Doctor's Review: Medicine on the Move

October 26, 2021


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Cross currents in osteoarthritis

The case of the knee that predicted rain

William, a 53-year-old anesthetist, presented at a physiatry clinic for worsening chronic left knee pain over the past five years, with occasional buckling, swelling and stiffness. Pain was typically worse with weight-bearing activities. He joked that he could predict rain, since barometric changes caused throbbing pain that would even awaken him at night.


Physical examination revealed a male of healthy weight, normal vitals, no systemic signs of gout or of seronegative arthritides. He had no hypermobile joints, but had findings of 1+ laxity in the right sacroiliac joint, with mild restriction in the right hip internal rotation due to a previous acetabular fracture in a motor vehicle accident. Standing alignment revealed moderate genu varum with left knee mild effusion (bulge sign), positive Lachman’s and pivot shift tests, and 1+ laxity on anterior drawer testing. McMurray’s test was painful on loading the left lateral compartment. Stressing the collateral ligaments showed no laxity; patellofemoral inhibition tests were negative, and no extension lag was noted. Hamstrings were much tighter on the affected side, with visible atrophy of the left thigh, especially the vastus medialis. The foot showed moderate hyperpronation on weightbearing, with preserved longitudinal arches on tiptoeing, but shoe wear wasn’t grossly uneven. Neurologic exam was otherwise normal. Gait assessment revealed reduced left knee extension on heel strike, with more difficulty going down stairs. No walking aids or braces were used.

X-rays revealed grade 1–2 osteoarthritis (OA) with lateral joint space narrowing and spurring of the tibial prominences. Ultrasound study revealed a small effusion without Baker’s cyst or ligament tears.


Significant medical history included a partial tear of the left anterior cruciate ligament (ACL) from ball hockey 30 years earlier, aggravated by playing touch football 15 years ago, when the knee swelled up considerably. Subsequent surgery revealed a completely torn, retracted ACL, with loss of the lateral compartment cartilage. An abrasion arthroplasty was carried out, but ACL repair wasn’t recommended due to chronicity and degeneration.

William’s postoperative rehabilitation was long and included physiotherapy with ultrasound, interferential current therapy and aquatic exercise. Despite this, he still had pain, feelings of instability and swelling. Oral nonsteroidal anti-inflammatory drugs (NSAIDs) were not an option, due to a history of peptic ulcer disease, so he tried topical diclofenac solution and gel. William also took supplements of omega 3-6-9 fatty acids and glucosamine sulfate (500 mg TID), which he found difficult to take consistently and eventually stopped due to lack of efficacy. He wore a knee brace for prolonged upright activities, and customized foot orthotics for hyperpronated feet.

In 2011, symptoms worsened after a fall, with fracture dislocation of the contralateral right ankle requiring urgent open reduction and internal fixation. Postoperative pain medications included oxycodone/acetaminophen, codeine/acetaminophen and pregabalin. During the postsurgical period, increased weightbearing on the left leg worsened left knee pain, for which he took duloxetine briefly.


William hoped he could return to his active lifestyle without relying on medications, so his doctor suggested a trial of N-acetyl glucosamine (NAG) 2 g daily, combined with supervised graduated exercise. After one month, he reported significant pain relief. He continued with 1 g NAG daily, optimal nutrition (avoiding sugar and refined carbs) and further rehabilitation. For activity-related flare-ups, he took devil’s claw herbal supplements and used a topical compounded dimethyl sulfoxide (DMSO) gel. One year later, he was able to participate in a 30-minute charity run and won 2nd place for his age category. The following year, he completed a 5k run in 36 minutes. Prior to these runs, he underwent platelet-rich plasma injections to his left knee. He continues taking NAG about 3 times/week with his workouts, which include kickboxing and floorball. Best of all, William reports, he can’t predict rain anymore.

Before and after stats

Pretreatment ratings: NRS (numeric rating scale) for pain, 6/10 (range 3–8/10); KOOS (Knee disability and Osteoarthritis Outcome Score), 105/ 168; WOMAC (Western Ontario and McMaster Universities Arthritis Index) subscales for pain, 9/20, stiffness, 3/8, and function difficulty, 25/68; and Lequesne index for knee OA, 14/25.

Posttreatment ratings: NRS pain, 1/10 (range 0–3/10); KOOS, 23/ 168; WOMAC pain, 1/20, stiffness, 0/8, function difficulty, 3/68; and Lequesne index, 4/25.

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Showing 1 comments

  1. On October 15, 2016, Ian Maxwell said:
    A single case study, what's the point?

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