By Shalmali Pal
Total hip arthroplasty can markedly improve quality of life in patients with Down syndrome, but the comorbidities and developmental disability associated with the chromosomal abnormality need to be taken into consideration when planning surgery and rehabilitation.
The life expectancy for people with Down syndrome (DS) has increased dramatically, from 25 years in 1983 to 60 years in 2014.1 Many patients with DS, the most commonly occurring chromosomal abnormality, are graduating from high school, going to college, building careers or holding jobs, marrying, and becoming active members of society.
But, as with the general population, these 400,000 adults in the US also have to contend with the aging process and its related health issues, including musculoskeletal disorders that require surgical intervention. More than 285,000 total hip arthroplasty (THA) procedures are performed annually in the US,2 and patients with Down syndrome account for more of those procedures each year, although exact numbers are hard to come by.
The developmental disability associated with Down syndrome, as well as musculoskeletal issues that can make THA more technically challenging, have led to concerns among some practitioners as to whether the surgery is appropriate in patients with the condition. But Down syndrome itself is no reason to rule out a patient as a viable surgical candidate, according to experts who spoke with LER. In fact, THA can be valuable in this population, experts say, but certain factors do need to be taken into consideration to ensure optimal outcomes.
Reliable surgical intervention
The majority of adult patients with DS are eligible for THA, according to Allan Gross, MD, a professor of orthopedic surgery at the University of Toronto in Canada and lead investigator for the Replacement Arthroplasty in Down Syndrome (RADS) Study Group.
“I canʼt remember the last time I turned down a patient with Downʼs for joint replacement,” Gross said. “They come to us with pretty good function, and after the surgery, they continue to function well. The most important aspects are to give top-of-the-line implants and aftercare, the same as you would with any patient.”
Published studies on THA in patients with Down syndrome report a high degree of success. In 2011, the RADS group reported THA results in seven patients (nine hips) with an average age of 34.8 years.3 At six weeks postsurgery, the average Harris Hip Score (HHS) improved from 41.1 preoperatively to 59.1 (out of 100 points). The HHS improvements held at one year (79.8) and two years (85.2), as well as eight years (70.9) postprocedure.
“We contend that THA is a reliable surgical intervention in patients with DS and may be performed in symptomatic patients,” the group concluded.
A 2013 review article4 looked at data from four studies encompassing 42 hips that reported the clinical outcomes of THA in patients with DS. The survival rates were between 81% and 100% at a mean follow-up of 105 months, which the review authors called “encouraging…overall clinical results are good, providing these patients with reliable pain relief and good function.”
The review also noted that successful treatment involved the use of standard acetabular and femoral components, the use of supplementary acetabular screw fixation to enhance component stability, and the use of constrained liners to treat intra-operative instability.
For Gross, constrained liners represent an advance in THA hardware that is tailor-made to address one of the main barriers to this procedure in patients with DS: They are prone to ligamentous hyperlaxity and muscle hypotonia that can cause instability, subluxation, and potentially an increased risk of THA dislocation.
“One of the reasons that surgeons have been hesitant to do THA in these patients has been the higher chance of dislocation,” Gross acknowledged. “But with the constrained liners, the head is constrained into the cup so itʼs much more difficult to dislocate. Another option in Downʼs patients is to use a large femoral head because it takes a lot more force to dislocate. Both of these technologies have improved in the last ten years, which makes dislocation less of an issue with normal usage, assuming thereʼs no trauma.”
Additionally, his group wrote, constrained liners “provide more reliable pain relief as there is no motion between the [head] and the acetabular bone.”3
Another surgical boon has been the movement away from performing THA with a posterior-lateral approach and toward an anterior-medial approach, which also reduces the risk for hip dislocation, explained Eric Robertson, PT, DPT, who is the director of Kaiser Permanente’s Hayward Fellowship in Advanced Orthopaedic Manual Therapy in Hayward, CA, a clinical assistant professor at the University of Texas at El Paso, and a spokesperson for the American Physical Therapy Association.
Of course, some patients will require surgical revision. In the study by Grossʼs group, two patients met that criteria: One experienced stem loosening at year five while the other had loosening of the femoral stem 16 years postsurgery as a result of proximal femoral osteolysis.3
But instances of failure are probably not any more common in patients with DS than in the general population, suggested orthopedic surgeon Michael Marks, MD, a spokesperson for the American Academy of Orthopaedic Surgeons.
He cautioned against assuming that the THA in these patients failed because of the DS.
“I think itʼs important to do a root-cause analysis: Did it fail because of technical errors? If there was no trauma, like a fall, is there an issue with the hardware? Did it happen because the patient or the caregiver didn’t follow postop instructions? There are lots of different reasons for failure that apply to THA patients whether they have Downʼs or not,” Marks said.
In the absence of a fall or a serious infection, THA in these patients should last at least a couple of decades, especially if they have the surgery earlier rather than later, Marks pointed out.
“If the average age of a THA patient in the general population is about sixty, then maybe weʼll consider the surgery in Downʼs patients in their forties if itʼs going to help them maintain their quality of life,” he said.
From a surgical perspective, THA in patients with DS is not that different from the general population, Gross and Marks agreed. The difference between the two populations is “all the support staff that you need to have in place, before and after surgery” for patients with DS, Marks said.
How to determine if a patient with DS is a candidate for THA? First, practitioners need to ascertain if patients are experiencing potentially debilitating hip pain. Thatʼs where communication becomes key. Obviously, patients who are highly functional and have advanced verbal skills may have no qualms about voicing complaints about hip pain, but thatʼs not always the case.
“We need to keep in mind that this is a population with a whole different variety of ability levels—their cognitive function, their ability to follow instructions, their ability to follow through—all of those are constant issues in this population,” stressed Debbie Caprielian, MPT, PT, president of Northstar Physical and Occupational Therapy Consulting Services in Norwalk, CA.
Healthcare professionals may have to rely on caregivers or family members to convey information about hip pain. A patient may call the caregiverʼs attention to the hip by pointing at it, for example, or caregivers may notice more gradual changes, such as a decrease in mobility or the development of a limp.
“You have to spend time with the caregivers and make sure that the pain is actually coming from the hip,” Gross emphasized. “In that respect, the preop assessment in these patients will require more time because you need to establish those lines of communication from the start.”
A determination that hip pain can be resolved with THA is not the end of the story. As with any surgery, the risks and benefits must be weighed, Robertson and Caprielian agreed.
Robertson said heʼd prefer to see a course of conservative rehabilitation with physical therapy (PT) before surgery is agreed upon, but once it is, education will be paramount, focusing specifically on the type of postoperative PT that will be provided, how much of it will be necessary, and any postop precautions.
“I wouldnʼt approach this population and say, ʻHere are your home exercises and your precautions,ʼ because you canʼt assume the same level of compliance as in the general population,” Robertson said. “The patientʼs entire support network is going to have to be extensively educated on what they can expect after the operation.”
Caprielian advised looking for red flags during the presurgical education process. For instance, if a discussion about postoperative issues, such as exercises, pain levels, and weight-bearing status, proves too overwhelming for the patient or caregiver beforehand, then it may not be the right time for surgery, she pointed out.
“The bottom line is that a high-functioning Downʼs client is probably the most pleasant person to work with. They want to please you; they want to do whatʼs right,” Caprielian said. “But if you sense any hesitation on the part of the patient or the caregivers, then who is the surgery really benefiting?”
Most standard PT protocols can be utilized in patients with DS, Robertson said, adding that “the great thing about this rehab is that it can be quite simple: Something like sitting down and standing up again can be an effective exercise in a post-THA population.”
A published post-THA protocol from Poland could apply to a patient with DS, Robertson said. The rehab algorithm calls for exercises done in supine positions, such as dorsiflexion of the foot and lower limb abduction, and standing positions, such as extending the operated hip joint against resistance.5
What the practitioner will need to ascertain is the level of assistance the patient will need to perform these exercises, and that will most likely mean more hands-on care and involvement, Robertson said.
“With the general THA population, they get PT initially in the hospital to improve mobilization, and then they are given a course of home exercises,” Robertson stated. “Again, thatʼs not something I would recommend for Downʼs patients because you canʼt count on their ability to perform exercises independently. They will need more guidance during exercise and rehab, and I think itʼs best if the PT can provide as much of that as possible.”
If compliance is an issue, Robertson suggested taking the same approach as with a less compliant typical patient—adapt the PT routine to reflect abilities and interests.
“I think itʼs a matter of getting to know the person; you donʼt need a detailed psychological profile,” he said. “Letʼs say the patient seems to get frustrated quickly; maybe you have more sessions that arenʼt as long in duration. Maybe the patient is interested in a particular sport; can you incorporate some of that into the PT? Itʼs similar to adapting a PT protocol to keep kids interested—games or puzzles—whatever is going to engage them.”
Caprielian suggested that physical therapists be prepared to do a lot of demonstration of exercises, possibly several times. If the patient or the caregiver still seems uncertain, she will do a hand-over-hand demo, physically guiding them through the exercise.
Marks recommends that a PT protocol take into consideration where the patient was in terms of mobility prior to the onset of pain.
“Many of these patients use assistive devices—a walker, a crutch, a cane—so you want to make sure that they can use them again. Iʼd recommend incorporating those devices into postoperative care,” he said.
For Gross, the immediate goal of PT should be to prevent post-THA complications to which patients with DS are particularly prone, such as dangerous blood clots and muscle atrophy.3,4 Over the long term, he likes to see patients who were mobile before THA continue on that track.
The quality-of-life question
Perhaps the least straightforward aspect of working with this population is determining if THA will lead to a better quality of life (QOL).
Of course, if the patient is complaining of pain in the affected area, and the surgery relieves that pain, thatʼs a win. And an ambulatory patient who is able to maintain an active lifestyle after THA also benefits.
But patients with DS do contend with other comorbidities, especially as they age, and these may impact THA outcomes. These include other musculoskeletal disorders, such as midcervical arthritis, and higher rates of obesity, hypothyroidism, visual impairment, and depression.6
Perhaps the most detrimental change in these patients is Alzheimer disease (AD). By age 40 years, almost all individuals with trisomy 21 will have the characteristic amyloid plaques and neurofibrillary tangles of AD, though not all develop symptoms.7
If a patient shows signs of dementia during the preoperative phase, what does that mean for THA? The experts offered mixed opinions.
In a 2013 study,8 Grossʼs group assessed post-THA QOL more than eight years after surgery in patients with DS and reported that the mean HHS improved to 84 points. They emphasized in the paper that early development of AD should be taken into account during the preoperative evaluation, and Gross told LER that the interaction between the early stages of cognitive decline and THA outcomes will depend on the patient and his or her support system.
“Making that determination will mean taking time to talk to the caregivers, because theyʼll have the best perspective on what the patient needs,” he said. “But, in terms of longevity of the THA and QOL, these patients are much less likely to be engaged in high-impact activities than the general population, so the beneficial results should be viable for a longer time.”
Caprielian is a bit more cautious. The onset of early AD doesnʼt make a patient ineligible for THA, she said. But the healthcare team does need to figure out how cognitive decline may complicate postoperative care.
“The surgery may take care of any short-term problems such as pain management. But if the client isnʼt able to respond to the postop PT, what are we accomplishing?” she said. “Once the dementia starts, many Downʼs patients become nonambulatory. If they are going to spend a lot of their time sitting, then what are they going to achieve after surgery?”
Caprielian emphasized the importance of discussing potential signs of AD preoperatively. These can include a reduction in interest in being social or conveying thoughts, lack of enthusiasm for usual activities, anxiety, uncooperativeness, and changes in coordination or walking. Itʼs the latter that Caprielian suggested the healthcare team look closely at before considering THA.
“We have some clients with DS whoʼve gone from being independent ambulators to completely wheelchair-bound; it can be a very fast decline. Others progress more slowly over many years. Itʼs difficult to predict that, but if you see a client is headed in that direction, that person may not be a candidate for joint replacement if they arenʼt in pain or complaining of pain,” she said.
It seems likely that attitudes about THA in patients with DS will change over time, as has happened with other patient populations. Marks pointed out that, during the early days of THA, many patient subgroups were not considered good prospects, but those opinions evolved. For example, once upon a time, 50 years was considered the minimum age for a joint replacement, he said.
“Another example is patients with parkinsonism who, unlike in Downʼs, have marked spasm, so we were reticent to do joint replacement, but we do them fairly routinely now,” he said. “There have always been patients who are initially put into the category of ʻWe should never do that.ʼ Over the years, weʼve changed our attitude about quality of life and what we can do to help patients continue to participate in society.”
Shalmali Pal is a freelance writer based in Tucson, AZ.
- Down Syndrome Facts. National Down Syndrome Society website. http://www.ndss.org/Down-Syndrome/Down-Syndrome-Facts/. Accessed February 27, 2015.
- OrthoInfo: Total Hip Replacement. American Academy of Orthopedic Surgeons website. http://orthoinfo.aaos.org/topic.cfm?topic=a00377. Accessed February 27, 2015.
- Kosashvili Y, Taylor D, Backstein D, et al. Total hip arthroplasty in patients with Down syndrome. Int Orthop 2011;35(5):661-666.
- Zywiel MG, Mont MA, Callaghan, JJ, et al. Surgical challenges and clinical outcomes of total hip replacement in patients with Down’s syndrome. Bone Joint J 2013;95-B(11 Suppl A):41-45.
- Stryla W, Pogorzala AM, Rogala P, Nowakowski A. Algorithm of physical therapy exercises following total hip arthroplasty. Pol Orthop Traumatol 2013;78:33-39.
- Barnhart RC, Connolly B. Aging and Down syndrome: implications for physical therapy. Phys Ther 2007;87(10):1399-1406.
- Down Syndrome and Alzheimerʼs Disease. Alzheimerʼs Association website. http://www.alz.org/dementia/down-syndrome-alzheimers-symptoms.asp. Accessed February 27, 2015.
- Gross AE, Callaghan, JJ, Zywiel MG, Mont MA, et al. Total hip arthroplasty in Down syndrome Patients: An improvement in quality of life. J Arthroplasty 2013;28(4):701-706.