Peter Helwig

Analysis of Efficacy and Failure in Proximal Humerus Fractures Treated With Locking Plates

Objective: The purpose of this study was to determine the efficacy of proximal humerus locking plates (PHLP) and to clarify predictors of loss of fixation. Design: Retrospective review of patients with proximal humerus fractures fixed with a PHLP. Setting: Five Level 1 trauma centers. Patients: One hundred fifty-three patients (111 female, 42 male) 18 years or older with a displaced fracture or fracture-dislocation of the proximal humerus treated with a PHLP between January 1, 2001 and July 31, 2005. Intervention: Demographic data, trauma mechanism, surgical approach, and perioperative complications were collected from the medical records. Fracture classification according to the AO/OTA, radiographic head-shaft angle, and screw tip-articular surface distance in true anteroposterior (AP) and axillary lateral radiographs of the shoulder were measured postoperatively. Varus malreduction was defined as a head-shaft angle of <120 degrees. Main Outcome Measurements: Statistical analysis was done to establish correlations between loss of fixation and postoperative head-shaft angle in the true AP radiograph, patient age, fracture type, trauma mechanism, number of locking head screws, and type of plate. Results: The mean age was 62.3 ± 15.4 years (22-92) and the mean injury severity score (ISS) was 9.5 ± 10.16 (4-57; n = 73). The surgical approach was deltopectoral (90.2%) or transdeltoid (9.8%). No intraoperative complications were reported. The mean postoperative head-shaft angle was 130 degrees (95 degrees to 160 degrees; SD = 13). The overall incidence of loss of fixation was 13.7%. There was a statistically significant association between varus reduction (<120 degrees) and loss of fixation (30.4% when the head-shaft angle was <120 degrees versus 11% when the head-shaft angle was ≥120 degrees; P = 0.02). Conclusion: This series presents the experience using PHLP in 5 Level 1 trauma centers. There were no intraoperative complications related to the locking plate systems. Despite the use of fixed-angle devices, loss of fixation occurred, primarily in the presence of varus malreduction. Our findings suggest that avoiding varus should substantially decrease the risk of postoperative failures.

Dual-Energy CT Virtual Noncalcium Technique: Detecting Posttraumatic Bone Marrow Lesions—Feasibility Study

PURPOSE To evaluate traumatized bone marrow with a dual-energy (DE) computed tomographic (CT) virtual noncalcium technique. MATERIALS AND METHODS In this prospective institutional review board-approved study, 21 patients with an acute knee trauma underwent DE CT and magnetic resonance (MR) imaging. A software application was used to virtually subtract calcium from the images. Presence of fractures was noted, and presence of bone bruise was rated on a four-point scale for six femoral and tibial regions by two radiologists. CT numbers were obtained in the same regions. Consensus reading of independently read MR images served as the reference standard. Image ratings and CT numbers were subjected to receiver operating characteristic curve analysis. RESULTS After exclusion of 16 regions owing to artifacts, MR imaging revealed 59 bone bruises in the remaining 236 regions (19 of 114 femoral, 40 of 122 tibial). Fractures were present in eight patients. Visual rating revealed areas under the curve of 0.886 and 0.897 in the femur and 0.974 and 0.953 in the tibia for observers 1 and 2, respectively. For CT numbers, the respective areas under the curve were 0.922 and 0.974. If scores of 1 and 2 (strong or mild bone bruise) were counted as positive, sensitivities were 86.4% and 86.4% and specificities were 94.4% and 95.5% for observers 1 and 2, respectively. The kappa statistic demonstrated good to excellent agreement (femur, kappa = 0.78; tibia, kappa = 0.87). CONCLUSION This DE CT virtual noncalcium technique can subtract calcium from cancellous bone, allowing bone marrow assessment and potentially making posttraumatic bone bruises of the knee detectable with CT.

Two-Year Results of Open-Wedge High Tibial Osteotomy With Fixation by Medial Plate Fixator for Medial Compartment Arthritis With Varus Malalignment of the Knee

PURPOSE The purpose of our study was to evaluate the complications, technique-related risks, and the clinical course of patients treated with high tibial osteotomy (HTO) for medial arthritis of the knee with varus malalignment. METHODS Forty-three of 46 consecutive patients (follow-up, 93.5%) treated with HTO using the TomoFix implant (Synthes, Solothurn, Switzerland) were followed-up for 24 months. Radiographic and clinical data were collected preoperatively as well as 6, 12, and 24 months after surgery using standard instruments (Lysholm and subjective International Knee Documentation Committee score). RESULTS Excellent and good results were achieved in 67.5% of patients. Thirty-seven patients (86.0%) reported clinical improvement at 24 months compared to preoperative status. Evaluation of the clinical course following HTO revealed a significant increase in function after 12 (P < .01) and 24 (P < .01), but not at 6 months (P = .336) after surgery. A further increase was found between 12 and 24 months (P = .017); 67.5% of the study population returned to their predisease sports activity level at 24 months after surgery. Except for 1 case of intra-articular fracture, no severe intraoperative complications were found. One case of nonunion that demanded additional surgery was observed. CONCLUSIONS HTO with an open-wedge technique using the TomoFix implant seems to be a safe and efficient procedure. Our data show that postoperative recovery is long, with a majority of patients not reaching a functional end-point by 6 or 12 months. In many patients, further improvement was found after 12 months, which might be related to a removal of the implant. LEVEL OF EVIDENCE Level IV, therapeutic case series.

High Complication Rate After Biplanar Open Wedge High Tibial Osteotomy Stabilized With a New Spacer Plate (Position HTO Plate) Without Bone Substitute

PURPOSE We performed a prospective clinical and radiographic evaluation after open wedge high tibial osteotomy (HTO) using the new Position HTO plate (Aesculap, Tuttlingen, Germany) without bone transplantation. METHODS Thirty-five open wedge HTOs with the Position HTO plate were performed without bone wedges. The mean patient age was 44.6 ± 9.2 years at the time of osteotomy, which was planned with mediCAD II software (Hectec, Niederviehbach, Germany). The Hospital for Special Surgery score, Lysholm-Gillquist score, Tegner activity level, and International Knee Documentation Committee subjective score were used for clinical assessment. We evaluated radiographs obtained preoperatively and at 2, 6, and 12 months postoperatively using full-weight-bearing anteroposterior whole-leg views and anteroposterior and lateral views of the knee. For statistical analyses, JMP 8.0.1 (SAS, Cary, NC) was used. RESULTS We observed an overall complication rate of 34% and a plate-related complication rate of 23%. Plate-related complications included loss of correction, fracture of the tibial plateau, screw failure, malunion, and fracture of the lateral cortical bone. A significant difference in the mechanical tibiofemoral angle of -1.3° ± 1.4° (P < .001) was found between the follow-up at 2 and 6 months. The mean Hospital for Special Surgery score was 74.8 ± 11.7 preoperatively, and it increased to 87.8 ± 11.0 (P < .001). The mean score on the Lysholm-Gillquist knee functional scoring scale was 55.5 ± 21.7 preoperatively, and it improved to 73.0 ± 23.9 (P < .001). The Tegner activity level was 2.6 ± 0.9 preoperatively, and it improved significantly at final follow-up to 3.7 ± 1.8 (P < .02). The International Knee Documentation Committee subjective score was 43.0 ± 14.9 preoperatively, and it increased to 66.1 ± 21 (P < .001). CONCLUSIONS We have shown a high plate-related complication rate and a significant loss of correction between 2 and 6 months of follow-up after open wedge HTO using the new Position HTO plate without bone wedges. The preoperatively planned mechanical tibiofemoral angle was not achieved. Despite these complications, the clinical outcome improved significantly. The Position HTO plate cannot be recommended with the presented technique. LEVEL OF EVIDENCE Level IV, therapeutic case series.

Does fixed-angle plate osteosynthesis solve the problems of a fractured proximal humerus? : A prospective series of 87 patients

Background and purpose There is considerable controversy about the treatment of complex, displaced proximal humeral fractures. Various types of head-preserving osteosynthesis have been suggested. This prospective case series was designed to evaluate the perioperative and early postoperative complications associated with fixed-angle implants and to record outcome after bone healing. Patients and methods Fractures of the proximal humerus were stabilized surgically in 87 patients (mean age 64 (16–93) years) by application of a fixed-angle plate (65 PHILOS, 22 T-LCP). There were 34 2-segment fractures, 42 3-segment fractures, and 11 4-segment fractures, including 7 dislocation fractures. Follow-up assessment after a minimum of 12 months was based on the Constant, UCLA, and DASH scores and on radiographs. Results Postoperative complications included soft tissue problems (n = 9), humeral head necrosis (n = 9), screw perforation (n = 11), secondary displacements (n = 14), and delayed fracture healing (n = 4). Treatment outcomes recorded on the various scores were very good in 60–82% of the cases. Interpretation Screw perforation of fixed-angle implants has replaced the complications of secondary displacement and implant loosening after using conventional plates. Even with the use of fixed-angle implants, fractures of the proximal humerus are associated with a high complication rate and sometimes poor outcome.

Treatment of periprosthetic femoral fractures with two different minimal invasive angle-stable plates: Biomechanical comparison studies on cadaveric bones

INTRODUCTION The introduction of fixed-angle plate osteosynthesis techniques has provided us a further means to treat periprosthetic femoral fractures. The goal of this experimental study is to evaluate the biomechanical properties and stability of treated periprosthetic fractures when using two different plate systems, which vary in the locking mechanism and the screw placement (monocortical or bicortical) with respect to the prosthesis stem. MATERIALS AND METHODS Using five pairs of formalin-fixed femora, a Vancouver B1 periprosthetic fracture was treated either with a 13-hole LISS(®) titanium plate using four monocortical periprosthetic screws or with a non-contact bridging plate (NCB) DF(®) plate using bicortical angle-stable blocked screws positioned ventrally or dorsally to the prosthesis stem. Bones were loaded under axial and cyclic compression with a progressively increased load until failure. Displacement at the osteotomy gap was measured during loading using an ultra-sound measuring system. RESULTS The mean displacement in the region of the fracture gap was not significantly different at any time during the experiments for the two models. The mean force resulting in subsequent model failure was similar in both models; the failure morphology varied slightly between the models, however. Four of the five LISS(®) models exhibited either a tear-out of the monocortical screws or a decortication from the bony shaft of the cortical lamella surrounding the screws. On the other side, two of the NCB models showed macroscopically visible fissures along the osteosynthesis plates at the height of the osteotomy gap, and were hence considered implant failures. Only one NCB model showed tear-out of the bicortically placed screws. CONCLUSION Bicortical screw placement provides more stable anchoring when compared to monocortical screw fixation. However, in relation to the amount of motion at the osteotomy gap and to failure loads, stabilisation of periprosthetic femoral fractures can be equally well achieved using either the LISS(®) plate with periprosthetic monocortical screws or the NCB plate with poly-axially placed bicortical screws.

Finite element analysis of four different implants inserted in different positions to stabilize an idealized trochanteric femoral fracture

Biomechanical analysis of the ideal placement of new intramedullary implants for stabilization of trochanteric fractures is not currently available. The aim of the presented study is to determine to what extent four intermedullary nails (Gliding-Nail, Gamma-Nail, PFN-A and Targon-PF), inserted in different positions, differ mechanically. A proximal femur was reconstructed on the basis of clinical CT data as a surface model. Load application equivalent to the one-leg stance phase during gait was assumed, taking into account a limited number of active muscle forces. The four implants were inserted cranially and caudally into the bone structure and a model of a trochanteric fracture was created. Criteria with point ratings were introduced to quantify a favourable fracture healing situation. Finite element simulation showed clear differences between the different implants with regard to the distributions of stress and strain at the two fracture surfaces in the model and the von Mises stress in the implant itself. It was apparent for three implants under investigation that the caudal position generated better fracture healing conditions than the cranial position. Only the Targon PF demonstrated better fracture healing conditions in the cranial position. Evaluation based on the point rating system revealed that the caudal position was the ideal position for the PFN-A, Gamma-Nail and Gliding-Nail. The Targon-PF demonstrated some advantages over the other implants in the caudal position.

Effect of Proximal Humeral Fractures on the Age-Specific Prevalence of Rotator Cuff Tears

BACKGROUND This study examined the effect of proximal humeral fractures on the age- and shoulder-specific prevalence of rotator cuff tears (RCTs) as well as the association with fracture severity, patient age, and clinical outcome. METHODS Sixty-three fractures were treated conservatively; in 114 cases, minimally invasive osteosynthesis, and in 125 cases, open reduction and plate fixation were performed without rotator cuff reconstruction. After 4.4 years, all 302 patients were clinically and sonographically examined. RESULTS We examined 139 two-part, 95 three-part, and 68 four-part fractures according to Neer and 134 A, 86 B, and 82 C fractures according to the AO classification. There were 52 patients (17%) with a complete rotator tear (RCT) only at the injured shoulder and 11 patients (4%) with a complete RCT only at the contralateral shoulder (p < 0.0001). Independent of the patients age at follow-up, the prevalence of an RCT in the fractured shoulder was 13% higher than the prevalence in the opposite shoulder. Four-part fractures showed a significant association with a complete RCT (p = 0.047).Of 74 patients with a satisfactory or poor Constant Score, 33 (44.6%) had RCTs. In the remaining 228 patients with a good to excellent result, only 26 (11.4%) had RCTs. We showed that 66% of the RCTs observed at the fractured shoulder were caused by trauma. There was no association between treatment modality and a complete RCT. CONCLUSION RCTs may need special attention in initial diagnostics, management, and follow-up especially in severe proximal humeral fractures.

Indications for computed tomography (CT-) diagnostics in proximal humeral fractures: a comparative study of plain radiography and computed tomography

BackgroundPrecise indications for computed tomography (CT) in proximal humeral fractures are not established. The purpose of this study was a comparison of conventional radiographic views with different CT reconstructions with 2 D and 3 D imaging to establish indications for additional CT diagnostics depending on the fractured parts.MethodsIn a prospective diagnostic study in two level 1 trauma centers, 44 patients with proximal humeral fractures were diagnosed with conventional X-rays (22 AP + axillary views, 22 AP + scapular Y-views) and CT (multi-planar reconstruction (MPR) and maximum intensity projection (MIP)) with 2 D and 3 D imaging. 3 observers assessed the technical image quality, the assessment of the relevant anatomical structures (2-sample-t-test) and the percentage of the osseous overlap of the proximal humerus (Welch-test) using a scoring system. The quality of the different diagnostic methods was assessed according to the number of fractured parts (Bonferroni-Holm adjustment).ResultsThere was significantly more overlap of the fractured region on the scapular Y-views (mean 71.5%, range 45–90%) than on axillary views (mean 56.2%, range 10.5–100%). CT-diagnostics allowed a significantly better assessment of the relevant structures than conventional diagnostics (p < 0.05) independently of the fracture severity (two-, three-, and four-part fractures).ConclusionConventional X-rays with AP view and a high-quality axillary view are useful for primary diagnostics of the fracture and often but not always show a clear presentation of the relevant bony structures such as both tuberosities, the glenoid and humeral head. CT with thin slices technology and additional 3 D imaging provides always a clear presentation of the fractured region. Clinically, a CT should be performed – independently of the number of fractured parts – when the proximal humerus and the shoulder joint are not presented with sufficient X-ray-quality to establish a treatment plan.

Do changes in dynamic plantar pressure distribution, strength capacity and postural control after intra-articular calcaneal fracture correlate with clinical and radiological outcome?

UNLABELLED Fractures of the calcaneus are often associated with serious permanent disability, a considerable reduction in quality of life, and high socio-economic cost. Although some studies have already reported changes in plantar pressure distribution after calcaneal fracture, no investigation has yet focused on the patients strength and postural control. METHOD 60 patients with unilateral, operatively treated, intra-articular calcaneal fractures were clinically and biomechanically evaluated >1 year postoperatively (physical examination, SF-36, AOFAS score, lower leg isokinetic strength, postural control and gait analysis including plantar pressure distribution). Results were correlated to clinical outcome and preoperative radiological findings (Böhler angle, Zwipp and Sanders Score). RESULTS Clinical examination revealed a statistically significant reduction in range of motion at the tibiotalar and the subtalar joint on the affected side. Additionally, there was a statistically significant reduction of plantar flexor peak torque of the injured compared to the uninjured limb (p<0.001) as well as a reduction in postural control that was also more pronounced on the initially injured side (standing duration 4.2±2.9s vs. 7.6±2.1s, p<0.05). Plantar pressure measurements revealed a statistically significant pressure reduction at the hindfoot (p=0.0007) and a pressure increase at the midfoot (p=0.0001) and beneath the lateral forefoot (p=0.037) of the injured foot. There was only a weak correlation between radiological classifications and clinical outcome but a moderate correlation between strength differences and the clinical questionnaires (CC 0.27-0.4) as well as between standing duration and the clinical questionnaires. Although thigh circumference was also reduced on the injured side, there was no important relationship between changes in lower leg circumference and strength suggesting that measurement of leg circumference may not be a valid assessment of maximum strength deficits. Self-selected walking speed was the parameter that showed the best correlation with clinical outcome (AOFAS score). CONCLUSION Calcaneal fractures are associated with a significant reduction in ankle joint ROM, plantar flexion strength and postural control. These impairments seem to be highly relevant to the patients. Restoration of muscular strength and proprioception should therefore be aggressively addressed in the rehabilitation process after these fractures.