3
have been advocating for them for years. Recursive holistic assessment processes for back pain that use intelligently designed frameworks and transdisciplinary team intelli- gence work [3]. Recently Christy Tomkins and I wrote a commentary for JAMA describing a rational process rather than a single test to “diagnose” the disease [4]. These processes are reproducible and researchable. Yet the Na- tional Institutes of Health and other policymakers have paralyzed the advancement of care for real people in the next 2 decades because they can’t reconcile their 20th- century mindset with our country’s 21st-century needs, budgets, and time frames. Jack believes that the future of medicine is exactly what we physiatrists do: build a cul- ture of care. Work with the other physicians as a team. Look at the patient’s goals, not the standard metrics. Share the planning and decision making with the patient. It’s old-time medicine, and it has been tossed out with the statistical games of the past 50 years. It is heartening to see that Drs. Ramirez-Del Toro and Prizinski’s letter reflects distress about our old ways. Fortu- nately, a lot of very influential 21st-century experts are catch- ing up with old Dr. Peirce [5-7]. For now, we can play the reductionist game if it gets us funding. However, we need to insist on teaching and researching the complex recursive process in spinal care or our patients and our society will suffer. Andrew J. Haig, MD Physical Medicine and Rehabilitation The University of Michigan Ann Arbor, MI A.J.H. Disclosure: 1B, consulting; 3A, multiple academic centers; 5B, occasional legal cases; 8B, NIH R-01H00592559: Center for Healthcare Research and Transformation; 9, president, International Rehab forum and Board of International Societies of PM&R http://dx.doi.org/10.1016/j.pmrj.2012.04.010 REFERENCES 1. Haig AJ, Adewole A, Yamakawa KSJ, et al. The ligament flavum at L45: Relationship with anthropomorphic factors and clinical find- ings in older persons with and without spinal disorders. PM R 2012;4:23-29. 2. Haig AJ, Tong HC, Yamakawa KS, et al. Predictors of pain and function in persons with spinal stenosis, low back pain, and no back pain. Spine 2006;31:2950-2957. 3. Haig AJ, Theisen M, Geisser ME, Michel B, Yamakawa K. Team decision making for spine team assessment: Standardizing the mul- tidisciplinary assessment for chronic back pain. Arch Phys Med Rehabil 2000;81:1281. 4. Haig AJ, Tomkins C. Diagnosis and treatment of lumbar spinal stenosis. JAMA 2010;303:71-72. 5. Barry MJ. Edgman-Levitan S. Shared decision making—the pinnacle of patient-centered care. N Engl J Med 2012;366:777-779. 6. Cottingham AH, Suchman AL. Litzelman DK. Enhancing the informal curriculum of a medical school: A case study in organizational culture change. J Gen Intern Med 2008;23:715-722. 7. Reuben DB, Tinetti ME. Goal-oriented patient care—an alternative health outcomes paradigm. N Engl J Med 2012;366:777-779. The Complexities Surrounding Decisions Related to Prosthetic Fitting in Elderly Dysvascular Amputees To the Editor, The Point/Counterpoint article in the January 2012 issue of PM&R addressed the challenging decision of whether to fit an elderly dysvascular patient with transfemoral (TF) amputation with a prosthetic limb [1]. We would like to express our appre- ciation to PM&R for publishing this work, to Drs Frieden and Brar for providing a conceptual framework to assist in the formulation of this decision, and to Dr Esquanazi for providing a stimulating counterpoint to this discussion. It is clear that there are no simple decision algorithms to guide clinical decision making, and the available scientific evidence is inadequate. Our goal in submitting this letter is to provide an addi- tional perspective, supplemented by more recent literature, which will, it is hoped, augment the discussion and assist readers as they address this critical issue. METABOLIC COST AND ENDURANCE The metabolic consequences of ambulation with a pros- thetic limb and their implications for fitting a TF prosthetic limb in patients with underlying cardiovascular disease are confusing, and clinicians tend to use various metabolic terms with inadequate precision. The rate of metabolic energy expenditure (mL O 2 /kg/min) is the rate at which oxygen is consumed during a given exercise task and is reflective of the instantaneous cardiac demand (heart rate, stroke volume, and blood pressure). Therefore, it may be related to symp- toms of angina or silent cardiac ischemia when exercise occurs at an intensity in which the oxygen demand of the myocardium exceeds the oxygen supply. In both amputees and nonamputees, the rate of metabolic energy expenditure increases with walking speed and is greater in amputees at any given walking speed. However, amputees choose a self- selected walking speed that is slower than nonamputees. The implications of this are that, if individuals with amputation are allowed to walk at their self-selected speed, then their rate of metabolic energy expenditure is the same as normal and there is no additional cardiac demand. It, therefore, should play little role in the decision to fit or not to fit a prosthetic limb. The metabolic cost of ambulation (mL O 2 /kg/m) in con- trast, is the amount of oxygen consumed per distance walked and is reflective of the efficiency and economy of ambulation. It is increased in amputees compared with nonamputees at all walking speeds. From a clinical perspective, increased meta- bolic cost is reflective of increased muscle work to walk a given distance. Functionally, this may result in more limited endurance and reduced walking distances. 540 LETTERS TO THE EDITOR

The Complexities Surrounding Decisions Related to Prosthetic Fitting in Elderly Dysvascular Amputees

Embed Size (px)

Citation preview

540 LETTERS TO THE EDITOR

have been advocating for them for years. Recursive holisticassessment processes for back pain that use intelligentlydesigned frameworks and transdisciplinary team intelli-gence work [3]. Recently Christy Tomkins and I wrote acommentary for JAMA describing a rational process ratherthan a single test to “diagnose” the disease [4]. Theseprocesses are reproducible and researchable. Yet the Na-tional Institutes of Health and other policymakers haveparalyzed the advancement of care for real people in thenext 2 decades because they can’t reconcile their 20th-century mindset with our country’s 21st-century needs,budgets, and time frames. Jack believes that the future ofmedicine is exactly what we physiatrists do: build a cul-ture of care. Work with the other physicians as a team.Look at the patient’s goals, not the standard metrics. Sharethe planning and decision making with the patient. It’sold-time medicine, and it has been tossed out with thestatistical games of the past 50 years.

It is heartening to see that Drs. Ramirez-Del Toro andPrizinski’s letter reflects distress about our old ways. Fortu-nately, a lot of very influential 21st-century experts are catch-ing up with old Dr. Peirce [5-7]. For now, we can play thereductionist game if it gets us funding. However, we need toinsist on teaching and researching the complex recursiveprocess in spinal care or our patients and our society willsuffer.

Andrew J. Haig, MDPhysical Medicine and Rehabilitation

The University of MichiganAnn Arbor, MI

A.J.H. Disclosure: 1B, consulting; 3A, multiple academic centers; 5B, occasionallegal cases; 8B, NIH R-01H00592559: Center for Healthcare Research and

Transformation; 9, president, International Rehab forum and Board of InternationalSocieties of PM&R

http://dx.doi.org/10.1016/j.pmrj.2012.04.010

REFERENCES1. Haig AJ, Adewole A, Yamakawa KSJ, et al. The ligament flavum at

L4�5: Relationship with anthropomorphic factors and clinical find-ings in older persons with and without spinal disorders. PM R2012;4:23-29.

2. Haig AJ, Tong HC, Yamakawa KS, et al. Predictors of pain and functionin persons with spinal stenosis, low back pain, and no back pain. Spine2006;31:2950-2957.

3. Haig AJ, Theisen M, Geisser ME, Michel B, Yamakawa K. Teamdecision making for spine team assessment: Standardizing the mul-tidisciplinary assessment for chronic back pain. Arch Phys MedRehabil 2000;81:1281.

4. Haig AJ, Tomkins C. Diagnosis and treatment of lumbar spinal stenosis.JAMA 2010;303:71-72.

5. Barry MJ. Edgman-Levitan S. Shared decision making—the pinnacle ofpatient-centered care. N Engl J Med 2012;366:777-779.

6. Cottingham AH, Suchman AL. Litzelman DK. Enhancing the informalcurriculum of a medical school: A case study in organizational culturechange. J Gen Intern Med 2008;23:715-722.

7. Reuben DB, Tinetti ME. Goal-oriented patient care—an alternative

health outcomes paradigm. N Engl J Med 2012;366:777-779.

The Complexities SurroundingDecisions Related to ProstheticFitting in Elderly DysvascularAmputees

To the Editor,The Point/Counterpoint article in the January 2012 issue of

PM&R addressed the challenging decision of whether to fit anelderly dysvascular patient with transfemoral (TF) amputationwith a prosthetic limb [1]. We would like to express our appre-ciation to PM&R for publishing this work, to Drs Frieden andBrar for providing a conceptual framework to assist in theformulation of this decision, and to Dr Esquanazi for providinga stimulating counterpoint to this discussion. It is clear that thereare no simple decision algorithms to guide clinical decisionmaking, and the available scientific evidence is inadequate.

Our goal in submitting this letter is to provide an addi-tional perspective, supplemented by more recent literature,which will, it is hoped, augment the discussion and assistreaders as they address this critical issue.

METABOLIC COST AND ENDURANCEThe metabolic consequences of ambulation with a pros-

thetic limb and their implications for fitting a TF prostheticlimb in patients with underlying cardiovascular disease areconfusing, and clinicians tend to use various metabolic termswith inadequate precision. The rate of metabolic energyexpenditure (mL O2/kg/min) is the rate at which oxygen isconsumed during a given exercise task and is reflective of theinstantaneous cardiac demand (heart rate, stroke volume,and blood pressure). Therefore, it may be related to symp-toms of angina or silent cardiac ischemia when exerciseoccurs at an intensity in which the oxygen demand of themyocardium exceeds the oxygen supply. In both amputeesand nonamputees, the rate of metabolic energy expenditureincreases with walking speed and is greater in amputees atany given walking speed. However, amputees choose a self-selected walking speed that is slower than nonamputees. Theimplications of this are that, if individuals with amputationare allowed to walk at their self-selected speed, then their rateof metabolic energy expenditure is the same as normal andthere is no additional cardiac demand. It, therefore, shouldplay little role in the decision to fit or not to fit a prostheticlimb.

The metabolic cost of ambulation (mL O2/kg/m) in con-trast, is the amount of oxygen consumed per distance walkedand is reflective of the efficiency and economy of ambulation.It is increased in amputees compared with nonamputees at allwalking speeds. From a clinical perspective, increased meta-bolic cost is reflective of increased muscle work to walk agiven distance. Functionally, this may result in more limited

endurance and reduced walking distances.

eiifeaoe

pomr

ptoptpmcpltactm

dcdc

541PM&R Vol. 4, Iss. 7, 2012

The final metabolic variable that needs to be consideredis the “relative energy cost” and its relationship to the anaerobicthreshold. The anaerobic threshold is a metabolic work rate thatresults in the utilization of anaerobic muscle metabolism inaddition to aerobic mechanisms to perform the work. Thistypically occurs at an exercise intensity between 45% and 60%of maximum rate of oxygen consumption (VO2 max) [2]. In theelderly dysvascular TF amputee walking with a prosthesis, thisresults in a relative energy cost of 63% of VO2 max [3], therefore,xceeding the anaerobic threshold. Once this exercise intensitys reached, there is a reduced ability to sustain that exercisentensity. The functional end result is that, if perceived exertion,atigue, and limitations in ambulatory endurance are severenough, then the likely outcome is a failure to achieve prostheticmbulation or to sustain it across time. This is supported by thebservation that elderly TF amputees that could achieve anxercise intensity of 50% of their predicted VO2 max were

significantly more likely to successfully use a prosthesis [4].In the Point/Counterpoint article [1], there is a suggestion

that the provision of a light-weight prosthesis may reduce theadverse metabolic consequences of ambulation. There havebeen many studies that have addressed this issue, and, al-though there are some inconsistencies in the results, themajority of the literature suggests that mass has no significanteffect on metabolic costs or rate of metabolic energy expen-diture during steady-state ambulation.

TRANSFER LIMBThe role of a prosthetic limb in facilitating independent

transfers (when ambulation is not a goal) is controversial andlikely amputation-level specific. The biomechanics of sit-to-stand and stand-to-sit tasks require significant joint exten-sion moments at both the hip and at the knee. In the case ofthe TF amputee, the prosthetic knee generates insignificantextension moments during the sit-to-stand task. Even whenusing the Power Knee (Össur Americas, Foothill Ranch, CA),which is designed to generate positive extension power, TFamputees do not generate a significant knee extension mo-ment. Although prosthetic knees with hydraulic resistanceand/or microprocessor control can theoretically control de-scent of the body center of mass during the stand-to-sit task,a recent study noted that this transitional movement is essen-tially a one-legged task performed by the intact limb in TFamputees [5]. A TF prosthetic limb, therefore, does notprovide a useful role to assist with transfers.

FUNCTIONAL TASK PERFORMANCEAlthough the discussion of single-limb standing balance

in the Point/Counterpoint article [1] primarily pertains tocardiovascular demand, it is important to point out that theliterature supports single-limb standing balance as a strongindependent predictor of ambulation. In a systematic review

article [6], it was the only physical capacity measure that was

correlated with mobility outcome, a finding that is corrobo-rated in a well-designed prospective cohort study [7]. The

otential value of single-limb standing balance as a predictorf future walking ability likely reflects the multimodal de-ands of balance, muscle strength, and muscle endurance

equired by this task.

COGNITIVE FACTORSThe effect of cognition on successful prosthetic provision

is controversial. In contrast to 2 older studies referenced inthe Point/Counterpoint article [1], more recent studies havenot shown a correlation between cognition and prostheticuse [7,8]. These somewhat contradictory findings indicatethat there may be a critical threshold of cognitive impairmentthat is necessary for successful prosthetic use. In addition, assuggested by the findings of O’Neill and Evans [9], certaincognitive domains may be more important predictors ofamputee mobility than others.

PREMORBID MOBILITYThe preamputation mobility level is increasingly being

recognized as an important factor in predicting mobilityoutcome after amputation [10,11] and after vascular surgical

rocedures [12,13]. As noted in the Point/Counterpoint ar-icle [1], patients who undergo amputation for complicationsf peripheral vascular disease and diabetes often have manyremorbid conditions that can adversely affect mobility. Inhe reported case, the patient was described as being “inde-endent in all activities of daily living and ambulation until 6onths ago [1].” A more detailed description is required to

ompletely integrate the effect of premorbid mobility onrosthetic decision making. To determine the effect of base-

ine comorbidities on function, mobility must be defined at aime point before the onset of the disability that led tomputation. Although there is no specific predictive modelurrently available to arrive at patient-specific recommenda-ions, the information gained can enhance clinical decisionaking.In addition to the above-mentioned factors that were

iscussed in the Point/Counterpoint article [1], a number ofritical issues that should be considered in prosthetic fittingecisions were not adequately addressed and will be dis-ussed below.

MENTAL HEALTH STATUS: DEPRESSIONDepressive symptoms are extremely common after ampu-

tation [14,15]. Depression has been associated with reducedmobility [11] as well as other more general indices of func-tional outcome [7]. Because depression can significantly affectmany aspects of amputee outcome, it should be evaluated aspart of every postamputation rehabilitation assessment, and, ifpresent, it should be treated to increase the likelihood of suc-

cessful prosthetic fitting and ambulation.

542 LETTERS TO THE EDITOR

RESIDUAL LIMB CHARACTERISTICSThe length and quality of the residual limb can profoundly

affect the probability of successful prosthetic ambulation. Alonger residual limb provides a longer lever arm and addi-tional functional muscle length in the hamstrings and rectusfemoris, which improves overall muscle power and torquegeneration. The shape, soft tissue characteristics, and sensi-tivity of the residual limb can also profoundly affect pros-thetic use. For instance, a patient with significant scar invag-ination and/or residual limb hypersensitivity will often beless likely to achieve a successful socket fit. Although somemanual muscle testing was reported in the case presentation,there was no mention of residual limb hip extensor andabductor strength; in the closed kinetic chain, these musclegroups are of vital importance to provide knee stability andpelvic stability, respectively. All of these residual limb factorsmust be considered in any decision to move forward, with thegoal of prosthetic fitting.

CONCLUSIONAlthough the Point/Counterpoint article [1] focuses al-

most entirely on whether or not a prosthesis should beprescribed, it is important to remember that the overall goalof amputee rehabilitation is in maximizing functional qualityof life while maintaining safety and minimizing the risk ofsecondary complications. In a marginal user, there would bean increased risk of falls that lead to injury, especially ifthe patient is anticoagulated (which is likely given that thecase reports a history of arterial thrombosis). In addition,there may be increased risk of residual limb and intact footskin breakdown with attempts at ambulation, especially inindividuals with diabetes.

In a case in which the prognosis for successful use of aprosthetic limb is relatively low and there is clear risk involved,other means of allowing a patient to achieve functional indepen-dence should be explored. In this case, the patient’s stated goal isto return home independently. Therapies can be refocused tooptimize manual wheelchair mobility and transfers without aprosthetic limb. The patient’s home environment can be as-sessed for improving accessibility, such as ramping the 3-stepentry and ensuring that doorways are wide enough to allowwheelchair passage. There is a common reductive bias that a“productive life” requires bipedal ambulation. There are cer-tainly many nonambulatory individuals with disabilities wholive very productive lives. In some cases in which ambulation isnot part of a rehabilitation goal, the rehabilitation team mustassist the patient in the psychosocial adaptation to this outcome.

It is challenging to provide a definitive answer to thequestion presented in this case. We have attempted to pro-vide an additional perspective, including the addition ofrecent pertinent literature to support the discussion whenpossible. Clearly, there is a need for continued prospective

studies to aid in this challenging decision.

David C. Morgenroth, MDJoseph M. Czerniecki, MD

Department of Veterans AffairsRegional Amputation Center

Puget Sound Health Care SystemDepartment of Rehabilitation Medicine

University of WashingtonSeattle, WA

D.C.M. Disclosure: 8A, Department of Veterans Affairs Career Development Award

J.M.C. Disclosure: nothing to disclose

http://dx.doi.org/10.1016/j.pmrj.2012.05.005

REFERENCES1. Frieden RA, Brar AK, Esquenazi A, Watanabe T. Fitting an older patient

with medical comorbidities with a lower-limb prosthesis. PM R 2012;4:59-64.

2. Forman DE, Myers J, Lavie CJ, Guazzi M, Celli B, Arena R. Cardiopul-monary exercise testing: Relevant but underused. Postgrad Med 2010;122:68-86.

3. Waters RL, Perry J, Antonelli D, Hislop H. Energy cost of walking ofamputees: The influence of level of amputation. J Bone Joint Surg Am1976;58:42-46.

4. Chin T, Sawamura S, Fujita H, et al. %VO2max as an indicator ofprosthetic rehabilitation outcome after dysvascular amputation. Pros-thet Orthot Int 2002;26:44-49.

5. Highsmith MJ, Kahle JT, Carey SL, et al. Kinetic asymmetry in trans-femoral amputees while performing sit to stand and stand to sit move-ments. Gait Posture 2001;34:86-91.

6. van Velzen JM, van Bennekom CA, Polomski W, Slootman JR, van derWoude LH, Houdijk H. Physical capacity and walking ability afterlower limb amputation: A systematic review. Clin Rehabil 2006;20:999-1016.

7. Schoppen T, Boonstra A, Groothoff JW, de Vries J, Goeken LN, EismaWH. Physical, mental, and social predictors of functional outcome inunilateral lower-limb amputees. Arch Phys Med Rehabil 2003;84:803-811.

8. Hanspal RS, Fisher K. Prediction of achieved mobility in prostheticrehabilitation of the elderly using cognitive and psychomotor assess-ment. Int J Rehabil Res 1997;20:315-318.

9. O’Neill BF, Evans JJ. Memory and executive function predict mobilityrehabilitation outcome after lower-limb amputation. Disabil Rehabil2009;31:1083-1091.

10. Johnson VJ, Kondziela S, Gottschalk F. Pre and post-amputation mo-bility of trans-tibial amputees: Correlation to medical problems, ageand mortality. Prosthet Orthot Int 1995;19:159-164.

11. Norvell DC, Turner AP, Williams RM, Hakimi KN, Czerniecki JM.Defining successful mobility after lower extremity amputation for com-plications of peripheral vascular disease and diabetes. J Vasc Surg2011;54:412-419.

12. Landry GJ. Functional outcome of critical limb ischemia. J Vasc Surg2007;45(Suppl A):A141-148.

13. Taylor SM, Kalbaugh CA, Blackhurst DW, et al. Determinants offunctional outcome after revascularization for critical limb ischemia:An analysis of 1000 consecutive vascular interventions. J Vasc Surg2006;44:747-755; discussion 55-56.

14. Darnall BD, Ephraim P, Wegener ST, et al. Depressive symptoms andmental health service utilization among persons with limb loss: Resultsof a national survey. Arch Phys Med Rehabil 2005;86:650-658.

15. Coffey L, Gallagher P, Horgan O, Desmond D, MacLachlan M. Psycho-social adjustment to diabetes-related lower limb amputation. Diabet

Med 2009;26:1063-1067.