Q: Today, osteoarthritis (OA) affects many elderly individuals. Differentiating between sciatica and OA

can be problematic when an individual presents to the office with a chief complaint of hip pain. What are some of the classic symptoms and diagnostic findings that may help the practitioner distinguish between hip OA and sciatica?


A: Given the number of disorders capable of causing hip pain, Kiplee Snell, MS, PA-C, emphasizes a thorough diagnostic workup. Snell says distinguishing between hip pain and sciatic pain can be a diagnostic challenge because pain and weakness in the piriformis muscle of the hip and weakness in the iliotibial band also cause sciatica.



However, entrapment of the sciatic nerve at the level of the piriformis muscle (not weakness of the muscle) can cause pain down the sciatic nerve, comments Joan McDaniel, PA-C, who notes this is a controversial opinion among practitioners.



Snell notes that the sciatic nerve runs between the two heads of the piriformis muscle. When the piriformis muscle is spastic, Snell says the sciatic nerve may be pinched. McDaniel points out that sciatica follows the sciatic nerve distribution but does not cause groin pain.



In the diagnostic workup of hip pain, Snell says clinicians must establish the location and characteristics of the pain. When it comes to true OA of the hip, Snell and McDaniel note these patients often present with groin pain. McDaniel adds that patients with hip OA may also have radiation down the antero-medial thigh but notes that this generally does not cause back pain. Snell says some patients presenting with hip pain may say they feel it directly above the hip joint in the back. However, McDaniel cautions that patients often call their low lateral back their hip. She says it is incumbent upon the practitioner to sort this out. Individuals with sciatica may experience low back pain, according to Snell but she says the most common symptom is pain that radiates through one buttock and down the back of the leg.


Eileen Roberts, PA-C, notes that OA is associated with an aching, throbbing type of pain while sciatica is more radicular in nature. Patients with sciatica pain may describe their pain as sharp, shooting or electric, according to Roberts. When it comes to sciatica pain, Snell says the extent of the pain can vary between individuals and may be described by patients as tingling, burning, prickly, aching or stabbing. Snell maintains that sciatica pain can be sudden or develop gradually. It can also be intermittent or continuous in nature, according to Snell.

McDaniel also points out that sciatica can commonly cause neurologic symptoms whereas OA of the hip does not.



During the physical exam, Snell recommends observing the patient’s gait and general ability to move around the examining room. She says one should carefully assess the patient’s range of motion (ROM) of the hip, comparing the affected side with the normal side to detect abnormalities. Roberts says abnormal hip motion, a positive Patrick’s test or painful ROM imply a joint problem. Range of motion testing includes passive hip flexion as well as internal and external rotation, according to Snell. Snell says the most predictive finding for OA is a decreased ROM with restriction in internal rotation.



Decreased sensation or tenderness along the posterior/lateral thigh and buttock are more consistent with sciatica, according to Roberts.



During the initial evaluation, Snell says clinicians should also determine if there are any precipitating events or predisposing activities that may have contributed to the hip pain. She notes that activities such as bending, coughing, sneezing or sitting can make sciatica pain worse. If there is a history of significant trauma, a fall or a motor vehicle accident, Snell advises practitioners to rule out a possible fracture.



When adults have acute hip pain, Snell says clinicians should have an index of suspicion for serious medical conditions. In addition to patients who have a history of traumatic injury, Snell says those with a history of osteoporosis, cancer, high-dose corticosteroid exposure or alcohol abuse are at a higher risk for bony hip pathology such as fracture, OA or avascular necrosis. Accordingly, she encourages clinicians to obtain X-rays for these patients during the initial evaluation.



Q: You have just made a working clinical diagnosis of hip OA as the cause for the patient’s hip pain. What are some standard X-ray views and common radiographic findings you look for when it comes to confirming OA of the hip?

A: Roberts obtains anterior-posterior as well as lateral X-ray views of both hips to diagnose OA. McDaniel says anterior-posterior radiographs are good for confirming hip OA. In Snell’s experience, plain films are the only imaging needed for accurate diagnosis and follow-up with hip OA.



As far as key X-ray findings go, all of the panelists look for osteophytes, non-uniform asymmetric joint space narrowing and sclerosis. Snell says other findings that are helpful in the differential diagnosis include subchondral cyst formation and loose intraarticular bodies. She says a lack of erosions rules out rheumatoid arthritis and normal mineralization rules out osteoporosis. Snell adds that weightbearing views are particularly important with elderly patients.



According to Snell, clinicians should reserve more advanced modalities such as MRI and CT for suspected complications and/or sequelae of arthritis.



Q: After confirming the diagnosis of hip OA, what are some treatment options you would recommend to patients?

A: McDaniel emphasizes that treatment options depend upon the degree of pain and loss of function. Snell concurs. She says it is also important to discuss the feasibility of a particular treatment regimen with the patient and whether it is a good fit for him or her in terms of patient compliance.



McDaniel says conservative treatments such as acetaminophen (Tylenol, Johnson and Johnson) and NSAIDs “frequently” relieve pain and improve function. In addition to those medications, Snell says other available pain management modalities include muscle relaxants, COX-II inhibitors, narcotic analgesics, viscosupplementation and pain patches.



For obese patients, McDaniel and Roberts emphasize the value of weight loss and exercise. They both advocate physical therapy as well.



In cases of moderate pain, McDaniel recommends increasing analgesia and prescribing a cane. McDaniel and Snell add that hydrotherapy is good for restoring motion in arthritic joints.



For acute or very painful flare-ups, Snell advises bed rest for up to a week in conjunction with pain medication. When pain is unremitting and/or refractory to the aforementioned modalities, Snell and McDaniel says one should consider possible surgical options.