The Indelible Footprint of Podiatric Medical Research from UTHSCSA
The rich history of podiatric medicine at the University of Texas Health Science Center at San Antonio (UTHSCSA) includes 70 years of patient care, 50 years of residency training, and 30 years of fellowship training. A recent paper in the International Wound Journal conducted a scientometric analysis of the most impactful institutions on diabetic foot research over the past 50 years and ranked UTHSCSA #10 in the US and #20 in the world.1 The UTHSCSA Podiatry Division (UT), in its robust research enterprise (Table 1), has impacted podiatric and limb preservation practice worldwide.
In this column, the author shares landmark studies and endeavors that today’s DPMs should know and evaluate for application in their practices.
Defining the Impact of the Diabetic Foot and Pioneering Modern Thinking
Since we serve a diverse South Texas population, UT produced some of the first data on the disproportionate risk of diabetic foot complications,2 amputations,3,4 mortality,5 and costs6 in minorities. UT researchers characterized the natural history of great toe amputations (as the hallux is the most common location for a DFU),7 increased foot pressures after hallux amputation,8 and described the spectrum of associated complications.9
Clinicians at the program reported long-term outcomes of transmetatarsal amputation10 and the risk of major reamputation in patients with diabetes,11 later quantified and stratified by level.12
Additionally, UT research found that patient functional status after diabetes-related amputations was more impaired the more proximal the amputation level.13
Charcot foot has been the subject of much study at UT, including describing its natural history,14 how deformity leads to increased peak plantar pressure,15 treatment with total contact casts,16 and the first study to describe using skin temperature to monitor response to treatment.17
UT was one of the first institutions to uncover a disturbing fact—that the white blood cell count is not a reliable indicator of foot infection in patients with diabetes.18–20 This then set up the modern dogma that diabetic foot infection is primarily a clinical, as opposed to laboratory, diagnosis.
Today, clinicians often use intravenous piperacillin/tazobactam for treatment of limb- and life-threatening diabetic foot infections, especially due to its broad-spectrum coverage and relative positive safety profile. This was due to a multicenter non-inferiority trial led by UT.21
UT researchers studied puncture wounds in those with diabetes and described their microbiological profile22 and serious risks, such as osteomyelitis23 and amputation.24 UT also cautioned providers that many of these patients have normal laboratory values, despite having serious infections from puncture wounds.20
The UT Diabetic Wound Classification
Perhaps the most notable contribution of UT is the UT Diabetic Wound Classification. First proposed in 1996,25 it improved upon existing classifications, adding consideration of depth and complications (infection and ischemia) as separate variables.26 The classification was easy to use and facilitated communication between specialists, but was also validated to be predictive of amputation.27 Today, the UT Diabetic Wound Classification is used worldwide by clinicians and researchers (Figure 1).
Pioneering Treatments and Comprehensive Care
After Lawrence Harkless, DPM, attended a 1981 course on total contact casting (TCC), UT over the next 25 years promoted the use of the TCC, which has become the gold standard in offloading the diabetic foot.28,29 Research from UT later proved that removable cast walkers (RCW) can offload as well as TCCs, resulting in a William J. Stickel Award from the Journal of the American Podiatric Medical Association.30 This provided the pivotal data for a NIH-sponsored randomized controlled trial comparing TCCs with RCWs and half-shoes in healing DFUs.31 A trial on skin stretching/expansion conducted at UT also received the 1998 William J. Stickel Silver Award from the Journal of the American Podiatric Medical Association.32
The UT program was responsible for some of the early and most impactful work on negative pressure wound therapy (NPWT) in the diabetic foot.33,34 University Hospital and the Texas Diabetes Institute were sites for the clinical trials and helped generate our understanding of the role of NPWT in the diabetic foot wound. The largest study on post-amputation wounds was led from UT, published in The Lancet, and has been cited 1174 times.35 It was that issue of The Lancet that included the statement on the cover, “Every 30 seconds, somewhere in the world, a limb is lost as a consequence of diabetes.”
Furthermore, research from UT solidified the role of equinus in increasing peak plantar forefoot pressures and the risk of ulceration.36 This resulted in a study, believed to be the first by a podiatrist, in the Journal of Bone and Joint Surgery on Achilles tendon lengthening to reduce plantar pressures and prevent ulcerations.37
Preventing Ulcers and Amputations
UT was one of the first centers to use sensors to define and quantify peak plantar pressures thresholds as a risk for DFU.38–42 Then UT studied the effect of various devices on the reduction of pressure and healing of wounds28,43 and shoes on the prevention of wounds.44
UT researchers recognized than many patients with diabetes and deformity needed surgical correction to reduce their risk of future ulceration and then asked the tough question: Is prophylactic diabetic foot surgery dangerous?45 This stratification of risk inspired the creation of the Diabetic Foot Surgery Classification.46
Temperature as a predictor of ulceration was first described by Paul Wilson Brand, MD, in the 1970s. He said a wound “heats up before it breaks down.” He recognized that the most frequent sign of inflammation was pain, but with neuropathy, patients lost the “gift of pain” and temperature could be used as a sensitive indicator.47 As technology became more accurate and accessible, UT studied the temperature difference between feet and validated Brand’s hypothesis.48–50 In the early 2000s, before remote patient monitoring (RPM) was even conceived, UT proved that home monitoring of foot skin temperatures prevented diabetic foot ulcerations and saved the health care system significant money.51
Making a Difference for Patients With Diabetes
With the culmination of decades of research, knowledge and experience, UT created the first disease management program for the diabetic foot, which ran as a pilot program in Texas for a private health insurance company. Over 2.5 years, the incidence of amputations decreased 50% and hospitalizations were reduced by 40%.52 Lavery concluded that, “A population-based screening and treatment program for the diabetic foot can dramatically reduce hospitalizations and improve clinical outcomes.”
The research from the UT program has created an impact across the globe, in the profession of podiatry, the specialty of the diabetic foot, and led to major changes in industry to combat the problem. And those who have left the university have continued to make an immeasurable difference in the field.
Lee C. Rogers, DPM, FFPM RCPS, is the Chief of Podiatry, the Louis T. Bogy Professor of Podiatric Medicine and Surgery, and Associate Professor/Clinical in the Department of Orthopaedics at UT Health San Antonio. He is the President of the American Board of Podiatric Medicine, Associated Editor of the Journal of the American Podiatric Medical Association, and a Fellow Faculty in Podiatric Medicine at the Royal College of Physicians and Surgeons of Glasgow.
References
1. Shen JM, Chen J, Feng L, Feng C. A scientometrics analysis and visualization of diabetic foot research from 1955 to 2022. Int Wound J. 2022; epub Sept. 26. doi: 10.1111/iwj.13964.
2. Lavery LA, Armstrong DG, Wunderlich RP, Tredwell J, Boulton AJM. Diabetic foot syndrome evaluating the prevalence and incidence of foot pathology in Mexican Americans and non-Hispanic whites from a diabetes disease management cohort. Diabetes Care. 2003;26(5):1435-1438.
3. Lavery LA, Ashry HR, van Houtum W, Pugh JA, Harkless LB, Basu S. Variation in the incidence and proportion of diabetes-related amputations in minorities. Diabetes Care. 1996;19(1):48-52.
4. Lavery LA, van Houtum WH, Ashry HR, Armstrong DG, Pugh JA. Diabetes-related lower-extremity amputations disproportionately affect Blacks and Mexican Americans. South Med J. 1999;92(6):593-599.
5. Lavery LA, van Houtum WH, Armstrong DG, Harkless LB, Ashry HR, Walker SC. Mortality following lower extremity amputation in minorities with diabetes mellitus. Diabetes Res Clin Pract. 1997;37(1):41-47.
6. Ashry HR, Lavery LA, Armstrong DG, Lavery DC, van Houtum WH. Cost of diabetes-related amputations in minorities. J Foot Ankle Surg. 1998;37(3):186-190.
7. Murdoch DP, Armstrong DG, Dacus JB, Laughlin TJ, Morgan CB, Lavery LA. The natural history of great toe amputations. J Foot Ankle Surg. 1997;36(3):204-208; discussion 256.
8. Lavery LA, Lavery DC, Quebedeax-Farnham TL. Increased foot pressures after great toe amputation in diabetes. Diabetes Care. 1995;18(11):1460-1462.
9. Quebedeaux TL, Lavery LA, Lavery DC. The development of foot deformities and ulcers after great toe amputation in diabetes. Diabetes Care. 1996;19(2):165-167.
10. Hosch J, Quiroga C, Bosma J, Peters EJ, Armstrong DG, Lavery LA. Outcomes of transmetatarsal amputations in patients with diabetes mellitus. J Foot Ankle Surg. 1997;36(6):430-434.
11. Armstrong DG, Lavery LA, Harkless LB, Van Houtum WH. Amputation and reamputation of the diabetic foot. J Am Podiatr Med Assoc. 1997;87(6):255-259. doi:10.7547/87507315-87-6-255
12. Izumi Y, Satterfield K, Lee S, Harkless LB. Risk of reamputation in diabetic patients stratified by limb and level of amputation: a 10-year observation. Diabetes Care. 2006;29(3):566-570.
13. Peters EJ, Childs MR, Wunderlich RP, Harkless LB, Armstrong DG, Lavery LA. Functional status of persons with diabetes-related lower-extremity amputations. Diabetes Care. 2001;24(10):1799-1804.
14. Armstrong DG, Todd WF, Lavery LA, Harkless LB, Bushman TR. The natural history of acute Charcot’s arthropathy in a diabetic foot specialty clinic. J Am Podiatr Med Assoc. 1997;87(6):272-278.
15. Armstrong DG, Lavery LA. Elevated peak plantar pressures in patients who have Charcot arthropathy. J Bone Joint Surg Am. 1998;80(3):365-369.
16. Lavery LA, Armstrong DG, Walker SC. Healing rates of diabetic foot ulcers associated with midfoot fracture due to Charcot’s arthropathy. Diabetic Medicine. 1997;14(1):46-49. doi:10.1002/(sici)1096-9136(199701)14:1<46::aid-dia291>3.0.co;2-t
17. Armstrong DG, Lavery LA. Monitoring healing of acute Charcot’s arthropathy with infrared dermal thermometry. J Rehabil Res Dev. 1997;34(3):317-321.
18. Armstrong DG, Perales TA, Murff RT, Edelson GW, Welchon JG. Value of white blood cell count with differential in the acute diabetic foot infection. J Am Podiatr Med Assoc. 1996;86(5):224-227.
19. Armstrong DG, Lavery LA, Sariaya M, Ashry H. Leukocytosis is a poor indicator of acute osteomyelitis of the foot in diabetes mellitus. J Foot Ankle Surg. 1996;35(4):280-283.
20. Lavery LA, Armstrong DG, Quebedeaux TL, Walker SC. Puncture wounds: normal laboratory values in the face of severe infection in diabetics and non-diabetics. Am J Med. 1996;101(5):521-525.
21. Harkless L, Boghossian J, Pollak R, et al. An open-label, randomized study comparing efficacy and safety of intravenous piperacillin/tazobactam and ampicillin/sulbactam for infected diabetic foot ulcers. Surg Infect. 2005;6(1):27-40.
22. Lavery LA, Harkless LB, Felder-Johnson K, Mundine S. Bacterial pathogens in infected puncture wounds in adults with diabetes. J Foot Ankle Surg. 1994;33(1):91-97.
23. Lavery LA, Harkless LB, Ashry HR, Felder-Johnson K. Infected puncture wounds in adults with diabetes: risk factors for osteomyelitis. J Foot Ankle Surg. 1994;33(6):561-566.
24. Armstrong DG, Lavery LA, Quebedeaux TL, Walker SC. Surgical morbidity and the risk of amputation due to infected puncture wounds in diabetic versus nondiabetic adults. J Am Podiatr Med Assoc. 1997;87(7):321-326.
25. Lavery LA, Armstrong DG, Harkless LB. Classification of diabetic foot wounds. J Foot Ankle Surg. 1996;35(6):528-531.
26. Armstrong DG, Lavery LA, Harkless LB. Validation of a diabetic wound classification system. The contribution of depth, infection, and ischemia to risk of amputation. Diabetes Care. 1998;21(5):855-859.
27. Oyibo SO, Jude EB, Tarawneh I, Nguyen HC, Harkless LB, Boulton AJ. A comparison of two diabetic foot ulcer classification systems: the Wagner and the University of Texas wound classification systems. Diabetes Care. 2001;24(1):84-88.
28. Armstrong DG, Lavery LA, Bushman TR. Peak foot pressures influence the healing time of diabetic foot ulcers treated with total contact casts. J Rehabil Res Dev. 1998;35(1):1-5.
29. Lavery LA, Vela SA, Lavery DC, Quebedeaux TL. Total contact casts: pressure reduction at ulcer sites and the effect on the contralateral foot. Arch Phys Med Rehabil. 1997;78(11):1268-1271.
30. Fleischli JG, Lavery LA, Vela SA, Ashry H, Lavery DC. 1997 William J. Stickel Bronze Award. Comparison of strategies for reducing pressure at the site of neuropathic ulcers. J Am Podiatr Med Assoc. 1997;87(10):466-472. doi:10.7547/87507315-87-10-466
31. Armstrong DG, Nguyen HC, Lavery LA, van Schie CH, Boulton AJ, Harkless LB. Off-loading the diabetic foot wound: a randomized clinical trial. Diabetes Care. 2001;24(6):1019-1022.
32. Armstrong DG, Lavery LA. 1998 William J. Stickel Silver Award. Mechanically assisted, delayed primary closure of diabetic foot wounds. J Am Podiatr Med Assoc. 1998;88(10):483-488. doi:10.7547/87507315-88-10-483
33. Armstrong DG, Lavery LA, Abu-Rumman P, et al. Outcomes of subatmospheric pressure dressing therapy on wounds of the diabetic foot. Ostomy Wound Manage. 2002;48(4):64-68.
34. Espensen EH, Nixon BP, Lavery LA, Armstrong DG. Use of subatmospheric (VAC) therapy to improve bioengineered tissue grafting in diabetic foot wounds. J Am Podiatr Med Assoc. 2002;92(7):395-397. doi:10.7547/87507315-92-7-395
35. Armstrong DG, Lavery LA, Diabetic Foot Study Consortium. Negative pressure wound therapy after partial diabetic foot amputation: a multicentre, randomised controlled trial. Lancet. 2005;366(9498):1704-1710.
36. Lavery LA, Armstrong DG, Boulton AJM, Diabetex Research Group. Ankle equinus deformity and its relationship to high plantar pressure in a large population with diabetes mellitus. J Am Podiatr Med Assoc. 2002;92(9):479-482.
37. Armstrong DG, Stacpoole-Shea S, Nguyen H, Harkless LB. Lengthening of the Achilles tendon in diabetic patients who are at high risk for ulceration of the foot. J Bone Joint Surg. 1999;81(4):535-538.
38. Stacpoole-Shea S, Shea G, Lavery L. An examination of plantar pressure measurements to identify the location of diabetic forefoot ulceration. J Foot Ankle Surg. 1999;38(2):109-115; discussion 179.
39. Armstrong DG, Peters EJG, Athanasiou KA, Lavery LA. Is there a critical level of plantar foot pressure to identify patients at risk for neuropathic foot ulceration? J Foot Ankle Surg. 1998;37(4):303-307. doi:10.1016/s1067-2516(98)80066-5
40. Lavery LA, Armstrong DG, Wunderlich RP, Tredwell J, Boulton AJM. Predictive value of foot pressure assessment as part of a population-based diabetes disease management program. Diabetes Care. 2003;26(4):1069-1073.
41. Lavery LA, Vela SA, Lavery DC, Quebedeaux TL. Reducing dynamic foot pressures in high-risk diabetic subjects with foot ulcerations. A comparison of treatments. Diabetes Care. 1996;19(8):818-821.
42. Ashry HR, Lavery LA, Murdoch DP, Frolich M, Lavery DC. Effectiveness of diabetic insoles to reduce foot pressures. J Foot Ankle Surg. 1997;36(4):268-271. doi:10.1016/s1067-2516(97)80071-3
43. Giacalone VF, Armstrong DG, Ashry HR, Lavery DC, Harkless LB, Lavery LA. A quantitative assessment of healing sandals and postoperative shoes in offloading the neuropathic diabetic foot. J Foot Ankle Surg. 1997;36(1):28-30. doi:10.1016/s1067-2516(97)80007-5
44. Lavery LA, Vela SA, Fleischli JG, Armstrong DG, Lavery DC. Reducing plantar pressure in the neuropathic foot: a comparison of footwear. Diabetes Care. 1997;20(11):1706-1710. doi:10.2337/diacare.20.11.1706
45. Armstrong DG, Lavery LA, Stern S, Harkless LB. Is prophylactic diabetic foot surgery dangerous? J Foot Ankle Surg. 1996;35(6):585-589.
46. Armstrong DG, Frykberg RG. Classifying diabetic foot surgery: toward a rational definition. Diabetic Medicine. 2003;20(4):329-331. doi:10.1046/j.1464-5491.2003.00933.x
47. Brand P. The Gift of Pain: Why We Hurt and What We Can Do About It. Zondervan, 1997.
48. Armstrong DG, Lavery LA, Liswood PJ, Todd WF, Tredwell JA. Infrared dermal thermometry for the high-risk diabetic foot. Phys Ther. 1997;77(2):169-175; discussion 176-177.
49. Armstrong DG, Lavery LA. Predicting neuropathic ulceration with infrared dermal thermometry. J Am Podiatr Med Assoc. 1997;87(7):336-337. doi:10.7547/87507315-87-7-336
50. Armstrong DG. Infrared dermal thermometry: The foot and ankle stethoscope? J Foot Ankle Surg. 1998;37(1):75-76. doi:10.1016/s1067-2516(98)80016-1
51. Lavery LA, Higgins KR, Lanctot DR, et al. Home monitoring of foot skin temperatures to prevent ulceration. Diabetes Care. 2004;27(11):2642-2647.
52. Lavery LA, Wunderlich RP, Tredwell JL. Disease management for the diabetic foot: effectiveness of a diabetic foot prevention program to reduce amputations and hospitalizations. Diabetes Res Clin Pract. 2005;70(1):31-37.
