An easy-to-remember acronym and a clinical framework can help general internal medicine physicians navigate complex reasons for hip pain, said Carlin H. Senter, MD, FACP, at Internal Medicine Meeting 2022 in Chicago.
She built her talk, “Hip Pain: The Essentials in Evaluation and Treatment,” around the essential diagnoses that internal medicine physicians should understand. Dr. Senter's diagnostic framework involves a memorably named clinical approach called HIPROT for all musculoskeletal problems: history, inspection, palpation, range of motion, and other tests.
This is a great framework to organize the physical exam, clinical presentation, and note, she said. “I can remember being a resident and a fellow and just repeating [it] as I work to make sure that I covered each part of the physical exam.”
Starting with history, asking patients to point to where the pain is worst is incredibly helpful for hip problems, Dr. Senter said. “If the patient says the pain is worst in the front at the inguinal crease, this is probably a hip joint problem, or also possibly but less commonly a hip tendon problem.”
During palpation, a soft tissue defect is probably a significant muscle tear or rupture, for which Dr. Senter would consider imaging. If the leg is shortened and externally rotated, that can indicate a hip fracture. If the patient is unable to bear weight or has a significant limp, they may have a fracture or inflammatory arthritis, said Dr. Senter, a primary care sports medicine doctor and professor and director of primary care sports medicine in the division of sports medicine and shoulder surgery at the University of California, San Francisco.
“When palpating the hip, it's also important as internists to have a broad differential, to remember that hip pathology could be abdominal pathology,” she said. “So remember to palpate the abdomen, and then move on to the hip palpation.”
Dr. Senter said she palpates the regions of the anterior superior iliac spine of the hip (origin of sartorius muscle), anterior inferior iliac spine (origin of rectus femoris muscle), pubic symphysis (origin of adductor muscles and insertion of rectus abdominus muscles). Laterally, she palpates the greater trochanter to evaluate for pain from the gluteus tendons or the tensor fascia latae or iliotibial band. Posteriorly she palpates the lumbar spine, the sacroiliac joints, the sciatic notch/piriformis muscle region, and the ischial tuberosity (origin of the hamstring tendon).
To assess passive range of motion, the examiner asks the patient to lie supine. The clinician then flexes the patient's hip by bringing the knee as far as possible to the chest. Next, while holding the hip at 90 degrees of flexion, the clinician externally and internally rotates the hip via the lower leg. Patients normally have 45 to 50 degrees of rotation, normally with more external rotation and less internal rotation.
If the patient has anterior hip pain with passive range of motion, most likely they have an intra-articular problem. In these cases, Dr. Senter then considers red flags such as stress fracture or septic arthritis. Once she rules these conditions out, she considers osteoarthritis (OA) in older patients or femoral acetabular impingement (FAI) +/- labral tear in younger patients.
The issue could also be extra-articular. “These ones are tricky. It could still be maybe hip flexor, adductor; those you have to kind of sort out with your physical exam,” depending on where the patient is tender and which strength maneuvers cause pain. On the other hand, if there's no anterior hip pain with passive range of motion, is the pain more lateral or is it more posterior? For lateral pain, she considers greater trochanteric pain syndrome, meralgia paresthetica, or a snapping iliotibial band. If there's posterior pain, she considers lumbar spine pathology, SI joint pathology, or a high hamstring rupture or tendonitis.
Dr. Senter highlighted four nonpharmacological treatments that physicians can offer every patient to help manage hip OA: weight loss, self-management educational programs, exercise, and tai chi, as was cited by a Feb. 9, 2021, review in JAMA.
Every patient who has either knee or hip OA should be given a foundational plan that incorporates some or all of these four treatment options, Dr. Senter said.
With respect to pharmacologic treatment for hip OA, oral NSAIDs are more effective than topical NSAIDs. Oral NSAIDs are recommended over acetaminophen, tramadol, nontramadol opioids, and duloxetine. With respect to injections, glucocorticoid steroid injections are a recommended treatment option while other types of injections such as growth factor injections and platelet-rich plasma are not recommended.
As for surgery, hip replacement works. Recovery time is six to 12 months; however, patients have excellent pain relief starting on postop day one. Replacements last a minimum of 10 to 20 years. “And interestingly, it turns out that hip replacement is an underused treatment for our patients with severe hip osteoarthritis. Hip replacement is particularly underused in certain patient populations that I want to highlight,” Dr. Senter said.
She cited a study published in the Journal of Bone and Joint Surgery in January 2003 showing that Black patients had significantly lower rates of hip replacements than White patients. Dr. Senter noted: “This [difference] was not explained by a difference in prevalence of OA between Black and White patients.” In a second study, published in Medical Care in 2003, Black and Hispanic patients reported significantly fewer joint replacements than White patients.
Dr. Senter also noted that the degree of underuse of hip replacement is three times greater in women than men, as published in the April 6, 2000, New England Journal of Medicine. “In this study, women were less likely to have discussed hip replacement with their physician compared to men,” Dr. Senter said. “So this body of literature reminds me to bring up hip replacement, especially in my patients with severe hip OA. I want to make sure that I'm discussing it with them, and that they know that it's an option.”
Greater trochanteric pain syndrome
What has been misnamed “bursitis” for years is really a tendinosis or a tendinopathy, or a partial-thickness tendon tear, causing greater trochanteric pain syndrome. It's a common problem, Dr. Senter said, affecting six out of every 1,000 people and women four times as often as men. Per a study in the Nov. 7, 2013, Journal of Arthroplasty, Dr. Senter said, “The level of disability and reduction in quality of life is similar to that in patients who have severe hip arthritis, quite disabling. It really affects people's quality of life.”
Twenty-nine percent of patients have ongoing pain five years after they've been diagnosed, Dr. Senter said. “And despite the common nature of this problem, we actually have very little out there as far as data to tell us what the best treatment is for our patients,” she said.
Steroid injections can help relieve symptoms from greater trochanteric pain syndrome in the short term, but repeated cortisone shots should be avoided due to a body of literature related to rotator cuff tendons and lateral epicondyle tendinopathy showing that repeated steroid injections may harm tendon tissue. “So I think it's reasonable to treat a patient with a greater trochanteric bursa injection. I will have a shared decision-making discussion with the patient, explaining that the injection is likely to have short-term benefit only and that we really shouldn't use it over and over again, because of the literature about tendon weakening.
Meralgia paresthetica is entrapment of the lateral femoral cutaneous nerve that creates a burning pain and decreased sensation of the lateral thigh. “So whenever you're thinking greater trochanter pain, also think about meralgia paresthetica. Does this patient have any neuropathic symptoms? If they do, it might be this,” she said.
The lateral femoral cutaneous nerve is a sensory nerve only. This problem is self-limited and usually lasts one to two months. The treatment is to reduce the pressure on the nerve. If symptoms persist beyond that timeframe, a nerve block can help for diagnostic and therapeutic purposes, Dr. Senter said.
Femoral acetabular impingement
FAI is an abnormal bony anatomy that forms in people ages 15 to 45 years and has a high prevalence in athletes. It can cause interarticular injury to the labrum and cartilage and can lead to early hip OA.
The hip labrum is a protective ring of fibrocartilage and contributes to hip stability. In FAI, abnormal bony growth occurs at the junction of the femoral head and neck, which is called cam impingement, or at the acetabulum, which is called pincer impingement. Often patients have a bit of both a cam and pincer type of impingement. When the femoral head flexes, it pinches at the superior anterior acetabulum, which can result in a tear at the superior anterior labrum, Dr. Senter said.
Physical therapy is the first treatment for patients with FAI, whether or not there is a labral tear, and aims to strengthen core and hip muscles. Activity modification also is useful. “If you have a patient who is involved in sports where they do lots of extremes of hip range of motion, so this might be ballet, this might be kickboxing, martial arts, these patients, if they reduce the hip range of motion, they're able to still excel in their sport,” Dr. Senter noted.
A steroid injection can be useful for diagnostic and therapeutic purposes. For example, a patient might have anterior hip pain that has not resolved with physical therapy and their physical exam points to either FAI or hip flexor (iliopsoas) tendinopathy. In this case, an ultrasound-guided corticosteroid injection into the hip joint that provides pain relief would support the diagnosis of FAI/labral tear, while a lack of relief would point to an extraarticular problem such as hip flexor tendinopathy.
For ongoing pain, Dr. Senter recommends advanced imaging of the hip, either an MRI or an MR arthrogram (in which gadolinium is injected into the hip joint). Many times radiologists are able to diagnose labral tears of the hip on an MRI alone, but in some cases they may prefer an MR arthrogram, so Dr. Senter recommends checking with your radiologist before ordering the study if you are not sure which they prefer. Post-MRI, Dr. Senter then refers patients to a sports medicine surgeon trained in hip arthroscopy.
Hip stress fractures
When taking a history of athletes with hip pain, Dr. Senter recommends asking patients five questions: Have they increased their running mileage? Do they have any dietary restrictions or history of eating disorders? Do they have a history of stress fractures? Do they have a family history of osteoporosis? What is their menstrual history, and is there any history of amenorrhea?
Hip stress fractures affect women more than men. These five questions evaluate risk factors for the female athlete triad (the combination of disordered eating, amenorrhea, and osteoporosis), which is also known as relative energy deficiency in sport, she said.
If concerned that a patient may have a hip stress fracture, Dr. Senter recommends a same-day AP and lateral hip radiograph. If this is normal, Dr. Senter encourages an urgent MRI to evaluate for a femoral neck stress reaction (prestress fracture) and to rule out a stress fracture.
There are two types of femoral neck stress fractures: compression side and tension side. Compression side fractures are more common and can be managed with non-weight-bearing activity and an urgent referral to sports medicine. Over time, this type of fracture will heal on its own. Patients benefit from relative rest, physical therapy, and ensuring that they are taking in enough food as fuel to support their physical activity.
Tension-side stress fractures can fracture all the way through, requiring hip replacement. These patients should be immediately non-weight-bearing and should have emergent orthopedic surgery consultation, Dr. Senter advised. “And in either case, if you have a high index of suspicion about a femoral neck stress fracture in the office, while you're waiting for imaging, I would make the patient non-weight-bearing just to be safe,” she said.