It is common knowledge that a complex activity or process will usually be performed better and more skillfully with greater repetition. Provision of health-care services is not an exception. In a study of Medicare claims data, Katz et al. found that dislocations after hip arthroplasty were nearly three times more frequent in patients of surgeons who performed a small number of arthroplasties per year compared with patients of surgeons who performed a large number of arthroplasties per year. Similarly, hospitals that performed a low volume of hip arthroplasties had nearly twice the mortality rate of high-volume hospitals1. In their discussion, the authors of this study suggested that concentrating hip arthroplasty surgery at regional centers should be considered to decrease mortality and complications.
In fracture care, most surgeons would agree that skill and experience obtained from repetition improve the ability to skillfully treat complex fracture problems and that some complex fractures are best treated in a hospital and by a surgeon who treats a lot of them. Orthopaedic trauma fellowships are designed to give young surgeons who want to treat complex fractures as part or most of their practice a head start on this process of gaining skill from experience and repetition. For multiply injured patients, it is well recognized that regionalizing trauma care leads to better chances for patient survival and improved outcomes, and some states have developed statewide trauma systems on the basis of this information2. Regionalized care also leads to better outcomes after major lower-limb trauma3.
How does this background information from these previous studies apply to hip fractures in elderly patients, a very common fracture problem that causes tremendous morbidity and mortality? For many reasons, hip fractures are generally not considered a referral fracture problem. The study by Forte et al. provides data and a perspective on how variations of hospital and surgeon volume of elderly patients with intertrochanteric hip fractures correlate with patient mortality in the first ninety days after injury. Similar to the hip arthroplasty study noted above and other health-care studies addressing the relationship between volume and outcome, and in keeping with common sense, the authors found decreased mortality for patients treated in high-volume hospitals compared with low-volume hospitals. However, the differences seen were much smaller than those that have been found in previous arthroplasty studies. The association with surgeon volume was even less clear since the group of surgeons in the lowest quartile for volume had the lowest mortality and the group in the second lowest quartile had the highest mortality, an unexpected result that is difficult to explain. Not surprisingly a variety of patient factors, such as age, sex, residence in nursing home, and comorbidities, affected patient mortality to a much greater degree than hospital or surgeon volume did. Indeed, only after the study controlled for these variables was a small effect of hospital volume detected. The authors acknowledge that it is difficult to accurately and completely detect comorbid conditions from the Medicare database, and this is a potential weakness of their data. Furthermore, they point out that the strong effect of comorbidities may mask a greater volume effect than was detected in their study.
Mortality in the first ninety days after injury was the only outcome assessed. This is an important point when considering the implications of this study. Surviving a hip fracture is clearly a major issue in the patient population in which these injuries occur, but other outcomes of hip fracture surgery are important. These include, but are not limited to, initial pain relief, perioperative complications, ability to walk, return to function, long-term pain, quality of life, and ability to live independently. Any or all of these important outcomes might be more affected by provider volume than ninety day mortality alone would be. However, without further study, the magnitude and type of effect that provider volume might have on these important hip fracture outcomes is purely speculative.
For the good of our health-care system and for the comfort and convenience of elderly patients and their families, it is good that the differences in mortality that were found in this study were small. Hip fractures have been a local health-care problem. Extensive shifts to regionalize care of hip fracture patients is not logical or possible in our current health-care system nor is it likely to be possible with any upcoming changes to our system. Hip fractures need to be cared for locally, and the data in this study indicate that any differences in mortality that exist based on provider volume are acceptably small. If further studies were to identify that volume has significant effects on other hip fracture outcomes, it is my belief that such information should be used to find ways to improve the processes in lower-volume hospitals rather than to regionalize the care of patients who have sustained a hip fracture.
*The author did not receive any outside funding or grants in support of his research for or preparation of this work. Neither he nor a member of his immediate family received payments or other benefits or a commitment or agreement to provide such benefits from a commercial entity.
1. Katz JN, Losina E, Barrett J, Phillips CB, Mahomed NN, Lew RA, Guadagnoki E, Harris WH, Poss R, Baron JA. Association between hospital and surgeon procedure volume and outcomes of total hip replacement in the United States Medicare population. J Bone Joint Surg Am. 2001;83:1622-9.
2. Mullins RJ, Mann NC, Hedges JR, Worrall W, Jurkovich GJ. Preferential benefit of implementation of a statewide trauma system in one of two adjacent states. J Trauma. 1998;44:609-17.
3. Mackenzie EJ, Rivara FP, Jurkovich GJ, Nathens AB, Egleston BL, Salkever DS, Frey KP, Scharfstein DO. The impact of trauma-center care on functional outcomes following major lower-limb trauma. J Bone Joint Surg Am. 2008;90:101-9.