Recently the Boston Celtics drafted Robert Williams with the 27th pick of the 2018 NBA Draft out of Texas A&M. A 6’9” center, Williams has not had the best introduction as part of the Celtics organization. Initially he overslept causing him to miss an introductory conference call. Then he missed his flight, and had to skip his first Summer League practice with the Celtics. Unfortunately, things have not gotten much better for Williams once he started playing in the NBA summer league games.
Williams sustained a left knee injury in the first half of the Celtics win over the 76ers, where he scored four points and grabbed a pair of rebounds before banging knees with a 76ers player. The initial diagnosis was a left knee bruise/contusion, which could’ve definitely explained his discomfort and continued time off the court. Sometimes bone bruises can be very painful, especially in the knee area, just ask NFL quarterback Sam Bradford.
Then last night, MassLive broke a story stating that Williams reportedly has an artery condition in both of his legs, a condition known as Popliteal Artery Entrapment Syndrome (PAES). Apparently NBA teams interested in Williams were aware of this condition at the time of the draft, including the Celtics, as was Texas A&M, where Williams played his college ball. The L.A. Clippers’ doctors, who performed Williams’ pre-draft physical, reportedly disseminated the results to the other organizations (a common practice) after discovering this condition. Obviously this did not deter the Celtics from drafting Williams, which should give you an idea of how significant of a concern of this condition presents.
So what is Popliteal Artery Entrapment Syndrome? As a sports medicine doctor I see all types of unique variants of the normal human anatomy, and PAES is one that I have read about but not personally seen in my practice – yet. This condition is probably misdiagnosed, as the complaints are often very vague, sometimes described as cramping, numbness, tiredness, and calf pain during exercise (this is called intermittent claudication).
In PAES, symptoms typically go away after about 3 to 5 minutes of rest, and if they do not then there are other conditions that need to be taken into consideration. PAES occurs because of an abnormal configuration of the muscles and tendons behind the knee, which when engorged with blood compress a vital blood vessel that delivers blood to the lower legs – the popliteal artery. This is basically the main artery that runs through and behind the back of the knee. Compression of this artery restricts blood flow to the lower leg, resulting in poor cell nutrition and slow development of symptoms.
So how do you get PAES? There are basically two options; either you’re born with it or you develop it. If you were born with it, this is secondary to large calf muscles (gastrocnemius or popliteus muscle). The condition can also develop over time, secondary to exercise and training, which in turn causes hypertrophy of the calf muscles, thereby compressing the popliteal artery.
Who is at risk for PAES? This condition most commonly occurs in male athletes under the age of 30 – Williams is 20. Certain sports increase the likelihood of developing the condition, including soccer, football, rugby, and runners. Reportedly less than 3% of people who are born with the muscle variant/defect that can lead to PAES develop the symptoms, consider it a case of bad luck for Williams.
How is this condition diagnosed? This is not something your typical family medicine doctor or orthopedic surgeon will usually diagnose. While many of them will be aware of the condition, typically the patient is referred to a sports medicine specialist or vascular surgeon for a complete work-up. Evaluation begins with checking the pulses of the foot and popliteal artery, first at rest. Certain diagnostic tests can be used to diagnose the condition including an ankle brachial index (ABI) with and without exercise – this test basically measures the blood pressure in the arms and legs before and after exercise. Another options include Duplex Ultrasound, Computed Tomographic Angiography (CTA), or Magnetic Resonance Angiography (MRA). Each of these options uses a form of imaging to evaluate the arteries and sometimes even the muscle and tendons as well.
Once diagnosed, what are the treatment options? The most common treatment is careful observation, along with modifications to lifestyle and exercise. Surgery can also be done to correct the problem, where the muscles and tendons are surgically released to alleviate the compression of the popliteal artery.
In Williams’ case, I completely expect the Boston Celtics medical staff to carefully observe him with serially monitored ABI’s of his lower extremities. If this issue continues to bother Williams, especially in the event of a situation where he has to play on back-to-back nights, surgery may be the best option. Surgery for this is typically pretty straightforward and often involves a quick hospital stay. A normal follow-up protocol includes serial ultrasounds of the repaired artery as well as lower extremity blood pressure checks at 4 weeks, 8 weeks and 1 year.
In review, new Boston Celtics draft pick Robert Williams was diagnosed with a condition called popliteal artery entrapment syndrome, which causes an aching, numb and tired pain in the calves after exercise and resolves with rest. The expectation is that Williams will be monitored closely, and his exercise schedule will be adjusted accordingly.