Rehabilitation of orthopedic and rheumatologic disorders. 3. Degenerative joint disease

S-67

Rehabilitation of Orthopedic and Rheumatologic Disorders. 3. Degenerative Joint Disease Victoria A. Brander, MD Northwestern University Medical School Chicago, IL 60611

Darryl L. Kaelin, MD Indiana University, Indianapolis, IN 46202 Terry H. Oh, MD Mayo Clinic, Rochester, MN 55905 Peter A.C. Lira, MD Baylor College of Medicine and Veterans Affairs Medical Center, Houston, TX 77030 ABSTRACT. Brander VA, Kaelin DL, Oh TH, Lim PAC. Rehabilitation of orthopedic and rheumatologic disorders. 3. Degenerative joint disease. Arch Phys Med Rehabi12000; 81:S-67-S-72. 9 This self-directed learning module highlights assessment and therapeutic options in the rehabilitation of patients with osteoarthritis. It is part of the chapter on rehabilitation of orthopedic and rheumatologic disorders in the Self-Directed Physiatric Education Program for practitioners and trainees in physical medicine and rehabilitation. New advances covered in this article include updates on conservative and operative treatment of lumbar spinal stenosis and pediatric hip diseases, prophylactic therapy for thromboembolic disease after lower limb joint replacement, new therapies for osteoarthritis, and the impact of exercise on outcome following hip replacement in active persons. 9 2000 by the American Academy of Physical Medicine and Rehabilitation 3 . 1 0 b j e c t i v e . m A 75-year-old m a n w h o m y o u have treated for several years for degenerative lumbar spinal stenosis has progressive, refractory pain a n d functional decline. Justify a surgical referral. Lumbar spinal stenosis (LSS) is the most common indication for spinal surgery in patients older than 65 years. Rates of surgery have increased eight fold from 1979 to 1992.1 Surgical referrals are often made because of pain and rapidly deteriorating neurologic status. In the majority of patients, however, the progression of neurologic deficits is insidious, and the efficacy of decompression in preventing progression of neurologic impairment has been questioned. In patients without rapidly progressive neurologic deficits, the surgical decision should be based on the degree of pain and physical disability rather than the degree of neuromuscular impairment. 2 A review of surgical series published between 1966 and 1991 suggested an overall success rate of 64%, 3 and there was no statistically significant relationship between outcome and patient age or gender, presence of pseudoclaudication, previous back surgery or spondylolisthesis, number of levels decompressed, or associated fusion. Most patients with central stenosis of the lumbar spine have relief of pseudoclaudication after surgical decompression, but symptoms return with time. J6nsson and associates' prospective 5-year follow-up study4 showed an excellent result in 52%, but the reoperation rate was 18% within 5 years. Prognostic factors associated with good surgical outcome were pronounced constriction of the spinal canal (<6mm anteroposterior diameter), prominent leg rather than back pain, no concomitant disease affecting walking ability, and symptom duration of less than 4 years.4

Decompressive laminectomy is the typical surgical procedure for LSS, with arthrodesis performed in selected cases to enhance spinal stability and/or to prevent progressive deformity. A study comparing lumbar laminectomy alone with arthrodesis showed superior relief of back pain with noninstrumented arthrodesis after 6 and 24 months. 5 Moreover, instrumented arthrodesis was the most costly option among the procedures. The factors associated with the decision for arthrodesis were the surgeon, presence of spondylolisthesis of more than 5mm, younger age, fewer stenotic segments, and greater preoperative back pain. 5 3 . 2 0 b j e c t i v e . m A 48-year-old m a n presents with a s e v e r a l - m o n t h history of progressive right hip pain. He describes no t r a u m a but recalls being told that he had a hip disorder treated as a y o u n g child. R a d i o g r a p h i c films reveal moderate degenerative joint disease. Explain h o w the treatment of congenital hip disease reduces the risk of developing degenerative joint disease. Normal hip growth and development occur as a result of a genetically determined balance of growth of the acetabulum in the presence of a well-centered spheric femoral head. The largest part of acetabular development is determined by age 8 years, 6 an important age for prognosis in many pediatric hip disorders. Outcome of these disorders (congenital hip dislocation and dysplasia, Legg-Calv6-Perthes disease, and slipped capital femoral epiphysis) is profoundly influenced by the age at disease onset and by the effects of treatment on the relationship between the femoral head and acetabular development. The natural history of many of these childhood hip disorders is the development of degenerative joint disease. Degenerative joint disease and clinical disability may develop in the conditions despite standard up-to-date Arch Phys Med RehabU Vol 81, March 2000

S-68

DEGENERATIVE JOINT DISEASE, Brander

treatment. Nonetheless, patients usually do well for many joint disease. More than 90% of the hips without deformity years.6 were painless, while 23% remained painless in deformed Congenital hip dislocation (CHD) occurs in about 1% of hips. 1~ Of patients requiring closed reduction to correct live births in the United States5 In more than 90% of cases CHD, 43% had radiographic evidence of degenerative joint of CHD, the acetabulum appears normal at birth. The disease on follow-up at an average of 31 years. H The remaining cases are thought to be due to in utero maldevel- long-term potential problems associated with successfully opment of a shallow acetabulum filled with fibrofatty reduced CHD are residual subluxation, dysplasia, and avastissue. 8 CHD affects girls seven times more often than boys cular necrosis. Residual subluxation after treatment invariand the left side more frequently than the right. The ably leads to degenerative joint disease and clinical disabilincidence is higher in cases involving breech delivery, ity. 12Long-term problems of residual dysplasia after treatment primapara, and oligohydramnios. There may be generalized for CHD and the absence of subluxation are difficult to ligamentous laxity secondary to the fetal effects of maternal predict, lz estrogens. 7 Routine neonatal screening has markedly reLegg-Calvr-Perthes disease causes femoral head deformiduced the incidence of dislocations requiring prolonged ties as a result of vascular embarrassment. Avascular necromanagement or surgery. CHD is suspected if a palpable click sis occurs five times more commonly in boys than in girls is felt when the infant's hip is brought into full flexion and and often follows an episode of transient hip synovitis and then gently abducted, thus reducing the hip (Ortolani sign), effusion.6 Onset is usually between ages 4 and 8 years. The or when it is slowly maneuvered into adduction and the head child will present with a limp, hip pain referred to the medial of the femur is brought over the acetabular rim (Barlow thigh and knee, and limited range of motion. The anatomic sign). With the hips and knees fully flexed and the heels changes that result from the vascular insufficiency are a resting on the table near the buttocks, a difference in the knee result of growth disturbance of the epiphyseal and physeal levels supports an apparent femoral shortening (Galeazzi plates, leading to shortening of the femoral neck, and sign). Clinical suspicion is confirmed with ultrasound.8 overgrowth of the trochanter. 8 During the healing process, Radiographs may be normal at birth but commonly show an asymmetric bony repair leads to femoral head deformity. Prognosis is better in younger children and if the epiphyincreased acetabular index, a broken Shenton's line, or a laterally and superiorly displaced femoral head. sis is only partially involved. Bed rest and immobilization Absence of a femoral head during early growth, such as in with traction are prescribed for the first 3 weeks, followed by developmental dysplasia of the hip, causes the acetabulum progressive range of motion and "containment" of the hip to have a flat shape but a normal diameter. Similarly, a during ambulation with a variety of orthoses. deformed head will stimulate the formation of a correspondIn severe necrosis or in older children, femoral osteotomy ingly deformed acetabulum if the deformation occurs at a is often necessary. Therapy may begin within 2 or 3 days young enough age. Radiographic evidence of subluxation after surgery, if internal fixation is used, or immediately after invariably leads to degenerative joint disease and clinical cast removal. Therapy should begin with gentle active disability in adulthood.6 The rate of deterioration is related assisted and active range of motion of the hip, followed by directly to the severity of subluxation and the age of the progressive resistive exercises to restore abduction and patient. 6 rotation. The child should be followed until maximum Congenital hip dysplasia and dislocation, if diagnosed in remodeling of the head is evident on x-ray. 6 In 20- to 40-year the newborn period, may be treated with a Pavlik harness or follow-up studies, 70% to 90% of patients with Legg-Calvrtraction device with a 95% chance of normal hip develop- Perthes disease are active and pain-free regardless of ment. 6 With increasing age at diagnosis, long-term outcome treatment. Pain, decreased range of motion, and loss of is less predictable. In these cases, the most common function are observed only in those patients with flattened, treatment is traction for 2 weeks, followed by closed irregular femoral heads or premature physeal closure. Bereduction and application of a spica cast. 9 Open reduction is yond 40 years, degenerative joint disease developed in the considered in the following situations: when closed reduc- overwhelming majority of patients by the sixth or seventh tion fails, when reduction can only be maintained with decade.6 forced hip abduction in the frog position, when the patient is Slipped capital femoral epiphysis (SCFE) is a disorder in at risk for avascular necrosis, when adductor tenotomy does which there is displacement of the capital femoral epiphysis not maintain stable reduction, or when the child is more than through the physeal plate. The term is actually a misnomer 2~89years of age. 7,9,11 in that the femoral head is held in the acetabulum by the The natural history of untreated CHD and hip dysplasia is ligamentum teres, and thus it is actually the neck that moves unknown, since cases are diagnosed only incidentally on upward and outward while the head remains in the acetaburadiographs or only after the patient experiences symptoms. lum. SCFE occurs during the rapid growth period of early There is considerable evidence that acetabular dysplasia adolescence, affecting boys two to five times more often leads to secondary degenerative joint disease, especially in than girls. 6 Onset can occur acutely after trauma or a fall, or female patients. Although no standard predictive radio- gradually with progressive pain and a limp. SCFE has been graphic parameters exist, an intact Shenton's line is believed classified into four clinical categories: pre-slip, acute, acute to be associated with a more favorable long-term progno- on chronic, and chronic. 6 A newer and probably more sis. 6.12 Long-term results of patients treated with a Pavlik important classification is stable versus unstable. In the harness are favorable. Twenty or more years after reduction, stable hip, weight bearing is possible. The unstable hip almost 70% of patients showed no evidence of degenerative presents with fracture-like symptoms and pain so severe that Arch Phys Med Rehabil Vol 81, March 2000

D E G E N E R A T I V E J O I N T DISEASE, Brander

S-69

weight bearing is impossible. In a large series of patients Normalized Ratio (INR), t o 2.0 to 3.0, have been shown with SCFE all of whom were treated with pinning in situ, the effective. Low-molecular-weight heparin (LMWH) was incidence of aseptic necrosis was significantly greater in found to be most effective in comparison with ADH and warfarin, although differences were small and its use was patients with unstable hips. 6 Radiographically, SCFE can be classified into mild, associated with slight increases in bleeding risk. Currently, moderate, and severe slips. This classification is most enoxaparin (30mg every 12 hours subcutaneously started 12 important in determining prognosis, since mild and moder- hours after surgery or when hemostasis is obtained) has an ate slips have excellent long-term prognosis when treated FDA- approved indication in prophylaxis against DVT in with pinning in situ, whereas severe slips tend to deteriorate both THA and TKA. Dalteparin (40mg daily) has gained an FDA indication in total hip replacement. with time. 6 In TKA, recommendations are less clear. IPC has been There are few longitudinal studies of patients with SCFE. In one study of 31 hips in 28 patients without interventional demonstrated to be effective, but is limited by patient treatment, there was follow-up for a mean of 41 years. activity and intolerance. LDUH and aspirin remain marginThirty-six percent of patients with mild slips had no ally effective. Several studies have compared fixed-dose degenerative joint disease; however, all those with moderate LMWH with warfarin for DVT prophylaxis and all showed and severe slips had evidence of degenerative joint disease. 6 the efficacy of LMWH to be superior to that of warfarin, Aseptic necrosis is the most devastating complication of although the overall incidence of DVT and major bleeding SCFE. The factors responsible for its development are acute remained substantial. Concomitant use of LMWH and IPC slips, unstable slips, over-reduction of acute slips, placement was recommended. Of importance in today's health-care market is costof pins in the superior lateral quadrant of the femoral head, effectiveness. Hull and associates 16 performed a cost analyand osteotomies of the femoral neck. 6 sis of a consecutive series of 1,436 patients who had undergone THA or TKA and were randomized to warfarin or 3.3 Objective.reDesign an appropriate strategy for LMWH for prophylaxis. The parameters that most affected deep vein thrombosis prophylaxis in both hip cost were price of the drug, charge for INR monitoring, and and knee arthroplasties. cost of major bleeding. Prophylaxis was more effective with Deep vein thrombosis (DVT) in the lower limbs is a major LMWH, but major bleeding was seen less frequently with postoperative complication in patients undergoing total joint warfarin. 16 In an analytic model of 10,000 patients comparreplacement (THA). The incidence in patients not receiving ing the same two drugs in THA, enoxaparin was found to be prophylaxis may be as high as 57% in THA and 84% in total more cost-effective by reducing the overall risk of thromboknee replacement (TKA).13 Virchow described three interre- embolic disease. J7 Methodologic concerns regarding spelated factors that could result in venous thrombosis: vessel cific assumptions limit confidence in these data. Length of prophylactic therapy is debated. A prospective, wall damage, altered coagulation, and venous stasis. Although direct vessel wall damage does not regularly occur, blinded, placebo-controlled investigation of dalteparin, activation of the clotting cascade and venous obstruction 5,000IU/daily, after THA found that prophylaxis for 28 days have been shown to occur during total joint replacement. significantly reduced DVT formation and symptomatic Several circulating indices of thrombosis and fibrinolysis pulmonary embolism compared with treatment for 7 days. rise during insertion of the femoral component, resulting in a No serious complications were experienced. Is An analytic THA hypercoagulable state. 14 Intraoperative hip dislocation model with 10,000 patients after THA compared discontinucauses transient cessation of venous blood flow and resultant ation of prophylaxis at hospital discharge with screening for venous stasis. Addition of a pneumatic foot pump appears to DVT at discharge with compression ultrasonography or overcome stasis and restore venous return, thereby reducing extending prophylaxis with warfarin for 6 or 12 weeks. Both ultrasonography and extended oral prophylaxis for 6 weeks thromboembolic risk.15 To reduce thromboembolic risk, the Fourth ACCP Consen- were cost-effective strategies when compared with stopping sus Conference on Antithrombotic Therapy recommends prophylaxis at hospital discharge. Extending prophylaxis to early mobilization, intermittent pneumatic compression 12 weeks added cost since the number of bleeding events (IPC), and epidural anesthesia when indicated in all patients induced was higher than the number of cases of pulmonary undergoing major lower limb orthopedic surgery. 13 Pooled embolism prevented. 19 data indicate that almost all forms of pharmacologic prophylaxis are useful in reducing the occurrence of DVT. Comparison studies have aided in determining the most effective 3.40bjective.mA 45-year-old former competitive tennis player presents I year after THA with leg strategies. Meta-analysis of THA studies suggests that low-dose pain after playing one set of tennis. Evaluate the unfractionated heparin (LDUH) and aspirin are more effeccontroversies over the effect of long-term exertive than placebo in preventing DVT, but both are inadcise on outcome in persons with hip replaceequate when compared with other prophylactic regimens. ment. Adjusted-dose heparin (ADH), in doses that maintain the THA is widely successful for patients with pain and activated partial thromboplastin time (APTT) at the upper range of normal, and warfarin given either the day before or disability from joint disease. It is being performed with the day of surgery and adjusted to prolong the International increasing frequency on patients of all ages. Early outcome Arch Phys Med Rehabil Vol 81, March 2000

S-70

DEGENERATIVE JOINT DISEASE, Brander

is excellent in more than 90% of cases in most published studies. Longer-term outcome, particularly in young patients, is less assured. After 10 years, revision rates are 10% to 30%. Aseptic loosening is the most common reason that hip arthroplasties require revision. Implant, host, and surgical technique issues can all contribute to early loosening. Many investigators believed that "cement disease" was the inciting event leading to loosening and subsequent revision. In an attempt to reduce the high revision rates 10 years after THA, cementless femoral components were designed in the 1980s. However, many cementless implants developed significant periprosthetic femoral osteolysis. This osteolysis is now believed to have many causes. One of the most significant factors is overload particulate debris. Wear of the polyethylene liner, methylmethacrylate cement, or metal results in microscopic debris, which stimulates a local immune response that leads to bone loss and loosening. In an effort to reduce particulate debris and osteolysis, many surgeons counsel their hip replacement patients to avoid activities that require repetitive joint stress or torque. Patients are told they may golf, walk, swim, or bike. They are usually advised against tennis, hiking, running, skiing, weight lifting, or other aggressive activities, irrespective of the patient's level of physical fitness. Very little literature is available to help define safe levels of activity. Several investigators have reported increased rates of osteolysis and revision in young subjects, and the presumption is that this difference is a consequence of the greater levels of activity in younger patients. In a study limited by retrospective design, the few subjects in the active groups, and the use of an antiquated implant, Kilgus and colleagues2~ reported a four-fold increase in revision rates in active subjects. Ritter and Meding, zl reporting the results of a questionnaire, found no difference in outcome between active and inactive subjects. Kobayashi22reported no correlation between activity and acetabular lysis. In a more rigorous investigation, Diduch and associates23 reported their experience with 114 knee replacements in young subjects. There was 94% 18-year survival. One-quarter of the patients were very active (tennis, skiing, bicycling, or strenuous labor) after surgery. There was no increased risk for revision in the active subjects. Exercise offers significant benefits for THA patients. Persons with osteoarthritis have reduced cardiopulmonary capacity compared with their age-matched controls which is reversible with endurance training. These patients also exhibit periarticular muscle weakness. Long and associates24 performed gait analysis on 18 THA subjects pre- and postoperatively. On completion of the study, 2 years after THA the patients' operated hip continued to show weakness. Gait characteristics, however, returned to normal. Because of the prolonged period of range-of-motion restrictions after surgery, many hip arthroplasty patients have small hip flexion contractures, tight hip flexors, and lateral rotators. Eccentric strength in abduction and rotation is often reduced. These physical impairments lead to increased risk for painful soft tissue conditions, such as iliotibial band pain syndrome, and for injury. Physical retraining is imperative prior to resumption of greater activity or sports. Arch Phys Med Rehabil Vol 81, March 2000

3.5 Objective.reEvaluate the utility of newer nonsurgical treatments in reducing disability from painful knee osteoarthritis. At the present time, there is no risk factor modification that has been proven to reduce disability from knee osteoarthritis. Primary preventive strategies, such as weight loss, preventing knee injury, and eliminating jobs that require repetitive knee bending and carrying heavy loads, are recommended.25 Recent epidemiologic data from the Framingham Osteoarthritis Study suggest that vitamin D might reduce radiographic progression of arthritis. Subjects with low levels of serum 1,25-hydroxyvitamin D had three times the risk of radiographic disease progression.26 Antioxidants may have a role in delaying degenerative arthritis. Vitamin C, through its effect on the vitamin C-dependent enzyme lysyl hydroxylase, is required for the stabilization of mature collagen. Animal data have shown a higher risk of experimentally induced arthritis in subjects with lower serum levels of vitamin C. In the Framingham study, persons with low oral vitamin C intake had a three-fold increase in radiographic progression of knee osteoarthritis. 25 HyaIuronic acid (hyaluronan and hylan G-F-20) injections were recently approved for use in painful knee osteoarthritis. It is proposed that injection of hyaluronic acid temporarily restores elastoviscosity to arthritic synovial fluid and thereby reduces stiffness. Through a purely local mechanical effect, hyaluronic acid may reduce inflammation and pain. Research into the disease-modifying capacities of this compound is limited. One group of investigators suggest that chondrocytes bathed in hyaluronic acid are stimulated to produce additional hyaluronic acid. In contrast, Smith and colleagues17 suggest a potential detrimental role. In a canine model of osteoarthritis, hyaluronic acid-injected knees exhibited more pathologic evidence of degeneration on sacrifice than did those that received saline injections. Clinical research published in peer-reviewed US journals is limited. In a double-blind, placebo controlled randomized trial, Wobig and associates28 compared hylan G-F-20 with saline in subjects with long-standing knee osteoarthritis (OA). Hylan G-F-20 was superior to saline in reducing weight-bearing pain. Maximum effect of treatment was seen at 8 to 12 weeks. Adams and associates 29 performed a multicenter, randomized double-blind controlled trial of hylan G-F-20 versus continuous therapy with nonsteroidal anti-inflammatory drugs (NSAIDs) in 90 subjects with knee OA. Pain was the primary outcome studied. The group receiving hylan G-F-20 had superior results compared with those receiving NSAIDs only at a telephone follow-up interview. Other investigators have reported modest improvement in pain and function either comparable with or slightly superior to that obtained with anti-inflammatory agents. Hyaluronic acid injections appear to be well tolerated. Systemic adverse events, such as pain, swelling, and a rash, were seen in 10 of 511 treated patients in seven published clinical trials. Hyaluronic acid injection is currently a recommended alternative therapy for knee arthritis. It is best utilized only if standard therapy (weight loss, exercise,

DEGENERATIVE JOINT DISEASE, Brander analgesics, NSAIDs) fails to provide satisfactory relief of pain in patients who are not candidates for knee replacement surgery. The injections are expensive but are covered by Medicare, Medicaid, and managed-care plans with preapproval. Chondroitin sulfate (CS), an oral preparation, is a widely popular alternative therapy for OA. It has been proposed that CS may stimulate synthesis of proteoglycan and collagens, while partially inhibiting enzymatic degradation. Several European clinical trials have assessed the efficacy of oral CS in subjects with OA. Morreale and associates 3~ performed a randomized, double-blind, placebo-controlled trial of CS and the NSAID diclofenac sodium in 146 subjects with knee OA. The NSAID-treated groups showed better early relief of pain and symptoms, which was reversed after discontinuation of the drug. The CS groups showed a later therapeutic response, which lasted 3 months after the treatment was discontinued. CS therapy has been reported to induce a reduction in total NSAID use and reports of pain. 31 Most published trials used doses of 1200rag of CS per day. 3~ Glucosamine is the salt of D-glucosamine, an amino sugar with sulfuric acid. Some investigators believe that oral glucosamine preferentially concentrates in articular cartilage. Major side effects are rare and appear to be primarily gastrointestinal. In short-term trials, glucosamine has been shown effective at reducing pain and stiffness in OA. In 4- or 8-week trials, several European studies have compared glucosamine with placebo or NSAIDs. Glucosamine has consistently been equal or superior to the comparison drug. These studies are all significantly limited by small sample size. 3~ Most published trials used doses of 1500mg of glucosamine a day. Chondroitin and glucosamine are frequently used in combination. There is a wide variation in actual concentration of these chemicals in the multitude of products on the market. Most of these preparations, like the widely popular "arthritis cure," combine 1500mg of glucosamine with 1200mg of CS daily. These products typically cost $40 to $80 per month. Patients commonly respond to their OA symptoms by limiting activity. The resulting restriction in motion leads to disuse atrophy, which promotes atrophy of cartilage and thinning of bone. This further compromises joint integrity and contributes to pain. Exercise is an extraordinarily promising avenue to use in managing the physical impairments and functional limitations associated with OA. 33-35 Persons with arthritis exhibit decreased aerobic conditioning compared with age-matched normal subjects. Aerobic conditioning programs improve aerobic capacity, 50-foot walk time, and scores for depression and anxiety in subjects with OA. 36 In general, physical training programs aim for 30 to 40 minutes of aerobic exercise (with warm-up and cooldown periods), maintaining a target heart rate or perceived exertion level, three to four times weekly. Aerobic conditioning programs should be "low impact," such as swimming or walking. In a quantitative prospective study, physical therapy individualized to the subjects' needs was shown to benefit those with severe OA of the knees, with improvement observed in strength, endurance, stair climbing, arising from a chair, pain, and walking ability. 37

S-71

Previous literature suggested that high-resistance exercises increase strain on articular tissues and that certain types of exercise (particularly isotonic and isokinetic) are unsafe for persons with arthritis or unstable joints. Consequently, initial muscle strengthening has traditionally been limited to isometric or isotonic programs with 1- to 2-pound weights. Recent studies seem to contradict that notion. 33,34In a rigorous, prospective randomized trial, Fisher and associates 33 reported increased strength, endurance, and speed, with no adverse effects, after a 16-week muscle-strengthening and endurance program in 15 subjects with advanced OA of the knee. It is now well recognized that exercise should be the cornerstone of all treatment programs for arthritis.

3.6 Objective.m Justify the use of inpatient rehabilitation after hip fracture. In light of the substantial physical and functional deficits associated with hip fracture, inpatient rehabilitation appears to be amply justified. Recent studies have evaluated the utility of acute rehabilitation versus skilled nursing care for patients with hip fracture. 38-4~ Kramer and associates 38 published a large prospective trial of community-dwelling hip fracture subjects. There was a stratified random sample of rehabilitation facilities and skilled nursing units. The study included 409 randomly selected hip fracture patients. The main outcome measures were cost, community residence at 6 months, activities of daily living (ADL), and walking ability. Outcome was adjusted for premorbid and social characteristics. Ultimately, there were no differences in the proportion of subjects discharged to home or in ADL ability between hip fracture patients treated in skilled nursing units and those treated in acute rehabilitation units. The Medicare costs were vastly different. The average cost of rehabilitation stay was $17,202; skilled nursing units providing rehabilitation cost $11,719 and traditional skilled nursing, $8,336. However, there was a large difference in the time spent institutionalized: patients treated in acute rehabilitation units averaged 19 days and those in skilled nursing units, 33 days. Similarly, Levi 39 reported no difference in functional skills or community dwelling status between subjects discharged to acute rehabilitation and those cared for in skilled nursing units at 6 months following hip fracture. However, those treated in acute rehabilitation units had significantly fewer days of institutionalization (17 days versus 38 days). Last, Kane and associates 4~ reported their findings of 606 hip fracture patients evaluated in the acute hospital setting and 6 weeks, 6 months, and 12 months after hospital discharge. Primary outcome measures were functional status, rehospitalization rate, and mortality. The functional outcomes of posthospital care were evaluated by the instrumental variables estimation approach to correct for selection bias caused by nonrandom assignment of treatment. The impact of discharge location on functional outcome was examined by one-way analyses of variance (ANOVA). They found that the more disabled patients were discharged to rehabilitation units. Hip fracture patients discharged directly to home had the highest rehospitalization rate. Hip fracture Arch Phys Med Rehabil Vol 81, March 2000

S-72

D E G E N E R A T I V E JOINT DISEASE, Brander

patients treated in r e h a b i l i t a t i o n units e x h i b i t e d the m o s t f u n c t i o n a l i m p r o v e m e n t . Patients d i s c h a r g e d to n u r s i n g h o m e s faired the worst. Thus, the current available literature in three large prospective trials s h o w s that acute i n p a t i e n t r e h a b i l i t a t i o n is s u p e r i o r to skilled n u r s i n g care or h o m e care f o l l o w i n g hip fracture (either in terms of r e d u c e d overall i n s t i t u t i o n a l i z a t i o n or i m p r o v e d f u n c t i o n a l o u t c o m e s ) , b u t at greater overall cost o f care. References I. Ciol MA, Deyo RA, Howell E, Kreif S. An assessment of surgery for spinal stenosis: time trends, geographic variations, complications, and reoperations. J Am Geriatr Soc 1996;44:285-90. 2. Stucki G, Liang MH, Lipson SJ, Fossel AH, Katz JN. Contribution of neuromuscular impairment to physical functional status in patients with lumbar spinal stenosis. J Rheumatol 1994;21:1338-43. 3. Turner JA, Ersek M, Hen-on L, Deyo R. Surgery for lumbar spinal stenosis. Attempted meta-analysis of the literature. Spine 1992;17: 1-8. *4. J6nsson B, Annertz M, Sj6berg C, Str~mqvist B. A prospective and consecutive study of surgically treated lumbar spinal stenosis. Part II. Five-year follow-up by an independentobserver. Spine 1997;22:293844. 5. Katz JN, Lipson SJ, Lew RA, Grobler LJ, Weinstein JN, Brick GW, et al. Lumbar laminectomy alone or with instrumented or noninstrumented arthrodesis in degenerative lumbar spinal stenosis: patient selection, costs, and surgical outcomes. Spine 1997;22:1123-31. *6. Weinstein SL. Natural history and treatment outcomes of childhood hip disorders. Clin Orthop 1997;344:227-42. 7. Churgay CA, Caruthers BS. Diagnosis and treatment of congenital dislocation of the hip. Am Faro Physician 1992;45:1217-28. *8, Saturen P. Skeletal disorders in children. In: Molnar G, editor. Pediatric rehabilitation. Baltimore: Williams & Wilkins, 1985:390419. 9. Heinrich SD, Missinne LH, Macewen GD.The conservative management of congenital dislocation of the hip after walking age, Clin Orthop 1992;281:34-40. 10. Fujioka E Terayama K, Sugimoto N, Tanikawa H. Long-term results of congenital dislocation of the hip treated with Pavlik harness. J Pediatr Orthop 1995;15:747-52. l 1. Malvitz TA, Weinstein SL.Closed reduction for congenital dysplasia of the hip: functional and radiographic results after an average of thirty years. J Bone Joint Surg Am 1994;76:1777-92. 12. Weinstein SL. Congenital hip dislocation: long-range problems, residual signs, and symptoms after successful treatment. Clin Orthop 1997;344:69-74. '13. Fourth ACCP Consensus Conference on Antithrombotic Therapy. Chest 1995; 108 Suppl:S225-522. 14. Sharrock NE, Go G, Harpel PC, Ranawat CS, Sculco TT, Salvti EA. The John Chamley Award. Thrombogenesis during total hip arthroplasty. Clin Orthop 1995;319:16-27. 15. Warwik D, Martin AG, Glew D, Bannister GC. Measurement of femoral vein blood flow during total hip replacement: duplex ultrasound imaging with and without the use of a foot pump. J Bone Joint Surg Br 1994;76:918-21. 16. Hull RD, Raskob GE, Pineo GF, Feldstein W, Rosenbloom D, Gafni A, et al. Subcutaneous low-molecular-weight heparin vs warfarin for prophylaxis of deep vein thrombosis after hip or knee implantation: an economic perspective. Arch Intern Med 1997;157:298-303. 17. Menzin J, Colditz GA, Regan MM, Richner RE, Oster G. Cost effectiveness of enoxaparin vs low-dose warfarin in the prevention of deep-vein thrombosis after total hip replacement. Arch Intern Med 1995; 155:757-64. 18. Dahl OE, Andreassen G, Aspelin T, Mtiller C, Mathiesen P, Nyhus S, et al. Prolonged thromboprophylaxis following hip replacement surgery-- results of a double-blindprospective, randomised placebocontrolled study with dalteparin. Thromb Haemost 1997;77:26-31. 19. Sarasin FP, Bounameaux H. Antithrombotic strategy after total hip replacement: a cost-effective analysis comparing prolonged oral

Arch Phys Med Rehabil Vol 81, March 2000

anticoagulants with screening for deep vein thrombosis. Arch Intern Med 1996;156:1661-8. 20. Kilgus DJ, Dorey F1, Finerman GAM, Amstutz HC. Patient activity, sports participation, and impact loading on the durability of cemented total hip replacements. Clin Orthop 1991;269:25-31. 21. Ritter M, Meding J. Total hip arthroplasty: can the patient play sports again? Orthopedics 1987; 10:1447-52. 22. Kobayashi S, Takaoka K, Saito N, Hisa K. Factors affecting aseptic failure of fixation after primary Chamley total hip arthroplasty. J Bone Joint Surg Am 1997;79:168-27. 23. Diduch DR, Insall JN, Scott WN, Scuderi GR, Font-Rodriguez D. Total knee replacements in young, active patients. J Bone Joint Surg Am 1997;79:575-81. 24. Long W; Dorr L, Healy B, Perry J. Functional recovery of noncemented hip arthroplasty. Clin Orthop 1993; 288:73-7. *25. Felson DT, Zbang Y. An update on the epidemiology of knee and hip osteoarthritis with a view to prevention. Arthritis Rheum 1998;4:134355. 26. McAlindon TE, Felson DT, Zhang Y, Hannan MT, Aliabadi E Weissman B, et al. Relation of dietary intake and serum levels of vitamin D to progression of osteoarthritis of the knee among participants in the Framingham study. Ann Intern Med 1996;125: 353-9. 27, Smith GN Jr, Meyers SL, Brandt KD, Mickler EA. Effect of intraarticular hyaluronan injection in experimental canine osteoarthritis. Arthritis Rheum 1998;4:976-85. 28. Wobig M, Dickhut A, Maier R, Vetter G. Viscosupplementation with hylan G-F-20: a 26-week controlled trial of efficacy and safety in the arthritic knee. Curr Ther 1998;20:410-23. 29. Adams ME, Atkinson MH, Lussier AJ, Schulz JI, Siminovitch KA, Wade JP, et al. The role of viscosupplementation with hylan G-F-20 (Synvisc) in the treatment of osteoarthritis of the knee: a Canadian multicenter trial comparing hylan G-F-20 alone, hylan G-F-20 with non-steroidal anti-inflammatorydrugs (NSAIDs) and NSAIDs alone. Osteoarthritis Cartilage 1995;3:215-25. 30. Morreale P, Manopulo R, Galati M, Boccanera L, Saponati G, Bocchi L. Comparison of the antiinflammatory efficacy of chondroitin sulfate and diclofenac sodium in patients with knee osteoarthritis. J Rheumatol t996;23: t 385-91. 31. L'Hirondel JL. Klinische Doppelblind-studie mit oral verabreichtem Chondroitinsulfatgegen Placebo bei der tibiofemoralen Gonarthrose, Litera Rheumatologica 1992;14:69-75. 32. Schiedermayer D. Glucosamine sulfate for the treatment of osteoarthritis. Alternative Medicine Alert 1998; 1:121-32. *33. Fisher NM, Pendergast DR, Gresham GE, Calkins E. Muscle rehabilitation: its effect on muscular and functional performance on patients with knee osteoarthritis. Arch Phys Med Rehabil 1991;72: 367-74. 34. Tan J, Baci N, Sepici V, Gener FA. Isokinetic and isometric strength in osteoarthritis of the knee. Am J Phys Med Rehabil 1995;74:364-9. *35. Kovar PA, Allegrante JP, MacKenzie CR, Perterson MGE, Gutin B, Charlson ME. Supervised fitness walking in patients with osteoarthritis of the knee. Ann Intern Med 1992;116:529-34. *36. Minor MA, Hewett JE, Webel RR, Anderson SK, Kay DR. Efficacy of physical conditioning exercise in patients with rheumatoid arthritis and osteoarthritis. Arthritis Rheum 1989;32:1396-1405. *37. Fisher NM, Gresham GE, Abrams M, Hicks J, Horrigan D, Pendergast DR, Quantitative effects of physical therapy on muscular and functional performance in subjects with osteoarthritis of the knees. Arch Phys Med Rehabil 1993;74:840-7. *38. Kramer AM, Steiner JR Scheenker RE, Eilertken TB, Hrincevich CA, Tropea DA, et al. Outcome and costs after hip fracture and stroke: a comparison of rehabilitation settings. JAMA 1997;277:396404. *39. Levi SJ. Posthospital setting, resource utilization, and self-care outcome in older women with hip fracture. Arch Phys Med Rehabil 1997:78:973-9. 40. Kane RL, Chen Q, Finch M, Blewett L, Bums R, Moskowitz M. Functional outcomes of posthospital care for stroke and hip fracture patients under Medicare. J Am Geriatr Soc 1998;46:1525-33. *Key References.