264 ‒ Hip, knee, ankle, and foot: common injuries, prevention, and treatment options

KEYPOINTS

• 01

  Hip problems in younger adults often trace back to how the hip formed.

  Cohen, a Manhattan orthopedic surgeon specializing in sports medicine, explains that hip dysplasia in infants can be corrected if caught early. In adults under 50, abnormal hip shape contributes to labral tears and early arthritis; in his practice, far more women than men under 50 have had hip issues.

• 02

  Femoral-neck stress fractures are high-risk and must not be missed.

  He separates stress fractures into high- and low-risk by the consequence of mistreatment. A tension-side femoral-neck stress fracture that becomes complete can lead to a hip replacement—devastating for someone in their 20s–40s. A 28-year-old runner with new hip pain needs imaging, not reassurance.

• 03

  Hip replacement has become remarkably successful.

  Once a debilitating operation 30 years ago, it is now often outpatient, with satisfaction rates around 90–95% and low complications—which is why Cohen weighs cortisone and other temporizing measures against simply replacing a worn-out hip.

• 04

  Hip fractures in older adults are deadly, and the numbers haven't improved.

  For people 65+ who fracture a hip, one-year mortality is about 15–30% depending on the study—roughly 20–30% for decades despite faster surgery—and about half of survivors lose a level of function, such as moving from no aid to a cane. Strength around the hips and bone health are the prevention.

• 05

  PRP evidence is mixed: decent for tennis elbow, weak for hip arthritis.

  Platelet-rich plasma contains 800–1,000 plasma proteins; preparations vary, so 'dose' is undefined. Tier 1–2 evidence supports PRP for tennis elbow, but it doesn't seem to work well in hip arthritis. Saline injections also help some patients in trials, underscoring placebo effects.

• 06

  Stem cell marketing is largely inaccurate.

  A study by NYU colleagues of about 1,000 websites promoting stem cell therapy found 94% made inaccurate statements, such as guaranteed new cartilage. Cohen advises skepticism toward '100% guaranteed' claims.

• 07

  An ACL tear raises arthritis risk whether or not it's reconstructed.

  About 50% of people with an ACL tear develop significant knee arthritis within 15–20 years, and surgery doesn't seem to change that. One analysis suggested treating about 90 people to save one ACL. Any mechanical trauma to a joint raises arthritis risk; a shoulder dislocation makes shoulder arthritis 10–20 times more likely.

• 08

  Graft choice depends on age.

  Reconstruction often uses the central third of the patellar tendon (about 10 mm of a ~30 mm tendon, with bone plugs from kneecap and tibia). Under about age 34, allograft (donor) tissue has unnecessarily high re-rupture rates; for a hiker in their 40s, allograft is reasonable.

• 09

  Knee replacement satisfaction lags behind hips.

  About 85% of knee-replacement patients are satisfied—meaning 15% aren't. Recovery is nonlinear: about 80% of improvement comes by six months, with continued gains up to a year. Cohen sees patients about 10 days after surgery; many walk without a cane.

• 10

  Tendon degeneration is part of aging.

  You may not be able to do everything you did at 20–30 because tendon degeneration is a biological process affecting everyone; cortisone can harm tendons, and Cohen has seen problems after a single dose.

• 11

  Save the meniscus when you can; sham-surgery studies don't apply to everyone.

  The meniscus spreads force across the knee, so losing it accelerates arthritis—especially in knock-kneed or bow-legged people who already overload one compartment. Peripheral tears with good blood supply can be sewn back; bucket-handle tears can flip into the joint. Cohen says the sham-surgery trials showing no benefit studied degenerative tears in arthritic knees; a young person with a repairable tear and no arthritis should strongly consider fixing it.

• 12

  Arthritis often 'flips' from silent to painful after a minor event.

  Cartilage wears away slowly as a low burn; then a stumble, a twist while lifting or a small further meniscus tear tips the joint into a painful, inflamed state. That's why patients often blame a trivial event for long-developing disease.