Peter Attia MD264 ‒ Hip, knee, ankle, and foot: common injuries, prevention, and treatment options
CHAPTERS
- 0:00 – 9:52
Hip Anatomy, Developmental Dysplasia, and What Arthritis Is
Adam Cohen describes the ball-and-socket anatomy of the hip and how developmental dysplasia leads to a shallow socket, edge loading and later arthritis. Peter Attia shares his son's experience with a Pavlik harness, and the two discuss ultrasound screening and the biology of cartilage and chondrocytes.
- •The hip is a deep, concentric ball-and-socket joint that is more stable than the shoulder
- •If the ball is not seated in the socket early in life, the acetabulum forms shallow and edge-loads
- •Cohen says people with dysplastic hips will get arthritis, though not necessarily symptomatic arthritis
- •Ultrasound is increasingly used to avoid missing dysplastic hips
- •Cartilage is smoother than ice on ice and avascular, and its chondrocytes can die or become senescent under overload
- 9:52 – 18:49
Diagnosing Hip Pain Under 50 and Femoral Neck Stress Fractures
Cohen explains how he thinks through hip pain by tissue layer and location, then focuses on stress fractures in endurance athletes. They cover the compression versus tension side distinction, MRI diagnosis, avascular necrosis risk, and treatment with rest or pinning.
- •Hip pain is assessed from deep to superficial layers, including referred pain from the back
- •Femoral neck stress fractures present as groin pain that depends on weight bearing
- •MRI is the gold standard, and a stress reaction is a pre-stress fracture
- •A complete fracture can cut off blood supply to the femoral head and cause avascular necrosis
- •Compression-side fractures are treated with crutches and rest, while tension-side fractures often get three pins
- 18:49 – 25:26
Sex Differences, Femoroacetabular Impingement, and Labrum Function
Attia asks about differences between men and women in hip injuries. Cohen describes femoroacetabular impingement with a cam lesion, its link to growth plate closure and high-stress sports, and the role of the labrum and round ligament in stability.
- •Ligamentous laxity and dysplasia are more prevalent in women, while FAI is more common in men
- •A cam bump at the head-neck junction pinches the labrum and cartilage and raises arthritis risk
- •Cohen says the prevailing theory ties it to delayed growth plate closure from repetitive stress in sports like hockey, football and basketball
- •The labrum helps seal the ball with a suction effect, and matters more when the hip is malformed
- •The ligamentum teres is a secondary restraint that should be left alone in unstable hips
- 25:26 – 28:03
Hip Replacement Procedure and Why Recovery Improved
Cohen explains the components of a total hip replacement and why recovery is now so much easier, pointing to anterior approaches that spare muscle and better perioperative management. Attia notes the polyethylene liner is the same material used decades ago.
- •The neck is removed, a metal stem goes into the femur, and a metal cup with a plastic liner goes into the socket
- •Older posterior approaches cut through the gluteal muscles, while anterior approaches spare muscle and ligaments
- •Medications to reduce blood loss and better medical management have made surgery safer
- •Resurfacing preserves bone in young patients but is done less often now, according to Cohen
- 28:03 – 37:15
Gluteal Tendon Problems in Older Adults and Strengthening for Prevention
Cohen describes tears of the gluteus medius and minimus as the rotator cuff of the hip and explains why they degenerate with age. He and Attia discuss strengthening the abductors, hip flexors and adductors, including eccentric training, as prevention for hip and knee injuries.
- •Glute medius and minimus tendons degenerate with age through cellular senescence and are painful and slow to heal
- •Cohen would pick the abductors as the one muscle group to strengthen starting in the early teens
- •A South Korean study found smaller psoas volume in elderly patients with femoral neck fractures
- •Hip flexors are often tight from sitting, and flexibility imbalances affect the glutes and hamstrings
- •Attia describes eccentric adductor training such as DNS Star as high-value maintenance
- 37:15 – 42:28
Hip Fractures in the Elderly and High One-Year Mortality
Attia raises the 15 to 30% one-year mortality after hip fracture in people over 65. Cohen explains why, covering underlying disease, the need for surgery, the team approach to optimization, and the loss of function many patients suffer.
- •Everyone with a hip fracture needs surgery, since non-operative treatment would be essentially a death sentence
- •Many deaths follow another serious illness, with the fracture as the last straw
- •A team approach with geriatric specialists optimizes patients within about 48 hours and allows earlier discharge
- •Mortality has stayed around 20% for decades, and about 50% of survivors lose a level of function
- •Cohen shares an anecdote about a 40-year-old patient told he had a 30% chance of dying
- 42:28 – 56:16
Biologics, PRP and the Reality of Stem Cell Therapies
Attia asks where stem cells fit in. Cohen explains PRP, bone marrow concentrate and fat, why the products called stem cells are not, FDA limits on manipulation, and where the evidence is strongest. They discuss why trials are hard and the registry effort to improve data.
- •PRP is made by spinning blood, and Cohen says it works well for tennis elbow and gluteus medius tears among tendons, with the best data in knee arthritis
- •Cohen says there is no true stem cell therapy for these uses, and FDA rules restrict anything beyond minimal manipulation
- •Biologics appear to be symptom-modifying rather than proven to regrow tissue
- •PRP trials suffer from unknown platelet concentration and quality, and a biologic registry aims to improve data
- •One NYU study found 94% of 1,000 stem cell websites made inaccurate statements
- 56:16 – 1:00:41
PRP Versus Cortisone and the Role of Cortisone in the Hip
The discussion compares PRP, hyaluronic acid and cortisone for knee arthritis over time. Cohen then answers Attia's question on cortisone in the hip, saying he prefers hip replacement in appropriate patients and noting an infection risk with injections shortly before surgery.
- •Cortisone works quickly but doesn't last, while PRP and hyaluronic acid look better over a year
- •The combination of hyaluronic acid and PRP appeared more effective in one well-done study
- •Whether PRP delays knee replacement is still unknown
- •Cohen doesn't love cortisone in the hip because of cartilage concerns, and favors replacement given 90 to 95% satisfaction
- •An injection right before hip replacement increases infection risk
- 1:00:41 – 1:09:19
Knee Anatomy and Forces Through the Joint
Cohen walks through the knee's anatomy, including the patella, cruciate and collateral ligaments, and menisci. They discuss forces such as seven times body weight behind the kneecap in a squat, whether running is bad for knees, and why alignment from hip to ankle matters.
- •The knee is inherently less stable than the hip, with cruciate and collateral ligaments and two menisci
- •The menisci distribute about 30% of knee load, and losing one causes rapid cartilage degeneration
- •Pressure behind the kneecap is about seven times greater in a regular squat
- •Inactivity is worst for cartilage, and chondrocytes respond to load, giving an inverted U-shaped curve
- •Good mechanical alignment, a line from hip center to ankle center through the knee, is protective
- 1:09:19 – 1:14:08
Arthritis Risk After ACL Tear and Inflammatypes
Cohen explains that after an ACL tear about half of people show arthritis signs in 15 to 20 years, regardless of reconstruction. He shares his own history of living without an ACL, and describes patients who stay chronically inflamed.
- •Loads through the cartilage change after ACL injury and don't fully normalize after reconstruction
- •About half of ACL-tear patients have signs of arthritis in 15 to 20 years, though not always symptomatic
- •Reconstruction is done to protect the meniscus and allow sports, and RCTs on it can't be done
- •Cohen went from age 15 to 30 without an ACL and has no arthritis, with straight alignment
- •A subset called inflammatypes show persistently elevated IL-1 and IL-6 in synovial fluid
- 1:14:08 – 1:25:31
How ACL Injuries Happen and How They Are Reconstructed
The conversation covers the mechanics of non-contact ACL injuries, higher risk in females, and the limited effect of prevention programs. Cohen then explains timing of surgery and graft choices including patellar tendon, hamstring, quad and allograft.
- •Most ACL injuries are non-contact, and females more often land in valgus with weak glutes
- •Prevention programs show a number needed to treat of about 90 to save one ACL
- •Cohen prefers to operate when the knee is quiet and likes prehab first
- •Patellar tendon autograft is still his gold standard but causes kneeling pain, so hamstring may suit gardeners or yoga practitioners
- •Allograft is reasonable for less active patients in their 40s but has higher re-rupture risk in those under 34
- 1:25:31 – 1:38:15
Defining Knee Arthritis and Meniscus Tear Management
Cohen distinguishes radiographic from symptomatic arthritis and describes it as a whole-joint disease. They then discuss types of meniscus tears, when to repair or trim, and why sham-surgery studies apply mostly to degenerative knees.
- •X-ray cartilage loss correlates poorly with symptoms, and arthritis involves synovium and bone too
- •A minor trauma can tip a long smoldering process into painful arthritis
- •Peripheral and bucket-handle tears are repaired, while some radial tears are trimmed
- •In patients with arthritis and a tear, Cohen often does nothing at first, but a young person with a repairable tear should have it fixed
- •Patellofemoral pain is distinguished from meniscal pain on exam and treated with PT, hip strengthening and sometimes blood flow restriction
- 1:38:15 – 1:49:41
Total Knee Replacement: Indications, Procedure, and Recovery
Cohen describes when knee replacement is considered, the role of body weight, the components and surgical details, and the year-long recovery. They also cover activity after hip and knee replacement and the role of alignment and navigation.
- •Replacement is discussed for advanced multi-compartment arthritis after failed conservative treatment, with the patient deciding when
- •Excess body weight multiplies knee load, and Cohen shows patients how much even small weight loss helps
- •The implant resurfaces the femur, tibia with a polyethylene piece, and sometimes the patella
- •Cohen tells patients recovery takes a year, and satisfaction around 85% is lower than for hips
- •Contact sports are discouraged, but skiing and tennis are allowed, and he uses computer navigation for alignment
- 1:49:41 – 1:53:43
Non-Surgical Options and Ankle Arthritis
Attia asks which knee problems should not be operated on. Cohen says ruptured patellar or quadriceps tendons need surgery while many meniscus and ACL cases can be managed conservatively. They then explain why ankles get arthritis less often than hips and knees.
- •Ruptured patellar or quadriceps tendons require surgery to restore knee extension
- •Some people with ACL tears cope without reconstruction if they avoid pivoting sports
- •Cohen had dozens of instability episodes during his years without an ACL
- •Prior trauma such as shoulder dislocation or ankle sprain raises arthritis risk
- •The ankle is very congruent and close to the floor, so it sees arthritis less often than hip and knee
- 1:53:43 – 1:58:50
Achilles Tendon Problems, Fluoroquinolones, and Prevention
Cohen and Attia begin on foot and ankle with Achilles tendinopathy, which is hard to treat surgically. They discuss fluoroquinolone-related rupture, and prevention through calf strength, flexibility, jumping and neuromuscular training.
- •Achilles tendinopathy has few good treatments, and Cohen doesn't see it leading to rupture
- •Cohen has seen ruptures within a week or two of a single fluoroquinolone dose and advises stopping and resting if pain develops
- •Maintaining calf strength and flexibility and avoiding over-training are suggested
- •Attia uses daily light jumping, and Cohen agrees neuromuscular training helps prevent lower-extremity injuries
- 1:58:50 – 2:13:18
Ankle and Foot Anatomy, Sprains, and Common Foot Injuries
Cohen walks through the bones, tendons and ligaments of the ankle and foot, then covers ankle sprains and cartilage injury. They go on to arch collapse and fusion, fifth metatarsal and navicular stress fractures, bunions and heel pain.
- •The ATFL is the most commonly sprained ligament, and persistent pain after a sprain warrants an MRI for cartilage injury
- •Posterior tibialis tendon failure and arch collapse can require fusion
- •Proximal fifth metatarsal fractures in the watershed zone often don't heal and may need a cast or screw
- •Repeated stress fractures prompt questions about energy deficiency and the female triad
- •Bunion surgery is reserved for painful cases, and heel pain has multiple distinct causes
- 2:13:18 – 2:18:40
Choosing a Good Orthopedic Surgeon
Attia asks how patients can pick a good surgeon. Cohen stresses listening, not feeling rushed and asking about alternatives, and Attia adds that surgeons should explain complication rates and next steps. They close with thanks.
- •Signs of a good surgeon include listening, eye contact and not feeling rushed
- •Asking about alternatives or non-operative options and noticing defensiveness is revealing
- •Attia wants to hear complication, infection and reoperation rates in the surgeon's own hands
- •A good clinician explains what happens next if the first plan doesn't work, as in ankle sprain follow-up
