| Class II Posterior Shell TLSO Improves Treatment of Thoracolumbar Fractures
Problem Statement: Low bone mineral density of osteoporotic patients with spinal fractures precludes spinal fusion as a treatment alternative. Spinal orthoses are widely prescribed to treat pain and deformity in patients with pathologic wedge and compression fractures from osteoporosis (Marsolais 1985), despite a lack of scientific evidence of their effectiveness in reducing pain and resisting deformity progression. There appears to be no reported studies on the effectiveness of orthotic treatment for pathologic thoracolumbar fractures in patients with osteoporosis.
Physicians typically prescribe dorsolumbar or lumbosacral corsets for thoracolumbar fractures, and frequently abandon orthotic treatment altogether when they fail to reduce symptoms. Some physicians still prescribe the Jewett or Cash hyperextension orthoses and are usually disappointed with the patient's noncompliance.
With an increasing elderly population and the limited mechanical treatments available, the Class II Posterior Shell-TLSO with Corset Front (PSTLSO) may have the potential to mechanically stabilize osteoporotic pathologic fractures in a tolerable fashion, while improving the quality of life for the patient.
Future Research: Primary mechanical and clinical questions yet to be answered are: (i) Does the PS-TLSO-CF stabilize the fractures? (ii) How much stiffness in the PSTLSO is optimal to achieve angular reduction and pain reduction? (iii) Will the addition of pelvic anterior tilt significantly improve the overall function? (iv) Does the PSTLSO significantly improve quality of life?
Significance of Osteoporosis: Osteoporosis is a major public health threat for 28 million Americans, 80% of whom are women. In the U.S. in 1997, 10 million individuals already have osteoporosis and 18 million more have low bone mass, placing them at increased risk for this disease. One out of every two women and one in eight men over 50 will have an osteoporosis-related fracture in a lifetime. More than two million American men suffer from osteoporosis, and an additional three million are at risk. Each year, 80,000 men suffer a hip fracture and one-third of these men die within a year. Osteoporosis can strike at any age. Osteoporosis is responsible for 1.5 million fractures annually, including 300,000 hip fractures, 700,000 vertebral fractures, 200,000 wrist fractures, and more than 300,000 fractures at other sites, estimated national direct expenditures (hospitals and nursing homes) for osteoporosis and related fractures is $14 billion each year. (Graves 1993, Kanis 1994, National Osteoporosis Foundation 1997, Ray 1997, Riggs 1995, US Congress Office of Technology Assessment 1994).
The role spinal orthoses play in the treatment of spinal fractures, low back pain and spinal deformity is well documented. However, little is known about the role of orthoses for the treatment of osteoporotic pathologic fractures of the thoracolumbar spine. Osteoporosis is one of the major musculoskeletal problems in the elderly.
It is well recognized that the veteran population is aging. Risk of spinal osteoporosis with vertebral fracture increases almost six-fold among those with a significant underlying disease known to affect calcium or bone metabolism; it is significantly increased in heavy smokers and alcohol users (Seeman 1983). In fiscal year 1988, nearly 10% of patients discharged from VA medical centers were diagnosed with alcohol dependence or abuse and with nutritional deficiencies and metabolic bone diseases (Department of Veterans Affairs, 1988).
Thus, increased risk of osteoporotic fractures represents a major concern in the VA. The proposed study and its long-term objectives are aimed at significantly improving the quality of life of veterans suffering from this debilitating disease.
Clinical History of the Posterior Shell TLSO: Because of low bone mineral density of osteoporotic patients with spinal fractures, spinal fusion is not a treatment alternative. While the Jewett and Cash hyperextension orthoses have been a standard for orthotic treatment for these patients, intolerance of high sternal pad pressures and resultant patient noncompliance have doomed these orthoses to failure. The continuing high demand for orthotic treatment for these patients has led to alternative approaches to orthotic treatment.
Fister and Beets first reported on the use of a posterior shell TLSO for postoperative immobilization of spinal fusion for scoliosis (Fister and Beets 1985). They used a custom-molded posterior device to prevent patient trunk movement during healing fusion. This concept was used first by Gavin in 1986 for orthotic treatment of deformity and pain from osteoporosis by utilizing the same mechanism of action reported by Fister and Beets.
The lack of angular change (hyperextension) in the posterior shell TLSO described by Fister and Beets was clinically inadequate for these patients with large angular deformities, and so a design variant utilizing a posterior shell of low density polyethylene with a corset front and a class III hyperextension lever (similar lever used in the Jewett and Cash) was developed. Hyperextension is applied with bilateral retracting shoulder straps in the same fashion as a Taylor type TLSO; this approach was not well tolerated since it used high magnitudes of retraction loads in the shoulder girdle.
The next approach was to lower the anterior force in the posterior shell to the thoracolumbar junction and mold two "leaf spring"-type polypropylene longitudinal struts into the polyethylene shell to increase retraction stiffness. This changes the lever class to a class II lever, and reduced the amount of retraction force in the shoulder girdle significantly and was well-tolerated by the patients.
Between 1988 and 1998, 77 posterior shell TLSOs were fitted by Gavin and coworkers. Diagnoses included mild traumatic fractures, spinal osteosarcoma, metastatic disease of the spine, osteomyelitis, adult Scheuermans disease kypnosis, postoperative for thoracolumbar spinal fusion, non-specific back pain; 28 of these patients were geriatric patients with anterior wedge and/or compression fractures of the thoracolumbar spine with osteoporosis. All traumatic and pathologic fractures were fitted with a class II lever hyperextension posterior shell TLSO and all others were fitted in sagittal plane neutral as reported by Fister and Beets. The addition of sequencing forces with the initial orthosis providing a class II hyperextension and a subsequent follow-up of adding anterior pelvic tilt in a second orthosis to enhance the hyperextension was attempted in two patients after six months in the first orthosis. All osteoporotic patients were followed for not less than six months and up to five years. Sex distribution was approximately 70% female, with age ranges from 55 to 96 years. There were two reports of noncompliance in this group of 28. The most common complaint was difficulty in donning, which is similar to complaints for all spinal orthoses. The two patients, with the additional sequence of anterior tilting of the pelvis, claimed that they "felt even better" in their new orthosis. However, all 28 patients reported short-term pain relief and an increase in daily activity function while in the orthoses.
References:
Contact John Kamp, CPO, at AmPro's Davenport office for a complete list of references.
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