Proximal fracture line extension in humeral shaft fractures

Introduction

Humeral shaft fractures are common injuries treated by orthopaedic surgeons. The purpose of this study is to evaluate displaced diaphyseal humerus fractures and describe the incidence and characteristics associated with non or minimally displaced fracture line extension into the proximal metadiaphyseal region of the humerus.

Methods and materials

All adult patients with diaphyseal humeral shaft fractures located within the distal two-thirds of the humeral shaft, treated at a single level I trauma institution between 2007 and 2020, were retrospectively identified. 202 patients with 203 fractures of the humeral shaft were included. Fracture patterns were classified according to AO/OTA classification and fracture line extension into the proximal metadiaphyseal region was evaluated on radiographs. Patient demographics, management details, and radiographic outcomes were obtained from review of the electronic medical record.

Results

Of 203 diaphyseal humerus fractures, 11.8 % (n = 24) had non or minimally displaced proximal extension of their main fracture line. This included 43.7 % (n = 7) of all proximal third junction diaphyseal fractures, 10.7 % (n = 16) of all middle third diaphyseal fractures, and 2.6 % (n = 1) of all distal third diaphyseal fractures. Patients with proximal fracture extension were, on average, older (61.7 versus 44.4 years, p < 0.001), and a higher percentage were female (75 % versus 45.5 %, p < 0.01) compared to patients without fracture proximal extension. Fractures with proximal extension were all closed fractures (n = 24), were more often sustained from low-energy fall (87.5 % versus 35.2 %, p < 0.001), and were more often spiral type fractures (62.5 % versus 17.2 %). Fractures with proximal extension were more often treated non-operatively (58.3 % versus 42.1 %, p < 0.01), but were found to have a higher rate of nonunion after non-operative treatment (17.6 % versus 8.1 %) compared to fractures without proximal extension. All operatively treated fractures that had proximal metaphyseal extension were secured with a fixation construct to achieve fixation proximal to the extent of the fracture line, most often into the humeral head and neck. Operative management with proximal fixation into the humeral head was also pursued for a patient with nonunion, including persistent lucency of the proximal extension line, after failed non-operative treatment. Mean follow-up was 35.5 weeks (range: 0-607 weeks).

Conclusions

Proximal fracture line extension in the setting of diaphyseal humerus fractures is not uncommon. Detection and consideration of this sometimes subtle finding is important when planning to treat these injuries operatively.

Intramedullary Free Gracilis for Dead-Space Obliteration and Stump Resurfacing in a Transfemoral Amputee With Recurrent Osteomyelitis

Background

A 72-year-old man with a history of delayed presentation for severe right lower extremity burns underwent through-knee amputation complicated by periprosthetic distal femur osteomyelitis. Subsequent transfemoral amputation was complicated by Stage IVB Cierny-Mader osteomyelitis despite appropriate medical and surgical treatment.

Methods

Due to the presence of threatened proximal femur intramedullary nail from prior intertrochanteric femur fracture, inability to further shorten femur, and lack of local soft-tissue options, we performed soft tissue reconstruction with free gracilis flap. The free gracilis flap was pulled proximally through the femoral canal to obliterate intramedullary dead space and provide distal femoral stump coverage.

Results

The stump was fully healed upon 6-month follow-up with computerized tomography demonstrating continued presence of gracilis flap within the femoral canal and no evidence of osteomyelitis. At 1-year follow-up, the patient was ambulatory using a prosthetic without recurrence of osteomyelitis.

Conclusions

Previous descriptions of intramedullary free muscle flaps for the treatment of osteomyelitis are limited in number, with its function being limited to dead-space obliteration. This report presents intramedullary free gracilis flap to be a viable option in above-knee amputees for combined dead space obliteration and stump resurfacing in the context of recurrent osteomyelitis.

Hospital transfer and delayed reduction of traumatic hip dislocations

INTRODUCTION

Native hip dislocations are high energy injuries that cause substantial patient morbidity. Expedient reduction has been demonstrated to improve patient outcomes. The objective of our study was to compare complication rates in patients with native hip dislocations who presented directly to a level-one trauma center with those transferred from an outside hospital (OSH). Our hypothesis was that those transferred from an OSH would experience a delay in reduction and subsequently would experience higher rates of avascular necrosis (AVN), post-traumatic arthritis (PTA), and need for secondary surgery.

MATERIAL AND METHODS

We conducted a retrospective chart review of all native hip dislocations from our level-one trauma center between January 2007 and December 2020. The initial query resulted 628 patients which was refined to 90 patients after excluding patients for incorrect diagnosis code or less than 6 months of follow-up. Our primary outcome was the development of AVN, PTA, and need for secondary surgery. Time from injury to reduction was recorded for all patients included.

RESULTS

For every one hour of delay in time to reduction, there was a 3.4% increase in the risk of developing AVN (p = 0.004) and a 4.3% increase in risk for developing PTA (p = 0.01). The risk of requiring a secondary surgery increased 4.6% for each hour of delay in reduction (p = 0.03). The average time to reduction of transferred patients was higher compared to those who presented directly to our center (13.8 h vs 5.7 h); however, transfer status was not found to be an independent risk factor for the measured outcomes.

CONCLUSIONS

Transfer status is not an independent risk factor for the development of AVN, PTA, or the need for a secondary surgery. However, transferred patients did experience an average delay of 8 h in time to reduction compared to those who presented directly to a trauma center. Of the 27 patients with a reduction delay greater than 12 h, 26 (96%) were transferred.

The influence of biplanar reduction and surgeon experience on proximal humerus fractures treated with ORIF

BACKGROUND

Treatment for proximal humerus fractures remains controversial. Studies of open reduction and internal fixation (ORIF) rarely account for reduction quality, while surgeon experience and sagittal plane reduction remain unstudied. In a retrospective case series analysis of AO/OTA C-type proximal humerus fractures treated with ORIF using a locking plate, we hypothesized that reduction quality would be associated with outcome, and reductions would improve with experience.

METHODS

We retrospectively identified 41 3- and 4-part proximal humerus fractures treated with ORIF by a single orthopaedic traumatologist. Two blinded traumatologists assessed injury and post-operative radiographs for medial calcar disruption and five measures of deformity. Major complications and functional outcome were assessed.

RESULTS

Outcome by ASES score was similar to previous reports (mean 73.6, std dev 22.5). Eleven of 35 patients (31.4%) with greater than six months follow-up experienced a complication. Post-reduction sagittal HSa<25° (RR = =9.44, p = =0.024) and medial calcar disruption (RR = =3.82, p = =0.009) were associated with complications. Post-reduction coronal and sagittal HSa improved with experience (p < 0.001 and p = =0.032, respectively) as did the likelihood of overall anatomic reduction (p = =0.006). ROC analysis found a threshold for superior reduction quality after 23 cases (AUC = =0.873, p < 0.001).

CONCLUSION

Sagittal reduction quality and medial calcar disruption were associated with complications. Additionally, reduction quality improved with experience. Future studies of proximal humerus ORIF should include multiplanar assessments of reduction while accounting for surgeon experience.

Orthopedic Surgeons Have Inadequate Knowledge of the Cost of Trauma-Related Imaging Studies

Radiographic imaging is integral to the diagnosis and treatment of orthopedic injuries. Previous studies have shown that orthopedists consistently underestimate the price of implants, but their knowledge of imaging charges is unknown. This study evaluated whether orthopedic residents and faculty could accurately estimate charges of imaging modalities at their respective institutions. A survey with 10 common imaging studies was sent to 8 academic level I trauma centers. Participants estimated the total charge of each imaging modality. This was compared with the actual charge at their institution. Seven centers produced 162 responders: 74 faculty and 88 residents. The differences between the estimated cost and the billing charge were calculated and broken down by training level and imaging modality. Overall, imaging charges were underestimated by 31% (P<.001), with 19.4% of estimates being within 20% of actual charges (95% confidence interval, 19.1-19.9). There was no difference between training levels (P=.69). There was greater than 1000% variation in charges between institutions. Orthopedists across training levels underestimate hospital charges associated with common imaging studies, and there is a large variation in charges between centers. Awareness of charges is important because charges affect clinical decision making and are relevant to practicing both cost-conscious and clinically sound medicine. [Orthopedics. 2019; 42(5):e454-e459.].

Long Bone Union Accurately Predicted by Cortical Bridging within 4 Months

Background:

Previous retrospective research found that the presence or absence of bridging callus within 4 months postoperatively discriminated accurately between eventual union and nonunion of fractures of the tibial shaft. However, there remains no consensus regarding early prognostication of long bone nonunion. We prospectively assessed the accuracy and reliability of the presence of any bridging callus within 4 months in a cohort that was expanded to include both tibial and femoral shaft fractures.

Methods:

We identified 194 consecutive fractures of the shaft of the tibia (OTA/AO type 42-A, B, or C) and femur (OTA/AO type 32-A, B, or C) that were treated with intramedullary nailing. Exclusions for inadequate follow-up (55), extended delay prior to nailing (10), and skeletal immaturity (3) resulted in a study population of 126 fractures (56 tibiae and 70 femora) in 115 patients. Digital radiographs made between 3 and 4 months postoperatively were independently assessed by 3 orthopaedic traumatologists. The accuracy of assessment of the presence of any bridging callus, bicortical bridging, and tricortical bridging to predict union or nonunion was assessed with chi-square analysis and by interobserver reliability (kappa statistic).

Results:

The nonunion rate was 4% (5 of 126 fractures). The presence of any bridging callus by 4 months accurately predicted union (121 of 122 fractures) and its absence predicted nonunion (4 of 4 fractures). There was 1 incorrect prediction of union for a fracture that failed to unite (p < 0.001). Bicortical or greater bridging predicted union when present (116 of 116 fractures) and nonunion when absent (5 of 10 fractures), incorrectly predicting that 5 healing fractures would go on to nonunion (p < 0.001). Tricortical or greater bridging predicted union when present (103 of 103 fractures) and nonunion when absent (5 of 23 fractures), incorrectly predicting that 18 healing fractures would go on to nonunion (p < 0.001). Interobserver reliability was calculated for any bridging (kappa value, 0.91), bicortical bridging (kappa value, 0.79), tricortical bridging (kappa value, 0.71), and the exact number of cortices bridged (kappa value, 0.67).

Conclusions:

The presence of any bridging callus within 4 months accurately predicts the final healing outcome for tibial and femoral shaft fractures treated with intramedullary nailing. This criterion is simple and reliable, and only standard radiographs are needed to make the determination. Basing the prognosis on the bridging of additional cortices risks overestimation of the nonunion rate and is associated with relatively poor reliability.

Practicality of exchanging transparent 3D CT for radiography for pelvic fractures

OBJECTIVE

We assess the utility of transparent 3D reconstructed CT images for evaluation of traumatic pelvic bony injuries compared to traditional radiographs.

METHODS

Radiographs and 3D reconstructed CT were anonymized and randomized before review by 4 board certified physicians using a standardized questionnaire and compared to a gold-standard axial CT by a fifth board certified physician.

RESULTS

49 patients were included. We found significant agreement (K=[0.5-0.92], p<0.001) and comparable accuracy (K=[0.36-0.38], p<0.02) and ghost images of radiographs and transparent 3D reconstructed CT without a difference in confidence (p=0.38).

CONCLUSION

Transparent 3D reconstructed CT images may be sufficient for pelvic trauma injury without the use of radiographs.

Pediatric calcaneal fractures

Although operative treatment of displaced, intra-articular fractures of the calcaneus in adults is generally accepted as standard practice, operative treatment for the same fractures in the skeletally immature remains controversial, potentially because the outcome for fracture types (intra- vs. extra-articular) and severity (displaced vs. nondisplaced) have been confounded in studies of children. We review herein the results of 21 displaced, intra-articular fractures in 18 skeletally immature patients, who were treated with open reduction and internal fixation using a standard surgical approach and protocol developed for adults. The average pre-operative Böhler's angle on the injured side was −5° (range: −35 – +35) compared to 31° (range: +22 – +47) on the uninjured side, indicating substantial displacement. There were no post-operative infections or wound healing problems, and all but one patient was followed to union (average follow-up: 1.5 years; range: 0.30–4.3 years). Maintenance of reduction was confirmed on follow-up radiographs with an average Böhler's angle of 31° (range: +22 – +49). We demonstrate that results for operative fixation of displaced, intra-articular calcaneal fractures in the skeletally immature are comparable to those in adults when the treatment protocol is the same.

Percutaneous stabilization of traumatic peroneal tendon dislocation

Level of Evidence: V, Expert Opinion

Endoscopic prosthesis augmentation of the lower esophageal sphincter in swine

HYPOTHESIS

Endoscopically delivered prostheses are safe, durable, and may augment a defective lower esophageal sphincter (LES).

METHODS

Pigs were studied as normal-LES or LES-weakened animals. A novel endoscopic delivery system was developed in order to place multiple hydrogel prostheses into the LES submucosa. Histopathology sections evaluated ultimate durability and the relationship of the prostheses to esophageal anatomy.

RESULTS

Overall, 97% of 179 prosthesis delivery attempts were successful. LES-weakened animals had LES pressures return to normal or supranormal values at 2 weeks and 2 months after prosthesis augmentation. Weakened gastric yield pressures improved to normal values at 2 weeks after prosthesis augmentation. The thickness of the muscular layers and the mucosal integrity of the esophagus was unaffected by the retained prostheses.

CONCLUSIONS

Endoscopically delivered hydrogel prostheses are safe and durable. These prostheses can successfully augment a defective sphincter without recognizable damage to the esophagus.

Effect of aerobic fitness on the physiological stress response in women

Stress reactivity was assessed in aerobically fit (n = 14) and unfit (n = 8) females during the follicular phase of the menstrual cycle. Participants completed the Spielberger State-Trait Anxiety Inventory and provided a urine sample for catecholamine analysis before and after mental stress testing, Stroop Color-Word Test. Blood pressure, heart rate, muscle tension, and skin conductance were measured during mental stress testing. Fit and unfit participants differed significantly in baseline heart rate but not in stress reactivity or in state or trait anxiety. These data suggest that aerobic fitness does not attenuate the stress response in women prior to menopause.

Spontaneous emission control in quantum well laser diodes

Spontaneous emission control has been achieved in GaAs/AlGaAs quantum well lasers by the use of Bragg reflectors to define a micro-cavity perpendicular to the quantum wells. The room temperature emission is inhibited whilst below 130K there is an enhancement. These changes to the spontaneous recombination process directly effect the threshold current producing a 25% reduction at room temperature. Theoretical modeling of the lasers is in agreement with the experimental results and highlights the effect of the micro-cavity in altering the overlap of the electro-magnetic field with the quantum well dipole oscillators.

Requirements for Epstein-Barr nuclear antigen 1 (EBNA1)-induced permanganate sensitivity of the epstein-barr virus latent origin of DNA replication

Epstein-Barr nuclear antigen 1 (EBNA1) activates DNA replication from the Epstein-Barr virus latent origin of DNA replication, oriP. EBNA1 binds cooperatively to four recognition sites in the dyad symmetry (DS) element of oriP, causing alterations in the origin DNA structure, which can be detected by the increased sensitivity of one Thy residue in two of the binding sites to permanganate oxidation. To better understand the significance of this EBNA1-induced origin distortion, we have investigated the DNA sequence and EBNA1 amino acid requirements for permanganate sensitivity. We have shown that the EBNA1 DNA binding and dimerization domains are sufficient to induce permanganate sensitivity and that amino acids 463-467, which form an extended chain that travels along the minor groove of the EBNA1 recognition site, play an important role in generating the DNA distortion. The EBNA1-induced permanganate sensitivity is independent of cooperative interactions between EBNA1 molecules on the origin and requires a specific sequence within the EBNA1 binding site. Using synthetic EBNA1 binding sites, we found that the inversion of a single AT base pair in the EBNA1 recognition sequence is sufficient to confer EBNA1-induced permanganate sensitivity. These studies indicate that permanganate oxidation can detect very minor alterations in DNA structure.

Cooperative assembly of EBNA1 on the Epstein-Barr virus latent origin of replication

The EBNA1 protein of Epstein-Barr virus (EBV) activates DNA replication by binding to multiple copies of its 18-bp recognition sequence present in the Epstein-Barr virus latent origin of DNA replication, oriP. Using electrophoretic mobility shift assays, we have localized the minimal DNA binding domain of EBNA1 to between amino acids 470 and 607. We have also demonstrated that EBNA1 assembles cooperatively on the dyad symmetry subelement of oriP and that this cooperative interaction is mediated by residues within the minimal DNA binding and dimerization domain of EBNA1.