JBJS Classics: Biomechanics of the Normal Elbow

jbjsclassics-2016OrthoBuzz regularly brings you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators highlight the impact that these JBJS articles have had on the practice of orthopaedics. Please feel free to join the conversation by clicking on the “Leave a Comment” button in the box to the left.

The classic 1981 JBJS article by B.F. Morrey et al. begs to be read carefully, in part because of the name of the lead author. More importantly, this study answers the question that arises with almost every patient with an elbow disorder: Is the achieved range of motion sufficient for activities of daily living? We can answer this question “yes” or “no” after reading this article, and in my own practice, I repeatedly refer to the information provided in it.

Dr. Morrey was an aerospace engineer who worked at NASA for two years before he attended medical school at the University of Texas Medical Branch. After his residency at the Mayo Clinic and after achieving a master’s degree in biomechanics from the University of Minnesota, he joined the staff at Mayo in 1978.

In this article, which integrates Dr. Morrey’s engineering and medical disciplines, he applied a high-tech device of that period (the triaxial electrogoniometer) to answer simple but eternal questions such as what degree of elbow flexion is needed to eat or perform personal hygiene.

It is the nature of human beings to notice particular joint impairments only when they disturb activities of daily living. Patient-reported outcome scores assessing subtle disturbances have recently been published, but we learned from Dr. Morrey’s article that patients with elbow flexion less than 130° will probably be reminded of their elbow problem whenever they try to use a telephone. (With today’s small cellular phones the problem might be even more accentuated.)

There is not much that a contemporary reviewer would criticise if this study were to be submitted today. Yes, the graphics would be nicer, and there would be more than 12 references. Modern computer-aided tools and methods for motion analysis might be more precise (and produce a mass of partially redundant data), but the results would remain essentially the same.

In fact, the question of functional elbow range of motion was revisited in JBJS by Sardelli et al. exactly 30 years after Dr. Morrey’s study appeared. Using modern three-dimensional optical tracking technology, Sardelli et al. found only minimal differences compared to findings in the Morrey et al. study. Only a few contemporary tasks like working on a computer (greater pronation) or using a cellular phone (greater flexion) appeared to require slightly more range of motion than previously reported.

Finally, it is the succinct and pointed results that amaze me whenever I recall the information from Dr. Morrey’s study. All we need to remember are four numbers: 100, 30, 130, and 50. Therein we are reminded that the patient needs to achieve a 100° arc of motion for flexion /extension (from 30° to 130°) and forearm rotation (50° of pronation and 50° of supination).

The authors were able to omit the conclusion sentence we see so often these days: “Further studies are needed…” The question about the minimal range of elbow motion needed to accomplish activities of daily living has been convincingly answered in this article. All residents should read this JBJS classic early, certainly before they examine their first patient with an elbow disorder.

Bernhard Jost, M.D.
JBJS Deputy Editor

JBJS JOPA Image Quiz: A 15-Year-Old Girl with Dislocated Patella

clou3_REV_9-13-16.jpgThis month’s Image Quiz from the JBJS Journal of Orthopaedics for Physician Assistants(JOPA) presents the case of a teenage girl who dislocated her patella while playing volleyball. The quiz provides four postreduction images, two radiographs and two fat-suppressed MRI scans, and then readers are presented with two questions:

  • What is the next best step in this patient’s treatment?
  • Which concomitant condition does NOT cause an increased risk of patellar instability?

JBJS Elite Reviewers: Updated

The JBJS Elite Reviewers Program publicly recognizes our best reviewers for their outstanding efforts. Reviewers who review 4 or more manuscripts per year, rarely decline an invitation to review a manuscript (responding within 48 hours), and complete highly graded reviews within 1 week are eligible for the program. Elite Reviewers receive the following benefits in recognition of their exemplary performance:

  • No submission fees for papers of which the reviewer is the first author (for 12 months)
  • Free CME credits for all reviews
  • Free online access to all JBJS publications
  • A letter to the reviewer’s department head from JBJS Editor-in-Chief, Marc Swiontkowski, MD, recognizing and commending his/her good work
  • Name recognition on the JBJS Elite Reviewers Program Web page and on the masthead of The Journal

For JBJS Consultant Reviewer Guidelines, visit http://bit.ly/2cWvYvc.

To learn how you can be a better reviewer visit http://bit.ly/2cRt1hY.

Here is an updated list of JBJS Elite Reviewers:

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What’s New in Hip Replacement

captureEvery month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.

This month, James Ninomiya, MD, MS, lead author of the September 21, 2016 Specialty Update on Hip Replacement, selected the five most clinically compelling findings from among the nearly 70 studies summarized in the Specialty Update.

Bearing Survivorship

–A meta-analysis found no differences in short- and medium-term implant survivorship among the following three bearing combinations used in THA patients younger than 65 years of age: ceramic on ceramic, ceramic on highly cross-linked polyethylene, and metal on highly cross-linked polyethylene.1

Insight into Aseptic Loosening

–Pathogen-associated molecular patterns (“endotoxins”) on particulate wear debris may be partially responsible for aseptic loosening. An in vitro/in vivo study found that macrophages that did not express the pathogen-associated molecular pattern receptor called TIRAP/Mal had significantly diminished secretion of inflammatory proteins. Patients with a genetic polymorphism suppressing that receptor exhibited decreased osteolysis during in vivo experiments. This suggests that some patients may be genetically more prone to aseptic loosening.

THA in Patients with RA

–A systematic review/meta-analysis of patients who were and were not taking a TNF-α inhibitor for rheumatoid arthritis prior to hip replacement found that those taking the drug had an increased risk of perioperative infection, with an odds ratio of 2.47.2 These results suggest that in order to decrease the risk of perioperative infections, it may be prudent to discontinue these drugs in advance of proposed joint replacement surgery.

Delaying THA for Femoral Head Osteonecrosis

–A systematic review/meta-analysis of patients with femoral head osteonecrosis concluded that injection of autologous bone marrow aspirate containing mesenchymal stem cells during core decompression was superior by a factor of 5 to core decompression alone in preventing collapse of the femoral head and delaying conversion to THA. This information may lead to new treatment paradigms for osteonecrosis.

Preventing Post-THA Dislocations

–A systematic review/meta-analysis that included more than 1,000 patients who underwent THA with a posterior or anterolateral approach found similar dislocation rates among those who were and were not given post-procedure restrictions in motion or activity.4   This suggests that the use of traditional hip precautions may not be necessary, and in fact may impede the rate of recovery following joint replacement surgery.


  1. Wyles CC, Jimenez-Almonte JH,  Murad MH, Norambuena-Morales GA, Cabanela ME, Sierra RJ, TrousdaleRT. There are no differences in short- to mid-term survivorship among total hip-bearing surface options: a network meta-analysis. Clin Orthop Relat Res. 2015 Jun;473(6):2031-41. Epub 2014 Dec 17.
  2. Goodman SM, Menon I, Christos PJ, Smethurst R, Bykerk VP. Management of perioperative tumour necrosis factor α inhibitors in rheumatoid arthritis patients undergoing arthroplasty: a systematic review and meta-analysis. Rheumatology (Oxford). 2016 Mar;55(3):573-82. Epub 2015 Oct 7.
  3. Papakostidis C, Tosounidis TH, Jones E, Giannoudis PV. The role of “cell therapy” in osteonecrosis of the femoral head. A systematic review of the literature and meta-analysis of 7 studies. Acta Orthop. 2016 Feb;87(1):72-8. Epub 2015 Jul 29.
  4. Van der Weegen W, Kornuijt A, Das D. Do lifestyle restrictions and precautions prevent dislocation after total hip arthroplasty? A systematic review and meta-analysis of the literature. Clin Rehabil. 2016 Apr;30(4):329-39. Epub 2015 Mar 31.

JBJS Editor’s Choice: Ankle Fractures—Is Hospitalization Ever Needed?

ankle_fracture_2016-10-19The practice of orthopaedic surgery is moving fairly rapidly to the outpatient environment. Advances in less invasive surgical procedures, regional anesthesia, and postoperative pain management have provided the foundation for this transition. The migration to outpatient surgery centers enables surgeons to use surgical teams more focused on orthopaedic technology and practice parameters. The concern that arises in everyone’s mind, though, is the issue of safety.

In the October 19, 2016 issue of JBJS, Qin et al. analyzed the NSQIP database and found that the outpatient surgical treatment of patients with a closed ankle fracture and minimal comorbidities resulted in lower risk of pneumonia and no difference in surgical morbidity, reoperations, and readmissions when compared with inpatient surgery.

The NSQIP dataset is voluntary and, as with any database, confounding variables are unavoidable. But these authors used propensity score matching and Bonferroni correction to minimize selection bias and manage multiple comparisons.

The study excluded emergency cases, cases with preoperative sepsis, and cases of open ankle fracture, and I can still foresee that patients with more severe fracture patterns, soft tissue compromise, and unstable medical comorbidities would be better off treated as inpatients. Nevertheless, it is reassuring that this study found no differences in complication or readmission rates. These findings reinforce the movement of orthopaedic surgical practice to the outpatient setting, and in my experience that movement is wholly welcomed by patients and their families.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

JBJS Webinar: Effective Management of the Infected Total Joint

infected-knee-for-webinar-postThe incidence of primary total knee and hip arthroplasty is increasing steadily. While the success rates of these procedures are remarkable, failures do occur, and periprosthetic joint infection is the leading culprit in such failures. The standard treatment when deep infection strikes is a two-stage revision.

On Monday, November 14, 2016 at 8:00 PM EST, The Journal of Bone & Joint Surgery (JBJS) will host a complimentary webinar that examines prognostic factors affecting the success of two-stage revision arthroplasty for infected knees and hips.

  • Tad M. Mabry, MD, coauthor of a matched cohort study in JBJS, will examine the impact of morbid obesity on the failure of two-stage revision TKA.
  • JBJS author Antonia F. Chen, MD, will discuss results from a retrospective study that revealed an association between positive cultures at the time of knee/hip component reimplantation and the risk of subsequent treatment failure.

Moderated by JBJS Deputy Editor Charles R. Clark, MD, the webinar will include additional perspectives from two expert commentators—Daniel J. Berry, MD and Andrew A. Freiberg, MD. The last 15 minutes will be devoted to a live Q&A session, during which the audience can ask questions of all four panelists.

Seats are limited, so register now!

Measuring Clubfoot Brace Adherence

clubfoot-braces_10_5_16Relapse of clubfoot deformity has been attributed to non-adherence to post-corrective bracing recommendations. The October 5, 2016 issue of The Journal of Bone & Joint Surgery contains a study by Sangiorgio, et al. in which wireless sensors measured the actual brace use in 44 patients aged 6 months to 4 years who were supposed to use a post-corrective foot abduction orthosis for an average of 12.6 hours per day. The authors compared the mean number of hours of daily brace use as measured by the sensors with the physician-recommended hours and with parent-reported hours of brace use.

Here’s what Sangiorgio et al. found:

–Median brace use recorded by the sensors was 62% of that recommended by the physician and 77% of that reported by parents.

–18% of the patients experienced relapse. The mean number of daily hours of brace use for those patients (5 hours a day) was significantly lower than the 8 hours per day for those who didn’t experience relapse.

While this study suggests that 8 hours or more of daily brace use may be helpful to prevent relapse, studies with larger cohorts will be needed to determine more definitive bracing minimums. Still, the authors say that “routine brace monitoring has the potential to accurately identify patients who are receiving an inadequate number of hours of brace use and facilitate more effective counseling of these families.”

JBJS: Mobile and Multimedia

15The Journal is one of the most valued sources of information for orthopaedists and orthopaedic researchers. Standards of excellence for the content we publish and the customer service that we provide are not going to change. However, the way in which people access content is changing rapidly. Today, content producers are faced with the challenge of providing their content through media that are accessible on-the-go.

Hence, the JBJSmedia YouTube channel. Here you’ll find information about JBJS products, procedure demonstrations, and webinars featuring top experts in the field— easily digestible and accessible on-the-go. You can easily find the videos you are looking for by going to the playlists tab.

The newest feature of our YouTube channel is the JBJS Podcast. These digital audio abstracts of specially selected JBJS articles are overlaid onto a video track and uploaded to the channel at the end of each month.

Please visit the JBJSmedia YouTube channel. If you have suggestions for better ways JBJS can deliver content, feel free to send an email to info@jbjs.org.

Subscribe to the JBJSmedia YouTube channel

Subscribe to the JBJS Podcast on iTunes

Contributed by

Nicholas Schepis

Social Media and Analytics Specialist, JBJS


Guest Post: Cautious Early Optimism about Medicare’s Bundled Payment Programs

jointOrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Richard Yoon, MD.

In a recent issue of JAMA, Dummit et al. analyzed cost and quality results from the Centers for Medicare & Medicaid Services (CMS) Bundled Payment for Care Improvement (BPCI) initiative. The authors compared joint-replacement results between hospitals that voluntarily participate in the BPCI program versus matched comparison hospitals that do not participate. Nearly 60,000 lower extremity joint replacement procedures from each hospital type were included in the analysis.

Medicare payments declined over time in both groups of hospitals, but the authors noted a greater decline in costs among the BPCI hospitals, primarily due to reduced utilization of post-institutional acute care. There were no statistical differences in quality between the BPCI hospitals and comparison hospitals, as measured by unplanned admissions, emergency department visits, and mortality at both 30 and 90 days. These results echo those reported by other pilots in the United States and suggest that similar programs could reduce cost per episode of care without compromising quality.

However, even proponents of the new programs are cautious. For example, in his JAMA editorial, Elliot Fisher, MD warns readers that because BPCI is a voluntary program, the results may not reflect the true impact of a more widespread bundled-payment model.  The incentives, he argues, could end up contributing to volume increases or shifts toward healthier—and “more profitable”—patients. As Fisher concludes, “Bundled payments leave the overarching incentive to increase volume solidly in place.”

In a separate JAMA Viewpoint article, Ibrahim et al. warn that another CMS program, the Comprehensive Care for Joint Replacement (CJR) model, could unintentionally amplify already existing racial disparities in elective joint replacement. CJR is a mandatory initiative in 67 randomly selected US metropolitan areas. The authors say that CJR might improve postoperative quality of care for minority patients after joint replacement, but that the program could also end up favoring healthier, well-insured patients.

Overall, at this early stage, these two CMS models offer promising, comprehensive approaches to joint replacement that may prove cost-saving without comprising quality of care. Results like the ones published by Dummit et al. are hopeful, but longer-term, outcomes-based, and cost-focused studies that include epidemiologic and racial impact must be performed as we move forward carefully.

Click here to read a previous OrthoBuzz post about BPCI.

Click here to read a previous OrthoBuzz post about CJR.

Richard Yoon, MD is a fellow in orthopaedic traumatology and complex adult reconstruction at Orlando Regional Medical Center.

Cardiopulmonary Effects of Scoliosis

ventilation-scatterplot_10_5_16The 3-dimensional spinal deformities associated with scoliosis may affect other organ systems. In the October 5, 2016 issue of The Journal, Shen et al. correlated radiographic severity of thoracic curvature/kyphosis with pulmonary function at rest and exercise capacity measured with a bicycle ergometer. Forty subjects with idiopathic scoliosis were enrolled in the prospective study (mean age 15.5 years), 33 of them female.

The study found no correlation between coronal thoracic curvature and static pulmonary function tests in the female patients. Female patients with a thoracic curve of ≥ 60° had lower blood oxygen saturation at maximal exertion during the exercise test, but overall exercise tolerance did not appear to be correlated with the magnitude of the thoracic curve and kyphosis. According to the authors, taken together, the many specific cardiopulmonary findings in this study suggest that “the cardiovascular system may be less affected than the respiratory system in patients with idiopathic scoliosis.”

Not surprisingly, exercise capacity was better in patients who performed regular aerobic exercise. Although physical training may not be able to change pulmonary pathology in this population, the authors emphasized that physical activity is still recommended for patients with idiopathic scoliosis for maintaining cardiovascular and peripheral muscle conditioning.