Outcomes of Nonoperatively Treated Vancouver B1 Fractures: Is Failure Common?

BACKGROUND: Periprosthetic fractures (PPFx) are a severe complication of total hip and hemiarthroplasty. Surgical treatment is typically performed but can result in major morbidity. Nonoperative PPFx management may provide a successful treatment alternative in select patients. METHODS: Vancouver B1 PPFx patients treated over a 10-year period were identified. Patient demographic data were retrospectively recorded. Injury and postoperative radiographs were reviewed. There were 48 patients who met the study criteria. Patients were divided into operative and nonoperative comparative cohorts. Outcome comparisons between the 2 cohorts included 1-year mortality, unplanned surgery within 24 months of injury, fracture union rate, and return to preinjury ambulation status. RESULTS: There was no difference in 1-year mortality between the nonoperative and operative cohorts (17 versus 8%; P = .32). We found no significant difference in unplanned surgery between the nonoperative and operative groups (8.7 versus 12%; P = .71), fracture union (100 versus 96%, P = .34), or return to ambulation status (86 versus 91%; P = .86). Nonoperative fractures were minimally displaced and within the metaphyseal region of the proximal femur without stem subsidence. Nonoperative fractures with subsequent treatment failure had initial fracture extension closer to the tip of the stem compared to successfully treated nonoperative fractures (5.5 versus 10.2 centimeters; P = .02). CONCLUSION: Select nonoperatively treated patients had infrequent need for unplanned surgery, high union rate, and return to their preinjury ambulation status. Nonoperative management is not appropriate for all Vancouver B1 PPFx, but those patients who have minimally displaced meta-diaphyseal fractures and partial remaining distal fixation can be successfully treated.

Biomechanical comparison of a novel tensioned cable construct versus tension band wiring for transverse patella fracture fixation.

PURPOSE: Tension band wiring (TBW) is the most widely accepted method for patella fracture fixation. The purpose of our study was to compare the biomechanical efficacy of a novel cable construct to TBW for the fixation of transverse patella fractures. The tensioned cable construct was hypothesized to have less fracture gapping after cyclic flexion-extension loading and greater ultimate load to failure as compared to TBW. METHODS: Transverse patellar osteotomies (AO/OTA 34C1.1) were performed on nine pairs of fresh-frozen human cadaveric whole legs (mean age 82.2 years, range 71-101). Treatment with TBW or tensioned cable construct was randomized within each specimen pair. Fracture site displacement was measured after 5000 flexion-extension cycles from 0° to 90° at 0.5 Hz. In load to failure testing, the knee was fixed at 45° of flexion and the quadriceps tendon was pulled proximally at 0.5 mm/sec until patella fixation failure. Comparisons were made using paired t-tests with alpha values of 0.05. RESULTS: Eight paired specimens completed the cyclic loading. The tensioned cable construct had significantly less fracture gapping than TBW (2.9 vs 10.9 mm; p = 0.020). Seven paired limbs underwent load to failure testing, which revealed no significant difference between the tensioned cable construct and TBW (1551.6 N vs 1664.0 N; p = 0.26). CONCLUSION: In this study of transverse patella fracture fixation, a tensioned cable construct demonstrated significantly less fracture gapping compared to TBW in response to cyclic loading with no significant difference in load at failure.

Iliac dysmorphism: defining radiographic characteristics and association with pelvic osseous corridor size.

INTRODUCTION: Insertion of iliac wing implants requires understanding of the curvilinear shape of the ilium. This study serves to quantitatively identify the area of iliac inner-outer table convergence (IOTC), characterize the iliac wing osseous corridor, and define the gluteal pillar osseous corridor. METHODS: Computed tomography scans of 100 male and 100 female hemipelves were evaluated. The iliac wing was studied using manual best-fit analysis of the bounds of the inner and outer cortices. The IOTC was defined as the location of the iliac wing with an intercortical width less than 5 mm. The shortest distance from the apex of the iliac crest to the superior border of the IOTC was defined as the iliac wing osseous corridor. Finally, the width of the gluteal pillar corridor from the gluteus medius tubercle to the ischial tuberosity was measured. RESULTS: The IOTC is an elliptical area measuring 22.3 cm2. All ilia had an area where the inner and outer cortices converged to an intercortical width of less than 5 mm; 48% converged to a single cortex. The shortest mean distance from the superior edge of the iliac crest to the beginning of the IOTC was 20.3 mm in men and 13.8 mm in women (p < 0.001). The gluteal pillar diameter averaged 5.3 mm in men and 4.3 mm in women (p < 0.001). DISCUSSION: All ilia converge to a thin and frequently unicortical central region. A 4.5 mm iliac wing lag screw will not breach the cortex if it remains within 20 mm or 14 mm distal to the cranial aspect of the iliac crest in males and females, respectively. Not only is the gluteal pillar smaller than previously thought, in 41% of males and 73% of females, it is not be large enough for 5 mm implants. CONCLUSION: This study quantitatively assesses the dimensions of the IOTC, the iliac crest osseous corridor, and the gluteal pillar. Overall, our findings provide improved understanding of the limits for implant use in the iliac wing as well as better appreciation of the complex osteology of the ilium. This will help surgeons to identify safe areas for implant placement and avoid inadvertent cortical penetration.

Intraoperative Comparative Femoral Rotation Imaging: Do not Overlook Parallax.

OBJECTIVE: To investigate the degree of error due to parallax during intraoperative rotational imaging involving the distal femur. METHODS: Twelve, fresh-frozen, lower-extremity cadaveric specimens were studied. The limbs were positioned supine and rotated until the posterior femoral condyles were superimposed using a C-arm. The C-arm was then repositioned to place the femoral condyles at the anterior and posterior margins of the image intensifier. The rotation necessary to resuperimpose the femoral condyles due to parallax was recorded. A second C-arm was then used from the contralateral side to simulate the rotational imaging technique to determine the magnitude and directionality of combined parallax. RESULTS: All 12 specimens demonstrated parallax, resulting in rotational discrepancies. Compared with central field of view alignment, the mean rotational discrepancy was 5.6 and 5.5 degrees for anterior and posterior positions, respectively. Contralateral imaging resulted in an additive effect with rotational differences of 9.0 and 12.6 degrees for bilateral anterior and posterior positions, respectively. CONCLUSIONS: Parallax causes rotational discrepancies with fluoroscopic imaging of the distal femur when the posterior femoral condyles are off-center in the imaging field of view. If femoral condyles are not centered when obtaining intraoperative rotational imaging of the uninjured and injured femurs, parallax can result in potentially clinically significant rotational deformity even if the femurs seem perfectly matched at the conclusion of surgery. We recommend perfectly centering of the posterior femoral condyles in the imaging field of view when obtaining lateral images of the distal femur to prevent this potentially overlooked contribution to malrotation.

Supraacetabular osseous corridor: defining dimensions, sex differences, and alternatives.

INTRODUCTION: The supraacetabular (SA) corridor extends from the anterior inferior iliac spine to the posterior ilium and can safely accommodate implants to stabilize pelvic and acetabular fractures. However, quantitative analysis of its dimensions and characteristics have not been thoroughly described. This study seeks to define the dimensions, common constriction points, and any alternative trajectories that would maximize the corridor diameter. METHODS: Computed tomography of 100 male and 100 female hemipelves without osseous trauma were evaluated. The corridor boundaries were determined through manual best-fit analysis. The largest intercortical cylinder within the pathway was created and measured. Alternative trajectories were tested within the SA boundaries to identify another orientation that maximized the diameter of the intercortical cylinder. RESULTS: The traditional SA corridor had a mean diameter of 8.3 mm in men and 6.2 mm in women. This difference in diameter is due to a more S-shaped ilium in women. A larger alternative SA corridor was found that had a less limited path through the ilium and measured 11.3 mm in men and 9.9 mm in women. These dimensions are significantly different compared to those of the traditional SA corridor in both men and women. CONCLUSIONS: In men, the SA corridor allows for the safe passage of most hardware used in pelvic and acetabular fractures. However, in women, the SA corridor is restricted by a more S-shaped ilium. An alternative trajectory was found that has a significantly larger mean diameter in both sexes. Ultimately, the trajectory of hardware will be dictated by the clinical scenario. When large implants are needed, especially in women, we recommend considering the alternative SA corridor.

Defining the iliac wing osseous fixation pathways: anatomy and implant constriction points.

INTRODUCTION: Insertion of iliac wing implants requires understanding of the curvilinear shape of the ilium. This study serves to quantitatively identify the area of iliac inner-outer table convergence (IOTC), characterize the iliac wing osseous corridor, and define the gluteal pillar osseous corridor. METHODS: Computed tomography scans of 100 male and 100 female hemipelves were evaluated. The iliac wing was studied using manual best-fit analysis of the bounds of the inner and outer cortices. The IOTC was defined as the location of the iliac wing with an intercortical width less than 5 mm. The shortest distance from the apex of the iliac crest to the superior border of the IOTC was defined as the iliac wing osseous corridor. Finally, the width of the gluteal pillar corridor from the gluteus medius tubercle to the ischial tuberosity was measured. RESULTS: The IOTC is an elliptical area measuring 22.3 cm2. All ilia had an area where the inner and outer cortices converged to an intercortical width of less than 5 mm; 48% converged to a single cortex. The shortest mean distance from the superior edge of the iliac crest to the beginning of the IOTC was 20.3 mm in men and 13.8 mm in women (p < 0.001). The gluteal pillar diameter averaged 5.3 mm in men and 4.3 mm in women (p < 0.001). DISCUSSION: All ilia converge to a thin and frequently unicortical central region. A 4.5 mm iliac wing lag screw will not breach the cortex if it remains within 20 mm or 14 mm distal to the cranial aspect of the iliac crest in males and females, respectively. Not only is the gluteal pillar smaller than previously thought, in 41% of males and 73% of females, it is not be large enough for 5 mm implants. CONCLUSION: This study quantitatively assesses the dimensions of the IOTC, the iliac crest osseous corridor, and the gluteal pillar. Overall, our findings provide improved understanding of the limits for implant use in the iliac wing as well as better appreciation of the complex osteology of the ilium. This will help surgeons to identify safe areas for implant placement and avoid inadvertent cortical penetration.

MRI-only occult geriatric hip fractures: is displacement common with nonoperative treatment?

INTRODUCTION: Although surgical fixation is routinely recommended for geriatric hip fractures, nonoperative treatment may be an option for certain stable fracture patterns. Occult hip fractures are nondisplaced fractures not evident on radiographs, but display intraosseous edema on MRI. Our aim is to report the rate of nonoperative treatment failure in patients with occult geriatric hip fractures. METHODS: All nonoperatively treated femoral neck or intertrochanteric femur fractures (AO/OTA 31A and 31B) from 2003 to 2018 were identified. Patients older than 65 years with negative radiographs but a hip fracture evident on MRI were included. Patients who died prior to fracture displacement or union were excluded. Charts and imaging were reviewed for demographic data, fracture type, clinical course, displacement, and whether corrective surgery was performed. RESULTS: Of 15 final study patients, there were 6 femoral neck and 9 intertrochanteric fractures. Two fractures displaced, both requiring surgery (2/15; 13.3%). Both displacements occurred in the femoral neck group (2/6; 33%) compared to none in the intertrochanteric cohort (0/9; 0%). This trend did not reach statistical significance (p = 0.14). CONCLUSION: Thirty-three percent (2/6, 33%) of femoral neck fractures displaced and required surgery. The remainder of the cohort (13/15, 87%) healed without complication, including all of the intertrochanteric fractures (9/9, 100%). Although this difference did not reach statistical significance, the results may better inform treatment discussions for geriatric patients with occult hip fractures diagnosed by MRI. LEVEL OF EVIDENCE: Level III.

Optimal Technical Factors During Operative Management of Low-Energy Femoral Neck Fractures.

OBJECTIVE: To determine if cancellous screw (CS) and sliding hip screw (SHS) technical factors during low-energy femoral neck fracture fixation affects a 24-month revision surgery rate and health-related quality of life (HRQL). DESIGN: Prospective randomized controlled study. SETTING: International, multicenter. PATIENTS: Eight hundred ninety-eight femoral neck fracture patients age 50 years and older. INTERVENTION: Patients were randomized to fracture stabilization with either CSs or a SHS device as part of the Fixation Using Alternative Implants for the Treatment of Hip Fractures (FAITH) trial. CS technical factors analyzed included screw diameter, short versus long screw threads, screw number and formation, screw orientation, and washer use. SHS technical factors studied were side plate length, supplemental screw use, lag screw position, and tip-apex distance. MAIN OUTCOME MEASUREMENTS: Revision surgeries within 24 months to promote fracture healing, relieve pain, treat infection, or improve function. In addition, HRQL measures were collected, including the SF-12 Physical Component Score and Western Ontario and McMaster Universities Osteoarthritis Index. RESULTS: The 3-screw inverted triangle pattern had a significantly lower revision surgery rate than a 3-screw triangle formation (P = 0.004). No other CS or SHS technical factors were predictive of revision surgery or affected a patient's HRQL (P > 0.05). CONCLUSIONS: A 3-screw inverted triangle pattern was superior to a 3-screw triangle formation. However, injury and patient factors such as fracture displacement, age, smoking status and sex play a more significant role in clinical outcomes for low-energy femoral neck fracture treatment. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

What Factors Increase Revision Surgery Risk When Treating Displaced Femoral Neck Fractures With Arthroplasty: A Secondary Analysis of the HEALTH Trial.

OBJECTIVES: HEALTH was a randomized controlled trial comparing total hip arthroplasty with hemiarthroplasty in low-energy displaced femoral neck fracture patients aged ≥50 years with unplanned revision surgery within 24 months of the initial procedure being the primary outcome. No significant short-term differences between treatment arms were observed. The primary objective of this secondary HEALTH trial analysis was to determine if any patient and surgical factors were associated with increased risk of revision surgery within 24 months after hip fracture. METHODS: We analyzed 9 potential factors chosen a priori that could be associated with revision surgery. The factors included age, body mass index, major comorbidities, independent ambulation, type of surgical approach, length of operation, use of femoral cement, femoral head size, and degree of femoral stem offset. Our statistical analysis was a multivariable Cox regression using reoperation within 24 months of index surgery as the dependent variable. RESULTS: Of the 1441 patients included in this analysis, 8.1% (117/1441) experienced reoperation within 24 months. None of the studied factors were found to be predictors of revision surgery (P > 0.05). CONCLUSION: Both total and partial hip replacements are successful procedures in low-energy displaced femoral neck fracture patients. We were unable to identify any patient or surgeon-controlled factors that significantly increased the need for revision surgery in our elderly and predominately female patient population. One should not generalize our findings to an active physiologically younger femoral neck fracture population. LEVEL OF EVIDENCE: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

The Diagnostic Accuracy of Radiographs and Magnetic Resonance Imaging in Predicting Deltoid Ligament Ruptures in Ankle Fractures.

BACKGROUND: Operative indications for supination-external rotation (SER) ankle fractures depend on the integrity of the medial structures. Despite the importance of assessing deep deltoid ligament injuries, the accuracy of common diagnostic tests has not been established. QUESTIONS/PURPOSES: The objective of this study was to compare the ability of injury (non-stress) and stress radiographs and magnetic resonance imaging (MRI) to diagnose deep deltoid ligament ruptures in operative SER ankle fractures. METHODS: Patients were included who underwent surgical fixation of SER ankle fractures and had appropriate injury and manual stress test radiographs, pre-operative ankle MRI, and intra-operative assessment of deep deltoid integrity by direct visualization. The medial clear space (MCS) was considered positive for all values over 5 mm on the injury or stress mortise radiographs. MRI analysis of the deep deltoid ligament injury was performed by blinded fellowship-trained musculoskeletal radiologists. Intra-operative direct visualization and assessment of the deltoid was performed using a direct medial ankle approach at the time of operative fracture fixation. RESULTS: Using intra-operative visualization as the gold standard, MCS measurements and MRI had differing abilities to diagnose a deep deltoid rupture. In cases where the MCS was less than 5 mm on injury radiographs and stress tests were performed, MCS measurements were much less accurate than MRI in predicting deltoid ruptures (46% versus 79%, respectively) with a high false positive rate (80%). In contrast, an MCS measurement of greater than 5 mm on injury radiographs was a strong predictor of deep deltoid rupture (accuracy of 95%). CONCLUSION: Compared with direct visualization of the deltoid ligament intra-operatively, these data support proceeding with surgery when the MCS on injury radiographs is greater than 5 mm without any additional stress tests or advanced imaging. When the MCS is less than 5 mm, we recommend MRI analysis because of its increased accuracy and decreased false positive rate. Improving our ability to diagnose deltoid ruptures will contribute to more effective management of patients with SER ankle fractures.

Trochleoplasty: Indications and Technique.

PURPOSE OF REVIEW: Trochlear dysplasia is a well-described risk factor for patellar instability. Trochleoplasty has emerged as a procedure within the surgical armamentarium for patellar instability, yet its role is unclear. A variety of trochleoplasty procedures have emerged. The purpose of this review is to clarify indications for trochleoplasty, outline the technical steps involved in performing common trochleoplasties and report the published outcomes and potential complications of these procedures. RECENT FINDINGS: Patellar instability with severe trochlear dysplasia is the main indication for trochleoplasty. Three types of trochleoplasty have emerged: (1) lateral facet elevation; (2) sulcus deepening; and (3) recession wedge. Deepening and recession wedge trochleoplasties are the most commonly performed. Trochleoplasty is a surgical option for addressing patellar instability in patients with severe trochlear dysplasia. Deepening and recession wedge trochleoplasties that address Dejour B and D dysplastic trochleas are the most studied, with both short- and midterm outcomes reported. Long-term outcomes are lacking and comparative studies are needed.

CD34+ cells seeded in collagen scaffolds promote bone formation in a mouse calvarial defect model.

Bone tissue engineering (BTE) holds promise for managing the clinical problem of large bone defects. However, clinical adoption of BTE is limited due to limited vascularization of constructs, which could be circumvented by pre-cultivation of osteogenic and endothelial derived cells in natural-based polymer scaffolds. However, until now not many studies compared the effect of mono- and cocultures pre-seeded in collagen before implantation. We utilized a mouse calvarial defect model and compared five groups of collagen scaffolds: a negative control of a collagen scaffold alone, a positive control treated with BMP-7, monocultures of either human osteoblasts (hOBs) or CD34+ cells, and a coculture of hOB and CD34+ cells. Each pre-seeded collagen scaffold was implanted in mice. After 6 weeks mice were sacrificed and their skulls prepared for volumetric and histologic analysis. We found that a monoculture of CD34+ cells and a coculture of hOB and CD34+ cells pre-cultured in the collagen scaffold increased bone regeneration to a similar extend. In these groups, greater amounts of new bone were found compared with hOB monocultures. Interestingly, monoculture of CD34+ cells demonstrated better fracture healing than monoculture of hOBs, emphasizing the possible role of angiogenesis. Our results are promising regarding a cellular based collagen BTE construct, but more work is needed to understand the complex interaction between the osteogenic and endothelial cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1505-1516, 2018.

The Effect of Soft Tissue Injuries on Clinical Outcomes After Tibial Plateau Fracture Fixation.

OBJECTIVE: To determine if ligamentous and meniscal injuries as determined by initial magnetic resonance imaging altered clinical outcomes after the fixation of tibial plateau fractures. DESIGN: Comparative cohort study. SETTING: Academic level I trauma center. PATIENTS/PARTICIPANTS: Eighty-two patients from a prospective database of operatively treated tibial plateau fractures met the inclusion criteria, which consisted of injury radiographs, preoperative knee magnetic resonance imaging (MRI), and a minimum of 12 months of clinical outcomes. INTERVENTION: In addition to radiographs and computed tomography scans for fracture assessment, an MRI was performed to detect tears in the medial and lateral menisci and complete ruptures of the cruciate ligaments (anterior cruciate ligament and posterior cruciate ligament) and collateral ligaments [lateral collateral ligament and medial collateral ligament (MCL)]. Surgical fixation of tibial plateau fractures was performed by a single surgeon based on injury patterns. MAIN OUTCOME MEASUREMENTS: Clinical outcomes included the Knee Outcome Survey Activities of Daily Living Scale, the Lower Extremity Functional Scale, the Short-Form 36, and knee range of motion. Secondary soft tissue surgeries and conversion to arthroplasty were also noted. RESULTS: On injury MRI, 60 patients (73%) had injuries to at least one soft tissue structure. At final follow-up, 2 patients (2%) had a secondary soft tissue surgery and 1 patient (1%) underwent total knee arthroplasty. Patient-reported outcomes and range of motion assessments were not significantly different in patients with and without medial meniscal tears, lateral meniscal tears, and complete MCL ruptures. CONCLUSIONS: In this cohort of patients with operative tibial plateau fractures, sutured lateral meniscal tears, untreated medial meniscus tears, and complete MCL ruptures did not significantly affect clinical outcomes. In addition, these data suggest that obtaining a preoperative MRI in patients with tibial plateau fractures to diagnose soft tissue injuries may not alter the surgical treatment or alter patient prognosis for midterm outcomes. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Role of Bone Marrow Aspirate in Orthopedic Trauma.

Bone marrow aspirate grafting entails mesenchymal stem cell-containing bone marrow harvesting and injection into a fracture site to promote bone formation. Although the use of bone marrow aspirate in orthopedic trauma is not widespread, an increasing number of studies are reporting clinical success. Advantages of using bone marrow aspirate are that it is readily obtainable, has low harvest morbidity, and can be easily and quickly injected. However, no universally accepted role for its use exists. Future studies directly comparing bone marrow aspirate with conventional techniques are needed to define its role in the treatment of orthopedic trauma patients.

Scapulothoracic Dissociation: Evaluation and Management.

Scapulothoracic dissociation is a rare, potentially limb- and life-threatening injury of the shoulder girdle. The injury is characterized by lateral displacement of the scapula resulting from traumatic disruption of the scapulothoracic articulation. The typical physical examination findings consist of substantial swelling of the shoulder girdle, along with weakness, numbness, and pulselessness in the ipsilateral upper extremity. Radiographic evaluation includes measurement of the scapular index on a nonrotated chest radiograph and assessment for either a distracted clavicle fracture or a disrupted acromioclavicular or sternoclavicular joint. Although vascular injury occurs in most patients, emergent surgery is performed only in patients with either limb-threatening ischemia or active arterial hemorrhage. Management of neurologic injury can be delayed if necessary. The location and severity of neurologic injury determine whether observation, nerve grafting, nerve transfer, or above-elbow amputation is performed. Skeletal stabilization procedures include plate fixation of clavicle fractures and reduction of distracted acromioclavicular or sternoclavicular joints. The extent of neurologic injury determines clinical outcomes. Medical Outcomes Study 36-Item Short Form scores are significantly lower in patients with complete brachial plexus avulsion injury than in patients with postganglionic injury.