hope for more productivity and less time on the DL from him moving forward. Having a cartilage restoration procedure might extend his career longevity, but would certainly require him to miss a significant amount of time in the near future. Even if Pedroia were to have surgery in the next few weeks, he would almost definitely miss a significant portion of next season, if not the whole year. Pedroia may decide that the potential upside of having the surgery does not outweigh the definitive downside of missing a substantial chunk of one his last seasons of professional baseball.  That would leave him in his current situation, with a less-than-perfect knee which might be manageable but is likely to flare up at times over the next few seasons.  At the end of the day, there is certainly no perfect solution for Pedroia and the Sox – how they handle it will certainly bear watching in the off-season and in upcoming years.