Proximal Humeral Fractures: More Data on Nonunion Risk
Proximal humeral fractures tend to occur in a bimodal distribution, namely, in younger, primarily male patients and in older (>65 years of age), primarily female patients. In the latter population, such fractures are often related to low bone density, and we in the orthopaedic community now recognize the imperative to evaluate at-risk individuals through measures such as DXA scanning and laboratory assessments of bone health in order to institute appropriate monitoring and pharmacotherapy.
Regarding the treatment of these fractures, several large trials have demonstrated that, for select fracture patterns, nonsurgical care results in clinical and functional outcomes that are equal to or better than surgical care with open reduction and internal fixation or arthroplasty. The question for treating clinicians is: are there proximal humeral fracture patterns that have higher rates of complications (chiefly nonunion) following nonsurgical care?
In a retrospective study reported in JBJS, Goudie and Robinson evaluated the rate of nonunion among patients who were treated nonoperatively for a proximal humeral fracture at their regional trauma center in the UK. They also sought to develop and validate a prediction model to assess nonunion risk, measuring the effect of 19 patient demographic and radiographic variables on healing.
Overall, 231 (10.4%) of the 2,230 included patients experienced nonunion. Among those with valgus angulation of the humeral head (395 patients), the nonunion prevalence was <1%, and none of the other variables evaluated were associated with increased risk of nonunion in a multivariable analysis. However, among the 1,835 patients with neutral or varus angulation of the head, the prevalence of nonunion was 12.4%, and decreasing head-shaft angle, increasing head-shaft translation, and smoking were independently predictive of nonunion.
Important to note is the residual pain and diminished function that often accompanies nonunion. Still, the authors rightly point out that “surgery aimed solely at preventing nonunion exposes patients to the risk of other complications that are not encountered with nonoperative treatment.” But, based on these findings about fracture morphology, they conclude that “medically fit patients with translated and/or angulated fractures should be counseled about smoking cessation and considered for surgery to avoid the debilitating effects of subsequent nonunion.” Patients with these fracture characteristics deserve closer scrutiny in our efforts to provide the best treatment for proximal humeral fractures.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
Click here for a JBJS Clinical Summary on proximal humeral fractures.
JBJS Classics: The Küntscher Method of IM Fixation
OrthoBuzz 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 about these classics by clicking on the “Leave a Comment” button in the box to the left.
In 1957 Gerhard Küntscher presented his work on intramedullary (IM) nailing to the American Academy of Orthopaedic Surgeons. His classic JBJS paper on the subject, published in January 1958, summarized his views on this comparatively new technique and encouraged other surgeons to use it for the treatment of long bone fractures and nonunions.
Küntscher pointed out that callus was very sensitive to mechanical stresses, and therefore any treatment method should aim at complete immobilization of the fracture fragments throughout the healing process. External splints, such as plaster casts, did not achieve that, and “inner splints” fixed to the outside of the bone damaged the periosteum.
In advocating for intramedullary fixation, Küntscher was careful to distinguish nails from pins. He was very complimentary about J. and L. Rush, who developed intramedullary pinning, but he pointed out that, unlike pins, nails allowed both longitudinal elasticity and cross-sectional compressibility if they were designed with a V-profile or clover-leaf cross section. This cross-sectional elasticity allowed the nail to fit the canal and expand during bone resorption.
Not only did Küntscher appreciate the biomechanics of the intramedullary nail, but he also pointed out the physical and psychological advantages of early mobilization, particularly in the elderly. He also emphasized that massage was unnecessary—and potentially harmful—during the recovery phase, claiming that any measures that make patients more conscious of their injuries are psychologically disadvantageous.
Küntscher used intramedullary nailing to treat fractures, nonunions, and osteotomies of the femur, tibia, humerus, and forearm. He accepted that it was “a most daring” approach that would destroy the nutrient artery, but he pointed out that proper nailing almost always prevented pseudarthoses and that antibiotics had checked the threat of infection. He said further that perioperative x-rays entailed short exposures and that the “electronic fluoroscope” had, even back then, practically eliminated the risk of x-ray injury to assistants.
The paper clearly illustrates Küntscher’s widespread knowledge and innovative skills. However, it was the subsequent development of locked nails that resulted in intramedullary nailing becoming the treatment of choice for femoral and tibial fractures. Time will tell if modern orthopaedic surgeons will catch up with Küntscher and use nailing for humeral and forearm diaphyseal fractures.
Charles M Court-Brown, MD, FRCSCEd
JBJS Deputy Editor
JBJS Classics: Understanding Proximal Humeral Fractures
The contributions to the field of shoulder surgery from Dr. Charles Neer are too numerous to document in any one commentary. A partial list would include shoulder arthroplasty (both hemi and total), the concept of impingement and acromial pathology, multidirectional instability, and the role of the AC joint in rotator cuff pathology.
Dr. Neer also made numerous contributions to the understanding of fracture care, including the distal femur and clavicle. But no area of fracture management was of greater interest to him and his colleagues at Columbia than the proximal humerus. This classic manuscript has been cited thousands of time and remains the seminal piece in the foundation of understanding fracture patterns in the proximal humerus—and the attendant treatment implications.
Dr. Neer introduced the concept of the four parts of the proximal humerus in this manuscript, and with it the implication of isolating the humeral-head blood supply in a four-part fracture. The impetus to understand the complication of avascular necrosis of the humeral head began with this manuscript, as did the critical debates regarding surgical versus nonsurgical intervention and replace-or-fix. An important area of ongoing debate is Neer’s definition of a “displaced” fracture in the proximal humerus as having > 1 cm of displacement. The orthopaedic community to this day is wrestling with this definition and its relevance to treatment and outcomes.
This classic manuscript also helped launch a decades-old conversation about the role of fracture or musculoskeletal-disease classification systems. Subsequent publications by Zuckerman and Gerber identified issues with inter- and intra-rater reliability when applying the Neer classification system to a set of radiographs. The reliability debate surrounding this classification system led us to understand the issue of forcing continuous variables (fracture lines are infinite in their trajectory and displacement) into dichotomous variables (a classification system). Because of Dr. Neer’s work and subsequent research, our community understands that when we make these classification designations, we will agree about 60% of the time (kappa statistic of 0.6). That level of agreement is not reflective of a “good” or “bad” classification system; rather, it’s a consequence of moving a continuous variable to a dichotomous variable.
So we remain indebted to Dr. Neer not only for laying the foundation for the treatment of patients with proximal humeral fractures, but also for vastly expanding our knowledge regarding the role, strengths, and weaknesses of disease and fracture-classification systems.
Marc Swiontkowski, MD
JBJS Editor-in-Chief
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