In the January 4, 2017 issue of The Journal, Swart et al. provide a well-done Markov decision analysis on the cost effectiveness of three treatment options for femoral neck fractures in patients between the age of 40 and 65: open reduction and internal fixation (ORIF), total hip arthroplasty (THA), and hemiarthroplasty. Plugging the best data available from the current orthopaedic literature into their model, the authors estimated the threshold age above which THA would be the superior strategy in this relatively young population.
For patients in this age group, traditional thinking has been to perform ORIF in order to “save” the patient’s native hip and avoid the likelihood of later revision arthroplasty. However, in this analysis THA emerges as a cost-effective option in otherwise healthy patients >54 years old, in patients >47 years old with mild comorbidity, and in patients >44 years old with multiple comorbidities.
On average, both THA and ORIF have similar outcomes across the age range analyzed. But ORIF with successful fracture healing yields slightly better outcomes and considerably lower costs than THA, whereas patients whose fracture does not heal with ORIF have notably worse outcomes than THA patients. This finding supports my personal bias that anatomical reduction and biomechanically sound fixation must be achieved in this younger population with displaced femoral neck fractures. The analysis confirmed that, because of poor functional outcomes with hemiarthroplasty in this population, hemiarthroplasty should not be considered. Poor hemiarthroplasty outcomes are likely related to the mismatch between the metal femoral head and the native acetabular cartilage, leading to fairly rapid loss of the articular cartilage and subsequent need for revision.
This analysis by Swart et al. provides very valuable data to discuss with younger patients and families when engaging in shared decision making about treating an acute femoral neck fracture. In my experience, most patients in this age group prefer to “keep” their own hip whenever possible, which puts the onus on the surgeon to gain anatomic reduction and biomechanically sound fixation with ORIF.
Marc Swiontkowski, MD
Orthopaedic journals and OrthoBuzz have devoted ample space to the apparent association between long-term bisphosphonate use and atypical femoral fractures. The latest insight into this relationship comes from Lim et al. in the December 7, 2016 edition of The Journal of Bone & Joint Surgery. The authors analyzed factors associated with delayed union or nonunion after surgical treatment of 109 atypical femoral fractures in patients who had an average 7.4-year history of bisphosphonate use.
Here’s what Lim et al. found among the 30% of patients studied who had delayed union or nonunion, relative to the 70% who had successful healing:
- Patient Factors: Patients who had problematic fracture healing had a higher BMI, longer duration of bisphosphonate exposure, and higher rate of prodromal symptoms.
- Radiographic/Fracture Factors: Supra-isthmic/subtrochanteric fracture location, femoral bowing of ≥10° in the coronal plane, and a lateral/medial cortical thickness ratio of ≥1.4 were predictive of problematic healing.
- Operative Factors: Iatrogenic cortical breakage around the fracture site and a ratio of ≥0.2 between the remaining gap and the cortical thickness on the anterior and lateral sides of the fracture site were associated with problematic fracture healing.
In an accompanying commentary on the study, Edward J. Harvey, MD notes that most trauma surgeons use cephalomedullary nails to treat atypical femoral fractures, but that “it is impossible from this manuscript to determine what effect the fixation technique had on the outcomes.” He therefore recommends a larger multicenter study using standardized therapy and bone biopsies to further improve understanding in this area.
How best to treat clavicle fractures remains a controversial question in orthopaedics. A study by Huttunen et al. in the November 2, 2016 JBJS does not resolve that controversy, but it sheds a little light on it.
The authors analyzed a validated Swedish hospital-discharge registry and determined that 44,609 clavicle fractures occurred in that country between 2001 and 2012. During that period, the incidence of clavicle fractures increased by 67%, from 35.6 to 59.3 per 100,000 person-years. During that same time, the rate of surgically treated clavicle fractures increased by 705%, from 2.5% of all clavicle fractures in 2001 to 12.1% in 2012. Surgical treatment was more common in men and in younger age groups. Nevertheless, nearly 90% of clavicle fractures were treated nonsurgically in 2012.
Huttunen et al. remain ambivalent in the discussion section of their study, saying that these and other recent findings “may support surgical treatment of young, active patients who need to return to their previous level of activity in the shortest possible time,” while noting that “high-quality evidence that surgery produces superior long-term results compared with nonoperative treatment remains lacking.”
Injuries to the musculoskeletal system are among the most common wounds of war. Compared with extremity injuries in the civilian population, injuries sustained in combat tend to be due to high-energy explosions and are associated with a greater degree of contamination and a longer timeline for recovery and healing. Importantly, the sequelae of musculoskeletal injuries sustained during combat tend to lead to more long-term disability than those affecting other organ systems.
In this month’s Editor’s Choice article, Rivera et al. review the current literature on combat injuries of the lower extremity and suggest that explosions are the most common mechanism of injury encountered by deployed service members. While exposure to an explosion does not necessarily result in a specific limb injury, the explosion mechanism does contribute to more severe injuries. Moreover, among service members who sustain open fractures of the tibia, foot, and ankle, infection is a common complication and is associated with more severe soft-tissue injury. As a result, surgeons who are deployed in combat settings are now performing more fasciotomies for limbs that are at risk. However, the outcomes and complication rates associated with these procedures are not well established, and the causes of late amputations are not always clear.
As part of a comprehensive review of this topic, Rivera et al. pose 3 important clinical questions that are ideal for translational research investigation. First, they ask, “What is the best way to manage and transport patients who have severe open fractures in order to minimize infection?” Indeed, while negative-pressure wound therapy (NPWT) appears to be a promising wound-care technique, additional study is needed in order to know how to best augment the standard of care for battlefield medicine. Second, “What is the best way to treat fasciotomy wounds and the late sequelae of the compartment syndrome?” In order to answer this question, a broader understanding of compartment syndrome detection and the indications for surgical treatment are needed. Finally, “What is the best way to select limbs for salvage and to optimize the reconstruction of injured tissues?” This question must explore not only the patient’s perspective but also the multitude of causes that lead to late amputation.
Thomas A. Einhorn, MD
Editor, JBJS Reviews
A substantial number of patients, old and young, who sustain a proximal humeral fracture are managed with Kirschner wires (K-wires). Surgeons are especially likely to opt for wires over other forms of fixation when they need to protect the repair of a concomitant neurovascular injury, or in cases in which the patient cannot tolerate a more invasive surgery.
However, there is a somewhat frequent and potentially lethal drawback to using wires about the shoulder girdle. This latest JBJS Case Connector “Watch” looks at several cases in which wires were adequately placed in the shoulder but subsequently moved to other parts of the body. It also identifies apparent risk factors for wire migration and provides some guidance for minimizing that risk. Finally, it encourages orthopaedists to seriously consider alternate fixation options, whenever feasible, to eliminate the risk of wire migration altogether.
Every 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, Arvind Nana, MD, co-author of the July 20, 2016 Specialty Update on musculoskeletal infection, selected the three most compelling discoveries from among the more than 100 studies cited in the Specialty Update, which focused on biofilms.
Dr. Nana and his co-authors provide a concise primer on the biology of biofilms, the network of microorganisms that adhere to implant surfaces and form a complex structure surrounded by a self-generated extracellular polymeric matrix. This matrix not only anchors bacteria to orthopaedic implants, but also provides a nearly impenetrable defense mechanism against the host immune system. Staphylococci are the most common biofilm-forming bacteria found in orthopaedics.
Persister Cells in Biofilms
So-called persister cells have an inherent tolerance to antimicrobial agents. Misconceptions about persisters have permeated the literature. The authors provide clarification about persisters:
- Persister cells CAN be reliably killed when the antimicrobial concentration is high enough. The minimum biofilm eradication concentration (MBEC) is lower when antimicrobial exposure is continuous and prolonged.1
- Decreasing the number of microorganisms with antimicrobial intervention is NOT good enough. Cure requires the total elimination of all viable microbes.
Biofilm in Orthopaedic Trauma
Biofilm formation in the setting of open fractures is concerning because biofilm can develop on bone and in soft tissues in a matter of hours. The assumption is that appropriate surgical techniques for open fractures, including therapeutic antibiotic administration, can decrease bioburden and provide fracture stability, thus modulating the acute, local inflammatory response and minimizing biofilm formation.2 However, current technology does not enable noninvasive quantification of biofilm activity and presence in a stable open fracture following wound closure.
Biofilm in Total Joint Arthroplasty
Traditionally, prosthesis-related biofilm infections in the US have been treated by a 2-stage exchange arthroplasty. Although biofilm from the implant is removed by extraction of the components, the potential exists for persistence of biofilm in the surrounding soft tissues. Most patients treated for periprosthetic joint infections also receive intravenous antibiotics, but a recent in vitro study demonstrated that administering cefazolin even at increased concentrations still resulted in persistent Staphylococcus biofilm on cobalt-chromium, polymethylmethacrylate, and polyethylene,3 which supports the need for explantation.
There is still room to develop novel treatment methods for eradicating biofilm in periprosthetic joint infections. Future novel treatment methods for eradicating implant biofilm will help minimize the morbidity associated with current accepted periprosthetic joint infection treatment options.
- Castaneda P, McLaren A, Tavaziva G, Overstreet D. Biofilm antimicrobial susceptibility increases with antimicrobial exposure time. Clin Orthop Relat Res. 2016 Jan 21.
- Pfeifer R, Darwiche S, Kohut L, Billiar TR, Pape HC. Cumulative effects of bone and soft tissue injury on systemic inflammation: a pilot study. Clin Orthop Relat Res. 2013 Sep;471(9):2815-21.
- Urish KL, DeMuth PW, Kwan BW, Craft DW, Ma D, Haider H, Tuan RS, Wood TK, Davis CM 3rd..Antibiotic-tolerant Staphylococcus aureus biofilm persists on arthroplasty materials. Clin Orthop Relat Res.2016 Feb 1.
Since its introduction in the late 20th century, the 2-stage induced membrane technique has been lauded for its bone-reconstruction advantages over alternatives such as distraction osteogenesis and vascularized bone. The cases presented in this month’s “Case Connections” demonstrate that the technique can work with a variety of bone-defect shapes, sizes, and locations.
The springboard case, from the August 10, 2016 edition of JBJS Case Connector, describes 3 cases of chronic post-infection osteomyelitis in children in whom large diaphyseal defects were successfully treated with the induced membrane technique. Three additional JBJS Case Connector case reports summarized in the article focus on:
- a 50-year-old diabetic man with a necrotic foot ulcer in whom an extensive midfoot defect was successfully treated with this technique
- successful induced-membrane treatment of a 7-year-old girl with congenital pseudarthrosis of the clavicle
- 2 cases of trauma-caused segmental bone loss that were treated successfully with the induced membrane technique
It is imperative to resolve all active infection before or during stage 1 of this procedure, and careful spacer removal prior to stage 2 is of paramount importance to prevent damage to the induced membrane.