Clinical evaluation and clinical features of osteoporosis

Bone Health Optimization Prior to Elective Orthopedic Surgery

Clinicians may see patients referred to them by orthopedists or by their institutional Fracture Liaison Service to evaluate bone health prior to elective orthopedic surgery (e.g., spinal fusions or total joint arthroplasty) or when patients who have a delay in fracture union or fusion to assess potential need for anabolic or antiresorptive therapies. Increasing evidence demonstrates the link between poor bone health and poor outcomes after orthopedic surgery. Bone health optimization before elective surgery can improve overall quality of care and prevent bone-related complications. The incidence of osteoporosis in patients with total hip or total knee arthroplasties is high. Bernatz and coworkers estimated the risk of osteoporosis after well-functioning total knee arthroplasty to be 36.7% with 60% of patients having osteopenia or osteoporosis. There is also the risk of bone loss around implants or prostheses, which has been linked with an increased rate of periprosthetic fractures. Furthermore, osteoporosis may also influence the choice of implant for arthroplasty by the orthopedic surgeon. Identifying patients with poor bone quality prior to replacement surgery can offer the orthopedic surgeon a chance to intervene and initiate treatment before surgery and continue treatment following surgery as indicated.

Poor bone health is also common in patients who undergo elective spine procedures and has been linked to poor outcomes and complications. A diagnosis of osteoporosis in patients who undergo elective spine procedures ranges from 10% to 20%, with 30% to 50% of patients having osteopenia. Patients with osteoporosis may be more likely to have fusion failure or an osteoporosis-related complication such as kyphosis, hardware failure, or fracture.

History

General health status should be noted, and clinical risk factors for fracture should be assessed. The number of clinical risk factors is associated with hip fracture risk, independent of bone density ( Fig. 199.1 ). It is important to start with identifying clinical risk factors used in fracture risk algorithms such as FRAX (see below). The first and most important risk factor is the presence of prevalent fracture (other than fingers, toes, face, or skull). The clinician should ask about a parental history of hip fracture, alcohol use, and smoking. Low body mass has been associated with increased fracture risk. In addition to clinical risk factors in FRAX, the clinician should ask about other factors such as level of sun exposure, endocrine disorders or hepatic or kidney failure, and history of rheumatic disease. Information on past and current medications should be gathered and evaluated, especially those medications that result in loss of bone mass (e.g., aromatase inhibitors, androgen deprivation treatment, anticonvulsants, and glucocorticoids). Factors that may increase the risk of falls such as neuromuscular disease (e.g., Parkinson disease), gait instability, or balance problems should be assessed. The patient should be asked about current smoking habits or overconsumption of alcohol (more than two drinks per day on average for men and one for women). Poor self-assessed health and dementia have also been associated with increased fracture risk.

Although some patients may describe bone pain, osteoporosis is not usually painful until the occurrence of a fracture. Approximately two thirds of vertebral fractures are not associated with significant clinical findings at the time they occur. Metabolic bone disease may also be associated with bone pain (see below).

Nutrition should be assessed. Especially important are intake levels of calcium and vitamin D. Determining whether patients are taking supplemental calcium or vitamin D is essential to understanding the entire nutritional profile. Online calcium calculators, such as the International Osteoporosis Foundation (IOF) calcium calculator, may be used. Food intolerances or eating disorders should be noted.

The patient should be asked about participation in any form of exercise (i.e., type of exercise, frequency, and intensity). Physical activity may be described as active, sedentary or non–weight-bearing. Exercise for bones should emphasize both weight bearing and strength training; these are key to improving bone health. Swimming and biking are not considered weight-bearing.

The patient should be asked if he or she remembers a fall in the last 12 months. If the patient has had a fall, it is a good time to ask the patient again about whether fractures occurred as a result of the fall and to do balance testing. Falls are the most important risk factor for osteoporotic fractures. It is important in the evaluation to ask about drugs and diseases that increase risk of falls, to educate patients about how to prevent falls, and to initiate treatments that will strengthen bones so that a fracture is a less likely consequence of falling.

With aging, individuals may also lose muscle mass (termed sarcopenia ), which then leads to falls and balance problems. Osteoporosis needs to be recognized as part of a fracture risk syndrome , which includes not only loss of bone mass and fracture but loss of muscle mass and balance as well. Understanding the patient’s balance and ability to walk are important. Use of ambulatory devices such as canes or walkers both in and outside the home should be documented.

The possibility of metabolic bone diseases other than osteoporosis should be considered. The clinician should consider osteomalacia as well as genetic metabolic bone diseases such as hypophosphatasia, hypophosphatemic rickets, X-linked hypophosphatemia, and osteogenesis imperfecta. Such diseases may present in children and adults. In rickets, which develops in children, symptoms and signs include growth retardation, bony deformity, severe genu valgum or varum, spinal curvature, frontal bossing, open fontanelles, rachitic rosary, and joint swelling. Affected individuals can also present with dental abscesses (due to defective dentin or enamel) and premature cranial synostosis. In adults, osteomalacia is not associated with any overt skeletal signs. However, adults with osteomalacia may complain of throbbing, aching bone discomfort, pseudofractures, osteoarthritis, osteophytes, or enthesopathy, which is abnormal mineralization at the bony insertion sites of tendons and ligaments. They also may have proximal muscle weakness and aching in their muscles. Hypophosphatasia also leads to impaired mineralization and osteomalacia. Patients may present with recurrent fractures in the thigh and foot bones, leading to chronic pain, and premature loss of secondary (adult) teeth; they are also at increased risk for joint pain and inflammation.

Another relative common genetic disorder that may present with a history of multiple fractures is osteogenesis imperfecta (OI). Different types of OI based on genetic mutations may present in utero, in newborns, and during childhood or adulthood. The key clinical features for diagnosis are a generalized connective tissue defect such as joint laxity, distinctive facial features (blue sclera), abnormal thoracic configuration (pectus excavatum), and vertebral compressions. Persistent pain is very common in untreated adults. The definitive diagnosis is made by molecular testing.

It is critically important to determine whether patients are experiencing functional disability and loss of quality of life as a result of their osteoporosis and fractures. Some vertebral fractures are “silent,” meaning that there is no measurable or reported disability outcome, but many fractures (especially those of the hip or multiple vertebrae) do result in disability that limits function ( Fig. 199.2 ). Although a general picture of patient function can be obtained from simply asking the patient open-ended questions, there are validated generic scales such as the HAQ and EQ5D as well as disease-targeted scales such as the OPAQ and Qualeffo-31 ( Fig. 199.3 ). The use of quality of life (QOL) measures in osteoporosis has been reviewed by Cranney and coworkers. Ultimately, self-reporting seems to be the most viable means of collecting such information for the individual practitioner. The disease-targeted scales have not been validated to measure changes in individuals over time. It may be that a few simple verbal self-report questions (e.g., How would you rate the quality of your life? How does your function compare to those of other people your age? Are there ways in which osteoporosis limits what you can do?) can give a practitioner important information while taking little time.

History of a Patient on Therapy

Some osteoporosis therapies have prolonged intervals between dosing (e.g., denosumab, which is given every 6 months). It is important at return visits to ask about occurrence of fragility fractures in all patients on osteoporosis therapies, as this may suggest lack of response or bone loss due to other secondary causes such as corticosteroid use. Patients on antiresorptive therapies should also be asked about planned and recent dental issues (e.g., tooth extraction and other complex dental procedures should not be done immediately before or after a recent denosumab injection).

Physical Examination

Accurate height measurement is an important part of the osteoporosis physical examination. Height measurement using a wall-mounted stadiometer is considered the gold standard; however, a patient’s current height obtained on a balance scale, although less accurate, may be used and should be compared to maximum height obtained as a young adult by either chart review or by examination of the patient’s driving license. The loss of 2 inches or 5 centimeters in height is considered an indicator of possible vertebral compression fracture(s). It is important to measure height annually and not just depend on the patient’s response to “Is your height the same as it was last time you were here?”

The spine should be evaluated for kyphosis (rounding of the upper back) or scoliosis and for spinal and paraspinal tenderness ( Fig. 199.4 ). Vertebral tenderness may suggest the possible presence of a fracture. If kyphosis is present, the possibility of pulmonary compromise should be considered and the patient examined for decrease in the distance between the bottom of the ribs and the top of the iliac crest (the iliocostal distance). A buffalo hump, easy skin bruisability, or striae may suggest Cushing’s syndrome. Blue sclerae may indicate osteogenesis imperfecta. A joint assessment may indicate a rheumatologic cause of low BMD. Thyromegaly should be noted. Bony deformity in the limbs may suggest rachitic change associated with vitamin D-deficient rickets, hypophosphatasia, or X-linked hypophosphatasia.

A neurologic examination may be done to identify muscle weakness or neurologic compromise that could predispose to falls (e.g., Parkinson disease increases risk of fracture two- to threefold). The ability of the patient to walk independently and do transfers from chair to standing or from table to sitting and standing should be observed. Use of any walking aids should be documented.

Measures of balance may include standing on one leg, tandem stance, and semi-tandem stance. Loss of muscle mass is also important and manual muscle testing of upper and lower extremities is recommended. A grip strength measurement can be added as one of the vital signs.